David J Edwards

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Grapefruit juice increases the oral availability of a variety of CYP3A4 substrates. It has been shown that recurrent grapefruit juice ingestion results in a loss of CYP3A4 from the small bowel epithelium. We now show that the reduction in intestinal CYP3A4 concentration is rapid; a 47% decrease occurred in a healthy volunteer within 4 hr after consuming(More)
Klebsiella pneumoniae is now recognized as an urgent threat to human health because of the emergence of multidrug-resistant strains associated with hospital outbreaks and hypervirulent strains associated with severe community-acquired infections. K. pneumoniae is ubiquitous in the environment and can colonize and infect both plants and animals. However,(More)
OBJECTIVES Phytochemical-mediated modulation of cytochrome P450 (CYP) activity may underlie many herb-drug interactions. Single-time point phenotypic metabolic ratios were used to determine whether long-term supplementation of Citrus aurantium , Echinacea purpurea , milk thistle (Silybum marianum), or saw palmetto (Serenoa repens) extracts affected CYP1A2,(More)
BACKGROUND AND PURPOSE Minocycline is a promising anti-inflammatory and protease inhibitor that is effective in multiple preclinical stroke models. We conducted an early phase trial of intravenous minocycline in acute ischemic stroke. METHODS Following an open-label, dose-escalation design, minocycline was administered intravenously within 6 hours of(More)
OBJECTIVE To determine the short-term and long-term risks of tuberculosis (TB) associated with CD4 cell recovery during antiretroviral therapy (ART). DESIGN Observational community-based ART cohort in South Africa. METHODS TB incidence was determined among patients (n = 1480) receiving ART for up to 4.5 years in a South African community-based service.(More)
OBJECTIVE To examine the effect of grapefruit juice on the disposition of cyclosporine after administration of oral and intravenous doses to healthy male subjects. METHODS Subjects received two oral doses of cyclosporine (7.5 mg/kg) and two intravenous doses (2.5 mg/kg infused for 3 hours), with each dose separated by a 1-week washout period. Grapefruit(More)
OBJECTIVE To study the disposition of single doses of phenytoin and itraconazole when administered alone and after chronic treatment with the other drug. METHODS Healthy male volunteers were randomized to two groups and studied in parallel. In group 1, a single 200 mg oral dose of itraconazole was administered on two occasions (alone and after 15 days of(More)
BACKGROUND Minocycline, a semi-synthetic tetracycline antibiotic, is an effective neuroprotective agent in animal models of cerebral ischemia when given in high doses intraperitoneally. The aim of this study was to determine if minocycline was effective at reducing infarct size in a Temporary Middle Cerebral Artery Occlusion model (TMCAO) when given at(More)
Questions on Life Satisfaction-Hypopituitarism (QLS-H) is a new quality-of-life (QoL) questionnaire developed for adults with hypopituitarism. To determine the effects of long-term GH treatment on QoL, we evaluated QLS-H Z-scores in 576 adult patients with GH deficiency (GHD) enrolled in HypoCCS, an international observational study, using data from five(More)
Grapefruit juice inhibits the metabolism of substrates for enzymes of the CYP3A subfamily. However, the identity of the inhibitor has not been established. Grapefruit juice was extracted into methylene chloride and chromatographed by HPLC, and the effect of the HPLC eluent on CYP3A activity was assessed by measuring 6beta-hydroxytestosterone formation in(More)