412 research outputs found
Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2008 update
Large amounts of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2005. These include long-term follow-up studies in large community-based cohorts or asymptomatic subjects with chronic HBV infection, further studies on the role of HBV genotype/naturally occurring HBV mutations, treatment of drug resistance and new therapies. In addition, Pegylated interferon α2a, entecavir and telbivudine have been approved globally. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings were discussed and debated. The earlier “Asian-Pacific consensus statement on the management of chronic hepatitis B” was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, special indications for liver biopsy in patients with persistently normal alanine aminotransferase, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune-suppressive medications or chemotherapy and patients in the setting of liver transplantation, are also included
A comparison of random forests, boosting and support vector machines for genomic selection
Genomic selection (GS) involves estimating breeding values using molecular markers spanning the entire genome. Accurate prediction of genomic breeding values (GEBVs) presents a central challenge to contemporary plant and animal breeders. The existence of a wide array of marker-based approaches for predicting breeding values makes it essential to evaluate and compare their relative predictive performances to identify approaches able to accurately predict breeding values. We evaluated the predictive accuracy of random forests (RF), stochastic gradient boosting (boosting) and support vector machines (SVMs) for predicting genomic breeding values using dense SNP markers and explored the utility of RF for ranking the predictive importance of markers for pre-screening markers or discovering chromosomal locations of QTLs
Estimation of the incidence of genital warts and the cost of illness in Germany: A cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Human papillomavirus (HPV) is a necessary cause of cervical cancer. HPV is also responsible for benign <it>condylomata acuminata</it>, also known as genital warts. We assessed the incidence of genital warts in Germany and collected information on their management to estimate the annual cost of disease.</p> <p>Methods</p> <p>This was a multi-centre observational (cross-sectional) study of genital warts in Germany. Data were collected from gynecologists, dermatologists, and urologists seeing patients with genital warts between February and April 2005. The number of patients with new and recurrent genital warts was used to estimate the incidence in Germany. We assessed resource use for patients with genital warts seen during a two-month period as well as retrospective resource use twelve months prior to the inclusion visit through a chart review. The mean costs of treatment of patients with genital warts from third-party payer and societal perspectives were estimated, and the total annual cost of genital warts was then calculated.</p> <p>Results</p> <p>For the incidence calculation 217 specialists provided information on 848 patients and 214 specialists provided resource use data for 617 patients to assess resource consumption. The incidence of new and recurrent cases of genital warts was 113.7 and 34.7 per 100 000, respectively, for women aged 14–65 years consulting gynecologists. The highest incidence was observed in women aged 14–25 years (171.0 per 100 000) for new cases and in women aged 26–45 years (53.1 per 100 000) for recurrent cases. The sample size for males was too small to allow a meaningful estimate of the incidence. The mean direct cost per patient with new genital warts was estimated at 378 euros (95% CI: 310.8–444.9); for recurrent genital warts at 603 euros (95% CI: 436.5–814.5), and for resistant genital warts at 1,142 euros (95% CI: 639.6–1752.3). The overall cost to third-party payers was estimated at 49.0 million euros, and the total societal cost at 54.1 million euros, corresponding to an average cost per patient of 550 euros and 607 euros, respectively.</p> <p>Conclusion</p> <p>The societal burden and costs of managing and treating genital warts in Germany are considerable. A vaccination programme using the quadrivalent human papillomavirus vaccine could provide a substantial health benefit and reduce the costs associated with genital warts in Germany.</p
The effects of an enhanced simulation programme on medical students' confidence responding to clinical deterioration
BACKGROUND: Clinical deterioration in adult hospital patients is an identified issue in healthcare practice globally. Teaching medical students to recognise and respond to the deteriorating patient is crucial if we are to address the issue in an effective way. The aim of this study was to evaluate the effects of an enhanced simulation exercise known as RADAR (Recognising Acute Deterioration: Active Response), on medical students’ confidence. METHODS: A questionnaire survey was conducted; the instrument contained three sections. Section 1 focused on students’ perceptions of the learning experience; section 2 investigated confidence. Both sections employed Likert-type scales. A third section invited open responses. Questionnaires were distributed to a cohort of third-year medical students (n = 158) in the North East of Scotland 130 (82 %) were returned for analysis, employing IBM SPSS v18 and ANOVA techniques. RESULTS: Students’ responses pointed to many benefits of the sessions. In the first section, students responded positively to the educational underpinning of the sessions, with all scores above 4.00 on a 5-point scale. There were clear learning outcomes; the sessions were active and engaging for students with an appropriate level of challenge and stress; they helped to integrate theory and practice; and effective feedback on their performance allowed students to reflect and learn from the experience. In section 2, the key finding was that scores for students’ confidence to recognise deterioration increased significantly (p. < .001) as a result of the sessions. Effect sizes (Eta(2)) were high, (0.68–0.75). In the open-ended questions, students pointed to many benefits of the RADAR course, including the opportunity to employ learned procedures in realistic scenarios. CONCLUSIONS: The use of this enhanced form of simulation with simulated patients and the judicious use of moulage is an effective method of increasing realism for medical students. Importantly, it gives them greater confidence in recognising and responding to clinical deterioration in adult patients. We recommend the use of RADAR as a safe and cost-effective approach in the area of clinical deterioration and suggest that there is a need to investigate its use with different patient groups
Osteopontin induces growth of metastatic tumors in a preclinical model of non-small lung cancer
Osteopontin (OPN), also known as SPP1 (secreted phosphoprotein), is an integrin binding glyco-phosphoprotein produced by a variety of tissues. In cancer patients expression of OPN has been associated with poor prognosis in several tumor types including breast, lung, and colorectal cancers. Despite wide expression in tumor cells and stroma, there is limited evidence supporting role of OPN in tumor progression and metastasis. Using phage display technology we identified a high affinity anti-OPN monoclonal antibody (hereafter AOM1). The binding site for AOM1 was identified as SVVYGLRSKS sequence which is immediately adjacent to the RGD motif and also spans the thrombin cleavage site of the human OPN. AOM1 efficiently inhibited OPNa binding to recombinant integrin αvβ3 with an IC50 of 65 nM. Due to its unique binding site, AOM1 is capable of inhibiting OPN cleavage by thrombin which has been shown to produce an OPN fragment that is biologically more active than the full length OPN. Screening of human cell lines identified tumor cells with increased expression of OPN receptors (αvβ3 and CD44v6) such as mesothelioma, hepatocellular carcinoma, breast, and non-small cell lung adenocarcinoma (NSCLC). CD44v6 and αvβ3 were also found to be highly enriched in the monocyte, but not lymphocyte, subset of human peripheral blood mononuclear cells (hPBMCs). In vitro, OPNa induced migration of both tumor and hPBMCs in a transwell migration assay. AOM1 significantly blocked cell migration further validating its specificity for the ligand. OPN was found to be enriched in mouse plasma in a number of pre-clinical tumor model of non-small cell lung cancers. To assess the role of OPN in tumor growth and metastasis and to evaluate a potential therapeutic indication for AOM1, we employed a KrasG12D-LSLp53fl/fl subcutaneously implanted in vivo model of NSCLC which possesses a high capacity to metastasize into the lung. Our data indicated that treatment of tumor bearing mice with AOM1 as a single agent or in combination with Carboplatin significantly inhibited growth of large metastatic tumors in the lung further supporting a role for OPN in tumor metastasis and progression
Current Antiviral Therapy of Chronic Hepatitis B: Efficacy and Safety
The treatment of chronic hepatitis B is in constant evolution. Interferon, the first agent licensed for chronic hepatitis B treatment, has been superseded by the growing popularity of nucleoside/nucleotide analogues (NA). However, resistance to these agents is a major challenge. Newer NAs, such as entecavir and tenofovir dipivoxil fumarate, have very low resistance rates and favorable safety profiles. Long-term use of these agents can effectively suppress hepatitis B virus DNA, leading to decrease in incidence of hepatitic flares, as well as in the development of cirrhosis and hepatocellular carcinoma. The efficacy and safety of various antiviral agents is discussed in this review
Pros and Cons of Peginterferon Versus Nucleos(t)ide Analogues for Treatment of Chronic Hepatitis B
The emergence of new and more potent treatment options has markedly changed the treatment landscape of chronic hepatitis B. Both peginterferon and nucleos(t)ide analogues have considerable advantages and limitations, and current treatment guidelines refrain from clearly suggesting a first-line treatment option. Peginterferon offers the advantage of higher sustained response rates in both hepatitis B early antigen (HBeAg)-positive and HBeAg-negative patients, at the price of considerable side effects and high costs. Nucleos(t)ide analogues offer easy daily oral dosing, and newly registered agents can maintain viral suppression for prolonged treatment duration. However, relapse is common after therapy discontinuation and extended therapy therefore often necessary. Prolonged treatment with nucleos(t)ide analogues may enhance chances of virologic and serologic response at the potential cost of the emergence of viral resistance and side effects. Baseline and on-treatment prediction of response may help select patients for peginterferon therapy and can aid individualized treatment decisions concerning therapy continuation or discontinuation
Dirichlet Multinomial Mixtures: Generative Models for Microbial Metagenomics
We introduce Dirichlet multinomial mixtures (DMM) for the probabilistic modelling of microbial metagenomics data. This data can be represented as a frequency matrix giving the number of times each taxa is observed in each sample. The samples have different size, and the matrix is sparse, as communities are diverse and skewed to rare taxa. Most methods used previously to classify or cluster samples have ignored these features. We describe each community by a vector of taxa probabilities. These vectors are generated from one of a finite number of Dirichlet mixture components each with different hyperparameters. Observed samples are generated through multinomial sampling. The mixture components cluster communities into distinct ‘metacommunities’, and, hence, determine envirotypes or enterotypes, groups of communities with a similar composition. The model can also deduce the impact of a treatment and be used for classification. We wrote software for the fitting of DMM models using the ‘evidence framework’ (http://code.google.com/p/microbedmm/). This includes the Laplace approximation of the model evidence. We applied the DMM model to human gut microbe genera frequencies from Obese and Lean twins. From the model evidence four clusters fit this data best. Two clusters were dominated by Bacteroides and were homogenous; two had a more variable community composition. We could not find a significant impact of body mass on community structure. However, Obese twins were more likely to derive from the high variance clusters. We propose that obesity is not associated with a distinct microbiota but increases the chance that an individual derives from a disturbed enterotype. This is an example of the ‘Anna Karenina principle (AKP)’ applied to microbial communities: disturbed states having many more configurations than undisturbed. We verify this by showing that in a study of inflammatory bowel disease (IBD) phenotypes, ileal Crohn's disease (ICD) is associated with a more variable community
Hepatitis B and Hepatocellular Carcinoma Screening Among Asian Americans: Survey of Safety Net Healthcare Providers
BackgroundPhysician patterns of screening for hepatitis B (HBV) and hepatocellular carcinoma (HCC) among Asian Americans are not well described.AimsTo describe HBV and HCC screening practices among providers with large Asian American populations.MethodsProviders within San Francisco's safety net system were surveyed with respect to HBV and HCC screening practices as well as knowledge, attitudes, and barriers to HCC screening.ResultsAmong the 109 respondents (response rate = 72%), 62% were aged >40, 65% female, 24% Asian, 87% primary care providers, and 48% had >25% Asian patients. Only 76% had screened >50% of their Asian patients for HBV and 43% had vaccinated >50% of eligible patients against HBV. Although 94% knew Asians were disproportionately affected by HCC, only 79% had screened for HCC in >50% of their Asian patients with chronic hepatitis B (CHB). A majority believed that HCC screening in CHB reduces HCC mortality (70%) and is cost-effective (57%). The most common HCC screening modality was AFP with abdominal ultrasound every 6-12 months (63%). Factors associated with HBV screening were familiarity with AASLD guidelines (OR 6.4, 95% CI 1.3-30.1, p = 0.02) and having vaccinated >50% of eligible patients against HBV (OR 2.2, 95% CI 1.1-4.5, p = 0.03). Factors associated with HCC screening using abdominal ultrasound every 6-12 months were having >25% Asian patients (OR = 4.5, 95% CI 1.3-15.3, p = 0.02) and higher HCC knowledge score (OR = 1.9 per item, 95% CI 1.01-3.6, p = 0.045).ConclusionsHBV and HCC screening rates and HBV vaccination among Asians from physician report is suboptimal. HCC screening is associated with having more Asian patients and higher provider knowledge. Provider education is essential in increasing rates of HBV and HCC screening among Asian Americans
Telbivudine versus entecavir in patients with undetectable hepatitis B virus DNA: a randomized trial
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