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R Stacey

Publications and source records attributed to R Stacey.

31 records · Page 2Linked to original sources
PubMed1976

Mitochondrial isocitrate dehydrogenase and isocitrate oxidation of rat ventral prostate.

Mitochondrial preparations isolated from rat ventral prostate were capable of oxidizing isocitrate by way of NADP isocitrate dehydrogenase (NADP-IDH) and NAD-IDH. NAD-IDH activity required ADP for activation. The pH responses for NAD-IDH and NADP-IDH were quite different. The results indicated that two different enzymes were involved in the NAD- and NADP-IDH activities. Indirect evidence indicated that NADPH-NAD transhydrogenase activity might also be involved in the mitochondrial pathway for isocitrate oxidation. NADP-IDH activity was significantly greater than NAD-IDH activity. The oxidation of isocitrate through IDH activity was coupled to the cytochrome system by NADPH- and NADH-cytochrome c reductase activities. Citrate, via isocitrate, oxidation proceeded at a much slower rate suggesting that aconitase activity could be limiting in the oxidation of citrate. In comparison to other tissues, the prostate oxidative enzyme activities are considerably lower. The results suggest that the accumulation of high prostate citrate levels is not due to a limitation imposed by a lack of IDH activity in prostate mitochondria.

Animals↗
PubMedDate not supplied

Aortic xenograft valve performance at eight years. A comparative study.

The medium-term performance of commercially available xenograft prostheses in the aortic position, was evaluated in 198 patients operated upon since 1975. No associated procedures were performed in these patients in whom a variety of prostheses was employed. The valve behaviour has been compared with other xenograft series, homografts and synthetic prostheses. There was a 5.5% hospital death rate and a 7.5% late mortality. Five late deaths were valve related, five were unrelated to the valve and four were of unknown cause but in elderly patients. At eight years, 86.1% of patients were alive, the majority functionally improved. Thromboembolic events were considerably fewer than those experienced with most non-biological prostheses, all but three events being transient. Re-operation for primary valve dysfunction was a safe procedure but re-operation for infected prostheses carried a high mortality. In comparing the aortic xenograft with other prostheses, severe dysfunction was found to occur with similar frequency in all prostheses up to eight years and was rare. Mild prosthetic dysfunction (asymptomatic diastolic murmur) occurs in about 25% of all tissue valves at eight years, including the homograft. The progression, or otherwise, of mild dysfunction has yet to be evaluated in currently available xenograft prostheses.

Adolescent↗