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Biomedical subjects

W Döhring

Publications and source records attributed to W Döhring.

49 records · Page 3Linked to original sources
PubMed1980

[Visualization of aorto-coronary bypass grafts with the aid of non-dynamic computer tomography].

To evaluate computer tomography (CT) for assessment of aorto-coronary bypass graft patency, 45 patients with 85 grafts were studied by non-dynamic CT before and after intravenous bolus injection of 50 ml contrast material. 28 patients had undergone postoperative coronary angiography (37 grafts patent, 11 occluded), while 17 (37 grafts) were studied in the early postoperative period without angiographic confirmation. 60 of 74 grafts (81.1%) which were angiographically patent or not checked by postoperative angiography could be visualized by CT. In patients in whom graft patency was documented by angiography, 32 of 37 grafts (86.5%) were identified correctly, including all 18 grafts (100%) to the left anterior descending branch (LAD). With the exception of one LAD graft which was judged differently by the two evaluators, none of the 11 definitely occluded grafts could be visualized by CT. The results suggest that non-dynamic CT allows correct identification of patent aorto-coronary bypass grafts in a high percentage of cases. So far, however, the method does not allow any deduction as to the functional status of the grafts.

Coronary Angiography↗
PubMed1980

[Computer tomography in the investigation of renal trauma (author's transl)].

Two patients with blunt renal injuries (Hodges grade I and II), and two further patients with spontaneous renal and/or retroperitoneal hemorrhage, were studied with excretory urography, isotope scanning, ultrasound, angiography, and computerized tomography. The most important additional information provided by the CT scan was the disclosure of small parenchymal lacerations, as well as the presence and extent of perirenal hematomas. These abnormalities could also be monitored with CT studies during the healing phases. Renal excursion studies during breathing and the usual tomography seem to be no longer necessary in renal trauma cases if one plans to utilize CT scanning. Likewise, the necessity for angiographic studies decreases. Ultrasound, however, may still be helpful in certain cases of perirenal hematoma.

Adult↗
PubMed1978

[Polarographic measurements of PO2 with a 95% response time of 7-10 msec (author's transl)].

A fast PO2 tracing with 95% delay times of 15-20 msec in routine is necessary for measurement of the PO2 jumps in the expired air, particularly for the precise measurement of the so-called dead-air plateau. A Clark type PO2 electrode has been developed which has the demanded property. This electrode has four characteristic features: (1) a glasscoated Pt cathode with a tip diameter of 0.3 mm (diameter of the Pt wire = 0.1 mm); (2) a differential screwdrive for feeding the cathode 50 micrometer per turn; (3) a 0.2- to 0.3-micrometer-thin polytetrafluorethylene membrane, and (4) a special polishment of the surface of the cathode. The electrode has a 95% response time of 15-20 msec in routine when tracing PO2 changes from 150 to 750 mm Hg. About 30% of the prepared electrodes have response times of 7-10 msec. The output of the electrode in air is stable within the first 3 h (deviation smaller than 0.2%) and then decreases within 10 h approximately 1% per hour. The response times are constant for more than 48 h. The output of the electrode is linear from 0 to 760 mm Hg PO2. Within the accuracy of measurement the output is independent of PCO2.

Electrodes↗
PubMed1978

[An improved modification of the micro-method according to Niesel and Thews for the measurement of O2-hb binding curves in whole blood and concentrated Hb solutions (author's transl)].

An improved modification of the photometric micro-method according to Niesel and Thews is described, which employs the diffusion principle. The O2-Hb binding curves of whole blood or concentrated Hb solutions (0.1-30 g%) can be measured within 0.5 h. Sample volume is approximately 7 microliter, wavelength is 578 nm. Several reproductions of the curve may be measured with one sample. The reproducibility of P50 is 0.5 Torr. In comparison with the Van Slyke method no systematic error is found.

Hemoglobins↗
PubMedDate not supplied

Thymic atrophy and rebound enlargement following chemotherapy for testicular cancer.

Serial thoracic CT scans of 50 consecutive patients with testicular cancer were reviewed. In 30 of them with metastatic disease treated according to the Einhorn Scheme changes in thymic size caused by cytostatic agents were studied. During chemotherapy 78.6 per cent of all patients examined developed thymic atrophy, followed by rebound enlargement that reached its culminating point 13 months after initiation of treatment. After that a slow (approximately 2 years) involution process began, until the initial size or somewhat smaller size was re-achieved. The other 20 patients with no evidence of metastases, and therefore not treated with chemotherapy, showed no changes in thymic size. Rebound thymic enlargement following cytostatic therapy for metastatic testicular cancer should not be mistaken for lymphadenopathy.

Adolescent↗