Matrix‐Metalloproteinase‐2 Predicts Arteriovenous Fistula Failure in Hemodialysis Patients

In hemodialysis patients the principal cause of arteriovenous fistula dysfunction is stenosis. Matrix‐metalloproteinase‐2 is implicated in the pathophysiological mechanism of stenosis development. Our study tried to assess the clinical impact of this protease on arteriovenous fistula survival. Seventy‐nine prevalent dialysis patients with functional arteriovenous fistulas were included in the study. The presence of stenosis and the serum levels of matrix‐metalloproteinase‐2 were determined at the beginning of the study. The patency of the arteriovenous fistulas was followed‐ up for two years. In multivariate regression; matrix‐metalloproteinase‐2 was a significant predictor of vascular access loss (HR = 1.104, 95%CI 1.033–1.179, P = 0.003). Patients with a level of matrix‐metalloproteinase‐2 lower than 50 ng/mL had a better survival of the arteriovenous fistulas. Matrix‐metalloproteinase‐2 was an even stronger predictor of fistula failure in the stenosis group (HR = 1.076, 95%CI 1.027–1.127, P = 0.002). In our study matrix‐metalloproteinase‐2 has a predictive value for arteriovenous fistula failure.     

Histopathological and immunohistochemical features of gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract. Major advances in their definition and classification and the understanding of their molecular mechanisms have recently been made. These advances have become a model of targeted therapy in oncology. The diagnosis of GISTs relies on histological arguments - proliferation of spindle cells, seldom of epithelioid cells or both spindle and epithelioid cells - and on immunohistochemical arguments - expression of CD117 usually associated with CD34 expression. The evaluation of the prognosis is essential and based on a simple algorithm using two prognostic parameters, tumor size and mitotic index. The aim of this paper is a complex histopathological assessment, using both classic and modern (immunohistochemistry) techniques, of the GISTs comprised in the study. GISTs occur mainly in older adults (median age 60-69 years), anywhere along the gastrointestinal tract but also retroperitoneal. Most of them were nodular (75%), tumor necrosis and mucosal ulceration being the most frequent encountered secondary alterations; these modifications proved to be significantly correlated with large tumor size and high malignancy. Immunohistochemical evaluation revealed that 77 (97%) cases of GISTs presented a positive reaction for CD117, 50 (63%) cases were positive for CD34, 19 (24%) were positive for SMA and only 10 (13%) were positive for S100. Immunohistochemical evaluation remains an important tool of pathology in the diagnosis of GISTs, in the differential diagnosis from other gastrointestinal mesenchymal tumors and represents the gold standard for diagnosis of these tumors and an eligibility criterion for imatinib therapy.     

Parental psychopathology and the risk of suicidal behavior in their offspring: results from the World Mental Health surveys

Previous research suggests that parental psychopathology predicts suicidal behavior among offspring; however, the more fine-grained associations between specific parental disorders and distinct stages of the pathway to suicide are not well understood. We set out to test the hypothesis that parental disorders associated with negative mood would predict offspring suicide ideation, whereas disorders characterized by impulsive aggression (for example, antisocial personality) and anxiety/agitation (for example, panic disorder) would predict which offspring act on their suicide ideation and make a suicide attempt. Data were collected during face-to-face interviews conducted on nationally representative samples (N=55?299; age 18+) from 21 countries around the world. We tested the associations between a range of parental disorders and the onset and persistence over time (that is, time since most recent episode controlling for age of onset and time since onset) of subsequent suicidal behavior (suicide ideation, plans and attempts) among offspring. Analyses tested bivariate and multivariate associations between each parental disorder and distinct forms of suicidal behavior. Results revealed that each parental disorder examined increased the risk of suicide ideation among offspring, parental generalized anxiety and depression emerged as the only predictors of the onset and persistence (respectively) of suicide plans among offspring with ideation, whereas parental antisocial personality and anxiety disorders emerged as the only predictors of the onset and persistence of suicide attempts among ideators. A dose-response relation between parental disorders and respondent risk of suicide ideation and attempt was also found. Parental death by suicide was a particularly strong predictor of persistence of suicide attempts among offspring. These associations remained significant after controlling for comorbidity of parental disorders and for the presence of mental disorders among offspring. These findings should inform future explorations of the mechanisms of intergenerational transmission of suicidal behavior.     

Endogenous activation of adenosine A(1) receptors accelerates ischemic suppression of spontaneous electrocortical activity

Cerebral ischemia induces a rapid suppression of spontaneous brain rhythms prior to major alterations in ionic homeostasis. It was found in vitro during ischemia that the rapidly formed adenosine, resulting from the intracellular breakdown of ATP, may inhibit synaptic transmission via the A(1) receptor subtype. The link between endogenous A(1) receptor activation during ischemia and the suppression of spontaneous electrocortical activity has not yet been established in the intact brain. The aim of this study was to investigate in vivo the effects of A(1) receptor antagonism by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) on the time to electrocortical suppression during global cerebral ischemia. Adult male Wistar rats under chloral hydrate anesthesia were subjected to 1-min transient "four-vessel occlusion" ischemic episodes, separated by 20-min reperfusion. The rats were injected intraperitoneally with either 1.25 mg/kg DPCPX dissolved in 2 ml/kg dimethyl sulfoxide (DMSO) or the same volume of DMSO alone, 15 min before the third ischemic episode. Time to electrocortical suppression was estimated based on the decay of the root mean square of two-channel electrocorticographic recordings. During the first two ischemic episodes, electrocortical suppression appeared after approximately 12 s in both groups. After DMSO administration, ischemic suppression remained unchanged. After DPCPX administration, the time to electrocortical suppression was increased by approximately 10 s, and bursts of activity were recorded during the entire ischemia. These effects disappeared within 15 h after DPCPX administration. Our data provide evidence that during cerebral ischemia endogenous activation of A(1) receptors accelerates the electrical "shut-down" of the whole brain.     

Putative virulence factors identified in Vibrio vulnificus strains isolated from oysters and seawater in Mexico

The presence of Vibrio vulnificus was analyzed in oyster and estuarine water samples from Mexico by PCR amplification of the vvhA gene and some putative virulence factors were tested. Samples were collected from 12 different sampling points over a one-year period; 31% samples were positive for V. vulnificus and all isolates were identified as biotype 1. All strains were cytotoxic and proteolytic, 98% showed adherence to epithelial cells, 91.4% were DNase-positive, 77.6% were mucinase-positive, 97.8% were lecithinase-positive and 79.8% were lipase positive. Regarding colony morphology, 51% strains were opaque, 20% were translucid, 28% were both opaque and translucid, and 80.8% showed a capsule. This is the first report on the isolation of V. vulnificus strains from environmental samples in Mexico, which may pose a health risk for local fisherman and seafood consumers.