Biomedical subjects

H Bessler

Publications and source records attributed to H Bessler.

26 records · Page 2Linked to original sources

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

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↗

PubMedDate not supplied

Beta-endorphin modulation of IL-1-induced IL-2 production.

We have studied the effects of natural opioids on interleukin-1 (IL-1) -induced interleukin 2 (IL-2) production by the lymphoid cell line EL-4. beta-Endorphin (beta-end) significantly enhanced IL-2 production by IL-1-stimulated EL-4 cells. Similar results were obtained using the LBRM33-1A5 cell line. beta-End induced significant enhancement (35-100%) of IL-1-induced IL-2 production at all concentrations of IL-1 tested (2-0.25 U/ml) and the effects were seen with both IL-1 alpha and IL-1 beta. The dose response of beta-end augmentation of IL-1-induced IL-2 production was bimodal, with peak activities seen at high (10(-8)-10(-10) M) and low (10(-16) M) beta-end concentrations. The specificity of beta-end effect was studied using the opioid antagonist naloxone. Naloxone completely abolished the enhancing effects of beta-end, indicating that the effects might be mediated through binding to opioid receptors. In addition, other opioid peptides, including gamma-endorphin and enkephalins, elicited similar effects. Northern blotting analysis revealed higher levels of IL-2 mRNA in beta-end-treated IL-1-induced EL-4 cells than in IL-1-induced control cells. Thus, beta-end might enhance IL-2 production by either augmenting the transcription rate or increasing IL-2 mRNA stability. These results suggest that beta-end might play an important role in the regulation of lymphokine production in the periphery in addition to its known interactions with IL-1 in the central nervous system.

Animals↗

PubMedDate not supplied

Functional and ultrastructural studies of Sezary cells.

A patient having clinical findings and typical ultrastructure of the peripheral white blood cells compatible with the diagnosis of Sézary syndrome is described. Studies of the synthesizing capacity of the Sézary cells showed a statistically significant increase in their capacity for protein and RNA synthesis, but no difference with regard to DNA synthesis as compared to normal lymphocytes.

Blood Proteins↗

PubMedDate not supplied

Clinical and ultrastructural observations in primary acquired sideroblastic anemia.

The clinical and laboratory findings in three patients with primary acquired sideroblastic anemia (PASA) are described. The results demonstrate that what seems to be a well defined entity of the large group of sideroblastic anemias, is in itself a heterogeneous subgroup, with differences capable of detection by more extensive studies. Electron microscopic examination of erythroid cell precursors confirmed previously described features such as deposition of large amounts of iron, mainly in the mitochondria. The precipitated serum proteins revealed an increased content of ferritin molecules only in the patients and not in control individuals, suggesting an increased supply of iron to the erythroid precursors. This finding could serve as an additional mechanism for the accumulation of iron in the erythroid precursors, considering also the defect in heme synthesis and increased permeability of the erythroid membrane for iron, described in this condition.

Aged↗