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Biomedical subjects

A Fuchs

Publications and source records attributed to A Fuchs.

At least 163 records · Page 9Linked to original sources
PubMed1983

[Contact urticaria caused by skin test in pyrazolone allergy].

About one third of patients with anaphylactic reactions to pyrazolones showed contact urticaria induced by to at least one pyrazolone after 30-60 min in patch test. This reaction was never observed in patients with various exanthemas or allergic contact dermatitis to these medicaments. Contact urticaria in patch test was mostly caused by propyphenazone, aminophenazone, and metamizole. The suspicious pyrazolone provoked positive results in only about 70%. No correlation could be found between contact urticaria in patch test and severity of allergic history, short interval before skin test and atopic constitution.

Adolescent↗
PubMed1982

[Estrogen and progesterone receptors in corpus uteri carcinoma and their clinical significance].

In 49 carcinomas of the endometrium of varying clinical stages the estrogen and progesterone receptors were studied by charcoal absorption methods. The cases were studied between 1979 and 1981. 64% of the investigated cases were receptor positive, 35% were receptor negative. Estrogen receptors were detected in 61% and progesterone receptors in 49% of the cases. Both estrogen and progesterone receptors were detected in 45% of the cases. The receptor status was correlated with the clinical stage, the microscopic differentiation and the age of the patient. In 30 cases with a follow-up of more than 3 months it was attempted to determine the prognostic value of the steroid receptor status in endometrial carcinoma. The treatment possibilities with progestational agents and antiestrogens and with tamoxifen were discussed in view of the receptor status.

Age Factors↗
PubMed1982

The importance of gestagen, tamoxifen and steroid receptors in the therapy of endometrial cancer. Report of an experiment.

Six human endometrial cancers in different clinical stages were xenotransplanted into thymusaplastic nude mice. Estrogen and progesterone receptors in the tumor tissue were determined in each case. Two carcinomas with both estrogen and progesterone receptors showed a better clinical course and grew more slowly in nude mice than the four carcinomas with no receptors at all. Treatment with the antiestrogen Tamoxifen in the carcinoma with positive estrogen receptors showed a significant growth retardation compared with the control group. Estrogen treatment gave accelerated growth, whereas gestagen treatment showed no significant effect. The progesterone receptor content of the receptor-positive tumor tissue might have been too small. None of the four receptor-negative carcinomas showed any influence of tumor growth during endocrine therapy. The results demonstrate the importance of receptor determination as a prognostic sign and, further, allow the endocrine therapy of endometrial carcinomas to be complemented with Tamoxifen in estrogen-receptor-positive tumor tissue.

Aged↗
PubMed1978

Bacterial breakdown of benomyl. I. Pure cultures.

With different soil and water samples as inoculum and the benzimidazole fungicides benomyl (either as Benlate or as the pure compound) and thiabendazole as selective agents, a large number of, mainly fluorescent, Pseudomonas strains were isolated which nearly all were able to grow in a mineral medium with benomyl as the sole source of carbon. However, no growth occurred with any of a series of other benzimidazole compounds, viz. benzimidazole, 2-aminobenzimidazole (2-AB), thiabendazole and fuberidazole. Although benomyl--or rather its non-enzymatic breakdown product methyl benzimidazol-2-yl carbamate (MBC)--was partially degraded to 2-AB, most probably n-butylamine, which arises after splitting off of the butylcarbamoyl side chain, was the actual carbon source for the Pseudomonas isolates. When incorporated in a lactate medium, 2-AB markedly inhibited the growth of Pseudomonas spp. at a concentration of 250 microgram/ml, with complete inhibition being attained at 500 microgram/ml. For Bacillus spp. grown in liquid peptone media benzimidazole compounds were inhibitory at concentrations of 500-1000 microgram/ml, with a toxicity increasing in the order: benzimidazole less than thiabendazole less than MBC less than 2-AB.

Bacillus↗
PubMed1978

Bacterial breakdown of benomyl. II. Mixed cultures.

Experiments with mixed bacterial cultures grown in liquid media which contained the benzimidazole fungicide benomyl, with or without Na-lactate, as source of carbon provided circumstantial evidence for cleavage of the benzimidazole heterocyclic ring. Yet, neither 2-aminobenzimidazole (2-AB) nor benzimidazole, as sole source of carbon, supported any bacterial growth. "Total 14C-balance analysis" experiments conclusively showed production of 14CO2 from [2-14C]methyl benzimidazol-2-yl carbamate (MBC), and thus cleavage of the benzimidazole nucleus: bioassays, however, showed that the actual rate of benomyl and MBC breakdown was only small, the parent compound benomyl being still recovered in substantial quantities after up to 80 days of incubation. Therefore, cleavage of the benzimidazole ring is probably a matter of cometabolism, n-butylamine which originates from the butylcarbamoyl side chain serving as the proper source of carbon. Besides radiolabelled 2-AB and CO2, an unknown metabolite was isolated which showed characteristics of a 2-AB-nucleotide. Probably, 2-AB was incorporated into bacterial DNA, which upon lysis of the bacterial cells gave rise to the nucleotide in question. Therefore, 2-AB might exert its inhibitory action by interfering with the normal functioning of DNA.

Bacteria↗
PubMed1976

Translocation, distribution and metabolism of triforine in plants.

After short-ter root-treatment of plants with 3H-triforine (labelled in the piperazine ring) or 14C-triforine (labelled in the side chain), the label was translocated primarily to the leaves present at the time of treatment, without any redistribution of the label taking place after termination of the treatment. Autoradiography showed the radioactivity to be very evenly distributed over the leaf blades, without any appreciable accumulation in leaf margins. In infected leaves, however, there was a tendency for increased accumulation at the infection sites. In dilute aqueous solution triforine was decomposed rather rapidly, the chemical half-life being three days only. From these solutions several non-fungitoxic degradtion products have been isolated and their chemical structures determined. In plants, decomposition of triforine was considerably slower than in aqueous solutions, the half-life of the compound varying depending on plant species. In plants, at least four conversion products could be demonstrated, one of which is piperazine. Whether the other three compounds are identical with or structurally related to the breakdown products found in aqueous solution is not yet known. Its low persistence and low animal toxicity suggest that triforine does not offer serious hazards to the environment.

Age Factors↗
PubMed1976

Classification of psychoactive drugs by visually evoked potentials in rabbits by means of multiple discriminant analysis. A possible way of predicting the clinical efficacy of new psychoactive drugs.

The influence of representatives of various groups of antipsychotic drugs on the visually evoked potential (EP) was investigated with the aid of a modified recording and evaluation technique for the rabbit EEG from cortical and subcortical structures. The starting point was the hypothesis that changes in the EP in animal experiments caused by representative members of these "substance groups" (neuroleptics with predominantly antipsychotic or predominantly sedative effect, and antidepressants with predominantly mood-brightening or predominantly sedative main components) make predictions of the clinical efficacy of "unknown" substances possible on the basis of clinical therapeutic principles of classification. Experiments were carried out with haloperidol and fluphenazine, chlorpromazine, amitriptyline and doxepin, and with imipramine and clomipramine, as representatives of these classes of substances. The hypothesis was checked by attempts to assign amitriptyline and chlorprothixene in varying dosage, haloperidol, benzperidol and mianserine to appropriate classes. As classification and assignment procedure we used stepwise multiple discriminant analysis (SWDA) according to our modification of the BMD 0 7 M Program. The purpose of the latter program, and its applicability to our studies, are described and discussed. It was found 1. that with EP data from animal experiments it is possible to classify various groups of psychoactive drugs on the basis of clinical therapeutic findings, using SWDA; 2. that assignment of "unknown" compounds can be based on this classification; 3. that hence with some caution predictions of the clinical effect of newly developed substances may be made on the basis of findings in animal experiments. The EP variables which contain most information for making up the separation formula and hence are of special importance, are investigated with respect to their possible neurophysiological evidential value, and their significance is discussed. It was found that the EP from the visual cortex are of particular significance for the separation of groups in the form presented here.

Animals↗