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Biomedical subjects

H C Scholz

Publications and source records attributed to H C Scholz.

9 recordsLinked to original sources

A highly specific one-step PCR - assay for the rapid discrimination of enteropathogenic Yersinia enterocolitica from pathogenic Yersinia pseudotuberculosis and Yersinia pestis.

Based on differences within the yopT-coding region of Yersinia. enterocolitica, Y pseudotuberculosis and Y pestis, a rapid and sensitive one-step polymerase chain reaction assay with high specificity for pathogenic Y enterocolitica was developed. By this method pathogenic isolates of Y enterocolitica can be easily identified and discriminated from other members of this genus. The entire coding sequence of the yopT effector gene of Y. pseudotuberculosis Y36 was determined.

Animals↗

S-layer variation in Bacillus stearothermophilus PV72 is based on DNA rearrangements between the chromosome and the naturally occurring megaplasmids.

Bacillus stearothermophilus PV72 expresses different S-layer genes (sbsA and sbsB) under different growth conditions. No stretches of significant sequence identity between sbsA and sbsB were detected. In order to investigate S-layer gene regulation in B. stearothermophilus PV72, we characterized the upstream regulatory region of sbsA and sbsB by sequencing and primer extension analysis. Both genes are transcribed from unique but different promoters, independently of the growth phase. Localization of sbsB in the sbsA-expressing strain PV72/p6 revealed that the coding region of the second S-layer gene sbsB is located not on the chromosome but on a natural megaplasmid of the strain, whereas the upstream regulatory region of sbsB was exclusively detected on the chromosome of PV72/p6. For sbsB expression, the coding region has to be integrated into the chromosomally located expression site. After the switch to sbsB expression, the sbsA coding region was removed from the chromosome but could still be detected on the plasmid of the sbsB-expressing strain PV72/p2. The sbsA upstream regulatory region, however, remained on the chromosome. This is the first report of S-layer variation not caused by intrachromosomal DNA rearrangements, but where variant formation depends on recombinational events between the plasmid and the chromosome.

Bacterial Proteins↗

Therapy with hyperbaric oxygen and cefazolin for experimental osteomyelitis due to Staphylococcus aureus in rats.

Hyperbaric oxygen (HBO2) is used as adjunctive therapy for chronic osteomyelitis, yet its efficacy remains controversial. A recently developed rat model for osteomyelitis due to Staphylococcus aureus was used to compare the results of treatment with HBO2, cefazolin, a combination of both, or no treatment. For the induction of tibial osteomyelitis, S. aureus was inoculated into the medullary cavity. Arachidonic acid was used as the sclerosing agent. With that procedure, an infection rate of 96% was attained. For long-term antibiotic treatment, a port system was developed and implanted. Hyperbaric treatment alone reduced the colony-forming units (CFU) from 2.9 x 10(6) to 6.2 x 10(5) x g(-1) of tibial bone. The effect on the infection was more pronounced with antibiotic therapy alone, 10.5 x 10(4) CFU per g of tibial bone were measured. However, changes were most marked using a 4-wk combination therapy consisting of HBO2 and an antibiotic agent. The colony count was 2.7 x 10(3) CFU. Each of the treatment modalities resulted in a significant therapeutic effect. The results not only demonstrated the effectiveness of HBO2 in the treatment of osteomyelitis, but revealed a potential additive effect with the combination of HBO2 and an antibiotic.

Animals↗

[Gambee single modified all-layer suture].

Our modified all-layer suture technique allows surgery of colon and rectum with a low rate of anastomotic leaks (2%). In experimental animal research on pigs we compared the modified all-layer suture with the Gambee and the stapling technique. The circulation was examined by radioactive marked microspheres, by microangiograms and by special injection preparations.

Anastomosis, Surgical↗

Parathyroid hormone in coronary artery disease--results of a prospective study.

Parathyroid hormone (PTH) influences the calcium metabolism of many different mammalian cell types; indeed, hypertension due to changes in muscle tone is a frequent symptom of hypercalcemic hyperparathyroidism. In a blind study of 81 patients with various forms of heart disease undergoing coronary angiography, the plasma concentrations of the midcarboxyl regional PTH immunoreactivity were determined. PTH concentrations were elevated in 26 of the 56 patients exhibiting organic coronary artery disease (CAD). The plasma PTH levels were highest in those patients with CAD affecting three vessels and in patients with evidence of myocardial infarction. PTH levels were not influenced by previous drug treatments, and did not correlate to stress hormone levels. We propose that increased PTH levels may be a marker for initiation or potentiation of calcium-dependent changes in vascular smooth muscle behavior inducing coronary functional and anatomic lesions typical of CAD.

Adult↗

Influence of long-time transportation stress on re-activation of Salmonella typhimurium DT104 in experimentally infected pigs.

In this study a Salmonella Typhimurium infection model in swine was used in order to investigate the influence of pre-mortal stress induced by long time period transportation on the re-activation of Salmonella in experimentally infected pigs. Salmonella free pigs were exposed to a highly virulent strain of Salmonella Typhimurium DT104 by direct intragastrical administration. Clinical parameters were monitored and the shedding rate in faeces was qualitatively and quantitatively determined by standard bacteriological procedures for 21 days. The distribution of the challenge organism in 14 different internal organs of transported and nontransported animals was determined. All infected animals developed clinical signs of salmonellosis 12 to 24 hours post infection. About 88 to 100% of the fecal samples were culture-positive up to post exposure day 6, and then varied from 71 to 92% until slaughter, respectively. At necropsy S. Typhimurium was recovered most frequently from caecum and ileocolic lymph nodes (83%), colon (79%), palatine tonsils (71%) and mandibular lymph nodes (62.5%). A negative impact of transportation stress on the shedding rate and the general condition of the animals was observed.

Animals↗

Improvement of an invA-based PCR for the specific detection of Salmonella typhimurium in organs of pigs.

The aim of this study was to investigate the suitability of the invA-based polymerase chain reaction (PCR) assay for the specific detection of Salmonella in organs of experimentally infected pigs and to compare these results to classical bacterial culture. While the PCR conditions specified in the "Deutsche Industrie Norm", DIN 10135 (section 35 LMBG, 1999), cutle based on the publication of Rahn et al. 1992, revealed various unspecific amplification products, modifications of the PCR conditions allowed the specific amplification of the invA fragment from inner organs. The modified PCR assay correlates exactly with cultivation results (as required by DIN Norm 6579) and enables the detection of Salmonella within 48 hours with equal sensitivity compared to routine cultivation.

Animals↗