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Biomedical subjects

R Schuster

Publications and source records attributed to R Schuster.

At least 109 records · Page 6Linked to original sources
PubMed1989

[HIV tests as preventive responsibility of public health offices].

4,382 blood samples were examined for HIV antibodies between August 1985 and the end of December 1988 at the Public Health office of the city of Augsburg. The prevalence of positive tests was 0.57% (n = 25). The rate at which various consultation offers were made use of was calculated for 1988. From 1985 to 1988 approximately 200 registered female prostitutes were regularly tested for HIV. It was only in 1985 that the HIV antibody test was positive in two women. Compared with 1984-1986 as basis there was a marked drop in the incidence of gonorrhoea to 71.7% and in 1988 to 6.5%.

AIDS Serodiagnosis↗
PubMed1989

[Finding Setaria equina in horses].

For the first time findings of Setaria equina (Abildgaard, 1789) in horses are reported from the German Democratic Republic. The nematodes, located in the peritoneum, were discovered in the course of autopsy. Based on a thorough analysis of the international literature, the paper discusses geographical distribution, morphology, cycle and diagnosis of this nematode as well as clinical symptoms mainly caused by the stages of the larvae.

Animals↗
PubMed1989

[Verminous pancreatitis in Anas platyrhynchos].

9 helminth species were found in a young mallard by helminthological dissection of its alimentary tract. The severe pathological alterations in the gut were caused by Filicollis anatis. One female acanthocephalan had entered the pancreas with its proboscis via one of the efferent ducts and caused an inflammation.

Animals↗
PubMed1988

A Chinese hamster cell cycle mutant arrested at G2 phase has a temperature-sensitive ubiquitin-activating enzyme, E1.

The effect of restrictive temperature on ubiquitin conjugation activity has been studied in cells of ts20, a temperature-sensitive cell cycle mutant of the Chinese hamster cell line E36. Ts20 is arrested in early G2 phase at nonpermissive temperature. Immunoblotting with antibodies to ubiquitin conjugates shows that conjugates disappear rapidly at restrictive temperatures in ts20 mutant but not in wild type E36 cells. The incorporation of 125I-ubiquitin into permeabilized ts20 cells is temperature-sensitive. Addition of extracts of another G2 phase mutant, FM3A ts85, with a temperature-sensitive ubiquitin activation enzyme (E1), to permeabilized ts20 cells at restrictive temperatures fails to complement their ubiquitin ligation activity. This indicates that the lesions in the two mutants are similar. Purified E1 from reticulocytes restores the conjugation activity of heat-inactivated permeabilized ts20 cells. Ubiquitin conjugation activity of cell-free extracts of ts20 cells was temperature-sensitive and could be restored by adding purified reticulocyte E1. Purified reticulocyte E2 or E3, on the other hand, did not restore the ubiquitin conjugation activity of heat-treated ts20 extracts. These results are consistent with the conclusion that ts20 has temperature-sensitive ubiquitin-activating enzyme (E1). The fact that two E1 mutants (ts20 and ts85) derived from different cell lines are arrested at the S/G2 boundary at restrictive temperatures strongly indicates that ubiquitin ligation is necessary for passage through this part of the cell cycle. The temperature thresholds of heat shock protein synthesis of ts20 and wild type E36 cells were identical. The implications of these findings with respect to a suggested role of ubiquitin in coupling between protein denaturation and the heat shock response are discussed.

Animals↗
PubMed1988

Determination of amino acids in biological, pharmaceutical, plant and food samples by automated precolumn derivatization and high-performance liquid chromatography.

An easy, rapid and sensitive method for the simultaneous determination of primary and secondary amino acids in different matrices, e.g. protein hydrolysates, pharmaceutical formulations, plant extracts, food samples and physiological fluids, is described. After minimum sample preparation amino acids were derivatized with two different reagents, o-phthalaldehyde-3-mercaptopropionic acid for primary and 9-fluorenylmethylchloroformate for secondary amino acids, by an automated precolumn derivatization technique. With minor adjustments of separation parameters this method can also be used to determine amino acids in different matrices. Analysis time including reaction, separation and reconditioning ranged from 20 min for hydrolysates to 60 min for physiological fluids. The separation was done on a reversed-phase column with a gradient of acetate buffer-acetonitrile as the mobile phase. The precision for peak areas of the individual amino acids was within a relative standard deviation of 2% for the hydrolysate assay and 2-5% for the physiological assay, and for retention times better than 0.7%. The detection limit with the diode array detector (ultraviolet-visible) was ca. 2-5 pmol, measured at 338 nm for primary and 266 nm for secondary amino acids; with the fluorescence detector 20-50 fmol were detectable at excitation and emission wavelengths of 230 and 455 nm for primary and 266 and 310 nm for secondary amino acids, respectively.

Amino Acids↗
PubMed1988

Interrelations between glycolysis and the hexose monophosphate shunt in erythrocytes as studied on the basis of a mathematical model.

A mathematical model is presented which comprises the reactions of glycolysis, the hexose monophosphate shunt (HMS) and the glutathione system in erythrocytes. The model is used to calculate stationary and time-dependent metabolic states of the cell in vitro and in vivo. The model properly accounts for the following metabolic features observed in vitro: (a) stimulation of the oxidative pentose pathway after addition of pyruvate due to a NADP-dependent lactate dehydrogenase as coupling enzyme between glycolysis and the oxidative pentose pathway, (b) relative share of the oxidative pentose pathway in the total consumption of glucose amounting to approximately 10% in the normal case and to approximately 90% under conditions of oxidative stress excreted by methylene blue. From the application of the model to in vivo conditions it is predicted that (c) under normal conditions glycolysis and the HMS are independently regulated by the energetic and oxidative load, respectively, (d) under conditions of enhanced energetic or oxidative load both glycolysis and the HMS are mainly controlled by the hexokinase; in this situation the highest possible values of the energetic and oxidative load which are compatible with cell integrity are strongly coupled and considerably restricted in comparison with the normal case, (e) the stationary states possess bifurcation points at high and low values of the energetic load.

Energy Metabolism↗
PubMed1988

[Peculiarities of theophylline therapy in childhood].

Profound knowledge of the pharmacokinetics of theophylline is a prerequisite to successful therapy. In children the clearance of theophylline is considerably greater than in adults. The required higher dosage in relation to body weight results in more pronounced oscillations of drug levels in serum. Investigations in 280 children in the age of 1 to 18 years with bronchial asthma, treated with theophylline compounds, confirm the necessity of individual dosage and surveillance of the drug level in serum. Instead of the determination of the drug level in serum, its measurement in saliva is sufficiently reliable and less molesting. Checks of drug level are also a valuable educational measure to improve patients' compliance with drug intake. The effectivity of asthma therapy in children could be decisively improved by an adequate formulation of a slow release preparation of theophylline.

Adolescent↗
PubMed1988

[Demonstration of dual liver systems after experimental auxiliary partial liver transplantation using the alternative of sequential hepatobiliary scintigraphy].

Hepatobiliary sequential scintigraphies by 99m Tc-ROTOP-EHIDA were carried out for judging the dual liver system after experimental auxiliary transplantation of a part of the liver. A functional advantage of the host liver in contrast to the transplant was found in all cases investigated. Ischemic transplant damages could be detected in all experiments and were scintigraphically recognised at an early stage. In addition to transplants with a functioning entire parenchyma, the investigations showed transplants with functionally active parenchyma zones and such ones without any functional evidence. A quantifiable determination of the global functional capacity of the hepatobiliary system of both livers was possible and also the evidence on residual functions. The different behaviour of the kinetics of the radio-pharmacon with normal function and in case of hepatic ischemia is discussed.

Animals↗
PubMed1988

[The parasite fauna of East Germany. 9. The helminth fauna of Lutra lutra].

Alimentary tract, liver, kidneys and lungs of 25 otters, died of several causes during 1982-1987 in GDR were included in helminthological investigations. Parasites were detected in 8 animals. One cestode: Taenia martis and 3 trematodes: Isthmiophora melis, Opisthorchis felineus and Pseudamphistomum truncatum are regarded to be certain parasites of this host. Other findings like Ligula intestinalis, Azygia luccii and Piscicola geometra and the fragment of a pseudophyllidean enter the alimentary tract with the food and pass through it.

Animals↗
PubMed1988

[Botfly larva skin infestation in a donkey].

In January 1987 7 larvae of Hypoderma diana were found in a donkey. The infection probably took place on a horse pasture in Fürstenwalde, Frankfurt (O.) region, grazed also by roes, the main hosts of H. diana.

Animals↗
PubMed1988

[Seasonal occurrence of Dicrocoelium dendriticum in intermediate hosts].

Epizootiological questions were studied on a permanent pasture of a farm situated in one of the dicrocoeliasis areas in the GDR during the 1986 grazing season. Helicella obvia snails and Formica fusca ants were found to be first and second intermediate hosts respectively. A total of 1,121 snails and 70 ants were dissected. The infestation rate with Dicrocoelium dendriticum stages in snails decreased in summer after the high spring peak and increased again in autumn. Paralysed ants were found only at temperatures below 20 degrees C. Parthenogenetic stages in snails were identified morphologically according to the structure of cercariae; the metacercariae isolated from the ants' body cavity were determined in animal experiments.

Animals↗
PubMed1987

Cooperative social coordination and aggression in male laboratory rats: effects of housing and testosterone.

A cooperative behavior, coordinated shuttling by pairs of laboratory rats in a rectangular chamber, can be influenced strongly by an interaction between housing and sex. Males and females learn readily when housed together socially, but individual housing ("isolation") causes severe deficits selectively in males. The aim of the present study was to examine the role of testosterone in the differential effects of housing on cooperation learning. Males of a Sprague-Dawley derived strain were housed socially or individually and treated daily in one of three ways (six groups, n = 6 per group): (1) castrated, injected with oil vehicle (without testosterone); (2) castrated, injected with 500 micrograms testosterone propionate (exogenous TP); and (3) sham operated, injected with oil (intact, endogenous testosterone). Socially housed pairs learned readily in all treatment groups, using strategies of coordination in which stereotyped contact or aggressive interactions were interpolated. Individual housing was associated with a deficit, but only in the TP-treated and intact groups in which some pairs either did not learn or performed poorly. The deficit was associated with violent fighting and extreme and stable differentiation into dominants and subordinates, the latter exhibiting prolonged freezing. Oil-treated castrates, when housed individually, were unimpaired and actually surpassed their socially housed counterparts on some measures. Their success was associated with an increase only in low-level aggression. The housing-hormone interaction in male rats suggests that testosterone influences the capacity to develop cooperative behavior by modulating both aggression and its consequences for the relationship between partners. The use of social interaction models, including cooperation, for the study of behavior-hormone interactions was also discussed.

Aggression↗
PubMed1987

[Parasites in East Germany. 8. Helminths of Ondatra zibethica].

In 1984/85 80 muskrats have been investigated by helminthological autopsy. Helminth infection was established in 72 animals. Altogether 4 trematodes, 7 cestodes and 2 nematodes were found. 2 cestodes were detected for the first time in the muskrat. Relations between parasite fauna and biotope are recognizable.

Animals↗
PubMed1987

[Budd-Chiari syndrome as a late complication following closure of an atrial septal defect].

A case of a Budd-Chiari syndrome in a 19-year-old female patient is reported who had undergone surgical closure of a secundum atrial septal defect 13 years before. 8 months before the development of the Budd-Chiari syndrome she started to take oral contraceptives. The clinical picture of the Budd-Chiari syndrome developed within several days. The inferior vena cava did not fill with contrast dye when an angiography was performed using the right vena iliaca approach. The contrast dye disappeared through collateral veins (vena azygos, vena hemiazygos). After 4 days of treatment with systemic streptokinase she underwent open-heart surgery. The orifice of the inferior vena cava was occluded to a diameter of 6 mm. No thrombi were found. The lesion was corrected with two patches, one in the right atrium and the other in the inferior vena cava. This case report demonstrates that a Budd-Chiari syndrome is a possible late complication after closure of an atrial septal defect which should be treated by surgery.

Adult↗
PubMed1987

[The auxiliary transplantation of a portion of liver in an animal experiment].

The authors inform about a model for auxiliary liver part transplantation in pig. Intra-abdominal narrowness which can lead to failure of the transplant can avoided by this model. In the transplant was carried out an extensive left resection with purse-string ligature of all visible vessels and cystic ducts. The resection surface is sealed by a tissue adhesive. An auxiliary transplanted part of the liver can also operate on a heterotopic location of the organism.

Animals↗