Search

The regenerative capabilities of the liver represent a paradigm for understanding tissue repair in solid organs. Regeneration after partial hepatectomy in rodent models is well understood, while regeneration in the context of clinically relevant chronic injuries is less studied. Given the growing incidence of fatty liver disease, cirrhosis, and liver cancer, interest in liver regeneration is increasing. Here, we will review the principles, genetics, and cell biology underlying liver regeneration, as well as new approaches being used to study heterogeneity in liver tissue maintenance and repair.

Depression and related mood disorders constitute an enormous burden on health, quality of life, and the global economy, and women have roughly twice the lifetime risk of men for experiencing depression. Here, we review sex differences in human brain physiology that may be connected to the increased susceptibility of women to major depressive disorder (MDD). Moreover, we summarize decades of preclinical research using animal models for the study of mood dysfunction that uncover some of the potential molecular, cellular, and circuit-level mechanisms that may underlie sex differences and disease etiology. We place particular emphasis on a series of recent studies demonstrating the central contribution of the circuit projecting from ventral hippocampus to nucleus accumbens and how inherent sex differences in the excitability of this circuit may predict and drive depression-related behaviors. The findings covered in this review underscore the continued need for studies using preclinical models and circuit-specific strategies for uncovering molecular and physiological mechanisms that could lead to potential sex-specific diagnosis, prognosis, prevention, and/or treatments for MDD and other mood disorders.

• The placenta is the first organ to form in mammals and is required for establishment of a maternal–fetal vascular interface capable of supplying the bioenergetic needs of the developing conceptus. • Multiple placental cell types engage in highly varied functions, from attachment, invasion, and vascular remodeling to cell fusion, hormone production, and nutrient transport. • Multiple mechanisms allow transport of waste and nutrients across the placenta, including diffusion, transporter protein-mediated (facilitated diffusion and active transporters), and receptor-mediated mechanisms. • The placenta is not an inert transport interface. It consumes 40%–60% of the oxygen and glucose delivered to the uterus at term. Thus conditions that alter placental metabolism can indirectly affect nutrient transport to the fetus. • Maternal and fetal health alter placental function, which in turn influences fetal adaptations and contributes to in utero fetal programming. • Abnormal placentation and placental infections can lead to preeclampsia (PE), fetal growth retardation, or preterm birth, which can have lifelong bearing on health. • In the United States, iatrogenic delivery is responsible for almost half the births that occur between 28 and 37 weeks of gestation, primarily caused by placental pathologies such as PE or intrauterine growth restriction. • Efforts to standardize placental examination after delivery are in progress so that connections between specific placental problems and poor outcomes can be better defined. In parallel, new advanced imaging techniques and biomarkers for placental function are being developed.

• Owing to their cutaneous, immunologic, and renal immaturity, newborns (especially premature neonates) are at increased risk of infection. • As a group of potentially life-threatening but often treatable diseases, infections must always be considered in a newborn with skin lesions. • Prompt diagnosis and initiation of therapy are crucial to prevent devastating long-term sequelae, particularly in instances of disseminated disease. • Staphylococcus aureus, Streptococcus species, Candida albicans, and herpes simplex virus are the most common causes of skin infections in the neonate.