1. The variability of electrographic data used up to now is too large to discriminate easily between normal and abnormal. 2. This variability is partly caused by errors in the measuring process and its consequences. A sepcial difficulty is found in determining the beginning and the end of QRS, so that instantaneous vector magnitudes related to the starting or ending moment of QRS will have a high variance and therefore a low comparability. Displacements of the heart will play an important role as a source of errors. 3. It therefore seems to be more appropriate to describe structure and changes in time of the vector loop. To this end 3 new functions v, w and u are described, all three invariant towards positional changes of the heart in space. The term v means a time-dependent function describing the first derivative of the length of the instantaneous resulting vector of all electrical sources. The term w indicates the projection of the first derivative of the instantaneous vector into a plane orthogonal to the resulting vector. Therefore, v is dependent on the change of all resulting electrical forces, whereas w is the velocity of the peak of the resulting vector on its way along the vector loop. The interpretation of u is complicated; u is a measure of how much the vector leaves a plane, in which it normally more or less remains; u is therefore a measure for the edgeside view of the vector loop. 4 These data are combined with the well-known vectorial data to form a system of vectorial description. 5 The interpretability of these data in physiological terms is exemplified. The description presented here allows to go back to cardiac processes in the proper sense and to largely elimenate external influences like those of the thoracic shape on the ecg and vcg. 6. This way of describing an ecg is specially adapted to the discrimination of normal and abnormal in preventive tests.

Adult↗

PubMedDate not supplied

Skin pharmacokinetics.

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Administration, Cutaneous↗

PubMedDate not supplied

Penetration of vitamin A acid into human skin.

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1-Propanol↗

PubMedDate not supplied

[Theory of methods to compare lead fields in electrocardiography (author's transl)].

A method is theoretically described to test the accuracy of various lead system of the ecg. The priniciple of this method consists in the following procedure. The heart position is changed maximally in a proband by varying the position of the body and by deep inspiration and exspiration. If the lead field is parallel, the recorded vector loops should by conventible into each other by merely rotating them electronically, because the cardiac determinants of the veg will scarcely be changed by a change in heart position. The deformations of the veg in the edgeside and broadside view are an appropriate measure of the inhomogenities (the "accuracy") of the lead field, mostly caused by the configuration of the chest and the inhomogeneous conductivity of the tissues and the resulting lack of parallelity in the lead lines of the field. Criteria to test the form of the vector loop are developed, measuring quantitatively the similarly of the loops recorded in different heart positions. The "best" lead is regarded to be that with greatest similarity of the loops in extreme dislocations of the heart.

Electrocardiography↗

PubMedDate not supplied

[Clinical trials in dermatology. The phase I trials].

Application of the new topical product on the diseased skin should be preceded by its safety evaluation on the healthy skin in human volunteers. We propose here guidelines for the evaluation of the irritation, sensitization, phototoxicity and photoallergy potentials for topical products. The methods for evaluation of percutaneous absorption are also discussed. The studies presented here are not the object of any regulations. Therefore, we propose here an approach for the safety evaluation of topical products in human volunteers.

Administration, Topical↗

PubMedDate not supplied

[Clinical trials in dermatology. Evaluation of the tolerability and efficacy of a topical anti-inflammatory treatment in atopic dermatitis].

Study designs for assessment of topical anti-inflammatory drugs in atopic dermatitis are discussed. Atopic dermatitis is a chronic disease with symmetrically distributed lesions. In order to avoid individual and spontaneous variation and to obtain an early impression of the efficacy of a new topical drug, bilaterally paired lesions can be used. Further drug development requires controlled double-blind parallel group design. General recommendations regarding inclusion criteria, and the measurement of efficacy and safety parameters are presented. Methods available for data evaluation and the particularities of different clinical designs are discussed.

Administration, Topical↗