Harry S. Smith

Infection and diabetes: The case for glucose control☆

This review summarizes data concerning the host resistance to infection in diabetes and the influence of an acute infection upon the endocrinologic-metabolite status of the diabetic patient. While it is well known that acute infections lead to difficulty in controlling blood sugar levels and the infection is the most frequently documented cause of ketoacidosis, controversy persists as to whether or not patients with diabetes mellitus are more susceptible to infection than age- and sex-matched nondiabetic control subjects. Our data obtained from the charts of 241 diabetic patients who were being followed as outpatients show a striking direct correlation between the overall prevalence of infection (p less than 0.001) and the mean plasma glucose levels (representing three or more fasting glucose determinations taken at times when no evidence of infection existed). There is a significant diminution in intracellular bactericidal activity of leukocytes with Staphylococcus aureus and Escherichia coli in subjects with poorly controlled diabetes in comparison with the control group. Serum opsonic activity for both Staph. Aureus and E. coli were significantly lower than in the control subjects. Taken together, the results from published reports as well as our data suggest to us that good control of blood sugar in diabetic patients is a desirable goal in the prevention of certain infections (Candida vaginitis, for example) and to ensure maintenance of normal host defense mechanisms that determine resistance and response to infection.

Effects of Parasite Population Density on Rate of Change of Host and Parasite Populations

The agencies in nature that influence population trends and levels of species are so numerous, and so interdependent and complex, that the only hope of understanding them appears to lie in studying the factors separately or in small related groups. The immediate objective is to reconstruct the effective environment by a sort of synthetic process, and the ultimate objective is to make it possible to evaluate the separate agencies by statistical analyses of field data. It is, of course, well known that population changes are associated with nutrition, with weather, with competition, with inherent changes in fecundity, and with the incidence of disease, parasites, and predators. The results of a considerable amount of research in these fields have been recorded. The writers will not undertake to discuss here these advances, as it would lengthen the paper unduly. Those interested in the causative agencies in population dynamics should refer to the various papers by: Thomas Park and associates on the effect of nutrition, and of competition, both interand intra-specific; Raymond Pearl, R. N. Chapman, V. Volterra, Janet Boyce, John Stanley, D. S. MacLagan, and A. C. Crombie on competition; F. S. Bodenheimer, James Davidson and associates, B. P. Uvarov, V. E. Shelford, L. C. Birch, and W. F. Cook on weather; and Paul Errington, G. F. Gause, A. J. Nicholson, W. R. Thompson, G. Salt, Marjory Walker, and Joyce Laing on

Immature circulating lymphocytes in severely malnourished Guatemalan children.

The percentage of peripheral blood lymphocytes forming rosettes with sheep erythrocytes (E-rosettes) was determined in 33 severely malnourished Guatemalan children, and in two groups of clinically well but mildly growth retarded children from the same environment. Mean E-rosettes in the acutely ill patients was lower than the value observed in the mildly malnourished children, although there was considerable overlap between groups. These data differ from previously published studies of severely malnourished children from other parts of the world in that not all patients had decreased values for E-rosettes, in contrast to the uniform depression reported by others. As all patients were clinically similar, the results suggest that there may be specific nutrient defects associated with protein-energy malnutrition that particularly affect immune function. In addition, in vitro incubation of lymphocytes from the acutely malnourished children with the thymic factor, thymosin fraction 5, increased the percentage of E-rosettes in a dose-dependent fashion. These data suggest that immature, thymosin-responsive T cells are present in circulation. It is possible that in vivo thymosin administration may be beneficial for malnourished individuals.