In adulthood, the main function of the testes is the production of male gametes. In this process, Sertoli cells are essential for sustained spermatogenesis, providing the developing germ cells with the physical and nutritional support required. The total number of Sertoli cells in adulthood determines the daily gamete production, since Sertoli cells can support only a limited number of developing germ cells. Considering that Sertoli cell proliferation only occurs during the immature period, proper development and proliferation of the Sertoli cells during the proliferative phase are crucial to male reproductive health in adulthood. The proliferation process of the Sertoli cells is finely regulated by an assortment of hormonal and paracrine/autocrine factors, which regulate the rate and extent of proliferation. In the present review, we discuss the most important hormonal and paracrine factors involved in the regulation of Sertoli cell proliferation, as well as the signaling mechanisms by which they exert their effects.

Aims: In-depth and updated systematic reviews evaluating telephone calls in type 2 diabetes (T2DM) management are missing. This study aimed to assess the effect of this intervention on glycemic control in T2DM patients when compared with usual care. Methods: We systematically searched for randomized controlled trials (RCT) on T2DM using Medline, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and LILACS, up to March 2021. The Risk of Bias 2.0 (Rob 2.0) tool and GRADE were used for the quality evaluation. The intervention effect was estimated by the change in glycated hemoglobin (HbA1c). PROSPERO registry CRD42020204519. Results: 3545 references were reviewed and 32 were included (8598 patients). Telephone calls, all approaching education, improved HbA1c by 0.33% [95% CI, −0.48% to −0.18%; I² = 78%; p < 0.0001] compared to usual care. A greater improvement was found when the intervention included pharmacologic modification (−0.82%, 95% CI, −1.42% to −0.22%; I² = 92%) and when it was applied by nurses (−0.53%, 95% CI, −0.86% to −0.2%; I² = 87%). Meta-regression showed no relationship between DM duration and HbA1c changes. Conclusion: The telephone call intervention provided a benefit regarding T2DM glycemic control, especially if provided by nurses, or if associated with patient education and pharmacological treatment modification.