Biomedical subjects

H J Wellensiek

Publications and source records attributed to H J Wellensiek.

At least 19 recordsLinked to original sources

PubMed2001

Structural analysis of glycolipids from Borrelia burgdorferi.

In this study the lipids of Borrelia burgdorferi, the causative agent of Lyme disease, were analyzed. Lipids comprise about 25-30% of the cell dry weight. The lipid fraction could be separated by HPTLC into 11 components. Staining of these components revealed two glycolipids and two phospholipids. The glycolipids represented about 50% of the total lipids and comprised only galactose as monosaccharide constituents. By means of mass spectrometric and gas chromatographic analysis both glycolipids could be identified as alpha-galactosyl-diacylglycerolipids with different fatty acid compositions. The phospholipids were identified as phosphatidylcholine and phosphatidylglycerol. Immunoassays with sera from patients with Lyme disease showed antibody reactivity only to the glycolipids, which was present in all stages of the disease. Other lipid components seemed to be non-immunogenic in Lyme disease. The glycolipids of B. burgdorferi may be, thus, considered promising candidates for diagnosis and possibly also for vaccination.

Blotting, Western↗

PubMed1998

Stages and syndromes of neuroborreliosis.

To ascertain the varieties of neuroborreliosis, 330 patients were identified at the Departments of Neurology in Würzburg and Giessen from 1979 to 1994. Patients who fullfilled at least one of three strict case definitions based on clinical and laboratory criteria were included in the study. Ninety-one per cent of the patients had second-stage neuroborreliosis (duration of symptoms < or = 6 months). The most common syndrome was a painful spinal meningoradiculitis, alone (37%) or in combination with a cranial radiculitis (29%). Meningoradiculitis cranialis (9%), isolated meningitis (4%) and erythema chronica migrans-associated mono/polyneuritis (3%) were further stage II features. Central nervous system involvement occurred either as an acute meningomyelitis or meningomyeloradiculitis (5%) and meningoencephalitis or meningenocephaloradiculitis (4%). Less than 9% of the patients ran a chronic course (stage III) with a disease duration between 6 months and 9 years, either as acrodermatitis chronica atrophicans associated mono- or polyneuritis (2%) or a chronic progressive encephalomyelitis (6%). Cerebrovascular neuroborreliosis (1%) occurred in both stages; however, the primary nature of the course was a chronic one. Involvement of other organs except the skin was rare (joints 3%, heart 1%) but elevated hepatic enzymes were frequent. Our study demonstrates that neuroborreliosis has to be considered in the differential diagnosis of a wide variety of neurological conditions. Cerebrospinal fluid analysis and the search for specific intrathecal antibody production are important diagnostic procedures.

Adolescent↗

PubMed1997

Detection and preliminary characterization of circulating immune complexes in patients with Lyme disease.

To investigate whether circulating immune complexes can be used as a disease marker for assessment of the activity of Lyme disease and for monitoring patients response to treatment, we tested 104 sera from patients with different stages of Lyme disease using the C1q enzyme-linked immunosorbent assay (ELISA) and a modified Raji cell test. Among 62 sera of patients with clinically active disease 27 sera (43.5%) reacted positively in the C1q-ELISA and 21 sera (33.9%) positively in the Raji cell test. In contrast, serum circulating immune complexes were found in less than 10% of 42 sera after antibiotic treatment. Similar results were obtained by both tests in 35 cerebrospinal fluid samples from patients with neuroborreliosis. Most importantly, dot blot analysis revealed the presence of both Borrelia burgdorferi-specific antigen(s) and host-derived components in the isolated immune complexes from serum samples of patients with active Lyme disease. These results indicate that detection of circulating immune complexes may be an useful parameter for judging the activity of Lyme disease. Moreover, preliminary characterization of spirochete-specific immune complexes implies new pathophysiological aspects of Lyme disease.

Antibodies, Bacterial↗

PubMed1995

Isolation and characterization of fibronectin-binding sites of Borrelia garinii N34.

Adherence of bacteria to host cell membranes is one of the initial steps of microbial pathogenicity. Numerous studies have suggested that fibronectin promotes this interaction in some bacterial species. In this study, we have examined the ability of Borrelia garinii to bind fibronectin. The binding of fibronectin to the spirochete was specific and saturable. Scatchard plot analysis of the binding data revealed two types of ligands on the spirochetal surface, one with high affinity and one with low affinity for fibronectin. The fibronectin-binding sites were solubilized from the surface of B. garinii N34 by lysozyme treatment. Fast protein liquid chromatography (FPLC) purification of the solubilized binding sites resulted in one band with a high fibronectin-binding activity and a molecular weight of ca. 147,000. FPLC-purified binding sites, fibronectin, and antibodies to fibronectin inhibited the adherence of the spirochete to epithelial cells competitively. These data provide strong support for the hypothesis that fibronectin-binding sites on the surface of B. garinii are involved in the adherence of the spirochete to their respective host cells.

Bacterial Adhesion↗

PubMed1988

[Suspected syphilis during pregnancy due to cross reactions in Borrelia infection].

A weakly positive titre (1:20) in the Treponema pallidum haemagglutination test and a highly positive titre (1:1280) in the fluorescence Treponema antibody absorption test, but negative result for IgM antibodies, were found in the serum of a 23-year-old pregnant woman. The cardiolipin microflocculation test was at first borderline positive, but negative on repeat. In the absence of a history of syphilis tests for Borrelia antibodies were performed. Those for antibodies against B. burgdorferi were highly positive in the ELISA test (550 units), in the indirect Borrelia immunofluorescence test 1:1280 for IgG antibodies and 1:160 for IgM antibodies. In the Borrelia-specific indirect haemagglutination test, which measures both IgG and IgM antibodies, the titres were 1:640 to 1:1280. These results confirmed the presence of an infection with B. burgdorferi and not with Treponema pallidum.

Adult↗

PubMed1985

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis immunoblotting as a serological tool in the diagnosis of syphilitic infections.

The utility of sodium dodecyl sulfate-polyacrylamide gel electrophoresis immunoblotting as a serological tool in the diagnosis of human syphilitic infections was examined. In model experiments, rabbits were immunized with Treponema pallidum or T phagedenis, and the antisera were tested for cross-reactivities with both sets of antigens. A major T. pallidum antigen with a molecular weight of ca. 17,000 appeared to be the most reliable specific antigenic marker as assessed by the immunoblotting technique with peroxidase-labeled second antibodies. Antibodies to this antigen were never detected in hyperimmune rabbit anti-T. phagedenis sera or in the sera of nonsyphilitic humans. In contrast, reactive antibodies were found in all syphilitic human sera and also in liquor samples that were positive in the passive hemagglutination test. Differentiation between immunoglobulin M and immunoglobulin G antibodies was directly possible by applying the respective specific second antibodies. Immunoblotting tests were performed with sera exhibiting low passive hemagglutination test titers and equivocal fluorescent treponemal antibody and rapid plasma reagin card reactions. In more than 60% of these cases, immunoblot positivity with respect to the 17,000-molecular-weight antigen was found. The same results were obtained with partially purified 17,000-molecular-weight antigen. The immunoblot technique should be useful as an additional diagnostic tool for differentiating between true and false-positive serological reactions.

Animals↗

PubMed1981

On the mechanism of membrane damage by Staphylococcus aureus alpha-toxin.

Rabbit or human erythrocytes lysed with Staphylococcus aureus alpha-toxin were solubilized with Triton X-100, and the toxin was subsequently isolated by gel chromatography, sucrose density gradient centrifugation, and reincorporation into liposomes. In the presence of Triton X-100, the toxin exhibited a sedimentation coefficient of 11S and eluted at a position between those of IgG and alpha 2-macroglobulin in gel chromatography. A single polypeptide subunit of 34,000 mol wt was found in SDS PAGE. In the electron microscope, ring-shaped or cylindrical structures were observed, 8.5-10 nm in diameter, harboring central pits or channels 2-3 nm in diameter. An amphiphilic nature of these structures was evident from their capacity to bind lipid and detergent, aggregation in the absence of detergents, and low elutability from biological and artificial membranes through ionic manipulations. In contrast to the membrane-derived form of alpha-toxin, native toxin was a water-soluble, 34,000 mol wt, 3S molecule, devoid of an annular structure. Because studies on the release of radioactive markers from resealed erythrocyte ghosts indicated the presence of circumscribed lesions of approximately 3-nm effective diameter in toxin-treated membranes, the possibility is raised that native alpha-toxin oligomerizes on and in the membrane to form an amphiphilic annular complex that, through its partial embedment within the lipid bilayer, generates a discrete transmembrane channel.

Animals↗

PubMed1980

Influence of the age of sheep red blood cells on virus-induced and hypotonic hemolysis.

The effect of red blood cell age on the susceptibility towards NDV- induced hemolysis has been investigated. It was found that young sheep red blood cells (SRBC), although more resistant to hypotonic hemolysis, are more susceptible towards viral hemolysis than older cells. This may be because young red blood cells have a higher content of neuraminic acid, which functions as a receptor for NDV.

Animals↗

PubMed1977

Antibodies to Acholeplasma laidlawii membrane lipids in normal guinea pig serum.

Acholeplasma laidlawii is killed and lysed by fresh normal guinea pig serum (GPS) without additional antibodies. Prior incubation of GPS with whole A. laidlawii organisms abolishes the killing activity of GPS. In the present study it was demonstrated that antibodies are present in normal GPS. The classical pathway, not the alternative pathway, of the complement sequence was activated by these antibodies in fresh normal GPS. The antibodies in GPS belong to the IgG class of immunoglobulins. They are directed predominantly against the membrane phospholipids of A. laidlawii. These antibodies may be induced either by natural infection of guinea pigs with A. laidlawii or by antigenic determinants of other microorganisms of food antigens.

Acholeplasma laidlawii↗

PubMed1976

Complement-mediated killing of Acholeplasma laidlawii by antibodies to various membrane components.

Mycoplasmas are useful models for biochemical studies of the mechanism of complement-mediated killing by antibodies to various membrane components. The purpose of this study was to determine the membrane antigens involved in immune killing of Acholeplasma laidlawii. Antibodies to A. laidlawii membrane total lipids, glycolipids, and phospholipids could be induced in rabbits after injection of reaggregates of the purified lipids with Mycoplasma hominis protein as the carrier. Killing of A. laidlawii membrane lipids were less effective than anti-membrane protein antisera in killing the organisms. Of the antisera to lipid components of A. laidlawii membranes, antiserum to phospholipids showed a more pronounced killing effect than antiserum to glycolipids. The antibodies to A. laidlawii in the rabbit antisera belong predominantly to the immunoglobulin G class of immunoglobulins. Double-diffusion tests in agar indicated that two immunologically reactive proteins are located on the membrane surface.

Acholeplasma laidlawii↗

PubMed1976

Lysis of Acholeplasma laidlawii by antibodies and complement.

Membranes of Acholeplasma laidlawii were used to determine the membrane components involved in immune lysis and to eventually detect enzymatic changes in the membrane components during this reaction. In a previous publication we reported that A. laidlawii can be killed by antibody and complement and that antibodies to membrane proteins are by far more effective than antibodies to membrane lipids in the complement-dependent killing of this organism. In this report we demonstrate that membrane damage occurs after the combined action of antibody and complement. In addition, the cytoplasmic enzyme hexokinase is released during immune killing. As visualized by electron microscopy, the organisms lost their cytoplasm and were transformed into ghosts. In the majority of organisms, tears in the membrane could be seen. Ultrastructural lesions of about 8.0 to 10 nm in diameter were visible when the organisms were incubated with antiserum and complement. 14C-labeled fatty acids were incorporated during growth into A. laidlawii membrane lipids. After incubation of labeled organisms with antiserum and complement, release of radioactive material into the supernatant and changes in the lipid composition were not observeed. Enzymatic degradation of membrane lipids of A. laidlawii during immune lysis was not detected.

Acholeplasma↗

PubMed1970