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Biomedical subjects

R Laufs

Publications and source records attributed to R Laufs.

At least 127 records · Page 7Linked to original sources
PubMed1989

[Hepatitis in drug poisonings].

In the period between 1983 and 1987 autopsies were carried out on 120 drug victims at the Institute for Forensic Medicine in Hamburg, and 93 cases were serologically tested for hepatitis B. It was found that 50 cases (54%) were positive for anti-HBc, 39 (42%) for anti-HBs, and 5 cases (5%) for HBsAg. The prevalence of hepatitis-B-virus markers was dependent upon the age of the victims. In 81% inflammatory alterations of the liver (including unspecific reactive hepatitis) were diagnosed histologically. The pathogenesis of these serological and pathomorphological findings is discussed. Drug addicts are a group at risk for hepatitis B, and it can spread on account of the epidemiological connection with other risk groups, e.g., prostitutes and homosexuals. Postmortem serological investigations for hepatitis markers proved to be a well-established and reproducible means of differentiating histopathological liver alterations.

Chemical and Drug Induced Liver Injury↗
PubMed1988

A new method for induction of specific polyclonal antibodies using immunostained proteins on nitrocellulose membrane, and HIV 1 core antigen and Escherichia coli verotoxin as examples.

Two polyclonal antibodies against verotoxin 1 and the core protein p24 of HIV 1 were raised in mice by a new immunization procedure. Both proteins were transferred to nitrocellulose, reacted with polyspecific antisera and the antigen-antibody complexes were then visualized by immunostaining. For preparation of antisera the stained protein bands were cut from the nitrocellulose sheets and implanted subcutaneously into the backs of BALB/c mice, without any adjuvant. A single booster was given 4 weeks later by implanting a second strip. All mice produced high titers of antibody directed against the antigen used for immunization. Thus, antibodies of high specificity can be elicited against protein bands in stained immunoblots.

Animals↗
PubMed1988

[Evaluation of the efficacy of a recombinant hepatitis B vaccine].

A recombinant vaccine against hepatitis B derived from yeast cells (Gen-HB-Vax, Co. MSD/Behring) has been evaluated in 59 healthy young volunteers (37 men, 22 women) with an average age of 24.4 years. The seroconversion rate was 100%, and no major side effects were observed. During a follow-up period of 24 months concentrations of antibodies against HBsAg were shown to decline to one tenth within 16 to 17 months. Triple vaccination led to protective antibody titres for about 27 months on average. Based on these findings we suggest the following recommendations concerning revaccination: an anti-HBs titre of more than 10,000 mIU/ml four weeks after third vaccination should be reassessed 3-5 years later, and titres between 1000 and 10,000 mIU/ml after 2-3 years. A control of the antibody titre should be performed after 1-2 years if the titre is 200-1000 mIU/ml after the third vaccination, and after 6-12 months if it is 100-200 mIU/ml. Antibody titres between 10 and 100 mIU/ml should already be reassessed about 3-6 months later. We recommend an immediate revaccination for persons with anti-HBs titres below 10 mIU/ml. This corresponds to the course of antibody concentrations which could be seen in former studies with the conventional serum-derived vaccine. Maximum anti-HBs titres are slightly below those observed with the serum-derived vaccine.

Adult↗
PubMed1987

HIV-infection in forensic autopsy cases.

Sudden and unexpected death and violent death of persons with a high risk of acquiring HIV-infections, especially homosexual males and intravenous drug abusers, have to be investigated by forensic autopsies. Therefore every forensic pathologist has to be aware of this infection and should try to make the proper diagnosis. Three typical cases are described: (1) suicide by hanging, (2) homicide by cutting the throat and (3) intravenous heroin overdose. Merely retrospectively it could be cleared up that the deceased were homosexual but did not manifestly suffer from AIDS. The morphological findings in the lymph nodes and the postmortem serological findings are described in detail.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Serological response to type 1-like somatic fimbriae in diarrheal infection due to classical enteropathogenic Escherichia coli.

Fimbriae from enteropathogenic Escherichia coli strain E2349/69 (0127:H6) and its plasmid-minus derivative, MAR20, were purified and characterized as type 1-like by their physicochemical and hemagglutination patterns. Sera from adult volunteers challenged with the diarrheagenic parent strain and the attenuated plasmid-minus derivative were examined to detect an immune response, using the purified fimbriae as antigens in an enzyme linked immunosorbent assay (ELISA) and immunoblot assay. An anti-fimbrial response was evident in sera of 7 of 10 volunteers fed the diarrheagenic parent strain E2348 but also in 8 of 9 individuals fed the attenuated, plasmid-cured, derivative MAR20. The antibody response appeared specific in that the sera failed to react in an ELISA and by immunoblot assay with type 1 fimbriae from other E. coli. These findings suggest that the type 1 fimbriae of this representative EPEC strain are antigenically distinct. The results of this investigation provide the first evidence of seroconversion to type 1-like fimbriae in infections caused by diarrheagenic E. coli.

Adult↗
PubMed1987

Plasmid-mediated formaldehyde resistance in Serratia marcescens and Escherichia coli: alterations in the cell surface.

The plasmid-mediated formaldehyde resistance of Serratia marcescens and Escherichia coli was examined. For that purpose the outer membranes of isogenic strains (with and without resistance plasmid) were compared. No quantitative or immunological differences in lipopolysaccharide of resistant and sensitive strains were noted. By contrast analysis of outer membrane proteins revealed that the sensitive variants had a higher protein content than the resistant strains. When outer membrane proteins were separated by SDS-PAGE the number of bands seemed identical for sensitive and resistant strains but the intensity of some of the bands was greater for the sensitive isolates. In addition, the surface hydrophobicity was greater for the resistance than for the sensitive strains. These findings suggest that the formaldehyde resistance plasmid of Serratia marcescens confer changes in cell surface proteins and surface hydrophobicity.

Bacterial Outer Membrane Proteins↗
PubMed1987

Phage-associated cytotoxin production by and enteroadhesiveness of enteropathogenic Escherichia coli isolated from infants with diarrhea in West Germany.

We assessed the frequency of isolating enteropathogenic Escherichia coli (EPEC) from the stools of infants with diarrhea, the enteroadhesiveness of the EPEC, their production of cytotoxin, and the association of cytotoxin synthesis with lysogenic phages. One hundred twenty-five isolates of EPEC obtained from 1,674 children with diarrhea; three were isolated from 868 controls. Thirty EPEC made elevated levels (greater than or equal to 10(4) 50% cytotoxic doses/mg of cell lysate protein) of a cytotoxin for HeLa cells, and cell-associated cytotoxicity for 27 of these isolates was neutralized by antibody to Shiga toxin. Cell lysates of these isolates were paralytic and lethal for mice. Phages from cytotoxin-producing strains were tested for toxin-converting capacity. Fifteen of 30 such strains harbored toxin-converting phages, and the cytotoxicity of 12 isolates of E. coli K12 transduced with these phages was neutralized by antibody to Shiga toxin. Fifty-seven EPEC exhibited either localized or diffuse adherence to HEp-2 cells, but only nine producers of elevated levels of cytotoxin were adherent.

Bacterial Adhesion↗
PubMed1987

A plasmid of enterohemorrhagic Escherichia coli O157:H7 is required for expression of a new fimbrial antigen and for adhesion to epithelial cells.

Of 14 strains of Escherichia coli O157:H7 isolated from patients with hemorrhagic colitis or hemolytic uremic syndrome that were examined for fimbriae, the presence of plasmids, and the ability to adhere to intestinal cells, 13 possessed a 60-megadalton plasmid and were fimbriated as assessed by electron microscopy. These strains adhered to Henle 407 intestinal cells but not to HEp-2 cells or erythrocytes. Three strains were cured of the plasmid and thereafter failed to express fimbriae and lost the ability to adhere to intestinal cells. Conversely, E. coli K-12 transformed with the 60-megadalton plasmid from each of the three strains produced fimbriae and was able to adhere to intestinal cells. A single fimbrial subunit of 16 kilodaltons was observed when purified fimbriae from the transformants and from the 60-megadalton plasmid-containing E. coli O157:H7 strains were disaggregated and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Antisera raised against one preparation of the purified fimbriae reacted strongly with 12 of 14 O157:H7 isolates in an agglutination assay and with purified fimbrial preparations from five E. coli O157:H7 strains in an enzyme-linked immunosorbent assay.

Animals↗
PubMed1987

Low prevalence of particle-associated reverse transcriptase activity in serum from patients with non A - non B hepatitis.

Sera from 367 patients presumed to have NANB hepatitis were screened for reverse transcriptase activity. In 29 cases significantly increased enzyme activities could be observed. In contrast, sera from 338 patients did not contain significant reverse transcriptase activities. 207 healthy individuals, 7 patients with hepatitis A and 6 patients with hepatitis B who served as controls were all negative for reverse transcriptase activity. The specificity of the enzyme assay was demonstrated by estimation of reverse transcriptase activity in sera from 10 "healthy" HIV-1-antibody positive individuals. In 3 out of 10 cases significant reverse transcriptase activity was observed associated with the human immunodeficiency virus. Our results indicate that the presence of particle-associated reverse transcriptase activity in serum from patients with NANB hepatitis is indicative of the presence of a retrovirus-like agent in these cases. However, the relatively low prevalence of reverse transcriptase positive cases associated with the NANB hepatitis makes it rather questionable whether this agent is a frequent and specific factor in the etiology of NANB hepatitis.

Acquired Immunodeficiency Syndrome↗
PubMed1987

[Clinical manifestations of rabies in the human. Case report and review].

Clinical symptoms and course in a 28 year old woman who suffered from rabies are reported. Neurophysiological and neuropathological findings in this patient, who died 21 days after developing initial symptoms, are presented in more detail. This disease appears to be rare in Central Europe. It can be treated effectively only by means of early detection and a special vaccination programme. Late recognition of lyssa specific symptoms in non-vaccinated patients is invariably associated with a fatal outcome. A review of current knowledge concerning rabies research is presented.

Adult↗
PubMed1987

[Oxacillin-resistant staphylococci in routine diagnosis].

Methicillin resistance is usually not detected by routine laboratory methods. With the aid of a method that facilitates in vitro detection of methicillin resistance 8.6% of our Staph. aureus strains and 42% of the coagulase-negative staphylococci proved to be resistant towards this antibiotic.

Humans↗
PubMed1986

Immunochemical analysis of plasmid-encoded proteins released by enteropathogenic Yersinia sp. grown in calcium-deficient media.

Enteropathogenic Yersinia sp. releases plasmid-associated proteins of low molecular mass (26-67 kilodaltons) at 37 degrees C. In this study, the optimum conditions for the release of proteins were assessed and the released proteins (RPs) were analyzed for the manner of release, immunochemical characteristics, and the location of the genes necessary for their synthesis. Protein release was strongly enhanced when growth media were markedly depleted of calcium ions by precipitation with oxalate or chelation with EGTA [ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid]. RP yields were greatest when Yersinia spp. were in the exponential growth phase. The RPs appeared to be released from the Yersinia spp. by secretion rather than by pinching off of membrane vesicles, because the RPs did not sediment during high-speed centrifugation nor were they contaminated to any significant degree with lipopolysaccharide. Moreover, immunoblot analysis revealed only traces of protein species related to RPs within the outer membranes of plasmid-positive Yersinia spp. grown at 37 degrees C under calcium-restricted conditions. Immunoblot studies also showed that the RPs of Y. enterocolitica serotypes O:3, O:8, and O:9 and the RP of Y. pseudotuberculosis serotype I are highly cross-reactive. Finally, the immunoprecipitates of the products of minicells which harbor Yersinia plasmids were used to demonstrate that at least three proteins immunochemically related to the released fraction were plasmid encoded. These results suggest that at least three of the RPs may be related to or identical with previously described plasmid-encoded Yersinia outer membrane proteins.

Bacterial Proteins↗
PubMed1986

Detection of Campylobacter pyloridis in patients with antrum gastritis and peptic ulcers by culture, complement fixation test, and immunoblot.

The association of Campylobacter pyloridis with antrum gastritis and peptic ulcers was described. We investigated antral biopsies from 180 patients who underwent gastroscopy. By culture or Gram stain or both, we found overall 98 (54%) of them to be positive for C. pyloridis. In the various groups the following percentages were found to be positive: normal antral mucosa 3% (n = 30); moderate superficial antrum gastritis, 49% (n = 83); severe superficial antrum gastritis, 86% (n = 44); duodenal ulcer, 83% (n = 54); and gastric ulcer, 72% (n = 18). A serological screening that used a complement fixation test yielded the following results: highest rates of positive complement fixation titers were seen in patients with severe gastritis and those with duodenal ulcers, both with 79%; the lowest incidence was in a group of 20 blood donors, with 5%. Positive complement fixation titers in gastritis patients also correlated well with characteristic patterns on immunoglobulin G and A immunoblots, while there was no specific reactivity observed on immunoglobulin M immunoblots.

Antibodies, Bacterial↗