Biomedical subjects

Thomas Behr

Publications and source records attributed to Thomas Behr.

5 recordsLinked to original sources

PubMed2005

Oligonucleotide microarray for identification of Enterococcus species.

For detection of most members of the Enterococcaceae, the specificity of a novel oligonucleotide microarray (ECC-PhyloChip) consisting of 41 hierarchically nested 16S or 23S rRNA gene-targeted probes was evaluated with 23 pure cultures (including 19 Enterococcus species). Target nucleic acids were prepared by PCR amplification of a 4.5-kb DNA fragment containing large parts of the 16S and 23S rRNA genes and were subsequently labeled fluorescently by random priming. Each tested member of the Enterococcaceae was correctly identified on the basis of its unique microarray hybridization pattern. The evaluated ECC-PhyloChip was successfully applied for identification of Enterococcus faecium and Enterococcus faecalis in artificially contaminated milk samples demonstrating the utility of the ECC-PhyloChip for parallel identification and differentiation of Enterococcus species in food samples.

DNA, Bacterial↗

PubMed2004

Vascular endothelial dysfunction and superoxide anion production in heart failure are p38 MAP kinase-dependent.

OBJECTIVE: The mitogen-activated protein (MAP) kinase system, especially the p38 MAP kinase, is activated in chronic heart failure (CHF). However, the role of vascular p38 MAP kinase in CHF has not been analyzed yet. METHODS AND RESULTS: In aortic rings from rats with CHF 10 weeks after myocardial infarction, acetylcholine-induced relaxation was attenuated (maximum relaxation, Rmax: 54+/-5%) compared to sham-operated animals (Rmax: 77+/-5%, p<0.01), while endothelium-independent relaxation elicited by sodium nitroprusside was not significantly changed. Aortic levels of phosphorylated p38 MAP kinase protein were significantly elevated in rats with CHF. In addition, phosphorylation of MAP kinase-activated protein kinase-2 (MAPKAPK-2), an index of p38 MAP kinase activity, was increased. Aortic superoxide anion generation was significantly enhanced in rats with CHF accompanied by elevation of the NAD(P)H oxidase subunit p47phox protein expression. Inhibition of p38 MAP kinase by treatment with the p38 MAP kinase inhibitor SB239063 (800 ppm in standard rat chow) reduced MAPKAPK-2 phosphorylation, preserved acetylcholine-induced relaxation (Rmax: 80+/-4%, p<0.01), and reduced vascular superoxide formation. SB239063 treatment did not affect blood pressure and left ventricular enddiastolic pressure. In aortic tissue from CHF animals treated with the angiotensin-converting enzyme (ACE) inhibitor trandolapril, p38 MAP kinase phosphorylation was significantly reduced. CONCLUSIONS: Vascular p38 MAP kinase is markedly activated in rats with CHF. Chronic p38 MAP kinase inhibition with SB239063 prevented endothelial vasomotor dysfunction through reduction of superoxide anion production.

Acetylcholine↗

PubMed2004

The sentinel node concept in head and neck cancer: solution for the controversies in the N0 neck?

BACKGROUND: The majority of patients with head and neck squamous cell carcinoma (HNSCC) who have a clinical N0 neck undergo neck dissection (ND) even though no lymph node metastases may be detected. With this background, our investigation critically analyzes the value of sentinel lymphadenectomy. METHODS: Ninety patients with HNSCC, all staged with an N0 neck, underwent intraoperative 99mTc-radiolabeled detection of up to three hot nodes (SN1-3) during elective ND and primary site resection. RESULTS: Sentinel lymphadenectomy (SN1-3) detected occult metastatic spread in 20 (22%) of 90 patients, whereas failure occurred in three of 90 patients. Metastatic spread was directed to level II in the majority (66.7%) of cases. If only the SN1 had been examined, the procedure would have failed in nine (39%) of 23 patients. CONCLUSION: Sentinel lymphadenectomy correctly identified the stage of metastatic disease in 97% of patients in cases in which up to three sentinel nodes were identified. If only the lymph node with the highest tracer activity had been excised, 39% of cancer-positive necks would have been missed. Selective ND identified metastatic disease in the additional 3% of patients.

Carcinoma, Squamous Cell↗

PubMed2004

Value of sentinel lymphadenectomy in head and neck cancer.

The increasing interest in the so-called sentinel node concept, which has recently been adapted to squamous cell carcinomas of the upper aerodigestive tract, can be explained by encouraging results in other tumor entities. Although the publications on this topic do not yet allow a final judgment on the significance of sentinel lymphadenectomy in head and neck squamous cell carcinoma, early results emphasize the importance of this new diagnostic and therapeutic concept. The basic prerequisite is a detailed knowledge of the existing method-specific limitations in this anatomic region. Critical and careful evaluation of the sentinel node concept is mandatory prior to its application to other tumor entities. Sentinel lymphadenectomy for head and neck cancer may prove helpful if the indications for its use are clearly defined.

Carcinoma, Squamous Cell↗

PubMed2003

Dopamine transporter imaging and SPECT in diagnostic work-up of Parkinson's disease: a decision-analytic approach.

As a diagnostic test for patients with suspected Parkinson's disease (PD), single photon emission computed tomography (SPECT) using [(123)I]FP-CIT tracer has better sensitivity but is more expensive than regular clinical examination (CE). Our objective was to evaluate the clinical and economic impacts of different diagnostic strategies involving [(123)I]FP-CIT SPECT. We developed a decision tree model to predict adequate treatment-month equivalents (ATME), costs, and incremental cost-effectiveness ratio (ICER) during a 12-month time horizon in patients with suspected PD referred to a specialized movement disorder outpatient clinic. In our cost- effectiveness analysis, we adopted the perspective of the German health care system and used data from a German prospective health care utilization study (n = 142) and published diagnostic studies. Compared strategies were CE only (EXAM+), SPECT only (SPECT+), SPECT following negative CE (SINGLE+), and SPECT following positive CE (DOUBLE+). Costs of SPECT amounted to euro;789 per investigation. Based on our model, expected costs (and ATME) were euro;946 (52.85 ATME) for EXAM+, euro;1352 (53.40 ATME) for DOUBLE+, euro;1731 (32.82 ATME) for SINGLE+, and euro;2003 (32.96 ATME) for SPECT+; performance of SPECT was induced in 0%, 54%, 56%, and 100% of the patients, respectively. DOUBLE+ was more effective and less expensive than SINGLE+ or SPECT+; thus these two do not offer reasonable choices. The ICER of DOUBLE+ compared to EXAM+ was euro;733 per ATME gained. In sensitivity analyses, the ICER of DOUBLE+ versus EXAM+ ranged from euro;63 to euro;2411 per ATME gained. Whether the diagnostic work-up of patients referred to a specialized movement disorder clinic with a high prevalence of PD should include [(123)I]FP-CIT SPECT depends on patient preferences and the decision maker's willingness to pay for adequate early treatment. SPECT should be used as a confirmatory test before treatment initiation and limited to patients with a positive test result in the clinical examination. These results should be adjusted to the specific setting and individual patient preferences.

Ambulatory Care Facilities↗