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Biomedical subjects

J L Simon

Publications and source records attributed to J L Simon.

At least 19 recordsLinked to original sources
PubMed1992

Activation induced changes in expression and structure of the IL-7 receptor on human T cells.

Activation of human peripheral blood T cells renders them capable of proliferating to IL-2, -4, and -7, and upregulates the receptors for IL-2 and -4. In this study the effect of activation on the receptor for IL-7 has been investigated. Scatchard analysis showed dual affinity binding of IL-7 to peripheral blood mononuclear cells (PBMC). Furthermore, activation of PBMC with anti-CD3 antibodies resulted in a 4-fold downregulation of both the high and low affinity IL-7 receptors. SDS-PAGE analysis of [125I]IL-7 cross-linked resting PBMC revealed a major complex of 104/107 kDa (reduced/non-reduced) and a minor complex of 184/178 kDa (reduced/non-reduced). In contrast, cross-linking of activated PBMC revealed a third prominent complex of 93 kDa (non-reduced) not seen on unstimulated cells. This 93 kDa complex was observed on purified activated peripheral blood T cells and T cell blasts. Moreover, on a panel of IL-7 responsive T cell clones the 93 kDa complex was the only major cross-linked product observed. These results demonstrate that T cell activation causes changes in both the level of expression of the IL-7 receptor and the nature of the proteins associated with the receptor. It is postulated that these changes in receptor structure may be related to the acquisition of responsiveness to the IL-7 growth signal.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1976

[Denitrification of waters on the way from surface to underground levels in a karstic area].

The failure of the biological processes of waters' recycling in their passing through the soil occurs more and more frequently in calcareous areas. This led us to consider the problem of conditions necessary to the good development of the biological activity. This uses enzymatic reactions activated by chemical elements in very low concentrations: the oligo-elements. The experimental study, in drainage basin in a calcareous area, consisted in finding the percentage of oligo-elements in the waters, in the soils and in the parent rocks. This allowed us to draw a map of the probable lack of oligo-elements and thus to foresee the vulnerability of phreatic waters.

Calcium Carbonate↗
PubMed1975

Multiple cerebral abscesses complicating hepatopulmonary amebiasis.

A 3-year-old boy with hepatopulmonary amebiasis treated with chloroquine phosphate for 20 days subsequently was found to have three brain abscesses and responded to prolonged combined therapy with metronidazole and chloroquine phosphate. Cerebral amebiasis should be considered in any patient with amebic dysentery, hepatic abscess, or pulmonary involvement in whom signs or symptoms of central nervous system involvement appear. A prolonged course of appropriate therapy with periodic brain scanning for evidence of improvement is suggested.

Brain Abscess↗
PubMed1975

The welfare effect of an additional child cannot be stated simply and unequivocally.

There is no single calculable welfare effect of an additional person. Rather, there are many different judgments, which may be negative or positive. The welfare effect depends upon the particular economic situation the child will be born into, which point in his life-cycle one refers to, whether he is expected to have a positive effect upon his particular sort of economy and society during and after his lifetime, and most of all, on the kind of welfare criterion used. Furthermore, no matter which welfare criterion is used, the welfare effect of an added individual summarized over time is especially sensitive to the particular assumptions made.

Adult↗
PubMed1975

Puzzles and further explorations in the interrelationships of successive births with husband's income, spouses' education and race.

When fertility is examined in the detail of individual parity progressions and birth-order transitions, important interactions between the effects of income and education are seen. Among the findings are: the negative effect of education on fertility is stronger at all parities for less educated compared to more highly educated women. Additional income has a more positive effect for more highly educated than for less educated women. For women with 0-8 years of education the effect of more income is positive when the family has no children but negative thereafter, but for college-educated women the effect of more income is positive. And additional income has a less positive (more negative) effect on fertility among nonwhites than among whites.

Adult↗