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Biomedical subjects

J L Stanford

Publications and source records attributed to J L Stanford.

At least 19 recordsLinked to original sources
PubMed1992

Reproductive factors in the etiology of hepatocellular carcinoma. The WHO Collaborative Study of Neoplasia and Steroid Contraceptives.

Data from a hospital-based case-control study conducted in four developing countries were analyzed to evaluate the role of reproductive factors in the etiology of liver cancer. Eighty-three patients newly diagnosed with primary liver cancer and 596 matched controls between the ages of 15 and 56 years completed study interviews. The relative risk of hepatocellular carcinoma was elevated significantly in women of high gravidity, an association that was attributable to the effects of full-term pregnancies. The adjusted relative-risk estimate in women who had ever had a full-term pregnancy was 1.6 (95 percent confidence interval = 0.6-4.1), and risk increased directly with the number of full-term pregnancies (P for trend = 0.03), rising to 3.8 among women with seven or more births compared to women with one to two births. Induced abortions and a history of miscarriage were unrelated to risk. These findings were unchanged after adjustment for a history of jaundice, lifetime number of sexual partners, or age at first sexual intercourse--variables which may be related to hepatitis B virus (HBV) exposure. Serum samples to determine HBV status were not collected, however, and it is not known whether the observed associations are independent of prior HBV infection.

Adolescent↗
PubMed1992

Slow bacterial infections or autoimmunity?

In this article, Graham Rook and John Stanford propose that a group of idiopathic diseases that are often associated with a degree of autoimmunity and arthritis, including rheumatoid arthritis, inflammatory bowel disease, sarcoidosis and psoriasis, are caused by extremely slow-growing bacteria. They suggest that these diseases are one end of a continuous spectrum caused by related slow-growing genera, which ranges from rheumatoid arthritis, through Takayasu's arteritis and Whipple's disease, to reach the conventional mycobacterioses such as tuberculosis and leprosy.

Autoantibodies↗
PubMed1992

Good concordance between two batches of new tuberculin in the Mantoux test.

Two batches of new tuberculin prepared from different unheated cultures of M. tuberculosis, 8 years apart, were tested for concordant skin reactions in the WHO standard Mantoux test. Both batches T1327 and T1456 were simultaneously injected (0.1 ml) into the dorsal aspects of the forearms of 123 school children, aged 11-13 years, who had been BCG vaccinated at birth. The mean size of the induration to T1327 was 10.3 (SD 4.4) mm and to T1456 it was 11.3 (SD 4.2) mm. There was a significant linear correlation between the indurations caused by both batches (r = 0.91, P < 0.0001). The discrepancies between the readings were all within the limits of a 5 mm category. The mean size of the BCG scar was 8.1 (SD 4.8) mm, and there was a trend associating smaller BCG scars with smaller tuberculin responses which did not reach statistical significance. The two different batches of new tuberculin gave remarkably concordant results in WHO standard Mantoux testing illustrating the stability of the production process and suggesting that the results obtained in studies using different batches of new tuberculin are comparable.

Adolescent↗
PubMed1992

Comparative study of skin testing with PPD and new tuberculins by the WHO Mantoux test.

PPD RT 23 tuberculin and two batches of new tuberculin (NT) were tested for concordant skin indurations in the WHO standard Mantoux test in 11- to 13-year-old Finnish school children BCG vaccinated at birth. All were double tested with RT 23 and with either batch T1327 (614 children) or with batch T1456 (312 children) of NT. The results were compared with data available from an earlier study employing RT 23 and T1327 in Ethiopian children, 50/134 of whom had a BCG scar. The mean induration to RT 23 after 72 h was slightly smaller than to the NTs. The individual readings for RT 23 had significant linear correlations with T1327 in Finland (r = 0.77) and in Ethiopia (r = 0.89), and for T1456 (r = 0.83; P < 0.001 for all three). Zero reactions were much fewer to NTs (5.5% to T1327 and 0.3% to T1456) than to RT 23 in Finland (18.2% and 9.3% respectively for the two groups). The results were similar in Ethiopian children. Our results indicate that RT 23 and the two NTs give concordant results, but NTs seem to be more specific, perhaps because they retain more species-specific antigens. Analysis of our results suggests that different peaks in the distribution of reaction sizes were due to responses to different antigens or combinations of antigens, and in the case of the largest reactions, to a different type of immunological response.

Adolescent↗
PubMed1992

Measurements of blood flow and histometry of the cellular infiltrate in tuberculin skin test responses of the typical Koch type and the non-turgid variant form (Listeria-type) in pulmonary tuberculosis patients and apparently healthy controls.

The typical turgid Koch type and the non-turgid variant form (Listeria-type) of the tuberculin skin test responses were studied in 76 newly diagnosed pulmonary tuberculosis patients and 29 apparently healthy factory worker controls from Surabaya in Indonesia; in general, the patients had more intense responses than the controls. The blood flow velocity (RBCflux) at the centre of the reaction was similar in all groups, but central relative slowing (a presumed forme fruste of severe ischaemia) was much more common in the Koch-type reactions in tuberculosis patients. In both groups of subjects, the overall density of cellular infiltrate (and the major populations of inflammatory cells) was greater in the typical Koch-type reactions than in the non-turgid variant reactions. Thus the Koch-type reactions were indubitably more intense in inflammatory terms than the non-turgid variant form, but the results of this study do not exclude the possibility that there were underlying qualitative differences in pathogenesis between reactions of the two types as well as the obvious difference in severity.

Adult↗
PubMed1991

Is Africa lost?

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Oral contraceptives and neoplasia of the ovary.

Epidemiologic literature on oral contraceptives in relation to primary ovarian cancer is reviewed. Compared to women who have never used oral contraceptives, women who have ever taken oral contraceptives have about a 30% reduction in risk for epithelial ovarian cancer, and five or more years of use is associated with a 50% reduction in risk. The protective effect of oral contraceptives persists for ten or more years after use is discontinued, and becomes apparent several years after beginning use. Effects of oral contraceptives are similar for malignant and borderline malignant epithelial ovarian cancer. Reduced risks among oral contraceptive users have been observed for all major histologic subtypes of epithelial ovarian cancer, and for women from developed and developing countries. Risk estimates for epithelial ovarian cancer in relation to oral contraceptive use stratified by age at diagnosis or parity are not uniform across studies. No consistent protective effect is apparent for non-epithelial ovarian tumors or benign ovarian tumors, including teratomas and cystadenomas, although limited data are available on the relationship between oral contraceptives and these neoplasms. Several areas for future research are described.

Contraceptives, Oral↗
PubMed1991

Susceptibility of captive wildfowl to avian tuberculosis: the importance of genetic and environmental factors.

This study reports the findings of an epidemiological survey of death due to avian tuberculosis in the captive collection of wildfowl at The Wildfowl and Wetlands Trust Centre, Slimbridge, Gloucestershire. Both genetic and environmental factors have been shown to affect the incidence of, and the birds' susceptibility to, the disease. Seasonal body condition was related to the occurrence of death due to the disease in both males and females. Birds from either hot or cold climates appeared to have a higher incidence than those from temperate climates. What the birds ate did not affect incidence but the method they used for obtaining their food did. Higher susceptibility was found in those species evolved for marine or arboreal habitats. Anomalies in susceptibility which suggest a higher level of genetic immunity in some groups have also been found. Reasons are put forward to explain these findings.

Animals↗
PubMed1991

Long-term storage of red blood cells and correlations between red cell and dietary fatty acids: results from a pilot study.

Levels of red blood cell (RBC) fatty acids were determined at baseline and 12 months after storage at -70 degrees C in 15 postmenopausal women to determine whether storage had a detrimental effect on the stability of fatty acids. Four-day diet records were also completed at baseline, allowing comparisons between RBC fatty acid levels and fatty acid levels computed from recent dietary intake. The major fatty acid composition of RBCs did not change substantially during 12 months of storage, and, in particular, for n-6 and n-3 fatty acids most correlations between baseline and 12-month values were greater than 0.90. We also found strong positive correlations between RBC and dietary fatty acids, including oleic, linoleic (18:2n-6), total n-6, and the polyunsaturated-to-saturated fat ratio. We concluded that frozen RBCs may be a useful measure of recent dietary intake for epidemiological studies.

Blood Preservation↗
PubMed1991

Improving on BCG.

BCG is the only vaccine for tuberculosis and leprosy known to be effective in at least some places. Unfortunately it tends to be less successful in just those areas of the developing world where a vaccine is most needed. Although molecular biology offers the prospect of alternatives, these still lie in the indefinite future, and the best use has to be made of BCG. A number of preparations are available from different manufacturers, and a vaccine should be selected with good evidence of efficacy, and a low incidence of complications. Selection of the optimal age for administering BCG should be based on factors pertaining in the area where it is to be used. The influence of contact with environmental mycobacteria, the age at which mycobacterial diseases occur, and the logistics of vaccine delivery must be taken into account. The addition of a suspension of killed Mycobacterium vaccae to BCG may increase its efficacy. Skin test data show that recognition of antigens common to all mycobacterial species and thought to be the first step in the protective immune response, is significantly enhanced by the additive. M. vaccae also contains a substance, or substances, "switching off" the tissue destructive aspect of the Koch phenomenon that is part of the immunopathology of tuberculosis. A suspension of killed M. vaccae alone can be used to enhance immune responses of persons unsuitable for BCG vaccination, such as those already tuberculin positive, and those with scars of earlier BCG vaccination.

Age Factors↗
PubMed1991

Histometric studies on cellular infiltrates of tuberculin tests in patients with sarcoidosis.

The density and microanatomical location of CD4 and CD8 lymphocytes and of monocytes/macrophages at the site of a tuberculin test were measured in 13 patients with sarcoidosis, and the results were compared with those seen in a group of healthy controls. The cellular infiltrate was significantly reduced in the sarcoid subjects compared with the controls for all cell phenotypes studied; the ratio of CD4 positive:CD8 positive lymphocytes was significantly increased in the sarcoid group. Clinically negative reactions showed substantial numbers of infiltrating mononuclear cells, although not as great as in clinically apparent reactions. A clinically negative tuberculin reaction does not necessarily imply anergy to the test substance and should not be termed "negative".

Adult↗
PubMed1990

Characteristic new members of the phthiocerol and phenolphthiocerol families from Mycobacterium ulcerans.

Diacyl phthiodiolone A and phenolphthiodiolone A lipids were isolated from two strains of Mycobacterium ulcerans. The diol units of the phthiodiolone A and phenolphthiodiolone A components were shown to have erythro stereochemistry by infrared spectroscopy and proton nuclear magnetic resonance of an acetal derivative. This stereochemistry is shared only by related diols from M. marinum, the diols from M. bovis, M. kansasii, M. leprae and M. tuberculosis having threo stereochemistry.

Fatty Alcohols↗