bluuebunny/crossref_metadata_2025 huggingface dataset:
Oestrogen treatment for tall stature in girls: estimating the effect on height and the error in height prediction
Authors: Venn Alison , Hosmer Trina , Hosmer David , Bruinsma Fiona , Jones Penelope , Lumley Judith , Pyett Priscilla , Rayner Jo‐Anne , Werther George
Published: May 2008

Objective  To determine the effect of oestrogen treatment on attenuating the growth of tall girls after adjusting for error in height prediction.

Design  Retrospective cohort study.

Patients  Tall girls assessed by Australian paediatric endocrinologists between 1959 and 1993. A total of 279 girls received oestrogen treatment (diethylstilboestrol or ethinyl oestradiol) and 367 girls were assessed but not treated.

Measurements  Estimated mature height (EMH) was calculated using radiographic assessment of bone age in adolescence. Final adult height was self‐reported at follow‐up. To control for error in the EMH predictions and their different distributions by treatment status, pairs of treated and untreated girls, matched on EMH within 1 cm, were selected for analysis. Covariate adjusted estimates of treatment effect (final height – EMH) were calculated.

Results  In the sample of 108 matched pairs, the mean difference between the final height and EMH was –1·4 cm (SE 0·29) in the treated group and 1·1 cm (SE 0·23) in the untreated group, giving an unadjusted treatment effect of –2·5 cm (95% CI –3·2 to 1·8). A regression model based on 107 pairs of treated and untreated girls contained a significant interaction between bone age at treatment initiation and treatment, which estimated an approximately 1 cm per year decrease in treatment effect. The treatment effect was greatest in those commencing treatment at an early bone age and was significant if initiated before a bone age of 15 years.

Conclusions  On average, oestrogen treatment resulted in an adult height that was less than predicted. Although treatment was more effective in the least mature girls, the mean height difference was relatively modest for most treated girls.
Hypothalamus–pituitary–adrenal axis evaluation in patients with hypothalamo–pituitary disorders: comparison of different provocative tests
Authors: Giordano R. , Picu A. , Bonelli L. , Balbo M. , Berardelli R. , Marinazzo E. , Corneli G. , Ghigo E. , Arvat E.
Published: May 2008

Background  The insulin tolerance test (ITT) is the gold standard test to evaluate hypothalamic–pituitary–adrenal (HPA) axis in suspected ACTH insufficiency. When contraindicated, alternative tests have been proposed such as metyrapone and ACTH stimulation test. 250 µg ACTH is a supramaximal dose and unreliable in this setting. The diagnostic reliability of 1·0 µg ACTH test is controversial and very low doses have been proposed.

Design  In 31 patients with hypothalamo–pituitary disorders and normal basal cortisol, we compared the diagnostic sensitivity, specificity and accuracy of metyrapone [metyrapone test (MET) 30 mg/kg p.o.], high (HDT, 250 µg i.v.), low (LDT, 1·0 µg i.v.) and very‐low (VLDT, 0·06 µg i.v.) dose ACTH tests. Receiver operator curve (ROC) analysis was applied with ITT as reference test.

Results  MET approached the best pairs of values for highest sensitivity (71·4% and 64·3%) and highest specificity (100% and 82·4%) using ACTH and 11‐deoxycortisol (11‐DOC) cut‐off of 17·3 pmol/l and 144·3 nmol/l. Either HDT or LDT sensitivity approached 71·4% with a specificity of 82·4% or 73·3% with a specificity of 80% for cortisol cut‐off of 582·1 or 477·3 nmol/l. VLDT approached the highest sensitivity (57·1%) and highest specificity (88·2%) for a cortisol cut‐off of 364·2 nmol/l.

Conclusion  Neither MET nor ACTH test can be considered completely reliable for the diagnosis of secondary hypoadrenalism, when compared with ITT that remains the best test. Either MET or ACTH stimulation test, at both high and low dose, show an overall similar reliability, provided that appropriated cut‐off values were considered; testing with very low ACTH doses seems to be misleading.
A common intron 2 polymorphism of the glucocorticoid receptor gene is associated with insulin resistance in men
Authors: Syed Akheel A. , Halpin Christina G. , Irving Julie A. E. , Unwin Nigel C. , White Martin , Bhopal Raj S. , Redfern Christopher P. F. , Weaver Jolanta U.
Published: May 2008

Objective  Clinical similarities between the metabolic syndrome and Cushing's syndrome have led to speculation of genetic association between them. The Bcl1 polymorphism in intron 2 of the glucocorticoid receptor (GR) gene has been associated with insulin resistance/hyperinsulinaemia. Our objective was to test the association of rs2918419, a T→C single nucleotide change in intron 2 downstream of the Bcl1 locus, with components of the metabolic syndrome and its interaction with the Bcl1 locus.

Design and methods  We genotyped a subsample of 325 White subjects (116 men) in the Newcastle Heart Project (NHP), a population‐based study in north‐east England. Gender‐specific statistical analysis by stepwise backward multiple regression was performed to test the association of allele status with adiposity, glucose and insulin responses to oral glucose tolerance test (OGTT), fasting lipids and blood pressure.

Results  Minor allele frequency was 0·14 for rs2918419 and 0·39 for the Bcl1 polymorphism. rs2918419 was associated with higher fasting insulin concentration and insulin resistance in men but not in women. Contrary to earlier studies, the Bcl1 polymorphism on its own was not associated with insulin resistance/hyperinsulinaemia in either gender. Subjects carrying variant rs2918419 alleles also had variant alleles at the Bcl1 locus. In men, but not women, Bcl1 variant alleles on a background of rs2918419 wild‐type alleles associated with lower fasting insulin compared to wild‐type alleles at both loci or variant alleles at both loci.

Conclusions  We report that rs2918419 was linked with hyperinsulinaemia and insulin resistance in men. Carrying Bcl1 variant alleles without rs2918419 was not associated with hyperinsulinaemia/insulin resistance. Previous reports of the association of Bcl1 polymorphism with obesity‐related characteristics may reflect linkage disequilibrium with rs2918419.
Bisphosphonate‐associated osteonecrosis of the jaw: does it occur in children?
Authors: Brown J. J. , Ramalingam L. , Zacharin M. R.
Published: May 2008

Background  Bisphosphonate use in adult patients has been linked to osteonecrosis of the jaw (ONJ). This complication has not been systematically assessed in a paediatric population receiving bisphosphonates.

Objective  To assess our cohort of paediatric patients treated with intravenous bisphosphonate for occurrence of ONJ.

Design  Observational study at a tertiary children's hospital.

Patients  A total of 42 paediatric patients with osteoporosis who received bisphosphonate infusions for a mean of 6·5 years (SD 2·7 years) were assessed clinically and radiographically for possible ONJ. Among 42, 37 patients had received disodium pamidronate 1 mg/kg/dose at a mean cumulative dose of 19·8 mg/kg and zoledronic acid (ZA) 0·05 mg/kg/dose at a mean cumulative dose of 0·49 mg/kg; four had received ZA and one received pamidronate alone. Invasive dental treatment during bisphosphonate treatment, a known risk factor for osteonecrosis, was specifically assessed.

Results  In all patients assessed, including 11 who had invasive dental treatment, there were no cases of osteonecrosis.

Conclusion  ONJ has so far not been demonstrated in this patient group.
A meta‐analysis of ant social parasitism: host characteristics of different parasitism types and a test of Emery’s rule
Authors: HUANG MING H. , DORNHAUS ANNA
Published: May 2008

Abstract 1. In ant social parasitism, the process by which parasite–host systems evolved and the types of invasion mechanisms parasites use are being debated. Emery’s rule, for example, states that social parasites are the closest relatives to their hosts. The present study uses previously published data to test whether Emery’s rule applies equally to all parasitism types (i.e. xenobiosis, temporary, dulosis, and inquilinism). In addition, this study also investigates other links between parasite–host relatedness and host biology, which has implications for understanding the invasion mechanisms used by certain parasites.

2. We find that xenobiotic parasites typically use distantly‐related host species that are of at least medium colony size. Temporary parasites often have multiple host species that are very closely related to the parasite and hosts with medium‐size colonies. Dulotic parasites frequently have multiple host species that are slightly less related and of any size. Lastly, inquiline parasites tend to have a single, very closely related, host species with medium‐size colonies.

3. Parasites tend to be more closely related to host species if they have a single host species or when the host has a large colony size. In contrast, parasites with multiple host species or hosts of small colony size tend to be less related to their hosts.

4. This study is the first to examine trends in ant social parasitism across all known parasite species. Our meta‐analysis shows that Emery’s rule applies to inquilinism and temporary parasitism, but not to dulosis and xenobiosis. Our results also suggest that both parasitism type and parasite–host relatedness predict the number of hosts and host colony size. It may be that a chemical mimicry mechanism allows invasion of large host colonies, but requires close relatedness of parasite and host, and concentration on a single host species.
Detecting prostate cancer by intracellular macrophage prostate‐specific antigen (PSA): a more specific and sensitive marker than conventional serum total PSA
Authors: Herwig R. , Mitteregger D. , Djavan B. , Kramer G. , Margreiter M. , Leers M. P. , Glodny B. , Haider D. G. , Hörl W. H. , Marberger M.
Published: May 2008

Background  Serum prostate‐specific antigen (PSA) is a standard method and a widely used marker for prostate cancer, but it has a poor specificity for early detection. Herein we demonstrate that intracellular macrophage PSA (imPSA) enables screening and differentiation between benign and malignant prostate disease.

Materials and Methods  The efficacy of intracellular macrophage PSA in circulating and tissue macrophages was therefore investigated in a double‐centre study of 38 prostate cancer patients and 36 healthy controls by fluorescent‐activated cell sorting analysis and immunohistology.

Results  Both methods uncovered the existence of PSA‐positive macrophages specific for patients with prostate cancer. In addition, we demonstrate the superiority of our new test over standard serum total PSA in a blinded double‐centre trial. ImPSA had a marked higher sensitivity and specificity than serum total PSA (imPSA: sensitivity 92%, specificity 92%, positive predictive value 92%; serum total PSA: sensitivity 79·5%, specificity 87·5%, positive predictive value 26·8%).

Conclusion  In this study, we demonstrate that imPSA is a new prostate cancer screening method that is highly sensitive and more specific than standard PSA testing.
Increased infiltration of Chlamydophila pneumoniae in the vessel wall of human veins after perfusion
Authors: Kupreishvili K. , Ter Weeme M. , Morré S. A. , Van Den Brule A. J. C. , Huybregts M. A. J. M. , Quax P. H. A. , Ten Velden J. , Van Hinsbergh V. W. M. , Stooker W. , Eijsman L. , Niessen H. W. M.
Published: May 2008

Background  Several studies have suggested an association between Chlamydophila pneumoniae (Cp) infection and atherosclerosis. A recent study detected Cp DNA in the saphenous vein of 12% of all patients before bypass grafting and in 38% of failed grafts. We used a system in which human veins were perfused with autologous blood under arterial pressure.

Materials and methods   Veins were surplus segments of saphenous veins of coronary artery bypass grafting (CABG) patients. Vein grafts were perfused with the blood of the same patient after CABG procedures. Veins were analysed for Cp‐specific membrane protein using immunohistochemical and PCR analysis. Veins were analysed before and after perfusion (up to 4 h). The number of Cp positive cells was then quantified in the vein layers.

Results  Cp protein was detected within macrophages only. In non‐perfused veins, Cp was present in the adventitia in 91% of all patients, in the circular (64%) and longitudinal (23%) layer of the media. No positivity was found in the intima. Perfusion subsequently resulted in a significant increase of Cp positive cells within the circular layer of the media that, however, differed strongly between different patients. Cp DNA was not detected by PCR in those specimens.

Conclusion  Cp protein was present in 91% of veins, but the number of positive cells differed remarkably between patients. Perfusion of veins resulted in increased infiltration of Cp into the circular layer. These results may point to a putative discriminating role of Cp with respect to graft failure between different patients.
Relevance of quantitative assessment of bleeding in haemorrhagic disorders
Authors: RODEGHIERO F. , KADIR R. A. , TOSETTO A. , JAMES P. D.
Published: May 2008

Summary. In the last few years, there has been a growing interest in the diagnosis of mild bleeding disorders (MBD) to find reliable tools for the assessment of their inherent bleeding risk and minimum criteria for the definition of a clinically useful diagnosis. Unlike in more severe haemorrhagic disorders, in MBD, the bleeding history may overlap with that reported by normal people. This problem has required the development of strategies that could allow the assessment of bleeding symptoms from both a qualitative (presence or absence) and quantitative (bleeding severity) aspect. An example of high quality clinical research in bleeding disorders was given by the systematic approach used for the evaluation of menorrhagia. For this symptom, the most common in women with bleeding disorders, the use of pictorial charts provided many new insights. Dr Kadir will review its use in a clinical context. The assessment of the whole bleeding history requires first, the development of reproducible tools to collect symptoms and secondly, formulation of easily applicable criteria to convert the collected data into clinical information. Dr Tosetto will propose a bleeding questionnaire in which clinical criteria were developed and validated, and show how a summative, quantitative index of bleeding severity (the Bleeding Score) could be used in von Willebrand disease. Finally, Dr James will review the development of quantitative analysis in children, a particularly important and difficult application, but one that needs to be tackled urgently.
New assays for monitoring haemophilia treatment
Authors: SHIMA M. , MATSUMOTO T. , OGIWARA K.
Published: May 2008

Summary.  Precise measurements of factor VIII (FVIII) or factor IX (FIX) activity are believed to be essential for clinical management in haemophilia, although discrepancies between factor levels and clinical severity have been recognized. Clot wave form analysis has demonstrated that different wave form patterns may be evident in severe haemophilia A patients with levels of FVIII activity <1 IU dL−1, and this might explain, in part, the phenotypic heterogeneity seen in these patients. In addition, the relatively new technique of computer‐assisted thrombelastography (TEG), in which coagulation is initiated by tissue factor, has revealed a considerable degree of variability in different patients in the presence FVIII levels, which are sufficient to normalize TEG parameters. In contrast, a global thrombin generation test (TGT) has been proposed as a sensitive and reliable method for assessing overall clotting function in haemophilia patients. Several studies have demonstrated a significant correlation between TGT and FVIII/FIX levels, and these measurements also appear to correlate with the clinical phenotype. The TGT may be very useful, therefore, for evaluating overall haemostasis in different clinical situations, although substantial inter‐assay and inter‐individual variations have been reported. Both the TEG and TGT have been found to be particularly helpful for monitoring haemostatic therapy with bypassing agents or conventional FVIII or FIX concentrates in patients with inhibitors. These global tests enable the selection of appropriate therapeutic agents in individual circumstances and offer the opportunity to tailor the most effective haemostatic treatment even during severe bleeding or major surgery.
Rare bleeding disorders
Authors: PEYVANDI F. , CATTANEO M. , INBAL A. , DE MOERLOOSE P. , SPREAFICO M.
Published: May 2008

Summary.  During the haemostatic response, the formation of a primary platelet plug limits bleeding and provides a surface for clotting factors to assemble and become activated. The initial platelet plug is stabilized by fibrin monomers, covalently cross‐linked by FXIII, forming a platelets‐fibrin thrombus. Defects in platelets as well as inherited deficiencies of coagulation factors including fibrinogen, FII, FV, FV + FVIII, FVII, FX, FXI and FXIII deficiencies, generally lead to lifelong bleeding disorders, whose severity of bleeding symptoms is heterogeneous in platelets abnormalities but generally inversely proportional to the degree of the factor deficiency in rare bleeding disorders (RBDs). The prevalence of platelet defects among the general population has not been established, whereas for RBDs it ranges from approximately 1 in 2 million to 1 in 500 000, being higher in countries where consanguineous marriages are diffused. As a consequence of the rarity of these deficiencies, the type and severity of bleeding symptoms, the underlying molecular defects, and the actual management of bleeding episodes are not well established. In this review the main features, diagnosis, available treatment options and treatment complications of the platelet disorders, caused by abnormalities in platelet receptors for adhesive proteins, platelet receptors for soluble agonists, platelet granules, signal transduction pathways, or procoagulant phospholipids will be discussed by Dr Cattaneo, whereas fibrinogen deficiency and FXIII deficiency will be described by Dr Inbal and Dr de Moerloose, respectively. Finally, the update of the Rare Bleeding Disorders Database will be presented by Dr Spreafico.
Interactions Between LHRH, Sex Steroids and “Inhibin” in the Control of LH and FSH Secretion
Authors: Labrie Fernand , Lagacé Lisette , Ferland Louise , Kelly Paul A. , Drouin Jacques , Massicotte Jocelyne , Bonne Claude , Raynaud Jean‐Pierre , Dorrington Jennifer H.
Published: May 2008

Using anterior pituitary cells obtained from adult male rats, 17β‐estradiol stimulated both spontaneous and LHRH‐induced LH and FSH secretion. After in vivo administration, estrogens showed inhibitory or stimulatory effects on gonadotropin secretion, the effect being dose‐ and time‐dependent. Contrary to estrogens, androgens had differential effects at the anterior pituitary level: they inhibited LH but stimulated FSH secretion. These in vitro data were confirmed by in vivo experiments using anti‐androgens. Sertoli cell culture medium was found to be a potent inhibitor of spontaneous FSH secretion while no effect was detected on LH release. When the gonadotropin response to LHRH was studied, Sertoli cell culture medium was a more potent inhibitor of FSH than LH release although clear inhibition of LHRH‐induced LH release did occur.
Some Comments on the Use of Antiandrogens for Male Contraception
Authors: Schenck B. , Neumann F.
Published: May 2008

“Pure” antiandrogens of the cyproterone or flutamide type have no or only a transient effect on testes function and spermatogenesis. They are not useful for male contraception. Only antiandrogens with antigonadotrophic (progestational) activity or combinations of “pure” antiandrogens with a central inhibitory steroid inhibit spermatogenesis and fertility. The inhibitory effect of cyproterone acetate on spermatogenesis is a direct one as has been shown in animal experiments (rats).

Most susceptible to cyproterone acetate are the accessory sexual glands, followed by the epididymis, the Sertoli cell and testes function.

Concerning the use of cyproterone acetate as a male contraceptive it seems to be very difficult to find a dose sufficient to inhibit fertility without influencing libido.
Progestational Activity of Natural and Synthetic Androgens
Authors: Jänne O. , Hemminki S. , Isomaa V. , Kokko E. , Torkkeli H. , Torkkeli T. , Vierikko P.
Published: May 2008

Uteroglobin, a progesterone‐regulated secretory protein in rabbit uterus, was used as a marker protein for studies on progestational activity of various natural and synthetic androgens. All the androgens investigated were able to induce uteroglobin synthesis in rabbit uterus; some of the synthetic androgens were even better inducers than progesterone itself. Our results suggest that androgens elicit their regulatory action on uteroglobin synthesis by way of progestin receptor mechanism, since: (i) There was an intimate correlation between the in vitro binding affinity to progestin receptor and the in vivo potency of the androgens to induce uteroglobin synthesis; (ii) Androgens were able to translocate cytosol progestin receptors to uterine nuclei; (iii) Dose‐response curves for uteroglobin induction were parallel for androgens and progestins, and (iv) Flutamide, a non‐steroidal antiandrogen, did not abolish androgen‐induced synthesis of uteroglobin or androgen‐promoted nuclear translocation of cytosol progestin receptors.

Both progesterone and androgens seem to control uteroglobin synthesis through mechanisms involving formation of new mRNA species, since in each case there was an increase in the uterine preuteroglobin‐mRNA activity, as evaluated by a cell‐free in vitro translation assay, which correlated with the amount of uteroglobin secreted into the uterine fluid. Some of the androgens studied (7α, 17α‐dimethyl‐19‐nortestosterone, 17α‐ethyl‐19‐nortestosterone and 11‐methylene‐17α‐methyl‐19‐nortestosterone) enhanced uteroglobin synthesis to the same or greater extent than progesterone. Interestingly, these steroids are also known to be very potent androgens. The progestational actions of androgens may be applicable to human tissues, too, since all the androgens investigated were bound by the human uterine progestin receptor in a fashion identical with the rabbit receptor.
Effects of Selective Depletion of Luteinizing Hormone and Testosterone on the Pituitary‐Gonadal Axis
Authors: Raj H. G. Madhwa , Dym Martin , Sairam M. R. , Dy Ruth Chen
Published: May 2008

Daily treatment of adult male rats with an antiserum specific to LH caused a precipitious fall in plasma testosterone levels by 18 h. The levels of FSH were unchanged thoughout the observation period (72 h). The fact that such low testosterone levels did not cause any alteration in FSH secretion strengthens the possibility that other factors (e. g. inhibin) may be involved in modulating FSH levels, in addition to testosterone.
Regulation of Leydig Cell Sensitivity and Responsiveness to LH/hCG
Authors: Purvis Ken , Clausen O. P. F. , Hansson V.
Published: May 2008

The present paper discusses some of the problems which are involved in evaluating hormonal effects on the responsiveness of Leydig cells to LH/hCG. It describes, with several examples, how different peptide and steroid hormones can alter the sensitivity and magnitude of the in vitro response of rat Leydig cells to gonadotrophins. These alterations in responsiveness and sensitivity may be mediated through effects on the number of LH/hCG. receptors (LH, prolactin, glucocorticoids), the activity of the phosphodiesterase (LH, androgens) or the steroidogenic enzymes (androgens, oestrogens, antiandrogens). The fact that the responsiveness and sensitivity of Leydig cells to LH/hCG can be manipulated in such a way, gives support to the proposals suggesting that regulation of target cell sensitivity to hormones may be as fruitful as the current attempts of controlling male fertility, which mainly aim at controlling hormone production.
Gonadotrophin‐Induced Reduction in LH‐Receptors and Steroidogenic Responsiveness of the Immature Rat Testis
Authors: Sharpe R. M. , McNeilly A. S.
Published: May 2008

The autoregulation of testicular LH‐receptors and steroidogenic responsiveness was assessed in rats following treatment with various doses of hCG or oLH. Irrespective of dose, both oLH and hCG caused greater LH‐receptor loss at 48 h than at 20 h after injection and the effectiveness of oLH was dramatically increased if treatment was spread over several injections. Maximal testosterone production in vitro was reduced by 50% at 20 h but not at 65 h after injection of 10 IU hCG, an effect which was not attributable to LH‐receptor loss. Sequential treatment with oLH failed to reduce testicular sensitivity or responsiveness to hCG despite causing 50% LH‐receptor loss. Cycloheximide significantly inhibited the hCG‐induced receptor loss at 20 h after injection but its effectiveness had largely diminished by 48 h.
Methodology of Immunofluorescence Cell Surface Staining with Special Reference to LH Receptors on Leydig Cells and Membrane Immunoglobulins
Authors: Brandtzaeg P. , Purvis K. , Hansson V.
Published: May 2008

In this paper methodological aspects of production, characterization and specificity control of fluorochrome conjugates are discussed, and some of our results with immunofluorescence tracing of membrane immunoglobulin (Ig) and LH/hCG receptors are reported. We give examples of paired immunofluorescence of different Ig components on human lymphocytes and colon epithelial cells, and describe the distribution of LH/hCG receptors on mature and immature as well as on desensitized rat Leydig cells.
Regulation of Leydig Cell Function by Prolactin, Growth Hormone and Luteinizing Hormone
Authors: Payne Anita H. , Zipf William B.
Published: May 2008

The effects of prolactin (PRL), growth hormone (GH) and luteinizing hormone (LH) on testicular LH receptor concentration and on testosterone synthesis in response to LH (testicular responsiveness) was studied in mature intact and hypophysectomized rats. Hypophysectomy reduced LH receptor concentration by 80% and testicular responsiveness to LH by 70%, 7 days after surgery. Daily treatment with LH initiated immediately following surgery resulted in a further dose‐dependent decrease in LH receptors and a dose‐dependent increase in testicular responsiveness. Loss of LH receptors was not due to occupancy of the receptor by exogenous LH. PRL (150 μg/day) or GH (150 μg/day) partially prevented the loss of LH receptors in hypophysectomized saline‐treated rats. The effect of PRL plus GH on LH receptor concentration was additive. The combination of LH (5 μg/day), PRL and GH prevented any loss of LH receptors after hypophysectomy. A positive effect of LH on its receptor occurred in the presence of PRL. Treatment of hypophysectomized rats with 5 μg LH + 150 μg PRL enhanced the effect observed with PRL alone on maintenance of LH receptors. PRL, administered together with higher doses of LH (25 or 50 μg/day) prevented LH from exerting a negative effect on LH receptor concentration. Similar treatment with GH plus LH neither allowed a positive effect of LH nor prevented higher doses of LH from exerting a negative effect on LH receptor concentration. Loss in testicular LH receptors was also demonstrated in intact rats which received a single administration of LH. Administration of 150 μg PRL for 3 days partially prevented the LH‐induced loss in LH receptors, while treatment with 150 μg GH had no effect on LH‐induced loss of testicular LH receptors.

Despite the ability of PRL to increase LH receptor concentration in hypophysectomized rats, PRL treatments did not enhance testicular responsiveness to LH. Only when LH was administered together with either PKL or G H was testicular responsiveness to LH maintained at intact control values. These data indicate that 1) maintenance of testicular LH receptor concentration in adult hypophysectomized rats is dependent on the combined effects of PKL, GH and LH; 2) PRL not only prevents LH from exerting a negative effect, but allows LH to have a positive effect in the hypophysectomized rat on the testicular LH receptor; 3) PRL and GH appear to act at different sites and by different mechanisms; and 4) hormonal regulation of L H receptor concentration appears to be distinct from hormonal regulation of testicular responsiveness to LH.
A New Binding Model: Gonadotropin Induced Inhibition of Testicular Functions via Receptor or Ethanol Soluble Factor Dissociation
Authors: Bhalla Vinod K.
Published: May 2008

The validity of the rapid equilibrium model as applied to the binding reaction between hLH/hCG and particulate receptors of rat testis is seriously challenged. The reaction is irreversible in nature and does not provide a reliable estimation of hormone affinity at different receptor concentrations. The effect of reaction volume alone in the binding reaction yields kd and Bmax values which show a definitive trend of receptor dissociation at higher reaction volumes. Buffer‐induced receptor loss from its particulate form is correlated with the recovery of ethanol‐soluble factors (J. biol. Chem. 251, 4947, 1976) in homogenate supernatants. In addition, time and buffer dependent loss of receptors from intact testes is also correlated with the appearance of ethanol‐soluble factors in the eluates by a perifusion technique.

Pretreatment of the testicular homogenate in vitro with 5 % ethanol reduces the number of receptor sites, an observation which is confirmed by in vivo administration of 20 % ethanol solution into adult male rats. Ethanol administration causes a dramatic reduction in the concentrations of LH specific receptor sites in the testis.

Taken together, the data refute the equilibrium binding model and support a new model which takes into consideration the basal level of receptor dissociation and predicts that increasing unlabelled hormone concentrations in the binding assays reduce the receptor population in the target tissue in a dose dependent manner. The significance of this model which adequately represents the data of many investigators including our own, is described.
Effects of Oestrogens and FSH on LH Stimulation of Steroid Production by Testis Leydig Cells from Immature Rats
Authors: van Beurden Wilma M. O. , Roodnat Bep , van der Molen Henk J.
Published: May 2008

Hypophysectomy of immature male rats results after 5 days in a decreased production of testosterone by isolated testis Leydig cells in response to LH. The LH responsiveness of the Leydig cells can be partly restored by treatment of the hypophysectomized rats with FSH. In continuation of previous reports on this subject (Steroids 28 (1976) 847; and 30 (1978) the following conclusions were derived from the results in the present paper:

1. After hypophysectomy of immature male rats the production of testosterone (T) as well as of 5‐pregnenolone (Δ5P) by isolated Leydig cells in response to LH is reduced.

2. Daily administration of FSH after hypophysectomy restores the Δ5P production in response to LH almost completely, but has a much smaller effect on the restoration of T production.

3. Administration of oestradiol benzoate (E2B) together with FSH has no effect on the restoration of LH‐stimulated Δ5P production, but causes a reduction of T production, when compared with Leydig cells from animals treated with FSH only.

4. Treatment of intact immature rats with E2B results in a decreased production of T and an increased production of Δ5P in isolated Leydig cells.

5. From experiments with labelled pregnenolone it appears that E2B and diethylstilboestrol (DES) inhibit the 17α‐hydroxylase activity of Leydig cells from intact as well as from hypophysectomized rats. This results in a reduced conversion of pregnenolone to C1:)‐steroids and in increased production of 3α‐hydroxy‐5α‐pregnan‐20‐one from δ5P.

6. The observed effects of FSH and E, were similar within a dose range of 100–10000 ng LH per 106 Leydig cells.
Inhibition of Testicular Steroids by Antibodies — A Feasible Approach to Male Contraception
Authors: Wickings E. J. , Nieschlag E.
Published: May 2008

The biological and immunological effects of immunisation against testosterone are reviewed and considered in regard to potential applications in male fertility control. In experimental animals active immunization with testosterone causes atrophy of the accessory reproductive glands, loss of sexual activity, increase in gonadotrophins, decrease in metabolic clearance rate of testosterone and prevention of fetal sexual differentiation. These findings can be described as “immunological castration”. Paradoxically, hyperplasia of the Leydig cells with excessively high testosterone levels in circulating blood occurs, while spermatogenesis remains intact. Thus infertility is achieved but at the expense of peripheral actions of testosterone. In addition, in actively immunized animals a high degree of immune complex nephritis is observed. Therefore, although a valuable research tool, immunization with testosterone does not represent a feasible approach to male fertility control.
Hormonal Regulation of Sertoli Cells
Authors: Means Anthony R. , Dedman John R. , Tindall Donald J. , Welsh Michael J.
Published: May 2008

The Sertoli cell is the primary target within the testis for both FSH and androgens. FSH binds to cell surface receptors, alters cyclic nucleotide metabolism and affects Ca++ flux. Cyclic AMP and Ca++, via an intracellular receptor protein, the calcium‐dependent regulator (CDR), control the cytoskeletal network which is comprised of microtubules and microfilaments. By affecting these intracellular components FSH regulates specific protein secretion and cell motility. In addition FSH results in an overall stimulation of protein synthesis and specifically modulates the levels of at least two intracellular regulatory proteins. Androgens bind to a specific cytoplasmic receptor which is translocated into the nucleus of interphase cells. This class of steroids is also involved in androgen binding protein metabolism but the precise mechanism of control is unknown. The interrelationships of FSH and androgen in the control of spermatogenesis is discussed. In addition, consideration is given to the possible development of male contraceptive by interfering with various steps in the mechanism of action of peptide and steroid hormones upon the Sertoli cell.
Structural Requirements for Steroid Binding to Androgen Binding Proteins
Authors: Tindall D. J. , Cunningham G. R. , Means A. R.
Published: May 2008

The physicochemical properties of androgen binding protein (ABP) and sex steroid binding globulin (SBG) are virtually indistinguishable, whereas both of these proteins are remarkably different from the androgen cytoplasmic receptor (CR). Certain compounds, such as cyproterone acetate and BOMT, inhibited binding of labelled androgen to CR but did not inhibit binding to ABP. These data suggested that a fundamental difference exists between the binding sites of ABP and CR. We have therefore examined the steroid specificity of binding to a large number of steroidal compounds in order to characterize the binding sites of these binding proteins and to determine their binding specificities. Binding to partially purified ABP and SBG was assayed by a modification of the steady‐state PAGE technique described by Ritzen et al. (1974) by dissolving competitive inhibitors along with 0.2 nM 3H‐DHT in the gel solution. Binding of CR was assayed by the ammonium sulfate precipitation assay described by Verhoeven et al. (1975).

A group of steroids was found which had high affinity for CR but low affinity for ABP. The structures of those steroids revealed that alterations at position 11 resulted in the greatest changes in binding affinity for ABP without changing significantly the binding affinity for CR. Whereas removal of the 19‐methyl group reduced binding for ABP, CR was not affected.

A second group of steroids had high affinity for ABP but low affinity for CR. The structures of these compounds demonstrate that modifications at positions C‐2 and C‐17 resulted in the greatest changes in affinity for CR without significantly changing the binding affinity for ABP. The 3‐keto and 17α‐hydroxy moieties appear to be essential for CR binding, whereas both of these positions can be modified and still maintain ABP ***
Histopathological Changes in Testes of Adult Inbred Rats Immunized Against Pachytene Spermatocytes or Sertoli Cells
Authors: Tung Pierre S. , Fritz Irving B.
Published: May 2008

Adult inbred Lewis/Wistar rats, immunized against pachytene spermatocytes or Sertoli cells prepared from maturing rats of the same strain, develop histopathological changes in the testes comparable in several respects to those reported by others in classical experimental allergic orchitis. Early changes in the structure of pachytene spermatocytes are followed by germ cell degeneration, and defoliation of germinal cells into the lumen. Concomitantly, abnormalities develop in Sertoli cell structure, and the lymph‐testis barrier becomes increasingly permeable. Sertoli cells are the only testicular somatic cells which appear to be directly sensitive during the immunologic response. Disturbances in Sertoli cell functions are postulated to be crucial in the etiology of aspermatogenesis. The data are discussed in relation to the possible roles in spermatogenesis of specific antigenic determinants present on the surfaces of mature Sertoli cells and advanced germinal cells located within the adluminal compartment of the seminiferous tubule.
In Vivo Effects on Spermatogenesis and In Vitro Metabolism of 5α‐Androstan‐3β,17β‐Diol by Testes, Prostate Glands and Seminal Vesicles
Authors: Ahmad Nazir , Warren Dwight W.
Published: May 2008

It has been shown that 17β‐hydroxy‐5α‐androstan‐3‐one (dihydrotestosterone, DHT), an irreversible metabolite of testosterone, is capable of maintaining spermatogenesis and sex accessory organs of adult rats. The same property has been displayed by 5α‐androstan‐3α,17β‐diol (3α‐diol). We have studied the effects of 5α‐androstan‐3β,17β‐diol (3β‐diol) in hypophysectomized rats. This steroid is also capable of maintaining spermatogenesis as well as the accessory glands of hypophysectomized rats. These effects of 3β‐diol are quantitatively better than with 3α‐diol. Incubation of teased testicular tissue, prostate glands and seminal vesicles with tritiated 3β‐diol showed that 3β‐diol is preferentially converted to 3α‐diol in the testis and DHT in the prostate glands but is not metabolized by the seminal vesicles. This would tend to indicate that the biological activity may be attributed to any one of the 5α‐reduced metabolites since the testes and prostate glands can metabolize 3β‐diol and the seminal vesicles could get the appropriate form of the steroid by conversion at a peripheral site with transport to the seminal vesicles. Incubation of testicular tissue with tritiated 3β‐diol and a steroidal inhibitor of 3β‐hydroxysteroid dehydrogenase showed 90% inhibition of 3β‐diol metabolism. In vivo studies with this inhibitor are underway to assess if 3β‐diol is biologically active without being converted to other steroids.
Control of Epididymal Sperm Motility; An Approach to Male Fertility Regulation
Authors: Chulavatnatol M. , Eksittikul T. , Toowicharanont P.
Published: May 2008

Thermal immobilization was designed as a simple approach to study factors controlling sperm motility. Heating dissected epididymis or isolated epididymal sperm at 48°C to 52°C for 5 min abruptly and completely immobilized the sperm. The thermally immobilized sperm showed some alteration of membrane lipids, as indicated by the response of the surface ATPase to temperature change. However, no qualitative change in the surface negative charge was detectable by the binding of the cells to DEAE‐Sephadex beads. The immobilized cells can metabolize ATP into ADP and AMP similar to the control epididymal sperm. The ATP‐dependent sliding or disintegration of sperm flagella was completely prevented in the immobolized cells. The findings suggested that heat‐treatment disrupted the integrity of the sperm membrane and the motile apparatus, resulting in the loss of sperm motility. The development of post‐testicular antifertility agents should aim at interfering specifically with these components of the sperm.
The Rat Germ Cell Adenylate Cyclase: Molecular Heterogeneity
Authors: Braun Theodor , Onoda James M.
Published: May 2008

The germ cell adenylate cyclase in subcellular fractions from testis homogenates was found in both the cytosol and particulate fraction, whereas in the subcellular fractions from epididymal spermatozoa homogenates, it was found to be exclusively in the particulate fraction. The particulate enzyme activities from testis tissue and epididymal sperm were solubilized by treatment with 1% Triton X‐100 in the presence of 250 mM Tris‐HCl, 150 mM KCl and 15% glycerol. The molecular weight of cytosol and detergent‐solubilized enzymes was estimated by gel‐exclusion chromatography. The apparent molecular weight of the cytosol enzyme was approximately 60 000 in the presence of 5 mM Tris‐HCl and about 44 000 daltons in the presence of 250 mM Tris‐HCl. The Triton X‐100 solubilized testis enzyme in the presence of 5 mM Tris‐HCl migrated mostly as a large aggregate, but dissociated into fragments of about 60 000 daltons in the presence of 250 mM Tris‐HCl and 0.1% Triton X‐100. The adenylate cyclase derived from epididymal sperm did not dissociate under the same conditions (i. e. with 250 mM Tris‐HCl and 0.1% Triton) and migrated as a large aggregate. The observed molecular heterogeneity of the testis cytosol and particulate adenylate cyclase under different experimental conditions most likely results from aggregation of a single form of the enzyme.
Methods for Evaluation of Antifertility Agents in the Male
Authors: Hammerstein J. , Brotherton Janet
Published: May 2008

The attainment and maintenance of azoospermia is first discussed as a parameter of the evaluation of antifertility agents in the male. Dangers lie in the possible non‐return of spermatogenesis and in practice the agents currently under test do not produce complete azoospermia. The relationships of fertility to sperm count, sperm motility and the proportion of spermatozoa with normal morphology is reviewed and found to be unreliable parameters in this respect. Their relative importance is believed to increase in the order indicated. Acid phosphatase, fructose and glycerophosphorylcholine should be measured as minimal parameters of the function of the prostate gland, the seminal vesicles and the epididymis respectively. All these parameters show great day‐to‐day variations requiring multiple estimations over long periods to indicate any real changes.

Sperm migration into midcycle cervical mucus in vitro (Kremer test) is recommended as a much more reliable indicator of potential fertility of a semen specimen on the basis of results presented for a trial with cyproterone acetate at 10 mg/day orally. During the treatment phase the sperm migration index in this test was consistently below the accepted level of fertility. Such spermatozoa also failed to migrate into the uterus of tubal‐ligated women whose husbands were taking the drug as indicated by uterine sperm recovery tests using a washing procedure. Finally, progress that has been made in the development of an in vitro fertilisation test for human spermatozoa is discussed. Possibilities are the use of dead human ovarian oocytes or of the zona‐free oocytes of laboratory animals.
Effects of Cyproterone Acetate (CPA) on Pituitary Gonadotrophin Release and on Androgen Secretion Before and After LH‐RH Double Stimulation Tests in Men
Authors: Moltz L. , Römmler A. , Schwartz U. , Hammerstein J.
Published: May 2008

CPA administration at a medium dosage of 10 mg daily for male fertility control resulted in reduced spermiograms and in a distinct decrease in basal T (70% reduction), DHT (50%), LH (30%) and FSH (40%). The episodic fluctuations in gonadotrophin secretion were not affected, but the spiking phenomenon of androgen secretion was completely abolished. Pituitary responses to LH‐RH were reduced significantly for both LH and FSH. Also the gradual increase of T and DHT in the course of the LH‐RH double stimulation tests was reduced. It is concluded that the progestational/antigonadotrophic action of CPA predominates over the antiandrogenic action. In addition, a direct effect at the testicular level is postulated.
Gonadotropin Suppression in Normal Males and Males with 1° Hypogonadism: Evaluation of Four Androgens
Authors: Cunningham G. R. , Silverman V. , Kohler P. O.
Published: May 2008

Serum concentrations of FSH and LH have been evaluated during treatment with four commonly prescribed androgens. In the first study, five adult males with primary gonadal failure were treated for four weeks with each of four regimens: 17α‐methyl testosterone [MT] (40 mg/day or 50 mg/day), fluoxymesterone [F] (50 mg/day), and testosterone cypionate [TC] (200 mg). LH was not suppressed by either dose of MT but was suppressed by F (P < 0.02). Both FSH and LH were suppressed for up to 3 weeks (P < 0.05) after a single injection of TC. In the second study, testosterone enanthate [TE] was evaluated as a contraceptive in 20 normal men. After two weeks (200 mg/week), the concentration of testosterone increased from 661 ± 29 ng/dl to approximately 1050 ng dl (P < 0.001) and serum gonadotropins had fallen to very low or undetectable levels. After 12 weeks of this regimen, 11 men had ≤ 1 million sperm/ml of semen, but 3 had ≥ 10 million sperm/ml. When 200 mg of TE was given every 3 weeks, serum levels of FSH and LH normalized and sperm density increased.

These studies indicate that exogenous androgens can be used to suppress gonadotropins and spermatogenesis; however, each of these four available androgens has limitations. A more potent, longer acting androgen with low toxicity is needed if this approach to the development of a male contraceptive is to be pursued.
Suppression and Recovery of Sperm Production in Men Treated with Testosterone Enanthate for One Year. A Study of a Possible Reversible Male Contraceptive
Authors: Steinberger Emil , Smith Keith D. , Rodriguez‐Rigau Luis J.
Published: May 2008

A group of 21 subjects was recruited among men requesting surgical sterilization to conduct a study on the efficacy of testosterone enanthate (TE) as a possible male contraceptive. Sixteen men completed the study. Administration of 200 mg TE (im) every 10 to 12 days maintained azoospermia. Less frequent injections (every 2 or 3 weeks) resulted in break‐through of sperm production. The azoospermia was associated with normal plasma testosterone levels, suppressed circulating FSH and undetectable LH. No untoward clinical side effects were noted. In 11 of the 16 subjects observations on recovery of sperm production were made. In all cases resumption of sperm production was noted. In two cases pregnancy occurred (5 to 7 weeks and 11 to 13 weeks after discontinuation of treatment). Since in most subjects long‐term recovery data were not available, observations on the quantitative aspects of recovery and relationship to the time interval after cessation of treatment could not be made.
The Induction of Cell‐mediated Immunity to Spermatozoa following Vasectomy in Inbred Mice
Authors: Tumboh‐Oeri A. G. , Roberts T. K.
Published: May 2008

Cell‐mediated immune response to washed, frozen and thawed mouse epididymal sperm after experimental vasectomy has been studied in vitro. Vasectomy without vasoligation results in cellular sensitization to sperm‐specific antigens. This is in contrast to conventional vasectomy where this does not occur. It is believed that the detected cellular response may be due to extravasation of spermatozoa. However, neither the antigen(s) responsible nor the mechanism(s) involved are clear.