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Mortgage discrimination alters the distribution of investment, opportunity, and economic advantage-key contributors of health disparities. Leveraging Home Mortgage Disclosure Act data, we assessed mortgage denial risk in 380 U.S. urban areas. We estimated the risks by census tract-relative to the urban-specific average-using a Bayesian spatial model with conditionally autoregressive distributions fitted with integrated nested Laplace approximation. This approach borrows information through spatial and non-spatial smoothing, resulting in stable estimates in the presence of sparse data. The method, publicly accessible, allows researchers to apply our approach, fostering deeper insights into mortgage lending discrimination and systematic neighborhood disinvestment.
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BACKGROUND: Disparities in rates of contraceptive use are frequently attributed to unequal access to and affordability of care. There is a need to better understand whether common definitions of affordability that solely relate to cost or to insurance status capture the reality of individuals' lived experiences. We sought to better understand how individuals with low incomes and the capacity for pregnancy conceptualized one domain of contraceptive access-affordability --in terms of health system and individual access and how both shaped contraceptive care-seeking in the US South. METHOD: Between January 2019 to February 2020, we conducted twenty-five life-history interviews with low-income individuals who may become pregnant living in suburban counties in Georgia, USA. Interviews covered the ways individual and health system access factors influenced care-seeking for family planning over the life course. Interview transcripts were analyzed using a thematic analysis approach to identify experiences associated with individual and health system access. RESULTS: Affordability was identified as a major determinant of access, one tied to unique combinations of individual factors (e.g., financial status) and health system characteristics (e.g., cost of methods) that fluctuated over time. Navigating the process to attain affordable care was unpredictable and had important implications for care-seeking. A "poor fit" between individual and health system factors could lead to inequities in access and gaps in, or non-use of contraception. Participants also reported high levels of shame and stigma associated with being uninsured or on publicly funded insurance. CONCLUSIONS: Affordability is one domain of contraceptive access that is shaped by the interplay between individual factors and health system characteristics as well as by larger structural factors such as health and economic policies that influence both. Assessments of the affordability of contraceptive care must account for the dynamic interplay among multilevel influences. Despite the expansion of contraceptive coverage through the Affordable Care Act, low-income individuals still struggle with affordability and disparities persist.
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Acessibilidade aos Serviços de Saúde , Pobreza , Humanos , Feminino , Adulto , Georgia , Serviços de Planejamento Familiar/economia , Adulto Jovem , Adolescente , Entrevistas como Assunto , Anticoncepção/estatística & dados numéricos , Anticoncepção/economia , Anticoncepção/métodosRESUMO
BACKGROUND: Studies find that delivery hospital explains a significant portion of the Black-White gap in severe maternal morbidity. No such studies have focused on the US Southeast, where racial disparities are widest, and few have examined the relative contribution of hospital, residential, and maternal factors. OBJECTIVE: This study aimed to estimate the portion of Georgia's Black-White gap in severe maternal morbidity during delivery through 42 days postpartum explained by hospital, residential, and maternal factors. STUDY DESIGN: Using linked Georgia hospital discharge, birth, and fetal death records for 2016 through 2020, we identified 413,124 deliveries to non-Hispanic White (229,357; 56%) or Black (183,767; 44%) individuals. We linked hospital data from the American Hospital Association and Center for Medicare and Medicaid Services, and area data from the Area Resource File and American Community Survey. We identified severe maternal morbidity indicator conditions during delivery or subsequent hospitalizations through 42 days postpartum. Using race-specific logistic models followed by a decomposition technique, we estimated the portion of the Black-White severe maternal morbidity gap explained by the following: (1) sociodemographic factors (age, education, marital status, and nativity), (2) medical conditions (diabetes mellitus, gestational diabetes, chronic hypertension, gestational hypertension or preeclampsia, and smoking), (3) obstetrical factors (singleton or multiple, and birth order); (4) access to care (no or third trimester care, and payer), (5) hospital factors that are time-varying (delivery volume, deliveries per full-time equivalent nurse, doctor communication, patient safety, and adverse event composite score) or measured time-invariant characteristics (ownership, profit status, religious affiliation, teaching status, and perinatal level), and (6) residential factors (county urban/rural classification, percent uninsured women of reproductive age, obstetrician-gynecologists per women of reproductive age, number of federally-qualified and community health centers, medically-underserved area [yes/no], and census tract neighborhood deprivation index). We estimated models with and without hospital fixed-effects, which account for unobserved time-invariant hospital characteristics such as within-hospital care processes or unmeasured hospital-specific factors. RESULTS: There was 1.8 times the rate of severe maternal morbidity per 100 discharges among non-Hispanic Black (3.15) than among White (1.73) individuals, with an explained proportion of 30.4% in models without and 49.8% in models with hospital fixed-effects. In the latter, hospital fixed-effects explained the largest portion of the Black-White severe maternal morbidity gap (15.1%) followed by access to care (14.9%) and sociodemographic factors (14.4%), with residential factors being protective for Black individuals (-7.5%). Smaller proportions were explained by medical (5.6%), obstetrical (4.0%), and time-varying hospital factors (3.2%). Within each category, the largest explanatory portion was payer type (13.3%) for access to care, marital status (10.3%) for sociodemographic, gestational hypertension (3.3%) for medical, birth order (3.6%) for obstetrical, and patient safety indicator (3.1%) for time-varying hospital factors. CONCLUSION: Models with hospital fixed-effects explain a greater proportion of Georgia's Black-White severe maternal morbidity gap than models without them, thereby supporting the point that differences in care processes or other unmeasured factors within the same hospital translate into racial differences in severe maternal morbidity during delivery through 42 days postpartum. Research is needed to discern and ameliorate sources of within-hospital differences in care. The substantial proportion of the gap attributable to racial differences in access to care and sociodemographic factors points to other needed policy interventions.
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BACKGROUND: There are significant racial disparities in in vitro fertilization outcomes, which are poorly explained by individual-level characteristics. Environmental factors such as neighborhood-level socioeconomic factors may contribute to these disparities. However, few studies have directly addressed this research question in a large, racially diverse cohort. OBJECTIVE: This study aimed to investigate whether neighborhood deprivation is associated with differences in in vitro fertilization outcomes. STUDY DESIGN: Our retrospective cohort study included 1110 patients who underwent 2254 autologous in vitro fertilization cycles between 2014 and 2019 at an academic fertility center in the Southeastern United States. Neighborhood deprivation was estimated using the Neighborhood Deprivation Index, a composite variable measuring community levels of material capital based on poverty, occupation, housing, and education domains. Using multivariable log-binomial generalized estimating equations with cluster weighting, risk ratios and 95% confidence intervals were estimated for cycle cancellation, miscarriage (defined as spontaneous pregnancy loss before 20 weeks after a confirmed intrauterine gestation), and live birth according to patient Neighborhood Deprivation Index. RESULTS: There were positive associations between increasing Neighborhood Deprivation Index (indicating worsening neighborhood deprivation) and body mass index, as well as increasing prevalence of tubal and uterine factor infertility diagnoses. The crude probability of live birth per cycle was lower among Black (24%) than among White patients (32%), and the crude probability of miscarriage per clinical pregnancy was higher among Black (22%) than among White patients (12%). After adjustment, the Neighborhood Deprivation Index was not significantly associated with risk of cycle cancellation or live birth. Results were consistent when analyses were stratified by race. CONCLUSION: Our research demonstrates racial disparities between Black and White women in the incidence of miscarriage and live birth following in vitro fertilization. Although the level of neighborhood deprivation was closely related to race, it did not have strong associations with in vitro fertilization outcomes in our population as a whole or within strata of race.
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Aborto Espontâneo , Infertilidade , Gravidez , Humanos , Feminino , Aborto Espontâneo/epidemiologia , Estudos Retrospectivos , Fatores Raciais , Fertilização in vitroRESUMO
Disparities in maternal-child health outcomes by race and ethnicity highlight structural differences in the opportunity for optimal health in the United States. Examples of these differences include access to state-level social policies that promote maternal-child health. States vary in their racial and ethnic composition as a result of the complex history of policies and laws related to slavery, Indigenous genocide and relocation, segregation, immigration, and settlement in the United States. States also vary in the social policies they enact. As a result, correlations exist between the demographic makeup of a state's population and the presence or absence of social policies in that state. These correlations become a mechanism by which racial and ethnic disparities in maternal-child health outcomes can operate. In this commentary, we use the example of three labor-related policies actively under consideration at state and federal levels (paid parental leave, paid sick leave, and reasonable accommodations during pregnancy) to demonstrate how correlations between state demographics and presence of these state policies could cause or exacerbate racial and ethnic disparities in maternal-child health outcomes. We conclude with a call for researchers to consider how the geographic distribution of racialized populations and state policies could contribute to maternal-child health disparities.
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PURPOSE: Patient-reported outcome (PRO) measures are increasingly important in evaluating medical care. The increased integration of technology within the healthcare systems allows for collection of PROs electronically. The objectives of this study were to Ashley et al. J Med Internet Res (2013) implement an electronic assessment of PROs in inpatient cancer care and test its feasibility for patients and Dawson et al. BMJ (2010) determine the equivalence of the paper and electronic assessment. METHODS: We analyzed two arms from a study that was originally designed to be an interventional, three-arm, and multicenter inpatient trial. A self-administered questionnaire based on validated PRO-measures was applied and completed at admission, 1 week after, and at discharge. For this analysis - focusing on feasibility of the electronic assessment - the following groups will be considered: Group A (intervention arm) received a tablet version, while group B (control arm) completed the questionnaire on paper. A feasibility questionnaire, that was adapted from Ashley et al. J Med Internet Res (2013), was administered to group A. RESULTS: We analyzed 103 patients that were recruited in oncology wards. ePRO was feasible to most patients, with 84% preferring the electronic over paper-based assessment. The feasibility questionnaire contained questions that were answered on a scale ranging from "1" (illustrating non achievement) to "5" (illustrating achieving goal). The majority (mean 4.24, SD .99) reported no difficulties handling the electronic tool and found it relatively easy finding time for filling out the questionnaire (mean 4.15, SD 1.05). There were no significant differences between the paper and the electronic assessment regarding the PROs. CONCLUSION: Results indicate that electronic PRO assessment in inpatient cancer care is feasible.
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Pacientes Internados , Neoplasias , Humanos , Estudos de Viabilidade , Hospitalização , Neoplasias/terapia , Eletrônica , Medidas de Resultados Relatados pelo PacienteRESUMO
BACKGROUND: It has been hypothesized that low access to healthy and nutritious food increases health disparities. Low-accessibility areas, called food deserts, are particularly commonplace in lower-income neighborhoods. The metrics for measuring the food environment's health, called food desert indices, are primarily based on decadal census data, limiting their frequency and geographical resolution to that of the census. We aimed to create a food desert index with finer geographic resolution than census data and better responsiveness to environmental changes. MATERIALS AND METHODS: We augmented decadal census data with real-time data from platforms such as Yelp and Google Maps and crowd-sourced answers to questionnaires by the Amazon Mechanical Turks to create a real-time, context-aware, and geographically refined food desert index. Finally, we used this refined index in a concept application that suggests alternative routes with similar ETAs between a source and destination in the Atlanta metropolitan area as an intervention to expose a traveler to better food environments. RESULTS: We made 139,000 pull requests to Yelp, analyzing 15,000 unique food retailers in the metro Atlanta area. In addition, we performed 248,000 walking and driving route analyses on these retailers using Google Maps' API. As a result, we discovered that the metro Atlanta food environment creates a strong bias towards eating out rather than preparing a meal at home when access to vehicles is limited. Contrary to the food desert index that we started with, which changed values only at neighborhood boundaries, the food desert index that we built on top of it captured the changing exposure of a subject as they walked or drove through the city. This model was also sensitive to the changes in the environment that occurred after the census data was collected. CONCLUSIONS: Research on the environmental components of health disparities is flourishing. New machine learning models have the potential to augment various information sources and create fine-tuned models of the environment. This opens the way to better understanding the environment and its effects on health and suggesting better interventions.
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Censos , Crowdsourcing , Humanos , Desertos Alimentares , Fonte de Informação , Aprendizado de MáquinaRESUMO
OBJECTIVES: To understand perinatal risks associated with social needs in pregnancy Methods. Multivariable log-binomial regression analyses adjusting for age, parity, and insurance were used to evaluate the relationship between any social need (e.g., housing, transportation, food, and intimate partner violence) and adverse perinatal outcomes (stillbirth, prematurity, maternal morbidity) in a cohort of English and Spanish-speaking patients who obtained prenatal care and birthed at our institution during a one-year period. RESULTS: Of 2,435 patients, 1,608 (66%) completed social needs screening at least once during prenatal care. The cohort was predominantly non-Hispanic Black (1,294, 80%) and publicly insured (1,395, 87%). Having one or more social need was associated with three-fold increased risk of stillbirth (aRR 3.35, 95%CI 1.31,8.6) and 14% reduction in postpartum care attendance (aRR 0.86, 95%CI 0.78-0.95) and was highest in individuals reporting transportation needs. CONCLUSIONS: Social needs during pregnancy were associated with increased risk of stillbirth.
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Violência por Parceiro Íntimo , Natimorto , Gravidez , Feminino , Humanos , Natimorto/epidemiologia , Determinantes Sociais da Saúde , Cuidado Pré-Natal , PartoRESUMO
The indirect effect of radiation plays an important role in radio-induced biological damages. Monte Carlo codes have been widely used in recent years to study the chemical evolution of particle tracks. However, due to the large computational efforts required, their applicability is typically limited to simulations in pure water targets and to temporal scales up to the µs. In this work, a new extension of TRAX-CHEM is presented, namely TRAX-CHEMxt, able to predict the chemical yields at longer times, with the capability of exploring the homogeneous biochemical stage. Based on the species coordinates produced around one track, the set of reaction-diffusion equations is solved numerically with a computationally light approach based on concentration distributions. In the overlapping time scale (500 ns-1 µs), a very good agreement to standard TRAX-CHEM is found, with deviations below 6% for different beam qualities and oxygenations. Moreover, an improvement in the computational speed by more than three orders of magnitude is achieved. The results of this work are also compared with those from another Monte Carlo-based algorithm and a fully homogeneous code (Kinetiscope). TRAX-CHEMxt will allow for studying the variation in chemical endpoints at longer timescales with the introduction, as the next step, of biomolecules, for more realistic assessments of biological response under different radiation and environmental conditions.
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Algoritmos , Difusão , Método de Monte Carlo , Simulação por ComputadorRESUMO
There are inequities in HIV outcomes among Black gay, bisexual, and other sexual minority men who have sex with men (GBMSM) compared to GBMSM overall, including access to transportation to HIV care. It is unclear if the relationship between transportation and clinical outcomes extends to viral load. We assessed the relationship between transportation dependence to an HIV provider and undetectable viral load among Black and White GBMSM in Atlanta. We collected transportation and viral load information from GBMSM with HIV from 2016-2017 (n = 345). More Black than White GBMSM had a detectable viral load (25% vs. 15%) and took dependent (e.g. public) transportation (37% vs. 18%). Independent (e.g. car) transportation was associated with undetectable viral load for White GBMSM (cOR 3.61, 95% CI 1.45, 8.97) but was attenuated by income (aOR. 2.29, 95% CI 0.78, 6.71), and not associated for Black GBMSM (cOR 1.18, 95% CI 0.58, 2.24). One possible explanation for no association for Black GBMSM is that there are more competing barriers to HIV care for Black GBMSM than White GBMSM. Further investigation is needed to confirm whether 1) transportation is unimportant for Black GBMSM or 2) transportation interacts with additional factors not considered in this analysis.
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Infecções por HIV , Equidade em Saúde , Minorias Sexuais e de Gênero , Masculino , Humanos , Homossexualidade Masculina , Georgia/epidemiologia , Carga Viral , Fatores Raciais , Comportamento SexualRESUMO
BACKGROUND: Pregnancy-related mortality in the United States is the greatest among all high-income countries, and Georgia has one of the highest maternal mortality rates-almost twice the national rate. Furthermore, inequities exist in rates of pregnancy-related deaths. In Georgia, non-Hispanic Black women are nearly 3 times more likely to die from pregnancy-related complications than non-Hispanic White women. Unlike health equity, a clear definition of maternal health equity is lacking, overall and in Georgia specifically, but is needed to reach consensus and align stakeholders for action. Therefore, we used a modified Delphi method to define maternal health equity in Georgia and to determine research priorities based on gaps in understanding of maternal health in Georgia. METHODS: Thirteen expert members of the Georgia Maternal Health Research for Action Steering Committee (GMHRA-SC) participated in an iterative, consensus-driven, modified Delphi study comprised of 3 rounds of anonymous surveys. In round 1 (web-based survey), experts generated open-ended concepts of maternal health equity and listed research priorities. In rounds 2 (web-based meeting) and 3 (web-based survey), the definition and research priorities suggested during round 1 were categorized into concepts for ranking based on relevance, importance, and feasibility. Final concepts were subjected to a conventional content analysis to identify general themes. RESULTS: The consensus definition of maternal health equity created after undergoing the Delphi method is: maternal health equity is the ultimate goal and ongoing process of ensuring optimal perinatal experiences and outcomes for everyone as the result of practices and policies free of interpersonal or structural bias that tackle current and historical injustices, including social, structural, and political determinants of health impacting the perinatal period and life course. This definition highlights addressing the current and historical injustices manifested in the social determinants of health, and the structural and political structures that impact the perinatal experience. CONCLUSION: The maternal health equity definition and identified research priorities will guide the GMHRA-SC and the broader maternal health community for research, practice, and advocacy in Georgia.
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Equidade em Saúde , Complicações na Gravidez , Gravidez , Humanos , Feminino , Técnica Delphi , Georgia , Consenso , Saúde Materna , PesquisaRESUMO
Highly public anti-Black violence may increase preterm birth in the general population of pregnant women via stress-mediated paths, particularly Black women exposed in early gestation. To examine spillover from racial violence in the US, we included a total of 49 high publicity incidents of the following types: police lethal force toward Black persons, legal decisions not to indict/convict officers involved, and hate crime murders of Black victims. National search interest in these incidents was measured via Google Trends to proxy for public awareness of racial violence. Timing of racial violence was coded in relation to a three-month preconception period and subsequent pregnancy trimesters, with the primary hypothesis being that first trimester exposure is associated with higher preterm birth odds. The national sample included 1.6 million singleton live births to US-born Black mothers and 6.6 million births to US-born White mothers from 2014 to 2017. Using a preregistered analysis plan, findings show that Black mothers had 5% higher preterm birth odds when exposed to any high publicity racial incidents relative to none in their first trimester, and 2-3% higher preterm birth odds with each log10 increase in national interest. However, post hoc sensitivity tests that included month fixed effects attenuated these associations to null. For White mothers, associations were smaller but of a similar pattern, and were attenuated when including month fixed effects. Highly public anti-Black violence may act as a national stressor, yet whether racial violence is associated with reproductive outcomes in the population is unknown and merits further research.
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Policy Points Policies that increase county income levels, particularly for middle-income households, may reduce low birth weight rates and shrink disparities between Black and White infants. Given the role of aggregate maternal characteristics in predicting low birth weight rates, policies that increase human capital investments (e.g., funding for higher education, job training) could lead to higher income levels while improving population birth outcomes. The association between county income levels and racial disparities in low birth weight is independent of disparities in maternal risks, and thus a broad set of policies aimed at increasing income levels (e.g., income supplements, labor protections) may be warranted. CONTEXT: Low birth weight (LBW; <2,500 grams) and infant mortality rates vary among place and racial group in the United States, with economic resources being a likely fundamental contributor to these disparities. The goals of this study were to examine time-varying county median income as a predictor of LBW rates and Black-White LBW disparities and to test county prevalence and racial disparities in maternal sociodemographic and health risk factors as mediators. METHODS: Using national birth records for 1992-2014 from the National Center for Health Statistics, a total of approximately 27.4 million singleton births to non-Hispanic Black and White mothers were included. Data were aggregated in three-year county-period observations for 868 US counties meeting eligibility requirements (n = 3,723 observations). Sociodemographic factors included rates of low maternal education, nonmarital childbearing, teenage pregnancy, and advanced-age pregnancy; and health factors included rates of smoking during pregnancy and inadequate prenatal care. Among other covariates, linear models included county and period fixed effects and unemployment, poverty, and income inequality. FINDINGS: An increase of $10,000 in county median income was associated with 0.34 fewer LBW cases per 100 live births and smaller Black-White LBW disparities of 0.58 per 100 births. Time-varying county rates of maternal sociodemographic and health risks mediated the association between median income and LBW, accounting for 65% and 25% of this estimate, respectively, but racial disparities in risk factors did not mediate the income association with Black-White LBW disparities. Similarly, county median income was associated with very low birth weight rates and related Black-White disparities. CONCLUSIONS: Efforts to increase income levels-for example, through investing in human capital, enacting labor union protections, or attracting well-paying employment-have broad potential to influence population reproductive health. Higher income levels may reduce LBW rates and lead to more equitable outcomes between Black and White mothers.
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População Negra , Mães , Adolescente , Peso ao Nascer , Feminino , Humanos , Lactente , Mortalidade Infantil , Recém-Nascido de Baixo Peso , Recém-Nascido , Gravidez , Estados Unidos/epidemiologiaRESUMO
Studies documenting self-reported experiences of discrimination over the life course have been limited. Such information could be important for informing longitudinal epidemiologic studies of discrimination and health. We characterized trends in self-reports of racial, socioeconomic status, and gender discrimination over time measured using the Experiences of Discrimination Scale, with a focus on whether individuals' reports of lifetime discrimination were consistent over time. Overall experiences of discrimination and the number of settings in which discrimination was reported in 1992, 2000, and 2010 were examined among 2,774 African-American and White adults in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Reports of "ever" experiencing discrimination decreased for all forms of discrimination across the 3 study visits. Approximately one-third (30%-41%) of the sample inconsistently reported ever experiencing any discrimination over time, which contributed to the observed decreases. Depending on the form of discrimination, inconsistent reporting patterns over time were more common among African-American, younger, less educated, and lower-income individuals and women-groups who are often most exposed to and severely impacted by the health effects of discrimination. Our findings highlight the possible underestimation of the lifetime burden of discrimination when utilizing the Experiences of Discrimination Scale to capture self-reports of discrimination over time.
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Racismo , Negro ou Afro-Americano , Feminino , Humanos , Grupos Raciais , Classe Social , População Branca , Adulto JovemRESUMO
BACKGROUND: Oliceridine is a biased ligand at the µ-opioid receptor recently approved for the treatment of acute pain. In a thorough QT study, corrected QT (QTc) prolongation displayed peaks at 2.5 and 60 minutes after a supratherapeutic dose. The mean plasma concentration peaked at 5 minutes, declining rapidly thereafter. OBJECTIVE: The purpose of this study was to examine the basis for the delayed effect of oliceridine to prolong the QTc interval. METHODS: Repolarization parameters and tissue accumulation of oliceridine were evaluated in rabbit left ventricular wedge preparations over a period of 5 hours. The effects of oliceridine on ion channel currents were evaluated in human embryonic kidney and Chinese hamster ovary cells. Quinidine was used as a control. RESULTS: Oliceridine and quinidine produced a progressive prolongation of the QTc interval and action potential duration over a period of 5 hours, paralleling slow progressive tissue uptake of the drugs. Oliceridine caused modest prolongation of these parameters, whereas quinidine produced a prominent prolongation of action potential duration and QTc interval as well as development of early afterdepolarization (after 2 hours), resulting in a high torsades de pointes score. The 50% inhibitory concentration values for the oliceridine inhibition of the rapidly activating delayed rectifier current (human ether a-go-go current) and late sodium channel current were 2.2 and 3.45 µM when assessed after traditional acute exposure but much lower after 3 hours of drug exposure. CONCLUSION: Our findings suggest that a gradual increase of intracellular access of drugs to the hERG channels as a result of their intracellular uptake and accumulation can significantly delay effects on repolarization, thus confounding the assessment of QT interval prolongation and arrhythmic risk when studied acutely. The multi-ion channel effects of oliceridine, late sodium channel current inhibition in particular, point to a low risk of devloping torsades de pointes.
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Arritmias Cardíacas , Canal de Potássio ERG1/antagonistas & inibidores , Compostos de Espiro/farmacocinética , Tiofenos/farmacocinética , Analgésicos Opioides/farmacocinética , Animais , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/fisiopatologia , Arritmias Cardíacas/prevenção & controle , Linhagem Celular , Cricetulus , Humanos , Concentração Inibidora 50 , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/metabolismo , Síndrome do QT Longo/fisiopatologia , Moduladores de Transporte de Membrana/farmacologia , Quinidina/farmacocinética , Distribuição Tecidual , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacocinéticaRESUMO
BACKGROUND AND PURPOSE: Recent observations in animal models show that ultra-high dose rate ("FLASH") radiation treatment significantly reduces normal tissue toxicity maintaining an equivalent tumor control. The dependence of this "FLASH" effect on target oxygenation has led to the assumption that oxygen "depletion" could be its major driving force. MATERIALS AND METHODS: In a bottom-up approach starting from the chemical track evolution of 1 MeV electrons in oxygenated water simulated with the TRAX-CHEM Monte Carlo code, we determine the oxygen consumption and radiolytic reactive oxygen species production following a short radiation pulse. Based on these values, the effective dose weighted by oxygen enhancement ratio (OER) or the in vitro cell survival under dynamic oxygen pressure is calculated and compared to that of conventional exposures, at constant OER. RESULTS: We find an excellent agreement of our Monte Carlo predictions with the experimental value for radiolytic oxygen removal from oxygenated water. However, the application of the present model to published radiobiological experiment conditions shows that oxygen depletion can only have a negligible impact on radiosensitivity through oxygen enhancement, especially at typical experimental oxygenations where a FLASH effect has been observed. CONCLUSION: We show that the magnitude and dependence of the "oxygen depletion" hypothesis are not consistent with the observed biological effects of FLASH irradiation. While oxygenation plays an undoubted role in mediating the FLASH effect, we conclude that state-of-the-art radiation chemistry models do not support oxygen depletion and radiation-induced transient hypoxia as the main mechanism.
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Consumo de Oxigênio , Oxigênio , Animais , Elétrons , Método de Monte Carlo , RadiobiologiaRESUMO
BACKGROUND: Preterm birth (PTB) accounts for the majority of perinatal morbidity and mortality in developed nations, accounting for 9.9% of all births in the U.S. in 2016. Prior research has primarily focused on disparities between Black and white mothers' rates of PTB due to racial segregation. However, population health scholarship has been limited on the fastest growing population in the U.S., Asian and Pacific Islanders (API). Racial residential segregation has been well studied, but relatively little research examines the effects of economic segregation on perinatal health. This cross-sectional analysis examines how economic segregation modifies risk for PTB among various API ethnic groups. METHODS: U.S. natality data were used to identify 134 Metropolitan Statistical Areas (MSA) with >500 API births from 2015 to 2017 (n = 766,711). Economic segregation was calculated for each MSA using 2017 income data using the Rank-Order Information Theory Index (H Index). Generalized Estimating Equations estimated the log-odds of PTB, allowing for modification by ethnicity. RESULTS: There is heterogeneity in PTB prevalence by ethnicity and the association of economic segregation is non-linear. The risk for PTB is higher in MSAs with both high and low H Index for Chinese, Filipino, Japanese, Korean, Vietnamese, and Other Pacific Islander mothers. The risk for PTB follows highest in MSAs with mid-range values of standardized H Index for Indian, Hawaiian, Guamanian, and Samoan mothers. Filipino, Hawaiian, Guamanian, and Other Pacific Islander mothers had the highest predicted risk for PTB at mean levels of economic segregation while Chinese mothers had the lowest. CONCLUSION: These findings are examined through the lens of immigration histories related to European colonialism, U.S. imperialism, and globalization. Importantly, the results suggest that current practices of aggregating API health data mask disparities in health and how socially stratifying processes like economic segregation may differ by ethnic group.
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BACKGROUND: Underserved subgroups are less likely to have optimal health prior to pregnancy. We describe preconception health indicators (behavior, pregnancy intention, and obesity) among pregnant Latina women with and without chronic stress in metro Atlanta. DESIGN: We surveyed 110 pregnant Latina women enrolled in prenatal care at three clinics in Atlanta. The survey assessed chronic stress, pregnancy intention, preconception behavior changes (taking folic acid or prenatal vitamins, seeking healthcare advice, any reduction in smoking or drinking), and previous trauma. RESULTS: Specific behaviors to improve health prior to pregnancy were uncommon (e.g., taking vitamins (25.5%) or improving nutrition (20.9%)). Just under half of women were experiencing a chronic stressor at the time of conception (49.5%). Chronically stressed women were more likely to be obese (aOR: 3.0 (1.2, 7.4)), less likely to intend their pregnancy (aOR: 0.3 (0.1, 0.7)), and possibly less likely to report any PHB (45.5% vs. 57.4%; aOR: 0.5 (0.2-1.1)). CONCLUSIONS: Chronically stress women were less likely to enter prenatal care with optimal health. However, preconception behaviors were uncommon overall.
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Cuidado Pré-Concepcional , Cuidado Pré-Natal , Feminino , Hispânico ou Latino , Humanos , Gravidez , Gestantes , Proibitinas , FumarRESUMO
The archaic definition and registration processes for stillbirth currently prevalent in Canada impede both clinical care and public health. The situation is fraught because of definitional problems related to the inclusion of induced abortions at ≥20 weeks' gestation as stillbirths: widespread uptake of prenatal diagnosis and induced abortion for serious congenital anomalies has resulted in an artefactual temporal increase in stillbirth rates in Canada and placed the country in an unfavourable position in international (stillbirth) rankings. Other problems with the Canadian stillbirth definition and registration processes extend to the inclusion of fetal reductions (for multi-fetal pregnancy) as stillbirths, and the use of inconsistent viability criteria for reporting stillbirth. This paper reviews the history of stillbirth registration in Canada, provides a rationale for updating the definition of fetal death and recommends a new definition and improved processes for fetal death registration. The recommendations proposed are intended to serve as a starting point for reformulating issues related to stillbirth, with the hope that building a consensus regarding a definition and registration procedures will facilitate clinical care and public health.
RéSUMé: La définition et les méthodes d'enregistrement archaïques des mortinaissances qui prévalent actuellement au Canada entravent à la fois les soins cliniques et la santé publique. La situation est délicate à cause des problèmes de définition que pose l'inclusion des avortements provoqués à ≥ 20 semaines de gestation parmi les mortinaissances : le recours généralisé au diagnostic prénatal et les avortements provoqués en cas d'anomalies congénitales graves ont entraîné une augmentation temporelle artéfactuelle des taux de mortinatalité au Canada et placé le pays dans une position défavorable dans les classements internationaux (de la mortinatalité). Les autres problèmes dans la définition et les méthodes d'enregistrement canadiennes des mortinaissances sont l'inclusion de la réduction fÅtale (pour les grossesses multifÅtales) parmi les mortinaissances et l'emploi de critères de viabilité inconsistants pour déclarer les mortinaissances. Nous examinons ici l'histoire de l'enregistrement des mortinaissances au Canada, nous justifions une révision possible de la définition de la mort fÅtale et nous recommandons une nouvelle définition et des méthodes d'enregistrement améliorées des morts fÅtales. Les recommandations proposées se veulent un point de départ à une reformulation des questions liées à la mortinatalité, dans l'espoir que l'établissement d'un consensus sur une définition et sur les méthodes d'enregistrement facilitera les soins cliniques et la santé publique.