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Humoral responses in coronavirus disease 2019 (COVID-19) are often of limited durability, as seen with other human coronavirus epidemics. To address the underlying etiology, we examined post mortem thoracic lymph nodes and spleens in acute SARS-CoV-2 infection and observed the absence of germinal centers and a striking reduction in Bcl-6+ germinal center B cells but preservation of AID+ B cells. Absence of germinal centers correlated with an early specific block in Bcl-6+ TFH cell differentiation together with an increase in T-bet+ TH1 cells and aberrant extra-follicular TNF-α accumulation. Parallel peripheral blood studies revealed loss of transitional and follicular B cells in severe disease and accumulation of SARS-CoV-2-specific "disease-related" B cell populations. These data identify defective Bcl-6+ TFH cell generation and dysregulated humoral immune induction early in COVID-19 disease, providing a mechanistic explanation for the limited durability of antibody responses in coronavirus infections, and suggest that achieving herd immunity through natural infection may be difficult.
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Infecções por Coronavirus/imunologia , Centro Germinativo/imunologia , Pneumonia Viral/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Idoso , Idoso de 80 Anos ou mais , Linfócitos B/imunologia , COVID-19 , Feminino , Centro Germinativo/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Baço/imunologia , Baço/patologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Agouti-related peptide (AgRP/Agrp) within the hypothalamic arcuate nucleus (ARC) contributes to the control of energy balance, and dysregulated Agrp may contribute to metabolic adaptation during prolonged obesity. In mice, three isoforms of Agrp are encoded via distinct first exons. Agrp-A (ENSMUST00000005849.11) contributed 95% of total Agrp in mouse ARC, whereas Agrp-B (ENSMUST00000194654.2) dominated in placenta (73%). Conditional deletion of Klf4 from Agrp-expressing cells (Klf4Agrp-KO mice) reduced Agrp mRNA and increased energy expenditure but had no effects on food intake or the relative abundance of Agrp isoforms in the ARC. Chronic high-fat diet feeding masked these effects of Klf4 deletion, highlighting the context-dependent contribution of KLF4 to Agrp control. In the GT1-7 mouse hypothalamic cell culture model, which expresses all three isoforms of Agrp (including Agrp-C, ENSMUST00000194091.6), inhibition of extracellular signal-regulated kinase (ERK) simultaneously increased KLF4 binding to the Agrp promoter and stimulated Agrp expression. In addition, siRNA-mediated knockdown of Klf4 reduced expression of Agrp. We conclude that the expression of individual isoforms of Agrp in the mouse is dependent upon cell type and that KLF4 directly promotes the transcription of Agrp via a mechanism that is superseded during obesity.NEW & NOTEWORTHY In mice, three distinct isoforms of Agouti-related peptide are encoded via distinct first exons. In the arcuate nucleus of the hypothalamus, Krüppel-like factor 4 stimulates transcription of the dominant isoform in lean mice, but this mechanism is altered during diet-induced obesity.
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Proteína Relacionada com Agouti , Fator 4 Semelhante a Kruppel , Neurônios , Animais , Camundongos , Proteína Relacionada com Agouti/genética , Proteína Relacionada com Agouti/metabolismo , Hipotálamo/metabolismo , Neurônios/metabolismo , Obesidade/genética , Obesidade/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismoRESUMO
We analysed the wild bee community sampled from 1921 to 2018 at a nature preserve in southern Michigan, USA, to study long-term community shifts in a protected area. During an intensive survey in 1972 and 1973, Francis C. Evans detected 135 bee species. In the most recent intensive surveys conducted in 2017 and 2018, we recorded 90 species. Only 58 species were recorded in both sampling periods, indicating a significant shift in the bee community. We found that the bee community diversity, species richness and evenness were all lower in recent samples. Additionally, 64% of the more common species exhibited a more than 30% decline in relative abundance. Neural network analysis of species traits revealed that extirpation from the reserve was most likely for oligolectic ground-nesting bees and kleptoparasitic bees, whereas polylectic cavity-nesting bees were more likely to persist. Having longer phenological ranges also increased the chance of persistence in polylectic species. Further analysis suggests a climate response as bees in the contemporary sampling period had a more southerly overall distribution compared to the historic community. Results exhibit the utility of both long-term data and machine learning in disentangling complex indicators of bee population trajectories.
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Biodiversidade , Animais , Abelhas/fisiologia , Michigan , Redes Neurais de Computação , Conservação dos Recursos NaturaisRESUMO
BACKGROUND: Prior animal and epidemiological studies suggest that per- and polyfluoroalkyl substances (PFAS) exposure may be associated with reduced birth weight. However, results from prior studies evaluated a relatively small set of PFAS. OBJECTIVES: Determine associations of gestational PFAS concentrations in maternal serum samples banked for 60 years with birth outcomes. METHODS: We used data from 97 pregnant women from Boston and Providence that enrolled in the Collaborative Perinatal Project (CPP) study (1960-1966). We quantified concentrations of 27 PFAS in maternal serum in pregnancy and measured infant weight, height and ponderal index at birth. Covariate-adjusted associations between 11 PFAS concentrations (>75% detection limits) and birth outcomes were estimated using linear regression methods. RESULTS: Median concentrations of PFOA, PFNA, PFHxS, and PFOS were 6.189, 0.330, 14.432, and 38.170 ng/mL, respectively. We found that elevated PFAS concentrations during pregnancy were significantly associated with lower birth weight and ponderal index at birth, but no significant associations were found with birth length. Specifically, infants born to women with PFAS concentrations ≥ median levels had significantly lower birth weight (PFOS: ß = -0.323, P = 0.006; PFHxS: ß = -0.292, P = 0.015; PFOA: ß = -0.233, P = 0.03; PFHpS: ß = -0.239, P = 0.023; PFNA: ß = -0.239, P = 0.017). Similarly, women with PFAS concentrations ≥ median levels had significantly lower ponderal index (PFHxS: ß = -0.168, P = 0.020; PFHxA: ß = -0.148, P = 0.018). CONCLUSIONS: Using data from this US-based cohort study, we found that 1) maternal PFAS levels from the 1960s exceeded values in contemporaneous populations and 2) that gestational concentrations of certain PFAS were associated with lower birth weight and infant ponderal index. Additional studies with larger sample size are needed to further examine the associations of gestational exposure to individual PFAS and their mixtures with adverse birth outcomes.
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Ácidos Alcanossulfônicos , Poluentes Ambientais , Fluorocarbonos , Complicações na Gravidez , Recém-Nascido , Lactente , Humanos , Feminino , Gravidez , Estudos de Coortes , Gestantes , Peso ao Nascer , Poluentes Ambientais/toxicidade , Fluorocarbonos/toxicidade , Complicações na Gravidez/induzido quimicamenteRESUMO
Research has been inconclusive as to whether stimulant treatment causes or exacerbates sleep problems in adolescents with ADHD. This study examined sleep differences in adolescents with ADHD as a function of stimulant use. Participants were adolescents with ADHD (N = 159, ages 12-14). Parents reported on receipt of stimulant treatment (n = 92, 57.86%; n = 47 amphetamines, n = 45 methylphenidate). Adolescents wore actigraphs and completed daily diaries assessing sleep and daily use of stimulants for 2 weeks. Sleep parameters included daily-reported bedtime, sleep onset latency (SOL), sleep duration, daytime sleepiness, and difficulty waking the following morning; and actigraphy-measured sleep onset time, total time in bed, and sleep efficiency. We estimated between- and within-individual associations between stimulant medication use and sleep indices with all stimulants, after removing adolescents using sleep aids and weekend days, and as a function of stimulant type. Adolescent sleep did not differ between those receiving and not receiving stimulant treatment. Within individuals using stimulants, we largely observed no significant differences between medicated and unmedicated days, though findings were most often significant for school days only. Small effects were found indicating longer SOL, later sleep onset time, and more daytime sleepiness related to medication use. In contrast, there were slight improvements to sleep duration and sleep efficiency related to methylphenidate use, though methylphenidate was also associated with later sleep onset time and more daytime sleepiness. Given the inconsistent and small effects, findings suggest that stimulant medication may impact sleep, but does not appear to be a primary contributor to sleep problems in adolescents with ADHD.
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Transtorno do Deficit de Atenção com Hiperatividade , Estimulantes do Sistema Nervoso Central , Distúrbios do Sono por Sonolência Excessiva , Metilfenidato , Transtornos do Sono-Vigília , Humanos , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/complicações , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Metilfenidato/uso terapêutico , Sono , Estimulantes do Sistema Nervoso Central/uso terapêutico , Distúrbios do Sono por Sonolência Excessiva/complicações , Distúrbios do Sono por Sonolência Excessiva/tratamento farmacológico , Transtornos do Sono-Vigília/tratamento farmacológico , Transtornos do Sono-Vigília/etiologiaRESUMO
BACKGROUND: Occupation is an important risk factor for lung cancer. This knowledge is mainly based on studies conducted on men, with the results being generalized to women. AIMS: We aimed to identify the relationship between different occupations and lung cancer in women. METHODS: Pooling study in which data were pooled from six case-control studies conducted at 13 Spanish hospitals and 1 hospital in Portugal. Each woman's longest held job was coded as per the ISCO-08. Results were adjusted for age, smoking, and exposure to residential radon. RESULTS: The study population comprised 1262 women: 618 cases and 644 controls. The reference group were white-collar workers. The adjusted multivariate analysis showed a higher risk of developing lung cancer among teaching professionals (odds ratio [OR]: 4.36; 95% confidence interval [CI] 1.73-11.02), cooks (OR: 3.59; 95% CI 1.52-8.48), domestic cleaners and helpers (OR: 2.98; 95% CI 1.54-5.78), homemakers (OR: 2.30; 95% CI 1.26-4.21) and crop farmers, livestock farmers and gardeners (OR: 2.06, 95% CI: 1.11-3.81). For adenocarcinoma, the highest risk was observed in teaching professionals, and for small-cell carcinoma, the highest risk was observed in cooks. Higher risks were observed for small-cell carcinoma compared to other histological types. CONCLUSIONS: Some occupations may be associated with an increased risk of lung cancer in women and this risk could vary by histologic subtype; however, further research is needed to confirm these associations. In any case, protection measures must be implemented in the workplace aimed at reducing the risk of lung cancer among women workers, and more studies exclusively focused on women are warranted.
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Neoplasias Pulmonares , Exposição Ocupacional , Ocupações , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/etiologia , Feminino , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/estatística & dados numéricos , Fatores de Risco , Estudos de Casos e Controles , Ocupações/estatística & dados numéricos , Pessoa de Meia-Idade , Espanha/epidemiologia , Adulto , Portugal/epidemiologia , Doenças Profissionais/epidemiologia , Doenças Profissionais/etiologia , Idoso , Fumar/efeitos adversos , Fumar/epidemiologia , Radônio/efeitos adversosRESUMO
BACKGROUND: Decreased mammography drives breast cancer disparities. Black women have lower rates of mammography completion than White women, and this contributes to disparities in outcomes. Points of disparity along the continuum for screening mammography remain underresearched. METHODS: The authors compared mammography referrals for Black and White women aged 40-74 years at a heterogeneous academic medical center. Completion of steps of the screening mammography continuum was compared between Black and White women within two age cohorts: 40-49 and 50-74 years. Multivariable logistic regression was used to evaluate the association between race and mammogram completion. RESULTS: Among 26,476 women, 3090 (12%) were Black, and 23,386 (88%) were White. Among Black women aged 50-74 years who were due for mammography, 40% had referrals, 39% were scheduled, and 21% completed mammography; the corresponding values for White women were 42%, 41%, and 27%, respectively. Similar differences in referral outcomes were noted for women aged 40-49 years, although Black women had lower rates of provider-initiated referrals (9% vs. 13%). Adjusted analyses for those aged 40-49 and 50-74 years demonstrated an association between Black race and lower rates of mammography completion (odds ratio [OR] for 40-49 years, 0.74; 95% CI, 0.57-0.95; p = .02; OR for 50-74 years, 0.85; 95% CI, 0.74-0.98; p = .02). In multivariable analyses, noncommercial insurance and higher comorbidity were associated with lower rates of mammography. Provider-initiated referral was positively correlated to mammogram completion. CONCLUSIONS: Black race was associated with 15%-26% lower mammography completion (adjusted). Both groups experienced the highest attrition after scheduling mammograms, although attrition was more precipitous for Black women. These findings have implications for future interventions, including increasing provider-initiated referrals and decreasing barriers to attending scheduled mammograms.
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Negro ou Afro-Americano , Neoplasias da Mama , Detecção Precoce de Câncer , Disparidades em Assistência à Saúde , Mamografia , Feminino , Humanos , Centros Médicos Acadêmicos/estatística & dados numéricos , População Negra , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/etnologia , Detecção Precoce de Câncer/estatística & dados numéricos , Mamografia/estatística & dados numéricos , Negro ou Afro-Americano/estatística & dados numéricos , Disparidades em Assistência à Saúde/etnologia , Disparidades em Assistência à Saúde/estatística & dados numéricos , Brancos/estatística & dados numéricos , Adulto , Pessoa de Meia-Idade , Idoso , Acessibilidade aos Serviços de Saúde , Washington/epidemiologiaRESUMO
BACKGROUND AND AIM: Staining for hepatitis B viral antigens is often done in liver biopsies from patients with chronic hepatitis B, but its correlates with clinical phenotypes are not well described. METHODS: Biopsies were collected from a large cohort of adults and children with chronic hepatitis B viral infection through the Hepatitis B Research Network. Immunohistochemical staining of sections was done for hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) and then centrally read by the pathology committee. The degree of liver injury and pattern of staining were then correlated with clinical characteristics, including the clinical phenotype of hepatitis B. RESULTS: Biopsies from 467 subjects were studied, including 46 from children. Immunostaining for HBsAg was positive in 417 (90%) with scattered hepatocyte staining being the most common pattern. HBsAg staining correlated best with serum levels of HBsAg and hepatitis B viral DNA; the absence of HBsAg staining was often a prelude to loss of HBsAg from serum. HBcAg staining was positive in 225 (49%), and, while cytoplasmic staining was more frequent than nuclear staining, both nuclear and cytoplasmic positivity were often seen in the same specimen. Staining for HBcAg correlated with both level of viremia and liver injury. No biopsies from inactive carriers had stainable HBcAg, while 91% of the biopsies from those with hepatitis B e antigen-positive chronic hepatitis B stained positively for HBcAg. CONCLUSION: Immunostaining for hepatitis B viral antigens may yield helpful insights into liver disease pathogenesis but appears to add little to commonly used serological and biochemical blood tests.
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Hepatite B Crônica , Hepatite B , Humanos , Antígenos de Superfície da Hepatite B , Hepatite B Crônica/patologia , Antígenos do Núcleo do Vírus da Hepatite B , Fígado/patologia , Hepatite B/diagnóstico , Vírus da Hepatite B/genética , DNA ViralRESUMO
Cognitive disengagement syndrome (CDS), previously referred to as sluggish cognitive tempo, is a set of symptoms characterized by excessive daydreaming, mental fogginess, and slowed behavior/thinking. Studies examining the association between CDS and academic functioning have reported mixed findings and have relied upon limited measures of CDS, broad ratings of academic impairment, and/or focused only on elementary-aged children. The current study examined the relationship between CDS and academic functioning in adolescents using a comprehensive, multi-informant, multi-method design. Participants were 302 adolescents (Mage = 13.17 years; 44.7% female; 81.8% White; 52% with ADHD) recruited in the fall of their 8th grade. Above and beyond ADHD inattentive symptoms, CDS symptoms were related to poorer homework performance, lower math fluency, and lower daily academic motivation across multiple informants, and teacher-reported CDS symptoms were related to lower grades. Findings were not moderated by ADHD diagnosis, suggesting that associations between CDS and academic outcomes do not differ for adolescents with and without ADHD. Findings demonstrate that CDS symptoms are uniquely associated with daily academic difficulties as well as global indices of academic performance. These findings have implications for assessing and monitoring CDS symptoms in interventions aiming to improve the academic functioning in adolescents with and without ADHD.
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BACKGROUND: The aim of the present study was to determine the impact of an innovative interprofessional educational activity on healthcare professional students' learning. The educational activity targeted student knowledge of opioid use disorder (OUD) and perceptions of working with an interprofessional team while caring for patients with OUD. METHODS: Students from nursing, pharmacy, physician assistant, dentistry, social work, and medicine programs were recruited to participate in the interprofessional educational activity. The educational experience included seven asynchronous modules and a virtual synchronous escape room. Prior to the educational programming, participants completed a pre-survey that assessed their knowledge and attitudes towards working on an interprofessional team and perceptions of patients with OUD. The asynchronous modules were required in order to participate in the escape room and each module contained its own pre/post quiz to assess student knowledge. RESULTS: A total of 402 students participated in the course. Prior to participating in the course, students disagreed that they had extensive educational experience with SUD (2.45 ± 0.79). The students displayed significant improvement in the knowledge based areas after completing the seven asynchronous modules. The largest significant area of knowledge-based improvement was seen in treatment of OUD where on the pre-quiz 65.54 ± 20.21% were answered correctly compared to 95.97 ± 9.61% on the post-quiz. Participation in the escape room significantly changed the students' perceptions of working in interprofessional teams while managing patients with OUD. Of the eleven perception variables assessed, seven showed a significant increase in the post-survey. Following the escape room, participants also strongly agreed that they now would refer patients to colleagues in other disciplines. CONCLUSIONS: An interprofessional educational experience including both an asynchronous course and virtual synchronous escape room can increase participant knowledge around OUD and may improve student perceptions of working with an interprofessional team and caring for patients with OUD.
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Transtornos Relacionados ao Uso de Opioides , Estudantes de Farmácia , Humanos , Currículo , Pessoal de Saúde , Atitude do Pessoal de Saúde , Relações InterprofissionaisRESUMO
INTRODUCTION: In contrast to standard-of-care treatment of newly diagnosed glioblastoma, there is limited consensus on therapy upon disease progression. The role of resection for recurrent glioblastoma remains unclear. This study aimed to identify factors for overall survival (OS) and post-progression survival (PPS) as well as to validate an existing prediction model. METHODS: This was a multi-centre retrospective study that reviewed consecutive adult patients from 2006 to 2019 that received a repeat resection for recurrent glioblastoma. The primary endpoint was PPS defined as from the date of second surgery until death. RESULTS: 1032 glioblastoma patients were identified and 190 (18%) underwent resection for recurrence. Patients that had second surgery were more likely to be younger (<70 years) (adjusted OR: 0.3; 95% CI: 0.1-0.6), to have non-eloquent region tumours (aOR: 1.7; 95% CI: 1.1-2.6) and received temozolomide chemoradiotherapy (aOR: 0.2; 95% CI: 0.1-0.4). Resection for recurrent tumour was an independent predictor for OS (aOR: 1.5; 95% CI: 1.3-1.7) (mOS: 16.9 months versus 9.8 months). For patients that previously received temozolomide chemoradiotherapy and subsequent repeat resection (137, 13%), the median PPS was 9.0 months (IQR: 5.0-17.5). Independent PPS predictors for this group were a recurrent tumour volume of >50cc (aOR: 0.6; 95% CI: 0.4-0.9), local recurrence (aOR: 1.7; 95% CI: 1.1-3.3) and 5-ALA fluorescence-guided resection during second surgery (aOR: 1.7; 95% CI: 1.1-2.8). A National Institutes of Health Recurrent Glioblastoma Multiforme Scale score of 0 conferred an mPPS of 10.0 months, a score of 1-2, 9.0 months and a score of 3, 4.0 months (log-rank test, p-value < 0.05). CONCLUSION: Surgery for recurrent glioblastoma can be beneficial in selected patients and carries an acceptable morbidity rate. The pattern of recurrence influenced PPS and the NIH Recurrent GBM Scale was a reliable prognostication tool.
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The brain renin-angiotensin system (RAS) is implicated in control of blood pressure (BP), fluid intake, and energy expenditure (EE). Angiotensin II (ANG II) within the arcuate nucleus of the hypothalamus contributes to control of resting metabolic rate (RMR) and thereby EE through its actions on Agouti-related peptide (AgRP) neurons, which also contribute to EE control by leptin. First, we determined that although leptin stimulates EE in control littermates, mice with transgenic activation of the brain RAS (sRA) exhibit increased EE and leptin has no additive effect to exaggerate EE in these mice. These findings led us to hypothesize that leptin and ANG II in the brain stimulate EE through a shared mechanism. Because AgRP signaling to the melanocortin MC4R receptor contributes to the metabolic effects of leptin, we performed a series of studies examining RMR, fluid intake, and BP responses to ANG II in mice rendered deficient for expression of MC4R via a transcriptional block (Mc4r-TB). These mice were resistant to stimulation of RMR in response to activation of the endogenous brain RAS via chronic deoxycorticosterone acetate (DOCA)-salt treatment, whereas fluid and electrolyte effects remained intact. These mice were also resistant to stimulation of RMR via acute intracerebroventricular (ICV) injection of ANG II, whereas BP responses to ICV ANG II remained intact. Collectively, these data demonstrate that the effects of ANG II within the brain to control RMR and EE are dependent on MC4R signaling, whereas fluid homeostasis and BP responses are independent of MC4R signaling.
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Angiotensina II , Metabolismo Energético , Leptina , Receptor Tipo 4 de Melanocortina , Proteína Relacionada com Agouti/metabolismo , Angiotensina II/farmacologia , Animais , Pressão Sanguínea/fisiologia , Encéfalo/metabolismo , Metabolismo Energético/fisiologia , Leptina/metabolismo , Leptina/farmacologia , Melanocortinas/metabolismo , Melanocortinas/farmacologia , Camundongos , Receptor Tipo 4 de Melanocortina/metabolismoRESUMO
BACKGROUND: Research examining the neural correlates of obesity has recently expanded. However, limited attention has focused on identifying unique brain signatures associated with obesity, particularly in adolescents. The aim of this study was to use surface-based approaches to examine the integrity of brain structures involved in processing the pleasurable effects of food with body mass and food reward sensitivity in adolescent girls. METHODS: Structural morphology of the nucleus accumbens, amygdala, pallidum, and orbitofrontal cortex was examined in 89 adolescent girls with body mass ranging from normal to obese. High-resolution T1-weighted MPRAGE images were used to characterize deep-brain nuclei with high-dimensional diffeomorphic mapping procedures, while cortical thickness was derived from the FreeSurfer toolkit. RESULTS: Results revealed that zBMI was significantly associated with the shape of the left amygdala (ß = -1.1, p < 0.021, 95% CI = -2.02, -0.16), volume of the right and left pallidum (ß = 49.66, p < 0.010, 95% CI = 11.74, 87.58; ß = 47.87, p < 0.017, 95% CI = 8.48, 87.25), and cortical thickness of the lateral and right medial orbitofrontal cortex (ß = -0.06, p < 0.001, 95% CI = -0.09, -0.04; ß = -0.05, p = 0.004, 95% CI = -0.08, -0.02). Sensitivity to food reward significantly predicted volume of the right nucleus accumbens (ß = 0.66, p = 0.047, 95% CI = 0.01, 1). Contrast mapping for surface shape of the amygdala revealed significant outward deformation of the posterior lateral left amygdala and an inward deformation of the basolateral left amygdala in the group with overweight/obesity. CONCLUSIONS: Integrity of the left amygdala and orbitofrontal cortex varies as a function of body mass, with greater localized amygdalar volume loss, pallidum volume, and increased cortical thinning of the orbitofrontal cortex occurring as weight increases. Thus, overweight/obesity may be associated with surface-based abnormalities in brain structures associated with processing of reward value related to food. Overall, findings highlight the importance of understanding changes in reward-related brain regions and how they pertain to variability in body mass in adolescent girls.
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Afinamento Cortical Cerebral , Sobrepeso , Adolescente , Encéfalo , Feminino , Humanos , Imageamento por Ressonância Magnética , Obesidade , RecompensaRESUMO
The renin-angiotensin system (RAS) within the brain is implicated in the control of fluid and electrolyte balance, autonomic functions, blood pressure, and energy expenditure. Mouse models are increasingly used to explore these mechanisms; however, sex and dose dependencies of effects elicited by chronic intracerebroventricular (ICV) angiotensin II (ANG II) infusion have not been carefully established in this species. To examine the interactions among sex, body mass, and ICV ANG II on ingestive behaviors and energy balance, young adult C57BL/6J mice of both sexes were studied in a multiplexed metabolic phenotyping system (Promethion) during chronic infusion of ANG II (0, 5, 20, or 50 ng/h). At these infusion rates, ANG II caused accelerating dose-dependent increases in drinking and total energy expenditure in male mice, but female mice exhibited a complex biphasic response with maximum responses at 5 ng/h. Body mass differences did not account for sex-dependent differences in drinking behavior or total energy expenditure. In contrast, resting metabolic rate was similarly increased by ICV ANG II in a dose-dependent manner in both sexes after correction for body mass. We conclude that chronic ICV ANG II stimulates water intake, resting, and total energy expenditure in male C57BL/6J mice following straightforward accelerating dose-dependent kinetics, but female C57BL/6J mice exhibit complex biphasic responses to ICV ANG II. Furthermore, control of resting metabolic rate by ANG II is dissociable from mechanisms controlling fluid intake and total energy expenditure. Future studies of the sex dependency of ANG II within the brain of mice must be designed to carefully consider the biphasic responses that occur in females.
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Angiotensina II , Angiotensina II/farmacologia , Animais , Pressão Sanguínea/fisiologia , Feminino , Homeostase , Infusões Intraventriculares , Injeções Intraventriculares , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Hypertension characterized by low circulating renin activity accounts for roughly 25%-30% of primary hypertension in humans and can be modeled experimentally via deoxycorticosterone acetate (DOCA)-salt treatment. In this model, phenotypes develop in progressive phases, although the timelines and relative contributions of various mechanisms to phenotype development can be distinct between laboratories. To explore interactions among environmental influences such as diet formulation and dietary sodium (Na) content on phenotype development in the DOCA-salt paradigm, we examined an array of cardiometabolic endpoints in young adult male C57BL/6J mice during sham or DOCA-salt treatments when mice were maintained on several common, commercially available laboratory rodent "chow" diets including PicoLab 5L0D (0.39% Na), Envigo 7913 (0.31% Na), Envigo 2920x (0.15% Na), or a customized version of Envigo 2920x (0.4% Na). Energy balance (weight gain, food intake, digestive efficiency, and energy efficiency), fluid and electrolyte homeostasis (fluid intake, Na intake, fecal Na content, hydration, and fluid compartmentalization), renal functions (urine production rate, glomerular filtration rate, urine Na excretion, renal expression of renin, vasopressin receptors, aquaporin-2 and relationships among markers of vasopressin release, aquaporin-2 shedding, and urine osmolality), and blood pressure, all exhibited changes that were subject to interactions between diet and DOCA-salt. Interestingly, some of these phenotypes, including blood pressure and hydration, were dependent on nonsodium dietary components, as Na-matched diets resulted in distinct phenotype development. These findings provide a broad and robust illustration of an environment × treatment interaction that impacts the use and interpretation of a common rodent model of low-renin hypertension.
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Acetato de Desoxicorticosterona , Hipertensão , Animais , Aquaporina 2 , Pressão Sanguínea/fisiologia , Desoxicorticosterona/farmacologia , Acetato de Desoxicorticosterona/farmacologia , Dieta , Hipertensão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Renina/metabolismo , Sódio/metabolismoRESUMO
BACKGROUND: Beverage and food taxes have become a popular 'best buy' public health intervention in the global battle to tackle noncommunicable diseases. Though many countries have introduced taxes, mainly targeting products containing sugar, there is great heterogeneity in tax design. For taxes levied as import tariffs, there is limited evidence of effectiveness in changing the price and sale of taxed products, while the evidence base is stronger for excise taxes levied as a fixed amount per quantity of product. This paper examines the effect of the Bermuda Discretionary Foods Tax, which was based on import tariff changes, on retail prices and sales of sugar-sweetened beverages (SSBs), and on selected fruits and vegetables that benefited from a tariff reduction. METHODS: We used weekly electronic point-of-sale data from a major food retailer in Bermuda. We assessed historical weekly sales and price data using an interrupted time series design on 2,703 unique products between the dates of January 2018 through January 2020, covering 103 weeks. RESULTS: By January 2020, the average price per ounce of SSBs increased by 26.0%, while the price of untaxed beverages (including waters and non-added sugar drinks) remained constant. The increasing price of SSBs was the sole observable structural driver of SSB market share, responsible for a decrease in the market share by nearly eight percentage points by the end of the study period. The subsidy on fruits and vegetables was ineffective in changing prices and sales, due to the relatively small 5% import tax decrease. CONCLUSIONS: The tax was largely passed through to consumers. However, several factors mitigated the impact of the tax on the prices paid for SSBs by consumers, including the specific design of the tax, price promotions and consumer responses. The experience of Bermuda provides important lessons for the planning of similar taxes in the future.
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Bebidas Adoçadas com Açúcar , Açúcares , Bebidas , Comércio , Humanos , Análise de Séries Temporais Interrompida , ImpostosRESUMO
BACKGROUND: Taxes on discretionary foods and sugar-sweetened beverages have emerged as a strategy for health promotion. Between 2018-2019, the Bermuda government introduced a phased tax on imported sugar-sweetened beverages, confectionery, products containing cocoa and pure sugar, and eliminated import duties on select healthy food items. The aim of this study was to conduct an mixed methods evaluation of perceptions of the tax among the general population and key stakeholders. METHODS: We conducted a survey of the general population (N = 400), and semi-structured interviews with key informants (N = 14) from the government, food and beverage, and health sectors to understand awareness, acceptability, and perceived impact of the tax after implementation. Survey data was analysed using thematic analysis, summary statistics, and Chi-squared tests. Key informant interviews were analysed using the framework method. RESULTS: General population respondents had high awareness of the sugar tax (94%) but low awareness of the healthy food subsidy (32%). Most respondents (67%) felt the tax was not an appropriate way to motivate healthier consumption due to beliefs the tax would not be effective (44%), and because of the high price of healthy food (20%). However, nearly half (48%) reported consuming fewer taxed products, primarily for health reasons but also motivated by price increases. Key informants indicated there was high awareness but limited understanding of the tax policy. Informants expressed support for taxation as a health promotion strategy, conditional on policy implementation. The lack of clear price differentiation between taxed and un-taxed products and the absence of accompanying health education were key factors believed to affect the impact of the tax. No informants were aware of use of tax revenues for health purposes and tax revenue was reportedly re-directed to other priorities after implementation. CONCLUSIONS: There was high awareness, but limited acceptability of the Bermuda sugar tax as implemented. Clarity in the tax policy, appropriateness of the tax mechanism, and use of revenue in alignment with the tax aim are critical components for acceptance. The absence of complementary education and health promotion affected acceptance and may limit potential health impacts. The lessons learned in Bermuda can inform similar policies in other settings.
Assuntos
Bebidas Adoçadas com Açúcar , Açúcares , Bermudas , Bebidas , Comércio , Humanos , ImpostosRESUMO
Research on the pretesting effect has shown that attempting to retrieve or generate information, even when unsuccessful, can potentiate the subsequent learning and remembering of that information. In the current research, we tested the hypothesis that when information can be accessed online, people may be less likely to retrieve or generate information on their own, thus making them less likely to benefit from the pretesting effect. The results of two experiments failed to provide support for this hypothesis. Participants remembered pretested information better than non-pretested information regardless of whether they were required to attempt to retrieve answers from memory or search for the answers using Google. The results suggest that the benefits of pretesting can be observed even when people rely on the internet to answer the questions they encounter.
Assuntos
Aprendizagem , Rememoração Mental , Humanos , InternetRESUMO
Stopping action depends on the integrity of the right inferior frontal gyrus (rIFG). Electrocorticography from the rIFG shows an increase in beta power during action stopping. Scalp EEG shows a similar right frontal beta increase, but it is unknown whether this beta modulation relates to the underlying rIFG network. Demonstrating a causal relationship between the rIFG and right frontal beta in EEG during action stopping is important for putting this electrophysiological marker on a firmer footing. In a double-blind study with a true sham coil, we used fMRI-guided 1-Hz repetitive transcranial magnetic stimulation (rTMS) to disrupt the rIFG and to test whether this reduced right frontal beta and impaired action stopping. We found that rTMS selectively slowed stop signal reaction time (SSRT) (no effect on Go) and reduced right frontal beta (no effect on sensorimotor mu/beta related to Go); it also reduced the variance of a single-trial muscle marker of stopping. Surprisingly, sham stimulation also slowed SSRTs and reduced beta. Part of this effect, however, resulted from carryover of real stimulation in participants who received real stimulation first. A post hoc between-group comparison of those participants who received real first compared with those who received sham first showed that real stimulation reduced beta significantly more. Thus, real rTMS uniquely affected metrics of stopping in the muscle and resulted in a stronger erosion of beta. We argue that this causal test validates right frontal beta as a functional marker of action stopping.NEW & NOTEWORTHY Action stopping recruits the right inferior frontal gyrus (rIFG) and elicits increases in right frontal beta. The present study now provides causal evidence linking these stopping-related beta oscillations to the integrity of the underlying rIFG network. One-hertz transcranial magnetic stimulation (TMS) over the rIFG impaired stopping and reduced right frontal beta during a stop-signal task. Furthermore, the effect on neural oscillations was specific to stopping-related beta, with no change in sensorimotor mu/beta corresponding to the Go response.
Assuntos
Ritmo beta , Lobo Frontal/fisiologia , Músculo Esquelético/fisiologia , Feminino , Humanos , Masculino , Músculo Esquelético/inervação , Estimulação Magnética Transcraniana/métodos , Adulto JovemRESUMO
Cyanobacteria possess unique intracellular organization. Many proteomic studies have examined different features of cyanobacteria to learn about the intracellular structures and their respective functions. While these studies have made great progress in understanding cyanobacterial physiology, the conventional fractionation methods used to purify cellular structures have limitations; specifically, certain regions of cells cannot be purified with existing fractionation methods. Proximity-based proteomics techniques were developed to overcome the limitations of biochemical fractionation for proteomics. Proximity-based proteomics relies on spatiotemporal protein labeling followed by mass spectrometry of the labeled proteins to determine the proteome of the region of interest. We performed proximity-based proteomics in the cyanobacterium Synechococcus sp. PCC 7002 with the APEX2 enzyme, an engineered ascorbate peroxidase. We determined the proteome of the thylakoid lumen, a region of the cell that has remained challenging to study with existing methods, using a translational fusion between APEX2 and PsbU, a lumenal subunit of photosystem II. Our results demonstrate the power of APEX2 as a tool to study the cell biology of intracellular features and processes, including photosystem II assembly in cyanobacteria, with enhanced spatiotemporal resolution.