{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T16:04:18Z","timestamp":1791475458924,"version":"4.3.4"},"reference-count":64,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,1,14]],"date-time":"2020-01-14T00:00:00Z","timestamp":1578960000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"German research foundation, Clinical Research Unit","award":["CRU NE 2190\/3-1"],"award-info":[{"award-number":["CRU NE 2190\/3-1"]}]},{"DOI":"10.13039\/501100009591","name":"Ministerium f\u00fcr Innovation, Wissenschaft und Forschung des Landes Nordrhein-Westfalen","doi-asserted-by":"publisher","award":["PtJ-Az: z1403ts006"],"award-info":[{"award-number":["PtJ-Az: z1403ts006"]}],"id":[{"id":"10.13039\/501100009591","id-type":"DOI","asserted-by":"publisher"}]},{"name":"EU-FP7-People-2013-ITN Growsperm","award":["603568"],"award-info":[{"award-number":["603568"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Cancer therapy and conditioning treatments of non-malignant diseases affect spermatogonial function and may lead to male infertility. Data on the molecular properties of spermatogonia and the influence of disease and\/or treatment on spermatogonial subpopulations remain limited. Here, we assessed if the density and percentage of spermatogonial subpopulation changes during development (n = 13) and due to disease and\/or treatment (n = 18) in tissues stored in fertility preservation programs, using markers for spermatogonia (MAGEA4), undifferentiated spermatogonia (UTF1), proliferation (PCNA), and global DNA methylation (5mC). Throughout normal prepubertal testicular development, only the density of 5mC-positive spermatogonia significantly increased with age. In comparison, patients affected by disease and\/or treatment showed a reduced density of UTF1-, PCNA- and 5mC-positive spermatogonia, whereas the percentage of spermatogonial subpopulations remained unchanged. As an exception, sickle cell disease patients treated with hydroxyurea displayed a reduction in both density and percentage of 5mC- positive spermatogonia. Our results demonstrate that, in general, a reduction in spermatogonial density does not alter the percentages of undifferentiated and proliferating spermatogonia, nor the establishment of global methylation. However, in sickle cell disease patients\u2019, establishment of spermatogonial DNA methylation is impaired, which may be of importance for the potential use of this tissues in fertility preservation programs.<\/jats:p>","DOI":"10.3390\/jcm9010224","type":"journal-article","created":{"date-parts":[[2020,1,15]],"date-time":"2020-01-15T10:30:27Z","timestamp":1579084227000},"page":"224","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["Development and Disease-Dependent Dynamics of Spermatogonial Subpopulations in Human Testicular Tissues"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2044-7013","authenticated-orcid":false,"given":"Joana M. D.","family":"Portela","sequence":"first","affiliation":[{"name":"Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 M\u00fcnster, Germany"},{"name":"Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Heckmann","sequence":"additional","affiliation":[{"name":"Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 M\u00fcnster, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joachim","family":"Wistuba","sequence":"additional","affiliation":[{"name":"Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 M\u00fcnster, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1210-2843","authenticated-orcid":false,"given":"Andrea","family":"Sansone","sequence":"additional","affiliation":[{"name":"Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 M\u00fcnster, Germany"},{"name":"Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ans M. M.","family":"van Pelt","sequence":"additional","affiliation":[{"name":"Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sabine","family":"Kliesch","sequence":"additional","affiliation":[{"name":"Center of Reproductive Medicine and Andrology, Department of Clinical and Surgical Andrology, Albert-Schweitzer-Campus 1, Building D11, 48149 M\u00fcnster, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefan","family":"Schlatt","sequence":"additional","affiliation":[{"name":"Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 M\u00fcnster, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nina","family":"Neuhaus","sequence":"additional","affiliation":[{"name":"Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 M\u00fcnster, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,1,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2263","DOI":"10.1210\/jc.2003-031725","article-title":"Klinefelter syndrome in adolescence: Onset of puberty is associated with accelerated germ cell depletion","volume":"89","author":"Wikstrom","year":"2004","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1093\/humupd\/dmi039","article-title":"Natural history of seminiferous tubule degeneration in Klinefelter syndrome","volume":"12","author":"Aksglaede","year":"2006","journal-title":"Hum. Reprod. Update"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1159\/000355599","article-title":"Male germ cell development in humans","volume":"81","author":"Stukenborg","year":"2014","journal-title":"Horm. Res. Paediatr."},{"key":"ref_4","first-page":"2859","article-title":"Is the protein expression window during testicular development affected in patients at risk for stem cell loss?","volume":"30","author":"Ferster","year":"2015","journal-title":"Hum. Reprod."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"636","DOI":"10.1093\/humrep\/dey025","article-title":"A diagnostic germ cell score for immature testicular tissue at risk of germ cell loss","volume":"33","author":"Heckmann","year":"2018","journal-title":"Hum. Reprod."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"296","DOI":"10.1046\/j.1365-2265.2003.01712.x","article-title":"Is inhibin B a potential marker of gonadotoxicity in prepubertal children treated for cancer?","volume":"58","author":"Crofton","year":"2003","journal-title":"Clin. Endocrinol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2613","DOI":"10.1093\/humrep\/dew234","article-title":"Gonadal function in boys with newly diagnosed cancer before the start of treatment","volume":"31","author":"Wigny","year":"2016","journal-title":"Hum. Reprod."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1391","DOI":"10.1016\/j.fertnstert.2003.09.078","article-title":"Sertoli cell inactivation by cytotoxic damage to the human testis after cancer chemotherapy","volume":"81","author":"Maymon","year":"2014","journal-title":"Fertil. Steril."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1460","DOI":"10.1038\/leu.2017.76","article-title":"Decreased spermatogonial quantity in prepubertal boys with leukaemia treated with alkylating agents","volume":"31","author":"Masliukaite","year":"2017","journal-title":"Leukemia"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1677","DOI":"10.1093\/humrep\/dey240","article-title":"Spermatogonial quantity in human prepubertal testicular tissue collected for fertility preservation prior to potentially sterilizing therapy","volume":"33","author":"Stukenborg","year":"2018","journal-title":"Hum. Reprod."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1016\/j.beem.2010.09.007","article-title":"Testicular function and fertility preservation in male cancer patients","volume":"25","author":"Jahnukainen","year":"2011","journal-title":"Best Pract. Res. Clin. Endocrinol. Metab."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1097\/MED.0000000000000156","article-title":"Testicular function and fertility preservation after treatment for haematological cancer","volume":"22","author":"Jahnukainen","year":"2015","journal-title":"Curr. Opin. Endocrinol. Diabetes Obes."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1002\/pbc.24679","article-title":"The cyclophosphamide equivalent dose as an approach for quantifying alkylating agent exposure: A report from the Childhood Cancer Survivor Study","volume":"61","author":"Green","year":"2014","journal-title":"Pediatr. Blood Cancer"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2463","DOI":"10.1093\/humrep\/dev190","article-title":"A European perspective on testicular tissue cryopreservation for fertility preservation in prepubertal and adolescent boys","volume":"30","author":"Picton","year":"2015","journal-title":"Hum. Reprod."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"966","DOI":"10.1093\/humrep\/dez043","article-title":"Testicular tissue cryopreservation: 8 years of experience from a coordinated network of academic centers","volume":"34","author":"Peters","year":"2019","journal-title":"Hum. Reprod."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2012","DOI":"10.1095\/biolreprod.104.028381","article-title":"Immunohistochemical profiling of germ cells within the human fetal testis: Identification of three subpopulations","volume":"71","author":"Gaskell","year":"2004","journal-title":"Biol. Reprod."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"849","DOI":"10.1002\/path.1587","article-title":"Pathobiological implications of the expression of markers of testicular carcinoma in situ by fetal germ cells","volume":"203","author":"Honecker","year":"2004","journal-title":"J. Pathol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2755","DOI":"10.1093\/humrep\/den295","article-title":"Germ cell differentiation in the marmoset (Callithrix jacchus) during fetal and neonatal life closely parallels that in the human","volume":"23","author":"Mitchell","year":"2008","journal-title":"Hum. Reprod."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1093\/molehr\/4.3.227","article-title":"The proliferation of spermatogonia in normal and pathological human seminiferous epithelium: An immunohistochemical study using monoclonal antibodies against Ki-67 protein and proliferating cell nuclear antigen","volume":"4","author":"Steger","year":"1998","journal-title":"Mol. Hum. Reprod."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5113","DOI":"10.1210\/jc.2002-020032","article-title":"Apoptosis and proliferation of human testicular somatic and germ cells during prepuberty: High rate of testicular growth in newborns mediated by decreased apoptosis","volume":"87","author":"Berensztein","year":"2002","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1652","DOI":"10.1016\/j.fertnstert.2016.09.002","article-title":"Establishing reference values for age-related spermatogonial quantity in prepubertal human testes: A systematic review and meta-analysis","volume":"106","author":"Masliukaite","year":"2016","journal-title":"Fertil. Steril."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1530\/REP-11-0290","article-title":"Differential marker protein expression specifies rarefaction zone-containing human Adark spermatogonia","volume":"143","author":"Staege","year":"2012","journal-title":"Reproduction"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3430","DOI":"10.1242\/dev.150284","article-title":"Spermatogonial kinetics in humans","volume":"144","author":"Saracino","year":"2017","journal-title":"Development"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1141","DOI":"10.1038\/s41422-018-0099-2","article-title":"The adult human testis; transcriptional cell atlas","volume":"28","author":"Guo","year":"2018","journal-title":"Cell Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1650","DOI":"10.1016\/j.celrep.2018.10.026","article-title":"The mammalian spermatogenesis single-cell transcriptome, from spermatogonial stem cells to spermatids","volume":"25","author":"Hermann","year":"2018","journal-title":"Cell Rep."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"599","DOI":"10.1016\/j.stem.2018.08.007","article-title":"Single-cell RNA sequencing analysis reveals sequential cell fate transition during human spermatogenesis","volume":"23","author":"Wang","year":"2018","journal-title":"Cell Stem Cell"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1501","DOI":"10.1016\/j.celrep.2019.01.045","article-title":"The neonatal and adult human testis defined at the single-cell level","volume":"26","author":"Sohni","year":"2019","journal-title":"Cell Rep."},{"key":"ref_28","first-page":"3478","article-title":"Identification of MAGE-1 and MAGE-4 proteins in spermatogonia and primary spermatocytes of testis","volume":"55","author":"Takahashi","year":"1995","journal-title":"Cancer Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2778","DOI":"10.1002\/1097-0142(20011201)92:11<2778::AID-CNCR10125>3.0.CO;2-S","article-title":"MAGE-A4, a germ cell specific marker, is expressed differentially in testicular tumors","volume":"92","author":"Aubry","year":"2001","journal-title":"Cancer"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Pohl, E., H\u00f6ffken, V., Schlatt, S., Kliesch, S., Gromoll, J., and Wistuba, J. (2019). Ageing in men with normal spermatogenesis alters spermatogonial dynamics and nuclearmorphology in Sertoli cells. Andrology, in press.","DOI":"10.1111\/andr.12665"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1093\/humrep\/den010","article-title":"Presumed pluripotency markers UTF-1 and REX-1 are expressed in human adult testes and germ cell neoplasms","volume":"23","author":"Kristensen","year":"2008","journal-title":"Hum. Reprod."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1104","DOI":"10.1093\/humrep\/deq053","article-title":"Screening for biomarkers of spermatogonia within the human testis: A whole genome approach","volume":"25","author":"Kirchhoff","year":"2010","journal-title":"Hum. Reprod."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"533","DOI":"10.1016\/j.stem.2017.09.003","article-title":"Chromatin and single-cell RNA-seq profiling reveal dynamic signaling and metabolic transitions during human spermatogonial stem cell development","volume":"21","author":"Guo","year":"2017","journal-title":"Cell Stem Cell"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"545","DOI":"10.1093\/molehr\/gar023","article-title":"Reduced expression of DNMT3B in the germ cells of patients with bilateral spermatogenic arrest does not lead to changes in the global methylation status","volume":"17","author":"Adiga","year":"2011","journal-title":"Mol. Hum. Reprod."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Nettersheim, D., Heukamp, L.C., Fronhoffs, F., Grewe, M.J., Haas, N., Waha, A., Honecker, F., Waha, A., Kristiansen, G., and Schorle, H. (2013). Analysis of TET expression\/activity and 5mC oxidation during normal and malignant germ cell development. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0082881"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1093\/molehr\/gaz017","article-title":"The DNA methylation profile of human spermatogonia at single-cell-and single-allele-resolution refutes its role in spermatogonial stem cell function and germ cell differentiation","volume":"25","author":"Spiess","year":"2019","journal-title":"Mol. Hum. Reprod."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"900","DOI":"10.1038\/nature02633","article-title":"Essential role for de novo DNA methyltransferase Dnmt3a in paternal and maternal imprinting","volume":"429","author":"Kaneda","year":"2004","journal-title":"Nature"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1014","DOI":"10.1093\/humrep\/dev053","article-title":"Aberrant DNA methylation patterns of spermatozoa in men with unexplained infertility","volume":"30","author":"Urdinguio","year":"2015","journal-title":"Hum. Reprod."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1080\/15592294.2016.1248007","article-title":"De novo methylation in male germ cells of the common marmoset monkey occurs during postnatal development and is maintained in vitro","volume":"12","author":"Gromoll","year":"2017","journal-title":"Epigenetics"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1111\/j.1365-2605.1989.tb01328.x","article-title":"Objective measurement of testicular volume by ultrasonography: Evaluation of the technique and comparison with orchidometer estimates","volume":"12","author":"Behre","year":"1989","journal-title":"Int. J. Androl."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2366","DOI":"10.1093\/humrep\/dex306","article-title":"Development of the testis in pre-pubertal boys with cancer after biopsy for fertility preservation","volume":"32","author":"Uijldert","year":"2017","journal-title":"Hum. Reprod."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1111\/andr.12142","article-title":"An alternative interpretation of cellular \u2018selfish spermatogonial selection\u2019-clusters in the human testis indicates the need for 3-D-analyses","volume":"4","author":"Pohl","year":"2016","journal-title":"Andrology"},{"key":"ref_43","unstructured":"Nieschlag, E., Behre, H.M., and Nieschlag, S. (2010). Testicular biopsy and histology. Andrology Male Reproductive Health and Dysfunction, Springer."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1159\/000339010","article-title":"Comparative marker analysis after isolation and culture of testicular cells from the immature marmoset","volume":"196","author":"Albert","year":"2012","journal-title":"Cells Tissues Organs"},{"key":"ref_45","first-page":"535","article-title":"Morphological and histometric study of human spermatogonia from birth to the onset of puberty","volume":"139","author":"Paniagua","year":"1984","journal-title":"J. Anat."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1111\/j.1365-2818.1985.tb02607.x","article-title":"Stereological estimation of the volume weighted mean volume of arbitrary particles observed on random sections","volume":"138","author":"Gundersen","year":"1985","journal-title":"J. Microsc."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"R71","DOI":"10.1530\/REP-15-0436","article-title":"On the origin of sperm epigenetic heterogeneity","volume":"151","author":"Laurentino","year":"2016","journal-title":"Reproduction"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"705","DOI":"10.1101\/gad.6.5.705","article-title":"Developmental pattern of gene-specific DNA methylation in the mouse embryo and germ line","volume":"6","author":"Kafri","year":"1992","journal-title":"Genes Dev."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Kubo, N., Toh, H., Shirane, K., Shirakawa, T., Kobayashi, H., Sato, T., Sone, H., Sato, Y., Tomizawa, S., and Tsurusaki, Y. (2015). DNA methylation and gene expression dynamics during spermatogonial stem cell differentiation in the early postnatal mouse testis. BMC Genom., 16.","DOI":"10.1186\/s12864-015-1833-5"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1354","DOI":"10.4161\/epi.6.11.17993","article-title":"DNA methylation imprinting marks and DNA methyltransferase expression in human spermatogenic cell stages","volume":"6","author":"Marques","year":"2011","journal-title":"Epigenetics"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"701","DOI":"10.1095\/biolreprod.103.016352","article-title":"Homing efficiency and proliferation kinetics of male germ line stem cells following transplantation in mice","volume":"69","author":"Nagano","year":"2003","journal-title":"Biol. Reprod."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"715","DOI":"10.1016\/j.stem.2012.07.017","article-title":"Spermatogonial stem cell transplantation into rhesus testes regenerates spermatogenesis producing functional sperm","volume":"11","author":"Hermann","year":"2012","journal-title":"Cell Stem Cell"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1093\/molehr\/gaw047","article-title":"In vitro differentiation of rat spermatogonia into round spermatids in tissue culture","volume":"22","author":"Reda","year":"2016","journal-title":"Mol. Hum. Reprod."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"611","DOI":"10.1111\/andr.12042","article-title":"Assessment of the optimal vitrification protocol for pre-pubertal mice testes leading to successful in vitro production of flagellated spermatozoa","volume":"3","author":"Dumont","year":"2015","journal-title":"Andrology"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1413","DOI":"10.3389\/fphys.2018.01413","article-title":"Haploid germ cells generated in organotypic culture of testicular tissue from prepubertal boys","volume":"9","author":"Poels","year":"2018","journal-title":"Front. Physiol."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"3813","DOI":"10.1158\/0008-5472.CAN-05-3754","article-title":"Testicular xenografts: A novel approach to study cytotoxic damage in juvenile primate testis","volume":"66","author":"Jahnukainen","year":"2006","journal-title":"Cancer Res."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"5174","DOI":"10.1158\/0008-5472.CAN-12-1317","article-title":"Autologous ectopic grafting of cryopreserved testicular tissue preserves the fertility of prepubescent monkeys that receive sterilizing cytotoxic therapy","volume":"72","author":"Jahnukainen","year":"2012","journal-title":"Cancer Res."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"1188","DOI":"10.1016\/S0022-5347(01)67029-0","article-title":"Quantitative histology of germ cells in the undescended testes of human fetuses, neonates and infants","volume":"154","author":"Cortes","year":"1995","journal-title":"J. Urol."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1022","DOI":"10.1053\/hupa.2000.16280","article-title":"Correlation between testicular biopsies (prepubertal and postpubertal) and spermiogram in cryptorchid men","volume":"31","author":"Nistal","year":"2000","journal-title":"Hum. Pathol."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"458","DOI":"10.1016\/j.juro.2013.08.075","article-title":"Immunofluorescent analysis of testicular biopsies with germ cell and Sertoli cell markers shows significant MVH negative germ cell depletion with older age at orchiopexy","volume":"191","author":"Li","year":"2014","journal-title":"J. Urol."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"1156","DOI":"10.1016\/S0140-6736(01)06274-2","article-title":"The importance of both an early orchidopexy and germ cell maturation for fertility","volume":"358","author":"Hadziselimovic","year":"2001","journal-title":"Lancet"},{"key":"ref_62","first-page":"133","article-title":"Ultramicroscopic studies on the seminiferous tubule in children from birth to puberty. I. Spermatogonia development","volume":"68","author":"Seguchi","year":"1974","journal-title":"Verh. Anat. Ges."},{"key":"ref_63","first-page":"46","article-title":"Infertility in cryptorchidism is linked to the stage of germ cell development at orchidopexy","volume":"68","author":"Hadziselimovic","year":"2007","journal-title":"Horm. Res."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"5664","DOI":"10.1182\/blood-2011-07-368746","article-title":"Epigenetic and molecular profiles of erythroid cells after hydroxyurea treatment in sickle cell anemia","volume":"118","author":"Walker","year":"2011","journal-title":"Blood"}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/9\/1\/224\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T13:19:45Z","timestamp":1760361585000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/9\/1\/224"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,1,14]]},"references-count":64,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2020,1]]}},"alternative-id":["jcm9010224"],"URL":"https:\/\/doi.org\/10.3390\/jcm9010224","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,1,14]]}}}