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Biomedical subjects

S Falk

Publications and source records attributed to S Falk.

At least 109 records · Page 6Linked to original sources
PubMed1987

Immunohistochemical studies of lymph nodes from LAS and AIDS patients.

Lymph nodes from eight LAS and six AIDS patients were studied by routine histology, immunohistochemistry, and ultraimmunohistochemistry. LAS lymph nodes show a peculiar follicular hyperplasia with a characteristic increase of proliferating dendritic and interdigitating reticulum cells. In AIDS, these cells are reduced and the expression of proliferation-associated antigens is diminished. The immunohistochemical analysis of dendritic and interdigitating reticulum cells and of proliferation-associated antigens in lymph nodes thus allows a clear distinction between LAS and AIDS and may have important prognostic implications.

AIDS-Related Complex↗
PubMed1987

Histogenesis of Kaposi's sarcoma associated with AIDS: a histologic, immunohistochemical and enzyme histochemical study.

Twenty-one cases (25 biopsies including 9 frozen biopsies) of Kaposi's sarcoma associated with the acquired immune deficiency syndrome (AIDS) were examined immunohistochemically, lectin-histochemically, and enzyme histochemically to ascertain the histogenesis of the lesion. The Kaposi's sarcomas were histologically subtyped according to a modified Schmid's classification (granulation tissue-like-, angiosarcoma-like- and spindle cell type). In almost all lesions, many atypical vasoforming cells and at least some spindle cells without definite evidence of vasoformation by conventional microscopy were positive for factor VIII-related antigen, BMA 120 (a new monoclonal antibody to an endothelial cell-specific antigen), Ulex europaeus I (UEA-I), alkaline phosphatase and ATPase. Linear reaction products for BMA 120 and UEA-I, suggesting the luminal surface of immature vascular channels, were sometimes recognized in the positive spindle cells. Electron micrographs confirmed endothelial characteristics, such as irregular and fragmented but distinct basal lamina and numerous pinocytotic vesicles, in both the UEA-I- and ATPase-positive spindle cells. Among spindle cells negative for the endothelial markers, there were many macrophages as a stromal reaction to tumor tissue, identified by monoclonal antibodies to macrophages (KiM 6, 7, 8 and EBM 11), acid phosphatase and alpha-naphthyl acetate esterase. The results of the immuno- and enzyme histochemical investigations did not correlate with the different histologic types of Kaposi's sarcoma. However, our results strongly suggest that tumor cells of Kaposi's sarcoma are derived from vascular endothelial cells rather than lymphatic endothelium.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Splenic erythropoiesis in rats under hypoxic and post-hypoxic conditions.

In rats chronic hypoxia causes extramedullary haematopoiesis mainly localized in the spleen. It is not known how splenic erythropoiesis develops and how it regresses after termination of hypoxia. In this study the spleen of rats exposed to chronic hypoxia was studied by light and electron microscopy; the findings were compared to relevant peripheral blood values. Splenic erythropoiesis begins almost immediately after exposure to hypoxia and reaches its maximum after 2-4 weeks. It occurs mainly in the splenic cords drawing upon local erythroblasts and is accompanied by an increase in splenic weight as well as a decrease in splenic iron stores. After termination of hypoxia marked phagocytosis by splenic cord macrophages diminishes the number of erythroblasts and of erythrocytes with a concomitant increase in splenic iron stores. Thus, splenic erythropoiesis appears to be inhibited as part of a rebound phenomenon and returned to normal by phagocytosis of erythroid cells within 4 weeks after cessation of the hypoxic stimulus.

Animals↗
PubMed1984

[Not Available].

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History, 20th Century↗
PubMed1978

External auditory canal cholesteatoma.

Cholesteatoma of the EAC is a rare otologic problem, particularly when keratosis obturans otica is excluded. The predominant features of EAC cholesteatoma are acute external symptoms, severe pain, recurrent physician visits, and paucity of X-ray findings. Poorly responding otitis externa should always alert the physician to the possibility of neoplasm, diabetes, or some other underlying condition which will not respond to just topical treatment. Cholesteatoma of the external auditory canal should also be considered in refractory cases of otitis externa. Three patients with EAC subperiosteal cholesteatoma are reviewed.

Adult↗
PubMedDate not supplied

Lifetime prolongation in voluntary alcohol-consuming rats (SHR) treated with clofibrate.

Clofibrate affects lipid and alcohol as well as drug and eicosanoid metabolism. Spontaneous hypertensive rats (SHR) further increase their high voluntary alcohol consumption during clofibrate feeding. The interaction of alcohol and clofibrate was studied in two long-term trials. Seventy-nine male SHR (aged 27 weeks) were offered increasing concentrations of ethanol, up to 30% (tap water ad lib), and 3 months later 0.5% clofibrate-food. Four groups were established: N, normal controls; NA, standard diet+alcohol; C, clofibrate feeding; and CA, clofibrate feeding + alcohol. Food intake, alcohol consumption, body weight, and laboratory values were recorded continuously. Life duration (weeks) after the start of the trial was 63.3 +/- 3.3 in N, 73 +/- 2.6 in NA, 77.7 +/- 4.3 in C, and 90.3 +/- 2.8 in CA. There were no alcohol-related liver findings in NA and CA. Most of the animals died of cardiac and renal failure. An increase of tumors in clofibrate-treated rats was not observed. Voluntary alcohol consumption or clofibrate feeding significantly lengthens lifetime, which is prolonged by 42% if ethanol is combined with clofibrate. This is obviously not mediated by the lipid lowering effect or an influence on body weight and blood pressure of either clofibrate or alcohol.

Alcohol Drinking↗
PubMedDate not supplied

The spleen in HIV infection--morphological evidence of HIV-associated macrophage dysfunction.

One-hundred spleens from HIV-infected patients which were studied by conventional morphological and immunohistochemical methods exhibited alterations in lymphatic tissue as well as in the mononuclear phagocyte system (MPS); these were probably related directly to HIV infection of lymphocytes and MPS cells. There was ample evidence of impairment of macrophage activation, accompanied by decreased expression of functional markers and an enhanced reactivity with antibodies against S100 protein. This impairment of macrophage function is related to the particular morphology and aggressive clinical behaviour of some opportunistic infections in AIDS.

Acquired Immunodeficiency Syndrome↗