[The effects of thioguanine, hydroxylamine and 5-bromodeoxyuridine on human chromosomes in vitro].
Explore the source record for details and available documents.
Bromodeoxyuridine↗
Biomedical subjects
W Engel
Publications and source records attributed to W Engel.
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↗
On the teratogenesis of round-headed spermatozoa: investigations with antibodies against acrosin, an intraacrosomally located acrosin-inhibitor, and the outer acrosomal membrane.
Acrosin, the outer acrosomal membrane (OAM) and an acrosin inhibitor were studied in testicular cells and ejaculated spermatozoa of fertile men and in those of an infertile patient with exclusively round-headed spermatozoa in his ejaculates. The investigations were performed with the aid of immunohistochemical techniques using specific antibodies against the three acrosomal markers isolated from boar spermatozoa. The spermatozoa of fertile men exhibit staining for acrosin, the OAM and the acrosin inhibitor in the cap region while the round-headed spermatozoa of the patient are totally negative for the three markers, clearly supporting the conclusions of other authors that round-headed spermatozoa lack acrosomes. The lack of the acrosin system was further substantiated by the gelatin substrate film technique. In the course of normal human spermatogenesis acrosin, the OAM and the acrosin inhibitor we first demonstrable in early round spermatids, namely in identical compartments adjacent to the cell nucleus. During spermatid differentiation the staining for the three markers becomes flattened over the nucleus, resulting in a cap-like structure in testicular spermatozoa. In contrast to the ejaculated round-headed spermatozoa, the early round spermatids in the testis of the infertile patient exhibit fluorescent staining for the three markers in the region adjacent to the nuclear membrane. In the course of further spermiogenesis, the staining did not extend over the nuclear membrane, as was observed during normal spermiogenesis, but became separated from the nuclear membrane, as was observed during normal spermiogenesis, but became separated from the nuclear membrane, was translocated at various locations in the cytoplasm and was finally eliminated with the loss of the cytoplasm. These results are in accordance with the results of electron microscopically investigations on the teratogenesis of round-headed spermatozoa. Furthermore, the developmental pattern of the acrosin inhibitor during normal and abnormal spermiogenesis supports the intraacrosomal location of the acrosin inhibitor recently described by Tschesche et al. (1982).
Acrosin↗
On the interaction of bull and boar acrosins with the zona pellucida of different mammalian species in vitro.
Acrosin was prepared from boar and bull spermatozoa and its lytic effect in vitro on the zona pellucida of mouse, golden hamster, rabbit, pig and cow was investigated. Depending upon the species studied, ovarian oocytes, ovulated oocytes and preimplantation embryos were obtained for the experiments. While in golden hamster and rabbit the zona pellucida was removed by both acrosins, this effect was absent for bull acrosin in cow and mouse eggs and for boar acrosin in pig and mouse eggs. In those species in which the zona pellucida was not removed by the acrosins after an incubation period of 2 hours even a prolongation up to 24 hours with higher amounts of acrosin, the addition of acrosomal extracts to the incubation buffer (Tyrode solution pH 7.2) or an increase of the pH value up to 8.6 of the acrosin solution had no effect upon the zona pellucida. Our results indicate that at least in vitro, acrosin does not possess the capacity to lyse the zona pellucida in a species specific fashion. Since the lytic effect of boar and bull acrosin on the zona pellucida of ovarian oocytes and preimplantation embryos is not different from that on ovulated oocytes it can be assumed that neither the maturation of the zona pellucida during oogenesis nor its modification after fertilization, change the susceptibility of the zona pellucida to acrosin digestion.
Acrosin↗
Evolution and development of the outer acrosomal membrane (OAM) and evidence that acrosin-inhibitors are proteins of the OAM.
An antiserum to the purified porcine outer acrosomal membrane (OAM) was raised in rabbits and the IgG fraction isolated by ammonium sulphate precipitation and ion exchange chromatography. The antibodies reacted exclusively with the acrosomal cap of the sperm head as revealed by indirect immunofluorescence. In addition they cross-reacted not only with the acrosomal part of the spermatozoa of all mammalian species tested (bull, horse, rabbit, rat, mouse, hamster, mole, antelope, monkey, man) but also with the spermatozoa of the cock (Class: birds) and the rainbow trout (Class: fish). All the species exhibited similar development of the acrosomal cap during spermatogenesis, with the appearance of the immunofluorescent stain in early round spermatids. In the mole the localization of the acrosome in elongated testicular spermatids differed from that in all other species: Instead of prominent fluorescence over the apical part of the sperm an equatorial belt was formed. The cross-reactivity of the anti-boar OAM antibody with the acrosomes of different vertebrate species at the morphological level was supported by the results of Western blotting experiments with purified boar OAM proteins and the SDS-extractable proteins of bull and human spermatozoa, respectively. Using anti-OAM antibodies and antibodies against the acrosin inhibitors I and II described recently by Tschesche et al. (1982), in absorption and Western blotting experiments, it was demonstrated that the acrosin inhibitor proteins are integrated in the outer acrosomal membrane.
Acrosin↗
Nekrozoospermia in mosaic Klinefelter's syndrome.
A patient with nekrozoospermia is presented. His clinical, andrological and endocrinological data are described. Cytogenetically a complex chromosomal mosaic of 46,XX; 46,XY; 47,XXY and 48,XXXY was found.
Adult↗
High incidence of minor chromosomal variants in teratozoospermic males.
Chromosomal analysis was performed on 109 males with teratozoospermia. Four cases of anomaly were found, including three cases of mosaic Klinefelter's syndrome and one balanced autosomal translocation. Among chromosomal heteromorphisms, 9qh+ was found in 25% of the patients. The fraction of malformed spermatozoa in the semen of the 9qh+ group is significantly higher than in the chromosomally normal group. It is speculated that heterochromatic variants like 9qh+ could be one of several unknown factors disturbing normal gametogenesis.
Chromosome Aberrations↗
On the expression of protamine genes in the testis of man and other mammals.
Protamines are low molecular weight, highly basic nuclear proteins involved in the condensation of sperm chromatin. cDNA clones for human protamine 1 and 2 (PRM1 and PRM2) were used for Northern blot experiments with RNA from different human tissues. Protamine transcripts, 0.6 kb and 0.9 kb in lengths for PRM1 and PRM2, respectively, were detected only in testicular RNA. The hybridization signals though did not produce sharp bands but enclosed a minor fraction of significant smaller transcripts. When polysomal RNA fractions were used in the hybridization, these shorter transcripts, 0.45 kb in length for PRM1 and 0.7 kb for PRM2, were specifically enriched. As demonstrated by in situ hybridization on human testis sections, the transcripts of both protamine genes are restricted to the central cell layer of the tubuli seminiferi corresponding to the spatial arrangement of postmeiotic cells. This result indicates that the protamine genes in the human are postmeiotically and haploid expressed. When cDNA clones of both protamines of the boar (BPrm-1 and BPrm-2) were used for hybridization experiments with the testicular RNA of those mammalian species which lack protamine 2 in their spermatozoa, the presence of transcripts for both protamines was detected. It can be assumed that mammals in general are endowed with at least two protamine genes which are both transcribed but are translationally regulated in a species-specific manner.
Animals↗
On the capacity of mouse spermatozoa for spontaneous acrosome reaction in the male and female genital tract.
The spontaneous acrosomal reaction of mouse spermatozoa during their passage through the male and female genital tract was studied by indirect immunofluorescence staining techniques using antibodies against the outer acrosomal membrane (OAM). Low rates of spontaneously acrosome-reacted spermatozoa could be observed during the passage through the male reproductive tract, namely 4% in the testis (SD +/- 0.8%) and in the caput epididymidis (SD +/- 1.5%), and up to 8% in the cauda epididymidis (SD +/- 0.5%) and in the ductus deferens (SD +/- 0.5%), whereas a higher value of 13% (SD +/- 1%) of reacted spermatozoa was obtained from the corpus epididymidis. Spermatozoa removed from the uterus 20 min up to 14 h post copulation (p.c.) exhibited a constant degree of 8% (SD +/- 6%) acrosomal reaction, whereas 43% (SD +/- 6%) of the oviductal sperms were acrosome-reacted, independent of the time of removal p.c. Rates of spontaneously acrosome-reacted spermatozoa from the male and female reproductive tract could be increased by 2-fold and up to 7-fold by an in vitro incubation in modified Tyrode's medium for 210 min. On the basis of our results wer postulate a basic level of spontaneously acrosome-reacted spermatozoa in the oviduct at ovulation time, which might be relevant to ensure the environmental conditions for the fertilization process. Additionally, we offer a possibility of optimizing in vitro fertilization techniques.
Acrosome↗
Analysis of meiotic chromosomes in ejaculates of infertile patients with an increased number of immature germ cells in semen samples.
Seventy-one semen samples of 60 infertile patients with a suggested high number of immature germ cells were assigned for chromosomal analysis. The sperm probes of nine patients did not contain immature germ cell stages apart from spermatids. In 22 probands we could only find early prophase stages or not readable metaphase structures. Only 25 patients could be analysed cytogenetically. The semen sample of each patient contained degenerated germ cell structures associated with desynaptic and fragmented/pulverized metaphase cells. It follows that in each analysed probe we could detect anomalies which can be attributed to errors in the gametic development process and which are possibly connected with the existing teratozoospermia and oligozoospermia. The easy practicality for cytogenetic analysis represents the most important advantage of the described method. The analysis of immature germ cell stages in semen samples makes it possible to bypass or to reduce the incidence of tests biopsies for meiotic chromosome investigation.
Chromosome Aberrations↗
Maternal serum placental growth hormone and insulinlike growth factor binding proteins 1 and 3 in pregnancies affected by fetal aneuploidy and other abnormalities: implications for prenatal diagnosis of trisomy 21.
In the present study, we determined circulating serum levels of human placental growth hormone (hPGH) and insulinlike growth factor binding proteins 1 and 3 (IGFBP-1 and IGFBP-3) using two-site radioimmunoassays during the gestational midtrimester of pregnancies affected by chromosomal disorders with the aim of identifying potential marker substances that might have a significant discriminative and predictive value for prenatal diagnosis of fetal chromosomal aberrations and of organ malformations such as neural-tube defect. Our results show that the maternal serum levels of hPGH were significantly elevated in pregnancies affected by chromosomal anomalies or organ malformations as compared with controls. The distribution of IGFBP-1 concentrations for all experimental groups except trisomy 21 were closely similar to the normal population. IGFBP-3 decreased slightly in pregnancies affected by Down syndrome. These findings suggest that hPGH may be useful as an additional marker in prenatal screening for Down syndrome.
Adolescent↗
[Chemical investigations of the discoloration of tooth enamel in the caries process].
Explore the source record for details and available documents.
Amino Acids↗
[Triple test: problem or enhancement of prenatal diagnosis].
Explore the source record for details and available documents.
Chorionic Gonadotropin↗