bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the relative importance of endocrine and paracrine factors in control of the levels of inhibin in testicular interstitial fluid
Authors: SHARPE R. M. , MADDOCKS S. 
Published: May 2008

SummaryThis study aimed to identify the role of endocrine (FSH, LH, testosterone) or paracrine (Leydig or germ cell) factors in control of the secretion of inhibin into testicular interstitial fluid (IF). This was done by measuring inhibin and testosterone levels in IF, and serum gonadotrophin and testosterone levels in adult rats following the destruction of Leydig cells with ethane dimethane sulphonate (EDS), alone or in combination with testosterone ester (TE) supplementation at various doses initiated at various times after EDS treatment. The effect of germ cell loss (induced by local testicular heating) on its own or in combination with the above treatments was also assessed.Treatment with EDS led to major increases in the levels of inhibin in IF and of FSH and LH in serum whilst testosterone levels in IF and serum fell to undetectable levels. Supplementation with TE (1–25 mg) for 21 days from the time of EDS treatment failed to prevent the initial (+3 days) increase in IF levels of inhibin but thereafter suppressed inhibin to control levels or lower and grossly suppressed FSH and LH levels, irrespective of whether the dose of TE administered did (25 or 5 mg) or did not (1 mg) prevent major seminiferous tubule damage. Partial regeneration of Leydig cells and normalization of testosterone levels occurred in rats 21 days after treatment with EDS alone but this failed to normalize inhibin and gonadotrophin levels. When supplementation with TE (25 mg) was initiated at 3, 6 or 9 days after EDS treatment, IF levels of inhibin were normalized within 3 days and maintained thereafter in parallel with suppression of serum FSH and LH to below control levels. Seminiferous tubule damage induced by local testicular heating (43°C for 30 min) led to increased IF levels of inhibin 3 and 14 days later, in parallel with increased serum levels of FSH (but not LH). Suppression of FSH to subnormal levels in heat‐exposed rats by TE treatment (25 mg) restored IF inhibin to control levels or below, a change which still occurred when Leydig cells were destroyed by EDS treatment.It is concluded that secretion of inhibin via the base of the Sertoli cell into testicular IF is controlled primarily by FSH, although local factors may play a minor role. These findings have important implications regarding the possible paracrine role(s) of inhibin in IF during puberty and in the normal adult testis.
Interaction of hCG with testicular interstitial fluid produces a leucotactic factor
Authors: VEIJOLA M. , RAJANIEMI H. 
Published: May 2008

SummaryAn intratesticular injection of hCG (5 ng) mixed with testicular interstitial fluid (IF) increases vascular permeability in the rat testis. The present results show that the permeability increase induced by this treatment is accompanied by a massive accumulation of polymorphonuclear leucocytes (PMNs) in both the testicular post‐capillary venules and the interstitium. Depletion of neutrophils in the circulation by treatment with anti‐neutrophil serum significantly inhibited the permeability increase induced by this treatment. An intratesticular injection of PMNs (107 cells) or hCG alone had no effect on permeability, but a combination of the two caused a significant increase in permeability. The PMNs were found to secrete a component in vitro which, when injected intratesticularly together with hCG, caused a permeability increase and a simultaneous massive accumulation of PMNs in the postcapillary venules and interstitium. This permeability increase was prevented by the serine protease inhibitor p‐aminobenzamidine, suggesting an involvement of the plasminogen activator system in the response. The results suggest that hCG interacts with an IF component to produce leucotactic factors that increase permeability indirectly by attracting PMNs to the tissue, and that the IF component may originate in the PMNs.
Computer‐assisted image analysis of sperm concentration in human semen before and after swim‐up separation: comparison with assessment by haemocytometer
Authors: CHAN S. Y. W. , WANG C. , SONG B. L. , LO T. , LEUNG A. , TSOI W. L. , LEUNG J. 
Published: May 2008

SummaryEvaluation of male fertility is based predominantly on results from semen analysis and determination of the sperm concentration is one of the main parameters of the analysis. The availability of a fully automated videomicrographic digital image analyser would offer both an objective and rapid method for determination of the sperm concentration. In the present study the sperm concentration in 327 semen samples was determined by haemocytometer according to the World Health Organization guidelines, and also by a computer‐assisted digital image analyser system. Results were classified according to the routine procedure (haemocytometer) before statistical analyses. The computerized measurements caused a shift to the right in the frequency distribution of sperm concentration. Sperm concentrations were more often overestimated significantly (P < 0.001) by the computerized measurements in semen samples with concentrations up to 80.0 × 106/ml. This overestimation seemed to be caused by the presence of particles in seminal plasma that were recognized incorrectly as sperm by the computer program. The computerized digital image analyser gave an average sperm concentration of 2.2 ± 0.6 × 106/ml (mean ± SEM) in 17 azoospermic semen samples while the routine procedure did not detect the presence of sperm cells. After removing the seminal plasma by washing and centrifugation with culture medium, and using the swim‐up procedure to harvest motile sperm, the computerized measurements showed comparable results with the routine procedure for those sperm preparations (n= 44) with sperm concentrations >5.0 × 106/ml. In sperm preparations with concentrations < 5.0 × 106/ml (n= 75) there was still a significant (P < 0.001) overestimation of the sperm concentration. These findings indicate that the CellSoft computer program has to be improved to allow correction for the particles present in seminal plasma which are not sperm. For determination of the sperm concentration in seminal plasma‐free preparations, an effective method to remove these particles is also necessary to obtain reliable results with the present computer‐assisted digital image analyser system.
A novel maturation marker for human Sertoli cells
Authors: BAUMAL R. , BAILEY D. , GIWERCMAN A. , SKAKKEBAEK N. , STRATIS M. , MARKS A. 
Published: May 2008

SummaryThe maturation of Sertoli cells at puberty is critical for the initiation and maintenance of spermatogenesis. Little is known about the factors which control Sertoli cell maturation. We have examined Sertoli cells in testicular specimens from 44 subjects, ranging in age from 6 months to 67 years, for reactivity with a mouse monoclonal antibody (M2A) using the immunoperoxidase reaction. We found positive reactivity with prepubertal but not postpubertal Sertoli cells, suggesting that the antigen defined by M2A was a marker of immature Sertoli cells. This marker may be useful for studying the factors which influence Sertoli cell maturation during development of the testis.
Bias to routine semen analysis by uncontrolled changes in laboratory environment—detection by long‐term sampling of monthly means for quality control
Authors: KNUTH U. A. , NEUWINGER J. , NIESCHLAG E. 
Published: May 2008

SummaryTo detect systematic bias in the results of routine semen analysis over time, monthly means of semen parameters determined by the recommended WHO methods were computed. The analysis was based on a total sample size of 1784 ejaculates and included 18 months of observation. In addition to slight changes of morphology estimates caused by a change of laboratory staff, a major bias in the measurement of sperm motility could be detected. This observation triggered a search for changes in protocols not previously given the required attention. It revealed that the newly introduced use of polypropylene syringes with a mounted needle for accurate measurement of seminal volume impaired sperm motility. More detailed investigation by computerized sperm motion analysis in 10 semen samples treated simultaneously in different ways revealed that predominantly it was the needle which caused the drop in proportion of motile sperm (glass cylinder: 50.3 ± 4.1% vs. syringe + needle: 26.6 ± 5.3%; mean f SEM) and not the contact with the plastic material alone (syringe alone: 43.4 ± 4.8%). Other motion parameters such as curvilinear velocity (36.0 ± 1.6 μm/sec), linearity (78.5 ± 8.4%) and lateral head displacement (3.8 ± 0.9) were not influenced by the different methods of handling. The results indicate that long‐term sampling of monthly means may serve as part of a quality control scheme in semen analysis.
Objective measurement of testicular volume by ultrasonography: evaluation of the technique and comparison with orchidometer estimates
Authors: BEHRE H. M. , NASHAN DOROTHÉE , NIESCHLAG E. 
Published: May 2008

SummaryUltrasonography of the scrotum is a valid and safe method for differentiating testicular and extratesticular disease. In the present study the accuracy and reproducibility of ultrasonographic estimation of testicular volume was evaluated. A high correlation (r= 0.992) between actual testicular volume (measured by weighing and water displacement) and the volume determined by ultrasonography was found on examination of 14 testes from patients at autopsy without any systematic under‐ or over‐estimation. The ultrasound method proved to be highly reproducible with a coefficient of variation of 7.0 ± 0.7%. Using different ultrasound scanners did not significantly influence the results obtained. The comparison of Prader orchidometer measurements, performed by four different clinical investigators, and ultrasonography in 256 patients revealed a significant correlation of 0.91, but the degree of correlation was dependent on the investigator's clinical experience. Volume estimates by comparative palpation appear to be valuable in most clinical settings. Ultrasonography provides an excellent tool for determining testicular volume when objective, accurate and reproducible measurements of testicular volume are required.
Use of laparoscopy in children with impalpable testes
Authors: DOIG CAROLINE M. 
Published: May 2008

SummaryOur experience in Manchester using laparoscopy in children with impalpable testes is detailed. Eighty‐seven testes were investigated in 77 patients. Of these, 36% had no testes, although in 28% evidence of a vas was found. In those testes which were found, surgery was performed, either orchidopexy or, if positioned high, microsurgery. Orchidectomy was rarely carried out (5 testes only).
Age‐dependent Sertoli cell responsiveness to germ cells in vitro
Authors: CASTELLÓN E. , JANECKI A. , STEINBERGER ANNA 
Published: May 2008

SummaryThis study investigated the effect of germ cells (>80% mid‐ and late‐pachytene spermatocytes) on the secretion of androgen binding protein (ABP) and transferrin by monolayer cultures of Sertoli cells isolated from rats aged 10, 18 or 26 days. There was an age‐dependent increase in secretion of ABP and transferrin. Treatment of the Sertoli cell monolayers with hypotonic buffer to remove residual germ cells reduced this increase significantly. On the other hand, addition of germ cells to hypotonic‐treated Sertoli cell monolayers increased both basal and FSH + testosterone‐stimulated ABP and transferrin secretion at all three ages, although Sertoli cells from 10‐day‐old animals showed the greatest response. Moreover, addition of germ cells reduced responsiveness to FSH + testosterone in Sertoli cell monolayers obtained from rats aged 18 or 26 days. In monolayers obtained from 10‐day‐old rats, the opposite effect was noted in the case of ABP secretion. The stimulatory effect of germ cells on ABP and transferrin secretion was proportional to their number, and was reversed 48 h after the germ cells added previously were removed by hypotonic treatment. Whereas the reversal was complete with cultures of Sertoli cells isolated from 18‐ and 26‐day‐old rats, approximately 40% of the stimulatory effect remained after removal of germ cells from cultures from the 10‐day‐old age group. Adhesion of germ cells to Sertoli cell monolayers was also found to be age‐dependent, with the largest proportion of added germ cells adhering to Sertoli cells isolated at 18 and 26 days of age. It is concluded that germ cells can significantly and differentially modulate the basal and hormone‐stimulated secretory activity of Sertoli cells in vitro and that Sertoli cell responsiveness to germ cells (pachytene spermatocytes) is age‐dependent and seems to appear early during the maturation process, before these germ cells appear in the testis.
Induction of infertility in female rats after active immunization with 24 kD antigens from rat testes
Authors: SHAHA C. , SURI A. , TALWAR G. P. 
Published: May 2008

SummaryA unique polyvalent antiserum against whole washed human sperm was used previously to identify groups of antigens on spermatozoa. The antiserum, designated as Antiserum I, recognized the acrosome on sperm from several species and on Western blots recognized a 40 kD antigen in human sperm extracts. Antiserum I caused agglutination of human sperm and prevented interaction of mouse sperm and oocytes. This serum also recognized a band of 24 kD in rat testicular cytosol. In the present study this group of 24 kD proteins was used as an antigen preparation to actively immunize female rats. Immunization was carried out with two different adjuvants: nor‐muramyl dipeptide and SPLPS (a thyalated derivative of lipopoly‐saccharide). Both groups of animals showed significant antibody titres as detected by indirect immunofluorescence and by sperm agglutination tests. In both groups over 80% of the animals remained infertile, compared to 13% of the controls. It is concluded that a group of antigens in rat testes recognized by Antiserum I offer promise as candidates for a contraceptive vaccine.
Evaluation of the Hamilton‐Thorn 2030 motility analyser for routine semen analysis in an infertility clinic
Authors: NEUWINGER J. , KNUTH U. A. , NIESCHLAG E. 
Published: May 2008

SummaryIn routine semen analysis of 242 patients the values of sperm concentration, sperm motility and progressive sperm motility were measured with the Hamilton‐Thorn semen analyser (HT) and compared to the data obtained by conventional semen analysis according to the guidelines of the WHO. Overall, the HT gave higher values for sperm concentration (mean difference 21.7 ± 46.2 times 106 ml‐1, mean ± SD). Motility values showed a corrlation of 0.67 (slope 0.94, P < 0.001) but were estimated lower by the HT than by conventional analysis (mean difference 7.3 ± 21.7%); this was caused by the overestimation of sperm concentration. In the range from 0 to 50% motility the HT yielded lower values and higher values from 50 to 100% motility. Progressive motility values of the HT agreed better with conventional analysis (WHO categories a+b): the mean difference of all values was 0.5 ± 19.5% (r = 0.74, slope = 1.0). The mean lateral head displacement measured by the HT increased with increasing sperm path velocity, but other significant correlations between sperm movement parameters could not be demonstrated. In many instances round cells and debris could not be distinguished from normal sperm. In conclusion, the HT system cannot replace conventional semen analysis in routine diagnosis.
Developmental changes in testicular interstitial cell populations, LH receptors and in the response to hCG in the rat
Authors: LEON MARINA D. , CALVO J. C. , CHARREAU E. H. , CHEMES H. E. 
Published: May 2008

SummaryHigh doses of hCG were administered to immature rats of different ages and the animals killed 48 h later. Serum testosterone increased 2 to 4‐fold over control values 48 h after hCG. In‐vitro androgen production showed different patterns according to age. Animals younger than 35 days, when treated with hCG, retained the ability to respond to in‐vitro gonadotrophic stimulation. This ability was lost in testes from rats aged 45 days. The number of free LH‐receptors 48 h after hCG diminished with increasing age to become non‐detectable at 35 and 45 days. In control animals the proportion of differentiated Leydig cells in relation to their mesenchymal precursors increased progressively with age to reach highest values at 45 days. hCG administration induced a shift of the cellular composition of the interstitium toward the more mature cell types. hCG has a predominantly trophic action on mesenchymal precursors in young rats, promoting their differentiation. These effects are minimal in the differentiated Leydig cells in older animals. It is proposed that the observed biochemical responses are the result of the balance between the increase in LH receptors and steroidogenic enzymes in the developing new generation of young Leydig cells and the down‐regulation of receptors and enzymatic lesions in fully differentiated Leydig cells.
In‐vitro production of precursor peptides for thyrotropin‐releasing hormone by human semen
Authors: PEKARY A. E. , REEVE J. R. , SMITH VIERKA P. , FRIEDMAN S. 
Published: May 2008

SummaryThyrotrophin‐releasing hormone (TRH) and related peptides occur in high concentrations in human semen. TRH derives from a 242‐amino acid precursor protein, prepro‐TRH, with six repetitive sequences of‐Lys‐Arg‐Gln‐His‐Pro‐Gly‐Lys/Arg)‐Arg‐connected by hydrophobic linking sequences. Antibodies to TRH‐Gly (pGlu‐His‐Pro‐Gly), a final precursor for TRH formation, were used to detect this tetrapeptide as well as other prepro‐TRH fragments which cross‐react with these antibodies. The total TRH‐Gly immunoreactivity decreased significantly after vasectomy. The TRH‐Gly immunoreactivity in semen increased significantly during in‐vitro incubation at 0 or 37d̀C, to a peak value at 5 h, followed by an exponential decline, with t1/2 equal to 11 h at 37d̀C. At 60d̀C, however, the TRH—Gly immunoreactivity rose continuously, attaining, after 20 h, a level 2.2 times that at the start of the incubation (P<0.001). Reversed‐phase high pressure liquid chromatography (HPLC) revealed both hydrophobic and hydro‐philic TRH‐Gly immunoreactive peptides in semen with both classes of peptides increasing significantly with heating to 60d̀C. Cation exchange chromatography of pooled human semen incubated at 60d̀C revealed a 4.3‐fold increase in a TRH‐Gly immunoreactive peak which co‐eluted with synthetic TRH‐Gly, and a 30% increase in another TRH‐Gly immunoreactive peak identified as Glu‐His‐Pro‐Gly. A minor, TRH‐Gly immunoreactive peak increased 50‐fold (P<0.001) during 20 h at 60d̀C. This material co‐eluted with Arg‐Gln‐His‐Pro‐Gly which is formed by enzymic cleavage of the paired basic residues flanking this sequence in prepro‐TRH. When synthetic Arg‐Gln‐His‐Pro‐Gly was incubated with fresh semen at 60d̀C a rapid conversion of most of this peptide to Glu‐His‐Pro‐Gly, Gln‐His‐Pro‐Gly and TRH‐Gly occurred within 30 min. These data are consistent with thermal inactivation of the amidation and degrading enzymes at 60d̀C while the trypsin‐like enzymes which cleave the precursor peptide at the paired basic residues remain relatively unaffected. Because other investigators have found the C‐terminal amidating enzymes to be associated with secretory vesicles and to be co‐secreted with the vesicular contents, we suggest that secretory epithelia of the male reproductive system secrete TRH and TRH‐related precursor peptides along with the alpha‐amidating enzymes which continue processing of prepro‐TRH in the post‐ejaculatory seminal fluid.
Extreme asthenozoospermia and chronic respiratory disease: a new variant of the immotile cilia syndrome
Authors: CHEMES H. E. , MORERO J. L. , LAVIERI J. C. 
Published: May 2008

SummaryTwo patients suspected of suffering from ciliary dyskinesis were investigated. They consulted for primary infertility and chronic respiratory disease. Functional lung studies showed obstructive changes in one patient. Both had immotile sperm with short, thick and rigid tails. Ultrastructural studies of nasal biopsies showed abnormal cilia with almost complete lack of inner dynein arms (mean number of inner arms per axoneme 0.67 ± 1.21 in patient 1 and 1.49 ± 1.17 in patient 2, compared with normal values of 5.3 ± 0.13). Other abnormalities included lack of parallel orientation of cilia and central translocation of microtubular doublets. Electron microscopy of sperm revealed hyperplasia of the fibrous sheath and axonemal disruption. This is the first report of an association of different anomalies in cilia and flagella leading to clinical manifestation of the immotile cilia syndrome. These findings emphasize the need for ultrastructural examination of respiratory cilia in men suffering from fibrous sheath alterations of sperm which so far have not been described in patients with the classical form of immotile cilia syndrome.
Influence of seminal vesicular fluid on the zinc content of human sperm chromatin
Authors: BJORNDAHL L. , KVIST U. 
Published: May 2008

SummaryChromatin zinc was studied using X‐ray microanalysis of spermatozoa obtained from split‐ejaculate fractions. Chromatin zinc, expressed as intensity ratio between zinc and sulphur (Zn/S), was unrelated to seminal zinc concentration, but was related inversely to markers of seminal vesicular secretion (fructose concentration and the proportion of zinc bound to ligands of seminal vesicular origin). It is concluded that the content of zinc in sperm chromatin can be reduced by the action of zinc ligands of seminal vesicular origin. An abnormally high contribution of seminal vesicular fluid to sperm‐rich fractions of the ejaculate thus creates a risk of depleting chromatin zinc and thereby impairing zinc‐dependent chromatin stability.
Acidification of epididymal fluid in the boar
Authors: RODRIGUEZ‐MARTINEZ H. , EKSTEDT E. , EINARSSON S. 
Published: May 2008

SummaryThe present study describes the measurement of pH made in vivo in the rete testis fluid and in different regions of the boar epididymis. Furthermore, samples of whole ejaculates, semen fractions, testicular (ductuli efferentes/rete testis), epididymal and deferential fluids collected from the same fertile boars, were analysed for their acid/base status with an automatic blood gas analyser. A pH gradient of acidity was found between the fluid entering the ductus epididymis (pH 7.2) and the region of sperm storage at the cauda (pH 6.5). A significantly lower concentration of bicarbonate ion was found in the cauda epididymidis (3–4 mM) compared to rete testis fluid (30 mM), which might be related to the quiescence of the spermatozoa. A significant increase in extracellular pH and bicarbonate concentration occurred at ejaculation, the bicarbonate levels being 9–10‐fold higher in the semen fraction rich in seminal vesicle fluid, where sperm showed higher motility, than in the cauda epididymis.