The effect of selected human steroid hormones upon the growth of dermatophytes with different adaptation to man

The inhibitory effect exerted by steroid hormones on thein vitro growth characteristics of dermatophytes is poorly understood. As a hypothesis this inhibition could result from fungal adaptation to the human host. Therefore, in this study the susceptibility of representative anthropophilic, zoophilic and geophilic dermatophytes to hormonal inhibition was compared. As a result, in agar dilution assaysprogesterone,testosterone, andestradiol proved to reduce fungal growth, whereashydrocortisone had no such effect. In general, anthropophilic dermatophytes were shown to be more responsive to steroid hormones than geophilic species, suggesting a correlation of steroid susceptibility with adaptation to human skin. However, since fungal response to hormones consisted of growth inhibition and occurred only at steroid concentrations much higher than present in human skin, it cannot be assumed to contribute to this adaptation.     

Analytic results for quantifying HIV infectivity

In a separate paper, we developed a mathematical model describing HIV infection and used it to suggest experiments for quantifying characteristic viral parameters. In this paper we generalize the model to any well-mixed assay system. We also present complete and rigorous derivations of fundamental results needed for the design and analysis of HIV infectivity assays. The model is applicable to infectious agents with multiple receptors for their target cell (e.g. HIV, Epstein-Barr virus and Plasmodium), and to blockers (both reversible and irreversible), as long as blocker and target cells are the same diffusion compartment.     

Liver-Fat Accumulation and Insulin Resistance in Obese Women with Previous Gestational Diabetes

Objective: We determined whether fat accumulation in the liver is associated with features of insulin resistance independent of obesity. Research Methods and Procedures: We recruited 27 obese nondiabetic women in whom liver fat (LFAT) content was determined by proton spectroscopy, intra-abdominal and subcutaneous fat by magnetic resonance imaging, and insulin sensitivity by the euglycemic insulin clamp technique. The women were divided based on their median LFAT content (5%) to groups with low (3.2 ± 0.3%) and high (9.8 ± 1.5%) liver fat. The groups were almost identical with respect to age (36 ± 1 vs. 38 ± 1 years in low vs. high-LFAT), body mass index (32.2 ± 0.6 vs. 32.8 ± 0.5 kg/m²), waist-to-hip ratio, intra-abdominal, subcutaneous, and total fat content. Results: Women with high LFAT had features of insulin resistance including higher fasting serum triglyceride (1.93 ± 0.21 vs. 1.11 ± 0.09 mM, p < 0.01) and insulin (14 ± 3 vs. 10 ± 1 mU/L, p < 0.05) concentrations than women with low LFAT. The group with high LFAT also had higher 24-hour blood pressures, and lower whole-body insulin sensitivity compared with the low-LFAT group. Discussion: In obese women with previous gestational diabetes, LFAT, rather than any measure of body composition, is associated with features of insulin resistance.     

Comparative analysis of chromatography peaks by computer and disc-integrator

A reliability study was conducted to compare a new, computerized method of measuring the areas under chromatographic curves with the traditional hand method of determining the areas. Three runs of 30 separate injections of standard inorganic phosphate were made using the chromatographic and dry-ashing procedure developed in the laboratory of the Department of Pharmacology of the USC School of Medicine. Results indicate that there is no statistically significant difference between the traditional method and the new computer method for amounts greater than 10 nm, and the computer method is more precise for amounts less than 10 nm. Hence, great savings in time and an increase in precision can be made by using a computer for these analyses.     

Making our diabetes patients' office visits more productive

Improving our health care procedures is ideally a collaborative and ongoing process, yet it takes time we may not feel we can easily afford. If we can consider how we might make even one change to improve our procedures, we might also be able to help improve not only the capabilities and skills of each member of our health care teams but also the ability of our patients to engage in effective diabetes self-care.