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Biomedical subjects

H R Peterson

Publications and source records attributed to H R Peterson.

7 recordsLinked to original sources

Autonomic influence on cardiovascular performance in diabetic subjects.

PURPOSE: Cardiomyopathy, coronary artery atherosclerosis, or autonomic neuropathy may affect the cardiovascular performance of the diabetic patient. To evaluate the role of parasympathetic nervous system activity on cardiovascular performance, 25 diabetic subjects who lacked symptoms, signs, or objective measurements of ischemia or cardiomyopathy were studied. PATIENTS AND METHODS: Diabetic subjects were classified according to their RR variation, an index of cardiac parasympathetic nervous system activity. Fourteen diabetic subjects had a normal RR variation of greater than 30 (D-NOR), and 11 diabetic patients had an abnormal RR variation of less than 20 (D-ABN). Fifteen age- and weight-matched, healthy, nondiabetic subjects (NOR) constituted the control group. All subjects had oxygen consumption, multigated acquisition determination of cardiac output, and work product measured before and during supine bicycle maximum exercise testing. RESULTS: There was no difference in the resting cardiac output among the groups. Resting work product, however, was greatest in the D-ABN group when compared with performance in the other two groups (D-ABN: 11,500 +/- 800; D-NOR: 9,000 +/- 600; NOR: 8,700 +/- 400; p less than 0.0025). This was due to an increase in both heart rate (p less than 0.025) and systolic blood pressure (p less than 0.015). In the diabetic subjects, there was an inverse relationship between the RR variation and resting work product (r = 0.47, n = 25, p less than 0.005). In response to exercise, the percent increase in cardiac output at matched percent maximum oxygen uptake was greatest in the NOR, D-NOR, and D-ABN groups, respectively (analysis of variance, p less than 0.01). In the diabetic subjects, there was a significant relationship between the RR variation and the maximum percent change in cardiac output (r = 0.41, n = 25, p less than 0.02). Compared with the NOR group, the maximum increase in work product was impaired in diabetic subjects (p less than 0.002) and not different between the D-NOR and D-ABN groups. CONCLUSIONS: The increase in resting work product and the poor cardiac output responses to exercise in the D-ABN group are due to a decrease in cardiac parasympathetic nervous system activity and can be suggested by an abnormal RR variation. This index of parasympathetic nervous system activity can help the physician identify that subset of diabetic patients that may need special consideration when exercise training is prescribed.

Adult↗

Depression in obese men.

Using the Beck depression inventory (BDI), we studied depression in young, healthy, male subjects who represented a wide range of body weight. Body mass index (BMI), defined as the weight (in kilograms) divided by the square of height (in meters), was used to classify subjects as obese (BMI greater than 31.1, n = 27), overweight (BMI = 27.8-31.1, n = 10) or acceptable weight (BMI less than 27.8, n = 26). BDI scores of 0-9 indicated no depression; scores of 10-15 indicated mild depression. BDI scores from 16 to 63 indicated increasing depression. No group of subjects (obese, overweight or acceptable weight subjects), had mean BDI scores suggesting depression. The mean BDI score for the obese subjects was 5.6 +/- 0.8 (mean +/- s.e.m.), which was significantly higher than the mean BDI scores for both the overweight subjects (2.5 +/- 1.1; P less than 0.04) and the acceptable weight subjects (1.5 +/- 0.3; P less than 0.001). There was a weak positive correlation of BDI with BMI (n = 63, r = 0.404, P less than 0.001). In addition, the obese subjects did form a heterogeneous group with four obese subjects (14.8 percent) having BDI score of 10 or greater. The overweight subjects had one subject (10 percent) with a BDI score of 12. None of the acceptable weight subjects had a BDI score of greater than 5. There was no correlation between waist/hip ratios and BDI scores (n = 37, r = 0.262, P = 0.118). We conclude that mild depression is present in some obese persons even when medically healthy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Body fat and the activity of the autonomic nervous system.

The cause of most cases of human obesity is unknown. Specific alterations in the activity of the autonomic nervous system may mediate and perhaps cause obesity in animal models. We therefore looked for alterations in autonomic activity in human obesity. Fifty-six healthy men with various percentages of body fat underwent autonomic testing while at rest. Significant correlations were found between the percentage of body fat and the variation in the R-R interval after beta-adrenergic blockade (r = -0.30, P less than 0.03), the heart rate (r = 0.30, P less than 0.03), the plasma norepinephrine concentration (r = -0.30, P less than 0.05), the plasma epinephrine concentration (r = -0.49, P less than 0.001), and the pupillary latency period (r = 0.39, P less than 0.01). Each of these variables reflects the activity of the sympathetic nervous system or parasympathetic nervous system or both. Depressions in sympathetic and parasympathetic activity were significantly but weakly associated with increasing percentages of body fat. These associations indicate that in obese persons, autonomic changes, though not necessarily causal, involve several organ systems. We suggest that autonomic alterations are important in human obesity, as they are in animal obesity. A disordered homeostatic mechanism may promote excessive storage of energy by decreasing sympathetic activity, while defending against weight gain by decreasing parasympathetic activity. The use of autonomic profiles holds promise for classifying human obesity and identifying obese patients at increased risk for various disorders.

Adipose Tissue↗

Familial DiGuglielmo syndrome.

DiGuglielmo syndrome is usually considered an idiopathic disorder occurring sporadically. A family in which DiGuglielmo syndrome occurred in 4 of 11 siblings is reported. A fifth sibling has developed unexplained marrow hypoplasia. Serial morphologic and cytochemical studies, supplemented by cytogenetic studies, documented the evolution of disease. Cytogenetic and environmental investigations did not explain this clustering of blood dyscrasias although a genetic predisposition to marrow damage by environmental factors cannot be excluded. The natural history of the disease in this sibship may consist of initial reactive changes in the marrow with subsequent progression to myelodysplasia with sideroblastosis and, finally, to DiGuglielmo syndrome.

Adult↗

The influence of student interest on teaching evaluation.

OBJECTIVES: To analyze the influence of student subject bias on the evaluation of didactic teaching. DESIGN: Prospective study evaluating the relationship between the interest of junior students in 30 clinical topics and the students' subsequent evaluations of lecturers for these topics. SETTING: University internal medicine junior core curriculum. PARTICIPANTS: 56 junior students. Lecturers were senior internal medicine residents. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: There was no correlation between mean student interest scores for the topics and either immediate or end-of-rotation lecturer evaluation scores (R = -0.14 and 0.09 and p = 0.47 and 0.61, respectively). For 20 of 30 topics (66%) more than 50% of the students assigned the same level of high, intermediate, or low interest. There was no significant difference (p = 0.84) in the mean lecturer evaluation scores for these three divergent groups. Analysis of individual lecturers' evaluation scores revealed stratification to a given range independent of student interest in the topic. CONCLUSIONS: Students do not appear to be biased by their degree of interest in a subject when evaluating teaching skills. It appears unlikely that specific teaching assignments need to be considered when evaluating competence in didactic teaching.

Attitude↗

The effect of an aldose reductase inhibitor on cardiovascular performance in patients with diabetes mellitus.

Because some aldose reductase inhibitor studies have demonstrated clinical improvement in scored neurological signs and symptoms of diabetic neuropathy, a prospective study of the effect on cardiovascular performance of sorbinil 250 mg/day for 12 months was conducted on patients with diabetic autonomic neuropathy who were free of atherosclerotic coronary artery disease and/or cardiomyopathy. After 1 year of treatment, the study group (n = 14) demonstrated significant improvement in both the resting cardiac output (P = 0.02), and the maximal cardiac output (P = 0.03). This observation suggests that the use of an aldose reductase inhibitor may be useful in treating suboptimal cardiovascular performance in patients with diabetic cardiac autonomic neuropathy.

Adult↗

Attitudes of diabetic men after implantation of a semi-rigid penile prosthesis.

Erectile impotence is a common and distressing problem in diabetic men. In order to examine the impact of a penile prosthesis on the quality of life of the recipients, we mailed a questionnaire to all patients (N = 49) who received a semi-rigid (Small-Carrion) prosthesis at the Seattle VAMC from 1976 to 1981. Fourteen patients with diabetes and 23 without diabetes returned the questionnaire. Direct comparisons showed no statistically significant differences between the responses of the two groups. Based on a scale of 1-7 (1 = worst, 4 = no change, 7 = best), the general effect of the operation on the quality of life of the recipients was 5.7 +/- 0.3 (Mean +/- SEM); the quality of intercourse was 5.1 +/- 0.3; the patient's perception of his partner's response to the prosthesis was 5.2 +/- 0.3; and the patient's perception of postoperative changes in his relationship with his partner was 5.6 +/- 0.3. Eighty-three percent of the patients were satisfied with the performance of the prosthesis. Most of the patients (86%) felt that their preoperative expectations had been fulfilled and would elect to have the procedure if they had it to do over again. However, five patients (14%) stated that they would not elect the operation again because their partners did not appreciate the operation (N = 2); the operation produced severe, prolonged pain (N = 1); or the patient's expectations had not been fulfilled (N = 2). Preoperative counseling should be used to foster realistic patient and partner expectations. This operation, which appears to improve the quality of life for most diabetic patients with erectile impotence, should be considered a part of standard care and not as a cosmetic procedure or extraordinary care.

Coitus↗