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Biomedical subjects

W Bartsch

Publications and source records attributed to W Bartsch.

67 records · Page 4Linked to original sources
PubMed1977

[Studies on antiarrhythmic effects and toxicity of quinidine and dihydroquinidine as well as defined mixtures of both in rats (author's transl)].

The antiarrhythmic and acute toxic actions of quinidine (Q) and dihydroquinidine (DHQ) were investigated in experiments in rats. 1. No significant difference was found between Q and DHQ with regard to the doses necessary to suppress electrically induced ventricular fibrillation in the heart (p greater than 0.05). 2. On oral administration, pure DHQ was slightly less toxic than pure Q. This difference is significant (p less than 0.05). It may be explained by a lower absorption rate of DHQ in the rat. Addition of 15 or 30% DHQ to Q did not produce any significant difference in the acute toxic doses (LD50) in comparison with pure Q (p greater than 0.05). 4. The results of a published clinical study showed that the antiarrhythmic actions of pure Q and "commercial" Q are the same with regard to quality, potency and duration. The frequency of side-effects after adminstration of the two alkaloids also did not differ. 5. Limitation or reduction of the DHQ content of pharmaceutical quality quinidine below a technically practicable level does not seem to be justified from a medical point of view from the results of the animal experiments presented and from the clinical study mentioned.

Administration, Oral↗
PubMed1976

Acute toxicity of various solvents in the mouse and rat. LD50 of ethanol, diethylacetamide, dimethylformamide, dimethylsulfoxide, glycerine, N-methylpyrrolidone, polyethylene glycol 400, 1,2-propanediol and Tween 20.

The LD50's of various solvents frequently used in toxicological work to improve the solubility of otherwise poorly soluble compounds were determined in the mouse and rat. The substances investigated were ethanol, dimethylacetamide, dimethylformamide, dimethylsulfoxide, glycerine, N-methylpyrrolidone, polyethylene glycol 400, 1,2-propanediol and Tween 20. The substances were administered under standardized conditions to groups of 10 animals (5 females, 5 males) (mice and rats) at doses that supplied at least 3 values lying between the LD16 and LD84. The median lethal dose and slope were determined with the aid of Finney's programmed probit analysis. The results are tabulated as LD50 ml/kg with 95% confidence limits. It is recommended that when using these solvents for pharmacological and toxicological investigations not more than a quarter of the LD50 should be used because otherwise there will be confusion between the deaths due to the substance being investigated and those due to the solvent.

Acetamides↗
PubMedDate not supplied

Increased surfactant protein A content in human alveolar macrophages in hypersensitivity pneumonitis.

Surfactant protein A (SP-A) appears to have an important function in the assembly and maintenance of the alveolar surfactant monolayer. SP-A has also been implicated in modulating the activity of immunoactive cells, such as increasing the bactericidal capacity of alveolar macrophages. In this immunocytochemical study the SP-A content of alveolar macrophages from seven patients with hypersensitivity pneumonitis was compared with the results obtained from six healthy controls. A polyclonal rabbit antibody against human SP-A was used for detection of SP-A in the cytoplasm of alveolar macrophages, applying the immunoperoxidase adhesive slide assay. In hypersensitivity pneumonitis a significant increase in the percentage of SP-A+ alveolar macrophages was observed as compared with the percentage in healthy controls. The intensity of the staining reaction was also increased in the alveolar macrophages of hypersensitivity pneumonitis. We conclude that the observed abnormalities in SP-A content in alveolar macrophages may play a role in the pathogenesis of hypersensitivity pneumonitis.

Adult↗
PubMedDate not supplied

[Clinical, endocrinological, histological and chromosomal investigations on Klinefelter's syndrome].

In a clinical study 101 patients with Klinefelter's syndrome (Kl. sy.) are evaluated. Clinical, endocrinological and histometrical aspects were of main interest. The results were compared with a group of patients with azoospermia by obstruction. The statistical evaluation showed significant differences concerning body-height, volume of ejaculate, size of testis, and the concentration of FSH and LH in serum. Histometrical investigations showed significant differences for the diameter of seminiferous tubules and their wall-thickness. The various degrees of Leydig-cell-increase at Kl. Sy. are described as--increased--excessively increased--and adenomalike. Sex-Chromatin was found positive in 62 of 64 cases of Klinefelter's syndrome, verified by chromosome analysis. The number of Barr-bodies ranged from 1-45 (200 cells evaluated) x mean was 9,6. The analysis of chromosomes in 64 cases showed a karyotype of 47,XXY in 59 cases, a 46, XY/47,XXY mosaic in 4 cases and 46,XX/46,XY/47,XXY mosaic in 1 case. The discussion pointed out, that Kl. sy. has no typical, but a variety of symptoms. The position of the evaluation of sex-chromatin for diagnosis and the possibilities of errors are discussed. The problem of fertility in Kl. sy. is mentioned, as we found two cases with complete spermatogenesis, yet with azoospermia, among our patients. The pathogenesis of the characteristical histological changes in testis with Kl. sy. remains open. The mechanism which may lead to the striking increase of Leydig-cells is discussed.

Adolescent↗