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Biomedical subjects

G Schmidt

Publications and source records attributed to G Schmidt.

At least 559 records · Page 31Linked to original sources
PubMed1978

[In vitro incubation of lenses. Model for testing substrate utilization of substances of the energy metabolism, demonstrated with bencyclane-hydrogen-fumarate (author's transl)].

When bovine lens homogenate was treated with bencyclane-hydrogen-fumarate, the carbohydrate metabolism was activated. This may chiefly be due to the fumarate part of the substance. A 24 H In vitro incubation of whole bovine lenses in TC-199 with and without bencyclane-hydrogen-fumarate did not show the above effect. On the model of former investigations by J.E. Harris et al. we modified the test procedure by selecting the medium and the time of incubation so that the endogenous carbohydrates of the lens were consumed, thus creating new metabolic balances. This metabolic condition allows investigations intended to activate metabolic processes and to restore the steady state of metabolic parameters. We investigated the effect of bencyclane-hydrogen-fumarate using the same method and found that given certain conditions the lens recovers when incubated for 2 h in TC-199 (containing 1 g glucose/1) with addition of a 10(-4) M solution of bencyclane-hydrogen-fumarate. The ATP-content of these lenses in particular gives proof of this result. As already observed in former investigations on homogenates, this effect is probably due to metabolization of the fumarate part of the bencyclane-hydrogen-fumarate by the citric acid cycle. The method used explains the differences observed when using lens homogenates or whole lenses under the same experimental conditions.

Adenine Nucleotides↗
PubMed1978

Structural studies on the immunogenic form of the enterobacterial common antigen.

It has been shown that enterobacterial common antigen is chemically linked to the hexose region of the R1-type lipopolysaccharide fo the Escherichia coli strain F470 which is immunogenic for this antigen. The number of R core stubs substituted is very small but it is a-parently sufficient to induce antibody formation to the enterobacterial common antigen in the rabbit.

Acetylglucosamine↗
PubMed1978

[Occurrence of diazepam in blood samples of drivers under the influence of alcohol (author's transl)].

Diazepam was determined by radioimmunoassay and gas chromatography in 2050 unselected blood or serum specimens of subjects, who were sus,ected of driving under the influence of alcohol in the years 1974 and 1976. A "cut-off" limit of 20 ng/ml was selected. Diazepam was found in 46 samples corresponding to 2.24%, 27 samples (1.3%) exhibited concentrations of 20--100 ng/ml, 14 samples (0.7%) of 100--500 ng/ml, 1 sample (0.05%) of 500--1000 ng/ml and 4 samples (0.2%, as related to the total of 2050 samples) of more than 1000 ng/ml. Furthermore, 44 blood specimens of subjects were analyzed, who had claimed diazepam intake before the blood sample was withdrawn. Diazepam was found in 27 cases corresponding to 61%. Finally, blood specimens of 219 unselected inpatients of a surgical ward were investigated; 59 of these (27%) were found to be diazepam-positive.

Alcoholic Intoxication↗
PubMed1978

Isolation of drugs from blood by column chromatography on Amberlite XAD-2.

An investigation was carried out on the isolation of 28 drugs from blood by column chromatography on Amberlite XAD-2. The following substances were added to postmortem blood specimens at concentrations generally of 1--10 microgram/ml: barbital, heptabarbital, hexobarbital, pentobarbital, phenobarbital, phenylbutazone, monocrotophos, amidopyrine, carbromal, diazepam, meprobamate, methaqualone, nitrazepam, phenazetin, chlorpromazine, dibenzepin, diphenhydramine, haloperidol, imipramine, mescaline, methadone, morphine, pentazocine, pethidine, tilidine, triflupromazine, verapamil, N-propylajmalinium bitartrate. The samples were purified by column chromatography on Amberlite XAD-2 and simple solvent extraction and subsequently quantitated by gas chromatography. By systematic variation of the conditions for adsorption of the drugs and desorption from the resin, revoveries of more than 80% after XAD-2 column chromatography could be achieved for most drugs. Thereby it was demonstrated, that in cases of fatal poisoning or emergencies this procedure is a valuable tool for forensic and clinical toxicologists who have to find out the toxic agent by chemical analysis of the blood.

Chromatography, Gas↗
PubMed1978

Intestinal colonization and virulence of Salmonella in mice.

Within 3 h after oral challenge of mice with Salmonella typhimurium, foci of infection developed in the Peyer's patches of the small intestine. The numbers of organisms in the cecum, although in excess of those found in the small intestine, were not firmly associated with the cecal wall but were present largely in the cecum's contents. The Peyer's patches at first were remarkably incapable of eliminating even small numbers of Salmonella, but at about 7 days after infection developed the ability to eliminate a less virulent strain of S. typhimurium. Selected strains of Salmonella of varied virulence, and hybrid Escherichia coli/Salmonella typhimurium with varied O-antigens, revealed that those of low virulence could multiply within the intestinal Peyer's patches at nearly the same rate as a virulent strain, and the ability to multiply within the Peyer's patches was not dependent upon O-antigen type or smooth lipopolysaccharide. The ability of these strains to adhere to intestinal mucosa in vitro did not reflect on their ability to colonize the Peyer's patches, although strains of high in vitro adhesive ability appeared in greater numbers initially after oral challenge. Anti-O serum, ineffective in reducing the in vitro adhesive ability of virulent S. typhimurium, when given with the oral challenge prevented Peyer's patch colonization but was unable to prevent the appearance of a systemic infection. Anti-H serum, although effective in vitro in preventing adherence, had no effect in vivo. These experiments suggest that adhesiveness is neither essential nor sufficient for the virulence of Salmonella and that the usual development of a systemic infection after colonization of the small intestinal Peyer's patches may be subverted by the presence of O-antibody.

Antibodies, Bacterial↗
PubMed1978

Influence of plaque control on the healing of experimentally-induced bone defects in the dog.

The aim of this investigation was to induce alveolar bone defects experimentally in dogs and to study the effects of mechanical tooth cleaning on their subsequent development. Thirty premolars from four beagle dogs were used. Bone defects were created by surgically exposing the adjacent alveolar bone and applying steel or silk ligatures around the roots of the chosen teeth. After 8 weeks the ligatures were removed. Dental plaque was allowed to accumulate on 20 premolars whereas daily plaque elimination by toothbrushing was carefully performed on 10 premolars. After 1, 3, and 6 months of plaque accumulation, gingival inflammation, periodontal pocket depth, gingival recession and the radiographically observed degree of bone destruction were registered. Histological examination was performed in conjunction with the registrations made 6 months after removal of the ligatures. The clinical, radiographic and histologic findings all confirm that a regeneration of the experimentally induced destruction of the periodontal tissues had taken place. This reaction was most evident in teeth exposed to mechanical plaque control. The remaining bone defects were consistently accompanied by recession of the gingival margin.

Alveolar Process↗
PubMed1978

[Liver diseases with microsomal antibodies. Frequency, clinical and immunological findings and course observations (author's transl)].

Microsomal antibodies (LKM-antibodies) differ in the indirect immunfluorescence by use of rat organ sections (kidney, stomach, and liver) from mitochondrial antibodies by there reaction with proximal renal tubules and hepatocytes while parietal cells usually fail to stain. In contrast to other humoral autoantibodies LKM-antibodies are rare. In a prospective study on 930 adults and 33 children with two third chronic hepatitis resp. cirrhosis frequency in the first group amounts to 0.38% and in the latter to 6.9% of all liver diseases. Among six patients with LKW-antibodies and chronic active hepatitis there were three children aged 4-13 and three adults between 45-55 years. On common results two children showed beside LKM-antibodies by absence of other immunphenomenons a rise of gamma-globulins in the electrophoresis and immunglobulin G as well as a chronic active hepatitis with necrosis leading in spite of initial rapid progression and persistent antibodies into inactive postnecrotiv cirrhosis. The other four patients showed no common course in respect to clinical, histological and immunological findings.

Adolescent↗
PubMed1977

Radioimmunological screening and gas chromatographic identification of diazepam in blood and serum.

A radioimmunoassay for the determination of diazepam in human blood and serum is presented. Diazepam is separated from the bulk of the biological material by adsorption at Amberlite XAD-2 and subsequent desorption with ethyl acetate. The extract thus obtained can be used directly for the determination od diazepam by radioimmunoassay and gas chromatography with electron capture detection. For the combined radioimmunological and gas chromatographic determination 0.5 ml of blood or serum are necessary, the lower detection limit being approx. 5 ng/ml for both of these procedures. A good reliability of the radioimmunoassay is established with respect to precision, accuracy and specificity. The quantitative results obtained by radioimmunoassay and gas chromatography correspond well with each other. The radioimmunological procedure enables the screening of more than 200 samples for diazepam by one technician within two working days.

Antibody Specificity↗