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Biomedical subjects

G Freund

Publications and source records attributed to G Freund.

At least 55 records · Page 3Linked to original sources
PubMed1977

[An electroencephalographic comparison of fentanyl and sulfentanil (author's transl)].

Equipotent analgesic doses of sulfentanil and fentanyl showed similar effects in 281 cases of clinical neuroleptanalgesia. In rabbits equimolecular doses of sulfentanil induced a deeper narcotic effect (burst suppression) than fentanyl. This supports the thesis of a coincidental increase of analgesic potency and narcotic effect in agonistic opioids. In equipotent doses the conventional EEG and the amplitude-frequency-spectra are equal. Quantificated analyses and statistical calculations show essentially similar changes in animal: - Fentanyl as well as sulfentanil changes only the dominant frequency in the theta-bands. - The percentage value increases only in the sigma-band, doesn't change in the alpha- and beta1-band and decreases in the theta-band, beta2--and beta3-band. - The power of sigma rises by a potency of ten in both substances; the change in the other frequencies shows similar sizes. Fentanyl and sulfentanil do not coure differences in the EEG.

Adult↗
PubMed1975

Induction of physical dependence on alcohol in rodents.

An ethanol withdrawal syndrome consisting of tremors and seizures can be induced in rats and mice. This syndrome closely resembles the physical signs observed in human patients during alcohol withdrawal. The criteria for an animal model of a human disease appear to be fulfilled regarding the etiological agent, course of illness, the similarity of physical and electrophysiological manifestations and response to therapeutic agents. Therefore these models should lend themselves for the elucidation of the pathogenesis at the molecular level of biological organization and for the development of new therapeutic approaches. Criteria for an optimal animal model of ethanol dependence are outlined. Withdrawal signs are classified into minor (startle threshold and exploratory behavior) and major types (tremors and seizures). Methods for quantification of tremors and seizures are described. The procedures for induction of the major withdrawal signs are classified according to the mode of ethanol administration designed to circumvent the animal's inherent aversion to the taste of ethanol: Oral (free feeding, behavioral modifications of free feeding and force feeding), parenteral and inhalation. Auxiliary procedures consist of pyrazole administration and weight reduction resulting in a decreased rate of ethanol metabolism. Exposure to low environmental temperatures increases consumption of ethanol containing diets without proportionately increasing the rate of ethanol metabolism. Auxiliary procedures for the induction of seizures during withdrawal consist of handling the animals and audiogenic stimuli. Advantages and limitations of various rodent models are evaluated in terms of the procedures (practicability, compounding variables) and their results (reproducibility, severity and yield of major withdrawal signs, objective quantification). It is concluded that none of the current methods fulfill all requisites for all types of experiments. The selection of methods best suited for a particular experiment depend upon its objectives.

Acoustic Stimulation↗
PubMed1973

Impairment of timing behavior after prolonged alcohol consumption in rats.

Prolonged alcohol consumption (5 months) concomitant with adequate nutrition was found to impair the acquisition and performance of timing behavior. Alcohol was administered in the form of a liquid diet containing 35 percent ethanol-derived calories as the only source of fluid and calories. One control group received the identical liquid diet with isocaloric substitution of sucrose for ethanol, and another control group received laboratory chow and water without restriction. Thirty days after ethanol was discontinued in the diet, the alcohol-consuming rats were severely impaired in acquisition and performance of timing behavior as compared to controls.

Alcohol Drinking↗