Biomedical subjects

H Schiekedanz

Publications and source records attributed to H Schiekedanz.

2 recordsLinked to original sources

PubMed1976

[Methods and problems of spermatogonia counts in histological section preparations].

The number of spermatogonia of the testicles is an important criterion for the assessment of the probable fertility prognosis. The determination of the mean content of spermatogonia per cross section of one tubulus seminiferus is considered as a standardized procedure in clinical practice. Counts of spermatogonia in 4 micron thick section preparations bear great errors. Such determinations have to be done on extremely thick sections. In the present study, this is proved by the results of morphometric investigations on nuclei of spermatogonia. On 89 testicle preparations autoptically obtained from children, measurements of the diameter and calculations of the relations of the axes as well as of the volumes of the nuclei of the spermatogonia are carried out.

Adolescent↗

PubMed1976

[Determination of statistical error using the hit method].

Referring to a histological example, an explanation is given which parameters of the hit procedure have an influence upon the magnitude of the random measuring errors. The dispersion of the measuring values decreases as the number of test points increases. Moreover, if the number of test points is equal, the dispersion is dependent on the relationship between test point distance and mean diameter of the object structures. It reaches a minimum if this ratio is greater than 1 or approximates 1. By subdividing a measurement with numerous test points into small sections it will be possible to calculate the standard deviation. For this, coarse-mesh test nets with few points are favourable.

Bone and Bones↗