Biomedical subjects

B McKnight

Publications and source records attributed to B McKnight.

77 records · Page 5Linked to original sources

PubMedDate not supplied

Risk factors for tubal infertility. Influence of history of prior pelvic inflammatory disease.

In order to explore possible etiologic differences between tubal infertility in women who had been physician-diagnosed as having pelvic inflammatory disease ("overt" PID) and in women who had not ("silent" pelvic inflammatory disease), we made use of self-reported data from a large, population-based, case-control study of infertility in King County, Washington. Responses from 33 infertile women with no history of physician-reported PID and 129 infertile women with such a history were compared to those of 501 fertile women. No cultures or blood for antibody titers were obtained. Logistic regression was used to compute the relative risks for silent and overt PID-related tubal dysfunction associated with various lifestyle and contraceptive habits in an effort to identify practices that potentially affect these outcomes. In general, practices associated with an increased risk of overt tubal disease, such as use of Dalkon Shield and other types of intrauterine devices, were also associated with an increased risk of silent tubal disease, but to a lesser extent. Women who used oral contraceptives for longer than three years had a decreased risk for silent disease (relative risk = 0.5, 95% confidence interval = 0.3-0.8), but their risk for overt disease did not decrease to the same extent (relative risk = 0.9, 95% confidence interval = 0.3-2.5). These results suggest that silent and overt tubal disease share many common lifestyle risk factors.

Adult↗

PubMedDate not supplied

Diet and genital warts: a case-control study.

BACKGROUND AND OBJECTIVES: Clinical observations support a substantial role for impaired immunity in the development of human papillomavirus (HPV) infections. Intake of vitamins, especially vitamins A and C, and alcohol consumption have been reported to influence immune response. GOAL OF THE STUDY: To examine the relationship between nutritional risk factors, including alcohol consumption, and the risk of genital warts. STUDY DESIGN: A case-control study was conducted among enrollees at four clinics of Group Health Cooperative in western Washington state. A total of 188 cases diagnosed with condyloma from April 1, 1987 to September 30, 1991 and 245 controls completed a semi-quantitative food frequency questionnaire. RESULTS: After adjustment for socioeconomic indicators, total energy intake, smoking and sexual behavior, a weekly consumption of two to four alcoholic drinks was associated with an almost doubled risk of genital warts (OR = 1.9, 95% confidence interval [CI] = 1.0-3.6). Consuming five or more alcoholic drinks per week was even more related to the risk of genital warts (OR = 2.4, 95% CI = 1.2-5.1). The risks tended to increase with the number of alcoholic drinks (P = 0.006). Vitamin A and C intakes as measured by a food frequency questionnaire did not alter the risk of condyloma. CONCLUSION: Moderately high consumption of alcohol is associated with increased risk of condyloma. Further biological and epidemiological studies are needed to explain this association.

Adolescent↗

PubMedDate not supplied

Power of affected sibling method tests for linkage.

When the mode of inheritance of a disease susceptibility (DS) gene is unknown, the affected sibling method can be applied to study whether a DS gene and a marker gene are linked. This method considers how k affected siblings (k > or = 2) share marker alleles identically by descent from their parents. Several nonparametric and likelihood ratio test statistics have been proposed for the use with affected sibling marker gene data. We compare the power of these proposed tests for linkage under different genetic models via simulation. We find that, in general, the likelihood ratio tests are slightly more powerful, but the gain in power may not warrant the additional computation burden imposed.

Alleles↗

PubMedDate not supplied

Randomized prospective trial of pure porcine and conventional bovine/porcine insulin.

Use of pure porcine insulin versus partially purified insulin of bovine/porcine origin might be expected to have certain clinical benefits, e.g., a lower incidence of skin reactions, a lower insulin dosage, better diabetes regulation, and greater preservation of endogenous insulin secretion. To test this hypothesis, we randomly assigned 112 newly diagnosed, untreated, insulin-dependent diabetic children to therapy with either pure porcine or partially purified bovine/porcine insulin. They were followed for 1 yr, data being available on at least 90 subjects at each visit. More skin reactions were found in the group treated with the bovine/porcine insulin. This insulin was of higher antigenicity, and binding of radiolabeled insulin (mean +/- SE) by serum from bovine/porcine insulin treatment was 35.5 +/- 2.6 versus 16.8 +/- 1.4% (P less than .001) for pure porcine insulin treatment 12 mo after initiation of insulin therapy. However, throughout the 12 mo of observation the levels of glycosylated hemoglobin, insulin dosage, fasting plasma glucose, and C-peptide concentration were similar for the groups. Reported incidences of hypoglycemia and nocturia were also similar. Thus, insulin-antibody formation and skin reactions were minimized by the use of pure porcine versus partially purified bovine/porcine insulin, but no other clinical advantages were apparent.

Animals↗

PubMedDate not supplied

The association of human papillomavirus antibodies with cervical cancer risk.

The association between viral human papillomavirus (HPV) DNA and cervical carcinoma has been well documented. However, less is known about the immune response to HPV infections and its relationship to cervical cancer risk. A higher prevalence of antibodies to HPV16 E7 among women with cervical cancer compared with controls has been reported, but reactivity to other antigens has not been systematically examined. Prevalence of serum IgG antibody reactivities to HPV6-encoded L1 and L2 and to HPV16- and HPV18-encoded E2, E4, E6, E7, L1, and L2 bacterial fusion proteins in a Western immunoblot assay were measured among cases with invasive cervical cancer (n = 69) and control women (n = 81). The intensities of the Western blot bands were graded as +1, +2, or +3 (0 = negative). Antibodies to HPV6 L1 and L2, HPV16 E7 and L2, and HPV18 L2 fusion proteins were observed among 39-62% of cases and 33-71% of controls. After systematic sampling for antibody reactivity to this range of fusion proteins, the sample was expanded to include 150 cases and 145 controls tested exclusively for reaction to HPV6 L1 and L2, HPV16 E7, and HPV16 and HPV18 L2. Relative risk was estimated for > or = +1, +1, and > or = +2 levels of reactivity after adjustment for confounding factors. Except for HPV16 E7, reactivity at the > or = +1 level did not distinguish cases from controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗