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Biomedical subjects

K Abt

Publications and source records attributed to K Abt.

33 records · Page 2Linked to original sources
PubMed1980

Age-related histochemical and histological changes in the knee-joint cartilage of C57B1 mice and their significance for the pathogenesis of osteoarthrosis. I. Oxidative enzymes.

For a better understanding of the part played by the aging of cartilage in the pathogenesis ofosteoarthrosis, we attempted to detect functional age-related changes in the knee-joint cartilage of C57B1 mice using histochemical methods and to correlate these changes with the concomitant histological changes. A comparison of 57- and 97-week-old mice revealed a statistically significant age-related focal loss of activity for a number of oxidative enzymes of the chondrocytes. There was an associated significant increase in regressive changes of the chondrocytes. A relation probably exists between these two changes, inasmuch as the focal loss of enzyme activity precedes and possibly gives rise to the regressive changes. A comparison with the changes described in the articular cartilage of other species including man suggests that the phenomena observed are inherent age-related changes. The loss of activity of all the enzymes investigated indicates a far-reaching derangement of cellular metabolism, leading to impaired synthesis of proteoglycans. Since these compounds are major determinants of the physical properties of articular cartilage, the changes described might render the cartilage more vulnerable and might thus play a major part in the pathogenesis of osteoarthrosis.

Aging↗
PubMed1979

Statistical problems in the analysis of comparative pharmaco-EEG trials.

Assuming already condensed data from the EEG power spectra, problems arising with the statistical analysis of such data in comparative pharmaco-EEG trials are discussed. Since, in general, there is only a limited number of subjects available in a study to evaluate and compare the effects of a number of drugs by means of the EEG, the experimental design is usually of the cross-over type. With respect to this design, the requirements for the application and for the appropriate analysis are stated. Further, the problems are indicated which arise when the number of subjects is not a multiple of the number of drugs and/or when there are missing values. Finally, the topic of repeated null hypothesis testing and the inflation of the overall significance level is treated. Suggestions are made how to at least partly avoid the indicated problems at the present stage of methodological statistical research.

Analysis of Variance↗
PubMed1979

[The effect of contrast volume on the radiographic demonstration of the gall bladder and bile duct (author's transl)].

No differences could be detected subjectively in the quality of cholangiograms after the use of varying amounts of contrast medium (20 and 30 ml iodoxaminic acid). Pharmacolinetic data which would indicate the use of either quantity are not available. Densitometric measurements carried out by us showed no significant statistical difference between the results of using 20 or 30 ml iodoxaminic acid.

Cholecystography↗
PubMed1979

A double-blind trial of synthetic salmon calcitonin in the treatment of acute pancreatitis.

A multicenter randomized double-blind trial on the use of synthetic salmon calcitonin (SCT) was carried out in 94 patients with acute pancreatitis. In addition to strict standard treatment--without aprotinin, atropine, or antacids--50 patients received daily 3 x 20 micrograms = 300 MRCU SCT intravenously and 44 patients received placebo for 6 days. Mortality rate was not influenced, overall mortality being 5.3%. The number of patients without pain and with normalized serum amylase on a given day was significantly higher in the group treated with SCT. Other parameters such as doses of analgesics, leukocyte count, and normalization of seven defined clinical and laboratory criteria within 6 days showed a positive trend without reaching significance.

Acute Disease↗
PubMed1977

[Quantification and statistical analysis of ordinal scale type data in psychiatry (author's transl)].

Observational data from psychiatric patients are usually of the ordinal scale type. Therefore, in the traditional one-rating-per-symptom-and-patient-situation, the resulting score values can be analysed only by applying nonparametric statistical methods. These methods are rather inefficient when--as is usual--there are only four-point-scales for evaluating the symptoms. Moreover, non-parametric methods are not available as of yet to take into consideration the often complex structure of data from psychiatric studies. This leads to the conclusion that the quantification of ordinal scale type data would be very desirable in order that parametric statistical methods could be applied. Such a method of quantification is proposed on the basis of the audiovisual psychiatric rating technique. It is shown that the data resulting from the many-ratings-per-symptom-and-patient-situation can be subjected to parametric statistical methods. In applying the proposed method, therefore, much better use could be made of and a maximum of information could be extracted from the data in psychiatric studies.

Humans↗
PubMed1976

The effects of the beta-adrenoceptor blocking agent LL 21-945 on renal hypertensive (Grollman) rats.

Prophylactic administration of LL 21-945 [4-(3-tert. butyl-amino-2-pivaloyloxypropoxy)-9-fluorenone] during 15 weeks to Grollman rats depressed the development of hypertension, tachycardia and myocardial pathogical changes. The tachycardia was eliminated and the degree of the myocardial pathological changes and coronary sclerosis was less severe than in the untreated Grollman rats. The survival rate was slightly improved with LL 21-945. With respect to the biochemical parameters studied, only a tendency of LL 21-945 to moderate the rises in blood cholesterol, total glycerides and urea was observed towards the end of the experiment.

Adrenergic beta-Antagonists↗