PubMed Health⌕ Search

Biomedical subjects

Gernot Kriegshäuser

Publications and source records attributed to Gernot Kriegshäuser.

6 recordsLinked to original sources

Reverse hybridization vs. DNA sequencing in the molecular diagnosis of Familial Mediterranean fever.

Familial Mediterranean fever (FMF) is an autosomal recessive inflammatory disorder predominantly affecting people living in or originating from areas around the Mediterranean Sea. It is caused by a number of mutations within the MEFV gene, which differently affect the severity of the disease phenotype. Because patients usually present with rather nonspecific clinical symptoms, MEFV genotyping can confirm and refine FMF diagnosis and improve treatment of affected individuals. We have performed a method comparison study on 100 Lebanese FMF patients to evaluate the potential of a rapid reverse-hybridization teststrip-based assay (FMF StripAssay) to serve as a first-line screening test for our population. When results obtained by reverse-hybridization and DNA sequencing of exons 2, 3, 5, and 10 were compared, the FMF StripAssay identified 144/149 mutations, and correctly typed all 12 different MEFV mutations covered. We conclude that reverse-hybridization provides a very rapid, accurate and easy-to-perform screening method, and, in combination with more comprehensive diagnostic methods, represents an efficient strategy for FMF genotyping.

Cytoskeletal Proteins↗

Central role for type I interferons and Tyk2 in lipopolysaccharide-induced endotoxin shock.

Toll-like receptor-4 activation by lipopolysaccharide (LPS) induces the expression of interferon-beta (IFN-beta) in a MyD88-independent manner. Here we report that mice devoid of the JAK protein tyrosine kinase family member, Tyk2, were resistant to shock induced by high doses of LPS. Basal and LPS-induced expression of IFN-beta and IFN-alpha4 mRNA in Tyk2-null macrophages were diminished. However, Tyk2-null mice showed normal systemic production of nitric oxide and proinflammatory cytokines and the in vivo response to tumor necrosis factor (TNF) was unperturbed. IFN-beta-null but not STAT1-null mice were also resistant to high dose LPS treatment. Together, these data suggest that Tyk2 and IFN-beta are essential effectors in LPS induced lethality.

Animals↗

Simultaneous detection of multiple familial hypercholesterolemia mutations facilitates an improved diagnostic service in South african patients at high risk of cardiovascular disease.

AIM: DNA testing can provide a definitive diagnosis of familial hypercholesterolemia (FH), even in the absence of the clinical characteristics of this inherited cardiovascular disease (CVD) subtype. Our aim was to design a rapid diagnostic assay capable of simultaneously analyzing seven point mutations in the low-density lipoprotein receptor (LDLR) gene, which occur at high frequency in South African FH patients. METHODS: The test is based on multiplex DNA amplification and hybridization to membrane strips presenting a parallel array of immobilized allele-specific oligonucleotide probes. RESULTS: A reverse-hybridization assay for genotyping LDLR point mutations D154N, D200G, D206E, C356Y, G361V, V408M, and P664L was set-up and validated using pretyped human DNA samples, as well as recombinant plasmid clones containing mutant alleles. The procedure is rapid (6 hours) and may be automated to a large extent. CONCLUSIONS: The new FH strip-assay forms an important part of the comprehensive cardiovascular genetic screen offered routinely to high-risk population groups in South Africa. A genetic approach based on FH testing in conjunction with other 'genetic' CVD risk factors is feasible and justified, since the spectrum of disease-related mutations have been defined to a large extent in the genetically distinct population groups of South Africa. Knowledge of a significantly increased CVD risk due to the presence of gene variations, which can be targeted for risk reduction by the avoidance of relevant environmental risk factors and the appropriate treatment, provides a powerful message to motivate people into implementing preventative measures based on their genetic profile.

Amino Acid Substitution↗

Model of the equine rhinitis A virus capsid: identification of a major neutralizing immunogenic site.

Mouse monoclonal antibodies (mAbs) were employed to select neutralization escape mutants of equine rhinitis A virus (ERAV). Amino acid changes in the ERAV mutants resulting in resistance to neutralization were identified in capsid protein VP1 at Lys-114, Pro-240 and Thr-241. Although the changes were located in different parts of the polypeptide chain, these mutants exhibited cross-resistance against all four mAbs employed, indicating that these residues contribute to a single immunogenic site. To explain this result, we constructed a model of the three-dimensional structure of the ERAV capsid based on comparison with the closely related foot-and-mouth disease virus (FMDV O(1)). According to this model, VP1 is folded so that Lys-114 is in the beta E-beta F loop of the polypeptide chain at a considerable distance from Pro-240 and Trp-241 in the C-terminal region. However, around the fivefold axis of symmetry, the C terminus of VP1 in each protomer extends to the beta E-beta F loop of the adjacent VP1 in the next protomer. We therefore propose that the immunogenic site in ERAV is formed as a result of the close proximity of the Lys-114 residue in the beta E-beta F loop of one VP1 molecule and of the Pro-240/Thr-241 residues in the adjacent VP1 polypeptide chain. In terms of the overall architecture of the viral capsid structure, this site in ERAV most closely resembles the immunogenic site 1 of FMDV O(1).

Amino Acid Sequence↗

Rapid genetic testing for Gaucher disease by reverse hybridization.

BACKGROUND: We evaluated a reverse hybridization method for the simultaneous detection of nine mutations that are associated with Gaucher disease. RESULTS AND CONCLUSION: Results were in agreement with those obtained by a polymerase chain reaction-restriction digestion method. The hybridization method produced results more quickly and with less operator input.

Gaucher Disease↗