longevity of osseointegrated implants are intensely influenced by biomechanical factors. control of these factors prevents mechanical complications, which include fracture of screws, components, or materials veneering the framework. in this study, the impact of length and threads pitch of dental implants on the stress distribution and maximum von mises stress in implant-abutment complex and jaw...

spreading depression (sd), discovered by leao in 1944, is a pathophysiological wave which propagates slowly in the brain (3 mm/min) and cause dramatic ionic and hemodynamic changes. sd appears to act through several mechanisms and receptors which have not completely understood. here, we studied the effect of inhibitory system in animal model of sd using immunohistochemistry technique. after imp...

abstract  background: the brain response to temporal frequencies (tf) has been already reported, but with no study reported for different tf with respect to various spatial frequencies (sf).  materials and methods: fmri was performed by 1.5t ge-system in 14 volunteers during checkerboard, with tfs of 4, 6, 8 and 10hz in low and high sfs of 0.5 and 8cpd.  results: average percentage bold signal ...

Adult bovine adrenal cortical cells in monolayer culture were used to study the induction of cholesterol side-chain-cleavage cytochrome P-450 by corticotropin (ACTH). In the presence of 1 microM ACTH, there was a 4-fold increase in cortisol production by these cells over a 72-hr period and a corresponding increase in total cytochrome P-450 content. The incorporation of [35S]methionine into a nu...

The importance of prostaglandins in the regulation of the renin-angiotensin system during development is not known. These experiments were conducted to examine the effects of prostaglandin synthesis inhibitors on basal and isoproterenol-induced plasma renin concentration and renin gene expression in the late-gestation fetal lamb. Eighteen lamb fetuses ranging in gestational age from 129 to 138 ...

Brain-derived neurotrophic factor (BDNF) is known to play a role in experience-dependent plasticity of the developing visual cortex. For example, BDNF acutely enhances long-term potentiation and blocks long-term depression in the visual cortex of young rats. Such acute actions of BDNF suggested to be mediated mainly through presynaptic mechanisms. A chronic application of BDNF to the visual cor...

Brain-derived neurotrophic factor (BDNF) is known to play a role in experience-dependent plasticity of the developing visual cortex. For example, BDNF acutely enhances long-term potentiation and blocks long-term depression in the visual cortex of young rats. Such acute actions of BDNF suggested to be mediated mainly through presynaptic mechanisms. A chronic application of BDNF to the visual cor...