Biomedical subjects

W Schill

Publications and source records attributed to W Schill.

21 records · Page 2Linked to original sources

PubMed1976

[Incidence of autologous spermatozoa antibodies in a group of unselected andrologic patients].

Determination of autologous sperm antibodies in the serum of 278 male adults of an unselected andrological patient material is reported. Positive test results were found in 3 patients using the macroscopic agglutination test according to Kibrick (1.1%), in 21 patients using the microscopical agglutination test according to Franklin-Dukes (7.6%), in 2 patients using the immobilization test according to Isojima (0.7%) and in 1 patient using the indirect immunofluorescence technique according to Coons and Kaplan (0.4%). Comparing the macroscopic and microscopic agglutination test a high degree of unspecific agglutinations were found in the latter excluding the microscopical agglutination test for the determination of antibodies. The relatively rare occurrence of autologous sperm antibodies in an unselected andrological patient material points to the fact that immunological methods seem to play no significant role in the diagnosis of male subfertility.

Antibody Formation↗

PubMedDate not supplied

Logistic analysis of studies with two-stage sampling: a comparison of four approaches.

This paper discusses the analysis of two-stage studies where covariates are missing or measured with error at the first stage of sampling and are validated at the second stage in a subsample. Four recently developed approaches, the weighted pseudo-likelihood method of Flanders and Greenland (1991), the pseudo-conditional likelihood methods of Breslow and Cain (1988) and Schill et al. (1993) and the maximum likelihood estimate obtained via the EM-algorithm (Wacholder and Weinberg, 1994) are reviewed, and some connections between them are established. It is shown that, with respect to odds ratio estimation, case-control designs can be analysed as if first-stage sampling had been prospective. The procedures are numerically compared with respect to asymptotic relative efficiency in a missing value setting.

Algorithms↗

PubMedDate not supplied

Biochemical and genetic investigation of round-headed spermatozoa in infertile men including two brothers and their father.

Acrosin and the outer acrosomal membrane (OAM) were studied in the spermatozoa of 9 infertile patients who differed in the number of round-headed spermatozoa between 14 and 71% in their ejaculates. These sperm components were also investigated in two infertile brothers who exhibited exclusively round-headed spermatozoa in their ejaculates, and in their fertile father. It turned out that round-headed spermatozoa lack both acrosin and the OAM as studied by indirect immunofluorescent and immunoperoxidase staining technique, gelatinolysis tests and by acrosin activity measurements. The normally shaped spermatozoa of 6 of the 9 infertile patients were found to be positive for acrosin and the OAM as expected, but in the remaining three patients even these spermatozoa were abnormal; in one patient they were unstainable for acrosin and in two patients they were unstainable both for acrosin and the OAM. These results have been confirmed by studies with the gelatinolysis test. The father of the two brothers with exclusively acrosomeless spermatozoa had more than 94% of normally shaped spermatozoa. However, only 10% of these spermatozoa were acrosin positive and only 30% were positive for the OAM. On the basis of these results we postulate that the mode of inheritance of the round-headed spermatozoa syndrome is polygenic rather than monogenic as suggested by previous authors.

Acrosin↗