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Biomedical subjects

M Ben-Yaakov

Publications and source records attributed to M Ben-Yaakov.

7 recordsLinked to original sources
PubMed1992

Activation of human eosinophil and neutrophil functions by haematopoietic growth factors: comparisons of IL-1, IL-3, IL-5 and GM-CSF.

We compared the effect of haematopoietic growth factors granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-1, IL-3, and IL-5 on the functional activation of human eosinophils and neutrophils from the same donor. All four colony-stimulating factors (CSF) enhanced the phagocytosis of Candida albicans by eosinophils and increased staphylococcal, but not Candida, killing. GM-CSF and IL-5 had a profound stimulating effect on eosinophil staphylocidal activity. GM-CSF and IL-3 enhanced the generation of leukotriene C4 (LTC4) induced by calcium ionophore A23187 and the release of arylsulphatase and beta-glucuronidase from specific and small granules of eosinophils. In contrast, IL-1 and IL-5 had no effect on degranulation. GM-CSF and IL-1 enhanced phagocytosis of C. albicans by neutrophils, and GM-CSF stimulated degranulation and the release of the enzymes beta-glucuronidase and arylsulphatase from neutrophils while IL-1 stimulated the release of arylsulphatase only. This study indicates that the eosinophil-active colony-stimulating factors can markedly enhance the host defence function of the eosinophil and even make it the equal of the neutrophil in staphylocidal activity. The CSF-activated eosinophil, however, may cause inappropriate inflammation and normal tissue damage.

Animals↗
PubMed1991

Immediate and late airway response of allergic rhinitis patients to segmental antigen challenge. Characterization of eosinophil and mast cell mediators.

Segmental antigen bronchoprovocation was used to define the nature of the inflammatory process in allergic airway disease. Bronchoalveolar lavage fluid obtained from allergic rhinitis patients 12 min after segmental antigen instillation (immediate response) revealed a significant increase in histamine and tryptase, but no cellular response. Repeat segmental lavage 48 h later (late response) showed marked and significant increases in both low and normal density eosinophils as well as striking elevations of eosinophil granular protein levels (major basic protein, eosinophil-derived neurotoxin, eosinophil cationic protein, and eosinophil peroxidase). Leukotriene C4, but not tryptase, concentrations were also consistently elevated in late lavage samples. Further, the late lavage samples showed a significant increase in interleukin-5 concentrations that correlated with the presence of eosinophils and eosinophil granular proteins. Neither eosinophils nor soluble mediators of eosinophils increased when normal subjects were similarly challenged with antigen. These data suggest that eosinophils are attracted to the airway during the late-phase allergic reaction and that IL-5 may produce changes in airway eosinophil density and promote the release of granular proteins to cause airway injury.

Adult↗
PubMed1977

Immunologic characteristics in relation to high and low leukemogenic activity of radiation leukemia virus variants. I. Cellular analysis of immunosuppression.

Infection of adult C57BL/6 mice with variants of the radiation leukemia virus resulted in variable leukemia incidence. One variant, designated D-RadLV, induced lymphatic leukemia in 0 to 25% of mice after virus inoculation directly into the thymus of young adult mice. The leukemia incidence could be increased to 80 to 100% by host exposure to x-rays. The second variant, A-RadLV, induced lymphatic leukemia in 80 to 100% of similarly inoculated mice without the need for additional radiation treatment. Adult mice were inoculated with D-radLV or A-RadLV. Both variants reduced the immune response to sheep erythrocytes whereas only D-RadLV had an immunosuppressive effect after immunization with a thymus-independent immunogen polyvinyl-pyrrolidone (PVP). Results of transfer experiments indicated that the immunosuppressive effects were expressed at the immunocompetent cell level. Thymus-derived cells were affected by A-RadLV since their immunocompetent function was impaired, whereas D-RadLV affected the marrow cell population of immunocytes. Exposure of D-RadLV-inoculated mice to x-rays induced functional impairment of both thymus and marrow cells. Since the radiation leukemia virus induces "T" lymphatic leukemia it could be proposed that the initial tropism of the virus to thymocytes would lead to high leukemia induction potential, whereas virus tropism to bone marrow cells would yield a low leukemia incidence. The coleukemogenic effect of x-rays could perhaps be related with its capacity to alter and introduce a change in virus-lymphoid cells interaction.

Animals↗
PubMed1975

Pathways in thymus- and bone marrow-derived lymphatic leukemia in mice.

The radiation- and radiation leukemia virus-induced leukemias in C57BL/6 strain mice were found to be of the thymus-derived (T) lymphocyte origin. Experimental evidence indicated that the interaction of the radiation leukemia virus with thymus-derived lymphoid cells and specifically with the thymus subpopulation bearing high levels of H-2 alloantigens were prerequisites for the development of high leukemia incidence in these test systems. In radiation leukemogenesis in C57BL/6 mice it was shown that within several days following the radiation treatment a "released" leukemogenic agent was found in the irradiated bone marrow; whereas, several days following chemical carcinogen leukemogenesis in SJL/J mice, established preleukemic or leukemic cells could be detected in the bone marrow. The analysis concerned with the lymphoid origin of chemical carcinogen-induced lymphatic leukemias in SJL/J mice indicated clearly that the carcinogen could affect different lymphoid populations. The majority of the chemical-induced leukemias were of the bone marrow-derived (B) lymphocyte origin, although some leukemias were of T lymphocyte origin, and some tumors could not be classified as either T or B leukemias, perhaps representing stem cells which do not carry the characteristic surface antigens for mature T and B cells.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1975

Enhancement and retardation of spontaneous reticulum cell neoplasm development in SJL/J mice.

The enhancement or delay in the appearance of spontaneous reticulum cell neoplasms (RCN-B) in SJL/J mice was tested. Immunosuppressive treatment with antithymocyte serum and prolonged antigenic stimulation by repeated injections of sheep erythrocytes, leukemogenic cell-free centrifugates, and multichain synthetic polypeptides had no effect on the incidence or latency of spontaneous tumor appearance. Treatment with mineral oil or incomplete Freund adjuvant markedly enhanced tumor appearance (though the abundance of plasma cells induced by these treatments did not evoke the development of plasmacytomas, nor did it affect the incidence of serum paraproteinemia among mice with spontaneous tumors). Treatment with cortisone acetate, however, markedly retarded spontaneous tumor development. Tumors occurring early due to mineral oil and adjuvant treatment all had the characteristics of "RCN-B plasma cell type," and tumors occurring late due to cortisone treatment were all of the "RCN-B reticulum cell type." The possible involvement of the stem cell pool size in the enhancement or delay of spontaneous tumor development was discussed.

Animals↗