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H J Kretschmann

Publications and source records attributed to H J Kretschmann.

At least 55 records · Page 3Linked to original sources
PubMed1975

[A method of rational particle counting (author's transl)].

A method is described, which simplifies the counting of particles in a known volume. The counting of neurons of a brain region is used as an example for this procedure. The total volume is processed by histological serial sections. The total area of all sections of this volume is divided into counting squares by an ocular grid, from which we get a sample. This sample is described by the frequency distribution. The real number of particles in the volume is estimated by the values of the frequency distribution. The way of dividing, the size and the way of selection of these counting squares for a certain exactness of the estimation is determined. The method can be used for non-systematic distribution of particles in morphological structures.

Animals↗
PubMed1975

[Determination of the number of cells with multiple nucleoli in histological sections (author's transl)].

A method has been described for correction of a bias, when cells with more than one nucleolus are counted by counting their nucleoli. The true numbers of cells and nucleoli per cell can be estimated by a system of linear equations, with coefficients depending on the thickness of the histological specimen, the average nuclear diameter and the probabilities of nuclear slices, which one gets by cutting a cell nucleus with a certain number of nucleoli. The presuppositions for this method have been discussed with respect to different practical situations. Uncorrected and corrected numbers of motoneurons in the nucl. n. oculomotorii of Tupaia belangeri have been compared.

Animals↗