Biomedical subjects
D Döring
Publications and source records attributed to D Döring.
[Assessing diagnostic possibilities using the sensitivity of findings].
The Bayes-formula gives the possibility in ambiguous situations for diagnostic decisions to use the sensitiveness of findings for estimating the diagnostic probabilities. In such a case in differential-diagnostic questionings can be proceeded from the equal probability of the diagnoses so that the probabilities obtained by means of computation are alone based on the sensitiveness of findings and not on subjective estimations. Combinations of findings (patterns of findings) of any kind taken from positive and negative findings can be analysed. The advantage consists above all in the fact that the sensitiveness of findings may be evaluated controllable, reproducible and independent of the subjective experience. In addition to this there is a theoretical advantage that the process of the diagnostic decision becomes better understandable. Nevertheless it is to be emphasized that diagnostic decisions finally are based on subject-specific interpretations of the findings and formal criteria deliver only additional aids of decision.
[General viewpoints in evaluating findings and making diagnostic decisions].
The process of diagnosis consists of establishment of findings, interpretation of findings and diagnostic decision. The general situation concerning decision is characterized by the fact that incorrect decisions may appear by falsely positive and falsely negative findings. On this assumption a diagnosis can only be confirmed with certain probability or excluded. Unequivocal decisions may be regarded as borderline cases of this situation concerning the decision. Their prerequisites are explained with the help of four-field table and diagrams belonging to this. If these conditions are not given, so that only a probable diagnosis can be made, then the indexes allow of an estimation of the degree of certainty of the evidence. By means of statistical models helps for decision can be obtained. The example of the Bayes-theorem is illustrated with the help of diagrams. In recent years another approach gathers momentum. The methods in question are so-called unclear approaches of the analysis of processes. They essentially support themselves on assessments by experts and on a programmed approach.
[Actual and theoretical points of view in the application of coronary therapeutic agents].
The medicamentous therapy of the angina pectoris vera and of the chronic ischaemic heart disease is at present based on three groups of medicaments: nitrate compounds, beta-blocking agents and calcium antagonists. The underlying therapeutic principle which is common for them consists in the reduction of the oxygen requirement of the myocardium so that an improvement of the complaints and a larger load capacity may be achieved. The improvement may be objectified also at the behaviour of the haemodynamics and the ECG under load. The so-called coronary dilating remedies and the beta-stimulators did not prove clinically. In the acute attack rapidly acting nitroglycerin compounds remain the remedies of choice. Also the permanent treatment should at first again use longer acting nitrate preparations. When despite a sufficient dosage no satisfying improvement takes place an additional prescription of beta-blocking agents is recommended. Calcium antagonists are suitable particularly for the vasospastic form of the angina pectoris. They can be used also as basis medicaments, however, according to the hitherto yielded experiences they do not possess any advantages in contrast to the proved nitrates and beta-blocking agents. When apart from the ischaemic heart disease a hypertension exists, the beta-blocking agents are particularly indicated. This is further important for certain forms of tachycardiac disturbances of rhythm, which partly also well response to calcium antagonists. In patients with disturbances of conduction (sinus node and atrioventricular nodes, bifascicular block) beta-blocking agents are contraindicated. If there are no signs of cardiac decompensation and radiologically the heart proves to be normally large, so there is no indication for the prescription of glycosides.
[Theoretical viewpoints of coronary hemodynamics relative to the localization of arterial stenoses and the collateral function with special reference to the so-called steal effect].
1. On a simple branched model of the vascular system is deduced that the restriction of the reserve of blood supply (coronary reserve) occurring in arterial constrictions depends not only on the degree of constrictions, but also on their type of distribution, by means of which peculiarities of the univascular diseases in contrast to the multivascular diseases are the result. 2. Constrictions further the formation of the collateral circulation, the size of which in the same initial pressure increases with the degree of constriction and the decrease of the peripheral resistance. 3. The effects of the collateral circulation are fully different for proximally and distally localized stenoses. Proximal stenoses lead the collateral circulation in direction to the narrowed area, peripheral narrowings of the circulation, however, to the counter-direction. 4. A Steal effect is possible only in peripheral narrowings of the circulation. Its haemodynamic conditions are described in detail. 5. As haemodynamic explanation for the positive dipyridamol test the hypothesis arises that it might refer to remarkable peripheral constrictions. 6. The application of vasodilators is from the haemodynamic point of view indicated above all in proximal constrictions, when distally from this there are interarterial anastomoses. Repression is necessary in peripheral narrowings, when their reserve of blood supply is already consumed by vasodilatation. In these cases is to be reckoned with a Steal effect.
[Case contribution to the question of side effects in the dipyridamol test].
Report on a case with disturbance of the cardiac rhythm (atrioventricular dissociation with ventricular extrasystoles) in connection with a dipyridamol test which regressed under therapy with euphyllin. This observation supports the demand of a continuous control of the ECG when the test is performed.
[Theory and critical aspects of the so-called steal effect of coronary dilators of the dipyridamole type].
The stenocardias appearing in the dipyridamol test are explained by the hypothesis of a steal effect. This notion is, concerning its contents, to be demarcated against other regulatory processes. With the help of a simple model can be made clear that the thesis of a steal effect stands in contradiction to haemodynamic basic conceptions and cannot be used for the explanation of the paradoxical effect of dipyridamol.
[The current clinical importance of corrected orthogonal derivations].
According to the theorectical basic conception corrected orthogonal derivations restrict themselves to the selective establishment of the dipol proportion of the cardio-electric field of the body surface. In contrast to this the 12 conventional derivations give a more comprehensive information which in the precordial region also includes non-dipolar field proportions. There is not infrequently the requirement of supplementing this conventional routine programme with the help of further derivations, since also by partly redundant informations the certainty of diagnostic decisions may be increased and circumscribed alterations of the field may become comprehensible. According to recent knowledge the offer of informations which smaller for the routine form of the ECG-evaluation may be extensively redeemed by the calculation of vectorial sizes, which presumes the machine evaluation of the ECG. Also the most trained imaginative faculty is not able to estimate more exactly the course of the vector loops from the 3 corrected derivations. As long as the economical and technical problems including the evaluation programmes for a machine processing of the ECG are not solved, the corrected derivations are of no clinical importance. Their use is restricted to only few centres interested in science.
[Investigations of the reaction kinetics in the formation of 7-chloro-2N-nitrosomethylamino-5-phenyl-3H-1,4-benzodiazepine-4-oxide (author's transl)].
The influence of alcohol, ascorbic acid, phenol and thiocyanic acid on the formation of N-nitrosochlordiazepoxide from chlordiazepoxide and nitrous acid was investigated by means of high-performance liquid chromatography.
[Share of various circulation parts on the increase of circulation time (appearance time) in mitral valve diseases].
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[Objective measurement of circulation time using ascorbic acid and hydrogen].
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[First experiences with the use of dopamine (hydroxytyramine) in cardiogenic shock].
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[Comparative studies on the diagnosis of ventricular hypertrophy using conventional and corrected orthogonal drainage after Frank and McFee. 4. Vectorcardiographic findings in dextral hypertrophy].
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[Mechanism of action of new sympathomimetics (dopamine and wyamine) and the ir therapeutic possibilities in cardiogenic shock].
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[Comparative studies on the diagnosis of ventricular hypertrophy with conventional and corrected orthogonal deviations by the Frank and McFee technic. 3. ECG findings in right side hypertrophy].
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[Comparative studies for diagnosis of ventricle hypertrophy iwth conventional and corrected Frank-McFee orthogonal derivation. 2. Vectocardiographic findings in left hypertrophy].
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[Comparative studies on the diagnosis of ventricular hypertrophy with conventional and corrected orthogonal Frank-McFee leads. 1. ECG findings in left hypertrophy].
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[Clinical aspects and pathology of a case of idiopathic aortic mediopathy].
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