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Biomedical subjects

E Günther

Publications and source records attributed to E Günther.

At least 55 records · Page 3Linked to original sources
PubMed1997

Streptococcal pyrogenic exotoxin A, streptolysin O, exoenzymes, serotype and biotype profiles of Streptococcus pyogenes isolates from patients with toxic shock syndrome and other severe infections.

The determination of protein M and T serotypes, biotypes and pyrogenic (erythrogenic) exotoxin A (SPE A), streptolysin O (SLO), streptokinase (SK), hyaluronidase (HA) and cysteine proteinase release by 212 S. pyogenes isolates from patients with severe invasive group A streptococcal (GAS) infections, among them 74 cases of streptococcal toxic shock syndrome (STSS) has been investigated. M1 or M3 serotypes were expressed by 25% of the isolates (53/212), whereas 59% (125/212) belonged to 15 other different serotypes and 16% (34/212) were untypeable. Of the 74 isolates from STSS patients, 42% (31/74) expressed M1 and to a lesser extent M3 serotypes versus 19% of the non STSS isolates (26/138). Among the ten different biotypes known, biotypes 1 and 3 were prevalent, particularly the former in the case of STSS isolates. SPE A was detectably produced by about 25% (54/212) of the strains. However, as high as 40.5% of the STSS isolates (30/74) versus 17.4% of non STSS isolates (24/138) released SPE A. Moreover, 67% of the SPE A producing strains were of serotype M1 or M3. SK and HA were released by 71% and 10% of the isolates respectively. All strains released SLO (4 to 256 HU/ml) and 85% cysteine proteinase. No relationship between toxin or enzyme titer and the type of disease or clinical origin of the strains was found. Culture supernatants of all isolates showed moderate to high lymphocyte transforming activity with index values ranging from 14.5 to 50.3 including those strains which did not release detectable amounts of SPE A suggesting that SPE C and other mitogenic factor(s) are released by the isolates investigated.

Adolescent↗
PubMed1996

Expression of both M protein and hyaluronic acid capsule by group A streptococcal strains results in a high virulence for chicken embryos.

The human pathogenic microorganism Streptococcus pyogenes can resist against phagocytic attack of human granulocytes. Streptococcal M protein and hyaluronic acid were identified as virulence factors involved in this protection. So far, no experiments have been reported which describe the contribution of both components together in one system. We used the chicken embryo as an in vivo phagocytosis model to investigate the role of both components on the virulence of streptococci. For this, isogeneic mutants of group A streptococcal strains (GAS) which lack hyaluronic acid capsule (cap-) or M protein (M-) expression were used for infection and their virulence was compared with laboratory strains which had lost their ability to produce one or both virulence factors after long-time laboratory passages on blood agar. The experiments revealed that strains producing both M protein and hyaluronic capsule were highly virulent. Only 1-10 colony-forming units were enough to cause a 50% lethality of 12-day-old chicken embryos. Those strains lacking one of these components showed a significant decrease in virulence. Finally, strains which failed to express either hyaluronic acid or M protein showed an additional tenfold decrease in virulence. This indicates a partial contribution of both M protein and hyaluronic acid to the virulence of GAS in the chicken embryo.

Animals↗
PubMed1996

Physical mapping of the Ring1, Ring2, Ke6, Ke4, Rxrb, Col11a2, and RT1.Hb genes in the rat major histocompatibility complex.

A contig of cosmids containing the Ring1, Ring2, Ke6, Ke4, Rxrb, and Col11a2 genes in the rat major histocompatibility complex has been established and aligned to the class II cluster (RT1.Hb). The relative order and the transcriptional orientations of these rat genes are the same as in their human and mouse homologues. The distances are also similar, except for the Col11a2 - class II interval, which is clearly shorter in rat and mouse compared with human. The previously defined Ke5 probe could be shown to map into the large Col11a2 gene.

Amino Acid Sequence↗
PubMed1996

[Functional MRI of the pharynx in obstructive sleep apnea using rapid 2D FLASH sequences].

Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager ("Vision", Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and polysomnography. A temporal resolution of 6 images/s and an in-plane resolution of 2.67 x 1.8 mm were achieved. The mobility of the tongue, soft palate and pharyngeal surface could be clearly delineated. The MRI findings correlated well with the clinical examinations. We propose ultrafast MRI as a reliable and non-invasive method of evaluating pharyngeal obstruction and their levels.

Adult↗
PubMed1996

Occurrence of extracellular hyaluronic acid and hyaluronatlyase in streptococci of groups A, B, C, and G.

Streptococci of serological groups A (GAS), B (GBS), C (GCS) and G (GGS) were examined in vitro using an optimized medium in respect of their ability to produce hyaluronic acid (HA) and hyaluronatlyase (HY). In this study, 614 GAS (including 123 streptococcal toxic shock syndrome strains, STSS), 247 GBS, 225 GCS and 143 GGS were investigated in qualitative and quantitative tests. Only 4% of GAS and 2.7% of GCS were able to express HA. In contrast to GAS, isolates of GCS showed a highly specific HA formation (to 1 g HA/g dry biomass). In all strains of GBS and GGS, not even a single isolate was positive for HA. HY expression was detectable in all four serological groups. In GAS, only 12.5% of strains were positive; the most common types being 22 and 4, whereas in GBS, GCS and GGS, 72.1%, 84% and 85.3% of isolates, respectively, could be reported as positive. The data suggest that the HA capsule only plays a secondary role in infections caused by GAS strains pathogenic for humans.

Bacterial Proteins↗
PubMed1996

Induction of heat shock protein 70 genes in human lymphocytes during fever therapy.

The induction of heat shock protein 70 (HSP70) genes has been studied in peripheral blood mononuclear cells of individuals undergoing fever therapy because of metastatic malignant melanoma. Induction of HSP70 was assessed at the protein level by metabolic labelling or, for the HLA-linked HSP70-1 and HSP70-2 genes, at the RNA level by in situ hybridization. However, de novo expression of HSP70 could be observed during fever (usually above 39 degrees C) in only about half of the cases. No simple threshold model for inducibility of HSP70 in vivo could be applied. The HSP70-1 gene was induced more easily than HSP70-2. Thus, heat-inducible HSP70 genes, including HLA-linked HSP70 genes, become expressed in human lymphocytes during fever, but not regularly.

Adult↗
PubMed1996

Chromosome mapping of rat histone genes H1fv, H1d, H1t, Th2a and Th2b.

Chromosome assignment of the rat histone genes H1t, H1d (H1.4), H1fv (H10), Th2a and Th2b is described. The testicularly expressed histone genes H1t, Th2a and Th2b could be assigned to rat chromosome (RNO) 17 by PCR analysis of somatic cell hybrid DNAs. The H1d gene was mapped to RNO17p12-->p11 by FISH. These genes might form a histone gene cluster homologous to that found on HSA6p21.3 in humans and MMU13A2-3 in mice. The rat histone H1fv gene was assigned to RNO7 by PCR. This result allows the inclusion of rat H1fv to an established conserved group of syntenic genes in rat, mouse and human on chromosomes RNO7, MMU15 and HSA22, respectively.

Animals↗
PubMed1995

Identification of a novel conserved human gene, TEGT.

A novel gene, TEGT (testis enhanced gene transcript), has been identified in humans. It does not belong to any known gene family of vertebrates. The deduced amino acid sequence of the gene and a bacterial protein of unknown function show low but significant homology and very similar hydrophobicity profiles. Two different transcripts of TEGT occur, which are due to alternative usage of two polyadenylation sites. The presence of a nuclear targeting motif indicates that the gene product might localize to the nucleus. The TEGT gene maps to human chromosome 12q12-q13 and belongs to a syntenic group, which is conserved in human, mouse, and rat.

Animals↗
PubMed1995

Characterization and mapping of a highly conserved processed pseudogene and an intron-carrying gene of the heat shock cognate protein 70 (Hsc70) gene family in the rat.

A processed pseudogene of the rat Hsc70 gene, Hsc70-ps1, is described, which still presents the open reading frame of the original gene. The pseudogene does not appear to be expressed. It maps to rat Chromosome (Chr) 2. The intron-carrying Hsc70 gene localizes to Chr 8. Hsc70-specific probes detect a large number of more than 20 cross-hybridizing fragments, which show only limited length polymorphism among various inbred rat strains.

Animals↗
PubMed1995

Penicillin-resistant Streptococcus pneumoniae in Germany: genetic relationship to clones from other European countries.

Penicillin-resistant Streptococcus pneumoniae strains isolated in different parts of Germany between 1982 and 1992 were compared with penicillin-resistant isolates, mainly of serogroups 6, 9, 14, 19 and 23, from other European countries. The main clones were recognised by their serotypes, antibiotic resistance patterns and penicillin-binding protein properties, and this typing was confirmed by multi-locus enzyme electrophoresis for a sample of 43 selected isolates. Eleven of the 14 resistant German isolates could be assigned to five genotypes isolated also in other countries. These included representatives of two distinct serotype 23F lineages predominant in Spain and France; a cluster of three serotype 6B isolates identical to clones in Spain, France, Finland and Hungary; and a serotype 9V clone of a type prevalent in Spain and now also in France. Serotype 19A clones of the type found in Hungary were not collected in Germany. The data suggest that two 23F lineages, represented by seven isolates from different locations, have become disseminated in Germany. Several resistant types found in the former West Germany resembled those found elsewhere in Western Europe whereas those from East Germany were distinct or, in one case, resembled a clone from Hungary. These data may reflect pre-unification travel patterns.

Bacterial Proteins↗
PubMed1995

Light and electron microscopic localization of the alpha 1-chain and the E1 and E8 domains of laminin-1 in mouse kidney using monoclonal antibodies to establish the orientation of laminin-1 within basement membranes.

To localize the different domains of the laminin-1 molecule in tissues and gain insight into their in vivo relevance, we raised rat anti-mouse monoclonal antibodies (MAbs) against the entire molecule. Then we tested eight of the 20 clones producing anti-laminin-1 MAbs to specify their reactivity towards the alpha 1-, beta 1-, and gamma 1-chains and the elastase-cleaved fragments of the laminin-1 molecule. We found three MAbs with high titers in ELISA that showed good reactivity in embedded tissue. One of these reacted specifically against the E1 fragment, one against the E8 fragment, and one MAb detected the alpha 1-chain of laminin-1 but not the beta 1- or gamma 1-chain. All three MAbs are useful for light immunohistochemical investigations on cryosections and on paraffin-embedded material, and for ultrastructural localization of laminin-1 in LR Gold-embedded mouse tissue. Antibody staining of the E1 and E8 domains of laminin-1 revealed distinct localization of the molecule in the proximal tubule basement membranes of mouse kidney. The short arms (E1) of the laminin-1 molecule are predominantly located in the lamina lucida and the long arms (E8) are oriented towards the lamina fibroreticularis. Therefore, both MAbs are useful for studies of the orientation of the laminin-1 molecule in basement membranes. The distal tubule basement membranes did not show any distinct pattern of laminin-1 distribution. In general, the distal tubules showed the strongest reactions over the entire width of the basement membrane for all three MAbs. In contrast, the proximal tubule basement membranes showed somewhat weaker reactivity but a distinct pattern of laminin-1 distribution, with the E1 fragments oriented towards the adjacent epithelial cell surface.

Animals↗
PubMed1995

Isolation and characterization of a mitogen characteristic of group A streptococci (Streptococcus pyogenes).

It has been supposed for many years that group A streptococci may elaborate more than the three well known erythrogenic toxins A, B or C (ETA, ETB, ETC). The analysis of the culture supernatant of streptococcal strain 27297 carrying neither genes for ETA nor ETC revealed mitogenic activity at pH 7.3 in isoelectric focusing. This mitogen of strain 27297 was purified by hydrophobic adsorption to Phenyl-Sepharose following FPLC chromatography on a Mono S column resulting in two proteins with mitogenic activity called AX and BX, respectively. Both differed in only one aminoterminal residue. The mitogenic activity of BX lacking one aminoterminal arginine was found to be about 100 times higher than that of AX. The aminoterminus of BX does not correspond to a predictable cleavage site for signal peptidase. We assume that BX was produced after translation by cleavage of the mature protein or the AX molecule with streptococcal proteinase (ETB) or an arginylaminopeptidase which is detectable on whole cells. The purified proteins BX and AX showed molecular weights of about 27 kDa in SDS electrophoresis and isoelectric points of 8.3 (AX) and 7.3 (BX) in isoelectric focusing, respectively. Both proteins were produced by practically all group A strains tested but not by groups B, C, G or H streptococci. Therefore, AX or BX seem to be proteins characteristic of group A streptococci.

Amino Acid Sequence↗
PubMed1994

Genetic aspects of the hsp70 multigene family in vertebrates.

The family of genes encoding heat shock proteins of about 70 kDa (hsp70) in vertebrates is reviewed under genetic aspects. After a detailed description of the various hsp70 genes more general characteristics of the organization and evolution of the multigene family are discussed.

Amino Acid Sequence↗