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Biomedical subjects

H Ostertag

Publications and source records attributed to H Ostertag.

At least 91 records · Page 5Linked to original sources

[Pre and intraoperative volume determination of craniopharyngioma cysts (author's transl)].

Exact cystic volume measurement is a prerequisite to proper 90Y dosage in the therapy of of intracavitary monocystic craniopharyngiomas. The method of intraoperative volume measurement by a radionuclide dilution technique is compared to results obtained by preoperative volumetry using computer tomography. Both methods gave congruous results. It is pointed out that gamma camera scintigrams are essential for the early detection of complications.

Adolescent↗

Short-lived radionuclides for the assessment of rapid cardiovascular drug effects.

Continuous monitoring of cardiac output and sequential studies of right ventricular ejection fraction and of fractional myocardial uptake of substances with high cell affinity can be realized using 13N (t 1/2 = 9.6 min) and 81mKr (t 1/2 = 13 sec). Thus, it is possible to measure rapid changes of absolute myocardial blood flow and of the inotropic state of the right heart myocardium. This is shown in patients who underwent interventions with Dipyridamole and with Dobutamine which produce a marked increase in myocardial blood flow or cardiac dynamics, respectively.

Cardiac Output↗

Early gastric cancer: a morphological study of 144 cases.

Within 144 early gastric cancers (EGC), the ulcerated type was most frequent (54.2%), followed by the superfical (29.9%) and protruded types (16%). 10.4% of EGC originated from adenomatous polyps of gastric mucosa. No positive correlation between hyperplastic polyps and occurrence of EGC could be stated. Antrum and corpus regions were preferred localization of EGC, harboring about 90% of the tumors. Histologic classification according to Laurén (1965) proved to be very reliable, revealing an intestinal type of EGC in 53.1% and a diffuse type in 32.4%. Primary anaplastic tumors seem to be very rare. Intestinal types were predominant in males, especially in the elderly patient. In about 50% the tumor was still limited to the mucosa with the exception of Type I, since those tumors originating from polyp infiltrated submucosa above and those without evidence of a preceding polyp, below average. Regional metastases were found in 4.2% with one primary tumor still limited to the mucosa. In the pure intestinal type of EGC metastases did not occur at all. Multicentricity of EGC was, with 2.8%, remarkably low, compared with the findings of others. Excluding malignancies, the only other noteworthy concurrent lesions were ulcer scars or chronic ulcers with 6.9% and B II resection for benign disease with 2.8%.

Adenocarcinoma↗

Ventilation studies with krypton-81m.

Nuclear medicine offers well-established methods for regional lung function assessment in the preoperative evaluation of patients with lung disease. The perfusion study with Tc-99m macroaggregates is simple and can be performed without special precautions in radiation shielding. The ventilation study with Xe-133, however, requires more elaborate apparatus as well as special procedures to collect the exhaled radioactive rare gas. Nuclear medicine departments with access to short-lived radionuclides from a nearby cyclotron can use the krypton isotope Kr-81m. The physical half-life of Kr-81m is 13 s. Its gamma energy of 190 keV is optimal for gamma cameras. Kr-81m can be used as a medical isotope in spite of its short half-life. It can be eluted with a continuously flowing gas from the generator containing the mother nuclide Rb-81 which has half-life of 4.6 h. This short half-life not only simplifies radiation protection but allows repeated studies in different projections as well. Examples of comparative studies with Xe-133 and Kr-81m are presented. The importance of taking not only anterior and posterior pictures but also lateral oblique views is stressed.

Half-Life↗

[Three different tumors in a case of synovial sarcoma of the hand].

Examining a 74 year old female patient with a nodular goiter, a tumor of the left thenar eminence with a concurrent radiolucent swelling in the adjoining second metacarpal was found. The diagnosis was a struma nodosa with regressive marginal changes, a hypervascularized monophasic synovial sarcoma of the wrist joint, and an enchondroma of the second metacarpal bone. Following the amputation of the forearm, no radiotherapy or cytotoxic therapy was performed. After a follow-up time of one year no metastases were detected.

Aged↗

Further investigations on the antioncogenic activity of A/PR8/34 (HON1)- influenza virus on polyoma virus induced tumors in newborn Wistar rats.

The oncogenic activity of polyoma virus in newborn Wistar rats can be significantly reduced by simultaneous vaccination with the A/PR8/34 (HON1) strain of influenza virus. The antioncogenic activity (AOA) of influenza virus suspensions was neutralized by the addition of homologous influenza antibodies, indicating that AOA was due to influenza virus and not to any non-viral material possibly present. The AOA of influenza virus was found to decline with storage at 4 degrees C and to depend critically on the relative doses of influenza virus and polyoma virus inoculated per animal. Simultaneous inoculation of animals with influenza and polyoma virus reduced significantly the antibody response to polyoma virus in all experiments, suggesting that influenza virus reduced the multiplication of polyoma virus. By contrast, the antibody response to influenza virus was significantly enhanced by inoculation with polyoma virus in some experiments, only. Influenza virus was found to reduce markedly the adsorption of polyoma virus on rat embryo fibroblast cells, suggesting that AOA could be at least partially due to interference of influenza virus with polyoma virus adsorption on target cells.

Animals↗

[131I] Hippuran renography in the detection of orthostatic hypertension.

Scintigrams in prone and standing positions were done in 11 hypertensive women. All had nephroptosis with ventral rotation. On the basis of the renograms, seven patients were identified as suffering from orthostatic hypertension. Nephropexy resulted in normalization of blood pressure in six of the seven patients and normalization of the renograms of all seven. We believe that sequence scintigrams in prone and standing positions offer a simple method of identifying patients with orthostatic hypertension.

Adult↗

Influence of vaccination with A/PR 8/34 (HO-N1) influenza virus on the oncogenic activity of polyoma virus in newborn Wistar rats.

Vaccination with the A/PR 8/34 (HO N1) strain of influenza virus can decrease significantly the oncogenic activity of polyomavirus in newborn Wistar rats. This effect was regularly observed when animals were vaccinated with 24 hr after birth, whereas vaccinations performed on Days 3 and 10 failed to influence the oncogenic potential of polyoma virus. In 3 series of experiments, influenza virus vaccination resulted in sigificantly decreased tumor rates, and, in a 4th series, in reduced tumor growth only. Heat inactivation of influenza virus failed to abolish its influence on the oncogenicity of polyoma virus. In most of the experiments, the antibody response to influenza virus was enhanced by inoculation of animals with polyoma virus. In contrast, polyoma virus antibody titers were, in some experiments, decreased, and, in others, not influenced by vaccination with influenza virus.

Animals↗