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Results for “randomized crossover trial”

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At least 397 records · Page 22Linked to original sources

PubMed1988

Spicy food and the stomach. Evaluation by videoendoscopy.

We used videoendoscopy to investigate the effect of eating spicy foods on the gastric mucosa. We employed four meals: a bland meal of unpeppered steak and french fries (negative control), a bland meal with 1950 mg of aspirin (positive control), a spicy Mexican meal (30 g of jalapeño peppers), and a pepperoni pizza. Twelve subjects (eight men and four women, aged 24 to 43 years) were studied in a randomized, crossover trial with the test meal given at the noon and evening meals; each subject received all four test meals. Each study consisted of a baseline endoscopy, which was repeated approximately 12 hours after the last test meal. Gastric and duodenal damage was scored using a modification of the Lanza scale. Eleven of 12 individuals taking the bland meal plus aspirin developed multiple gastric erosions (median score, C; which equates with "severe" injury). In contrast, the median endoscopic score for the other three meals was 0. Single cases of a single erosion were present after the Mexican meals and after the pizza meals. Another experiment was done to examine the effect of spices directly on the gastric mucosa; approximately 30 g of fresh jalapeño peppers was ground in a food processor and then placed directly into the stomach. Endoscopy after 24 hours revealed no visible mucosal damage. The ingestion of highly spiced meals by normal individuals is not associated with endoscopically demonstrable gastroduodenal mucosal damage.

Adult↗

PubMed1993

Fluoxetine's spectrum of action in premenstrual syndrome.

This study extends our previous report of the efficacy and tolerability of fluoxetine in severe premenstrual syndrome (PMS), describes which aspects of the disorder are responsive to such treatment, and assesses the relationship between steady-state drug level and clinical outcome. Twenty-one women with documented PMS satisfied criteria for late luteal phase dysphoric disorder (DSM-III-R) and accepted the offer of a double-blind, randomized crossover trial of fluoxetine hydrochloride 20 mg/day vs placebo. Symptom severity was measured with daily self-rating, monthly premenstrual assessment forms and psychiatric interviews after 3 months each of baseline, placebo and fluoxetine treatment. Compared with an inconsistent placebo response, fluoxetine produced marked improvement in 15 of 16 women completing the trial, eight showing virtually complete remission of PMS symptoms. Fluoxetine's efficacy extended over a range of affective, physical and behavioural symptoms; its superiority obtained whether it preceded or followed placebo. Three women withdrew due to adverse effects of fluoxetine, and 10 of 16 completing the trial reported at least one adverse effect of this agent. Compared with placebo, fluoxetine produced more (but usually transient) insomnia, sweating, gastrointestinal and menstrual disturbance. Plasma levels of fluoxetine and its active metabolite were not reliably associated with efficacy nor with side effects. Serotonergic agents appear to have considerable promise in treating a range of symptoms in women with severe PMS.

Adult↗

PubMed1986

A comparison between fenoterol/ipratropium bromide combinations and salbutamol administered as nebulizer solutions assessing dose-response and duration of action.

A double-blind, randomized crossover trial was carried out in 10 patients with reversible airways obstruction to assess dose-response and duration of action of 0.5 mg ipratropium combined with 1.25 mg, 2.5 mg or 5.0 mg fenoterol compared with 5.0 mg salbutamol given alone. Each solution was nebulized from a volume of 4 ml and administered via a mouth-piece at approximately the same time on each of 4 test days. Measurements were made of FEV1, FVC and PEFR before and at intervals after nebulization. The results showed that each dose of the combination produced greater improvements in the lung function parameters than did salbutamol alone and the degree of response was proportional to the dose of the combination. No significant treatment differences were recorded in systolic or diastolic blood pressure between any of the treatments, but the combined preparations produced significantly higher pulse rates than did salbutamol.

Aerosols↗

PubMed1983

[Comparative studies on biologic availability and pharmacokinetics of bromazepam in tablets].

Ten male volunteers participated in a randomized crossover trial to compare the bioavailability of bromazepam (7-bromo-1,3-dihydro-5-(2-pyridyl)-2H-1,4-benzodiazepin-2-one) from two different preparations (Normoc, the test preparation, and a commercially available standard preparation). A single dose of 6 mg bromazepam was given. There was no difference in the USP XX rotating basket dissolution test between both preparations. The pharmacokinetic parameters elimination half-life, maximum plasma concentration and area under the curve were not significantly different. With the test preparation, however, smaller interindividual differences were seen. Only the time to peak plasma concentration showed a statistically significant difference. The test preparation yielded a flatter and smoother plasma bromazepam concentration curve compared with the standard preparation. This seems favourable in the case of subchronic dosing with regard to side effects, e.g. sedation.

Adolescent↗

PubMed1983

Enhancement of theophylline clearance by oral activated charcoal.

A randomized crossover trial of the effect of oral activated charcoal on the kinetics of intravenous theophylline was carried out in six normal male subjects. After intravenous aminophylline (6 mg/kg), subjects received water or water with activated charcoal (140 gm) in divided doses over 12 hr. Serum theophylline concentrations were measured from 0 to 24 hr after the aminophylline infusion. Treatment with activated charcoal decreased the serum t 1/2 from 6.4 +/- 1.2 to 3.3 +/- 0.4 (SEM) hr and the serum AUC from 78 +/- 14 to 42 +/- 4 mg . hr/l. Percent decrease in AUC after treatment with charcoal correlated positively with the endogenous theophylline serum t 1/2 (r = 0.94). These results suggest that oral activated charcoal (1) enhanced the total body clearance of theophylline and (2) may be efficacious in the treatment of theophylline poisoning, especially in patients with prolonged serum t 1/2s of theophylline.

Adult↗

PubMed1996

Pre-exercise glycerol hydration improves cycling endurance time.

The effects of glycerol ingestion (GEH) on hydration and subsequent cycle ergometer submaximal load exercise were examined in well conditioned subjects. We hypothesized that GEH would reduce physiologic strain and increase endurance. The purpose of Study I (n = 11) was to determine if pre-exercise GEH (1.2 gm/kg glycerol in 26 ml/kg solution) compared to pre-exercise placebo hydration (PH) (26 ml/kg of aspartame flavored water) lowered heart rate (HR), lowered rectal temperature (Tc), and prolonged endurance time (ET) during submaximal load cycle ergometry. The purpose of Study II (n = 7) was to determine if the same pre-exercise regimen followed by carbohydrate oral replacement solution (ORS) during exercise also lowered HR, Tc, and prolonged ET. Both studies were double-blind, randomized, crossover trials, performed at an ambient temperature of 23.5-24.5 degrees C, and humidity of 25-27%. Mean HR was lower by 2.8 +/- 0.4 beats/min (p = 0.05) after GEH in Study I and by 4.4 +/- 1.1 beats/min (p = 0.01) in Study II. Endurance time was prolonged after GEH in Study I (93.8 +/- 14 min vs. 77.4 +/- 9 min, p = 0.049) and in Study II (123.4 +/- 17 min vs. 99.0 +/- 11 min, p = 0.03). Rectal temperature did not differ between hydration regimens in both Study I and Study II. Thus, pre-exercise glycerol-enhanced hyperhydration lowers HR and prolongs ET even when combined with ORS during exercise. The regimens tested in this study could potentially be adapted for endurance activities.

Adult↗

PubMedDate not supplied

Computer interview for screening blood donors for risk of HIV transmission.

To test the ability of a computer-based interview to detect factors related to the risk of the human immunodeficiency virus (HIV) among potential blood donors, and to determine donor reactions to the use of the computer, we compared the rate of detection of HIV-related factors elicited by the computer interview with the rate elicited by standard American Red Cross procedures (written questionnaires and face-to-face interviews) for assessment of donor suitability. The study was performed at a Red Cross blood donor center and a hospital. A consecutive sample of 294 male and female blood donors 18 to 75 years of age participated in a randomized crossover trial in which the order of the two methods was reversed. Among 272 prospective donors who provided complete data, the computer identified 12 who reported either behavior associated with a risk of acquiring HIV or symptoms compatible with AIDS. None of these 12 was so identified by face-to-face interviews or written questionnaires. Only one used the confidential unit exclusion procedure to prevent use of his donated blood. Tests for antibody to HIV were negative in blood from all 272 subjects. The subjects enjoyed the computer interview and judged it to be more private than the standard method for donor assessment.

AIDS Serodiagnosis↗

PubMed2007

Single dose oral ranitidine improves MRCP image quality: a double-blind study.

AIM: To investigate the possibility of whether a single 300 mg dose of ranitidine given orally 2-3h before magnetic resonance cholangiopancreatography (MRCP) could reduce the signal from the stomach and duodenum, and thus increase the conspicuousness of the biliary tree. MATERIALS AND METHODS: Thirty-five volunteers (22 female, 13 male), (age range 21-50) were underwent MRCP in a double-blind, placebo-controlled, randomized, crossover trial on a Philips Intera 1.5 T machine using a phased array surface coil. Imaging was carried out in the coronal oblique plane. Six 40 mm sections were acquired at varying angles to delineate the biliary tree and pancreatic duct. The 70 examinations were blindly scored by three consultants experienced in cholangiography. RESULTS: After ranitidine administration there was a significant decrease in signal from the stomach (mean=17.7, p=0.0005, CI 10, 25.3) and duodenum (mean=18.4, p=0.0005, 95%CI 9.6, 27.1) with a significant increase in conspicuousness of the distal common duct (mean=7.7, p=0.033, 95%CI 0.7, 14.7) and proximal common duct (mean=8.7, p=0.010 CI 2.2, 15.2). There were no adverse effects. CONCLUSION: Oral ranitidine is a cheap and effective agent to decrease signal from the upper gastrointestinal tract and to improve visibility of the biliary tree.

Adult↗

PubMed2004

In vivo distribution of a vaginal gel: MRI evaluation of the effects of gel volume, time and simulated intercourse.

A microbicide is designed to coat the vaginal epithelium and prevent transmission of HIV. Complete coverage is desired for optimal protection. In vivo factors affecting coverage have not yet been studied. This randomized crossover trial evaluates the effect of gel volume and patient activity upon vaginal epithelial coating. Gynol II gel was mixed with a magnetic resonance imaging (MRI) contrast agent. Ten women self-inserted, on separate visits, 3 or 5 mL of gel and underwent serial MRI scanning both before and after simulated intercourse. Gel spread was dependent upon time and volume. There was modest spread during the first hour and greater spread 6 h after insertion. Five milliliters of gel resulted in statistically significantly greater coverage immediately following insertion, within the first 30 min and at 6 h after insertion. Simulated intercourse greatly enhances gel spread. After simulated intercourse, the distribution of the gel at each volume was similar. Less leakage of gel was reported with the smaller volume.

Adult↗

PubMedDate not supplied

Optimizing levodopa pharmacokinetics: intestinal infusion versus oral sustained-release tablets.

Continuous duodenal infusion of carbidopa/levodopa has been shown to control motor fluctuations in advanced Parkinson's disease (PD). The authors compared the pharmacokinetics of levodopa and 3-O-methyldopa in patients with advanced PD after administration of an oral sustained-release levodopa preparation and after continuous intestinal levodopa infusion with a new formulation as a gel suspension. A randomized crossover trial was carried out in 12 patients. Carbidopa/levodopa was administered as an oral sustained-release tablet and by nasoduodenal continuous infusion for 3-week periods for each treatment. Plasma levodopa concentrations and motor performance were evaluated every 30 minutes during 3 test days of each treatment period. The average intraindividual coefficient of variation for the plasma levodopa concentrations after oral therapy was 34% and was significantly lower (14%, p < 0.01) during continuous infusion. Hourly video evaluations showed a significant increase in ON time during infusion and a significant decrease in OFF time and dyskinesia. Continuous intraduodenal delivery of a new carbidopa/levodopa formulation offers a means for markedly improved control of motor fluctuations in late stages of PD.

Administration, Oral↗

PubMed1992

Benefits and risks with glyburide and glipizide in elderly NIDDM patients.

OBJECTIVE: To compare the efficacy, benefits, and risks of glyburide and glipizide in elderly patients with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: Twenty-one elderly outpatients (mean age 70 yr) were treated for 8 wk, after being dose-titrated to achieve a fasting plasma glucose (FPG) concentration of less than 7.8 mM with glyburide or glipizide in a randomized crossover trial. FPG and postprandial plasma glucose, serum C-peptide, and HbA1c levels were measured. In 13 patients, self-monitoring of blood glucose (SMBG) with a memory meter was performed seven times per week. RESULTS: Glipizide (11.9 mg) and glyburide (8.4 mg) produced similar fasting and postprandial plasma glucose and HbA1c concentrations. No significant differences in basal or stimulated C-peptide levels were detected. Despite a few patient reports of hypoglycemia, a high incidence of SMBG readings less than 4.5 mM was attributed to the use of both drugs. CONCLUSIONS: Both treatments proved effective for glycemic control; however, both second-generation sulfonylureas are associated with a significant risk of hypoglycemia in elderly NIDDM patients. The proper use of sulfonylureas in this population should include close surveillance of ambulatory glucose monitoring and intensive and repeated patient education about the risks of hypoglycemia.

Aged↗

PubMed2005

Improvement of sympathetic response to exercise by oral administration of ascorbic acid in patients after myocardial infarction.

BACKGROUND: Recent studies indicated that excessive oxidative stress in an animal heart failure model injures both the sympathetic nerve endings and receptors, resulting in disturbance of norepinephrine release and sensitivity to norepinephrine. However, it has not been clarified whether this phenomenon is expressed clinically in patients with heart disease. Therefore, we examined the efficacy of ascorbic acid administration as an antioxidant vitamin in relation to the heart rate and norepinephrine response to exercise in patients after myocardial infarction. METHODS: In this randomized crossover trial, 21 male patients who had had myocardial infarction underwent symptom-limited ergometer cardiopulmonary exercise testing twice, that is, without and with ascorbic acid (2 g) administration. Plasma norepinephrine concentrations were assessed at rest and at peak exercise, and heart rate responsiveness to the norepinephrine increment from rest to peak exercise (DeltaHR/logDeltaNE) was calculated. RESULTS: In the exercise test after ascorbic acid administration, peak oxygen consumption (VO(2)) improved over baseline. Ascorbic acid administration significantly increased the change in heart rate and norepinephrine from rest to peak exercise and DeltaHR/logDeltaNE. The increment in heart rate was significantly correlated with peak VO(2) in each test. CONCLUSION: Ascorbic acid intake before exercise improved exercise capacity through enhancement of the heart rate and norepinephrine response to exercise in patients after myocardial infarction. These findings suggest that ascorbic acid intake improves sympathetic dysfunction resulting from injury by excessive oxidative stress after myocardial infarction.

Aged↗

PubMed1985

Management of recurrent urinary tract infections with patient-administered single-dose therapy.

In a randomized crossover trial, 38 women with recurrent urinary tract infections were assigned to use either continuous prophylaxis with trimethoprim-sulfamethoxazole or intermittent self-administered therapy (single-dose trimethoprim-sulfamethoxazole taken for acute urinary symptoms). The infection rate for patients on prophylaxis was 0.2 episodes/patient-year compared with 2.2 infections/patient-year for patients on self-administered therapy (p less than 0.001). Thirty-five of thirty-eight symptomatic episodes diagnosed by patients as infection were confirmed microbiologically, and 30 of the 35 infections responded clinically and microbiologically to patient-administered therapy with single-dose trimethoprim-sulfamethoxazole. No complications were seen in the 5 patients in whom therapy failed. The annual costs of prophylaxis and self-therapy were similar ($256 and $239, respectively) and both were less expensive than conventional therapy in women having 2 or more infections per year. In selected women, self-therapy is efficacious and economical compared with conventional therapy or prophylaxis.

Adolescent↗

PubMed1999

Frequency dependence of antidepressant response to left prefrontal repetitive transcranial magnetic stimulation (rTMS) as a function of baseline cerebral glucose metabolism.

BACKGROUND: Recent studies suggest that both high frequency (10-20 Hz) and low frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) have an antidepressant effect in some individuals. Electrophysiologic data indicate that high frequency rTMS enhances neuronal firing efficacy and that low frequency rTMS has the opposite effect. METHODS: We investigated the antidepressant effects of 10 daily left prefrontal 1 Hz versus 20 Hz rTMS with the hypothesis that within a given subject, antidepressant response would differ by frequency and vary as a function of baseline cerebral glucose metabolism. After baseline PET scans utilizing [18F]-Fluorodeoxyglucose, thirteen subjects participated in a randomized crossover trial of 2 weeks of 20 Hz paired with 2 weeks 1 Hz or placebo rTMS. RESULTS: We found a negative correlation between degree of antidepressant response after 1 Hz compared to 20 Hz rTMS (r = -0.797, p < .004). Additionally, better response to 20 Hz was associated with the degree of baseline hypometabolism, whereas response to 1 Hz rTMS tended to be associated with baseline hypermetabolism. CONCLUSIONS: These preliminary results suggest that antidepressant response to rTMS might vary as a function of stimulation frequency and may depend on pretreatment cerebral metabolism. Further studies combining rTMS and functional neuroimaging are needed.

Adult↗

PubMed1988

Efficacy of pancreatic enzyme supplementation in children with cystic fibrosis: comparison of two preparations by random crossover study and a retrospective study of the same patients at two different ages.

Two studies were performed in children with cystic fibrosis (CF) to compare the efficacy and tolerability of pancreatic enzymes prepared as enteric-coated microspheres with that of a conventional enzyme preparation. The parameters evaluated included the following: fecal fat excretion, coefficient of fat absorption, daily caloric intake, percent of diet as fats, proteins and carbohydrates, increase in height and weight, frequency and consistency of stools, palatability of the preparation, and patient compliance. The first study was an open randomized crossover trial of an enteric-coated microsphere preparation (Pancrease) versus conventional pancreatin given alone or with cimetidine. With Pancrease compared to conventional pancreatin, a significant improvement was observed in all the digestive parameters in addition to better patient compliance. In the second study, the response of a group of CF patients given Pancrease for at least 3 months (3-67 months) was retrospectively compared with the response to conventional pancreatin, which had been given to the same patients from 10 months to 8 years earlier. In comparison to conventional pancreatin, Pancrease provided better digestive efficacy and greater increases in the growth rate of teenage patients. With Pancrease, the number of daily dosage units is decreased even when fat intake is increased. No adverse reactions were seen with either of the enzyme preparations used in these studies.

Adolescent↗

PubMed2004

Quantification of prosthetic outcomes: elastomeric gel liner with locking pin suspension versus polyethylene foam liner with neoprene sleeve suspension.

For this randomized crossover trial, we compared two common transtibial socket suspension systems: the Alpha liner with distal locking pin and the Pe-Lite liner with neoprene suspension sleeve. Our original hypotheses asserted that increased ambulatory activity, wear time, comfort, and satisfaction would be found with the elastomeric suspension system. Thirteen subjects completed the study. Following 2.5-month accommodation to each condition, ambulatory activity was recorded (steps/minute for 2 weeks), and subjects completed three questionnaires specific to prosthesis use and pain: the Prosthesis Evaluation Questionnaire (PEQ), a Brief Pain Inventory (BPI) excerpt, and the Socket Comfort Score (SCS). Upon completion, subjects selected their favored system for continued use. Ten subjects preferred the Pe-Lite and three the Alpha. Subjects spent 82% more time wearing the Pe-Lite and took 83% more steps per day. Ambulatory intensity distribution did not differ between systems. No statistically significant differences were found in questionnaire results. Subject feedback for each system was both positive and negative.

Adult↗

PubMedDate not supplied

Effect of probenecid on the natriuresis and renin release induced by bumetanide in man.

In a randomized crossover trial in six normal male subjects, the effect of pretreatment with probenecid on natriuresis and renin release in response to bumetanide was studied. The subjects received 120 mEq sodium and 80 mEq potassium per day. A single dose of 2 mg bumetanide was administered on the fourth morning after pretreatment with either placebo or probenecid. Creatinine and uric acid were measured in serum and urine, plasma renin activity was determined by radioimmunoassay of angiotensin I, and plasma and urine concentrations of bumetanide were measured by a highly sensitive radioimmunoassay method. Probenecid reduced both natriuresis and hyperreninemia induced by bumetanide. This effect is postulated to be due not to a direct action on sodium excretion but is probably secondary to inhibition of renal tubular secretion of bumetanide. Consequently, these findings appear to support the concept that the quantity of bumetanide delivered to the tubular lumen is an important determinant of its diuretic effect.

Adult↗

PubMed2004

Effect of a nighttime magnetic field exposure on sleep patterns in young women.

Since poor sleep quality is associated with multiple health problems, it is important to understand factors that may affect sleep patterns. The purpose of this study was to determine the effect of a continuous, 60-Hz, nighttime magnetic field exposure on sleep outcomes in young women sleeping at home. The study was a randomized crossover trial, comparing intervention (0.5-1.0 micro T above ambient levels) with ambient magnetic field levels, during two 5-night measurement periods. Subjects lived in the Seattle, Washington, area and were 20-40 years of age, had regular menstrual cycles, were not taking oral contraceptives, and had not breastfed or been pregnant during the previous year. The study was conducted between March and September of 2001. Sleep outcomes were measured via actigraphy. The range of magnetic field exposure was 0.001-0.50 micro T during the ambient period and 0.41-1.21 micro T during the intervention period. Sleep outcomes were not significantly different between the intervention and the ambient measurement periods. The intervention magnetic field had no effect on sleep patterns, suggesting that this exposure may not be an important factor in predicting sleep of young women who sleep at home.

Adult↗