Search PubMed⌕ Search

Biomedical subjects

D Kayser

Publications and source records attributed to D Kayser.

7 recordsLinked to original sources
PubMed1992

A national validation study of the acute-toxic-class method--an alternative to the LD50 test.

In a national collaborative study an alternative to the classical LD50 test--the acute-toxic-class method--was validated. With this testing procedure mortality ranges are determined between defined dose levels that are used for classification and labelling in the European Community. The results were compared with LD50 data obtained from the literature which were categorized according to the defined dose levels. The results of this collaborative study have shown that the acute-toxic-class method allows allocation to the toxicity classes of very toxic, toxic, harmful and unclassified in the same manner as on the basis of the classical LD50 tests. The acute-toxic-class method uses fewer animals and subjects fewer animals to pain and distress than the LD50 test and yields the same information on toxic signs in the treated animals. Identical classifications were obtained by the six participating laboratories in 86% of the tests. This demonstrates that the acute-toxic-class method results in excellent reproducibility in comparison to the classical LD50 test and that this new method is a reliable alternative to the LD50 test.

Animal Testing Alternatives↗
PubMed1989

A differentiated approach to testing skin sensitization. Proposal for a new test guideline skin sensitization.

The present EEC and OECD Guidelines for testing skin sensitization have been reviewed in light of scientific evidence demonstrating that those methods which use Freund's Complete Adjuvant (FCA) are likely to be more accurate in predicting a probable skin-sensitizing effect of a new substance in humans than those methods not employing Freund's Complete Adjuvant. In this new test guideline, therefore, the primary testing of a substance should be carried out using one of the recommended Adjuvant methods. In special cases a non-adjuvant method may be performed in addition. Not all of the seven methods in the EEC Guideline or eight methods in the OECD Guideline have been included, but in a proposal for an updated test protocol two Adjuvant tests (Maximization test by Magnusson and Kligman and Optimization test by Maurer), and two non-Adjuvant tests (Open Epicutaneous test by Klecak and Buehler test) are suggested. The criteria for selecting these methods are based on the fact that they are well validated and widely used on a broad basis by the scientific community. Furthermore, it is considered appropriate to permit the use of a lower number of animals than presently recommended for the testing of skin sensitization. This is also in agreement with aspects of animal welfare.

Animals↗
PubMed1989

[Long-term results following surgery or radioiodine treatment of solitary autonomous adenoma of the thyroid gland].

128 patients were investigated after surgery (n = 72) or 131-iodine therapy (n = 56) of a scintigraphically solitary, hyperfunctioning adenoma of the thyroid gland. The median follow-up period amounted to 10.6 years. Recurrent hyperthyroidism was observed in six patients after surgery and in one patient after 131-iodine therapy. Hypothyroidism occurred in one patient after 131-iodine therapy. The percentage of 131-iodine treated patients with a normal TSH-response to TSH-releasing hormone (TRH) increased during the follow-up period from 57 to 90%, whereas after surgery the percentage of patients showing a normal TSH-response to TSH decreased from 58 to 31%. This latter observation points to persistent hyperfunctioning tissue areas inducing late recurrent hyperthyroidism in 8.3% of the patients who underwent surgery.

Adenoma↗
PubMed1977

[The demonstration of pharmacological active substances in the portal vein blood of dogs after occlusion of the superior mesenteric artery (author's transl)].

The experimental occlusion of the superior mesenteric artery in dogs is followed by a significant rise of serotonin-, kinin- and katecholamin-concentrations in the portal vein blood. The rise of the prostaglandin-F2alpha-concentration occurred only immediately after the occlusion or reopening of the occluded superior mesenteric artery. Under our experimental conditions the measured concentrations of these substances in the portal vein blood are too low and ineffective for the development of peptic erosions in the stomach as observed after occlusion of the superior mesenteric artery. On the other hand a possible additiv effect of the underswelling concentrations in these different substances cannot be excluded.

Animals↗
PubMed1975

Effect of pentazocine on the evoked potentials recorded in the primary somesthetic cortical areas of guinea pigs.

The influence of pentazocine on the evoked potentials registered in the primary somesthetic cortical area in guinea pigs under pentobarbital anesthesia was studied. The stimulation was applied in the contralateral lip and the evoked cortical responses from different zones on the cortex stereotaxically localized were registered. Pentazocine (5-10 mg/kg i.v.) induced a significant increase in the latency of the evoked potentials as compared with controls. Since morphine does not modify these potentials, the effect of pentazocine is interpreted as being a direct one on the primary pain pathway.

Animals↗