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Biomedical subjects

T A Pearson

Publications and source records attributed to T A Pearson.

At least 163 records · Page 9Linked to original sources
PubMed1988

Hypercholesterolemia in patients undergoing coronary bypass surgery: are they aware, under treatment, and under control?

Hypercholesterolemia is an important determinant of progressive atherosclerosis in both vein grafts and native vessels after coronary artery bypass surgery. We demonstrated that nearly half of all patients admitted for coronary bypass have elevated cholesterol levels before surgery. Of these, half are unaware of the elevations in cholesterol level, and few are undergoing any treatment. The results suggest that lipids should be measured before coronary bypass surgery to optimize postoperative risk reduction education.

Adult↗
PubMed1987

Multiple risk factors for coronary artery disease: behavioral factors in preventive cardiology.

The prevention of ischemic heart disease requires intervention on the natural history of coronary artery disease (CAD). Because a variety of so-called risk factors influence that natural history, it is logical to consider modification of these risk factors as a way to prevent CAD. Although this approach is effective in both the primary and secondary prevention of CAD, this presentation will focus on behavioral intervention on multiple risk factors in the secondary prevention of CAD (i.e., after the initial cardiac event). A number of studies have suggested that lifestyle modification plays an important role in preventing CAD recurrence or death. Risk factors that require this modification of human behavior include: low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, cigarette smoking, obesity, hypertension, physical activity and, although controversial, coronary prone personality. The assessment of these multiple factors can be performed in most acute care settings. The intervention on the factors requires a structured approach to the patient, taking advantage of the heightened awareness and concern at the time of a cardiac event. Often, several behaviors require modification simultaneously and other disciplines (behavioral medicine, nutrition, exercise physiology) are often useful when integrated into a single treatment plan. Involvement of the patient's social support network is essential. The effectiveness of the modification of each risk factor is assessed, as a means of recognizing behavior change as a way to prevent recurrence of the disease.

Behavior Therapy↗
PubMed1987

Clustering of personality traits in youth and the subsequent development of cancer among physicians.

Using 14 personality measures obtained while the subjects were in medical school, the resulting profiles of 972 physicians were clustered into five groups using a two-stage cluster analysis procedure. Subjects were followed over a 30-year period to determine the cumulative survival rate (proportion of subjects remaining free of cancer) in each group. Statistically significant group differences in survival rate were found, with the group characterized by acting out and emotional expression having the most favorable curve (less than 1% developing cancer). The group characterized as "loners," who may well have suppressed their emotions, had the most unfavorable survival curve and was 16 times more likely to develop cancer than was the group characterized by acting out and emotional expression.

Follow-Up Studies↗
PubMed1987

Atherosclerosis in the hypercholesterolemic hare. Comparison of coronary artery lesions induced by dietary cholesterol in the hare and the rabbit.

Atherosclerotic lesions in coronary arteries were compared in 10 hybrid hares and 14 rabbits after induction of hypercholesterolemia, using a cholesterol-enriched diet. All proximal portions of hare coronary arteries contained intimal lesions, often with severe luminal stenosis. These lesions were characterized by the presence of foam cells, smooth muscle cells, and areas of atheronecrosis. Foam cells were also found focally in the media. As part of the intimal changes, iron deposition was present in 65% and calcification was present in 32.5% of proximal segments examined. The proportion of segments with intimal lesions and the intima/media cross-sectional area ratios (I/M ratios) were greatest in proximal segments with stepwise decreases in the mid and distal segments. As area of myocardial infarction was present in one hare. In contrast, 46.5% of proximal segments of rabbit coronary arteries had no intimal lesions and those lesions present had no calcium or iron deposition. No infarction was observed in rabbit hearts. The proportion of segments with lesions and the mean I/M ratios were significantly greater in the hare than the rabbit, with proximal and mid coronary segments showing the most marked differences. The hare appears to develop coronary artery lesions more like those seen in man, with high grade, proximal stenoses occurring uniformly in hypercholesterolemic animals. In contrast, the atherosclerosis developing in rabbit coronary arteries is less uniform and includes involvement of intramyocardial arterioles. The hare offers several advantages as a model of human atherosclerosis.

Animals↗
PubMed1987

Precursors of hypertension in black compared to white medical students.

Data were collected on 433 black medical students at Meharry Medical College (MMC) and 573 white medical students at The Johns Hopkins University School of Medicine (JHMS) during the period of 1958 through 1965 consisting of baseline measurement of some possible precursors of hypertension. Similar methods were employed in both cohorts. Comparison as to prevalence and significance of hypertension precursors revealed the following: Black males had significantly higher casual and resting blood pressures than whites (p less than 0.01); and higher mean changes in blood pressure following the cold pressor test. White males had a significantly higher mean change in heart rate following cold pressor test (p less than 0.01). Upon exercise black males had significantly higher mean change in blood pressure and heart rate (p less than 0.01). There appears to be more blood pressure lability in blacks as indicated by higher mean SBP + DBP changes following the cold pressor test, and by mean pulse pressure level at peak exercise. The difference in blood pressure lability observed between blacks and whites in young adulthood may be one of the earliest identifiers of later differences in the incidence of hypertension. However, of even more importance is the difference in blood pressure levels between the two groups, though both are normotensive.

Adult↗
PubMed1987

The association of risk factors with arteriographically defined coronary artery disease: what is the appropriate control group?

Although the use of arteriography to define coronary artery disease is considered the optimal method for determining associations of risk factors with atherosclerosis, the strengths of associations found have varied greatly between arteriographic studies. To assess whether such associations are affected by changes in the arteriographic definition of absence of disease, the authors evaluated one sample of patients undergoing coronary arteriography. The prevalence of specific risk factors by the extent of atherosclerosis (0-24, 25-49, and greater than or equal to 50% maximal stenosis) was determined, as were their associations with coronary artery disease (greater than or equal to 50% stenosis), using persons with 0-24 or 0-49% maximal stenosis, separately, as control groups. Among both males and females, analysis showed increased prevalence of risk factors with increasing atherosclerosis, with greater similarity of those who had moderate atherosclerosis to the cases than to those who had minimal atherosclerosis. The strength of association of arteriographically defined coronary disease with age, hypertension, diabetes, low and high density lipoprotein cholesterol, smoking, and family history generally varied inversely with the extent of atherosclerosis permitted within the control group. These findings indicate that epidemiologic understanding of associations of risk factors with atherosclerosis may be weakened by including persons with moderate, subclinical atherosclerosis within the control group.

Adult↗
PubMed1987

Comparison of modified Minitek system with Staph-Ident system for species identification of coagulase-negative staphylococci.

A modified Minitek system (BBL Microbiology Systems, Cockeysville, Md.) for species identification of coagulase-negative staphylococci was compared with the Staph-Ident system (Analytab Products, Plainview, N.Y.). The conventional method of Kloos and Schleifer (J. Clin. Microbiol. 1:82-88, 1975) was used as the reference method for identification. When tested with 78 coagulase-negative staphylococcal isolates from 63 children with cancer. Minitek concurred with the conventional identification in 67 (86%) isolates and Staph-Ident concurred in 61 (78%) isolates. Identification of species other than Staphylococcus epidermidis was better with Staph-Ident (19 of 23 isolates) than with Minitek (14 of 23 isolates). Concordance of results was likewise high, 88% (7 of 8) for Minitek and 100% (8 of 8) for Staph-Ident in studies with eight coagulase-negative staphylococcal strains obtained from the American Type Culture Collection (Rockville, Md.). We conclude that the modified Minitek system is a practical and reliable test for identifying coagulase-negative staphylococci in clinical microbiology laboratories. Its versatility and larger repertoire of biochemical tests may offer advantages over the Staph-Ident system.

Coagulase↗
PubMed1987

The effects of age on outcome after coronary bypass surgery.

To study the effects of increasing age on outcome after coronary artery bypass grafting (CABG), 684 patients who underwent CABG from 1980 to 1985 were entered into a noncurrent prospective study. Patients were matched by date of operation and placed into three groups according to age: (1) 70 and older, (2) 55 to 69, or (3) less than 55. In addition to intraoperative and postoperative data collected on all patients, follow-up was obtained on 97% of the patients at a mean of 30 +/- 16 months. Older patients were more often female (p less than .002), and white (p less than .001) and had more preexisting cerebrovascular disease (p less than .0001), peripheral vascular disease (p less than .001), unstable angina (p less than .0001), and longer mean bypass pump times (p less than .001). Older patients had a higher hospital mortality (9.3% vs 2.2%), suffered more complications, including stroke, wound infection, reoperation for bleeding, need for intropic drug support, and prolonged ventilation, and had longer mean postoperative hospital stays (14 vs 9 days, p less than .0001). After discharge, mortality rates were similar in all groups, as was recurrence of symptoms and degree of rehabilitation. While patient age at operation significantly influenced hospital mortality and morbidity, this appeared to be a consequence of the greater frequency of risk factors in patients over 70 years of age. In addition, late follow-up failed to demonstrate any significant differences based on age alone in survival or functional status among patients undergoing CABG.

Activities of Daily Living↗
PubMed1987

Clonal mapping of the human aorta. Relationship of monoclonal characteristics, lesion thickness, and age in normal intima and atherosclerotic lesions.

The surfaces of 8 aortas from women heterozygous for G-6-PD isoenzymes were mapped for an examination of the relationships of monoclonality, lesion type, lesion thickness, and age of the patient. The percent B isoenzyme value of samples of normal intima (n = 315), fatty steak (n = 68), or fibrous plaque (n = 64) was used to define monoclonality, expressed as the [Z] score, the number of standard deviations from the mean percent B isoenzyme of samples of underlying media. Intimal thickness increased significantly with type of lesion, such that intima less than fatty streak less than fibrous plaque, and with the age of the patient. The percentage of monoclonal portions also increased with lesion type, such that 1% of samples of normal intima were monoclonal, compared with 4.4% of fatty streaks and 12.5% of fibrous plaques (P less than 0.005). Monoclonality increased with intimal thickness when normal intima, fatty streaks, and fibrous plaques were combined (P = 0.0001). When examined separately, normal intima showed a direct correlation between monoclonality and intimal thickness. In contrast, the monoclonality of fatty streaks was inversely associated with thickness (P = 0.016) and the monoclonality of fibrous plaques not related to thickness. When entered into a multiple regression model, lesion type and age, but not lesion thickness, significantly predicted monoclonality. The lack of association of intimal thickness with monoclonality suggests that it is the type of lesion that determines monoclonality and not merely its thickness. This implies that mechanisms other than clonal selection are responsible for the monoclonal characteristics of human atherosclerotic lesions.

Adult↗
PubMed1986

Coffee consumption and the incidence of coronary heart disease.

We conducted a prospective investigation of the effect of coffee consumption on coronary heart disease in 1130 male medical students who were followed for 19 to 35 years. Changes in coffee consumption and cigarette smoking during follow-up were examined in relation to the incidence of clinically evident coronary disease in comparisons of three measures of coffee intake--base-line intake, average intake, and most recent intake reported before the manifestation of coronary disease. Clinical evidence of coronary disease included myocardial infarction, angina, and sudden cardiac death. In separate analyses for each measure of coffee intake, the relative risks for men drinking five or more cups of coffee per day, as compared with nondrinkers, were approximately 2.80 for all three measures in the univariate analyses (maximum width of 95 percent confidence intervals, 1.27 to 6.51). After adjustment for age, current smoking, hypertension status, and base-line level of serum cholesterol, the estimated relative risk for men drinking five or more cups of coffee per day (using the most recent coffee intake measure), as compared with those drinking none, was 2.49 (maximum width of 95 percent confidence interval, 1.08 to 5.77). The association between coffee and coronary disease was strongest when the time between the reports of coffee intake and the coronary event was shortest. These findings support an independent, dose-responsive association of coffee consumption with clinically evident coronary heart disease, which is consistent with a twofold to threefold elevation in risk among heavy coffee drinkers.

Adult↗
PubMed1986

Importance of risk factors in the angiographic progression of coronary artery disease.

Although specific risk factors correlate with the development of clinical coronary events, little is known about their importance in patients with established coronary artery disease (CAD). A numerical scoring system was used to assess serial coronary angiograms in subjects who had detailed risk factor determinations. Strong linear correlations were demonstrated between the extent of progression of CAD and diastolic blood pressure (BP) (p = 0.002), systolic BP (p = 0.094), the number of cigarette pack-years smoked among current smokers (p = 0.022), fasting blood glucose level (p = 0.017) and low levels of physical activity at leisure (p = 0.097). This analysis of sequential coronary angiograms identifies BP, cigarette smoking, diabetes mellitus and physical activity as important risk factors in the progression of CAD. These variables merit attention in the management of patients with symptomatic CAD and in secondary coronary prevention trials investigating risk factor modification.

Adult↗
PubMed1986

A possible relationship between figure drawing data collected in medical school and later health status among physicians.

Figure drawings obtained while subjects were in medical school were scored using two different scales: (a) Sophistication-of-Body-Concept, a scoring system that measures the overall quality of the drawings; and (b) Conventionality/deviancy of the drawings, as determined by the relative frequency with which 42 different characteristics occurred in the total sample of drawings. Figure drawings were obtained from 1951 to 1964. As of 1984, subjects were classified into 1 of 11 health outcome (disease) categories plus a "healthy" category. Statistical analysis included one-way analyses of variance and multiple logistic regression in which age and cigarette consumption were controlled. Several statistically significant differences among groups were noted with respect to Conventionality/deviancy, but not with respect to Sophistication-of-Body-Concept.

Adult↗
PubMed1986

Long-term effects of cigarette smoking and moderate alcohol consumption on coronary artery diameter. Mechanisms of coronary artery disease independent of atherosclerosis or thrombosis?

Epidemiologic studies have shown that cigarette smoking (increased risk) and moderate alcohol consumption (decreased risk) have opposite effects in coronary artery disease. To investigate whether they act via the common mechanism of affecting the coronary diameter, 31 white men with arteriographically normal coronary arteries were evaluated. Histories of cigarette smoking (never smoked, exsmoker, or current smoker) and alcohol consumption (nonuser or low user versus moderate users with an average of one drink per day) were analyzed for an association with coronary diameters. Nonsmokers had larger left main and left anterior descending diameters than either exsmokers or current smokers (p = 0.0001 and 0.004). Moderate alcohol users had large left main and left anterior descending diameters than nondrinkers (p = 0.009 and 0.01). Neither association was removed after adjustment for the other risk factor. These data suggest that smoking and moderate alcohol use have significant, independent, and opposite effects on long-term coronary diameter. These effects may be important mechanisms through which these behaviors alter the risk of coronary artery disease.

Adult↗
PubMed1986

Moderate alcohol consumption and coronary artery disease. A review.

An inverse association between moderate alcohol consumption and coronary artery disease has been demonstrated in epidemiologic studies of diverse design. These include ecologic correlations, case-control, longitudinal and clinical studies. The consistency, strength and independence of the inverse relationship argues persuasively for a causal association. These data also suggest that both abstention and heavy alcohol use are associated with an increased risk for coronary artery disease. The effect of moderate alcohol consumption on lipoprotein and apolipoprotein levels is a biologically plausible and likely mechanism for this inverse association. Alcohol consumption elevates HDL cholesterol, although it is unclear whether the HDL subfractions HDL-2 and HDL-3 are beneficially altered. Recent evidence, however, suggests that the apolipoproteins may be more important indicators of coronary artery disease, and moderate alcohol consumption does beneficially alter these proteins. Alcohol may also affect coronary artery disease by other mechanisms, which may include fibrinolytic activity, coagulation, blood pressure, coronary vasoreactivity, and sociobehavioral factors.

Adult↗