Search PubMed⌕ Search

Biomedical subjects

J Abel

Publications and source records attributed to J Abel.

At least 91 records · Page 5Linked to original sources
PubMed1985

Pharmacokinetic data analysis of alfentanil after multiple injections and etomidate-infusion in patients undergoing orthopedic surgery.

The pharmacokinetics of Alfentanil, a new short acting analgesic, and Etomidate, a very short acting hypnotic compound, were studied in patients undergoing orthopedic surgery. Anesthesia was induced by bolus i.v. injection of Alfentanil and Etomidate, whereas the maintenance was performed by continuous infusion of Etomidate and repetitive i.v. injections of Alfentanil. The kinetics of the analgesic can be described by a two-compartment model; the elimination half-life has a mean value of 64.8 +/- 38.5 min. No cumulation of the drug was seen in spite of multiple injections. Concerning Etomidate it is not clear whether one or two compartments are needed. The mean elimination half-life is 29.4 +/- 6.2 min. The results suggest a possible shortening of the half-life of Etomidate in the presence of Alfentanil.

Adult↗
PubMed1984

The kinetics of bupivacaine (Carbostesin) plasma concentrations during epidural anesthesia following intraoperative bolus injection and subsequent continuous infusion.

Plasma levels of bupivacaine were measured in 25 patients undergoing major abdominal surgery. The pharmacokinetic analysis of these data shows: (1) under a short term treatment, i.e. in the initial phase where multiple injections are given, the kinetic properties are in accordance with linear kinetic theory. The data can best be fitted to a two-compartment-model. (2) under a longterm treatment, i.e. infusion for more than 50 h, a very high accumulation occurs in contradiction to this theory. Therefore, the calculation of plasma levels from initial kinetic data is not feasible.

Adult↗
PubMed1983

Plasma levels of alfentanil and etomidate in patients and their relation to compressed power spectral analysis of the EEG.

In 22 patients alfentanil-etomidate anesthesia was used for orthopedic procedures using for the induction period 300 micrograms/kg of the hypnotic and 100 micrograms/kg of the opioid. Maintenance of anesthesia consisted of 20 micrograms/kg of alfentanil given every 15 min and 20 micrograms/kg/min of etomidate given over an infusion. The patients were intubated and mechanically ventilated with pure oxygen. In order to access the state of vigilance with respect to etomidate and alfentanil plasma levels, EEG power spectra were computed from electrical cortical activity of the occipital region (P3-O1); respectively venous blood samples were assayed by means of gas chromatography for alfentanil and etomidate plasma concentration. In the EEG power spectrum, anesthesia replaced the high dominant alpha-peaks of the control-awake period by a disharmonious pattern over the whole frequency range (0.5-16.0 Hz). At the end of anesthesia vigilance recording indicated a correlation with plasma etomidate level. Once concentration had dropped below 100 ng/ml power spectra were characterized by a stable harmonious peak in the alpha-range (8.0-10.0 Hz). Plasma levels above 100 ng/ml induced a fluctuating pattern with peaks in the theta to delta band (0.5-8.0 Hz); the latter was characterized by drowsiness and a reduced respiratory drive. Opioid plasma levels above 100 ng/ml with etomidate levels below 80 ng/ml did not influence to the same extent. EEG power spectra seem to be a useful tool in pinpointing to a reduced state of vigilance. Such a state when present with opioid ingestion is often accompanied by respiratory depression.

Adult↗
PubMed1982

Induction by 3-methylcholanthrene of microsomal cytochromes and enzyme activities in mouse liver after subchronic ingestion of cadmium chloride.

The dose-dependence of the effect of Cadmium chloride (Cd) on the induction by 3-methylcholanthrene (MC) of the microsomal cytochromes b5 and P-450, seven monooxygenase activities and the arylepoxide hydrase was investigated in the livers of male random bred mice (NMRI Hannover). The animals were treated with 6.0; 3.0; 1.0 and 0.3 mumoles Cd++/kg/day for 20 days and subsequently with MC for three days (20 mg MC/kg/day). Cytochrome P-450 of control animals receiving MC only was not induced, and presumably kinetic inhibition of three monooxygenase activities was observed at the highest Cd-dosage. However, treatment with the two intermediate Cd-dosages resulted in induction by MC of both microsomal cytochromes and of 5 hydroxylating activities, leaving unaffected only the arylhydrocarbon hydroxylase. Previous work had shown that Cd alone in this dose range is without effect on microsomal enzymes. Therefore, Cd exerts a stabilizing or permissive effect on the phenotypic expression of some microsomal enzymes, but not of the arylhydrocarbon hydroxylase, within the MC-dependent induction process in mouse liver.

Animals↗
PubMed1981

[Functional dynamics of obstructive ileal conduits in children (author's transl)].

Bad late results following ileal conduit are usually caused by stomal obstruction. Poor emptying of the conduit, ureteric reflux and infection all combine to produce a pathological result. A manometric procedure to assess the functional performance of the conduit is presented. This allows for the diagnosis of early obstruction and decompensation. The most important measurements are a resting pressure of 1.2 kPa and the emptying pressure of 1.7 kPa and a compliance varying from 10 ml per kPa to 71 ml per kPa. The conduit must be isoperistaltic.

Adolescent↗
PubMed1981

[Plasma level of etidocaine within the first two hours after axillary plexus block in healthy adults and patients with renal insufficiency (author's transl)].

The plasma level of etidocaine was studied within the first two hours of axillary block in 7 patients with renal insufficiency and 7 healthy adults. After 15-20 min the maximum of plasma concentration was found in the group with renal failure and after 30-45 min in the healthy adults. 30 min after the block the plasma level was 1,26 +/- 0,62 mug/ml in the ill patients and only 0,73 +/- 0,31 in the normal group. Using a mathematical model the ratio of permeation into the blood is significantly higher in the group with renal failure than in the healthy adults. The main reason for these results seems to be the acidosis, which is often combined with renal insufficiency. The meaning of these results for regional anaesthesia in patients like these is discussed.

Acetanilides↗
PubMed1980

[Plasma concentrations of etidocaine after supraclavicular plexus block (author's transl)].

10 patients without concomitant hepatic or renal diseases were given brachial plexus block (Winnie) with etidocaine and the plasma concentrations of the drug were measured. The quantity of local anaesthetic was determined solely by the body weight and amounted to 4 mg/kg body weight. The mean peak concentration was 1.39 microgram/ml, the highest single concentration measured was 1.74 microgram/ml. Peak levels were reached within 40 minutes after administration of the local anaesthetic.

Acetanilides↗
PubMed1979

Additional induction of microsomal cytochrome(s) P 450 in mouse liver by consecutive application of cadmium chloride and phenobarbital.

Mice were treated intraperitoneally over 20 days with 0,30; 0,10 and 0,03 mg Cd+2/kg.day. Subsequent induction of microsomal metabolism by 50 mg phenobarbital/kg.day over 5 days revealed increased microsomal cytochrome P 450 content in Cd+2-pretreated animals as compared to animals treated only with phenobarbital. The microsomal cadmium content of animals having received cadmium plus phenobarbital was about 5 times higher than that of animals treated with cadmium alone. The only enzyme activity found to be changed by cadmium in induced microsomes was ethylmorphine-N-deethylation. In phenobarbital-free animals no microsomal changes by cadmium could be detected.

Animals↗
PubMed1978

[Experimental differentiation in animals of oral and inhaled lead burden from combined absorption of industrial emissions].

Trials in sheep and rabbits were performed in an area of industrial immissions in the summer months of 1974--1976, to differentiate oral and inhalative lead actions. The animals lived at different distances and in different directions from a lead emitting factory. Hematological and biochemical assays showed that only the measure of the activity of aminolevulinic acid dehydratase produces most significant results of the inhalative influences of lead. To state effects after oral ingestions the estimation of ALA-D and of free erythrocyte porphyrines were suitable. The inhalation of air with lead content between 2 and 14 micrograms/m3 reduced the activity of ALA-D, if the lead content of feed did not exceed the value of 35 ppm. After feeding a lead concentration of more than 35 ppm, the influence of the inhalative action was superposed by the action of the oral intake. The inhalative action can only be demonstrated after a low oral intake. The results indicate that inhalative actions of lead can be proven in an open field area around a lead emitting factory.

Absorption↗
PubMed1978

[Cattle vaccination against Q fever in the rural district of Bratislava].

Cattle attendants on two farms in the Outer Bratislava district showed symptoms of Q-fever. The blood of the cows in these farms was found to contain antibodies to Coxiella burnetti and the causative agent of the disease was detected in milk samples of aborting cows by biological assays on hamsters (Mesocricetus auratus). The naturally invaded dairy cows with antibodies in the blood and heifers without antibodies were vaccinated with different doses of inactivated suspension of C. burnetii in stage I. A different antibody reaction to vaccination was obtained after the application of a four-fold amount of vaccine. It was proved that the animals did not excrete the causative agent of the infection even after administration of lower doses of the vaccine on the 120th day after vaccination.

Animals↗