PubMed HealthSearch

Biomedical subjects

R Engelman

Publications and source records attributed to R Engelman.

4 recordsLinked to original sources

Experimental approaches to nutrition and cancer: fats, calories, vitamins and minerals.

Chronic energy intake restriction (CEIR) inhibits lymphoproliferative disease, autoimmune-based renal disease and mammary adenocarcinoma in mice of numerous short-lived strains (MRL/lpr, C3H/Bi, C3H/Ou). Doubling and tripling of life span and health span and inhibition of development of diseases associated with aging could be attributed to restriction of calories but not to restriction of dietary fat in the absence of calorie restriction. In mice of both long- and short-lived strains, CEIR dramatically prevents the waning of immunologic vigor that commonly occurs with aging, delays thymic involution, impairs formation of circulating immune complexes, prevents the renal injury that accompanies autoimmune disease, and significantly forestalls development of genetically determined lymphoproliferative or neoplastic disease. Evidence suggests that CEIR may exert these beneficial influences in part through regulation of cellular proliferation. Trace elements, particularly zinc, as well as vitamins may play important roles in maintaining immunocompetence and also appear to be of significance in the dietary prevention of certain experimental cancers.

Animals

Pulmonary lymphangiomyomatosis.

Pulmonary lymphangiomyomatosis is a rare but distinct clinical and pathological entity. It is characterized by hamartomatous proliferation of smooth muscle around the lymphatic vessels of the lung, mediastinum, and retroperitoneum. It occurs only in menstruating women and girls and is manifested by spontaneous pneumothorax and chylous pleural or abdominal effusion. As it progresses, the lungs become increasingly involved with subsequent pulmonary insufficiency and recurrent infection. Eventually death results. This entity has not been reported previously in the surgical literature even though the thoracic surgeon is called on to both establish the diagnosis and aid in palliation. The hypothesis that the disease is estrogen dependent is reviewed and the desirability of estrogen ablation in patients with positive estrogen receptors is suggested.

Abdominal Neoplasms

Does intermittent coronary perfusion offer greater myocardial protection than continuous aortic cross-clamping?

There has been considerable controversy concerning the relative merits of intermittent coronary perfusion vs. continuous aortic cross-clamping for cardiac procedures requiring ischemic arrest. Using the isovolumic ventricular balloon model and "stop-freeze" biopsy techniques, myocardial contractility (LV dp/dt max, length-tension, and force-velocity relationships) and metabolism (adenine nucleotides, creatine phosphate, and glycogen) were studied in 46 intact dogs supported by normothermic cardiopulmonary bypass and subjected to either 60 minutes of continuous ischemic arrest or to four 15-minute intervals of ischemia each followed by 5 minutes of reperfusion. Following ischemia the hearts were reperfused for 30 minutes and defibrillated after the first 10 minutes. There were no significant differences in either metabolic parameters or contractile function between the groups. Although partial regeneration of adenosine triphosphate and glycogen occurred during reperfusion, only creatine phosphate achieved normal values and the end result was no difference between the two techniques. These data indicate that 5 minutes of coronary reperfusion between consecutive episodes of ischemic arrest affords no greater intraoperative protection of the myocardium than does continuous aortic cross-clamping.

Adenine Nucleotides