Neural connectivity of alexithymia: Specific association with major depressive disorder.

BACKGROUND: Alexithymia has been frequently associated with major depression disorders (MDD). Yet little is known about the exact relationship of alexithymia and MDD. In order to explore this subject matter, the neural connectivity associated with alexithymia in people with MDD and matched nonclinical controls were compared. METHODS: Twenty-two females diagnosed with first-episode MDD and twenty-one matched nonclinical controls were MRI brain-scanned with diffusion-tensor-imaging and resting-state-functional-imaging methods, and self-reported the Chinese 20-item Toronto Alexithymia Scale. RESULTS: Voxel-wise multiple regression analysis showed a group interaction effect regarding the correlation between white-matter-connectivity and alexithymia. Significant correlations were observed at the corpus-callosum in MDDs and at the right superior-longitudinal-fasciculus in the controls. These findings were then used to derive seeds for analyzing resting-state-functional-connectivity in each group separately. The results further revealed that alexithymia in MDDs were associated with reduced functional-connectivity in the right precentral-gyrus and several regions of the brain on the right which are associated with cognitive regulation in the default-mode-network. In contrast, among the control subjects, alexithymia was correlated with increased functional-connectivity between the right inferior-frontal-gyrus-triangularis and the right superior-occipital-lobe, which is associated with emotional response to external stimuli. LIMITATIONS: Better participant selection, especially recruitment of medication-free samples, and the engagement of additional alexithymia assessments, should be considered in future investigations. CONCLUSIONS: These findings supported our a priori hypothesis that MDDs and controls have distinct white-matter correlates of alexithymia, and these corresponded to the existing proposed neural correlates for the cognitive and affective characteristics of alexithymia respectively. Extended impacts of these microstructural changes on remote functional networks might help explain the distinct behavioral characteristics of alexithymia for these groups, as well as implications for therapeutic intervention of MDD

Persistent Infection and Promiscuous Recombination of Multiple Genotypes of an RNA Virus within a Single Host Generate Extensive Diversity

Recombination and reassortment of viral genomes are major processes contributing to the creation of new, emerging viruses. These processes are especially significant in long-term persistent infections where multiple viral genotypes co-replicate in a single host, generating abundant genotypic variants, some of which may possess novel host-colonizing and pathogenicity traits. In some plants, successive vegetative propagation of infected tissues and introduction of new genotypes of a virus by vector transmission allows for viral populations to increase in complexity for hundreds of years allowing co-replication and subsequent recombination of the multiple viral genotypes. Using a resequencing microarray, we examined a persistent infection by a Citrus tristeza virus (CTV) complex in citrus, a vegetatively propagated, globally important fruit crop, and found that the complex comprised three major and a number of minor genotypes. Subsequent deep sequencing analysis of the viral population confirmed the presence of the three major CTV genotypes and, in addition, revealed that the minor genotypes consisted of an extraordinarily large number of genetic variants generated by promiscuous recombination between the major genotypes. Further analysis provided evidence that some of the recombinants underwent subsequent divergence, further increasing the genotypic complexity. These data demonstrate that persistent infection of multiple viral genotypes within a host organism is sufficient to drive the large-scale production of viral genetic variants that may evolve into new and emerging viruses

Gray matter reduction associated with emotion regulation in female outpatients with major depressive disorder: A voxel-based morphometry study

Objective: Though emotion dysregulation is the key feature in major depressive disorder, and structural changes in brain areas of depressed patients have been found, it is unknown how these regional volume alterations correlate with the ability to regulate emotion in the depressed population. Method: We examined the gray matter concentration (GMC) and volume (GMV) in 17 depressed patients and 17 healthy volunteers using a voxel-based morphometry (VBM) study. Images were acquired using a 1.5 T MRI scanner, and were spatially normalized and segmented. Statistical comparisons were performed using the general linear model. The identified volumetric alterations in the depressed participants were correlated with their performance on an emotion regulation task that involved reduction of positive or negative emotions to emotional pictures that were selected according to their individual ratings. Results: The depressed participants showed specific difficulty in regulating negative emotion, though not positive emotion, which was associated with reduced GMV and concentration in the anterior cingulate cortex (ACC) and the inferior orbitofrontal cortex (OFC). Decreased GMC in the superior temporal cortex was also found in people with major depressive disorder. Conclusions: Abnormal structures in the ACC and OFC and the dysregulation of negative emotion may relate to the pathology of major depressive disorder. © 2009 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex

Medication adherence and subjective weight perception in patients with first-episode psychotic disorder

Introduction: Medication adherence is critical to the management of psychotic disorder. Different factors associated with medication adherence have been investigated in previous studies. However, the association with subjective weight perception, which is related to the weight gain side effect of antipsychotics, has not been thoroughly investigated. Subjective weight perception may not equal objective weight status. This study tests the hypothesis that medication adherence is related to subjective weight perception in a group of patients with first-episode psychotic disorder who have taken antipsychotics for one year. Methods: This study recruited 160 participants with one-year histories of first-episode psychotic disorder and measured their actual and perceived weights, amount of weight gain in the past year, body size satisfaction and medication adherence levels. The associations between medication adherence and both the actual and perceived weight status were analyzed controlling for other confounding factors including insight, drug attitude, illness severity and other medication side effects. Results: Stepwise multiple regression analysis found that the participants' perceived weight status, negative attitude toward their drugs and insight were the major factors associated with poor medication adherence. Of the participants who perceived themselves as being overweight, 86% believed that antipsychotics were responsible. Among those who had such beliefs, 72% had reduced their antipsychotic dosages on their own. About half of the participants had gained more than 7% of their baseline weight and 43.1% of the participants were found to be overweight after one year of treatment with antipsychotics. Conclusions: The results of this study indicate that medication adherence is associated with perceived weight status. Healthcare professionals should be aware of this relationship and address this issue early in the management of patients. Apart from weight management programs, education on a correct weight perception should be carried out with the promotion of proper drug attitudes and better insight for the improvement of medication adherence in the early course of psychotic disorder.link_to_subscribed_fulltex

Bone marrow involvement by nasal NK cell lymphoma at diagnosis is uncommon

To look for subtle evidence of marrow involvement in nasal NK cell lymphoma at diagnosis, we retrospectively studied trephine biopsy specimens from 25 consecutive patients by 2 sensitive techniques: CD56 immunohistochemistry and Epstein-Barr virus-encoded RNA in situ hybridization (EBER ISH). Only 2 patients had marrow involvement by NK cell lymphoma at diagnosis. In 3 additional patients, marrow involvement developed during or after systemic recurrence. All 5 positive cases were revealed by EBER ISH, but only 3 cases showed CD56 immunoreactivity. Among the 5 cases, only 2 were recognized by morphologic assessment. All 5 patients died, often within a short period, compared with a mortality of 50% for patients without demonstrable marrow involvement. Marrow involvement is distinctly uncommon in nasal NK cell lymphoma at diagnosis, and EBER ISH is the most sensitive technique for the demonstration of occult NK cell lymphoma. Despite the low frequency of marrow involvement in nasal NK cell lymphoma, EBER ISH is worthwhile to identify the minor subgroup of patients with a high likelihood of early death due to disease and when autologous bone marrow or peripheral blood stem cell transplantation is contemplated.link_to_subscribed_fulltex