bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of ethane dimethane sulphonate (EDS) on seminiferous tubule function in rats
Authors: O'LEARY P. C. , JACKSON A. E. , IRBY D. C. , DE KRETSER D. M. 
Published: May 2008

SummaryThe effects of a single injection of ethane dimethane sulphonate (EDS) on aspects of seminiferous tubule function were assessed over a period of 49 days. Ethane dimethane sulphonate, which is known to cause destruction of Leydig cells, reduced the levels of testosterone in both serum and testicular interstitial fluid for 21 days, after which recovery occurred. The low testosterone levels were associated with elevated serum levels of LH and FSH. Daily sperm production was decreased from 14 to 42 days post‐EDS but returned to control levels at 49 days. The production of seminiferous tubule fluid, measured after unilateral efferent duct ligation, decreased significantly at 7 and 14 days but then recovered. The testicular content of androgen binding protein (ABP) was decreased from 14 to 28 days but returned to normal thereafter. These results demonstrate significant effects on seminiferous tubule function, which may be due to the decrease in testosterone or be associated with a direct effect of EDS.
Simple model and empirical method for the estimation of spontaneous pregnancies in couples consulting for infertility
Authors: COMHAIRE F. H. 
Published: May 2008

SummaryBased on simple theoretical models and on the analysis of data of over 12 000 couples, a simple formula is proposed to predict the probability of spontaneous (treatment‐independent) pregnancies in couples consulting for infertility after at least 12 months of unprotected intercourse. For a duration of infertility of between 12 months and 48 months the probability of conception per cycle of exposure is 4 × 0.97n× (a) × (bm) × (bf), where n is the number of months of unsuccessful trial to conceive, a refers to the type of infertility (primary vs secondary), bm depends on the severity of impairment of semen parameters, and bf relates to the age and pathology of the female partner. Some tentative values for these factors are calculated.
Ontogeny and cellular origin of a rat seminiferous tubule factor(s) that inhibits LH‐dependent testosterone production by interstitial cells in vitro
Authors: SYED V. , KHAN S. A. , LINDH M. , RITZÉN E. M. 
Published: May 2008

SummaryPrevious studies have shown the presence of a peptide in spent media from incubated seminiferous tubules (SMST), which inhibits LH stimulation of testosterone production by rat Leydig cells in vitro. The present study has investigated whether the secretion of this inhibitor changes during development in the rat. Seminiferous tubules obtained from rats aged 10, 20, 25, 30, 35, 40, 42, 50 or 60 days were incubated at 32°C for 24 h. Spent media from these incubations were then added to interstitial cells isolated from the testes of rats aged 60 days. Spent media from rats aged 10–30 days had no effect on basal or oLH‐stimulated testosterone production by interstitial cells during 3‐h incubation. Significant inhibition of LH‐stimulated testosterone production was, however, observed with SMST from rats aged 35–60 days. Spent media prepared using tubules from normal, prenatally irradiated (Sertoli cell‐enriched) or seminiferous tubules, depleted of peritubular cells, had no effect on basal, but inhibited LH‐stimulated, testosterone production. Spent media from peritubular cell cultures had no effect on basal or LH‐stimulated testosterone production by interstitial cells. The inhibitory effect of SMST was also dependent on the age of the rats providing the target cells. Interstitial cells from rats aged 10, 20, 50 or 60 days were responsive to the inhibitor while cells from rats aged 30 and 40 days were not. The results of the present study demonstrate that the seminiferous tubule factor(s), which inhibits LH action on interstitial cells, is first secreted at 35 days, a time when the most mature germ cells present are in the early maturation phase. Moreover, interstitial cells are responsive to this factor in both immature (10–20 day‐old) and mature (50–60 day‐old) rats, but not at ages in between these times. It is suggested that the adult Sertoli cell is the major source of the interstitial cell inhibitor.
4‐Bromo‐7‐hydroxyindan oxime — a new potent spermicidal agent
Authors: YU Z.‐H. , GU Z.‐P. , ZHANG X.‐D. , WAN F. 
Published: May 2008

SummaryThe spermicidal effect of eleven chelating agents with a ring structure was evaluated using human spermatozoa. All were potent spermicides in vitro. 4‐Bromo‐7‐hydroxyindan oxime (S‐11) was the most potent and its lowest effective concentration for immobilizing sperm within 20 sec was 0.02 mg/ml; its toxicity was also the lowest of the compounds tested with an acute LD50 of 2936 mg/kg. In rabbits, S‐11 caused no local irritation to the conjunctiva or quadriceps femoris muscle at a concentration of 0.02 mg/ml. Heart, liver, kidney, spleen, lung and vagina showed no pathological changes when vaginal pessaries containing 1 or 10 mg of S‐11 were administered daily, six times a week for 90 days. When vaginal pessaries of 8 or 40 mg S‐11 were administered on days 7–15 after mating, no significant abnormality in general appearance, in the viscera or bone development of foetuses were found.
Effect of an LHRH‐agonist on testicular microcirculation in hypophysectomized rats
Authors: DAMBER J. E. , BERGH A. , WIDMARK A. 
Published: May 2008

SummaryThe effect of an LHRH‐agonist on testicular vasomotion was studied in adult hypophysectomized rats. At 0.5 and 1 h after injection of 1 μg LHRH‐agonist, no effect on vasomotion was observed, but after 2 h the pulsatile blood flow pattern had changed to continuous flow in 50% of the rats. At 4 h after treatment with LHRH‐agonist, vasomotion was not detected in the testis of any rat. In addition, at the latter time an increased number of polymorphonuclear leucocytes (PMNs) were observed in testicular microvessels, and some PMNs had migrated into the interstitial space. These findings are discussed in relation to the well‐known stimulatory effect of LHRH‐agonists on testicular interstitial fluid volume.
Some effects of furazolidone on the testis and plasma levels of testosterone, luteinizing hormone and prolactin in mature male turkeys
Authors: ALI B. H. , SILSBY J. L. , LOSETH K. J. , CRABO B. , HALAWANI M. E. EL 
Published: May 2008

SummaryAdult male turkeys were treated orally with furazolidone at doses of 1, 2.5, S or 20 mg/kg for 14 days and their plasma analysed for luteinizing hormone (LH), testosterone and prolactin (PRL) concentrations before, during and after treatment. At 20 mg/kg the drug produced a significant decrease in the plasma levels of LH and testosterone at the end of treatment, whereas at 5 mg/kg the drug had no significant effect. Prolactin concentrations were unaffected by any of the drug doses used. Intramuscular injection of luteinizing hormone releasing hormone (LHRH) at a dose of 5 μg/kg produced after 30 min a significant rise in plasma levels of LH, an effect that was decreased significantly by treatment with 20 mglkg furazolidone. Incubation of normal turkey semen with graded doses of furazolidone or nitrofura‐zone for up to 30 min resulted in a dose‐ and time‐dependent decrease in sperm motility. At a concentration of 20 mg/ml a complete absence of sperm motility was observed after incubation with either drug, although, on the whole, nitrofurazone seemed more potent than furazolidone as a sperm‐immobilizing agent. Histological changes occured in the 20 mg/kg group and consisted of a decrease in spermatocyte production, corrugation of sperm cell nuclear envelopes and distention of the endoplasmic reticulum of elongate spermatids. It is concluded that furazolidone depresses pituitary LH output but may, in addition, directly affect spermatogenesis and sperm motility.
Characterization of insulin binding and comparative action of insulin and insulin‐like growth factor I on purified Leydig cells from the adult rat
Authors: RIGAUDIERE N. , LOUBASSOU S. , GRIZARD G. , BOUCHER D. 
Published: May 2008

SummaryInsulin binding and insulin action were characterized in adult rat Leydig cells, purified on discontinuous Percoll gradients. Binding of [125I]‐porcine insulin was found to be dependent on time, temperature, cell concentration and Leydig cell specific gravity. Competition relative to porcine insulin (100) was as follows: insulin‐like growth factor I (IGF‐I): < 1; proinsulin: 5; guinea‐pig insulin: 2; hCG, ovine prolactin and bovine GH: O. High and low affinity binding sites for insulin were identified on purified Leydig cells with Ka values of 1.2 × 109 and 0.3 × 108 m‐1 with 10 300 and 34 000 binding sites per cells, respectively. Using primary cultures of Leydig cells in serum‐free medium, the action of insulin on steroidogenesis was studied and compared with IGF‐I action. Insulin and IGF‐I used at 1–35 nM enhanced basal testosterone production in a dose‐dependent manner; the effect was significant 4 h after administration. Insulin or IGF‐I also potentiated the effect of hCG on steroidogenesis during short‐term incubation (4 h). Insulin was shown to improve hCG responsiveness without modifying sensitivity to hCG. Moreover, neither cell number nor hCG‐binding was altered by insulin, IGF‐I or a combination of the two. Concomitant treatment with insulin and IGF‐I at half‐maximal and maximally effective doses, in the presence or absence of hCG, indicated that the two factors synergized in the stimulation of testosterone production via a common saturable mechanism.
Randomized clinical trial of testosterone replacement therapy in hypogonadal men
Authors: CONWAY ANN J. , BOYLAN LYN M. , HOWE C. , ROSS GLYNIS , HANDELSMAN D. J. 
Published: May 2008

SummaryWe have compared the pharmacokinetics and pharmacodynamics of the three commonly used testosterone formulations in a prospective, randomized cross‐over clinical trial. Plasma free and total testosterone and their ratio (proportion of unbound testosterone), sex hormone‐binding globulin (SHBG), oestradiol, LH and FSH were measured in 15 hypogonadal men (nine hyper‐ and six hypo‐gonadotrophic) who underwent, in a randomized sequence, three treatment periods each separated by an intervening washout period. The treatments were: (i) intramuscular injection of 250 mg mixed testosterone esters at 2‐weekly intervals, (ii) oral testosterone undecanoate 120 mg bd, and (iii) subcutaneous testosterone pellets (6 times 100 mg). Pellet implantation gave the most prolonged effect with free and total testosterone levels being elevated for up to 4 months. This was accompanied by prompt and sustained suppression of plasma LH and FSH, an increase in plasma levels of oestradiol but no change in SHBG levels. In contrast, intramuscular injections induced marked but reproducible week‐to‐week fluctuations in free and total testosterone, which resulted in a small decrease in plasma SHBG levels, less marked suppression of LH and FSH and a smaller increase in plasma levels of oestradiol. Oral testosterone undecanoate produced the most variable plasma levels of free and total testosterone with a peak in the first treatment week and a fall thereafter and, despite maintenance of testosterone levels within the physiological range, there was no significant suppression of plasma levels of LH and FSH, and oestradiol levels were unchanged but levels of SHBG and total cholesterol were decreased. Free testosterone levels were increased disproportionately during testosterone treatment as the proportion of unbound testosterone was increased by all three treatments. All three testosterone preparations lowered plasma levels of urea and all were without biochemical or haematological toxicity. Reported sexual function was better maintained and side‐effects were fewer with parenteral compared with oral treatments. The marked decrease in SHBG and cholesterol levels during oral testosterone undecanoate, when com pared with parenteral treatments, occurred despite lesser androgenic effects (suppression of gonadotrophin levels and reported sexual function), which suggests that the liver is exposed to excessive androgenic load via the portal vein during oral treatment with testosterone esters. It is concluded that testosterone pellets give the closest approximation to zero‐order (steady‐state) delivery conditions for up to 4 months after a single insertion. This is the most satisfactory approximation to physiological androgen replacement currently available, although improvements in androgen preparations are required.
Multivariate discriminate analysis of the relationship between the hypo‐osmotic swelling test and the in‐vitro fertilizing capacity of human sperm
Authors: CHAN S. Y. W. , WANG C. , NG M. , SO W. W. K. , HO P. C. 
Published: May 2008

SummaryMultivariate discriminant analysis was used to evaluate the usefulness of routine semen parameters and the hypo‐osmotic swelling test (HOST) as predictors of the in‐vitro fertilizing capacity of human sperm as assessed by the zona‐free hamster egg penetration assay (HEPA). Eighty‐eight semen samples from untreated patients attending an infertility clinic were analysed. Semen samples were classified into the following three groups before statistical analysis: group l—positive sperm penetration (≥10%, >n = 39); group 2—rderline penetration rates for HEPA (>0 but <10%, n= 39) and group 3—gative sperm penetration (0, n= 10). The percentage of sperm with normal morphology and sperm count were found to be significant in discriminating between semen samples exhibiting different in‐vitro fertilizing capacity. These two discriminating variables in combination gave an overall correct classification rate of 45.5%. The multivariate discriminant analysis was also performed after excluding the data of group 2 semen samples (n= 39), which exhibited borderline sperm penetration rates. As a result, three discriminating variables including semen volume, sperm count and the percentage of sperm with normal morphology were selected. These three variables in combination could accurately predict whether a semen sample would exhibit positive sperm penetration (group 1) or negative sperm penetration (group 3) with an overall accuracy of 75.5%. The percentage of swollen sperm after hypo‐osmotic treatment was not related to the HEPA result, as determined by linear correlation and multiple regression analyses, and did not give additional information about the in‐vitro fertilizing capacity of sperm as evaluated by multivariate discriminant analysis.
Recovery of sperm production following the cessation of gossypol treatment: a two‐centre study in China
Authors: MENG G.‐D. , ZHU J.‐C. , CHEN Z.‐W. , WONG L.‐T. , ZHANG G.‐Y. , HU Y.‐Z. , DING J.‐H. , WANG X.‐H. , QIAN S.‐Z. , WANG CHRISTINA , MANCHIN D. , PINOL A. , WAITES G.M.H. 
Published: May 2008

SummaryA number of variables were investigated in 46 men who had stopped taking gossypol for their predictive association with the degree and time of recovery of spermatogenesis. Thirty‐nine (87%) of the men were azoospermic at cessation of gossypol treatment. In those with sperm present the geometric mean concentration and total sperm count were 8.3 × 106/ml and 30.7 × 106, respectively. Twenty‐eight men (61%) recovered to a defined threshold of spermatogenic function (sperm concentration 20 × 106/ml), with a median recovery time of 1.1 years. However, 18 men (39%) had not recovered to this degree of spermatogenic function after a median follow‐up of 1.9 years and, of these, 10 (22%) remained azoospermic. The influence of individual baseline variables on the time to defined recovery was examined using Kaplan‐Meier curves for groups and their joint effect by Cox's regression model. The failure of recovery was strongly associated with longer treatment, greater total dose of gossypol, smaller testicular volume, elevated FSH concentrations and, to a lesser extent, with greater body weight.
A study on budding protrusions of human seminiferous tubules
Authors: TERADA T. , HATAKEYAMA S. 
Published: May 2008

SummaryIn order to elucidate the morphogenesis of seminiferous tubular protrusions, histometric, microscopic and electron microscopic studies were performed on the testes of 202 Japanese men, including 117 sudden deaths, 75 hospital deaths and 10 prostatic cancer cases. Protrusions usually occurred at outer convexes of multibending tubular portions and were divided into dome, sessile, pedunculated and multi‐branched types. Aggregated Sertoli cells were present in dome‐type protrusions as a major component, and spermatogenesis associated with active mitoses of spermatogonia was induced with development of protrusions. Protruding walls consisted of inner compact and outer loose layers. Distribution of lipid droplets in Sertoli cell cytoplasm in protrusions was different from those in the original tubules. The incidence of protrusions peaked in the forties and sixties, respectively, in the case of hospital and sudden death cases with underlying tubular atrophy. The findings suggest that tubular protrusions take place as a compensatory reaction for declining spermatogenesis, and therefore, probably represent a regenerative phenomenon in hypospermatogenic testes.
Effects of local heating of the testis on testicular blood flow and testosterone secretion in the rat
Authors: GALIL K. A. A. , SETCHELL B. P. 
Published: May 2008

SummaryExposure of one or both testes of rats to heating at 43°C for 30 min resulted in a significant reduction in blood flow per testis, as measured using microspheres. The effects on the testes of unilateral and bilateral heating were similar, although the changes in FSH levels in peripheral blood were in general less marked after unilateral heating. Testicular blood flow fell, along with testicular weight, beginning at 24 days and reaching minimum values 14–21 days after heating. Both blood flow per testis and testicular weight were beginning to recover 35 days post‐heating and blood flow per testis was normal by 56 days following heat treatment, although testicular weight was still slightly reduced at that time. Heating one or both testes to 42°C produced similar but smaller responses 21 days later, whereas temperatures of 41°C or lower were without effect on the parameters measured, except for some rises in serum LH and FSH. With slight reductions in blood flow, there were corresponding increases in testicular venous testosterone concentration so that testosterone secretion was unaffected. Further reductions in blood flow at 14 and 21 days after heating to 43°C were not fully compensated by an increase in the concentration of testosterone in testicular venous blood, with the result that testosterone secretion fell.
Effect of age and busulphan treatment on the hsp70 gene‐related transcript level in rat testes
Authors: KRAWCZYK Z. , SZYMIK N. 
Published: May 2008

SummaryNorthern blot analysis was used to determine the expression pattern of a testis‐specific, heat shock gene (hsp70)‐related transcript (hst70 RNA) in rats during sexual maturation, following administration of busulphan and in aged rats with progressive tubular degeneration. The level of the hst70 RNA in testes of rats aged 4, 7, 12,19, 21 or 24 months decreased gradually with age. In the atrophic testes of old rats with tubules depleted of germ cells, the hst70 transcript was undetectable. Transient arrest of spermatogenesis in rats aged 2 months following injection of a single dose of busulphan (10 mg/kg) resulted in a parallel but transient decrease in the transcript level to undetectable values, followed by its reappearance after resumption of spermatogenesis. The transcript was absent from testes containing tubules depleted of spermatocytes and spermatids and reappeared when a new generation of round spermatids repopulated the seminiferous tubules. Possible expression of the hst70 gene prior to the formation of early spermatids is discussed.
Effect of gossypol on the concentration of sodium and potassium in the rat epididymis
Authors: KAUR S. 
Published: May 2008

SummaryThe effects of administration of gossypol acetic acid (7.5 mg/kg daily for 4 weeks) on the concentration of Na+ and K+ in the rat epididymis was assessed. Epididymal fluid samples, collected by micropuncture, from the caput, corpus, proximal cauda and distal cauda epididymis from gossypol‐treated and control animals were analysed for Na+ and K+ concentrations. Gossypol‐treated males failed to impregnate healthy females, presumably because their sperm were immotile. In gossypol‐treated rats, Na+ levels decreased significantly (P<0.01) in the caput, corpus, proximal and distal cauda epididymis. In contrast, the K+ concentration was increased significantly (P<0.05) only in the caput and corpus epididymis. This altered electrolyte milieu may be responsible, to some extent, for immotility and hence infertility.
The effect of long‐term treatment with crude cotton seed oil on pituitary and testicular function in men
Authors: GUI‐YUAN Z. , MENG‐CHUN J. , JIN‐LAI C. , WEN‐QING Y. 
Published: May 2008

SummaryIn a previous study, compensatory dysfunction of the Leydig cell was identified in men in whom spermatogenesis had failed to recover after gossypol treatment. In this study, LHRH‐ (100 μg i.v.) and hCG (3000 IU i.m.)‐stimulation tests were conducted in four controls and in 45 men who had used crude cotton seed oil as their cooking oil. The patients were divided into two groups: group A‐17 men with normospermia or oligospermia and group B‐28 men who were azoospermic. The basal serum LH and FSH concentrations were within the normal range in group A, whereas those in group B were increased markedly. There was no significant difference in testosterone levels between the two groups, although the levels were significantly lower than in the controls. The response of LH and FSH to LHRH, and of testosterone to hCG stimulation, were within the normal range in group A, whereas in group B the response to the LHRH test was increased significantly while their response to the hCG test was reduced markedly. It was concluded that the functions of the pituitary and Leydig cells remained unchanged in group A after long‐term use of crude cotton seed oil, and that once azoospermia has occurred, it is followed by total testicular failure as indicated by the responses to LHRH and hCG tests.
Elastase as an indicator of silent genital tract infection in infertile men
Authors: MIĆIĆ S. , MACURA M. , LALIC N. , DOTLIĆ R. 
Published: May 2008

SummaryDue to the absence of clinical symptoms, silent genital tract inflammation can be diagnosed only by laboratory tests. In this study we have evaluated seminal plasma elastase levels, using an immunoabsorbent assay, in a group of 84 infertile men. Seminal plasma levels of elastase were correlated with the number of white blood cells in the ejaculate, the number of peroxidase‐positive leucocytes and with sperm culture. A high number of leucocytes (> 10) and a significantly higher number of men with peroxidase‐stained leucocytes exceeding 106/ml was found in a group of men with elastase levels >250 ng/ml. There was a significant correlation between sperm culture results and elastase levels, most men with negative sperm culture having a lower seminal plasma elastase level. Following the treatment with antibiotics of men with an elevated elastase level, sperm parameters improved in 67% of those in whom elastase levels were lowered after treatment. In those men with persisting elevated levels of elastase improvement of sperm parameters was found in only 10%. It is concluded that an elevated level of elastase is a sensitive indicator of asymptomatic genital tract infection and that a single determination gives a reliable criterion and relatively exact quantification of infection.