Molecular Characterization, Distribution, and Dynamics of Hepatitis C Virus Genotypes in Blood Donors in Colombia

Hepatitis C virus (HCV) is a frequent cause of acute and chronic hepatitis and a leading cause for cirrhosis of the liver and hepatocellular carcinoma. HCV is classified in six major genotypes and more than 70 subtypes. In Colombian blood banks, serum samples were tested for anti-HCV antibodies using a third-generation ELISA. The aim of this study was to characterize the viral sequences in plasma of 184 volunteer blood donors who attended the ""Banco Nacional de Sangre de la Cruz Roja Colombiana,`` Bogota, Colombia. Three different HCV genomic regions were amplified by nested PCR. The first of these was a segment of 180 bp of the 5`UTR region to confirm the previous diagnosis by ELISA. From those that were positive to the 5`UTR region, two further segments were amplified for genotyping and subtyping by phylogenetic analysis: a segment of 380 bp from the NS5B region; and a segment of 391 bp from the E1 region. The distribution of HCV subtypes was: 1b (82.8%), 1a (5.7%), 2a (5.7%), 2b (2.8%), and 3a (2.8%). By applying Bayesian Markov chain Monte Carlo simulation, it was estimated that HCV-1b was introduced into Bogota around 1950. Also, this subtype spread at an exponential rate between about 1970 to about 1990, after which transmission of HCV was reduced by anti-HCV testing of this population. Among Colombian blood donors, HCV genotype 1b is the most frequent genotype, especially in large urban conglomerates such as Bogota, as is the case in other South American countries. J. Med. Virol. 82: 1889-1898, 2010. (C) 2010 Wiley-Liss, Inc.

Use of multiple channel pH monitoring for evaluation of ultra-distal reflux in patients after fundoplication for treatment of Barrett`s esophagus

Dysplasia and esophageal adenocarcinoma may arise in patients with Barrett`s esophagus after fundoplication esophageal pH monitoring showing no acid in esophagus. This suggests the need to develop methodology to evaluate the occurrence of ultra-distal reflux (1 cm above the LES). The objective of the study was to compare acid exposition in three different levels: 5 cm above the upper border of the LES, 1 cm above the LES and in the intrasphincteric region. Eleven patients with Barrett`s esophagus after Nissen fundoplication with no clinical, endoscopic and radiologic evidence of reflux were selected. Four-channel pH monitoring took place: channel A, 5 cm above the upper border of the LES; channel B, 1 cm above the LES; channel C, intrasphincteric; channel D, intragastric. The results of channels A, B and C were compared. There was significant increase in number of reflux episodes and a higher fraction of time with pH <4.0 in channel B compared to channel A. There was significant decrease in fraction of time with pH <4.0 in channel B compared to channel C. Two cases of esophageal adenocarcinoma were diagnosed in the studied patients. The region 1 cm above the upper border of the LES is more exposed to acid than the region 5 cm above the upper border of the LES, although this exposure occurred in reduced levels. The region 1 cm above the upper border of the LES is less exposed to acid than the intrasphincteric region.

Distribution of lymph nodes in the mesorectum: how deep is TME necessary?

Background Standardization of total mesorectal excision (TME) had a great impact on decreasing local recurrence rates for the treatment of rectal cancer. However, exact numbers and distribution of lymph nodes (LN) along the mesorectum remains controversial with some studies suggesting that few LNs are present in the distal third of the mesorectum. Methods Eighteen fresh cadavers without a history of rectal cancer were studied. The rectum was removed by TME and then was divided into right lateral, posterior and left lateral sides, which were further subdivided into 3 levels (upper, middle and lower). A pathologist determined the number and sizes of the LNs in each of the nine areas, b linded to their anatomical origin. Results Overall, the mesorectum had a mean of 5.7 LNs (SD=3.7) and on average each LN had a maximum diameter of 3.0 mm (SD=2.7). There was no association between the mean number or size of LNs with gender, BMI, or age. There was a significantly higher prevalence of LNs in the posterior location (2.8 per mesorectum) than in the two lateral locations (0.8 and 1.2 per mesorectum; p=0.02). The distribution of LNs in the three levels of the rectum was not significant. Conclusions The distribution of LNs reinforces the fact that TME should always include the distal third of the mesorectum. Care must be taken to not violate the posterior aspect of the mesorectum.

Chinese wool auctions: Failed agribusiness reform or future marketing channel?

The spectacular though short-lived operation of China's wool auctions graphically illustrates problems in reforming China's agribusiness sector. A selective coverage of product type and participants, a highly contrived process of price discovery, and an urgent need for parallel reform in related areas all led to the demise of the auctions and are a barrier to their re-emergence as a viable wool marketing channel. Despite the challenges facing wool auctions, this paper argues that they still have much to offer the marketing of wool in China.

The structure of versutoxin (delta-atracotoxin-Hv1) provides insights into the binding of site 3 neurotoxins to the voltage-gated sodium channel

Background: Versutoxin (delta-ACTX-Hv1) is the major component of the venom of the Australian Blue Mountains funnel web spider, Hadronyche versuta. delta-ACTX-Hv1 produces potentially fatal neurotoxic symptoms in primates by slowing the inactivation of voltage-gated sodium channels; delta-ACTX-Hv1 is therefore a useful tool for studying sodium channel function. We have determined the three-dimensional structure of delta ACTX-Hv1 as the first step towards understanding the molecular basis of its interaction with these channels. Results: The solution structure of delta-ACTX-Hv1, determined using NMR spectroscopy, comprises a core beta region containing a triple-stranded antiparallel beta sheet, a thumb-like extension protruding from the beta region and a C-terminal 3(10) helix that is appended to the beta domain by virtue of a disulphide bond. The beta region contains a cystine knot motif similar to that seen in other neurotoxic polypeptides. The structure shows homology with mu-agatoxin-l, a spider toxin that also modifies the inactivation kinetics of vertebrate voltage-gated sodium channels. More surprisingly, delta-ACTX-Hv1 shows both sequence and structural homology with gurmarin, a plant polypeptide. This similarity leads us to suggest that the sweet-taste suppression elicited by gurmarin may result from an interaction with one of the downstream ion channels involved in sweet-taste transduction. Conclusions: delta-ACTX-Hv1 shows no structural homology with either sea anemone or alpha-scorpion toxins, both of which also modify the inactivation kinetics of voltage-gated sodium channels by interacting with channel recognition site 3. However, we have shown that delta-ACTX-Hv1 contains charged residues that are topologically related to those implicated in the binding of sea anemone and alpha-scorpion toxins to mammalian voltage-gated sodium channels, suggesting similarities in their mode of interaction with these channels.

Genotypic distribution of hepatitis C among hepatitis C and HIV co-infected patients in Brazil

Information on hepatitis C virus (HCV) genotypic distribution among HIV-HCV co-infected patients is lacking in Brazil as well as other Latin American countries. The objective of this study was to evaluate the level of exposure to different risk factors associated with HCV transmission among a group of co-infected patients and to characterize the genotypic distribution of HCV in this cluster. A series of 100 HIV-HCV co-infected patients was analysed. The data to be analysed were collected from specific laboratory tests. Information was collected through a questionnaire. HCV genotyping was carried out by sequencing the 5 ` non-coding region of HCV. Chi-square and Fischer association tests or Kruskal-Wallis test were used to study the association between HCV transmission-related variables and the established genotypes. In conclusion, exposure to multiple risk factors associated with HCV transmission was common among HIV co-infected patients and an association between HCV genotype 3 and intravenous drug user was observed.

Vascular density and distribution of vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 (Flk-1) are significantly higher in patients with deeply infiltrating endometriosis affecting the rectum

Objective: To analyze vascular density and immunolocalization of angiogenic vascular endothelial growth factor (VEGF) and its receptor Flk-1 in the proliferative and secretory eutopic human endometrium. and in three different sites of endometriosis: the ovary, bladder, and rectum. Design: Prospective study. Setting: University hospital. Patient(s): Thirty women with endometriosis (10 ovarian, 1.0 bladder, 10 rectal) and 32 control women (10 proliferative endometrium, 10 secretory endometrium, 4 normal ovary, 4 normal bladder, 4 normal rectum). Intervention(s): Normal endometrial samples were obtained from women during laparoscopic ablation of subserous myoma, and biopsy specimens of endometriosis were obtained from patients undergoing surgery for the diagnosis and treatment of endometriosis. Normal tissues of ovary, bladder, and rectum were obtained from these organs beside the lesions of endometriosis. Main Outcome Measure(S): Blood vessels were quantified according to the number of von Willebrand factor-positive endothelial cells. The VEGF and Flk-1 distribution were evaluated semiquantitatively by immunohistochemical staining. Result(s): More blood vessels were found in cases of endometriosis, particularly rectal endometriosis, compared with the respective control samples and with the eutopic endometrium, and they were localized in endometrial stroma around the glands. The VEGF and Flk-1 expression levels were also higher in cases of endometriosis, especially rectal endometriosis. Conclusion(s): Vascularization and VEGF and Flk-1 expression are significantly higher in deeply infiltrating endometriosis affecting the rectum, reinforcing the hypothesis that antiangiogenesis therapy may constitute a new modality of treatment, especially in cases of deep endometriosis involving the rectum.

Collagen Fiber and Versican Distribution Within the Lamina Propria of Fetal Vocal Folds

Objectives: To analyze the presence and distribution of collagen fibers and versican in human vocal fold lamina propria of fetal larynges. Study Design: Cross sectional analysis of cadaveric vocal folds of human fetuses. Methods: Seven fetal larynges obtained from 28- to 36-week-old fetuses were analyzed with the Picrosirius-polarization method, immunohistochemistry, and image analysis. Results: Collagen fibers within the lamina propria exhibited a monolaminar distribution pattern and spatial arrangement in ""wicker basket."" Versican distribution was larger in the superficial and intermediate layers when compared to the deep layer. Conclusion: Our findings suggest that collagen and versican distribution and arrangement within the lamina propria in the developing fetus are important for vocalization at birth.

Prevalence and distribution of the GBV-C/HGV among HIV-1-infected patients under anti-retroviral therapy

Infection with GB virus C (GBV-C) or hepatitis G virus (HGV) is highly prevalent among HIV/AIDS patients. GBV-C/HGV viremia has not been associated with liver disease and seems to slow HIV disease progression. To study the GBV-C/HGV genotypes prevalence among HIV/AIDS patients and its association with HIV viral load (VL) and CD4+ lymphocyte counts. From February 2003 to February 2004, we analyzed 210 HIV-1-infected subjects who were on anti-retroviral therapy (ART). For 63 of them a PCR-nested to the non-coding 5` (5`NCR) region of the GBV-C/HGV was done, and for 49 a DNA direct sequencing was done. A phylogenetic analysis was performed by PHYLIP program. 63(30%) of the HIV-1-infected patients were co-infected with GBV-C/HGV. The phylogenetic analysis revealed the following genotypes (and respective relative frequencies): 1(10%), 2a (41%), 2b (43%), and 3 (6%). Co-infected patients presented lower HIV-1 VL and higher T CD4+ lymphocyte cells counts as compared with patients negative for GBV-C/HGV sequences (log = 4.52 vs. 4.71, p = 0.036), and T CD4+ lymphocyte counts (cells/mm(3) = 322.6 vs. 273.5, p = 0.081, respectively). T CD4+ cells counts equal to, or higher than, 200/mm(3) were significantly more common among co-infected patients than among HIV-infected-only patients (p = 0.042). The lowest T CD4+ cells counts were associated with genotype 1 and the highest with genotype 2b (p = 0.05). The GBV-C/HGV infection prevalence was 30% among HIV-1-infected subjects, and was associated with lower VL and higher CD4+ lymphocyte counts. GBV-C/HGV genotype 2b may be associated with better immunological response. Published by Elsevier B.V.

Ventilation Distribution Studies Comparing Technegas and ""Gallgas"" Using (68)GaCl(3) as the Label

Ventilation distribution can be assessed by SPECT with Technegas. This study was undertaken in piglets with different degrees of ventilation inhomogeneity to compare PET using (68)Ga-labeled pseudogas or ""Gallgas"" with Technegas. Methods: Twelve piglets were studied in 3 groups: control, lobar obstruction, and diffuse airway obstruction. Two more piglets were assessed for lung volume (functional residual capacity). Results: In controls, SPECT and PET images showed an even distribution of radioactivity. With lobar obstruction, the absence of ventilation of the obstructed lobe was visible with both techniques. In diffuse airway obstruction, SPECT images showed an even distribution of radioactivity, and PET images showed more varied radioactivity over the lung. Conclusion: PET provides detailed ventilation distribution images and a better appreciation of ventilation heterogeneity. Gallgas with PET is a promising new diagnostic tool for the assessment of ventilation distribution.

POISSON DISTRIBUTION TO ANALYZE NEAR-THRESHOLD MOTOR EVOKED POTENTIALS

Motor unit action potentials (MUAPs) evoked by repetitive, low-intensity transcranial magnetic stimulation can be modeled as a Poisson process. A mathematical consequence of such a model is that the ratio of the variance to the mean of the amplitudes of motor evoked potentials (MEPs) should provide an estimate of the mean size of the individual MUAPs that summate to generate each MEP. We found that this is, in fact, the case. Our finding thus supports the use of the Poisson distribution to model MEP generation and indicates that this model enables characterization of the motor unit population that contributes to near-threshold MEPs. Muscle Nerve 42: 825-828, 2010

Congenital Hyperinsulinism in Brazilian Neonates: A Study of Histology, KATP Channel Genes, and Proliferation of beta Cells

Congenital hyperinsulinism (CHI) is a rare pancreatic beta-cell disease of neonates, characterized by inappropriate insulin secretion with severe persistent hypoglycemia, with regard to which many questions remain to be answered, despite the important acquisition of its molecular mechanisms in the last decade. The aim of this study was to examine pancreatic histology, beta-cell proliferation (immunohistochemistry with double staining for Ki-67/insulin), and beta-cell adenosine triphosphate-sensitive potassium channels genes from 11 Brazilian patients with severe medically unresponsive CHI who underwent pancreatectomy. Pancreatic histology and beta-cell proliferation in CHI patients were compared to pancreatic samples from 19 age-matched controls. Ten cases were classified as diffuse form (D-CHI) and 1 as focal form (F-CHI). beta-cell nucleomegaly and abundant cytoplasm were absent in controls and were observed only in D-CHI patients. The Ki-67 labeling index (Ki-67-LI) was used to differentiate the adenomatous areas of the F-CHI case (10.15%) from the ""loose cluster of islets`` found in 2 D-CHI samples (2.29% and 2.43%) and 1 control (1.54%) sample. The Ki-67-LI was higher in the F-CHI adenomatous areas, but D-CHI patients also had significantly greater Ki-67-LI (mean value = 2.41%) than age-matched controls (mean value = 1.87%) (P = 0.009). In this 1st genetic study of CHI patients in Brazil, no mutations or new polymorphisms were found in the 33-37 exons of the ABCC8 gene (SUR1) or in the entire exon of the KCNJ11 gene (Kir 6.2) in 4 of 4 patients evaluated. On the other hand, enhanced beta-cell proliferation seems to be a constant feature in CHI patients, both in diffuse and focal forms.