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T Pfeifer

Publications and source records attributed to T Pfeifer.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Traumatic occlusion of the internal carotid artery as an injury sequela of soccer].

The largest number of people engaged in sports in Germany play football. There were about 1.5 million sports injuries annually in the previous Federal Republic of Germany. Steinbrück (5) reported that the highest number was found in football players, in whom the injuries of the legs are most frequent. Head and vascular injuries are unusual and seldom in football players. We report on the case of a patient who received an elbow blow from his opponent. He developed a stroke with hemiparesis because of a traumatic dissection of the A. carotis interna.

Adult↗
PubMed1993

[3D-CT and angiography of cast preparations of pelvic vessels: demonstration of arterial blood supply of the acetabulum].

Anatomical studies of the arterial blood supply of the acetabulum were performed utilizing conventional angiography and 3D-CT on 27 hip specimens. In 16 cases the arterial arborization was filled with undiluted barium-sulfate via the internal artery and in 11 cases with a solution of resin and lead power. 3 specimens out of 30 were excluded because of extravasation using barium-sulfate in one case and incomplete filling with resin in 3 cases. Conventional angiograms were performed in all specimens and in preparations with resin/lead power additional three-dimensional reconstructions of the surface of the acetabulum and arterial cast were done with 3D-CT. 3D-CT shows precise relationship of the arteries to the acetabulum in any spatial plane and definition of vascular supply without elaborate preparation. 3D-CT is superior to non-selective conventional angiography because of better definition of arterial arborization. Filling with resin and lead powder is optimal for anatomical studies because of its reliability and stability. It permits comparative 3D-CT and conventional x-ray examination and subsequent preparation of the vessels in corrosion technique. The advantages of 3D-CT in vessels of cadaver specimens should encourage research on its viability in patients.

Acetabulum↗
PubMed1993

Belief network for grading prostate lesions.

A Bayesian belief network for grading prostatic lesions into eight primary Gleason grades was developed and tested. The network employs 13 diagnostic clues, 8 based on tissue architectural features and 5 based on nuclear features. For every diagnostic clue, three to five different outcomes are specified by membership functions. The network works in a robust fashion and attained agreement with consensus visual grading in 241 of 256 microscopic fields.

Adenocarcinoma↗
PubMed1992

[The value of tumor volumetry as opposed to bidimensional determination of tumor size during follow-up of hepatic metastases from colorectal carcinoma].

36 patients with liver metastases due to colorectal carcinoma under treatment with arterial perfusion chemotherapy of the liver with 5-fluoro-2-desoxyuridine (FUDR) via a subcutaneous pump were investigated by axial liver CT at 6-monthly intervals. In all examinations a dynamic CT scan with intravenous bolus injection of contrast medium was carried out following a native scan. Changes in tumour size were documented by means of 1. volumetry and 2. bidimensional measurement according to WHO criteria. Since we were not able to assess small newly developing lesions within the liver using the volumetric classification, the WHO-classification showed much higher sensitivity in cases of progressive disease. In addition, volumetric determination of tumour size by means of region-of-interest technique proved to be rather impracticable in clinical routine compared to bidimensional measurement.

Aged↗
PubMed1992

[The place of portangiography in the follow-up control of locoregional chemotherapy].

101 portangiographies in patients with liver metastases from colorectal primaries who underwent hepatic intraarterial or intraperitoneal chemotherapy were performed and studied between January 1991 and February 1992. 81% of the examinations did not involve complications. In 19% of the angiographies abnormalities of the arterial perfusion of the liver, like occlusion, dissection or narrowing of hepatic arteries, were found. We conclude that portangiography is a very important investigation before regional chemotherapy.

Angiography↗
PubMed1991

Inhibition of the myocardial Ca(2+)-current (ICa) by the enantiomers of DPI 201-106 and BDF 8784.

1. We studied the stereoselectivity of the effects of the enantiomers of the cardiotonic agent DPI 201-106 (4-[3'-(4"-benzhydryl-1"-piperazinyl)-2'-hydroxypropoxy]-1H-indole-2- carbonitrile, DPI) and its methyl-for-carbonitrile analogue BDF 8784 on cardiac calcium currents (ICa) of guinea-pig ventricular myocytes. The actions of the S- and R-enantiomers were compared with those of the racemate. 2. Racemic, S- and R-DPI depressed ICa in a concentration-dependent manner, the IC50 values were 1.1 mumol l-1 for racemic and S-DPI, and 1.2 mumol l-1 for R-DPI, respectively. Racemic, S- and R-BDF 8784 also reduced ICa, the respective IC50 values were 3.6 mumol l-1 for racemic BDF 8784, 1.3 mumol l-1 for S-BDF 8784 and 1.1 mumol l-1 for R-BDF 8784. 3. Neither the DPI nor the BDF 8784 enantiomers alter the time course of inactivation of ICa. The steady-state inactivation curve for ICa was shifted along the voltage axis to negative membrane potentials. The block of ICa was dependent on the membrane potential and increased with membrane depolarization. 4. Our findings indicate that DPI and BDF 8784 inhibit ICa in a non-stereoselective manner, which contrasts the opposite effects of the DPI enantiomers on Na+ channels.

Animals↗
PubMed1991

Characterization of the effects of the new inotropic agent BDF 9148 in isolated papillary muscles and myocytes of the guinea-pig heart.

1. The cardiotonic agent BDF 9148 (4-[3'-(1''-benzhydryl-azetidine-3''-oxy)-2'-hydroxypropoxy]-1H-indole- 2-carbonitrile) is structurally related to DPI 201-106 (4-[3'-(4''-benzhydryl-1''-piperazinyl) -2'-hydroxypropoxy]-1H-indole-2-carbonitrile) which is known to modify cardiac sodium channels. In guinea-pig papillary muscles, both compounds increase force of contraction with similar concentration-response curves. Like DPI 201-106, BDF 9148 prolongs the action potential duration in a tetrodotoxin-sensitive manner. With high concentrations (greater than 3 microM), however, the action potential duration shortens again. In order to elucidate the underlying changes in membrane currents, we have investigated the effects of BDF 9148 in isolated ventricular myocytes of the guinea-pig heart. 2. In isolated cells, a concentration of 1 microM BDF 9148 prolonged the action potential duration and markedly enhanced unloaded cell shortening, indicating that the procedure of cell isolation does not abolish the effect of the drug. 3. Membrane currents were studied with the single electrode voltage clamp technique. With clamp steps from -80 mV to -40 mV, BDF 9148 (1 microM) induced a slowly decaying inward current which was suppressed by tetrodotoxin. Therefore, like DPI 201-106, BDF 9148 slows the inactivation of the sodium channels. 4. In order to quantify the effects of BDF 9148 and DPI 201-106 on sodium current inactivation, we have measured the inward current amplitude still present at 100 ms after a depolarizing clamp step from -80 mV to -30 mV. Both drugs increased this current component in a concentration-dependent manner; however, BDF 9148 had a larger effect in the low concentration range.5. The calcium current was inhibited by BDF 9148 and DPI 201-106 in a concentration-dependent manner; the pD2 values were 5.70 and 5.95, respectively.6. The two compounds are thought to produce similar positive inotropic effects by imposing a sodium load on the muscle cells via modification of the sodium channels. The differences in action potential duration could be due to different contributions of ionic currents other than sodium or calcium currents and of pump and exchange currents. At present, there is not sufficient data to identify clearly distinct current components responsible for the differences in action potential prolongation.

Action Potentials↗
PubMed1991

Value of the cribriformity factor in grading prostatic carcinoma.

Architectural and histometric features for the objective grading of prostate adenocarcinoma in histologic specimens were analyzed in five cases each of Gleason primary grades 2, 3A, 3B, 3C, 4A and 4B, selected as "typical" for the histopathologic images. Tissue sections from the selected cases were stained by the Feulgen method. Fifteen fields for each grade, for a total of 4,430 glands, were digitized by a video-based microphotometer at low resolution (pixel spacing of 2 microns). Outer and inner outlines of the glandular epithelium were traced manually using a mouse. For each field the number of glands, the gland area, the lumen area, the area of the glandular epithelium and the cribriformity factor were computed. The gland area and its variance proved to be useful indicators for lower-grade lesions, whereas the variance of cribriformity resulted in an excellent grading indicator in the Gleason 3-4 range when cribriform glands were present.

Adenocarcinoma↗