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Biomedical subjects

D Riedel

Publications and source records attributed to D Riedel.

59 records · Page 4Linked to original sources

Mortality study of Canadian male farm operators: cancer mortality and agricultural practices in Saskatchewan.

The present investigation involved an analysis of approximately 70,000 male Saskatchewan farm operators, a subset of the 365,000 Canadian farm operators to be investigated in the Canadian Farm Operator Mortality Study. The results of the Saskatchewan analysis indicate that during the interval studied, overall mortality among Saskatchewan farmers was 25% lower than that for all Saskatchewan men, and that, during the same time interval, the risk of death from all types of cancer was also about 25% lower among Saskatchewan farmers than to all Saskatchewan men. Although the present study indicates that overall mortality of death from cancer was 25% lower among Saskatchewan male farmers, there was a relationship between non-Hodgkin's lymphoma mortality and acres sprayed for weeds; a similar risk relationship between expenditures on fuel oil and risk of death from non-Hodgkin's lymphoma was also evident. The magnitude of risk for Saskatchewan farmers is probably greater than that reflected in the estimates in this study, due to the likelihood of misclassification of exposure. There is a particular need for further studies in this area to improve the quantification of farming-related exposures, and to study the exposure history of individuals who develop non-Hodgkin's lymphoma.

Adult↗

Monokines: stimulatory and inhibitory regulator molecules of myelopoiesis in vitro.

The conditions for monocytes to secrete molecules that are involved in myelopoiesis, i.e. Colony Stimulating Factors (CSFs), Interleukin-1 (IL-1) and Tumor Necrosis Factor-alpha (TNF-alpha) were investigated. Whereas secretion of these molecules by monocytes is negligible in a quiescent state, activation of monocytes with Interferon-gamma (IFN-gamma) results in mRNA accumulation and subsequent protein secretion of CSF for granulocytes (G-CSF) and for monocytes (M-CSF). Under identical conditions mRNA-transcripts of TNF-alpha, IL-1-alpha and IL-1-beta genes were induced. Whereas IFN-gamma induces secretion of TNF-alpha protein, protein secretion of IL-1 by monocytes failed to occur in response to an IFN-gamma stimulus. However, the presence in culture of IFN-gamma in combination with TNF-alpha induced secretion of IL-1. Although IL-1 regulates the production of CSF for granulocytes and monocytes (GM-CSF) by IL-1 receptive T-lymphocytes, and is therefore involved in upregulatory mechanisms of myeloid growth, it may be able to suppress growth of myelopoietic progenitor cells (MPC) as well, when hematopoietic cultures are depleted of cells, that have the potential to secrete CSFs. Similarly, IFN-gamma, although being a major inducer of CSF secretion by monocytes, was shown to inhibit myeloid colony growth when exposed to purified MPC and allowed to synergize with TNF-alpha.

Biological Factors↗

[Epidemiological study of onchocercosis in 5 villages of the valley of the Sanaga (Cameroon)].

The study carried out in five villages in the Sanaga Valley of Cameroon was concerned with the prevalence of the disease, the level of infection and an evaluation of the effect of the parasites on the health of the people. Entomological data were also collected. The study was concerned with the onchocerciasis found in the forest area where the disease is hyperendemic. The males are infected moreoften than the females. Among the adults the skin and lymphatic lesions are extremly important. It was found that as the visual acuity diminishes with age, from age forty many for the people are blind. The villages most affected are those situated near the Sanaga rapids where there is a concentration of the breeding sites of the vectors.

Adolescent↗