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Biomedical subjects

J Guardia

Publications and source records attributed to J Guardia.

At least 19 recordsLinked to original sources
PubMed1992

Findings on Doppler echocardiography in asymptomatic intravenous heroin users.

To detect potential cardiac abnormalities induced by intravenous heroin use, 68 persons without a previous episode of infective endocarditis were studied by Doppler echocardiography. A control group of 41 normal subjects was studied for comparison. The following measurements were considered: (1) diameter of heart chambers, (2) systolic left ventricular function, (3) morphologic valvular abnormalities, (4) presence of valve regurgitations, (5) Doppler indexes of diastolic function, and (6) estimation of pulmonary arterial resistances. Results showed no significant differences regarding the size of the heart chambers or systolic left ventricular function. A significantly higher incidence of valvular abnormalities (focal thickening or valve prolapse) was found in drug addicts (p = 0.0009) at the mitral and tricuspid valves, as was valvular regurgitation detected by Doppler (p = 0.04). Also, a significantly prolonged deceleration time of mitral and tricuspid early diastolic Doppler flow was found in the study group (p = 0.0001 and 0.027, respectively) although a different hemodynamic condition in the study group (pharmacologically reduced preload) precluded these findings to be attributable to an actual diastolic dysfunction. No differences were observed in pulmonary arterial resistances. It is concluded that mitral and tricuspid valve abnormalities can be detected by echocardiography in asymptomatic intravenous heroin users, whereas no apparent effects are observed in morphologic or functional parameters of cardiac structures other than the valves.

Adolescent↗
PubMed1992

Interferon-alpha in acute posttransfusion hepatitis C: a randomized, controlled trial.

To assess the efficacy of interferon-alpha in acute hepatitis C, 28 patients with acute posttransfusion hepatitis were randomized to receive 3 million units of recombinant interferon-alpha three times weekly for 12 wk or no treatment. Biochemical, histological and serological parameters were monitored during 1 yr of follow-up. Serum ALT levels were normal at the end of therapy in 73% of treated patients and only in 38% of control patients (p = 0.06); these differences disappeared at 6 and 12 mo of follow-up. Anti-hepatitis C virus seroconversion occurred later and at a lower rate in the group of patients who received interferon-alpha. Treated patients had a trend toward less severe hepatic lesions with lower histological activity as compared with the control group, but no statistical differences were observed. No severe side effects of interferon-alpha were detected during the study. In summary, a 3-mo course of interferon-alpha in acute hepatitis C is safe and might have some effect in diminishing disease activity only during the treatment period; however, and probably because of a small sample size, no benefit of interferon-alpha in the long-term outcome of this disease was demonstrated.

Adolescent↗
PubMed1992

Evaluation of anti-HCV positive blood donors identified during routine screening.

Of 30,231 donors tested, 368 (1.2%) were anti-HCV positive. Of these, 254 have been evaluated, with the following results: only 25% have a history of parenteral risk, seroprevalence increases with age and approximately 80% of those that are anti-HCV positive in our population are probably infected with HCV. In addition, an unexpectedly large number of these persons have chronic and/or severe liver disease and will require combined diagnostic approaches for accurate evaluation.

Age Factors↗
PubMed1992

Hepatitis C virus (HCV) circulates as a population of different but closely related genomes: quasispecies nature of HCV genome distribution.

Sequencing of multiple recombinant clones generated from polymerase chain reaction-amplified products demonstrated that the degree of heterogeneity of two well-conserved regions of the hepatitis C virus (HCV) genome within individual plasma samples from a single patient was consistent with a quasispecies structure of HCV genomic RNA. About half of circulating RNA molecules were identical, while the remaining consisted of a spectrum of mutants differing from each other in one to four nucleotides. Mutant sequence diversity ranged from silent mutations to appearance of in-frame stop codons and included both conservative and nonconservative amino acid substitutions. From the relative proportion of essentially defective sequences, we estimated that most circulating particles should contain defective genomes. These observations might have important implications in the physiopathology of HCV infection and underline the need for a population-based approach when one is analyzing HCV genomes.

Amino Acid Sequence↗
PubMed1992

Long-term immunogenicity and efficacy of hepatitis B vaccine in hemodialysis patients.

Although the efficacy of hepatitis B vaccines in patients under chronic hemodialysis treatment has been well documented, the persistence of immunity in this population remains largely unknown. In this study we have followed 60 hemodialysis patients up to 3 years after primary hepatitis B vaccination (four doses of recombinant hepatitis B vaccine; Engerix B, 20 mg/dose) to evaluate the persistence of immunity (as indicated by serum levels of antibody to hepatitis B surface antigen-anti-HBs-higher than or equal to 10 mIU/ml). Fourty-four (73%) patients developed anti-HBs levels above 10 mIU/ml after vaccination; the remaining 16 (27%) vaccinees were considered nonresponders and were given a booster dose that again failed to elicit an immunoresponse. After 3 years of follow-up, 18 out of 44 (41%) responders had no detectable anti-HBs levels in the serum (antibody loss occurring within 8 and 12 months in 3 cases, within 1 and 2 years in 13, and within 2 and 3 years in 2 other cases). When compared with the responders that lost their antibodies during the follow-up period, those who remained immunoreactive 3 years after vaccination was initiated were younger and had higher anti-HBs levels at 8 months of follow-up. Two hepatitis B virus infections were detected among nonresponders during the follow-up period. Based on these data, we conclude that patients undergoing chronic hemodialysis therapy not only have lower response rates to hepatitis B vaccination than healthy adults, but also that these are frequently transient.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1991

[Primary solid hepatic sarcoma. Diagnosis by cytological puncture].

The clinical case of a 56 year old patient who developed a grafted hepatic tumoration on a year after diagnosis of liver cirrhosis of alcoholic etiology is reported. Diagnosis of the mass was made by fine needle aspiration punction ecographically guided obtaining a cellular block which, upon anatomopathological study, revealed the presence of a malignant mesenchymal tumor; a leiomyosarcoma. Not only is this type of primary hepatic tumor rare but its appearance on a liver of alcoholic cirrhosis is also of interest. It is much more common to find primary hepatic tumors of epithelial origin, concretely hepatocarcinomas. The value of this finding is discussed with the importance of the ecographically guided punction enabling the establishment of a precise histological diagnosis being underlined. The prognosis of malignant hepatic mesenchymal tumors is commented upon as well as the long survival associated to the same, which, in this case, was longer than 18 months.

Biopsy, Needle↗
PubMed1991

Clinical significance of two forms of IgM antibody to hepatitis delta virus.

Separation of 7-8 S and 19 S forms of serum IgM antibodies to the hepatitis delta virus by rate-zonal centrifugation was carried out on serum from 24 patients with hepatitis delta virus infection: 4 patients with acute, self-limited hepatitis; 5 patients with hepatitis delta virus superinfection progressing to chronicity; and 15 patients with chronic hepatitis delta virus. The high molecular weight IgM form (19 S) was predominantly detected in acute hepatitis delta virus cases, whereas the low molecular weight (7 S) form was found in chronic hepatitis delta virus cases. The serological profile of these two forms of IgM antibody to hepatitis delta virus was investigated in serial samples from five patients with acute hepatitis delta virus superinfection that evolved to chronic hepatitis delta virus. We found that, in the acute stage of the disease, the 19 S form was predominant, whereas 6 mo later a predominance of 7-8 S IgM was observed. These results suggest that IgM antibody to hepatitis delta virus antibody forms are different in acute and chronic hepatitis delta virus infection and that their detection only helps in differentiating an acute infection from a chronic infection but not a hepatitis delta virus-hepatitis B virus-HBV coinfection from hepatitis delta virus superinfection in the acute stage of the disease.

Acute Disease↗
PubMed1991

Influence of human immunodeficiency virus infection on cell-mediated immunity in chronic D hepatitis.

To determine whether the abnormalities of cell-mediated immunity described in chronic D hepatitis are associated with hepatitis D virus (HDV) infection or concomitant human immunodeficiency virus (HIV) infection, serologic and tissue hepatitis B virus (HBV) and HDV markers and T lymphocyte subsets were studied in serum samples from 38 patients with chronic D hepatitis, 26 of whom had HIV infection. Patients with chronic D hepatitis and HIV infection had significantly lower peripheral blood T4:T8 ratios resulting from a significant increase in T8+ (suppressor/cytotoxic) cells, while numbers of T lymphocyte subsets were normal in cases with chronic D hepatitis only. HIV+ patients showed an increase in HBV replication (identified by hepatitis B core antigen in liver and hepatitis B e antigen and HBV DNA in serum) and in HDV replication (tissue D antigen and HDV RNA) without evidence of more active liver disease. Probably the immunologic disturbances detected in chronic D hepatitis are secondary to HIV infection, do not contribute to the pathogenesis of liver injury, and are associated with increased viral B and D replication.

Adolescent↗
PubMed1991

Digoxygenin-labelled DNA-probe: a rapid non-radioactive method for hepatitis B virus DNA detection in serum.

The sensitivity and specificity of two non-radioactive spot hybridization assays for hepatitis B virus DNA (HBV-DNA) using biotin and digoxygenin-labelled DNA probes were investigated in parallel in 122 serum samples from patients with chronic hepatitis B and 50 controls. The results were compared with an isotopic technique using a 32P-labelled probe. HBV-DNA was detected in 56 (80%) out of 70 hepatitis B "e" antigen (HBeAg)-positive cases and in 4 (8%) out of 52 antibody to hepatitis B "e" antigen (anti-HBe)-positive cases using the digoxygenin or 32P-labelled probes. No false positives were found with either method. Using the biotin-labelled probe, 16% of sera gave discordant results, which were considered to be false positive. The time required for detection of serum HBV-DNA was 2 hours for the non-radioactive probes and 16 hours for the isotopic probes. This study suggests that the digoxygenin-labelled probe for detection of HBV-DNA is the most rapid and sensitive method for routine diagnosis of viral replication in clinical laboratories.

Alanine Transaminase↗
PubMed1991

[Long term follow-up of non-symptomatic HBsAg carriers].

232 asymptomatic HBsAg carriers were controlled between May/1986 and May/1990. The were detected in our blood bank between 1974 and 1976 or during pregnancy or delivery period after 1981. 23 of 232 (10%) became negative during the follow-up, this happening more frequently in carriers after 5 years of follow-up. Only 2 of 209 carriers with HBsAg were HBeAg positive and 1 of these was also DNA-VHB positive. None of the HBeAg negative carriers showed DNA-VHB; only 5 had increased transaminases. 7 were anti-VHC positive, these individuals experiencing more frequent increases in transaminases. The results of this study suggests that the determination of transaminases, viral activity markers, anti-HD, anti-VHC in HBsAg carriers are enough to identify those with hepatic disease.

Adolescent↗
PubMed1979

[Etiologic diagnosis of pneumoccocal pneumonia by counterimmunoelectrophoresis (author's transl)].

The antigenic composition of the pneumoccocal capsule and its easy detection by counterimmunoelectrophoresis led us to carry out a comparative study of this method and the results obtained from cultures. A series of 159 patientes with suspected bacterial pneumonia were included in the study. Blood cultures were prepared for all of the patients; sputum cultures were practiced on 35 and cultures of pleural fluid on 32. Serum from all of the patients, urine from 104, sputum from 34, and pleural fluid from 16 were analyzed by counterimmunoelectrophoresis for pneumoccocal antigen. This method was particularly useful for detecting the germ in sputum and pleural fluid. Furthermore, a higher number of positive indexes in serum were obtained by counterimmunoelectrophoresis than by blood cultures (p less than 0.01). This was also true for tests with sputum and pleural fluid. Urine tests resulted in an even greater number of detections. Counterimmunoelectrophoresis is thus a simple, quick method for detecting pneumococcus and is especially useful when accompanied by cultures tests, since they are complementary. We were able to discover a positive indication of penumoccocus in bacterial pneumonia in 39.6 percent of cases with this technique, as opposed to 15 percent using cultures alone.

Antigens, Bacterial↗