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Biomedical subjects

B O Oluwole

Publications and source records attributed to B O Oluwole.

4 recordsLinked to original sources

Gene regulation by mechanical forces.

Endothelial cells are subjected to various mechanical forces in vivo from the flow of blood across the luminal surface of the blood vessel. The purpose of this review was to examine the data available on how these mechanical forces, in particular cyclic strain, affect the expression and regulation of endothelial cell function. Studies from various investigators using models of cyclic strain in vitro have shown that various vasoactive mediators such as nitric oxide and prostacyclin are induced by the effect of mechanical deformation, and that the expression of these mediators may be regulated at the transcription level by mechanical forces. There also seems to be emerging evidence that endothelial cells may also act as mechanotransducers, whereby the transmission of external forces induces various cytoskeletal changes and second messenger cascades. Furthermore, it seems these forces may act on specific response elements of promoter genes.

Animals↗

Comparison of active infective endocarditis involving a previously stenotic versus a previously nonstenotic aortic valve.

No previous studies, either clinical or morphologic, have compared findings in patients with active infective endocarditis (IE) involving a previously stenotic versus a previously nonstenotic aortic valve. Clinical and cardiac necropsy findings were analyzed in 96 patients with active IE involving the aortic valve. Of the 96 patients, 25 (26%) had active IE superimposed on a previously stenotic aortic valve and 71 (74%) on a previously nonstenotic aortic valve. The patients with stenotic aortic valves compared with those with nonstenotic aortic valves had significantly higher mean ages (61 vs 47 years), a higher percentage > 60 years of age (52 vs 24%), a higher percentage of men (92 vs 73%), a higher frequency of an absent or unknown predisposing factor to infection (68 vs 38%), a lower frequency of a precordial murmur of aortic regurgitation (44 vs 79%), a lower percent with a long duration (> 60 days) of signs and symptoms of active IE (4 vs 23%), a larger mean heart weight (594 vs 514 g), a higher percentage with aortic valve calcific deposits (100 vs 24%), and a higher frequency of associated ring abscess (84 vs 52%). Thus, active IE superimposed on a stenotic aortic valve differs in some features compared with active IE on a nonstenotic aortic valve. Because ring abscess is so common when active IE involves a stenotic aortic valve in adults, operative intervention at an early stage may be warranted.

Adult↗