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Biomedical subjects

R G James

Publications and source records attributed to R G James.

15 recordsLinked to original sources
PubMed2000

Quantitative trait loci on chromosomes 3 and 17 influence phenotypes of the metabolic syndrome.

Recent research has emphasized the importance of the metabolic cluster, which includes glucose intolerance, dyslipidemia, and high blood pressure, as a strong predictor of the obesity-related morbidities and premature mortality. Fundamental to this association, commonly referred to as the metabolic syndrome, is the close interaction between abdominal fat patterning, total body adiposity, and insulin resistance. As the initial step in identifying major genetic loci influencing these phenotypes, we performed a genomewide scan by using a 10-centiMorgan map in 2,209 individuals distributed over 507 nuclear Caucasian families. Pedigree-based analysis using a variance components linkage model demonstrated a quantitative trait locus (QTL) on chromosome 3 (3q27) strongly linked to six traits representing these fundamental phenotypes [logarithm of odds (lod) scores ranged from 2.4 to 3.5]. This QTL exhibited possible epistatic interaction with a second QTL on chromosome 17 (17p12) strongly linked to plasma leptin levels (lod = 5.0). Situated at these epistatic QTLs are candidate genes likely to influence two biologic precursor pathways of the metabolic syndrome.

Blood Glucose↗
PubMed1999

Learn how to aid organizational change.

Key points. Change agents are members of the organization through whom the organization figures out how to improve itself. Change agents can provide the focused attention that is required to develop "organizational horsepower." Change agents should be selected from the very best people in the organization. Change agents can come from all areas and all levels of the organization.

Leadership↗
PubMed1999

Foundation for change built on four cornerstones.

Clear purpose and balanced goals, sponsorship and leadership, user-friendly processes, and commitment and capability are four key elements necessary to bring about effective change in organizations. The ability to change effectively and efficiently is an absolute necessity for health care organizations in today's marketplace. To best build employee support for change, leaders must use a combination of education, persuasion, rewards, recognition, participation, and conversation.

Benchmarking↗
PubMed1996

Influence of androgenicity on adipocytes and precursor cells in female rats.

We examined the effects of overexposure of testosterone (T) on fat cell morphology and adipocyte precursor pools in inguinal and retroperitoneal fat depots of ovariectomized rats. In both tissues peripubertal T decreased weights without affecting adipocyte mean cell size or the size distribution profiles, but adipocyte number was decreased by 65% in the inguinal and by 38% in the retroperitoneal depots. Immunofluorescent flow cytometry utilizing a specific antibody to rat adipose tissue lipoprotein lipase was used to quantify regional precursor cell populations. T sharply reduced the percentages of differentiated and undifferentiated preadipocytes in the inguinal depot, from 43.2 +/- 5.3 to 23.5 +/- 2.1% and from 57.7 +/- 4.0 to 43.6 +/- 5.3%, respectively, with a concomitant increase in fibroblasts from 1.6 to 32.9%. On the other hand, T had no effect on retroperitoneal preadipocyte pools. Perinatal androgenization exacerbated the decline in the inguinal weight (1.4 +/- 0.1 vs. 2.2 +/- 0.1g) but otherwise did not influence the actions of peripubertal T. Androgens may thus act in a tissue-specific manner to regulate fat cell growth potential in the femoral region in the female.

Adipocytes↗
PubMed1993

Rating the urgency of coronary angiography: results of an expert panel process. Ontario Coronary Angiography Panel.

OBJECTIVE: To rate the urgency of coronary angiography for patients with ischemic heart disease. Ratings were made for patients with varying degrees of symptoms and noninvasive cardiac test results. DESIGN: A panel of 10 cardiologists rated 354 case scenarios which presented varying combinations of clinical factors that may affect urgency. MEASUREMENTS: The case scenarios were rated by each panelist on a waiting time scale consisting of six categories which ranged from the requirement for emergency angiography to a delay of up to three months. A seventh category represented the lack of urgent need for angiography. The contribution of each clinical factor to urgency of coronary angiography was determined. MAIN RESULTS: Symptom class as defined by a modification to the Canadian Cardiovascular Society grading scale for angina pectoris, results of exercise stress tests and results of imaging studies were the major determinants of urgency. In cases of unstable angina, rest electrocardiography is of importance. These factors explained at least 95% of the variance in the case urgency scores. There was agreement by at least five of the panelists on urgency score in 84% of cases. The assigned urgency varied from 6.7, representing no urgent need for angiography, for minimally asymptomatic angina with no positive noninvasive test results, to immediate angiography for cardiogenic shock. Other factors had minimal or negligible effects on urgency. CONCLUSIONS: The urgency of need for coronary angiography was addressed by an explicit method incorporating the judgements of a panel of expert cardiologists, permitting derivation of a scoring system for rating priority of individual patients in the face of waiting lists. These methods illustrate an approach to problems presented by procedure waiting lists.

Adult↗
PubMed1991

Quantitation of GLUT1 and GLUT4 mRNA using a solution hybridization assay.

The development of a solution hybridization assay for detecting GLUT1 and GLUT4 mRNA is described. The details of this assay are described in which copy RNA is used to quantitate messenger RNA in total RNA samples. This solution hybridization assay is highly specific and reproducible and is significantly more sensitive than Northern blotting. Since GLUT mRNAs can be quantitated in as little as 25 mg tissue, this technique is essential when the supply of tissue is limited. Furthermore, the elimination of gel-based separation techniques allows for mRNA quantitation in several hundred samples within two days following isolation of samples.

Animals↗
PubMed1988

Regional adipocyte precursors in the female rat. Influence of ovarian factors.

A flow cytometric immunofluorescence procedure utilizing a specific antibody to rat adipose tissue lipoprotein lipase (LPL) was developed to quantify differentiated and undifferentiated preadipocytes present in the adipose tissue vascular stroma. This method is highly sensitive and specific for cells capable of synthesizing LPL in significant quantities. Pubescence in female rats was associated with an increase in differentiated preadipocytes and in fat cell number with enlargement of the fat depots in the perirenal, parametrial, and the subcutaneous dorsal and femoral regions. A concomitant decline in the percentage of undifferentiated preadipocytes occurred in all but the femoral depot. Ovariectomy reduced pubertal adipose growth in the femoral and parametrial but not the dorsal or perirenal regions. Furthermore, the femoral undifferentiated preadipocyte pool was not preserved in the ovariectomized animals. Thus, ovarian factors influence the pubescence-associated regional preadipocyte differentiation and conversion to adipocytes. The femoral depot contains an ovarian-dependent infinite pool of fat cell precursors. These features could account for the association between ovarian hormones and body fat topography.

Adipose Tissue↗
PubMed1977

The effects of heart rate, myocardial ischemia and vagal stimulation on the threshold for ventricular fibrillation.

The minimum current required to cause ventricular fibrillation was determined by electrical stimulation of the normal or ischemic canine left ventricle. The threshold for ventricular fibrillation in the normal heart decreased when the heart rate was rapid. Strong vagal stimulation did not affect the ventricular fibrillation threshold when the heart rate was fixed. The fall in the ventricular fibrillation threshold in the presence of acute myocardial ischemia was greater and more prolonged when the heart rate was rapid. These findings indicate the importance of the immediate correction of tachycardia in patients suffering from acute myocardial infarction.

Animals↗