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Biomedical subjects

P Fishman

Publications and source records attributed to P Fishman.

At least 127 records · Page 7Linked to original sources
PubMed1978

SEM observations on Sendai virus-induced fusion of embryonic mouse erythroblasts.

The events of fusion of 11- and 16-day embryonic mouse liver erythroblasts induced by Sendai virus (SV) were followed with the scanning electron microscope (SEM). Erythroid precursors incubated with the virus showed numerous 'pores' on the cell membrane. The cell fusion began with the appearance of a fine 'meshwork' structure between the adjacent cells, followed by a gradual formation of a common cell membrane and terminated with the appearance of polykaryons, in which the nuclei were easily recognized when located in the vicinity of the polykaryon membrane. There was no difference in the process of fusion between erythroblasts at identical and those at different stages of maturation.

Animals↗
PubMed1977

Correlation between movement of concanavalin A membrane receptors and cytolysis. A scanning electron microscopy study.

The present study was undertaken to test whether cytolysis induced by Concanavalin A (Con A) requires lateral mobility of membranal lectin receptor sites into caps. Treatment of interphase murine mastocytoma cells with 10(-4) M colchicine promoted cap formation by Con A in about 30% of the cells, followed by cytolysis. Pretreatment of the cells with NaN3, low temperature, or glutaraldehyde decreased the degree of capping and, to the same extent, the degree of cytolysis. The addition of antibodies to cells bound with Con A increased the appearance of capping and cytolysis. A linear relationship with a high correlation coefficient exists between the degree of capping and cytolysis, suggesting that lateral mobility of membrane Con A receptors is required for cytolysis by the lectin. The process of cap formation by Con A up to the stage of cytolysis was followed by scanning electron microscopy.

Animals↗
PubMed1977

Acid-base balance and plasma composition in the aestivating lungfish (Protopterus).

Upon entering into aestivation, Protopterus aethiopicus develops a respiratory acidosis. A slow compensatory increase in plasma bicarbonate suffices only to partially restore arterial pH toward normal. The cessation of water intake from the start of aestivation results in hemoconcentration and marked oliguria. The concentrations of most plasma constituents continue to increase progressively, and the electrolyte ratios change. The increase in urea concentration is disproportionately high for the degree of dehydration and constitutes an increasing fraction of total plasma osmolality. Acid-base and electrolyte balance do not reach a new equilibrium within 1 yr in the cocoon.

Acclimatization↗
PubMed1977

Scanning and transmission electron microscopy study on the plasma cells of a patient with multiple myeloma.

The ultrastructural features of the plasma cells of a 32-year-old patient suffering from multiple myeloma are described. The high percentage (90%) of plasma cells in the bone marrow aspirate permitted the examination of an almost homogenous population. The appearance of the plasma cells seen with the transmission electron microscope did not differ from that described in other reports. The surface architecture of the plasma cells, such as revealed by the scanning electron microscope, differed from that of the normal and pathological white blood cells. Of particular interest were the membrane-bound portions of the cytoplasm seen as 'buddings', or round bodies in the vicinity of the plasma cells which contained most probably pathological proteins.

Adult↗
PubMed1977

Erythroid precursor fusion induced by Sendai virus.

The ultrastructural events of the interaction of Sendai virus (SV) with fetal mouse erythroid precursors, and SV-induced fusion of erythroid precursors at different maturation stages are described. SV was shown to affect the erythroid nuclei causing interruption of the nuclear membrane, enlargement of the nucleolus and nuclear fusion. SV induced fusion also between dividing and non-dividing cells.

Animals↗
PubMed1977

Ferritin phagocytosis.

The in vitro events of phagocytosis of ferritin and of cationized ferritin by normal eosinophils and the eosinophilic cells of two patients with hypereosinophilic syndrome are described. After one minute of incubation, the cells showed a noticeable pseudopod formation, while after five minutes, ferritin-containing vacuoles were seen in both the normal and the patients' eosinophils. No alterations of the specific granules were observed in cells incubated for 90 minutes or less. Ferritin was observed in the membrane-bound vacuoles, but not in the specific granules of the cells. There was no difference in phagocytic activity of the patients' eosinophils as compared with the normal eosinophils, as well as between phagocytosis of ferritin and of cationized ferritin.

Eosinophilia↗
PubMed1976

Chloramphenicol induced inhibition of platelet protein synthesis: in vitro and in vivo studies.

Chloramphenicol (CAP), an antibiotic which causes various blood dyscrasias, was shown to inhibit in vitro protein synthesis of human blood platelets. The effect is dose- and time-dependent, it is reversible after incubation for 2 h, and is comparable with the suppression achieved by cycloheximide (CXM). Electron microscopic examination revealed swelling and destruction of mitochondria. Administration of CAP to dogs produced a progressive inhibition of platelet protein synthesis as shown by a reduction in the rate of [3H]leucine incorporation into protein. The maximal inhibitory effect of the antibiotic was reached 0.5-4.0 h after its administration, when minimal leucine incorporation values of 9-40% of the control were measured. The suppressive effect of CAP was followed by an overshoot in the incorporation of [3H]leucine, up to a maximum of 602% of the value at zero time of the experiment.

Animals↗
PubMed1976

Intramitochondrial crystalline inclusions in the liver of a patient with hyperthyroidism.

The case of a female patient with hyperthyroidism and slightly impaired liver function is described. Histological examination of liver biopsy did not reveal any pathological findings. Electron microscopic examination revealed crystalline inclusions in a great number of the mitochondria of the liver cells, as well as increased size of the mitochondira. Similar findings were obtained upon examination of a liver biopsy performed six months after start of treatment for hyperthyroidism. Examination of the skin, muscle and white blood cells did not show the presence of such inclusions in the mitochondria. The significance of these findings in the liver cells is discussed.

Female↗
PubMed1976

Erythropoietic events in cultured embryonic mouse spleen.

The events of erythropoiesis in cultured embryonic mouse spleens isolated on the 12th day of gestation were compared with those occurring in spleens of corresponding gestational days in vivo. It was found that the development of erythroid precursors in the cultured spleen depended on the presence of erythropoietin in the culture medium. A progressive increase in the number of erythroid precursors, with a marked shift to mature cells, was observed in spleens cultured with erythropoietin. Although the origin of the hemocytoblasts in the spleen isolated in the earliest stage of its development remains obscure, the present study provided evidence that erythropoiesis in the embryonic mouse spleen was indigenous to this organ and did not result from colonization of erythroid precursors originating in the liver.

Animals↗
PubMed1975

Hematopoiesis in the embryonic mouse spleen. II. Alterations after phenylhydrazine administration to the mothers.

The effect of phenylhydrazine (PHZ) on the hematopoietic events in the embryonic spleen of C57Bl/6J mice was examined by light and electron microscopy. Following PHZ in injections to the mothers, the embryonic spleen revealed a marked increase in erythroid precursors, with a shift to mature cells. This phenomenon was part of a more generalized stimulation of erythorpoiesis, expressed by a shift to mature red cell precursors in the embryonic livers and an increase in the percentage of non-nucleated cells in the embryonic peripheral blood. Concomitantly stimulation of phagocytosis in the spleen of embryos in the early gestational days and increased vascularity were observed, and a later effect of granulocytopoietic stimulation. The effect on erythropoiesis in the embryonic spleen might be a sequence of erythropoietin stimulation, either in the mothers or the fetuses, due to anemia and hypoxia following PHZ injections.

Anemia↗
PubMed1975

Paroxysmal cold hemoglobinuria. Transmission and scanning electron microscopy features of erythrocytes.

Djaldetti, Meir, Elion, Dorith, Bessler, Hana, and Fishman, Pnina: Paroxysmal cold hemoglobinuria. Tranmission and scanning electron microscopy features of erythrocytes. Am J Clin Pathol 63. 804-810, 1975. The case history of a patint with paroxysmal cold hemoglobinuria of the chronic iduipathic type is reported. The patient showed a marked dependency on the external temperature, with severe hemolytic anemia and hemoglobinuria during the winter. Examination of the erythrocytes with the transmission electron microscope showed abnormal forms identified as ropalocytes, whereas examination with the scanning electron microscope revealed "holes" in the erythrocytes. (Key words: Paroxysmal cold hemoglobinuria' Ultrastructure of erythrocytes.

Adult↗
PubMed1975

Transfer of iron-dextran across the placenta.

In pregnant mice. 55Fe-labeled iron-dextran (Imferon) is transferred across the placenta. It was detected in the bone marrow, liver, spleen and peripheral blood of the pregnant animal, as well as in the embryonic liver erythroid precursors and peripheral blood. Uptake by liver and peripheral blood cells of pregnant anemic mice and by liver erythroid precursors of anemic embryos was significantly higher than in normal control animals. Electron-microscopic examination revealed that the iron deposits in the embryonic liver erythroid precursors had the same structure as the injected Imferon.

Animals↗
PubMed1975

Ultrastructural study of the erythropoietic events in human embryonic livers.

The ultrastructural features of the erythropoietic events in 5- to 9-week embryonic livers are described. By the 5th week of gestation, the human embryonic liver becomes an active site of erythropoiesis represented by the formation of reticular-mesenchyme cells and hemocytoblasts. At the 6--7th week, the first proerythroblasts and islands of polychromatophilic and orthochromatic erythroblasts can be detected. From this stage, by the 8th week of embryonic development, the liver assumes its function as a fully developed embryonic organ. In the embryonic livers studied there were no signs of granuloor lymphopoiesis. Although megakaryocytes were found in the 8-week embryonic liver, there is no evidence that these cells are produced in the liver. Macrophages were found in the 5-week embryonic liver.

Embryo, Mammalian↗
PubMed1975

Corticosteroid effect on eosinophils in vitro: ultrastructural studies.

The effect of corticosteroids, ultracortene and ACTH, on the eosinophilic cells of a patient with hypereosinophilic syndrome has been studied in vitro. Both drugs caused a marked decrease in the number of specific granules, a disappearance of their surrounding membrane and an almost complete destruction of their crystals. In addition, vacuolization of the cytoplasm, swelling of the mitochondria and distortion of their cristae were found. Incubation of the eosinophils with the antihistaminic drug mepyramine, did not produce ultrastructural alterations.

Adrenal Cortex Hormones↗