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Biomedical subjects

R Dietz

Publications and source records attributed to R Dietz.

At least 325 records · Page 18Linked to original sources
PubMed1978

Effects of beta-adrenergic blocking agents on peripheral vascular resistance.

The effects of the beta-adrenergic blocking agents propranolol, pindolol, atenolol, bunitrolol, and methypranol on the vascular resistance of isolated perfused hindlimbs of rats were investigated. At concentrations of 0.01 microgram/ml in the perfusate dl-propranolol and pindolol significantly increased vascular resistance by blockade of beta2-receptor mediated vasodilatation, whereas atenolol, bunitrolol and methypranol had no effect on peripheral resistance at this concentration. With increasing concentrations up to 10 microgram/ml all drugs, with the exception of atenolol, caused vasodilatation. We conclude that the specificity of beta-blocking agents can be established in the isolated perfused hindlimb vasculature of rats through its effect on vascular resistance. The lack of inhibition of vascular beta2-receptors at low concentrations of atenolol and also bunitrolol and methypranol show relative selectivity for beta1-receptors. The differential effects of beta-adrenergic agents on vascular resistance may have significance for the clinical use of the drugs.

Adrenergic beta-Antagonists↗
PubMed1978

[Lymphography for the prognosis of carcinoma of the cervix (author's transl)].

Ninety-two patients with carcinoma of the cervix, who had lymphograms before treatment, were observed for a period of three to five years. In patients with lymph node metastases 57.1% were found to have recurrences or metastases, or died during that period. Amongst patients with normal lymphograms the corresponding figure was 11.3%. These findings were true for each stage of the disease. Follow-up studies with histological examination of the lymph nodes have shown that the prognosis of carcinoma of the cervix is totally different if lymph node metastases are present. Separation into cases with good and bad prognosis can be achieved by pre-treatment lymphography. The radiological findings concerning lymph nodes should therefore be included in the classification of carcinoma of the cervix; the T.N.M. calssification of U.I.C.C. makes this possible.

Female↗
PubMed1978

Effects of central and peripheral angiotensin blockade in hypertensive rats.

The angiotensin II (AII) antagonist [Sar1-Ala8]AII (Saralasin) was injected into the brain ventricles (IVT) and intravenously (IV) in five different types of hypertensive unanesthetized rats. Renal hypertension was studied 16-22 days after kidney clipping. Intravenous infusions of cumulative doses (0.1-100 microgram/kg per min) and IVT injections (5-40 microgram) of Saralasin did not change mean arterial pressure (MAP) in controls and in one-clip, one-kidney Goldblatt hypertension, whereas MAP decreased in one-clip, two-kidney Goldblatt hypertension following IV and IVT Saralasin. In two-clip, two kidney hypertensive rats, IVT Saralasin decreased MAP but was ineffective when infused IV. Both IV and IVT Saralasin increased MAP in DOC hypertension. In spontaneously hypertensive (SH) rats, IV Saralasin increased MAP; IVT injection decreased MAP. The effect of IVT Saralasin in SH rats persisted 15-20 h after nephrectomy. We conclude that plasma AII may contribute to peripheral and central mechanisms of blood pressure regulation. The dissociation of the effects of IV and IVT Saralasin and the persistance of blood pressure decrease in nephrectomized SH rats following IVT Saralasin further support a role for locally formed brain angiotensin.

Angiotensin II↗
PubMed1978

What makes the renin-angiotensin system a pathogenic factor?

Three types of renal hypertension in the rat have been compared with respect to blood pressure increase, activity of the RAS, and secretion of aldosterone and corticosterone: type I - unilateral stenosis of the renal artery in the presence of an intact contralateral kidney; type II - unilateral stenosis of the renal artery after contralateral nephrectomy; type III - bilateral stenosis of the renal arteries. Blood pressure rose more rapidly and reached higher values in type II and type III hypertension than in type I hypertension. In the latter group, the activity of the RAS was more stimulated than in types II and III. The marked stimulation of the RAS in type I hypertension is ascribed to the negative fluid and sodium balance, which is the consequence of a pressure-induced diuresis of the unclamped contralateral kidney. Suppression of the activity of the RAS by a 4-week pretreatment with DOC-TMA and saline or by the administration of DOCA and saline as from the induction of renal artery stenosis did not prevent the development of hypertension caused by the clamping of one renal artery (type I). In spontaneously hypertensive rats of the stroke-prone substrain, high dietary salt intake caused higher blood pressure values and a higher incidence of cerebral lesions than normal dietary salt intake. Low salt intake was followed by a marked stimulation of the RAS, but blood pressure rose only slightly and no symptoms of cerebrovascular lesions were observed. It is concluded that neither in hypertension induced by renal artery stenosis nor in spontaneously hypertensive rats, the RAS contributes significantly to the increase in blood pressure nor does it play a major part in the pathogenesis of vascular lesions. These seem to be related to the retention of sodium, which may be obtained by renal artery stenosis, by excessive salt intake, or by the administration of a mineralocorticoid and salt.

Angiotensin II↗
PubMed1978

[Therapy of primary oat-cell carcinoma of the larynx (author's transl)].

The case of primary oat-cell carcinom of the larynx with metastases in the thyreoid gland and paratracheal lymphnodes is reported on. The different methods of treatment are examined, used examples of the much more common oat-cell carcinoma of the lung. The applicability of the methods to oat-cell carcinoma of the larynx is discussed. Our treatment scheme of surgery and extended radiation is used if the tumor is known to be locally restricted.

Adult↗
PubMed1977

Irreversible shock in rats after injection of microspheres into the renal artery.

After injection of microspheres into both renal arteries of rats, an irreversible shock syndrome develops, resulting in death within 4-12 h. Ligation of both renal pedicles after injection of microspheres prevents the shock. It is presumed that kininogenases released from the kidneys participate in the pathogenesis of the shock syndrome.

Animals↗
PubMed1977

[Prostate carcinoma: determination of progression following high-voltage therapy (author's transl)].

The fourth report of our long-term study concerns 70 cases of primary radiotherapy. The side effects of our radiation technique are minimal and temporary; in over 80% of the cases, potency was not affected. The morphologically demonstrable changes in the tumor tissue, in the original glandular parenchyma, and in the fibromuscular stroma leading to the vessels following high-voltage therapy are described. Three types of progressive patterns, based on the grade of histologic regression, can be determined. In more than half of the cases, with increasing distance from the source of radiation, no tumor or only minimal residual tumor was demonstrable. Sensibility and resistance of carcinoma of the prostate are not dependent upon the grade of differentiation of the tumor. A prognostic statement concerning the success of radiation therapy from initial histologic findings is not possible here. The occurrence of metastases in 18% of the cases following radiation probably resulted from the inexactness of the purely clinical determination of the stage of the tumor. The isolated, local treatment of prostate carcinoma through radiotherapy is justified only after exact determination of the stage of the tumor, i.e., certain exclusion of metastases via a diagnostic lymphadenectomy.

Adenocarcinoma↗