Academic literature on the topic 'Testis, embryology'
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Journal articles on the topic "Testis, embryology"
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Burgu, Berk, and Onur Telli. "Embryology of Testis and Theories of Testicular Descent." Türk Üroloji Seminerleri/Turkish Urology Seminars 1, no. 3 (July 1, 2010): 47–51. http://dx.doi.org/10.5152/tus.2010.01.
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Agras, Koray. "Embryology of Undescended Testis and Mechanisms of Testicular Descent." Türk Üroloji Seminerleri/Turkish Urology Seminars 25, no. 1 (October 1, 2012): 17–22. http://dx.doi.org/10.5152/tus.2012.05.
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Suresh, N. M., Subramanya Katttepura, Khizer Hussain Afroze, Ramesh P., and Apurva Bhaskar. "Evaluation of incidence of cryptorchidism with special reference to anatomical and clinical aspects." International Journal of Contemporary Pediatrics 5, no. 4 (June 22, 2018): 1388. http://dx.doi.org/10.18203/2349-3291.ijcp20182533.
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Background: Cryptorchidism is simply defined as the absence of one or both testes from the scrotum. It is the most common birth defect of the male genitalia. The testis may be located intra-abdominal or inguinal. This article mainly deals with embryology, etiology, anatomy and incidence types of cryptorchidism in Tumakuru rural district.Methods: This study was interdepartmental and prospective, consisting of 66 cases conducted at the Department of Pediatric Surgery and Anatomy and the period of study was from April 2013- March 2017. Cryptorchidism has been classified into 1) Intra-abdominal, 2) Inguinal, 3) Ectopic testis (perineum).Results: Out of 66 cases, testis in inguinal canal is the most common incidence followed by the intra-abdominal and Ectopic testis. Least found was ectopic and torsion in the inguinal canal. Complications are torsion and vanishing testis.Conclusions: This condition is repairable in a vast majority of cases. Early diagnosis and surgical intervention have to be carried out to correct this defect.
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Rojas, Mariana, and Ruth Prieto. "Embryology of the Female Genital System." International Journal of Medical and Surgical Sciences 1, no. 2 (October 26, 2018): 153–66. http://dx.doi.org/10.32457/ijmss.2014.019.
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Until the seventh week of human embryonic development of both sexes have very similar primordia of genitalia represented by two undifferentiated gonads two mesonephric ducts, which originate the male genital tract and two paramesonephric ducts develop the female genital tract. Genital tubercle, two labiouretrales folds and two labioscrotal folds: Externally the same basic elements that are distinguished in both sexes. From SRY gene expression that occurs during the eighth week a series of morphophysiological events leading establishing a clear sexual dimorphism starts. If the resulting gonad is a testis produced hormones induce masculinization of internal and external genitalia, as well as outline the breast. However, if an ovary is formed or not formed gonads, internal and external genitalia develop in female sense. Genetic sex is not always related to the differentiation of external genitalia or genital tract that is why we consider separately each. This article explores the morphological differentiation into male and female connection, as well as the molecular regulation of the gonads, genital tract and external genitalia.
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Goel, Sandeep, Mayako Fujihara, Naojiro Minami, Masayasu Yamada, and Hiroshi Imai. "Expression of NANOG, but not POU5F1, points to the stem cell potential of primitive germ cells in neonatal pig testis." REPRODUCTION 135, no. 6 (June 2008): 785–95. http://dx.doi.org/10.1530/rep-07-0476.
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Gonocytes are primitive germ cells that are present in the neonatal testis and are committed to male germline development. Gonocytes differentiate to spermatogonia, which establish and maintain spermatogenesis in the postnatal testis. However, it is unknown whether large animal species have pluripotency-specific proteins in the testis. Nanog and Pou5f1 (Oct3/4) have been identified as transcription factors essential for maintaining pluripotency of embryonic stem cells in mice. Here, we show that NANOG protein was expressed in the germ cells of neonatal pig testes, but was progressively lost with age. NANOG was expressed in most of the lectin Dolichos biflorus agglutinin- and ZBTB16-positive gonocytes, which are known gonocyte-specific markers in pigs. NANOG was also expressed in Sertoli and interstitial cells of neonatal testes. Interestingly, POU5F1 expression was not detected at either the transcript or the protein level in neonatal pig testis. In the prepubertal testis, NANOG and POU5F1 proteins were primarily detected in differentiated germ cells, such as spermatocytes and spermatids, and rarely in undifferentiated spermatogonia. By using a testis transplantation assay, we found that germ cells from 2- to 4-day-old pigs could colonize and proliferate in the testes of the recipient mice, suggesting that primitive germ cells from neonatal pig testes have stem cell potential.
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Huang, Xiaoyan, Jun Zhang, Li Lu, Lanlan Yin, Min Xu, Youqun Wang, Zuomin Zhou, and Jiahao Sha. "Cloning and expression of a novel CREB mRNA splice variant in human testis." Reproduction 128, no. 6 (December 2004): 775–82. http://dx.doi.org/10.1530/rep.1.00036.
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Identification of genes specifically expressed in adult and fetal testis is important in furthering our understanding of testis development and function. In this study, a novel human transcript, designated human testis cAMP-responsive element-binding protein (htCREB), was identified by hybridization of adult and fetal human testis cDNA probes with a human cDNA microarray containing 9216 clones. The htCREB transcript (GenBank Accession no. AY347527) was expressed at 2.35-fold higher levels in adult human testes than in fetal testes. Sequence and ntBLAST analyses against the human genome database indicated that htCREB was a novel splice variant of human CREB. RT-PCR-based tissue distribution experiments demonstrated that the htCREB transcript was highly expressed in adult human testis and in healthy sperm, but not in testes from patients with Sertoli cell-only syndrome. Taken together, these results suggest that the htCREB transcript is chiefly expressed in germ cells and is most likely involved in spermatogenesis.
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Asghari-Givehchi, Shohreh, and Mohammad Hossein-Modarressi. "Identification and expression analysis of zebrafish testis-specific gene 10 (tsga10)." International Journal of Developmental Biology 63, no. 11-12 (2019): 623–29. http://dx.doi.org/10.1387/ijdb.190053mm.
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Several clinical studies suggest that testis-specific gene antigen 10 (TSGA10) is a cancer-testis antigen with a discernible expression pattern in the testis. Recent studies have highlighted that TSGA10 overexpression in HeLa cells impairs the transcriptional activity of hypoxia-inducible factor alpha (HIF-1α) and inhibits angiogenesis. In this study, we used the zebrafish as a powerful model organism to identify and characterize the orthologue of TSGA10. We analyzed the gene expression pattern by RT-PCR and whole mount in situ hybridization and overexpressed the tsga10 protein by mRNA microinjection. Our results revealed that during early development, tsga10 expression is enriched, but gradually subsides between 0 and 72 hours post fertilization (hpf). There was no detectable transcript at the larval stages. In adult fish, we found high expression levels of tsga10 in the testis and unfertilized egg and low levels of gene expression in the brain, eyes and muscle. Overexpression of tsga10, using tsga10 mRNA microinjection into one-cell stage embryos, resulted in angiogenic and morphological defects at 24 and 48 hpf. This study clarified the expression pattern of tsga10 in different developmental stages and adult tissues, suggesting that tsga10 may have a related biological role in different cell types and tissues. Our results indicate that tsga10 mRNA at embryonic stages is maternally deposited, indicating a transient functional role during embryogenesis. Our findings suggest that tsga10 is a human orthologous gene relevant for future studies to elucidate its mechanism of action in angiogenesis.
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Barber, Hugh R. K. "Embryology of the gonad with reference to special tumors of the ovary and testis." Journal of Pediatric Surgery 23, no. 10 (October 1988): 967–72. http://dx.doi.org/10.1016/s0022-3468(88)80396-8.
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Rabinowitz, Ronald, and William C. Hulbert. "Consultation with the specialist." Pediatrics In Review 15, no. 7 (July 1, 1994): 272–74. http://dx.doi.org/10.1542/pir.15.7.272.
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Introduction The term cryptorchidism originates from the Greek kryptos (concealed) and orchis (testis). The definition of the term cryptorchidism is appropriate; not only is the testis concealed, but so is much information regarding this common condition. More than 200 years ago, John Hunter described descent of the testis during the last 3 months of gestation and reported that testes that remain in the abdomen are unhealthy and do not function well. He also discussed the possibilities of failure to descend causing testicular abnormality and testicular abnormalities causing failure to descend. Cryptorchidism represents the most common genital abnormality seen by pediatric urologists. The incidence is 1 in 125 boys. The incidence is much higher in premature infants (1 in 3), and the lower the birth weight, the greater the incidence of cryptorchidism. This condition is seen in approximately 1 in 30 full-term infants, but in many of them, the testicles will descend during the first few months of life. There is a higher incidence of cryptorchidism associated with many chromosomal and single gene defects as well as with multiple malformation syndromes. In addition, there is a higher incidence of cryptorchidism in the siblings and sons of those who have or had cryptorchidism. We will describe the anatomy of both the cryptorchid and retractile testis and discuss the embryology of testicular descent, with an emphasis on hormonal factors.
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Bird, Daniel, Stefan Bagheri-Fam, Li Li, Meiyun Yong, Raymond Lai, Janelle Ryan, Dagmar Wilhelm, Jacob Eswarakumar, and Vincent Harley. "Testis determination requires the function of a specific FGFR2 isoform." Mechanisms of Development 145 (July 2017): S145. http://dx.doi.org/10.1016/j.mod.2017.04.407.
Full textDissertations / Theses on the topic "Testis, embryology"
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Quinn, Feargal M. J. "Unilateral cryptorchidism : an evaluation of the undescended and scrotal testes in an animal model." Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295360.
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Cravo, Roberta Mascioli. "Controle da expressão do gene ALDH1A2 (RALDH2) durante o desenvolvimento: uma abordagem filogenética." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/42/42134/tde-11112008-154726/.
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O ácido retinóico (AR) é essencial para a embriogênese. A principal enzima sintetizadora de AR durante o desenvolvimento é a ALDH1A2 (RALDH2), uma retinaldeído desidrogenase que converte retinaldeído a AR. Para entendermos como o gene da aldh1a2 é regulado identificamos regiões evolutivamente conservadas (ECRs) em vertebrados e testamos seu potencial regulatório. Identificamos uma ECR localizada no intron1 da aldh1a2, conservada em anfíbios, aves e mamíferos que atua como um enhancer em estruturas derivadas de ectoderme, endoderme e mesoderme. Animais transgênicos transientes e permanentes mostram a ativação desse enhancer na região da placa do teto do tubo neural e epicárdio, local onde esse enhancer é ativado em células derivadas do órgão pro-epicárdico após o contato e/ou proximidade com células do miocárdio. A identificação de um enhancer conservado no gene da aldh1a2 suporta a idéia de que esse gene possui uma regulação modular e mostra que a abordagem evolutiva é uma eficiente ferramenta para a identificação de mecanismos de controle desse gene.Retinoic acid (RA) is essential for embryogenesis. The key RA synthetic enzyme during early development is ALDH1A2 (RALDH2), a retinaldehyde dehydrogenase that converts retinaldehyde into RA. To understand how aldh1a2 is regulated we screened the gene for evolutionary conserved regions (ECRs) among vertebrates and assayed their regulatory potential. We describe an aldh1a2 intron 1 ECR (identified as RALDH2.2) that is conserved in amphibians, avians and humans and acts as an enhancer in derivatives of ectoderm, endoderm and mesoderm. Transient and stable transgenesis in mice reveal strong activity of the raldh2 intron 1 enhancer at the roof plate of the neural tube and at the growing epicardium. Transgenic mice indicate that the enhancer is activated in proepicardium-derived cells by contact and/or close proximity to the myocardium. The identification of an aldh1a2 conserved enhancer supports the idea of a modular regulation and shows that the evolutionary approach is an efficient tool to identify control mechanisms of the aldh1a2 gene.
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Naudin, Stéphane. "Le développement embryo-larvaire du danio zébré (Brachydanio rerio) : évaluation de ce modèle pour la mesure de la toxicité des effluents et des sédiments : apports de l'analyse d'images pour les mesures biométriques de l'essai embryo-larvaire." Metz, 1996. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1996/Naudin.Stephane.SMZ9609.pdf.
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La mesure de la toxicité d'effluents et de sédiments peut être réalisée au laboratoire par un grand nombre de bioessais. Les performances de l'essai portant sur le développement embryo-larvaire du danio zébré (brachydanio rerio) ont été évaluées pour de tels échantillons après plusieurs mises au point méthodologiques. Nous avons ainsi déterminé les domaines de tolérance de cet organisme d'essai à différents paramètres physico-chimiques du milieu (pH, oxygène dissous, dureté, ammoniac) de manière à pouvoir évaluer leur contribution à la toxicité constatée au cours des essais. D'autre part, les avantages de l'analyse d'images ont été évalués pour le comptage des larves, la mesure de leur taille et le repérage d'individus malformés. Appliqués à différents effluents industriels et urbains, les concentrations toxiques minimales mises en évidence par l'essai embryo-larvaire sur le danio zébré se sont avérées plus élevées mais du même ordre de grandeur que celles apportées par deux essais chroniques portant sur selenastrum capricornutum et/ou ceriodaphnia dubia. La sensibilité du modèle poisson à l'ammoniac et à une substance tératogène (dibutylphtalate) que peuvent contenir les effluents urbains justifie son intégration dans une batterie de bioessais. De plus, nous avons constaté une faible dispersion des valeurs témoins des critères d'effet relevés au cours des essais embryo-larvaires. Pour évaluer la toxicité d'échantillons de sédiment, cet essai s'est montré, par contre, moins pertinent que le test microtox (photobacterium phosphoreum) appliqué au sédiment entierEffluent and sediment toxicity can be measured by a great number of bioassays in laboratory conditions. The reliability of the embryo-larval stage test using zebra danio (brachydanio rerio) was evaluated for effluent and sediment samples using several methodological improvements. We determined the tolerance range of this organism to different physico-chemical parameters (pH, dissolved oxygen, hardness, un-ionized ammonia) in order to evaluate their contribution to the toxicity noticed during the tests. The advantages of using an image analysis technique in order to count and measure larvae and detect gross morphological deformities were also assessed. After testing different industrial and municipal wastewaters, the minimum toxic concentrations detected by the embryo-larval test on zebra danio were greater but in the same order of magnitude as the ones obtained by two chronic bioassays on Selenastrum capricornutum and/or ceriodaphnia dubia. The sensitivity of the "fish" model to un-ionized ammonia and a teratogenic compound (dibutylphthalate) often found in municipal wastewaters justifies its integration into a battery of bioassays. Furthermore, we found the control values of the toxic end-points to be homogeneous among the embryo-larval stage tests. On the other hand, this test showed a lower relevance to measure sediment toxicity in comparison to the Microtox test (photobacterium phosphoreum) applied on whole sediment
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Melo, Luana Felix de. "Desenvolvimento embríonário do fígado do Tubarão-azul, Prionace glauca (Linnaeus, 1758), Elasmobranchii, Carcharhiniformes." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/10/10132/tde-15062018-155713/.
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O Tubarão azul (Prionace glauca), popularmente conhecido como cação-azul dentre todas as espécies de tubarão é a mais abundante no ambiente marinho, podendo ser encontrado em todos os mares. Com a diversidade das espécies, a descrição de qualquer fígado especifico, dificilmente poderá ser utilizada como um modelo. Juntamente com essa variabilidade, algumas características fisiológicas dos peixes contribuem para ampliar seu polimorfismo hepático, entretanto pode ser considerado o ponto inicial para os estudos comparativos e filogenéticos entre os vertebrados. O fígado dos peixes aparece como em todos os outros vertebrados, como um órgão chave que vai controlar muitas funções vitais e realizar um papel proeminente na fisiologia dos peixes, tanto no anabolismo (proteínas, lipídios e carboidratos) e no catabolismo (nitrogênio, glicogenólises e desintoxicação). Por outro lado, deve ser considerado como um órgão alvo para muitos parâmetros biológicos e ambientais que podem alterar a estrutura e o metabolismo do fígado, como por exemplo, a alimentação, toxinas, parasitas, microrganismos e metais pesados acumulados. Nos peixes o fígado é localizado ventralmente na cavidade celomática, ajustando-se ao espaço disponível na cavidade do corpo. Foi realizada através da microscopia de luz e eletrônica de varredura a morfologia estrutural do desenvolvimento do fígado do tubarão azul nos 33 espécimes, divididos em diferentes tamanhos de embriões e fetos de 4 cm até 45 cm, comparados com um indivíduo adulto fêmea de 2 metros. A contagem de hepatócitos e vacúolos de gordura foi pela morfometria, através da técnica de pontos em fotomicrografias aleatórias. Nos resultados obtidos, pode-se notar que o fígado ocupava 20% do tamanho do animal. Microscopicamente, observou a presença de diferentes tamanhos de vacúolos de armazenamento de lipídio nos hepatócitos, diferença nas proporções de hepatócitos, linfócitos e vasos sanguíneos que diminui à medida que aumenta a estocagem de lipídios, consequentemente diminuindo a visibilidade da estrutura do fígado. Maior visualização de vacúolos translúcidos intracitoplasmáticos microgoticular aumentando gradativamente para macrogoticulares. Sugerindo assim que a presença de lipidios seja para manutenção dos filhotes, flutuabilidade e reserva energéticado animal, indicando que ele armazena gordura em seu fígado desde o início da embriogênese.The blue shark (Prionace glauca), popularly known as blue dogfish among all shark species is the most abundant in the marine environment, and can be found in all seas. With the diversity of species, the description of any specific liver can hardly be used as a model. Together with this variability, some physiological characteristics of the fish contribute to increase its hepatic polymorphism, however, it can be considered the starting point for comparative and phylogenetic studies among vertebrates. Fish liver appears as in all other vertebrates as a key organ that will control many vital functions and play a prominent role in fish physiology, both in anabolism (proteins, lipids and carbohydrates) and in catabolism (nitrogen, glycogenolysis and detoxification). On the other hand, it should be considered as a target organ for many biological and environmental parameters that can alter the structure and metabolism of the liver, such as food, toxins, parasites, microorganisms and accumulated heavy metals. In fish, the liver is located ventrally in the coelomic cavity, adjusting to the available space in the body cavity. The structural morphology of blue shark liver development in 33 specimens divided into different sizes of embryos and fetuses from 4 cm to 45 cm was compared to a female adult of 2 meters, using light microscopy and scanning electron microscopy. The counts of hepatocytes and fat vacuoles were by morphometry, using the technique of points in random photomicrographs. In the results obtained, it can be noted that the liver occupied 20% of the size of the animal. Microscopically, it observed the presence of different sizes of lipid storage vacuoles in hepatocytes, a difference in the proportions of hepatocytes, lymphocytes and blood vessels that decreases as lipid storage increases, consequently decreasing the visibility of the liver structure. Greater visualization of microcyticular intracytoplasmic translucent vacuoles gradually increasing for macrogoticulares. Thus suggesting that the presence of lipids is for the maintenance of the puppies, buoyancy and energy reserve of the animal, indicating that it stores fat in its liver from the beginning of embryogenesis.
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Souza, Aline Fernanda de. "Estudo biológico das células germinativas caninas." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/10/10132/tde-14112013-150423/.
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Células germinativas embrionárias são células pluripotentes derivadas das células germinativas primordiais que surgem no período do desenvolvimento embrionário. Sendo precursoras na maturação dos gametas sendo para a proliferação e formação de novas gerações de células germinativas. Estudos em modelos animais com células troncos embrionárias pluripotentes têm sido realizados com sucesso no tratamento de muitas doenças genéticas, principalmente em modelos caninos devido a homologia com humanos. Portanto, objetivamos estabelecer um estudo da biologia das células erminativas caninas para futuras pesquisas, visando sua viabilidade terapêutica. Foram utilizadas fêmeas de cães sem raça definida (SRD), foram submetidas à ovario-salpinge-histerectomia, oriundas de campanhas de castração realizadas por associações e/ou organizações não governamentais na cidade de Pirassununga. Os embriões coletados foram analisados através de um cronograma histológico e também mensurados através da medida Crown-Rump(CR), em seguida em condições ésteres micro-dissecados na região paramesonéfrica próximo a região dos somitos. Os fragmentos foram isolados e colocados em cultivo com meio apropriado para o desenvolvimento e propagação das células germinativas primordiais (PGCs). Obteve-se sucesso nos cultivos com embriões em idades gestacionais próximas a 24 á 32 dias de gestação, nos quais demonstraram uma morfologia arredondada, pequena. Na microscopia eletrônica de varredura e transmissão observamos tamanhos variados entre as células aderidas umas as outras, mostrando um núcleo bem evidente e em seu citoplasma observou-se diversos tipos de organelas celulares, principalmente mitocôndrias. A análise imunohistoquímica revelou a presença de marcadores Oct4, sugerindo a presença de células pluripotentes e germinativas. Imunofenotípicamente as células através da citometria de fluxo revelou baixa expressão para o marcadore Oct4 enquanto que para os marcadores CD 34, C-Kit houve expressão.RT-PCR mostrou expressão do marcador para pluripotencialidade Oct4 e Sox2 e pela técnica de Western Blotting identificou a expressão da proteína específica para Oct4. Portanto estes achados sugerem com sucesso o estabelecimento de cultivo e proliferação e desenvolvimento das células germinativas primordiais caninas.Embryonic germ cells are pluripotent cells derived from primordial germ cells which arise during embryonic development. These cells are precursors in the maturation of gametes and for proliferation and formation of new generations of germ cells. Studies using animal models for pluripotent embryonic stem cells have been conducted successfully in the treatment of many genetic diseases, especially using canine models, due the homology between canine and humans. Therefore, we aimed to establish a study of canine biology of germ cells for future research, aiming viability therapy. For this study, we used female mongrel dogs (SRD), which underwent ovary- salpingo- hysterectomy, arising from castration campaigns run by associations and/or NGOs in Pirassununga city. The embryos collected were analyzed using histology methods following the timeline and measure by measuring Crown-Rump (CR) then in an environment without contaminants (sterile) the embryos were micro-dissected focusing in the paramesonephric region near the region of somite where the germ cells are. The fragments were isolated and placed in culture with a specific media for the development and spread of primordial germ cells (PGCs). Success was achieved in cultures with embryos at a gestational age close to 22 to 30th days of gestation, in which the cells showed a rounded morphology and small. In electron microscopy and transmission analyses, sizes were observed between the cells attached to each other, showing a conspicuous nucleus and in the cytoplasm was observed several types of cell organelles, especially mitochondria. Immunohistochemical analysis revealed the positive immunolabeling for Oct4, suggesting the presence of pluripotent cells and germ cells. The analyses using immunophenotyping by flow cytometry showed low expression for Oct4 while for CD34 and C-kit markers had positive expression. RT-PCR showed expression of the pluripotency markers Oct4 and Sox2. By the technique of Western Blotting identified protein expression specific for Oct4. Thus these findings suggest the successful establishment of culture, proliferation and development of primordial germ cells canine.
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Vellutini, Bruno Cossermelli. "Desenvolvimento e ciclo reprodutivo da bolacha-do-mar Clypeaster subdepressus (Echinodermata: Echinoidea) de São Sebastião, SP." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-17022009-105310/.
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Desenvolvimento e ciclo reprodutivo da bolacha-do-mar Clypeaster subdepressus (Echinodermata: Echinoidea) de São Sebastião, SP Resumo: Este trabalho descreve o desenvolvimento embrionário, larval e juvenil da bolacha-do-mar Clypeaster subdepressus sob microscopia de luz e eletrônica de varredura. Analisamos também o ciclo reprodutivo da espécie a partir de cortes histológicos das gônadas. A evolução morfológica da ordem Clypeasteroida (bolachas-do-mar), cerca de 55 milhões de anos atrás, esteve relacionada à ocupação de fundos arenosos. Dados morfológicos recentes e fósseis sugerem que durante a evolução das bolachas-do-mar houve retenção de características juvenis na fase adulta. Obtivemos gametas através da injeção de KCl em indivíduos adultos e fizemos a fecundação in vitro. Mantivemos os embriões e larvas em culturas a 26°C, e alimentamos as larvas com microalgas. Os óvulos (diâmetro médio de 160µm) são esféricos translúcidos e brancos. Após a entrada do espermatozóide, o envelope vitelínico endurece entre 2 e 6min; o pró-núcleo masculino inicia a migração da região periférica do óvulo até o centro 5min depois, levando 12min à 0,1µm/s para se fundir ao pró-núcleo feminino. As clivagens são holoblásticas, com a formação de macrômeros, mesômeros e micrômeros. A blástula forma-se entre 3,5 e 6,5h após a fecundação (hpf), desenvolve cílios e eclode da membrana de fertilização 7,5hpf. A gastrulação inicia-se na placa vegetativa com a ingressão unipolar das células mesenquimais primárias 10hpf. A extensão do arquêntero, ingressão das células mesenquimais secundárias e formação do esqueleto larval estendem-se até 30hpf. Em menos de 48hpf os espaços celômicos estão formados e no terceiro dia as larvas iniciam sua alimentação. O hidróporo abre-se na superfície abanal da larva e a invaginação do vestíbulo ocorre entre o braço pós-oral e o póstero-dorsal, do lado esquerdo, ao redor do quinto dia. O vestíbulo funde-se ao celoma esquerdo formando o rudimento, que desenvolve espinhos e pés ambulacrais ainda dentro da larva. As larvas tornam-se competentes ~20d após a fecundação e somente iniciam a metamorfose pela manhã, após contato com areia do habitat dos adultos ou microalgas. Após a eversão completa do rudimento, o epitélio larval regride por 1h30min. Jovens pós-metamórficos não têm boca ou ânus; possuem 15 espinhos e 15 pés ambulacrais (de 2 tipos); 5 esferídios na superfície oral; a superfície aboral ainda não possui esqueleto, exceto os remanescentes do esqueleto larval. Rudimentos do esqueleto da lanterna de Aristóteles estão organizados em 5 conjuntos com 1 dente, 2 hemipirâmides, 2 epífises cada; rudimento da rótula encontra-se intercalado entre os conjuntos. Hemipirâmides e dentes formam-se 2d após a metamorfose (dpm); dentes tornam-se mais robustos e as hemipirâmides se fundem formando as pirâmides 7dpm. O tubo digestório aparece e o ânus abre-se na superfície aboral 2dpm. A membrana peristomial torna-se funcional formando a boca 7dpm. Pedicelárias oficéfalas e tridentadas surgem na região posterior 14dpm e 30dpm, respectivamente. O crescimento dos jovens criados em laboratório foi lento: jovens pós-metamórficos tinham ~250µm de diâmetro e atingiram ~500µm de diâmetro 8 meses depois. Descrevemos 6 estágios de maturação gonadal para machos e fêmeas de C. subdepressus. Encontramos estágios de proliferação e gametas maduros com maior freqüência entre dezembro e março (verão), enquanto estágios de recuperação predominaram de maio a setembro (inverno). Fêmeas apresentaram um período de recuperação mais longo do que machos. A área ocupada pelo epitélio germinativo em um túbulo gonadal em corte transversal foi menor em indivíduos maduros. No estágio prematuro, as gônadas estiveram mais pesadas. Dados sugerem que exista um ciclo reprodutivo anual nas populações de C. subdepressus em São Sebastião, onde a recuperação das gônadas ocorre no inverno, o acúmulo de nutrientes a partir de outubro e a liberação de gametas entre fevereiro e março.Embryonic, larval, and juvenile development of the sea biscuit Clypeaster subdepressus is described with light and scanning electron microscopy. The reproductive cycle of the species is analyzed based on histological sections of the gonads. The morphological evolution of the order Clypeasteroida (sand dollars and sea biscuits), about 55 million years ago, was associated with the occupation of sand beds. Data on morphology of living and fossil echinoids suggests that during the evolution of sea biscuits juvenile characters were retained into adulthood. We obtained ripe gametes by KCl injection into the perivisceral coelomic cavity of adults and fertilized the eggs in vitro. We kept embryos and larvae in cultures at 26 °C and fed larvae with microalgae. Eggs (mean diameter of 160 m) are spherical, translucent, and white. After sperm entry, the vitelline envelope hardens between 2 and 6 min; male pro-nucleus begins to migrate towards the center of the egg 5 min later, taking 12 min at 0.1 m/s to fuse with the female pronucleus. Cleavages are holoblastic with the formation of macromeres, mesomeres, and micromeres. Blastulae are formed between 3.5 and 6.5 h after fertilization (hpf), develop cilia, and hatch 7.5 hpf. Gastrulation begins on the vegetal plate with the unipolar ingression of primary mesenchyme cells 10 hpf. Archenteron extension, ingression of secondary mesenchyme cells, and the formation of larval skeleton occurs until 30 hpf. In less than 48 hpf the celomic pouches are formed and on day 3 larvae begin to feed. Hidropore opens on the abanal surface of larvae while vestibule invagination takes place between the post-oral and postero-dorsal arms on the left side 5 dpf. Vestibule fuses with the left celom forming a rudiment which develops spines and podia still inside the larvae. Larvae become competent _20 d after fertilization and only metamorphose in the morning, after contact with sand from adult populations or food. After complete eversion of the rudiment, the larval epidermis retraction takes 1 h 30 min. Post-metamorphic juveniles do not have anus or mouth; they have 15 spines and 15 podia (of 2 types); 5 sphaeridia on the oral surface; aboral surface does not have plates, except for the remnants of larval spicules. Rudiments of the Aristotles lantern are organized in 5 groups. Each group has 1 tooth, 2 hemipiramids, and 2 epiphysis; a rudiment rotula is placed between the groups. Hemipiramids are formed 2 d after metamorphosis (dpm); teeth become more robust and hemipiramids fuse into piramids 7 dpm. The digestive tract appears and the anus opens on the aboral surface 2 dpm. The peristomial membrane is functional and the mouth opens 7 dpm. Ophicephalous and tridentate pedicellariae appear on the posterior region 14 dpm and 30 dpm, respectively. Growth of juveniles reared in the laboratory was slow: post-metamorphic juveniles were _250 m in diameter and reached _500 m 8 months later. We described 6 stages of gonadal growth in males and females of C. subdepressus. We found premature stages and ripe gametes more frequently between December and March (summer), while recovery stages were dominant from May until September (winter). Females have a longer period of growing stage than males. The area occupied by the germinal epithelium on a transverse section of a gonadal lobe is lower in mature stage. Gonads are heavier during the premature stage. Data suggest that C. subdepressus from São Sebastião has an annual reproductive cycle where gonadal recovery occurs during winter, nutrient storage by October, and spawning between February and March.
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Constantino, Maria Vitória Piemonte. "Morfologia e organogênese em dois períodos gestacionais em suínos (Sus scrofa domesticus)." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10132/tde-01072013-090720/.
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O estudo objetivou caracterizar o desenvolvimento morfológico e organológico de embriões suínos da raça Landrace (Sus scrofa domesticus) aos 20 (n=6) e 30 (n=7) dias pós inseminação artificial (p.i.), utilizando técnicas macroscópicas e microscópicas, além da análise morfométrica dos principais órgãos (coração, pulmão, fígado e mesonefro), inferindo sua importância na manutenção do concepto. Os embriões aos 20 p.i. apresentaram macroscopicamente pele translúcida; prosencéfalo, mesencéfalo e rombencéfalo; vesícula óptica sem pigmentação da retina; arcos branquiais; curvatura cervical; broto do membro torácico em forma de \"remo\"; fígado; coração; mesonefro; somitos e vascularização dermal. Nas análises histológicas, visualizaram-se as vesículas encefálicas; arcos branquiais; vesícula óptica sem pigmentação da retina; flexura encefálica; na região torácica e abdominal o coração e o fígado respectivamente; mesonefro (rim primitivo); intestino primitivo e somitos. Morfometricamente, os principais órgãos (coração, fígado e mesonefro) dos embriões aos 20 dias p.i., não diferiram significativamente (p<0,05), demonstrando desenvolvimento organológico apropriado a esta fase. As avaliações morfológicas e histológicas dos embriões aos 30 dias p.i. revelaram características semelhantes aos de 20 dias p.i., exceto pela presença do 4º ventrículo encefálico; curvatura cervical acentuada; fosseta nasal; vesículas ópticas com pigmentação da retina; membros torácicos e pélvicos com distinção dos dígitos; cauda; fígado volumoso e coluna vertebral, macroscopicamente; e pela presença das vesículas encefálicas secundárias; medula espinhal; medula oblonga; 3º ventrículo encefálico; coluna vertebral; pulmão; intestino primitivo e metanefro, microscopicamente. Entretanto, as análises estatísticas revelaram que as avaliações morfometricas do coração, pulmão, fígado e mesonefro diferiram entre si (p<0,05) em relação ao desenvolvimento dos principais órgãos. A comparação entre as médias das áreas totais do coração, fígado e mesonefro, pelo teste Mann-Whitney, indicaram que os embriões, aos 20 e 30 dias p.i., apresentaram diferença significativa (p<0,05). Este estudo sugeriu que a taxa de uniformidade e desenvolvimento dos embriões podem ser determinantes para a manutenção do concepto durante o período gestacional. Porém, mais estudos são necessários para elucidar os mecanismos acerca do desenvolvimento embrionário no terço inicial da gestação a fim de minimizar as perdas gestacionais na espécie suína.The study aimed to characterize the morphological and organology development of Landrace pigs embryos (Sus scrofa domesticus) at 20 days (n=6) and 30 days (n=6) post artificial insemination (p.i.) through macroscopic and microscopic techniques, besides morphometric analysis of the major organs (heart, lung, liver and mesonephros) inferring its importance in the conseptus maintenance. Embryos at 20 days p.i. macroscopically presented translucent skin; forebrain, midbrain and hindbrain; optic vesicle without retinal pigmentation; branquial arches; cervical curvature; forelimb budshaped \"paddle\"; liver; heart; mesonephros; somites and dermal vasculature. In the histological analysis were visualized the encephalic vesicles (forebrain, midbrain and hindbrain); branquial arches with its respective pouches and clefts; encephalic flexure; in the thoracic and abdominal portion the heart and liver respectively; mesonephros (primitive kidney); primitive gut and somites. Morphometrically, the major organs (heart, liver and mesonephros) of embryos at 20 days p.i. did not differ significantly (p<0.05) demonstrating organologycal appropriate development at this stage. The morphological and histological evaluations of embryos at 30 days p.i. revealed similar characteristics to the embryos at 20 days p.i., except for the presence of the 4th encephalic ventricle; accentuated cervical curvature; nasal pit; optic vesicles with pigmentation of the retina; thoracic and pelvic members with distinction of the digits; tail, voluminous liver, and vertebral column, macroscopically; and the presence of secondary encephalic vesicles; spinal cord; medulla oblongata; 3rd encephalic ventricle; vertebral column; lung; \"U-shaped\" intestine, and mesonephros, microscopically. However, statistical analyzes revealed that the morphometric evaluations the heart, lung, liver and mesonephros differ significantly (p<0,05) regarding the development of the major organs. The comparison between the means of the total areas of the heart, liver and mesonephros, through Man-Whitney test indicated that the embryos at 20 and 30 days p.i., demonstrated significant differences (p<0,05). This study suggested that the embryo uniformity and development rate may be crucial in the maintenance of the conceptus during the gestational period. However, more studies are necessary to elucidate the mechanisms of the embryonic development regarding the first third of pregnancy in order to minimize gestational losses in swine.
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Palazzi, Eduardo Gimenes. "Efetividade da tripsina sobre embriões murinos infectados experimentalmente com BoHV-1." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-03012011-090553/.
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O presente trabalho avaliou a efetividade do tratamento com tripsina (TT) na eliminação do BoHV-1 Colorado, causador da Rinotraqueíte Infecciosa Bovina (IBR). Camundongos fêmeas Swiss, com idade entre 6 e 8 semanas, foram superovuladas com 0,2mL a 5UI de hormônio eCG e, após 48h com hCG e acasaladas com machos inteiros da mesma linhagem e idade. Após 18 horas, as fêmeas foram eutanasiadas e, através de abertura no peritônio, os zigotos foram coletados. Foram separados zigotos para cinco ensaios que forneceram os seguintes dados: o BoHV-1 Colorado altera a taxa de clivagem e a morfologia do embrião; a tripsina, seguindo recomendações da IETS, não danifica o embrião; os embriões expostos aos vírus e submetidos ao TT não alteram sua morfologia e taxa de clivagem; foram detectados (nested-PCR+) vírus viáveis (MDBK+) após o TT. Estes resultados demonstram que o TT não foi efetivo para eliminar o BoHV-1 Colorado, porém em alguns ensaios o TT demonstrou eficiência na inativação do vírus o que torna-o um importante método de controle in vitro.This study evaluated the effectiveness of treatment with trypsin (TT) in the elimination of BoHV-1 Colorado, which causes infectious bovine rhinotracheitis (IBR) Swiss female mice, aged 6 and 8 weeks, were superovulated with 0.2 mL 5UI hormone eCG and 48h after hCG and mated with males of the same lineage and age. After 18 hours, females were euthanized, and through na opening in the peritoneum, the zygotes were collected. Zygotes were separated for five trials that provided the following data: the Colorado BoHV-1 alters the cleavage rate and embryo morphology; trypsin, following recommendations of the IETS, does not damage the embryo; the embryos exposed to the virus and subjected to TT does not change their morphology and cleavage rate; were detected (nested-PCR +) viable virus (MDBK +) after the TT. These results demonstrate that TT was not effective to eliminate the BoHV-1 Colorado, but in some tests showed the TT efficiency in inactivating the virus makes it na important method of control in vitro.
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Costa, Marcos Sawada Simões. "A sinalização pelo ácido retinóico e a origem evolutiva das câmaras cardíacas." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/42/42134/tde-09062009-110021/.
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Nos últimos anos, nós propusemos um modelo de duas etapas para a padronização antero-posterior do coração. Ácido retinóico (AR) produzido pela enzima RALDH2 induz o destino sino atrial nos precursores cardíacos posteriores. Subsequentemente, estes precursores adquirem a capacidade de expressar RALDH2, formando uma onda caudo-rostral desta enzima. A nossa hipótese é que esta onda surgiu nos para padronizar as células precursoras da bomba circulatória ancestral em regiões de influxo e efluxo, resultando na origem das câmaras cardíacas. Para testar se a onda cauro-rostral é ancestral nos vertebrados, nós mapeamos a expressão de RALDH2 em relação ao campo cardíaco em anfíbios, vertebrados basais e no cordado invertebrado anfioxo. Nossos dados sugerem que o modelo de duas etapas está presente em anfíbios e peixes. Clonagem do gene RALDH em lampréias indica presença de AR no campo cardíaco. Em anfioxo, a caracterização do padrão de expressão do ortólogo da RALDH2 revela ausência da onda caudo-rostral. Nossos resultados sugerem que a onda caudo-rostral de RALDH2 foi cooptada nos vertebrados para padronizar o campo cardíaco no eixo AP, o que corrobora a hipotése de que este mecanismo foi importante na origem evolutiva das câmaras cardíacas.In the last years, we have proposed a 2-step model for the establishment of cardiac chamber identities. Retinoic acid (RA) produced by its synthetic enzyme RALDH2, induces an atrial fate in posterior cardiac precursors of amniote embryos. Subsequently, a RALDH2 caudorostral wave engulfs posterior precursors. Our hypothesis is that this wave evolved in vertebrates to pattern an ancestral circulatory pump into AP fields, which were later fashioned into cardiac chambers. To test whether the wave is an ancestral or derived feature of amniotes, we mapped expression of RALDH2 in relation to the cardiac field in amphibians, basal vertebrates and the amphioxus. Our data suggests RA signaling patterns amphibian and piscine hearts. Cloning of RALDH in lampreys shows that RA synthesis takes place in the heart field. In the amphioxus, cloning of RALDH reveals a vertebrate-like expression pattern, although the RALDH2 wave is absent. Our results support the hypothesis that the caudorostral wave of RALDH2 was coopted to pattern the vertebrate cardiac field. This supports the hypothesis that the caudorostral wave of RALDH2 was an important player in the evolutionary origin of the cardiac chambers.
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Alvarez, Camila Wenceslau. "Fissura pré-forame incisivo uni/bilateral e fissura pós-forame incisivo associadas: estudo genético-clínico." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/61/61132/tde-27012011-100819/.
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Objetivo: Contribuir para a ampliação do conhecimento das fissuras orais, descrevendo, sob o aspecto genético-clínico, uma amostra de indivíduos com fissura pré-forame incisivo uni/bilateral incompleta e fissura pós-forame incisivo associadas. Casuística e metodologia: Foram selecionados 356 indivíduos com fissura pré-forame incisivo uni/bilateral incompleta, sem acometimento do arco alveolar, associada à fissura pós-forame incisivo, cadastrados e em tratamento no Hospital de Reabilitação de Anomalias Craniofaciais da Universidade de São Paulo, Bauru, SP. Dados de razão sexual, idade parental na época da concepção, consanguinidade parental, recorrência familial, lateralidade da fissura e presença de anomalias associadas à fissura foram investigados. Para análise dos resultados foram destacados dois grupos (Grupos I e Grupo II) da amostra total. No Grupo I foram incluídos os indivíduos que apresentaram fissura pré-forame incisivo cicatricial, independentemente do tipo de acometimento pós-forame. Indivíduos do Grupo I, que, além de apresentarem fissura pré-forame incisivo cicatricial apresentaram também algum tipo de microforma de fissura pós-forame incisivo, foram destacados para formarem também o Grupo II. Testes estatísticos de comparação foram realizados entre os Grupos e o restante da amostra e entre a amostra total e dados da literatura pertinente. Resultados e Discussão: Observou-se diferença estatisticamente significativa entre a amostra total e os dados da literatura em relação à lateralidade da fissura, razão sexual, consanguinidade, recorrência familial e presença de anomalias associadas. Observou-se, ainda, diferença estatisticamente significativa entre o Grupo II e o restante da amostra total quanto à idade paterna e, entre os Grupos I e II e a amostra total, em relação à ocorrência de múltiplas anomalias associadas à fissura. A amostra estudada apresentou, em geral, as mesmas características genético-clínicas do grupo das fissuras pré e transforame incisivo (FL/P). As diferenças encontradas não permitiram afirmar a distinção da fissura pré-forame associada à fissura pós-forame incisivo, sem acometimento do arco alveolar (FL+FP) das FL/P. Da mesma forma não foi possível afirmar, pelos resultados obtidos, que os Grupos I e II eram distintos da amostra total. Conclusão: Embora não se possa afirmar que FL+FP seja distinta das FL/P, suas características peculiares apontam para essa diferenciação. Os indivíduos com quadros de microformas de fissura constituem um grupo alvo de investigações sobre possíveis mecanismos genéticos que levam à gravidade variável dessas malformações.Purpose: To contribute to the expansion of knowledge about oral clefts, describing the clinical and genetic aspect of a sample of individuals with cleft lip associated with cleft palate, without alveolar arch involvement, showing or not other abnormalities. Patients and methods: We selected 356 patients with incomplete cleft lip uni/bilateral associated with cleft palate, without alveolar arch involvement, registered and in treatment at the Hospital de Reabilitação de Anomalias Craniofaciais da Universidade de São Paulo, Bauru, SP. Data for sexual ratio, parental age at the time of conception, parental consanguinity, familial recurrence, laterality of cleft and presence of associated anomalies were investigated. Regarding the analysis of the results two groups were detached (Group I and Group II) from the total sample. In Group I it was included individuals who had healed cleft lip, regardless of the type of palate involvement. Individuals in Group I, which, besides having had healed cleft lip also had some type of microform cleft palate were also detached to form Group II. Statistical tests were performed for comparison between groups and remainder of the sample, and between the total sample and literature data. Results and Discussion: There was a statistically significant difference between the total sample and literature data regarding laterality of the cleft, sexual ratio, consanguinity, familial recurrence and presence of associated anomalies. There was also a statistically significant difference between Group II and the remainder of the sample regarding paternal age, and between Groups I and II and the total sample in relation to the occurrence of multiple anomalies associated with cleft. The sample has, in general, the same genetic and clinical characteristics of the group of cleft lip with or without cleft palate (CL/P). The differences did not allow distinction between cleft lip associated cleft palate without involvement of the alveolar arch (CL+CP) and CL/P. Likewise it is not possible to affirm, from the results obtained, that Groups I and II are distinct from the total sample. Conclusion: Although we can not say that CL+CP is distinct from the CL/P, its peculiar features indicate to this differentiation. Individuals with microforms of cleft constitute a target group for research on possible genetic mechanisms that lead to varying severity of these malformations.
Books on the topic "Testis, embryology"
1
England, Marjorie A. Picture tests in embryology. London: Wolfe Medical Publications, 1989.
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England, Marjorie A. Picture tests in embryology. Chicago: Year Book Medical Publishers, 1989.
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Joint American-Swiss Seminar on Alternative Embryotoxicity and Teratogenicity Tests (1984 Zurich, Switzerland). In vitro embryotoxicity and teratogenicity tests: Joint American-Swiss Seminar on Alternative Embryotoxicity and Teratogenicity Tests, Zürich, November 12, 1984. Edited by Homburger Freddy and Goldberg Alan M. Basel, Switzerland: New York, 1985.
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Johnson, Kurt E. Anatomy: Review for USMLE, step 1. 3rd ed. Alexandria, Va: J&S Publishing Company, 2006.
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Johnson, Kurt E. Anatomy: Review for USMLE, step 1. 2nd ed. Alexandria, Va: J&S Pub. Co., 1998.
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Johnson, Kurt E. Anatomy: Review for new national boards. Alexandria, Va: J&S Pub. Co., 1992.
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The Testicular Descent in Human: Origin, Development and Fate of the Gubernaculum Hunteri, Processus Vaginalis Peritonei, and Gonadal Ligaments. Springer, 2000.
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The Testicular Descent in Human: Origin, Development and Fate of the Gubernaculum Hunteri, Processus Vaginalis Peritonei, and Gonadal Ligaments. Springer, 2011.
Find full textBook chapters on the topic "Testis, embryology"
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Hutson, John. "The Testis." In Clinical Embryology, 437–41. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-26158-4_46.
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Sekaran, Prabhu. "Congenital Abnormalities of the Testis and Epididymis." In Clinical Embryology, 443–47. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-26158-4_47.
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Silber, Sherman. "Testis Development, Embryology, and Anatomy." In Fundamentals of Male Infertility, 3–12. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76523-5_1.
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Hutson, John. "Testis Embryology, Anatomy and Physiology." In Endocrine Surgery in Children, 271–79. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-54256-9_19.
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Ansell, I. D. "Testis — Embryology and Normal Structure." In Atlas of Male Reproductive Pathology, 13–16. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4868-6_1.
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Davidoff, Michail S., Ralf Middendorff, Dieter Müller, and Adolf F. Holstein. "Development of the Testis." In Advances in Anatomy, Embryology and Cell Biology, 45–48. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-00513-8_6.
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Kucera, Pavel, and Eric Raddatz. "Environmental Pollution and Embryonic Development: Relevance of Standardized Toxicological Tests." In Experimental Embryology in Aquatic Plants and Animals, 389–94. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4615-3830-1_23.
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Matteo, Maria. "Assisted Reproductive Technology." In Practical Clinical Andrology, 237–50. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-11701-5_18.
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AbstractThe human species is biologically distinguished by low fertility. In fact, with each menstrual cycle, a couple at the peak of their reproductive capacity has only about a 30% chance of conceiving. The WHO states infertility as “a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected intercourse.”Assisted reproductive technology (ART) consists of all treatments or procedures that include the in vitro handling of both human oocytes and sperm or of embryos, for the purpose of establishing a pregnancy.The techniques are usually divided into three broad categories: First level techniques: Intrauterine and Intracervical Insemination (IUI/ICI), the simpler and less invasive ones, such as intrauterine insemination (IUI) with or without Intracervical Insemination (ICI) ovarian stimulation. Second level techniques: the more complex and more invasive ones that can be performed under local anesthesia or deep sedation, which differ from the basic techniques as they involve manipulation of female and male gametes and because they require in vitro fertilization. Among these techniques the IVF (In Vitro Fertilization and Embryo Transfer), ICSI (Intracytoplasmic Sperm Injection), and the possible cryopreservation of male and female gametes and embryos. Third level techniques procedures that require general anesthesia with intubation, including: laparoscopic egg retrieval, intra-tubal transfer of male and female gametes (GIFT), zygotes (ZIFT) and /or embryos (TET) laparoscopically; microsurgical sampling of gametes from the testicle: Testicular Sperm Extraction (TESE), Microsurgical Testicular Sperm Extraction (microTESE), Testicular Sperm Aspiration (TESA); microsurgical sampling of gametes from the epididymides: Percutaneous Epididymal Sperm Aspiration (PESA) and Microsurgical Epididymal Sperm Aspiration (MESA). In all assisted reproduction techniques, the seminal fluid receives a treatment able to induce capacitation “in vitro” so that the activated spermatozoa, at the threshold of the acrosomal reaction, can interact with the mature oocytes. Preimplantation Genetic Screening (PGS) and Preimplantation Genetic Diagnosis (PGD) are highly specialized procedures which involve removing three to four cells from a 5–6 day old blastocyst and testing them for chromosomal abnormalities prior to transferring the embryo into a woman’s uterus. According to data reported from the European IVF-Monitoring Consortium (EIM) for the European Society of Human Reproduction and Embryology (ESHRE), the clinical pregnancy rates (PR) per aspiration and per transfer are 28.0% and 34.8%, respectively. After ICSI, the corresponding rates are 24% and 33.5%. ART can alleviate the burden of infertility on individuals and families, but it can also present challenges to public health as evidenced by the high rates of multiple delivery, preterm delivery, and low birth-weight delivery experienced with ART.
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"Descent of the Testis." In Clinical Embryology, 230–33. CRC Press, 1998. http://dx.doi.org/10.1201/9781482264463-58.
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"Development of the Testis and its D ucts." In Clinical Embryology, 226–29. CRC Press, 1998. http://dx.doi.org/10.1201/9781482264463-57.
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