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Biomedical subjects

G Richter

Publications and source records attributed to G Richter.

At least 253 records · Page 14Linked to original sources
PubMed1981

On the mechanism of inhibitory effect of violamycin antibiotics on the transcription by bacteriophage T3-induced RNA polymerase.

The effect of three components of the anthracycline antibiotic violamycin on the transcription of bacteriophage T3 DNA by bacteriophage T3-induced RNA polymerase has been investigated in a cell-free system. The glycosides of violamycin BI possess the highest inhibitory activity, whereas those of violamycin BII and violamycin A show a reduced inhibitory effect. Concentrations of violamycin BI depressing the incorporation of (3H)UMP into RNA chains have only a slight effect on the binding of the T3 RNA polymerase to T3 DNA and on the incorporation of GTP as the first nucleotide. This shows that the primary target of the antibiotic is not the initiation of the RNA synthesis. The binding of violamycin BI to T3 DNA causes a strong reduction of the elongation rate of the RNA chains.

Aminoglycosides↗
PubMed1981

[Capillary embolization. Part II. Occlusion of the entire arterial system of experimentally induced renal tumors ].

221 renal rat tumors (induced by Dimethylnitrosamine) are embolized by gelfoam powder, IBC/Lipiodol and Ethibloc/Glucose. The effect of those embolization media is compared to ligation and glucose perfusion. Recurrencies and rate of surviving tumor tissue are dependent on the stage of the neoplasm, sufficient capillary propagation of the medium, and exact volume-dependent embolization. It could be proven that large areas of renal rat tumors are equally supplied by the main artery and parasitary collaterals. Only homogeneous distribution and complete downstream propagation of the embolization medium from the main artery to the capillaries will achieve breakdown of this parasitary supply. Glucose governed Ethibloc embolization achieves in 80% of tumors with a 6 fold renal volume and in 50% of larger tumors complete necrosis. It has the lowest complication rate of all tested materials.

Animals↗
PubMed1981

[Effect of the polyether antibiotic "monensin" on the rumen fermentation and fattening results of crossbreeding bulls of dairy cattle and fattening hybrids].

The influence of the polyether antibiotic Monensin on the rumen fermentation and the fattening results of fattening hybrids (genotype 61) and crossbreeding bulls of dairy cattle (genotype 19) was ascertained in two feeding experiments (E1 and E2). Caused by the supplementation of the antibiotic, the molar acetate quota decreased (1.9 to 4.8 Mol %) and the molar propionate concentration increased (0.2 to 2.9 Mol %) in the rumen fluid of crossbreeding bulls of dairy cattle and of fattening hybrids, it is, however, below the range described in literature. With the exception of the fattening hybrids in E1, the supplementation of Monensin resulted in the diminished intake of dry matter, the daily increase of the live weight of all groups of fattening bulls was higher (E1: fattening hybrids: 1106 resp. 1199g; crossbreeding bulls of dairy cattle: 1037 resp. 1058 g; E2: 997 resp. 1024 g; 895 resp. 981 g without resp. with Monensin). After the Monensin supplementation the crossbreeding bulls of dairy cattle showed a distinctly bigger decrease of the feed intake and a rise of the live weight increase than the fattening hybrids. For this reason the genotypes of dairy cattle showed in both experiments after the Monensin supplementation a bigger decrease of expenditure (0.8 resp. 7.1% and 5.6 resp. 11.3% in experiments 1 and 2) than the fattening hybrids.

Animals↗
PubMed1981

[Peas (Pisum sativum L.) as a mixed feed component for laying hens].

Percentages of 0, 10, 20 and 30% peas (Pisum sativum) of the variety "Nadia" in the mixed feed with methionine supplementation were tested with 2,100 laying hybrids of the species White Leghorn in the age period between the 22nd and 73rd week of their lives which were kept in 3-storeyed cages. The feeding of peas had no influence on feed intake, laying performance, the weight of the individual egg, the stability of the egg shell, body weight, mortality, the hemoglobin content and the hematocrit value of the blood. With the increasing percentage of peas the consumption per animal and day and the expenditure of energy and methionine/cystine per 100 g egg decreased and that of lysine increased (p less than 0.05). On the basis of the investigations the conclusion is drawn that in laying hen feed supplemented with methionine a quota of up to 30% peas is possible without a decrease in performance.

Amino Acids↗
PubMed1981

Capillary embolization with Ethibloc: new embolization concept tested in dog kidneys.

Collateral vessels in tumors and arteriovenous malformations limit the effectiveness of therapeutic embolization. Capillary propagation of embolization media represents a possible solution of the problem. Embolization with Ethibloc (Hamburg-Norderstedt), a vegetable protein dissolved in alcohol, was performed in 15 renal arteries of dogs. Three embolized kidneys were completely resorbed, and four kidneys showed complete necrosis microscopically. Ethibloc in combination with 40% glucose guarantees homogenous embolization of the entire arterial bed including the capillaries. No complications were observed in other organs.

Animals↗
PubMed1980

[Capillary embolization. Part I: occlusion of the entire arterial system of the rat kidney (author's transl)].

Effect of tumor embolization is limited by parasitary blood supply. The influence of those collaterals should be decreased by transporting the embolization medium into the capillaries and tumor sinusoids. Controlled and safe capillary embolization is developed from studies of obtainable radiodensity, viscosity, and occlusion mechanism of Gelfoam-powder, IBC, and Ethibloc. The efficiency of these substances is compared to simple arterial ligation in experimental series with 400 Wistar rats. It is shown that ligation is comparable to insufficient capillary transport of the medium leaving islands of microscopically intact parenchyma. Easy application and total necrosis is guaranteed only by Ethibloc. Success of embolization is strictly volume dependent. Preinjected glucose is mandatory for homogenous distribution and peripheral transport.

Animals↗
PubMed1980

[Requirements of turkeys kept on the ground with respect to energy and crude protein content of mixed feeds].

In four experiments with 9,500 turkeys assorted according to sex, three energy levels (500, 550 and 600 EFh (energetic feed units for hens = 14,6 kJ net energy body fat of hens)/kg feed) were combined with three levels of crude protein (250, 300 and 350 g/kg feed) in the mixed feed (9 rations) and tested under conditions of keeping the turkeys on the ground from hatching to their 42nd day of life. The feed consumption of the turkeys did not correlate with the energy content of the mixed feed. The energy consumption of the groups whose mixed feed had a high energy content (550 and 600 EFh) was significantly higher than that of groups whose feed had a low energy content. With the increasing content of crude protein in the mixed feed the consumption of crude protein per turkey and test period rose significantly. Due to the increase of the content of energy and crude protein, the live weight gain increased after a 28- and 42-day test period; the growth-stimulating effect was more distinct with male animals. Mortality had no connections with nutrition. For the starting-off feed for turkeys an energy content of < 580 EFh with 300 g crude protein per kg mixed feed up to the 4th/5th week of life is recommended.

Animal Feed↗
PubMed1980

Allergic contact dermatitis from methylisothiocyanate in soil disinfectants.

Observations on nine patients with occupational dermatitis from methylisothiocyanate (MITC) lead to the following conclusions: 1. MITC causes primarily a toxic dermatitis, but as a strong sensitizer it induces sensitization as well. 2. Cross reactions between MITC and benzylisothiocyanate, the active agent of Sulbentin antimycotics, were not seen. 3. In patient a MITC acid burn on one foot and leg caused systemic poisoning from absorption with reversible damage to the liver parenchyma.

Adult↗
PubMed1980

[Occupational dermatoses in the pharmaceutical industry].

The analysis of the total of 76 occupational dermatoses registered after 1962 in the pharmaceutical industry of the district of Dresden results in the following statements: The morbidity must be regarded as three times higher than in other branches of the chemical industry. Compared with the average dates of all occupational dermatoses, those in the pharmaceutical industry need a shorter induction time for starting. On the other hand, they are to be cured faster and with less recurrences. The lists of causal agents are heterogeneous and differ largely from those of drug induced eczemas of our clinical patients or of employees in public health services. Examples are given for a predictive recognizing of strong contact sensitizers by means of their chemical structure.

Acetonitriles↗
PubMed1979

Detergent properties of water-soluble choline phosphatides. Selective solubilization of acyl-CoA:lysolecithin acyltransferase from thymocyte plasma membranes.

Several analogs of lysolecithin were found to solubilize human erythrocyte ghosts comparably or even better than other detergents. Derivatives with aliphatic chains of 12 to 14 carbons were most effective. The phosphorylcholine detergents apparently possess low protein-denaturing properties, since they, for the first time, allowed the solubilization of enzymatically active acyl-CoA:lysolecithin acyltransferase from thymocyte plasma membranes. The solubilized enzyme was not sedimented at 177,000 x g for 60 min and penetrated into Sepharose 6B gels. Low detergent concentration resulted in a selective extraction of the acyltransferase (about 70%) as compared to alkaline phosphatase, nucleotide pyrophosphatase, gamma-glutamyltransferase or Mg2+-ATPase (30 to 40%). The selectivity was reflected in sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns of soluble and sedimentable membrane fractions; three bands of approximately 53, 84, and 94 x 10(3) daltons were enriched in the supernatants, whereas one band of about 68 x 10(3) daltons was concentrated in the pellet. The preferential extraction of acyltransferase may be related to particularly high affinity of lysolecithin analogs for this enzyme, which at higher concentrations was competitively inhibited by these detergents. The inhibitor constants ranged from 1400 micron for the C10 analog (ET-10-H) to 80 micron for the compound with 16 carbons (ET-16-H) per aliphatic chain.

Animals↗
PubMed1979

[Investigations concerning the use of the rumen fermentation regulator monensin in feeding fattening bulls].

In two digestion experiments with wethers and seven feeding experiments with 198 fattening bulls with rations rich in (greater than 55% of the dry matter intake from roughage), the influence of the antibiotic monensin on the digestibility of the ration, on rumen-physiologic characteristic values and on fattening and slaughtering results was investigated. The digestibility of the organic matter and the crude nutrients was not significantly influenced by the use of monensin (20 mg/kg dry matter). The administration of 200 mg monensin per fattening bull and day resulted in an increase of the molar concentration of propionate in the rumen fluid by 9.7 mol%, the concentration of acetate and butyrate decreased by 7.3 resp. 2.8 mol %. On an average of the seven experiments the intake of dry matter was diminished by 5.1% through the use of monensin, the live weight increase remained almost unaffected (3.0% additional increase), feed and energy requirement per kg live weight were improved by 7.9%. The fattening results do not always correspond in the various experiments. The results of the dressing of the carcass, the composition of the carcass and the quality of the meat remained unaffected by the administration of monensin.

Animal Nutritional Physiological Phenomena↗
PubMed1979

The expression of a plant genome in hnRNA and mRNA.

Representation of genomic kinetic sequence classes and sequence complexities were investigated in nuclear and polysomal RNA of the higher plant Petroselinum sativum (parsley). Two different methods indicated that most if not all polysomal poly(A) -RNA is transcribed from unique sequences. As measured by saturation hybridization in root callus and young leaves 8.7% and 6.2%, respectively, of unique DNA were transcribed in mRNA corresponding to 13.700 and 10.000 average sized genes. Unique nuclear DNA hybridized with an excess of polysomal poly(A)mRNA to the same extent as with total polysomal RNA. 3H-cDNA - poly(A)mRNA hybridization kinetics revealed the presence of two abundance classes with 9.200 and about 30 different mRNAs in leaves and two abundance classes with 10.500 and 960 different mRNAs in callus cells. The existence of plant poly(A)hnRNA was proven both by its fast kinetics of appearance, its length distribution larger than mRNA, and its sequence complexity a few times that of polysomal RNA.

Base Sequence↗
PubMed1979

[Hormonal desexing of boars with chlormadinone acetate].

Chloromadinone acetate produces a dependable desexualising effect on boar by contant administration in feed rations of 30 mg per die over 70 days. Sexual odour thus can be widely eliminated. Other aspects studied in a group of 107 boars are body weight development, sexual behaviour, slaughter yield, and skin quality.

Animals↗
PubMed1979

[Effect of temperature on RNA synthesis in Escherichia coli CRT 266 (dna Bts) following infection with bacteriophage T3].

Infection of the temperature-sensitive E. coli CRT 266 (dnaBts) with T3-phages at the temperature of 30 degrees C and 35 degrees C, respectively, induced T3-specific RNA synthesis with a maximum rate at 7 min (30 degrees C) and 4.5 min (35 degrees C) after infection. At temperatures above 40 degrees C no T3-induced RNA synthesis could be observed. Infection of E. coli CR 34--45 (dnaB+) with T3 phages at 30 degrees C, 35 degrees C and at temperatures above 40 degrees C, however, produced T3-specific RNA synthesis. The maximum of T3-induced RNA synthesis could be observed between 7 min and 3 min depending on the temperature during infection. The inability to form T3-specific RNA after infection of E. coli CRT 266 at nonpermissive temperatures may be a cause for the absence of the formation of T3 phages and lysis of the host cells.

Chloramphenicol↗