Idiopathic infertility in married couples in the light of cytogenetic analysis and sperm penetration assay.

We have selected 47 couples with unexplained infertility in order to analyse a possible link between sperm dysfunction studied in males in in vitro conditions and karyotype analysis of somatic cells. In order to identify so called "idiopathically infertile" couples we had to exclude any change in reproductive organs in both partners or in spermiogram which would qualify any of spouses into known category of infertility. We have revealed chromosome aberrations (translocations and marker chromosomes) in 19% of infertile males and in 6% of infertile females. Idiopathically infertile males had an overall decreased ability of sperm function (measured by proportion of penetrated hamster oocytes by human sperm) in comparison to fertile controls, however, still well placed within physiological range of values. Only sperm from a patient with identified translocation was clearly below the normal level of penetration (20% of penetrated oocytes), however, also the patients with revealed chromosome variant polymorphisms presented statistically lower values of penetration in comparison to fertile controls (39% vs 57%, p<0.05). On the contrary, patients with marker chromosomes did not exhibit affected sperm function. It can be speculated that only particular chromosome aberration in group of idiopathically infertile males may affect sperm functional capability (measured in vitro), however, the intragonadal genetic analysis has to be recommended in order to confirm such a causative link.

Unconscious violinists and the use of analogies in moral argument.

Analogies are the stuff out of which normative moral philosophy is made. Certainly one of the most famous analogies constructed by a philosopher in order to argue for a specific controversial moral conclusion is the one involving Judith Thomson's unconscious violinist. Reflection upon this analogy is meant to show us that abortion is generally not immoral even if the prenatal have the same moral status as the postnatal. This was and still is a controversial conclusion, and yet the analogy does seem to reveal in a very vivid way what makes abortion a reasonable response to a terrible situation. But Thomson's example has frequently been attacked on all sides for not being truly analogous to abortion. Here I develop a brand new analogy that sheds light on the issue with which Thomson was concerned, while at the same time avoiding most of the more serious objections made to her analogy.

Chromosomal anomalies as a predisposing factor for male infertility.

A "genetic factor" can be the reason for about 20% of male infertility cases. This could be due to chromosomal aberrations in sperm with immediate effect on conception or may result in recurrent spontaneous abortions of paternal origin. Techniques for the analysis of sperm chromosomal aberrations are still far from ideal. Sperm penetration to zona-free hamster oocytes and random in situ hybridization with sperm DNA using a range of fluorescent probes--are currently under investigation. Sperm chromosome analysis was performed in three distinct subgroups, (a) healthy, fertile individuals, (b) healthy but infertile subjects, and (c) carriers of chromosomal aberrations in lymphocytes. Sperm chromosomal aberrations occur in normal and fertile population in range from 1.9% to 15.8%. The aberrations are concerned both with number and structure of chromosomes. In infertile individuals, the main chromosome aberrations observed were translocations and pericentric inversions. Several hypotheses are also described indicating possible reasons for subfertility due to chromosomal anomalies. There are few gene families that can be involved in the regulation of spermatogenesis, mainly located on the Y-chromosome. Identification of defective gene(s) may lead to novel therapeutic strategies for infertility treatment.

Studies on 17-1A antigen gene regulation in nonexpressing A549 and A431 cells, as compared to expressing pancreatic carcinoma (Capan 2) cells, reveal a complex mechanism of repression of this gene.

Elements controlling high expression of the 17-1A antigen gene in pancreatic carcinoma cells (Capan 2) reside within the two regions: proximal (-193 to +3) and distal (-877 to -518). We demonstrate here that some factors present in nuclear extracts from nonexpressing cells bind specifically to the control elements, important for gene expression. Our results suggest that nonexpressing cells may either lack at least one of the factors necessary for activation or may contain their modified forms. A major difference between expressing and nonexpressing cells was found in the region containing core enhancer sequence. Moreover, nonexpressing cells display a complex pattern of DNA-protein interactions in this region, suggesting that these cells contain factors acting negatively mainly on the enhancer sequence. Our results however, indicate that the mechanism of repression is much more complicated than expected.

Binding of low mobility group proteins with DNA examined in homologous and heterologous systems by gel retardation assay.

The interaction of low mobility group proteins (LMG), isolated from chromatin of pancreatic carcinoma cells (CAPAN-2), with fragments of 5'-flanking region of the antigen 17-1A gene was studied by gel retardation assay. The LMG proteins, which formed complexes with DNA were extracted from the gels and identified by polyacrylamide gel electrophoresis under denaturing conditions. The proteins of Mw about 100, 60, 55 and 48 kDa, which formed specific complexes with fragments of 5'-flanking region of the antigen 17-1A gene, were identified.

Nuclear proteins from Capan-2 cell line form specific complexes with the 17-1A antigen gene promoter.

To determine the location of sites important for the function of the 17-1A antigen gene promoter and to characterize the protein factors binding to these sites, fragments of the promoter region were analysed by gel retardation assay with nuclear extracts from Capan 2 cell line. At least two separate regions, which specifically bind nuclear proteins, were identified within the 5'flanking region of the 17-1A antigen gene. These regions have been located between nucleotides -877 to -518 (distal region) and -193 to +3 (proximal region) and presumably participate in regulation of expression of the 17-1A antigen gene.

Binding of low mobility group protein from rat liver chromatin with histones studied by chemical cross-linking.

The protein of molecular weight about 160 kD (designated LMG160) was isolated from purified low mobility group chromatin proteins. Polyclonal antibody directed against the LMG160 protein in mouse was raised. The specificity of the antibody was determined with the use of ELISA. Using chemical cross-linking procedure followed by immunoprecipitation with the antiLMG160 antibody complex formation with chromatin proteins was demonstrated. Among the proteins that form complexes with LMG160, histones H3, H2A, and H4 were identified (Western blotting technique).

Non-histone chromatin proteins during various stages of activity of immunocompetent cells.

Qualitative and quantitative changes of non-histone chromatin proteins of spleen cells during the primary immune response to sheep red blood cells and aggregated human gamma-globulin were described. Synthesis of non-histone chromatin proteins was measured by labelling with 3H-tryptophan during culture of spleen cells in vitro. Chromatin was isolated and labelled proteins were analysed by polyacrylamide gel electrophoresis. During the immune response to both antigens in chromatin of spleen cells three new fractions of non-histone chromatin proteins were synthesized: fractions F1 - M = 12 000 and H - M = 3 000, specific for sheep red blood cells and fractions I1 - M less than 3 000 and B - M = 120 000, specific for human gamma-globulin. The third antigen-non-specific fraction was synthesized at the time when the primary immune reaction was finishing. These new fractions were synthesized only in one of the analysed subpopulations of spleen cells. In thymocytes (non-fully-differentiated lymphoid cells) all these fractions were absent. Changes of non-histone chromatin proteins in thymocytes during the immune response were similar to those found during stimulation to proliferation by phytohemagglutinin in vitro.