Cystic Fibrosis Lung Transplant Recipients Have Suppressed Airway Interferon Responses during Pseudomonas Infection.

Lung transplantation can be lifesaving in end-stage cystic fibrosis (CF), but long-term survival is limited by chronic lung allograft dysfunction (CLAD). Persistent upper airway Pseudomonas aeruginosa (PsA) colonization can seed the allograft. While de novo PsA infection is associated with CLAD in non-CF recipients, this association is less clear for CF recipients experiencing PsA recolonization. Here, we evaluate host and pathogen contributions to this phenomenon. In the context of PsA infection, brushings from the airways of CF recipients demonstrate type 1 interferon gene suppression. Airway epithelial cell (AEC) cultures demonstrate similar findings in the absence of pathogens or immune cells, contrasting with the pre-transplant CF AEC phenotype. Type 1 interferon promoters are relatively hypermethylated in CF AECs. CF subjects in this cohort have more mucoid PsA, while non-CF PsA subjects have decreased microbiome α diversity. Peri-transplant protocols may benefit from consideration of this host and microbiome equilibrium.

A Multicenter Collaboration for Simulation-Based Assessment of ACGME Milestones in Emergency Medicine.

STATEMENT: In 2014, the six allopathic emergency medicine (EM) residency programs in Chicago established an annual, citywide, simulation-based assessment of all postgraduate year 2 EM residents. The cases and corresponding assessment tools were designed by the simulation directors from each of the participating sites. All assessment tools include critical actions that map directly to numerous EM milestones in 11 different subcompetencies. The 2-hour assessments provide opportunities for residents to lead resuscitations of critically ill patients and demonstrate procedural skills, using mannequins and task trainers respectively. More than 80 residents participate annually and their assessment experiences are essentially identical across testing sites. The assessments are completed electronically and comparative performance data are immediately available to program directors.

Cadherin-26 (CDH26) regulates airway epithelial cell cytoskeletal structure and polarity.

Polarization of the airway epithelial cells (AECs) in the airway lumen is critical to the proper function of the mucociliary escalator and maintenance of lung health, but the cellular requirements for polarization of AECs are poorly understood. Using human AECs and cell lines, we demonstrate that cadherin-26 (CDH26) is abundantly expressed in differentiated AECs, localizes to the cell apices near ciliary membranes, and has functional cadherin domains with homotypic binding. We find a unique and non-redundant role for CDH26, previously uncharacterized in AECs, in regulation of cell-cell contact and cell integrity through maintaining cytoskeletal structures. Overexpression of CDH26 in cells with a fibroblastoid phenotype increases contact inhibition and promotes monolayer formation and cortical actin structures. CDH26 expression is also important for localization of planar cell polarity proteins. Knockdown of CDH26 in AECs results in loss of cortical actin and disruption of CRB3 and other proteins associated with apical polarity. Together, our findings uncover previously unrecognized functions for CDH26 in the maintenance of actin cytoskeleton and apicobasal polarity of AECs.

IL1RL1 asthma risk variants regulate airway type 2 inflammation.

Genome-wide association studies of asthma have identified genetic variants in the IL1RL1 gene, but the molecular mechanisms conferring risk are unknown. IL1RL1 encodes the ST2 receptor (ST2L) for IL-33 and an inhibitory decoy receptor (sST2). IL-33 promotes type 2 inflammation, which is present in some but not all asthmatics. We find that two single nucleotide polymorphisms (SNPs) in IL1RL1 - rs1420101 and rs11685480 - are strongly associated with plasma sST2 levels, though neither is an expression quantitative trait locus (eQTL) in whole blood. Rather, rs1420101 and rs11685480 mark eQTLs in airway epithelial cells and distal lung parenchyma, respectively. We find that the genetically determined plasma sST2 reservoir, derived from the lung, neutralizes IL-33 activity, and these eQTL SNPs additively increase the risk of airway type 2 inflammation among asthmatics. These risk variants define a population of asthmatics at risk of IL-33-driven type 2 inflammation.

Paper Tape Prevents Foot Blisters: A Randomized Prevention Trial Assessing Paper Tape in Endurance Distances II (Pre-TAPED II).

OBJECTIVE: To determine whether paper tape prevents foot blisters in multistage ultramarathon runners. DESIGN: Multisite prospective randomized trial. SETTING: The 2014 250-km (155-mile) 6-stage RacingThePlanet ultramarathons in Jordan, Gobi, Madagascar, and Atacama Deserts. PARTICIPANTS: One hundred twenty-eight participants were enrolled: 19 (15%) from the Jordan, 35 (27%) from Gobi, 21 (16%) from Madagascar, and 53 (41%) from the Atacama Desert. The mean age was 39.3 years (22-63) and body mass index was 24.2 kg/m (17.4-35.1), with 31 (22.5%) females. INTERVENTIONS: Paper tape was applied to a randomly selected foot before the race, either to participants' blister-prone areas or randomly selected location if there was no blister history, with untaped areas of the same foot used as the control. MAIN OUTCOME MEASURES: Development of a blister anywhere on the study foot. RESULTS: One hundred six (83%) participants developed 117 blisters, with treatment success in 98 (77%) runners. Paper tape reduced blisters by 40% (P < 0.01, 95% confidence interval, 28-52) with a number needed to treat of 1.31. Most of the study participants had 1 blister (78%), with most common locations on the toes (n = 58, 50%) and heel (n = 27, 23%), with 94 (80%) blisters occurring by the end of stage 2. Treatment success was associated with earlier stages [odds ratio (OR), 74.9, P < 0.01] and time spent running (OR, 0.66, P = 0.01). CONCLUSION: Paper tape was found to prevent both the incidence and frequency of foot blisters in runners.

Phosphoproteomics Identifies CK2 as a Negative Regulator of Beige Adipocyte Thermogenesis and Energy Expenditure.

Catecholamines promote lipolysis both in brown and white adipocytes, whereas the same stimuli preferentially activate thermogenesis in brown adipocytes. Molecular mechanisms for the adipose-selective activation of thermogenesis remain poorly understood. Here, we employed quantitative phosphoproteomics to map global and temporal phosphorylation profiles in brown, beige, and white adipocytes under ß3-adrenenoceptor activation and identified kinases responsible for the adipose-selective phosphorylation profiles. We found that casein kinase2 (CK2) activity is preferentially higher in white adipocytes than brown/beige adipocytes. Genetic or pharmacological blockade of CK2 in white adipocytes activates the thermogenic program in response to cAMP stimuli. Such activation is largely through reduced CK2-mediated phosphorylation of class I HDACs. Notably, inhibition of CK2 promotes beige adipocyte biogenesis and leads to an increase in whole-body energy expenditure and ameliorates diet-induced obesity and insulin resistance. These results indicate that CK2 is a plausible target to rewire the ß3-adrenenoceptor signaling cascade that promotes thermogenesis in adipocytes.

ThermoMouse: an in vivo model to identify modulators of UCP1 expression in brown adipose tissue.

Obesity develops when energy intake chronically exceeds energy expenditure. Because brown adipose tissue (BAT) dissipates energy in the form of heat, increasing energy expenditure by augmenting BAT-mediated thermogenesis may represent an approach to counter obesity and its complications. The ability of BAT to dissipate energy is dependent on expression of mitochondrial uncoupling protein 1 (UCP1). To facilitate the identification of pharmacological modulators of BAT UCP1 levels, which may have potential as antiobesity medications, we developed a transgenic model in which luciferase activity faithfully mimics endogenous UCP1 expression and its response to physiologic stimuli. Phenotypic screening of a library using cells derived from this model yielded a small molecule that increases UCP1 expression in brown fat cells and mice. Upon adrenergic stimulation, compound-treated mice showed increased energy expenditure. These tools offer an opportunity to identify pharmacologic modulators of UCP1 expression and uncover regulatory pathways that impact BAT-mediated thermogenesis.

EHMT1 controls brown adipose cell fate and thermogenesis through the PRDM16 complex.

Brown adipose tissue (BAT) dissipates chemical energy in the form of heat as a defence against hypothermia and obesity. Current evidence indicates that brown adipocytes arise from Myf5(+) dermotomal precursors through the action of PR domain containing protein 16 (PRDM16) transcriptional complex. However, the enzymatic component of the molecular switch that determines lineage specification of brown adipocytes remains unknown. Here we show that euchromatic histone-lysine N-methyltransferase 1 (EHMT1) is an essential BAT-enriched lysine methyltransferase in the PRDM16 transcriptional complex and controls brown adipose cell fate. Loss of EHMT1 in brown adipocytes causes a severe loss of brown fat characteristics and induces muscle differentiation in vivo through demethylation of histone 3 lysine 9 (H3K9me2 and 3) of the muscle-selective gene promoters. Conversely, EHMT1 expression positively regulates the BAT-selective thermogenic program by stabilizing the PRDM16 protein. Notably, adipose-specific deletion of EHMT1 leads to a marked reduction of BAT-mediated adaptive thermogenesis, obesity and systemic insulin resistance. These data indicate that EHMT1 is an essential enzymatic switch that controls brown adipose cell fate and energy homeostasis.

Human BAT possesses molecular signatures that resemble beige/brite cells.

Brown adipose tissue (BAT) dissipates chemical energy and generates heat to protect animals from cold and obesity. Rodents possess two types of UCP-1 positive brown adipocytes arising from distinct developmental lineages: "classical" brown adipocytes develop during the prenatal stage whereas "beige" or "brite" cells that reside in white adipose tissue (WAT) develop during the postnatal stage in response to chronic cold or PPARγ agonists. Beige cells' inducible characteristics make them a promising therapeutic target for obesity treatment, however, the relevance of this cell type in humans remains unknown. In the present study, we determined the gene signatures that were unique to classical brown adipocytes and to beige cells induced by a specific PPARγ agonist rosiglitazone in mice. Subsequently we applied the transcriptional data to humans and examined the molecular signatures of human BAT isolated from multiple adipose depots. To our surprise, nearly all the human BAT abundantly expressed beige cell-selective genes, but the expression of classical brown fat-selective genes were nearly undetectable. Interestingly, expression of known brown fat-selective genes such as PRDM16 was strongly correlated with that of the newly identified beige cell-selective genes, but not with that of classical brown fat-selective genes. Furthermore, histological analyses showed that a new beige cell marker, CITED1, was selectively expressed in the UCP1-positive beige cells as well as in human BAT. These data indicate that human BAT may be primary composed of beige/brite cells.

Cure kinetics of composites using video imaging.

PURPOSE: To study the rate of curing, three composites, Heliomolar (Vivadent), Z100 (3M), and Renew (Bisco) were investigated METHODS: Volumetric shrinkage was measured at 25 degrees C using the Acuvol with an RG610 red filter. The dynamic measurements were made in the single view mode. RESULTS: Detailed kinetic studies for Renew determined the effect of varying the light intensity (100mW - 500mW) and irradiation time (3 seconds - 30 seconds) on the rate of curing. A measurement of the gel time of composites and a kinetic constant is reported. ANOVA followed by a Fisher's LSD test and a Kruskall-Wallis test were used for analysis of the data. The gel times follow the order of Heliomolar > Renew > Z100 at 20 seconds and 500 mW. Irradiation time had no significant effect on the gel time of Renew. Light intensity had a significant effect on the gel time of Renew.

Volumetric shrinkage of composites using video-imaging.

OBJECTIVE: This study involves investigation of the use of video-imaging for measurement of volumetric shrinkage of composites. METHODS: Six composites were tested for volumetric shrinkage using video-imaging. The volumetric shrinkage was measured using the single- and multi-view volumetric reconstruction modes. All composites were cured using a VIP(TM) curing light for 40s at 500 mW/cm(2). Dynamic shrinkage was measured using the single-view mode with a red filter placed over the detector opening. RESULTS: Analysis of the volumetric shrinkage values by a one way ANOVA for each composite showed no difference for the single- and multi-view measurement mode. The shrinkage values determined by video-imaging were compared to those measured for the same composites by mercury dilatometry by one way ANOVA followed by a paired comparison using the Bonferroni method. CONCLUSION: The video-imaging technique gives reproducible results for volumetric shrinkage of composites comparable to those measured by dilatometry.