31 research outputs found

    Serologic Reactivity Reflects Clinical Expression of Ulcerative Colitis in Children

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    Background In contrast to pediatric Crohn's disease (CD), little is known in pediatric ulcerative colitis (UC) about the relationship between disease phenotype and serologic reactivity to microbial and other antigens. Aim The aim of this study was to examine disease phenotype and serology in a well-characterized inception cohort of children newly diagnosed with UC during the PROTECT Study (Predicting Response to Standardized Pediatric Colitis Therapy). Methods Patients were recruited from 29 participating centers. Demographic, clinical, laboratory, and serologic (pANCA, ASCA IgA/IgG, Anti-CBir1, and Anti-OmpC) data were obtained from children 4-17 years old with UC. Results Sixty-five percent of the patients had positive serology for pANCA, with 62% less than 12 years old and 66% 12 years old or older. Perinuclear anti-neutrophil cytoplasmic antibodies did not correspond to a specific phenotype though pANCA ò100, found in 19%, was strongly associated with pancolitis (P = 0.003). Anti-CBir1 was positive in 19% and more common in younger children with 32% less than 12 years old as compared with 14% 12 years old or older (P < 0.001). No association was found in any age group between pANCA and Anti-CBir1. Relative rectal sparing was more common in +CBir1, 16% versus 7% (P = 0.02). Calprotectin was lower in Anti-CBir1+ (Median [IQR] 1495 mcg/g [973-3333] vs 2648 mcg/g [1343-4038]; P = 0.04). Vitamin D 25-OH sufficiency was associated with Anti-CBir1+ (P = 0.0009). Conclusions The frequency of pANCA in children was consistent with adult observations. High titer pANCA was associated with more extensive disease, supporting the idea that the magnitude of immune reactivity may reflect disease severity. Anti-CBir1+ was more common in younger ages, suggesting host-microbial interactions may differ by patient age

    The leaf-level emission factor of volatile isoprenoids: caveats, model algorithms, response shapes and scaling

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    In models of plant volatile isoprenoid emissions, the instantaneous compound emission rate typically scales with the plant's emission potential under specified environmental conditions, also called as the emission factor, E-S. In the most widely employed plant isoprenoid emission models, the algorithms developed by Guenther and colleagues (1991, 1993), instantaneous variation of the steady-state emission rate is described as the product of E-S and light and temperature response functions. When these models are employed in the atmospheric chemistry modeling community, species-specific E-S values and parameter values defining the instantaneous response curves are often taken as initially defined. In the current review, we argue that E-S as a characteristic used in the models importantly depends on our understanding of which environmental factors affect isoprenoid emissions, and consequently need standardization during experimental E-S determinations. In particular, there is now increasing consensus that in addition to variations in light and temperature, alterations in atmospheric and/or within-leaf CO2 concentrations may need to be included in the emission models. Furthermore, we demonstrate that for less volatile isoprenoids, mono- and sesquiterpenes, the emissions are often jointly controlled by the compound synthesis and volatility. Because of these combined biochemical and physico-chemical drivers, specification of E-S as a constant value is incapable of describing instantaneous emissions within the sole assumptions of fluctuating light and temperature as used in the standard algorithms. The definition of E-S also varies depending on the degree of aggregation of E-S values in different parameterization schemes (leaf- vs. canopy- or region-scale, species vs. plant functional type levels) and various aggregated E-S schemes are not compatible for different integration models. The summarized information collectively emphasizes the need to update model algorithms by including missing environmental and physico-chemical controls, and always to define E-S within the proper context of model structure and spatial and temporal resolution

    Updated Efficacy and Safety Data and Impact of the EML4-ALK Fusion Variant on the Efficacy of Alectinib in Untreated ALK-Positive Advanced Non-Small Cell Lung Cancer in the Global Phase III ALEX Study.

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    At the prior data cutoff (February 9, 2017) the ALEX trial showed superior investigator-assessed progression-free survival (PFS) for alectinib versus crizotinib in untreated, anaplastic lymphoma kinase (ALK)-positive, advanced NSCLC (hazard ratio = 0.47, 95% confidence interval: 0.34-0.65, p &lt; 0.001). The median PFS in the alectinib arm was not reached versus 11.1 months with crizotinib. Retrospective analyses suggest that the echinoderm microtubule-associated protein-like 4 gene-ALK variant (EML4-ALK) may influence ALK-inhibitor treatment benefit. We present updated analyses, including exploratory subgroup analysis by EML4-ALK variant, after an additional 10 months' follow-up (cutoff December 1, 2017). Patients were randomized to receive twice-daily alectinib, 600 mg, or crizotinib, 250 mg, until disease progression, toxicity, death, or withdrawal. PFS was determined by the investigators. Baseline plasma and tissue biomarker samples were analyzed by using hybrid-capture, next-generation sequencing to determine EML4-ALK variant. Baseline characteristics were balanced. Investigator-assessed PFS was prolonged with alectinib (stratified hazard ratio = 0.43, 95% confidence interval: 0.32-0.58). The median PFS times were 34.8 months with alectinib and 10.9 months with crizotinib. EML4-ALK fusions were detectable in 129 patient plasma samples and 124 tissue samples; variants 1, 2, and 3/ab did not affect PFS, objective response rate, or duration of response. Investigator-assessed PFS was longer for alectinib than for crizotinib across EML4-ALK variants 1, 2, and 3a/b in plasma and tissue. Despite longer treatment duration (27.0 months in the case of alectinib versus 10.8 months in the case of crizotinib), the safety of alectinib compared favorably with that of crizotinib. Alectinib continues to demonstrate superior investigator-assessed PFS versus crizotinib in untreated ALK-positive NSCLC, irrespective of EML4-ALK variant

    The impact of employment equity regulations on psychological contracts in South Africa

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    This article will show the impact of employment equity legislation on the psychological employment contracts of the three main employee groupings in South African society. This study is important in that it fills the gap in the literature that identifies labour market regulations as an important shaping influence on the psychological contract. More than 500 managers from across South African industry and from all ethnic groups were surveyed to identify differences in psychological contracts and attitudes towards the social transformation regulations. We found that the legislation has impacted differentially on the three groupings mainly in terms of their loyalty to stay with their organizations, the focus on their career development in terms of the external labour market and the degree to which they felt they had been affected by the legislation. Additionally we find that the perceived linkage between job satisfaction and labour turnover is significantly weakened by labour market legislation in the case of the beneficiaries of the legislation, but that this may not be the case for those negatively affected by the legislation. The findings have significant implications for the HRM practices of multinationals operating in societies with significant labour market regulatory interventions

    Long-term evolution of upper stratospheric ozone at selected stations of the Network for the Detection of Stratospheric Change (NDSC)

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    The long-term evolution of upper stratospheric ozone has been recorded by lidars and microwave radiometers within the ground-based Network for the Detection of Stratospheric Change (NDSC), and by the space-borne Solar Backscatter Ultra-Violet instruments (SBUV), Stratospheric Aerosol and Gas Experiment (SAGE), and Halogen Occultation Experiment (HALOE). Climatological mean differences between these instruments are typically smaller than 5% between 25 and 50 km. Ozone anomaly time series from all instruments, averaged from 35 to 45 km altitude, track each other very well and typically agree within 3 to 5%. SBUV seems to have a slight positive drift against the other instruments. The corresponding 1979 to 1999 period from a transient simulation by the fully coupled MAECHAM4-CHEM chemistry climate model reproduces many features of the observed anomalies. However, in the upper stratosphere the model shows too low ozone values and too negative ozone trends, probably due to an underestimation of methane and a consequent overestimation of ClO. The combination of all observational data sets provides a very consistent picture, with a long-term stability of 2% or better. Upper stratospheric ozone shows three main features: (1) a decline by 10 to 15% since 1980, due to chemical destruction by chlorine; (2) two to three year fluctuations by 5 to 10%, due to the Quasi-Biennial Oscillation (QBO); (3) an 11-year oscillation by about 5%, due to the 11-year solar cycle. The 1979 to 1997 ozone trends are larger at the southern mid-latitude station Lauder (45°S), reaching ?8%/decade, compared to only about ?6%/decade at Table Mountain (35°N), Haute Provence/Bordeaux (?45°N), and Hohenpeissenberg/Bern(?47°N). At Lauder, Hawaii (20°N), Table Mountain, and Haute Provence, ozone residuals after subtraction of QBO- and solar cycle effects have levelled off in recent years, or are even increasing. Assuming a turning point in January 1997, the change of trend is largest at southern mid-latitude Lauder, +11%/decade, compared to +7%/decade at northern mid-latitudes. This points to a beginning recovery of upper stratospheric ozone. However, chlorine levels are still very high and ozone will remain vulnerable. At this point the most northerly mid-latitude station, Hohenpeissenberg/Bern differs from the other stations, and shows much less clear evidence for a beginning recovery, with a change of trend in 1997 by only +3%/decade. In fact, record low upper stratospheric ozone values were observed at Hohenpeissenberg/Bern, and to a lesser degree at Table Mountain and Haute Provence, in the winters 2003/2004 and 2004/2005
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