1
|
Khanehzad M, Abbaszadeh R, Holakuyee M, Modarressi MH, Nourashrafeddin SM. FSH regulates RA signaling to commit spermatogonia into differentiation pathway and meiosis. Reprod Biol Endocrinol 2021; 19:4. [PMID: 33407539 PMCID: PMC7789255 DOI: 10.1186/s12958-020-00686-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 12/17/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Spermatogenesis is a complex process that is controlled by interactions between germ cells and somatic cells. The commitment of undifferentiated spermatogonia to differentiating spermatogonia and normal spermatogenesis requires the action of gonadotropins. Additionally, numerous studies revealed the role of retinoic acid signaling in induction of germ cell differentiation and meiosis entry. MAIN TEXT Recent studies have shown that expression of several RA signaling molecules including Rdh10, Aldh1a2, Crabp1/2 are influenced by changes in gonadotropin levels. Components of signaling pathways that are regulated by FSH signaling such as GDNF, Sohlh1/2, c-Kit, DMRT, BMP4 and NRGs along with transcription factors that are important for proliferation and differentiation of spermatogonia are also affected by retinoic acid signaling. CONCLUSION According to all studies that demonstrate the interface between FSH and RA signaling, we suggest that RA may trigger spermatogonia differentiation and initiation of meiosis through regulation by FSH signaling in testis. Therefore, to the best of our knowledge, this is the first time that the correlation between FSH and RA signaling in spermatogenesis is highlighted.
Collapse
Affiliation(s)
- Maryam Khanehzad
- Department of Anatomy, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Roya Abbaszadeh
- Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | - Seyed Mehdi Nourashrafeddin
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of Pittsburgh, Pittsburgh, USA.
- School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
2
|
Diagnosis and hormonal treatment of male infertility. Actas Urol Esp 2020; 44:321-327. [PMID: 32241672 DOI: 10.1016/j.acuro.2019.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/28/2019] [Indexed: 11/22/2022]
Abstract
Male infertility is a frequently observed medical condition that is related to the functioning of extremely complex organs such as the pituitary gland and the gonads. The diagnosis and proper management of infertile men is challenging for modern medicine, given the high expectations and demands of current patients, mainly due to the economic and emotional expenses aroused by this "relationship issue". In many cases, patients should receive therapies aimed at improving the functioning of that complex hormonal axis, instead of treating their underlying problem; thus, seeking to optimize the production of gametes with better conditions and improve fertilization rates without requiring assisted procedures.
Collapse
|
3
|
Rougier C, Hieronimus S, Panaïa-Ferrari P, Lahlou N, Paris F, Fenichel P. Isolated follicle-stimulating hormone (FSH) deficiency in two infertile men without FSH β gene mutation: Case report and literature review. ANNALES D'ENDOCRINOLOGIE 2019; 80:234-239. [PMID: 31439307 DOI: 10.1016/j.ando.2019.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 02/01/2019] [Accepted: 06/22/2019] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Congenital FSH deficiency is an exceptional cause of male infertility most often attributed to FSH β gene mutations. The few published cases report azoospermia, severe testicular hypotrophy and normal testosterone levels associated with normal virilization. We report the exploration of two young men aged 26 and 27 years with severe sperm abnormalities, moderate testicular hypotrophy and isolated FSH deficiency. METHODS Several FSH, LH, total testosterone and inhibin B assays and FSH β gene sequencing were performed. RESULTS FSH was almost undetectable at baseline and poorly responsive to GnRH test, whereas LH was normal at baseline and increased after GnRH test. Testosterone levels were within the adult range, while inhibin B levels were upper-normal to high. No FSH β gene mutations were found. Exogenous FSH treatment was followed by spontaneous pregnancy in one case and required intra-cytoplasmic sperm injection (ICSI) in the other. CONCLUSIONS The paradoxical high levels of inhibin B reflect the presence of functional Sertoli cells and may explain the isolated FSH deficiency. An intra-gonadal factor stimulating inhibin B secretion is discussed.
Collapse
Affiliation(s)
- Charlotte Rougier
- Department of Endocrinology and Reproductive Medicine, University Hospital of Nice, 151, route de Saint-Antoine, 06200 Nice, France.
| | - Sylvie Hieronimus
- Department of Endocrinology and Reproductive Medicine, University Hospital of Nice, 151, route de Saint-Antoine, 06200 Nice, France
| | - Patricia Panaïa-Ferrari
- Department of Biochemistry and Hormonology, University Hospital of Nice, 151, route de Saint-Antoine, 06200 Nice, France
| | - Najiba Lahlou
- Department of Biological Endocrinology, CHU Cochin, AP-HP, 75014 Paris, France
| | - Françoise Paris
- Department of Hormonology and Pediatric Endocrinology, University Hospital of Montpellier, 34295 Montpellier, France
| | - Patrick Fenichel
- Department of Endocrinology and Reproductive Medicine, University Hospital of Nice, 151, route de Saint-Antoine, 06200 Nice, France
| |
Collapse
|
4
|
Zheng J, Mao J, Cui M, Liu Z, Wang X, Xiong S, Nie M, Wu X. Novel FSHβ mutation in a male patient with isolated FSH deficiency and infertility. Eur J Med Genet 2017; 60:335-339. [DOI: 10.1016/j.ejmg.2017.04.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 02/04/2017] [Accepted: 04/05/2017] [Indexed: 10/19/2022]
|
5
|
Şimşek E, Montenegro LR, Binay C, Demiral M, Acıkalin MF, Latronico AC. Clinical and Hormonal Features of a Male Adolescent with Congenital Isolated Follicle-Stimulating Hormone Deficiency. Horm Res Paediatr 2016; 85:207-12. [PMID: 26625121 DOI: 10.1159/000442289] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/09/2015] [Indexed: 11/19/2022] Open
Abstract
AIM Our aim was to describe the clinical and genetic findings in an adolescent male with isolated follicle-stimulating hormone (FSH) deficiency and demonstrate the efficacy of recombinant human FSH (rhFSH) replacement in this case. METHODS A 14.5-year-old adolescent male was referred with normal pubertal development and small testes. Serum testosterone, FSH, and luteinising hormone (LH) were measured at baseline and after gonadotropin-releasing hormone (GnRH) stimulation. Testicular biopsy was performed, and rhFSH replacement was administered for 6 months. The patient's FSHβ gene was amplified and sequenced. RESULTS Basal and GnRH-stimulated FSH levels were undetectable, in contrast with increased LH levels under both conditions. Histopathological investigation of a testicular biopsy specimen revealed a reduced number of Sertoli cells, the absence of germ cells, Leydig cell hyperplasia, and a thickened basement membrane in seminiferous tubules. The testicular size changed from 1 ml at baseline to 6 ml after 6 months of rhFSH replacement. Sequencing of the FSHβ gene exon 3 revealed a new missense mutation (c.364T>C, resulting in p.Cys122Arg) in a homozygous state in the patient; both parents and a sister carried the same mutation in a heterozygous state. We also compared our case with all similar cases published previously. CONCLUSION We herein described an adolescent male with isolated FSH deficiency due to a novel FSHβ gene mutation associated with a prepubertal testes size and normal virilisation.
Collapse
Affiliation(s)
- Enver Şimşek
- Department of Paediatric Endocrinology, Eskisehir Osmangazi University School of Medicine, Eskisehir, Turkey
| | | | | | | | | | | |
Collapse
|
6
|
Ulloa-Aguirre A, Lira-Albarrán S. Clinical Applications of Gonadotropins in the Male. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 143:121-174. [PMID: 27697201 DOI: 10.1016/bs.pmbts.2016.08.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The pituitary gonadotropins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) play a pivotal role in reproduction. The synthesis and secretion of gonadotropins are regulated by complex interactions among several endocrine, paracrine, and autocrine factors of diverse chemical structure. In men, LH regulates the synthesis of androgens by the Leydig cells, whereas FSH promotes Sertoli cell function and thereby influences spermatogenesis. Gonadotropins are complex molecules composed of two subunits, the α- and β-subunit, that are noncovalently associated. Gonadotropins are decorated with glycans that regulate several functions of the protein including folding, heterodimerization, stability, transport, conformational maturation, efficiency of heterodimer secretion, metabolic fate, interaction with their cognate receptor, and selective activation of signaling pathways. A number of congenital and acquired abnormalities lead to gonadotropin deficiency and hypogonadotropic hypogonadism, a condition amenable to treatment with exogenous gonadotropins. Several natural and recombinant preparations of gonadotropins are currently available for therapeutic purposes. The difference between natural and the currently available recombinant preparations (which are massively produced in Chinese hamster ovary cells for commercial purposes) mainly lies in the abundance of some of the carbohydrates that conform the complex glycans attached to the protein core. Whereas administration of exogenous gonadotropins in patients with isolated congenital hypogonadotropic hypogonadism is a well recognized therapeutic approach, their role in treating men with normogonadotropic idiopathic infertility is still controversial. This chapter concentrates on the main structural and functional features of the gonadotropin hormones and how basic concepts have been translated into the clinical arena to guide therapy for gonadotropin deficit in males.
Collapse
Affiliation(s)
- A Ulloa-Aguirre
- Research Support Network, Universidad Nacional Autónoma de México (UNAM)-National Institutes of Health, Mexico City, Mexico.
| | - S Lira-Albarrán
- Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| |
Collapse
|
7
|
Nistal M, Paniagua R, González-Peramato P, Reyes-Múgica M. Perspectives in Pediatric Pathology, Chapter 18. Hypogonadotropic Hypogonadisms. Pediatric and Pubertal Presentations. Pediatr Dev Pathol 2016; 19:291-309. [PMID: 27135528 DOI: 10.2350/16-04-1810-pb.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Manuel Nistal
- 1 Department of Pathology, Hospital La Paz, Universidad Autónoma de Madrid, Madrid, Spain
| | - Ricardo Paniagua
- 2 Department of Cell Biology, Universidad de Alcala, Madrid, Spain
| | | | - Miguel Reyes-Múgica
- 3 Department of Pathology, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| |
Collapse
|
8
|
Jin JM, Yang WX. Molecular regulation of hypothalamus-pituitary-gonads axis in males. Gene 2014; 551:15-25. [PMID: 25168889 DOI: 10.1016/j.gene.2014.08.048] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 07/24/2014] [Accepted: 08/24/2014] [Indexed: 10/24/2022]
Abstract
The hypothalamic-pituitary-gonadal axis (HPG) plays vital roles in reproduction and steroid hormone production in both sexes. The focus of this review is upon gene structures, receptor structures and the signaling pathways of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The hormones' functions in reproduction as well as consequences resulting from mutations are also summarized. Specific characteristics of hormones such as the pulsatile secretions of GnRH are also covered. The different regulators of the HPG axis are introduced including kisspeptin, activin, inhibin, follistatin, androgens and estrogen. This review includes not only their basic information, but also their unique function in the HPG axis. Here we view the HPG axis as a whole, so relations between ligands and receptors are well described crossing different levels of the HPG axis. Hormone interactions and transformations are also considered. The major information of this article is depicted in three figures summarizing the current discoveries on the HPG axis. This article systematically introduces the basic knowledge of the HPG axis and provides information of the current advances relating to reproductive hormones.
Collapse
Affiliation(s)
- Jia-Min Jin
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
| |
Collapse
|
9
|
Ramaswamy S, Weinbauer GF. Endocrine control of spermatogenesis: Role of FSH and LH/ testosterone. SPERMATOGENESIS 2014; 4:e996025. [PMID: 26413400 PMCID: PMC4581062 DOI: 10.1080/21565562.2014.996025] [Citation(s) in RCA: 215] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 12/04/2014] [Indexed: 12/21/2022]
Abstract
Evaluation of testicular functions (production of sperm and androgens) is an important aspect of preclinical safety assessment and testicular toxicity is comparatively far more common than ovarian toxicity. This chapter focuses (1) on the histological sequelae of disturbed reproductive endocrinology in rat, dog and nonhuman primates and (2) provides a review of our current understanding of the roles of gonadotropins and androgens. The response of the rodent testis to endocrine disturbances is clearly different from that of dog and primates with different germ cell types and spermatogenic stages being affected initially and also that the end-stage spermatogenic involution is more pronounced in dog and primates compared to rodents. Luteinizing hormone (LH)/testosterone and follicle-stimulating hormone (FSH) are the pivotal endocrine factors controlling testicular functions. The relative importance of either hormone is somewhat different between rodents and primates. Generally, however, both LH/testosterone and FSH are necessary for quantitatively normal spermatogenesis, at least in non-seasonal species.
Collapse
Affiliation(s)
- Suresh Ramaswamy
- Center for Research in Reproductive Physiology (CRRP); Department of Obstetrics, Gynecology & Reproductive Sciences; University of Pittsburgh School of Medicine; Magee-Womens Research Institute; Pittsburgh, PA USA
| | | |
Collapse
|
10
|
Regulation of spermatogenesis: An evolutionary biologist's perspective. Semin Cell Dev Biol 2014; 29:2-16. [DOI: 10.1016/j.semcdb.2014.03.007] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/28/2014] [Accepted: 03/04/2014] [Indexed: 02/03/2023]
|
11
|
Casarini L, Pignatti E, Simoni M. Effects of polymorphisms in gonadotropin and gonadotropin receptor genes on reproductive function. Rev Endocr Metab Disord 2011; 12:303-21. [PMID: 21912887 DOI: 10.1007/s11154-011-9192-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Gonadotropins, the action of which is mediated at the level of their gonadal receptors, play a key role in sexual development, reproductive functions and in metabolism. The involvement of the gonadotropins and their receptor genotypes on reproductive function are widely studied. A large number of gonadotropins and their receptors gene polymorphisms are known, but the only one considerable as a clear, absolute genetic marker of reproductive features or disfunctions is the FSHR Asn680Ser polymorphism, since it modulates ovarian response to FSH. The aim of these studies would to be the prediction of the genetic causes of sex-related diseases to enable a customized clinical setting based on individual response of patients undergoing gonadotropin stimulation. In this review we discuss the latest information about the effects of polymorphisms of the gonadotropins and their receptor genes on reproductive functions of both male and female, and discuss their patho-physiological implications.
Collapse
Affiliation(s)
- Livio Casarini
- Department of Medicine, Endocrinology, Metabolism and Geriatrics, University of Modena and Reggio Emilia, via P. Giardini 1355, 41126 Modena, Italy
| | | | | |
Collapse
|
12
|
Bernard DJ, Fortin J, Wang Y, Lamba P. Mechanisms of FSH synthesis: what we know, what we don't, and why you should care. Fertil Steril 2010; 93:2465-85. [DOI: 10.1016/j.fertnstert.2010.03.034] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 03/11/2010] [Indexed: 12/17/2022]
|
13
|
Allan CM, Lim P, Robson M, Spaliviero J, Handelsman DJ. Transgenic mutant D567G but not wild-type human FSH receptor overexpression provides FSH-independent and promiscuous glycoprotein hormone Sertoli cell signaling. Am J Physiol Endocrinol Metab 2009; 296:E1022-8. [PMID: 19293333 DOI: 10.1152/ajpendo.90941.2008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have characterized the in vivo actions of human wild-type FSH receptor (FSHR) overexpressed in Sertoli cells of transgenic (Tg) mice (TgFSHRwt) compared with transgenic overexpression of the human activated mutant FSHR*D567G (TgFSHR*D567G). Testicular TgFSHRwt expression significantly elevated specific FSH binding (>2-fold, P < 0.01) relative to nontransgenic testes, similar to increased FSH binding in TgFSHR*D567G testes. Isolated TgFSHRwt Sertoli cells exhibited higher FSH-stimulated cAMP levels compared with non-Tg or TgFSHR*D567G cells but did not display the elevated FSH-independent basal cAMP levels found in TgFSHR*D567G Sertoli cells. Furthermore, Sertoli cell overexpression of TgFSHR*D567G but not TgFSHRwt allowed promiscuous cAMP responses to human chorionic gonadotropin (300 IU/ml) and TSH (30 mIU/ml), demonstrating increased constitutive signaling and altered glycoprotein hormone specificity via the intracellular D567G substitution rather than FSHR overexpression. Despite elevating Sertoli cell FSH sensitivity, overexpression of TgFSHRwt had no detectable effect upon normal testis function and did not stimulate Sertoli and germ cell development in testes of gonadotropin-deficient hypogonadal (hpg) mice, in contrast to the increased meiotic and postmeiotic germ cell development in TgFSHR*D567G hpg testes. Increased steroidogenic potential of TgFSHR*D567G hpg testes was demonstrated by elevated Cyp11a1 and Star expression, which was not detected in TgFSHRwt hpg testes. Androgen-regulated and Sertoli cell-specific Rhox5 gene expression was increased in TgFSHR*D567G but not TgFSHRwt hpg testes, providing evidence of elevated LH-independent androgen activity due to mutant FSHR*D567G. Hence, transgenic FSHR overexpression in Sertoli cells revealed that the D567G mutation confers autonomous signaling and steroidogenic activity in vivo as well as promiscuous glycoprotein hormone receptor activation, independently of FSHR overexpression alone.
Collapse
Affiliation(s)
- Charles M Allan
- ANZAC Research Institute, Concord Hospital, Sydney NSW 2139, Australia.
| | | | | | | | | |
Collapse
|
14
|
Allan CM, Garcia A, Spaliviero J, Jimenez M, Handelsman DJ. Maintenance of Spermatogenesis by the Activated Human (Asp567Gly) FSH Receptor During Testicular Regression Due to Hormonal Withdrawal1. Biol Reprod 2006; 74:938-44. [PMID: 16452461 DOI: 10.1095/biolreprod.105.048413] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The first activating mutation of the FSH receptor (FSHR*D567G) was identified in a gonadotropin-deficient hypophysectomized man who exhibited persistent spermatogenesis and fertility with only androgen replacement. We have determined the ability of FSHR* activity to maintain spermatogenesis and/or steroidogenesis during gonadotropin and androgen deprivation in mature transgenic FSHR* mice (Tg(Abpa-FSHR*D567G)1Cmal), hereafter referred to as Tg-FSHR* mice. Testes of untreated adult Tg-FSHR* males were equivalent in weight to nontransgenic controls but exhibited increased total Sertoli cell (24%) and spermatogonia (34%) numbers and nonsignificantly elevated spermatocyte-spermatid numbers (13%-17%). During sustained GNRH1 agonist treatment that markedly reduced (96%-98%) serum LH and testosterone (T) and decreased serum FSH (68%-72%), the testes of GNRH1 agonist-treated Tg-FSHR* mice remained significantly larger than treated nontransgenic controls. After 4 wk of gonadotropin suppression, Sertoli cell numbers were reduced in Tg-FSHR* testes to levels comparable with nontransgenic testes, whereas spermatogonia numbers were maintained at higher levels relative to nontransgenic testes. However, after 8 wk of GNRH1 agonist treatment, the total spermatogonia, spermatocyte, or postmeiotic spermatid numbers were reduced to equivalent levels in Tg-FSHR* and nontransgenic mice. FSHR* effects were further examined in gonadotropin-deficient hypogonadal Gnrh1hpg/Gnrh1hpg (Gnrh1(-/-)) mice during testicular regression following withdrawal of T after maximal T-stimulated spermatogenesis. After 6 wk of T withdrawal, spermatogonia, spermatocyte, and postmeiotic spermatid numbers in Tg-FSHR* Gnrh1(-/-) testes decreased to levels found in untreated Tg-FSHR* Gnrh1(-/-) testes. Basal serum T levels in untreated Tg-FSHR* Gnrh1(-/-) males were 2-fold higher than Gnrh1(-/-) controls, but following T treatment/withdrawal, serum T and epididymal weights declined to basal levels found in nontransgenic Gnrh1(-/-) mice. Therefore, FSHR* was unable to sustain circulating T or androgen-dependent epididymal size or postmeiotic spermatogenic development. We conclude that FSHR* activity enhances Sertoli and spermatogenic development in normal testes but has limited ability to maintain spermatogenesis during gonadotropin deficiency, in which the testicular response provided by the FSHR*D567G mutation resembled typical FSH-mediated but not steroidogenic activity.
Collapse
Affiliation(s)
- Charles M Allan
- Andrology Laboratory, University of Sydney, ANZAC Research Institute, Concord Hospital, Sydney, New South Wales 2139, Australia.
| | | | | | | | | |
Collapse
|