Relationship between the development of precore and core promoter mutations and hepatitis B e antigen seroconversion in patients with chronic hepatitis B virus

Chinese patients with chronic hepatitis B virus (332 with and 44 without cirrhosis-related complications) were studied. Fifty percent of patients <30 years old had precore mutations. The prevalence of precore mutations among hepatitis B e antigen (HBeAg)-positive patients, although lower than that among anti-HBe-positive patients (P = .031), was already high (44.2%). Median HBV DNA level in anti-HBe-positive patients was 1.5 × 106-1.55 × 106 copies/mL, irrespective of the presence or absence of precore mutations. There was no difference in the prevalence of precore mutations between patients with and without complications (P, not significant). However the prevalence of core promoter mutations was higher among patients with complications than among those without complications (90.5% vs. 69.3%, respectively; P = .003). In conclusion, precore mutations occurred in a large proportion of Chinese patients with chronic hepatitis B virus before HBeAg seroconversion. The development of complications was not related to precore mutations but was probably due to the persistence of significant viremia after HBeAg seroconversion.published_or_final_versio

Prognostic factors in severe exacerbation of chronic hepatitis B

Forty-seven patients with severe hepatitis B exacerbation were compared with patients who had mild exacerbation (n = 96) or no exacerbation (n = 96). Seventeen patients (36.2%) died or underwent liver transplantation. Preexisting cirrhosis and a prothrombin time (PT) of >30 s were associated with adverse outcome in 60.9% and 87.5% of patients, respectively. The rate of adverse outcome increased to 92.3% when albumin levels of ≤35 g/L and bilirubin levels of >200 μM were present. Other factors associated with adverse outcomes included peak bilirubin level, peak PT, time to reach peak PT, and the presence of encephalopathy and/or ascites. There was no difference in the frequency of precore mutations in patients with severe or mild exacerbation or without exacerbation. A significantly lower prevalence of core promoter mutants was found in patients with severe exacerbation (50%), compared with those who had mild exacerbation (81.3%; P = .004). Patients with severe exacerbation of hepatitis B with poor prognostic factors should be considered for early liver transplantation.published_or_final_versio

Feasibility Study and Performance Analysis of a Gyroless Orientation Tracker

Inertial orientation tracking systems commonly use three types of sensors: accelerometers, magnetometers, and gyroscopes. The angular rate signal is used to obtain a dead reckoning estimate, whereas the gravitational and local magnetic field measures allow us to apply a correction and to obtain a drift-free result. Considering the present market of inertial MEMS sensors, the current consumption of gyroscopes represents a major part of the power budget of wireless inertial sensor nodes, which should be minimized given the mobility of the application. This paper introduces an orientation tracking algorithm, based on an unscented Kalman filter, that does not require angular rate data for tracking human movements up to 450 degrees/s, which is a reasonable value for many applications. Since accelerometers measure other accelerations beside gravity and magnetometers are prone to magnetic disturbances, adaptive techniques are applied in order to reduce the influence on the estimations. The performance of the system is quantitatively analyzed and compared to an estimator that includes angular rate information

P-48 / S. Maeyaert P-48: Pixel-based Optical Feedback to Correct Ageing and Non-uniformities in Large-area Displays

Current AM addressing with peripheral drivers is not suited to tackle the problem of individual pixel deterioration for example due to aging or non-uniformity of different pixels in the display (a problem proportional to the size of the display). Therefore we pro-pose to integrate the driver electronics underneath each pixel, deviating from current display layouts. Thus it be-comes possible to implementing optical feedback for each pixel. A prototype of a driver with an optical feed-back loop was designed in a high voltage CMOS technology with integrated optical detectors. 1

Precore and core promoter mutations at the time of HBeAg seroclearance in Chinese patients with chronic hepatitis B

Objective: To determine the prevalence of precore and core promoter (CP) mutations before, at and after HBeAg seroclearance in Chinese patients. Methods: Precore and CP mutations were determined in 93 patients with chronic hepatitis B 12-24 months before, at and 12 months after the time of HBeAg seroclearance. Results: No significant changes were found in the prevalence of precore or CP mutations before, at and after HBeAg seroclearance. Seven patients (7.8%) had HBeAg seroreversion within 1 year of HBeAg seroclearance. There was no significant difference in the prevalence of precore and CP mutations between patients with and without HBeAg seroreversion. 68.3% and 48.7% of patients harbored the same precore and CP genotypes throughout. 32.0% patients with precore mutations and 8.9% patients with CP mutations before HBeAg seroclearance had reversion to wild type within 1 year of HBeAg seroclearance. Patients with genotype C patients had a higher prevalence of CP mutations before HBeAg seroclearance compared with patients with genotype B (82.4% vs. 44%, P = 0.001). Conclusions: Precore and CP mutations existed in a substantial proportion of Chinese patients before HBeAg seroclearance. The replication of precore and, to a lesser extent, CP mutants could be suppressed around the time of HBeAg seroclearance. © 2006 The British Infection Society.link_to_subscribed_fulltex

P-51 / H. De Pauw P-51: Mjollnir: A 300-Output Cascadeable High-Voltage Display Driver

A new high-voltage driver, originally designed for an 800x600 passive matrix AFLC display application, is integrated in a 0.35µm CMOS technology. The IC features 65V driving capability on all 300 outputs and is able of generating all kinds of complex high-voltage waveforms that are constituted out of 8 voltage levels (7 high-voltage levels and ground). 1

Epidemiological study of hepatitis B virus genotypes, core promoter and precore mutations of chronic hepatitis B infection in Hong Kong

Background/Aims We conducted a population study to document the prevalence of hepatitis B virus (HBV) genotypes in Hong Kong. Methods HBV genotypes, core promoter (CP) and precore mutations were determined in 776 asymptomatic patients. Results 92.6% patients had single genotype [B (32.5%), C (62.5%)]. 99.1% of genotype B was subtype Ba. Patients with age 51 years (32.5% vs. 41%, respectively, P=0.028). Compared to patients with genotype C, patients with genotype B had a higher cumulative rate (P=0.018) and younger age (40.1 vs. 34.2 years, respectively, P=0.018) of HBeAg seroconversion. There were no differences in the HBV DNA levels between patients with genotypes B and C, and with wild-type and mutants of CP and precore regions. By multivariate analysis, patients with genotype C and with CP mutations had higher alanine aminotransferase (ALT) levels. Conclusions B and C were the two most common HBV genotypes in Hong Kong. The former had a higher chance of earlier HBeAg seroconversion and lower ALT levels. The prevalence of genotype B was lower in patients with age <50, probably related to influx of immigrants from China since 1949. © 2004 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.link_to_subscribed_fulltex