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Biomedical subjects

N Hahn

Publications and source records attributed to N Hahn.

7 recordsLinked to original sources
PubMed1978

Tissue response to overdenture therapy.

Patients who had received overdenture treatment provided with uniform standards were recalled and studied. Two examiners simultaneously and independently evaluated the tissue response using a variety of indices. Data comparisons were made between overlaid teeth and control teeth and between overlaid teeth as a function of time to assess any effects of the treatment. Patients who did not apply fluoride to retained tooth roots had a high incidence of caries. No other significant differences were noted between the health of overlaid teeth compared to control teeth. Patients demonstrated large variations in their ability to maintain low plaque levels and healthy tissues. Despite this, on a longitudinal basis over 2 years, patients were able to maintain plaque levels and gingival response at clinically acceptable standards.

Consumer Behavior↗
PubMed1977

[Local ventricular wall motion, local myocardial flow, and blood flow distribution in a poststenotic myocardial region in patients with coronary heart disease (author's transl)].

In 10 patients with coronary heart disease, local ventricular wall motion, local poststenotic flow, and distribution of myocardial perfusion were determined in the underperfused myocardium before and after 8 mg of Oxyfedrin intravenously. In 8 of the 10 patients there was a uniform reaction consisting of an improvement of wall motion, increase in flow, and homogeneity of flow distribution. These parallel changes of local wall movement and local blood flow in a poststenotic underperfused part of the myocardium can most probably be explained by the positively inotropic action of Oxyfedrin with a consecutive increase in blood flow. The results show that a therapeutic affect in patients with a coronary stenosis less than 60% in the left descending artery can be obtained with a positively inotropic substance.

Adult↗
PubMed1977

Tumor cure and cell survival after localized radiofrequency heating.

Radiofrequency electromagnetic fields at 13.56 MHz were used to heat locally EMT-6 sarcomas and KHJJ carcinomas in BALB/cKa mice. Temperature profiles obtained in tumors during treatment showed uniform temperature distribution throughout the tumor volume with no systemic hyperthermia. Temperature could be maintained at a stable level throughout treatment by adjustment of power. Tumors were treated at 43 degrees, 43-5 degrees, and 44 degrees, for 5, 10, 20, 30, and 40 min. The EMT-6 tumor was highly sensitive to cure by radiofrequency heating: a 5-min exposure at 44 degrees resulted in cure of almost 50% of the tumors. Cure rate was a function of temperature and of duration of exposure. The KHJJ carcinoma was somewhat more resistant to cure by radiofrequency heating, although most of the animals treated at 43.5 degrees or above were cured of their tumors. In an effort to explain the remarkable effectiveness of radiofrequency heating, tumor cell survival studies were done on EMT-6 tumors treated in situ. Cell inactivation by radiofrequency heating was similar to that for hot water bath heating. However, direct cell killing cannot account for the observed cures, and an additional mechanism must be responsible for tumor eradication.

Animals↗
PubMed1976

[The effects of dihydroergo-corine,-cryptine and-cristine on Haemodynamics in experimental cardiogenic shock].

Experimental results demonstrate, that serial ligatures of the side brances of the anterior descending and circumflex artery in the openchest dog produce a hemodynamic and electrocardiographic criteria fullfilling cardiogrenic shock. The application of the alpha-receptor-blocking agens Hydergin is followed by a statistically significant increase of the mean aortic pressure, the left ventricular systolic pressure and the mean blood flow in the femoral artery. The left ventricular enddiastolic pressure in the left ventricular enddiastolic pressure in the left ventricle decreases statistically not significant, dp/dtmax is unchanged. Hydergin effects a slope of the increased peripheral vascular ristance; if the peripheral vascular risistance is lowered during cardiogenic shock, there will not be a further lowering after treatment. The results show, that Hydergin causes a dilation of peripheral vasoconstricted vessels without unwanted hemodynamic side effects.

Animals↗
PubMed1975

[The effect of a dimenhydrinate combination of the cardiovascular system and cerebral blood circulation in the anaesthetized dog].

The influence of Vertigo-Vomex (VV) and Vertigo-Vomex Retard (VVR) on the perfusion rate of the a. carotis interna and on the peripheral circulation was tested in 30 anaesthetized dogs. These drugs represent beta-dimethylamino-ethyl-benzhydrylether-1,3-dimethyl-8-chloroxanthine (dimenhydrinate, Vomex A) with the addition of pyridine-3-carbonic acid (nicotinic acid, niacin) and pyridoxine-HCl (vitamin B6) and its retard preparation. A) Angiographic researches of the brain vessels after i.v. injection of VV. B) Perfusion rate in the a. carotis int. by electromagnetic flowmeter; measurements of blood pressure, heart rate, and acid-base balance; reactions after injection of niacin, dimenhydrinate, and pyridoxine-HCl as well as after a combination of both. C) Same measurements as in B but after oral application. In one out of four cases there was a dilation of the brain vessels, in two cases there was a small one, in one case there was none. Niacin induces a short-lasting augmentation of the perfusion rate in the a. carotis int. simultaneously with rising aortic blood pressure. Dimenhydrinate with pyridoxine-HCl slightly increases the heart rate. Combined with niacin the perfusion rate shortly increases immediately after injection of niacin without any rise of blood pressure but combined with a fall in blood pH and standard bicarbonate. After oral application of VVR there was a slight but not significant augmentation of the perfusion rate in the a. carotis int. combined with rising blood pressure but with no change of the blood pH. Therefore the certain intivertigineous effect of VV and VVR cannot be explained by a rise of the perfusion rate in the inner ear or in the brain. In view of our results the central effect of dimenhydrinate combined with niacin and pyridoxine-HCl hypothetically may be improved by metabolic influences on the cells and their membranes.

Acid-Base Equilibrium↗