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Biomedical subjects

G Steinbach

Publications and source records attributed to G Steinbach.

At least 91 records · Page 5Linked to original sources
PubMed1993

[The toxin-producing ability of salmonella from bovine test material].

Cell-free supernatants of 40 Salmonella strains of different serovars were tested for the existence of enterotoxic substances in the rabbit skin permeability factor test, rabbit ileal loop test, tissue culture assays (CHO K1, RTG-2), and baby mouse test. There were differences in the test results between the strains even within the same serovar. Correlation coefficients between the results of different toxin tests were low. It is therefore improbable that the "enterotoxic activity" of Salmonella is caused by only one toxic substance. The activities revealed in the different test systems could not be related to virulence or the epizootiological behaviour of the strains. The in vitro occurrence of the virulence factor "enterotoxin production" is lower for Salmonella than for E. coli and V. cholerae.

Animals↗
PubMed1993

Vaccines in salmonellosis control in animals.

1. It has been demonstrated that it was possible, under the conditions of the former GDR (East Germany), to decisively decrease the occurrence of Salmonella in livestock by means of the consequent combination of a good management including hygienic measures and of immunoprophylactic measures. This is one of the most important conditions for reducing the risk of food poisoning in man. 2. If using Salmonella live vaccines, cross immunity can be put to use. 3. Amount and duration of Salmonella shedding by calves can be decreased using orally administered live vaccines. 4. The immunogenicity of the S. typhimurium mutant serving as vaccine strain for Zoosaloral "Dessau" was retained after its 60-MDa plasmid had been deleted.

Animals↗
PubMed1993

Enhancement of the echogenicity of flowing blood by the contrast agent perflubron.

RATIONALE AND OBJECTIVES: Perflubron, or perfluorooctylbromide, is an effective ultrasound and computed tomography contrast agent in a lecithin emulsion form. The authors studied acoustical properties of perflubron emulsion in static human and flowing porcine blood for concentrations from 0% to 30% weight per volume. METHODS: Propagation velocity (c), the intensity attenuation coefficient (mu), density (rho), and particle size were measured directly. Because the backscatter of flowing blood is dependent on shear rate, relative echogenicity was measured as a function of perflubron concentration in whole porcine blood, in a laminar flow system, at shear rates of 16.0 to 68.5 sec-1 for realtime sector scanner images obtained at 7.5 MHz. RESULTS: Neat perflubron is a colorless liquid with density of 1.93 g.mL-1 and velocity of 630 m.sec-1. The following values were obtained at 4.7 MHz in static human blood (hematocrit 44%) at expected human in vivo blood concentrations of 3.1% perflubron versus pure human blood: rho = 1.11 versus 1.05 g.mL-1, c = 1,480 versus 1,576 m.sec-1, mu = 1.00 versus 0.36 dB.cm-1. The mean echogenicity of whole porcine blood increased substantially with perflubron concentration and was inversely proportional to blood shear rate. CONCLUSION: Adding 3.1% concentration of perflubron increased image echogenicity at all shear rates studied, ranging from 70% at 68.5 sec-1 (16.3 cm.sec-1) up to 180% at 16.0 sec-1 (3.8 cm.sec-1). Perflubron enhancement of blood is marked and demonstrates shear rate dependence like that of whole blood.

Blood Flow Velocity↗
PubMed1993

Course of infection and humoral immune reaction in calves infected orally with different Salmonella serovars.

5 groups of five calves each were orally infected with the salmonella serovar S. agona, S. dublin, S. enteritidis, S. infantis or S. typhimurium. The course of infection and the humoral immune response against 5 antigen preparations of the homologous and the 4 heterologous salmonella serovars were monitored in each group. Antibodies against two different protein antigens and against two differently prepared LPS antigens were determined by ELISA and the level of H-agglutinin was assessed by micro agglutination test. All 5 serovars proved to be virulent for calves. The specificity of antibodies produced following the infection are not always consistent with the Kauffmann-White scheme. There was a relation of age and strain for infection on immune response, whereas the severity of infection did no correlate with an increase of antibody production. The serological tests used were good for investigation of a defined host-parasite-interaction but not satisfactory for serovar specific diagnosis of salmonella infection in cattle.

Animals↗
PubMed1993

[Control of salmonella infections in animal herds--basis for a reduction of salmonella entries into food].

Control measures against Salmonella infections in livestock are discussed on the basis of an epidemiological classification of Salmonella serovars important for animals and/or humans. Special attention is paid to immunoprophylaxis carried out additionally to generally accepted zoo sanitary measures. Available Salmonella vaccines are described and their major characteristics discussed briefly. Schemes are presented for the administration of vaccines in cattle, pigs and poultry. They have to be rationally integrated into general control concepts. They should serve as recommendations for the practical use in animal farms. It is concluded that given consequent combination and enforcement of the described measures the occurrence of Salmonella serovars important for animals and/or humans can be reduced decisively in livestock, thus minimizing introduction into the food chain for the sake of improved consumer protection.

Animals↗
PubMed1992

[Methodical studies of transmucosal oxygen partial pressure measurement in the calf and dog].

Transcutaneous PO2-measurement has been thought being non practicable in veterinary medicine. Consequently, the measuring method has been slightly modified. PO2 was taken from the mucous membrane of the lower surface of tongue. This has been practised in 6 dogs and 10 calves. We achieved a significant correlation between transmucosal and arterial PO2, taken simultaneously in each animal. Considering these results the use of transmucosal measurement may be recommended for a trend-measuring in anesthesized animals. Nevertheless, there has to be pointed out that transmucosal PO2 has to be interpreted regarding its complexity.

Animals↗
PubMed1992

[Detection of enterotoxin production in bovine Salmonella isolates].

54 Salmonella-strains (7 serovars) of bovine origin isolated from faecal samples, rectal swabs as well as from organs of emergency-slaughtered or dead animals were tested for enterotoxin production (heat-labile and heat-stable) in rabbit-ileal-loop-assay (RILT), skin-permeability-factor-test (HPT), CHO- and Y1-cell-culture-assay and in baby-mouse-test (BMT). The cell-free supernatants (CFS) were used in the tests. The Y1-cells did not respond to the Salmonella toxins. While the RILT was suitable, the CHO-cell-assay proved to be the most sensitive and easy-to-handle system. The results confirm the frequent occurrence of the biological property of enterotoxin production within the species Salmonella enterica. Therefore, this property is in our opinion not useful as an epizootological marker for salmonellae.

Animals↗
PubMed1992

Monofrequency oscillation technique in healthy and pneumonic calves younger than 2 months--physiological values and methodological aspects.

Using the monofrequency oscillation technique, the oscillatory measured resistance of the respiratory system (Ros) was determined in healthy and pneumonic calves younger than 2 months. Using a face mask, measurements were done in unsedated animals directly in the calfhouse. 106 clinically healthy calves were examined to determine the physiological range of Ros. Calves suffering from pneumonia showed significantly higher values of Ros which were positively correlated with the severity of pneumonic lesions as established by pathological investigations. In healthy calves, the variability of Ros due to biological aspects was found to be much higher than methodologically caused variability. It is concluded that the monofrequency oscillation technique is useful especially in individual investigations, e.g. control of therapy.

Airway Resistance↗
PubMed1990

[Use in hemodialysis and hemofiltration of CY 216 (Fraxiparine) administered via intravenous bolus in patients with acute and chronic renal insufficiency with and without hemorrhagic risk].

The effectiveness and safety of CY 216 as anticoagulant for extracorporeal circulation were evaluated in 403 haemodialysis of haemofiltration sessions performed in 33 patients with chronic [24] or acute [9] renal failure; 149 of the sessions were carried at risk of haemorrhage. Initially CY 216 was administered as a bolus intravenous injection in doses of 7,500 anti-Xa Institut Choay units (AXa.IC.U) to patients under 50 kg, 15,000 AXa.IC.U to patients weighting between 50 and 80 kg and 22,500 AXa.IC.U to patients over 80 kg. Subsequently dosage was adjusted according to clinical results. With a median dose of 250 AXa.IC.U per kg, no haemorrhage was observed. Blood restitution was satisfactory in 84.6% of the cases, extracorporeal circulation was without clotting of fibrin deposit in 90% of the cases and the incidence of total coagulation was only 0.5%. Using CY 216 seems to be effective in preventing coagulation in the extracorporeal circuit and was well tolerated by all patients whether or not they were carried at risk of haemorrhage.

Acute Kidney Injury↗
PubMed1990

[The dynamics of the microbial count in experimentally-induced salmonellosis of calves].

Numerical developments of pathogens were followed up in intestinal matter, mucosa, and lymph nodes as well as in spleen and liver of calves which had been orally infected with Salmonella (S.) dublin or S. typhimurium. Massive flooding of the organism with Salmonellae and eventually fatal proliferation were found to be possible immediately after infection or after some days of pathogen-host equilibrium. Complete elimination of Salmonellae was found to be achievable even after infestation of spleen and liver. Intestinal lymph nodes, in addition to intestinal mucosa and intestinal matter, proved to be of decisive relevance to pathogenesis of the infection and to persistence of germs.

Animals↗
PubMed1989

In vivo measurement of subcutaneous glucose concentrations with an enzymatic glucose sensor and a wick method.

An amperometric enzyme electrode and a wick technique were used for measurement of glucose in sc. tissue of sheep. When wicks were left implanted long enough to equilibrate with interstitial fluid, sc. glucose could have been reproducibly determined with the necessary accuracy. It was demonstrated that sc. tissue glucose concentrations in sheep are about 30% higher than in whole blood and are on the level of plasma glucose. This allows interpretation of sc. glucose sensor currents since results of in vitro-calibrations cannot be transferred to in vivo conditions. When an enzymatic sensor was implanted in the sc. compartment, the sensor signals were closely related to changes of blood glucose. These in vivo experiments indicate that short term glucose-monitoring with an subcutaneously implantable glucose sensor is feasible and so may provide a possible access to glycemic control. Further experiments will have to show, if glucose-controlled insulin infusions based on the output of a sc. glucose sensor will be able to maintain stable normoglycemia.

Animals↗
PubMed1988

A potentially implantable enzyme electrode for amperometric measurement of glucose.

A membrane limited amperometric enzyme electrode suitable for glucose measurement in biological fluids was developed. The sensor consists of a central platinum wire (0.3 mm) surrounded by a stainless steel tubing (0.8-1.0 mm outer diameter; 2-4 cm length). By successive dipcoating procedures, layers from cellulose acetate, glucose oxidase (crosslinked with glutaraldehyde) and polyurethane are placed on its surface. The platinum is polarized at +700 mV against steel. In vitro results: Electrodes are stable for at least 6 days. They exhibit a linear range extending to 500 mg/dl glucose. Response times are less than 100 sec. The sensors are not dependent on stirring and are relatively insensitive to changes of pH. Dependency of glucose measurement upon dissolved oxygen is negligible at oxygen concentrations above 0.5 mg/l. In vivo results: Preliminary studies in sheep using subcutaneously implanted needles indicate that short term glucose monitoring is feasible.

Animals↗