Search PubMed⌕ Search

Biomedical subjects

J M Oliveira

Publications and source records attributed to J M Oliveira.

12 recordsLinked to original sources
PubMed1998

Distinct prevalence of antibodies to the E2 protein of GB virus C/hepatitis G virus in different parts of the world.

Since the identification of the new human virus, GB virus C (GBV-C)/hepatitis G-virus (HGV), in 1995/1996, reverse transcription polymerase chain reaction remained the sole available diagnostic tool for GBV-C/HGV infection. Recently, a serologic test based on the detection of antibodies to the putative envelope protein 2 (anti-E2) has been introduced. We used this assay for a seroepidemiological survey including 3,314 healthy individuals from different parts of the world, 123 patients from Germany who were suspected to have an increased risk of acquiring GBV-C/HGV infection, 128 multiple organ donors, and 90 GBV-C/HGV RNA positive persons. In European countries, anti-E2 seropositivity ranged from 10.9% (Germany) to 15.3% (Austria). In South Africa (20.3%) and Brazil (19.5%), even higher anti-E2 prevalence rates were recorded. In Asian countries like Bhutan (3.9%), Malaysia (6.3%), and the Philippines (2.7%), anti-E2 positivity was significantly lower. GBV-C/HGV anti-E2 prevalence in potential "risk groups," i.e., patients on hemodialysis and renal transplant recipients, did not vary significantly from anti-E2 seroprevalence in German blood donors. Anti-E2 and GBV-C/HGV RNA were found to be mutually exclusive, confirming the notion that anti-E2 has to be considered as a marker of past infection.

Antibodies, Viral↗
PubMed1997

Epidemiological survey of infection with hepatitis B virus in the savannah and wetlands (Pantanal) of central Brazil.

An epidemiological survey of the prevalence of hepatitis B virus (HBV) was conducted in the county of Nossa Senhora do Livramento, Mato Grosso state, central Brazil. This rural county has a largely stationary population of low socio-economic status, and is divided into savannah-type vegetation and wetland. Overall, 740 subjects aged > 9 years were selected at random, interviewed and bled so that seropositivities of various HBV markers (surface antigen and antibodies to this antigen and to core antigen) could be determined. At least one marker was found in 169 (22.8%) of the subjects but only nine (1.2%) carried the surface antigen. Vegetation type (wetland v. savannah) was not associated with HBV infection but male gender, increasing age, and having had sexual experience were each associated with the infection. The prevalence of HBV markers was higher in immigrants (32.5%) than in native individuals (21.1%), many immigrants apparently having acquired the infection before settling in the study area.

Adolescent↗
PubMed1995

Surface modifications of a glass and a glass-ceramic of the MgO-3CaO.P2O5-SiO2 system in a simulated body fluid.

A glass of nominal composition (wt%) 17.25 MgO-52.75 3CaO.P2O5-30 SiO2 and a glass-ceramic obtained from it showed surface modifications when immersed in an acellular medium having a composition similar to that of human blood plasma. A (Ca, P)-rich layer, with an approximate Ca/P atomic ratio of 1.7, identified as hydroxyapatite, developed on both samples. The precipitated film on the glassy sample was weakly bonded, whereas that formed on the glass-ceramic was strongly adherent. The apatite precipitated during the in vitro tests on both samples grew as a needle-like structure with crystals about 150-200 nm long and 50-70 nm thick, as measured on specimens soaked for 1 month in the simulated body fluid (SBF). The presence of calcium and phosphate ions in the SBF contributed to the precipitation of the (Ca, P)-rich layers on both specimens.

Binding Sites↗
PubMed1994

Familial hypertension and albuminuria in normotensive type I diabetic patients.

An inherited predisposition to hypertension may increase susceptibility to nephropathy in type I diabetes. We evaluated the influence of a family history of essential hypertension on albuminuria in normotensive, normoalbuminuric type I diabetic patients. Forty-two diabetics (12.9 +/- 2.04 years) were divided into three groups according to tertiles of albumin excretion rate (group 1, 1.27 +/- 0.35; group 2, 2.43 +/- 0.49; group 3, 6.37 +/- 3.43 micrograms/min; P < .001). Familial hypertension was considered to be present if the patient had one parent or grandparent on antihypertensive therapy. The three groups did not differ concerning age, diabetes duration, insulin requirement, body mass index, blood pressure, and urinary glucose excretion. Albumin excretion rate did not correlate with any parameter studied. The frequency of hypertension was significantly lower among the relatives of the patients from group 1 compared with those from groups 2 and 3 (28.6% versus 64.3% versus 78.6%, P < .03). Our data suggest that a familial antecedent of hypertension in normoalbuminuric type I diabetic patients is associated with a high normal albumin excretion rate not related to increases in blood pressure. Early changes in renal hemodynamics, seen in patients with a predisposition to hypertension, may contribute to increments in albuminuria even within the normal range.

Adolescent↗
PubMed1992

Coronary artery bypass surgery with intermittent aortic cross-clamping.

Despite the generally accepted use of cardioplegia for myocardial protection during cardiac revascularization and other operations, non-cardioplegic methods have been used by many surgeons throughout the world. We have prospectively studied 229 patients consecutively subjected to isolated coronary artery bypass surgery from March 1990 to February 1991 by a single surgeon who used intermittent aortic cross-clamping for construction of the distal anastomoses. The mean age of the patients was 58.9 +/- 8.9 years. One hundred and nine patients (47.6%) with unstable angina were subjected to urgent or emergent surgery and 129 (56.3%) had a previous myocardial infarction. The mean number of grafts per patient was 3.0. The ischaemic time per graft was 6.5 +/- 1.4 min. At least one internal mammary artery was used in 98% of the cases (1.4 internal mammary artery grafts/patient). Hospital mortality was 0.9% (two patients, in neither case related to the procedure). Only nine patients (3.9%) required inotropes and none needed intra-aortic counterpulsation. The analysis of serum enzymes specific of myocardial lesion showed a CPK-MB/CPK ratio of 10.5 +/- 10.2 after surgery, 6.4 +/- 6.6% at 24 h after surgery, and 6.9 +/- 2.6% by the 5th day. Only four patients (1.7%) had ECG criteria of myocardial infarction. These results were compared retrospectively with those of the 40 immediately preceding patients (December 1989 to February 1990), in whom crystalloid cardioplegia had been used. There were no differences between the two groups with regard to age, prevalence of unstable angina and of previous myocardial infarction, and technique used.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Ventricular septal defects and arteriovenous fistulas, with and without valvular lesions, resulting from penetrating injury of the heart and aorta.

Thirty-one patients with post-traumatic intracardiac shunts or arteriovenous fistulas were treated surgically in the past 8 years. All patients had had penetrating injuries of the heart, ascending aorta, or aortic arch 1 week to 4 years earlier, but only three had an early emergency operation. Eleven patients (35%) had ventricular septal defects and seven (23%) had other types of intracardiac fistulas. The remaining 13 patients had fistulas between the aorta and the main pulmonary artery or innominate vein. Nine patients (29%) had injury of one of the four cardiac valves. All patients but six with aorta-innominate vein fistulas were operated on with the assistance of cardiopulmonary bypass. All affected valves were successfully repaired. There were no operative deaths but two patients (6%) died late. The remaining 29 patients were alive and well when last seen, with no signs of residual shunt and with good valve function. The high prevalence of late complications necessitates routine investigation of patients with penetrating injuries of the heart and the aorta. Surgical correction carries a low mortality and morbidity and is advised in all patients with symptoms.

Adult↗
PubMed1988

Medtronic Hall valve replacement in a third-world population group. A review of the performance of 1000 prostheses.

Between May 1980 and December 1984, 1000 Medtronic Hall prostheses (538 mitral and 462 aortic) were implanted in 852 patients (mean age 30 +/- 15 years) of a third-world type of population group. The most common valve lesions were aortic and mitral regurgitation, and 32% of the patients were in New York Heart Association class IV or greater. Double valve (aortic and mitral) operations were performed in 209 patients. The 782 operative survivors were followed up for 2 to 6.5 years (mean 3.5 years) for a cumulative 2676 patient-years. Valve performance was analyzed in each position separately for valve-related complications. Results for the whole group for the following events are expressed in both linearized (percent/patient-year) and actuarial (percent +/- standard error of the mean freedom at 5 years) terms, respectively: valve-related mortality, 2.9 and 92 +/- 2; reoperation, 1.9 and 90 +/- 2; systemic thromboembolism, 3.3 and 85 +/- 2; thrombotic obstruction, 1.2 and 95 +/- 1; prosthetic valve endocarditis, 0.7 and 97 +/- 1; anticoagulant-related hemorrhage, 0.7 and 98 +/- 1; and periprosthetic leak, 0.7 and 97 +/- 1. Corresponding composite figures for valve failure were 4.3 and 85 +/- 2, and for all valve-related morbidity and mortality were 6.7 and 75 +/- 3. Thrombotic obstruction (fatal in 71% of the cases), anticoagulant-related hemorrhage (61% fatal), and prosthetic endocarditis (44% fatal) were the most lethal complications. Although the differences did not reach statistical significance, aortic prostheses appeared to have a higher incidence of complications than the mitral prostheses. When analyzed against the background of an essentially noncompliant population group, the Medtronic Hall prosthesis proved to be reliable and remarkably free from structural failure. The high incidence of thromboembolism and thrombotic obstruction still mandates anticoagulation.

Adult↗
PubMedDate not supplied

Immunization against hepatitis B in children from endemic zone: evaluation of the antibody response against the DNA recombinant vaccine (Engerix B-20 MCG).

A previous seroepidemiological study in the rural zone of Vargem Alta (ES) SouthEast of Brazil, showed a prevalence of up to 9% of hepatitis B surface antigen (HBsAg) in some areas. One hundred susceptible children aging 1 to 5 years old were selected and immunized with a recombinant DNA hepatitis B vaccine (Smith-Kline 20 mcg) using the 0-1-6 months vaccination schedule. Blood samples were collected at the time of the first vaccine dose (month 0) in order to confirm susceptible individuals and 1,3,6 and 8 months after the first dose, to evaluate the antibody response. Our results showed that two and five months after the second dose, 79% and 88% of children seroconverted respectively, reaching 97% after the third dose. The levels of anti-HBs were calculated in milli International Units/ml (mIU/ml) and demonstrated the markedly increase of protective levels of antibodies after the third dose. These data showed a good immunogenicity of the DNA recombinant hepatitis B vaccine when administered in children of endemic areas.

Brazil↗