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Biomedical subjects

P Bar-Sella

Publications and source records attributed to P Bar-Sella.

10 recordsLinked to original sources
PubMed1990

Vitamin B12 and folate levels in long-term vegans.

Serum vitamin B12, serum folate and red blood cell (RBC) folate levels were examined among 36 strict vegans of 5-35 years' duration. Vitamin B12 levels among the vegans were generally lower than in a control population. Most of the vegans had vitamin B12 values less than 200 pg/ml. RBC folate levels were normal but serum folate levels among the vegans were higher than among the controls. None of the vegans had any hematologic evidence of vitamin B12 deficiency, however four of them had neurologic complaints. Long-standing vegans should be monitored for vitamin B12 levels.

Adolescent↗
PubMed1985

Fenestrated capillaries in human parietal and rabbit diaphragmatic peritoneum.

Samples of parietal peritoneum from 20 patients (11 of them chronic uremics) and biopsies of diaphragmatic peritoneum from 5 apparently normal female New Zealand rabbits were examined by electron microscopy. One out of 20 patients and 3 out of 5 rabbits showed fenestrated capillaries. This report is the first published demonstration of the existence of fenestrated capillaries in human parietal and rabbit diaphragmatic peritoneum. They represented a small fraction of the peritoneal microvascular bed which was mainly formed by capillaries of the continuous type. Fenestrae of the observed fenestrated capillaries showed diaphragms. Results of this study indicate that different peritoneal microvascular segments can show different microvascular ultrastructures and possibly have a different physiology and different mechanisms of transperitoneal transfer of water and solutes.

Animals↗
PubMed1984

Heterogeneous density and ultrastructure of rabbit's peritoneal microvasculature.

In this study, samples of mesenteric diaphragmatic peritoneum and peritoneum covering the inner side of the ventral abdominal wall of apparently normal rabbits were examined under electron microscopy. Mesentery appeared as the most vascularized peritoneal segment (71.1% of the total number of observed capillaries). Diaphragmatic and parietal peritoneum contributions to the total examined microvascular bed were of 17.9% and 10.9% respectively. Only 3.2% of peritoneal diaphragmatic capillaries were of the fenestrated type. This qualitative and quantitative heterogeneity of the peritoneal microcirculation combined with the different contribution of each peritoneal segment to the total peritoneal surface area, the different mesothelial cell density of visceral and parietal peritoneum, and the different permeability of parietal visceral peritoneum suggest that, in vivo, whole organ permeability studies would eventually show just an average of an unknown distribution of segmental peritoneal permeabilities.

Abdominal Muscles↗
PubMed1981

Correlation between radionuclides uptake and ultrastructural features of tight junctions in the capillary wall of meningiomas.

The uptake of Tc-99m pertechnetate and Co-57 bleomycin and the ultrastructure of small blood vessels were studied in 10 cases of meningioma. When thin sections of 120 contact areas between adjacent endothelial cells were examined, 92% of the intercellular contacts contained one to three punctate tight junctions. Freeze fracture preparations revealed fascia occludens with one to four sealing strands. These findings are consistent with the high permeability the meningiomas displayed for both of the radiopharmaceuticals.

Capillaries↗
PubMed1981

Ultrastructural and clinical observations on skin metastases from breast cancer patients following intralesional treatment with MER/BCG vaccine.

Ultrastructural and clinical investigations were carried out on skin metastases in patients with advanced breast cancer, following intralesional therapy with MER/BCG vaccine. A total of 65 tumoral lesions in 5 patients were injected with MER. Clinical responses were correlated with light and electron microscopic observations. Regressing tumor lesions showed substantial macrophage and lymphocyte infiltration and severe damage to tumor cells. Activated macrophages with secondary lysosomes and contacts between macrophages and tumor cells were widely observed. In 1 patient with limited cellular immune response, clinical regression was not evident and many tumor cells were ultrastructurally intact.

BCG Vaccine↗
PubMed1979

Ultrastructural basis for different pertechnetate uptake patterns by various human brain tumours.

Patterns of pertechnetate uptake were correlated with ultrastructural properties of the endothelial wall in 14 human brain tumours. In tumours with reduced uptake of the radionuclide, intercellular tight junctions were observed whereas absence of intercellular tight junctions was characteristic of all tumours with an increased uptake of pertechnetate. In some tumours with increased uptake, fenestrated endothelial wall was seen while in others non-fenestrated wall was evident. We concluded that intercellular junctions and not fenestrations affect the permeability of brain tumours to pertechnetate.

Astrocytoma↗