Articoli di riviste: "Ultrastructure analysis"

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Savchenko, S. V., N. G. Oshchepkova, N. P. Bgatova, Yu S. Taskaeva, E. V. Kuznetsov, V. P. Novoselov e A. Yu Letyagin. "Ultrastructural analysis of changes in myocardial blood microvessels in severe burn shock". Сибирский научный медицинский журнал 41, n. 3 (16 giugno 2021): 71–77. http://dx.doi.org/10.18699/ssmj20210310.

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Burn injury is an important medical problem, as it is accompanied by high mortality rates in burn shock. Aim of the study was to conduct an ultrastructural stereological analysis of changes in the blood microvessels of the left ventricular myocardium in burn shock.Material and methods. Myocardial samples during the early section were collected 2 hours after the detection of biological death in the victims from severe burn shock (3 men and 2 women); age group 32-44 years. An ultrastructural study of endothelial cells of the microvasculature of the left ventricular myocardium was carried out.Results and discussion. The development of severe burn shock is accompanied by changes in the ultrastructure of the endothelial cells of the blood microvessels of the left ventricular myocardium, which is associated with intracellular degradation and exocytosis. These ultrastructural changes may indicate impairment of vesicular transport in the endothelium of the myocardial microvessels in burn shock. A feature of the ultrastructure of the endothelium was the heterogeneity of the endothelial cells of the blood capillaries due to the revealed dark and light endothelial cells, which differ in the saturation of the cytoplasm with organelles. The new data obtained on changes in the ultrastructure of the endothelium of the microvasculature of the left ventricular myocardium can be informative in the development of approaches to intensive therapy of cardioprotective direction in combustiological patients with burn shock.

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Matei, Constantin I., Caroline Boulocher, Christelle Boulé, Michael Schramme, Eric Viguier, Thierry Roger, Yves Berthier, Ana-Maria Trunfio-Sfarghiu e Marie-Geneviève Blanchin. "Ultrastructural Analysis of Healthy Synovial Fluids in Three Mammalian Species". Microscopy and Microanalysis 20, n. 3 (18 marzo 2014): 903–11. http://dx.doi.org/10.1017/s1431927614000415.

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AbstractA better knowledge of synovial fluid (SF) ultrastructure is required to further understand normal joint lubrication and metabolism. The aim of the present study was to elucidate SF structural features in healthy joints from three mammalian species of different size compared with features in biomimetic SF. High-resolution structural analysis was performed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) and environmental SEM/wet scanning transmission electron microscopy mode complemented by TEM and SEM cryogenic methods. Laser-scanning confocal microscopy (LCM) was used to locate the main components of SF with respect to its ultrastructural organization. The present study showed that the ultrastructure of healthy SF is built from a network of vesicles with a size range from 100 to a few hundred nanometers. A multilayered organization of the vesicle membranes was observed with a thickness of about 5 nm. LCM study of biological SF compared with synthetic SF showed that the microvesicles consist of a lipid-based membrane enveloping a glycoprotein gel. Thus, healthy SF has a discontinuous ultrastructure based on a complex network of microvesicles. This finding offers novel perspectives for the diagnosis and treatment of synovial joint diseases.

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Shoemark, Amelia, Thomas Burgoyne, Robert Kwan, Mellisa Dixon, Mitali P. Patel, Andrew V. Rogers, Alexandros Onoufriadis et al. "Primary ciliary dyskinesia with normal ultrastructure: three-dimensional tomography detects absence of DNAH11". European Respiratory Journal 51, n. 2 (febbraio 2018): 1701809. http://dx.doi.org/10.1183/13993003.01809-2017.

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In primary ciliary dyskinesia (PCD), motile ciliary dysfunction arises from ciliary defects usually confirmed by transmission electron microscopy (TEM). In 30% of patients, such as those with DNAH11 mutations, apparently normal ultrastructure makes diagnosis difficult. Genetic analysis supports diagnosis, but may not identify definitive causal variants. Electron tomography, an extension of TEM, produces three-dimensional ultrastructural ciliary models with superior resolution to TEM. Our hypothesis is that tomography using existing patient samples will enable visualisation of DNAH11-associated ultrastructural defects. Dual axis tomograms from araldite-embedded nasal cilia were collected in 13 PCD patients with normal ultrastructure (DNAH11 n=7, HYDIN n=2, CCDC65 n=3 and DRC1 n=1) and six healthy controls, then analysed using IMOD and Chimera software.DNAH11 protein is localised to the proximal ciliary region. Within this region, electron tomography indicated a deficiency of >25% of proximal outer dynein arm volume in all patients with DNAH11 mutations (n=7) compared to other patients with PCD and normal ultrastructure (n=6) and healthy controls (n=6). DNAH11 mutations cause a shared abnormality in ciliary ultrastructure previously undetectable by TEM. Advantageously, electron tomography can be used on existing diagnostic samples and establishes a structural abnormality where ultrastructural studies were previously normal.

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Redler, Andrea, Selenia Miglietta, Edoardo Monaco, Roberto Matassa, Michela Relucenti, Matthew Daggett, Andrea Ferretti e Giuseppe Familiari. "Ultrastructural Assessment of the Anterolateral Ligament". Orthopaedic Journal of Sports Medicine 7, n. 12 (1 dicembre 2019): 232596711988792. http://dx.doi.org/10.1177/2325967119887920.

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Background: The anterolateral ligament (ALL) has been identified as a structure on the lateral side of the knee, but debate exists regarding whether it is a capsular thickening or a ligament. Hypothesis: A detailed ultrastructural characterization of the ALL and its ultrastructure collagen arrangement will reveal it more closely resembles ligamentous tissue than joint capsule. Study Design: Descriptive laboratory study. Methods: Eight paired knee samples from 4 fresh-frozen male cadavers were used for this study. Samples were harvested from the ALL, the joint capsule, and the medial collateral ligament (MCL). All samples were evaluated with light microscopy (LM), transmission electron microscopy (TEM), and variable pressure scanning electron microscopy (VP-SEM). With LM, the 3 tissues were analyzed and their morphology described. With TEM, the ultrastructure and collagen characteristics were quantified and compared among specimens. Then, the 3-dimensional characteristics were compared with VP-SEM. Results: Ultrastructure analysis demonstrated similar morphology between the ALL and MCL, with significant differences in these 2 structures as compared with the joint capsule. On LM, the ALL and MCL were characterized by the presence of a dense collagen fiber oriented in the longitudinal and transversal directions of the fiber bundles, while the joint capsule was found to have a more disorganized architecture. On TEM, the collagen fibers of the ALL and MCL demonstrated similar ultrastructural morphology, with both having collagen fibers in parallel, longitudinal alignment. A quantitative analysis was also performed, with the mean (± SD) diameter of fibrils in the ALL and MCL being 80 ± 2.66 nm and 150 ± 3.35 nm, respectively (all P < .001). The VP-SEM highlighted that ALL and MCL morphology demonstrated arrangements of fiber bundles that are densely packed and organized, in contrast to the disorganized fibers of the joint capsule. Conclusion: The ALL and MCL have comparable ultrastructures that are distinctly different from the joint capsule, as visualized on LM, TEM, and VP-SEM. Clinical Relevance: The ALL should be considered a distinctive structure of the knee, although strictly connected to the surrounding capsule.

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Moreno, Silvana Ramos Farias, Jorge José de Carvalho, Ana Lúcia Nascimento, Adriano Arnobio, Beni Olej, Margareth de Oliveira Timóteo, Luiz Querino de Araújo Caldas e Mário Bernardo Filho. "Ultrastructural analysis of kidney, liver and duodenum isolated from treated rats with Ginkgo Biloba extract and effects of this medicinal plant on the biodistribution of the padiopharmaceutical sodium pertechnetate". Brazilian Archives of Biology and Technology 51, spe (dicembre 2008): 185–90. http://dx.doi.org/10.1590/s1516-89132008000700030.

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Ginkgo biloba extract (EGb) has been used to treat memory and concentration deficits, acts as platelet activating factor antagonism and prevents against damages caused by free radicals. EGb is a standardized extract that contains 24% flavonoids and 6% terpenoids. The aim of this work was to evaluate the possible influence of an EGb on the ultrastructure of some organs isolated from rats and on the biodistribution of sodium pertechnetate (99mTcO4Na). The animals were treated with EGb and after six days, received 99mTcO4Na. The organs were isolated and fixed for ultrastructural analysis. The results showed that EGb has modified the ultrastructure of kidney, liver and duodenum and altered the biodistribution of 99mTcO4Na (P<0.05). It is speculated that the substances present in the EGb could act directly or generate metabolites capable to promote changes on the biodistribution of 99mTcO4Na and on the morphology of organs at ultrastructural level.

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Brantner, Christine A., Ryan M. Hannah, James P. Burans e Robert K. Pope. "Inactivation and Ultrastructure Analysis ofBacillus spp. andClostridium perfringensSpores". Microscopy and Microanalysis 20, n. 1 (febbraio 2014): 238–44. http://dx.doi.org/10.1017/s1431927613013949.

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AbstractBacterial endospores are resistant to many environmental factors from temperature extremes to ultraviolet irradiation and are generally more difficult to inactivate or kill than vegetative bacterial cells. It is often considered necessary to treat spores or samples containing spores with chemical fixative solutions for prolonged periods of time (e.g., 1–21 days) to achieve fixation/inactivation to enable electron microscopy (EM) examination outside of containment laboratories. Prolonged exposure to chemical fixatives, however, can alter the ultrastructure of spores for EM analyses. This study was undertaken to determine the minimum amount of time required to inactivate/sterilize and fix spore preparations from several bacterial species using a universal fixative solution for EM that maintains the ultrastructural integrity of the spores. We show that a solution of 4% paraformaldehyde with 1% glutaraldehyde inactivated spore preparations ofBacillus anthracis,Bacillus cereus,Bacillus megaterium,Bacillus thuringiensis, andClostridium perfringensin 30 min, andBacillus subtilisin 240 min. These results suggest that this fixative solution can be used to inactivate and fix spores from several major groups of bacterial spore formers after 240 min, enabling the fixed preparations to be removed from biocontainment and safely analyzed by EM outside of biocontainment.

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Chen, Weixin, Riming Liu, Suo Tao, Weixing Shen, Weihong Zhou, Chao Song, Huanhua Lu e Chungen Xing. "Ultrastructural Analysis of Human Gallstones using Synchrotron Radiation µCT". Combinatorial Chemistry & High Throughput Screening 22, n. 1 (3 maggio 2019): 13–17. http://dx.doi.org/10.2174/1386207322666190222122007.

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Objective: Gallstone formation is a pathological process of mineralization in the human body. Determination of the morphology and ultrastructure of gallstones holds the key to understanding the pathophysiology of gallbladder disease. Synchrotron radiation phase-contrast Xray microtomography is a novel technology, which is designed for comprehensive analysis of gallstone ultrastructure. Materials and Methods: Nine human gallstones were obtained from the Department of Pathology, Qingpu branch of Zhongshan Hospital Affiliated to Fudan University (China), and scanned by synchrotron radiation µCT (SR µCT). The imaging data generated by SR µCT scan were analyzed. Results: The three-dimensional ultrastructure of human gallstones corresponding to their cholesterol and bile pigment composition was determined. Conclusions: The ultrastructure of gallstones exhibits considerable diversity and complexity. The synchrotron radiation phase-contrast X-ray microtomography is a valuable tool for in-depth study of human gallstones.

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Jiao, Lin, Jue Wang e Lingling Zhu. "A Comparative Study of Endometriosis and Normal Endometrium Based on Ultrasound Observation". Applied Bionics and Biomechanics 2022 (30 aprile 2022): 1–12. http://dx.doi.org/10.1155/2022/7934690.

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In order to compare the microscopic ultrastructure of eutopic endometrium and normal endometrium in patients with endometriosis, to study the specific pathogenesis of endometriosis. In this paper, on the basis of using B-ultrasound technology, several patients with endometriosis were subjected to B-ultrasound to observe the ultrastructure of the eutopic uterine endometrium and compared with the pictures of normal endometrium to carry out the specific analysis between the two ultrastructural comparisons. This study is based on the analysis of B-ultrasound images of patients with endometriosis, compares the difference between their ultrastructure and normal human body, and conducts specific pathological diagnosis and analysis to find out the impact of the endometrium in place. The specific factors of the occurrence of lesions and the corresponding treatment methods are proposed. The experimental results show that the ultrastructure of endometriosis eutopic endometrium is different from that of normal endometrium. The microvilli of secretory cells and the cilia of ciliated cells of the former are abnormally increased and lengthened, and they are superior to B-ultrasound technology. The success rate of the examination is 93.75%, which can play an important role in the specific examination process of patients with endometriosis, as one of the actual indicators of detection. Under the electron microscope, microvilli are tiny finger-like protrusions extending from the cell membrane and the cytoplasm on the free surface of the cell, surrounded by the cell membrane and perpendicular to the cell membrane surface.

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Burette, Alain C., Thomas Lesperance, John Crum, Maryann Martone, Niels Volkmann, Mark H. Ellisman e Richard J. Weinberg. "Electron tomographic analysis of synaptic ultrastructure". Journal of Comparative Neurology 520, n. 12 (11 giugno 2012): 2697–711. http://dx.doi.org/10.1002/cne.23067.

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Blanco-Máñez, Rosana, Miguel Armengot-Carceller, Teresa Jaijo e Francisco Vera-Sempere. "Axonemal Symmetry Break, a New Ultrastructural Diagnostic Tool for Primary Ciliary Dyskinesia?" Diagnostics 12, n. 1 (6 gennaio 2022): 129. http://dx.doi.org/10.3390/diagnostics12010129.

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Diagnosis testing for primary ciliary dyskinesia (PCD) requires a combination of investigations that includes study of ciliary beat pattern by high-speed video-microscopy, genetic testing and assessment of the ciliary ultrastructure by transmission electron microscopy (TEM). Historically, TEM was considered to be the “gold standard” for the diagnosis of PCD. However, with the advances in molecular genetic techniques, an increasing number of PCD variants show normal ultrastructure and cannot be diagnosed by TEM. During ultrastructural assessment of ciliary biopsies of patients with suspicion of PCD, we observed an axonemal defect not previously described that affects peripheral doublets tilting. To further characterize this defect of unknown significance, we studied the ciliary axonemes by TEM from both PCD-confirmed patients and patients with other sino-pulmonary diseases. We detected peripheral doublets tilting in all the PCD patients, without any significant difference in the distribution of ciliary beat pattern or mutated gene. This defect was also present in those patients with normal ultrastructure PCD subtypes. We believe that the performance of axonemal asymmetry analysis would be helpful to enhance diagnosis of PCD.

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Claeys, Myriam, Nurul Dwi Handayani, Vladimir V. Yushin, Prabowo Lestari, Antarjo Dikin, Johannes Helder e Wim Bert. "Self-pressurised rapid freezing, a time-efficient and affordable cryo-fixation method for ultrastructural observations on unhatched cyst nematodes". Nematology 22, n. 1 (5 settembre 2019): 103–10. http://dx.doi.org/10.1163/15685411-00003287.

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Summary Ultrastructural analysis of the early development of nematodes is hampered by the impermeability of the eggshell to most commonly used fixatives. High-pressure freezing (HPF), a physical cryo-fixation method, facilitates a fast rate of fixation, and by using this method the issue of the uneven delivery of fixative is circumvented. Although HPF results in a superior preservation of the fine structure, the equipment costs impede a wider application of this method. Self-pressurised rapid freezing (SPRF) is an alternative low-cost cryo-fixation method, and its usefulness was evaluated in an ultrastructural study of the eggshell and the cuticle of unhatched second-stage juveniles (J2) of Globodera rostochiensis and Heterodera schachtii. A comparison with conventional (chemical) fixation demonstrates that SPRF fixation results in a remarkably well-preserved ultrastructure of the entire egg including both the eggshell and the cellular details of the unhatched J2. Therefore, SPRF fixation is proposed as an affordable, relatively easy-to-use and time-efficient technique to study the ultrastructure of unhatched J2 and eggs of nematodes.

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Veziers, Joëlle, Maurice Lesourd, Christophe Jollivet, Claudia Montero-Menei, Jean-Pierre Benoit e Philippe Menei. "Analysis of brain biocompatibility of drug-releasing biodegradable microspheres by scanning and transmission electron microscopy". Journal of Neurosurgery 95, n. 3 (settembre 2001): 489–94. http://dx.doi.org/10.3171/jns.2001.95.3.0489.

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Object. Stereotactically guided implantation of biodegradable microspheres is a promising strategy for delivery of neurotrophic factors in a precise and spatially defined brain area. The goal in this study was to show the biocompatibility of poly(D,L,lactide-co-glycolide) microspheres with brain tissue at the ultrastructural level and to analyze the three-dimensional (3D) ultrastructure after intrastriatal implantation of these microparticles. Methods. Scanning and transmission electron microscopy were used to study the microspheres and their environment after implantation in an inert material (gelatin) and in the rat striatum. Observations were made at different time periods, ranging from 24 hours to 2 months postimplantation. Conclusions. The progressive degradation of the microspheres, with vacuolization, deformation, and shrinkage, was well visualized. This degradation was identical in microspheres implanted in the inert material and in the rat brain tissue, independent of the presence of macrophages. The studies preformed in the striatum permitted the authors to demonstrate the structural integrity of axons in contact with microspheres, confirming the biocompatibility of the polymer. Furthermore, scanning electron microscopy showed the preservation of the 3D ultrastructure of the striatum around the microparticles. These microparticles, which can be stereotactically implanted in functional areas of the brain and can release neurotrophic factors, could represent, for some indications, an alternative to gene therapy.

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Blanchon, Sylvain, Marie Legendre, Mathieu Bottier, Aline Tamalet, Guy Montantin, Nathalie Collot, Catherine Faucon et al. "Deep phenotyping, including quantitative ciliary beating parameters, and extensive genotyping in primary ciliary dyskinesia". Journal of Medical Genetics 57, n. 4 (26 novembre 2019): 237–44. http://dx.doi.org/10.1136/jmedgenet-2019-106424.

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BackgroundPrimary ciliary dyskinesia (PCD) is a rare genetic disorder resulting in abnormal ciliary motility/structure, extremely heterogeneous at genetic and ultrastructural levels. We aimed, in light of extensive genotyping, to identify specific and quantitative ciliary beating anomalies, according to the ultrastructural phenotype.MethodsWe prospectively included 75 patients with PCD exhibiting the main five ultrastructural phenotypes (n=15/group), screened all corresponding PCD genes and measured quantitative beating parameters by high-speed video-microscopy (HSV).ResultsSixty-eight (91%) patients carried biallelic mutations. Combined outer/inner dynein arms (ODA/IDA) defect induces total ciliary immotility, regardless of the gene involved. ODA defect induces a residual beating with dramatically low ciliary beat frequency (CBF) related to increased recovery stroke and pause durations, especially in case of DNAI1 mutations. IDA defect with microtubular disorganisation induces a low percentage of beating cilia with decreased beating angle and, in case of CCDC39 mutations, a relatively conserved mean CBF with a high maximal CBF. Central complex defect induces nearly normal beating parameters, regardless of the gene involved, and a gyrating motion in a minority of ciliated edges, especially in case of RSPH1 mutations. PCD with normal ultrastructure exhibits heterogeneous HSV values, but mostly an increased CBF with an extremely high maximal CBF.ConclusionQuantitative HSV analysis in PCD objectives beating anomalies associated with specific ciliary ultrastructures and genotypes. It represents a promising approach to guide the molecular analyses towards the best candidate gene(s) to be analysed or to assess the pathogenicity of the numerous sequence variants identified by next-generation-sequencing.

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Jerônimo, Gustavo Henrique, D. Rabern Simmons, Timothy Yong James e Carmen Lidia Amorim Pires-Zottarelli. "Boothiomyces angulosus and Boothiomyces elyensis: two new combinations in the Terramycetaceae (Rhizophydiales, Chytridiomycota)". Nova Hedwigia 109, n. 3 (1 novembre 2019): 399–412. http://dx.doi.org/10.1127/nova_hedwigia/2019/0536.

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The genus Rhizophydium was proposed by A. Schenk in 1858 to accommodate the inoperculate taxa previously placed in Chytridium. The morphological delineation encompassed around 235 species that have now been segregated into different genera based on molecular and zoospore ultrastructural analyses. However, some taxa have never been investigated for phylogenetic position or zoospore ultrastructural characters. The aim of this study was to use morphology, zoospore ultrastructure and molecular analyses to verify the placement of our isolates of Rhizophydium angulosum and R. elyense in the Rhizophydiales phylogeny. These isolates produced angular zoosporangia, characteristic of Terramycetaceae representatives, and grouped within the Boothiomyces clade in analyses of complete ITS and partial LSU regions of rDNA. Transmission electronic microscopy (TEM) analysis revealed that R. angulosum produces zoospores with the same ultrastructural characters described from Boothiomyces representatives. In addition, R. elyense presented sufficient characteristics that support its morphological delineation from Boothiomyces macroporosus, the type species of the genus. Based on molecular, morphological, and ultrastructural analyses, we transfer R. angulosum and R. elyense to Boothiomyces.

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Felšöová, Andrea, Tibor Sloboda, Lukáš Hudec, Miroslav Koblížek, Petr Pohunek, Vendula Martinů, Žofia Varényiová, Simona Kadlecová e Jiří Uhlík. "Quantitative Assessment of Ciliary Ultrastructure with the Use of Automatic Analysis: PCD Quant". Diagnostics 11, n. 8 (29 luglio 2021): 1363. http://dx.doi.org/10.3390/diagnostics11081363.

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The ciliary ultrastructure can be damaged in various situations. Such changes include primary defects found in primary ciliary dyskinesia (PCD) and secondary defects developing in secondary ciliary dyskinesia (SCD). PCD is a genetic disease resulting from impaired ciliary motility causing chronic disease of the respiratory tract. SCD is an acquired condition that can be caused, for example, by respiratory infection or exposure to tobacco smoke. The diagnosis of these diseases is a complex process with many diagnostic methods, including the evaluation of ciliary ultrastructure using transmission electron microscopy (the golden standard of examination). Our goal was to create a program capable of automatic quantitative analysis of the ciliary ultrastructure, determining the ratio of primary and secondary defects, as well as analysis of the mutual orientation of cilia in the ciliary border. PCD Quant, a program developed for the automatic quantitative analysis of cilia, cannot yet be used as a stand-alone method for evaluation and provides limited assistance in classifying primary and secondary defect classes and evaluating central pair angle deviations. Nevertheless, we see great potential for the future in automatic analysis of the ciliary ultrastructure.

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Li, Qiu-yue, Peng-hui Yang, Xin Huang, Xin-long Li, Min-yi Luo, Bi-juan Xiao, Zi-ming Zhao, Si-yi Li e Hua-feng Pan. "Gastric Mucosa Pathology in Rats with Precancerous Lesions of Gastric Cancer with Spleen Deficiency and Blood Stasis". Evidence-Based Complementary and Alternative Medicine 2022 (24 settembre 2022): 1–11. http://dx.doi.org/10.1155/2022/1366597.

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Objective. This research aimed at better understanding the histopathological development of precancerous lesions of gastric cancer (PLGC) and organelle ultrastructure changes. Methods. Sprague-Dawley rats were randomly assigned to the model and control groups. Model rats drank N-methyl-N′-nitro-N-nitrosoguanidine solution, while control rats drank pure water ad libitum. At 1, 3, 5, 6, and 8 months after the start of feeding, eight rats were randomly chosen from each group, and gastric mucosa tissues were removed for histopathological analysis. H&E staining was applied to analyze the pathological histological structure of the rat gastric mucosa via a light microscope, and the ultrastructural changes were observed via a transmission electron microscope. Results. Gastric mucosal pathologies of model rats such as mucosal atrophy, intestinal metaplasia, inflammatory lesions, and even intraepithelial neoplasia deteriorated over time. The endoplasmic reticulum gap widened, the mitochondrial endothelial cristae were disrupted, the nuclear membrane thickened, and chromatin condensed with heterotypic alterations in the main and parietal cells. Additionally, endothelial cell enlargement and thickening of the microvascular intima were seen. Conclusion. Our research showed that the PLGC progression of rats is correlated with the pathological alteration axis of “normal gastric mucosa-gastric mucosa inflammatory changes-intestinal metaplasia with mild dysplasia-moderate to severe dysplasia.” Ultrastructure analysis of model rats is compatible with the structural changes in the gastric mucosa with spleen deficiency and blood stasis. The pathological evolutionary axis and ultrastructural analysis are helpful for evaluating potential novel herbal therapies for PLGC.

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Hirashima, Shingo, Keisuke Ohta, Tomonoshin Kanazawa, Akinobu Togo, Risa Tsuneyoshi, Yoshihiro Miyazono, Jingo Kusukawa e Kei-ichiro Nakamura. "Correlative imaging of collagen fibers and fibroblasts using CLEM optimized for picrosirius red staining and FIB/SEM tomography". Microscopy 69, n. 5 (14 maggio 2020): 324–29. http://dx.doi.org/10.1093/jmicro/dfaa024.

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Abstract Conventional imaging for three-dimensional (3D) ultra-architectural analysis of collagen fibers and fibroblasts is time-consuming and requires numerous ultrathin sections to search the target area. Currently, no method allows 3D ultra-architectural analysis of predetermined areas including spatial relationships between collagen fibers and fibroblasts in vitro. Herein, we developed a new method for in vitro analysis of the 3D ultrastructure of fibroblasts and collagen fibers using CLEM optimized for picrosirius red staining and FIB/SEM tomography. Collagen fibers were observed between, rather than on top of, stacked cells. This method offers the advantage of mesoscopic and ultrastructural analysis, thus minimizing bias and ensuring accurate observation.

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Olm, Mary A. K., João E. Kögler, Mariangela Macchione, Amelia Shoemark, Paulo H. N. Saldiva e Joaquim C. Rodrigues. "Primary ciliary dyskinesia: evaluation using cilia beat frequency assessment via spectral analysis of digital microscopy images". Journal of Applied Physiology 111, n. 1 (luglio 2011): 295–302. http://dx.doi.org/10.1152/japplphysiol.00629.2010.

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Ciliary beat frequency (CBF) measurements provide valuable information for diagnosing of primary ciliary dyskinesia (PCD). We developed a system for measuring CBF, used it in association with electron microscopy to diagnose PCD, and then analyzed characteristics of PCD patients. 1 The CBF measurement system was based on power spectra measured through digital imaging. Twenty-four patients suspected of having PCD (age 1–19 yr) were selected from a group of 75 children and adolescents with pneumopathies of unknown causes. Ten healthy, nonsmoking volunteers (age ≥17 yr) served as a control group. Nasal brush samples were collected, and CBF and electron microscopy were performed. PCD was diagnosed in 12 patients: 5 had radial spoke defects, 3 showed absent central microtubule pairs with transposition, 2 had outer dynein arm defects, 1 had a shortened outer dynein arm, and 1 had a normal ultrastructure. Previous studies have reported that the most common cilia defects are in the dynein arm. As expected, the mean CBF was higher in the control group ( P < 0.001) and patients with normal ultrastructure ( P < 0.002), than in those diagnosed with cilia ultrastructural defects (i.e., PCD patients). An obstructive ventilatory pattern was observed in 70% of the PCD patients who underwent pulmonary function tests. All PCD patients presented bronchial wall thickening on chest computed tomography scans. The protocol and diagnostic techniques employed allowed us to diagnose PCD in 16% of patients in this study.

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Geis, G., H. Leying, S. Suerbaum, U. Mai e W. Opferkuch. "Ultrastructure and chemical analysis of Campylobacter pylori flagella." Journal of Clinical Microbiology 27, n. 3 (1989): 436–41. http://dx.doi.org/10.1128/jcm.27.3.436-441.1989.

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Garris, David R., e Bryan L. Garris. "Cytomorphometric analysis and surface ultrastructure of developing decidua". Tissue and Cell 35, n. 4 (agosto 2003): 233–42. http://dx.doi.org/10.1016/s0040-8166(03)00036-3.

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Taylor, Wilson A. "Comparative analysis of megaspore ultrastructure in Pennsylvanian lycophytes". Review of Palaeobotany and Palynology 62, n. 1-2 (gennaio 1990): 65–78. http://dx.doi.org/10.1016/0034-6667(90)90017-d.

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Li, Li, Yongcong Hong, Da Huo e Pumo Cai. "Ultrastructure analysis of white spot syndrome virus (WSSV)". Archives of Virology 165, n. 2 (6 dicembre 2019): 407–12. http://dx.doi.org/10.1007/s00705-019-04482-9.

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Talbot, Neil C. "Ultrastructure analysis of cultured preimplantation pig blastocyst tissues". Theriogenology 49, n. 1 (gennaio 1998): 220. http://dx.doi.org/10.1016/s0093-691x(98)90573-8.

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Hashimoto, Ken, Shari Topper, Harry Sharata e Mohammad Edwards. "CHILD Syndrome: Analysis of Abnormal Keratinization and Ultrastructure". Pediatric Dermatology 12, n. 2 (giugno 1995): 116–29. http://dx.doi.org/10.1111/j.1525-1470.1995.tb00137.x.

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Roels, Frank, Antoon Claeys, Hugo Coen, Ingrid Kerckaert, Frederik Zukowski, Jacques Keyser, Claire Bourgain e Elisabeth Hooghe. "Quantitation of ultrastructure by light microscopical image analysis". Biology of the Cell 63, S1 (1988): 27–27. http://dx.doi.org/10.1016/0248-4900(88)90205-5.

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26

Castro, María A., e Fidel A. Roig. "WOOD ULTRASTRUCTURE OF ANCIENT BURIED LOGS OF FITZROYA CUPRESSOlDES". IAWA Journal 28, n. 2 (2007): 125–37. http://dx.doi.org/10.1163/22941932-90001629.

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Abstract (sommario):

The anatomy and ultrastructure of subfossil wood of Fitzroya cupressoides from the late Pleistocene (>50,000 14C years before present) were compared with those of extant F. cupressoides trees from southern Chile, using light microscopy (polarized light and ftuorescence), scanning electron microscopy coupled with an energy dispersive X-ray spectroscopy system, and transmission electron microscopy. The ancient wood showed an unchanged gross wood structure, loss of cell wall birefringence, loss of lignin autoftuorescence, and a loss of the original microfibrillar pattern. The energy dispersive X-ray spectroscopy analysis indicated higher than normal contents of S, Cl, and Na in subfossil wood. Ultrastructural modifications in the cell wall of the subfossil wood could have important implications for further studies involving isotopic and wood anatomical measurements of ancient wood.

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27

Ellzey, J. T., J. P. Drake, L. Dader e P. Boentges. "A Morphometric Analysis of Early Effects of Ethanol on Hepatocyte Organelles from Peromyscusmaniculatus". Microscopy and Microanalysis 4, S2 (luglio 1998): 1064–65. http://dx.doi.org/10.1017/s1431927600025447.

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Pathological changes of hepatocytes from rats fed a 30% ethanol-derived calories diet for three weeks include noticeable ultrastructural changes including steatosis and hypertrophy of the smooth endoplasmic reticulum. We sought to examine hepatocytes of deer mice administered ethanol in an inhalation chamber for two weeks to determine if subtle changes occur in hepatocyte organelles prior to steatosis.Two strains of Peromyscus maniculatus, ADH-positive possessing hepatic cytosolic alcohol dehydrogenase and ADH-negative deer mice lacking this enzyme were purchased from the Peromyscus Genetic Stock Center (Univ. of South Carolina). They tested negatively for Hanta viruses. A morphometric analysis of the ultrastructure of ADH+(n=14) and ADH- (n=14) controls as well as experimentals exposed to chronic, intoxicating levels of ethanol was conducted. Blood ethanol levels were maintained between 1.25-1.75 mg/ml for two weeks in the experimentals.

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28

Repin, Nikolay, Larisa Marchenko, Tatyana Govorukha e Anatoliy Goltsev. "Opportunities of Electron Microscopy When Solving Cryobiological Tasks. Retrospective Analysis". Problems of Cryobiology and Cryomedicine 32, n. 1 (30 marzo 2022): 3–13. http://dx.doi.org/10.15407/cryo32.01.003.

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Abstract (sommario):

The history of the development and use of low-temperature electron microscopic methods of freeze-fracture, freeze-substitution and others in cryobiological research at the Institute for Problems of Cryobiology and Cryomedicine of the National Academy of Sciences of Ukraine is presented in this article. These methods’ possibilities in studying the processes of crystal formation in cryoprotectant solutions, cell suspensions, and tissues under various freezing conditions are demonstrated. Some results of the analysis of ultrastructural changes in biological systems of various organization levels, at different stages of ontogenesis, under the influence of cooling in a wide temperature range (from 37 to –196°C) are presented. The use of a high resolution electron microscopic method in combination with an accessory technical equipment and some methodological techniques allowed to obtain fundamental results important for cryobiology on ice crystals formation and localization in the intracellular volume, the temperature-dependent transmembrane proteins redistribution, changes in the ultrastructure of erythrocytes and their membranes during hypothermic storage.

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29

Syed, Sadatullah, Syed M. Yassin, Abdulrahman Yahya Almalki, Salma Abubaker Abbas Ali, Abdulaziz M. Maken Alqarni, Yousef M. Moadi, Abdulrahman Masoud Alkhaldi et al. "Structural Changes in Primary Teeth of Diabetic Children: Composition and Ultrastructure Analysis". Children 9, n. 3 (26 febbraio 2022): 317. http://dx.doi.org/10.3390/children9030317.

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Diabetes affects the developing enamel by altering the mineralization process, which can have a detrimental effect on oral health. The objectives of this study were to examine the ultrastructure and composition of surface enamel in primary teeth of diabetic children and its clinical implications. Hundred extracted primary teeth from diabetic children (Test group: n = 50) and healthy children (Control group: n = 50), between 6 and 12 years of age, were subjected to scanning electron microscopy to qualitatively examine the enamel surface. Energy dispersive X-ray (EDX) analysis was performed to investigate the mass percentage of calcium (Ca) and phosphorous (P) in the surface enamel. Ultrastructural aberrations of surface enamel were observed in the test group teeth. Additionally, prism perforations were seen at the junction of rod and inter-rod enamel and the prisms were loosely packed. An even aprismatic layer of surface enamel was evident in the control group teeth. There was a statistically significant difference (p < 0.05) of Ca and P mass percentage between the test and control group teeth. The mean mass percentage rates of Ca and P were 33.75% and 16.76%, respectively. A poor surface characteristic and elemental composition of the enamel surface of primary teeth is observed in diabetic children. Therefore, appropriate caries preventive measures are mandatory to maintain the structural integrity of the tooth in these patients.

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30

Czerwik-Marcinkowska, Joanna, e Bohuslav Uher. "Cyanophytes on limestone rocks in the Szopczański Gorge (Pieniny Mountains) – their ecomorphology and ultrastructure". Acta Societatis Botanicorum Poloniae 80, n. 3 (2011): 205–9. http://dx.doi.org/10.5586/asbp.2011.013.

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This study is devoted to the ecomorphology and ultrastructure of cyanophytes on limestone rocks collected in the Szopczański Gorge (Pieniny Mountains) during the years 2006-2008. There were selected cyanophyte species for examination such as following: Nostoc microscopicum, Phormidium favosum, Leptolyngbya foveolarum, Tolypothrix distorta var. penicillatum, Pseudanabaena catenata. The ultrastructural analysis (TEM) confirmed that the structure and placement of the thylakoids is genus/species specific.

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31

Andrzejewska-Golec, Emilia, Joanna Makowczyńska e Krystyna Marek. "Cream-coloured and green-coloured lines of the nonmorphogenic callus of Plantago asiatica L. - ultrastructure analysis". Acta Societatis Botanicorum Poloniae 74, n. 3 (2011): 187–92. http://dx.doi.org/10.5586/asbp.2005.024.

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The ultrastructure of two lines of nonmorphogenic Plantago asiatica callus was compared. The ultrastructure of most organelles of cream-coloured and green-coloured lines of these callus lines was similar. Among the plastides no difference in prevalence and composition of proplastides and amyloplasts was observed. The main difference lies in the presence of chlororoplasts in green callus. The phenomena of vacuolisation and tracheogenesis in both lines were found.

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32

Dačić, Stefan, Aleksandar Mitić, Jelena Popović, Dragica Simonović Dačić e Marko Igić. "Ultrastructure of adhesive bond of composite to dentin". Acta Facultatis Medicae Naissensis 31, n. 1 (1 marzo 2014): 67–73. http://dx.doi.org/10.2478/afmnai-2014-0007.

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SUMMARY Ultrastructure of adhesive bond is a significant indicator of the efficiency of the bond between material and dental tissue. Bonding between composite and hard dental tissue is also most commonly assessed by measuring bonding strength or by absence of marginal gap along restoration interface. The aim of this investigation was to estimate ultrastructural features of the bond between composite materials and dentin after using two adhesive techniques. Twenty Class V cavities on extracted teeth were prepared and restored for scanning electron microscope (SEM) analysis of composite bonding to dentin. Adhesion was achieved by Adper Single Bond 2-ASB/3M ESPE or by Adper Easy One-AEO/3M ESPE. Photopolymerization of adhesives and composite material Filtek Ultimate FU/3M ESPE was performed using halogen light (Elipar Highlight 3M ESPE). After vertical sections through crown of teeth and composite restorations, surfaces of sections were treated with 37% phosphoric acid-60s and 2% NaOH-60s to remove the smear layer and obtain a better view of adhesive bond. SEM analysis of adhesive bond showed better micromorphological bonding of composite to dentin after etch and rinse adhesive technique (ASB/FU matherials) than after self-etch technique (AEO/FU materials). In etch and rinse technique, the ultrastructure of adhesive bond to dentin was composed of adhesive and hybrid layers, with resin processes in dentinal canals. In self-etch technique, apart from adhesive and hybrid layers, resin processes were rare or were not observed at all. Better ultastructural bonding of composite restoration to dentin was obtained with etch and rinse adhesive technique.

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33

Garcia-Giner, Victoria, Zexiang Han, Finn Giuliani e Alexandra E. Porter. "Nanoscale Imaging and Analysis of Bone Pathologies". Applied Sciences 11, n. 24 (17 dicembre 2021): 12033. http://dx.doi.org/10.3390/app112412033.

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Abstract (sommario):

Understanding the properties of bone is of both fundamental and clinical relevance. The basis of bone’s quality and mechanical resilience lies in its nanoscale building blocks (i.e., mineral, collagen, non-collagenous proteins, and water) and their complex interactions across length scales. Although the structure–mechanical property relationship in healthy bone tissue is relatively well characterized, not much is known about the molecular-level origin of impaired mechanics and higher fracture risks in skeletal disorders such as osteoporosis or Paget’s disease. Alterations in the ultrastructure, chemistry, and nano-/micromechanics of bone tissue in such a diverse group of diseased states have only been briefly explored. Recent research is uncovering the effects of several non-collagenous bone matrix proteins, whose deficiencies or mutations are, to some extent, implicated in bone diseases, on bone matrix quality and mechanics. Herein, we review existing studies on ultrastructural imaging—with a focus on electron microscopy—and chemical, mechanical analysis of pathological bone tissues. The nanometric details offered by these reports, from studying knockout mice models to characterizing exact disease phenotypes, can provide key insights into various bone pathologies and facilitate the development of new treatments.

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34

Overby, Darryl, Jeffrey Ruberti, Haiyan Gong, Thomas F. Freddo e Mark Johnson. "Specific Hydraulic Conductivity of Corneal Stroma as Seen by Quick-Freeze/Deep-Etch". Journal of Biomechanical Engineering 123, n. 2 (1 ottobre 2000): 154–61. http://dx.doi.org/10.1115/1.1351888.

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Previous studies of the hydraulic conductivity of connective tissues have failed to show a correspondence between ultrastructure and specific hydraulic conductivity. We used the technique of quick-freeze/deep-etch to examine the ultrastructure of the corneal stroma and then utilized morphometric studies to compute the specific hydraulic conductivity of the corneal stroma. Our studies demonstrated ultrastructural elements of the extracellular matrix of the corneal stroma that are not seen using conventional electron microscopic techniques. Furthermore, we found that these structures may be responsible for generating the high flow resistance characteristic of connective tissues. From analysis of micrographs corrected for depth-of-field effects, we used Carmen-Kozeny theory to bound a morphometrically determined specific hydraulic conductivity of the corneal stroma between 0.46×10−14 and 10.3×10−14 cm2. These bounds encompass experimentally measured values in the literature of 0.5×10−14 to 2×10−14 cm2. The largest source of uncertainty was due to the depth-of-field estimates that ranged from 15 to 51 nm; a better estimate would substantially reduce the uncertainty of these morphometrically determined values.

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35

Marquez, Gonzalo J., Marta A. Morbelli e Gabriela E. Giudice. "Palynological analysis of Sphaeropteris gardneri (Cyatheaceae, Pteridophyta)". Anais da Academia Brasileira de Ciências 82, n. 2 (giugno 2010): 361–67. http://dx.doi.org/10.1590/s0001-37652010000200012.

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Abstract (sommario):

The spore morphology and wall ultrastructure of Sphaeropteris gardneri (Hook.) R.M. Tryon from Brazil were analyzed with LM, SEM and TEM. The spores are trilete with an ornamentation formed of short low ridges with spines in their margins. The exospore is 2.5μm thick, two- layered in section and single or branched channels are present. The perispore is 1.2μm thick and two-layered. The inner layer has three strata: the inner stratum is formed of a network of branched and fused threads, the middle stratum has threads with a radial orientation and in the outer stratum thin, dark fibres are immersed in a less dense contrasted matrix. The outer layer of the perispore is the one that forms the echinate-ridges and is constituted of threads arranged in a compact way. Globules of different sizes are observed on the surface. The differences found in the perispore ornamentation and ultrastructure in Alsophila, which was previously studied, and those of Sphaeropteris, show a tendency to wall complexity.

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36

Andreevskaya, S. G., N. V. Shevlyagina e J. R. Pseunova. "Morphological Сhanges of S. Aureus Cultivated in the Presence of Antibacterial Drugs". Medicina 8, n. 2 (2020): 31–49. http://dx.doi.org/10.29234/2308-9113-2020-8-2-31-49.

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The search for new methods for identifying the pathogen in biological material, including microscopic, remains relevant. The study of ultrastructural changes of microorganisms as a result of exposure to various groups of antibiotics is important, because the morphology of the bacterial cell varies considerably depending on the conditions of cultivation. The purpose of the study: 1. To identify the nature of changes in the ultrastructure of preserved bacterial cells of S. aureus, cultivated in the presence of antibiotics. 2. To determine the viability of that part of the population of S. aureus, which remained exposed to suppressive concentrations of antibacterial drugs. 3. To determine whether the ultrastructural changes of the reference strain S. aureus ATCC 25923 in the proposed conditions completely reflect the nature of these changes for strains isolated from clinical material. Materials and methods. Three strains of S. aureus isolated from biological material and the reference strain S. aureus ATCC 25923 were used to investigate the S. aureus ultrastructure. The analysis was carried out on the basis of data obtained using scanning electron microscopy (SEM). In the process of sample preparation, the technique of imprinting bacteria from agarized nutrient medium was applied. Results and conclusions. The most common feature for the strains of clinical isolates of S. aureus was the formation of a large number of bacterial cells of a specific disc-shaped form in zones of influence of bacteriostatic antibiotics. In terms of the use of bactericidal drugs, part of the population remained spherical, the other part had irregular contours. Changes in the size of bacterial cells in growth suppression zones were multidirectional. Cultivation of bacteria under conditions of exposure to suppressive concentrations of antibacterial drugs stimulated the production of exocellular matrix. The ultrastructural changes of phenotypic variability of the reference strain S. aureus ATCC 25923 did not fully correspond to changes in the morphology of the bacterial cells of the strains of clinical isolates. The viability of bacteria remaining in the zones of growth suppression has been confirmed in all cases of antibiotic exposure, except gentamicin. Thus, the study revealed the nature of changes in the ultrastructure of S. aureus as manifestations of phenotypic variability of microorganisms in response to the presence of antibacterial drugs with different mechanisms of action.

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37

Ndiaye, Papa Ibnou, Bernard Marchand, Cheikh Tidiane Bâ, Jean-Lou Justine, Rodney Alan Bray e Yann Quilichini. "A comparative study of the ultrastructural characteristics of the mature spermatozoa of two fellodistomids Tergestia clonacantha and T. laticollis and contribution to the phylogenetic knowledge of the Gymnophalloidea". Parasite 27 (2020): 67. http://dx.doi.org/10.1051/parasite/2020066.

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Abstract (sommario):

The ultrastructure of the mature spermatozoa of Tergestia clonacantha and T. laticollis collected from the digestive tracts of fishes from New Caledonia is described using transmission electron microscopy and compared to that of related species. The spermatozoa of the two species exhibit the general pattern described in most digeneans, namely two axonemes with the 9 + “1” pattern of the Trepaxonemata, nucleus, mitochondrion, cortical microtubules, an external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. The spermatozoa of T. clonacantha and T. laticollis show the same ultrastructural model with some specificities in each case, particularly in the disposition of the structures in the posterior extremities of the spermatozoon. This study confirms that ultrastructural characters of the mature spermatozoon are useful tools for the phylogenetic analysis of the Digenea.

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38

Foston, Marcus B., Chistopher A. Hubbell e Art J. Ragauskas. "Cellulose Isolation Methodology for NMR Analysis of Cellulose Ultrastructure". Materials 4, n. 11 (7 novembre 2011): 1985–2002. http://dx.doi.org/10.3390/ma4111985.

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39

Petry, Franz, e J. Robin Harris. "Ultrastructure, fractionation and biochemical analysis of Cryptosporidium parvum sporozoites". International Journal for Parasitology 29, n. 8 (agosto 1999): 1249–60. http://dx.doi.org/10.1016/s0020-7519(99)00080-6.

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40

Lunn, M., e S. Wright. "Analysis of the Ultrastructure of the Canine Zona Pellucida". Microscopy and Microanalysis 12, S02 (31 luglio 2006): 270–71. http://dx.doi.org/10.1017/s1431927606066281.

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41

Kario, K., T. Matsuo e H. Tankawa. "Xanthine urolithiasis: Ultrastructure analysis of renal and bladder calculi". International Urology and Nephrology 23, n. 4 (luglio 1991): 317–23. http://dx.doi.org/10.1007/bf02549601.

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42

Büning, Jürgen, e Sylvia Sohst. "The flea ovary: Ultrastructure and analysis of cell clusters". Tissue and Cell 20, n. 5 (gennaio 1988): 783–95. http://dx.doi.org/10.1016/0040-8166(88)90023-7.

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43

Barroso, P. A. A., L. R. F. M. Paulino, B. R. Silva, G. L. Vasconcelos, D. S. Gomes, M. F. Lima Neto, A. W. B. Silva et al. "Effects of dexamethasone on growth, viability and ultrastructure of bovine secondary follicles cultured in vitro". Zygote 28, n. 6 (27 agosto 2020): 504–10. http://dx.doi.org/10.1017/s0967199420000416.

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Abstract (sommario):

SummaryThis study aimed to evaluate the effects of dexamethasone on development, viability, antrum formation and ultrastructural integrity of bovine secondary follicles cultured in vitro for 18 days. Bovine ovaries were obtained from slaughterhouses and secondary follicles of ~150–200 µm diameter were isolated and cultured in the laboratory in TCM-199+ alone or supplemented with different concentrations of dexamethasone (1, 10, 100 and 1000 ng/ml). Follicle viability was evaluated after the culture period, using calcein-AM (viable) and ethidium homodimer (nonviable). Follicle diameters and antrum formation were evaluated at days 0, 6, 12 and 18. Before or after in vitro culture, follicles were fixed for histological and ultrastructural analysis. Follicle diameters were evaluated using analysis of variance and Kruskal–Wallis test, while chi-squared test was used to evaluate the percentage of viable follicles and antrum formation (P < 0.05). Follicles cultured for 6 days with all treatments increased their diameters significantly, but there was no significant difference between treatments at the end of the culture period. In vitro cultured follicles showed antral cavity formation at the end of the culture period, but no influence of dexamethasone was seen. Ultrastructural analysis showed that follicles cultured with dexamethasone (1, 10, 100 and 1000 ng/ml) had well preserved granulosa cells. However, oocytes from follicles cultured with 10, 100 or 1000 ng/ml dexamethasone showed signs of degeneration. It can be concluded that follicles cultured in vitro in the presence of dexamethasone demonstrated continuous in vitro growth, but oocytes from follicles cultured with 10, 100 or 1000 ng/ml dexamethasone had poor ultrastructure.

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Karakaş, Pınar, Memduha Gülhal Bozkır, Fahri Dere, Enver Melik, Emine Babar Melik, Mehmet Kaya e Sait Polat. "The Effects of Maternal Deprivation on the Hippocampal Structure in Adult Rats". Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 36, n. 03 (maggio 2009): 356–62. http://dx.doi.org/10.1017/s0317167100007113.

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Abstract (sommario):

Objectives:To examine the ultrastructural effects of maternal deprivation during developmental periods of limbi-chypothalamo-pituitary-adrenal system on hippocampal dendritic structures in adult rats.Methods:The experiments were carried out with male and female wistar rats in our department. The rats were mated and, after birth, the pups were divided into four groups. The first group (control group) pups remained undisturbed with their dam until postweaning day 22. Maternal deprived groups were separated from their dams for 24 hours at postnatal day 4, 9 and 18. The subjects were provided with food and water ad libitum until 3-months-of-age. At the third month, the rats were transcardially perfused, samples were taken from CA1 and CA3 regions of the hippocampus. Tissues were prepared for electron microscopy.Results:When the data were analyzed, there were no differences between male and female rats in both ultrastructure and semiquantitative analysis of axodendritic synapses. The ultrastructure of Group 1 was seen as normal while in the second Group some neurons nuclear envelope made deep invagination into the nucleus. Additionally, axodendritic synapses were found normal. In Group 3, micrographs and axodendritic synapses were showed normal structure. However, in Group 4 in some neurons invaginations were seen similar to Group 2. Axodendritic synapses were found to be normal.Conclusion:These experiments establish that MD in rats produces slight ultrastructural changes and decreases the number of synapses in CA1 and CA3 subregions of the hippocampus.

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Wang, Shuo, Yuhong Sun, Lulu Xia, Hanyue Li, Yan Xu e Xianming Hua. "Effects of Twin Inclined Plane Device on Adaptation and Ultrastructure Variations in Condyle of Growing Rats". BioMed Research International 2019 (14 novembre 2019): 1–10. http://dx.doi.org/10.1155/2019/3069347.

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Abstract (sommario):

Objective. This study investigates the effects of using a twin inclined plane device (TIPD) on the remolding and ultrastructure variation of mandibular condyle in growing rats. Materials and Methods. Forty-eight male Wistar rats (six weeks old, body weight of approximately 190–210 g) were divided into experimental group (wearing appliance, n = 32) and control group (no appliance, n = 16). Samples were collected on days 3, 14, 30, and 60. The immunohistochemical analysis for vascular endothelial growth factor (VEGF) and type II collagen was carried out. Tartrate-resistant acid phosphatase (TRAP) reaction was performed to evaluate the osteoclastic activity. Three-dimensional morphometric images were reconstructed for morphometric analysis by microcomputed tomography (micro-CT). The ultrastructure of the condylar surface was observed by scanning electron microscopy (SEM). Results. The expression of VEGF significantly increased, while the expression of type II collagen decreased in the experimental group at days 30 and 60. Furthermore, the enhanced osteoclast activity was observed under the subchondral bone, which was highest at day 30, and decreased to the lowest at day 60 in the experimental group. In addition, adaptive subchondral bone remolding in the posterior part of the condyle was observed at day 60 in the experimental group, and the SEM revealed the ultrastructure variations after installation of the TIPD. However, these changes began to reverse after 30 days. Conclusion. Condylar tissue changes point to the osteoclastic activity in the posterior region of the condyle. These adaptive changes point to bone resorption in the posterior condyle. Type II collagen and VEGF contribute to the MCC remolding induced by the TIPD. The ultrastructural changes in the posterior condylar area in response to mechanical stresses are recoverable at the initial stage.

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Sukkhee, Nutchar, Tappadit Mitparian, Tassaporn Kanjanarakha, Sinlapachai Senarat, Niwat Kangwanrangsan, Gen Kaneko e Jes Kettratad. "Spermatozoon of the wild scalloped perchlet, Ambassis nalua (Hamilton, 1822): Ultrastructure and morphometric analysis". Veterinary Integrative Sciences 20, n. 1 (6 settembre 2021): 199–208. http://dx.doi.org/10.12982/vis.2022.016.

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Abstract (sommario):

The description of sperm morphology is fundamental in the reproductive biology of fishes, but this information is limited in the family Ambassidae. Our report hence focused on the ultrastructure and morphometric analysis of spermatozoa in a pelagic fish Ambassis nalua. All fish (n = 75) were obtained during January and March 2017 from the Estuarine Pranburi River, Thailand. The standard length of fish used in this study was 3.4 ± 0.12 cm (mean ± standard deviation). All specimens were considered mature based on the abundance of spermatozoa in the testis. The testicular organs were collected and observed using standard histology and transmission electron microscopy (TEM). Ultrastructural observation associated with morphometric analysis showed that spermatozoa are structurally long cells of approximately 51.17 ± 4.54 µm total length, composed of a head, a midpiece and a tail. The head had no acrosome, and the granular structure of condensed chromatin was observed within the ovoid nucleus. The midpiece consisted of a short cylindrical region with the length of 1.29 ± 0.87 µm in diameter, having the centriolar complex organization and eight mitochondria (approx. 0.32 ± 0.02 µm each). The uniflagellar tail was clearly identified with a classical 9+2 arrangements of microtubules. Based on these characteristics, the spermatozoon of wild scalloped perchlet are considered as uniflagellate anacrosomal aquqsperm. The morphological features, including the number of mitochondria, may be used for further cryopreservation and in the evolutionary biology of this species.

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van der Walt, Karin, David J. Burritt e Jayanthi Nadarajan. "Impacts of Rapid Desiccation on Oxidative Status, Ultrastructure and Physiological Functions of Syzygium maire (Myrtaceae) Zygotic Embryos in Preparation for Cryopreservation". Plants 11, n. 8 (13 aprile 2022): 1056. http://dx.doi.org/10.3390/plants11081056.

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Abstract (sommario):

Syzygium maire is a highly threatened Myrtaceae tree species endemic to New Zealand. Due to its recalcitrant seed storage behaviour, cryopreservation is the only viable long-term ex situ conservation option for this species. This study investigated viability, oxidative stress, thermal properties, and ultrastructure of zygotic embryo axes (EAs) desiccated to various moisture contents (MC). Fresh EAs had a MC of c. 1.9 g/g with 100% viability but rapid desiccation to MC < 0.3 g/g significantly reduced viability and decreased the activities of the enzymatic antioxidants superoxide dismutase, catalase and glutathione peroxidase, with a sevenfold increase in the production of protein carbonyls and lipid peroxides. Differential Scanning Calorimetry analysis showed no thermal events in EAs desiccated to a MC of <0.2 g/g, indicating that all freezable water had been removed, but this was lethal to both EAs and enzymatic antioxidants. The ultrastructure of desiccated EAs showed signs of plasmolysis, while fully hydrated EAs exposed to cryogenic temperature had ultrastructural disintegration and membrane damage. The decline in enzymatic antioxidant activities and the increase in lipid peroxidation suggest that S. maire EA viability loss is due to oxidative stress rather than structural impacts.

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48

Kessimian, N., B. J. Langner, P. N. McMillan e H. O. Jauregui. "Lectin binding to parietal cells of human gastric mucosa." Journal of Histochemistry & Cytochemistry 34, n. 2 (febbraio 1986): 237–43. http://dx.doi.org/10.1177/34.2.3511142.

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Abstract (sommario):

A light microscopic and ultrastructural analysis of lectin receptors on parietal cells from human gastric mucosa was performed utilizing 12 biotinylated lectins in conjunction with an avidin-biotin-peroxidase complex. Peanut agglutinin conjugated directly to peroxidase was also used. Several fixatives and fixation regimens were evaluated for optimal preservation of parietal cell saccharide moieties. Formalin proved to be the most practical fixative for light microscopic studies. A periodate-lysine-paraformaldehyde (PLP) combination provided good preservation of lectin binding capacity but yielded relatively poor ultrastructure. Conversely, glutaraldehyde provided excellent preservation of ultrastructure but a somewhat diminished lectin binding activity, which was overcome by using long incubation times and high concentrations of reagents. Parietal cells reacted strongly with Bandieraea simplicifolia, Dolichos biflorus, peanut agglutinin, and soybean agglutinin (all specific for galactosyl/galactosaminyl groups) and weakly with Ulex europaeus (specific for fucose). At the light microscopic level a beaded, perinuclear staining pattern was observed which, ultrastructurally, corresponded to an intense staining of intracytoplasmic canaliculi. The membranes of the intracytoplasmic canaliculi were characterized by an abundance of galactosyl residues, a paucity of fucosyl groups, and a lack of mannosyl and glucosyl residues. The biochemical and physiological significance of these findings is discussed.

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Grant, K. W., N. J. Anderson, J. A. Hammarback, A. Sweatt, B. Dawson, P. Moore e W. G. Jerome. "Laser Capture Microscopy as an Aid to Ultrastructural Analysis". Microscopy and Microanalysis 6, S2 (agosto 2000): 842–43. http://dx.doi.org/10.1017/s1431927600036709.

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Laser capture microdissection (LCM) is a technique that provides homogenous cell populations for molecular and light microscopic analysis. During viewing by a standard wide-field microscope, a specific cell is selected. Heat from a near-infrared laser melts an ethylene vinyl acetate (EVA) transparent film which bonds to the individual selected cell. Several thousand cells can be selected and captured using this method. A homogeneous subpopulation of cells may be collected, one at a time, by histologic characteristics and/or histochemical staining from frozen sections, deparaffinized tissue, cell cultures or a blood smear.Previously, this technique has primarily been used to capture cells for DNA or RNA analysis. This study was undertaken to investigate the possibility of capturing a subpopulation of cultured cells in order to study their ultrastructure with the transmission electron microscope (TEM). We report here that cultured cells can be processed, captured and embedded for electron microscopy, in such a manner as to maintain ultrastructure.

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Soran, Maria-Loredana, Ildiko Lung, Ocsana Opriș, Otilia Culicov, Alexandra Ciorîță, Adina Stegarescu, Inga Zinicovscaia et al. "The Effect of TiO2 Nanoparticles on the Composition and Ultrastructure of Wheat". Nanomaterials 11, n. 12 (16 dicembre 2021): 3413. http://dx.doi.org/10.3390/nano11123413.

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The present work aims to follow the influence of TiO2 nanoparticles (TiO2 NPs) on bioactive compounds, the elemental content of wheat, and on wheat leaves’ ultrastructure. Synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and transmission electron microscopy (TEM). The concentration of phenolic compounds, assimilation pigments, antioxidant capacity, elemental content, as well as the ultrastructural changes that may occur in the wheat plants grown in the presence or absence of TiO2 NPs were evaluated. In plants grown in the presence of TiO2 NPs, the amount of assimilating pigments and total polyphenols decreased compared to the control sample, while the antioxidant activity of plants grown in amended soil was higher than those grown in control soil. Following ultrastructural analysis, no significant changes were observed in the leaves of TiO2-treated plants. Application of TiO2 NPs to soil caused a significant reaction of the plant to stress conditions. This was revealed by the increase of antioxidant capacity and the decrease of chlorophyll, total polyphenols, and carotenoids. Besides, the application of TiO2 NPs led to significant positive (K, Zn, Br, and Mo) and negative (Na, Mn, Fe, As, Sr, Sb, and Ba) variation of content.

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