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Biomedical subjects

G Schmidt

Publications and source records attributed to G Schmidt.

At least 523 records · Page 29Linked to original sources
PubMed1980

Characterization of the phenol soluble and insoluble nonhistone proteins of in vivo (32)P-labelled rat liver nuclei by high-resolution gel electrophoresis.

The (32)P-labelling patterns of phenol soluble and insoluble nonhistone proteins of in vivo labelled rat liver nuclei freed of the soluble nuclear proteins have been determined after separation by high-resolution gel electrophoresis. The bulk of the proteins of the nuclear residues was phenol soluble. Seven percent of the proteins of the nuclear residues was obtained with the aqueous phase. As shown in this paper both fractions contain (32)P-labelled proteins but they represent different types of nonhistone proteins.

Animals↗
PubMed1980

Isolation and characterization of salt-soluble, unsheared chromatin.

From rat liver nuclei depending on the extraction time, 10 to 20% of total chromatin has been extracted with a solution containing 0.1 M ammonium sulfate, 2 mM MnCl2, 0.1 M Tris-HCl, pH 7.9. We term this chromatin chromatin S. It has a protein: DNA ratio of 1.3, the full amount of the 5 histones in an undegraded state, and a RNA: DNA ratio of approximately 0.2. Its nonhistone protein pattern, obtained by gel electrophoresis exhibits a rich spectrum of proteins in a broad range of molecular weights. Electrophoretic analysis of the DNA fragments obtained by micrococcus nuclease digestion of chromatin S yields the same digestion pattern as that of nuclei. Thus, chromatin S fulfils an essential criterion of unsheared chromatin. In contrast to other chromatin preparations described so far, this chromatin is soluble at a salt concentration of 0.1 M ammonium sulfate. We have shown previously that it exhibits a compact conformation, low intrinsic viscosity and low radius of gyration obtained by light scattering measurements. Its mean molecular weight was determined to be nearly 10(8).

Animals↗
PubMed1980

[Intensified adsorption of viruses to cell cultures: improved virus isolation? (author's transl)].

Two procedures to improve virus cultivation from clinical material were evaluated: an intensified adsorption with 0.2 ml inoculum and 20 h rocking in a Bellco rocker and a low-speed centrifugation of the material onto the cultured cells. Prototype strains from 5 virus families (adenoviruses, herpes simplex virus, vaccinia virus, enteroviruses, parainfluenza 2) as well as original specimens from patients (adenovirus, herpesvirus, enterovirus) were studied by endpoint titration in comparison with the standard procedure. In adenoviruses, a quantitative immunofluorescence was performed too. In endpoint titrations, the centrifugation method did almost never lead to an increased virus titer, as compared with the standard method. However, in the immunofluoresence evaluation of adenoviruses the values attained were 3- to 4-fold higher. On the other hand, the intensified adsorption method led to an increased sensitivity in most adenovirus titrations with 4- to 25-fold titer increment, with prototype and original material. The procedure was ineffective in all other viruses studied.

Adsorption↗
PubMed1980

Cervical stenosis following minor gynecologic procedures on DES-exposed women.

The findings associated with diethytlstilbestrol (DES) exposure in utero are expanding rapidly. Structural abnormalities in both the cervix and uterus are well documented; in addition the authors have noted indications of an abnormal healing response in these women. Locally destructive methods such as cryosurgery, cauterization, and excision have resulted in permanent and significant physical damage. Caution is advised in attempting even minor gynecologic procedures on DES-exposed offspring.

Abnormalities, Drug-Induced↗
PubMed1979

[Thoracic actinomycosis with superior vena cava obstruction (author's transl)].

In a 40-year-old farmer's wife presenting with fatigue, shortness of breath on exertion and occasional extrasystoles a space-occupying lesion of the mediastinum leading to obstruction of venous return in the superior vena cava was found. Prior to intended surgery the patient suddenly died following cerebral haemorrhage. Actinomycosis of the mediastinum leading to almost complete stenosis of the superior vena cava was found at necropsy.

Actinomycosis↗
PubMed1979

Effects of dichlorvos (DDVP) inhalation on the activity of acetylcholinesterase in the bronchial tissue of rats.

The experiments presented here deal with the effects of the inhalation of dichlorvos [dimethyl-(2,2 dichlorvinyl)-phosphate, DDVP] vapor on acetylcholinesterase (ACHE) activity in rat bronchial tissue. Exposure to DDVP concentrations of 0.8 and 1.8 micrograms/l for 3 days reduced ACHE activity in the bronchial tissue (62.8 +/- 0.8 and 51.6 +/- 1.6% of the control), but did not elicit any changes in blood ACHE activity (101 +/- 4.5% of the control each). Higher concentrations (4.3 micrograms/l) induced a decline in ACHE activity also in the blood (38.2 +/- 1.1% of the control). In the histochemical preparations used to demonstrate ACHE activity in bronchial tissue (thiolacetic acid method), a staining of the bronchial glands and smooth muscles characteristic of the enzyme activity was strongly reduced after exposure of the animals to even the lowest dose applied (0.2 microgram/l). The question of whether localized inhibition of ACHE in the bronchial tissue might cause increases in airway resistance due to activation of a broncho-bronchial reflex is discussed. This efferent cholinergic mechanism has been found to be at least partly responsible for maintenance of bronchospasm and hypersecretion in chronic obstructive diseases of the respiratory system.

Acetylcholinesterase↗
PubMed1979

Investigation of cardiac glycoside levels in human post mortem blood and tissues determined by a special radioimmunoassay procedure.

Even after the introduction of radioimmunological methods the question of a cardiac glycoside causing or contributing to the death of a patient can not be answered satisfactorily. By means of a special radioimmunoassay procedure for digoxin as well as for the structurally related methyl- and acetylderivatives we measured the concentrations in human blood and post mortem tissues. We investigated the glycoside contents in the blood of intravenously digitalised (Novodigal) al) patients before and after death. At autopsy blood specimens were taken from the heart and the femoral vein. We found an increase of the glycoside level up to a highly toxic range (7--15 ng/ml) especially in the heart blood. Thus post mortem blood levels of digoxin and its derivatives are not suitable for a final decision in alleged cases of fatal poisonings. Measuring various concentrations in tussues and body fluids of the above cardiac glycosides mentioned revealed the kidney concentration to be of high value in confirming a digitalis poisoning. This organ and the heart show the highest tissue concentrations. Interpretations of fatal digitalis poisonings should be based on the additional knowlege of these concentrations. Individual cardiac glycosides may be analyzed by a combination of thin layer chromatography and radioimmunoassay.

Cardiac Glycosides↗
PubMed1979

[Frequency of positive diazepam-screening in post-mortem examinations (author's transl)].

The post-mortem blood specimens of 389 forensic autopsies were analyzed for diazepam. The age of the cases investigated was above 10 years and the survival time was less than 12 hours. Eighteen samples corresponding to 4.6% were found to be diazepam-positive. These 18 samples were distributed equally between men and women. The proportion of diazepam-positive samples was increased in the groups of suicide and poisoning (alcohol and opiates). The association between diazepam intake and poisoning was statistically highly significant. No correlation was found between diazepam intake and age. Alcohol was found to occur significantly more often in the group of the diazepam positive cases as compared to the diazepam negative group.

Adolescent↗
PubMed1979

[Impairment of performance by alcohol and diazepam (author's transl)].

An investigation was carried out on the effect of the intake of diazepam and alcohol on simple performance tests. The combined administration of diazepam and alcohol led to an increase of the plasma diazepam concentration as compared to that obtained after diazepam without alcohol. Furthermore, after combined intake of diazepam and alcohol a decrease of performance was observed, that was significantly higher, than the effects obtained after either alcohol or diazepam alone. This impairment was especially noticeable duirng the first hour of the experiment, i.e. until the plateau of the diazepam plasma concentration was reached, while afterwards a correlation between diazepam plasma concentration and impairment of performance could not be established. The relevance of these findings for the interpretation of diazepam plasma concentrations in relation to the impairment of performance are discussed.

Achievement↗
PubMed1979

[A screening radioimmunoassay for 1,4-benzodiazepines in human blood, serum, and urine using anti-oxazepam-hemisuccinate-antibodies (author's transl)].

A simple and specific radioimmunoassay (RIA) was developed for the determination of oxazepam and other 1,4-benzodiazepines in human blood serum and urine (e.g., diazepam, desmethyldiazepam, chlorazepate). For serum a 1:10 dilution, for urine a 1:100 dilution is recommended. Blood and hemolyzed samples need prior extraction by Amberlite XAD-2. The antisera were raised by immunizing "White New Zealand"-rabbits with an oxazepam-3-hemisuccinate bovine serum albumin conjugate. Using 0.1 ml serum dilution the sensitivity is 0.01 mg/l per tube. Especially higher concentrations show a tendency toward underestimation. Being not limited to a single 1,4-benzodiazepine derivative, the specificity of the antisera is also suitable for a screening analysis. Compared to thin-layer chromatographic analysis of urine this assay shows improved sensitivity (0.05--0.1 mg/l in 0.1 ml of a 1:100 dilution = 1 microliter of urine). For forensic investigations, an analysis in the sequence of urine-RIA, blood/serum-RIA, blood/serum-"electron-capture"-gas-liquid chromatography (ECD-GLC) seems to be a helpful approach. Blood levels of diazepam and desmethyldiazepam determined by RIA and GLC after extraction are in satisfactory agreement.

Benzodiazepines↗