Dilated Endoplasmic Reticulum Research Articles

L-ORNITHINE INDUCES ACUTE NECROTIZING PANCREATITIS IN RATS

Introduction: We have recently shown in a pilot study that L-ornithine (L-Orn), a downstream product of L-arginine, causes severe acute pancreatitis in rats. Aim: To determine dose- and time-responses of biochemical and histological parameters of L-Orn-induced pancreatitis. Methods: Male Wistar rats were injected i.p. with 1-6 g/kg L-Orn or 3 g/kg D-ornithine (D-Orn) and sacrificed 0-168 h or 1 month afterwards. Results: 3 g/kg L-Orn significantly increased the serum and ascitic amylase and pancreatic trypsin activities, whereas pancreatic amylase activity was decreased. We observed massive interstitial edema, inflammatory cell infiltration, apoptosis and necrosis of acinar cells. Electron microscopy of pancreatitic tissue revealed large autophagic vacuoles containing zymogen granules, lipid droplets, severe nuclear damage and dilated endoplasmic reticulum in acinar cells. L-Orn induced degradation of IkB proteins (associated with elevated interleukin-1β levels), oxidative stress and heat shock protein 72 expression in pancreas. Administration of 1-2 g/kg L-Orn or 3 g/kg D-Orn did not cause pancreatic damage, whereas 4-6 g/kg L-Orn killed the animals within hours (not due to pancreatitis). Conclusions: We have characterized dose- and time-responses of this new, non-invasive and reproducible model of acute pancreatitis. Supported by OTKA, MTA.

Melatonin and roentgen irradiation‐induced acute radiation enteritis in Albino rats: An animal model

Roentgen irradiation can affect normal cells, especially the rapidly growing ones such as the mucosal epithelial cells of the small intestine. The small intestine is the most radiosensitive gastrointestinal organ and patients receiving radiotherapy directed to the abdomen or pelvis may develop radiation enteritis. Although roentgen rays are widely used for both imaging and therapeutic purposes, our knowledge about the morphological changes associated with radiation enteritis is lacking. This study tries to tests the hypothesis that "the intake of melatonin can minimize the morphological features of cell damage associated with radiation enteritis". We performed this investigation to test our hypothesis and to examine the possible radioprotective effects of melatonin in acute radiation enteritis. To achieve these goals, an animal model consisting of 60 Albino rats was established. The animals were divided into five groups: Group 1, non-irradiated; Group 2, X-ray irradiated (X-ray irradiation, 8 Grays); Group 3, X-ray irradiated-pretreated with solvent (ethanol and phosphate buffered saline); Group 4, non-irradiated-group treated with melatonin, and Group 5, X-ray irradiated-pretreated with melatonin. The small intestines were evaluated for gross (macroscopic), histological, morphometric (light microscopy), and ultrastructural changes (transmission electron microscopy). We found morphological variations among the non-irradiated-group, X-ray irradiated-group and X-ray irradiated-intestines of the animals pretreated with melatonin. The development of acute radiation enteritis in X-ray irradiated-group (Groups 2 and 3) was associated with symptoms of enteritis (diarrhea and abdominal distention) and histological features of mucosal injury (mucosal ulceration, necrosis of the epithelial cells). There was a significant reduction of the morphometric parameters (villous count, villous height, crypt height and villous/crypt height ratio). Moreover, the ultrastructural features of cell damage were evident including: apoptosis, lack of parallel arrangement of the microvilli, loss of the covering glycocalyx, desquamation of the microvilli, vacuolation of the apical parts of the cells, dilatation of the rough endoplasmic reticulum, and damage of the mitochondrial cristae. In the non-irradiated-group and in X-ray irradiated-intestines of the animals pretreated with melatonin (Group 5), these changes were absent and the intestinal mucosal structure was preserved. Administration of melatonin prior to irradiation can protect the intestine against X-rays destructive effects, i.e. radiation enteritis. The clinical applications of these observations await further studies.

A rodent model of NASH with cirrhosis, oval cell proliferation and hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a well recognized complication of advanced NASH (non-alcoholic steatohepatitis). We sought to produce a rat model of NASH, cirrhosis and HCC. Adult Sprague-Dawley rats, weighing 250-300g, were fed a choline-deficient, high trans-fat diet and exposed to DEN in drinking water. After 16 weeks, the animals underwent liver ultrasound (US), sacrifice and assessment by microscopy, immunohistochemistry and transmission electron microscopy (TEM). US revealed steatosis and focal lesions in 6 of 7. All had steatohepatitis defined as inflammation, advanced fibrosis and ballooning with Mallory-Denk bodies (MDB) with frank cirrhosis in 6. Areas of more severe injury were associated with anti-CK19 positive ductular reaction. HCC, present in all, were macro-trabecullar or solid with polyhedral cells with foci of steatosis and ballooned cells. CK19 was positive in single or solid nests of oval cells and in neoplastic hepatocytes. TEM showed ballooning with small droplet fat, dilated endoplasmic reticulum and MDB in non-neoplastic hepatocytes and small droplet steatosis in some cancer cells. This model replicated many features of NASH including steatohepatitis with ballooning, fibrosis, cirrhosis and hepatocellular carcinoma. Oval cell proliferation was evident and the presence anti-CK 19 positivity in the cancer suggests oval cell origin of the malignancy.

Attenuation of Zn-Induced Acute Pancreatitis in Wistar Rat Fed on Cu- and Mg- Enriched Modified Poultry % MathType!Translator!2!1!AMS LaTeX.tdl!TeX -- AMS-LaTeX!% MathType!MTEF!2!1!+-% feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaacbeGaa8xrai% aa-DgacaWFNbWaaWbaaSqabeaaiiqacqGFOoqwaaaaaa!3A49! $$Egg^{\Psi } $$

Zinc (Zn) consumption has increased in many populations either due to the increased intake of Zn-fortified foods as in the USA or in agricultural food stuffs as in some Indian states during the last decade. Its excessive intake has been reported to induce acute pancreatitis (AP) in many studies due to increase in oxidative stress that was further reported to cause Cu and Mg deficiencies. This led us to design a modified poultry egg (ME(Psi)) enriched with Cu and Mg along with other antioxidants, and its efficacy on Zn-induced AP was studied in male Wistar rats. In one set, the rats were fed on equacaloric semi-synthetic basal diet containing 20 mg Zn/kg diet (control, group I), and Zn-induced AP-I diet and AP-II diet containing 40 and 80 mg Zn/kg diet (groups II and III) for 180 days, respectively. In another set, the rats were initially fed on Zn-induced AP-I and AP-II diets for 90 days and then shifted to ME(Psi)-mixed Zn-induced AP-I and AP-II diets in groups IIME and IIIME for another 90 days. At the end of the experiment, data displayed increased serum and urinary Zn, Cu, and Mg levels in groups II and III rats, which were reduced and approached closer to control group I after ME(Psi) feeding in groups IIME and IIIME rats. Transmission electron microscopic studies of acinar cells revealed progressive dilation, vesicularization, and degeneration of endoplasmic reticulum (ER), and decrease in zymogen granules (ZG) in groups II and III rats in contrast to their curvilinear or concentric long parallel running cisternal profile of ER in control group I. The treatment of ME(Psi) helped in the restoration of the ER profile and ZG number, approaching closer to the control group I. The degree of recovery was dependent upon the degree of toxicity caused by the amount of Zn given in the diet. The results of this study suggest that ME(Psi)-mixed diet can protect the acinar cells from the deleterious effects of Zn by decreasing the oxidative stress.

Disruption of the transcription factor recombination signal‐binding protein‐Jκ (RBP‐J) leads to veno‐occlusive disease and interfered liver regeneration in mice†

Liver sinusoid (LS) endothelial cells (LSECs) support hepatocytes in resting livers and proliferate during liver regeneration to revascularize regenerated liver parenchyma. We report that recombination signal-binding protein-Jkappa (RBP-J), the critical transcription factor mediating Notch signaling, regulates both resting and regenerating LSECs. Conditional deletion of RBP-J resulted in LSEC proliferation and a veno-occlusive disease-like phenotype in the liver, as manifested by liver congestion, deposition of fibrin-like materials in LSs, edema in the space of Disse, and increased apoptosis of hepatocytes. Regeneration of liver was remarkably impaired, with reduced LSEC proliferation and destroyed sinusoidal structure. LSEC degeneration was obvious in the regenerating liver of RBP-J-deficient mice, with some LSECs losing cytoplasm, and organelles protruding into the remnant plasma-membrane of LSs to hamper the microcirculation and intensify veno-occlusive disease during liver regeneration. Hepatocytes were also degenerative, as shown by dilated endoplasmic reticulum, decreased proliferation, and increased apoptosis during liver regeneration. Molecular analyses revealed that the dynamic expression of several related molecules-such as vascular endothelial growth factor, vascular endothelial growth factor receptors 1 and 2, interleukin-6, and hepatocyte growth factor-was disturbed. Notch/RBP-J signaling may play dual roles in LSECs: in resting liver it represses proliferation, and in regenerating liver it supports proliferation and functional differentiation.

Alteration in ultrastructural morphology of bovine embryos following subzonal microinjection of bovine viral diarrhea virus (BVDV)

The aim of the present study was to evaluate the development and ultrastructure of preimplantation bovine embryos that were exposed to bovine viral diarrhea virus (BVDV) in vitro. The embryos were recovered from superovulated and fertilized Holstein-Friesian donor cows on day 6 of the estrous cycle. Compact morulae were microinjected with 20 pl of BVDV suspension (10(5.16) TCID(50)/ml viral stock diluted 1:4) under the zona pellucida (ZP), then washed in SOF medium and cultured for 24-48 h. Embryos were evaluated for developmental stages and then processed immunocytochemically for the presence of viral particles, using fluorescent anti-BVDV-FITC conjugate. Ultrastructure of cellular organelles was analysed by transmission electron microscopy (TEM).After microinjection of BVDV under the ZP, significantly more (p<0.001) embryos (83.33%) were arrested at the morula stage compared with the intact control (30.33%). Immunocytochemical analysis localized the BVDV-FITC signal inside the microinjected embryos. TEM revealed: (i) the presence of virus-like particles in the dilated endoplasmic reticulum and in cytoplasmic vacuoles of the trophoblast and embryoblast cells; (ii) the loss of microarchitecture: and (iii) abnormal disintegrated nuclei, which lacked reticular structure and the heterochromatin area. In all, the embryo nuclear structure was altered and the microarchitecture of the nucleolus had disappeared when compared with the nuclei from control embryos. Dilatation of the intercellular space and the loss of the intercellular gap junctions were often observed in bovine BVDV-exposed embryos. These findings provide evidence for the adverse effect of BVDV virus on the development of bovine embryos, which is related to irreversible changes in the ultrastructure of cell organelles.

Ultrastructural changes in rat thyroid tissue after acute organophosphate poisoning and effects of antidotal therapy with atropine and pralidoxime: A single-blind, ex vivo study

Background: Organophosphate (OP) insecticides are widely used in both agricultural and landscape pest control, and the potential for human exposure to these compounds is significant. Objectives: The aims of this study were to investigate the effects of acute poisoning with the OP methamidophos and the effects of antidotal therapy with atropine and pralidoxime on rat thyroid tissue ultrastructure. Methods: In this single-blind, ex vivo study, male Wistar albino rats weighing 220 to 230 g were divided into 4 treatment groups. Group 1 received a median lethal dose of methamidophos (30 mg/kg) via oral gavage. Group 2 received saline via oral gavage and served as the control group for group 1. Group 3 received methamidophos (30 mg/kg) via oral gavage, and after 8 minutes atropine 0.05 mg/kg and pralidoxime chloride (2-FAM) (40 mg/kg) were administered intraperitoneally (IP). Atropine was titrated to reverse signs of cholinergic excess. Group 4 received saline via oral gavage followed by IP injections and served as the control for group 3. Rat thyroid tissues were examined using electron microscopy, and the histologic changes were examined by a histopathologist who was blinded to treatment. All rats were euthanized by intracardiac blood collection. The rats in groups 1 and 2 were euthanized 8 minutes after treatment. The rats in groups 3 and 4 were euthanized 96 hours after treatment. Results: Thirty-four male rats (aged 16 weeks) were included in the study. The rats were grouped accordingly: group 1 (n = 10); group 2 (n = 7); group 3 (n = 10); and group 4 (n = 7). The mean (SD) pseudocholinesterase (FCE) activity was significantly lower in the methamidophos-treated rats (group 1) compared with the corresponding control group (group 2) (32.6 [17.0] vs 579.4 [59.0] U/L, respectively; P < 0.001). PCE activity was significantly higher in rats treated with atropine and 2-PAM (group 3) (392.5 [39.4] U/L; P < 0.001) compared with those not receiving antidotal therapy (group 1). Group 1 experienced changes in thyrocytes and organelles that were not detected in the antidote-treated rats in group 3. These changes included follicular cell nuclei exhibiting an increase in chromatin content, pyknotic nuclei, mitochondrial degeneration, dilated granular endoplasmic reticulum cisternae, reduced microvilli, and intraluminal cellular debris. Within follicular cells, formation of vacuoles filled with fine granular material was noted. Conclusion: Acute OP poisoning was associated with histopathologic effects in rat thyroid tissue that appeared to be mitigated by antidotal therapy in this small animal study. More extensive studies using immunohistochemical methods are needed.

Dichlorvos-induced hepatotoxicity in rats and the protective effects of vitamins C and E

Dichlorvos is an organophosphate insecticide that is widely used in pest control. Vitamin C (200 mg/kg) + vitamin E (200 mg/kg), dichlorvos (1.6 mg/kg), or a combination of vitamin C (200 mg/kg) + vitamin E (200 mg/kg) + dichlorvos (1.6 mg/kg) was given to rats via oral gavage for 7 weeks. When rats of the dichlorvos-treated group and the vitamins + dichlorvos-treated group were compared with the control group, body weights were decreased and liver weights were increased significantly at the end of the 4th and 7th week. Serum total protein, albumin, triglyceride, low density lipoprotein-cholesterol (VLDL-cholesterol) levels were decreased, and serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl-transferase (GGT), lactate dehydrogenase (LDH), and total cholesterol levels were increased significantly at the end of the 4th and 7th week in the dichlorvos- and vitamins + dichlorvos-treated rats. There was a statistically significant difference for all biochemical parameters when the vitamins + dichlorvos-treated group was compared with the dichlorvos-treated group at the end of the 4th and 7th week. In an electron microscopic investigation, swelling of mitochondria and dilatation of endoplasmic reticulum were observed in liver cells of the dichlorvos- and vitamins + dichlorvos-treated rats at the end of the 4th and 7th week. As a result, vitamins C and E reduced dichlorvos hepatotoxicity, but vitamins C and E did not confer complete protection.

Histology and ultrastructure of Aedes albopictus larval midgut infected with Bacillus thuringiensis var. israelensis

Histological and ultrastrucutural alterations in the midgut of Aedes albopictus larvae infected with Bacillus thuringiensis var. israelensis (Bti) were observed by light and transmission electron microscopy (TEM). Two formulations of Bti were used: granulated and powder, with 0.2% active ingredient in 90 larvae of Ae. albopictus distributed in three containers containing 30 larvae each (one control group and two test groups). The midgut epithelium of the control group presented flattened and elongated cells with mace-shape with a narrow base. Midgut epithelium cells' surface was convex and had a large circular nucleus located in the median-apical portion of the cell. These cells also presented a basal lamina with a small accumulation of extracellular fibrous matrix, thus characterizing a basal membrane, with a muscle layer and a peritoneal membrane more externally. After Bti ingestion, the larvae stopped/slowed their natural movements down in 5 min. After 30 min approximately, the swimming movements stopped completely. Internally, the intestinal cells showed a disorganization of the basal processes, dilatation and fragmentation of the rough endoplasmic reticulum, with intense cytoplasmic vacuolization. There were concentric dense laminas accumulated in the cytoplasm, and these residual membranous bodies were seen greatly increased in size after 60 min. Mitochondria, fragments of rough endoplasmic reticulum and other remainder organelles were surrounded and segregated from the cytoplasm by exocytosis. This article reports the histopathological alterations in the midgut of Ae. albopictus after infection with Bti and contributes to a better understanding of the mode of action of this bacterial strain used as bioinsecticide against mosquito larvae.

Ethanol-related increases in degenerating bodies in the Purkinje neuron dendrites of aging rats

Chronic ethanol consumption in aging rats results in regression of Purkinje neuron (PN) dendritic arbors ([Pentney, 1995 Measurements of dendritic pathlengths provide evidence that ethanol-induced lengthening of terminal dendritic segments may result from dendritic regression. Alcohol Alcohol. 30, 87–96]), loss of synapses (Dlugos and Pentney, 1997), dilation of the smooth endoplasmic reticulum (SER), and the formation of degenerating bodies within PN dendrites ([Dlugos, C.A., 2006a. Ethanol-Related Smooth Endoplasmic Reticulum Dilation in Purkinje Dendrites of Aging Rats. Alcohol., Clin. Exp. Res. 30, 883–891,Dlugos, C.A., 2006b. Smooth endoplasmic reticulum dilation and degeneration in Purkinje neuron dendrites of aging ethanol-fed female rats. Cerebellum. 5, 155–162]). Dilation of the SER and the formation of degenerating bodies may be a predictor of dendritic regression. Ethanol-induced effects on mitochondria may be involved as mitochondria cooperate with the SER to maintain calcium homeostasis. The purpose of this study was to determine whether degenerating body number and mitochondrial density and structure are altered by chronic ethanol treatment in PN dendrites. Male, Fischer 344 rats, 12 months of age, were fed an ethanol or pair-fed liquid diet, or rat chow for a period of 10, 20, or 40 weeks (15 rats/treatment; 45 rats/treatment duration). Ethanol-fed rats received 35% of their calories as ethanol. At the end of treatment, all animals were euthanized, perfused, and tissue prepared for electron microscopy. The densities of degenerating bodies and mitochondria, mitochondrial areas, and the distance between the SER and the mitochondria were measured. Results showed that there was an ethanol-related increase in degenerating bodies compared to controls at 40 weeks. Ethanol-induced alterations to mitochondria were absent. Correlation of the present results with those of previous studies suggest that degenerating bodies may be formed from membrane reabsorption during dendritic regression or from degenerating SER whose function has been compromised by dilation.

Cellular changes in the prostatic stroma of glucocorticoid-treated rats

Glucocorticoid hormones (GCs) have been widely used for the treatment of prostate cancer because of their inhibitory property against tumour growth. However, their mechanism of action in the prostate has received little attention. Excess GCs can lead to peripheral insulin resistance resulting in hyperglycaemia and hyperinsulinaemia. Insulin plays an important role as a cellular stimulant and high levels are related to low levels of androgens. Our objective has been to describe the effects of insulin resistance induced by dexamethasone treatment on the morphology of rat ventral prostate. Male adult Wistar rats received daily intraperitoneal injections of dexamethasone or saline for five consecutive days after which the rats were killed and the ventral prostate was removed, weighed and prepared for conventional and transmission electron microscopy (TEM). Dexamethasone treatment resulted in atrophy and decreased proliferative activity of prostatic epithelial cells. TEM analysis revealed changes in the epithelium-stroma interface, with some interruptions in the basement membrane. Fibroblasts showed a secretory phenotype with dilated endoplasmic reticulum. Smooth muscle cells exhibited a contractile pattern with 50% atrophy, an irregular membrane and twisted nuclei. Mitochondrial alterations, such as enlarged size and high electron density in the mitochondrial matrix, were also detected in smooth muscle cells. Insulin resistance induced by dexamethasone is thus associated with epithelial atrophy similar to that described for diabetic rats. However, GCs are responsible for morphological changes in the stromal cell population suggesting the activation of fibroblasts and atrophy of the smooth muscle cells.

Secretion of collagen I and tenascin is modulated by laminin‐111 in 3D culture of human adenoid cystic carcinoma cells

Adenoid cystic carcinoma is a frequent malignant salivary gland neoplasm with high levels of recurrence and metastasis. This neoplasm expresses prominent extracellular matrix (ECM). We are studying regulatory mechanisms underlying secretion of ECM molecules in adenoid cystic carcinoma. We have previously demonstrated that laminin modulates the phenotype of a human adenoid cystic carcinoma (CAC2) cell line. Thus, this molecule would be a good candidate to regulate secretion of ECM molecules in these cells. Here we analysed the role played by laminin-111 [formerly laminin-1; Aumailley et al. (2005). Matrix Biol. 24, 326] stimulating secretory activity of CAC2 cells. Three-dimensional cultures of cells in laminin-111 (treated) or agarose (controls) were studied by light and electron microscopy. Ultrastructural analysis of CAC2 cells grown within laminin-111 showed pseudocysts filled with secretory-like material. Cells exhibited prominent and dilated endoplasmic reticulum and coated and uncoated vesicles. Ultrastructural findings suggested that laminin-111 induced secretory activity in CAC2 cells. We further investigated this point by light microscopy, immunofluorescence and confocal microscopy. Histochemistry showed periodic acid-Schiff (PAS)-positive diastase-resistant material in CAC2 cells treated by laminin-111. This material could represent laminin-induced secretion of ECM molecules. We searched for collagen I and tenascin in CAC2 cells treated by laminin-111. Confocal microscopy and immunoblot showed that laminin-111 enhanced secretion of collagen I and tenascin in CAC2 cells. We suggest that laminin-111 modulates secretion of collagen I and tenascin in cells derived from human adenoid cystic carcinoma.

Protective effects of Terminalia arjuna against Doxorubicin-induced cardiotoxicity

Terminalia arjuna has been marked as a potential cardioprotective agent since vedic period. The present study was aimed to investigate the effects of butanolic fraction of Terminalia arjuna bark (TA-05) on Doxorubicin (Dox)-induced cardiotoxicity. Male wistar rats were used as in vivo model for the study. TA-05 was administered orally to Wistar rats at different doses (0.42 mg/kg, 0.85 mg/kg, 1.7 mg/kg, 3.4 mg/kg and 6.8 mg/kg) for 6 days/week for 4 weeks. Thereafter, all the animals except saline and TA-05-treated controls were administered 20 mg/kg Dox intraperitonially. There was a significant decrease in myocardial superoxide dismutase (38.94%) and reduced glutathione (23.84%) in animals treated with Dox. Concurrently marked increase in serum creatine kinase-MB (CKMB) activity (48.11%) as well as increase in extent of lipid peroxidation (2.55-fold) was reported. Co-treatment of TA-05 and Dox resulted in an increase in the cardiac antioxidant enzymes, decrease in serum CKMB levels and reduction in lipid peroxidation as compared to Dox-treated animals. Electron microscopic studies in Dox-treated animals revealed mitochondrial swelling, Z-band disarray, focal dilatation of smooth endoplasmic reticulum (SER) and lipid inclusions, whereas the concurrent administration of TA-05 led to a lesser degree of Dox-induced histological alterations. These findings suggest that butanolic fraction of Terminalia arjuna bark has protective effects against Dox-induced cardiotoxicity and may have potential as a cardioprotective agent.

Respiratory Toxicologic Pathology of Inhaled Diacetyl in Sprague-Dawley Rats

Inhalation of butter flavoring vapors by food manufacturing workers causes an emerging lung disease clinically resembling bronchiolitis obliterans. Diacetyl, an alpha-diketone, is a major component of these vapors. In rats, we investigated the toxicity of inhaled diacetyl at concentrations of up to 365 ppm (time weighted average), either as six-hour continuous exposures or as four brief, intense exposures over six hours. A separate group inhaled a single pulse of ~1800 ppm diacetyl (92.9 ppm six-hour average). Rats were necropsied 18 to 20 hours after exposure. Diacetyl inhalation caused epithelial necrosis and suppurative to fibrinosuppurative inflammation in the nose, larynx, trachea, and bronchi. Bronchi were affected at diacetyl concentrations of 294.6 ppm or greater; the trachea and larynx were affected at diacetyl concentrations of 224 ppm or greater. Both pulsed and continuous exposure patterns caused epithelial injury. The nose had the greatest sensitivity to diacetyl. Ultrastructural changes in the tracheal epithelium included whorling and dilation of the rough endoplasmic reticulum, chromatin clumping beneath the nuclear membrane, vacuolation, increased inter-cellular space and foci of denuded basement membrane. Edema and hemorrhage extended into the lamina propria. These findings are consistent with the conclusion that inhaled diacetyl is a respiratory hazard.

Large Cell Variant Ovarian Small Cell Carcinoma: Case Report

Ultrastructural data about large cell variant ovarian small cell carcinoma (LCV-SCC) are scarce and contradictory and the role of transmission electronmicroscopy (TEM) is not clear in the assessment of such tumors. The authors present a case of LCV-SCC without hypercalcemia in a 30-year-old woman. The diagnosis was confirmed by histopathological and immunohistochemical studies. Cytopathological examination of peritoneal washing showed a population of large neoplastic cells. TEM demonstrated that the neoplasia comprised two types of cells: one type showed many coarse secretory granules without dense core, and the other type was without granules and showed dilated endoplasmic reticulum and sometimes indented nuclei. The present case indicates that different underlying ultrastructural patterns, not yet well known, exist in connection with the pathological and clinical behaviour of LCV-SCC. TEM might play a role in the identification of subtypes of LCV-SCC with different prognostic and therapeutic impact.

Autophagy as an ultrastructural marker of heavy metal toxicity in human cord blood hematopoietic stem cells

Stem cells are a key target of environmental toxicants, but little is known about their toxicological responses. We aimed at developing an in-vitro model based on adult human stem cells to identify biomarkers of heavy metal exposure. To this end we investigated the responses of human CD34+ hematopoietic progenitor cells to hexavalent chromium (Cr[VI]) and cadmium (Cd). Parallel cultures of CD34+ cells isolated from umbilical cord blood were exposed for 48 h to 0.1 μM and 10 μM Cr(VI) or Cd. Cultures treated with 10 μM Cr(VI) or Cd showed marked cell loss. Ultrastructural analysis of surviving cells revealed prominent autophagosomes/autophagolysosomes, which is diagnostic of autophagy, associated with mitochondrial damage and replication, dilatation of the rough endoplasmic reticulum and Golgi complex, cytoplasmic lipid droplets and chromatin condensation. Treated cells did not show the morphologic hallmarks of apoptosis. Treatment with 0.1 μM Cr(VI) or Cd did not result in cell loss, but at the ultrastructural level cells showed dilated endoplasmic reticulum and evidence of mitochondrial damage. We conclude that autophagy is implicated in the response of human hematopoietic stem cells to toxic concentrations of Cr(VI) and Cd. Autophagy, which mediates cell survival and death under stress, deserves further evaluation to be established as biomarker of metal exposure.

Identification of SVIP as an Endogenous Inhibitor of Endoplasmic Reticulum-associated Degradation

Misfolded proteins in the endoplasmic reticulum (ER) are eliminated by a process known as ER-associated degradation (ERAD), which starts with misfolded protein recognition, followed by ubiquitination, retrotranslocation to the cytosol, deglycosylation, and targeting to the proteasome for degradation. Actions of multisubunit protein machineries in the ER membrane integrate these steps. We hypothesized that regulation of the multisubunit machinery assembly is a mechanism by which ERAD activity is regulated. To test this hypothesis, we investigated the potential regulatory role of the small p97/VCP-interacting protein (SVIP) on the formation of the ERAD machinery that includes ubiquitin ligase gp78, AAA ATPase p97/VCP, and the putative channel Derlin1. We found that SVIP is anchored to microsomal membrane via myristoylation and co-fractionated with gp78, Derlin1, p97/VCP, and calnexin to the ER. Like gp78, SVIP also physically interacts with p97/VCP and Derlin1. Overexpression of SVIP blocks unassembled CD3delta from association with gp78 and p97/VCP, which is accompanied by decreases in CD3delta ubiquitination and degradation. Silencing SVIP expression markedly enhances the formation of gp78-p97/VCP-Derlin1 complex, which correlates with increased degradation of CD3delta and misfolded Z variant of alpha-1-antitrypsin, established substrates of gp78. These results suggest that SVIP is an endogenous inhibitor of ERAD that acts through regulating the assembly of the gp78-p97/VCP-Derlin1 complex.

Histopathological and Biochemical Toxic Effect of Amiodarone on Thyroid Gland in Albino Rat

Backgrounds: Amiodarone AMD (Cordarone) was a benzofuran derivative, used in management of angina and refractory ventricular arrhythmia. Its effect on the thyroid gland structure and function was investigated in this study. Material and Methods: Fifty adult male albino rats were used and divided into three groups. The first group was consisted of 10 rats which served as control, received distilled water orally (1ml). The second group was consisted of 20 rats used as therapeutic dose treated group, received 40 mg/Kg b. w. of amiodarone while the third group was consisted of 20 rats used as a toxic dose treated group which received 60 mg/Kg b. w. of amiodarone orally daily for three months. Body weight of animals was determined. Serum concentration of tri-iodothyonine (T3), thyroxine (T4), thyrotrophin (TSH), interleukin 6 (IL6), tumour marker P53 and tissue residue for amiodarone in plasma, fat, liver, lung, thyroid gland and heart was determined. Results: Specimens from thyroid gland were taken and prepared for light and electron microscope examination. Highly significant decrease in body weight (P<0.001) were observed in both therapeutic and toxic doses treated groups in comparison to the control one. A very highly significant increase (P<0.001) of serum (T4 & T3) with Concomitant suppression of (TSH) (P<0.001). Serum levels of IL6 and P53 showed also a very highly significant increase (P<0.001). Amiodarone concentration in plasma, fat, liver, lung, thyroid gland and heart showed significant increase in therapeutic dose treated group and highly significant increase in toxic dose treated group. Histopathological examination of thyroid gland of therapeutic dose treated group by light microscope showed marked evidence of thyotoxicosis in the form of microcystic follicular changes and peripheral scalloping, cellular degeneration with scanty cytoplasm and vesicular nuclei appeared. These changes became more severe in toxic dose treated group in the form of epithelial hyperplasia with atypical nuclear features. Thyroid tissue damage with haemorrhage and necrosis. Electron microscopic examination showed a remarkable cellular changes in the form of dilated rouph endoplasmic reticulum, inclusion lysosomes, dilated Golgi bodies, mitochondrial distension and nuclear degeneration. In both treated groups these changes were dose related.

Identification of a Transcription Factor, BHLHB8, Involved in Mouse Seminal Vesicle Epithelium Differentiation and Function1

The seminal vesicle is a male accessory sex organ that develops from segments of the Wolffian duct adjacent to the urogenital sinus. It produces most of the seminal plasma in both humans and rodents. To date, very few transcription factors have been linked to the development and differentiation of seminal vesicles. In this study, we have examined the role of basic helix-loop-helix (BHLH) B8 transcription factor expressed at high levels in the adult seminal vesicle and during seminal gland differentiation. Immunofluorescent studies indicate that BHLHB8 is expressed within the epithelial layer of the seminal layer of the seminal vesicle following branching morphogenesis but prior to full maturation of cell morphology and function. Analysis of mice that do not express BHLHB8 (Bhlhb8(-/-)) indicates no deficiency in the initial development of the seminal vesicle. However, morphological and ultrastructural analysis indicates disruption of the epithelial cellular architecture. The seminal vesicle epithelial layer of 2-mo-old Bhlhb8(-/-) mice shows extensive cellular degeneration based on the appearance of reduced microvilli, altered granule size, and dilated endoplasmic reticulum and Golgi apparatus. The seminal vesicle epithelial cells also degenerate prematurely, as evidenced by disruption of nuclear architecture and significant accumulations of autophagic bodies. These results identify BHLHB8 as a regulator in establishing and stabilizing the secreting epithelial cells of the seminal vesicle.

Female reproductive toxicology of cadmium

The aim of this study was to determine effects of Cd on the structure of ovary, oviduct and uterus after an experimental administration. Animals were divided into three groups. In group A rabbits received cadmium i.p. and were killed after 48 h. In group C Cd was administered p.o. for 5 month. The group K was the control. Decreased relative volume of growing follicles and increased stroma after Cd administration were detected. The number of atretic follicles was significantly higher after administration of Cd. The most frequent ultrastructural alterations observed were undulation of external nuclear membrane, dilatation of perinuclear cistern and endoplasmic reticulum. In all studied types of cells mitochondria with altered structure were found. In the oviduct the highest amount of epithelium in the group with long-term Cd administration was found. Microscopic analysis showed oedematization of the oviduct tissue, caused by disintegration of the capillary wall. An electron microscopic analysis showed dilatation of perinuclear cistern. The intercellular spaces were enlarged and junctions between cells were affected. Mainly after a long-term cadmium administration nuclear chromatin disintegration was present. In the uterus a significant change was determined in the relative volume of glandular epithelium. Increase of stroma was a sign of uterus oedamatization caused by damage in the wall of blood vessels and subsequent diapedesis. After Cd administration alteration in uterus were less expressed, in comparison with ovary and oviduct. Alteration of nuclear chromatin contain following Cd administration suggests degenerative functional changes.