PubMed Health⌕ Search

Biomedical subjects

J R Bianchine

Publications and source records attributed to J R Bianchine.

At least 19 recordsLinked to original sources
PubMed1992

Rifabutin absorption in humans: relative bioavailability and food effect.

The relative bioavailability of the capsule dose form (150 mg) and the effect of high-fat food were assessed in a randomized, three-way crossover trial of rifabutin in 12 healthy male volunteers. Each subject received a single 150 mg dose as a solution (treatment A, fasted) or a capsule with food (treatment B) and without food (treatment C), with a 2-week washout period. Serial plasma and urine samples were obtained for 168 and 48 hours, respectively, and rifabutin and its active metabolite, 25-O-deacetyl-rifabutin, quantitated by a validated HPLC procedure. The mean +/- SD maximum concentration for rifabutin in plasma was 238 +/- 65, 156 +/- 52, and 188 +/- 50 ng/ml, time to reach peak concentration was 2.5 +/- 0.4, 5.4 +/- 1.6, and 3.0 +/- 1.1 hours, and the area under the plasma concentration-time curve from zero to infinity [AUC(0-infinity)] was 2989 +/- 726, 2640 +/- 891, and 2516 +/- 601 ng.hr/ml for the solution and the capsule during the fed and fasted states, respectively. Percentage of dose excreted in the urine as unchanged rifabutin was 11.0% +/- 2.4%, 11.4% +/- 4.9%, and 9.1% +/- 2.1% for treatments A, B, and C, respectively. The corresponding AUC(0-infinity) values for the equiactive metabolite 25-O-deacetyl-rifabutin, were 400 +/- 184, 361 +/- 187, and 298 +/- 102 ng.hr/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1987

Disposition of aspirin and its metabolites in the semen of man.

The study was undertaken to determine the distribution of aspirin and its metabolites in the semen of humans after an oral dose of aspirin. Each of seven healthy male volunteers was given a single oral dose of 975 mg of aspirin on an empty stomach together with 200 mL of water. Timed samples of blood and semen were obtained from each subject, and the concentrations of aspirin, salicylic acid, and salicyluric acid determined by a specific high-performance liquid chromatographic assay. The mean peak concentration of aspirin was 6.5 micrograms/mL in plasma (range, 4.9-8.9 micrograms/mL), reached in 26 minutes (range, 13-33 minutes). The half-life of aspirin was 31 minutes. The concentration ratio of aspirin (semen/plasma) was 0.12 (except for one subject in whom it was 0.025). The mean peak concentration of salicylate in plasma was 49 micrograms/mL (range, 42-62 micrograms/mL), reached in 2.5 hours (range, 2.0-2.8 hours). Salicylate distributed rapidly into semen and maintained a concentration ratio (semen/plasma) of 0.15. Salicyluric acid (the glycine conjugate of salicylic acid) was found in the semen. Its high concentration in some subjects' semen (four times the concurrent plasma concentration) was attributed to contamination of semen sample with residual urine, containing salicylurate, in the urethra of those who urinated after the dose of aspirin. Possible side effects of aspirin and salicylate in semen include adverse effects on fertility, male-medicated teratogenesis, dominant lethal mutations, and hypersensitivity reactions in the recipients.

Adolescent↗
PubMed1985

MPTP and parkinsonism.

Explore the source record for details and available documents.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1984

Improved method for the determination of aspirin and its metabolites in biological fluids by high-performance liquid chromatography: applications to human and animal studies.

An improved method has been developed for the determination of acetylsalicylic acid, salicylic acid, gentisic acid, and salicyluric acid in plasma and urine of rabbits and man. Samples are extracted with dichloromethane containing mephenytoin as an internal standard, the solvent is evaporated under reduced pressure, the residue reconstituted and analyzed by high-performance liquid chromatography. Extraction efficiencies, linearity and assay precision were determined. This method has been applied to human bioavailability studies and the data are presented.

Animals↗
PubMed1984

Controlled-release carbidopa/levodopa in the treatment of Parkinsonism.

Controlled release carbidopa/levodopa (CSR-1) was compared to standard carbidopa/levodopa in a double-blind, crossover study of 20 Parkinson's disease patients. The most consistent finding in a variety of clinical measurements was the superiority of standard carbidopa/levodopa to CSR-1. Increased dosages of CSR-1 resulted in reduced Parkinson symptoms, suggesting that a more potent controlled-release formulation might prove to be more efficacious than CSR-1.

Aged↗
PubMed1984

Effects of the acute rising dose administration of chlorine dioxide, chlorate and chlorite to normal healthy adult male volunteers.

Chlorine dioxide is under consideration for use as a water disinfectant alternative to chlorination in the United States. A rising dose tolerance study was undertaken to assess the relative safety and tolerance of acute administration of chlorine dioxide and its byproducts, chlorite and chlorate, to normal healthy adult male volunteers. In evaluation of an extensive battery of laboratory tests and vital signs, no adverse physiological effects were identified. This provided a data base upon which a controlled 5-month study trial of these substances in normal healthy volunteer subjects was designed.

Adult↗
PubMed1984

The effects of chronic administration of chlorine dioxide, chlorite and chlorate to normal healthy adult male volunteers.

The physiological impact of chronic 12 week ingestion of chlorine dioxide and its byproducts, chlorite and chlorate, was compared to the effects of chlorine, chloramine and untreated water. The water disinfectant solutions were administered daily (500 ml, 5 ppm) to normal healthy adult male volunteers. An extensive battery of tests was used to evaluate the physiological impact of the ingested water disinfectants. Upon analysis of both quantitative and qualitative parameters it was concluded that the 12 week chronic administration of chlorine dioxide and its byproducts was accompanied by no clinically important physiological effects.

Adult↗
PubMed1984

The effects of chronic administration of chlorite to glucose-6-phosphate dehydrogenase deficient healthy adult male volunteers.

Under controlled laboratory conditions, the safety of daily ingestion of 5 ppm chlorine dioxide, chlorite and chlorate by normal healthy adult males has been established. To determine the effect upon potentially susceptible individuals, a parallel chronic human investigation was undertaken. Study subjects were three healthy adult males deficient in glucose-6-phosphate dehydrogenase. These volunteers received 500 ml of sodium chlorite at a concentration of 5 ppm daily for twelve consecutive weeks; the subsequent observation period extended an additional eight weeks. Upon evaluation of an extensive battery of tests designed to measure the biochemical and physiological response to chlorite ingestion, no clinically significant changes were detected.

Adult↗
PubMed1983

Identification of long chain dicarboxylic acids in the serum of two patients with Reye's syndrome.

Sera from two patients with Reye's Syndrome were analysed by computerized capillary gas chromatography--mass spectrometry profiling techniques. The most striking abnormalities were the accumulation of long chain dicarboxylic acids. Four saturated dicarboxylic acids (dodecanedioic, tetradecanedioic, hexadecanedioic, and octadecanedioic), and six unsaturated long chain dicarboxylic acids (dodecenedioic, tetradecenedioic, tetradecadienedioic, hexadecenedioic, octadecadienedioic, and octadecenedioic) were identified. The C16 and C13 dicarboxylic acids have never been reported for Reye's Syndrome or any other dicarboxylic acidemias. The data might reflect marked increase of extramitochondrial omega-oxidation of long chain fatty acids or impaired metabolism of omega-dicarboxylic acids formed in Reye's patients.

Child↗
PubMed1983

Pharmacokinetics of a sustained-release trimazosin tablet formulation.

Pharmacokinetics and bioavailability of a trimazosin sustained-release tablet (SRT) formulation (300 mg) were studied in healthy volunteers. In the first study of 12 subjects, the bioequivalence of trimazosin, 100 mg, in a standard tablet (ST) and in a capsule was demonstrated. After that, the bioavailability of one SRT (300 mg) was compared with that of the STs, (100 mg three times a day), in 19 subjects. Maximum plasma concentration (Cmax) after SRT (8.1 +/- 3.0 mg/L) was significantly lower than that observed after ST (13.5 +/- 2.3 mg/L), time to peak was strongly delayed by a factor 7, and the time when plasma concentrations were higher than half of Cmax (t Cmax/2) was longer (10.4 +/- 3.2 vs 2.3 +/- 0.6 hours, p less than 0.001). Bioavailability of the SRT (300 mg) as measured by the area under the curve (AUC00) was about 65% of the ST. At the seventh dose, after single daily doses of the SRT in 12 subjects, the mean Cmax values were not significantly higher than after the first dose (8.6 +/- 3.2 mg/L vs 7.7 +/- 2.2 mg/L), t Cmax/2 values were the same (10.4 hours), and the AUC0-24 hr was comparable to AUC00 calculated after the first dose. Steady-state plasma concentration of trimazosin was obtained rapidly. No accumulation of trimazosin or its metabolite occurred.

Adolescent↗
PubMed1983

Effect of oral contraceptives on the rat brain and pituitary beta-endorphin.

The purpose of this study was to investigate the effect of oral administration of progesterone (15 micrograms norethindrone, NE) in presence and absence of estradiol (1 microgram ethinyl estradiol, EE2) on the CNS levels of beta-endorphin like immunoreactivity (beta-EI) in female rats. In acute study (5 days), NE alone did not change beta-EI significantly in pituitary. NE and EE2 together decreased beta-EI by 37% (47% at 10X dose). In chronic study (7 weeks), 2NE had no significant effect on pituitary beta-EI, however, NE and EE2 together at 10X dose decreased it by 14%. In the hypothalamus, NE alone or in presence of EE2 had no significant effect on beta-EI, but 10X dose of NE+ EE2 caused 50 and 76% decrease in beta-EI in acute and chronic study. Striatum was the only tissue where NE alone caused a decrease of 82% in beta-EI when given acutely and 52% when given chronically. EE2 had some protective effect on this decrease since when given together (NE+EE2) the decrease in beta-EI was 21% in acute and 43% in chronic study. Thus our results, along with other studies on the regulation of gonadotropin levels by opioids, suggest that oral contraceptives alter the level of beta-EI and in turn may regulate the release of gonadotropins. Morphine and endogenous opioids have been shown to decrease gonadotropin secretion in various species including humans, apparently by suppressing the release of LH-RH from the hypothalamus (1-5). The opiate antagonist naloxone not only causes up to 10-fold increase in the secretion of gonadotropins (1,3, 6-9) but also opposes the negative feedback effect of steroids on the hypothalamic-pituitary-gonadotropin axis (8), suggesting a regulatory interaction between the endogenous opioids, gonadotropins and gonadal steroids. Like ACTH, the secretion of beta-endorphin is inhibited by glucocorticoids (10). Naloxone induced release of LH is facilitated by estradiol in humans (11) suggesting an antagonistic effect of estradiol on the endogenous opioids. beta-endorphin may play a significant role in neurochemical mechanisms of gonadotropin release in the human menstrual cycle. A preovulatory increase of beta-endorphin in serum occurs 2 days prior to LH surge and a postovulatory decrease in beta-endorphin occurs 5 days later.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1983

Salicylic acid plasma levels following multiple doses of Norgesic Forte and aspirin.

Plasma salicyclic acid levels from the recommended multiple dose regimen of Norgesic Forte (orphenadrine citrate, aspirin, and caffeine) were compared to those from an equivalent multiple dose regimen of aspirin alone in 24 volunteers. The drugs were administered double-blind so that side effects could also be compared. No statistically significant differences were found between Norgesic Forte and aspirin in peak or trough levels, time to peak level, area under the curve, or mean steady-state level of salicylic acid. Mean steady-state levels averaged 154 +/- 46 (+/- SD) and 152 +/- 49 micrograms/ml on days 5 and 10 following Norgesic Forte versus 161 +/- 49 and 154 +/- 47 micrograms/ml following aspirin. Thus, the aspirin in Norgesic Forte provides an anti-inflammatory amount of salicylic acid equivalent to that of plain aspirin. There was no evidence that the combination of orphenadrine citrate, caffeine, and aspirin in Norgesic Forte caused increased or unusual side effects compared with aspirin alone.

Adult↗
PubMed1983

Identification and characterization of the glucuronide metabolite of diethyldithiocarbamic acid in the bile from the isolated perfused rat liver by gas chromatography and mass spectrometry.

The glucuronide metabolite of diethyldithiocarbamic acid has been identified in bile from the isolated perfused rat liver. The bile was chromatographed on XAD-2 resin, pertrimethylsilylated with BSTAF + 1% TMCS, identified and characterized by combined gas chromatography and mass spectrometry. The glucuronide characterized as the silylated derivative showed no molecular ion but a small fragment ion at M-15(598).

Animals↗