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P Reynolds

Publications and source records attributed to P Reynolds.

108 records · Page 6Linked to original sources
PubMed1983

Isolation and characterization of the RAD3 gene of Saccharomyces cerevisiae and inviability of rad3 deletion mutants.

The RAD3 gene of Saccharomyces cerevisiae is required for nicking of DNA containing pyrimidine dimers or interstrand crosslinks. We have cloned the RAD3 gene and physically mapped it to 2.6 kilobase of DNA. A DNA segment of the cloned RAD3 insert was ligated into plasmid YIp5, which transforms yeast by homologous integration, and shown to integrate at the RAD3 site in chromosome V, thus verifying the cloned DNA segment to be the RAD3 gene and not a suppressor. The RAD3 gene encodes a 2.5-kilobase mRNA, extending between the Kpn I site and the Sau3A1/BamHI fusion junction in plasmid pSP10, and the direction of transcription has been determined. The 2.5-kilobase transcript could encode a protein of about 90,000 daltons. We also show the deletions of the RAD3 gene to be recessive lethals, indicating that the RAD3 gene plays an important role in other cellular processes in addition to incision of damaged DNA.

Journal Article↗
PubMed1979

In-vitro reactions of lymphocytes in rheumatoid arthritis and other rheumatic diseases.

Various lymphocyte functions and the percentage of different subpopulations have been measured in groups of patients with seropositive rheumatoid arthritis, seronegative ankylosing spondylitis, and psoriatic arthritis, Sjögren's syndrome, sicca complex, and in normal controls. Several abnormal results were found--in the responses to mitogens, in the antibody-dependent cytotoxic test, and in the percentages of EA rosettes (antibody sensitised chick red cells test) and surface immunoglobulin-bearing cells. In the light of these findings cytotoxicity and lymphocyte subpopulations were measured in further groups of rheumatoid arthritis patients in whom the disease was at different stages. The results showed that the changes in cytotoxic potential occurred in patients with active arthritis. Correlation tests showed significant positive associations between the percentage of SE rosette-forming cells (sheep red cells test) and the mitogenic responses to phytohaemagglutinin and concanavalin A, and between the percentage of EA rosette-forming cells and the levels of antibody-dependent cytotoxicity. The results are discussed in the light of our understanding of cellular subpopulations in the immune system.

Adolescent↗
PubMed1975

Scanning electron microscopy of proliferating bile ductules.

Rats were subjected to ligation of the common bile duct to provoke bile ductular proliferation and were studied at intervals from 1 day to 6 weeks. After perfusion fixation with glutaraldehyde, and ethanol dehydration, blocks of liver were frozen in liquid nitrogen, fractured, and returned to ethanol prior to critical point drying. Examination with the scanning electron microscope showed a remarkable proliferation of bile ductules and preductules in addition to canalicular dilation. The ductules were surrounded by a longitudinal array of collagen fibers. The luminal surfaces contained many microvilli and cable-like structures, some identifiable as cilia by transmission electron microscopy. The present techniques offer the possibility for a reevaluation of obstructive jaundice and cholestasis.

Animals↗
PubMedDate not supplied

The four county study of childhood cancer: clusters in context.

Observations of childhood 'cancer clusters' in small communities in central California prompted us to examine the distribution of childhood cancer in communities throughout the region to see if the overall cancer rate or the distribution of 'cancer clusters' was unusual for agricultural towns where pesticide exposure might be elevated. The distribution of rates was evaluated using a variety of methods: comparison of rates to the regional average, evaluation of the empirical observed versus expected Poisson distribution of events, and multivariate modelling using Poisson regression. These analyses suggest that there were no previously undiscovered communities with excess rates, although the index community which prompted the initial investigation does stand out as unusual. We discuss the impact of a range of forces of morbidity on the likelihood of 'cancer clusters' and the distributions of observed and expected numbers of cancers in a population of locales.

Adolescent↗
PubMedDate not supplied

Lung cancer in nonsmoking women: a multicenter case-control study.

The association between exposure to environmental tobacco smoke and lung cancer in female lifetime nonsmokers was evaluated using data collected during the first 3 years of an ongoing case-control study. This large, multicenter, population-based study was designed to minimize some of the methodological problems which have been of concern in previous studies of environmental tobacco smoke and lung cancer. Both a cancer control group and a population control group were selected in order to evaluate recall bias. A uniform histopathological review of diagnostic material was conducted for case confirmation and detailed classification. Biochemical determination of current exposure to tobacco and screening of multiple sources of information to determine lifetime nonuse were utilized to minimize misclassification of smokers as nonsmokers. A 30% increased risk of lung cancer was associated with exposure to environmental tobacco smoke from a spouse, and a 50% increase was observed for adenocarcinoma of the lung. A statistically significant positive trend in risk was observed as pack-years of exposure from a spouse increased, reaching a relative risk of 1.7 for pulmonary adenocarcinoma with exposures of 80 or more pack-years. The predominant cell type of the reviewed, eligible lung cancer cases was adenocarcinoma (78%). Results were very similar when cases were compared to each control group and when separate analyses were conducted for surrogate and personal respondents. Other adult-life exposures in household, occupational, and social settings were each associated with a 40-60% increased risk of adenocarcinoma of the lung. No association was found between risk of any type of lung cancer and childhood exposures from a father, mother, or other household members.

Adult↗
PubMedDate not supplied

The relationship between social ties and survival among black and white breast cancer patients. National Cancer Institute Black/White Cancer Survival Study Group.

The relationship between social ties, stage of disease, and survival was analyzed in a population-based sample of 525 black and 486 white women with newly diagnosed breast cancer. There were significant differences between the two race groups in reported social ties. Using logistic regression to adjust for the effects of age, race, study area, education, and the presence of symptoms, there was little or no evidence for an association between individual network measures of social ties and stage of disease. However, a summary measure of social networks was found to be associated modestly with late stage disease, attributable in part to significantly more advanced disease among black, but not white, women reporting few friends and relatives [relative risk (RR) = 1.8; 95% confidence interval (CI) = 1.1-3.0]. With adjustments for differences in stage of disease and other covariates, and with the use of Cox proportional hazards modeling to estimate hazard ratios, the absence of close ties and perceived sources of emotional support were associated significantly with an increased breast cancer death rate. White women in the lowest quartile of reported close friends and relatives had twice the breast cancer death rate of white women in the highest quartile (RR = 2.1; 95% CI = 1.1-4.4). Notably, both black and white women reporting few sources of emotional support had a higher death rate from their disease during the 5-year period of follow-up (RR = 1.8; 95% CI = 1.3-2.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗