Search PubMed⌕ Search

Biomedical subjects

L Jung

Publications and source records attributed to L Jung.

At least 19 recordsLinked to original sources
PubMed1991

Determination of tertatolol enantiomers in biological fluids by high-performance liquid chromatography.

A stereospecific high-performance liquid chromatographic method for the quantification of (-)- and (+)-tertatolol in plasma and urine is described. The method involves solid-phase extraction followed by derivatization with S(+)-naphthylethylisocyanate to form the urea derivative, which is more sensitive to fluorescence detection. The separation of the diastereomeric derivatives was performed by reversed-phase high-performance liquid chromatography. Fluorimetric detection (lambda excitation = 220 nm, lambda emission = 320 nm) allows the quantification of tertatolol enantiomers down to 6 ng/ml. The assay was used to study the pharmacokinetic profile of tertatolol enantiomers following oral administration of racemic tertatolol; preliminary results suggest enantioselective absorption and/or disposition of tertatolol.

Adrenergic beta-Antagonists↗
PubMed1991

Pharmacological study in vivo of the new topical anti-inflammatory steroid 21-thiol-9 alpha-fluoro-11 beta,17 alpha-dihydroxy-16 alpha-methyl-3,20-dione-21-acetylamino cysteine.

The pharmacological evaluation, using animal models, of 21-thiol-9 alpha-fluoro-11 beta, 17 alpha-dihydroxy-16 alpha-methyl-3,20-dione- 21-acetylamino cysteine (CMJ), a new steroidal anti-inflammatory compound, is reported. The results obtained show a significant anti-inflammatory activity for CMJ. Comparison with dexamethasone indicates that CMJ is about 9 to 10 times less active in vivo. Of particular interest, however, is the dissociation of local and systemic activities of CMJ, since this compound was shown to be practically devoid of systemic activity (about 970 times less active than dexamethasone) after subcutaneous administration in rats. It is therefore expected that the topical use of CMJ in therapy may not cause the side effects provoked by many of the corticosteroids currently used.

Abscess↗
PubMed1990

Interaction of tertatolol with rifampicin and ranitidine pharmacokinetics and antihypertensive activity.

The interaction of the new beta-receptor antagonist tertatolol with rifampicin and ranitidine was investigated in ten patients with arterial hypertension (WHO stages I-II). They were treated orally with a single dose of tertatolol 5 mg alone and, after randomized allocation, with ranitidine 150 mg twice daily or rifampicin 600 mg once daily for 1 week each (tertatolol 5 mg was concurrently administered on the seventh day of the treatment phases). Following each therapeutic phase, circadian blood pressure values as well as kinetic parameters were obtained. On treatment with tertatolol alone, maximum plasma concentrations were 123.7 +/- 32.4 ng/ml (mean +/- SD) and were reached after 1.95 +/- 1.77 hours. The tertatolol elimination half-life was 9.0 +/- 7.1 hours. Coadministration of ranitidine did not significantly alter the kinetic parameters and antihypertensive effect of tertatolol. Rifampicin, however, decreased the maximum plasma levels of tertatolol to 80.6 +/- 18.5 ng/ml and markedly shortened the elimination half-life to 3.4 +/- 2.6 hours (p less than 0.01 compared with tertatolol alone). Urinary excretion of parent tertatolol and unchanged 4-hydroxy tertatolol was decreased under rifampicin, and a tendency to a reduction in the effect of tertatolol on circadian blood pressure values was observed. Twenty-four hours after administration, the heart rate in those patients on tertatolol alone (68 +/- 6 beats/min) was lower than in those on tertatolol plus rifampicin (74 +/- 7 beats/min). In conclusion, a pronounced pharmacokinetic interaction, with a limited consequence in terms of pharmacodynamic effects, was found in the present study when tertatolol was administered with rifampicin, but not with ranitidine.

Adrenergic beta-Antagonists↗
PubMed1990

[Longterm results of McIntosh hemiarthroplasty of the knee in patients with rheumatoid arthritis of the knee].

A series of 35 knees operated on between 1967 and 1977 was reviewed. The follow up of 5 years or longer revealed over 40% of excellent and good results. The analysis of over 50% of poor results is suggestive of inadequate indications for hemiarthroplasty of the knee. In authors opinion Mc Intosh procedure should be still performed providing the indications are very accurate.

Adult↗
PubMed1988

Pharmacokinetics of veralipride after chronic administration in humans.

A pharmacokinetic study of veralipride (N-[(1-allyl-2-pyrroli dinyl)methyl]-5-sulfamoyl-o-veratramide) was performed in healthy volunteers during a chronic administration. The pharmacokinetic model based on the hypothesis of a double site for drug absorption, previously used after a single-dose oral administration, was developed to fit the data obtained after chronic administration. The empirical model used allows correct depiction of the behavior of the drug in the body, especially secondary peaks. According to the results, veralipride pharmacokinetics did not show any change upon chronic administration.

Adult↗
PubMed1988

Stereoselective blockade of alpha-adrenoceptors by berbine derivatives.

The effects of the two enantiomers of berbine (5,6,13,13a-tetrahydro-8H-dibenzo[a,g]quinolizine) and of derivatives obtained by introducing various substitutions on aromatic rings were investigated on alpha 1- or alpha 2-adrenoceptor subtypes. Binding studies carried out on rat cerebral cortex membranes using [3H]prazosin or [3H]yohimbine showed that the affinities of the (+) and (-)enantiomers for alpha 1 and alpha 2 binding sites were different and were differently modified by substitutions added to the berbine nucleus, leading to alpha 1- and alpha 2-selective compounds. Experiments performed on the isolated rat aorta and in pithed rats in vivo demonstrated the alpha-blocking property of berbine derivatives and confirmed the stereoselectivity of the effects of the (+) and (-)enantiomers on alpha 1- and alpha 2-adrenoceptor subtypes.

Adrenergic alpha-Antagonists↗
PubMed1987

A double-peak phenomenon in the pharmacokinetics of veralipride after oral administration: a double-site model for drug absorption.

Equal doses of veralipride have been given to 12 healthy volunteers by three different administrations--intravenous infusion, oral solution, and oral capsules--in a randomized cross-over design. After the intake of the solution, but not after infusion or capsules, two maximum plasma concentrations have been observed and interpreted, according to a double-site model for drug absorption.

Administration, Oral↗
PubMed1985

Quantitative determination of tertatolol in biological fluids by gas chromatography-mass spectrometry.

Quantitative determination of tertatolol concentrations in plasma and urine was performed by gas chromatography-mass spectrometry in the chemical-ionization mode with ammonia after successive extractions of the beta-blocking drug in alkaline, acid and final alkaline medium. [2H9]Tertatolol, isotopically stable under the operating conditions employed, was used as an internal standard, thus allowing quantities of 1 ng/ml to be specifically determined. Overall analytical error was less than 10%. Prior to isothermal chromatography at 240 degrees C on a column packed with 3% SE-30, both compounds were silylated with bis(trimethylsilyl)trifluoroacetamide. Detection was performed by monitoring the quasimolecular ions of tertatolol, m/z 368 and m/z 377, for the [2H9]tertatolol in the chemical-ionization mode with ammonia. The calibration curves obtained had linear characteristics for the concentration range 1-1125 ng/ml.

Administration, Oral↗
PubMed1985

Quantitative analysis of veralipride in plasma and urine by gas chromatography-mass spectrometry and gas chromatography with flame-ionization detection.

A highly sensitive and selective quantitative assay for unchanged veralipride has been developed. The compound is extracted from alkalized samples (plasma or urine) with dichloromethane and converted to its trimethylated derivative by reaction with trimethylanilinium hydroxide. The reaction mixture is then chromatographed on a 3% OV-1 column. Trimethylated derivatives of plasma samples were assayed by selected-ion monitoring in the chemical-ionization mode and quantified by comparing the intensity of the quasi-molecular ion m/z 426 (M + H) with the intensity of the corresponding ion from trideuterated internal standard, m/z 429 (M + H). Flame-ionization detection was used for the assay of urine samples. The peak height ratio of trimethylated veralipride over trimethylated sulpiride, the internal standard, was used for quantitation of urine samples. A relative standard deviation of less than 10% was found when quantifying 10 ng/ml veralipride in plasma or 1 microgram/ml in urine.

Capsules↗
PubMed1985

Primary dose-dependent pharmacokinetic study of veralipride.

A dose-dependent pharmacokinetic study of veralipride (a new post-menopausal "hot flushes" regulator) was developed in humans after oral solution administration (100, 150, 200, and 250 mg). In most cases, two maxima of plasma drug concentrations occurred, probably due to a double intestinal site of absorption. From model independent pharmacokinetic parameters, it can be concluded that a linearity in the tested range doses exists.

Adult↗
PubMed1984

Impairment of responses to novelty by apomorphine and its antagonism by neuroleptics in mice.

The effects of several doses of apomorphine (AP: 0.062-8 mg/kg) on novelty preference (NP) in male Swiss mice were studied. AP induced a dose-dependent reduction of NP as well as of locomotor activity. The decrease in NP appeared to be related to the effect of the drug in reducing locomotion, and may be explained by a drug-induced increase in perseverance and stereotypy interfering with locomotion and NP by response incompatibility. These results contrast with those obtained with methamphetamine (MA) in a previous study (Misslin and Ropartz 1981) replicated here which also shows a reduction of NP. Furthermore, the neuroleptic thioridazine did not antagonize the effects of AP or MA on NP in mice, whereas the substituted benzamides tiapride and sulpiride did so. The substituted benzamides appear to act selectively on a restricted dopamine receptor population.

Animals↗