Systematic evaluation of the adrenocortical function in patients with paracoccidioidomycosis

Limited cortisol response to ACTH stimulation has been documented in 22 to 48% of patients with paracoccidioidomycosis (PM). Different approaches to interpret the test and inadequate selection of patients preclude an accurate appraisal of the actual incidence of adrenal insufficiency in PM. Rapid cosyntropin (ACTH) stimulation tests were performed in 38 consecutive patients (9 with the localized and 29 with the disseminated form of PM) and 40 normal controls. Subnormal cortisol responses to ACTH (60 minutes post-ACTH values below 455 nmol/l, 95% confidence limits) were found in only 4 patients (14%) with disseminated PM. If a retrospective sample of 6 patients studied previously (in whom tests were indicated due to clinical suspicion of Addison's disease) were included, or if the absolute cortisol increment above baseline was used for interpretation, we would find figures closer to those previously reported (23 and 24%, respectively). These data reflect that non-systematic evaluation or selection of a substandard criterion to interpret the test overestimates the frequency of adrenocortical insufficiency in PM.     

Impaired conversion of exogenous arachidonic acid by platelets to thromboxane B2 and correction of that deficiency by interferon-alpha

In the course of an investigation of cyclooxygenase and 12-lipoxygenase activity in platelets of patients with myeloproliferative syndrome receiving treatment with interferon-alpha 2 patients showed unusual results which have not been reported so far. Both patients had thrombocytosis, in one case associated with polycythaemia. In platelets of both patients, a reduced conversion of exogenous 14C arachidonic acid to TXB2 was observed accompanied by a shift in conversion to PGE2 and 12-HETE in one patient and to 12-HETE alone in the other before therapy. These findings were paradoxically associated with evidence of enhanced platelet activation in vivo. Treatment of both patients with interferon-alpha resulted in reversal of the biochemical abnormalities and in clinical remission.     

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.     

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.     

The platelet rebound phenomenon during PGI2-infusion occurs at the receptor level

In 6 patients treated with continuous prostaglandin I2 (PGI2)-infusion using a portable pump at a rate of 5 ng/kg/min for 7 days drug receptor interaction of [3H]Iloprost, a stable PGI2 analogue, with a particulate platelet membrane fraction was investigated. Saturation binding experiments of the high affinity platelet prostacyclin receptor performed before and at the end of PGI2 infusion revealed a significant increase of dissociation constant (Kd) and increase in maximal number of binding sites (Bmax). These findings suggest that continuous long-term PGI2 infusion results in a functional desensitization of the membrane-bound PGI2 platelet receptor with a decrease in receptor affinity and an increase in number of binding sites as suggested earlier based upon platelet sensitivity behaviour.