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E Köhler

Publications and source records attributed to E Köhler.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

Low correlation of serology with detection of Chlamydia trachomatis by ligase chain reaction and antigen EIA.

The aim of the present study was to evaluate the diagnostic accuracy of serology by using new assays for the detection of genus and species-specific IgG, IgM, IgA and secretory IgA antibody in female sex workers. Cervical swabs and first void urine (FVU) from 314 female sex workers were submitted to nucleic acid amplification by ligase chain reaction (LCx, Abbott). Concomittantly, blood samples were tested for the presence of IgG, IgM and IgA antibodies using a genus-specific assay (rELISA, Medac) and species-specific test (SeroCT, Orgenics). Chlamydia trachomatis infection was detected in a total of 30 (9.6%) female sex workers by LCR. With rELISA, seroprevalences for IgG, IgM, and IgA antibody to Chlamydia were 88.9%, 19.1% and 62.7%, respectively. IgG and IgA antibody prevalences against C. trachomatis (SeroCT) were 65.0% and 23.9%, respectively. In comparison to the positive LCR results obtained from cervical swab and/or FVU, the sensitivity of rELISA for Chlamydia IgG, IgA and IgM detection was 93.3%, 83.3% and 16.7%, respectively. With SeroCT, the sensitivity for C. trachomatis-specific IgG and IgA detection was 86.7% and 33.3%, respectively. The specificities of both serologic tests in comparison to LCR were very low. In conclusion, the correlation of serology with active C. trachomatis infection of the lower genital tract is very low. According to our results, serologic testing for Chlamydia can exclude active infection of the lower genital tract with a high reliability (> or = 95%). However, detection of C. trachomatis can only be reliably achieved by nucleic acid amplification assays.

Antibodies, Bacterial↗
PubMedDate not supplied

Does aldosterone-induced cardiac fibrosis involve direct effects on cardiac fibroblasts?

To investigate the hypothesis that aldosterone plays a role in the development of fibrosis, cultured fibroblasts from adult rat heart have been examined for their expression of aldosterone receptors and the effects of aldosterone on collagen synthesis. Binding assays with both 3H-aldosterone and 3H-RU26752 in intact cardiac fibroblasts and cytosolic extracts from cardiac fibroblasts failed to reveal expression of aldosterone receptors. However, using the method of reverse transcription-polymerase chain reaction, we could demonstrate the expression of mRNA for the mineralocorticoid receptor in both cardiac fibroblasts and neonatal rat cardiomyocytes. Functional studies investigating the effect of aldosterone on collagen synthesis (3H-proline incorporation into collagenous protein) revealed that aldosterone does not stimulate collagen synthesis in cardiac fibroblasts at concentrations (10(-8) to 10(-9) M) observed in primary or secondary hyperaldosteronism. At higher concentrations (10(-6) to 10(-7) M) aldosterone inhibited collagen synthesis. Expression of collagen genes I alpha 1, III alpha 1, IV alpha 1 and of the collagenase gene was not affected by aldosterone. The collagen gene VI alpha 2 was also found to be expressed in cultured cardiac fibroblasts, and its expression was also independent of aldosterone. The data indicate that fibrosis is not due to a direct effect of aldosterone on fibroblast collagen synthesis.

Aldosterone↗
PubMedDate not supplied

[Quantitative comparison of ribosome binding sites of twelve nucleotide sequences from Escherichia coli (RNA- and DNA phages) based on triplet patterns (author's transl)].

The molecular structure of ribosome binding sites of ten phage genes and two messengers of Escherichia coli were compared concerning the signation parts which are presumably used by ribosomes for recognition and binding. With a simple calculation based on triplet patterns sofar unknown agreements between all of these sequences were found. In several cases it was shown that agreements between old sequences are easier recognizable if the purine- and pyrimidine bases are put into the triplets instead of the four A, G, C, and U (T) bases. In such cases "homologous" parts of sequences were recognized with more distinctness. This is true in our case for the double triplet (hexaplet) py-pu-pu-pu-pu-(pu) and the binding site triplet py-pu-pu, which are preceding the initiator. These triplets are in specific positions in all twelve sequences which were compared. The different course of the quaternary and the binary conformity curves (diagram 1) may show for the investigated area that the RNA phage gene-part is organized according to the well known quaternary triplet code. On the contrary the phage phi-gene-part seems to be organized according to a more simple, binary triplet sequence of purine and pyrimidine bases. The binary sequence seems to be the more original, the quaternary the derived one.

Base Sequence↗
PubMedDate not supplied

[Quantitative chloramphenicol detection in serum and cerebrospinal fluid of infants with bacterial meningitis].

Twenty-six meningitic infants aged less than one year were administered daily oral or intravenous doses from 44 to 170 mg chloramphenicol per kg body weight. Serum levels measured were 5.4 to 55.0 micrograms.ml-1, and CSF concentrations from 0.9 to 20.2 micrograms.ml-1 were noted. Since, in particular for younger infants, (i) there is no clear relationship between dose and blood level and (ii) one cannot unambiguously infer the CSF concentration from the blood level we recommend that initial doses for meningitic infants be chosen according to age-adjusted dosage instructions and, from day 2 onwards, doses be corrected as a function of CSF and blood levels (CSF greater than 10 micrograms.ml-1 and serum less than 50 micrograms.ml-1).

Bacterial Infections↗