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Biomedical subjects

G Beckmann

Publications and source records attributed to G Beckmann.

At least 37 records · Page 2Linked to original sources
PubMed1992

Sensitivity in vitro of mature and immature mouse thymocytes to dexamethasone cytotoxicity and its correlation to poly ADP-ribosylation.

Mouse thymocytes were fractionated into heavy (subtype I, 79% of total cell number), medium (subtype II, 18%) and light (subtype III, 3%) ones by Percoll density centrifugation and they were identified as immature (subtype I and II) and mature (subtype III) thymocytes based on their proliferative response to mitogens. Whereas the nuclear activity of poly (ADP-ribose) polymerase (EC 2.4.2.30) in the subtype III was only one half that of denser subtypes, it increased two-fold upon mitogen stimulation. The sensitivity of three thymocyte subtypes to the dexamethasone cytotoxicity, as judged by the extent of the DNA cleavage, depletion of NAD and cell viability, was highest in the subtype I and lowest in the subtype III. The possible involvement of poly ADP-ribosylation in the apoptotic (programmed) cell death during intrathymic development of immature to mature thymocytes is discussed.

Animals↗
PubMed1990

[Lectin agglutination for the characterization of intestinal treponema isolates from different animal species].

The study presents the results of lectin-associated agglutinations of intestinal strains of treponemes isolated from pigs, dogs, mice and rats. At all 95 isolates are investigated, within the type strains for Treponema hyodysenteriae serotype 1-4 and Treponema innocens. Reactions with Concanavalin A and the Limulus-polyphemus-Lectin are often seen (twenty lectins used). Three out of four type strains for Treponema hyodysenteriae show an identical pattern of reaction, which is often seen in Treponema strains from dysentery suspected cases, too. Basing on these data a ranging in groups of lectin agglutination is proposed.

Agglutination Tests↗
PubMed1983

[Lead and cadmium contamination of foods and feeds from selected areas of the Erfurt district. 4. Lead in vegetables grown in culture centers of the Erfurt region].

For the purpose of determining the effect of heavy metal emissions of a great town on the lead and cadmium levels of vegetables that are of relevance to food supply, we analyzed 193 samples of vegetables from the important vegetable-growing centre of Erfurt during a 3-year period. With regard to the main wind direction and the infrastructure of the town, the samples were collected at four different areas under vegetable. Apart from a single exception, the lead and cadmium contents were inferior to the maximum tolerances provided by the regulation concerning the contents of foreign substances in foods, the metal contents of leaf vegetables being higher than those of brassicaceous plants. Vegetable samples from areas with heavier emission burdens showed somewhat higher metal contents. In contrast to this, the cadmium contents did not exhibit such differences. The highest lead and cadmium contents were found in spinach. To elucidate the effect of the washing and blanching techniques used in industrial processing, 23 spinach preserves were analyzed in addition; as expected, the heavy metal contents were reduced by these techniques. In summary, our investigations evidence that the main vegetables cauliflower, white cabbage, red cabbage, savoy cabbage, as well as lettuce and spinach (grown in the district of Erfurt) contribute but little to total food contamination if we consider the amounts consumed on an average.

Brassica↗
PubMed1981

[Contamination of foods and feeding stuffs from selected areas of the district of Erfurt with lead and cadmium. 2. Burden in agricultural products in the effective range of a lead emitter as compared to a control area].

Using the inverse voltammetric method already described (cf. Part I), the authors determined the lead and cadmium contents in 126 forage samples and 86 cereal samples from the surroundings of a lead emitter (area A) and from the control area B. To assess the heavy metal burden in forage plants at different growth stages, 33 samples of plants taken from both areas at the first stage of growth, not yet used for feeding, were analyzed. The lead burdens in the samples from area A varied with the distance from the emitter, a works which processes pure lead. 20 of the 87 forage samples from this area exhibited lead contents greater than 10 mg/kg of dry matter. 11 of the 55 cereal samples (grains) there taken contained more than 0.5 mg of lead/kg of fresh matter. As expected, there was no correlation between the cadmium values and the lead contents. These results are compared with those obtained from samples from the control area (39 forage samples and 31 cereal samples). Conclusions are drawn as to the agricultural use of land in the area of the emitter.

Agriculture↗
PubMed1981

Inhibition of renal accumulation of lysozyme (basic low molecular weight protein) by basic proteins and other basic substances.

Together the two rat kidneys accumulated a total of 31.7 +/- 1.6% of the intravenously injected amount of 7 nmoles egg-white-lysozyme (measured as iodine 125 lysozyme) within 10 min. The low molecular weight protein lysozyme and other basic substances were injected simultaneously in order to evaluate whether these basic substances can inhibit the renal lysozyme accumulation. The inhibitory effect of various basic compounds was dose-dependent with a maximal reduction of lysozyme accumulation to 11.7 +/- 0.08%. The basic substances could be divided into three groups depending upon the micromolar amount injected at which a 50% inhibition was achieved (0.3-1.2 micromoles: cytochrome C, ribonuclease; 10.9 micromoles; spermine; 501-688 micromoles: L-arginine, L-lysine). The neutral myoglobin had no effect on renal lysozyme accumulation. The inhibitory potency appeared to increase with increasing molecular weight and pI value of the substance tested. Microperfusion experiments of proximal convoluted tubules of rat kidney revealed that luminal reabsorption of the basic lysozyme can be inhibited by the basic protein cytochrome C in a dose-dependent fashion. In these experiments the perfusion solution contained 57 micromol .l-1 lysozyme, an intratubular lysozyme concentration at which the tubular lysozyme reabsorption was found to be about 80% saturated. A 50% inhibition of the tubular endocytic lysozyme reabsorption was achieved a cytochrome C concentration of 102 micromol.l-1.

Animals↗
PubMed1979

[Contamination of foods and feeding stuffs from selected areas of the Erfurt district with lead and cadmium. I. Determination of lead and cadmium in vegetable material by inverse voltammetry].

An inverse voltammetric method is used for determining the trace elements lead and cadmium in vegetable foods and feeding stuffs. The organic meterials are mineralized by nitric acid vapour and, in the second stage, with the addition of perchloric acid. The procedure is very sensitive and suited for routine work. The detection limits are: 0.66 ng/ml for lead, and 0.30 ng/ml for cadmium. The error of the method is: VPb = 20.5% and VCd = 28.6%. The respective recoveries of amounts of lead and cadmium added to the samples prior to digestion were: 102.0 +/- 10.8% and 101.6 +/- 11.4%.

Animal Feed↗
PubMed1975

[Larynx lesions and sudden death (author's transl)].

Several recently observed cases of "Sudden Death" caused by larynx lesions give reason for a special discussion of this problem. At the Institute of Legal Medicine only six cases were found in 10.747 autopsies between 1949 and 1970. A brief description of the anatomical structure of the larynx is followed by a discussion of the 4 general pathological entities, which might be the etiological cause of laryngeal obstruction: 1. Abnormalities 2. Disturbances of circulation 3. Inflammations 4. Tumors Besides the question of the forensic-medical importance of such fatal cases, the difficulty of evaluating some of the patho-morphologic and histologic findings is discussed. Simultaneously attention is drawn to the frequent lack of a clinical history, so that life-supporting measures wuch as tracheotomy and others are applied very late or not at all. Finally the problem of forensic evaluation of larynx-cysts and their etiology is presented. In this context the clarification of a causal relationship with possible previous intubations of the larynx is of major importance.

Adult↗