bluuebunny/crossref_metadata_2025_split huggingface dataset:
Insulin‐like growth factor‐I and transforming growth factor‐α stimulate differentiation of type A spermatogonia in organ culture of adult mouse cryptorchid testes
Authors: TAJIMA Y. , WATANABE D. , KOSHIMIZU U. , MATSUZAWA T. , NISHIMUNE Y. 
Published: May 2008

SummaryThis study assessed the effect of growth factors on testicular germ cell differentiation in vitro. Testicular fragments of experimentally prepared cryptorchid testes of adult mice were cultured for 9 days in serum‐free media containing various concentrations of IGF‐I, TGF‐α, FGF, and PDGF. Their histology was then examined under a light microscope. Each type of germ cell and mitotic cell in the seminiferous tubules was counted per 1000 Sertoli cells. IGF‐I at a concentration of 10 ng/ml induced maximal differentiation of type A spermatogonia. TGF‐α at concentrations ranging from 1 to 10 ng/ml also stimulated differentiation, whereas FGF and PDGF did not show any stimulation of spermatogonial differentiation in this experimental system.
High and unchanged sperm counts of Finnish men
Authors: VIERULA M. , NIEMI M. , KEISKI A. , SAARANEN M. , SAARIKOSKI S. , SUOMINEN J. 
Published: May 2008

SummarySeveral recent reports have suggested that the sperm counts of normal men are declining in most countries. In this study the sperm counts of Finnish men, and their possible changes during the past 28 years, were investigated. The material consisted of semen samples from 238 normal healthy men of unknown fertility and 5481 men from infertile couples. The means (medians) of semen volume, sperm density and total sperm count in normal men were 3.3 (3.0) ml, 133.9 (94.0) × 106/ml and 396.6 (309.0) × 106, respectively. These parameters and the relative frequency distribution of the sperm density were similar to those reported elsewhere in the 1940s. Multiple linear regression analysis revealed a significant decrease in semen volume, whereas sperm density and total sperm count of infertile men had not changed significantly during the past 28 years. In addition, no change in sperm counts was associated with the year of men's birth.
Chromomycin A3‐staining as an indicator of protamine deficiency and fertilization
Authors: LOLIS D. , GEORGIOU I. , SYRROU M. , ZIKOPOULOS K. , KONSTANTELLI M. , MESSINIS I. 
Published: May 2008

SummaryMature mammalian spermatozoa have a compact and stable nuclear structure conferred by protamines instead of histones, which are present in all other cellular types. Chromomycin A3 (CMA3) is a useful tool for the detection of protamine deficiency in sperm chromatin. The purpose of this study was to correlate the percentage of spermatozoa staining positively for CMA3 with sperm parameters and in‐vitro fertilization of human oocytes. Spermatozoa were collected from 56 fertile and 18 infertile men, and washed twice in PBS, fixed in two changes of methanol: acetic acid (3: 1 v: v) spread on rinsed slides treated with APES and dried. Twenty‐four of the semen samples were subjected to both Percoll and swim‐up, and were stained subsequently with CMA3. CMA3‐stained spermatozoa were expressed as a percentage in a count of 200 spermatozoa. A substantial variation in the percentage of CMA3‐stained cells was observed in ejaculated human spermatozoa, varying between 8% and 77%. A strong negative correlation (r= ‐0.64, p < 0.001) was found between sperm count and the percentage of CMA3‐stained spermatozoa. No correlation was found between CMA3‐stained spermatozoa and their motility, while excessive sperm morphological abnormalities were related positively to CMA3‐staining. Spermatozoa in samples exhibiting low (8–62%) CMA3‐staining had significantly higher fertilizing rates in vitro than did samples exhibiting high (49–77%) CMA3‐staining. The mean percentage of CMA3‐stained spermatozoa after swim‐up or Percoll preparation (26% vs 31%) did not differ significantly. These results demonstrate a close relationship between CMA3‐staining, fertilization and sperm count, and suggest potential application of this marker for the prediction of sperm quality and fertilizing capacity.
Testicular germ cell populations in the adult rat after continuous in‐vivo testicular infusion of inhibin‐A and activin‐A
Authors: ADEEKO A. O. , DUNNE E. , MATHER J. , MOORE A. , MORRIS I. D. 
Published: May 2008

SummaryThis study investigated the in‐vivo effects of inhibin‐A and activin‐A on germ cell subpopulations in the adult rat testis. Each animal received a total of 2 μg (dose 5 ng/0.5 μl/h) of activin, inhibin or 0.1% bovine serum albumin (vehicle control) delivered intratesticularly into the left testis via a cannula connected to an abdominal minipump implant. To establish whether the hormones exerted any effect on procarbazine‐induced germ cell depletion, a single intraperitoneal dose of this agent was given to a group of the rats 24 h after the start of testicular infusion of activin or inhibin. Rats were killed 14 days later. Inhibin treatment caused a reduction in the number of round spermatids without altering serum FSH levels. In procarbazine‐treated rats, infusion of inhibin reduced the number of pachytene spermatocytes and reduced blood FSH levels simultaneously. Infusion of activin had no significant effect on the numbers of germ cells, but reduced the number of dead cells in the seminiferous tubules of procarbazine‐treated rats. The data would therefore suggest that the effects of inhibin and activin on the seminiferous epithelium are influenced by the testicular microenvironment, and that they are capable of influencing the growth and survival of germ cells by both FSH‐ and non FSH‐mediated mechanisms. Further experiments are needed to identify the physiological role(s) of inhibin and activin in spermatogenesis.
Clinical and genetic variability in XX sex‐reversed patients
Authors: MANIERI C. , TAGLIABUE M. , NOVI R. F. , BISCEGLIE C. DI , ARDUINO C. , FORNENGO R. , BRANCALEONI V. , MARTINA V. 
Published: May 2008

SummaryThree 46, XX hypogonadal subjects are described who exhibited different clinical and genetic characteristics. Two patients, with complete sex‐reversal, are sterile males with hypogonadal features; the third patient, with partial sex‐reversal, presented with a eunuchoid appearance and with ambiguous genitalia. Polymerase chain reaction (PCR) amplification of DNA from these patients showed the presence of a translocation of the sex‐determining region of the Y chromosome (Sry) only in the first two patients described.
Superoxide anion scavenging capacity of human seminal plasma
Authors: GAVELLA M. , LIPOVAC V. , VUČIĆ M. , ROČIĆ B. 
Published: May 2008

SummaryThis study has investigated the antioxidant capacity of human seminal plasma due to the presence of both high and low molecular weight antioxidant factors. Methods for the measurement of superoxide dismutase‐like activity (SOD‐like) and total antioxidant status (TAS) were automated, and had a within‐run coefficient of variation of 7.3% for SOD‐like activity and 4.8% for TAS. In 69 semen samples from unselected infertile men, SOD‐like activity in seminal plasma ranged from 2 to 16 U/ml, with a mean of 6.9 ± 2.8 U/ml. As SOD‐like activity was correlated positively with levels of citric acid (p<0.0001), zinc (p<0.0002) and acid phosphatase activity (p<0.0005), and there was no correlation with fructose levels, our results suggest that prostatic secretions are an important source of superoxide anion scavengers. Evaluation of SOD‐like activity in infertile men with accessory sex gland infections (n= 12) showed significantly lower activity (p<0.003) compared to values found in 12 infertile men without signs of infection. The values obtained for total antioxidant status (equivalent to the antioxidant capacity of alpha‐tocopherol analogue) ranged from 1.7 to 2.3 mmol/L, with a mean of 2.1 ± 0.1 (n= 40), reflecting the protective activity of ascorbate, urate and albumin, and to a very low extent of glutathione and taurine. The data obtained by TAS assay correlated with fructose, a major marker of vesicular secretion (p<0.005), suggesting that low molecular weight components with antioxidant capacity derive partly from the seminal vesicles. The results indicate that the relative contribution of antioxidant defence systems capable of counteracting the deleterious action of superoxide anions, depends on the secretory activity of accessory sex glands and is independent of excessive ROS production due to increased oxidative stress.
Are the characteristics of spermatozoa in the insemination medium useful for predicting in‐vitro fertilization results?
Authors: PARINAUD J. , RICHOILLEY G. , MOUTAFFIAN H. , VIEITEZ G. , MIEUSSET R. 
Published: May 2008

SummaryTo determine whether the characteristics of Percoll‐selected spermatozoa are more predictive of in‐vitro fertilization (IVF) results than are those of native semen, 118 semen samples from patients undergoing an IVF attempt were studied. Motility, using computer‐assisted sperm analysis, and morphology were recorded before and after sperm selection on a Percoll gradient. Percoll selection increased the percentage of morphologically normal spermatozoa (58.2 ± 19.9% versus 47.9 ± 17.9%; p <0.0001). This increase concerned almost all abnormalities and especially abnormalities of the midpiece (cytoplasmic droplets and bent tails). However, morphology of spermatozoa in the Percoll fraction had the same predictive value for IVF as did that for whole semen. Concerning motility, all parameters, except linearity, were improved by Percoll preparation, and their predictive value for IVF results was significantly higher in the Percoll fraction than in native semen. Therefore, it is concluded that, even if sperm characteristics are improved dramatically after Percoll selection, only motility analysis then gave more practical information than did analysis of sperm characteristics in native semen. This suggests that impairment of spermiogenesis, which presumably induces sperm abnormalities, is more important than are the actual characteristics of the spermatozoa.
Maturation of sperm motility in the epididymis of the common marmoset (Callithrix jacchus) and the cynomolgus monkey (Macaca fascicularis)
Authors: YEUNG C. H. , MORRELL J. M. , COOPER T. G. , WEINBAUER G. F. , HODGES J. K. , NIESCHLAG E. 
Published: May 2008

SummaryThe acquisition by spermatozoa of the capacity for movement upon liberation from the epididymal duct into buffer is one of the obvious changes associated with sperm maturation and, hence, studies of sperm kinematics might provide good indices for sperm maturation. Profiles of development in the movement pattern of spermatozoa taken from six regions of the epididymis were established in marmoset and cynomolgus monkeys using computer‐assisted sperm analysis. Motion of spermatozoa from initial regions was sluggish and irregular, then developed in the more distal region into erratic movement effected by an increase in the vigour of flagellation as reflected by curvilinear velocity. The tendency of immature spermatozoa to display circular motion was more common in the marmoset than in the cynomolgus monkey. In the marmoset the most drastic changes in percentage motility and kinematic parameters of spermatozoa occurred between the distal caput and the proximal corpus; maximal values for these parameters were found around the distal corpus epididymis. For the cynomolgus spermatozoa the sharpest gain in percentage motility was also achieved between the caput and proximal corpus epididymis, but with full kinematic development in the proximal cauda epididymis. These maturational changes were not synchronous among spermatozoa from the same site as they moved along the epididymis, as reflected in the heterogeneity of each sample in the kinematic properties of individual spermatozoa, especially those from the proximal corpus epididymis. The maturational profiles in the monkeys are comparable to the situation in the human, for which they may provide a useful model.
The effect of bradykinin and the bradykinin antagonist Hoe 140 on kinematic parameters of human spermatozoa
Authors: YEUNG C. H. , SPIER B. , COOPER T. G. , NACKE P. , NIESCHLAG E. 
Published: May 2008

SummaryBradykinin (BK) has been suggested to be an active substance in the disputed therapeutic use of kallikrein to improve semen quality. The effects of exogenous BK and its antagonist Hoe 140, which acts on one of the bradykinin receptors (BK2), were examined in two groups of patients attending the fertility clinic: those with asthenozoospermia (group I) and normozoospermia (group II). Bradykinin (10 nM–1 μM) added to washed human spermatozoa had no effect on most kinematic parameters and caused only a marginal increase (7%) in curvilinear velocity at 50 nM in group I patients; however, this increase was not suppressed by concomitant addition of the BK antagonist. The bradykinin antagonist itself had no effect on the percentage motility or kinematic motility parameters of washed human spermatozoa in either group of patients. The motility of spermatozoa in semen was also unaffected by the presence of the bradykinin antagonist. It is concluded that bradykinin does not act exogenously on washed spermatozoa nor endogenously on spermatozoa in semen to stimulate motility via BK2 receptors, regardless of the initial quality of the sperm motility.
Transplantation of the testis; from the past to the present
Authors: BARTEN E. J. , NEWLING D. W. W. 
Published: May 2008

SummarySince the development of surgery, the possibility of testis transplantation has fascinated man for centuries. Hunter and Berthold are considered to be the most important investigators in this field and, in addition, to be the founders of modern endocrinology. The association of testis transplantation with rejuvenation led to widespread popularity for this treatment in the first three decades of the twentieth century. At the same time, controversies concerning the aim of the treatment have coloured the early years of endocrinology. In the 1960s renewed interest in the subject arose for experimental reasons, leading to the development of microsurgical techniques for autotransplantation of high‐lying undescended testes in children. Homologous testis transplantation has never become a subject of great interest, probably for ethical reasons. This possible treatment for hypogonadism, however, has been developed experimentally and has been performed in man only in Russia and China, evidently with success. The details of these studies and their outcomes are discussed.
Scanning electron microscopy shows inhibited gubernacular development in relation to undescended testes in oestrogen‐treated mice
Authors: SHONO T. , HUTSON J. M. , WATTS L. , GOH D. W. , MOMOSE Y. , MIDDLESWORTH B. , ZHOU B. , RAMM‐ANDERSON S. 
Published: May 2008

SummaryThe morphological relationship between transabdominal testicular descent and the `swelling reaction' of the gubernaculum was investigated in oestrogen‐treated fetal mice by using scanning electron microscopy (scanning EM). In addition, flutamide was also administered to pregnant mice to determine whether androgens cause gubernacular growth and transabdominal testicular descent in offspring. In oestrogen‐treated fetal mice, scanning EM showed that both the gubernacular ‘swelling reaction’ and transabdominal testicular descent were inhibited, in addition to inhibition of Müllerian duct regression. The gubernaculum showed a flat, thin bulb (widest diameter 0.25 ± 0.04 mm) and an elongated cord (1.28 ± 0.41 mm) after oestrogen treatment in utero, which was significantly different in appearance from that in normal control mice (width 0.44 mm ± 0.06 mm, p < 0.001; length 0.27 ± 0.19 mm, p < 0.0001). However, flutamide‐treated mice showed much more normal gubernacular enlargement and transabdominal testicular descent. The width of the gubernacular bulb after flutamide exposure was 0.44 ± 0.05 mm, which was comparable to that in control animals; the length of the intra‐abdominal gubernaculum (0.44 ± 0.15 mm) was slightly longer than in controls (p < 0.02).These results suggest that both the swelling reaction of the gubernaculum and transabdominal testicular migration are blocked by prenatal exposure to oestrogen. However, oestrogen exposure of the fetus does not block the swelling reaction of the gubernaculum by acting as an antiandrogen.
Viability of ram spermatozoa in relation to the abstinence period and successive ejaculations
Authors: OLLERO M. , MUIÑO‐BLANCO T. , LÓPEZ‐PÉREZ M. J. , CEBRIÁN‐PÉREZ J. A. 
Published: May 2008

SummaryFor successful fertilization, a functionally constituted sperm plasma membrane is necessary, and this is clearly dependent on the sperm maturation process. The latter involves a series of complex changes which result from a sequence of events occurring at different points within the epididymis. The transit time through the epididymis can be influenced by external factors such as sexual stimulus and ejaculatory frequency. The present work was undertaken to determine changes in ram sperm viability and other sperm quality characteristics in relation to ejaculatory frequency.Three successive ejaculates were collected from rams during three different abstinence periods (collected every day, every 2 days and every 3 days). Cell viability (membrane integrity determined by fluorescence staining), progressive individual motility, and other in vitro parameters of sperm quality were evaluated. Second ejaculates showed the highest cell viability of the three periods studied, and increased as the abstinence period lengthened. The maximum proportion of viable cells (average 60%) was obtained in the second ejaculate after an abstinence period of 3 days. Likewise, overall and progressive individual motilities were higher in second ejaculates, the maximum value being 70% after 3 days of abstinence. The percentage of damaged or acrosome‐reacted spermatozoa was greater after 1 day of abstinence than after the other periods analysed, whereas the first ejaculate showed the highest value in all periods.Differences in ejaculate volume were correlated strongly with both variables considered (abstinence period and ejaculate number). In the third ejaculate, about 27% more volume was obtained after 3 days of abstinence than after abstinence for 1 or 2 days. Sperm concentration increased significantly as the abstinence period lengthened, and also decreased significantly with ejaculate number in all cases. Therefore, the total number of spermatozoa in the ejaculate was clearly dependent on the abstinence period and the ejaculate number.In conclusion, the results obtained suggest that using the second and/or a mixture of second and third ejaculates would improve the results in artificial insemination and in fertility studies. In addition, the use of better quality semen would facilitate progress in semen cryopreservation studies.
Immunodetection of cell adhesion molecules and extracellular matrix proteins in rat Leydig cell cultures
Authors: DENDUCHIS B. , SCHTEINGART H. , CIGORRAGA S. , VIANELLO S. E. , CASANOVA M. B. , LUSTIG L. 
Published: May 2008

SummaryCell adhesion molecules (CAMs) as well as extracellular matrix (ECM) proteins were identified in Leydig cell cultures using immunohistochemical and Western blot analysis. Leydig cells were isolated from 60‐day‐old rats and cultured for 4 days. For immunofluorescence and immunoperoxidase techniques, Leydig cells were incubated with antisera to ECM proteins (antibodies to laminin, type IV collagen and fibronectin); antisera to integrins (antibodies to β1, α3, α5 and α6 integrin subunits) and antisera to cell‐to‐cell adhesion molecules (antibodies to N‐CAM and N‐cadherin). Results of the two immunohistochemical techniques were similar. Laminin and type IV collagen were detected in the perinuclear area of Leydig cell cytoplasm and cell processes as bright granular immunofluorescence or as a brown reaction product using the immunoperoxidase technique. Leydig cells expressed α3 and α6 integrin subunits (mainly laminin receptors), while no reaction was detected with antibodies to the α5 integrin subunit (fibronectin receptor). Leydig cells also expressed cell‐to‐cell adhesion molecules such as N‐CAM and N‐cadherin.Using Western blot analysis, Leydig cell extracts incubated with antibodies to laminin revealed two bands of around 200 kDa, which is characteristic of laminin 1 light chains. A band with electrophoretic mobility similar to that of the α2 (IV) collagen chain from EHS sarcoma and a band of around 230 kDa similar to fibronectin were also detected in Leydig cell extracts using specific antisera.Leydig cells incubated with antibodies to the α3 integrin subunit revealed two bands below 120 kDa. Finally, Western blot results showed that Leydig cells expressed N‐CAM as two faint bands of around 140 kDa and N‐cadherin as a 120 kDa band. The present data suggest that Leydig cells in culture are able to synthesize ECM proteins and express ECM receptors (integrins), as well as cell‐to‐cell adhesion molecules such as N‐CAM and N‐cadherin.
Extensive polymorphism and geographical variation at a positively selected MHC class II B gene of the lesser kestrel (Falco naumanni)
Authors: ALCAIDE MIGUEL , EDWARDS SCOTT V. , NEGRO JUAN J. , SERRANO DAVID , TELLA JOSÉ L. 
Published: May 2008

AbstractUnderstanding the selective forces that shape genetic variation in natural populations remains a high priority in evolutionary biology. Genes at the major histocompatibility complex (MHC) have become excellent models for the investigation of adaptive variation and natural selection because of their crucial role in fighting off pathogens. Here we present one of the first data sets examining patterns of MHC variation in wild populations of a bird of prey, the lesser kestrel, Falco naumanni. We report extensive polymorphism at the second exon of a putatively functional MHC class II gene, Fana‐DAB*1. Overall, 103 alleles were isolated from 121 individuals sampled from Spain to Kazakhstan. Bayesian inference of diversifying selection suggests that several amino acid sites may have experienced strong positive selection (ω = 4.02 per codon). The analysis also suggests a prominent role of recombination in generating and maintaining MHC diversity (ρ = 4Nc = 0.389 per codon, θ = 0.017 per codon). Both the Fana‐DAB*1 locus and a set of eight polymorphic microsatellite markers revealed an isolation‐by‐distance pattern across the Western Palaearctic (r = 0.67; P = 0.01 and r = 0.50; P = 0.04, respectively). Nonetheless, geographical variation at the MHC contrasts with relatively uniform distributions in the frequencies of microsatellite alleles. In addition, we found lower fixation rates in the MHC than those predicted by genetic drift after controlling for neutral mitochondrial sequences. Our results therefore underscore the role of balancing selection as well as spatial variations in parasite‐mediated selection regimes in shaping MHC diversity when gene flow is limited.