Chronic carriers of hepatitis B surface antigen in an endemic area for schistosomiasis mansoni in Brazil

Data on the association of schistosomiasis and hepatitis B in field-based studies are scarce. Two areas have been selected for this study: i) Queixadinha, endemic for schistosomiasis, with a population of 693 individuals, and ii) Capão, a control non-endemic area, with 515 inhabitants. Sera of all individuals in both areas were tested for hepatitis B infection, yearly, from 1994 to 1997. In the first area hepatitis B was found in 32.1% of children up to one year old and reached a peak of 68.7% in the age range of 15 to 19 years. In the control area the prevalence of hepatitis B was under 5% up to 19 years of age and the highest prevalence was observed in adults over 45. HBsAg was detected in 9.4% of the individuals living in the endemic area for schistosomiasis and in 1.4% of the controls (OR=4.98; 95%CI=3.7-6.7). The index of chronicity of HBsAg was not statistically different in the studied areas (8.1% x 7.3%; OR = 1.09; 95%CI= 0.42-3.03), nor was it different for people with and without schistosomiasis in Queixadinha (8.7% x 7.0%). We conclude that the Schistosoma mansoni infection has not altered the course of hepatitis B in the studied area.

Prognosis of schistosomiasis mansoni patients infected with hepatitis B virus

A clinical study on the evolution of patients with schistosomiasis mansoni has been conducted since 1983 at the outpatient clinic of the Infectious and Parasitic Disease Service in the Clementino Fraga Filho University Hospital in Rio de Janeiro, Brazil, comparing prevalence of positive tests for HBsAg, anti-HBsAg, and anti-HBc among patients infected with Schistosoma mansoni coming from various regions of Brazil and with different clinical forms of the disease. A non-significant predominance of HBsAg, anti-HBsAg, and anti-HBc was detected among patients with the hepatosplenic form of schistosomiasis, who presented a more severe clinical evolution with a higher frequency of hematemesis and/or melena, in addition to the development of macronodular cirrhosis and a worse prognosis as compared to patients with the toxemic form, schistosomiasis-infection and the hepatointestinal form.

The Epidemiological Impact of Antimeningococcal B Vaccination in Cuba

The incidence of invasive meningococcal disease (IMD) before (1984-1988) and after (1989-1994), a nationwide intervention with VA-MENGOC-BC vaccination started in 1989, was compared. The prevaccination period incidence density (ID> 8.8/ 105 year-person) was higher than the postvaccination ID (ID< 6.5/ 105 year-person). The percentage proportional differences from the start to the end of each period of ID in the vaccinal period was higher (87%) than the prevaccinal (37%) with significant differences among vaccinated groups (< 25 years old). A break-point (Chow test) was confirmed by the decrease in the ID between 1989 and 1990 in children under 1 year old, 5-9, 10-14, 15-19 and 50-54 years. Comparison of ID using maps showed a decrease in IMD in all municipalities during the postvaccination period. These findings support the epidemiological impact of VA-MENGOC-BC vaccination in the reduction of IMD morbidity.

Constitutive activity and inverse agonism at the α(₁a) and α(₁b) adrenergic receptor subtypes.

The α(1b)-adrenergic receptor (AR) was, after rhodopsin, the first G protein-coupled receptor (GPCR) in which point mutations were shown to trigger constitutive (agonist-independent) activity. Constitutively activating mutations have been found in other AR subtypes as well as in several GPCRs. This chapter briefly summarizes the main findings on constitutively active mutants of the α(1a)- and α(1b)-AR subtypes and the methods used to predict activating mutations, to measure constitutive activity of Gq-coupled receptors and to investigate inverse agonism. In addition, it highlights the implications of studies on constitutively active AR mutants on elucidating the molecular mechanisms of receptor activation and drug action.

Impacto de la utilización de hígados de donantes anti-HBc positivo en pacientes trasplantados por hepatitis B

El nostre objectiu és avaluar l’impacte de la utilització de fetges de donants anti-HBc positius en pacients trasplantats per hepatitis B, els quals van ser revisats de manera retrospectiva. La probabilitat acumulada d’hepatitis B post-trasplantament al 1er, 5é i 10é any va ésser del 3,7%, 8,3% i 8,3% en els receptors d’un empelt anti-HBc+ en comparació amb el 2,7%, 9,8% i 9,8% en els que varen rebre un empelt anti-HBc- (p=0,99). La probabilitat de supervivència al 1er, 5é i 10é any dels receptors d’un òrgan anti-HBc+ va ésser del 87%, 82% i 58% front al 87%, 82% i 74% en els que varen rebre un anti-HBc- (p=0,73). La utilització de donants anti-HBc positius no afecta ni a la supervivència ni al desenvolupament de hepatitis B en pacients trasplantats per VHB.

Comparative genetic analyses point to HCP5 as susceptibility locus for HCV-associated hepatocellular carcinoma.

BACKGROUND & AIMS: Recently, genetic variations in MICA (lead single nucleotide polymorphism [SNP] rs2596542) were identified by a genome-wide association study (GWAS) to be associated with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) in Japanese patients. In the present study, we sought to determine whether this SNP is predictive of HCC development in the Caucasian population as well. METHODS: An extended region around rs2596542 was genotyped in 1924 HCV-infected patients from the Swiss Hepatitis C Cohort Study (SCCS). Pair-wise correlation between key SNPs was calculated both in the Japanese and European populations (HapMap3: CEU and JPT). RESULTS: To our surprise, the minor allele A of rs2596542 in proximity of MICA appeared to have a protective impact on HCC development in Caucasians, which represents an inverse association as compared to the one observed in the Japanese population. Detailed fine-mapping analyses revealed a new SNP in HCP5 (rs2244546) upstream of MICA as strong predictor of HCV-related HCC in the SCCS (univariable p=0.027; multivariable p=0.0002, odds ratio=3.96, 95% confidence interval=1.90-8.27). This newly identified SNP had a similarly directed effect on HCC in both Caucasian and Japanese populations, suggesting that rs2244546 may better tag a putative true variant than the originally identified SNPs. CONCLUSIONS: Our data confirms the MICA/HCP5 region as susceptibility locus for HCV-related HCC and identifies rs2244546 in HCP5 as a novel tagging SNP. In addition, our data exemplify the need for conducting meta-analyses of cohorts of different ethnicities in order to fine map GWAS signals.

Hepatitis B virus exposure in human immunodeficiency virus seropositive Cuban patients

In order to estimate the prevalence of serological markers of exposure to Hepatitis B Virus (HBV), 295 subjects were selected at random from the National Registry of human immunodeficiency virus positive subjects. Evidence of exposure to HBV was defined as: testing Hepatitis B surface antigen (HBsAg) and anti-Hepatitis B core antigen (anti-HBc) positive or anti-HBc positive only. Overall, 133 (45.5%) were positive for anti-HBc and 15 (5.1%) resulted positive to HBsAg. Significant statistical association was found between male sex and exposure to HBV (p<0.01). Homosexual or bisexual behavior was found to be strongly associated to HBV exposure (p<0.001). In conclusion, the prevalence of HBV serological markers is higher in Cuban HIV positive subjects compared to the Cuban general population.

Respiratory syncytial virus groups A and B in Porto Alegre, Brazil, from 1990 to 1995 and 1998

We analyzed the respiratory syncytial virus (RSV) groups and their epidemiological pattern that were detected over the course of seven years in southern Brazil. The two RSV groups co-circulated each year, but frequencies of groups A and B varied both between and within yearly outbreaks. In 1991, group A predominated over group B (p=0.0016). RSV outbreaks analyzed showed a temperature-dependent pattern and no association with rainfall, similarly to other countries from southern South America. Knowledge of the variants is important in terms of both diagnosis and definition of a vaccine composition.

Prevalence of antibodies to hepatitis B core antigen in blood donors in the middle west region of Brazil

The prevalence of antibodies to hepatitis B core antigen in 552 prime blood donors was of 9.4%. The majority (71.2%) has antibodies to hepatitis B surface antigen. The hepatitis B surface antigen was present in 0.7%, all of them antibodies to hepatitis B core antigen positive.

Simultaneous B(0)- and B(1)+-map acquisition for fast localized shim, frequency, and RF power determination in the heart at 3 T.

High-field (>or=3 T) cardiac MRI is challenged by inhomogeneities of both the static magnetic field (B(0)) and the transmit radiofrequency field (B(1)+). The inhomogeneous B fields not only demand improved shimming methods but also impede the correct determination of the zero-order terms, i.e., the local resonance frequency f(0) and the radiofrequency power to generate the intended local B(1)+ field. In this work, dual echo time B(0)-map and dual flip angle B(1)+-map acquisition methods are combined to acquire multislice B(0)- and B(1)+-maps simultaneously covering the entire heart in a single breath hold of 18 heartbeats. A previously proposed excitation pulse shape dependent slice profile correction is tested and applied to reduce systematic errors of the multislice B(1)+-map. Localized higher-order shim correction values including the zero-order terms for frequency f(0) and radiofrequency power can be determined based on the acquired B(0)- and B(1)+-maps. This method has been tested in 7 healthy adult human subjects at 3 T and improved the B(0) field homogeneity (standard deviation) from 60 Hz to 35 Hz and the average B(1)+ field from 77% to 100% of the desired B(1)+ field when compared to more commonly used preparation methods.

Hepatitis B infection among patients attending a sexually transmitted diseases clinic in Rio de Janeiro, Brazil

Hepatitis B virus (HBV) has a low endemicity in Rio de Janeiro, Brazil. Sexual transmission must play an important role in this virus, but the prevalence and risk factors have never been properly investigated. The aim of this paper is to determine the prevalence and risk factors for HBV infection in patients attending a Sexually Transmitted Diseases Clinic of the Universidade Federal Fluminense, from the State of Rio de Janeiro, Brazil. In a retrospective study, HBV seroprevalence was investigated in 440 patients. Serum of each patient was assayed for antibodies against hepatitis B core antigen (anti-HBc), hepatitis B surface antigen (HBsAg) and antibodies against hepatitis B surface antigen (anti-HBs). Demographic and risk factor data were extracted from clinic notes. The overall seroprevalence of exposure markers for HBV (anti-HBc, HBsAg and anti-HBs) were 13%, 3.4% and 8.5% respectively. Homo/bisexual behaviour, anal intercourse, HIV infection, positive serology for syphilis and blood transfusion were predictors of the HBV exposure. Among demographic data, age and place of birth were associated with the anti-HBc seropositivity.

Detection of coronary stenoses with contrast enhanced, three-dimensional free breathing coronary MR angiography using the gadolinium-based intravascular contrast agent gadocoletic acid (B-22956).

PURPOSE: To determine the diagnostic value of the intravascular contrast agent gadocoletic acid (B-22956) in three-dimensional, free breathing coronary magnetic resonance angiography (MRA) for stenosis detection in patients with suspected or known coronary artery disease. METHODS: Eighteen patients underwent three-dimensional, free breathing coronary MRA of the left and right coronary system before and after intravenous application of a single dose of gadocoletic acid (B-22956) using three different dose regimens (group A 0.050 mmol/kg; group B 0.075 mmol/kg; group C 0.100 mmol/kg). Precontrast scanning followed a coronary MRA standard non-contrast T2 preparation/turbo-gradient echo sequence (T2Prep); for postcontrast scanning an inversion-recovery gradient echo sequence was used (real-time navigator correction for both scans). In pre- and postcontrast scans quantitative analysis of coronary MRA data was performed to determine the number of visible side branches, vessel length and vessel sharpness of each of the three coronary arteries (LAD, LCX, RCA). The number of assessable coronary artery segments was determined to calculate sensitivity and specificity for detection of stenosis > or = 50% on a segment-to-segment basis (16-segment-model) in pre- and postcontrast scans with x-ray coronary angiography as the standard of reference. RESULTS: Dose group B (0.075 mmol/kg) was preferable with regard to improvement of MR angiographic parameters: in postcontrast scans all MR angiographic parameters increased significantly except for the number of visible side branches of the left circumflex artery. In addition, assessability of coronary artery segments significantly improved postcontrast in this dose group (67 versus 88%, p < 0.01). Diagnostic performance (sensitivity, specificity, accuracy) was 83, 77 and 78% for precontrast and 86, 95 and 94% for postcontrast scans. CONCLUSIONS: The use of gadocoletic acid (B-22956) results in an improvement of MR angiographic parameters, asssessability of coronary segments and detection of coronary stenoses > or = 50%.

Prevalence of hepatitis B and C virus markers among malaria-exposed gold miners in Brazilian Amazon

Hepatitis B and C virus markers were assessed during a survey on malaria in gold mine camps in southern Brazilian Amazon in order to identify risk factors associated to these viral diseases. The study comprised 520 subjects, most of them were gold miners. Missing subjects totaled 49 (8.6%). Among these 520, 82.9% had HBV markers and 7.1% were HBsAg positive. Previous hospitalization, surgery, sexually transmitted diseases and incarceration were quite common among surveyed people, but there is no association between total HBV markers and these factors. On other hand, HBsAg was independently associated to history of sexually transmitted diseases and history of surgery after adjustment. The most frequent HBsAg subtypes identified, adw2 (59%), predominates in populations of Northeast Brazil. The most surveyed people were immigrants coming from that area suggesting that immigrants carried HBV themselves to the study area. Immunoblot (RIBA) confirmed-anti-HCV were found in 2.1%. The only variable associated to anti-HCV in multivariate analysis was illicit intravenous drug. Lack of HCV infection in subjects with such a high HBV markers prevalence reinforces the opinion that HCV is transmitted by restricted routes when compared to HBV. Furthermore, gold miners in Amazon may be considered as a risk group for HBV infection, but not for HCV.