Cortisol during human fetal life: Characterization of a method for processing small quantities of newborn hair from 26 to 42 weeks gestation.

OBJECTIVE: Fetal cortisol may be reflected in hair collected shortly after birth. The objective of this study was to determine the range of human fetal hair cortisol concentrations (HCC) in live-born neonates using an approach for processing small quantities of hair. MATERIALS AND METHODS: Hair was cut on the day of birth from neonates and their mothers, born between 26 and 42 weeks gestational age (GA). HCC was determined by enzyme immunoassay. Maternal sociodemographics and birth data were collected. T-tests, ANOVA, Pearson correlation, and Wilcoxon Signed Rank test were used as appropriate. RESULTS: Ninety maternal and neonatal hair samples were cut from 79 term (T) and 11 preterm (PT) delivered pregnancies. All samples weighed ≥2.5 mg. Fetal HCC correlated with GA (r = .25, p = .02) and birth weight (r = .25, p = .03) and was lower in PT (4.3 ± .3 LN pg/mg) than T (5.3 ± .1, LN pg/mg, p < .001) neonates. No significant relationships were seen between fetal HCC and maternal characteristics or maternal HCC. Fetal HCC was significantly higher than maternal HCC. CONCLUSION: Fetal cortisol exposure was determined using this approach for processing small amounts of hair. Preterm neonates have significantly lower HCC than term neonates and fetal HCC is associated with GA at delivery and birth weight. Fetal HCC is significantly higher than maternal HCC cut on the same day. These data provide novel information on the intrauterine fetal cortisol environment.

YAP-dependent mechanotransduction is required for proliferation and migration on native-like substrate topography.

Native vascular extracellular matrices (vECM) consist of elastic fibers that impart varied topographical properties, yet most in vitro models designed to study the effects of topography on cell behavior are not representative of native architecture. Here, we engineer an electrospun elastin-like protein (ELP) system with independently tunable, vECM-mimetic topography and demonstrate that increasing topographical variation causes loss of endothelial cell-cell junction organization. This loss of VE-cadherin signaling and increased cytoskeletal contractility on more topographically varied ELP substrates in turn promote YAP activation and nuclear translocation, resulting in significantly increased endothelial cell migration and proliferation. Our findings identify YAP as a required signaling factor through which fibrous substrate topography influences cell behavior and highlights topography as a key design parameter for engineered biomaterials.

A randomized controlled pilot study of inflammatory gene expression in response to a stress management intervention for stem cell transplant caregivers.

Few studies have addressed whether stress-associated physiological changes in caregivers are reversible by psychological interventions mitigating distress. We report on pro-inflammatory, sympathetic, and oxidative stress gene expression in response to stress management for caregivers of allogeneic hematopoietic stem cell transplant (Allo-HSCT) patients. Following randomization by permuted block to either treatment as usual (TAU, n = 11) or a stress management intervention (PsychoEducation, Paced Respiration, and Relaxation, PEPRR, n = 13), twenty-four caregivers were selected at the conclusion of a larger trial of 149 caregivers. PEPRR was provided one-on-one beginning around transplant. Genome-wide transcriptional profiling was conducted on peripheral blood mononuclear cells collected prior to randomization and on completion of PEPRR 3 months post-transplant. Bioinformatics analysis of differentially expressed genes indicated reduced activity of transcription control pathways associated with inflammation (NF-κB), sympathetic nervous system (CREB), and oxidative stress (NRF2) in caregivers receiving PEPRR compared to TAU aligning with reductions in stress, depression, and anxiety. This suggests that PEPRR may alter transcriptomic effects reported for distressed individuals.

Use of protein-engineered fabrics to identify design rules for integrin ligand clustering in biomaterials.

While ligand clustering is known to enhance integrin activation, this insight has been difficult to apply to the design of implantable biomaterials because the local and global ligand densities that enable clustering-enhanced integrin signaling were unpredictable. Here, two general design principles for biomaterial ligand clustering are elucidated. First, clustering ligands enhances integrin-dependent signals when the global ligand density, i.e., the ligand density across the cellular length scale, is near the ligand's effective dissociation constant (KD,eff). Second, clustering ligands enhances integrin activation when the local ligand density, i.e., the ligand density across the length scale of individual focal adhesions, is less than an overcrowding threshold. To identify these principles, we fabricated a series of elastin-like, electrospun fabrics with independent control over the local (0 to 122 000 ligands µm(-2)) and global (0 to 71 000 ligand µm(-2)) densities of an arginine-glycine-aspartate (RGD) ligand. Antibody blocking studies confirmed that human umbilical vein endothelial cell adhesion to these protein-engineered biomaterials was primarily due to αVß3 integrin binding. Clustering ligands enhanced cell proliferation, focal adhesion number, and focal adhesion kinase expression near the ligand's KD,eff of 12 000 RGD µm(-2). Near this global ligand density, cells on ligand-clustered fabrics behaved similarly to cells grown on fabrics with significantly larger global ligand densities but without clustering. However, this enhanced ligand-clustering effect was not observed above a threshold cut-off concentration. At a local ligand density of 122 000 RGD µm(-2), cell division, focal adhesion number, and focal adhesion kinase expression were significantly reduced relative to fabrics with identical global ligand density and lesser local ligand densities. Thus, when clustering results in overcrowding of ligands, integrin receptors are no longer able to effectively engage with their target ligands. Together, these two insights into the cellular responses to ligand clustering at the cell-matrix interface may serve as design principles when developing future generations of implantable biomaterials.

Chemical processing and shampooing impact cortisol measured in human hair.

PURPOSE: The assessment of cortisol in hair has gained popularity as a means to measure retrospective hypothalamic-pituitary-adrenal activity in a number of species; however, cortisol levels from human hair subjected to typical chemicals for cosmetic or hygienic purposes may be altered by the chemicals used. The purposed of this study was to determine if exposure of hair to chemical processing or shampooing impacts cortisol values. METHODS: Human hair not exposed to prior chemical processing was cut from the posterior vertex region of the head of 106 human subjects as close to the scalp as possible. The hair sample was divided into 4-6 full-length clusters depending on quantity of hair available. Each hair sample was processed for baseline (native) cortisol and remaining clusters were exposed to five standard chemical hair treatments (Experiment 1) or were shampooed 15 or 30 times (Experiment 2). Hair was ground and cortisol levels were determined by enzyme immunoassay (EIA). Comparisons were made between native hair and processed hair using paired t-tests and Pearson correlation. RESULTS: Hair cortisol as assessed by EIA was significantly altered by chemical processing but in somewhat different ways. Exposure to bleach (harshest exposure), demi-perm (least exposure) or 15-30 shampoos resulted in a significant decrease in cortisol level while exposure to varying percentages of peroxides increased cortisol measured. There were no differences in cortisol levels associated with sex, age or tobacco use in the native hair for this particular group. CONCLUSION: Chemical processing and frequent shampooing affect cortisol levels measured in hair. Chemically processed or excessively shampooed hair should be avoided when recruiting subjects for hair cortisol studies.

Kinetic and mechanistic insight into the thermodynamic degradation of saxagliptin.

The dipeptidyl peptidase-IV inhibitor saxagliptin (Onglyza) can undergo a thermodynamically favored cyclization to form the corresponding cyclic amidine. The kinetics and mechanism of this conversion were examined to develop a commercial synthesis that afforded saxagliptin with only trace levels of this key byproduct. Important findings of this work are the identification of a profound solvent effect and the determination of an autocatalytic pathway. Both of these phenomena result from transition structures involving proton transfer.

Inhibition of SOCS1-/- lethal autoinflammatory disease correlated to enhanced peripheral Foxp3+ regulatory T cell homeostasis.

Suppressor of cytokine signaling 1-deficient (SOCS1(-/-)) mice, which are lymphopenic, die <3 wk after birth of a T cell-mediated autoimmune inflammatory disease characterized by leukocyte infiltration and destruction of vital organs. Notably, Foxp3(+) regulatory T cells (Tregs) have been shown to be particularly potent in inhibiting inflammation-associated autoimmune diseases. We observed that SOCS1(-/-) mice were deficient in peripheral Tregs despite enhanced thymic development. The adoptive transfer of SOCS1-sufficient Tregs, CD4(+) T lymphocytes, or administration of SOCS1 kinase inhibitory region (KIR), a peptide that partially restores SOCS1 function, mediated a statistically significant but short-term survival of SOCS1(-/-) mice. However, the adoptive transfer of SOCS1-sufficient CD4(+) T lymphocytes, combined with the administration of SOCS1-KIR, resulted in a significant increase in the survival of SOCS1(-/-) mice both short and long term, where 100% death occurred by day 18 in the absence of treatment. Moreover, the CD4(+)/SOCS1-KIR combined therapy resulted in decreased leukocytic organ infiltration, reduction of serum IFN-γ, and enhanced peripheral accumulation of Foxp3(+) Tregs in treated mice. These data show that CD4(+)/SOCS1-KIR combined treatment can synergistically promote the long-term survival of perinatal lethal SOCS1(-/-) mice. In addition, these results strongly suggest that SOCS1 contributes to the stability of the Foxp3(+) Treg peripheral population under conditions of strong proinflammatory environments.

Inhibition of type 1 diabetes correlated to a Lactobacillus johnsonii N6.2-mediated Th17 bias.

Although it is known that resident gut flora contribute to immune system function and homeostasis, their role in the progression of the autoimmune disease type 1 diabetes (T1D) is poorly understood. Comparison of stool samples isolated from Bio-Breeding rats, a classic model of T1D, shows that distinct bacterial populations reside in spontaneous Bio-Breeding diabetes-prone (BBDP) and Bio-Breeding diabetes-resistant animals. We have previously shown that the oral transfer of Lactobacillus johnsonii strain N6.2 (LjN6.2) from Bio-Breeding diabetes-resistant to BBDP rodents conferred T1D resistance to BBDP rodents, whereas Lactobacillus reuteri strain TD1 did not. In this study, we show that diabetes resistance in LjN6.2-fed BBDP rodents was correlated to a Th17 cell bias within the mesenteric lymph nodes. The Th17 bias was not observed in the non-gut-draining axillary lymph nodes, suggesting that the Th17 bias was because of immune system interactions with LjN6.2 within the mesenteric lymph node. LjN6.2 interactions with the immune system were observed in the spleens of diabetes-resistant, LjN6.2-fed BBDP rats, as they also possessed a Th17 bias in comparison with control or Lactobacillus reuteri strain TD1-fed rats. Using C57BL/6 mouse in vitro assays, we show that LjN6.2 directly mediated enhanced Th17 differentiation of lymphocytes in the presence of TCR stimulation, which required APCs. Finally, we show that footpad vaccination of NOD mice with LjN6.2-pulsed dendritic cells was sufficient to mediate a Th17 bias in vivo. Together, these data suggest an interesting paradigm whereby T1D induction can be circumvented by gut flora-mediated Th17 differentiation.

Modeling fatigue over sleep deprivation, circadian rhythm, and caffeine with a minimal performance inhibitor model.

Sleep loss, as well as concomitant fatigue and risk, is ubiquitous in today's fast-paced society. A biomathematical model that succeeds in describing performance during extended wakefulness would have practical utility in operational environments and could help elucidate the physiological basis of sleep loss effects. Eighteen subjects (14 males, 4 females; age 25.8 +/- 4.3 years) with low levels of habitual caffeine consumption (<300 mg/day) participated. On night 1, subjects slept for 8 h (2300-0700 h), followed by 77 h of continuous wakefulness. They were assigned randomly to receive placebo or caffeine (200 mg, i.e., two sticks of Stay Alert gum) at 0100, 0300, 0500, and 0700 during nights 2, 3, and 4. The psychomotor vigilance test (PVT) was administered periodically over the 77-h period of continuous wakefulness. Statistical analysis reveals lognormality in each PVT, allowing for closed-form median calculation. An iterative parameter estimation algorithm, which takes advantage of MatLab's (R2007a) least-squares nonlinear regression, is used to estimate model parameters from subjects' PVT medians over time awake. In the model, daily periodicity is accounted for with a four-component Fourier series, and a simplified binding function describes asymptotic fatigue. The model highlights patterns in data that suggest (1) the presence of a performance inhibitor that increases and saturates over the period of continuous wakefulness, (2) competitive inhibition of this inhibitor by caffeine, (3) the persistence of an internally driven circadian rhythm of alertness, and (4) a multiplicative relationship between circadian rhythm and performance inhibition. The present inhibitor-based minimal model describes performance data in a manner consistent with known biochemical processes.