Effects of Somatosensory Stimulation on Dream Content in Gymnasts and Control Participants: Evidence of Vestibulomotor Adaptation in REM Sleep

Somatosensory stimulation of the leg muscles in REM sleep appears to perturb virtual orientation in dream experiences. According to our model of vestibulomotor adaptation (Sauvageau, Nielsen, & Montplaisir, 1996), the dreaming mind attempts to compensate for such destabilizing stimulation by increasing eye movement activity or by modifying dream content, among other possible reactions. Effective compensation may be more easily achieved by participants who are adapted to the disruptive stimulation or who possess highly developed vestibulomotor skills. To examine this possibility, we studied the effects of Somatosensory stimulation on the dreams of 6 gymnasts and 6 control participants aged 9 to 16 years. Results provide some support for the expectations that 1) imposed Somatosensory information is processed by the central nervous system in REM sleep, 2) unilateral stimulation induces an upset in virtual orientation, 3) gymnasts are more resistant to these disruptive effects of stimulation than are control participants, and 4) because of long-term adaptation, the dream content of gymnasts does not differ markedly from that of controls. Though preliminary and in need of replication, the findings are compatible with the notion that the developed vestibular skills of gymnasts protects them to some extent from the effects of a disruptive Somatosensory stimulus during sleep.     

Identification of hemorphins in a cathepsin D bovine hemoglobin hydrolysate by radioimmunoassay and photodiode array detections

Summary Morphinomimetic peptides have been purified from hemoglobin enzymatic hydrolysates and a significant amount of evidence has been accumulated indicating that the generation of these peptides (hemorphins) might occur in vivo. In order to investigate their putative physiological role and processing from hemoglobin in vivo, two methods were developed: a specific radioimmunoassay and a UV spectra comparison analysis. These methods were applied to a cathepsin D bovine hemoglobin hydrolysate and allowed the detection of two hemorphin-7 peptides. This observation supports the putative implication of cathepsin D in the in vivo release of hemorphins. Among the two methods used in this study, the immunological approach exhibits higher sensitivity and represents a useful method to investigate the in vivo role and physiological processing of hemorphins.     

Obstructive Sleep Apnoea Modulates Airway Inflammation and Remodelling in Severe Asthma

Background

Obstructive sleep apnoea (OSA) is frequently observed in severe asthma but the causal link between the 2 diseases remains hypothetical. The role of OSA-related systemic and airway neutrophilic inflammation in asthma bronchial inflammation or remodelling has been rarely investigated. The aim of this study was to compare hallmarks of inflammation in induced sputum and features of airway remodelling in bronchial biopsies from adult patients with severe asthma with and without OSA.

Materials and Methods

An overnight polygraphy was performed in 55 patients referred for difficult-to-treat asthma, who complained of nocturnal respiratory symptoms, poor sleep quality or fatigue. We compared sputum analysis, reticular basement membrane (RBM) thickness, smooth muscle area, vascular density and inflammatory cell infiltration in bronchial biopsies.

Results

In total, 27/55 patients (49%) had OSA diagnosed by overnight polygraphy. Despite a moderate increase in apnoea-hypopnoea index (AHI; 14.2±1.6 event/h [5–35]), the proportion of sputum neutrophils was higher and that of macrophages lower in OSA than non-OSA patients, with higher levels of interleukin 8 and matrix metalloproteinase 9. The RBM was significantly thinner in OSA than non-OSA patients (5.8±0.4 vs. 7.8±0.4 μm, p<0.05). RBM thickness and OSA severity assessed by the AHI were negatively correlated (rho = -0.65, p<0.05). OSA and non-OSA patients did not differ in age, sex, BMI, lung function, asthma control findings or treatment.

Conclusion

Mild OSA in patients with severe asthma is associated with increased proportion of neutrophils in sputum and changes in airway remodelling.     

Heat stress reduces the contribution of diazotrophs to coral holobiont nitrogen cycling

Efficient nutrient cycling in the coral-algal symbiosis requires constant but limited nitrogen availability. Coral-associated diazotrophs, i.e., prokaryotes capable of fixing dinitrogen, may thus support productivity in a stable coral-algal symbiosis but could contribute to its breakdown when overstimulated. However, the effects of environmental conditions on diazotroph communities and their interaction with other members of the coral holobiont remain poorly understood. Here we assessed the effects of heat stress on diazotroph diversity and their contribution to holobiont nutrient cycling in the reef-building coral Stylophora pistillata from the central Red Sea. In a stable symbiotic state, we found that nitrogen fixation by coral-associated diazotrophs constitutes a source of nitrogen to the algal symbionts. Heat stress caused an increase in nitrogen fixation concomitant with a change in diazotroph communities. Yet, this additional fixed nitrogen was not assimilated by the coral tissue or the algal symbionts. We conclude that although diazotrophs may support coral holobiont functioning under low nitrogen availability, altered nutrient cycling during heat stress abates the dependence of the coral host and its algal symbionts on diazotroph-derived nitrogen. Consequently, the role of nitrogen fixation in the coral holobiont is strongly dependent on its nutritional status and varies dynamically with environmental conditions.Subject terms: Microbial ecology, Climate-change ecology     

Vascular smooth muscle cell expression of ectonucleotidase CD39 (ENTPD1) is required for neointimal formation in mice

Vascular smooth muscle cell (VSMC) migration and proliferation are critical steps in the pathogenesis of atherosclerosis, post-angioplasty restenosis, neointimal hyperplasia, and chronic allograft rejection. Extracellular nucleotides are known to influence both migration and proliferation of VSMC. Although it is well established that vascular endothelial Cd39/ENTPD1 regulates blood nucleotide concentrations, whether Cd39 associated with VSMC also impacts vascular wall pathology has not been investigated. The objective of this paper is to determine levels of expression of Cd39 on VSMC and functional consequences of gene deletion in vitro and in vivo. Cd39 is the major ectonucleotidase in VSMC, as shown by substantive decreases in ecto-ATPase and -ADPase activity in Cd39-null cells compared to wild type. Significant decreases in neointimal lesion formation are observed in Cd39-null mice at 21 days post arterial balloon injury. Stimulated Cd39-null VSMC have pronounced proliferative responses in vitro. However, using Transwell systems, we show that Cd39-null VSMC fail to migrate in response to ATP, UTP, and PDGF. Cd39 is the dominant ectonucleotidase expressed by VSMC. Deletion of Cd39 in mice results in decreased neointimal formation after vascular injury and is associated with impaired VSMC migration responses in vitro.     

A Comprehensive Analysis of Common and Rare Variants to Identify Adiposity Loci in Hispanic Americans: The IRAS Family Study (IRASFS)

Obesity is growing epidemic affecting 35% of adults in the United States. Previous genome-wide association studies (GWAS) have identified numerous loci associated with obesity. However, the majority of studies have been completed in Caucasians focusing on total body measures of adiposity. Here we report the results from genome-wide and exome chip association studies focusing on total body measures of adiposity including body mass index (BMI), percent body fat (PBF) and measures of fat deposition including waist circumference (WAIST), waist-hip ratio (WHR), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) in Hispanic Americans (n_max = 1263) from the Insulin Resistance Atherosclerosis Family Study (IRASFS). Five SNPs from two novel loci attained genome-wide significance (P<5.00x10^-8) in IRASFS. A missense SNP in the isocitrate dehydrogenase 1 gene (IDH1) was associated with WAIST (rs34218846, MAF = 6.8%, P_DOM = 1.62x10^-8). This protein is postulated to play an important role in fat and cholesterol biosynthesis as demonstrated in cell and knock-out animal models. Four correlated intronic SNPs in the Zinc finger, GRF-type containing 1 gene (ZGRF1; SNP rs1471880, MAF = 48.1%, P_DOM = 1.00x10^-8) were strongly associated with WHR. The exact biological function of ZGRF1 and the connection with adiposity remains unclear. SNPs with p-values less than 5.00x10^-6 from IRASFS were selected for replication. Meta-analysis was computed across seven independent Hispanic-American cohorts (n_max = 4156) and the strongest signal was rs1471880 (P_DOM = 8.38x10^-6) in ZGRF1 with WAIST. In conclusion, a genome-wide and exome chip association study was conducted that identified two novel loci (IDH1 and ZGRF1) associated with adiposity. While replication efforts were inconclusive, when taken together with the known biology, IDH1 and ZGRF1 warrant further evaluation.