Tesis: "Ultrastructure (Biology)"

1

Goss, Steven Philip Allan. "Ultrastructure and Mitosis of Glaucosphaera vacuolata." W&M ScholarWorks, 1993. https://scholarworks.wm.edu/etd/1539625804.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Ridden, John. "Studies on the cell biology of the human sebaceous gland." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.258034.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Kurmann, Marie Helena. "Pollen wall ultrastructure and development in selected gymnosperms /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487322984316368.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Taylor, Wilson A. "Comparative analysis of sporoderm ultrastructure in fossil and extant lycopods /." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487599963591563.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Hossler, Fred E. "Ultrastructure Atlas of Human Tissues." Digital Commons @ East Tennessee State University, 2014. http://amzn.com/1118284534.

Texto completo

Resumen

Presents a variety of scanning and transmission electron microscope images of the major systems of the human body. This book looks at the structure and function of tissues at the subcellular and molecular level, an important perspective in understanding and combating diseases. https://dc.etsu.edu/etsu_books/1047/thumbnail.jpg

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Griffin, Bethany Ann. "Taxonomic Implications of Sporanglial Ultrastructure Within the Subfamily Melobesioideae Corallinales, Rhodophyta)." W&M ScholarWorks, 1997. https://scholarworks.wm.edu/etd/1539626098.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Bedell, Mark T. "Phylogenetic Implications of Sporangial Ultrastructure in the Subfamily Lithophylloideae (Corallinales, Rhodophyta)." W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539626209.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Osborn, Jeffrey Mark. "Comparative ultrastructure of fossil gymnosperm pollen and implications regarding the origin of angiosperms /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487757723994964.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

au, Lynleys@calm wa gov, and Lynley M. Stone. "Floral Biology and Propagation of Blue-Flowered Conospermum Spp." Murdoch University, 2003. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040824.145625.

Texto completo

Resumen

Blue-flowered Conospermum are endemic to Western Australia, and show great potential as cut flowers. Propagation from cuttings or seed proved difficult, and root initiation in vitro is problematic. This thesis examines the floral biology of the species and the possibility of using somatic embryogenesis to overcome propagation problems. A survey of explant tissue types for C. eatoniae and C. caeruleum was carried out to identify tissue that could be induced into embryogenic pathways. Vegetative, semi-floral and floral buds were initiated into culture from February to June, but were found unsuitable for embryogenesis, producing shoots, callus or dying in culture. Leaves from in vitro leaf cultures formed callus in the presence of 2,4-D and BAP, but were unable to differentiate into embryos in the presence of a variety of growth regulator combinations and concentrations. Immature zygotes died in culture. Direct embryogenesis and/or embryogenic callus was observed on mature zygotes of the species C. caeruleum, C. spectabile, C. dorrienii and C. brownii, and somatic embryos were maintained in culture for up to 18 months for C. caeruleum. Maturation and germination of somatic embryos proved difficult; treatments of cold, ABA, desiccation or mannitol did not induce maturation. It appears that developmental pathways in Conospermum are well defined and are difficult to alter in vitro. It was concluded that somatic embryogenesis has limited commercial potential in these species. Conospermum species have an active pollination mechanism where the style is held in a state of tension when the flower opens. When pressure is applied at the base of the style by an insect, the style flicks downwards, striking the insect pollinator and releasing pollen from the anther in a single dusty mass. However, the breeding systems of blue-flowered Conospermum have not previously been well explored. Flowers on a C. eatoniae inflorescence opened from the basal end upwards acropetally, with the terminal two or three buds never opening. Fruit and seed set occurred only from the basal one to three buds. Isolation of C. eatoniae and C. amoenum flowers showed they were unable to self-pollinate in the absence of insect pollinators. Experiments to determine the timing of the peak of stigmatic receptiveness were inconclusive. Pollen germinated and penetrated the stigma 0 ¡V 6 days after anther dehiscence. Pollen loads on the stigma did not relate to the number of pollen tubes observed down the style. Controlled pollinations of cultivated C. eatoniae at a field station using self and cross pollen, revealed compatibility with a range of pollen genotypes, as pollen tubes were observed extending down the style. However, late-acting incompatibility could not be ruled out as controlled crosses failed to set any seed as flowers were shed from the bush. DNA analysis of open pollinated C. eatoniae seed progeny from two plants from a field station and two plants in natural bushland revealed very different pollination habits. Plants from the field station showed no outcrossing, with progeny closely resembling the maternal parent, whereas plants from the wild population showed outcrossing with several different paternal parents. These results suggest self-pollinated seed can be reliably obtained in a plantation situation using stands of ramets of the same clone. Alternatively, assuming that the required insect pollinators are present in a cultivated stand, it should be possible to obtain cross pollinated seed by surrounding the maternal plant with the desired paternal parent. Unusual pollen behaviour was observed for many blue-flowered species, a white-flowered species of Conospermum, and close relative, Synaphea petiolaris. Up to three pollen tubes emerged from the triporate pollen in vitro, and at rates of up to 55 Ýms-1. This rate was maintained for only 2 s but is greater than 20 times faster than reported in the literature for any species, in vitro or in vivo. Pollen with multiple tubes was also observed on the stigma in vivo in C. amoenum flowers. Changing the osmotic pressure of the germination medium by altering sucrose concentration influenced the number of tubes to emerge from the pollen grain; generally the number of tubes decreased as sucrose increased. However, the rate of tube growth was unaffected. The addition of calcium channel blockers to the germination medium had no effect on Conospermum growth rate, nor did they eliminate pulses of tube growth. Observation of Conospermum pollen ultrastructure revealed similarities to Gramineae pollen. The tube cytoplasm was packed with vesicles filled with material of similar electron density to the cell wall. Few golgi were identified, and the apical end of the tube contained these vesicles, smaller secretory vesicles and mitochondria. This is atypical of the tip, which is normally free of large vesicles. Distinct zones in the cytoplasm were not identified, which is similar to Gramineae. Like the grasses, Conospermum appears to pre-manufacture cell wall material and store it in vesicles ready for rapid germination and extension. A biological function of multiple pollen tube emergence with such rapid growth was not elucidated. This research has shown Conospermum to be a complex and very interesting genus. Further investigation into the remarkable growth of multiple pollen tubes would enhance our knowledge of the biological processes involved in tube growth and the process of fast wall formation. The potential benefits to the cut flower industry of commercialising some of these species warrants further effort to find an efficient method of propagation. Introduction into horticulture may be the only means by which these threatened species will survive.

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Kokinos, John Peter. "Studies on the cell wall of dinoflagellate resting cysts : morphological development, ultrastructure, and chemical composition." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/17366.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Smith, Todd Garrett. "Life histories, ultrastructure, molecular biology and phylogenetic relationships of Hepatozoon species, Phylum Apicomplexa, suborder adeleorina." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ35324.pdf.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Mak, Kai-yu, and 麥啟宇. "Substratum effects of micro- and nano-structures on cellular behavior." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/202233.

Texto completo

Resumen

Substratum effects of micro- and nano-scaled structures on mammalian cell lines have experienced rapid developments during past decades. Tremendous studies have shown that micro- and nano- scaled surface morphology has great influences on cellular behavior and has great potential application in medical device design and organs regeneration. Although a variety of cell types have been used in cell-substrate studies for different purposes, information about how the cellular response of hepatic cells to the nanoporous and microgrooved structures is still insufficient The effects of groove/ridge width of the microgrooved structures on the mammalian cell culturing is usually overlooked. In this thesis, the cellular response of hepatic cells to the nanoporous and microgrooved is studied, including the cell spreading, cell elongation, cell alignment, and cell motility. Also, the effects of groove/ridge width are addressed on three mammalian cell lines (BEL-7402, MIHA, and HeLa). Three experiments were performed. Firstly, the effect of nanoporous surface on hepatic cell line, BEL-7402, was studied. The nanoporous surface (140 nm) was fabricated by anodize alumina membrane and microcontact printing techniques on PDMS surface. Cellular behaviors were analyzed with scanning electron microscope and time-lapse imaging. The results showed that cell projected area was reduced with cell migration speed was promoted on porous surface when compared with flat control surface. Secondly, the effect of microgrooves surface (10 μm, 30 μm and 50μm, with equal ridge and groove width) on hepatic cell line, BEL-7402, was studied. The microgrooved surface was fabricated by microcontact printing on PDMS. Cellular behaviors were analyzed with scanning electron microscope and time-lapse imaging. The results showed that cell elongation, alignment and directional migration was promoted by the groove structure when comparing with flat surface. Thirdly, the effect of microgrooved PDMS surfaces with varied ridge width and groove width on three mammalian cell lines (BEL-7402, MIHA, and HeLa)was studied. Microgrooved PDMS surfaces with nine combination of ridge width (5 μm, 10 μm and 30 μm) and groove width (5 μm, 10 μm and 30 μm) were fabricated using photolithography and soft lithography. The results showed that all grooved structures have almost same affection on the cellular response, independent of the cell type. Also, our result showed that the cell elongation displayed same pattern on all micrgrooved surfaces, independent of the groove/ridge width changes. In addition, our result showed that microgrooved surface that contained 10 μm ridge or groove were less effective in aligning cells. On the other hand, microgrooved surface 5×5, 5×30, 30×5 and 30×30 showed most effective in aligning cell when compare with other grooved surface and flat control surface. Our result provide information on how cell response to surface morphology at nano-scale and micro-scale. These informations are highly conducive for the liver regeneration, cancer metastasis study, and other tissue engineering research. published_or_final_version Electrical and Electronic Engineering Master Master of Philosophy

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Semper, Amanda Elizabeth. "New techniques for the ultrastructural identification of human skeletal muscle fibre types in frozen thin sections and freeze-fracture replicas." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670383.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Yao, Lan. "Fabrication, characterization and application of the novel bionanomaterials /." View online ; access limited to URI, 2008. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3328736.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Bui, Loan T. "Ultrastructural characterisation of some tissues of the Echinococcus granulosus hydatid cyst." Thesis, Queensland University of Technology, 1999. https://eprints.qut.edu.au/37007/1/37007_Bui_1999.pdf.

Texto completo

Resumen

Echinococcus granulosus is a small endoparasitic tapeworm which is recognised as one of the world's major zoonoses affecting humans and domestic animal. The adult worm inhabits the intestinal tract of a variety of canids, while the larval or metacestode stage develops in the organs of sheep, cattle, pigs, other ungulates, or humans and causes hydatid disease. Hydatid disease constitutes a serious public health problem with considerable morbidity and mortality. At present, effective treatment and control programs for this disease have not been achieved. Major deficiencies still exist in our understanding of many fundamental aspects of hydatid disease, including epidemiology, diagnosis and the structural biology of E. granulosus. This study has examined the ultrastructure of some tissues of the E. granulosus hydatid cyst, with the emphasis placed on the protoscolex structure. Systematic comparative descriptions of ultrastructure of the E. granulosus protoscolex have been presented in this study. Regional variation of both the tegument and parenchyma has been demonstrated. Moreover, by applying a variety of post fixation processing methods for transmission electron microscopy (the conventional method, alternative fixation methods using uranyl acetate or osmium tetroxide-potassium ferricyanide as post fixatives, and freeze-substitution) some structures of the tegument which have not been previously reported were revealed. The advantages of the different fixation methods for transmission electron microscopy were also highlighted. Detailed ultrastructural descriptions of the brood capsule, attachment stalk and cell nest of the hydatid cysts were obtained in this study. A glycocalyx was widely distributed on the hydatid cyst, including on brood capsule, attachment stalk and protoscolex. The presence of the glycocalyx on the rostellum of the protoscolex was detected for the first time. The glycocalyx was best revealed after the use of the osmium tetroxide-potassium ferricyanide fixation method. Variations of the morphology of the tegumentary projections, tegumentary vesicles and tegumentary cells among the body regions of the protoscolex were shown and ultrastructural differences of the spinose and filamentous microtriches were demonstrated. A more detailed structure of the tegumentary vesicles was distinguished using alternative preparation methods for transmission electron microscopy, and this was compared with previous reports. Several types of tegumentary vesicle were described for the first time in the present study. This data indicates the advantages of a variety of preparation methods for preserving tegumentary vesicles, as several vesicle types were revealed with greater clarity after the osmium tetroxide-potassium ferricyanide and freeze-substitution method. The ultrastructure of the tegumentary cells also was described in the present study for the first time. Regional structural variation of the tegumentary cells was found, and this corresponded to regional variations noted in the distal cytoplasm of the tegument. The functional variation of these cells in different body regions of the protoscolex was discussed. A systematic description of the extracellular matrix, including the basement membrane and interstitial matrix, of the protoscolex was provided in this study. A number of functions were proposed, based on the ultrastructural information obtained. The other parenchymal tissues, such as excretory system, calcareous corpuscle and nervous system, were briefly investigated. The excretory system of E. granulosus protosoclex reported in my study revealed ultrastructural similar to the excretory system of other cestodes. Similarly, the ultrastructure of calcareous corpuscle and nervous system was found to be comparable with previous descriptions. The present ultrastructural study has supported and extended previously reported information on the morphology of the tegument and has provided evidence for possible functions of the E. granulosus protoscolex. The ultrastructure of the parenchymal cells and tissues provide valuable information for further research and understanding of the biology of the E. granulosus.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Introíni, Gisele Orlandi. "Analise ultra-estrutural de espermatozoides de especies de bivalves marinhos." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317967.

Texto completo

Resumen

Orientador: Shirlei Maria Recco-Pimentel Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-14T15:41:26Z (GMT). No. of bitstreams: 1 Introini_GiseleOrlandi_D.pdf: 4339953 bytes, checksum: 12ffc20df8da4d8930c265634e22d822 (MD5) Previous issue date: 2009 Resumo: Aplicações de Microscopias Eletrônicas de Transmissão (TEM) e Varredura (SEM) têm contribuído para a sistemática de moluscos bivalves e classificações de táxons mais abrangentes. Em muitos casos, os resultados dessas ferramentas metodológicas têm notavelmente complementado os estudos comparativos da anatomia interna e dos caracteres conquiliológicos, contribuindo para uma ampla compreensão das relações filogenéticas entre os representantes da classe Bivalvia. A morfologia dos espermatozóides de inúmeros táxons importantes das subclasses Pteriomorphia e Heterodonta permanece pouco ou nada estudada. A análise de espécies dessas subclasses pode corroborar estudos que abordam taxonomia e filogenia. No presente trabalho, foi realizado o estudo da ultraestrutura dos espermatozóides de espécies de bivalves das famílias Veneridae, Donacidae, Tellinidae (Ordem Veneroida, Subclasse Heterodonta,), Mytilidae (Mytiloida), Isognomonidae (Pterioida) e Ostreidae (Ostreoida) (pertencentes à Subclasse Pteriomorphia). Os espermatozóides de todas as espécies de bivalves analisadas, com exceção da espécie Tellina lineata, apresentaram uma morfologia típica de animais marinhos que liberam seus gametas fertilizando seus ovos na água do mar. A microscopia eletrônica de transmissão forneceu importantes caracteres que auxiliaram na diferenciação entre os espermatozóides das espécies Isognomon bicolor e I. alatus (única coletada em território estrangeiro); Donax hanleyanus e D. gemmula; Macoma biota e M. constricta. A célula gamética masculina de Tellina lineata foi considerada modificada, portadora de acrossomo cônico e curto, núcleo longo e helicoidal, mitocôndrias alongadas que se estendiam sobre a periferia da base nuclear, estruturas longas que se dispunham ortogonalmente (mas que não apresentavam o padrão convencional dos centríolos) e um flagelo simples. Na literatura acerca dos Bivalvia, considerase a cabeça alongada mais eficiente na penetração de óvulos que possuem ampla camada gelatinosa. O espermatozóide de Tivela mactroides (em comparação com aquele produzido por Anomalocardia brasiliana) possibilitou a descrição de determinadas características que podem contribuir para vantagens adaptativas nos ambientes nos quais os bivalves ocorrem. Uma característica interessante da cabeça alongada dos espermatozóides dos membros da família Veneridae é a presença de curvatura. Populações de Mytella podem ocorrer tanto em costões rochosos quanto em bancos de sedimento areno-lamoso. Não houve diferença entre essas populações e foi sugerido que ambas se tratam de M. charruana. A presença de perforatorium no espermatozóide de Mytella charruana permite sua alocação na subfamília Mytilinae. As descrições disponíveis na literatura sobre a morfologia do gameta masculino de ostras mostram uma significativa semelhança entre as espécies investigadas, corroborando o status monofilético da família Ostreidae. Segundo os resultados apresentados é possível afirmar que a espécie Crassostrea brasiliana ocorre na região de Cananéia. Conclui-se que os dados da tese mostraram-se especialmente importantes por revelarem os detalhes internos mais sutis dos espermatozóides, ampliando o crescente entendimento da estrutura, biologia e desenvolvimento dos espermatozóides de bivalves das famílias Isognomonidae, Veneridae, Donacidae, Tellinidae, Mytilidae e Ostreidae. Abstract: The ultrastructure of bivalve spermatozoa can be species-specific and often provide valuable taxonomic traits for systematic reviews and phylogenetic reconstructions. Transmission and scanning electron microscopy was an efficient tool to differentiate the spermatozoan structure of species sharing many conchological characters, which could lead to equivocal identification. We analyzed sperm ultrastructural features that were useful for taxonomic issues with regard to Isognomon bicolor and Isognomon alatus (Isognomonidae); Macoma constricta, Macoma biota and Tellina lineata (Tellinidae); Donax hanleyanus and Donax gemmula (Donacidae). The data revealed that the bivalve species studied here, except T. lineata, produce primitive-type spermatozoa, typical of marine invertebrates in which eggs are fertilized in the surrounding water. We, also, compared the ultrastructure of spermatozoa from the bivalves Anomalocardia brasiliana and Tivela mactroides (Veneridae). The spermatozoa of both species contain a curved nucleus with a short cone-shaped acrosome. There were six mitochondria and glycogen clusters in the middle piece of the T. mactroides sperm cell. Possibly, the glycogen clusters and the higher mitochondria number correspond to an adaptive advantage in turbulent waters. Increasing the sperm life expectance also increases the odds of finding the eggs and accomplishing fertilization. Oysters of the genus Crassostrea and mussels of the genus Mytella, commercially important in Brazil, were also investigated in this thesis. The sperm ultrastructure of the specimens described herein and molecular studies, confirm the presence of Crassostrea brasiliana (Ostreidae) in Cananéia. Spermatozoa of mussel specimens of the genus Mytella, from two populations living in distinct habitats (muddy-sand sediment and rocky shores), were examined by transmission electron microscopy. The spermatozoa of all specimens shared the same ultrastructural pattern suggesting that the analyzed specimens, which live in distinct habitats, indeed belong to a same species, which was identified as M. charruana (Mytilidae) based on conchological analysis. The presence of an axial rod in sperm cells upholds the inclusion of M. charruana in the subfamily Mytilinae. In conclusion the electron microscopy was an efficient method to solve some particular taxonomic issues. The present spermatozoan ultrastructural studies have provided new and welcome data about the families Isognomonidae, Veneridae, Tellinidae, Donacidae, Ostreidae and Mytilidae. The results showed in this thesis could be valuable in future phylogenetic analyses. Doutorado Biologia Celular Doutor em Biologia Celular e Estrutural

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Lunn, Matthew O'Brien. "A Morphological Study of the Canine Zona Pellucida: A Heterogeneous Ultrastructure and Barrier." University of Dayton / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1311785290.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Burkhart, Brenna. "Ultrastructure of Spermiognesis in the Yellow-Bellied Sea Snake, Pelamis platurus(Squamata: Elapidae: Hydrophiinae)." Wittenberg University Honors Theses / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=wuhonors1398955341.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Yusuf, Mohammed Abdi Sheikh. "Reproductive biology, ultrastructure and molecular characterisation of Liposcelis bostrychophila (Badonnel) (Liposcelididae: Psocoptera) and its intracellular rickettsial endosymbionts." Thesis, King's College London (University of London), 1999. https://kclpure.kcl.ac.uk/portal/en/theses/reproductive-biology-ultrastructure-and-molecular-characterisation-of-liposcelis-bostrychophila-badonnel-liposcelididae-psocoptera-and-its-intracellular-rickettsial-endosymbionts(85130f8f-d26f-4288-90cf-47cdd1d759c1).html.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Davidson, Jeannette. "The cardiac pathophysiology and ultrastructure in dietary copper deficiency and repletion in young and older sedentary and exercise trained rats /." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487759914758281.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Nunes, Erika Takagi [UNESP]. "Farfantepenaeus brasiliensis (Crustacea : Penaeoidea): morfologia do hepatopâncreas e sua relação com os metais pesados encontrados no litoral sul do Espírito Santo." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/100568.

Texto completo

Resumen

Made available in DSpace on 2014-06-11T19:30:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-12Bitstream added on 2014-06-13T19:19:45Z : No. of bitstreams: 1 nunes_et_dr_rcla.pdf: 1685568 bytes, checksum: fc39ac0ad20fd32933d7b0fda0680782 (MD5) O hepatopâncreas dos crustáceos, também conhecido como glândula digestiva, passa por modificações morfo-funcionais em resposta a fatores como dieta, variações de temperatura, ciclo de muda, estágio reprodutivo e contaminação. Este trabalho objetivou analisar, morfologicamente, através de técnicas de microscopia eletrônica e de luz, o hepatopâncreas de fêmeas adultas do camarão-rosa Farfantepenaeus brasiliensis, em dois diferentes estágios de desenvolvimento gonadal, coletadas em Guarapari, Espírito Santo, Brasil, bem como relacionar esta espécie às condições ambientais, comparativamente ao camarão Xiphopenaeus kroyeri. A microscopia eletrônica de varredura evidenciou hepatopâncreas de tamanhos semelhantes nas fêmeas com gônadas desenvolvidas (DE) e naquelas esgotadas (ES), apresentando-se como um órgão não-lobado e recoberto por tecido conjuntivo com poros. Histologicamente, foram identificados cinco tipos celulares nos túbulos: células E (embrionárias), R (reabsortivas), F (fibrilares), B (vesiculares) e M (basais). Comparado às DE, o epitélio hepatopancreático das fêmeas ES mostrou-se mais escamoso, acidófilo, delimitando um amplo lúmen que contem partes das células B e R; nestas, ainda, as células M estiveram mais evidentes. As células R mostraram escassez em organelas, mitocôndrias apicais, vacúolos marcados para polissacarídeos ácidos, além de gotas lipídicas vistas principalmente nas fêmeas ES. As células F, fortemente marcadas pelo azul de bromofenol, apresentaram vesículas de secreção próximas às microvilosidades, retículo endoplasmático rugoso bem desenvolvido, em arranjo circular ou com cisternas dilatadas. As células B foram marcadas pela presença de grandes corpos digestivos com conteúdo polissacarídico neutro, sendo eliminado, posteriormente... The hepatopancreas of crustaceans, also known as the digestive gland, undergoes morphological and functional changes in response to factors such as diet, temperature variations, moult cycle, reproductive stage and contamination. This study aimed to analyze, morphologically, by means of electron and light microscopies, the hepatopancreas of adult females of the pink shrimp Farfantepenaeus brasiliensis at two different stages of gonadal development, collected in the southern coast of Espirito Santo, Brazil, as well as to relate this species to the environmental conditions, compared to Xiphopenaeus kroyeri shrimp. The scanning electron microscopy revealed similar size in the hepatopancreas of females with developed gonads (DE) and those with exhausted gonads (ES). It presents as a non-lobed organ covered by connective tissue with pores. Histologically, five cell types were identified in tubules: E (embryonic), R (reabsorptive), F (fibrillar), B (vesicular) and M (basal). Compared to those DE females, the hepatopancreas from ES females showed a more flattened epithelium, acidophilus and delimiting a large lumen which contains parts of R and B cells; in these, also, the M cells were more evident. R cells showed shortage in organelles, apical mitochondria, vacuoles marked for acid polysaccharides, and lipid droplets seen mainly in female ES. F cells were strongly marked by bromophenol blue and presented secretory vesicles near the microvilli, well-developed rough endoplasmic reticulum in circular arrangement, or even with dilated cistern. B cells were marked by the presence of large digestive bodies with neutral polysaccharide content, being later eliminated inside the tubular lumen. The observed features also allowed us to infer the possible stages of moult in which the shrimps were. Although some... (Complete abstract click electronic access below)

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Jesus, Carlos Massuretti de [UNESP]. "Análise comparativa das glândulas pós-faríngeas e sua participação na utilização de lipídeos pelas formigas (Hymenoptera : Formicidae)." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/106581.

Texto completo

Resumen

Made available in DSpace on 2014-06-11T19:35:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-06-10Bitstream added on 2014-06-13T21:08:01Z : No. of bitstreams: 1 jesus_cm_dr_rcla.pdf: 5009514 bytes, checksum: ebcdbcc7d94f909d06c62d92fa2387e4 (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Uma característica típica das formigas e algumas vespas é a presença das glândulas pós-faríngeas, estrutura que se encontra somente nesses grupos de organismos, fato que deve ter contribuído para o seu sucesso evolutivo. Apesar dos primeiros estudos com as glândulas pós-faríngeas existirem há mais de 100 anos, somente nos últimos 20 elas tem recebido maior atenção dos pesquisadores. Assim, a presente pesquisa teve por objetivo realizar uma análise comparativa da morfologia das glândulas pós-faríngeas e verificar sua participação na utilização de lipídeos ingeridos por três espécies de formigas com padrões alimentares distintos. Para tal, foi realizado análise ultramorfologica e ultraestrutural das glândulas pós-faríngeas; quantificação da ingestão de lipídeos e carboidratos, e verificação do trajeto destes compostos pelo sistema digestório das operárias; análise autorradiográfica do processo de incorporação do ácido oléico marcado radioativamente pelas glândulas pósfaríngeas das operárias. Os resultados encontrados sugerem que cada uma das espécies apresenta uma particularidade: as glândulas pós-faríngeas de Camponotus vittatus podem ser um sítio de reserva energética para o indivíduo; as operárias de Atta laevigata deslocam parte dos lipídeos ingeridos para o intestino médio, evitando o seu acúmulo nas glândulas pós-faríngeas, ao passo que foram encontradas pela primeira vez dois tipos de células nas glândulas pósfaríngeas de Pachycondyla villosa. Além disso, o trajeto percorrido pelos alimentos hidrossolúveis no interior do sistema digestório das operárias compreende a cavidade infrabucal, papo e ventrículo. Enquanto que os lipídeos passam pela cavidade infrabucal, glândulas pós-faríngeas e papo, mas não atingem o ventrículo; com exceção de A. laevigata em que foram encontrados... (Resumo completo, clicar acesso eletrônico abaix A typical gland found only in ants and some wasps species is the postpharyngeal gland, which could have contributed to the evolutionary success of these social insects. The first studies regarding the morphology and function of the postpharyngeal glands were conducted about 100 years ago, and only in the last 20 years researches gave more attention to its importance. Thus, this study aimed at comparing the morphology of postpharyngeal glands and to verify their participation in the use of lipids ingested by three ant species. For this purpose, we performed: 1- Ultrastructural and Ultramorphology analysis of the postpharyngeal glands; 2 – the flow of lipids and carbohydrates inside the digestory systeam; 3 - the incorporation of radiolabeled oleic acid by the postpharyngeal using autoradiografic methods. Our results suggest that each species has a particularity: the postpharyngeal glands of Camponotus vittatus may be act as a site of food reserve, the workers of Atta laevigata prevent the accumulation of oleic acid in the postpharyngeal glands by sending lipids ingested to midgut. On the other hand, Pachycondyla villosa has specialized cells to eliminate of lipids from the postpharyngeal glands. Moreover, water-soluble diets were found in infrabucal pockets, crop and ventriculi, while lipid-soluble diets were found in infrabucal pockets, postpharingeal glands and crop; except for A. laevigata, which also had lipids in their midgut. Autorradiografic analysis showed that oleic acid is absorbed by the epithelium of... (Complete abstract click electronic access below)

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Naldoni, Juliana 1986. "Taxonomia e interação parasito-hospedeiro na infecção de mixosporídeos em pintado (Pseudoplatystoma corruscans) e cachara (Pseudoplatystoma fasciatum) oriundos de ambiente natural e de sistemas de cultivo." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314570.

Texto completo

Resumen

Orientador: Edson Aparecido Adriano Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-16T13:39:03Z (GMT). No. of bitstreams: 1 Naldoni_Juliana_M.pdf: 1582116 bytes, checksum: 5cbf606558b1018c4716a9502d2dd73a (MD5) Previous issue date: 2010 Resumo: Parasitos do filo Myxozoa são cosmopolitas, infectam peixes em diversas regiões e estão entre os mais importantes patógenos de peixes, tanto em ambiente natural, como em sistemas de criação, onde podem causar prejuízos importantes. Este trabalho teve por objetivo o estudo da interação parasito-hospedeiro em infecções de peixes do gênero Pseudoplatystoma, pintado (Pseudoplatystoma corruscans), cachara (Pseudoplatystoma fasciatum) e o híbrido (pintado x cachara), causadas por parasitos do filo Myxozoa. Os peixes estudados foram oriundos de ambiente natural, Pantanal Mato-Grossense e de sistemas de criação, pisciculturas dos Estados de São Paulo e do Mato Grosso do Sul. Durante este trabalho foi possível estudar e descrever duas novas espécies de Henneguya infectando Pseudoplatystoma spp. Henneguya sp. 1 foi descrito infectando pintado híbrido de sistemas de criação nos Estados de São Paulo e Mato Grosso e as respectivas prevalências foram 100 e 36, 7%. Devido à intensidade de infecção, com vários plasmódios em um mesmo filamento, o desenvolvimento do parasito produziu importante redução de área do epitélio branquial. A análise ultra-estrutural revelou uma única parede plasmodial ligada à zona do ectoplasma por vários canais de pinocitose. A outra espécie (Henneguya sp. 2) foi encontrado infectando simultaneamente brânquia de exemplares de pintado e cachara obtidos em ambiente natural, no Pantanal Mato-Grossense. A prevalência foi de 17,1% para ambas espécies de peixes examinados. A análise histopatológica revelou o desenvolvimento do parasito no tecido conectivo sub-epitelial do filamento branquial, estando os plasmódios envolvidos por uma cápsula de tecido conectivo. O plasmódio produziu uma leve compressão dos tecidos adjacentes, mas nenhum infiltrado inflamatório foi observado no sítio da infecção. A análise ultra-estrutural mostrou uma única parede plasmodial conectada com o ectoplasma através de numerosos canais de pinocitose. Abstract: Myxozoa are cosmopolitan parasites and are among the most important pathogens of wild and cultivated fish. The aim of the present study was to investigate the host-parasite interaction in fish of the genus Pseudoplatystoma infected by Myxozoan parasites: the spotted sorubim (Pseudoplatystoma corruscans), barred sorubim (Pseudoplatystoma fasciatum) and a hybrid of the two species. Specimens were obtained from the natural environment in the Mato Grosso wetlands and fish farms in the states of São Paulo and Mato Grosso do Sul, Brazil. Two news species of Henneguya were described infecting Pseudoplatystoma ssp. Henneguya sp.1 was described infecting the hybrid on fish farms in the states of São Paulo and Mato Grosso do Sul (Brazil), with a prevalence of 100 and 36.7%, respectively. Due to the intensity of the infection, with several plasmodia in a single gill filament, the development of the parasite caused an important reduction in the area of functional epithelium. The ultrastructural analysis revealed a single plasmodial wall connected to the ectoplasma zone through several pinocytotic canals. Henneguya sp.2 was found infecting the gills of both the spotted and barred sorubim caught in the natural wetland environment. The prevalence was 17.1% in both species of fish. The histopathological analysis revealed that the parasite develops in the sub-epithelial connective tissue of the gill filaments and the plasmodium is surrounded by a capsule of connective tissue. The plasmodia caused slight compression of the adjacent tissues, but no inflammatory infiltrate was observed at the infection site. The ultrastructural analysis revealed a single plasmodial wall connected to the ectoplasma zone through numerous pinocytotic canals. Mestrado Parasitologia Mestre em Parasitologia

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Tekle, Yonas Isaak. "Phylogeny and Taxonomy of Childia (Acoela) : New characters for unraveling acoel phylogenies from molecules, ultrastructure, immunocytochemistry and confocal microscopy." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Universitetsbiblioteket [distributör], 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6315.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Dubbs, Wesley Emanuel. "Chlorophyll Characterization of Three Mistletoes and the Chloroplast Ultrastructure within Aerial and Endophytic Tissues of Phoradendron Juniperinum." PDXScholar, 1994. https://pdxscholar.library.pdx.edu/open_access_etds/4747.

Texto completo

Resumen

The aerial shoot pigments of three epiphytic mistletoes and their hosts were examined and the results were found to concur with earlier reports. Emphasis was placed on the mistletoe Phoradendron juniperinum. Absorbance spectroscopy indicated a very similar ratio of pigments in both the aerial tissue of the mistletoe and its juniper host. Spectroscopic examination found the presence of chlorophyll in the endophytic tissue of the genus Phoradendron for the first time. Total chlorophyll concentrations of the endophytic tissue of Phoradendronjuniperinum were found to be approximately 10% that of aerial shoots. However, chlorophyll alb ratios of endophytic tissue were 40% of those in aerial tissue. The dwarf mistletoe Arceuthobium tsugense was found to have about 1/3 the chi content of its host and of the two Phoradendron species examined. However, the endophytic concentrations of chlorophyll of A. tsugense were 250% higher than those found in compatible Phoradendron tissue. Ultrastructural inspection of Phoradendron juniperinum revealed chloroplasts of the aerial shoots to be typical of C3 plants, yet they were small and contained little relative stroma lamella. This is characteristic of plants with unequal complement of the two photosystems. Examination of the endophytic system indicated that the most likely source of the chlorophyll to be plastids with enlarged thylakoid channels. These plastids were termed endophytic-chloroplasts Experiments were performed to establish whether the synthesis of the chlorophyll within the endophytic system was via a light-independent pathway or by means of light penetration into mistletoe tissue and stimulation of the typical angiosperm light-dependent pathway. However, results as to the biosynthesis of chlorophyll were inconclusive. These experiments did indicate that chlorophyll was still present in endophytic tissue of Phoradendron juniperinwn after 11 months without aerial shoots, whether enclosed in complete darkness or not. Microscopic examination of tissue did not revile the presence of any light conductive tissues in either the parasite or its host.

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Mattison, Richard Geoffrey. "Studies on the ultrastructure and biology of paramphistome parasites (Trematoda: Digenea) of ruminants and freshwater gastropods in northern India." Thesis, Queen's University Belfast, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336130.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Bonfiglio, Neuranei Salete. "Estereologia e ultra-estrutura da mucosa da parte proximal do duodeno de camundongos submetidos ao alcoolismo experimental." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/318047.

Texto completo

Resumen

Orientador: Wílson de Mello Junior Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-06T16:09:13Z (GMT). No. of bitstreams: 1 Bonfiglio_NeuraneiSalete_D.pdf: 15888948 bytes, checksum: 45a4be7d8ec7427f7950c635442ae685 (MD5) Previous issue date: 2006 Resumo: o alcoolismo consiste num dos grandes problemas de farmacodependência do mundo, gerando uma das principais preocupações em saúde pública. Inúmeras são as complicações gastrointestinais decorrentes do consumo de bebidas alcoólicas. O recente foco de estudos científicos concentra-se em substâncias que podem interferir na preservação, manutenção e função da barreira intestinal, com diversos mecanismos biológicos não totalmente conhecidos. Investigações dessa natureza podem prover informações para entender o papel das repetidas exposições de etanol em baixa concentração sobre a morfofisiologia da mucosa do intestino delgado e estabelecer correlações com a toxicidade aguda já conhecida. Camundongos C57B/6 constituem modelos experimentais para estudos morfológicos, fisiológicos, bioquímicos, nutricionais e farmacológicos, importantes para a compreensão do alcoolismo. O presente trabalho analisou a morfologia da parte proximal da mucos a duodenal da linhagem de camundongos C57B/6. Submetidos ao tratamento crônico com etanol 4,2% foram divididos em 2 grupos: controle (GC) e alcoólico (GA). O GC recebeu, diariamente, 30 ml de dieta líquida (Sustacal) com dextrose(Dextrosol) no equivalente calórico do etanol 4,2% e o GA, dieta líquida (Sustacal), acrescida de etanol 4,2%. Ambos os grupos receberam água ad libitum. Após 8 semanas de tratamento, os animais foram submetidos à eutanásia para coleta e processamento do duodeno destinado as técnicas microscópicas e estereológicas. A análise histológica revelou que os animais alcoólicos apresentaram vilos duodenais mais curtos e largos, com grande perda de epitélio, especialmente no ápice. Áreas de mucosa apareceram aplainadas, sem vilos. Estereologicamente, houve redução na densidade de superfície de vilos e numérica de células caliciformes. A ultra-etrutura evidenciou imagens de morte celular por apoptose, autofagia e necrose nos animais alcoólicos. Os dados sugerem que doses clinicamente aceitáveis de etanol representam risco para a manutenção da integridade do vilo duodenal, interferindo na sobrevivência da barreira intestinal e, possivelmente, na sua fisiologia. Portanto, a ação lesiva do etanol é preocupante para consumidores leves Abstract: A1coholism consists in one of the greatest problems of pharmacodependence, generating one of the main concerns in world public health. Several gastrointestinal complications decurres from alcoholic beverage consumption. The recent scientific studies enphasys is concentrated in substances that can interfere on preservation, maintenance and function of the intestinal barrier throught several mechanisms that are not well known. lnquiries of this nature can provi de knowledge to understand the role of repeated expositions of ethanol in low concentration on the morpho-physiology of the intestinal mucosa establishing correlations with the already known acute toxicity. C57BL/6 mice constitute experimental models for works related to morphologic, physiological, biochemical, nutritritional and pharmacological effects of ethanol, such studies are important means to understand human a1coholism. The present work analyzed the morphology of the proximal part of the duodenal mucosa of the mice lineage C57BL/6 submitted to a chronic ethanol 4,2% treatment, and divided into two groups: control (GC) and alcoholic (GA). Daily, the GC received 30 ml of a liquid nutritionally adequated diet (Sustacal) with dextrose (Dextrosol) in the equivalent caloric of etanol 4.2% and the GA received liquid diet (Sustacal) increased by etanol 4.2% (v/v). Both groups had received water ad libitum. After 8 weeks of treatment, the animaIs had been submitted to euthanasia for duodenum sampling and proceeding in order to microscopical and estereological techniques. Histological analysis showed that the animals from the GA presented shorter and enlarged duodenal villi with great loss of epithelium specially in apex. Mucosa areas seemed to be smooth, without villous. Estereologically, there was reduction in the surface density of villi and numerical density of goblet cells. ln alcoholic animals, the ultra-structural characteristics seen evidenced cell death: apoptosis, autophagy, and necrosis. This data suggest that the consumption of quantities clinically acceptable of ethanol represent risk to the maintenance of the duodenal villous integrity, interfering in the survival of the intestinal barrier and, possibly, in its physiology. Therefore, facts indicate that ethanol harmful action is concorning to whom is a light drinker Doutorado Anatomia Doutor em Biologia Celular e Estrutural

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Fávaro, Wagner José 1980. "Reatividade hormonal e ultra-estrutura do lobo ventral da prostata de ratos (Ratus norvegicus) submetidos ao uso cronico simultaneo de etanol e nicotina." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/318011.

Texto completo

Resumen

Orientador: Valeria Helena Alves Cagno Quitete Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-06T20:48:50Z (GMT). No. of bitstreams: 1 Favaro_WagnerJose_M.pdf: 3700284 bytes, checksum: 4b1aec37ebb6981bbfdb52290cf218ca (MD5) Previous issue date: 2006 Resumo: o álcool e a nicotina têm ação prejudicial sobre o funcionamento da glândula prostática. Contudo, os mecanismos moleculares e celulares envolvidos nas alterações prostáticas, bem como suas correlações com a patogênese glandular permanecem desconhecidos. Assim, os objetivos do presente estudo foram caracterizar as alterações estruturais das células epiteliais e do estroma e, a expressão dos receptores androgênicos e estrogênicos a. na próstata ventral de ratos sob o efeito da ação concomitante de nicotina e etanol, bem como cada uma dessas drogas isoladamente, além dos níveis plasmáticos dos hormônios testosterona e estrógenos. Também, foi objetivo estabelecer associações das interações epitélio-estromal úente a possível pato gênese glandular. Um total de 40 ratos macho (Rattus norvegicus), com 75 dias de idade, foi dividido em quatro grupos: Grupo controle (10 animais) recebeu água ad libitum; Grupo alcoolista (10 animais) recebeu etanol diluído a 10% Gay Lussac (10% v/v) ad libitum; Grupo nicotina (10 animais) recebeu um total de 0,125mg/l00g de peso corpóreo/diariamente de nicotina (Sigma, St. Louis, USA) por via subcutânea; Grupo nicotina-álcool (10 animais) recebeu tratamento simultâneo com etanol e nicotina, nas mesmas concentrações que nos grupos alcoolista e nicotina. Após 90 dias de tratamento, todos os animais foram sacrificados e amostras do lobo ventral da próstata foram coletadas para análises macroscópicas, microscopias de luz e eletrônica de transmissão e imunomarcações dos receptores androgênicos e estrogênicos a., além das dosagens hormonais. Os resultados revelaram: atrofia dos órgãos genitais masculinos como testículos e vesículas seminais; atrofia epitelial; neoplasia intra-epitelial prostática; desorganização das organelas envolvidas no processo secretor; hipertrofia estromal; presença de microácinos e células inflamatórias e célula muscular lisa com fenótipo secretor. Também, houve diminuição significativa dos rúveis séricos de testosterona e aumento dos níveis séricos de estrógenos nos animais dos grupos nicotina álcool, alcoolista e nicotina em relação aos animais controles, bem como a expressão dos seus respectivos receptores. Assim, concluiu-se que fatores extrínsecos como etanol e nicotina são componentes de risco à homeo~tase da glândula prostática, levando a ocorrência da pato gênese do órgão, a qual poderá ser associada à processos tardios de malignescência glandular Abstract: Alcohol and nicotme act negatively on the prostatic gland function. However, molecular and cellular mechanisms mvolved m the prostatic alteration, as well as their correlations with glandular pathogenesis remam unclear. Then, the main objective of this study was to identifY the features of the epithelial and stromal prostatic structure and to characterize the expression of the androgenic and a estrogenic receptors in rats submitted to chronic nicotme and alcohol use simultaneously, besides each one of these drugs alone. Moreover, it was mtended to establish the stromal-epithelial mteraction in a possible glandul~ pathogenesis. A total of 40 male rats, aged 75 days, were divided mto 4 groups: Control group (10 animaIs) received tap water ad libitum; Alcoholic group (10 animaIs) received diluted 10% Gay Lussac ethanol ad libitum; Nicotme group (10 animaIs) received a 0.125 mg/100 g body weight dose ofnicotine daily; Nicotine-Alcohol group (10 animaIs) received simultaneous alcohol and nicotme treatment, m the same concentration as the alcoholic and nicotine groups. Afier 90 days of treatment, the animaIs were sacrificed and samples ITom the ventrallobe ofthe prostate were collected and processed for transmission electron and light microscopies, immunological techniques to androgenic and a estrogenic receptor expression and radioimmunoassay techniques to measure testosterone and estrogen levels. The results showed atrophied testes and seminal vesicle, atrophied prostatic epithelial cells, prostatic mtraepithelial neoplasm, disorganization of cellular organelles mvolved m the glandular process, inflammatory cells, diminished testosterone levels and their receptors besides mcreased estrogen levels. All alterations were verified m the different experimental groups, bemg more mtense m the alcohol-nicotme, alcoholic and nicotme groups, respectively. Then, it can be concluded that extrmsic factors like ethanol and nicotme are risk compounds to prostatic homeostasis, leadmg to occurrence of glandular pathogenesis which could be related to glandular malignancy late Mestrado Anatomia Mestre em Biologia Celular e Estrutural

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Monteiro, Juliana Castro. "Associação de ciclosporina e Heteropterys aphrodisiaca (no-de-cachorro) adminstrados a ratos wistar : estrutura, ultra-estrutura e morfometria testicular." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317863.

Texto completo

Resumen

Orientador: Mary Anne Heidi Dolder, Sergio Luis Pinto da Matta Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-10T09:43:10Z (GMT). No. of bitstreams: 1 Monteiro_JulianaCastro_M.pdf: 5278625 bytes, checksum: 63e213bed61e034d07b8ef348696a065 (MD5) Previous issue date: 2007 Resumo: TA ciclosporina A (CsA) possui potentes propriedades imunossupressivas e tem sido amplamente usada na terapia de transplantes de órgãos, aumentando as taxas de sobrevivência dos enxertos, e no tratamento de algumas doenças auto-imunes. Apesar de ser um importante medicamento, diversas reações colaterais são verificadas, entre elas a toxicidade testicular, levando à infertilidade masculina. Heteropterys aphrodisiaca é uma planta com indicações de estimulante e potente afrodisíaco, que aumenta o peso corporal e testicular e o volume das células de Leydig nos testículos de ratos adultos. Assim o efeito da associação dessas drogas foi estudado em ratos Wistar em idade reprodutiva, com avaliação da morfometria, estrutura e ultra-estrutura testicular. Foram utilizados 30 ratos divididos em 5 grupos: I- controle; II- tratamento com CsA; III- concomitante uso de CsA e H. aphrodisiaca; IV- pré-tratamento com H. aphrodisiaca por 30 dias, seguido de CsA por 26 dias; V- tratamento com H. aphrodisiaca. CsA foi administrada na dose de 15 mg/kg/dia e H. aphrodisiaca na dose de 0.5 ml de infusão preparada com 25g de raízes secas/100 ml água fervente. Os tratamentos foram administrados diariamente por gavagem, durante 56 dias. Aumento do peso corporal foi observado em todos os grupos, mas os grupos II e III tiveram menor ganho de peso. O peso dos testículos e dos órgãos sexuais acessórios, assim como a proporção e o volume dos compartimentos tubular e intersticial não alteraram nos grupos tratados. Com a administração de CsA houve aumento na proporção de tecido conjuntivo e redução na proporção de células de Leydig que, além disso, eram menores e com citoplasma mais denso que as células dos animais de outros grupos tratados. Por outro lado, a infusão de H. aphrodisiaca resultou em aumento do volume nuclear das células de Leydig. Os níveis de testosterona plasmáticos, o número de células de Leydig por testículo e por grama de testículo aumentou significativamente nos animais do grupo III. CsA causou degeneração das células germinativas, vacuolização nas células de Sertoli, espermátides arredondadas anormais e atrofia das organelas envolvidas na síntese de esteróides nas células de Leydig. H. aphrodisiaca causou vacuolização nas células de Sertoli, perda do contato e espaçamento entre as células germinativas e aumento de retículo endoplasmático liso e mitocôndrias nas células de Leydig. O tratamento concomitante e sequencial com CsA e H. aphrodisiaca foi efetivo em manter a ultra-estrutura das células de Leydig. Nesses tratamentos, as alterações observadas no epitélio seminífero foram a combinação das modificações observadas em cada tratamento separadamente. Entretanto, H. aphrodisiaca exerceu um efeito protetor no epitélio germinativo, uma vez que as modificações encontradas nesses grupos foram menos severas em relação ao grupo tratado somente com CsA Abstract: Cyclosporine A (CsA) has potent immunosuppressive properties and it has markedly improved the ability of transplant patients to survive grafts and is also used in some autoimmune diseases. However, the drug has several side effects, including testicular toxicity, leading to male infertility (and temporary impotence?). Stimulant and aphrodisiac properties has been attributed to the plant, Heteropterys aphrodisiaca. Data from other experiments suggests that the root extract can increase body and testicular weight and the volume of Leydig cells in rat testis. Thus, the present work was undertaken to study the association of the drug and the medicinal herb in Wistar rats, evaluating testicular morphometry, structure and ultrastructure. Thirty adult rats were used, divided into five groups: I- control; II¿ CsA; III¿ simultaneous use of CsA and H. aphrodisiaca; IV- H. aphrodisiaca for 30 days and CsA sequentially for another 26 days; V- H. aphrodisiaca. CsA was administered at a dose of 15 mg/kg/day and/or H. aphrodisiaca at a dose of 0.5 ml of the infusion prepared with 25g of roots/100ml boiling water, daily by gavage, during 56 days. Increased body weight was observed for all groups, but the animals that received CsA for 56 days showed the smallest body weight gain. The testis and accessory sex organs weights were unchanged. The volume and volumetric proportion of seminiferous tubules and interstitial compartments did not alter in all treated groups. Morphometry showed increased connective tissue volumetric proportion and decreased Leydig cell volumetric proportion in CsA-treated rats. The Leydig cells of CsA-treated animals were smaller and more dense than other groups. On the other hand, the H. aphrodisiaca infusion resulted in an increase in Leydig cell nuclear volume. The plasma testosterone levels and number of Leydig cells per testis increased significantly in group III. Using transmission electron microscopy, it was possible to ascertain that CsA caused germ cell degeneration, Sertoli cell vacuolization, abnormal round spermatids and atrophy of the organelles involved in steroid synthesis in Leydig cells. H. aphrodisiaca caused Sertoli cell vacuolization, loss of germ cell attachment and expanded intercellular spaces between germ cells and Leydig cells with more mitochondria and smooth endoplasmic reticulum. The simultaneous and sequential treatment with H. aphrodisiaca and CsA was effective in maintaining the Leydig cell ultrastructure. In these treatments, the seminiferous epithelium alterations were a combination of the modifications observed for each isolated treatment. However it can be stated that H. aphrodisiaca had a protective effect on the testicular tissue, since less severe modifications were found for this group in relation to the rats that received only CsA Mestrado Biologia Celular Mestre em Biologia Celular e Estrutural

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Predes, Fabricia de Souza. "Associação de cadmio e Ginko biloba em ratos : avaliação dos testiculos quanto a modificações de estrutura, ultra-estrutura e morfometria." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317865.

Texto completo

Resumen

Orientador: Mary Anne Heidi Dolder, Sergio Luis Pinto da Matta Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-10T09:49:19Z (GMT). No. of bitstreams: 1 Predes_FabriciadeSouza_M.pdf: 1559316 bytes, checksum: e206924da33f15ad0daf61b7e2a85726 (MD5) Previous issue date: 2007 Resumo: o cádmio (Cd) é um dos poluentes ambientais importantes que causam danos a vários órgãos e tecidos, incluindo os testículos. O objetivo deste trabalho é investigar o efeito protetor e curativo do extrato de G biloba (GbE) nos testículos de ratos adultos Wistar tratados com dose única de Cd. Trinta animais foram divididos aleatoriamente em 5 grupos que receberam: Grupo 1: água por 56 dias ( controle); Grupo 2: GbE por 56 dias; Grupo 3: CdClz (dose única) e água por 56 dias; Grupo 4: CdCh (dose única) e GbE por 56 dias (Cd + GbE); Grupo 5: pré-tratamento com GbE por 30 dias e CdCh no 31° dia (GbE-Cd). O GbE foi administrado diariamente na dose de 100 mg/Kg de peso corporal por gavagem. O cloreto de cádmio (CdCh) foi injetado intraperitonealmente em dose única de 3 umol/Kg de corporal. Após a coleta de sangue, os ratos foram fixados por perfusão com Kamovsky modificado. Fragmentos de testículo incluídos em metacrilato foram secionados na espessura de 3um e corados com azul de toluidina/borato de sódio 1% para estudo morfométrico em miCroscopia óptica. Para observação em microscópio eletrônico de transmissão fragmentos de testículo foram refixados com tetróxido de ósmio 1 % no mesmo tampão a 4°C, desidratados em acetona e incluídos em Epoxy. Cortes ultrafinos foram feitos com navalha de diamante e contrastados com acetato do uranila 2% e citrato de chumbo 2%. Os níveis de testosterona plasmática obtida por RIA não foram alterados neste estudo. Não houve alteração do peso corporal e testicular, do epidídimo e das glândulas acessórias, vesícula seminal e próstata além do índice gonadossomático. A proporção volumétrica e o volume absoluto dos componentes testiculares não alteraram após os tratamentos. O grupo 3 que recebeu somente Cd teve redução significativa no volume individual das células de Leydig. Entretanto, animais que receberam GbE como pré tratamento ou GbE após a dose de Cd não apresentaram esta redução. Isto sugere que GbE é eficaz em manter o volume das células de Leydig em ratos tratados com Cd. O número de células de Leydig não variou nos grupos estudados. Em microscopia eletrônica foram visíveis os efeitos do Cd nos testículos. Nas células de Sertoli foram observados vacuolização citoplasmática, alterações nas junções celulares e acúmulo de gotículas de lipídio e corpos residuais. Espaços intercelulares expandidos foram observados no epitélio germinativo. Cromatina irregularmente condensada e acrossoma anormal foram encontradas em espermátides alongadas. Algumas células endoteliais sofreram alterações morfológicas no núcleo e perderam algumas junções. As células de Leydig mostraram o citoplasma denso com organelas, como retículo endoplasmático liso e mitocôndrias, mal definidas. A administração de GbE após a dose de Cd mostrou-se eficaz em manter a ultraestrutura normal dos testículos do rato. Diferentemente, o pré-tratamento com GbE não foi eficaz em proteger o epitélio seminífero da toxicidade do Cd. Entretanto, as células de Leydig apresentaram morfologia normal com o retículo endoplasmático liso bem definido e numerosas mitocôndrias. Conclui-se que a administração de GbE por 56 dias após dose única de 3 umol de CdCh é capaz de proteger todo o parênquima testicular dos efeitos tóxicos do Cd. Entretanto, o pré-tratamento com GbE não protegeu o epitélio seminífero, mas foi eficaz em proteger as células de Leydig dos efeitos tóxicos do cádmio Abstract: Cadmium is one of the important environmental pollutants that affect various organs and tissues, including the testis. The aim of this study was to investigate the protective and curative effect of G. biloba extract (GbE) on cadmium-induced testis damage of adult Wistar rats. Thirty rats were randomly divided in five groups that consisted in :Group 1: water for 56 days (control); Group 2: GbE for 56 days; Group 3: CdClz (single dose) and water for 56 days; Group 4: CdCh (single dose) and GbE for 56 days (Cd + GbE); Group 5: pre-treatment with GbE for 30 days and CdCh on the thirty-first day (GbE-+Cd).The GbE was administered daily in a dose of 100 mg/Kg BW by gavage. The cadmium chloride (CdCh) was injected i.p. in a single dosage of 3 umol/Kg BW. After blood collection, rats were fixed by whole-body perfusion in Karnovsky fixative. Methacrylate-embedded testis fi-agments were sectioned at 3um thickness and stained with toluidine blue/sodium borate 1 % for morphometric study in the light microscope. For electron microscopy transmission examination, testis fragments were post-fixed with 1 % osmium tetroxide in the same buffer at 4°C, dehydrated in acetone and embedded in epoxy resin. Ultrathin sections were cut with a diamond knife and stained with 2% uranyl acetate and 2% lead citrate prior to observation. Plasma testosterone values obtained by the RIA method were not modified in this study. No change occurred in the average of corporal and testicular weight, gonadosomatic index, epididymis and accessory glands weight. The volumetric proportion and absolute volume oftesticular componenfs did not change after the treatments. Group 3 had a significant reduction in Leydig cell individual volume. However, animals that received GbE as pre-treatment or GbE after a cadmium dose did not present this reduction of Leydig cell volume. This suggests that GbE is effective in maintaining Leydig cell volume in cadmium-damaged testis. The number ofLeydig cells did not vary in any group studied. In electron microscopy observations, this Cd dose caused visible alterations in the testis. Cytoplasmic vacuolation, disruption oftight junctions, accumulation oflipid droplets and residual bodies were observed in Sertoli cells. Expanded intracellular spaces were observed between the tubule cells. Irregularly condensed chromatin and abnormal acrosomes were found in late spermatids. Endothelium was affected, showing some disruption of tight junetions and morphologieally altered nuclei. Leydig eells showed a dense eytoplasm with poorly defined organelles sueh as SER and mitoehondria. The administration of GbE after the Cd dose is effeetive in maintaining almost normal rat testis ultrastructure. However, GbE pretreatment was not able to protect testis from Cd toxicity, since toxicity signals were observed in the seminiferous epithelium. However, Leydig cells showed the normal morphology with well-defined and abundant smooth endoplasmic reticulum and mitochondria. It can be concluded that, GbE administration for 56 days after a single dose of 3 umol of CdCh could protect the testicular parenchyma from Cd toxic effects. However, GbE pretreatment did not protect the seminiferous epithelium, although it was effective in protecting Leydig cells from Cd toxic effeets Mestrado Biologia Celular Mestre em Biologia Celular e Estrutural

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Moya, Juliana Siqueira. "Espermiogenese e morfologia dos espermatozoides de Iporangaia pustulosa (Arachnida : Opiliones: Laniatores)." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317861.

Texto completo

Resumen

Orientadores: Mary Anne Heidi Dolder, Karina Carvalho Mancini Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-10T15:52:17Z (GMT). No. of bitstreams: 1 Moya_JulianaSiqueira_M.pdf: 6061809 bytes, checksum: 3498b49d3b5da2af4c020b2cec6420ed (MD5) Previous issue date: 2008 Resumo: Iporangaia pustulosa (Arachnida: Opiliones) é uma espécie de opilião pertencente à subordem Laniatores. Machos adultos desta espécie tiveram seus aparelhos reprodutores dissecados, e seus testículos e vesículas seminais processados para microscopias de luz e eletrônicas de transmissão (convencional e citoquímica - E-PTA) e varredura. O aparelho reprodutor de I. pustulosa é composto por um testículo tubular, dois ductos deferentes que se unem em uma grande vesícula seminal. O testículo apresenta cistos com células germinativas em diferentes fases de desenvolvimento. A espermiogênese é centrípeta e caracterizada por: (1) ausência de formação de flagelo; (2) centro cinético reduzido a dois centríolos do tipo 9+0; (3) formação de manchete de microtúbulos, que auxiliam na compactação nuclear e na determinação da forma celular; (4) gradual compactação cromatínica nas diferentes fases das espermátides até a total compactação nos espermatozóides; (5) desenvolvimento de uma invaginação citoplasmática em direção ao núcleo, desprovida de organelas; (6) acrossomo formado a partir de vesículas do Golgi, composto por uma vesícula acrossomal, um material denso sub-acrossomal, mitocôndrias e pequenas vesículas associadas; (7) espermatozóides ovais, aflagelados, com membrana plasmática ondulada. Pelo método de E-PTA foram detectadas proteínas básicas em diferentes estruturas ao longo do desenvolvimento da espermiogênese. Os espermatozóides formados são liberados dos cistos no centro do testículo e são armazenados na vesícula seminal. Dispersos pela luz da vesícula, os espermatozóides apresentam os mesmos componentes observados no testículo, porém adquirem projeções extracelulares aderidas às ondulações da membrana recobrindo a superfície celular, exceto na região do acrossomo. Essas projeções são adquiridas gradualmente ao longo da extensão da vesícula seminal e são recobertas por um material amorfo na extremidade semelhante a um glicocálice. A espermiogênese de I. pustulosa e a morfologia dos espermatozóides testiculares e vesiculares são semelhantes ao descrito para a espécie Vonones sayi, também pertencente à sub-ordem Laniatores. Por não ocorrer formação de axonema durante a espermiogênese, os espermatozóides de I. pustulosa são aflagelados e tais projeções podem estar envolvidas no transporte do espermatozóide, sua ancoragem no interior da fêmea ou ainda no reconhecimento do óvulo Abstract: Iporangaia pustulosa (Arachnida: Opiliones) is a harvestman species belonging to the Laniatores suborder. Adult males of this species had their reproductive tracts dissected and their testis and seminal vesicles were processed for light, transmission (routine preparations and cytochemistry: E-PTA) and scanning electron microscopy. The reproductive tract of I. pustulosa is composed of a tubular testis and two deferent ducts that connect to a large seminal vesicle. The testis presents cysts of germ cells in different developmental stages. Spermiogenesis in I. pustulosa is centripetal and characterized by (1) the lack of flagellum formation; (2) the kinetic center reduced to two centrioles of the 9+0 type; (3) the microtubule manchette formation; (4) the gradual chromatin condensation from spermatids to spermatozoa; (5) the cytoplasmic invagination development, without organelles, that extends into the nucleus; (6) the acrosome formed by Golgi vesicles, composed of acrossomal vesicles, a subacrosomic dense material, associated mitochondria and small vesicles; (7) the oval aflagellated spermatozoa, with a wavy plasma membrane. With the E-PTA method, basic proteins were detected in different structures throughout spermiogenesis. The spermatozoa are released from the cysts in the center of the testis and are kept in the seminal vesicle lumen. There, the spermatozoa present the same components observed in the testis, however they acquire extracellular projections, which adhere to the wavy membrane covering the cell surface, except in the acrosome area. These projections are acquired gradually along the seminal vesicle length and are covered by an amorphous material on their tips, resembling a glycocalix. The spermiogenesis of I. pustulosa as well as the morphology of testicular and seminal vesicle spermatozoa are similar to that described for Vonones sayi, also belonging to the Laniatores suborder. As axoneme formation does not occur during the spermiogenesis, I. pustulosa spermatozoa are aflagellated and their projections could help to transport sperm along the male and female reproductive tracts, anchor the spermatozoa inside the female and/or play a role in oocyte recognition Mestrado Biologia Celular Mestre em Biologia Celular e Estrutural

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Nunes, Erika Takagi. "Farfantepenaeus brasiliensis (Crustacea : Penaeoidea) : morfologia do hepatopâncreas e sua relação com os metais pesados encontrados no litoral sul do Espírito Santo /." Rio Claro : [s.n.], 2011. http://hdl.handle.net/11449/100568.

Texto completo

Resumen

Orientador: Maria Izabel Souza Camargo Coorientador: Adriane C. Araújo Braga Banca: Daniela Carvalho dos Santos Banca: Aparecida do Carmo Zerbo Tremacoldi Banca: Karina Ribeiro Banca: Tatiana da Silva Souza Resumo: O hepatopâncreas dos crustáceos, também conhecido como glândula digestiva, passa por modificações morfo-funcionais em resposta a fatores como dieta, variações de temperatura, ciclo de muda, estágio reprodutivo e contaminação. Este trabalho objetivou analisar, morfologicamente, através de técnicas de microscopia eletrônica e de luz, o hepatopâncreas de fêmeas adultas do camarão-rosa Farfantepenaeus brasiliensis, em dois diferentes estágios de desenvolvimento gonadal, coletadas em Guarapari, Espírito Santo, Brasil, bem como relacionar esta espécie às condições ambientais, comparativamente ao camarão Xiphopenaeus kroyeri. A microscopia eletrônica de varredura evidenciou hepatopâncreas de tamanhos semelhantes nas fêmeas com gônadas desenvolvidas (DE) e naquelas esgotadas (ES), apresentando-se como um órgão não-lobado e recoberto por tecido conjuntivo com poros. Histologicamente, foram identificados cinco tipos celulares nos túbulos: células E (embrionárias), R (reabsortivas), F (fibrilares), B (vesiculares) e M (basais). Comparado às DE, o epitélio hepatopancreático das fêmeas ES mostrou-se mais escamoso, acidófilo, delimitando um amplo lúmen que contem partes das células B e R; nestas, ainda, as células M estiveram mais evidentes. As células R mostraram escassez em organelas, mitocôndrias apicais, vacúolos marcados para polissacarídeos ácidos, além de gotas lipídicas vistas principalmente nas fêmeas ES. As células F, fortemente marcadas pelo azul de bromofenol, apresentaram vesículas de secreção próximas às microvilosidades, retículo endoplasmático rugoso bem desenvolvido, em arranjo circular ou com cisternas dilatadas. As células B foram marcadas pela presença de grandes corpos digestivos com conteúdo polissacarídico neutro, sendo eliminado, posteriormente... (Resumo completo, clicar acesso eletrônico abaixo) Abstract: The hepatopancreas of crustaceans, also known as the digestive gland, undergoes morphological and functional changes in response to factors such as diet, temperature variations, moult cycle, reproductive stage and contamination. This study aimed to analyze, morphologically, by means of electron and light microscopies, the hepatopancreas of adult females of the pink shrimp Farfantepenaeus brasiliensis at two different stages of gonadal development, collected in the southern coast of Espirito Santo, Brazil, as well as to relate this species to the environmental conditions, compared to Xiphopenaeus kroyeri shrimp. The scanning electron microscopy revealed similar size in the hepatopancreas of females with developed gonads (DE) and those with exhausted gonads (ES). It presents as a non-lobed organ covered by connective tissue with pores. Histologically, five cell types were identified in tubules: E (embryonic), R (reabsorptive), F (fibrillar), B (vesicular) and M (basal). Compared to those DE females, the hepatopancreas from ES females showed a more flattened epithelium, acidophilus and delimiting a large lumen which contains parts of R and B cells; in these, also, the M cells were more evident. R cells showed shortage in organelles, apical mitochondria, vacuoles marked for acid polysaccharides, and lipid droplets seen mainly in female ES. F cells were strongly marked by bromophenol blue and presented secretory vesicles near the microvilli, well-developed rough endoplasmic reticulum in circular arrangement, or even with dilated cistern. B cells were marked by the presence of large digestive bodies with neutral polysaccharide content, being later eliminated inside the tubular lumen. The observed features also allowed us to infer the possible stages of moult in which the shrimps were. Although some... (Complete abstract click electronic access below) Doutor

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Smith, Michaela Madeleine 1972. "Maintenance of ultrastructural integrity during dehydration in a desiccation tolerant angiosperm as revealed by improved preservation techniques." Monash University, Dept. of Biological Sciences, 2002. http://arrow.monash.edu.au/hdl/1959.1/8323.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Reinhardt, Camille. "Impact de la voie d’import mitochondrial contrôlée par le complexe AIF/CHCHD4 sur la survie des cellules cancéreuses et la réponse aux traitements anticancéreux." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS542.

Texto completo

Resumen

Dans la majorité des cas, les mitochondries sont nécessaires à la tumorigenèse et à la réponse des cellules cancéreuses aux signaux générés par les facteurs micro-environnementaux (exemples : privation de nutriments, hypoxie) ou par les traitements anticancéreux (exemples : chimiothérapie, radiothérapie). Presque toutes les protéines mitochondriales sont codées par le génome nucléaire et importées dans l'organelle. Des machineries d'import ont donc évolué afin de répondre aux besoins d'import protéique. Dans ce contexte, la machinerie régulée par CHCHD4/Mia40 fonctionne dans l’espace intermembranaire et contrôle l’import d’un groupe de protéines (substrats) qui joue des rôles importants dans la survie et la réponse au stress. Les substrats de CHCHD4/Mia40 sont impliqués dans un vaste panel d’activités mitochondriales qui inclut la biogenèse des complexes de la chaîne respiratoire, l’homéostasie lipidique, le stockage du calcium, ainsi que l'ultrastructure et la dynamique mitochondriale. Ce programme de thèse a été dédié à l’étude de la voie d’import CHCHD4/Mia40 dans les cellules cancéreuses et a porté un intérêt tout particulier à l'un des substrats CHCHD4/Mia40 qui façonne l'ultrastructure mitochondriale. En utilisant des techniques d’ARN interférence et de sur-expression de protéines recombinantes, dans un modèle de cancer du côlon, nous avons montré que l’expression du substrat étudié a un effet crucial sur la prolifération et la croissance tumorale. Nos données ont également impliqué cette protéine dans la réponse aux traitements anticancéreux. Dans l'ensemble, ces travaux ouvrent un nouveau champ d'investigations qui non seulement permettra de mieux comprendre la plasticité métabolique des cellules cancéreuses, mais aidera également à identifier de nouveaux biomarqueurs métaboliques In the vast majority of cases, mitochondria are required for tumorigenesis and also for the tumoral response to signals generated by the microenvironmental factors (e.g. nutrient deprivation, hypoxia) or to the effects of anti-cancer treatments (e.g. chemotherapy, radiotherapy). As almost all mitochondrial proteins are nuclear-encoded and imported into the organelle, specialized import machineries have evolved in order to meet the need for protein import. Among these machineries, the one that operates in the intermembrane space and is controlled by CHCHD4/Mia40, regulates the import of a group of proteins (substrates) that play important roles in survival and stress response. Substrates of CHCHD4/Mia40 are involved in a broad panel of mitochondrial activities that includes the biogenesis of respiratory chain complexes, lipid homeostasis, calcium storage, as well as ultrastructure and mitochondrial dynamics. This thesis program was dedicated to the study of the CHCHD4/Mia40 import pathway in cancer cells, with a particular interest for one of the CHCHD4/Mia40 substrates that shapes mitochondrial ultrastructure. Using RNA interference approach and recombinant protein overexpression technique, in a colon cancer model, we showed that the expression of this substrate had a crucial effect on proliferation and tumor growth. Our data also involved this protein in the response to anti-cancer treatments. All together, this work opens a new field of investigations that will not only shed new lights on the metabolic plasticity of cancer cells but also help to identify new metabolic biomarkers

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Jesus, Carlos Massuretti de. "Análise comparativa das glândulas pós-faríngeas e sua participação na utilização de lipídeos pelas formigas (Hymenoptera : Formicidae) /." Rio Claro : [s.n.], 2011. http://hdl.handle.net/11449/106581.

Texto completo

Resumen

Orientador: Odair Correa Bueno Banca: Maria Santina de Castro Morini Banca: Neusa de Lima Nogueira Banca: Roberta Cornélio Ferreira Nocelli Banca: Priscila Cintra Socolowski Resumo: Uma característica típica das formigas e algumas vespas é a presença das glândulas pós-faríngeas, estrutura que se encontra somente nesses grupos de organismos, fato que deve ter contribuído para o seu sucesso evolutivo. Apesar dos primeiros estudos com as glândulas pós-faríngeas existirem há mais de 100 anos, somente nos últimos 20 elas tem recebido maior atenção dos pesquisadores. Assim, a presente pesquisa teve por objetivo realizar uma análise comparativa da morfologia das glândulas pós-faríngeas e verificar sua participação na utilização de lipídeos ingeridos por três espécies de formigas com padrões alimentares distintos. Para tal, foi realizado análise ultramorfologica e ultraestrutural das glândulas pós-faríngeas; quantificação da ingestão de lipídeos e carboidratos, e verificação do trajeto destes compostos pelo sistema digestório das operárias; análise autorradiográfica do processo de incorporação do ácido oléico marcado radioativamente pelas glândulas pósfaríngeas das operárias. Os resultados encontrados sugerem que cada uma das espécies apresenta uma particularidade: as glândulas pós-faríngeas de Camponotus vittatus podem ser um sítio de reserva energética para o indivíduo; as operárias de Atta laevigata deslocam parte dos lipídeos ingeridos para o intestino médio, evitando o seu acúmulo nas glândulas pós-faríngeas, ao passo que foram encontradas pela primeira vez dois tipos de células nas glândulas pósfaríngeas de Pachycondyla villosa. Além disso, o trajeto percorrido pelos alimentos hidrossolúveis no interior do sistema digestório das operárias compreende a cavidade infrabucal, papo e ventrículo. Enquanto que os lipídeos passam pela cavidade infrabucal, glândulas pós-faríngeas e papo, mas não atingem o ventrículo; com exceção de A. laevigata em que foram encontrados... (Resumo completo, clicar acesso eletrônico abaix Abstract: A typical gland found only in ants and some wasps species is the postpharyngeal gland, which could have contributed to the evolutionary success of these social insects. The first studies regarding the morphology and function of the postpharyngeal glands were conducted about 100 years ago, and only in the last 20 years researches gave more attention to its importance. Thus, this study aimed at comparing the morphology of postpharyngeal glands and to verify their participation in the use of lipids ingested by three ant species. For this purpose, we performed: 1- Ultrastructural and Ultramorphology analysis of the postpharyngeal glands; 2 - the flow of lipids and carbohydrates inside the digestory systeam; 3 - the incorporation of radiolabeled oleic acid by the postpharyngeal using autoradiografic methods. Our results suggest that each species has a particularity: the postpharyngeal glands of Camponotus vittatus may be act as a site of food reserve, the workers of Atta laevigata prevent the accumulation of oleic acid in the postpharyngeal glands by sending lipids ingested to midgut. On the other hand, Pachycondyla villosa has specialized cells to eliminate of lipids from the postpharyngeal glands. Moreover, water-soluble diets were found in infrabucal pockets, crop and ventriculi, while lipid-soluble diets were found in infrabucal pockets, postpharingeal glands and crop; except for A. laevigata, which also had lipids in their midgut. Autorradiografic analysis showed that oleic acid is absorbed by the epithelium of... (Complete abstract click electronic access below) Doutor

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Schultes, Klaus. "Ultrastructural characterization of ultraviolet induced corneal disease : an animal model." Master's thesis, University of Cape Town, 1994. http://hdl.handle.net/11427/27046.

Texto completo

Resumen

The majority of ancient people worshipped the sun and viewed it as a health - bringing deity. During the eighteenth and nineteenth century therapeutic benefits of sunlight exposure were beginning to be understood and by the end of the nineteenth century the importance of ultraviolet radiation was being realized. Danish physician Niels Finsen, whom many regard as the father of ultraviolet phototherapy, also stressed that it was ultraviolet radiation in the solar spectrum which cause sunburn. We now recognize that the small portion of ultraviolet radiation which reaches the earth's surface is not necessarily therapeutic, but in fact could be harmful to humans. There are numerous accounts of the harmful effects of UV radiation to the skin and the eye as a whole. These effects may be caused by either acute or chronic exposure to UV radiation. For example, some acute effects of UV-B radiation include conjunctivitis and photokeratitis. "Snow blindness" and "arc welders eye" are further examples of acute ultraviolet damage specifically to the surface of the cornea. On the other hand, chronic exposure to ultraviolet radiation is thought to be responsible for pterygia, climatic droplet keratopathy Hill and Maske (1989), cancers of the external eye, cataracts and various types of retinal diseases. The present study is an extension of ongoing studies on ultraviolet radiation damage to the cornea in the Department of Ophthalmology, University of Cape Town and Groote Schuur Hospital. Their specific interest lies in the causes and treatment of climatic droplet keratopathy. The aims of the present study are: 1) Establish a possible role of ultraviolet B radiation in human corneal diseases such as climatic droplet keratopathy and pterygium using the rabbit as an animal model. 2) Determine by means of SEM the initial effects and subsequent recovery of the epithelium after a 3-hour dose of ultraviolet B radiation. We refer to this study as "acute" response to ultraviolet B radiation. 3) To try and confirm the effects observed by SEM with ultrastructural studies using TEM. 4) In addition, we are also looking at the possible effects after exposing rabbit cornea to a daily dose of low level ultraviolet B radiation, over a long period of time. We refer to this as chronic exposure to ultraviolet B radiation. It is hoped that by exposing rabbits to ultraviolet light, principally ultraviolet B radiation, diseases similar to those found in humans could be simulated and disease progression studied. People are generally exposed to substantial amounts of UV radiation for a very long time. Since people generally live longer they will be exposed to an ever-increasing amount of solar UV radiation and subsequently, there is an increasing risk of developing corneal diseases. The possible threat to the ozone is also a real possibility and could lead to increased levels of ultraviolet radiation reaching the earth's surface. This will require a greater understanding of the very nature of corneal damage due to acute and chronic exposure. This study focusses mainly on the acute response to UV-B radiation since most studies have investigated effects of prolonged exposure to UV light. Accordingly, much less is known about acute exposure. Many people suffering from acute UV B radiation effects probably never visit the ophthalmologist or wait for a couple of days. This could also contribute to the fact that effects of short-term damage is not well documented.

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Stander, Cornelia Steynberg. "An ultrastructural and light microscopic study of melanocyte differentiation in chick embryos." Master's thesis, University of Cape Town, 1991. http://hdl.handle.net/11427/27149.

Texto completo

Resumen

The embryonic source and chemical nature of those factor/s directing the in vivo differentiation of melanocytes from crest cells are as yet unknown. To begin to address this issue, it is important to establish exactly when and where these signa/s first exert their effects. Therefore, in the present study, overtly differentiated melanocytes containing melanin were quantitated in developing Black Australorp X New Hampshire Red chick embryos. In contrast to previous studies, it was found that embryos synthesize melanin from as early as Day 5 of development, and that at this stage, the melanocytes are predominantly dermally located. Between 5 and 8 days, the numbers of both dermal and epidermal melanocytes increase, after which the dermal melanocyte population declines rapidly while the number of epidermal melanocytes continues to increase. These findings suggest that premelanocytes do not have to be epidermally located to initiate terminal differentiation and implicate the dermis as a possible source of melanocyte inducing factor/s. The next step was to examine stages of development prior to the onset of pigment production. For this reason, tyrosinase was purified for use as antigen in the production of a polyclonal antibody. The antibody was tested for specificity by western blotting, - immunocytochemistry and immunoinhibition procedures. Lack of specificity was demonstrated, rendering it unsuitable as an antibody marker for early melanocytes. Fowl melanocytes are thought to differentiate into either eumelanosome- or pheomelanosome synthesizing cells. To test the validity of this concept, embryonic skin of the red/black cross breed were screened for possible mixed type melanocytes by electron microscopy. The melanocytes contained melanosomes with a matrix of irregularly arranged filaments amongst typical eumelanogenic melanosomes. This suggests that these chick melanocytes may synthesize both eumelanosomes and pheomelanosomes in single cells. In a further study on pure breeding New Hampshire Reds, it was found that the melanocytes contained a mixture of typical and less typical pheomelanosomes. Outer membrane indentations in the latter melanosome type suggest that tyrosinase may enter these pheomelanosomes by a mechanism related to that proposed for the melanosomes of goldfish.

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Leite, Rodrigo Paula 1981. "Efeitos da associação de cloreto de cadmio e guarana (Paullinia cupana) no testiculo de ratos Wistar : analise morfometrica, estrutural e ultraestrutural." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317840.

Texto completo

Resumen

Orientador: Mary Anne Heidi Dolder Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-10T17:43:57Z (GMT). No. of bitstreams: 1 Leite_RodrigoPaula_M.pdf: 5609286 bytes, checksum: 3ec427e58604a2e57788f27cb168bf44 (MD5) Previous issue date: 2008 Resumo: O guaraná (Paullinia cupana Mart. var. Sorbilis) é uma planta originária do Brasil encontrada na região da Bacia Amazônica. Estudos prévios vêm demonstrando a propriedade antioxidante do extrato de guaraná e sua capacidade neutralizar radicais livres. Essa planta é tradicionalmente usada com fins terapêuticos diversos e recentemente tem-se investigado sua capacidade de atuar no tratamento de patologias relacionadas ao desequilíbrio da atividade oxidante da célula. O cádmio é um metal pesado com propriedades tóxicas aos organismos e a contaminação por este elemento torna-se preocupante devido ao seu grande efeito cumulativo e meia vida biológica longa. Esse metal tem sido considerado um importante poluente ambiental, sendo as suas principais fontes de exposição o despejo industrial, a poluição atmosférica e o tabaco. Sabe-se que a natureza tóxica do cádmio é, em parte, devida à sua ação oxidante no organismo, estimulando a produção de radicais livres que causam danos celulares. Os testículos são particularmente vulneráveis aos efeitos tóxicos desse metal, sendo que neste órgão a propriedade cumulativa do cádmio parece ser acentuada. Portanto, os testículos atuam como um importante modelo experimental para estudos referentes aos efeitos tóxicos do cádmio e à possíveis alternativas terapêuticas para os efeitos adversos deste metal. Baseando-se nestas informações, o presente estudo avaliou o potencial do guaraná em atenuar os danos causados pelo cádmio no testículo de ratos Wistar adultos. Foram desenvolvidos dois modelos experimentais diferentes: 1o- administração preventiva do guaraná durante 56 dias antes da exposição ao cádmio; 2o- administração do guaraná durante 56 dias após a exposição ao cádmio. Para análises comparativas, também foram montados um grupo tratado somente com cádmio e um grupo tratado somente com guaraná. As amostras de testículo foram coletadas e submetidas a análises histológicas, morfométricas e ultra-estruturais, e os resultados obtidos estão expostos em dois artigos científicos Abstract: Guaraná (Paullinia cupana Mart. var. Sorbilis) is a Brazilian plant, found in the Amazon basin. Previous studies have demonstrated the antioxidant properties of guaraná and its potential to neutralize free radicals. This plant is traditionally used for several therapeutic purposes and, recently, has been investigated to ascertain the potential of guaraná to counterbalance cellular oxidative disorders. Cadmium is a toxic heavy metal, and the contamination by this element is more harmful due to its long biological half-life, and therefore its accumulation in the organism. This metal is considered important for environmental pollution, in which exposition occurs through industrial wastes, atmospheric pollution and tobacco smoking. Cadmium is known to be toxic partly due to its oxidative effect in the organism, stimulating the production of free radicals that cause cellular damage. The testicles are particularly vulnerable to the toxic effects of this metal and this organ has higher cumulative properties. Therefore the testicles are an important experimental model for studies of the toxic effects of cadmium and the possible therapeutic alternatives for the adverse effects of this metal. Based on this information, the present study evaluated the potential of guaraná to attenuate the harm caused by cadmium in adult rat testicles. Two experimental models were developed: 1) Preventive administration of guaraná during 56 days before exposition to cadmium; 2) Administration of guaraná during 56 days after exposition to cadmium. For comparative analysis, a group was also treated only with cadmium or only with guaraná. Testicle samples were collected and submitted to histological, morphometrical and ultrastructural analysis and the results are presented in the form of two scientific articles. The results show that guaraná is beneficial in both experimental models, contributing to the maintenance of testicular morphology Mestrado Biologia Celular Mestre em Biologia Celular e Estrutural

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Nordin, Anders. "Buellia species with pluriseptate spores and the Physciaceae (Lecanorales, Ascomycotina) : Taxonomic, phylogenetic and ultrastructural studies." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-4879-8/.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Jones, Christopher David Stanford. "On the cross-sectional form of the patella in several primates." Title page, table of contents and abstract only, 2003. http://web4.library.adelaide.edu.au/theses/09PH/09phj764.pdf.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Lacchia, Ana Paula Stechhahn. "Estruturas secretoras em orgão vegetativos e reprodutivos de especies de Anacardiaceae : anatomia, histoquimica e ultra-estrutura." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315567.

Texto completo

Resumen

Orientadores: Sandra Maria Carmello-Guerreiro, Marilia de Moraes Castro, Lia Ascensão Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-08T00:05:44Z (GMT). No. of bitstreams: 1 Lacchia_AnaPaulaStechhahn_D.pdf: 8477823 bytes, checksum: a1685fc288b20acce389a79bd6302d17 (MD5) Previous issue date: 2006 Resumo: Anacardiaceae é composta por 70 gêneros com aproximadamente 600 espécies de distribuição principalmente pantropical, com poucas de regiões temperadas. A classificação infrafamiliar mais amplamente utilizada, proposta por Engler (1892), divide a família em cinco tribos: Anacardieae, Rhoeae, Semecarpeae, Spondiadeae e Dobineeae. No presente trabalho, foram estudadas uma espécie da tribo Anacardieae (Anacardium humile St.Hil), uma espécie da tribo Rhoeae (Lithraea molleoides (Vell.) Engl. e duas espécies da tribo Spondiadeae (Spondias dulcis G.Forst e Tapirira guidnensis Aubl.). As estruturas secretoras dos órgãos vegetativos e reprodutivos destas espécies foram caracterizadas anatômica e histoquimicamente e apenas os canais secretores foram caracterizados ultra-estruturalmente. Os canais têm epitélio unisseriado; os associados ao floema são resiníferos (lato sensu) e os medulares de A. humile e S. dulcis, são mucilaginosos. A presença de canais produzindo secreções quimicamente distintas em um mesmo órgão, de uma mesma espécie, está sendo descrita pela primeira vez neste tranalho. Em A. humile, L. molleoides e T.guianensis os canais estão associados ao floema da pétala, sépala, receptáculo, pedicelo florais de todas as flores e ao floema do mesofilo ovariano das flores pistiladas e do pistilódio das flores estaminadas de L. molleoides e, T. guianensis. Canais também são encontrados no fruto e pedúnculo de A. humile e no fruto de T. guianensis. Os canais têm epitélio unisseriado; os florais de A. humile, L. molleoides e T. guianensis são resiníferos (lato sensu), os do fruto e pedúnculo de A. humile são resiníferos (stricto sensu) e os do fruto de T. guianensis são resiníferos (lato sensu). Em uma mesma espécie os canais secretores presentes em diferentes órgãos podem produzir substâncias distintas¿Observação: O resumo, na íntegra poderá ser visualizado no texto completo da tese digital Abstract: Anacardiaceae is comprised of 70 genera with approximately 600 species of pantropical distribution, mainly, with few species from temperate regions. The most used infrafamilial classification, proposed by Engler (1892), divides this family in five tribes: Anacardieae, Rhoeae, Semecarpeae, Spondiadeae, and Dobineeae. In the present work, there were studied a species from Anacardieae tribe (Anacardium humile St.Hil), a species from Rhoeae tribe (Lithraea molleoides (Vell.) Engl., and two species from Spondiadeae tribe (Spondias dulcis G.Forst and Tapirira guianensis Aubl.). The secretory structures of the vegetative and reproductive organs of these species were characterized anatomically and histochemically, and the secretory canals present in them were ultrastructurally characterized. The canals present uniseriate epithelium; the ones associated to the phloem are resiniferous (lato sensu) and the medullar ones of A. humile and S. dulcis are mucilaginous. The presence of canals that produce chemically distinct secretions in the same organ of a species is being described for the first time. In A. humile, L. molleoides, and T. guianensis, the canals are associated to the phloem of petal, sepal, receptacles, and ovarian mesophyll; only in the pistil-like structure of the male flowers of L. molleoides and T. guianensis, there are found some canaIs. The canals are also found in the fruit and peduncle of A. humile and in the fruit of T. guianensis. The canaIs have uniseriate epithelium; the floral canaIs of A. humile, L. molleoides, and T. guianensis are resiniferous (lato sensu), the ones from fruit and peduncle of A. humile are resiniferous (stricto sensu), and the ones from the fruit of T. guianensis are resiniferous (lato sensu). In the same species, the secretory canaIs present in different organs may produce distinct substances...Note: The complete abstract is available with the full electronic digital thesis or dissertations Doutorado Doutor em Biologia Vegetal

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Chuffa, Luiz Gustavo de Almeida 1982. "Estrutura e biometria dos ovarios de ratas adultas UChA e UChB (consumidoras voluntarias de etanol)." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317531.

Texto completo

Resumen

Orientador: Francisco Eduardo Martinez Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-11T07:02:25Z (GMT). No. of bitstreams: 1 Chuffa_LuizGustavodeAlmeida_M.pdf: 17135101 bytes, checksum: 8f33ca2035c16a60e6aeaeb2a8f607d9 (MD5) Previous issue date: 2008 Resumo: O alcoolismo crônico está inserido no grupo das principais doenças classificadas como oriundas de distúrbios mentais, sendo as mulheres mais atingidas em relação aos homens. Embora, o álcool conduza inicialmente a estímulos emocionais benéficos para o organismo, proporcionando aumento da euforia, do prazer, entre outros, seu uso excessivo e prolongado pode promover efeitos colaterais indesejáveis, inclusive sobre a reprodução. Na literatura existem poucos estudos envolvendo as conseqüências do alcoolismo crônico em fêmeas. O presente trabalho tem como objetivo elucidar as alterações manifestadas no ovário de ratas adultas UChA e UChB (consumidoras voluntárias de etanol a 10%). Após o período de tratamento, 42 ratas subdivididas em três grupos experimentais (UChA, UChB e Wistar) foram eutanasiadas por decapitação, e os ovários coletados e processados para análise em microscopia de luz e eletrônica de transmissão. O material foi corado com Hematoxilina e Eosina, Tricrômico de Masson, Azul de Toluidina, ácido periódico de Schiff, Giemsa, Feulgen e, empregou-se o método enzimológico para atividade da fosfatase ácida e alcalina. Os parâmetros: peso corpóreo e dos genitais, índice de ganho de peso, duração dos ciclos estrais e dosagens hormonais (FSH, LH, _-estradiol e progesterona) foram avaliados. A análise estatística foi realizada com 5% de significância. Não houve diferença significativa entre o peso dos animais no início e final do experimento, embora, ao final do experimento, os animais do grupo UChB apresentaram maior índice de ganho de massa. O peso relativo dos ovários dos animais UChB mostrou-se significativamente menor comparado ao grupo Wistar. As dosagens hormonais não apresentaram diferenças estatísticas entre os grupos. Os animais UChA e UChB revelaram as maiores médias de duração dos ciclos estrais e permanência na fase de estro. Nota-se estágios diferenciados de proliferação celular e atresia folicular avançada nos ovários, variando entre os grupos UChA e UChB. Nas variedades bebedoras, a túnica albugínea apresentou-se fibrosa e o estroma medular predominantemente celular. Estroma fibrocelular e túnica albugínea fibrosa estão presente no grupo controle. O grupo UChA apresentou reações metacromáticas entre as células da granulosa dos folículos em crescimento, enquanto regiões delimitadas na parede dos folículos primários, em desenvolvimento e antrais apresentaram intensa metacromasia nos animais UChB. Os grupos UChA e UChB apresentaram reações PAS-positivo no tecido glandular intersticial, enquanto nos animais controles essas reações ficaram restritas na zona pelúcida de ovócitos e entre as células da granulosa de folículos secundários. Os folículos antrais do grupo UChB apresentaram forte reação à fosfatase ácida (FA), comparados aos grupos UChA e controle. Nos animais UChA, os corpos lúteos hemorrágicos e em regressão, destacaram reação à FA com presença de grumos associados. A fosfatase alcalina (FAL) demarcou ampla vascularização nos corpos lúteos dos animais UCh, enquanto que a teca interna dos folículos secundários do grupo UChB reagiram intensamente com a FAL. A análise ultra-estrutural revelou corpos lúteos com vacúolos autofágicos no citoplasma e início de picnose nuclear nas linhagens UCh. As células da granulosa apresentaram núcleos com marginalização da cromatina e mitocôndrias edemaciadas. Conclui-se que há irregularidades do ciclo estral e, consequentemente, alterações estruturais nos ovários das linhagens UChA e UChB Abstract: Chronic alcoholism belongs to the group of diseases classified as originated from mental disturbs, being the women more affected than men. Although ethanol intake causes benefic stimulus to the organism, like increase in euphoria and pleasure, excessive and prolonged use can cause side effects, even to the reproduction. On the literature, there were few researches involving chronic alcoholism and female. In regard to the current incidence of early and late alcoholism in women, and its consequences to the reproduction, the aim of this study was to evaluate the UChA and UChB (10% ethanol voluntary intake) adult rat ovary structure. After the experimental period, 42 rats divided into three groups (UChA, UChB and Wistar control) were killed, by decapitation method, and their ovaries collected to the light and electronic microscopy analysis. Ovary slides were stained with HE, Masson¿s tricromic, toluidine blue, Periodic Acid Schiff and tissue was cryofrozen to further acid/alkaline phosphatase histochemical techniques. Final body weight, reproductive organs weight, body weight gain index, estrous cycle duration and hormone dosages (FSH, LH, _-oestradiol and progesterone) were analyzed. The statistical analysis was made using 5% of significance. There was no significative difference between the groups as to initial and final body weights, although the UChB rats showed an increased body mass gain at the final treatment period. The UChB ovaries relative weight was significantly lower comparing to the control. The hormonal levels did not differ among the groups. The UChA and UChB groups presented prolonged estrous cycles and persistent oestrous phases. Different stages of atresia and proliferation on follicle cells were found varying in UChA and UChB ovaries. The tunica albuginea showed fibrous tissue and cellular stromal components in ethanol drinking animals. Fibrocellular stroma and fibrous tunica albuginea were present in the control group. The UChA group showed metachromatic reaction between the growing follicles granulosa cells, whereas, in the UChB rats, intense metachromasia appeared on small, growing and antral follicles. The UCh groups presented PAS-positive reaction in the interstitial glandular tissue, while in control animals these reactions were restricted to the zona pelucida of oocytes and among granulosa cells of secondary follicles. The antral follicles of the UChB rats showed a high intensity reaction to acid phosphatase (AP), when compared to UChA and control groups. In UChA animals, the hemorrhagic and regression corpora lutea had AP reaction with the presence of associated clumps. Alkaline phosphatase (ALP) marked a hypervascularization in corpora lutea of UCh rats. In UChB strain, internal theca layers of growing follicles, reacted strongerly with ALP in contrast to UChA and control groups. The ultrastructural analysis revelated in UCh strain, corpus luteum with autofagic vacuoles and pyknotic nuclei at the initial stage. The UCh granulosa cells resented irregular nucleus with chromatin marginalization and edematous itochondria. In conclusion, there were estral cyclicity irregularities, caused by chronic ethanol intake in the UCh groups, which were consequently reflected as morphologic alterations in the ovaries structure Mestrado Biologia Celular Mestre em Biologia Celular e Estrutural

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Fank-de-Carvalho, Suzane Margaret. "Contribuição ao conhecimento da anatomia, micromorfologia e ultraestrutura foliar de Amaranthaceae do Cerrado." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317998.

Texto completo

Resumen

Orientador: Sonia Nair Bao Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia Made available in DSpace on 2018-08-17T17:33:24Z (GMT). No. of bitstreams: 1 Fank-de-Carvalho_SuzaneMargaret_D.pdf: 16381065 bytes, checksum: 37dffed971377c79c257dea1b955e34c (MD5) Previous issue date: 2011 Resumo: A família Amaranthaceae no sensu lato, incluindo Chenopodiaceae, é formada por cerca de 2.360 espécies, 145 delas encontradas no Brasil; 94 espécies subsistem em diversas fitofisionomias do Bioma Cerrado, 71 são endêmicas de diferentes regiões e biomas brasileiros e 27 aparecem em listas regionais de espécies ameaçadas de extinção. Visando contribuir para o conhecimento das espécies dessa família, foram estudados aspectos ecológicos, micromorfológicos, anatômicos e ultraestruturais de folhas de Amaranthaceae nativas do Brasil, com ênfase nos gêneros Alternanthera, Gomphrena, Froelichiella, Hebanthe e Pfaffia. As espécies nativas de regiões abertas de cerrado apresentam adaptações que favorecem a sobrevivência em condições adversas (seca e fogo), tais como raízes tuberosas ou lenhosas e xilopódios, hábito herbáceo e/ou subarbustivo, pilosidade densa nas porções aéreas, senescência de ramos aéreos durante as fases mais secas, dependência de fogo ou chuva para rebrotação e/ou floração, frutificação rápida seguida de dispersão anemocórica, epidermes com cutículas bem desenvolvidas e metabolismo fotossintético C4. O comportamento pirofítico das espécies favorece o estabelecimento pioneiro das mesmas, principalmente nas áreas abertas do Cerrado. As superfícies foliares de algumas espécies do gênero Gomphrena apresentam cristais de cera epicuticular do tipo plaquetas, orientadas paralelamente, aspecto anteriormente descrito apenas em espécies de Chenopodiaceae. Em duas espécies foram encontrados fungos Ascomyceto colonizando folhas, cujos aspectos ultraestruturais foram descritos. A anatomia Kranz foi caracterizada em seis espécies do gênero Gomphrena, que também possuem cloroplastos dimórficos, demonstrando estrutura foliar compatível com o metabolismo fotossintético C4. Na análise das duas espécies do gênero Alternanthera (uma C3 e outra intermediária C3-C4) verificou-se que a posição das organelas nas células da bainha pode ser um elemento chave na determinação do tipo metabólico. As espécies de Froelichiella, Hebanthe e Pfaffia possuem anatomia e ultraestrutura compatíveis com o metabolismo C3. A anatomia foliar e a ultraestrutura das espécies estudadas apresentam um padrão já descrito para outras espécies da família Amaranthaceae, exceto para os gêneros Hebanthe e Froelichiella, cuja descrição anatômica e ultraestrutural foi realizada pela primeira vez. A evolução do metabolismo C4 pode estar relacionada, pelo menos em parte, ao desenvolvimento da anfiestomia associada à maior espessura do limbo foliar em espécies herbáceas. Plastoglóbulos bem desenvolvido foram encontrados em cloroplastos de algumas das espécies do Cerrado e parecem associados aos mecanismos de defesa, além do metabolismo de lipídios. A família Amaranthaceae pode ser um bom marcador da biodiversidade de dicotiledôneas de pequeno porte e da capacidade de regeneração das áreas de campos rupestres, campos úmidos e outros tipos de vegetação aberta dos cerrados. A riqueza de informações obtidas durante o estudo de espécies dessa família ilustram a importância da ampliação das pesquisas básicas e aplicadas em suas espécies, especialmente as que ocorrem naturalmente no Cerrado. A ampliação do conhecimento relativo à anatomia e à especialização das organelas de diferentes gêneros para o metabolismo fotossintético pode contribuir para o entendimento da evolução da via C4 e do ambiente onde as plantas se especializaram. O estudo do Bioma Cerrado pretende ampliar as justificativas para esforços de preservação de sua biodiversidade. Abstract: The Amaranthaceae family sensu lato, including Chenopodiaceae, is comprised of approximately 2,360 species, 145 of them found in Brazil. 94 species exist in various vegetation types of the Cerrado, 71 are endemic to different regions and Brazilian biomes, and 27 appear in regional lists of endangered species. To contribute to the knowledge of this family species the ecological aspects, micromorphology, anatomy and ultrastructure of leaves of brazilian Amaranthaceae were studied, with emphasis on the genera Alternanthera, Gomphrena, Froelichiella, Hebanthe and Pfaffia. The native species of open areas of Cerrado (a savannah-like vegetation) exhibit adaptations that promote survival in adverse conditions (drought and fire), such as tuberous or woody roots, xylopodium, herbaceous or subshrub habit, dense pubescence in aerial portions, senescence of shoots and leaves during the driest season, dependence on rain or fire to resprout and/or flowering, fruiting followed by rapid wind dispersion, tick cuticle on epidermis and C4 photosynthetic metabolism. The species' fire behavior favors their establishment as pioneers, especially in open areas of the Cerrado. Leaf surfaces of some species of the genus Gomphrena present epicuticular wax crystals in platelet form, oriented in parallel, an aspect previously described only in Chenopodiaceae species. In two of the species studied Ascomycete fungi were found colonizing its leaves, and ultrastructural aspects were described. Kranz anatomy was found in six species of the genus Gomphrena, which also have dimorphic chloroplasts, showing leaf structure compatible with the C4 photosynthetic metabolism. In the analysis of two species of Alternanthera (a C3 and a C3-C4 intermediate) showed that besides the Kranz anatomy, the position of organelles in bundle sheath cells can be a key element in determining the metabolic type. The Froelichiella, Hebanthe and Pfaffia species have leaf anatomy and ultrastructure consistent with C3 metabolism. The leaf anatomy and ultrastructure have a pattern already described for other species of the Amaranthaceae family, except for the genera Hebanthe and Froelichiella, whose anatomical and ultrastructural aspects were described for the first time. The evolution of C4 metabolism may be related, at least in part, to the development of amphystomy associated with increased leaf thickness in herbaceous species. Large plastoglobuli were found in chloroplasts of some Cerrado species and appear associated with defense mechanisms, and lipid metabolism. The Amaranthaceae family can be a good marker of the biodiversity of nonwoody Eudicotyledons with ability to regenerate areas of rocky fields, wet grasslands and other open vegetation of the cerrado. These results illustrate the importance of expansion of basic and applied research in Amaranthaceae species, especially those that occur naturally in Brazilian cerrados. The expansion of knowledge concerning the anatomy and the specialization of organelles of different genera to perform its photosynthetic metabolism may contribute to understanding of the evolution of C4 pathway and the environment where plants specialize. The study of Cerrado Biome aims to broaden the justification for efforts to preserve its biodiversity. Doutorado Biologia Celular Doutor em Biologia Celular e Estrutural

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Huber, Mary Christine. "An ultrastructural study of the symbiotic relationships of four strains of Bradyrhizobium japonicum with glycine max /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841152.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Gramse, Georg. "Studying Electrostatic Polarization Forces at the Nanoscale. Dielectric constant of supported biomembranes measured in air and liquid environment." Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/83359.

Texto completo

Resumen

The objective of my thesis was to develop novel techniques and methods to probe the dielectric properties of biomembranes in air and their natural environment - liquid solution. The dielectric constant ε(r) of biomembranes is a parameter especially important in cell electrophysiology as it ultimately determines the ion membrane permeability, the membrane potential formation or the action potential propagation velocity, among others. However, no technique is able to provide this quantity with the required nanoscale spatial resolution and in electrolyte solution. AFM is an extremely versatile tool to investigate electric properties at the nanoscale, and hence constitutes a good candidate technique to approach the quantification of the nanoscale dielectric properties of biomembranes. Although a few AFM techniques exist, capable of investigating polarization properties, it remains difficult to extract quantitative values of εr from the measurements, especially in liquid environment. One reason for this is on the instrumental side, since for studies at the nanoscale very small quantities have to be measured, that can be easily overwhelmed by electronic noise as it maybe for example the case in current sensing based techniques. Electrostatic Force sensing techniques may in principle have an advantage here, since the used cantilevers for force detection are extremely sensitive and naturally, undesired nonlocal electrical signals from the cantilever are suppressed. Another important aspect is attributed to a lack of sufficiently precise quantitative models to relate measured force with the dielectric constant value of the sample. Indeed, for measurements on insulating substrates like mica or glass that are sometimes required for biological samples, still no quantitative model is available. Moreover, successful measurements of dielectric properties in liquid media, that is fundamental for the functionality of some biological samples, has not been shown until now. As consequence of the existing limitations for quantitative dielectric imaging the objectives of this work were to extend the quantitative capabilities of Electrostatic Force Microscopy to image the dielectric constant of biomembranes with nanoscale spatial resolution. In particular, the three objectives I addressed in the work are: 1. To evaluate the possibility to perform quantitative dielectric measurement on biomembranes on metallic substrates and in air with Electrostatic Force Microscopy that may offer higher precision with respect to current sensing techniques. 2. To extend the applicability of quantitative dielectric measurement to the case of thick insulating substrates in order to facilitate its use with biomembranes that cannot be prepared on metallic substrates. 3. To develop a setup for dielectric imaging in liquid environment based either on current detection or on the principles of electrostatic force microscopy. Finally to perform nanoscale dielectric measurements on bio-membranes in their natural liquid environment. How each of these objectives could be reached is detailed in my thesis. El objetivo de mi tesis era desarrollar nuevas técnicas y métodos para medir las propiedades dieléctricas de biomembranas en aire y en su medio natural, es decir, en solución líquida. La constante dieléctrica (εr) de las biomembramas es un parámetro especialmente importante en la electrofisiología celular, ya que fundamentalmente determina la permeabilidad iónica de la membrana, la formación del potencial de membrana o la velocidad de propagación del potencial de acción, entre otros. El AFM es una herramienta extremadamente versátil para investigar propiedades eléctricas a nanoescala, y por ello constituye una buena técnica candidata para la cuantificación de las propiedades dieléctricas de las biomembranas a nanoescala. Aunque existen algunas técnicas basadas en el AFM capaces de investigar las propiedades de polarización, continúa siendo difícil extraer valores cuantitativos de εr de las medidas, especialmente en medio líquido. Una de las razones radica en la parte instrumental, ya que para los estudios en la nanoescala tienen que medirse cantidades muy pequeñas, y este proceso puede verse entorpecido por ruido electrónico como puede ser el caso, por ejemplo, en las técnicas basadas en la detección de corriente eléctrica. En principio, las técnicas de detección de fuerza electroestática disponen aquí de una ventaja, ya que las sondas utilizadas para la detección de la fuerza son extremadamente sensibles y naturalmente se suprimen señales eléctricas no locales y no deseadas. Otro aspecto importante se atribuye a la falta de modelos cuantitativos suficientemente precisos para relacionar la fuerza medida con el valor de la constante dieléctrica de la muestra. En realidad, para realizar medidas en sustratos aislantes como son la mica o el vidrio, que a veces son necesarios para muestras biológicas, todavía no se dispone de ningún modelo cuantitativo. Por otra parte, hasta ahora no se han publicado medidas de propiedades dieléctricas en medio líquido, que para algunas muestras biológicas es fundamental para mantener la funcionalidad. Como consecuencia de las limitaciones existentes de las medidas dieléctricas, el objetivo de este trabajo fue extender las capacidades cuantitativas de la Microscopía de Fuerzas Eletroestáticas para hacer imágenes dieléctricas de biomembranas con resolución espacial a nanoescala en substratos conductores, aislantes y en medio líquido.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Motheo, Tathiana Ferguson [UNESP]. "Maturação in vitro de oócitos caninos: influência da suplementação hormonal seriada sobre a ultraestrutura oocitária." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/105924.

Texto completo

Resumen

Made available in DSpace on 2014-06-11T19:35:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-01-11Bitstream added on 2014-06-13T19:05:28Z : No. of bitstreams: 1 motheo_tf_dr_jabo.pdf: 1420704 bytes, checksum: de5c6be1107a0e6fcda8a993e1569d8c (MD5) Relativamente ao uso de técnicas de reprodução assistida em canídeos, a maturação e a fertilização in vitro (MIV) e (FIV), tem como principal objetivo a preservação do genoma dos canídeos ameaçados de extinção. Entretanto, os meios de cultivo empregados para maturação são adaptações de metodologias adotadas para outras espécies. Inúmeros estudos avaliaram a suplementação dos meios com gonadotrofinas, estrógeno, progesterona, antioxidantes, proteínas e entre outros, porém, nenhum deles releva a ação seriada de hormônios sobre a maturação de oócitos caninos. Deste modo, o objetivo do presente estudo foi o de avaliar os efeitos da suplementação seriada do meio de maturação com gonadotrofina coriônica humana (hCG) e progesterona (P4), em diferentes momentos do processo de MIV de oócitos caninos. Vinte e três cadelas, com idades entre 1 a 7 foram selecionadas por meio de citologia vaginal, dosagem de progesterona e agrupadas em dois grupos: Fase Folicular (n=12) e Fase Não FolicularDiestro (n=11). Os ovários foram obtidos durante o procedimento de ovariohisterectomia (OH) e somente complexos cumulus-oócito (COCs) grau 1 e diâmetro superior a 120 μm foram selecionados. A avaliação foi feita por meio de microscopia eletrônica de varredura (MEV) e transmissão (MET), antes e após o período de cultivo in vitro por 96h em 5 meios: I (hCG + P4 durante 96 h), II (hCG nas primeiras 48 h de MIV), III (hCG nas primeiras 48h e P4 após 48h), IV (P4 após 48h de MIV) e V (sem suplementação durante 96h de MIV). Os resultados revelaram que a morfologia, assim como a ultraestrutura oocitárias não são afetadas pela fase do ciclo estral. Entretanto, oócitos da fase folicular quando submetidos ao processo de MIV em meios suplementados com hormônios são mais sensíveis e responsivos a sua ação, quando comparados... On the use of assisted reproduction techniques in dogs, in vitro, maturation (IVM) and fertilization (IVF) has the main goal to preserve the genome of endangered canids. However, the culture media used for maturation are adapted from those used in other species. Numerous studies evaluated the supplementation with gonadotropins, estrogens, progesterone, antioxidants and proteins on the IVM media, however none of them assessed the effects of a bi-phasic human chorionic gonadotropin (hCG) and progesterone (P4) supplementation on in vitro maturation media of canine oocytes. Thus, the aim of the present study was to evaluate the effects of a bi-phasic system using human chorionic gonadotrophin (hCG) and progesterone (P4) on IVM media of canine oocytes. Twenty-three female dogs, including 12 from follicular phase (FF) and 11 from non-folicular phase (FN) aged 1-7 years underwent ovariohysterectomy (OH). After the procedure, the ovaries were sliced and cumulus-oocyte complexes (COCs) released. Only COCs grade 1, with diameter greater than 120 μm were selected. Scanning electron microscopy (SEM) and transmission (TEM) were carried out before and after 96h of in vitro maturation (IVM) in 5 different culture media: I (TCM-199 + hCG + P4 for 96 h), II (TCM -199 + hCG within 48h of IVM), III (TCM-199 + hCG in the first 48h and after 48h P4), IV (TCM-199 + P4 after 48h of IVM) and V (no hormone supplementation during 96h of IVM. The results revealed that the oocyte morphology and ultrastructure are not affected by the phase of the estrous cycle. However, follicular phase oocytes undergoing IVM are more sensitive and responsive to hormonal supplementation of the IVM media when compared to oocytes from the non-follicular phase. The association or the bi-phasic human chorionic gonadotropin (hCG) and... (Complete abstract click electronic access below)

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Motheo, Tathiana Ferguson. "Maturação in vitro de oócitos caninos : influência da suplementação hormonal seriada sobre a ultraestrutura oocitária /." Jaboticabal, 2013. http://hdl.handle.net/11449/105924.

Texto completo

Resumen

Orientador: Wilter Ricardo Russiano Vicente Coorientador: Eliandra Antônia Pires Buttler Coorientador: Maricy Apparício Ferreira Banca: Ana Paula Coelho Ribeiro Banca: Idércio Luiz Sinhorini Banca: Aracélle Elisane Alves Banca: Naiara Zoccal Saraiva Resumo: Relativamente ao uso de técnicas de reprodução assistida em canídeos, a maturação e a fertilização in vitro (MIV) e (FIV), tem como principal objetivo a preservação do genoma dos canídeos ameaçados de extinção. Entretanto, os meios de cultivo empregados para maturação são adaptações de metodologias adotadas para outras espécies. Inúmeros estudos avaliaram a suplementação dos meios com gonadotrofinas, estrógeno, progesterona, antioxidantes, proteínas e entre outros, porém, nenhum deles releva a ação seriada de hormônios sobre a maturação de oócitos caninos. Deste modo, o objetivo do presente estudo foi o de avaliar os efeitos da suplementação seriada do meio de maturação com gonadotrofina coriônica humana (hCG) e progesterona (P4), em diferentes momentos do processo de MIV de oócitos caninos. Vinte e três cadelas, com idades entre 1 a 7 foram selecionadas por meio de citologia vaginal, dosagem de progesterona e agrupadas em dois grupos: Fase Folicular (n=12) e Fase Não FolicularDiestro (n=11). Os ovários foram obtidos durante o procedimento de ovariohisterectomia (OH) e somente complexos cumulus-oócito (COCs) grau 1 e diâmetro superior a 120 μm foram selecionados. A avaliação foi feita por meio de microscopia eletrônica de varredura (MEV) e transmissão (MET), antes e após o período de cultivo in vitro por 96h em 5 meios: I (hCG + P4 durante 96 h), II (hCG nas primeiras 48 h de MIV), III (hCG nas primeiras 48h e P4 após 48h), IV (P4 após 48h de MIV) e V (sem suplementação durante 96h de MIV). Os resultados revelaram que a morfologia, assim como a ultraestrutura oocitárias não são afetadas pela fase do ciclo estral. Entretanto, oócitos da fase folicular quando submetidos ao processo de MIV em meios suplementados com hormônios são mais sensíveis e responsivos a sua ação, quando comparados... (Resumo completo, clicar acesso eletrônico abaixo) Abstract: On the use of assisted reproduction techniques in dogs, in vitro, maturation (IVM) and fertilization (IVF) has the main goal to preserve the genome of endangered canids. However, the culture media used for maturation are adapted from those used in other species. Numerous studies evaluated the supplementation with gonadotropins, estrogens, progesterone, antioxidants and proteins on the IVM media, however none of them assessed the effects of a bi-phasic human chorionic gonadotropin (hCG) and progesterone (P4) supplementation on in vitro maturation media of canine oocytes. Thus, the aim of the present study was to evaluate the effects of a bi-phasic system using human chorionic gonadotrophin (hCG) and progesterone (P4) on IVM media of canine oocytes. Twenty-three female dogs, including 12 from follicular phase (FF) and 11 from non-folicular phase (FN) aged 1-7 years underwent ovariohysterectomy (OH). After the procedure, the ovaries were sliced and cumulus-oocyte complexes (COCs) released. Only COCs grade 1, with diameter greater than 120 μm were selected. Scanning electron microscopy (SEM) and transmission (TEM) were carried out before and after 96h of in vitro maturation (IVM) in 5 different culture media: I (TCM-199 + hCG + P4 for 96 h), II (TCM -199 + hCG within 48h of IVM), III (TCM-199 + hCG in the first 48h and after 48h P4), IV (TCM-199 + P4 after 48h of IVM) and V (no hormone supplementation during 96h of IVM. The results revealed that the oocyte morphology and ultrastructure are not affected by the phase of the estrous cycle. However, follicular phase oocytes undergoing IVM are more sensitive and responsive to hormonal supplementation of the IVM media when compared to oocytes from the non-follicular phase. The association or the bi-phasic human chorionic gonadotropin (hCG) and... (Complete abstract click electronic access below) Doutor

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Marigo, Adji Mama. "Etude Ultrastructurale de la Spermiogenèse et du Spermatozoïde chez les Cestodes. Apports en Taxonomie et Phylogénie." Doctoral thesis, Universitat de Barcelona, 2011. http://hdl.handle.net/10803/109219.

Texto completo

Resumen

La présente Thèse constitue une contribution à la connaissance de l’ultrastructure de la spermiogenèse et du spermatozoïde chez les Cestodes. Nous y présentons de nouvelles données spermatologiques ultrastructurales d’espèces appartenant à six ordres différents : Acanthobothrium crassicolle Wedl, 1855 (Tetraphyllidea), Aporhynchus menezesi Noever et al., 2010 (Trypanorhyncha), Barsonella lafoni de Chambrier et al., 2009 (Proteocephalidea), Clestobothrium crassiceps (Rudolphi, 1819) (Bothriocephalidea), Echinobothrium euterpes (Neifar et al., 2001) (Diphyllidea) et Molluscotaenia crassiscolex (von Linstow, 1890) (Cyclophyllidea). Les résultats obtenus sur la spermiogenèse et le spermatozoïde sont comparés avec ceux de Cestodes déjà étudiés, spécialement avec ceux appartenant aux ordres objet de notre étude. Enfin, nous discutons sur l’utilité des différents caractères spermatologiques ultrastructuraux en Taxonomie, Systématique et Phylogénie. L’étude spermatologique de Clestobothrium crassiceps constitue le premier travail fait sur le genre Clestobothrium et la onzième espèce de l’ordre Bothriocephalidea récemment créé. Les résultats obtenus sont comparés avec ceux des autres espèces de cet ordre, mais aussi avec ceux des Diphyllobothriidea, l’autre ordre créé à partir de l’ancien ordre des Pseudophyllidea. Concernant la spermiogenèse, les caractères les plus intéressants sont le type II de spermiogenèse et le corps intercentriolaire très réduit. On peut remarquer aussi le type II de spermatozoïde qui présente un anneau de microtubules corticaux, probablement une autapomorphie pour les Bothriocephalidea. L’étude ultrastructurale du Diphyllidea Echinobothrium euterpes montre la formation de deux flagelles de longueur différente. Dans les stades avancés de la spermiogenèse, après la fusion proximodistale, l’axonème court disparaît pour donner naissance à un spermatozoïde présentant un seul axonème. La spermiogenèse est du type I et le spermatozoïde correspond au type IV. Autres caractères intéressants chez les Diphyllidea sont la forte réduction ou absence de microtubules corticaux et la présence de masses denses associées aux centrioles dans la zone de différentiation. Ce dernier caractère peut être une synapomorphie pour les espèces de cet ordre. Aporhynchus menezesi présente un type I de spermiogenèse et un type I de spermatozoïde. Notre étude apporte les premières données chez la superfamille des Gymnorhynchoidea. Nous confirmons chez les Trypanorhyncha l’absence de corps en crête et la présence d’un arc de microtubules corticaux dans le spermatozoïde. L’étude de Acanthobothrium crassicolle est le troisième dans ce genre et confirme le type I de spermiogenèse et le type II de spermatozoïde. Ce type de spermatozoïde constitue la plus importante différence entre les onchobothriidés et les phyllobothriidés. Nous confirmons aussi la présence d’un arc de microtubules corticaux. Cependant, il est observé une hétérogénéité au niveau du corps intercentriolaire chez les Tetraphyllidea-Onchobothriidae. Barsonella lafoni est la septième espèce de l’ordre Proteocephalidea dont l’ultrastructure du spermatozoïde est analysée. Elle montre le patron I pour la spermiogenèse et aussi pour le spermatozoïde. Ces résultats sont concordants avec ceux des autres espèces étudiées, sauf Sandonella sandoni. Un corps intercentriolaire réduit et un arc de microtubules corticaux sont des caractères constamment présents chez les proteocephalidés étudiés. Chez B. lafoni nous avons décrit pour la première fois la présence d’un matériel dense aux électrons dans la zone de différentiation pendant les stades initiaux de la spermiogenèse. Il s’agit d’un caractère typique des ordres basaux des Eucestoda. Finalement, Molluscotaenia crassiscolex suit le type IV de spermiogenèse et son spermatozoïde est du type VI. Ces deux patrons coïncident chez les autres dilepididés étudiés. La morphologie particulière du corps en crête est le caractère le plus intéressant. Il est partiellement détaché dans sa partie moyenne. Nos résultats sont comparés avec les Dilepididae s.l. The present Thesis constitutes a contribution to the knowledge of ultrastructure of spermiogenesis and the spermatozoon of cestodes. New spermatological data concerning species belonging to six orders of Eucestoda are presented. These species are Clestobothrium crassiceps (Rudolphi, 1819) (Bothriocephalidea), Echinobothrium euterpes (Neifar et al., 2001) (Diphyllidea), Aporhynchus menezesi Noever et al., 2010 (Trypanorhyncha), Acanthobothrium crassicolle Wedl, 1855 (Tetraphyllidea), Barsonella lafoni de Chambrier et al., 2009 (Proteocephalidea), and Molluscotaenia crassiscolex (von Linstow, 1890) (Cyclophyllidea). The obtained results on spermiogenesis and the spermatozoon are compared with the available data on the remaining eucestodes, particularly with the orders discussed in the present study. Moreover, the usefulness of different spermatological characters for Taxonomy, Systematics and Phylogeny is discussed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Bolinder, Kristina. "Pollen and pollination in Ephedra (Gnetales)." Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-140771.

Texto completo

Resumen

Ephedra (Gnetales) is a gymnosperm genus with a long evolutionary history; the first dispersed pollen grains with affinity to the group are known already from the Permian. This thesis focuses on the evolutionary history of the group and different aspects of its pollination mechanisms. Despite the limited number of extant species of the genus (50-60), and a low morphological and genetic divergence among species, there is variation in pollination syndrome in the genus. The prevailing state in Ephedra, and most gymnosperms, is wind pollination. It is therefore surprising that one species, E. foeminea, is insect-pollinated. Together with co-workers I documented the pollination syndromes of E. foeminea and a sympatric species, E. distachya, based on long term field experiments in north-eastern Greece and aerodynamic investigations and calculations. Placing the results into an evolutionary framework reveals that the insect-pollinated species E. foeminea is sister to the remaining (mostly wind-pollinated) genus, and indicates that insect pollination is the ancestral state in the Gnetales. During the course of evolution of the group there has been a shift to wind pollination, which may have played a crucial role for the diversification of the crown group in the Paleogene. Pollination biology is often correlated with the morphology of the pollen such that pollen grains of anemophilous plants are small with a smooth surface, whereas pollen grains of entomophilous plants are larger with an ornamented surface and a covering of pollenkitt. The pollen morphology of Ephedra can be broadly divided into two types: an ancestral type with an unbranched pseudosulcus between each pair of plicae, and a derived type with a branched pseudosulcus between each pair of plicae. Further, the pollen morphology and ultrastructure of the pollen wall in Ephedra are to some degree correlated with the pollination syndrome and capability of long distance dispersal. Pollen of E. foeminea has a denser ultrastructure, as a result a higher settling velocity and is therefore capable of flying shorter distances than does pollen of the anemophilous E. distachya, and other investigated anemophilous species that show a more spacious ultrastructure of the pollen grain. These results can be useful in the reconstruction of the pollination mechanism of extinct taxa of the Ephedra-lineage in the future.

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Renegar, Dorothy-Ellen A. "Histology and Ultrastructure of Montastraea cavernosa and Porites astreiodes During Regeneration and Recruitment: Anthropogenic Stressors and Transplant Success." NSUWorks, 2015. http://nsuworks.nova.edu/occ_stuetd/38.

Texto completo

Resumen

Corals combine photosynthesis and calcification in an intricate and delicately balanced relationship to form large biomineralized structures that are dominant features of tropical coastlines worldwide. Coral reefs have great scientific and economic importance but have recently experienced widespread decline attributed to increasing anthropogenic pressure on reef systems. Physical damage events, such as ship groundings, when coupled with existing nutrient stress and changing global climate present a poor outlook for successful natural recovery of reef communities. The main goal of the proposed research is to better understand how environmental factors, both local and global, affect the coral holobiont and influence overall coral fitness. The target species of this research, Montastraea cavernosa and Porites astreoides, are important and widespread Caribbean reef-builders. While it has been shown that nutrient and pCO2 stress affect coral growth and calcification, study of specific effects on coral tissue and reproductive success has not received significant attention in the literature despite considerable current interest. This study addresses this data gap in quantitatively examining the effect of elevated nutrients and pCO2 on 1) P. astreoides recruit survivorship, development, early calcification, and symbiotic zooxanthellae morphology; 2) M. cavernosa and P. astreoides wound regeneration, tissue characteristics over time at the histological and ultrastructural level, and trends in symbiotic zooxanthellae morphology; and 3) survival, growth and histological/ultrastructural characteristics of M. cavernosa and P. astreoides fragments transplanted to the field and in the laboratory. Histological and ultrastructural observations from corals transplanted to the field are then compared to ex-situ laboratory experimental corals. In the fleshy and large-polyped faviid M. cavernosa, healing of a linear wound was characterized by granulation of new tissue across the wound site, facilitated by coalescent granular amoebocytes. The wound healing strategy of this species appears to progress with wound closure and re-epithelialization before calcification resumes, as actively calcifying calicodermis was generally not observed at the healing front. Tissue regeneration in the small-polyped P. astreoides was characterized by formation of multiple islands of eosinophilic healing fronts along the depth of the wound track, and an accumulation of granular amoebocyte cells in regenerating tissue. The wound healing strategy of this species appeared to result in re-epithelialization of exposed body wall without necessarily closing the wound. Elevated pCO2 significantly reduced survivorship in P. astreoides recruits, and both nutrient enrichment and elevated pCO2 significantly reduced wound regeneration rate in M. cavernosa and P. astreoides. In both species, phosphate enrichment had the greatest deleterious effect on wound repair. A significant application of this study is the identification of possible zooxanthellar morphological indices of elevated nutrients and ocean acidification. The similarity in starch, lipid and uric acid accumulation patterns in Symbiodinium sp. from P. astreoides recruits and coral fragments of both species indicate a correlation between these anthropogenic stressors and the intracellular accumulation of excess carbon and nitrogen by the symbiont. Zooxanthellar carbon accumulation, in the form of starch and/or lipid, was the greatest under elevated nitrate. Zooxanthellar nitrogen accumulation, in the form of uric acid, was the greatest under elevated CO2. Comparison of zooxanthellar metrics between the field corals (P. astreoides, and M. cavernosa) and ex-situ corals and recruits indicated that carbon accumulation in Symbiodinium from field corals was consistently significantly less than in the ex-situ experimental P. astreoides recruits and M. cavernosa fragments exposed to elevated nitrate. This indicates that the field corals were likely not exposed to elevated nitrate at the time of collection. Both M. cavernosa and P. astreoides adults in the field accumulated significantly less uric acid than their counterparts in the tissue repair experiment, indicating that the field corals were exposed to higher pH and lower CO2 than the ex-situ corals. These results suggest that the field corals were not exposed to nutrient concentration profiles similar to the experimental treatments, particularly elevated nitrate. However, histological metrics indicated that the transplanted corals were subjected to increasing sedimentation stress over time. Overall, nitrate was found to affect recruits and adults on a similar scale, while phosphate and pCO2 affected carbon and nitrogen storage more in recruits compared to adults. While nutrients and pCO2 had no mechanistic effect on regeneration at histological level, ultrastructural metrics indicate an impact on the mutualistic energy exchange between the symbiotic partners, partially decoupling symbiosis. Effects were generally found to be greater in P. astreoides compared to M. cavernosa, and the unique life history strategy of the subject species and differences in their endosymbiont physiology reveal distinct responses to elevated nutrients and pCO2. Although the laboratory findings were not necessarily applicable to field observations, they provide insight into factors that may influence fragment success in the field. Quantitative assessment of the effect of elevated nutrients and pCO2 is thus useful in management decisions involving water quality standards, and is essential in the prediction of future coral condition and resilience.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Tesis sobre el tema "Ultrastructure (Biology)"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros