Sertoli Cell Phagocytosis: An Essential Event for Spermatogenesis

During spermatogenesis, most male germ cells undergo apoptosis, and the cytoplasmic portions of the elongating spermatids are shed as residual bodies (RB). Both apoptotic germ cells (AGC) and RB must be phagocytosed by Sertoli cells, which are essential to maintain testicular homeostasis for normal spermatogenesis. The phagocytosis of AGC and RB by Sertoli cells confers various meanings, including elimination of apoptotic components, removal of autoantigens, and the recycle of degenerated substrates as an energy source. Sertoli cell phagocytosis can be regulated by various mechanisms. The impairment of Sertoli cell phagocytosis may disrupt tissue homeostasis in the testis, thereby impairing to testicular function and spermatogenesis. This chapter discusses the mechanisms underlying phagocytic removal of AGC and RB by Sertoli cells and the consequences of this biological event for spermatogenesis and male fertility

Innate Immune Defense in the Male Reproductive System and Male Fertility

To protect the male germ cells from adverse immune reaction, the male reproductive system adopts special immune environment such as immunoprivileged status. The male genital organs can be infected by various microorganisms via hematogenous dissemination and ascending genitourinary tracts. To overcome the immunoprivileged status, the male genital organs also adopt their own innate defense against microbial infection. The tissue-specific cells in the male reproductive system are well equipped with innate immune machineries, including pattern recognition receptors (PRRs) and their negatively regulatory system. PRR-initiated immune responses must be tightly regulated by the negative regulatory system for the maintenance of immune homeostasis. The immune homeostasis can be disrupted by unrestrictive innate immune response, which may lead to inflammatory conditions in the male genital tracts, an important etiological factor contributing to male infertility. This chapter describes the current understanding of the innate immune responses in the male reproductive system and their effects on male fertility

Indigenous sharing, collaboration and synchronous learning

Online learning is progressively accepted in Indigenous communities with the realized potential for sharing, collaboration and learning for adults living in remote and isolated communities. This study used a design-based research approach that provided opportunity to integrate the current literature, literacy practitioners\u27 views and community members\u27 self identified literacy needs to generate ten draft guiding principles which guided this study. A collaborative community engagement project was created by the community members in consideration of these principles and presented in three iterations in a synchronous environment which will lead to design-based principles for working with technology and Indigenous communities. This paper examines the framework and approach for this study, provides a short literature review and presents the draft guiding principles drawn from data collected from the stakeholders and from which the project was created

Leituras da Orfandade família, Declínio do Pai e Ausência de Lei. uma Abordagem do Universo Ficcional de Rubem Fonseca.

RESUMO Observamos na contemporaneidade que a família assume formas diferentes às que possuía quando foi formulada, no século XVIII. Caracterizada por inúmeras transformações, já não possui uma estrutura tão fixa. A partir das narrativas de Henri, A força humana, Feliz ano novo e O cobrador, de Rubem Fonseca; não deixando de visitar outros trabalhos do escritor, discutiremos e examinaremos as configurações da família contemporânea. Neste sentido, analisaremos as representações da relação do sujeito com as novas estruturas familiares, o declínio da imago paterna e as consequências que essas transformações trazem à subjetividade, bem como as formas pelas quais tais relações são encenadas literariamente pelo escritor brasileir

Variability of Bio-Clinical Parameters in Chinese-Origin Rhesus Macaques Infected with Simian Immunodeficiency Virus: A Nonhuman Primate AIDS Model

BACKGROUND: Although Chinese-origin Rhesus macaques (Ch RhMs) infected with simian immunodeficiency virus (SIV) have been used for many years to evaluate the efficacy of AIDS vaccines and therapeutics, the bio-clinical variability of such a nonhuman primate AIDS model was so far not established. METHODOLOGY/PRINCIPAL FINDINGS: By randomizing 150 (78 male and 72 female) Ch RhMs with diverse MHC class I alleles into 3 groups (50 animals per group) challenged with intrarectal (i.r.) SIVmac239, intravenous (i.v.) SIVmac239, or i.v. SIVmac251, we evaluated variability in bio-clinical endpoints for 118 weeks. All SIV-challenged Ch RhMs became seropositive for SIV during 1-2 weeks. Plasma viral load (VL) peaked at weeks 1-2 and then declined to set-point levels as from week 5. The set-point VL was 30 fold higher in SIVmac239 (i.r. or i.v.)-infected than in SIVmac251 (i.v.)-infected animals. This difference in plasma VL increased overtime (>100 fold as from week 68). The rates of progression to AIDS or death were more rapid in SIVmac239 (i.r. or i.v.)-infected than in SIVmac251 (i.v.)-infected animals. No significant difference in bio-clinical endpoints was observed in animals challenged with i.r. or i.v. SIVmac239. The variability (standard deviation) in peak/set-point VL was nearly one-half lower in animals infected with SIVmac239 (i.r. or i.v.) than in those infected with SIVmac251 (i.v.), allowing that the same treatment-related difference can be detected with one-half fewer animals using SIVmac239 than using SIVmac251. CONCLUSION/SIGNIFICANCE: These results provide solid estimates of variability in bio-clinical endpoints needed when designing studies using the Ch RhM SIV model and contribute to the improving quality and standardization of preclinical studies

TAM receptors and the regulation of erythropoiesis in mice

TAM receptors (Tyro3, Axl and Mer) are expressed in hematopoietic tissues, but their roles in hematopoiesis are largely unknown. This study shows that Axl and Mer play an important role in regulating erythropoiesis