Lack of association between the LPR and VNTR polymorphisms of the serotonin transporter gene and cocaine dependence in a Spanish sample

We genotyped the LPR and VNTR polymorphisms of the serotonin transporter gene in 504 cocaine-dependent patients and 508 controls. No association was detected with either polymorphism or with any haplotype combination. This study provided no evidence that these polymorphisms confer susceptibility to cocaine dependence in our sample.     

Weight loss is a major contributor to improved sexual function after bariatric surgery

Background

The relative contribution of anthropometric, hormonal, and metabolic changes after bariatric surgery (BS) on sexual function (SF) in severely obese subjects is not well established.

Methods

Prospective observational case series study of 39 men undergoing BS. SF was assessed by means of the international index of erectile function (IIEF) before and at 1 year after surgery. At the same time points, anthropometric (body mass index, waist circumference), hormonal (testosterone, sex hormone binding globulin, estradiol, gonadotropins, inhibin B, prolactin, leptin), and metabolic parameters (insulin sensitivity, C-reactive protein, lipid profile, hemoglobin A1c, presence of hypertension or sleep apnea) were assessed.

Results

BS was associated with marked weight loss (77.18 % excess weight loss), improved IIEF score (baseline: 54.85 ± 16.59, 1 year: 61.21 ± 14.10; p < 0.01), gonadal function (testosterone: baseline 256.36 ± 120.98, 1 year: 508.01 ± 161.90; p < 0.001), and improved metabolic profile. However, on multivariate regression analysis whereas changes in body mass index (beta: ?0.677, p = 0.001), and baseline IIEF score (beta: ?0.397, p = 0.023), were independent predictors of the changes in the IIEF score at 1 year after surgery, changes in hormonal and metabolic factors were not. Variables in the model accounted for 66 % of the postsurgical variation in the IIEF score. Similar results were found when the different IIEF-sexual domains were evaluated, except for intercourse satisfaction for which no independent predictor was identified.

Conclusions

Weight loss’s beneficial effects on SF occurring after BS are beyond the parallel improvement in gonadal and metabolic profiles.     

Viral hepatitis in liver transplantation

Liver transplantation is the only alternative for patients with end-stage liver disease. Viral hepatitis B and C are among the most common causes of cirrhosis and hepatocellular carcinoma and a frequent indication for liver transplantation. Hepatitis B virus immunoglobulin and nucleot(s)ide analogues have facilitated the management of patients with hepatitis B who have received liver transplants and resulted in excellent long-term outcomes. On the contrary, recurrence of hepatitis C is the main cause of graft loss in most transplant programs. Current therapeutic approaches are far from optimal, because sustained virologic responses are only achieved in one-third of treated patients, and adverse effects are common and severe. However, the rapid development of direct-acting antivirals against hepatitis C virus will change the management of this disease and in a few years prevent graft infection with this virus.     

Myocardial edema: a translational view

Myocardial edema occurs in a large number of myocardial pathologies particularly during ischemia-reperfusion, and may contribute to cell dysfunction and death occurring in these conditions. Cardiomyocyte cell volume is tightly regulated by modifications in cytosolic osmolality. Changes in membrane water permeability through aquaporin and connexin hemichannels also contribute to cell volume changes while caveolae may be important in sensing cell volume changes sensing and associated signaling. Ischemia-reperfusion alters these mechanisms and increases microvascular permeability by endothelial hypercontracture-induced gap formation, endothelial cell death and basal membrane disruption. Detection of myocardial edema by MRI has many useful diagnostic applications in acute myocardial infarction and other conditions. However, discrimination between intra and extracellular myocardial edema is presently difficult at the bench and impossible at the bedside. Developing methods to differentiate intra from extracellular myocardial water should allow a better understanding of the mechanisms and consequences of myocardial edema and, as a consequence lead to new diagnostic and therapeutic applications.     

Cultural diversification promotes rapid phenotypic evolution in Xavánte Indians

Shifts in social structure and cultural practices can potentially promote unusual combinations of allele frequencies that drive the evolution of genetic and phenotypic novelties during human evolution. These cultural practices act in combination with geographical and linguistic barriers and can promote faster evolutionary changes shaped by gene-culture interactions. However, specific cases indicative of this interaction are scarce. Here we show that quantitative genetic parameters obtained from cephalometric data taken on 1,203 individuals analyzed in combination with genetic, climatic, social, and life-history data belonging to six South Amerindian populations are compatible with a scenario of rapid genetic and phenotypic evolution, probably mediated by cultural shifts. We found that the Xavánte experienced a remarkable pace of evolution: the rate of morphological change is far greater than expected for its time of split from their sister group, the Kayapó, which occurred around 1,500 y ago. We also suggest that this rapid differentiation was possible because of strong social-organization differences. Our results demonstrate how human groups deriving from a recent common ancestor can experience variable paces of phenotypic divergence, probably as a response to different cultural or social determinants. We suggest that assembling composite databases involving cultural and biological data will be of key importance to unravel cases of evolution modulated by the cultural environment.