Hair Collection for Cortisol Among Youth Experiencing Homelessness.

Background: Investigations of chronic physiological stress measured by hair cortisol are rapidly expanding among community samples of adolescents and adults. However, research examining physiological stress among youth experiencing homelessness is nascent despite the youth's increased risk for adverse exposures and subsequent impaired mental health.

Objective: This article aimed to examine the feasibility of collecting hair for measuring cortisol among diverse youth experiencing homelessness and gain an understanding of variation in participation.

Protocol to Measure Hair Cortisol in Low Mass Samples From Very Preterm Infants.

Background: Hair cortisol is a measure of chronic or repeated hypothalamic-pituitary-adrenal axis activation in response to physical or psychological stressors. Hair cortisol has been successfully used as a measure of chronic stress in adults and children; however, its use as a valid measure in preterm infants has been limited by challenges in measuring cortisol in the low mass samples collectable from these infants.

Objectives: The purpose of this report is to present a novel protocol for the measurement of hair cortisol in very low mass hair samples.

Collecting Hair Samples for Hair Cortisol Analysis in African Americans.

The hormone cortisol is typically assessed in saliva, serum, or urine samples. More recently, cortisol has been successfully extracted from hair, including humans. The advantage of hair cortisol concentration is that it reflects a retrospective representation of hypothalamic-pituitary-adrenal (HPA) axis function over time, much like hemoglobin A1C represents glycemic control.

Supplementation with eicosapentaenoic acid and docosahexaenoic acid reduces high levels of circulating proinflammatory cytokines in aging adults: A randomized, controlled study.

Background: High levels of circulating proinflammatory cytokines are characteristic of inflammaging, a term coined to describe age-related chronic systemic inflammation involved in the etiology of many age-related disorders including nonhealing wounds. Some studies have shown that supplementing diets with n-3 polyunsaturated fatty acids (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) lowers systemic levels of key proinflammatory cytokines associated with inflammaging. However, findings from the few studies that have focused exclusively on older adults are inconclusive.

Oxytocin Levels in Community-Collected Saliva Samples Transported by Dry Versus Wet Ice.

Oxytocin (OT), a neuropeptide produced primarily in the hypothalamus, is associated with both critical physiological and psychological processes, particularly stress and feelings of affiliation. Increasingly, researchers are seeking ways to reliably incorporate OT as an outcome biomarker in clinical research. Previously, OT levels were measured in plasma or urine.

Manipulation of oxygenation and flow-induced shear stress can increase the in vitro yield of platelets from cord blood.

A method to produce clinically useful platelets in vitro would help overcome the frequent shortages, donor deferrals, disease transmission, and alloimmunization with volunteer donor-derived platelets. Using CD34 positively selected cord blood cells, we investigated ways to increase platelet quality and yield in a three-dimensional modular perfusion bioreactor system. We found a two- to threefold increase in platelet numbers produced only when the early phases of the culture process were carried out at 5% oxygen, versus when 20% oxygen was used throughout the culture period (p<0.

Effect of increased HoxB4 on human megakaryocytic development.

In order to produce clinically useful quantities of platelets ex vivo we may need to firstly enhance early self-renewal of hematopoietic stem cells (HSCs) and/or megakaryocyte (Mk) progenitors. The homeodomain transcription factor HoxB4 has been shown to be an important regulator of stem cell renewal and hematopoiesis; however, its effect on megakaryopoiesis is unclear. In this study, we investigated the effect of HoxB4 overexpression or RNA silencing on megakaryocytic development in the human TF1 progenitor cell line; we then used recombinant tPTD-HoxB4 fusion protein to study the effect of exogenous HoxB4 on megakaryocytic development of human CD34 positively-selected cord blood cells.

Prolonged continuous in vitro human platelet production using three-dimensional scaffolds.

Objective: Methods producing human platelets using growth on plastic, on feeder layers, or in suspension have been described. We hypothesized that growth of hematopoietic progenitors in a three-dimensional (3D) scaffold would enhance platelet production sans feeder layer.

Materials And Methods: We grew CD34 positively selected human cord blood cells in surgical-grade woven polyester fabric or purpose-built hydrogel scaffolds using a cocktail of cytokines.

Transgene expression after stable transfer of a mammalian artificial chromosome into human hematopoietic cells.

Objective: The transfer of mammalian artificial chromosomes (MACs) to hematopoietic stem and progenitor cells (HSPCs) presents a promising new strategy for ex vivo gene therapy that alleviates numerous concerns surrounding viral transduction along with a unique platform for the systematic study of stem cell biology and fate. Here we report the transfer of a satellite DNA-based artificial chromosome (an ACE), made in mouse cells, into human cord blood hematopoietic cells.

Materials And Methods: A GFP-Zeo-ACE encoding the genes for humanized Renilla green fluorescence protein (hrGFP) and zeomycin resistance (zeo) was transferred into CD34 positively selected cord blood cells using cationic reagents.