Biomedical subjects
Publications and source records attributed to L Montano.
Several, more or less successful, medical treatments have been proposed for idiopathic male infertility. We assessed the effect of high-dose FSH (150 IU) in patients with idiopathic oligospermia in comparison with patients given low doses. In the high-dose group, there was a significant rise in spermatozoid concentration (p < 0.0001), mobility (p < 0.0001) and morphology (p < 0.007).
BACKGROUND: In the summer of 1985, the McGill Epidemiology Rapid Response Unit undertook a study comparing two areas exposed to emissions of 'sour gas' refineries to an unexposed area. One operational objective of the project was the identification and survey of all the people who had lived in the study area but had since moved (outmigrants). METHODS: We estimated the number of outmigrants (people who had ever lived in the area during the period 1957 to 1985) to be 3363 by using information obtained from our cross-sectional survey and from population statistics for the area of interest. Ten different methods combined lead to the identification of approximately 87% of all the outmigrants who left the study area during that period. We used vital statistics to identify the outmigrants who had died and mailed questionnaires to obtain the necessary information from the others. RESULTS: We confirmed the vital status of approximately 46% of them (1532/3363). The results from the outmigrant survey showed that they were younger than area residents, that they experienced lower rates of heart disease and hypertension and that they had moved for health reasons in only 1.3% of the cases. These findings were similar across comparison areas. CONCLUSION: We concluded that there was no effect due to migration bias on the cross-sectional study results. This evidence considerably strengthened the conclusions regarding the effects of exposure, a benefit that largely justified the cost of identifying and surveying the outmigrants.
The relationship between the histological diagnosis and serological and tissue markers of HBV replication in 41 Greek and 29 British patients with chronic HBV infection were studied. All the nine Greek and 13 British patients who were HBeAg positive had HBV-DNA in serum and HBcAg expression in the hepatocytes. The majority (73%) of these patients had active liver disease. Forty seven per cent of the Greek and 19% of the British patients who were anti-HBe positive continued to display HBcAg in the liver with or without HBV-DNA detected in serum. All but three of these patients had persistently active liver disease. Continuing inflammatory activity in the liver, however, was also found in 31% of anti-HBe positive patients who had no evidence of HBV replication. In these patients, other factors such as delta agent, NANB viruses, alcohol abuse or an autoimmune reaction initiated by HBV may be contributory.
Heroin abusers are frequently found to have abnormal liver function tests and hepatic histology. Hepatitis viruses A, B, and NANB, other drugs or drug contaminants and excessive alcohol consumption are factors thought to contribute. One hundred and sixteen heroin abusers attending a London treatment centre were studied. Sixty two (53%) had a raised aspartate transaminase. This was not explained by current infection with hepatitis A and B, cytomegalo or Epstein-Barr viruses, excessive alcohol consumption (greater than 80 g/day) or concomitant drug taking. Abnormal liver function tests were as frequent in those with markers of current or past HBV infection as those without and there was evidence that both HBV infection and the cause of the abnormal liver function tests were acquired in the first few years of intravenous drug abuse. Liver biopsies from eight patients showed chronic hepatitis with a mild lobular and portal inflammatory infiltrate, fatty change and prominent sinusoidal cells. Electron microscopy showed cytoplasmic trilaminar tubular structures and dense fused membranes in dilated endoplasmic reticulum. These clinical, biochemical, serological, and histological features would suggest a major role for NANB virus infection in the aetiology of hepatitis in heroin abusers.
Delta antigen (delta) is a transmissible agent requiring hepatitis B virus (HBV) for its replication. Antibody to delta (anti-delta) was present in nine of 71 (13%) British HBV carriers: six were intravenous drug abusers and two were haemophiliacs. Anti-delta was negative in 30 HBsAg positive homosexuals. Cirrhosis was common in patients with anti-delta and those with anti-delta positive cirrhosis were significantly younger than those with anti-delta negative cirrhosis. In British HBV carriers delta infection is associated with intravenous drug abuse and haemophilia and perhaps a more rapid progression of chronic liver disease.
Hepatitis B viral DNA present in the liver of HBe antigen positive chimpanzee carriers is in the form of viral molecules (3.2 Kb) and no integration into host DNA was observed. The 3.2 Kb form was not detected in the serum. Other discrete HBV DNA species with faster mobilities than the major 3.2 Kb were consistently detected both in the liver and in the serum and their possible significance is discussed.
The authors review a large body of contemporary immunohistologic findings on the tissue distribution of T lymphocytes in normal and pathological conditions. The suggestions for technological advances in this field are: signal amplification using mixtures of monoclonal antibodies directed against different epitopes on the same antigen (e.g. OKT4A+B+D), triple layer amplification systems using hapten-labelled antibodies, and informative double staining methods with combinations of antibodies labelled with different fluorochromes or enzymes. Review of histological observations in a series of human diseases suggests that imbalances of OKT4+ and OKT8+ subsets of T lymphocytes may represent different types of immunoregulatory disorders. Rheumatoid arthritis and sarcoidosis appear to involve a high level of OKT4+ subpopulation response coupled with an associated appearance of a special type of HLA-DR+ macrophages. It remains to be seen whether normal or self-limited immunological responses (early stages of bacterial infection or delayed-type hypersensitivity reactions) produce OKT4+ and macrophage responses that are characteristically different. Meanwhile, excessive levels of OKT8+ cells have been found in a wide range of recognized or presumed immunoregulatory disorders including: graft-vs.-host reaction and viral infections. These disorders, as well as primary biliary cirrhosis and lichen planus, appear to possess both overlapping and disparate clinical characteristics, and the immunohistological observations may reflect the functional heterogeneity of OKT8+ populations in these diseases. These studies show that histologically meaningful heterogeneity can already be demonstrated for the OKT8+ lymphocyte group.
an analysis of the expression of the histocompatibility antigens in the livers of patients with chronic hepatitis B virus infection and normal subjects has demonstrated an increased expression of HLA-A, B, C antigens on the hepatocytes of patients with a low level of viral replication (HBe antibody positive) as compared with patients who exhibit a high level of viral replication (HBe antigen positive) and controls. This increase in the expression of histocompatibility antigens on the hepatocytes was associated with a decrease in the membrane expression of viral antigens by the same cells. These differences in the density of HLA and viral antigen display may influence the efficiency of T-cell cytolysis of hepatitis B virus-infected hepatocytes.
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