Structure and immunohistochemistry of the human lenticulostriate arteries.

BACKGROUND: Data about the structure and immunohistochemistry of the lenticulostriate arteries (LSAs), although very important for medical research and clinical practice, have been rarely reported in literature. MATERIALS AND METHODS: Fourty serially sectioned LSAs were stained with hematoxilin and eosin, and prepared for immunohistochemistry. RESULTS: Our examination revealed a typical endothelial lining and a narrow subendothelial space with subintimal smooth muscle cells occasionally. The internal elastic lamina was fragmented or absent in the smallest LSAs branches. The mediacoat, with a mean diameter of 148.5 µm, contained typical smooth muscle cells which formed 14.2 layers on average and showed a positive immune reactions for alfa-actin, desmine, laminin and collagen IV. The thin adventitial coat contained fibroblasts, collagen fibers, and nerve bundles, with the strongest immunopositivity to thyrosin hydroxilase. The immune reactions against CD31 and CD34 proteins,endothelial nitric oxide synthase, S 100 protein, neurofilament protein and synaptophysin,seem to be performed in the LSAs wall for the first time. Similarly,the thickness of the LSAs wall and its coats have never been reported, nor the number of the smooth muscle cell layers. CONCLUSIONS: Our results related to the structure and immunohistochemistry of the LSAs could be important in cerebrovascular pathology, neurology and neurosurgery.

Glucose-dependent insulinotropic polypeptide-producing K cells in dexamethasone-treated rats.

Some studies indicate that diabetes mellitus exerts an influence on the gastrointestinal tract and its diffuse neuroendocrine system (DNES) in regard to cellular density and neuroendocrine content. Since there is no data about relationship between experimentally induced non-insulin-dependent (type 2) diabetes mellitus (NIDDM) on the gut K cells, the aim of our study was to investigate immunohistochemical, stereological and ultrastructural changes of rat K cells after 12 days of dexamethasone treatment. Twenty male Wistar rats aged 30 days were given daily intraperitoneally 2 mg kg(-1) dexamethasone (group DEX, 10 rats) or saline (group C, 10 rats) for 12 days. Tissue specimens were obtained from each antrum with corpus and different parts of the small (SI) and large intestine (LI) of all animals. Immunohistochemistry was carried out using antisera against the GIP and insulin. Transmission electron microscopy was also used. Although, according to the literature data, rat K cells are present in the duodenum and jejunum and, to a lesser extent, in the ileum, in the present study we observed that those cells were abundant also in all parts of the LI. We observed generally that GIP-producing K cells were augmented in all parts of SI and decreased in the LI of DEX rats. Insulin immunoreactivity (ir) coexpressed with GIP-ir in K cells and was stronger in the SI of DEX rats as compared with C rats. We also found by electron microscopy that small intestinal K cells have features not only of GIP-secreted but also of insulin-secreted cells. We concluded that dexamethasone treatment caused proliferation of K cells in the rat SI, and simultaneously transformation of GIP-producing K cells to insulin-synthesizing cells.

Expression of heat shock protein 70 (HSP70) in patients with colorectal adenocarcinoma--immunohistochemistry and Western blot analysis.

The role of heat shock protein 70 (HSP70) expression has been investigated in various types of tumors. There are only little and controversial data about its clinical relevance in colorectal carcinoma, one of the most common carcinomas observed in humans. In this study we investigated expression of HSP70 in human colonic carcinoma and possible correlation with clinicopathology. To assess patterns (cytosolic and membrane) of HSP70 expression, the 48 surgically removed colorectal adenocarcinomas and 12 normal colonic and rectal mucosal samples were examined by immunohistochemistry and Western-blot. According to results of immunohistochemistry, expression of cytoplasmic HSP72 was significantly higher in colorectal carcinoma compared with normal and adjacent mucosa (p<0.01). In addition, there was significant increase in HSP72 expression in lymph node-positive compared to node-negative group (p<0.001). Dukes C2 stage of colonic cancer showed significantly higher immunohistochemical score than Dukes B2 and B1 stage groups (p< 0.05 i.e. p< 0.02). There was no relation between expression of HSP72 and degree of tumor differentiation. Using Western blot analyses, we noticed elevated levels of cytosolic HSP70 in colorectal cancer cells compared to normal. Densitometric analysis of blots of plasma membrane HSP70 expression has shown decrease in colorectal cancer cells compared to normal mucosa. According to our results, overexpression of HSP72 in malignant tissues of patients with colorectal carcinoma is related to tumor progression, suggesting that these proteins could play an important role not only in tumorigenesis but also in the development of drug resistance. Further research is necessary to clarify the mechanisms responsible for differential HSP70 expression as well as its definitive role in colorectal cancer.

Diapedesis of thrombocytes from capillary into the intercellular space of interscapular brown adipose tissue and their increase by Ca-Sandoz.

Diapedetic capacity of the rat thrombocytes to leave capillaries of the interscapular brown adipose tissue (IBAT) and infiltrate the interstitium has been observed by conventional electron-microscopy. Thrombocytes that reach IBAT interstitium are morphologically completely different from lumenary ones. The interstitial thrombocyte has a prominet head region (1.51 x 2.12 microns) and very long phylopodium (3.43 microns). Experimental conditions which induced drastic changes in morphology of interstitial thrombocytes were: sucrose overfeeding (10% over 2 days); a 24 hour starving after sucrose overfeeding and Ca-Sandoz drinking (480 mg/L Ca2+ during 2 days). The thrombocytes in the IBAT interstitium can be classified as activated according to: a) pseudopode extension; b) swollen open canalicullar system (OCS); c) endocytosis via coated pits and vesicles; and d) structural changes in alpha granules excreted to the interstitium through OCS. In the IBAT interstitium of 24-hour starved rats after sucrose overfeeding, a thrombocytic layer was observed. It was suggested that thrombocyte adrenalin, stored in dense bodies, was selectively included in the IBAT supply without mediation of the central nervous system.

Pancreatic polypeptide cells of rat pancreas after chronic ethanol feeding.

Male Wistar rats, (2 months old) were randomly divided into two groups according to the diet offered (C-control and E-ethanol treated rats). Final body weight was significantly increased but pancreatic weight as a percentage of body weight was decreased in ethanol treated rats. Volume density, number of pancreatic poly peptide (PP)-cells per islet and per micron 2 of islet were significantly increased. PP-cells were abundant and occupied the whole periphery of islets in the splenic part of the pancreas. Those cells showed strong immunopositivity. At the ultrastructural level PP granules had predominantly less electron density. The mean diameter of PP granules was significantly increased and the number of granules of larger diameter was greater in the E group of rats, than in the controls.

Gastrin producing G-cells after chronic ethanol and low protein nutrition.

Male Wistar rats, (2 months old), randomly divided according to the diet offered to four groups (C-control; A- alcoholized, PD-protein-deprived, A-PD- alcoholized protein-deprived). In group A and A-PD rats, the number of gastrin producing G-cells was significantly lower. The volume density of G-cells was significantly decreased in alcoholic rats. Fasting serum gastrin level (FSGL) significantly raised due to combined effect of alcohol consumption and protein malnutrition. In group A rats, the profile area of G-cells and their nuclei increased. In PD rats, the profile area of G cells also increased. There were no differences in nucleus/cell ratio due to alcohol ingestion alone, but it decreased significantly in PD and A-PD rats. Pale and lucent types of granules were predominantly seen in G-cells of animals of group A and A-PD. Mean diameter of granules increased in A, PD and A-PD rats. Other endocrine cells (ECL, D, EC) also decreased in number in A rats. Somatostatin producing D-cells decreased significantly in A-PD rats, both in fundic and pyloric mucosa.

Diagnostic procedures of pleural malignant mesothelioma: our experience.

PURPOSE: The morphology of the epithelioid malignant mesothelioma (MM) of the pleura is similar to lung adenocarcinoma involving pleura. The aim of this study was to evaluate the value of immunohistochemistry in the accurate diagnosis of MM, especially of the epithelioid type with needle biopsy of the pleura. MATERIALS AND METHODS: The diagnosis of MM was established with pleural needle biopsy and tumor immunophenotyping in 30 patients. A broad spectrum of monoclonal antibodies was applied: HBME-1, E-cadherin, calretinin, cytokeratin 5/6, vimentin, thyroid transcription factor (TTF-1) and surfactant apoprotein A (SP-A). RESULTS: We diagnosed 24 epithelioid, 2 biphasic and 4 sarcomatoid MM. HMBE-1 was the most sensitive tumor marker of the epithelioid type, being positive in 100% of the cases. Calretinin, E-cadherin and cytokeratin 5/6 were positive in 70%, 73%, and 50% of all tumors, respectively. TTF-1 and SP-A were negative in all MM. Vimentin was positive in spindle cells of all sarcomatoid and biphasic MM (20%). CONCLUSION: The accurate diagnosis of MM is mandatory for appropriate treatment decision (surgical or nonsurgical). Our results demonstrate that HMBE-1 is a most useful diagnostic antibody for epithelioid MM, and TTF-1 for lung adenocarcinoma (its thyroid origin excluded) involving pleura.