The Ultrastructure of Skeletal Muscle Capillaries of Streptozotocin Diabetic Rats and the Therapeutic Effect of Benfluorex.

Diabetes mellitus is a serious disease worldwide and causes other associated diseases. In this study, we observed the effect of streptozotocin (STZ)-induced diabetes and benfluorex treatment on muscular capillary ultrastructure. Adult male rats were used as the test subjects and each individual was intraperitoneally injected with one dose of STZ (45 mg/kg) to induce diabetes. Doses (50 mg/kg) of benfluorex were given to the subjects with tap water by intragastric gavage application once daily for 21 days. At the end of day 21, muscle tissues were obtained from animals and examined under transmission electron microscopy. From the data obtained with the electron microscope, it was observed that the control group had typical continuous capillary vascular structures in their muscles, while STZ caused disruptive disorder of the muscle cells in the capillary wall of the STZ-diabetic group. Additionally, the thickening of the basement membrane around endothelial cells, loss of mitochondrial crista in the muscle cells, enlarged endothelial cells, and narrowed vessel lumen were observed in the muscle tissue. The findings of our study revealed that STZ-induced diabetes disrupted the vascular structure, while benfluorex partially improved it.

Distribution of spleen connective tissue fibers in diabetic and vitamin C treated diabetic rats.

We investigated the distribution of connective tissue fibers in diabetic and vitamin C treated diabetic rat spleen. Rats were divided into three groups: group A, control; group B, diabetic; group C, vitamin C treated diabetic. Diabetes was induced by streptozotocin. Vitamin C was administered intragastrically for 21 days. Spleen tissues were examined by light microscopy after staining with Masson's trichrome, Gomori silver impregnation and van Gieson. In group B, we found accumulation of collagen fibers in the trabeculae, in the capsule and around the central artery and splenic sinusoids. Splenic cord thickening due to fibrosis was observed. Reticular fibers accumulated principally in the white and red pulps of the spleen and focal reticular fiber thickening was observed in the dense fiber areas. Partial elastic fiber rupture was observed among the fibers of the elastic lamina of the arteries in the hilum. By contrast, the distribution of collagen fibers in group C was similar to group A. Collagen fiber accumulation was decreased in group C compared to group B. We found little reticular fiber thickening in group C and elastic fibers maintained their integrity and were better organized than in group B. Our findings suggest that appropriate doses of vitamin C may exert beneficial effects on the structure of the connective tissue fibers in the diabetic spleen.

Vitamin D and melatonin protect the cell's viability and ameliorate the CCl4 induced cytotoxicity in HepG2 and Hep3B hepatoma cell lines.

Carbon tetrachloride (CCl4) is widely used to induce liver toxicity in in vitro/in vivo models. Lipid peroxidation (LPO) begins with toxicity and affects cell viability. Recently, the beneficial effects of melatonin and Vitamin D on cell proliferation in human normal and cancer cells were found. This study was planned to evaluate antioxidant and cytoprotective activity of melatonin and Vitamin D in CCl4 induced cytotoxicity in HepG2 and Hep3B hepatoma cell lines. Based on the cytotoxicity assay, melatonin and Vitamin D were evaluated for cytotoprotective potential against CCl4 induced toxicity in HepG2 and Hep3B liver cell lines by monitoring cell viability, LPO and glutathione (GSH) level. Different dosages of CCl4 (0.1, 0.2, 0.3 and 0.4 % v/v) were applied to HepG2 and Hep3B cells in order to determine the most toxic dosage of it in a time dependent manner. The same experiments were repeated with exogenously applied melatonin (MEL) and Vitamin D to groups treated with/without CCL4. Cell viability was determined with MTT measurements at the 2nd, 24th and 48th h. GSH content and Malondialdehyde levels were measured from the cell lysates. As a result, both melatonin and Vitamin D administration during CCl4 exposure protected liver cells from CCl4 induced cell damage. Increase in LPO and decrease in GSH were found in the CCl4 groups of both cells. Contrary to these results administration of MEL and Vitamin D on cells exhibited results similar to the control groups. Therefore, melatonin and Vitamin D might be a promising therapeutic agent in several toxic hepatic diseases.

Response of thymus lymphocytes to streptozotocin-induced diabetes and exogenous vitamin C administration in rats.

Diabetes causes oxidative stress, which in turn generates excessive free radicals resulting in cellular damage. Vitamin C is an antioxidant that protects tissues and organs from oxidative stress. The thymus is one of the most important lymphoid organs, which regulates T-lymphocyte proliferation and maturation. The aim of this study is to investigate the protective effects of vitamin C on the thymus of streptozotocin (STZ)-induced diabetic rats. The mitotic activity and cell integrity of thymic lymphocytes were explored. Wistar Albino rats were divided into three groups: control (Group 1), STZ-diabetes (Group 2) and vitamin C-treated STZ-diabetics (Group 3). Rats received a single intraperitoneal injection of 45 mg/kg STZ to induce diabetes. Vitamin C (20 mg/kg) was administered intragastrically. Semithin and ultrathin sections were examined under a light or an electron microscope, respectively. Considerable numbers of mitotic lymphocytes were observed in the thymus of control rats. In the diabetic rats, however, numbers of mitotic lymphocytes decreased to ∼57% of controls, and cell division abnormalities were observed. Additionally, diabetic rats showed degeneration in the structure of the thymus including trabecular thickening, accumulation of lipid vacuoles, heterochromatic nuclei and loss of mitochondrial cristae. Degradation of medullar and cortical integrity was also detected. In the vitamin C-treated STZ-diabetic group, the structure of the thymus and mitotic activity of the lymphocytes were similar to the control group. These results suggest that vitamin C protects the thymus against injury caused by diabetes and restores thymocyte mitotic activity.

Evaluation of patulin toxicity in the thymus of growing male rats.

Patulin is a mycotoxin produced by several Penicillium, Aspergillus, and Byssachlamys species growing on food products. In this study, we investigated the effects of patulin on the thymus of growing male rats aged five to six weeks. The rats were receiving it orally at a dose of 0.1 mg kg-1 bw a day for either 60 or 90 days. At the end of the experiment, the thymus was examined for histopathology by light microscopy and for epidermal growth factor (EGF) and its receptor (EGFR) by immunolocalisation. For morphometry we used the Bs200prop program to analyse images obtained with the Olympus BX51 light microscope. Cell ultrastructure was studied by electron microscopy. In rats treated with patulin, the thymus showed haemorrhage, plasma cell hyperplasia, a dilation and fibrosis in the cortex, enlarged interstitial tissue between the thymic lobules, enlarged fat tissue, thinning of the cortex, and blurring of the cortico-medullary demarcation. Electron microscopy showed signs of cell destruction, abnormalities of the nucleus and organelles, and loss of mitochondrial cristae. However, no differences were observed in thymus EGF and EGFR immunoreactivity between treated and control rats.

Effect of patulin on the interdigitating dendritic cells (IDCs) of rat thymus.

Patulin is a common fungal contaminant of ripe apples used for the production of apple juice concentrates and it is also present in other fruits, vegetables and food products. Patulin is a secondary metabolite produced by species of the genera Penicillium, Aspergillus and Byssochlamys. Patulin has been reported to be mutagenic, carcinogenic and teratogenic. Antigen-presenting cells (APCs) are of prime importance in the innate immune response; they capture antigen in tissues and then migrate to the lymphoid organs to present the antigen to T lymphocytes. Thus, they are crucial for the initiation of immunity. Interdigitating dendritic cells (IDCs) are a subset of APCs that are present at the lymphatic organs. In the thymus, they act in positive and negative selection during T cell development. In the present study, patulin was administered orally to growing male rats aged 5-6 weeks. A dose of 0.1 mg kg(-1) bw day(-1) was given to rats for a period of 60 or 90 days daily. The effect of patulin on the IDCs of thymus was investigated by transmission electron microscopy (TEM), and the results were evaluated in terms of cell destruction. In the rats of the control group, it was observed that the IDCs had an indented nucleus, a clear cytoplasm and numerous membrane extensions. In the cytoplasm, a well-developed golgi complex, mitochondria, granular endoplasmic reticulum and a small number of lysosomal structures were observed. At day 60 of patulin-treated rat groups (P-60), loss of cristae in mitochondria and chromatin margination and lysis in the nucleus were found. It was observed that the IDCs had a perinuclear area of cytoplasm surrounded by a peripheral electron-lucent zone. In the cytoplasm of the 90-day patulin-treated rat group (P-90), a peripheral electron-lucent zone was also found, similar to the P-60 group. Additionally increase in vesicular and lysosomal structures, increase in apoptotic bodies and condensation of chromatin in the nucleus were noted. It was observed that patulin leads to apoptotic body formation and cell apoptosis in the IDCs of rat thymus especially in the P-90-treated groups.

Effects of patulin on thymus capillary of rats.

Patulin is a mycotoxin that is produced by species of Penicillum, Aspergillus, and Byssochylamys molds that may grow on a variety of foods including fruit, grains and cheese. Patulin, at a dose of 0.1 mg kg(-1) bw day(-1) was administered orally to growing male rats aged 5-6 weeks for a period of 60 or 90 days. The dose of patulin used in the present study was based on estimated human exposure levels. At the end of these periods, the thymus glands of patulin-treated and control Wistar rats were removed and ultrastructural changes in capillary cells of the thymus of patulin-treated Wistar rats were determined by electron microscopy. The walls of thymus capillaries of the 60-day patulin-treated rat groups (P-60) exhibited degeneration observable in electron microscopic sections. For example, loss of cytoplasm and mitochondrial cristae of cells, swollen endothelial cells, increased thickness of the basement membrane, closed lumen of capillaries, accumulation of fibrous material at the periphery of the capillaries and nuclear anomalies were seen in these sections. Such degeneration and changes were also observed in sections of capillaries of the 90-day patulin-treated rat groups (P-90). The levels of degeneration of endothelial cell nucleus of P-90 were greater than those of P-60. This study demonstrated the ultrastructural degeneration of thymus capillary cells of patulin-treated rats. The results obtained from this study may provide a guide to research dealing with the toxic effects of patulin on tissue and organ ultrastructure.

Juvenile non-hyaline fibromatosis: juvenile hyaline fibromatosis without prominent hyaline changes.

Juvenile hyaline fibromatosis (JHF) is a rare autosomal recessive disease of the connective tissue. It is characterized by papulonodular skin lesions, soft tissue masses, gingival hypertrophy, osteolytic bone lesions and flexion contractures of the large joints. Here, we report a 14-year-old girl with characteristic clinical features of JHF with early fatal outcome. Dermatopathologic examination of the early lesions however constantly lacked the so-called hyalin changes in multiple skin biopsies. According to our experience; dermatopathological features of this entity is not often and always consists of classical hyalinisation. Only larger lesions with long duration should expected to be exhibiting those features. Therefore we suggest that; JHF may often present itself as Juvenile Non-Hyaline Fibromatosis: JHF without prominent hyaline changes. And thus this fact should not change the actual diagnosis and prognostic implications.

Ultrastructural determination of gingival Langerhans cells in alloxan-induced diabetic rats.

The ultrastructure of Langerhans cells has not been fully investigated in diabetes-associated gingival tissues. The present study was carried out to investigate the ultrastructure of gingival Langerhans cells in alloxan-induced diabetic rats. Gingival biopsies were obtained from 22 diabetic and 18 control rats. Langerhans cells were observed by transmission electron microscopy (TEM) in the basal layers of healthy oral epithelium. On rare occasions, Langerhans cells were found in the suprabasal layers of the oral epithelium. Langerhans cells in the oral epithelium of diabetic rats were seen in the basal and suprabasal layers. Usually, Langerhans cells had clear cytoplasm and convoluted or indented nuclei and few or no specific granules. The clear cytoplasm contained mitochondria, lysosomes and a small number of rough-surfaced endoplasmic reticulum regions, but it lacked tonofilament. Occasionally, centrioles were also observed in the cytoplasm. The membrane of Langerhans cells had no junctional complexes such as desmosomes. In diabetic rats, Langerhans cell precursors were developed into specific granule-bearing cells. Both Langerhans cells and their granules were more frequent in the gingiva of diabetic rats than in the control group. These data suggest that Langerhans cells play an important role in explaining the pathogenesis and development of diabetic gingivitis.

Characterization of the ultrastructure of gingival mast cells in alloxan-induced diabetic rats.

The morphological changes of gingival mast cells of alloxan-induced diabetic rats were studied by electron microscopy. The following observations were made. The cell nucleus and cytoplasm degenerated. The electron density of the granules in the cell cytoplasm clearly decreased. Some granules had dense irregular threads and the granules were surrounded by a thin vacuole. A ghost vacuole formed in some mast cells and disorganized materials accumulated in the cytoplasm. The mast cell nuclei were generally irregular and degenerating mast cells had pyknotic nuclei. General destruction of the cell membrane and granule shedding in some samples was noted and mitochondria with atypical cristae in the cytoplasm of the mast cells were seen. We conclude that the characteristics of the ultrastructure of gingival mast cells in diabetics are distinctive and should be used as criteria for pathogenesis of gingival inflammation.

The investigation of the ultrastructural neutrophil changes in alloxan-induced diabetes in rats: response to a chemotactic challenge.

Experimental diabetes is one of the most popular conditions in which to study the relation between neutrophil leukocyte activity and periodontal destruction. The aetiology of neutrophil dysfunction in the gingival tissue associated with diabetes has yet to be clarified. Diabetes in rats decreases neutrophil chemotactic activity in proportion to the severity of this systemic disorder. The present study was carried out to evaluate the relationship between the severity of diabetes and the neutrophil response to two chemotactic agents, and to correlate the observed neutrophil defects with the degree of diabetes. In this study two chemotactic agents, casein (0.2 microl, 2 mg ml(-1)) or N-formylmethionylleucylphenylalanine (FMLP; 0.2 microl, 10(-4) M), were placed into the gingival crevices of alloxan-induced diabetic rats. Gingival biopsies were taken 15 min later and then at 5-min intervals up to 45 min and investigated by electron microscopy. Adherence and migration were observed in the rats with moderate diabetes 30 min after the application of casein. There was chemotaxis after 35 min of administration of the peptide FMLP. By 40 min neutrophils with pyknotic nuclei were observed. At 45 min neutrophils with a decreased number of granules were present. As the severity of the diabetes increased, the neutrophils degenerated and were structurally distorted. In the rats which had alloxan-induced diabetes there was abnormal periodontal damage. This damage is thought to be related to dysfunctional neutrophils. These findings many contribute to an answer to the following question: why is there an apparent variability in the susceptibility of periodontal breakdown in diabetics?

The ultrastructure of the capillaries in the gingiva of alloxan-induced diabetic rats.

The diabetic effects of alloxan (type I diabetes mellitus) were investigated in 40 Wistar albino rats (18 controls and 22 diabetics). Alloxan in sterile physiological saline was injected into animals intravenously. After the induction of diabetes with alloxan, the ultrastructure of the capillaries in the gingiva was examined by transmission electron microscopy. The thickness of the basement membranes was observed closely adherent to the endothelial cells of the capillary alloxan-diabetic rats. It was greatly thickened owing to the increase in its amorphous, granular and filamentous material with occasional scattered collagen fibres. In some sections, the capillary lumens of the diabetics were closed by epithelial cells. Loss of cytoplasmic material and hyalinization were seen in some smooth muscle cells. In addition, the mitochondrial cristae of smooth muscle cell and epithelial cells disappeared. There was endothelial integrity throughout the smooth muscle cells.

Juvenile colloid milium associated with conjunctival and gingival involvement.

Juvenile colloid milium is an uncommon cutaneous disease characterized by translucent papules distributed on sun-exposed areas with early onset. Association of juvenile colloid milium with conjunctival and gingival deposits is uncommon and interesting. We report a case of juvenile colloid milium associated with conjunctival and gingivai deposits of an amyloid-like homogeneous eosinophilic material. It seems that all 3 of these in our patient may be different expressions of the same pathologic disease.

Effects of chronic alcohol consumption on myocardial ischemia in rats.

The effects of chronic alcohol consumption on myocardial ischemia and gas perfusion with 95% O(2)-5% CO(2) were investigated in isolated rat heart. Eighteen adult male Wistar rats were used. Rats were assigned into six groups for each group to contain three rats: normal, alcoholic, normal ischemic, alcoholic ischemic, normal ischemic and 95% O(2)-5% CO(2) perfused, alcoholic ischemic and 95% O(2)-5% CO(2) perfused, respectively. Alcohol (7.2%, v/v) was given to rats by a modified liquid diet for 21 days. Rats were anaesthetized with ketamine (1-2mg kg(-1)). Hearts were quickly isolated. Normal and alcoholic rat hearts were directly sent to the electron microscopic preparation. The other hearts were cut into small pieces and put into Krebs solution. The solution was continuously bubbled using 95% N(2)-5% CO(2) 20 min for ischemia. After removal of normal ischemic and alcoholic ischemic heart specimens for electron microscopic examination, the remaining hearts of the last two groups were bubbled with 95% O(2)-5% CO(2) for another 20 min for the purpose of reperfusion and then were also prepared for electron microscopic examination. The hearts were investigated with a transmission electron microscope (Jeol 100 CXII TEM). Twenty-one days of chronic alcohol consumption was found to have no significant effect on myocardial ischemia determined by transmission electron microscopic examination. Our results suggest that there is no significant relationship between 21 days of alcohol consumption by a liquid diet and myocardial protection.