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Biomedical subjects

J Steinmann

Publications and source records attributed to J Steinmann.

At least 73 records · Page 4Linked to original sources
PubMed1991

Detection of hepatitis B virus DNA in serum with nucleic acid probes labelled with 32P, biotin, alkaline phosphatase or sulphone.

To facilitate the clinical application of dot-blot hybridization for assaying hepatitis B virus (HBV) DNA, we compared the ability of nucleic acid probes labelled with 32P or with various non-radioactive markers to detect HBV DNA in patient serum. Cloned HBV DNA was hybridized with (1) 32P-labelled HBV DNA cloned in M13, (2) the 32P-labelled HBV RNA probe included in the HepProbe kit, (3) an alkaline phosphatase-labelled synthetic oligonucleotide of HBV, (4) biotin-labelled HBV DNA, and (5) sulphonated HBV DNA. Detection was either by autoradiography or an enzymatic colour reaction. The lowest level of detection of cloned HBV DNA was achieved with the 32P-labelled HBV RNA probe (0.3 pg HBV DNA, corresponding to 3 x 10(4) genomes in 50 microliters), followed by the 32P-labelled DNA probe (0.3-2 pg), sulphonated DNA (1-2 pg), biotin-labelled DNA (4 pg), and an alkaline phosphatase-labelled synthetic oligonucleotide (30 pg). Subsequently, sera from 159 patients with various constellations of HBsAg, HBeAg, and anti-HBe were tested with the most sensitive radioactive method (HepProbe) and the corresponding nonradioactive method (sulphonation). The overall concordance rate was 71% (r = 0.42). Compared with HepProbe results, sulphonation showed a sensitivity of 80% and a specificity of 67%. We conclude that radiolabelling (in particular 32P-labelling of HBV RNA) still allows the most sensitive and reliable detection of HBV DNA in patient serum using conventional dot-blot hybridization.

Alkaline Phosphatase↗
PubMed1991

[Virucidal efficacy of inorganic per-compounds].

Among 7 inorganic per-compounds tested potassium permanganate as 1% solution showed the greatest virucidal efficacy against poliovirus type I and reached a reduction rate of 4.1 after 30 sec exposure time. Potassium peroxomonosulfate produced a reduction rate of 5.6 after 5 min, whereas perchloric acid and sodium perborate needed 15 min and hydrogen peroxide 60 min to show a reduction of 10(4) of the infectivity level. Potassium peroxodisulfate and sodium perborate yielded a reduction rate of 0.9 and 1.3, respectively. With protein load a slight reduction of antiviral efficacy was observed, whereas with extended standing times only the reduction rate of sodium percarbonate was lowered from greater than or equal to 4.9 to 2.0 after 60 min exposure time.

Antiviral Agents↗
PubMed1991

Serological responses to herpes simplex virus type 1 (HSV-1) analysed with enzyme-linked immunosorbent assay (ELISA) and western blot (WB).

Serological response of 56 patients to primary and recurrent herpes simplex virus type 1 (HSV-1) infection were studied by enzyme-linked immunosorbent assay (ELISA) and by Western blot analysis (WB). ELISA test showed a high sensitivity in detecting IgG, IgM, and IgA antibodies. From 27 patients with recurrent infection, 13 (48%) had IgM antibody. The percentage of patients positive for IgA was similar among those with primary (72.4%) or recurrent (81%) infection. The band pattern in WB alone did not allow to distinguish between patients with primary or recurrent infections. Furthermore, no correlation between the particular viral proteins and clinical manifestation could be determined. The kinetics of antibody response could be followed with both methods.

Adolescent↗
PubMed1990

Evaluation of the commercially available HepProbe kit for detection of hepatitis B virus DNA in serum.

The commercially available HepProbe kit involving the use of a 32P-labeled RNA probe was evaluated for its sensitivity, specificity, and reproducibility in detecting hepatitis B virus (HBV) DNA in patient serum by dot blot hybridization. The level of detection was 0.3 pg, corresponding to 3 x 10(4) genomes in 50 microliters of serum. A total of 181 serum samples were tested; 53 (82%) of 65 patients positive for both hepatitis B surface antigen and hepatitis e antigen were positive for HBV DNA compared with only 12 of 74 (16%) hepatitis B surface antigen-positive but hepatitis e antigen-negative individuals. In addition, among all patients positive for HBV DNA, there was a statistically significant correlation between the concentration of HBV DNA in serum and the presence or absence of hepatitis e antigen. None of the 42 hepatitis B surface antigen- and hepatitis e antigen-negative patients tested was positive for HBV DNA. Reproducibility was 87%, with all discordant results representing borderline positives. The results indicate that HepProbe can be employed as a sensitive and reliable assay for HBV DNA in patient serum.

DNA, Viral↗
PubMed1990

Immunogenicity testing of food proteins: in vitro and in vivo trials in rats.

The immunogenicity of an industrially produced bacterial food protein (single cell protein, SCP) was analyzed in a comparative study. SCP, casein and ovalbumin were injected into or fed to rats. The systemic response was tested in vitro with a lymphocyte transformation test and in vivo with a footpad swelling assay. Feeding of casein induced cell-mediated reactivity against casein, while feeding of SCP or ovalbumin had no effect. One injection of casein led to sensitization compared with three injections of SCP. Prior feeding of SCP did not abrogate the response to injected SCP. The footpad swelling test is suggested as a particularly effective model for helping to determine the immunological risk of foodstuffs to man.

Animals↗
PubMed1990

[Detection of rotavirus infection chains by electropherotyping].

518 fecal specimens were examined by SDS-PAGE after rotavirus had been detected by an ELISA. The material was collected from 239 patients in three children's hospitals in Bremen over a period of one year. Seventy-two percent of the children had a nosocomial infection. Eight electropherotypes could be distinguished by electrophoresis, one of which (type C) dominated (61.1%). In the neonatal wards of the children's hospitals one main electropherotype (type C) was detected throughout the year. In contrast, different electropherotypes could be detected simultaneously in the isolation wards. Some other electropherotypes were found only in certain hospitals. Our examinations demonstrate that by these additional electrophoretic investigations infection chains within children's hospitals can be detected and that the endemic occurrence of rotavirus in neonatal wards is less dependent on those types circulating in the general population.

Child↗
PubMed1988

Thermal recovery after passage of the pulmonary circulation assessed by deconvolution.

For indicator-dilution studies, complete thermal recovery after passage of heat through the pulmonary circulation would be desirable. However, the results in the literature obtained by extrapolation techniques are inconsistent. To overcome problems of the extrapolation approach, transport functions of the pulmonary circulation (including the left heart) were computed by deconvolution of pulmonary arterial and aortic pairs of thermodilution curves after central venous indicator injection (10 ml of an ice-cold blood indocyanine green dye mixture). Thermal recovery was determined as the finite integral of the transport function. Thirteen mongrel dogs under piritramid-N2O anesthesia were examined under base-line conditions, in orthostasis to alter the distribution of pulmonary blood flow (9 dogs), and in oleic acid edema (8 dogs). Using the deconvolution approach, thermal recovery was 0.97 +/- 0.04 under base-line conditions, 0.96 +/- 0.03 in orthostasis, and 0.96 +/- 0.05 in pulmonary edema. Thermal recovery determined from extrapolated dilution curves was greater than 100% in all groups, a physically impossible finding. It is concluded that thermal recovery is incomplete but insensitive with respect to the distribution of blood flow and to the size of the extravascular compartment. Monoexponential extrapolation is unsuited for the determination of thermal recovery.

Animals↗
PubMed1988

[Quantitative and qualitative findings of hepatitis B virus-associated antigens, receptors and antibodies in the course of the acute phase of hepatitis B infection].

UNLABELLED: Receptors for pHSA may be the links between HBV and hepatocytes. Therefore, we evaluated the correlation between serum binding activity for pHSA during the acute phase of hepatitis B in relation to the decrease of surface antigen concentration. METHODS: 130 sera from 22 patients with acute (HBeAg-positive) hepatitis B were obtained weekly during an average interval of 7 weeks after the onset of the disease. R-pHSA were tested by RIA in 4 titre steps (1:50, 1:500, 1:5000, 1:50,000). HBsAg was analysed quantitatively by RIA according to the standard serum of the Paul-Ehrlich-Institute.

Acute Disease↗
PubMed1988

Evaluation of monoexponential extrapolation of transpulmonary thermal-dye kinetics by use of a new model-free deconvolution algorithm.

This study evaluates the routine mathematic approach (monoexponential extrapolation) for analysis of transpulmonary thermal-dye dilution curves and estimates the effects of systemic-indicator recirculation by use of a deconvolution technique. Fifteen dogs anesthetized with N2O-piritramid were studied before and after induction of pulmonary edema by oleic acid. After introduction of central venous indicator (10 ml of a mixture of cold blood and indocyanine green dye), dilution data were recorded from the pulmonary artery and the ascending aorta. The conclusions were: (1) monoexponential extrapolation yields reasonably good estimates of the mean transit times of dye; (2) mean transit times of heat are usually overestimated by monoexponential extrapolation; (3) extravascular lung thermal volume assessed by monoexponential extrapolation is overestimated by 2.03 ml/kg of body mass under baseline conditions; and (4) the prepulmonary volume of distribution of heat exceeds that of dye by 1.4 ml/kg of body mass, thus increasing the overestimation of pulmonary extravascular heat-accessible space by the conventional technique.

Algorithms↗
PubMed1988

Multi-centre evaluation of the Behring ELISA Processor II.

A multi-centre evaluation of the Behring ELISA Processor II in connection with the Enzygnost-tests from Behringwerke was performed by 3 laboratories following the ECCLS Guidelines for the Evaluation of Analysers in Clinical Chemistry. The performance characteristics were studied with analytical tests for anti-HBs1), HBsAg and anti-CMV2). This evaluation represents, to our knowledge, the first trial in clinical virology with guidelines primarily designed for clinical chemistry. The evaluation revealed that the highly automated Behring ELISA Processor II is a reliable tool in the virological laboratory. The data obtained showed low imprecision and good accuracy. The washing unit proved to be very efficient. No carry-over of reagents was detected in the dispenser system. Several improvements for further developments of the analyser are suggested. This multi-centre study has shown that the ECCLS protocol can be used to evaluate analysers and test systems in clinical virology.

Autoanalysis↗
PubMed1985

[Echovirus 11 outbreak among premature newborn infants in a neonatal intensive care unit].

During a period of 3 weeks, 17 premature neonates 4 of them weighing less than 1000 g at birth became infected with echovirus 11 in a neonatal intensive-care unit. Beside 3 inapparent infections, severe 'septicaemic' illness was observed among 5 premature neonates combined with meningitis and apnoeic attacks. 4 neonates presented meningitis as the predominant clinical feature and 3 showed gastrointestinal symptoms without neurological involvement. 2 children experienced a febrile illness with apnoea and bradycardia. All babies recovered. Echovirus 11 could be isolated in 51 of 74 (68.9%) specimens, mainly from stool samples. The source of this epidemic outbreak has remained unclear. Virus isolations and serological examinations of antibodies of the IgM class showed that one mother and her eldest child and 3 staff members of the unit had been infected during this epidemic outbreak. The agent was identified as an antigenic variant of echovirus 11 resembling other echoviruses of this type which were isolated in other children hospitals in Bremen during this outbreak.

Adult↗
PubMed1983

Chemical linkage of erythrocytes and viral antigen in the hemolysis-in-gel (HIG) test for viral antibodies.

The sensitivity of the hemolysis-in-gel (HIG) test with rubella antigen is not improved by chemical linkage of the virus to the erythrocytes, and after such modification, IgM specific antibodies are not detectable. In the influenza HIG test with tetraazotized o-dianisidine (TOD), chromic chloride and potassium periodate as coupling reagents, increased sensitivity was observed with allantoic fluid of infected eggs as antigen. If Tween-ether treated hemagglutinin is used in the HIG test, zones of hemolysis are detectable only after treatment of the erythrocytes with TOD, chromic chloride and potassium periodate.

Allantois↗