71 research outputs found

    Genome-wide association analysis of GAW17 data using an empirical Bayes variable selection

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    Next-generation sequencing technologies enable us to explore rare functional variants. However, most current statistical techniques are too underpowered to capture signals of rare variants in genome-wide association studies. We propose a supervised coalescing of single-nucleotide polymorphisms to obtain gene-based markers that can stably reveal possible genetic effects related to rare alleles. We use a newly developed empirical Bayes variable selection algorithm to identify associations between studied traits and genetic markers. Using our novel method, we analyzed the three continuous phenotypes in the GAW17 data set across 200 replicates, with intriguing results

    Genome-wide case-control study in GAW17 using coalesced rare variants

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    Genome-wide association studies have successfully identified numerous loci at which common variants influence disease risks or quantitative traits of interest. Despite these successes, the variants identified by these studies have generally explained only a small fraction of the variations in the phenotype. One explanation may be that many rare variants that are not included in the common genotyping platforms may contribute substantially to the genetic variations of the diseases. Next-generation sequencing, which would better allow for the analysis of rare variants, is now becoming available and affordable; however, the presence of a large number of rare variants challenges the statistical endeavor to stably identify these disease-causing genetic variants. We conduct a genome-wide association study of Genetic Analysis Workshop 17 case-control data produced by the next-generation sequencing technique and propose that collapsing rare variants within each genetic region through a supervised dimension reduction algorithm leads to several macrovariants constructed for rare variants within each genetic region. A simultaneous association of the phenotype to all common variants and macrovariants is undertaken using a linear discriminant analysis using the penalized orthogonal-components regression algorithm. The results suggest that the proposed analysis strategy shows promise but needs further development

    Hepatic Sarcoidosis Mimicking Hilar Cholangiocarcinoma: Case Report and Review of the Literature

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    Sarcoidosis is a multisystemic granulomatous disease of unknown etiology. Hepatic involvement was reported in about 11% of patients with sarcoidosis. However, cases of sarcoidosis in which the granuloma is solitary and limited in the liver are very rare. A 51-year-old woman with tumors in the liver underwent extended left lobectomy with caudate lobectomy and bile duct resection. The tumor was located between segment 4 and the hilar region. Some daughter nodules were found in the left lobe, which were regarded as intrahepatic metastasis. Our case displayed clinical and radiologically distinct findings, which are very similar to those of hilar cholangiocarcinoma restricted to the liver. This report demonstrates that sarcoidosis can show solitary hepatic involvement in the absence of thoracic lymphadenopathy. In such a case, it is difficult to distinguish the diagnosis from other malignant neoplasms. In conclusion, the diagnosis of hepatic sarcoidosis has to be made through prudent and comprehensive investigations that include a full clinical history of sarcoidosis in other organs. Despite utilizing several detailed diagnostic modalities, the definitive diagnosis of cases of solitary sarcoidosis may remain difficult. In these cases, surgical treatment including liver resection should be considered in order to avoid missing a suitable opportunity for treatment

    Eosinophilic Enteritis Confined to an Ileostomy Site

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    Eosinophilic enteritis is a rather rare condition that can manifest anywhere from esophagus to rectum. Its description in the literature is sparse, but associations have been made with collagen vascular disease, malignancy, food allergy, parasitic or viral infections, inflammatory bowel disease, and drug sensitivity. We present the case of a 41-year-old male diagnosed with ulcerative colitis who underwent proctocolectomy with ileal pouch anal anastomosis and loop ileostomy formation utilizing Seprafilm®, who later developed eosinophilic enteritis of the loop ileostomy site. This is the first report of eosinophilic enteritis and its possible link to the use of bioabsorbable adhesion barriers

    Hepatitis B virus infection among different sex and age groups in Pakistani Punjab

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    <p>Abstract</p> <p>Background</p> <p>Hepatitis B virus (HBV) infection is a serious health problem in the developing countries including Pakistan. Various risk factors are responsible for the spread of this infectious disease. Prevalence of HBV infection in apparently suspected individual of Punjab province of Pakistan was analyzed during January 2008 to December 2010. Current study was aimed to investigate the epidemiology and risk factors of HBV infection.</p> <p>Methodology</p> <p>Four thousand eight hundred and ninety patients suffering from chronic liver disease were screened for the presence of HBV DNA using qualitative Real Time PCR methodology to confirm their status of infection. A predesigned standard questionnaire was filled for all the patients that included information about the possible risk factors.</p> <p>Results</p> <p>A total of 4890 ELISA positive patients were screened for Hepatitis B virus infection. Of these 3143 were positive for HBV, includes 68.15% males and 31.85% females. Male were observed to be more frequently infected as compared to the female with a positivity ratio of 2.14: 1. The rate of infection increases with the passage of time in the course of three years. Highest frequency of infection was found in the age of 21-30 was 34.93% followed by 23.83% in 31-40. Only (13.39%) were belonging to the age group 11-20 year. The rate of infection declines with increasing age as shown by age groups 41-50 (16.13%) and 51-60 (7.09%). While children aged 0-10 and very old >60 age groups were very less frequently 1.49% and 1.65% infected respectively. Important risk factors contributing to HBV spread include barber risk (23.60%), blood transfusion (4.04%), History of injection 26.19%, Reuse of syringes 26.60%, dental risk (11.20%) and surgical procedure (4.26%). Among the entire respondents trend sharing personal items was very common. History of injection, barber risk, surgery and dental procedure and reuse of syringes appear as major risk factors for the transmission.</p> <p>Conclusion</p> <p>Male were more frequently exposed to the risk factors as compared to female. Similarly the younger age group had high rate of infection as compared to the children's and the older age groups. Reuse of syringes', barber risk and History of injection were main risk identified during the present study. To lower HBV transmission rate Government should take aggressive steps towards massive awareness and vaccination programs to decrease the burden of HBV from the Punjab province of Pakistan.</p

    A comparison of hepatitis B viral markers of patients in different clinical stages of chronic infection

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    Hepatitis B viral markers may be useful for predicting outcomes such as liver-related deaths or development of hepatocellular carcinoma. We determined the frequency of these markers in different clinical stages of chronic hepatitis B infection. We compared baseline hepatitis B viral markers in 317 patients who were enrolled in a prospective study and identified the frequency of these tests in immune-tolerant (IT) patients, in inactive carriers , and in patients with either hepatitis B e antigen ( HBeAg)- positive or HBeAg-negative chronic hepatitis or cirrhosis. IT patients were youngest (median age 27 years) and HBeAg- negative patients with cirrhosis were oldest (median age 58 years) (p = 0.03 to < 0.0001). The male to female ratio was similar both in IT patients and in inactive carriers, but there was a male preponderance both in patients with chronic hepatitis and in patients with cirrhosis (p < 0.0001). The A1896 precore mutants were most prevalent in inactive carriers (36.4%) and HBeAg- negative patients with chronic hepatitis (38.8%; p < 0.0001), and the T 1762/A1764 basal core promoter mutants were most often detected in HBeAg- negative patients with cirrhosis (65.1%; p = 0.02). Genotype A was detected only in 5.3% of IT patients, and genotype B was least often detected in both HBeAg-Positive patients with chronic hepatitis and cirrhosis (p = 0.03). The hepatitis B viral DNA levels were lowest in inactive carriers (2.69 log(10) IU/mL) and highest in IT patients (6. 80 log(10) IU/mL; p = 0.02 to < 0.0001). At follow-up, HBeAg-positive and HBeAg-negative patients with cirrhosis accounted for 57 of 64 (89.1%) liver-related deaths (p < 0. 0001). Differences in baseline hepatitis B viral markers were detected in patients in various clinical stages of hepatitis B virus infection. HBeAg-positive and HBeAg- negative patients with cirrhosis accounted for the majority of the liver-related fatalities

    An Intronic Variant in the GRP78, a Stress-Associated Gene, Improves Prediction for Liver Cirrhosis in Persistent HBV Carriers

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    Background: Our previous study indicated that a common variant (rs430397 G>A) in the intron 5 of glucose-regulated protein 78 (GRP78) gene was associated with risk and prognosis of primary hepatocellular carcinoma (HCC), including HBV- and cirrhosis-related HCC. rs430397 polymorphism may be a contributing factor or biomarker of HBV infection or HBV-related cirrhosis. Methodology/Principal Findings: 539 non-HBV-infected individuals, 205 self-limited infection and 496 persistent HBV infection were recruited between January 2001 and April 2005 from the hospitals in Southern China. Genomic DNA was genotyped for rs430397. The associations between the variation and susceptibility to liver cirrhosis (LC) in persistent HBV infection were examined. We observed that individuals carrying allele rs430397A were more likely to become HBV-related LC. When persistently infected patients were divided into four subgroups, patients with phase IV had an increased allele A and genotype AG compared with phase I and/or phase III. Decreased serum albumin and prolonged plasma prothrombin time (PT) were showed in LC patients carrying genotype AA. Furthermore, rs430397 genotype had an increased susceptibility to LC with dose-dependent manners (P-trend = 0.005), and the genotype did constitute a risk factor for the development of advanced LC (Child-Pugh classification C and B, P-trend = 0.021). Conclusions/Significance: rs430397 polymorphism may be a contributing factor to LC in persistent HBV carriers. © 2011 Zhu et al.published_or_final_versio

    Evaluation of Genetic Susceptibility Loci for Chronic Hepatitis B in Chinese: Two Independent Case-Control Studies

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    BACKGROUND: A recent genome-wide scan has identified two genetic variants in the HLA-DP region strongly associated with hepatitis B infection in Japanese. This study evaluates the effects of these risk variants in Chinese, where the HBV infection is the most popular in the world. METHODS AND FINDINGS: We have assessed the relationship between these two single nucleotide polymorphisms (rs3077 and rs9277535) and chronic hepatitis B infection in two independent case-control studies. The first population in Chinese Han included 736 patients and 782 spontaneously recovered controls. The second set was established in Chinese Zhuang minority of 177 patients and 208 controls. Both A alleles of rs3077 and rs9277535 significantly deceased the risk to CHB in Chinese Han (OR = 0.540, 95%CI: 0.464-0.628, P = 4.068×10(-16) and OR = 0.696, 95%CI: 0.601-0.806, P = 1.062×10(-6), respectively). Conceivably, rs9277535 was found to be associated with decreased risk of the disease in Chinese Zhuang, with an OR of 0.606 (95%CI, 0.441-0.833, P = 0.002). CONCLUSION: Chronic hepatitis B susceptibility loci in HLA-DP region (rs3077 and rs9277535) identified by genome-wide scan in Japanese population were validated in Chinese population. These findings might provide clues to develop screening and surveillance strategies

    Ledipasvir and Sofosbuvir Plus Ribavirin for Treatment of HCV Infection in Patients With Advanced Liver Disease

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    BACKGROUND & AIMS: There are no effective and safe treatments for chronic hepatitis C virus (HCV) infection of patients who have advanced liver disease. METHODS: In this phase 2, open-label study, we assessed treatment with the NS5A inhibitor ledipasvir, the nucleotide polymerase inhibitor sofosbuvir, and ribavirin in patients infected with HCV genotypes 1 or 4. Cohort A enrolled patients with cirrhosis and moderate or severe hepatic impairment who had not undergone liver transplantation. Cohort B enrolled patients who had undergone liver transplantation: those without cirrhosis; those with cirrhosis and mild, moderate, or severe hepatic impairment; and those with fibrosing cholestatic hepatitis. Patients were assigned randomly (1:1) to receive 12 or 24 weeks of a fixed-dose combination tablet containing ledipasvir and sofosbuvir, once daily, plus ribavirin. The primary end point was sustained virologic response at 12 weeks after the end of treatment (SVR12). RESULTS: We enrolled 337 patients, 332 (99%) with HCV genotype 1 infection and 5 (1%) with HCV genotype 4 infection. In cohort A (nontransplant), SVR12 was achieved by 86%-89% of patients. In cohort B (transplant recipients), SVR12 was achieved by 96%-98% of patients without cirrhosis or with compensated cirrhosis, by 85%-88% of patients with moderate hepatic impairment, by 60%-75% of patients with severe hepatic impairment, and by all 6 patients with fibrosing cholestatic hepatitis. Response rates in the 12- and 24-week groups were similar. Thirteen patients (4%) discontinued the ledipasvir and sofosbuvir combination prematurely because of adverse events; 10 patients died, mainly from complications related to hepatic decompensation. CONCLUSION: The combination of ledipasvir, sofosbuvir, and ribavirin for 12 weeks produced high rates of SVR12 in patients with advanced liver disease, including those with decompensated cirrhosis before and after liver transplantation. ClinTrials.gov: NCT01938430
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