摘要:

Summary.Primordial germ cells in the mouse are known to be derived from the epiblast. They can be identified histochemically, by their high alkaline phosphatase activity. At 8 dpost coitumthey have been observed within the embryonic part of the egg cylinder, at the posterior end of the primitive streak. Earlier, at 7.25 dayspost coitum, we have observed them embedded in the extra‐embryonic mesoderm, as a tight clump. Germ cell counts over the 7–8 d period of gastrulation have been made. They are consistent with either of two models: (1) derivation of the germ cell lineage from a very small stem cell pool, followed by a constant rate of proliferation, and (2) derivation from a larger initial stem cell pool, followed by a period when germ cells are differentiating but not dividing.From their initial extra‐embryonic location, germ cells spread into the mesoderm of the primitive streak, and the endoderm of the yolk sac and hind gut. Active locomotion is probably required for their passage up the dorsal mesentery and into the genital ridges. Mutant alleles at two loci,W(White‐spotting) andSl(Steel), drastically reduce the number of germ cells reaching the ridges. Since those that succeed in reaching the ridges suffer little if any delay, the defect is unlikely to be due to reduced powers of locomotion, but rather to a failure of proliferation or survival.Wacts cell‐autonomously: its gene product is thec‐kitpolypeptide, a transmembrane tyrosine kinase receptor.Slacts through the tissue environment, and has been shown to encode a peptide growth factor variously termed SCF (stem cell factor) or MGF (mast cell growth factor). SCF is presumed to act as a ligand for thec‐kitreceptor molecule, in a signal transduction pathway functioning not only in primordial germ cells, but also in the other two cell types affected byWandSl, namely haemopoietic stem cells and melanoblasts.A few days after colonizing the genital ridges, germ cells (XX or XY) in an ovary enter meiosis, but in a testis they undergo mitotic arrest and do not enter meiosis until a week after birth, as primary spermatocytes. The inhibitory effect is exerted by some diffusible substance emanating from the somatic tissue of the testis: germ cells at a sufficient distance from the testis are able to enter meiosis and develop as oocytes. Thus the phenotypic sex of a germ cell (oocyte or spermatocyte) is determined by its tissue environment, not by its own chromosome

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02647.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Book reviewed in this article:René Lorenz:Dynamische Ultraschallanatomie des Abdomens. Leitfaden für Klinik und Praxis.R. Ackermann, J. E. Altwein, P. Faul (Hrsg):Aktuelle Therapie des Prostatakarzinom

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02648.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.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 testes biopsies for meiotic chromosome investigatio

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02649.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.An account is given in this paper of a method of identifying the fluorescence body (f‐body) as a marker of the Y‐chromosome. Also covered by this method is poor decondensation of spermatozoal nuclei when exposed to action of 1.25% of papain, 0.155% of DTE, and 0.025% of DMSO. Quinacrine mustard was used as fluorescent stain, its final concentration being 0.0025%. For staining, spermatozoa were suspended for 1–5 h. Average f‐body frequency accounted for 41.0 ± 5.1% in 35 ejaculates from 22 bulls. The overall variation coefficient amounted to 12.4% and thus was higher than each of the single values individually recorded from six bulls which were involved with three or four ejaculates (3.6–7.0%). F‐bodies could not be detected by the method generally used on human spermatozoa. The applicability of the f‐body test to quantification of Y spermatozoa in experimental separation of androspermatozoa and gynospermatozoa is discussed and is demonstrated

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02650.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.Anin vitronuclear chromatin decondensation test, and quantitative nuclear ultramorphology analysis, were performed on 18 males judged to be infertile, by two failures inin vitrofertilization, and 16 fertile males. These two clinical groups only differed significantly in (1) the direction of their chromatin stability change, which took place 30–120 min post‐ejaculation while stored in the seminal plasma, and (2) in the incidence of the hypoelongated sperm‐head. Generally, the fertile male group exhibited positive chromatin stability change after prolonged storage, and low incidence of hypoelongated sperm heads, and vice versa in the unexplained infertile group. When the nuclear chromatin decondensation test and quantitative ultramorphology analysis were performed in step‐wise fashion, it was possible to correctly classify 94% of the fertile cases with 6% of false‐negative, and 89% of the unexplained infertile cases with 11% of false‐positive. Therefore, it appears that these tests might be of benefit clinically for identifying functional properties of sperm‐cells in unexplained infertile males, which cannot be detected by routine s

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02651.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.Characterized antihuman sperm monoclonal antibodies from mice were evaluated using the hemizona assay (HZA) to determine whether sperm: zona binding was effected. The seven monoclonal antibodies were characterized using human sperm in agglutination, immobilization, and penetration assays. Semen was provided by four fertile men and used in the HZA to determine if the presence of a monoclonal antibody would affect tight binding of the sperm to the zona pellucida. Pre‐incubation of MA‐14 for 1 h with the sperm induced a 33–54% reduction of the number of tightly bound sperm. This antibody reacts to an antigen located on the acrosome and midpiece. Experiments in which there was no pre‐incubation of the antibody with sperm, resulted in no significant reduction in the number of sperm bound in the HZA. These findings suggest that an anti‐human sperm antibody produced in mice can modulate sperm: zona binding. Reduction in zona binding could indicate a cause of immune‐related infertility and this test may be useful in selecting an antigen for contraceptive vaccine

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02652.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.The distribution of membrane filipin‐sterol complexes (FSC) was examined ultra‐structurally in cauda epididymal sperm from normal and hypercholesterolaemic rabbits. Membrane FSC were quantitatively analysed on replicas of filipin‐treated cells. We determined a significant difference in FSC concentration in the plasma membrane of the acrosome region (PMAR) of hypercholesterolaemic animals compared to normal rabbits. Hypercholesterolaemic animals had 0.56 ± 0.05 FSC complex per μm2(enriched Cholesterol diet: Diet 2) in the marginal segment of PMAR; 0.62 ± 0.05 FSC complex per μm2(enriched Cholesterol and fish oil diet: Diet 3) and only 0.28 ± 0.01 FSC complex per μm2for normal animals (Control Diet 1). In the principal (anterior) segment we found 0.54 ± 0.10 FSC complex per μm2(Diet 2), 0.56 ± 0.03 FSC complex per μm2(Diet 3) and 0.30 ± 0.04 FSC complex per μm2(Control Diet 1). We also counted 0.47 ± 0.1 FSC complex per μm2in the equatorial segment of PMAR for Diet 2, 0.27 ± 0.05 and 0.28 ± 0.04 FSC complex per μm2in Diet 1 and Diet 3 respectively. Diet 4 (fish oil) did not differ from the control. An increase in the Cholesterol (Chol) level in biological membranes or a difference in the Chol membrane domains could cause a variation in the membrane rigidity that could modify the sperm membrane fusion capacity and functionality. The results presented in this paper are in agreement and could explain the decrease in the kinetic of the sperm acrosome reaction that we have observed in experimentally hypercholesterolaemic rabbits (Díaz‐Fontdev

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02653.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.Between May 1985 and March 1992, 172 patients suffering from chronic erectile dysfunction (21–70 years old) underwent constantcorpus cavernosumautoinjection therapy (CAT) with a standardized papaverine‐phentolamine mixture (16385 injections). Thereafter 41 patients continued CAT with the single agent papaverine (1257 injections). On the basis of both these 17642 protocol auto‐injections, and over 6 years of experience with intracavernosal autoinjection therapy we conclude that, especially with the papaverine‐phentolamine mixture, CAT constitutes an effective therapy (full rigidity in 95.8%) with tolerable side‐effects for chronic erectile dysfunction when preceded by careful patient selection and thorough multi‐disciplinary evaluation. This is especially so in the case of arterial and/or neurogenic aetiology of the erectile dysfunction. In addition, the contraindications must be strictly observed, the treatment and technique fully explained, and a regular follow‐up instituted. CAT is generally well accepted by the patients and their partners (98.8% /97.6%) and has distinct positive effects on self‐esteem (77.8%), performance anxiety (84.4%), and partnership (79.5%). The most serious side‐effect was prolonged erection (25 out of 17642 injections). In 6 patients reversible fibrotic changes near the tunica albugi

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02654.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.In a population of 8500 men attending the andrology outpatient clinic, 200 men (2.35%) were recorded as having some disturbances with the descent of the testes into the scrotum. Medical history of the patients revealed that 51 underwent unilateral orchidopexy; 40 bilateral orchidopexy; and 24 were treated with human chorionic gonadotropin in order to induce descent of their testes. In addition, 6 patients reported spontaneous descent of the testes, and 13 others were found to be unilaterally cryptorchid upon physical examination. Results of semen analysis, hormonal profile, testes position, and testicular volume were compared to those of 105 proven fertile men. The major finding of this study shows that post‐partum undescended testes suffer from primary Sertoli cell malfunction as reflected by elevated serum follicle stimulating hormone levels. Serum luteinizing hormone and testosterone levels were within the normal range. Surgical descent of the testes did not improve sperm production, proved by low sperm quality of all the study groups, compared to the cryptorchid group. Among the patients who were operated on, no correlation was found between age at operation and semen variables. All groups showed poor sperm quality which can be defined as oligoteratoasthenozoospermia. The degree of spermatogenic damage was in the following order of diagnosis or treatment: bilateral orchidopexy>cryptorchid testes>hormonal treatment>unilateral orchidopexy>late spontaneous descent of the testes. Thus, it is advisable to postpone surgical treatment of cryptorchidism and apply this only after a waiting period, and if the hormonal approach has failed to descend the testi

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02655.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02656.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY