The human testis undergoes dramatic developmental and structural changes during puberty, including proliferation and maturation of somatic niche cells, and the onset of spermatogenesis. To characterize this understudied process, we profiled and analyzed single-cell transcriptomes of ∼10,000 testicular cells from four boys spanning puberty and compared them to those of infants and adults. During puberty, undifferentiated spermatogonia sequentially expand and differentiate prior to the initiation of gametogenesis. Notably, we identify a common pre-pubertal progenitor for Leydig and myoid cells and delineate candidate factors controlling pubertal differentiation. Furthermore, pre-pubertal Sertoli cells exhibit two distinct transcriptional states differing in metabolic profiles before converging to an alternative single mature population during puberty. Roles for testosterone in Sertoli cell maturation, antimicrobial peptide secretion, and spermatogonial differentiation are further highlighted through single-cell analysis of testosterone-suppressed transfemale testes. Taken together, our transcriptional atlas of the developing human testis provides multiple insights into developmental changes and key factors accompanying male puberty.
Unlike pediatric kidney donors, there is no literature regarding the growth of pediatric donor pancreatic transplant grafts. Our center prospectively followed three pediatric donor grafts after transplant by measuring two dimensions of the graft at postoperative day one and then at one, two, and three months post-transplant surgery with the hypothesis that the grafted pancreas would not grow like pediatric kidney donors given the fundamental physiologic differences between these two organs. Two grafts were stable to minimally larger in size, the third case decreased in size. Interestingly, all patients had an excellent clinical response with normalization of HbA1c. Further study will be required to understand the natural history of pancreatic transplants from a pediatric donor. Volumetric assessment with magnetic resonance imaging (MRI) is proposed as the next step for better evaluation of graft size.
As the population ages, the transplant community will continue to see "elderly" patients with end-stage kidney disease who are seeking transplantation. In this report we describe long-term outcomes of 315 primary kidney transplants performed at the University of Florida in recipients aged > or = 60 years and compare them to results from 3 younger recipient cohorts. Among recipients > or = 60 years, patient survival was significantly worse than for younger recipients but no differences in graft or death-censored graft survival were seen. We suspect that although patient survival was worst in the oldest group, there were likely other causes of graft loss within the younger groups that balanced the effects of death on graft survival in the oldest group. Among recipients aged > or = 60 years, patient survival at 10 years was 55% for living-donor kidney recipients and 46% for deceased-donor kidney recipients. African-American recipients had a higher risk of mortality and graft loss in all age groups after deceased donor kidney transplantation but not after living donor transplantation. Delayed graft function negatively impacted outcomes among all recipients and the adverse effects were greater after deceased donor than living donor transplantation. These effects were also seen within the oldest recipient age group. Increased donor age was a significant risk factor for death and graft loss among all age groups after deceased donor kidney transplantation but not among living-donor kidney recipients. More specifically, recipients aged > or = 60 years who received kidneys from donors > or = 60 years demonstrated significantly worse outcomes when compared to those receiving donor kidneys < 60 years. The presence of diabetes mellitus in recipients > or = 60 years was not a significant risk factor for mortality or graft loss after transplantation. Acceptable results can be obtained after kidney transplantation in recipients aged > or = 60 years. Future investigations should focus on improving recipient selection in the elderly population, identifying strategies to minimize DGF in deceased donor kidneys, understanding all variables involved in the risk associated with recipient race, and increasing living donor transplantation across all age groups.
