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Biomedical subjects

D M Randall

Publications and source records attributed to D M Randall.

6 recordsLinked to original sources
PubMed2001

Experimental mood inductions in persons at high and low risk for alcohol problems.

High-risk and low-risk participants (defined on the basis of presence or absence of family history of alcohol problems) were compared on reactions to positive and negative mood inductions and a nonalcoholic beer taste test that followed. After the negative induction, high-risk participants experienced negative affect more intensely than low-risk participants. In the taste test, high-risk participants drank more nonalcoholic beer than low-risk participants. The results imply that high-risk participants, compared with low-risk participants, (a) are more reactive to negative emotion-arousing stimuli and (b) are more strongly motivated to drink alcohol in negative emotion-arousing situations.

Adult↗
PubMed2000

Open-label, nonrandomized study of the effects of gatifloxacin on the pharmacokinetics of midazolam in healthy male volunteers.

STUDY OBJECTIVE: To confirm findings from an in vitro study that showed gatifloxacin did not substantially inhibit cytochrome P450 (CYP) 3A4 model substrate metabolism. DESIGN: Open-label, nonrandomized trial. SETTING: Clinical pharmacology unit. SUBJECTS: Fourteen healthy adult men. INTERVENTION: Using midazolam probe methodology, the clearance of midazolam in the presence of multiple-dose gatifloxacin was evaluated. MEASUREMENTS AND MAIN RESULTS: Typical steady-state concentrations of gatifloxacin 400 mg once/day had no effect on midazolam clearance, and gatifloxacin pharmacokinetics were unaffected by midazolam. All doses of both agents were well tolerated. CONCLUSION: Data from this in vivo trial support in vitro experience with gatifloxacin and suggest that interactions are unlikely between gatifloxacin and drugs that are metabolized by CYP3A.

Adult↗
PubMed2000

Interchangeability of 400-mg intravenous and oral gatifloxacin in healthy adults.

STUDY OBJECTIVE: To evaluate the interchangeability of 400-mg intravenous and oral doses of gatifloxacin. DESIGN: Randomized, open-label, crossover study. SETTING: GFI Pharmaceutical Services, Inc., Evansville, Indiana, USA. SUBJECTS: Twenty-four healthy men and women (12 of each gender), aged 18-42 years. INTERVENTIONS: Subjects received single doses of gatifloxacin 400 mg either by intravenous infusion over 1 hour or a 400-mg tablet orally with 240 ml of water, each dose separated by a 1-week washout. Plasma concentrations of gatifloxacin were determined by a validated high-performance liquid chromatography; pharmacokinetic parameters were calculated using noncompartmental methods. Distributions of pharmacokinetic parameter values were summarized by route of administration and gender. Effects of treatment on pharmacokinetic parameter values of gatifloxacin were assessed by an analysis of variance model suitable for a two-way, two-treatment, crossover design. Clinical evaluations were performed to assess drug safety and tolerability. MEASUREMENTS AND MAIN RESULTS: Intravenous and oral gatifloxacin were considered interchangeable because both routes were bioequivalent with respect to area under the curve (AUC; 90% confidence interval for the ratio of geometric means contained within 0.8-1.25). The plasma concentration-time profile after intravenous administration was similar and comparable in extent of exposure (AUC0-infinity) with that for the oral route when equal doses were administered to men and women. The absolute bioavailability of gatifloxacin after oral administration was 96%, consistent with bioequivalence of the 400-mg intravenous and oral doses. The drug was well tolerated; the frequency of adverse events was comparable after intravenous and oral administration. CONCLUSION: Intravenous and tablet formulations of gatifloxacin are bioequivalent and therefore interchangeable. This permits greater flexibility in choosing oral or parenteral therapy, with the possibility of avoiding hospitalization based on knowledge that oral administration will deliver therapeutic exposure to the drug, or abbreviating hospital stay due to ease of switching from intravenous to oral therapy.

Administration, Oral↗
PubMed1986

Alternate form reliability and equivalency of the Rey Auditory Verbal Learning Test.

Assessed alternate form reliability and equivalency for the Rey Auditory Verbal Learning Test (AVLT) in a clinical sample. A test-retest, counterbalanced design was utilized with a diagnostically heterogenous group of 85 VA Medical Center patients. The mean test-retest interval was 140 min. Alternate form reliability coefficients were highly significant, all p less than .001, and ranged from .60 to .77. The forms yielded comparable means with differences of less than 1 point on each of the five learning trails and the postinterference (VI) and recognition trials. Total words recalled on trials I through V differed by less than 3 points across forms. From a statistical point of view, when the alternate form was administered second it was slightly more difficult than the original. In the reverse order, the two measures were comparable. Overall, differences between forms lacked clinical significance and the tests were judged to be equivalent measures.

Adult↗
PubMed1985

Test-retest stability of the WAIS-R in a clinical sample.

This study assessed WAIS-R test-retest stability for a sample of 21 psychiatric and neurological patients. The test-retest interval ranged from 2 weeks to 144 weeks, with a mean of 38 weeks. Subtest stability coefficients were highly significant; only Similarities, r(19) = .45, p less than .05, fell below a correlation of .74. The Verbal, Performance, and Full Scale IQs yielded highly significant stability coefficients (.79, .88, and .86). Nevertheless, the range of gain or loss for any single individual was comparatively large. On the Full Scale IQ, 18 of 21 (86%) subjects showed changes of 3 points or more, and 8 of 21 (38%) actually changed IQ classifications. Gain or loss in total score was unrelated to initial level of brightness on the Full Scale, age at initial testing, or days between examinations. Conversely, gain or loss on the Full Scale was associated strongly with years of education, r(19) = .55, p less than .01. When the sample was divided into brain-damaged and psychiatric subgroups, the difference in retest gain on the Full Scale IQ was nonsignificant.

Brain Damage, Chronic↗