Biomedical subjects

R McLeish

Publications and source records attributed to R McLeish.

4 recordsLinked to original sources

PubMed2000

Combined RAF1 protein expression and p53 mutational status provides a strong predictor of cellular radiosensitivity.

The tumour suppressor gene, p53, and genes coding for positive signal transduction factors can influence transit through cell-cycle checkpoints and modulate radiosensitivity. Here we examine the effects of RAF1 protein on the rate of exit from a G2/M block induced by gamma-irradiation in relation to intrinsic cellular radiosensitivity in human cell lines expressing wild-type p53 (wtp53) protein as compared to mutant p53 (mutp53) protein. Cell lines which expressed mutp53 protein were all relatively radioresistant and exhibited no relationship between RAF1 protein and cellular radiosensitivity. Cell lines expressing wtp53 protein, however, showed a strong relationship between RAF1 protein levels and the radiosensitivity parameter SF2. In addition, when post-irradiation perturbation of G2/M transit was compared using the parameter T50 (time after the peak of G2/M delay at which 50% of the cells had exited from a block induced by 2 Gy of irradiation), RAF1 was related to T50 in wtp53, but not mutp53, cell lines. Cell lines which expressed wtp53 protein and high levels of RAF1 had shorter T50s and were also more radiosensitive. These results suggest a cooperative role for wtp53 and RAF1 protein in determining cellular radiosensitivity in human cells, which involves control of the G2/M checkpoint.

Amino Acid Sequence↗

PubMed1998

Representing metabolic pathway information: an object-oriented approach.

MOTIVATION: The University of Minnesota Biocatalysis/Biodegradation Database (UM-BBD) is a website providing information and dynamic links for microbial metabolic pathways, enzyme reactions, and their substrates and products. The Compound, Organism, Reaction and Enzyme (CORE) object-oriented database management system was developed to contain and serve this information. RESULTS: CORE was developed using Java, an object-oriented programming language, and PSE persistent object classes from Object Design, Inc. CORE dynamically generates descriptive web pages for reactions, compounds and enzymes, and reconstructs ad hoc pathway maps starting from any UM-BBD reaction. AVAILABILITY: CORE code is available from the authors upon request. CORE is accessible through the UM-BBD at: http://www. labmed.umn.edu/umbbd/index.html.

Databases, Factual↗

PubMed1995

Decreased non-esterified fatty acid suppression and features of the insulin resistance syndrome occur in a sub-group of individuals with normal glucose tolerance.

To investigate causes of increased triglyceride concentrations in subjects with normal glucose tolerance (determined by oral glucose tolerance testing using World Health Organization criteria) 883 healthy subjects (389 men and 494 women) between 40 and 65 years of age were studied. Subjects were divided by gender into four groups according to 120-min glucose concentrations. Individuals in the highest quartile of glucose concentration had the highest mean triglyceride concentrations (p < 0.0001) and highest mean non-esterified fatty acid (NEFA) concentrations (p < 0.0001). There was also a clustering of cardiovacular risk factors normally associated with the insulin resistance syndrome in subjects in this group. Regression analysis showed that the most important determinants of triglyceride levels were smoking (men p = 0.001, women p = 0.005), waist:hip ratio (men p = 0.01, women p < 0.001) and NEFA suppression (men p = 0.02, women p = 0.005). NEFAs suppressed 16.7% in women compared to 2.4% in men during the first 30 min of the oral glucose tolerance test (p < 0.001). These results show that a clustering of cardiovascular risk factors associated with decreased NEFA suppression occurs in a sub-group of subjects with normal glucose tolerance and that the pattern of NEFA suppression differs between men and women.

Adult↗

PubMed1995

Fetal growth and insulin resistance in adult life: role of plasma triglyceride and non-esterified fatty acids.

Reduced fetal growth is associated with insulin resistance and a high prevalence of glucose intolerance in adult life. Because babies who are growth retarded have elevated levels of triglyceride and non-esterified fatty acids (NEFA), and because similar abnormalities are observed in subjects with the insulin resistance syndrome, impaired regulation of lipid metabolism could be one of the mechanisms explaining the link between reduced fetal growth and insulin resistance. We have, therefore, measured fasting plasma triglyceride and NEFA, and the insulin-mediated suppression of NEFA during an oral glucose tolerance test in 93 men and women aged 50, born in Preston, whose birthweight and body size at birth had been recorded. Elevated fasting plasma triglycerides and reduced NEFA suppression during the oral glucose tolerance test were associated with the male sex, glucose intolerance, central obesity as indicated by a high waist to hip ratio and insulin resistance as measured by a short insulin tolerance test. However there were no statistically significant relationships between the birth measurements and the circulating lipid levels. Moreover in regression analyses the relationships between thinness at birth and insulin resistance or glucose intolerance in adult life were unaffected by the addition of triglyceride or NEFA in the models. These results suggest that the link between reduced fetal growth and insulin resistance in the adult is not mediated by an abnormal regulation of lipid metabolism.

Administration, Oral↗