1
|
Loebenstein M, Thorup J, Cortes D, Clasen-Linde E, Hutson JM, Li R. Cryptorchidism, gonocyte development, and the risks of germ cell malignancy and infertility: A systematic review. J Pediatr Surg 2020; 55:1201-1210. [PMID: 31327540 DOI: 10.1016/j.jpedsurg.2019.06.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/18/2019] [Accepted: 06/28/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND/AIM Cryptorchidism, or undescended testis (UDT) occurs in 1%-4% of newborn males and leads to a risk of infertility and testicular malignancy. Recent research suggests that infertility and malignancy in UDT may be caused by abnormal development of the neonatal germ cells, or gonocytes, which normally transform into spermatogonial stem cells (SSC) or undergo apoptosis during minipuberty at 2-6 months in humans (2-6 days in mice). We aimed to identify the current knowledge on how UDT is linked to infertility and malignancy. METHODS Here we review the literature from 1995 to the present to assess the possible causes of infertility and malignancy in UDT, from both human studies and animal models. RESULTS Both the morphological steps and many of the genes involved in germ cell development are now characterized, but the factors involved in gonocyte transformation and apoptosis in both normal and cryptorchid testes are not fully identified. During minipuberty there is evidence for the hypothalamic-pituitary axis stimulating gonocyte transformation, but without known direct control by LH and androgen, although FSH may have a role. An arrested gonocyte maybe the origin of later malignancy at least in syndromic cryptorchid testes in humans, which is consistent with the recent finding that gonocytes are normally absent in a rodent model of congenital cryptorchidism, where malignancy has not been reported. CONCLUSION The results of this review strengthen the view that malignancy and infertility in men with previous UDT may be caused by abnormalities in germ cell development during minipuberty. TYPE OF STUDY Systematic review (secondary, filtered) LEVEL OF EVIDENCE: Level I.
Collapse
Affiliation(s)
- Moshe Loebenstein
- Douglas Stephens Surgical Research Group, Murdoch Children's Research Institute, Melbourne, Australia; Department of Paediatrics, University of Melbourne, Australia
| | - Jorgen Thorup
- Department of Paediatric Surgery, Rigshospitalet, Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dina Cortes
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Section of Endocrinology, Department of Pediatrics, Copenhagen University Hospital Hvidovre, Denmark
| | - Erik Clasen-Linde
- Department of Pathology, Copenhagen University Hospital Rigshospitalet, Denmark
| | - John M Hutson
- Douglas Stephens Surgical Research Group, Murdoch Children's Research Institute, Melbourne, Australia; Department of Paediatrics, University of Melbourne, Australia; Department of Urology, The Royal Children's Hospital, Melbourne, Australia
| | - Ruili Li
- Douglas Stephens Surgical Research Group, Murdoch Children's Research Institute, Melbourne, Australia; Department of Paediatrics, University of Melbourne, Australia.
| |
Collapse
|
2
|
Matuszczak E, Komarowska MD, Sankiewicz A, Ołdak Ł, Gorodkiewicz E, Debek W, Milewski R, Tylicka M, Hermanowicz A. Plasma concentration of MMP-1 and MMP-2 in boys with cryptorchidism and its lack of correlation with INSL3 and inhibin B. Scandinavian Journal of Clinical and Laboratory Investigation 2019; 79:412-418. [PMID: 31295049 DOI: 10.1080/00365513.2019.1637534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The matrix metalloproteinases are enzymes capable of remodeling of extracellular matrix, and modulate the behavior of cells. Maturation of gubernaculum and spermatogenesis demand proper equilibrium of metalloproteinases and their inhibitors. The aim of this survey was to investigate the levels of matrix metalloproteinase type 1 (MMP-1) and matrix metalloproteinase type 2 (MMP-2) in the plasma of children with unilateral cryptorchidism along with levels of Insulin-like Peptide 3 (INSL3) and inhibin B. INSL3 have a role in gubernaculum development. Inhibin B is produced by Sertoli cells, and its levels reflect the status of the testis germinative epithelium. Fifty boys with an undescended testicle, aged 1-4 years (median = 2.4 years) were enrolled into the study. Fifty boys with inguinal hernia aged 1-4 years, served as controls (median age = 2.1 years). Investigators assessed the MMP-1 and MMP-2 concentrations using Surface Plasmon Resonance Imaging. The levels of INSL-3 and inhibin B were assessed using commercial enzyme-linked immunosorbent assay ELISA. The median concentration of MMP-1 and MMP-2 in the blood plasma of patients with unilateral cryptorchidism, was nearly 2-folds higher than in controls. The great area under the ROC curve with the cut off value of 0.865 for MMP-1, and 0.819 for MMP-2, indicates the high clinical sensitivity and specificity of the test of plasma levels of MMP-1 and MMP-2 for boys with cryptorchidism. The increased plasma levels of MMP-1 and MMP-2, probably reflect the level of apoptosis of the germ cells in undescended testicles, in response to the heat stress during the period of prepubertal testis development. In the group of cryptorchid boys, we found slightly lower concentrations of INSL3, without statistical significance and without correlation with MMP-1 and MMP-2 levels. There were no significant differences in the levels of inhibin B in the group of boys with cryptorchidism and boys with inguinal hernia and it also did not correlate with MMP-1 and MMP-2 concentrations.
Collapse
Affiliation(s)
- Ewa Matuszczak
- Department of Pediatric Surgery, Medical University of Bialystok , Bialystok , Poland
| | | | - Anna Sankiewicz
- Department of Electrochemistry, University of Bialystok , Bialystok , Poland
| | - Łukasz Ołdak
- Department of Electrochemistry, University of Bialystok , Bialystok , Poland
| | - Ewa Gorodkiewicz
- Department of Electrochemistry, University of Bialystok , Bialystok , Poland
| | - Wojciech Debek
- Department of Pediatric Surgery, Medical University of Bialystok , Bialystok , Poland
| | - Robert Milewski
- Department of Medical Statistics, University of Bialystok , Bialystok , Poland
| | - Marzena Tylicka
- Department of Biophysics, Medical University of Bialystok , Bialystok , Poland
| | - Adam Hermanowicz
- Department of Pediatric Surgery, Medical University of Bialystok , Bialystok , Poland
| |
Collapse
|
3
|
Li R, Vannitamby A, Yue SSK, Handelsman D, Hutson J. Mouse minipuberty coincides with gonocyte transformation into spermatogonial stem cells: a model for human minipuberty. Reprod Fertil Dev 2018; 29:2430-2436. [PMID: 28531375 DOI: 10.1071/rd17100] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 04/27/2017] [Indexed: 11/23/2022] Open
Abstract
As the transient postnatal hormone surge in humans, known as 'minipuberty', occurs simultaneously with key steps in germ-cell development, we investigated whether similar changes occur in the hypothalamic-pituitary-testicular axis of neonatal mice at a time that would coincide with gonocyte transformation into spermatogonial stem cells (SSC). Serum and testes were collected from C57Bl/6 mice at embryonic Day 17 (E17), birth (postnatal Day 0; P0) and daily until P10. Serum FSH and testosterone levels in both serum and testes were analysed and gene expression of FSH receptor (Fshr), luteinising hormone receptor (Lhr), anti-Müllerian hormone (Amh), octamer-binding transcription factor 4 (Oct-4), membrane type 1 metalloprotease (Mt1-mmp), proto-oncogene C-kit and promyelocytic leukaemia zinc finger (Plzf ) was quantified by real-time polymerase chain reaction. We found a transient surge of serum and testicular testosterone levels between P1 and P3 and a gradual increase in FSH from P1 to P10. Testis Lhr expression remained low from P0 until P10 but Fshr expression peaked between P3 and P6 (P<0.01). The same was found for Oct-4 expression (a gonocyte marker), which surged between P3 and P6 (P<0.01). Mt1-mmp expression peaked at P3 (P<0.05). The expression pattern of both C-kit and Plzf (SSC markers) was similar with a steady increase from P1 to P10. These results show a transient activation of the hypothalamic-pituitary-testicular axis postnatally with increases in serum and testicular testosterone at P1-P3 and testicular Fshr (but not Lhr) at P3-P6. These changes coincide with increases in gene expression of Oct4, Mt1-mmp, Plzf and C-kit, reflecting gonocyte activation, migration and transformation into SSC. In conclusion, these findings suggest that 'minipuberty' does occur in mice and that gonocyte transformation may be driven by a transient FSH signalling pathway.
Collapse
Affiliation(s)
- Ruili Li
- F Douglas Stephens Surgical Research Group, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Vic. 3052, Australia
| | - Amanda Vannitamby
- F Douglas Stephens Surgical Research Group, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Vic. 3052, Australia
| | - Sarah S K Yue
- F Douglas Stephens Surgical Research Group, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Vic. 3052, Australia
| | - David Handelsman
- Andrology Laboratory, ANZAC Research Institute Concord Hospital, University of Sydney, NSW 2139, Australia
| | - John Hutson
- F Douglas Stephens Surgical Research Group, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Vic. 3052, Australia
| |
Collapse
|
4
|
Aydos OS, Yukselten Y, Ozkavukcu S, Sunguroglu A, Aydos K. ADAMTS1 and ADAMTS5 metalloproteases produced by Sertoli cells: a potential diagnostic marker in azoospermia. Syst Biol Reprod Med 2018; 65:29-38. [PMID: 29737873 DOI: 10.1080/19396368.2018.1467512] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In this study, our aim was to detect protein levels of A Disintegrin and Metalloproteinase with Thrombospondin Motifs 1 and 5 (ADAMTS1 and ADAMTS5) proteases and to examine the effect of in vitro FSH supplementation on protease production in cultured Sertoli cells. The expression of metalloproteases, ADAMTS1, and ADAMTS5 were investigated in Sertoli cell cultures as well as in ejaculate of azoospermic men which then were compared with ejaculates of the fertile control group. A total of 15 azoospermic men, diagnosed as obstructive (OA, n = 5) and nonobstructive (NOA, n = 10) azoospermia were included in the study. ADAMTS1, ADAMTS5 and FSH receptors (FSHR) were found to be expressed 2.56, 2.10, and 2.66-fold less in Sertoli cells of NOA patients, than those of OA (p < 0.05). After rFSH was added onto Sertoli cell cultures of NOA patients, their expression did not increase significantly and did not reach to levels of control group. Evaluation of ejaculates revealed that the expression of ADAMTS1 and ADAMTS5 were insignificantly 1.03 and 1.1-fold higher in OA group (p > 0.05), respectively; however, in the NOA group, their expression were 1.70 and 1.96-fold lower, respectively, when compared with the fertile control group (p < 0.05) which was statistically significant. As a conclusion, the present study has revealed that insufficiency of ADAMTS1 and ADAMTS5 expression in Sertoli cells may have an important role in the etiology of male infertility. As expected due to low FSHR expression, rFSH response is impaired in NOA patients with relatively low ADAMTS expression response; therefore, such patients might hardly benefit from rFSH treatment. Further studies with larger cohorts may reveal ADAMTSs' potential use as a predictive marker for positive sperm retrieval in azoospermic patients who are scheduled to undergo testicular sperm extraction. Abbreviations: ADAM: A Disintegrin and Metalloproteinase; ADAMTS1 and ADAMTS5: A Disintegrin and Metalloproteinase with 10 Thrombospondin Motifs 1 and 5; ADAMTS: A Disintegrin and Metalloproteinase with Thrombospondin; ABP: androgen binding protein; CAMs: cell adhesion molecules; ECM: extracellular matrix; FSH: follicle stimulating hormone; FSHR: FSH receptors; HRP: horseradish peroxidase; MMP: matrix metalloproteinases; MP: metalloproteinases; NOA: nonobstructive azoospermia; OA: obstructive azoospermia; TIMP-1: tissue inhibitor of metalloproteinase-1.
Collapse
Affiliation(s)
- Oya Sena Aydos
- a Department of Medical Biology , School of Medicine, Ankara University , Ankara , Turkey
| | - Yunus Yukselten
- a Department of Medical Biology , School of Medicine, Ankara University , Ankara , Turkey
| | - Sinan Ozkavukcu
- b Center for Assisted Reproduction, Department of Obstetrics and Gynecology , Ankara University School of Medicine , Ankara , Turkey
| | - Asuman Sunguroglu
- a Department of Medical Biology , School of Medicine, Ankara University , Ankara , Turkey
| | - Kaan Aydos
- c Department of Urology , School of Medicine, Ankara University , Ankara , Turkey
| |
Collapse
|
5
|
Vikraman J, Hutson JM, Li R, Thorup J. The undescended testis: Clinical management and scientific advances. Semin Pediatr Surg 2016; 25:241-8. [PMID: 27521715 DOI: 10.1053/j.sempedsurg.2016.05.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Undescended testes (UDT), where one or both testes fail to migrate to the base of the scrotum, can be congenital (2-5% of newborn males) or acquired (1-2% of males). The testis may be found in any position along its usual line of descent. Cryptorchidism affects the developing testicular germ cells and increases the risk of infertility and malignancy. Clinical management aims to preserve spermatogenesis and prevent the increased risk of seminoma. Examination to document the testicular position will guide the need for imaging, medical management and the surgical approach to orchidopexy.
Collapse
Affiliation(s)
- Jaya Vikraman
- Douglas Stephens Surgical Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Melbourne, Victoria, Australia
| | - John M Hutson
- Douglas Stephens Surgical Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Melbourne, Victoria, Australia; Department of Urology, The Royal Children׳s Hospital, 50 Flemington Rd, Parkville, Victoria 3052, Australia.
| | - Ruili Li
- Douglas Stephens Surgical Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Jorgen Thorup
- Department of Paediatric Surgery and Surgical Clinic, Rigshospitalet, Copenhagen, Denmark; Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| |
Collapse
|
6
|
Verkauskas G, Malcius D, Eidukaite A, Vilimas J, Dasevicius D, Bilius V, Hadziselimovic F. Prospective study of histological and endocrine parameters of gonadal function in boys with cryptorchidism. J Pediatr Urol 2016; 12:238.e1-6. [PMID: 27321556 DOI: 10.1016/j.jpurol.2016.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 05/03/2016] [Indexed: 11/30/2022]
Abstract
INTRODUCTION A transient increase in gonadotropins and testosterone during mini-puberty causes gonocytes to differentiate into Ad spermatogonia, which establish male germ cell memory and male-specific DNA methylation pathways. Over half of patients with unilateral cryptorchidism and the majority of patients with bilateral cryptorchidism display an abnormal spermiogram, which indicates that unilateral cryptorchidism is a bilateral disease; therefore, it represents a serious andrological problem. The aim of this study was to evaluate relationships between hormonal parameters and testicular biopsy findings in boys with cryptorchidism. METHOD Seventy-one boys (median age 15 months; range 7-65 months) who underwent orchidopexy (24% had bilateral cryptorchidism) were tested for serum LH, FSH, and inhibin B. With ipsilateral testis biopsy histology, we determined the tubular fertility index (TFI), Ad spermatogonia counts, and Ad/tubular index (Ad/T). We compared age groups (<18 vs. >18 months old); groups with and without Ad spermatogonia; groups with unilateral and bilateral cryptorchidism; and extreme groups with high infertility risk (HIR; n = 12; TFI <0.2; Ad/T = 0) and low infertility risk (LIR; n = 9; TFI >0.9; Ad/T>0.02). RESULTS Of the specimens, 38% had no Ad spermatogonia. Age was significantly negatively correlated with TFI and Ad/T, but positively correlated with FSH. Median LH values were significantly higher in LIR than in HIR groups. Unilateral and bilateral cryptorchidism showed similar TFI, Ad/T, and hormone concentrations. The areas under ROC curves for FSH, LH, and inhibin B (0.66, 0.601, and 0.599, respectively) showed low diagnostic value for predicting HIR (no Ad spermatogonia). CONCLUSION Our observation of lower plasma LH levels in the group with the most pronounced testicular pathology was the opposite of what we would have expected if testicular pathological changes were caused by a primary gonadal defect. Therefore, low plasma LH levels in the HIR group confirmed the notion that this group of patients with cryptorchidism had hypogonadotropic hypogonadism. The estimated incidence of defective mini-puberty in boys with cryptorchidism could be as high as 50%. Testicular biopsies from boys with cryptorchidism lacked Ad spermatogonia. Fertility parameters worsened with age. Significantly lower basal LH in the HIR group indicated hypogonadotropic hypogonadism. Serum hormone levels could not predict histological biopsy findings.
Collapse
Affiliation(s)
| | - Dalius Malcius
- Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Audrone Eidukaite
- State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Juozas Vilimas
- Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | | | | | - Faruk Hadziselimovic
- Institute for Cryptorchidism Research, Kindermedizinisches Zentrum, Liestal, Switzerland
| |
Collapse
|
7
|
Li R, Vannitamby A, Zhang JG, Fehmel EL, Southwell BR, Hutson JM. Oct4-GFP expression during transformation of gonocytes into spermatogonial stem cells in the perinatal mouse testis. J Pediatr Surg 2015; 50:2084-9. [PMID: 26386877 DOI: 10.1016/j.jpedsurg.2015.08.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 08/24/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND/AIM In cryptorchidism perinatal failure to switch off Oct4, a germ cell (GC) marker, may lead to carcinoma in situ. We aimed to analyze Oct4 expression during mouse gonocyte transformation into spermatogonial stem cells (SSC). MATERIALS AND METHODS Testes from OG2 (Oct4-promoter driven eGFP) mice at embryonic day (E) 17 and postnatal day P0-10 underwent immunohistochemistry and immunoblotting. Antibodies against MVH, AMH, Ki67, and c-Kit were visualized by confocal microscopy. Numbers of Oct4-GFP(+) GC and Oct4-GFP(-) GC/tubule were counted using ImageJ. Data were analyzed using nonparametric one-way ANOVA. RESULTS GC from E17-P4 were Oct4-GFP(+). Numbers of Oct4-GFP(-) GC/tubule increased from P6-10, whereas Oct4-GFP(+) GC/tubule numbers remained similar between P6 and P10. Sertoli cells proliferated from E17-P10, whereas GC only proliferated from P2. Gonocytes (Oct4-GFP(+)/c-Kit(-)) central in tubules migrated to the basement membrane to become prospermatogonia (Oct4-GFP(+)/c-Kit(-)) and then SSC (Oct4-GFP(+)/c-Kit(+)) from day 4 and further developed into Oct4-GFP(-)/c-Kit(+) at P6. CONCLUSION In Oct4-GFP mice both centrally located gonocytes and prospermatogonia located at the tubular basement membrane were Oct4-GFP(+)/c-Kit(-) before further developing into SSC (Oct4-GFP(+)/c-Kit(+)). This indicates that Oct4 is important in gonocyte transformation into SSC. Understanding this process will aid GC tumor diagnostics and fertility potential in boys with UDT undergoing orchidopexy.
Collapse
Affiliation(s)
- Ruili Li
- FD Stephens Surgical Research Group, Murdoch Childrens Research Institute, Parkville, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC 3052, Australia.
| | - Amanda Vannitamby
- FD Stephens Surgical Research Group, Murdoch Childrens Research Institute, Parkville, VIC 3052, Australia
| | - Jian-Guo Zhang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Emma L Fehmel
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Bridget R Southwell
- FD Stephens Surgical Research Group, Murdoch Childrens Research Institute, Parkville, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC 3052, Australia
| | - John M Hutson
- FD Stephens Surgical Research Group, Murdoch Childrens Research Institute, Parkville, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC 3052, Australia; Urology Department, The Royal Children's Hospital, Parkville, VIC 3052, Australia.
| |
Collapse
|
8
|
Zhang C, Lai JH, Hu B, Zhang S, Zhao J, Li W. A chromatin modifier regulates Sertoli cell response to mono-(2-ethylhexyl) phthalate (MEHP) via tissue inhibitor of metalloproteinase 2 (TIMP2) signaling. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:1170-82. [DOI: 10.1016/j.bbagrm.2014.08.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 08/03/2014] [Accepted: 08/11/2014] [Indexed: 10/24/2022]
|
9
|
Li R, Thorup J, Sun C, Cortes D, Southwell B, Hutson J. Immunofluorescent Analysis of Testicular Biopsies with Germ Cell and Sertoli Cell Markers Shows Significant MVH Negative Germ Cell Depletion with Older Age at Orchiopexy. J Urol 2014; 191:458-64. [DOI: 10.1016/j.juro.2013.08.075] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/26/2013] [Indexed: 10/26/2022]
Affiliation(s)
- Ruili Li
- Surgical Research Laboratory, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- Department of Pediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Jorgen Thorup
- Department of Pediatric Surgery, Rigshospitalet, Copenhagen, Denmark
- Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
| | - Cong Sun
- Environmental and Genetic Epidemiology Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- Department of Pediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Dina Cortes
- Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
| | - Bridget Southwell
- Surgical Research Laboratory, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- Department of Pediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - John Hutson
- Surgical Research Laboratory, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- Department of Pediatrics, University of Melbourne, Parkville, Victoria, Australia
- Urology Department, Royal Children’s Hospital, Parkville, Victoria, Australia
| |
Collapse
|
10
|
Li R, Zhang JG, Churchill J, Sourial M, Southwell B, Hutson JM. Reply to letter to the editor. J Pediatr Surg 2013; 48:270. [PMID: 23331830 DOI: 10.1016/j.jpedsurg.2012.10.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 10/24/2012] [Indexed: 11/20/2022]
|
11
|
|