Downstream of Ras, the serine/threonine kinase, B-raf, has recently been reported to be mutated, among other carcinomas, in a substantial subset of primary melanomas with a preponderance of the oncogenic V599E transition. As the risk of melanoma is enhanced by intermittent ultraviolet (UV) exposure but is less with chronic UV exposure, we here studied B-raf kinase domain (exon 15) mutations in ...

Objective: Intermittency is routinely used as a protective strategy against CNS and pulmonary hyperbaric oxygen (HBO2) toxicity, however exact mechanisms of protection are not known. This study was designed to optimize intermittent HBO2 exposures by variable duration of HBO2 cycles. Methods: Rats were exposed to O2 at 2.8 ATA delivered either continuously for 6 h or intermittently with 10 min a...

BACKGROUND The efficacy of fibrinolytic therapy is limited by the small surface area of the clot that is available for the binding of the thrombolytic agent, such as tissue-type plasminogen activator (t-PA). We hypothesized that exposure of the clot to ultrasound during thrombolytic treatment could enhance lysis through perturbation of the thrombus, which would expose additional fibrin binding ...

In mammals, the pupillary light reflex is mediated by intrinsically photosensitive melanopsin-containing retinal ganglion cells that also receive input from rod-cone photoreceptors. To assess the relative contribution of melanopsin and rod-cone photoreceptors to the pupillary light reflex in humans, we compared pupillary light responses in normally sighted individuals (n = 24) with a blind indi...

OBJECTIVE To compare the effects of continuous and intermittent celecoxib treatment in patients with knee or hip osteoarthritis in flare. METHODS In this 24-week, prospective, randomised, double-blind, placebo-controlled study, patients were randomly assigned to receive continuous (n = 62) or intermittent (n = 61) treatment with celecoxib 200 mg once daily. The primary efficacy end point was ...

Chronic constant hypoxia (CCH) and chronic intermittent hypoxia (CIH) are known to have deleterious effects on the central nervous system. Because of the difference in the pattern of hypoxic exposure, it is possible that the pathological outcome would vary. The N-acetyl aspartate/creatine (NAA/Cr) ratio is a reliable marker of neuronal integrity, and this can be noninvasively measured by proton...

Various forms of preventive and prophylactic antimicrobial therapies have been proposed to combat HIV (e.g. pre-exposure prophylaxis), tuberculosis (e.g. isoniazid preventive therapy) and malaria (e.g. intermittent preventive treatment). However, the potential population-level effects of preventative therapy (PT) on the prevalence of drug resistance are not well understood. PT can directly affe...

Configurations derived from classical concepts of waverider and Busemann biplane have great potential of use in aerodynamic design of highspeed vehicles with air-breathing jet engines due to their ability to provide both high lift-to drag ratio and intense preliminary compression of the flow before air intakes. The issues of conceptual design of highspeed vehicles based on the use of waverider ...

Common neurobiological substrates contribute to the progressively increased behavioral effects (i.e., sensitization) that occur with repeated intermittent treatments of cocaine and morphine. Consequently, repeated exposure to cocaine can augment responding to morphine (termed cross-sensitization). Drug-induced sensitization in rats may model aspects of the dysfunction in motivation that are imp...