Effect of Obesity on Acute Ozone-Induced Changes in Airway Function, Reactivity, and Inflammation in Adult Females

We previously observed greater ozone-induced lung function decrements in obese than non-obese women. Animal models suggest that obesity enhances ozone-induced airway reactivity and inflammation. In a controlled exposure study, we compared the acute effect of randomized 0.4ppm ozone and air exposures (2 h with intermittent light exercise) in obese (N = 20) (30<BMI<40Kg/m2) vs. non-obese (N = 20) (BMI<25Kg/m2) non-smoking 18–35 year old women. We measured spirometry and bronchial reactivity to inhaled methacholine (3h post-exposure). Inflammation and obesity markers were assessed in the blood (pre, 4h post, and 20h post exposures) and induced-sputum (4h post-exposures and on 24h pre-exposure training day, no exercise): measures of C reactive protein (CRP) (blood only), leptin (blood only), adiponectin, interleukins IL-6, IL-1b, and IL-8, and tumor necrosis factor alpha, and sputum cell differential cell counts. The pre- to post-exposure decrease in forced vital capacity after ozone (adjusted for the change after air exposure) was significantly greater in the obese group (12.5+/-7.5 vs. 8.0+/-5.8%, p<0.05). Post ozone exposure, 6 obese and 6 non-obese subjects responded to methacholine at ≤ 10mg/ml (the maximum dose); the degree of hyperresponsiveness was similar for the two groups. Both BMI groups showed similar and significant ozone-induced increases in sputum neutrophils. Plasma IL-6 was increased by exercise (4 hr post air exposure vs. pre) only in the obese but returned to pre-air exposure levels at 20hr post-exposure. Plasma IL-6 was significantly increased at 4hr post ozone exposure in both groups and returned to pre-exposure levels by 20h post-exposure. These results confirm our previous findings of greater post-ozone spirometric decrements in obese young women. However, acute ozone-induced airway reactivity to methacholine and airway inflammation did not differ by obesity at the exposure and exercise levels used

Observation-Driven Estimation of the Spatial Variability of 20th Century Sea Level Rise

Over the past two decades, sea level measurements made by satellites have given clear indications of both global and regional sea level rise. Numerous studies have sought to leverage the modern satellite record and available historic sea level data provided by tide gauges to estimate past sea level rise, leading to several estimates for the 20th century trend in global mean sea level in the range between 1 and 2 mm/yr. On regional scales, few attempts have been made to estimate trends over the same time period. This is due largely to the inhomogeneity and quality of the tide gauge network through the 20th century, which render commonly used reconstruction techniques inadequate. Here, a new approach is adopted, integrating data from a select set of tide gauges with prior estimates of spatial structure based on historical sea level forcing information from the major contributing processes over the past century. The resulting map of 20th century regional sea level rise is optimized to agree with the tide gauge-measured trends, and provides an indication of the likely contributions of different sources to regional patterns. Of equal importance, this study demonstrates the sensitivities of this regional trend map to current knowledge and uncertainty of the contributing processes

Loss of CXCL12/CXCR4 signalling impacts several aspects of cardiovascular development but does not exacerbate Tbx1 haploinsufficiency

The CXCL12-CXCR4 pathway has crucial roles in stem cell homing and maintenance, neuronal guidance, cancer progression, inflammation, remote-conditioning, cell migration and development. Recently, work in chick suggested that signalling via CXCR4 in neural crest cells (NCCs) has a role in the 22q11.2 deletion syndrome (22q11.2DS), a disorder where haploinsufficiency of the transcription factor TBX1 is responsible for the major structural defects. We tested this idea in mouse models. Our analysis of genes with altered expression in Tbx1 mutant mouse models showed down-regulation of Cxcl12 in pharyngeal surface ectoderm and rostral mesoderm, both tissues with the potential to signal to migrating NCCs. Conditional mutagenesis of Tbx1 in the pharyngeal surface ectoderm is associated with hypo/aplasia of the 4th pharyngeal arch artery (PAA) and interruption of the aortic arch type B (IAA-B), the cardiovascular defect most typical of 22q11.2DS. We therefore analysed constitutive mouse mutants of the ligand (CXCL12) and receptor (CXCR4) components of the pathway, in addition to ectodermal conditionals of Cxcl12 and NCC conditionals of Cxcr4. However, none of these typical 22q11.2DS features were detected in constitutively or conditionally mutant embryos. Instead, duplicated carotid arteries were observed, a phenotype recapitulated in Tie-2Cre (endothelial) conditional knock outs of Cxcr4. Previous studies have demonstrated genetic interaction between signalling pathways and Tbx1 haploinsufficiency e.g. FGF, WNT, SMAD-dependent. We therefore tested for possible epistasis between Tbx1 and the CXCL12 signalling axis by examining Tbx1 and Cxcl12 double heterozygotes as well as Tbx1/Cxcl12/Cxcr4 triple heterozygotes, but failed to identify any exacerbation of the Tbx1 haploinsufficient arch artery phenotype. We conclude that CXCL12 signalling via NCC/CXCR4 has no major role in the genesis of the Tbx1 loss of function phenotype. Instead, the pathway has a distinct effect on remodelling of head vessels and interventricular septation mediated via CXCL12 signalling from the pharyngeal surface ectoderm and second heart field to endothelial cells

Age and African-American race impact the validity and reliability of the asthma control test in persistent asthmatics

Abstract Background The Asthma Control Test (ACT) is widely used to assess asthma control, yet the validity and reliability of the test have not been specifically evaluated in adolescents or African-Americans. We conducted a prospective psychometric study of the ACT in African-American (AA) and non-African-American (nAA) adolescents with persistent asthma, with emphasis on the clinical utility of the test for medical decision making. Methods Participants completed the ACT and performed spirometry. A physician conducted a guidelines-based assessment of asthma control, blinded to the ACT score. Study procedures were repeated 6–8 weeks later. The ACT-based asthma control assessment was compared to physician assessment. Results For baseline and follow-up visits, internal consistency, as measured using Cronbach’s alpha, was 0.80 and 0.81 in AA teens and 0.80 and 0.83 in nAA teens. Intraclass correlation coefficients were 0.59 and 0.76 in AA and nAA teens, respectively, with stable asthma control over time. Agreement between ACT and physician assessment was moderate in AA teens and fair in nAA teens. An ACT score of ≤19 showed reduced sensitivity for not well controlled asthma in both groups, while a score of ≤21 had the greatest area under the ROC curve. ACT scores were marginally responsive to change in control status. Conclusions Concerns for the ACT’s ability to detect uncontrolled asthma in adolescents emphasizes the need for a more comprehensive evaluation of asthma control in clinical settings. A higher threshold ACT score to define not well controlled asthma may be needed if the ACT is to be used for medical decision making. Trial registration ClinicalTrials.gov: NCT02671643 , NCT02662413

SHP-2 Promotes the Maturation of Oligodendrocyte Precursor Cells Through Akt and ERK1/2 Signaling In Vitro

Background: Oligodendrocyte precursor cells (OPCs) differentiate into oligodendrocytes (OLs), which are responsible for myelination. Myelin is essential for saltatory nerve conduction in the vertebrate nervous system. However, the molecular mechanisms of maturation and myelination by oligodendrocytes remain elusive. Methods and Findings: In the present study, we showed that maturation of oligodendrocytes was attenuated by sodium orthovanadate (a comprehensive inhibitor of tyrosine phosphatases) and PTPi IV (a specific inhibitor of SHP-2). It is also found that SHP-2 was persistently expressed during maturation process of OPCs. Down-regulation of endogenous SHP-2 led to impairment of oligodendrocytes maturation and this effect was triiodo-L-thyronine (T3) dependent. Furthermore, overexpression of SHP-2 was shown to promote maturation of oligodendrocytes. Finally, it has been identified that SHP-2 was involved in activation of Akt and extracellular-regulated kinases 1 and 2 (ERK1/2) induced by T3 in oligodendrocytes

Common Functional Correlates of Head-Strike Behavior in the Pachycephalosaur Stegoceras validum (Ornithischia, Dinosauria) and Combative Artiodactyls

BACKGROUND: Pachycephalosaurs were bipedal herbivorous dinosaurs with bony domes on their heads, suggestive of head-butting as seen in bighorn sheep and musk oxen. Previous biomechanical studies indicate potential for pachycephalosaur head-butting, but bone histology appears to contradict the behavior in young and old individuals. Comparing pachycephalosaurs with fighting artiodactyls tests for common correlates of head-butting in their cranial structure and mechanics. METHODS/PRINCIPAL FINDINGS: Computed tomographic (CT) scans and physical sectioning revealed internal cranial structure of ten artiodactyls and pachycephalosaurs Stegoceras validum and Prenocephale prenes. Finite element analyses (FEA), incorporating bone and keratin tissue types, determined cranial stress and strain from simulated head impacts. Recursive partition analysis quantified strengths of correlation between functional morphology and actual or hypothesized behavior. Strong head-strike correlates include a dome-like cephalic morphology, neurovascular canals exiting onto the cranium surface, large neck muscle attachments, and dense cortical bone above a sparse cancellous layer in line with the force of impact. The head-butting duiker Cephalophus leucogaster is the closest morphological analog to Stegoceras, with a smaller yet similarly rounded dome. Crania of the duiker, pachycephalosaurs, and bighorn sheep Ovis canadensis share stratification of thick cortical and cancellous layers. Stegoceras, Cephalophus, and musk ox crania experience lower stress and higher safety factors for a given impact force than giraffe, pronghorn, or the non-combative llama. CONCLUSIONS/SIGNIFICANCE: Anatomy, biomechanics, and statistical correlation suggest that some pachycephalosaurs were as competent at head-to-head impacts as extant analogs displaying such combat. Large-scale comparisons and recursive partitioning can greatly refine inference of behavioral capability for fossil animals

Inhibition of ICAM2 induces radiosensitisation in oral squamous cell carcinoma cells

We recently identified genes and molecular pathways related to radioresistance of oral squamous cell carcinoma (OSCC) using Affymetrix GeneChip. The current study focused on the association between one of the target genes, intercellular adhesion molecule 2 (ICAM2), and resistance to X-ray irradiation in OSCC cells, and evaluated the antitumor efficacy of combining ICAM2 small interfering RNA (siRNA) and X-ray irradiation. Downregulation of ICAM2 expression by siRNA enhanced radiosensitivity of OSCC cells with the increased apoptotic phenotype via phosphorylation (ser473) of AKT and activation of caspase-3. Moreover, overexpression of ICAM2 induced greater OSCC cell resistance to the X-ray irradiation with the radioresistance phenotype. These results suggested that ICAM2 silencing is closely related to sensitivity of OSCC cells to radiotherapy, and that ICAM2 may be an effective radiotherapeutic target for this disease

Inhibition of apoptosis in neuronal cells infected with Chlamydophila (Chlamydia) pneumoniae

Background Chlamydophila (Chlamydia) pneumoniae is an intracellular bacterium that has been identified within cells in areas of neuropathology found in Alzheimer disease (AD), including endothelia, glia, and neurons. Depending on the cell type of the host, infection by C. pneumoniae has been shown to influence apoptotic pathways in both pro- and anti-apoptotic fashions. We have hypothesized that persistent chlamydial infection of neurons may be an important mediator of the characteristic neuropathology observed in AD brains. Chronic and/or persistent infection of neuronal cells with C. pneumoniae in the AD brain may affect apoptosis in cells containing chlamydial inclusions. Results SK-N-MC neuroblastoma cells were infected with the respiratory strain of C. pneumoniae, AR39 at an MOI of 1. Following infection, the cells were either untreated or treated with staurosporine and then examined for apoptosis by labeling for nuclear fragmentation, caspase activity, and membrane inversion as indicated by annexin V staining. C. pneumoniae infection was maintained through 10 days post-infection. At 3 and 10 days post-infection, the infected cell cultures appeared to inhibit or were resistant to the apoptotic process when induced by staurosporine. This inhibition was demonstrated quantitatively by nuclear profile counts and caspase 3/7 activity measurements. Conclusion These data suggest that C. pneumoniae can sustain a chronic infection in neuronal cells by interfering with apoptosis, which may contribute to chronic inflammation in the AD brai

Mass balance of the Greenland and Antarctic ice sheets from 1992 to 2020

Ice losses from the Greenland and Antarctic ice sheets have accelerated since the 1990s, accounting for a significant increase in the global mean sea level. Here, we present a new 29-year record of ice sheet mass balance from 1992 to 2020 from the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE). We compare and combine 50 independent estimates of ice sheet mass balance derived from satellite observations of temporal changes in ice sheet flow, in ice sheet volume, and in Earth's gravity field. Between 1992 and 2020, the ice sheets contributed 21.0±1.9g€¯mm to global mean sea level, with the rate of mass loss rising from 105g€¯Gtg€¯yr-1 between 1992 and 1996 to 372g€¯Gtg€¯yr-1 between 2016 and 2020. In Greenland, the rate of mass loss is 169±9g€¯Gtg€¯yr-1 between 1992 and 2020, but there are large inter-annual variations in mass balance, with mass loss ranging from 86g€¯Gtg€¯yr-1 in 2017 to 444g€¯Gtg€¯yr-1 in 2019 due to large variability in surface mass balance. In Antarctica, ice losses continue to be dominated by mass loss from West Antarctica (82±9g€¯Gtg€¯yr-1) and, to a lesser extent, from the Antarctic Peninsula (13±5g€¯Gtg€¯yr-1). East Antarctica remains close to a state of balance, with a small gain of 3±15g€¯Gtg€¯yr-1, but is the most uncertain component of Antarctica's mass balance. The dataset is publicly available at 10.5285/77B64C55-7166-4A06-9DEF-2E400398E452 (IMBIE Team, 2021)