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Biomedical subjects

H Bessler

Publications and source records attributed to H Bessler.

At least 91 records · Page 5Linked to original sources
PubMed1987

Production of interleukin-1 by mononuclear cells of newborns and their mothers.

The ability of peripheral blood mononuclear cells derived from newborn infants, their mothers and healthy adults to produce interleukin 1 (IL-1) was examined. It was found that newborn and maternal mononuclear cells have a normal capacity to produce IL-1. In addition, a lower stimulatory activity of IL-1 production was found in maternal serum, suggesting another mechanism for the suppression of the maternal immune system during pregnancy. Furthermore, evidence is presented on the existence of sex-related blocking factors in the maternal serum which affect IL-1 production.

Adult↗
PubMed1987

Effect of pentoxifylline on E-rosette formation and on the mitogenic response of human mononuclear cells.

Pentoxifylline (Trental) has been shown to increase the intracellular cAMP concentration. In the present study we have examined the capacity of the drug to affect E-rosette formation by T lymphocytes. In addition, the mitogenic response of human lymphocytes to phytohemagglutinin (PHA) and concanavalin A (con A) was studied. The drug exerted a dose dependent inhibitory effect on E-rosette formation and on the proliferative response of lymphocytes to PHA and con A. It is suggested that this inhibitory effect is most probably due to the increased intracellular levels of cAMP induced by the drug.

Adult↗
PubMed1987

Difference in the placental ferritin levels measured by a specific monoclonal antibody enzymoassay in preterm and term delivery.

The use of a new monoclonal antibody (MoAb) enzymoassay for the specific measurement of placental ferritin (PLF) enabled it to be quantitatively determined in the sera of pregnant women, women at full-term and preterm delivery, and in their newborns. High levels of PLF were measured in the sera of pregnant women at 17 weeks of gestation up to full-term delivery as compared with normal adult women who mostly lack PLF. The level of PLF in the serum was irrespective of the total ferritin level. In full-term newborns, PLF concentration was lower than that found in their mothers although it increased compared to healthy adults. It was further found that in the blood of women who delivered at 29-36 weeks, PLF was undetected or was very low. Accordingly their preterm infants also exhibited very low or undetectable PLF in their serum. These results suggest the possible use of PLF as a prognostic indicator in pregnancy.

Adult↗
PubMed1987

New monoclonal antibody enzymoassay for the specific measurement of placental ferritin isotype in hematologic malignancies.

A new enzymoimmunoassay, specific for the measurement of placental ferritin (PLF) isotype, has been described. Two monoclonal antibodies (McAbs) with different binding specificities to placental ferritin have been used in this assay. One antibody (CM-G-8) binds to all ferritins, whereas the second (CM-H-9) binds to placental ferritin only. In addition, a second enzymoassay was developed for the measurement of total common serum ferritin using CM-G-8 McAb. Serum levels of total ferritin and PLF were measured in healthy individuals and in patients with lymphoproliferative diseases and multiple myeloma. The majority of normal subjects were deficient in PLF in the serum. Increased serum levels of PLF were observed in patients with Hodgkin's lymphoma and non-Hodgkin's lymphoma of low and intermediate grades, as well as in patients with acute lymphocytic leukemia (ALL). Total ferritin was also elevated in these patients. Chronic lymphocytic leukemia (CLL) and multiple myeloma patients exhibited normal levels of common serum ferritin, whereas PLF in the serum was lacking.

Antibodies, Monoclonal↗
PubMed1986

Effect of pentoxifylline on the phagocytic activity, cAMP levels, and superoxide anion production by monocytes and polymorphonuclear cells.

The effect of pentoxifylline (Trental) on the phagocytic capacity, cAMP levels, and superoxide anion production of human peripheral blood monocytes and polymorphonuclears (PMNs) was studied. The drug inhibited the phagocytosis of latex particles by both monocytes and PMNs in a dose-dependent manner. In addition, superoxide anion production during the phagocytic process was also reduced following incubation of the cells with pentoxifylline. It is suggested that this inhibitory effect is due to the increased intracellular levels of cAMP induced by the drug.

Cyclic AMP↗
PubMed1986

Cord serum inhibits allogeneic mixed lymphocyte reaction and stimulates lymphokine production.

An inhibitory activity on the two-way allogeneic mixed lymphocyte reaction (MLR) was detected in maternal and cord serum at delivery. The inhibitory effect of the maternal serum was found to be more pronounced and was detected in almost all sera tested, whereas the inhibitory capacity of cord sera was observed in only 70% of the cases. In addition, a lower stimulatory activity for interleukin-2 (IL-2) production was found in the maternal serum, suggesting an additional mechanism for the suppression of the maternal immune system during pregnancy. On the other hand, a higher stimulatory activity for IL-2 production was observed in cord serum as compared with adult normal serum. The possibility that a fetal humoral factor is involved in the regulation of the immune system via the stimulation of IL-2 production is discussed.

Adult↗
PubMed1986

Thrombopoietic activity in preterm newborns and infants.

Platelet count and thrombopoietic activity were investigated in preterm infants at birth and during their first four months of life. Thrombopoiesis stimulating factor activity in cord serum was significantly lower than that of adults and of the respective mothers. No difference was noted between thrombopoietic activity in cord serum in the various gestational ages studied--that is, 24 through 39 weeks. Preterm infants followed during their first four months of life showed a mean platelet count significantly higher than that observed in term infants at the respective age. Furthermore, thrombocytosis was found in premature thriving infants at the age of 1 and 2 months. It is suggested that this thrombocytosis is responsible for the low thrombopoietic activity observed in these infants during their first four months of life.

Adult↗
PubMed1986

Thrombopoietic activity in newborn infants.

Platelet count and thrombopoietic activity were investigated in newborns and in infants during their first 4 months of life. Four-day-old newborns, although not thrombocytopenic, showed a significantly reduced platelet count as compared to that of control adults. Furthermore, a significantly lower thrombopoietic activity was found in the sera of newborns compared to that in the sera of adults. In addition, the thrombopoiesis-stimulating factor (TSF) activity in cord serum was significantly lower than that in the mothers' sera. Since 7 of 37 newborns examined in the present study showed a very low TSF activity, lower than that found in the saline controls, the possibility that an inhibitor for thrombopoiesis exists in the newborns is suggested and discussed. The follow-up study revealed a low TSF activity in the sera of 1-month-old infants followed by a gradually increased activity, reaching in the 4th month levels similar to those of adults. Concomitantly with the rise in TSF activity in the serum, an increased platelet count was observed.

Blood Platelets↗
PubMed1986

The effect of propranolol on protein synthesis and phagocytosis by polymorphonuclear leukocytes from newborn, children and elderly individuals.

The effect of propranolol on protein synthesis by polymorphonuclear (PMN) leukocytes was assessed in subjects from four age categories: elderly individuals, grown-up children, small children and newborn babies. This function was inhibited in PMN cells from individuals of all age groups, but inversely proportional to the age of the individual, i.e. the younger the subject, the more inhibited was the protein synthesis by his PMN leukocytes. The phagocytic capacity of the PMN cells of elderly subjects was decreased in comparison with that of individuals from the younger age groups. Propranolol inhibited this cell function in cells from subjects of all categories, although the inhibition was more pronounced in the cells of the younger groups. The difference in the degree of inhibition of the cell function observed in the various age groups may indicate different functional properties of the cell membrane.

Aged↗
PubMed1985

Phagocytic activity in mouse embryonic liver and spleen following hemolysis.

Phenylhydrazine (PHZ) was injected into pregnant mice and the number of phagocytizing cells was counted in the embryonic livers and spleens at 11th to 14th gestational days. A marked increase in the number of phagocytizing cells was observed in the embryonic spleen, whereas in the embryonic liver it was only slightly enhanced. This observation indicates that the response to hemolytic events is similar in embryonic and adult mammals.

Animals↗
PubMed1982

Pattern of liver erythropoiesis in embryos of polycythemic mice.

Polycythemia induced by hypoxia in pregnant mice caused a marked reduction in the total number of erythroid precursors in the 10th, 11th, and 12th day embryonic livers, as compared with controls. In addition, the maturation of the erythroid precursors in the 11th day embryonic livers of polycythemic mice was markedly inhibited in comparison with that of controls, whereas on the following days of gestation the erythropoiesis in embryonic livers of both polycythemic and control mice exhibited a similar pattern. It is suggested that the reduced erythropoiesis in the 11th day embryonic liver of polycythemic mothers provides a stimulation for embryonic erythropoietin production. Subsequently, it triggers the maturation of progenitor erythroid cells in the livers and induces an increased erythropoietic activity in the plasma of 12th and 13th day pregnant polycythemic mice as was observed in our previous study.

Animals↗
PubMed1981

Increased erythropoiesis in embryonic spleen of polycythemic mice. An indicator for erythropoietin production by the embryo.

The hemopoietic events in the embryonic mouse spleen were investigated in fetuses of polycythemic mothers. 12th and 13th day embryonic spleens showed a marked increase in the number of erythroid precursors at an advanced maturation stage, as compared to controls. In addition, an increased erythropoietic activity, measured by 59Fe incorporation into red blood cells of posthypoxic polycythemic mice, was found in the plasma of 12th and 13th day pregnant polycythemic mice, compared with controls, i.e. plasma of nonpregnant nonpolycythemic mice, of nonpregnant polycythemic mice, and of 12th and 13th day pregnant nonpolycythemic mice. Since polycythemic mice are presumed to have low erythropoietin level, the stimulation of erythropoiesis in the embryonic spleens of polycythemic mothers suggests that fetal erythropoiesis is independent of the maternal one. Moreover, the present results indicate that fetuses of polycythemic mothers not only produce their own erythropoietin, but are also able to increase markedly the maternal erythropoietin as a consequence of hypoxemic conditions.

Animals↗
PubMed1981

The effect of partial splenectomy on platelet production in mice.

The effect of total and partial splenectomy on the number and production of circulating platelets was studied in mice. Five days after total and partial splenectomy the number of the peripheral blood platelets increased by 87% and 60%, respectively and the incorporation of 75selenium methionine (75Se-Met) into platelets was enhanced indicating that the thrombocytosis was due to increased platelet production. The results obtained by the two operative procedures were compared. Since previous work from our laboratory has shown that a factor produced by splenic lymphocytes affects the platelet number in mice, it is suggested that the differences in the number of circulating platelets observed in animals after total and partial splenectomy may reflect a difference in the number of spleen lymphocytes removed.

Animals↗
PubMed1981

The effect of tetracycline administration on iron absorption in mice.

The effect of perorally administered tetracycline, chloramphenicol and streptomycin, antibiotics known as inhibitors of protein synthesis, on the iron absorption in mice was examined. Tetracycline caused a marked decrease in iron absorption observed shortly after its administration. On the other hand, both chloramphenicol and streptomycin caused a marked increase in iron absorption. There was no difference between results when bivalent or trivalent iron was given. The possible mechanisms for the explanation of the effect of these antibiotics on iron transfer through the small intestine mucosa are discussed.

Animals↗
PubMed1980

Ultrastructural studies on the lymphocyte subpopulations of disaggregated mouse spleens.

The lymphocyte subpopulations of disaggregated spleens of adult C57Bl/6J mice were examined by transmission and scanning electron microscopy as well as by rosette formation. The results showed that most lymphocyte subpopulations are constituted of cells with relatively smooth surfaces. Rosette formation showed that the proportion of E rosettes, compatible with the presence of T cells, was of 25%, whereas that of erythrocyte antibody complement (EAC) rosettes, indicating B cells, was 9%.

Animals↗