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Biomedical subjects

A Nyska

Publications and source records attributed to A Nyska.

At least 91 records · Page 5Linked to original sources
PubMed1995

Assessment of the nucleolar organizer regions by automated image analysis in benign and malignant colonic tumours and adjacent tissues in rats.

An automated computer image analysis technique was used to study the morphological parameters of argyrophilic nucleolar organizer regions (AgNORs) in chemically induced rat colonic tumours of different grades. Different nuclear parameters were of different diagnostic value. For distinguishing tumorous tissue from normal tissue all the parameters studied were capable of serving as diagnostic markers. Malignant processes could, however, be more reliably detected by means of the area of the nucleus, nuclear shape factor, area of AgNOR and ratio of AgNOR area to nuclear area. In macroscopically normal tissue adjacent to a tumour, the values of all the AgNOR parameters studied were similar to those in tumorous tissues. It can be concluded that the initial stages in tumorigenesis are accompanied by changes in all of the nucleus and AgNOR parameters, but as malignancy develops, only some of these parameters continue to change. Close correlations between nuclear parameters in malignant tissue suggest that for diagnostic purposes only nuclear and AgNOR areas should be used.

Adenocarcinoma↗
PubMed1995

Aldose reductase (EC 1.1.1.21) activity and reduced-glutathione content in lenses of diabetic sand rats (Psammomys obesus) fed with acarbose.

The effects of acarbose on cataract development, lens aldose reductase (EC 1.1.1.21) activity and lenticular reduced-glutathione content in diabetic sand rats (Psammomys obesus) were determined. Diabetic sand rats (diet-induced) were fed on diets with or without acarbose (0.4 g/kg) for 39 d. Daily plasma glucose, cataract incidence, aldose reductase and glutathione content were evaluated. After 19 d on acarbose, daily plasma glucose profile was significantly reduced compared with that of sand rats not receiving acarbose. Cataract incidence was markedly lower in sand rats treated with acarbose. After 20 d, cataracts had developed in 90% of the animals fed without acarbose, whereas none was observed in sand rats fed with acarbose. After 37 d acarbose treatment the incidence of cataracts reached only 30%. Compared with untreated animals, lens aldose reductase activity was significantly lower in sand rats fed with acarbose for 39 d (7.6 (SE 0.78) v. 3.5 (SE 0.55) mumol NADPH/mg protein per min respectively, P < 0.001). Concomitantly, significantly higher lenticular protein and reduced-glutathione contents (90 (SE 23) v. 240 (SE 23.5) micrograms/mg tissue respectively, P < 0.001 and 369 (SE 48.6) v. 645 (SE 71.1) micrograms/mg tissue respectively, P < 0.001) were found. These results suggest that decreasing hyperglycaemia, accompanied by lower aldose reductase activity obtained by acarbose, led to a significant preventive effect on cataract development in sand rats.

Acarbose↗
PubMed1995

Pathology of lymphoid organs in low birth weight infants subjected to antigen-related diseases: a morphological and morphometric study.

The pathology of lymphoid organs in 38 low birth weight (LBW) human infants has been evaluated by morphological and morphometric features. The gestational ages of infants ranged from 22 to 32 wks and their age at death varied from 1 hr to 153 days post partum. Infants were divided into 3 groups: 1) without antigenic effects, 2) with mild (bronchopneumonia), and 3) with severe antigenic effects, mainly sepsis. In mildly affected LBW infants, the fetal type of the immune reaction was found. It continued during the period studied (till 5 mths) and was manifested in the reaction of macrophages and the transformation of lymphocytes to lymphoblasts. Reactive centres of follicles and mature plasmocytes were not found. During the first months of postnatal development, an increase in the amount of lymphocytes in the lymphoid organs and in the rate of proliferation of reticular epithelium and a decrease in the area of the cortex in the thymus were found in all infants. In severely affected infants, the number and the size of follicles in the spleen decreased significantly and the total number of cells decreased more than 3 times. Similar changes were found in lymph nodes. These changes as well as the weak reaction of the thymus are the main features of the insufficiency and fast devastation of the lymphoid system. A compensatory increase in the number of neutrophils and eosinophils in the red pulp of the spleen and lymph nodes was found after the second week.

Bronchopneumonia↗
PubMed1995

Skin diseases in a Merino sheep herd related to an excessively rainy winter in a Mediterranean climatic zone.

A retrospective study is presented here in which an outbreak of dermatophilosis and morbidity of fleece rot in a sheep herd grazing throughout the year in the Carmel hills are described for the first time in a Mediterranean climatic zone. Both diseases were closely related to intense and prolonged rains during the winter months of 1991/1992. Morbidity of dermatophilosis appeared after 650 mm and that of fleece rot after 1320 mm of precipitation. The pathogenesis of these diseases is discussed.

Animals↗
PubMed1995

Ameloblastic fibroma in a young cat.

The results of a histological and histochemical study of an ameloblastic fibroma in the maxilla of a young cat are presented. Staining with Picrosirius red revealed the presence of collagen fibers of abnormal packing in the ectomesenchymal component of the tumor. A discussion relating to the classification of the tumor with reference to those in humans is presented.

Animals↗
PubMed1995

Intracranial gangliocytoma in a dog.

The clinical, pathologic, immunohistochemical, and electron microscopic characteristics of a pure intracranial gangliocytoma in a 6-year-old spayed female dog are presented. The tumor is very rare in humans, and has not been previously reported in the dog. The most remarkable feature of this tumor was that it was composed of a single neuronal cell type without the presence of glial elements, as demonstrated by the negative immunohistochemical reaction to glial fibrillary acidic protein.

Animals↗
PubMed1995

Histomorphometry of long bone growth plate in swimming rats.

In exercises involving running, muscle power and gravitational forces act together to affect bone mass in accordance with Wolff's law. However, the direct effect of muscle activity on bones in non-weight-bearing activities, such as swimming, has not been explored. Previous data indicate that swimming exerts a positive effect on bone growth and development in young rats. We performed a histomorphometric study on the effect of swimming on the growth plate and subepiphyseal area of young adult rats. The experiments were carried out on 28 12-week-old albino Sabra rats. One group of 14 rats was trained to swim 1 hour/day, 5 days a week, for 12 weeks. Another group of 14 rats served as controls. The proximal femur and humerus of each animal were examined histomorphometrically. There was an increase in the subepiphyseal cancellous bone trabecullae of the femur. In the growth plate there was an increase in the number of column cells and proliferative cells. These changes were more pronounced in the femur than the humerus. We conclude that swimming induces an increase in subepiphyseal cancellous bone in young adult rats by enhancing growth plate activity.

Animals↗
PubMed1995

A survey of dermatophilosis in Israeli dairy cattle.

In Israel, dermatophilosis was found to inflict severe lesions, especially in first-calving cows during the first weeks post-parturition. Decreased milk production (by 40% on average) was also noted. Acute exudative dermatitis was observed in these animals. Severely reacting animals (570 in 38 kibbutz herds and 15 animals in 4 family herds) were treated with antibiotics. All these animals also suffered either from endometritis/metritis or mastitis. The "tumoral" form of dermatophilosis was observed on 3-week-old or younger calves. Dermatophilosis was especially prevalent (89.4%) in dairy herds in which intensive showering of lactating cows is practised during the spring and summer months, in comparison to the family herds where the morbidity rate was lower (6.6%). Morbidity rates were found to be higher in the humid Mediterranean Coastal Plain (66.3%) than in the arid or semi-arid regions (Negev and Arava Valley) of Southern Israel (3.7%). Five clinical forms of dermatophilosis and the epizootiological aspects of the disease in Israeli dairy herds are described. It is concluded that a reduction in the prevalence of dermatophilosis could be achieved by decreasing the frequency and the intensity of showering currently applied under the kibbutz management system.

Actinomycosis↗
PubMed1994

Adverse reactions in cattle to a capripox vaccine.

Capripox vaccine (strain 0240) caused severe generalised skin reactions in vaccinated dairy cattle in two herds, whereas beef cattle did not develop reactions. All the reacting animals developed lumpy skin disease-like lesions. The incidence of skin lesions in first-lactation cows in herd A was 22.9 per cent and in herd B 29.3 per cent, mainly in the post-calving period. In older cows, the incidence was 10 per cent in herd A and 12.4 per cent in herd B. In herd B the high-yielding lactating cows were the most severely affected. There was a decrease of 3.5 per cent in milk production in each herd over a period of 12 days, and six first calving animals (3.5 per cent) and six cows (1.5 per cent) were slaughtered. A capripox virus was isolated from the animals with severe lesions, and was also demonstrated by electron microscopy. The histopathological lesions were similar to those of lumpy skin disease. The extent of the lesions appeared to be stress-related and, to a lesser degree, correlated with age and breed.

Animals↗
PubMed1994

An XRF study of trace elements accumulation in kidneys of tumor-bearing mice after treatment with cis-DDP with and without selenite and selenocistamine.

The effect of cis-DDP treatment with and without selenite and selenocistamine was studied on kidneys of tumor-bearing mice. The amounts of cis-DDP, selenite, and selenocistamine injected were chosen so as to be compatible with the treatment of humans. The animals were sacrificed at 7, 14, and 28 d after treatment. The kidneys were removed and subjected to trace element analysis by a novel X-ray fluorescence (XRF) method and for pathological assessment. The results show that following treatment with cis-DDP, K, Fe, Cu, and Zn reach a maximum level after 7 d; K, Fe, and Cu levels were significantly reduced by the addition of selenite. The level of Zn was reduced only in groups treated with selenite whereas that of K and Cu was reduced also in groups treated with selenocistamine with and without cis-DDP. The greatest increase in Pt and Se levels was reached 1 wk after injection with cis-DDP, with and without selenocompounds, and in the case of Pt was partly reduced by addition of selenite. Se returned to control values 2 wk after injection, although Pt was still high in all groups 2 and 4 wk after injection. The results corroborate the findings of our previous studies. The effect of selenocistamine in cis-DDP treated mice was partly insufficient. The pathological examination of the kidneys did not show any differences in the effect of various additives during the study.

Animals↗
PubMed1994

Gingival hyperplasia induced by calcium channel blockers: mode of action.

Gingival hyperplasia is a known side effect in patients treated with diphenylhydantoin, cyclosporin and the calcium channel antagonists. The present study proposes a mechanism by which calcium channel antagonists may induce gingival hyperplasia. The calcium antagonist induces blockage of the aldosterone synthesis in zona glomerulosa of the adrenal cortex since this pathway is calcium-dependent, cyclic nucleotide-independent. This may produce a feedback stimulation of an increase in pituitary secretion of ACTH which affects zona glomerulosa hyperplasia. This hyperplasia is merely related by accumulation of steroid intermediate products (androgens) that are transformed to testosterone because of an increase in 17-alpha-hydroxylase enzyme activity. Elevated levels of testosterone may act on the gingival cells and matrix to produce gingival hyperplasia.

Adrenocorticotropic Hormone↗
PubMed1994

Clinical and pathological description of a chronic form of bovine papular stomatitis.

This communication describes a hitherto unreported chronic form of bovine papular stomatitis in young cattle. Diagnosis was based on the clinical disease, histological findings, electron microscopical characterization of the causative virus, and virus isolation. A description of the acute form of the disease is presented for comparison.

Acute Disease↗
PubMed1994

Bilateral complex odontoma in a Swiss (CD-1) male mouse.

The present report describes the morphological features of a spontaneous, bilateral, complex odontoma of the incisor teeth in an 87-week-old male Swiss mouse (Crl: CD-1(ICR)BR). This report constitutes the second report of an odontogenic tumour in a Swiss mouse and the first describing a bilateral complex odontoma in this strain of mouse. The report emphasizes the importance of thoroughly examining the oral cavity for dental tumours.

Animals↗
PubMed1994

The effect of irradiation on expression of HLA class I antigens in human brain tumors in culture.

The immunosuppressive effects of irradiation are well known; however, under certain circumstances irradiation also augments the local immune response by as yet undefined mechanisms. Because of the importance of HLA class I antigen in immune regulation and the fact that killing of tumor cells by cytotoxic T cells is HLA antigen-restricted, the authors studied HLA class I antigen expression in eight glioblastomas multiforme, four meningiomas, and four medulloblastomas. Twenty fragments of each tumor specimen were placed in short-term cultures immediately after resection. For each tumor, control Sample 1 was not irradiated. Sample 2 was irradiated on Day 1, and two groups of the remaining pieces of each tumor (specimens 3 to 10) were irradiated on two consecutive days. Escalating radiation doses were given, starting at 200 cGy/day for Sample 2 up to 1000 cGy/day for Sample 10. The total dose range was 200 to 2000 cGy. Corresponding nonirradiated tumor fragments served as controls. Four hours after irradiation, each sample was processed and stained for HLA class I antigen using the immunoperoxidase technique. The tumor cells were intensely stained in nonirradiated glioblastomas and meningiomas, whereas no staining was observed in medulloblastomas. In four of the eight glioblastomas and in all four meningiomas, irradiation augmented HLA class I antigen expression compared to controls. This effect was dose-dependent and was maximum in the 1200 cGy-treated specimens. No change was observed in the other four glioblastomas or in the medulloblastomas. The data suggest that irradiation does not decrease and may even induce HLA class I antigen expression in some brain tumors. This may be one of the mechanisms by which immunotherapy operates after irradiation. Further studies are required to elucidate optimum radiation doses and fractionation as well as optimum timing of immunotherapy.

Brain Neoplasms↗
PubMed1994

Parapox infection in a gazelle kid (Gazella gazella).

A captured gazelle kid (Gazella gazella) held in a mixed herd of sheep and goats in Israel developed the characteristic lesions of contagious ecthyma. Clinical diagnosis was confirmed by electron microscopy and histopathology examinations of infected tissue.

Animals↗
PubMed1994

Interstitial cell (Leydig) tumor in an eland (Taurotragus oryx).

We observed an interstitial cell tumor in an 18-mo-old captive eland bull (Taurotragus oryx) in Tel Aviv, Israel. The histological description of the tumor in the eland was similar to that described in cattle; however, the appearance of a moderate amount of lipid vacuoles in the cytoplasm of the neoplastic cells was uncharacteristic for bovine interstitial cell tumors. The eland also had clinical signs of gynecomastia.

Animals↗