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Biomedical subjects

A E Silva

Publications and source records attributed to A E Silva.

At least 37 records · Page 2Linked to original sources
PubMed1994

Hepatitis C and E in non-A non-B fulminant hepatic failure: a polymerase chain reaction and serological study.

A significant proportion of patients with fulminant hepatic failure have clinical, biochemical and histological features suggestive of acute viral hepatitis, without serological evidence of either hepatitis A or B. The contribution of hepatitis C to such cases of non-A non-B fulminant hepatic failure is presently uncertain while hepatitis E is well recognized as a cause of fulminant hepatic failure in endemic areas. Nested polymerase chain reaction for detection of both hepatitis C and E virus as well as two serological assays for anti-hepatitis C virus and anti-hepatitis E virus western blotting (both IgG and IgM) were performed on acute sera of 42 consecutive cases of non A, non B-fulminant hepatic failure and on convalescent sera of 17 of 20 patients who underwent orthotopic liver transplantation. Fresh liver tissue, obtained at the time of transplantation, was also studied by polymerase chain reaction in eight cases. Evidence of an acute hepatitis E virus infection (hepatitis E virus RNA amplified from serum by polymerase chain reaction or serum IgM positive to western blot) was found in eight patients. One patient had anti-HCV at presentation but assays on later sera proved negative. Convalescent sera and sera obtained after orthotopic liver transplantation were all negative to both anti-HCV assay systems, but HCV RNA was not found in either serum or liver tissue in any case.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Diagnosis of chronic hepatitis C: comparison of immunoassays and the polymerase chain reaction.

We evaluated a series of first- and second-generation enzyme-linked immunoassays for anti-HCV and compared the findings to those with two confirmatory assays, the recombinant immunoblot assay and serum HCV RNA, in patients with chronic hepatitis C, primary biliary cirrhosis, and chronic hepatitis B. All second-generation immunoassays had good sensitivities (98-100%). Interestingly, detection of HCV RNA had a sensitivity of only 93%, although it was 100% specific. The recombinant immunoblot assay and a peptide-based immunoassay also had good specificity (97% and 100%, respectively), whereas the second-generation immunoassay based on recombinant proteins had a high rate of false positivity, particularly among patients with primary biliary cirrhosis and hyperglobulinemia (specificity 68%). Thus, the diagnosis of HCV infection appears to require the use of more than one test. Whereas a second-generation enzyme-linked immunoassay can be used as an initial test, a confirmatory test (such as recombinant immunoblot assay or determination of hepatitis C viral RNA) may be required if the diagnosis remains uncertain.

Cohort Studies↗
PubMed1993

Treatment of duodenal ulcer with omeprazole or ranitidine in a Brazilian population: a multicenter double-blind, parallel group study.

Two hundred and forty-one patients with at least one ulcer at stage A1 or A2, measuring at least 5 mm in its larger diameter, were included in this Brazilian double-blind randomized study. Patients received omeprazole 20 mg in the morning (n = 120) or ranitidine 300 mg at night (n = 121) for 2 wk; unhealed ulcers were treated for an additional 2 wk. At the end of 4 wk, unhealed ulcers were treated openly with omeprazole 20 mg o.m. for 4 wk. Healing rates at 2 and 4 wk were 67.3% and 92.9% for omeprazole and 39.8% and 82.0% for ranitidine (per protocol analysis). Results were similar when analyzed as intention to treat (p significant in favor of omeprazole). Epigastric day-time pain was the most common of all symptoms (89.2%), but only heartburn at day 15 showed a significantly better response to omeprazole than to ranitidine. A multivariate analysis (logit analysis) showed that the odds in favor of healing were greater for small ulcers, nonsmokers, and omeprazole treatment.

Adult↗
PubMed1992

Sister-chromatid exchanges in beta-thalassaemic patients under conditions of in vivo and in vitro depletion of folic acid.

In order to investigate the effect of folate depletion, lymphocyte sister-chromatid exchange (SCE) rates were compared among homozygous beta-thalassaemic patients with low folic acid levels, heterozygous beta-thalassaemic patients with normal folate levels and healthy persons with normal haemoglobin, in cultures with both normal and depleted folate conditions. Significantly higher SCE rates were found in homozygous patients in all assays, but the in vitro folate depletion did not induce an increase in SCE frequency in any group.

Adolescent↗
PubMed1989

Plasma folate and vitamin B12 levels in beta-thalassemia heterozygotes.

Plasma folic acid and vitamin B12 levels of 21 heterozygous beta-thalassemic patients from São José do Rio Preto, SP, Brazil did not differ from those of family member controls or of controls matched for age, sex and socioeconomic status. All values were within the normal range for folic acid (3-17 ng/ml) and vitamin B12 (200-950 pg/ml). A highly significant positive correlation (P less than 0.01) between folic acid and B12 levels was observed both in thalassemic patients (r = 0.93) and in the controls (r = 0.97).

Adolescent↗
PubMed1981

Correlation between circulating antigens detected by the radioimmunoprecipitation-polyethylene glycol assay (RIPEGA) and C1q-binding immune complexes in human schistosomiasis mansoni.

Circulating schistosome antigens (CSA) and circulating immune complexes (CIC) were investigated in serum from 420 patients infected with Schistosoma mansoni. The radioimmunoprecipitation-polyethylene glycol assay with [125I] anti-S. mansoni rabbit antibodies appeared as a sensitive and specific method to quantify CSA. In fact, more than 75% of the patients showed significant levels of CSA. C1q-binding CIC were also detected in 70% of subjects with schistosomiasis. In addition, a close correlation was observed between levels of CSA and CIC. These data suggest that part of the CIC present in human schistosomiasis are formed by schistosome specific antigens.

Antigen-Antibody Complex↗
PubMedDate not supplied

Hand-assisted laparoscopic nephrectomy versus transperitoneal anterior approach in living donors for renal transplantation.

The objective of this study was to compare two surgical approaches for living donor nephrectomy: transperitoneal anterior approach and the hand-assisted laparoscopic nephrectomy. Between January 2001 and October 2003 we performed 63 kidney transplantations from living donors. The transperitoneal anterior approach was used in 36 cases and the hand-assisted laparoscopic nephrectomy in 27. Outcomes were compared in terms of hospital stay, postoperative analgesia, and graft quality. Mean hospital stay was 4.7 days in the transperitoneal anterior approach group and 3.7 days in the hand-assisted laparoscopic group (P < .005). Postoperative analgesia dosage was significantly lower in the hand-assisted laparoscopic group (P < .001). Surgical complications and graft quality were similar. We concluded that hand-assisted laparoscopic nephrectomy patients had shorter hospital stays and less pain in the postoperative period, with better cosmetic results and equivalent graft quality compared to transperitoneal anterior approach patients.

Adult↗
PubMedDate not supplied

Hepatitis B vaccine--proposal for a standardized assessment of immune response.

The authors developed a comparative study of the various methods of assessment of immune response to Hepatitis B vaccine. Eighty-six health care professionals underwent a vaccination programme with three doses of plasma-derived vaccine against Hepatitis B (H-B-Vax, Merck, Sharp & Dohme) given intramuscularly. Assessment of immune response was carried out three months after the end of the programme, by radioimmunoassay (RIA) and enzyme immunoassay (EIA). The results showed that the semi-quantitative assessment of Anti-HBs antibodies by RIA or EIA was perfectly comparable to the reference method (quantitative determination of antibodies by RIA). In view of these findings, the authors suggest a standardization of assessment of immune response to the vaccine, thus permitting correct planning of booster doses and easier comparison between different studies.

Adolescent↗
PubMedDate not supplied

Autoantibodies before, during and after administration of recombinant interferon-alpha for chronic viral hepatitis.

This study was undertaken to investigate the presence of autoantibodies in patients with chronic viral hepatitis B and C, before, during and after interferon-alpha (IFN-alpha) therapy and to study their relation to dose and type of IFN-alpha and response to treatment. Fifty patients with chronic hepatitis were divided in two groups, a control-group of 21 patients (10 type B and 11 type C) who were followed for 6 months without treatment and an IFN-group consisting of 29 patients (8 type B and 21 type C) who received IFN therapy for 6 months. Serum samples were tested for a range of antibodies at the start of the study, during therapy and at the end of the 6 month period. Antibodies tested for included: antinuclear, smooth muscle, antimitochondrial, parietal cell and thyroid microsomal. Four (8%) of the total patient group had autoantibodies at the beginning of the study (two in each group). During the follow-up period no patient in the control group developed antibodies compared with 3 (11%) patients in the treatment group. Autoantibodies developed in patients treated with higher doses of IFN and were found in those patients who tended to show a poor response to IFN-therapy. Further studies are needed to establish the relationship between poor response to IFN-alpha and development of autoantibodies.

Adult↗
PubMedDate not supplied

Immunogenicity of low-dose intramuscular and intradermal vaccination with recombinant hepatitis B vaccine.

The study is a randomized trial using recombinant DNA vaccine to determine whether an intramuscular 10 micrograms dose or intradermal 2 micrograms induces satisfactory anti-HBs levels compared to the standard dose of intramuscular 20 micrograms. Participants were 359 healthy medical and nurse students randomly allocated to one of the three groups: Group I-IM 20 micrograms; Group II-IM 10 micrograms; Group III-ID 2 micrograms at 0, 1 and 6 months. Anti-HBs titres were measured after complete vaccine schedule by ELISA/Pasteur. Baseline variables were similar among groups and side effects were mild after any dose. Vaccines in the IM-10 micrograms group had seroconversion rate and geometric mean titre (GMT 2344 IU L-1), not significant different from the IM-20 micrograms group (GMT 4570 IU L-1). On the contrary, 21.4% of the ID-2 micrograms recipients mount antibody concentration below 10 IU L-1 and GMT of 91 IU L-1, a statistically significant difference compared with the standard schedule IM-20 micrograms (p < 0.001). A three dose regimen of half dose IM could be considered an appropriate schedule to prevent hepatitis B in young health adults which is of relevance to the expansion of hepatitis B vaccine programme.

Adolescent↗
PubMedDate not supplied

[Human pulmonary adiaspiromycosis. A new case of disseminated form].

A case of disseminated pulmonary form of adiaspiromycosis is reported. This is the second case of the disease found in Brasilia, DF. The patient, a 42-year-old peasant, lived in Corrente - State of Piaui, where he certainly acquired the infection. He was admitted to the Social Security Hospital, in Brasilia, with fever, chills, dry cough and dyspnea. At that time, he had been sick for about ten months and the decision of seeking medical care in Brasilia resulted from an exacerbation of the symptoms that had occurred two months before. At a right thoracotomy for a lung biopsy, disseminated white nodular lesions, a few millimeters in diameter, could be observed on the lung surface. Microscopically, round structures, 300 microns or more in diameter, identified as adiaconidia of Chrysosporium parvum var. crescens were seen in the center of some of these lesions. The tisssue response to the causative agent consisted of microabscesses, surrounded by cells in palisading arrangement, and granulomas of the mixed and foreign body types. The two kinds of lesions were thought to represent evolutive stages of the inflammatory process, and to be related to different exposures to the conidia, on separated occasions. The suppurative lesions would be recent lesions, started some weeks or a few months before, while the others, in which the granulomatous reaction predominated, were possibly older lesions, with an evolutions of at least several months.

Adult↗
PubMedDate not supplied

[The optimization of the use of economic resources for vaccination against hepatitis B in professionals in the health area].

In order to optimize the employment of financial resources to be allocated for hepatitis B vaccination programs involving health care workers, two different aspects were studied: the need of a pre-vaccination screening and the efficacy of low-doses schedules of HBV vaccine by the intradermal (ID) route. The economical analysis (a cost-minimization study) showed that when the prevalence of immune individuals is higher than 11% it is more cost-effective to perform pre-vaccination screening. This situation was observed in the employees group. For students and doctors vaccination without screening was the best approach. Regarding the schedules, 3 doses of HBV vaccine by the intramuscular (IM) route (group A) were compared to first dose by the ID route and second and third doses by the IM route (group B) and to first and second doses by the ID route and the last dose by the IM route (group C). After the third dose, soroconversion rates in groups A and B (92% and 93%, respectively) and geometric mean titers of antiHBs (1278 UI/L and 789.6 UI/L) were similar, and both were different from group A (p < 0.05), showing that alternative vaccination schedules may be cost-effective.

Brazil↗
PubMedDate not supplied

[Prevalence of serologic markers of hepatitis B and D viruses in children of the Caiabi and Txucarramãe tribes from the Indian Reservation of Xingu, central Brazil].

The medical literature has shown that the inhabitants of the Amazon region are highly affected by hepatitis B and delta viruses infection, but this has never been studied in Indian children by age group. A study of the prevalence of serological markers of hepatitis B and delta viruses in Indian children aged 0 to 14 years living in the PIX was carried out. This Park is located in Central Brazil, a region which is in the transition between the savannab to the south and the Amazon jungle to the north. To determine the prevalence of HBV and HDV markers in Indian children and to characterize the route of HBV transmission in this region. Out of the 17 tribes living in the PIX, two--the Caiabi and the Txucarramãe--were chosen because both live in the North part of the Park, but have quite different ways of life. The overall prevalence of HBV serum markers was: HBsAg, 4.5%; anti-HBs, 39.6%; anti-HBc, 44.1%; any marker of HBV, 47.3%; and anti-HDV, 0.0%. However, a striking difference in the prevalence of hepatitis B markers was observed between the two tribes: younger Caiabi children were much less affected than the Txucarramãe ones. The prevalence of HBsAg in fertile women was 12%, being anti-HBe positive. Our data suggest that HBV infection is highly prevalent among Indian children living in this Indigenous Park and vertical infection is not an important route of transmission in either tribes.

Adolescent↗
PubMedDate not supplied

[Glomerulonephritis associated with hepatitis c virus infection].

We report 4 patients with glomerulonephritis (GN) associated with hepatitis C virus (HCV) infection seen between August 1993 and July 1996. Two of them were male and median age was 41 years. Anti-HCV was detected by enzyme-immunoassay and HCV-RNA by PCR. Serum cryoglobulins, 24-hour proteinuria, and erythrocyte dismorphism were also determined. Viremia, cryoglobulinemia, hematuria and proteinuria were observed in all patients. Liver biopsies revealed inflammatory activity in 3 cases, and renal biopsies revealed membranoproliferative glomerulonephritis in 3 patients and mesangial proliferative glomerulonephritis in 1 patient. Two patients are on specific therapy for HCV infection (IFN in combination with ribavirin) and have presented clinical and laboratory improvement. The occurrence of active liver disease and viremia concurrent with urinary alterations suggests viral involvement in renal disease, a conclusion supported by the by improvement of urinary alterations observed after treatment for HCV. We conclude that the search for viral markers in patients with GN is important since their detection could change the therapeutic approach.

Adult↗
PubMedDate not supplied

Evaluation of an enzyme immunoassay for hepatitis C virus antibody detection using a recombinant protein derived from the core region of hepatitis C virus genome.

This study was undertaken to evaluate an enzyme immunoassay (EIA) for hepatitis C virus antibody detection (anti-HCV), using just one antigen. Anti-HCV EIA was designed to detect anti-HCV IgG using on the solid-phase a recombinant C22 antigen localized at the N-terminal end of the core region of HCV genome, produced by BioMérieux. The serum samples diluted in phosphate buffer saline were added to wells coated with the C22, and incubated. After washings, the wells were loaded with conjugated anti-IgG, and read in a microtiter plate reader (492 nm). Serum samples of 145 patients were divided in two groups: a control group of 39 patients with non-C hepatitis (10 acute hepatitis A, 10 acute hepatitis B, 9 chronic hepatitis B, and 10 autoimmune hepatitis) and a study group consisting of 106 patients with chronic HCV hepatitis. In the study group all patients had anti-HCV detected by a commercially available EIA (Abbott), specific for HCV structural and nonstructural polypeptides, alanine aminotransferase elevation or positive serum HCV-RNA detected by nested-PCR. They also had a liver biopsy compatible with chronic hepatitis. The test was positive in 101 of the 106 (95%) sera from patients in the study group and negative in 38 of the 39 (97%) sera from those in the control group, showing an accuracy of 96%. According to these results, our EIA could be used to detect anti-HCV in the serum of patients infected with hepatitis C virus.

Adolescent↗
PubMedDate not supplied

Epidemiology of acute hepatitis B in a university hospital in São Paulo, Brazil: retrospective study of two five-year periods.

CONTEXT: HBV infection is endemic in Brazil and acute HBV infection is still a common disease. OBJECTIVE: To analyze incidence, risk factors and evolution of acute HBV infection. SETTING: University Hospital. PATIENTS: 357 patients with acute HBV infection, comparing two periods: 1985-1989 vs. 1990-1994. RESULTS: The overall incidence declined from 50 new cases/year in 1985-89 (30% of all cases) to 25 new cases/year in 1990-94 (8% of all cases). Transmission among male homosexuals (3.9% of cases in 85-89) declined to 1.3% in 90-94 (p > 0.05). Amongst health care workers (HCW) it declined from 8.2% to 2.0% (p = 0.02). Conversely, heterosexual transmission increased from 4.8% to 10.1% (p = 0.06). Chronification of HBV infection following the acute episode was observed in 1.7%. Fulminant hepatic failure was seen in 3.4%. However, 27.2% of patients were lost to follow-up before normalization of the biochemical tests. CONCLUSIONS: The different patterns of risk factors observed is probably related to measures for preventing AIDS and to HCW vaccination programs. Chronification following acute episodes was not a common event.

Acute Disease↗