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Biomedical subjects

J Ostrowski

Publications and source records attributed to J Ostrowski.

At least 127 records · Page 7Linked to original sources
PubMed1987

Serum retinol level in patients with colorectal premalignant and malignant lesions.

Serum retinol levels were determined by a fluorometric method in patients with colorectal cancer or polyps and those with inflammatory bowel disease. Serum retinol levels in patients with benign or malignant colorectal polyps and stage B cancer (modified Dukes' classification) were similar to those found in controls. By contrast, serum retinol levels were significantly lower in patients with Dukes' stage C or D. Among cancer patients that were followed after surgical treatment serum retinol levels did not differ significantly from those found in controls. Patients who died of metastases during follow-up possessed very low serum retinol levels. These findings suggest that a decreased serum retinol level in cancer patients is a consequence rather than a precursor of the neoplastic process. Furthermore, this study suggests that the marked decrease in serum retinol level might be an indicator of poor prognosis in colorectal cancer patients after surgery.

Adult↗
PubMed1987

Leukoplakia of the vulva locally treated by 13-cis-retinoic acid.

Repeated topical application of 13-cis-retinoic acid resulted in complete disappearance of leukoplakia of the vulva in 8 out of 16 patients, among them 2 out of 3 with recurrence after vulvectomy. A considerable regression of leukoplakia was seen in 7 other patients, usually after 1 to 2 months of daily retinoid treatment. After 2-4 months of maintenance therapy and during 3-7 months of the follow up period no recurrences were seen. Side effects of treatment could be managed. Serum retinol level was found to be lower in patients then in healthy subjects. The results suggest that patients with chronic epithelial vulvar dystrophies could benefit from local retinoid treatment, especially in cases with advanced dystrophies until now qualified for vulvectomy.

Administration, Topical↗
PubMed1986

Liver function and pharmacokinetics of molsidomine and its metabolite 3-morpholinosydnonimine in healthy volunteers.

Plasma levels of N-carboxy-3-morpholinosydnonimine ethyl ester (molsidomine, Corvaton) and its pharmacologically active metabolite 3-morpholinosydnonimine (SIN-1) were measured in six healthy male and female volunteers after single intravenous and oral dosing of 4 mg molsidomine. Additionally indocyanine green and phenazone (antipyrine) clearances were determined to estimate hepatic blood flow and metabolic liver function in each subject. The pharmacokinetic parameters of molsidomine were similar to already published data in healthy volunteers and patients. The plasma level of SIN-1 formed was always lower than the molsidomine level but obviously reflects the corresponding molsidomine concentration time course in plasma. Indocyanine green plasma clearance was reduced by 15%. after intravenous dosing of 4 mg molsidomine. There was no clear-cut relationship between the plasma clearances of molsidomine and phenazone in these subjects with normal metabolic liver function.

Adult↗
PubMed1985

Pharmacokinetics of an extended-release dosage form of molsidomine in patients with coronary heart disease.

Molsidomine (N-carboxy-3-morpholino-sydnonimine-ethylester; Cassella-Riedel Pharma GmbH, Frankfurt/M. FRG) has an antianginal effect for up to 3-5 h after oral administration of 2 mg Corvaton [1]. Plasma levels of the parent drug can be measured during this interval. A new galenic formulation (Corvaton retard) has been developed to prolong the duration of the therapeutic action and to improve patient compliance. The present study was carried out to establish whether the in vitro dissolution profile of the tablet was reflected in vivo, thus permitting prediction of plasma molsidomine levels in patients with coronary heart disease.

Aged↗
PubMed1985

Mean time and first-pass metabolism.

The theoretical principles are outlined for estimating the fraction of a drug undergoing first-pass metabolism using only the plasma levels found after a single oral dose. Data for 3 drugs are used to illustrate the method. It involves analysis of the parent drug and the metabolite formed during the first passage through the gut wall and liver and evaluation of their total mean times. The mean time characteristics of molsidomine, nortriptyline and propranolol are considered and they confirm the theoretically deduced dependency of the mean time of the parent drug and the metabolite. Whether the results are more precise than those obtained from comparison of areas after oral and intravenous administration is discussed. From the data presented it is clear that the mean time method depends on the scatter inherent in the data. In order to estimate the true first-pass effect, greater scatter requires an increased number of data pairs, i.e. subjects. If intravenous data are not available, however, the method described provides a rough but worthwhile estimate of the first pass effect.

Humans↗
PubMed1985

Pharmacokinetics of molsidomine in humans.

The pharmacokinetics of molsidomine were investigated in the plasma and urine of healthy male volunteers and patients with coronary heart disease after intravenous and/or oral administration of different galenic dosage forms of molsidomine. Following the rapid attainment of mean peak concentration (15 +/- 7 mg/ml) 0.5 to 1.0 hour after single oral dosing of 2 mg of molsidomine, the plasma levels of the unchanged drug decline monoexponentially with a mean half-life of 1.6 +/- 0.8 hours. Molsidomine is absorbed almost completely. Its absolute bioavailability (44 +/- 15%) and a 14C-labeled triale give evidence of quick biotransformation of molsidomine to active metabolites. Less than 2% of the unchanged drug appear in the urine, but renal excretion is the main route of elimination of the metabolites in humans (90% to 95%). The kinetics parameters after administration of multiple dosages of 4 mg of molsidomine over 29 days do not account for accumulation of or enzyme induction by molsidomine. The finding of obvious good correlations between plasma levels of the predrug molsidomine and corresponding pharmacodynamic data can be made plausible by the time course of concentration values of the active metabolite SIN-1 in plasma.

Animals↗
PubMed1985

Relationship between pharmacokinetics and pharmacodynamics of molsidomine and its metabolites in humans.

The pharmacokinetic properties and hemodynamic effect of molsidomine and its pharmacologically active metabolite SIN-1 were investigated in 13 healthy volunteers following single oral doses. Hemodynamic changes were measured by finger plethysmography (peripheral arterial resistance), impedance plethysmography (venous distensibility), heart rate, and blood pressure. Plasma concentrations of molsidomine, SIN-1, and SIN-1C were measured by means of high-pressure liquid chromatography. Oral administration of rapidly dissolving tablets of molsidomine (2 tablets of 4 mg), a sustained-release form of molsidomine (8 mg), and SIN-1 (4 mg) caused an increase of the a/b ratio of the finger plethysmogram and an increase of the venous distensibility. Heart rate and blood pressure remained unaffected. The time course of the peripheral arterial effect mimicked the time course of plasma concentrations of molsidomine and SIN-1. Similar to the results in animals, molsidomine was metabolized in humans to SIN-1 and subsequently degraded to the inactive metabolite SIN-1C. The kinetic profile of both metabolites could be followed in the plasma. The rate-limiting step in the metabolic sequence of molsidomine was found to be enzymatic hydrolysis and decarboxylation of molsidomine to SIN-1. Concentration-response curves of the a/b ratio of the finger plethysmogram showed that the plasma concentrations required to produce a definite effect are much higher for molsidomine than for SIN-1. This shows that the pharmacodynamically active form of molsidomine in humans is the metabolite SIN-1. The changes in the finger plethysmogram produced by SIN-1 suggest that in addition to the effect on the venous site, SIN-1 also dilates the peripheral arterial site.

Adult↗
PubMed1985

Vitamin A (retinol) level in colon and lung cancer patient sera.

Serum vitamin A (retinol) level was determined in colon and lung cancer patients. As a control served young healthy people and non cancer hospital patients at the age similar to those with tumors. Vitamin A content in cancer patients was found to be statistically lower as compared to control groups.

Colonic Neoplasms↗
PubMed1985

[HPLC determination of troxerutin in plasma and urine following oral administration in man].

A high-performance liquid chromatographic method (HPLC) is described for the analysis of 3',4',7-tri-O-(beta-hydroxy-ethyl)-rutoside (troxerutin) in human plasma and urine. After separation of interfering substances on XAD-2 trihydroxyethylrutoside is converted to tetrahydroxyethylrutoside by 2-chlorethanol in alkaline medium. After HPLC-separation tetrahydroxyethylrutoside is quantified by fluorescence detection. The pharmacokinetics of troxerutin were measured in plasma after oral administration to man. The relative bioavailability of the drug from Venelbin was 97.8 +/- 37.1% compared to an aqueous standard solution.

Anticoagulants↗
PubMed1984

Determination of pirlindole in plasma and urine by high-performance liquid chromatography.

A high-performance liquid chromatographic method is described for the analysis of pirlindole [2,3,3a,4,5,6-hexahydro-8-methyl-1H-pyrazino(3,2,1-jk)carbazole hydrochloride], a new antidepressive drug. The drug was extracted from plasma into dichloromethane, and the analysis was carried out on a reversed-phase column, the effluent being monitored by fluorescence detection. The method is selective and sensitive (limit of detection 1-2 ng/ml plasma). Urine analysis was done by direct injection of the diluted sample. The method was applied to the analysis of plasma and urine samples of eight healthy male volunteers who received a 75-mg oral dose of a tablet formulation of pirlindole. The method was also applied to a study in three beagle dogs which received pirlindole (1 mg/kg) by infusion (0.1 mg/kg/min) and orally (10 mg/kg) to estimate the absolute bioavailability of the drug.

Animals↗