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Biomedical subjects

A Krebs

Publications and source records attributed to A Krebs.

At least 109 records · Page 6Linked to original sources
PubMed1979

Polyploidization and hemiploidization induced by PUVA in vivo.

To obtain additional information on the in vivo injury induced by PUVA treatment, primary cultures were initiated from biopsies of the uninvolved skin of 15 PUVA-treated psoriatic patients, and the cells generated were analysed for morphological and chromosomal modifications. Three biopsies were obtained from each patient, the first one before commencing PUVA therapy (control) and the other two during the course of therapy. It was found that PUVA treatment has diverse effects on the mitotic activity, mitotic mechanisms and chromosomes of the cutaneous cells: (1) an inhibition of cell proliferation during the early stages of therapy followed by a reversion to normal proliferation as the PUVA treatments were continued; the production of (2) cells with more than one nucleus, (3) macrocells, (4) cells with micronuclei, (5) polyploid cells, (6) haploid cells, (7) cells with 13 chromosomes denoting a twofold reduction in the normal number of metaphase chromosomes, (8) end-associations of the chromosomes as in the pachytene phase of meiosis (9) diplotene chromosomes, and (10) chromosomal translocations.

Cell Division↗
PubMed1979

[Perspective of tuberculosis control--role of preventive chemotherapy (author's transl)].

After a short review of measures for control and eradication of infectious diseases in general and especially of tuberculosis, the indications of chemoprophylaxis and preventive chemotherapy of tuberculosis are discussed. Using results of a double-blind controlled trial on preventive chemotherapy in a high risk group (persons with fibrotic lung lesions), cost, benefit and side effects of preventive chemotherapy are analysed. Preventive chemotherapy in high risk persons is an effective measure in advanced stage of tuberculosis control. Recommendations to reduce side effects are given.

Diabetes Complications↗
PubMed1978

[Qualitative and quantitative investigations of the skin nerves of patients with psoriasis light- and electronmicroscopical study (author's transl)].

This study was aimed at investigating the role of the nerves in the pathomechanism of psoriasis. The structure of skin nerves of 10 patients with active psoriasis and of 6 healthy control persons has been studied by means of the microscope and the electron-microscope. Eight of the patients were subjected to punch biopsies of psoritatic plaques as well as clinically normal skin. No qualitative difference could be detected between the skin nerves from psoriatic patients and from healthy persons. Quantitative investigations showed that the density of myelinated and unmyelinated axons in psoriatic skin nerves did not differ from that in normal skin nerves in a statistically significant degree. This means that the ratio of myelinated to unmyelinated axons was alike in both normal and psoriatic skin nerves. Also the diameter distribution of myelinated and unmyelinated axons was similar. The difference in the degree of myelinisation and in the myelinperiodicity between psoriatic and control skin was not statistically significant. Neither qualitative nor quantitative morphologic alterations in the skin nerves of psoriatic persons could be detected.

Adult↗
PubMed1978

[Papillon-lefèvre syndrome].

Papillon-Lefèvre syndrome in a 13-year-old boy is described. His two great-grandfathers were first-degree cousins (consanguinity). However, no other case of the syndrome nor of palmoplantar keratoderma exists in the family. The palmoplantar keratoderma, which had started before becoming 1 year of age, is usually more pronounced during spring and autumn as well as during feverish diseases. However, it is of the transgradient type and is not necessarily very severe. The loss of the deciduous and permanent teeth was a consequence of severe juvenile parodontitis and of bone destruction. The boy could extract his teeth easily by himself and has total prothesis since the age of 14 years. Every treatment was unsuccessful.

Adolescent↗
PubMed1977

Induction of multinucleate cells by 8-MOP and UV treatment in vitro and in vivo.

Fibroblast cells were treated with a single dose of 8-methoxypsoralen (8-MOP) and long-wave UV irradiation in vitro and the cytotoxic effects of the treatment followed up for 5 passages. During the first passage, there was an inhibition in cell proliferation, the induction of chromosomal aberrations and the production of macrocells as well as cells with more than one nucleus. In the subsequent passages, the proliferation rate of the cells gradually normalized but there was a concomitant increase in chromosomal aberrations and in the number of macrocells and multinucleate cells. Specimens, which were taken from the uninvolved skin of psoriatic patients who had been treated between 20 and 40 times with an oral dose of 8-MOP and black light irradiation (PUVA) also revealed the presence of binucleate, tetranucleate and multinucleate epidermal cells as well as binucleate and tetranucleate dermal fibroblasts.

Cell Nucleus↗
PubMed1977

Photo-onycholysis induced by 8-methoxypsoralen.

Two patients, who we had under surveillance since 1969, were found to develop photo-onycholysis from orally administered 8-methoxypsoralen and sunlight irradiation. Morphological examination of the nail bed revealed characteristics of a microtrauma. The photosensitizing effect of the drug induced the generation numerous binucleate, tetranucleate and multinucleate epithelial cells as well as numerous binucleate and tetranucleate fibroblasts in the dermis.

Administration, Oral↗
PubMed1977

[The role of preventive chemotherapy in the present tuberculosis epidemiology of GDR (author's transl)].

The risk of "Gesunde Befundträger" (healthy carriers of pulmonary lesions) to develop pulmonary tuberculosis is compared with that of persons with X-ray shadows in the lung. In the group of "Gesunde Befundträger" this risk can be further differentiated, being highest among males with positive tuberculin skin test and more extended X-ray shadows in the lung. Judging from a follow-up of 4 years in the double-blind trial on isoniazid preventive treatment in persons with fibrotic lesions, the risk of developing pulmonary tuberculosis is reduced by 2/3 by giving 300 mg isoniazid daily during 24 weeks. In the present epidemiological stage of tuberculosis in GDR, preventive treatment of persons with highest risk of developing tuberculosis disease is the most promising prophylactic measure. The recommedations to reduce side-effects must be observed.

Adolescent↗
PubMed1976

[The frequency and form of manifestation of liver damage under INH therapy].

It is reported on 305 clinically examined patients with the diagnosis of a functional colon syndrome. In 65 patients somatic diseases were found to be the possible triggering factors. In contrast to a comparative group in the other 240 patients in the former anamnesis more frequently allergies, appendectomies and chronic application of purgatives were to be established. The most frequent complaints were irregularity of defaecation in form of spastic obstipation (62.9%) or diarrhoea (35.4%), intolerance to foodstuff (100%), pain in the colon(66.7%) and meteorism (65.4%). The 4th decennium was most frequently concerned in men as well as in women.

Alcoholism↗
PubMed1976

On the monomeric structure and proposed regulatory properties of phosphoenolpyruvate carboxykinase of Escherichia coli.

Phosphoenolpyruvate carboxykinase (ATP:oxaloacetate carboxy-lyase (transphosphorylating)) (EC 4.1.1.49) has been purified to homogeneity from Escherichia coli. The enzyme shows the same molecular weight (ca. 65000) either by sedimentation equilibrium under nondenaturing conditions or by polyacrylamide gel electrophoresis in the presence of detergent, indicating that the enzyme has a monomeric structure. We have confirmed the previous observation that NADH is an inhibitor of this enzyme, but we have failed to detect the previously reported appearance of homotropic cooperativity with respect to substrate binding the presence of this inhibitor. Lack of such homotropic interactions is in harmony with our conclusion that the enzymes is a monomer. Replacement of Mg2+ by Mn2+ in the assay medium lowers the Km for phosphoenolpyruvate by an order of magnitude, but does not affect the characteristics of inhibition by NADH.

Escherichia coli↗
PubMed1976

[A follow-up of x-ray-treated tuberous hemangiomas after 15-20 years (author.s transl)].

The treatment of hemangiomas with X-rays has been sharply criticized because of their tendency to involute spontaneously. It has been the aim of this catamnestic study to re-examine for X-ray injury those patients, whose hemangiomas were irradiated 15-20 years ago. The findings indicate that signs of roentgenoderma can appear already with 800 r and increase rapidly over 1,500 r. The observed irreversible damages, however, were mostly not grave, but admonish a certain amount of restraint. An assessment of the effectiveness of low X-ray doses still requires verification considering a faster spontaneous involution.

Dose-Response Relationship, Radiation↗