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Biomedical subjects

R Dietz

Publications and source records attributed to R Dietz.

At least 271 records · Page 15Linked to original sources
PubMed1983

Effects of cocaine and desipramine on the neurally evoked overflow of endogenous noradrenaline from the rat heart.

1 Stimulation of postganglionic cardiac sympathetic nerves produced a stimulation frequency-dependent overflow of endogenous noradrenaline from the otherwise isolated rat heart. 2 Such nerve stimulation also produced increases in heart rate. There was significant correlation between heart rate increases and corresponding noradrenaline concentrations in the coronary venous effluent. 3 Cocaine (3 X 10(-5)M) caused a significant reduction in both the noradrenaline overflow and the heart rate increase, produced by nerve stimulation for 1 min at 4 Hz. 4 Desipramine (10(-6)M) caused a significant increase in the noradrenaline overflow produced by stimulation for 1 min (4 Hz) with a mean increase of approximately 60%. There was no significant effect on the heart rate increase produced by such stimulation. 5 The opposite effects of cocaine (3 X 10(-5)M) and desipramine (10(-6)M) on noradrenaline overflow are attributed to differences in the local anaesthetic properties of these agents.

Animals↗
PubMed1983

[Diagnosis and radio-chemotherapy of the neuroblastoma in adults].

The neuroblastoma in the adult is a rare disease which has a bad prognosis. Until now, there are no generally accepted therapy conceptions. The clinical symptoms of the patient whose case is presented here were above all pains in the pelvic region. The histologic diagnosis was difficult and could be proved only by additional examinations of other metastases. Although the primary tumor was searched for intensively, is was only found 20 months later. Especially radiotherapy, but also chemotherapy (CYVADIC regimen) have proved to be effective. Above all, the quality of life could be largely maintained over a period of 26 months.

Adult↗
PubMed1983

[Comparative studies on the immunostimulation by whole-body irradiation or vincristine sulphate].

Comparative experimentations were performed on Sprague-Dawley rats in order to study the immunostimulation by whole-body irradiation with 60Co gamma radiation (doses between 0.5 and 2 Gy) or application of vincristine sulphate (doses between 1.5 and 6 micrograms per 100 g body weight). The primary production of antibodies against erythrocytes of sheep was determined as immunity parameter. An immunostimulation was observed in all experiments. The irradiated groups showed the highest stimulation after 1 Gy, and the most stimulating dose of vincristine was 6 micrograms/100 g body weight. The radiogenic stimulation was more significant. As a reason for these stimulations, the authors suppose the different sensitivity of individual lymphocyte populations participating in the induction of the humoral immune response which leads to a relatively greater inactivation of T suppressor lymphocytes.

Animals↗
PubMed1982

Intracerebroventricular angiotensin II increases arterial blood pressure in rhesus monkeys by stimulation of pituitary hormones and the sympathetic nervous system.

Intracerebroventricular injections of angiotensin II in anesthetized rhesus monkeys increase systemic blood pressure and heart rate. These effects are accompanied by an increase in plasma ADH, cortisol, adrenaline and noradrenaline. Angiotensin II may participate in central mechanisms of blood pressure regulation by its stimulatory effect on the sympathetic nervous system, on ADH and on ACTH release in primates.

Angiotensin II↗
PubMed1982

Dysfunction of the adrenergic system in phosphate depleted rats.

Plasma catecholamines and vascular response to noradrenaline were studied in phosphate depleted rats. Phosphate depletion was induced in rats by dietary phosphorus deprivation for 6 weeks. Basal plasma concentrations of noradrenaline, adrenaline and dopamine were elevated in phosphate depleted rats compared to pairfed control rats. After exposure to cold (4 degrees C, 45 min) the rise in plasma catecholamines was much more pronounced in phosphate depleted rats. In the isolated perfused rat heart, the uptake of tritiated noradrenaline was unchanged. In the isolated perfused hindlimb preparation the vascular response to noradrenaline, but not to potassium chloride and arginine-vasopressin was significantly diminished in phosphate depleted rats. It is concluded that in phosphate depletion sympathetic activity is elevated and vascular response to noradrenaline diminished.

Animals↗
PubMed1982

Complications after combination of chemotherapy and radiation for malignant brain tumours.

The combination of chemotherapy and irradiation for the treatment of malignant intracerebral tumours is increasing, and survival times longer than those after monotherapy are reported. The suitability of simultaneous radio-chemotherapy using BCNU-Bleomycin, a regimen in which has been followed 38 patients of this hospital (up to 31 December 1981) is critically discussed. Statistics of 30 patients with treatment ended by 31 December 1980 and case histories of two patients with fatal complications, aspergillosis in the one and necrotizing colitis in the other, are presented. The value of the various agents used for chemotherapy is discussed with respect to the survival rates and observed side effects in all the patients. The use of Bleomycin is questioned.

Adult↗
PubMed1982

[Radiotherapy of bladder malignomas with rapid electrons (author's transl)].

After having been submitted to mainly transurethral electroresection, a not selected group of patients (n = 143) with bladder carcinomas of different, mostly advanced stages (TIS and TI = 4 patients, T2 = 33, T4 = 13) was irradiated with the circular accelerator (betatron) applying a telecentric pendulum method with a small angle. The total dose of 5100 rd (51 Gy) which we wanted to achieve hitherto was administered to 129 patients; 14 patients received a lower dose. Radiogenic complications were unimportant. Only 25 patients presented a cystitis during and after radiotherapy which disappeared after treatment. A contracted bladder as final condition was seen in 5.5% (8 patients) of all irradiated patients. The three-year survival rate of all stages was 44.9%, the five-year survival rate of 31.3%.

Cystitis↗
PubMed1982

[Combination of radiotherapy and selective chemotherapy in the treatment of advanced ovarian carcinomas].

A report is given on 160 patients suffering from ovarian carcinomas the stages which were exactly determined by TNM classification. 32 patients had tumors of the stages T1-T3, 128 patients had tumors of the stage T4. All T3 subgroups showed favorable results after radical surgery and a postoperative combination of radiotherapy and selective cytostatic chemotherapy. The therapy plans including radiotherapy had more advantages than those without radiotherapy. Furthermore, the cytostatic treatment was more successful after a chemotherapy resistance test than after blind administration of cytostatic drugs.

Female↗
PubMed1982

Morphogenesis of hypertensive vascular lesions.

Accelerated hypertension is a convenient model for studying the pathomechanism of hypertensive vascular lesions. It has not been settled, however, whether such lesions are really equivalent to those developing slowly in the course of experimental hypertensive vascular disease. In the present study, early vascular lesions of accelerated hypertension have been compared with those of hypertensive vascular disease by using two complementary techniques: small-molecule plasma-protein label (Ferrlecit) and a macromolecular tracer protein (horse ferritin). Two kinds of vascular lesions have been distinguished. Non-destructive vascular lesions exhibit necrotic smooth-muscle cells with intracellular deposition of Ferrlecit-labelled plasma proteins and intact basement-membrane barrier to the macromolecular tracer. Destructive vascular lesions, in turn, are characterized by the breakdown of the basement-membrane barrier to the macromolecular tracer. Incipient destructive lesions are identified as dissecting microaneurysms initiated by small ruptures of the basement membrane framework. Both non-destructive vascular lesions and incipient destructive vascular lesions end in confluent medial destruction that precedes the formation of fibrinoid necrosis. The localization and morphology of vascular lesions is identical both in hypertensive vascular disease and in accelerated hypertension. Circumstantial evidence strongly suggests that non-destructive vascular lesions are caused by arterial contraction. Nevertheless, the possibility that non-destructive lesions are but abortive forms of destructive ones cannot be excluded.

Animals↗