Browsing by Subject "Light microscopy"

Now showing 1 - 7 of 7
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    A quantitative investigation of microvascular changes in the thyroid gland after infrared ,IR, laser radiation
    (Murcia : F. Hernández, 1999) Parrado, C.; Carrillo de Albornoz, F.; Vidal, L.; Perez de Vargas, I.
    We present an ultrastructural study of thyroid capillaries in which 50-day-old rats Wistar rats, were irradiated with an infrared (IR) laser, (total dose, 46.80 ~ / c m ~th)e, tissue quantified 1 day after ending treatment and a quantitative capillary analysis carried out by light and electron microscopy. Light microscopy was used to calculate capillary volume density revealing a significant increase in the irradiated rats. The quantitative measurement of parameters by electron microscopy required a two stage analysis: Level I, Electron Microscopy (Magnification ~ 5 , 0 0 0 ) ;a nd Level 11, Electron Microscopy (Magnification ~26,000)A. t Level I, the following parameters were measured in each capillary: capillary area, capillary diameter, luminal area, luminal diameter, endothelial area, nuclear area and mean endothelial thickness. At Level 11, pinocytotic vesicle diameter and their numerical density in endothelial cells were evaluated. Electron microscopic analysis revealed an increased luminal area in the capillaries of the irradiated rats. They also presented a decrease in endothelial cell thickness and vesicular diameter and an increase in vesicle numerical density. This latter increase is indicative of presumptive changes in capillary permeability, but the possible functional significance of these morphological changes in the endothelial cells requires further investigation.
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    Computer-aided morphometric analysis of the developing concentric structure of the human fetal intestinal tube
    (Murcia : F. Hernández, 2002) Bagyánszki, M.; Kovács, É.G.; Resch, B.A.; Román, V.; Resch, B.E.; Fekete, Eva
    The Image-Pro Plus 3.0 morphometric program was used to study the region-specific organization of the human fetal intestine across the radial axis of the gut at weeks 12 and 18 of gestation. The thicknesses of the epithelium, the submucosa, the muscular layers and the myenteric ganglia were measured in resin-embedded semithin sections. Statistical analysis of the collected data was performed by using the two-way ANOVA, the SNK test and the Pearson correlation. The structural changes relating to the gut morphogenesis within this developmental period were followed both light and electron microscopically. The various tissues forming the radial axis of the intestinal tube exhibited different trends concerning their individual development. The thickness of the epithelium did not change in the fetal period investigated, although the epithelial surface displayed characteristic ultrastructural changes. The thickness of the submucosal layer increased significantly, but with different dynamics along the longitudinal axis, whereas the increases in size of the muscular layers and the myenteric ganglia did not differ significantly along the longitudinal axis of the embryonic intestine. The Pearson correlation revealed a significant correlation between the development of the circular muscle layer and that of the myenteric plexus along the whole length of the intestinal tube. The epithelium, the submucosa and the longitudinal muscle layers developed independently between weeks 12 and 18 of gestation.
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    Detection of anti-mullerian hormone receptor II protein in the postnatal rat testis from birth to sexual maturity
    (Murcia : F. Hernández, 2006) Mendis-Handagama, S.M.L.C.; Di Clementi, N.; Ariyaratne,H.B.S.; Mrkonjich, L.
    Anti-Mullerian hormone (AMH) produced by the immature Sertoli cells negatively regulates the postnatal Leydig cell (i.e. adult Leydig cells/ALC) differentiation, however, the mechanism is sparsely understood. AMH negatively regulates the steroidogenic function of fetal Leydig cells (FLC) and ALC. However, when this function is established in the ALC lineage and whether AMH has a function in FLC in the postnatal testis are not known. Therefore, the objectives of this study were to examine the presence of AMH receptor type II (AMHR-II) in FLC and cells in the ALC lineage in the postnatal mammalian testis using the rat model Male Sprague Dawley rats of days 1, 5, 7-21, 28, 40, 60 and 90 were used. AMHR-II in testicular interstitial cells was detected in testis tissue using immunocytochemistry. Findings showed that the mesenchymal and the progenitor cells of the ALC lineage, were negative for AMHR-II. The newly formed ALC were the first cell type of the ALC lineage to show positive labeling for AMHR-II, and the first detection was on postnatal day 13, although they were present in the testis from day 10. From days 13-28, labeling intensity for AMHR-II in the ALC was much weaker than those at days 40-90. FLC were also positive. The time lag between the first detection of the newly formed ALC in the testis and the first detection of AMHR-II in them suggests that the establishment of the negative regulatory role of AMH on ALC steroidogenesis does not take place immediately upon their differentiation; no change in cell size occurs during this period. The absence of AMHR-II in mesenchymal cells suggests that it is unlikely that the negative regulatory effect of AMH on ALC differentiation in the postnatal testis is achieved via a direct action of AMH on mesenchymal cells. The presence of AMHR-II in postnatal FLC suggests a possible role by AMH on FLC, which warrants future investigations.
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    Effects of N-acetylcysteine on human ovarian tissue preservation undergoing cryopreservation procedure
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Fabbri, Raffaella; Sapone, Andrea; Paolini, Moreno; Vivarelli, Fabio; Franchi, Paola; Lucarini, Marco; Pasquinelli, Gianandrea; Vicenti, Rossella; Macciocca, Maria; Venturoli, Stefano; Canistro, Donatella
    The aim of the study was to evaluate the effects of the antioxidant N-acetylcysteine (NAC), added in freezing/thawing solutions, on reactive oxygen species (RRS) levels and on ovarian tissue preservation after cryopreservation. Ovarian samples from 10 subjects suffering from cancer diseases were cryopreserved using the slow freezing/rapid thawing standard protocol without or with NAC supplementation. RRS levels produced during cryopreservation were monitored by electron paramagnetic resonance (EPR) spectroscopy. The preservation of fresh ovarian tissue (t0), thawed tissue (t1 and t1 NAC) and thawed tissue maintained at 4°C for 2 hrs (t2 and t2 NAC) was analysed by light microscopy, transmission electron microscopy, Ki67 immunohistochemical and TUNEL analysis. It was possible to design a maximum peak for RRS production at t1, which slightly decreased at t2. NAC reduced the extent of RRS levels in cryopreserved ovarian tissues if compared with non-supplemented ones, although not restoring RRS production to baseline values. Comparative analysis between the two cryopreservation protocols showed that a better preservation of morphological characteristics, proliferation index and DNA integrity of ovarian tissue was obtained using NAC and no differences between t1NAC and t2NAC were observed. The employment of NAC during cryopreservation procedure could be anuseful strategy for preserving the function of endogenous cellular systems. Nevertheless, further studies on the viability of thawed ovarian tissue are needed to support the feasibility of this approach in clinical settings.
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    Fine reconstruction of the pancreatic ductular system at the onset of pancreatitis
    (Murcia : F. Hernández, 2002) Endoh, H.; Ashizawa, N.; Niigaki, M.; Hamamoto, N.; Niigaki, Ma.; Kaji, T.; Katsube, T.; Watanabe, M.; Naora, H.; Otani, Hiroki; Kinoshita, Y.
    The three-dimensional structure of the pancreatic ductular system (from the intercalated duct to the intercellular secretory canaliculus) is controversial and unclear. The aim of this study is to reveal the threedimensional structure of the pancreatic ductular sysytem at the onset of pancreatitis. One day following rat pancreatic duct ligation, dilated lumina from the pancreatic ductular system were reconstructed by light microscopic and scanning electron microscopic examination of pancreatic tissue serial sections. The existence of the intra-acinar duct, which is formed only by centroacinar cells and interconnects the adjacent central lumina in an acinus, was demonstrated. The intercellular secretory canaliculi, which are the terminal parts of the pancreatic ductular system, anastomose and end blindly in the intercellular space located between adjacent lateral surfaces of the acinar cells. The intercalated ducts, the intra-acinar ducts, the central lumina, and the intercellular secretory canaliculi are arranged together in a complex connecting and branching system. However, there were no anastomoses found among the central lumina or acini.
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    In search for a gold-standard procedure to count motor neurons in the spinal cord
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Ferrucci, Michela; Lazzeri, Gloria; Flaibani, Marina; Biagioni, Francesca; Cantini, Federica; Madonna, Michele; Bucci, Domenico; Limanaqi, Fiona; Soldani, Paola; Fornai, Francesco
    Counting motor neurons within the spinal cord and brainstem represents a seminal step to comprehend the anatomy and physiology of the final common pathway sourcing from the CNS. Motor neuron loss allows to assess the severity of motor neuron disorders while providing a tool to assess disease modifying effects. Counting motor neurons at first implies gold standard identification methods. In fact, motor neurons may occur within mixed nuclei housing a considerable amount of neurons other than motor neurons. In the present review, we analyse various approaches to count motor neurons emphasizing both the benefits and bias of each protocol. A special emphasis is placed on discussing automated stereology. When automated stereology does not take into account sitespecificity and does not distinguish between heterogeneous neuronal populations, it may confound data making such a procedure a sort of “guide for the perplex”. Thus, if on the one hand automated stereology improves our ability to quantify neuronal populations, it may also hide false positives/negatives in neuronal counts. For instance, classic staining for antigens such as SMI-32, SMN and ChAT, which are routinely considered to be specific for motor neurons, may also occur in other neuronal types of the spinal cord. Even site specificity within Lamina IX may be misleading due to neuronal populations having a size and shape typical of motor neurons. This is the case of spinal border cells, which often surpass the border of Lamina VII and intermingle with motor neurons of Lamina IX. The present article discusses the need to join automated stereology with a dedicated knowledge of each specific neuroanatomical setting.
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    Nephrotoxicity of cypermethrin in rats. Histopathological aspects
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Alalwani, Aisha D.
    Cypermethrin (CYP) is an important type II pyrethroid pesticide widely used to protect crops against pests and insect infestations. However, its toxicity is a risk to both human health and the surrounding environment. The present study was conducted to investigate the nephrotoxic effect and histopathological changes caused by cypermethrin in the kidney tissues of adult wistar rats. In this study, 30 Wistar rats were equally divided into three groups. G1, control animals; G2 and G3 treated with various sub lethal doses of CYP for 30 days as follows: G2, administered low dose (1/100 of LD50) of CYP; G3, administered high dose (1/50 of LD50) of CYP. The damage to different organelles of renal proximal and distal cells was observed using transmission electron microscopy. Histopathological damage in kidney samples was confirmed using morphological and histological measures. The results showed that CYP caused significant histopathological damage to the renal proximal and distal tubules of treated rats. Compared to control samples, CYP caused marked alterations in the dimensions of nucleus, ovoid and filamentous mitochondria of the treated cells. In conclusion, cypermethrin is found to be toxic to mammals. It caused marked ultrastructural damage to the renal proximal and distal tubules of wistar rats and the intensity of nephrotoxicity correlated with the dose of oral administration.