bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of epididymal sperm maturation in the golden hamster
Authors: WEISSENBERG R. , YOSSEFI S. , OSCHRY Y. , MADGAR I. , LEWIN L. M. 
Published: May 2008

SummaryDuring passage of hamster spermatozoa through the epididymis their maturation is shown to involve changes in the sperm head, midpiece (mitochondria) and tail. The sum of these changes results in a dramatic increase in the fertilizing potential of the spermatozoa. When comparable numbers of spermatozoa from the caput or corpus epididymis were injected into one uterine horn of mature females, following ovulation induction, and spermatozoa from the cauda epididymis were injected into the contralateral horn, no fertilization was observed with caput epididymal spermatozoa, 1.7% of oocytes were fertilized by corpus epiddymal spermatozoa, whereas 79.5% fertilization was obtained with cauda epididymal spermatozoa. Total sperm numbers increased from caput to corpus to cauda [28.3 ± 12.2, 40.6 ±20.8, 1434 ±62 mihon, respectively]. The percentage of progressively motile spermatozoa increased from 27.9 ±6.4 to 33.8 ± 4.8 to 70 ± 10.7 during this passage. Viability, measured by exclusion of the dye, propidium iodide, was significantly less in spermatozoa from the cauda than from the proximal or mid‐caput epididymis. The percentage of the live cells that were stained intensely by rhodamine‐123 (a measure of mitochondrial membrane potential) increased during epididymal passage from 22.8 ±7.8% in the proximal caput epididymis to 57.2 ± 16.5% in the cauda epididymis. Staining with acridine orange (a measure of DNA packaging in the sperm head) indicated an increase in chromatin condensation in cauda epididymal spermatozoa, when compared to those obtained from the caput or corpus.
Development of sperm motility patterns in the murine epididymis
Authors: SOLER C. , YEUNG C. H. , COOPER T. G. 
Published: May 2008

SummaryThe maturation of sperm motility in the epididymis of the mouse was assessed using a computer‐assisted sperm analysis system. Spermatozoa were immotile in the most proximal regions of the epididymis but developed motility rapidly in the proximal caput epididymis; the percentage motility remained high thereafter. In the caput, flagellar beat was erratic with little progression, but in the proximal corpus region circular movement patterns were reflected in reduced linearity (LIN) and straightness (STR) of the sperm tracks, although velocities were little changed and wobble (WOB) increased. In the mid‐corpus region, however, all velocities, LIN, STR and WOB, increased markedly. In more distal regions there was little change in these parameters. Distribution curves of the kinematic parameters of spermatozoa obtained from each region indicated that the most heterogeneous population was that from the mid‐corpus epididymis; the most homogeneous was that from the mid‐cauda region. Individual sperm tracks revealed slowly progressing spermatozoa in the distal caput, transforming to motion in small circles, interrupted by more linear progression. More distally, linear progression was interrupted by looping movements and a generally progressive path was observed thereafter, with less deviation from the average path as the spermatozoa matured. Spermatozoa displaying motion compatible with passing the uterotubal junction were first found in the proximal corpus epididymis, in agreement with earlier in‐vivo fertilization studies on where fertilizing capacity is achieved with epididymal spermatozoa.
Androgen regulation of intra‐ and extra‐thymic T cells and its effect on sex differences in the immune system
Authors: KIMURA MOTOHIKO , TOMITA YOSHIHKO , WATANABE HISAMI , SATO SHOTARO , ABO TORU 
Published: May 2008

SummaryMale predominance of malignant diseases and female predominance of autoimmune diseases is widely known in humans. To elucidate one of the underlying mechanisms, we examined whether sex differences exist at the level of extra‐thymic T cells in various organs of mice under physiological conditions. Effects of castration and testosterone administration were also examined. Intra‐ and extra‐thymic T cells with T cell receptors (TCR) of bright and intermediate intensities, respectively, and with nil and high levels of the interleukin‐2 receptor β‐chain, respectively, were identified by immunofluorescence. Of the three strains tested, it was demonstrated that intermediate TCR cells were predominant in the liver of female mice. In the liver of male mice after bilateral orchidectomy, mononuclear cells increased and intermediate TCR cells predominated as if they were female; testosterone treatment prevented this immunological consequence of orchidectomy. As extra‐thymic T cells comprise a considerable proportion of self‐reactive forbidden clones and possess cytotoxic activity against syngeneic tumour cells, the present results suggest a possible relationship between (a) physiologically low levels of extra‐thymic T cells in males and the male predominance of malignancy, and (b) the high levels of extra‐thymic T cells in females and female predominance of autoimmune diseases.
Tight underpants and trousers and risk of dyspermia
Authors: PARAZZINI F. , MARCHINI M. , LUCHINI L. , TOZZI L. , MEZZOPANE R. , FEDELE L. 
Published: May 2008

SummaryThe association between the wearing of tight underpants and trousers and risk of dyspermia has been analysed using data from a case–control study. Cases included infertile men with a diagnosis of unexplained dyspermia. Normospermic men of infertile couples were eligible as controls. In comparison with men usually wearing loose underpants, the odds ratio (OR) of dyspermia was 1.9 (95% confidence interval, CI, 0.9–4.1) in those wearing tight underwear. Likewise, the OR of dyspermia was 1.6 (95% CI 0.9–3.0) in men reporting usually wearing tight trousers (including jeans), in comparison with those wearing loose trousers.
Reagents that activate GTP‐binding proteins trigger the acrosome reaction in human spermatozoa
Authors: DOMÍNGUEZ L. , DÍZ A. , FORNÉS M. W. , MAYORGA L. S. 
Published: May 2008

SummaryThe acrosome reaction is a specialized exocytotic process. In the mouse there is compelling evidence that receptor‐mediated activation of GTP‐binding proteins by factors in the zona pellucida of oocytes is a central event in the acrosome reaction. Several reagents are able to affect GTP‐binding proteins directly, bypassing the receptor–ligand step for activation. We have assessed the effect of several of these compounds on human spermatozoa, monitoring cell vitality and the acrosome reaction simultaneously using the triple‐stain technique. GTPγS and aluminium fluoride complexes promote sperm activation very efficiently; amphiphilic peptides capable of activating Go and Gi, also elicit the acrosome reaction. The results indicate that activation of heterotrimeric GTP‐binding proteins is sufficient to trigger acrosome exocytosis in human spermatozoa.
A strategy for identifying candidate sperm antigens for immunocontraception: isolation of human testis cDNA clones using polyclonal antisera directed against hamster acrosomal membrane preparation
Authors: ADOYO P. A. , MOORE A. , MOORE H. D. M. 
Published: May 2008

SummaryComponents of the mammalian sperm acrosome that have been conserved during evolution are probably essential for fertilization and are therefore potential antigens for the development of an immunocontraceptive vaccine. In order to identify such protein components, a series of specific polyclonal antisera were generated by immunizing rabbits with purified acrosomal membrane fractions from hamster epididymal spermatozoa. Antisera were finally selected using immunological and in‐vitro fertilization assays, and used to then screen a human testis Λgt11 cDNA library. As a result of this screening over 70 clones were identified, selected and purified. The cDNAs were amplified by polymerase chain reaction (PCR) and the inserts characterized by restriction enzyme digestion and oligonucleotide probing techniques. The functional activity of β‐galactosidase fusion proteins expressed by these clones was tested by a hamster in‐vitro fertilization assay (IVF). Fusion protein from three clones (HA5‐2, HA6‐2 and HB4‐1) inhibited significantly fertilization and reduced spermzona binding compared to controls. To date, sequence data has been obtained from HB4‐1 (1.75 kb). The first 1132 nucleotides displayed > 96% homology to human testis‐specific lactate dehydrogenase (LDH‐C4) gene, the product of which is a known candidate antigen for a contraceptive vaccine. This finding suggests that a strategy involving the screening across species for conserved moieties of the mammalian acrosome may be useful for identifying candidate antigens for immunocontraception.
Subcapsular intratesticular assay: a preliminary screening method for putative male antifertility drugs
Authors: XU Y. E. , WANG Y. I. , LIN N. , ZHANG J.‐W. , QIAN S. Z. 
Published: May 2008

SummaryThe subcapsular intratesticular assay was developed for the preliminary screening of male antifertility agents. In the assay, small amounts of the test sample are injected twice, 1 week apart just beneath the tunica albuginea of the testes of rats. The rats were killed within 3 weeks of treatment to examine epididymal spermatozoa and the histology of the testis and epididymis.There is an excellent agreement between this method and the modified MB‐50 assay developed by the World Health Organization. To date, more than 300 samples have been assayed, of which the results of 10 plant‐derived compounds are reported here. Not one active sample has been missed as confirmed by the modified MB‐50 method, although one compound which was positive in the subcapsular assay did not show antifertility action in the in‐vivo assay. Compared with the latter assay, the advantages of this method are: simplicity, time‐saving, rat‐saving and the need for far smaller amounts of test sample. The absence of false‐negative results makes the subcapsular intratesticular assay applicable as a preliminary screening method to test potential male fertility regulating agents.
Severe asthenozoospermia: a structural and functional study
Authors: GOPALKRISHNAN K. , PADWAL V. , D'SOUZA S. , SHAH R. 
Published: May 2008

SummaryEjaculates from 25 patients with severe asthenozoospermia (all spermatozoa immotile or only non‐progressively motile) were studied to identify individually the cause of impaired motility. Multiple tests were performed, viz. light and electron microscopic studies and sperm function tests. An objective scoring was applied to both the routine and the functional analyses. Three categories of samples were identified: (1) necrozoospermia (n=9), where sperm viability was very poor; (2) structural tail abnormality as seen by light microscopy (n=4); and (3) ultrastructural abnormality (n=12). In the last category, one case showed absence of dynein arms; this was associated with mitochondrial abnormalities. Mitochondrial abnormality with normal tail components was observed in the majority (n=7) and accessory fibre abnormality in four cases. The scoring system revealed that, functionally, all samples were abnormal whereas routine analysis showed 15 samples to be subnormal and 10 to be abnormal, which indicates the need for functional analysis. Because of the multiple defects seen in these samples, there is a need for a battery of sperm function tests. This study indicates that mitochondrial defects are one of the causes that may account for the loss of sperm motility in the patient population.
Effects of progesterone on human spermatozoa prepared for in‐vitro fertilization
Authors: EMILIOZZI C. , CORDONIER H. , GUÉRIN J. F. , CIAPA B. , BENCHAÏB M. , FÉNICHEL P. 
Published: May 2008

SummaryProgesterone has been tested in vitro with human spermatozoa to verify its physiological effects and its possible therapeutic use in cases of male infertility. Progesterone induced a rapid, dose‐dependent influx of calcium in capacitated and non‐capacitated spermatozoa with a half‐maximally effective dose of 30 nM. The agonist, 19‐nortestosterone, was much less potent that progesterone itself. Progesterone‐induced calcium influx was not inhibited by a similar concentration (0.1 μg/ml) of RU 486, a classical progesterone antagonist. The increase in intracytoplasmic calcium levels was unable to induce the acrosome reaction (AR) even after incubation for 5 h, when this was evaluated by double staining, using a monoclonal antibody GB24 raised against the inner acrosome membrane and ethidium homodimer as a vital probe. However, after incubation for 5 h, progesterone was able to enhance the tyrosine phosphorylation of a 95 kD sperm protein, which is phosphorylated progressively during capacitation in well‐defined culture media. Incubation of spermatozoa with 1 or 10 μg/ml progesterone for 3 or 30 min did not induce major modifications of hyperactivated movement when analysed by computer‐assisted semen analysis. Progesterone secreted by cumulus cells may physiologically increase sperm intracytoplasmic free calcium during capacitation. This priming effect may facilitate the acrosome reaction, induced by binding to the zona pellucida, without enhancing spontaneous acrosome reaction prematurely. It therefore seems useful to propose progesterone as a means of accelerating capacitation during in vitro fertilization in cases of male infertility.
Prolactin and testosterone: their role in male sexual function
Authors: CARANI C. , GRANATA A. R. M. , FUSTINI M. FAUSTINI , MARRAMA P. 
Published: May 2008

SummaryThe role of androgens in the sexuality of men is still not completely clear. Men with severe hyperprolactinaemia frequently show mild hypogonadism, and many complain of loss of libido and penile erectile dysfunction (ED). We studied the night‐sleep related erections and the penile response to visual erotic stimuli (VES) in 44 men: 13 with severe hypogonadism (Group 1; serum testosterone <1.4 ng/ml), 10 with mild hypogonadism (Group 2; serum testosterone 2–3.5 ng/ml), nine with severe hyperprolactinaemia and mild hypogonadism (Group 3) and 12 control men (Group 4). All of the patients complained of loss of libido and ED. Group 1 showed significantly impaired night erections when compared with any of the other three groups, but no differences were detected between Groups 2, 3 and 4. The penile response to VES did not show any significant difference between the four groups, but was lower in Group 1 than in Group 4. These data confirm that night erections are androgen‐dependent, but also suggest that there are two thresholds for serum testosterone: one below which sexual behaviour is impaired with normal night erections, and a lower threshold below which night erections are also impaired. The penile response to VES was confirmed as being only partially androgen‐independent. Furthermore hyperprolactinaemia does not affect night erections or the penile response to VES, suggesting that its effect on libido and sexual behaviour is due mainly to modulation of the psychological pattern of the patient.
In‐vitro initiation of forward motility in testicular spermatozoa
Authors: JAISWAL B. S. , MAJUMDER G. C. 
Published: May 2008

SummaryInitiation of forward motility in vitro was investigated in goat and ram spermatozoa obtained from the rete testis. No forward motility was generated in the immotile testicular spermatozoa when they were incubated in a modified Ringer's solution containing theophylline (30 mM) and epididymal plasma (2 mg protein/ml). However, these reagents induced non‐progressive flagellar movement in approximately 25% of spermatozoa. Bicarbonate (25 mM) induced forward motility in approximately 16% of the goat/ram testicular spermatozoa. Theophylline was essential for the bicarbonatemediated activation of sperm motility, but epididymal plasma had no significant effect on this activation process. Theophylline activated progressive motility in testicular spermatozoa in a dose‐dependent manner, the maximum effect occurring after incubation for 10 min with 30 mM theophylline. The initiation profile of in‐vitro motility of goat/ram spermatozoa from the caput epididymis closely resembled that of testicular spermatozoa except that induction of motility in the caput spermatozoa was dependent both on bicarbonate and epididymal plasma. The data indicate that, unlike caput epididymal spermatozoa, initiation of motility in testicular spermatozoa is not dependent on motility‐promoting protein(s) in epididymal plasma.
Detection of Chlamydia trachomatis in the prostate by in‐situ hybridization and by transmission electron microscopy
Authors: CORRADI Gy. , BUCSEK M. , PÁNOVICS J. , VEREBÉLYI A. , KARDOS M. , KÁDÁR A. , FRANG D. 
Published: May 2008

Summary Chlamydia trachomatis infection has been investigated in the prostate gland using in‐situ DNA hybridization and transmission electron microscopy. Sixty‐four samples of tissue removed by trans‐urethral resection or by open surgery from men with benign prostatic hypertrophy (BPH), were examined histologically and 20 of the cases were found to be positive for mononuclear cell infiltration. Some samples were then investigated using in‐situ hybridization and transmission electron microscopy. Out of 20 tissue samples with mononuclear cell infiltration, nine were found to be positive for C. trachomatis infection.
Immunohistochemical detection of immature Sertoli cell markers in testicular tissue of infertile adult men: a preliminary study
Authors: STEGER K. , REY R. , KLIESCH S. , LOUIS F. , SCHLEICHER G. , BERGMANN M. 
Published: May 2008

SummaryTesticular biopsy specimens from oligozoospermic infertile patients are characterized by different types of spermatogenic impairment in adjacent seminiferous tubules, a phenomenon called mixed atrophy. In order to evaluate possible involvement of the state of Sertoli cell differentiation, the distribution pattern of anti‐Müllerian hormone (AMH), vimentin and cytokeratin intermediate filament proteins was investigated by means of immunohistochemistry. AMH immunoactivity occurs in Sertoli cells of the normal postnatal prepubertal testis, but it is absent in the adult testis with normal spermatogenesis. In the case of mixed atrophy, AMH immunoactivity was found in Sertoli cells of tubules showing spermatogenic arrest at the level of spermatogonia and in tubules showing Sertoli‐cell‐only (SCO) syndrome. Vimentin was expressed regularly in Sertoli cells independent of spermatogenic impairment or the state of Sertoli cell differentiation. Cytokeratin immunoactivity occurs in Sertoli cells of the normal postnatal prepubertal testis. Furthermore, cytokeratin expression was found in Sertoli cells of tubules showing spermatogenic arrest at the level of spermatogonia and in some SCO tubules. Co‐expression of AMH and cytokeratin suggests that spermatogenic impairment such as spermatogenic arrest and SCO syndrome in human seminiferous tubules is associated with a population of Sertoli cells showing a prepubertal stage of development. The different pattern of AMH and cytokeratin expression in SCO tubules indicates that Sertoli cells in SCO syndrome show a mosaic pattern of differentiation.
Testicular gamma‐aminobutyric acid and circulating androgens in Syrian and Djungarian hamsters during sexual development
Authors: FRUNGIERI M. B. , GONZALEZ‐CALVAR S. I. , CHANDRASHEKAR V. , RAO J. N. , BARTKE A. , CALANDRA R. S. 
Published: May 2008

SummarySeveral factors, besides luteinizing hormone (LH), participate in the modulation of testicular function. A number of neurotransmitters are reported to be involved in this process, including a stimulatory action of gamma‐aminobutyric acid (GABA) on steroidogenesis in the rat testis. The purpose of this study was to investigate the testicular pattern of GABA and glutamic acid, one of its main precursors, during sexual maturation in two seasonally breeding species: Syrian (golden) and Djungarian hamsters. Plasma androgen levels were also measured. The animals were maintained under long‐day photoperiod (16:8, L:D) and were killed at 23, 30, 36, 46, 60, and 90 days of age. A different pattern of developmental changes in body and testicular weight was observed in these two species. GABA was present in the testes at all ages studied. GABA concentration and content showed a sharp elevation in the prepubertal period in golden as well as Djungarian hamsters. However, glutamic acid concentrations remained nearly constant during development in both species. Glutamic acid content increased gradually with age in the golden hamster, while a marked peak at 36 days of age was detected in the Djungarian hamster. Plasma testosterone and dihydrotestosterone levels were maximal at pubertal age in both species. The plasma levels of 5α‐androstane‐3α,17β‐diol increased significantly at 30 days of age in the golden hamster while in Djungarian hamsters this steroid remained unchanged. These results suggest that glutamic acid may serve as a precursor for GABA biosynthesis in the testis. In addition, changes in testicular GABA and plasma androgen levels might reflect a modulatory effect of this neurotransmitter in the acquisition of steroidogenic capability during development.
Sertoli cell barrier dysfunction and spermatogenetic cycle breakdown in the human testis: a lanthanum tracer investigation
Authors: MEYER J. M. , MEZRAHID P. , VIGNON F. , CHABRIER G. , REISS D. , RUMPLER Y. 
Published: May 2008

SummaryThe introduction of nitrate of lanthanum in fixative solutions for testicular biopsies improves ultrastructural observations of the blood–testis barrier. In complete (normal) spermatogenesis, junctional specializations impede the diffusion of lanthanum into the adluminal compartment. They clearly exhibit a three‐storied disposition in orthogonal sections. In maturation arrest, lanthanum passes easily through the junctional specializations surrounding the germ cells and up to the lumen. In irregular hypospermatogenesis, the Sertoli cell barrier is permeable, but diffusion of the tracer is less significant and variable. Unexpectedly, in germ cell aplasia, the barrier remains efficient.
Leydig cells secrete factors which increase vascular permeability and endothelial cell proliferation
Authors: COLLIN O. , BERGH A. 
Published: May 2008

SummaryAdult intact control rats, and animals treated with human chorionic gonadotrophin (hCG) or with ethane dimethane sulphonate (EDS) to deplete Leydig cells, were injected with bromodeoxyuridine (BrdU) to label proliferating cells. Apoptotic cells were visualized by in‐situ end labelling (ISEL) of fragmented DNA. Three per cent of testicular endothelial cells were labelled with BrdU and few were apoptotic in intact testes. The BrdU endothelial cell labelling index was increased by hCG‐treatment and decreased in Leydig cell‐depleted testes. Immunohistochemical staining showed that Leydig cells and testicular macrophages contain immunoreactive vascular endothelial growth factor (irVEGF). The ability of testicular cells to stimulate angiogenesis was studied further by transplanting interstitial cells or seminiferous tubule segments under the kidney capsule. A prominent vascular network was observed around interstitial cell grafts, but not around tubule grafts. Treatment of transplanted rats with human chorionic gonadotrophin (hCG, 50 i.u.) resulted in an accumulation of PMN‐leukocytes and an increase in vascular permeability in the remaining testis and in interstitial cell grafts. Interstitial cells from Leydig cell‐depleted (EDS‐treated) testes were also transplanted under the kidney capsule. This type of graft caused only a discrete stimulation of angiogenesis, and there was no increase in vascular permeability around the graft after hCG treatment.It is suggested that Leydig cells secrete angiogenic factors and that they are the source of the inflammation mediator(s) produced in the testis after hCG treatment. The high proliferation rate in endothelial cells suggests continuous remodelling of the testicular microvasculature, but the functional significance of this remains unknown.