Effect of aminoglutethimide on ACTH plasma levels in Cushing's disease and Nelson syndrome]

Out of all steroidogenesis inhibitors aminoglutethimide is most frequently used agent for so-called chemical adrenalectomy, especially in oncological cases. The present studies aimed at assessing an effect of the inhibition of cortisol synthesis on plasma ACTH in patients treated with aminoglutethimide. According to the rules of negative feedback, an increase in plasma ACTH should be expected. Aminoglutethimide has been administered to 24 patients with Cushing's disease for 1-6 months. Plasma ACTH did not increase but statistically significantly decreased despite a decrease in blood cortisol. It indicates that aminoglutethimide directly inhibits ACTH secretion. No return of the normal circadian rhythm of cortisol and ACTH release suggests that the drug exerts an effect on ACTH release regulating mechanisms. No definite results were achieved in patients with Nelson syndrome treated with aminoglutethimide for a short period of time. Plasma ACTH levels tend to decrease but no statistical significance was observed in comparison with placebo. It may depend on markedly increased corticotrophin secretion in Nelson tumors.     

MPDA: Microarray pooled DNA analyzer

Background  

Microarray-based pooled DNA experiments that combine the merits of DNA pooling and gene chip technology constitute a pivotal advance in biotechnology. This new technique uses pooled DNA, thereby reducing costs associated with the typing of DNA from numerous individuals. Moreover, use of an oligonucleotide gene chip reduces costs related to processing various DNA segments (e.g., primers, reagents). Thus, the technique provides an overall cost-effective solution for large-scale genomic/genetic research. However, few publicly shared tools are available to systematically analyze the rapidly accumulating volume of whole-genome pooled DNA data.     

Kallikrein effect on the acquisition and extinction of conditioned reflexes in rats

The effect of kallikrein was studied on the acquisition and extinction of conditioned reactions in rats. It was demonstrated that kallikrein in doses of 50 and 100 mu/kg i.p. accelerated the process of learning in these animals. The observed effect might be connected with a rise in the activity of kininogenic enzymes in the central nervous system.     

Altered Fronto-Temporal Functional Connectivity in Individuals at Ultra-High-Risk of Developing Psychosis

Background

The superior temporal gyrus (STG) is one of the key regions implicated in psychosis, given that abnormalities in this region are associated with an increased risk of conversion from an at-risk mental state to psychosis. However, inconsistent results regarding the functional connectivity strength of the STG have been reported, and the regional heterogeneous characteristics of the STG should be considered.

Methods

To investigate the distinctive functional connection of each subregion in the STG, we parcellated the STG of each hemisphere into three regions: the planum temporale, Heschl’s gyrus, and planum polare. Resting-state functional magnetic resonance imaging was obtained from 22 first-episode psychosis (FEP) patients, 41 individuals at ultra-high-risk for psychosis (UHR), and 47 demographically matched healthy controls.

Results

Significant group differences (in seed-based connectivity) were demonstrated in the left planum temporale and from both the right and left Heschl’s gyrus seeds. From the left planum temporale seed, the FEP and UHR groups exhibited increased connectivity to the bilateral dorsolateral prefrontal cortex. In contrast, the FEP and UHR groups demonstrated decreased connectivity from the bilateral Heschl’s gyrus seeds to the dorsal anterior cingulate cortex. The enhanced connectivity between the left planum temporale and right dorsolateral prefrontal cortex was positively correlated with positive symptom severity in individuals at UHR (r = .34, p = .03).

Conclusions

These findings corroborate the fronto-temporal connectivity disruption hypothesis in schizophrenia by providing evidence supporting the altered fronto-temporal intrinsic functional connection at earlier stages of psychosis. Our data indicate that subregion-specific aberrant fronto-temporal interactions exist in the STG at the early stage of psychosis, thus suggesting that these aberrancies are the neural underpinning of proneness to psychosis.