bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acrosome reaction stimulated by the GTP non‐hydrolizable analogue GTPγS is blocked by phospholipase A2 inhibitors in human spermatozoa
Authors: DOMÍNGUEZ L. , YUNES R. M. F. , FORNÉS M. W. , MAYORGA L. S. 
Published: May 2008

SummaryPhospholipase A2 (PLA2, EC 3.1.1.4) is involved in the cascade of signalling events leading to the acrosome reaction in human spermatozoa. In order to study the role of PLA2 in the acrosome reaction triggered by GTPγS, a non‐hydrolizable analogue of GTP, two well‐known PLA2 inhibitory reagents were used: dexamethasone (1 mM, a synthetic glucocorticoid), and 2‐(p‐amylcinnamoyl)amino‐4‐chlorobenzoic acid (ONO‐RS‐082, 320 μg/ml). Normal human spermatozoa were incubated for 3 h under capacitating conditions and treated with several reagents [GTPγS, dexamethasone, ONO‐RS‐082, arachidonic acid (AA) and lysophosphatidylcholine (LPC)], alone or in different combinations. In confirmation of earlier reports, GTPγS induced the acrosome reaction. On the other hand, dexamethasone and ONO‐RS‐082 were both able to inhibit the acrosome reaction induced by GTPγS. However, when AA or LPC was added after dexamethasone or ONO‐RS‐082, the acrosome reaction reached values close to those obtained using GTPγS alone. It is concluded that PLA2 probably plays an active role in the acrosome reaction triggered by GTP‐binding proteins.
Systemically administered gonadotrophin‐releasing hormone enhances copulatory behaviour in castrated, testosterone‐treated hyperprolactinaemic male rats
Authors: DENNISON E. , BAIN P. A. , BARTKE A. , MELISKA C. J. 
Published: May 2008

SummaryHyperprolactinaemic male rats exhibit deficits in copulatory behaviour which can be reversed by a single injection of GnRH. We tested whether systemically administered GnRH can stimulate copulatory behaviour independently of LH‐mediated increases in plasma testosterone levels. Gonadectomized, pituitary‐grafted adult male Fischer 344 rats bearing implants of 5, 10 or 20 mm capsules of testosterone were administered a single injection of 500 ng GnRH or saline s.c., 30 min prior to copulation tests. Pituitary‐grafted castrates displayed copulatory deficits, relative to sham‐operated castrates with identical levels of testosterone replacement. Administration of 500 ng GnRH to pituitary‐grafted castrates bearing 10 mm testosterone implants significantly increased the proportion of rats that mounted, intromitted and ejaculated during a 30 min test. This treatment also reduced significantly the latency of intromission and ejaculation, and increased significantly the frequency of intromission. The copulatory behaviour of the sexually unresponsive, pituitary‐grafted castrates bearing 5 mm testosterone implants, or of the more sexually responsive castrates bearing 20 mm testosterone implants, was not altered significantly by GnRH injections. These results support the hypothesis that copulatory deficits in moderately hyperprolactinaemic rats are due in part to reduced hypothalamic GnRH release, and suggest that GnRH can stimulate sexual behaviour in these animals via mechanisms that are independent of luteinizing hormone‐induced testosterone release. However, a threshold level of testosterone (achieved with 10 mm implants) appears to be required for GnRH to elicit this effect.
Influence of Escherichia coli on motility parameters of human spermatozoa in vitro
Authors: DIEMER T. , WEIDNER W. , MICHELMANN H. W. , SCHIEFER H.‐G. , ROVAN E. , MAYER F. 
Published: May 2008

SummaryThe influence of E. coli on human sperm motility was studied in vitro. Semen samples were prepared by a swim‐up technique and adjusted to 22 times106 spermatozoa/ml. Samples were then inoculated with different concentrations of a uropathogenic strain of E. coli, serotype 06, with initial sperm/bacteria ratios varying between 10:1 and 10000:1.Motion parameters were analysed by computer‐aided motility analysis directly, and 2, 4 and 6 h after inoculation. In a second series of experiments, bacterial replication was inhibited by addition of chloramphenicol. In a third series, the effect of E. coli culture filtrates on sperm motility was investigated.The direct inhibitory effect of E. coli on progressive motility of spermatozoa was found to depend upon the bacterial concentration. A distinct inhibitory effect was observed only at a sperm/bacteria ratio of approximately 1, achieved by growth of E. coli during the experiments. For modality of motion, no distinct changes were observed. When growth of bacteria was prevented by chloramphenicol, no inhibitory effect on sperm motility was detected. Sperm motility was not inhibited by E. coli culture filtrates. Analysis by electron microscopy revealed multiple adhesions of E. coli to spermatozoa, causing variable ultrastructural damage as probable morphological correlates of immobilization.
Epididymal oxytocin in the rat: its origin and regulation
Authors: HARRIS G. C. , FRAYNE J. , NICHOLSON H. D. 
Published: May 2008

SummaryOxytocin is localized to the Leydig cells of the testis in the rat and several other species where it is postulated to play a role in steroidogenesis and seminiferous tubule contractility. Oxytocin has also been detected in the epididymis of the ram where active uptake of the peptide from luminal fluid has been demonstrated. This study was performed to investigate whether oxytocin is present in the rat epididymis, and the origin of the peptide. Immunoactive oxytocin was detected in the epididymis of all control animals examined (147.7±41.7 pg/g). Total epididymal oxytocin was reduced significantly following castration (p<0.05). Testosterone treatment also reduced the epididymal concentration of the peptide in both intact and castrated rats. Efferent duct ligation (EDL) did not affect the presence of oxytocin in the epididymis. Immunoactive oxytocin was localized in discrete cells of the epithelium of the caput epididymis, with less staining apparent in the initial segment and cauda epididymis. Staining disappeared from the caput epididymis following castration, but reappeared following testosterone supplementation. No obvious alteration in staining was observed in the cauda epididymis after EDL.These data demonstrate for the first time the presence of oxytocin in the epididymis of the rat and that the peptide may be regulated by androgens. They further suggest an epididymal source of the peptide.
Smoking and male reproduction: a review
Authors: VINE M. F. 
Published: May 2008

SummaryBecause of the large number of men worldwide who smoke and the fact that cigarette smoke contains known mutagens and carcinogens, there has been concern that smoking may have adverse effects on male reproduction. A review of the epidemiological literature indicates that cigarette smoking is associated with modest reductions in semen quality including sperm concentration, motility and morphology. The associations between male smoking and sperm concentration and motility are stronger among studies of ‘healthy’ men (e.g. volunteers and sperm donors) than among men from infertility clinic populations. Smoking has also been associated with alterations in hormone levels in males, for example increases in the levels of oestrone and oestradiol. Despite modest reductions in semen quality and altered hormone levels among smokers compared to non‐smokers, studies have not shown a reduction in male fertility in association with paternal smoking. There is some evidence to suggest that paternal smoking is associated with congenital anomalies and childhood cancer (with ORs in positive studies generally < 2.0). Smoking has not been shown to be mutagenic to human spermatozoa, although studies have been small and have had methodological shortcomings. It is concluded that, although smokers as a group may not experience reduced fertility, men with marginal semen quality who wish to have children may benefit from quitting smoking, since several small studies indicate the potential for improved semen quality after quitting smoking. More research on the benefits of quitting smoking among men with marginal semen quality is needed. Methodological improvements in studies aimed at clarifying the association between paternal smoking and reproductive and developmental outcomes in offspring should include obtaining accurate paternal smoking dose information, evaluating smoking exposure information in relation to various time windows (e.g. prior to conception, during gestation), and controlling for potential confounders and modifying factors such as age and maternal smoking habits. More sensitive and specific laboratory assays and increased sample sizes are required to establish whether smoking induces mutations in human spermatozoa.
Assessment of sperm motion characteristics in infertile renal transplant recipients using computerized analysis
Authors: EID M. M. , ABDEL‐HAMID I. A. , SOBH M. A. , EL‐SAIED M. A. 
Published: May 2008

SummaryA total of 34 kidney transplant recipients (18 infertile and 16 fertile) and 31 non‐transplant persons (15 infertile and 16 fertile) were included in this study. All subjects were assessed clinically and by measurement of basal concentrations of total testosterone, FSH, cyclosporine whole blood trough levels, serum creatinine, haemoglobin and semen analysis using computer‐aided sperm analysis (CASA) as well as scrotal ultrasonography to evaluate testicular dimensions. Our results demonstrate a significant decrease (p<0.05) in sperm concentration, the percentage of motile spermatozoa, straight line velocity (VSL), linearity (LIN) and velocity of average path (VAP) among infertile transplant patients in comparison with the fertile transplant group. Serum testosterone, FSH levels and testicular dimensions did not differ significantly (p>0.05) between fertile and infertile transplant recipients. Both sperm concentration and VSL were inversely correlated to the cyclosporine whole blood trough levels (p<0.05). The time spent on haemodialysis was inversely correlated (p<0.05) with the percentage of motile spermatozoa and the amplitude of lateral head displacement (ALH). In conclusion, CASA is valuable in evaluation of sperm motility in infertile renal transplant patients. Stabilization of the cyclosporine whole blood trough level within the target therapeutic level and correction of anaemia (if any) could improve the fertility potential in kidney transplant recipients.
Characterization of human sperm antigens reacting with antisperm antibodies from autologous sera and seminal plasma: comparison among infertile subpopulations
Authors: PARADISI R. , BELLAVIA E. , PESSION A. L. , VENTUROLI S. , BACH V. , FLAMIGNI C. 
Published: May 2008

SummaryImmunoblotting techniques were used to characterize the reactivity of human sperm antigens with sperm antibodies from different groups of infertile subjects. Sperm antigens of each subject were tested with autologous sperm antibodies present in serum and seminal plasma in order to assess whether there were qualitative differences in the antigenic structure of spermatozoa among the various infertile groups. Sixty‐one infertile males, divided into six groups according to changes in the two main semen parameters (sperm concentration and motility), entered the study. Immunoreactivity to several antigens, in both serum and seminal plasma, was usually demonstrated in infertile subjects. Using a complex statistical package no significant difference was found in the distribution of antigens between groups; this included previously termed ‘fertility‐related antigens’ (28, 35, 57 and 62kDa proteins). This suggests that the most relevant sperm antigens involved in reproduction have no particular relationship to sperm concentration and motility.
Sperm concentrations and quality in β‐thalassaemia major
Authors: JENSEN C. E. , ABDEL‐GADIR A. , COX C. , TUCK S. M. , WONKE B. 
Published: May 2008

SummaryWe report semen analyses in eight patients with β‐thalassaemia major, with poor results in all but the youngest. The causation is multi‐factorial with iron deposition in the pituitary gland resulting from life‐long dependence on blood transfusions being a major factor. We speculate on other contributing causes, but further research is required to elucidate these. Improving haematological care means that these men are increasingly surviving to adult life. Relevant techniques to enable them to achieve their desire for fatherhood are considered.
Detection and enrichment of carcinoma‐in‐situ cells in semen by an immunomagnetic method using monoclonal antibody M2A
Authors: MENG F. J. , ZHOU Y. , SKAKKEBÆK N. E. , MARKS A. , GIWERCMAN A. 
Published: May 2008

SummaryCarcinoma‐in‐situ (CIS) is a precursor of germ cell cancers in the testis. Early detection and treatment of CIS can prevent the development of invasive cancer. We have developed an immunomagnetic approach for enrichment of CIS cells from semen. Immunomagnetic beads were coated with monoclonal antibody (mAb) M2A, which is specific for seminoma and CIS. In preliminary mixing experiments, cultured human HEY cells, which express the M2A surface antigen, were added to semen samples and recovered selectively by incubation with M2A‐coated immunomagnetic beads followed by magnetic activated cell sorting (MACS). Application of this procedure to ejaculates from five subjects with CIS and 22 control subjects with no evidence of testicular neoplasia resulted in the preferential recovery of a population of large round cells from a 0.5 ml semen sample obtained from CIS subjects (median 1 times 104, range 2 times 103 to 2 times 104) relative to controls (median 2 times 102; range 0 to 103), with no overlap between the two groups (p<0.001). These results suggest that a subpopulation of large round cells recovered from the semen of CIS patients by incubation with M2A‐coated immunomagnetic beads and MACS are CIS cells. Immunomagnetic enrichment of CIS cells in semen will facilitate the definitive identification of exfoliated CIS cells in ejaculates and could be an important first step in a non‐invasive screening procedure for testicular CIS.
Oral health in preschool children with asthma
Authors: STENSSON MALIN , WENDT LILL‐KARI , KOCH GÖRAN , OLDAEUS GÖRAN , BIRKHED DOWEN 
Published: May 2008

Objective.  The aim of this study was to investigate oral health and its determinants in 3‐year‐old and 6‐year‐old children with asthma.Methods and subjects.  Caries and gingivitis were examined in 127 asthmatic (all children with asthma in a selected area and born during a specific time period) and 117 matched, healthy control children.The parents were interviewed regarding various oral‐health‐related factors.Results.  The mean dfs (± standard deviation) in the 3‐year‐old with asthma was 1.4 ± 3.2 compared with 0.5 ± 1.2 in the controls (P < 0.05). The corresponding figures for the 6‐year‐old were 2.5 ± 3.9 and 1.8 ± 2.8. The 3‐year‐old asthmatic children had more gingival bleeding than the healthy controls (P < 0.05). There were no significant differences in gingivitis in the 6‐year‐old children. Asthmatic children reported higher consumption of sugar‐containing drinks and were more frequently mouthbreathers than healthy children (P < 0.05). In 3‐year‐old children with asthma and immigrant background, the mean dfs was higher compared with immigrant children in the control group (P < 0.01).Conclusion.  The results indicate that preschool children with asthma have higher caries prevalence than healthy children. The factors discriminating for caries in asthmatic children are higher intake of sugary drinks, mouth breathing, and immigrant background.
The clinically related predictors of dental fear in Taiwanese children
Authors: LEE CHEN‐YI , CHANG YONG‐YUAN , HUANG SHUN‐TE 
Published: May 2008

Background.  Dental fear has been singled out as one of the most troublesome problems facing paediatric dentistry today. Children with dental fear may avoid visiting dentists; therefore, their oral health protection is often compromised. However, the aetiology of dental fear is still not entirely understood.Objective.  This study investigated the dental visiting habit, the previous dental experiences, the conditioning pathway, and the clinically related predictors of dental fear in children.Design.  The dental history of 247 children (2–10 years old) was obtained when they came to a dental clinic for treatment. The level of dental fear in these children was assessed using the Children's Fear Survey Schedule–Dental Subscale (CFSS‐DS). Observers rated the clinically anxious responses and uncooperative behaviour towards dental treatment in these children. Three stepwise regression analyses were performed to determine significant predictors of CFSS‐DS score, clinically anxious responses, and uncooperative behaviour of children, respectively.Results.  We found that the CFSS‐DS score and clinical anxiety have different predictors, but age ≤ 3.99 years old and cooperativeness in the first dental visit were important predictors for both the CFSS‐DS score and the clinical anxiety. Furthermore, the other predictors of the CFSS‐DS score were maternal dental fear, unbearable pain during the first dental visit, and visiting dentists in a regular dental clinic; the other predictors of clinical anxiety were first‐born, regular dentist, and CFSS‐DS score. Finally, the only significant predictor for uncooperative behaviour was clinical anxiety.Conclusion.  Children's dental fear and their anxious response during dental treatment were dynamic processes that consisted of many different factors. The direct conditioning of subjective experience of pain was more important than the objective pathway of child dental fear, and the indirect conditioning does not seem influential in this study sample.
Characterization of Tomato curly stunt virus: a new tomato‐infecting begomovirus from South Africa
Authors: Pietersen G. , Idris A. M. , Krüger K. , Brown J. K. 
Published: May 2008

The biological and molecular characterization of a virus recognized as a distinct begomovirus species, Tomato curly stunt virus (ToCSV), first observed in South Africa in 1997, is reported here. Whitefly‐transmission and host‐range studies were carried out using a Bemisia tabaci colony identified as the B‐biotype. The experimental host range of ToCSV spanned primarily species in the Solanaceae and Fabaceae. The complete ToCSV genome (2·766 kb) was amplified by PCR, cloned, and the DNA sequence determined. Phylogenetic analysis revealed that ToCSV was most closely related to Tobacco leaf curl Zimbabwe virus (TbLCZV), at 84% nucleotide identity, indicating that ToCSV is a new species in the genus Begomovirus that is probably endemic to southern Africa. The ToCSV genome sequence contained all of the hallmark coding and non‐coding features characteristic of other previously recognized monopartite begomoviruses. ToCSV is only the second begomovirus described from southern Africa that infects solanaceous species. Neither a begomoviral DNA‐B component nor a satellite‐like DNA molecule was detected by PCR in extracts of ToCSV‐infected plants.
Genome‐wide identification of pathogenicity genes in Xanthomonas oryzae pv. oryzae by transposon mutagenesis
Authors: Wang J. C. , So B. H. , Kim J. H. , Park Y. J. , Lee B. M. , Kang H. W. 
Published: May 2008

A transposon mutant library was constructed from the bacterial blight pathogen Xanthomonas oryzae pv. oryzae (Xoo) KACC10331 by Tn5 transposon mutagenesis. The susceptible rice cultivar Milyang 23 was inoculated with a total of 24 540 mutants resistant to kanamycin and 67 avirulent or reduced‐pathogenicity mutant strains were selected for study. Southern hybridization verified that 84 mutant strains had single‐copy insertions and their single‐transposon insertion sites were identified by sequencing analysis combined with thermal asymmetric interlaced (TAIL)‐PCR. The single‐transposon‐tagged sequences of 21 mutant strains belonged to pathogenicity‐related genes previously reported in Xanthomonas species, while the other 46 single‐transposon‐tagged sequences included diverse functional genes encoding, five cell‐wall‐degrading enzymes, three fimbrial and flagella assembly regulators, five regulatory proteins, 15 metabolic regulators and 18 hypothetical proteins, which were identified as novel pathogenicity genes of Xoo.
Unravelling the conundrum of river response to rising sea‐level from laboratory to field. Part II. The Fly–Strickland River system, Papua New Guinea
Authors: PARKER GARY , MUTO TETSUJI , AKAMATSU YOSHIHISA , DIETRICH WILLIAM E. , WESLEY LAUER J. 
Published: May 2008

AbstractThe most recent deglaciation resulted in a global sea‐level rise of some 120 m overca12 000 years. A moving boundary numerical model is developed to predict the response of rivers to this rise. The model was motivated by experiments at small scale, which have identified two modes describing the transgression of a river mouth: (i) autoretreat without abandonment of the river delta (no sediment starvation at the topset–foreset break); and (ii) sediment‐starved autoretreat with abandonment of the delta. In the latter case, transgression is far more rapid, and its effects are felt much further upstream of the river mouth. A moving boundary numerical model that captures these features in experimental deltas is adapted to describe the response of the Fly–Strickland River system, Papua New Guinea. In the absence of better information, the model is applied to the case of sea‐level rise without local climate change in New Guinea. The model suggests that: (i) sea‐level rise has forced the river mouth to transgress over 700 km since the last glacial maximum; (ii) sediment‐starved autoretreat has forced enough bed aggradation to block a tributary with a low sediment load and create the present‐day Lake Murray; (iii) the resulting aggradation was sufficient to move the gravel–sand transition on the Strickland River upstream; (iv) the present‐day Fly Estuary may be, in part, a relict river valley drowned by sea‐level rise and partially filled by tidal effects; and (v) the Fly River is presently reforming its bankfull geometry and prograding into the Fly Estuary. A parametric study with the model indicates that sediment concentration during floods plays a key role in determining whether or not, and to what extent, transgression is expressed in terms of sediment‐starved autoretreat. A sufficiently high sediment concentration can prevent sediment‐starved autoretreat during the entire sea‐level cycle. This observation may explain why some present‐day river mouths are expressed in terms of deltas protruding into the sea, and others are wholly contained within embayments or estuaries in which water has invaded landward.