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1.
Feasibility and Diagnostic Potential of Pulmonary Transit Time Measurement by Contrast Echocardiography: A Pilot Study
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Bill J Gurley Ashley Swain Gary W Barone D Keith Williams Philip Breen C Ryan Yates Leslie B Stuart Martha A Hubbard Yudong Tong Sreekhar Cheboyina 《Drug metabolism and disposition》2007,35(2):240-245
Phytochemical-mediated modulation of P-glycoprotein (P-gp) and other drug transporters may give rise to many herb-drug interactions. Serial plasma concentration-time profiles of the P-gp substrate, digoxin, were used to determine whether supplementation with goldenseal or kava kava modified P-gp activity in vivo. Twenty healthy volunteers were randomly assigned to receive a standardized goldenseal (3210 mg daily) or kava kava (1227 mg daily) supplement for 14 days, followed by a 30-day washout period. Subjects were also randomized to receive rifampin (600 mg daily, 7 days) and clarithromycin (1000 mg daily, 7 days) as positive controls for P-gp induction and inhibition, respectively. Digoxin (Lanoxin, 0.5 mg) was administered p.o. before and at the end of each supplementation and control period. Serial digoxin plasma concentrations were obtained over 24 h and analyzed by chemiluminescent immunoassay. Comparisons of area under the curve (AUC)((0-3)), AUC((0-24)), C(max,) CL/F, and elimination half-life were used to assess the effects of goldenseal, kava kava, rifampin, and clarithromycin on digoxin pharmacokinetics. Rifampin produced significant reductions (p < 0.01) in AUC((0-3)), AUC((0-24)), CL/F, t(1/2), and C(max), whereas clarithromycin increased these parameters significantly (p < 0.01). With the exception of goldenseal's effect on C(max) (14% increase), no statistically significant effects on digoxin pharmacokinetics were observed following supplementation with either goldenseal or kava kava. When compared with rifampin and clarithromycin, supplementation with these specific formulations of goldenseal or kava kava did not appear to affect digoxin pharmacokinetics, suggesting that these supplements are not potent modulators of P-gp in vivo. 相似文献
4.
Factors influencing family physicians to enter rural practice: Does rural or urban background make a difference?
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Pharmacological interactions between serotonin and dopamine on behavior in the squirrel monkey 总被引:2,自引:1,他引:1
The behavioral effects of GBR 12909, a selective dopamine uptake inhibitor, were determined in squirrel monkeys trained to
respond under a fixed-interval (FI) schedule of stimulus termination and a second-order schedule of IV drug self-administration.
Intermediate doses of GBR 12909 increased FI response rate markedly, and the highest dose decreased response rate below control
values. The 5HT uptake inhibitors, alaproclate and fluoxetine, and the 5HT agonist, quipazine, attenuated the behavioral-stimulant
effects of GBR 12909, whereas the 5HT2A/2C antagonist, ritanserin, enhanced the behavioral-stimulant effects of the lowest dose. GBR 12909 reliably maintained self-administration,
and ritanserin increased response rate maintained by the highest dose. The dopamine agonist, quinpirole, increased FI response
rate in only one of three subjects, and ritanserin enhanced the behavioral-stimulant effects of quinpirole in that subject.
The dopamine agonist, apomorphine, only decreased FI response rate, and ritanserin did not alter its behavioral effects. The
pharmacological profile of GBR 12909 administered alone and in combination with selective 5HT drugs in the present study was
similar to that obtained previously with cocaine, further demonstrating that 5HT can reliably modulate the behavioral effects
of psychomotor stimulants with prominent dopaminergic actions.
Received: 9 July 1996 / Final version: 22 November 1996 相似文献
7.
Carol E. Golin Katherine Tiller E. Byrd Quinlivan Catherine A. Grodensky Maureen Boland 《AIDS and behavior》2007,11(1):72-83
The epidemiology of HIV infection in the US in general, and in the southeast, in particular, has shifted dramatically over the past two decades, increasingly affecting women and minorities. The site for our intervention was an infectious diseases clinic based at a university hospital serving over 1,300 HIV-infected patients in North Carolina. Our patient population is diverse and reflects the trends seen more broadly in the epidemic in the southeast and in North Carolina. Practicing safer sex is a complex behavior with multiple determinants that vary by individual and social context. A comprehensive intervention that is client-centered and can be tailored to each individual’s circumstances is more likely to be effective at reducing risky behaviors among clients such as ours than are more confrontational or standardized prevention messages. One potential approach to improving safer sex practices among people living with HIV/AIDS (PLWHA) is Motivational Interviewing (MI), a non-judgmental, client-centered but directive counseling style. Below, we describe: (1) the development of the Start Talking About Risks (STAR) MI-based safer sex counseling program for PLWHA at our clinic site; (2) the intervention itself; and (3) lessons learned from implementing the intervention. 相似文献
8.
OBJECTIVE: To determine if conventional sperm parameters, specific characteristics of sperm motion determined by computer-aided semen analysis (CASA), sperm penetration assay (SPA), and/or spontaneous acrosome reaction assay could best predict fertility outcome after intrauterine insemination (IUI) from frozen donor sperm. DESIGN: A retrospective analysis of 2,245 cycles of therapeutic donor IUIs were initially studied; 1,147 cycles that met selection criteria were used in this report. SETTING: A university-based assisted reproductive technology center. PATIENTS, PARTICIPANTS: All IUIs were performed on women with documented patency of at least one fallopian tube, ovulatory cycles, and who did not receive human menopausal gonadotropins. Sperm donors had to be used for at least four different recipients (mean of 15) and at least 14 different cycles of insemination (mean of 41). INTERVENTIONS: None. MAIN OUTCOME MEASURE: Pregnancy. RESULTS: Statistical comparisons were made between donors of different relative fertility by using the Mann-Whitney test, Spearman's rank correlation, and multiple regression analysis. These analyses demonstrated that the most significant predictors of the fertility of frozen-thawed donor sperm were curvilinear velocity, straight line velocity, and the total number of motile sperm inseminated. The number of sperm with spontaneous acrosome reactions negatively correlated with fertility outcome, and SPA provided no predictive value. CONCLUSIONS: Our study supports the hypothesis that the study of sperm motion characteristics using CASA after thawing and washing of cryopreserved sperm is a better predictor of fertile outcome after IUI than analysis of fresh semen. 相似文献
9.
Toxoplasma encephalitis is the commonest cause of intracranial mass lesions in AIDS patients. Effective therapy includes pyrimethamine plus sulfadiazine, clindamycin with pyrimethamine, and co-trimoxazole. This study examines the efficacy of oral co-trimoxazole in 20 AIDS patients with toxoplasmosis and seeks to confirm the experience of Torre et al. 相似文献
10.
OBJECTIVE: To test, using a primate model, a new approach for achieving individualized pituitary-ovarian responses to controlled ovarian hyperstimulation. DESIGN: Normal ovulatory adult monkeys were selected and randomly assigned to one of the three groups according to onset of spontaneous menses. They had no prior exposure to gonadotropin-releasing hormone (GnRH) antagonist or exogenous gonadotropin therapies. SETTING: The laboratories of The Jones Institute for Reproductive Medicine were used. PATIENTS, PARTICIPANTS: Normal adult macaque females were studied. INTERVENTIONS: Monkeys received hormonal therapies of gonadotropins in combination with GnRH antagonist. MAIN OUTCOME MEASURE(S): Pituitary luteinizing hormone (LH) secretion and ovarian estrogen and progesterone production were monitored. RESULTS: Adding GnRH antagonist to ongoing human follicle-stimulating hormone (hFSH) stimulation can prevent unwanted LH surges, whether begun at early, mid, or late points in the stimulation protocol. CONCLUSIONS: The flexible protocol for administration of hFSH with GnRH antagonist yielded satisfactory results, with apparent advantages of economy, convenience, and individuality of treatment compared with GnRH agonist plus gonadotropin regimens used currently. 相似文献