PubMed Health⌕ Search

Biomedical subjects

G Rüttimann

Publications and source records attributed to G Rüttimann.

10 recordsLinked to original sources

[Retrolental cloudiness of the vitreous humor in the rat eye].

Small globular vitreous opacities were observed by routine slit lamp eye examinations in aged Sprague-Dawley rats. This finding occurs first in about 5% of the animals at the age of 58-89 weeks. In rats 101-134 weeks old, the incidence of this finding increases up to approximately 20%. Wistar rats show these vitreous opacities only rarely; and if so, they occur at the age of at least 101-134 weeks. The histological examinations revealed retrolental protein globules without any inflammatory response which probably consist of lens cortex material. The lenses showed a fragmentation with small gaps of the capsule at the posterior pole as well as posterior sutural cataracts. We believed that strain and age dependent degenerative changes of the posterior lens capsule are the cause of the extrusion of lens protein into the vitreous.

Aging↗

Inhibition of pentagastrin-stimulated acid secretion after subcutaneous administration of a new somatostatin analogue.

Somatostatin, a peptide present in hypothalamus, gastric mucosa, and pancreas suppresses several gastrointestinal functions. Its short half life has prevented clinical use. We have therefore evaluated the effect of subcutaneous administration of a new synthetic somatostatin analogue, in comparison with a placebo, on pentagastrin stimulated acid secretion in six healthy volunteers. On different days, acid secretion was measured continuously, after a basal 30 minutes, for six hours during 3 micrograms/kg/h of intravenous pentagastrin. Acid secretion was measured with a marker technique (0.1% phenol red) to correct for duodenal volume loss. Blood was drawn in regular intervals to measure plasma somatostatin concentrations by radio immunoassay. One hour after starting the pentagastrin infusion, a single subcutaneous injection of either 100 micrograms somatostatin analogue, or placebo (isotonic saline) was given. In a follow up study, somatostatin was given subcutaneously in a dose of 200 micrograms. No difference in efficacy was observed between the two doses. A single subcutaneous injection of the somatostatin analogue significantly suppressed acid secretion for five hours (p less than 0.01). Maximal inhibition was approximately 75%. Mean elimination half life of the analogue was approximately 80 minutes. We suggest that the new somatostatin analogue might be useful for clinical use.

Adult↗

Toxicological evaluation of cyclosporin A.

Toxicological studies in a variety of different animal species have shown that cyclosporin A (CS-A) is a unique immunosuppressant, since it does not cause myelotoxic, teratogenic, mutagenic, or carcinogenic effects. This is undoubtedly due to the fact CS-A produces its immunosuppressive effects by a specific action on T lymphocytes rather than by a cytotoxic mechanism. The incidence of acute inflammatory lesions was also not significantly higher in treated animals than in controls. Clear-cut organ toxicity only occurred in rats and cynomolgus monkeys, where at high doses nephro- and hepatotoxicity were observed.

Animals↗

Toxicological evaluation of fluproquazone.

The toxicological characteristics of 4-(p-fluorophenyl-1-isopropyl-7-methyl-2-(1H)quinazolinone (fluproquazone), an analgesic with distinct antiinflammatory properties, were evaluated in acute and chronic toxicity studies as well as in reproduction toxicity, carcinogenicity and mutagenicity studies. The following overall results were obtained: The acute oral toxicity in mice, rats, and rabbits is of low order. In the chronic oral studies fluproquazone was generally well tolerated when given to rats and dogs for 13 weeks, to dogs and monkeys for 52 weeks, to mice for 78 weeks and to rats for 104 weeks. In particular, there was no indication of gastrointestinal irritations or lesions in any of these studies. The results of the studies in dogs and rats showed the major target organs for the toxicity of fluproquazone to be the liver and kidney, where mild, reversible changes were observed. These findings were considerably less severe than those found with several other antiphlogistic-analgesic compounds. In the reproduction toxicity studies, the only drug-related effects seen in experiments on female fertility or peri- and postnatal development in rats were a prolongation of pregnancy and an impairment of delivery leading to an increased perinatal mortality. These findings may be related to an inhibition of prostaglandin synthesis by fluproquazone. Similar effects are known to occur after administration of other inhibitors of prostaglandin synthesis. The oral teratological studies in rats and rabbits did not reveal any embryolethal or teratogenic effects. The drug had no mutagenic effects in either the micronucleus test and the dominant-lethal test using mice, or in the Ames-Test using Salmonella typhimurium. The carcinogenicity studies showed that fluproquazone has no carcinogenic potential in rats and mice.

Animals↗