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Biomedical subjects

R Müller

Publications and source records attributed to R Müller.

At least 703 records · Page 39Linked to original sources
PubMed1983

[Enzyme activities in the blood serum from rats with chronic liver damage. part 3: Effect of thioacetamide].

Liver damage was produced in male Wistar rats aged 15 weeks by daily oral administration of 40 mg/kg thioacetamide over a period of 24 weeks. All of the animals were weighed once a week. Furthermore, the duration of hexobarbital anaesthesia and the activities of the enzymes ASAT, ALAT, GIDH, LDH, LAP and alkaline phosphatase in the serum were determined in 6 experimental and 4 control animals after 3 d and 1, 2 and 4 weeks, and then at intervals of 4 weeks. For the purpose of comparison the same investigations were performed (under identical experimental conditions) both in rats fed normally and rats starved for 24 h to which a single dose of thioacetamide was applied. The histological study of the livers revealed destruction of the lobule architecture and profuse bile-duct proliferations after 12 weeks. Cirrhosis was observed after 16 weeks. The activities of ASAT, ALAT, GIDH and LDH increased for a short time and then returned closely to normal. During the whole experimental period, the LAP and alkaline phosphatase activities remained in the pathological range, as well as the duration of hexobarbital anaesthesia. Enzyme diagnosis is not suitable for assessing the degree of severity of a liver damage produced by thioacetamide.

Acetamides↗
PubMed1982

[Clinical relevance of immunoglobulin M antibody fraction against hepatitis B core antigen (anti-HBc-IgM) (author's transl)].

Forty-four anti-HBc positive patients with various liver diseases were followed up over 2-3 years with enzyme-immunological determinations of the IgM fraction of anti HBc (anti-HBc-IgM). Patients with acute virus hepatitis B (n = 10) had anti-HBc-IgM titres greater than or equal to 10(-3) in the acute phase. In the reconvalescent phase the titre decreased significantly but was still detectable at a level of 10(-1) two years after the onset of the disease. In patients with HBs-antigen positive chronic active hepatitis (n = 25) the anti-HBc-IgM was always detectable when HBe-antigen was positive. Patients with HBe-antigen negative chronic active hepatitis B showed various anti-HBc-IgM findings. Patients with liver diseases not due to hepatitis B virus infections (n = 9) were always anti-HBc-IgM negative. Thus with the help of anti-HBc-IgM determinations acute hepatitis B virus infection can be diagnosed in HBs-antigen negative people. On the other hand it is not suitable for differentiation between acute and chronic hepatitis B infections in HBs-antigen positive persons.

Adult↗
PubMed1982

[Brachycurie therapy of tumors--renaissance of a radio-oncologic method].

In the past years there is a worldwide renaissance in interstitial low dose-rate implantation of tumors in many sites of origin. This renaissance is due to the development of new artificial radioisotopes (Au-198, Ir-192 and particularly I-125), the refinement of application techniques with after-loading devices and the introduction of computerized dosimetry. It is the opinion of a number of widely experienced radiotherapists that interstitial implants represent the treatment of choice "par excellence" and one of the ways to overcome the treatment resistance of inoperable malignant tumors. For this reason we have introduced the method of permanent and removable implantation of inoperable brain tumors, head and neck cancers and prostate carcinomas with 125I-seeds at the University of Erlangen-Nürnberg. Our first clinical impressions are very encouraging. The techniques of implantation used, the properties and advantages of 125I-seeds, dosimetric considerations and problems related to radiation protection are described.

Brachytherapy↗
PubMed1982

Modification of liver microsomal lipids by halothane metabolites; a multi nuclear NMR spectroscopic study.

N-trifluoroacetyl phosphatidyl ethanolamine was found as an intermediate of biotransformation of halothane after intense in vivo exposure of non-induced and phenobarbital induced rabbits. The metabolite has been identified in detergent treated liver microsomes by 31P-NMR-spectroscopy and in microsomal lipid extracts by 19F-NMR- and 1H-NMR-spectroscopy as well as by thin layer chromatography. The same exposure changed phospholipid composition of liver microsomal membranes: most prominent was a substantial decrease of the ratio of phosphatidyl ethanolamines to phosphatidylcholines.

Animals↗
PubMed1982

[Epidemiology of drug use in Switzerland].

A description of the consumption patterns of medicaments is given on the base of a survey taken of 1081 randomly selected persons between the ages of 15 and 74, originating from all three parts of Switzerland. On the whole, the data show a high inclination among the population to manipulate one's own condition by the intake of medicaments. Particularly among the younger age groups, the inclination to self-medication is high.

Adolescent↗
PubMed1982

A novel non-heme iron-containing dioxygenase. Chloridazon-catechol dioxygenase from Phenylobacterium immobilis DSM 1986.

Previously we purified an enzyme from Phenylobacterium immobilis DSM 1986, which cleaves the catechol derivative of the herbicide Chloridazon [5-amino-4-chloro-2-phenyl-3 (2H)-pyridazinone] in the meta position. The enzyme, which could be crystallized, proved in Ouchterlony double-diffusion tests to consist of a single protein species. No cross-reaction was observed with other meta-cleaving enzymes. Its light absorption spectrum showed a maximum at 279 nm (epsilon = 310 mM -1 cm -1), shoulders at 289 nm and 275 nm and a very weak band at around 430 nm (epsilon = 1.14 mM -1 cm -1). The amino acid analysis showed a slight excess of acidic amino acids, in agreement with the pl of 4.5. Surprisingly the enzyme per se is completely inactive, although it contains one non-dialysable iron atom per submit. It has to be activated by preincubation with ferrous ions or ascorbate. The enzyme activated this way is autoxidizable and returns to its non-activated state in the presence of oxygen. During the reaction with the substrate, this inactivation seems to be enhanced about 100 times. Since this kind of activation and inactivation is not observed in other meta-cleaving enzymes, this enzyme seems to represent a new type of a non-heme iron dioxygenase. We tentatively propose the name Chloridazon-catechol dioxygenase for this enzyme.

Amino Acids↗
PubMed1982

Specificity and localization of the hepatitis B virus-associated protein kinase.

The nature of the protein kinase (PK) which phosphorylates the core protein of hepatitis B virus in vitro was studied. The PK copurified with the core particles during rate zonal centrifugation and gel chromatography. It showed the same size heterogeneity as the core particles, which consisted of a main fraction of 28-nm particles and a subfraction of 22- to 26-nm particles. DNA-containing heavy core particles with a density of 1.33 to 1.35 g/ml and less endogenous PK than did the light cores. The phosphorylation reaction had a rapid initial phase (several minutes) and a slow but long-lasting second phase (many hours). The PK had a high affinity for ATP (KM = 0.5 mumol/liter). Only few of the several hundred P21.9 subunits in one core particle were phosphorylated in vitro. The only amino acid which was phosphorylated in vitro was serine. The resistance of the introduced phospho group against alkaline phosphatase showed that the PK acceptor, and probably the enzyme itself, was located inside the core particle.

Adenosine Triphosphate↗
PubMed1982

Immunological detection and quantification of carcinogen-modified DNA components.

Both the detection and quantitation of defined reaction products of chemical carcinogens with DNA, especially at low levels of DNA modification and in small numbers of target cells, require highly sensitive analytical techniques. The sensitivity of radiochromatographic methods is limited by the specific radioactivity of the respective carcinogens and by the relatively large amounts of DNA required for analysis. Furthermore, their application is restricted to experiments with radiolabelled carcinogens synthesized in the laboratory. These shortcomings can be circumvented by the use of high-affinity antibodies specifically directed against DNA components structurally modified by carcinogens, in combination with sensitive immunoassay procedures. Such immunological methodology, using both conventional antisera and monoclonal antibodies, has recently become available and is rapidly being developed further. We review here the properties of the antibodies thus far produced, the techniques applied for their development and characterization, and the immunoassay procedures currently in use. Some examples of the application of the new immunoanalytical methods are given.

Antibody Specificity↗
PubMed1982

[Blood-pressure response to ergometric work in normotensive subjects, aged 20-50 years].

Blood-pressure response to ergometric work in normotensive subjects, aged 20-50 years. 1. A standardized ergometric procedure is suitable for diagnosis, especially in borderline hypertension and for the prognostic judgment of stable hypertension. However, knowledge about the age and sex-dependent values of normal exercise blood pressure is scanty. 2. Therefore, the normal blood-pressure and heart-rate response during and until 5 mins after ergometric work (50 to 100 watts) was investigated in 323 normotensive subjects (173 males, 150 females), aged 20 to 50 years. 3. At an equal work load, the systolic blood pressures were not significantly different between men and women, or within the age decades. However, diastolic blood pressure response was significantly (p less than 0.05-p less than 0.001) influenced by age. 4. The upper limit for normal blood pressure in men and women between the ages of 20 and 50 years is 200/100 mm Hg (means + 1 SD) at a work load of 100 watts, and corresponding heart rates of 126 +/- 13 and 145 +/- 10 beats/min, respectively. A normal blood-pressure response in the recovery phase is at most 140/90 mm Hg (means + 1 SD) in the fifth minute. 5. The results are of clinical importance for the assessment of blood pressure during and after ergometric work.

Adult↗