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M Dorsch

Publications and source records attributed to M Dorsch.

47 records · Page 3Linked to original sources
PubMed1991

16S rRNA sequences of Bartonella bacilliformis and cat scratch disease bacillus reveal phylogenetic relationships with the alpha-2 subgroup of the class Proteobacteria.

The primary structures of 16S rRNAs of Bartonella bacilliformis, an isolate of the cat scratch disease (CSD) bacillus, and a strain phenotypically similar to the CSD bacillus were determined by reverse transcriptase sequencing. These microorganisms were found to be members of the alpha-2 subgroup of the class Proteobacteria. The sequence from B. bacilliformis was most closely related to the rRNA of Rochalimaea quintana (91.7% homology), the etiologic agent of trench fever. The sequence from the isolate of the CSD bacillus showed the greatest homology with Brucella abortus (89.7%) and, when compared with oligonucleotide catalog data, formed a cluster with Rhodopseudomonas palustris, Pseudomonas carboxidovorans, Nitrobacter species, and Bradyrhizobium species. The 16S rRNA sequence was also determined for the Cleveland Clinic isolate, which was previously shown to be phenotypically similar to and approximately 30% related, by DNA hybridization, to the CSD bacillus. The Cleveland Clinic isolate was isolated from a patient not diagnosed with CSD. The rRNAs from these bacteria exhibited 98.2% homology, confirming that this isolate is a second species in the same genus as the CSD bacillus. Our data suggest that neither B. bacilliformis nor the CSD bacillus is the etiologic agent of bacillary epithelioid angiomatosis.

Alphaproteobacteria↗
PubMed1990

Infiltrating ductal carcinoma of the breast in South Australia. Implications of trends in tumour diameter, nodal status and case-survival rates for cancer control.

The SA Central Cancer Registry gained sufficient information from routine pathology reports to record both the diameter and the nodal status for approximately half the infiltrating ductal carcinomas of the breast that were diagnosed in that State between 1980 and 1986. Of these, 27% of cancers had diameters of less than 2.0 cm at diagnosis and a similar proportion measured 4.0 cm or more. Almost half (48% of cancers) showed evidence of axillary nodal metastasis. Although the over-all variation in diameters by socioeconomic status did not approach statistical significance, lesions tended to be smaller in cases from the upper than the middle or lower socioeconomic areas of Adelaide. There also was evidence of earlier diagnosis during a breast self-examination campaign, but only a marginal increase in case-survival rates that readily was attributable to chance. A relatively poor case-survival rate applied in non-metropolitan areas, especially among older women, after adjusting for the available information on the stage of disease at diagnosis. A more limited access to treatment services may have been responsible. It will be important in a State-wide mammographic screening programme to provide for ready access by women in non-metropolitan areas to both screening and follow-up treatment services.

Age Factors↗
PubMed1990

Taxonomic and phylogenetic studies on a new taxon of budding, hyphal Proteobacteria, Hirschia baltica gen. nov., sp. nov.

Four strains of budding, hyphal bacteria, which had very similar chemotaxonomic properties, were isolated from the Baltic Sea. The results of DNA-DNA hybridization experiments, indicated that three of the new isolates were closely related, while the fourth was only moderately related to the other three. Sequence signature and higher-order structural detail analyses of the 16S rRNA of strain IFAM 1418T (T = type strain) indicated that this isolate is related to the alpha subclass of the class Proteobacteria. Although our isolates resemble members of the genera Hyphomicrobium and Hyphomonas in morphology, assignment to either of these genera was excluded on the basis of their markedly lower DNA guanine-plus-cytosine contents. We propose that these organisms should be placed in a new genus, Hirschia baltica is the type species of this genus, and the type strain of H. baltica is strain IFAM 1418 (= DSM 5838).

Bacteria↗
PubMed1990

Brucella abortus 16S rRNA and lipid A reveal a phylogenetic relationship with members of the alpha-2 subdivision of the class Proteobacteria.

On the basis of ribosomal 16S sequence comparison, Brucella abortus has been found to be a member of the alpha-2 subdivision of the class Proteobacteria (formerly named purple photosynthetic bacteria and their nonphototrophic relatives). Within the alpha-2 subgroup, brucellae are specifically related to rickettsiae, agrobacteria, and rhizobiae, organisms that also have the faculty or the obligation of living in close association to eucaryotic cells. The composition of Brucella lipid A suggests a close phylogenetical relationship with members of the alpha-2 group. The chemical analysis of the lipid A fraction revealed that Brucella species contain both glucosamine and diaminoglucose, thus suggesting the presence of a so-called mixed lipid A type. The serological analysis with polyclonal and monoclonal antibodies is in agreement with the existence of mixed lipid A type in B. abortus. The amide-linked fatty acid present as acyl-oxyacyl residues were 3-O-C(16:0)12:0, 3-O-C(16:0)13:0, 3-O-C(16:0)14:0, and 3-O-C(18:0)14:0. The only amide-linked unsubstituted fatty acid detected was 3-OH-C16:0. The ester-linked fatty acids are 3-OH-C16:0, 3-OH-C18:0, C16:0, C17:0, and C18:0. Significant amounts of the large-chain 27-OH-C28:0 were detected together with traces of 25-OH-C26:0 and 29-OH-C30:0. Comparison of the Brucella lipid composition with that of the other Proteobacteria also suggests a close phylogenetical relationship with members of the alpha-2 subdivision. The genealogical grouping of Brucella species with pericellular and intracellular plant and animal pathogens as well as with intracellular plant symbionts suggests a possible evolution of Brucella species from plant-arthropod-associated bacteria.

Bacteria↗
PubMed1989

Phylogenetic evidence for the relationship between the genera Mobiluncus and Actinomyces.

Partial reverse transcriptase sequencing of 16S rRNA from Mobiluncus curtisii and M. mulieris clearly indicate that the genus Mobiluncus is not a member of the Bacteroidaceae but belongs to the order Actinomycetales. The highest degree of relationship is found with the genus Actinomyces which is supported by the presence of common physiological properties.

Actinomyces↗
PubMed1987

Cloning and expression in Escherichia coli of Proteus vulgaris genes for 16S ribosomal RNA.

In contrast to the established systems of plasmid-coded homologous ribosomal DNA (rDNA) cistrons in Escherichia coli little is known about the fate of heterologous rRNA. In order to study expression of foreign rDNA, rRNA cistrons from Proteus vulgaris were cloned in phage vector Charon 35, subcloned in pBR322 and transformed in E. coli. The inserts of two clones (pPM2 and pPM14) were characterized by restriction analysis and Southern hybridization. Each of them harboured a complete rrn cistron. The location of rRNA genes of clone pPM2 was also verified by R-loop analysis. The 5' flanking region of the 16S rRNA of pPM2 was sequenced and compared to the E. coli counterparts. High-level homologies exist in the functional parts of this region, e.g. promoters, box A and RNAase III recognition site. The copy number of pPM2 and pPM14 was estimated to be 8 and 10, respectively. Clones showed a markedly reduced growth rate (generation time about 57 to 70 min) as compared to the non-transformed cells (generation time 40 min). rDNA cistrons of P. vulgaris were properly expressed and the transcripts are processed as demonstrated by the presence of 16S rRNA from P. vulgaris in both ribosomes and 30S ribosomal subunits isolated from the transformed E. coli cells. The fraction of heterologous rRNA in ribosomes was about 25%.

Amino Acid Sequence↗
PubMedDate not supplied

Residual cftr expression varies with age in cftr(tm1Hgu) cystic fibrosis mice: impact on morphology and physiology.

Mouse models for cystic fibrosis (CF) mimic intestinal manifestations of the human disease, but the lung disease phenotypes are lacking in most strains. In this work, the issue was addressed whether aging of the respiratory tract leads to lung pathophysiology in the exon 10 insertional mutant cftr(tm1Hgu) mouse. Weight gain, body weight and life-span of cftr(tm1Hgu) mice were significantly reduced compared with control mice. cftr(tm1Hgu) mice expressed 20, 21 or 37% (median) of wild-type cystic fibrosis conductance transmembrane regulator (cftr) mRNA transcript in lungs, intestine and kidney. Wild-type cftr mRNA in renal and respiratory epithelia varied with age from levels similar to Ztm:MF1 controls at the age of 2 and 4 months to levels seen in patients with CFTR splice mutations beyond the age of 6 months. The morphology of the bronchi and more distal airways was apparently normal in cftr(tm1Hgu) mice during their first year of life. The alveolar surfactant phospholipid pool was increased in cftr(tm1Hgu) mice by 1.5- to 2-fold compared with Ztm:MF1 controls. Alveolar clearance of gamma-labelled scandium oxide - the first report of lung clearance measurement in living mice - was reduced in cftr(tm1Hgu) mice compared with littermate controls. Although no progressive lung pathology was seen in the cftr expression of cftr(tm1Hgu) mice, surfactant phospholipid homeostasis, and alveolar and mucociliary clearance were abnormal. Therefore, the described model is useful for studying the initial CF lung pathophysiology.

Aging↗
PubMedDate not supplied

Incorporation of a Calliphora arylphorin gene into the germ line of Drosophila by p-element-mediated transformation.

Two arylphorin gene clones were inserted into the transposable p-element vector Carnegie 20 and injected into Drosophila rosy- mutants. Transponed animals were selected by their red eye colour and remated. We demonstrate by hybridization experiments the stable integration of the injected genes in the germ line of Drosophila. However, the incorporated genes are not expressed.

Animals↗
PubMedDate not supplied

Tumor-cell-targeted cytokine gene transfer in experimental models for cancer therapy.

The genetic manipulation of tumor cells to express immunostimulatory molecules provides a current approach for the analysis of immune reactions against tumor cells in vivo. Experiments with multiple cytokines have demonstrated that an array of different host effector cells can be recruited by different cytokines in vivo, but more studies are necessary to distinguish cytokine-specific effects from as yet uncharacterized influences of different tumor models. A technically feasible clinical application of this approach is to be seen in the generation of vaccines by introducing such immunostimulatory genes into cancer cells and boosting systemic immune reactions against the unmodified cells. The experimental basis of these vaccination studies is critically discussed.

Animals↗