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B Rehbock

Publications and source records attributed to B Rehbock.

5 recordsLinked to original sources
PubMed2004

[Diagnostic imaging of pulmonary lymphangiosis carcinomatosis].

The diagnosis of pulmonary lymphangiosis carcinomatosa (PLC) is of great importance for the prognostically-oriented therapy stratification of tumor patients. In this field, high-resolution computed tomography (HRCT) is the state of the art in imaging. Using HRCT, it is possible to identify pulmonary parenchymal structures in a detailed fashion to evaluate interstitial patterns. This step is preceded by an x-ray of the thorax that detects pathological findings and rules out other diseases. The typical characteristics of PLC are described with particular attention to HR-phenomenology, and discussed in comparison with the literature regarding anatomy and pathogenesis. Finally, conclusions are drawn for differential diagnosis and supported by characteristic cases.

Carcinoma↗
PubMed2003

[Chest examination protocol with a reduced dose using a multi-slice spiral CT].

PURPOSE: Comparison of multi-slice computed tomography (MSCT) for examination of the chest using two protocols differing in tube voltage (kV) and effective tube current (mAs), as to image quality, diagnostic quality and radiation dose. MATERIAL AND METHODS: Re-staging examinations of 20 patients with bronchial carcinoma on a MSCT (Somatom Volume Zoom, Siemens AG, Forchheim) with 140 kV/100 mAseff and again after an average interval of 4.5 months, a second examination using 120 kV/80 mAseff, employing identical detector width (4 x 2.5 mm), slice, pitch, increment, kernel and selecting the same use or non-use of contrast medium. Image quality, delineation of mediastinal and pulmonary anatomy and pathology, and frequency of artifacts were evaluated by two radiologists and the effective radiation doses were calculated. RESULTS: Subjective image quality was good to very good for both protocols, and no significant differences were found for visualizing anatomic and pathologic structures in mediastinum and lung. Only the region surrounded by the shoulder girdle showed significantly more artifacts with 120 kV/80 mAsff, but without loss of diagnostic quality. The effective doses were 8 mSv (women) and 6 mSv (men) for 140 kV/100 mAseff versus 4.3 mSv and 3.3 mSv for 120 kV/80 mAseff. CONCLUSIONS: In view of the equal diagnostic quality of both images, CT of the chest should be obtained with 120 kV and 80 mAseff rather than with 140 kV/100 mAseff, regardless of the slightly lower aesthetic quality of the former. This will keep the radiation dose as low as possible. Follow-up examinations should be obtained with even further dose reduction (low dose CT).

Aged↗
PubMed1997

Analysis of oxylipins by high-performance liquid chromatography with evaporative light-scattering detection and particle beam-mass spectrometry.

The metabolism of 13S-hydroperoxy-9Z,11E,15Z-octadecatrienoic acid was investigated in a crude enzyme extract from mung bean seedlings (Phaseolus radiatus L.). Hydroperoxide-metabolizing activity was mainly due to a hydroperoxide lyase and, to a lesser extent, to an allene oxide synthase and a peroxygenase. Oxylipins originating from hydrolysis and cyclization of the allene oxide synthase product 12,13-epoxy-9Z,11,15Z-octadecatrienoic acid and from peroxygenase catalysis were identified by high-performance liquid chromatography (HPLC) particle beam-mass spectrometry (PB-MS) and quantified by normal-phase HPLC with an evaporative light-scattering detector (ELSD). An advantage of this methodology was the possibility to avoid extensive derivatization procedures commonly used for the gas chromatographic analysis of oxylipins. Owing to a comparable sample inlet system, the ELSD served an important analytical pilot function for the PB-MS: Qualitatively identical chromatographic patterns were obtained with both detection systems. The HPLC system enabled the separation of methyl 12-oxo-phytodienoate, methyl 11-hydroxy-12-oxo-9Z,15Z-octadecadienoate, methyl 12-oxo-13-hydroxy-9Z,15Z-octadecadienoate, methyl 9-hydroxy-12-oxo-10E,15Z-octadecadienoate, methyl 13-hydroxy-9Z,11E,15Z-octadecatrienoate, methyl 15,16-epoxy-13-hydroxy-9Z,11E-octadecadienoate, and methyl 13-hydroperoxy-9Z,11E,15Z-octadecatrienoate on a Lichrospher DIOL column within 33 min. Compared with a diode array detector, the ELSD proved to be more sensitive, in the case of methyl 12-oxo-13-hydroxy-9Z, 15Z-octadecadienoate by a factor of about 15. In addition, volatile metabolites were analyzed by capillary gas chromatography. The yield of the hydroperoxide lyase product 2E-hexenal was 49%, whereas the sum of oxylipins reached about 15%.

Aldehyde-Lyases↗