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Biomedical subjects

T B Vree

Publications and source records attributed to T B Vree.

At least 289 records · Page 16Linked to original sources
PubMed1981

Midazolam as a sedative on regional anesthesia. Preliminary results.

Diazepam is widely used as a sedative for loco-regional anesthesia. The venous irritation and long duration of action and hangover may be a drawback. We compared 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a] [1,4]benzodiazepine (midazolam, Ro 21-3981, Dormicum), a new water-soluble benzodiazepine, with diazepam for cardio-respiratory changes, onset time, duration of action, amnesia and venous irritation after a single i.v. shot in loco-regional anesthesia.

Anesthesia, Conduction↗
PubMed1980

Therapeutic monitoring of valproic acid.

Valproic acid, a new type of antiepileptic drug, has developed into one of the drugs of first choice in all types of epilepsy with the exception of infantile spasms and partial seizures. Due to its short biological half-life, a steady-state plasma concentration will be reached rapidly after initiation of therapy. However, no direct relationship between this plasma concentration and the clinical effect can be found. In autoradiography experiments, brain distribution appears to change with time, suggesting a gradual accumulation of the drug or its metabolites in certain brain areas. Two metabolites are detected in monkey and human blood plasma. Valprolactone is also found in brain tissue, but the substance is rapidly eliminated. beta, gamma-Unsaturated valproic acid has the longest half-life and is found in concentrations that can be quantitated by routine gas chromatographic analysis. The therapeutic effect appears to correlate better with dosage per kilogram body weight than with the actual plasma concentrations. Routine monitoring of valproate plasma concentrations in epileptic patients seems to be of limited value.

Aging↗
PubMed1980

Gamma-hydroxybutyric acid as hypnotic. Clinical and pharmacokinetic evaluation of gamma-hydroxybutyric acid as hypnotic in man.

Gamma-Hydroxybutyric acid (GOH) was administered to three groups of four patients in 50, 75 or 100 mg/kg dose respectively, and sleep effects were scored, by sleep observation and questionnaire; GOH plasma levels were determined at 75-100 mg/kg, saliva and urine excretion at 100 mg/kg. Sleep induction was rapid and irresistible, subjects awoke at plasma levels of 90 micrograms/ml; sleep scores were good for 75 mg/kg, excellent for 100 mg/kg, notably on mood. For 75 or 100 mg/kg GOH had virtually disappeared from the blood eight hours after intake; twelve hours after intake no more GOH was detectable in urine; no correlation between plasma- and saliva levels was found. Plasma levels for 100 mg/kg dose were not at an anaesthetic level. So, GOH is a safe and good hypnotic at 75 or 100 mg/kg in clinical use.

Humans↗
PubMed1978

Determination of trimethoprim and sulfamethoxazole (co-trimoxazole) in body fluids of man by means of high-performance liquid chromatography.

A high-performance liquid chromatographic method for the determination of trimethoprim, sulfamethoxazole and its metabolite and a series of structurally related sulfonamides is described. The half-life time of elimination of sulfamethoxazole and its metabolite N4-acetylsulfamethoxazole is 9 h for both compounds. The renal excretion rate of sulfamethoxazole depends strongly on the urinary pH. The renal excretion rate of the metabolite N4-acetylsulfamethoxazole is not dependent on the urinary pH.

Chromatography, High Pressure Liquid↗
PubMed1977

Mass spectrometry of cannabinoids.

The mechanism of fragmentation of cannabinoids to fragments m/e 314, 299, 271, 258, 246, 243, and 231 is given. Cannabidiol cannabinoidiol, cannabinol, delta6- and delta1-tetrahydrocannabinol, cannabichromene, cannabicyclol, derivatives with pentyl, propyl, and methyl side chains, their methyl ethers, and cis-trans and ortho-para isomers were analyzed by GLC-mass spectrometry using different energies for fragmentation during GLC elution. The following mechanism was distinguished: loss of a methyl radical, ring closure and rotation, McLafferty rearrangement, retro Diels-Alder, internal protonation, isomerization and internal bond formation, and one-step fragmentation to m/e 231.

Cannabinoids↗
PubMed1976

Radip induction of ether anaesthesia and controlled maintenacne by a combination of intravenous and inhalation administration without the risk of explosion.

The induction and maintenance of anaesthesia with ether using a combined intravenous infusion and a constant low inspired concentration are discribed. Predictions from a mathematical model were checked against animal experiments. Anaesthesia occurred within 5 min. The mehtod obviates the need for explosive mixtures.

Anesthesia, Endotracheal↗