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Biomedical subjects

T Wendt

Publications and source records attributed to T Wendt.

69 records · Page 4Linked to original sources

[Hemodynamic side effects of an ionic and a nonionic roentgen contrast medium in patients with heart valve diseases and pulmonary hypertension].

The purpose of this study was to compare the hemodynamic side effects of an ionic and a nonionic contrast medium intra-individually. 20 patients with valvular heart disease (NYHA III-IV) and pulmonary hypertension (PPAsyst greater than or equal to 40 mm Hg) received injections of 40 ml iopamidol (0.8 osmol/kg) and 40 ml amidotrizoate (2.1 osmol/kg) into the right atrium. Heart rate and cardiac output, as well as right atrial, pulmonary-artery, pulmonary-capillary, and aortic pressures were measured. Peripheral and pulmonary vascular resistance and stroke volume were calculated. Right atrial pressure increased more after amidotrizoate (p less than 0.001). Pulmonary artery pressure was elevated with both contrast media to the same extent. An increase in aortic pressure was seen after iopamidol, while a decrease occurred after amidotrizoate (p less than 0.01). Amidotrizoate caused a more marked increase in heart rate (p less than 0.001) and cardiac output (p less than 0.001). Stroke volume was increased with both contrast media. Pulmonary vascular resistance decreased after amidotrizoate as well as after iopamidol, but systemic vasodilatation was more pronounced following injection of amidotrizoate (p less than 0.001). In general, iopamidol caused less hemodynamic side effects than amidotrizoate. Thus, nonionic low osmolality contrast media provide decreased risks in patients with valvular heart disease and elevated pulmonary artery pressures undergoing angiocardiography and intravenous digital subtraction angiocardiography.

Adult↗

[Radiotherapy of seminoma: small-volume irradiation at the stage pT1N0M0--prophylactic irradiation of the mediastinum].

122 patients suffering from seminoma were irradiated between 1971 and 1981 at the Radiotherapy Department of the University of Munich. 113 patients were available for retrospective analysis. The ten year actuarial survival for all patients was 93%. The survival rate in stage pT1N0M0 (UICC classification) was 100%, in stage pT2-4-xN0M0 97%, in stage pT1-4-xN1-3M0 93%, and in stage pT1-xN4M0/pT1-xN1-4M1 69%. Using a stage adapted target volume, the exclusive irradiation of the paraaortic nodes in the stage pT1N0M0 led to a cure-rate of 100%. Because of this result, and due to the improved tolerance and lower exposure to the remaining testis we recommend this method. The effectiveness of radiotherapy, also in advanced seminomas, the benefit of prophylactic mediastinal irradiation and the therapeutic modalities for treatment of extragonadal seminomas are discussed.

Cobalt Radioisotopes↗

[Radiotherapy of precancerous conditions in the ENT area].

Precancerous lesions of the oral cavity and the larynx are usually treated by surgery, because a complete histological examination for detecting an invasive carcinoma is important and, on the other hand, modern surgery procedures yield very satisfactory functional results. High-dose irradiation of inoperable high-risk precancerous lesions of the larynx may be taken into account. Experiences in the irradiation of inoperable low-risk lesions with different doses are very rare. The carcinoma in situ should be treated like an invasive carcinoma. 10 years of experience in radiotherapy of precancerous lesions of the larynx in 23 patients are reported.

Carcinoma in Situ↗

[Life-threatening complications in 1741106 cases of ergometry].

No life-threatening complications occurred in exercise-testing in 384 938 athletes. Among 1 356 168 patients the most frequent complication was ventricular fibrillation (1:15 000). The step test was associated with a two-fold diminution of fibrillations when compared to bicycle ergometry in the supine position and with a four-fold decrease when compared to conventional bicycle ergometry. Pulmonary oedema, a typical complication, occurred once in 29 000 bicycle ergometries in supine position. Infarctions were seen 3.5 times more frequently between 1950 and 1977 (1:26 000) than in the following four years (1:92 000). Fatal cardiac infarction occurred in 1:42 000 before 1978 and in 1:644 000 thereafter. It was the sole cause of death. Present data show a potentially life-threatening risk of 1:9000 ergometries in patients. Considering the favourable trend at present, a risk of 1:12 000 can be expected in conditions of an experienced investigator. Defibrillation facilities ready for use must be available in any ergometry.

Adult↗

Thyroglobulin levels to follow-up patients with treated differentiated thyroid carcinoma.

Serum thyroglobulin (hTg) measurements by commercial radioimmunoassay were performed in the follow-up of 118 patients with differentiated thyroid carcinoma undergoing I-131 local and whole-body scans following surgery and I-131 therapy. Patients with positive anti-hTg antibodies (23% of cases) were excluded. In all remaining I-131 accumulating residual, recurrent, or metastatic tumors, hTg levels were elevated (greater than 6.25 ng/ml, minimum detectable value). Twelve patients with neither recurrence nor metastases had elevated hTg levels. Sensitivity and specificity depended on the threshold used for elevate d hTg levels. At an hTg-threshold of 6.25 ng/ml sensitivity has 100%, specificity has 82%. As hTg levels were reported to depend on endogenous TSH stimulation, it is not yet advisable to replace I-131 scans totally by hTg determination. After having determined an hTg "baseline" below detectable values (less than 6.25 ng/ml), we reduced the number of I-131 scans by half. However, elevated hTg levels were an indication for an I-131 scan. Therefore, on the basis of 23% of our patients who had anti-hTg antibodies the need exists to develop a commercial assay which is independent from antibodies.

Adult↗

[Diameter changes of epicardial coronary arteries and coronary stenoses after intracoronary application of SIN 1, a molsidomine metabolite].

The vasodilating effects of intracoronary injections of 0.4 mg SIN 1, the active metabolite of molsidomine, on epicardial coronary arteries and coronary stenoses were evaluated in 14 patients with coronary artery disease in a double-blind randomized fashion versus placebo. 9 additional patients with well-definable coronary stenoses received 0.4 mg SIN 1 as well. Diameter changes of nonstenotic coronary arteries in proximal, medial and distal coronary segments as well as changes of the residual luminal diameters within coronary stenoses were determined before (K), immediately after (M1) and 10 minutes after (M2) intracoronary application of SIN 1; in addition, aortic pressure and heart rate were monitored continuously. Aortic pressure and heart rate did not change after SIN 1 or placebo. After SIN 1, the diameter of nonstenotic coronary arteries increased in proximal segments by + 9% (M1) and + 11.7% (M2), in medial segments by + 17.6% (M1) and + 17.6% (M2), in distal segments by + 26.4% (M1) and + 28.8% (M2). Within coronary stenoses, the residual luminal diameters showed a mean increase by 31.5% (M1) and 48.3% (M2). Placebo did not alter coronary diameters significantly. SIN 1 effectively dilates nonstenotic and especially stenotic epicardial coronary arteries, as it is already known for nitrates and calcium-channel blockers. By intracoronary injections, the direct effects on coronary vessels can be detected without interference with systemic effects. The increase in residual luminal diameters within dynamic coronary stenoses after SIN 1 is most likely an important antianginal mechanism also for molsidomine.

Coronary Disease↗

[Influence of cold-stimuli on hemodynamics and coronary diameters. Provocation of coronary artery spasm].

In 32 patients with coronary heart disease the influence of different cold-stimuli on hemodynamic parameters and coronary artery diameter was examined during left heart catheterization. The cold pressor test (CPT) and the cold air inhalation test (CAIT) were applied to 16 patients in random sequence. 16 patients served as control group. Systolic and diastolic blood pressure increased more under CPT (by 15 and 10 mm Hg respectively) than under CAIT (by 10 and 3 mm Hg). Heart rate and left ventricular enddiastolic pressure did not change. Proximal and distal coronary segment diameters showed a slight, not statistically significant increase under cold-stimuli. All 4 patients with a history of angina pectoris at rest developed coronary spasm, some with ischemic ECG changes; spasm and symptoms disappeared spontaneously when the cold-stimulus was withdrawn. Patients with a history of angina pectoris under cold conditions showed no pathological reactions. It is concluded that two different mechanisms may cause angina pectoris under cold-stimuli. First, the oxygen-consuming effect of an increase in blood pressure, and secondly, an immediate coronary vasospastic reaction. The combined use of CPT and CAIT seems to be an effective and safe means of identifying patients with a tendency to coronary artery spasms.

Adult↗

[Value of posttherapeutic scintigraphy for the demonstration of distant metastases of differentiated carcinomas of the thyroid gland].

The value of posttherapeutic scintigraphy performed at discharge with the remaining radioactivity after an ablative radio-iodine therapy was studied in 190 patients with differentiated carcinomas of the thyroid gland (54% papillary and 46% follicular carcinomas). 163 patients (86%) had no signs of disease. 33 patients had distant metastases. In six out of them, the examination method allowed a first demonstration of metastases. In seven further cases, additional, hitherto unknown foci were found. There was a specificity of 100% and a sensitivity of 82% (no false positive findings, six false negative findings). Further to the usual image-producing examination methods (native X-ray diagnosis, sonography and CT), posttherapeutic scintigraphy furnishes early information about the formation of distant metastases. Therefore it is helpful to indicate a regional percutaneous X-ray therapy and to assess the prognosis.

Adenocarcinoma↗

[Role of percutaneous radiotherapy in the primary treatment of papillary carcinomas of the thyroid gland (author's transl)].

The value of post-operative percutaneous radiotherapy is examined by evaluating the case records of 27 patients with papillary carcinomas of the thyroid gland of stage pT4 NO MO and pT1-4 pN1-3 MO. A loco-regional disappearance was observed in 95% (20/21) of the post-irradiated patients. In half of all patients not post-irradiated, no loco-regional disappearance of the tumor was achieved; a formation of metastases was found later on in these patients. The percutaneous irradiation has been recommended for years by radiologists, but it is not accepted everywhere. The results suggest the necessity of radiotherapy in case of the above mentioned tumor stages.

Carcinoma, Papillary↗

[Results of radiologic and combined surgical and radiologic treatment of oropharyngeal carcinomas (author's transl)].

A report is given on therapy results of 99 cases of oropharyngeal carcinoma (ICD 146) treated between 1971 and 1979. The healing rate is 80% for the NO stades I and II, 47% for stade III and 37% for stade IV. About one third of all patients of all stades were exclusively irradiated, about two thirds were submitted to a combined surgical and radiologic treatment. The authors study the time after which local recurrences are appearing and describe different irradiation methods. The combined treatment seems to be superior to primary radiotherapy even in NO stades.

Humans↗

[Unusual posture-dependent backache as leading symptom of a thoracic aortic aneurysm].

The clinical investigation of a 71 year old male patient, suffering from chronic recurrent back pain, shows an unusual, position-dependent symptomatology of the pain. A penetrating, inoperable aneurysm of the thoracic aorta can be proved to be responsible for the patients complaints and causing his death in the course. Regarding the findings of the clinical investigation and the computed tomography as well as the postmortal findings, the pain-causing mechanisms are discussed.

Aged↗

Contrast-enhanced MRI of the breast after limited surgery and radiation therapy.

OBJECTIVE: Posttherapeutic changes in the breast after tumorectomy (TE) and radiation therapy (RT) may mimic or obscure recurrent or new malignancies and thus interfere with conventional diagnostic studies. We investigated the enhancement of tissue during variable time intervals after therapy with contrast-enhanced MRI in 62 patients. MATERIALS AND METHODS: We report the results of 77 studies in 62 patients undergoing TE and RT. We include only those studies with at least 24 months of clinical and mammographic follow-up (n = 60) or histopathologic results (n = 17). RESULTS: Up to 9 months after therapy, differentiation between posttherapeutic changes and recurrence was frequently impossible because of the strong enhancement. Ten to 18 months after therapy, this posttherapeutic enhancement subsided slowly with some interindividual variations. After 18 months posttherapy, no significant enhancement was encountered in 30 of 32 cases. Diffuse or focal enhancement was present in all recurrent tumors and all recurrences were correctly diagnosed. Furthermore, 4 of 11 recurrences and 10 of 18 single recurrent foci were detected by MR alone, based on focal enhancement. CONCLUSION: Accordingly, contrast-enhanced MR is not recommended during the first 9 months after therapy. Nine to 18 months after therapy, it may be helpful in those two-thirds of cases where the scar does not enhance. If enhancement takes place (one-third of cases), it may represent either scar or tumor, and in such circumstances, enhanced MR is of no value. After 18 months, enhanced MRI has proven a valuable additional tool. By correctly detecting or excluding recurrent tumor, it can significantly improve diagnostic accuracy.

Breast↗