Both cholera enterotoxin and certain prostaglandins have been shown to stimulate intestinal fluid secretion in vivo, to cause ion flux changes in vitro similar to those caused by addition of cyclic 3',5'-adenosine monophosphate (cyclic AMP), and to activate intestinal mucosal adenyl cyclase. It has been suggested that the effects of the enterotoxin on intestinal cyclic AMP metabolism may be ind...

In vitro frog gastric mucosa was employed as a model for a combined physiological, biochemical, and ultrastructural study of the morphological changes which accompany the onset of acid secretion by the oxyntic cell. The histamine H2-receptor antagonist metiamide was used to provide a reproducible control state. Stimulation of acid production by theophylline resulted in a 10-fold increase in pla...

Studies in nonhuman primates indicate that changes in the thickness and integrity of the vaginal epithelium affect the transmission rates of HIV-1, but few studies have examined the normal variations that may occur in the vagina of normal macaques as a result of aging or changes in the menstrual cycle. This study was conducted to determine if differences occur in the thickness of the vaginal mu...

Glassy polycarbonate was subjected to cyclic stresses and the changes in its structure were studied by DSC, positronium annihilation lifetime spectroscopy (PALS), and SAXS. On increased exposure to cyclic loading, the enthalpy overshoot near T s increased in a manner similar to increasing physical aging. However, the 'hole' size as revealed by PALS increased, unlike physical aging. SAXS reveals...

objective: cell vital function has correlation with mechanical loadings that cell experiences. here, effects of in-vitro combined cyclic-static stretch on proliferation of human mesenchymal stem cell (hmsc) were evaluated. materials and methods: hmscs were cultured on gelatin coated elastic membranes, and exposed to stretch loading. four different regimes of cyclic, static, combined cyclic-sta...