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Biomedical subjects

E Ritter

Publications and source records attributed to E Ritter.

At least 55 records · Page 3Linked to original sources
PubMed1991

Kinetics of induction of cytosolic benzaldehyde: NADP and propionaldehyde: NAD aldehyde dehydrogenase activities in rat livers from male Wistar rats.

The time courses of induction of liver cytosolic aldehyde dehydrogenases using benzaldehyde and propionaldehyde as substrates and NADP and NAD as co-factors after i.p. and intragastric (i.g.) administration of 2-acetylaminofluorene (2-AAF), 20-methylcholanthrene (20-MC), beta-naphthoflavone (beta-NF) and benzo[alpha]pyrene (B[alpha]P) were investigated in male Wistar rats. 2-AAF did not induce the aldehyde dehydrogenase activities with any substrate:co-factor combination. The other three inducers all induced the oxidation of the aldehydes in a reversible manner. With an i.p. route of administration (one daily dose for four consecutive days) (20-MC) was the most potent inducer giving a 240-fold increase of benzaldehyde: NADP activity on the ninth day. beta-NF elevated the activity 20-fold with peak activity at day 7, while B[alpha]P gave maximal induction on day 5 with a 60-fold increase in activity over the corresponding value for normal liver. The i.g. administration resulted in a weaker but coordinated induction of activity with peak activity on the sixth day for the different inducers. The activity ratio benzaldehyde:NADP/propionaldehyde:NAD, 0.78 in normal rats, was altered in all induced states to a level close to 4. The interpretation of our work supports the hypothesis that the inducers in this respect use the same mechanisms of induction. The differences noted can be explained by variations in the exposure of the liver to the administered dose and/or by differences in receptor affinity. The inducibility of benzaldehyde:NADP aldehyde dehydrogenase in rat liver exceeds by orders of magnitude the ability of the same inducers to increase the amount of the activity of other drug metabolizing enzymes such as glutathione S-transferase, cytochrome P450 and cytochrome b5. The reversible, drug-dependent induction characterized in normal rat liver in this work differs entirely from the persistent constitutive elevation of the same enzymes in preneoplastic liver nodules.

2-Acetylaminofluorene↗
PubMed1991

Hepatic portal venous gas identified by computed tomography in a patient with blunt abdominal trauma: a case report.

An abdominal computed tomographic (CT) scan in a middle-aged man injured in a high-speed motor vehicle accident demonstrated the presence of portal venous gas. Findings on initial peritoneal lavage were entirely negative. Exploratory celiotomy performed because of increasing abdominal pain and leukocytosis revealed gangrene of the cecum. This report illustrates the importance of the finding of portal venous gas on CT scan in patients with blunt abdominal trauma.

Abdominal Injuries↗
PubMed1990

Localization by restriction fragment length polymorphism mapping in potato of a major dominant gene conferring resistance to the potato cyst nematode Globodera rostochiensis.

A major dominant locus conferring resistance against several pathotypes of the root cyst nematode Globodera rostochiensis was mapped on the linkage map of potato using restriction fragment length polymorphism (RFLP) markers. The assessment of resistance versus susceptibility of the plants in the experimental population considered was based on an in vivo (pot) and an in vitro (petri dish) test. By linkage to nine RFLP markers the resistance locus Gro1 was assigned to the potato linkage group IX which is homologous to the tomato linkage group 7. Deviations from the additivity of recombination frequencies between Gro1 and its neighbouring markers in the pot test led to the detection of a few phenotypic misclassifications of small plants with poor root systems that limited the observation of cysts on susceptible roots. Pooled data from both tests provided better estimates of recombination frequencies in the linkage interval defined by the markers flanking the resistance locus.

Animals↗
PubMed1990

[The extent of bacterial contamination of keratoplasty donor eyes post mortem].

In order to determine the initial bacterial contamination of corneal donor material the abraded epithelia from 125 donors, i.e., 250 globes, were examined immediately after enucleation. Of these, 49 (19.6%) were sterile, while 201 (80.4%) were contaminated. Monoinfection was identified in 174 globes and mixed infection in 27. The pathogen most frequently isolated was Pseudomonas aeruginosa. Neither the donor's age not the time elapsed between death and enucleation had any influence on the contamination rate. Prolonged hospitalization of donors leads to an increase in gram-negative bacteria. The necessity of antibacterial prophylaxis prior to keratoplasty is pointed out.

Adolescent↗
PubMed1990

Estimation of recombination frequencies and construction of RFLP linkage maps in plants from crosses between heterozygous parents.

The construction of a restriction fragment length polymorphism (RFLP) linkage map is based on the estimation of recombination frequencies between genetic loci and on the determination of the linear order of loci in linkage groups. RFLP loci can be identified as segregations of singular or allelic DNA-restriction fragments. From crosses between heterozygous individuals several allele (fragment) configurations are possible, and this leads to a set of formulas for the evaluation of p, the recombination frequency between two loci. Tables and figures are presented illustrating a general outline of gene mapping using heterozygous populations. The method encompasses as special cases the mapping of loci from segregating populations of pure lines. Formulas for deriving the recombination frequencies and information functions are given for different fragment configurations. Information functions derived for relevant configurations are also compared. A procedure for map construction is presented, as it has been applied to RFLP mapping in an allogamous crop.

Alleles↗
PubMed1990

[Microbial colonization of the upper respiratory tracts of day care children in relation to acute morbidity episodes].

The upper respiratory tracts of 20 children attending a crèche were studied for bacteria up to the 128th day of crèche attendance. To this end nose and throat swabs as well as double blood withdrawals were to determine antibodies against various respiratory viruses. The germ spectrum thus obtained was correlated with the acute pathological processes occurring during the period of investigation. In addition to the normal flora, the nasopharynx of infection-stable children was, with one exception, only populated with gram-positive pathopotent bacteria during the first four months of crèche attendance. In infection-labile children, however, gram-negative pathopotent bacteria, blastomycetes of the Candida group as well as Mycoplasma, virus and mixed infections were discovered apart from gram-positive bacteria. This broad germ spectrum should be taken into wider consideration in the chemotherapy of respiratory infections.

Bacteria↗
PubMed1988

Decreased thrombogenicity of vascular prostheses following gas denucleation by hydrostatic pressure.

The high rate of thrombosis of 1.0-mm polytetrafluoroethylene (PTFE) grafts has limited their use in microvascular surgery. One possible reason for this is the blood-gas interface due to entrapped air in the interstices. The present study examines the effect on patency rates of elimination of this blood-gas interface by high pressurization. Comparing pressurized and nonpressurized grafts in the same animals showed a patency rate of 100 percent at 7 days for treated grafts, while the control (nonpressurized) grafts had all clotted by 1 hour. The implications for microvascular surgery as well as vascular surgery in general are discussed.

Animals↗
PubMed1987

Effect of oxytetracycline and erythromycin on Syrian hamsters after intratracheal infection with Mycoplasma pneumoniae.

Male Syrian hamsters were infected intratracheally with Mycoplasma pneumoniae and treated here after for ten days with either OTC or erythromycin. The purpose of this study was to investigate whether there exists a relation between the persistence of M. pneumoniae in the lungs and the infection dose respectively the days passed after infection before starting treatment with antibiotics. The influence of antibiotic therapy on the immune response of the hamsters was also investigated.

Animals↗
PubMed1985

Aldehyde dehydrogenase activities in hepatocyte nodules and hepatocellular carcinomas from Wistar rats.

The activities of aldehyde dehydrogenases using benzaldehyde and propionaldehyde as substrates and NADP and NAD as coenzymes were determined in normal liver, hepatocyte nodules and hepatocellular carcinomas from male Wistar rats. Hepatocyte nodules were produced by intermittent exposure of rats to 0.05% 2-acetylaminofluorene or by initiation with diethylnitrosamine followed by selection using 2 weeks of dietary exposure to 0.02% 2-acetylaminofluorene and partial hepatectomy. The activities of propionaldehyde:NAD and benzaldehyde:NADP aldehyde dehydrogenases were increased in hepatocyte nodules of all types as well as in most hepatocellular carcinomas. The most prominent elevation of enzyme activity was found in the cytosol of persistent hepatocyte nodules (35-60 times) and some hepatocellular carcinomas (92 times) using benzaldehyde and NADP. The benzaldehyde:NADP aldehyde dehydrogenase activity varied considerably between different nodules suggesting the existence of a subpopulation of hepatocyte nodules with very high enzymatic activities. The activity of propionaldehyde:NAD aldehyde dehydrogenase activity as well as of gamma-glutamyltransferase did not show substantial internodular variations. The activity of benzaldehyde:NADP aldehyde dehydrogenase in individual carcinomas investigated in these experiments varied extensively. The data did not support the idea that all hepatomas had been developed from pre-neoplastic nodules with very high activity of this enzyme.

2-Acetylaminofluorene↗