Physiological activation of the nephron central command drives endogenous kidney tissue regeneration

Tissue regeneration is limited in several organs including the kidney, contributing to the high prevalence of kidney disease globally. However, evolutionary and physiological adaptive responses and the presence of renal progenitor cells suggest existing remodeling capacity. This study uncovered a novel endogenous tissue remodeling mechanism in the kidney that is activated by the loss of body fluid and salt and involves a unique niche of chief cells called macula densa (MD) that control resident progenitor cells via secreted angiogenic, growth and extracellular matrix remodeling factors, cytokines and chemokines. Serial intravital imaging, MD Wnt mouse models and transcriptome analysis provide functional and molecular characterization of this newly identified MD program for kidney regeneration complemented with human and therapeutic translation. The concept that chief cells responding to organ-specific physiological inputs control local progenitors and direct them to remodel or repair tissues may be applicable to other organs and diverse tissue regenerative therapeutic strategies.

Antimicrobial peptides of human saliva

Among the many functions of human saliva, its digestive and protective properties have attracted the most interest. Human saliva contains a number of physical, physicochemical and chemical agents that protect oral tissues against by various microorganisms and their metabolic products. Among such protective factors, the flushing effect of saliva flow is the most important one, not only because it so effectively removes exogenous and endogenous microorganisms and their products into the gut but also because a steady supply of saliva guarantees continuous presence of both non-immune and immune factors in the mouth. The most important antimicrobial peptides in saliva are: histatins, defensins, lactoferrin, cathelicidins, mucins, calprotectin, lysozyme, oral peroxidase. Antimicrobial peptides are components of complex host secretions, acting synergisticaly with other innate defence molecules to combat infection and control resident microbial populations throughout the oral cavity.

Meaningful social interactions between older people in institutional care settings

This paper is a contribution to the developing understanding of social relationships in institutional care settings. It focuses on two areas that have been neglected in research: the reasons for and types of social interaction in institutional settings, and the ways in which the context of people's lives shapes social interaction. The paper draws on ethnographic observations conducted in four care settings in Scotland using a symbolic interactionist perspective. It finds that residents communicate and interact, and that the personal, cultural and structural contexts frame social interaction and influence the ways that residents use humour, express sexuality, and show hostility. The paper concludes that residents create social interactions in which action is embedded, but do so within specific structural and cultural contexts. These contexts ‘control’ resident action by establishing frameworks for the interpretation of meaning. At the same time, each facet of context is ‘controlled’ by the ways in which residents actively take on the ‘role’ of others, and project ‘self’ and a ‘label’.