Microcystin-LR promote intestinal secretion of water and electrolytes in rats.

We showed previously that exposure to microcystin-LR causes renal toxic effects in isolated perfused rat kidney, and that inflammatory mediators from supernatants of macrophages stimulated by microcystin-LR are involved in this process. The aim of this research was to examine water and electrolytes secretion in vivo, induced by microcystin-LR and supernatant of macrophages stimulated for this toxin (SUP.MphiS + MCLR), using perfused rat ileal segment and ligated intestinal loop models. We found microcystin-LR at 1 microg/ml (0.09 +/- 0.003* vs. control 0.07 +/- 0.001 g of secretion/2 cm of loop; P < 0.05*) and the SUP.MphiS + MCLR after 18 h postinoculation (0.10 +/- 0.003 vs. control 0.03 +/- 0.002 g/cm) caused intestinal secretion. In addition, microcystin-LR caused significant sodium secretion (-2.18 +/- 0.72* vs. control 2.18 +/- 0.50 microEq g(-1) min(-1)), potassium (-0.26 +/- 0.04* vs. control 0.32 +/- 0.03 microEq g(-1) min(-1)), chloride (MCLR = -3.29 +/- 1.93* vs. control 0.88 +/- 1.25 microEq g(-1) min(-1)) and water (-0.012 +/- 0.004* vs. control 0.002 +/- 0.002 ml g(-1) min(-1)). We also demonstrated SUP.MphiS + MCLR to induce intestinal secretion of electrolytes (sodium, potassium, chloride) and water. These findings suggested that microcystin-LR and lamina propria macrophages-derived mediators are able to induce intestinal secretion in vivo, probably via inhibition of protein phosphatase.     

Genetic Analysis of PARK2 and PINK1 Genes in Brazilian Patients with Early-Onset Parkinson's Disease

Parkinson''s disease is the second most frequent neurodegenerative disorder in the world, affecting 1-2% of individuals over the age of 65. The etiology of Parkinson''s disease is complex, with the involvement of gene-environment interactions. Although it is considered a disease of late manifestation, early-onset forms of parkinsonism contribute to 5–10% of all cases. In the present study, we screened mutations in coding regions of PARK2 and PINK1 genes in 136 unrelated Brazilian patients with early-onset Parkinson''s disease through automatic sequencing. We identified six missense variants in PARK2 gene: one known pathogenic mutation, two variants of uncertain role, and three nonpathogenic changes. No pathogenic mutation was identified in PINK1 gene, only benign polymorphisms. All putative pathogenic variants found in this study were in heterozygous state. Our data show that PARK2 point mutations are more common in Brazilian early-onset Parkinson''s disease patients (2.9%) than PINK1 missense variants (0%), corroborating other studies worldwide.     

Occult hepatitis B virus infection in liver transplant patients in a Brazilian referral center

Estimates of occult hepatitis B virus (HBV) infection prevalence varies among different studies depending on the prevalence of HBV infection in the study population and on the sensitivity of the assay used to detect HBV DNA. We investigated the prevalence of occult HBV infection in cirrhotic patients undergoing liver transplantation in a Brazilian referral center. Frozen liver samples from 68 adults were analyzed using a nested polymerase chain reaction assay for HBV DNA. The specificity of the amplified HBV sequences was confirmed by direct sequencing of the amplicons. The patient population comprised 49 (72.1%) males and 19 (27.9%) females with a median age of 53 years (range=18-67 years). Occult HBV infection was diagnosed in three (4.4%) patients. The etiologies of the underlying chronic liver disease in these cases were alcohol abuse, HBV infection, and cryptogenic cirrhosis. Two of the patients with cryptic HBV infection also presented hepatocellular carcinoma. Markers of previous HBV infection were available in two patients with occult HBV infection and were negative in both. In conclusion, using a sensitive nested polymerase chain reaction assay to detect HBV DNA in frozen liver tissue, we found a low prevalence of occult HBV infection in cirrhotic patients undergoing liver transplant, probably due to the low prevalence of HBV infection in our population.     

Consensus on melanonychia nail plate dermoscopy

This statement, focused on melanonychia and nail plate dermoscopy, is intended to guide medical professionals working with melanonychia and to assist choosing appropriate management for melanonychia patients. The International Study Group on Melanonychia was founded in 2007 and currently has 30 members, including nail experts and dermatopathologists with special expertise in nails. The need for common definitions of nail plate dermoscopy was addressed during the Second Meeting of this Group held in February 2008. Prior to this meeting and to date (2010) there have been no evidence-based guidelines on the use of dermoscopy in the management of nail pigmentation.     

Evaluation of Schistosomiasis Mansoni Morbidity by Hepatic and Splenic Elastography

In patients with Mansoni schistosomiasis, it is fundamental to evaluate the disease morbidity, which is reflected by the severity of periportal fibrosis (PPF) and parameters of portal hypertension, as analyzed by ultrasonography (US). This study aimed to evaluate the morbidity of schistosomiasis by hepatic and splenic point shear-wave elastography (pSWE) and relate this to US parameters. The PPF pattern, the diameter of the portal and splenic veins and the size of the spleen were evaluated by US. Then, liver and spleen pSWEs were assessed in 74 patients using the same equipment. As the PPF pattern progressed, the splenic pSWE values significantly increased. Significant correlations between splenic pSWE, the longitudinal and transverse lengths of the spleen and the diameters of the portal and splenic veins were observed. These findings, however, were not observed through hepatic pSWE. In conclusion, the splenic pSWE has the potential for assessing morbidity in schistosomiasis mansoni.