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Biomedical subjects

M B Engler

Publications and source records attributed to M B Engler.

27 records · Page 2Linked to original sources
PubMed1992

Dietary gamma-linolenic acid lowers blood pressure and alters aortic reactivity and cholesterol metabolism in hypertension.

OBJECTIVE: To determine the effects of dietary gamma-linolenic acid upon blood pressure, aortic reactivity and cholesterol metabolism in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. DESIGN: Randomized parallel-group study. METHODS: SHR and WKY rats were fed a purified diet containing either sesame or borage oil rich in gamma-linolenic acid for 7 weeks. Blood pressure measured by the tail-cuff method and weight were monitored weekly. At the end of the study, intra-arterial pressor responses to norepinephrine and angiotensin II, and reactivity of isolated aortic rings to norepinephrine, angiotensin II, KCl and acetylcholine were determined. Serum cholesterol and triglycerides were measured. Hepatic and intestinal enzymes and receptors of cholesterol metabolism were also measured. RESULTS: Dietary borage oil significantly decreased blood pressure in SHR and WKY rats compared with sesame oil-fed rats. Pressor responses to norepinephrine and angiotensin II, and aortic reactivity to norepinephrine, angiotensin II, KCl and acetylcholine were not significantly different. The borage oil diet increased serum cholesterol levels in WKY rats and hepatic B-hydroxy-3-methylglutaryl coenzyme A reductase in SHR. CONCLUSION: These data indicate that dietary borage oil has a blood pressure lowering effect in hypertensive and normotensive rats. However, the effect cannot be explained by altered sensitivity to humoral and neural vasoconstrictors or changes in cholesterol metabolism. Other mechanisms should be investigated.

Angiotensin II↗
PubMed1992

Cardiovascular disease prevention: knowledge and attitudes of graduate nursing students.

Graduate nursing students were surveyed to determine the knowledge and attitudes of cardiovascular disease prevention. Questionnaires were self-administered to first-year graduate nursing students (n = 50) in a school of nursing prior to and following a physiology course with cardiovascular disease prevention content. In general, the results demonstrated that the respondents were least knowledgeable regarding the prevalence of smoking, the gender differences in high-density lipoprotein (HDL)-cholesterol levels, the influence of body weight on lipids and the recommended percentages of calories from dietary fat. A significant improvement in knowledge was noted after the course. Positive attitudes regarding the importance of cardiovascular disease prevention and the partnership between patients and clinicians necessary to manage risk were identified. These attitudes did not change significantly following the course. These results indicate that graduate education which emphasizes cardiovascular disease prevention increases knowledge. Coupled with positive attitudes and healthy personal lifestyle behaviours, knowledge of cardiovascular disease prevention may enhance the ability of nurses to integrate preventive standards into clinical practice and ultimately decrease the risk of cardiovascular disease.

Adult↗
PubMed1992

Effect of omega-3 fatty acids, docosahexaenoic and eicosapentaenoic, on norepinephrine-induced contractions.

The relaxant responses of the rat thoracic aorta to omega-3 fatty acids, docosahexaenoic and eicosapentaenoic, on norepinephrine- and potassium-induced contractions were investigated. Relaxation was enhanced in vessels contracted with norepinephrine. Docosahexaenoic acid at concentrations as low as 1, 3, and 10 microM evoked significant relaxant responses (15, 23, 30%) in norepinephrine-contracted vessels as compared with responses (5, 9, 12%) in potassium-contracted vessels. Results for eicosapentaenoic acid under similar conditions were 3, 8, and 19% in norepinephrine-contracted vessels and 3, 3, and 8% in potassium-contracted vessels. Pretreatment with eicosapentaenoic (10 microM) or docosahexaenoic acids (1-10 microM) decreased the contractile response to physiologic concentrations of norepinephrine. In the presence of calcium-free medium, the omega-3 fatty acids (1-30 microM) significantly abolished sustained norepinephrine contractions but did not reduce the phasic contractions when incubated prior to norepinephrine contraction. Comparatively, the effects of docosahexaenoic acid were greater than eicosapentaenoic acid. These findings suggest that the relaxant effects of the omega-3 fatty acids are specific to the mode of contraction, i.e., alpha-adrenoceptor stimuli. This effect may be related to intracellular calcium mechanisms, since both fatty acids reversed norepinephrine-induced sustained contractions in the absence of extracellular calcium.

Animals↗
PubMed1990

Docosahexaenoic acid (22:6n3)-induced relaxation of the rat aorta.

Dietary consumption of fish and fish oil supplements, containing eicosapentaenoic acid and docosahexaenoic acid, has been associated with favorable alterations in the cardiovascular system, such as, a reduction in blood pressure. Therefore, the effects of docosahexaenoic acid (22:6n3) on isometric tension of rat aortic smooth muscle were investigated. A concentration-dependent (1-127 microM) relaxation (6-30%) was induced by 22:6n3 in non-precontracted vessels. Docosaehexaenoic acid, concentration dependently (1-44 microM) reversed contractions of rat aortic rings induced by phenylephrine (7-43%) and by U44069 (8-52%). These results indicate that the relaxant effects produced by 22:6n3 in the rat aorta are concentration-dependent and not specific to the contractile agonist.

Animals↗
PubMed1985

The effects of magnetic resonance imaging on intravenous infusion devices.

We evaluated the effects of magnetic resonance imaging on the accuracy of three types of intravenous infusion pump devices, IVAC 530, IMED 927 and IMED 960/965. The devices were exposed to a 2,800-gauss static magnetic field at a pulsed radio frequency of 11.9 MHz operating at a maximum power of 1,200 W. Each device was tested at low, medium and fast flow rates in a controlled environment and during magnetic resonance imaging. Intravenous therapy could be carried out normally during magnetic resonance diagnostic imaging only with the IVAC 530 infusion device.

Humans↗
PubMed1984

Actuarial analysis of the risk of undergoing repeat cardiac valve replacement.

One thousand five hundred ninety-eight patients who underwent cardiac valve replacement were reviewed. One hundred fifty-two patients (10 percent) required a second valve replacement. The indications for repeat valve replacement were prosthetic valve dysfunction in 53 patients (35 percent), development of a new valvular lesion in 46 patients (30 percent), simple closure of a perivalvular leak in 14 patients (9 percent), change of the valve poppet in 13 patients (8 percent), severe hemolysis or emboli in 21 patients (14 percent), and prosthetic valve endocarditis in 5 patients (3 percent). The mean preoperative New York Health Association functional class improved from 3 to 1.5 in the nonreoperated patients and from 2.9 to 1.8 in patients who underwent a second valve replacement. Similarly, the mean cardiac index improved from 2.5 to 2.9 and from 2.5 to 2.8 in nonreoperated and reoperated patients, respectively. The operative mortality rate was 14 percent in the nonreoperated patients and 16 percent at second operation in the reoperated patients. Using actuarial techniques, the risk of repeat valve replacement was 1 to 4 percent per year. Long-term survival was compared between groups. Using actuarial techniques, the estimated survival rates at 1, 5, and 10 years were 89 percent, 69 percent, and 52 percent, respectively in nonreoperated patients and 87 percent, 60 percent, and 37 percent in reoperated patients. This study has documented the excellent improvement in functional and hemodynamic state after second cardiac valve replacement. The operative mortality and long-term survival rates were similar to those of the nonreoperated patients. Patients having repeat cardiac valve replacement can expect good improvement in length and quality of life.

Actuarial Analysis↗