Browsing by Subject "GERM-CELLS"

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  • Kujjo, Loro L.; Laine, Tiina; Pereira, Ricardo J. G.; Kagawa, Wataru; Kurumizaka, Hitoshi; Yokoyama, Shigeyuki; Perez, Gloria I. (2010)
  • Masliukaite, Ieva; Hagen, Julie M.; Jahnukainen, Kirsi; Stukenborg, Jan-Bernd; Repping, Sjoerd; van der Veen, Fulco; van Wely, Madelon; van Pelt, Ans M. M. (2016)
    Objective: To collect published data on spermatogonial quantity in the testes of healthy children and calculate the reference values of spermatogonial quantities throughout prepuberty. Design: Systematic literature search in PubMed and EMBASE focusing on the number of spermatogonia per transverse tubular cross section (S/T) and spermatogonial density per cubic centimeter (cm(3)) of testicular volume (S/V) throughout prepuberty. Setting: None. Patient(s): None. Intervention(s): None. Main Outcome Measure(s): Polynomial meta-regression analyses of S/T and S/V of healthy boys from the ages of 0 to 14 years. Result(s): We found six papers describing original quantitative data on S/T and S/V of healthy boys (total n = 334 and 62, respectively) that were suitable formeta-analysis. Polynomialmeta-regression analyses of S/T and S/V demonstrated a clear pattern of spermatogonial quantity throughout prepubertal life. This consisted of a decline during the first 3 years of life, a gradual increase until the ages of 6 to 7 years, a plateau until the age of 11 years, and a sharp incline reaching pubertal numbers at 13 to 14 years of age. The association between S/T and S/V allowed us to perform S/T to S/V extrapolation, creating reference S/V (rS/V) values throughout prepubertal life from a cohort of 372 boys. Conclusion(s): Spermatogonial quantity varies during testicular development toward puberty. The values found in this study may serve as a baseline clinical reference to study the impact of diseases and adverse effects of gonadotoxic treatments on spermatogonial quantity in prepubertal testes. Spermatogonial quantity reference values may also help to evaluate the quality of testicular biopsy samples acquired for fertility preservation of prepubertal boys. Copyright (C) 2016 The Authors. Published by Elsevier Inc. on behalf of the American Society for Reproductive Medicine.
  • Goossens, E.; Jahnukainen, K.; Mitchell, R. T.; van Pelt, A. M. M.; Pennings, G.; Rives, N.; Poels, J.; Wyns, C.; Lane, S.; Rodriguez-Wallberg, K. A.; Rives, A.; Valli-Pulaski, H.; Steimer, S.; Kliesch, S.; Braye, A.; Andres, M. M.; Medrano, J.; Ramos, L.; Kristensen, S. G.; Andersen, C. Y.; Bjarnason, R.; Orwig, K. E.; Neuhaus, N.; Stukenborg, J. B. (2020)
    BACKGROUND: Infertility is an important side effect of treatments used for cancer and other non-malignant conditions in males. This may be due to the loss of spermatogonial stem cells (SSCs) and/or altered functionality of testicular somatic cells (e.g. Sertoli cells, Leydig cells). Whereas sperm cryopreservation is the first-line procedure to preserve fertility in post-pubertal males, this option does not exist for prepubertal boys. For patients unable to produce sperm and at high risk of losing their fertility, testicular tissue freezing is now proposed as an alternative experimental option to safeguard their fertility. OBJECTIVE AND RATIONALE: With this review, we aim to provide an update on clinical practices and experimental methods, as well as to describe patient management inclusion strategies used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss. SEARCH METHODS: Based on the expertise of the participating centres and a literature search of the progress in clinical practices, patient management strategies and experimental methods used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss were identified. In addition, a survey was conducted amongst European and North American centres/networks that have published papers on their testicular tissue banking activity. OUTCOMES: Since the first publication on murine SSC transplantation in 1994, remarkable progress has been made towards clinical application: cryopreservation protocols for testicular tissue have been developed in animal models and are now offered to patients in clinics as a still experimental procedure. Transplantation methods have been adapted for human testis, and the efficiency and safety of the technique are being evaluated in mouse and primate models. However, important practical, medical and ethical issues must be resolved before fertility restoration can be applied in the clinic. Since the previous survey conducted in 2012, the implementation of testicular tissue cryopreservation as a means to preserve the fertility of prepubertal boys has increased. Data have been collected from 24 co-ordinating centres worldwide, which are actively offering testis tissue cryobanking to safeguard the future fertility of boys. More than 1033 young patients (age range 3 months to 18 years) have already undergone testicular tissue retrieval and storage for fertility preservation. LIMITATIONS, REASONS FOR CAUTION: The review does not include the data of all reproductive centres worldwide. Other centres might be offering testicular tissue cryopreservation. Therefore, the numbers might be not representative for the entire field in reproductive medicine and biology worldwide. The key ethical issue regarding fertility preservation in prepubertal boys remains the experimental nature of the intervention. WIDER IMPLICATIONS: The revised procedures can be implemented by the multi-disciplinary teams offering and/or developing treatment strategies to preserve the fertility of prepubertal boys who have a high risk of fertility loss.