158 research outputs found
Th17 Responses Are Not Induced in Dextran Sodium Sulfate Model of Acute Colitis
Dextran sodium sulfate (DSS) is a widely used chemical model for inflammatory bowel disease (IBD). It is thought that imbalances in the T helper (Th) cell subsets contribute to IBD. Recent studies suggest that the acute DSS-colitis model is polarized toward a Th1/Th17 profile based on RT-PCR analysis of colonic tissues. In the current study we determined whether colonic Th cells from DSS-colitis mice were skewed toward the Th17 profile. Mice were treated with 5% DSS for 7 days and colonic T cells isolated and examined for production of IFN-γ (Th1 cell), IL-4 (Th2 cell) and IL-17 (Th17 cell) by intracellular flow cytometry. We found that the percentage of colonic Th17 cells were similar to non-treated controls but the percentage of Th1 cells were elevated in DSS-colitis mice. These results suggest that in the acute DSS-colitis model the colonic Th cells exhibit a Th1 profile and not a Th17 profile
Prevalence of Otolaryngologic Diseases in South Korea: Data from the Korea National Health and Nutrition Examination Survey 2008
Objectives. The aims of this study were to evaluate the prevalence of otolaryngologic diseases in Korea. Methods. We obtained data from the 2008 Korea National Health and Nutrition Examination Surveys (KNHANES), which were cross-sectional surveys of the civilian, non-institutionalized population of South Korea (n=4,930). A field survey team that included an otolaryngologist, nurses, and interviewers moved with a mobile examination unit and performed otolaryngologic interviews and physical examinations. Results. The prevalence of subjective hearing loss, tinnitus, preauricular fistua, tympanic membrane perforation, and cholesteatoma were 11.97%, 20.27%, 2.08%, 1.60%, and 1.18%, respectively. Dizziness and vestibular dysfunction were common among Korean adults, since 23.33% of the participants reported symptoms of dizziness or imbalance, and the prevalence of vestibular dysfunction was 3.86%. The prevalence of nasal diseases was relatively high, as the prevalence of allergic rhinitis, chronic rhinosinusitis, and a deviated nasal septum were 28.01%, 7.12%, and 42.94%, respectively. Subjective dysphonia was found in 6.60% of the participants, and the prevalence of subjective dysphonia increased with age. Conclusion. This is the first nation-wide epidemiologic study to assess the prevalence of otolaryngologic diseases by both the Korean Otolaryngologic Society and the Ministry of Health and Welfare. Considering the high prevalence of otolaryngologic diseases in Korea, the results call for additional studies to better prevent and manage otolaryngologic diseases
GABAergic inhibition is weakened or converted into excitation in the oxytocin and vasopressin neurons of the lactating rat
BACKGROUND: Increased secretion of oxytocin and arginine vasopressin (AVP) from hypothalamic magnocellular neurosecretory cells (MNCs) is a key physiological response to lactation. In the current study, we sought to test the hypothesis that the GABA(A) receptor-mediated inhibition of MNCs is altered in lactating rats. RESULTS: Gramicidin-perforated recordings in the rat supraoptic nucleus (SON) slices revealed that the reversal potential of GABA(A) receptor-mediated response (E(GABA)) of MNCs was significantly depolarized in the lactating rats as compared to virgin animals. The depolarizing E(GABA) shift was much larger in rats in third, than first, lactation such that GABA exerted an excitatory, instead of inhibitory, effect in most of the MNCs of these multiparous rats. Immunohistochemical analyses confirmed that GABAergic excitation was found in both AVP and oxytocin neurons within the MNC population. Pharmacological experiments indicated that the up-regulation of the Cl(−) importer Na(+)-K(+)-2Cl(−) cotransporter isotype 1 and the down-regulation of the Cl(−) extruder K(+)-Cl(−) cotransporter isotype 2 were responsible for the depolarizing shift of E(GABA) and the resultant emergence of GABAergic excitation in the MNCs of the multiparous rats. CONCLUSION: We conclude that, in primiparous rats, the GABAergic inhibition of MNCs is weakened during the period of lactation while, in multiparous females, GABA becomes excitatory in a majority of the cells. This reproductive experience-dependent alteration of GABAergic transmission may help to increase the secretion of oxytocin and AVP during the period of lactation
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
How do shared emotions among group members influence group effectiveness? The role of broadening -and -building interactions.
This research explores how positive emotions shared among group members influence group effectiveness, and how broadening-and-building interactions mediate this relationship. Literatures on emotions have focused primarily on individual emotions. Moreover, prior research has neither conceptually specified nor empirically tested the causal mechanisms that explain how and why group emotions influence group outcomes. I sought to fill this gap by introducing broadening-and-building interactions as a group level mechanism. Drawing from the broaden-and-build theory of positive emotions (Fredrickson, 1998) at the individual level, I proposed that groups that shared an emotion of joy would exhibit more frequent broadening-and-building interactions (i.e., building on each other's ideas, morale-building communication and active affirmation) than groups that shared neutral emotions. In turn, broadening-and-building interactions were expected to enhance group creativity, members' satisfaction with the group and member learning but decrease groups' decision quality. To test the hypotheses, I conducted an experiment with 72 workgroups with multi-method measures (survey, observation, objective performance rating). The results showed that broadening-and-building interactions were indeed the key mechanism that explained the relationship between a group emotion of joy and group effectiveness. An analysis of variance indicated that groups experiencing a shared emotion of joy showed more frequent broadening-and-building interactions than groups experiencing neutral emotions. Regression analyses demonstrated that broadening-and-building interactions, in turn, increased group creativity and members' satisfaction with the group but decreased group decision-making performance. The results showed that positive group emotions, through broadening-and-building interactions, did not always lead to positive outcomes and resulted in negative outcomes as well, depending on the type of group tasks. Mediation analyses confirmed the overall proposed sequence of relations: a group emotion of joy → broadening-and-building interactions → group effectiveness. I discuss the discrepancies between observed and self-reported broadening-and-building interactions and the theoretical contributions of the research to group, individual emotions, and group emotions literatures, as well as the practical implications for organizations. Future research directions are specified with a focus on group member interactions as a mechanism associated with different discrete emotions (i.e., a group emotion of anxiety) and on the optimal balance between positivity and negativity in group emotions and member interactions.Ph.D.ManagementOccupational psychologyPsychologySocial SciencesSocial psychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/125206/2/3186744.pd
Network Structure of Affective Communication and Shared Emotion in Teams
This paper identifies the relative effectiveness of two mechanisms of emotional contagion on shared emotion in teams: explicit mechanism (active spreading of one’s emotion) and implicit mechanism (passive mimicry of others’ emotion). Using social network analysis, this paper analyzes affective communication networks involving or excluding a focal person in the process of emotional contagion by disaggregating team emotional contagion into individual acts of sending or receiving emotion-laden responses. Through an experiment with 38 pre-existing work teams, including undergraduate or MBA project teams and teams of student club or co-op officers, we found that the explicit emotional contagion mechanism was a more stable channel for emotional contagion than the implicit emotional contagion mechanism. Active participation in affective communication, measured by outdegree centrality in affective communication networks, was positively and significantly associated with emotional contagion with other members. In contrast, a team member’s passive observation of humor, measured by ego network density, led to emotional divergence when all other members engaged in humor communication. Our study sheds light on the micro-level process of emotional contagion. The individual-level process of emotional convergence varies with the relational pattern of affective networks, and emotion contagion in teams depends on the interplay of the active expresser and the passive spectator in affective networks
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