RESUMEN
Plasmodium parasites cause malaria with disease outcomes ranging from mild illness to deadly complications such as severe malarial anemia (SMA), pulmonary edema, acute renal failure, and cerebral malaria. In young children, SMA often requires blood transfusion and is a major cause of hospitalization. Malaria parasite infection leads to the destruction of infected and noninfected erythrocytes as well as dyserythropoiesis; however, the mechanism of dyserythropoiesis accompanied by splenomegaly is not completely understood. Using Plasmodium yoelii yoelii 17XNL as a model, we show that both a defect in erythroblastic island (EBI) macrophages in supporting red blood cell (RBC) maturation and the destruction of reticulocytes/RBCs by the parasites contribute to SMA and splenomegaly. After malaria parasite infection, the destruction of both infected and noninfected RBCs stimulates extramedullary erythropoiesis in mice. The continuous decline of RBCs stimulates active erythropoiesis and drives the expansion of EBIs in the spleen, contributing to splenomegaly. Phagocytosis of malaria parasites by macrophages in the bone marrow and spleen may alter their functional properties and abilities to support erythropoiesis, including reduced expression of the adherence molecule CD169 and inability to support erythroblast differentiation, particularly RBC maturation in vitro and in vivo. Therefore, macrophage dysfunction is a key mechanism contributing to SMA. Mitigating and/or alleviating the inhibition of RBC maturation may provide a treatment strategy for SMA.
Asunto(s)
Anemia , Malaria Cerebral , Plasmodium yoelii , Niño , Humanos , Animales , Ratones , Preescolar , Eritropoyesis , Esplenomegalia , Eritrocitos , MacrófagosRESUMEN
While environmental justice (EJ) research in the United States has focused primarily on the social distribution of chronic pollution risks, previous empirical studies have not analyzed disparities in exposure to both chronic (long-term) and acute (short-term) pollution in the same study area. Our article addresses this limitation though a case study that compares social inequities in exposure to chronic and acute pollution risks in the Greater Houston Metropolitan Statistical Area, Texas. The study integrates estimates of chronic cancer risk associated with ambient exposure to hazardous air pollutants from the Environmental Protection Agency's National-Scale Air Toxics Assessment (2005), hazardous chemical accidents from the National Response Center's Emergency Response Notification System (2007-2011), and sociodemographic characteristics from the American Community Survey (2007-2011). Statistical analyses are based on descriptive comparisons, bivariate correlations, and locally derived spatial regression models that account for spatial dependence in the data. Results indicate that neighborhoods with a higher percentage of Hispanic residents, lower percentage of homeowners, and higher income inequality are facing significantly greater exposure to both chronic and acute pollution risks. The non-Hispanic black percentage is significantly higher in neighborhoods with greater chronic cancer risk, but lower in areas exposed to acute pollution events. Households isolated by language--those highly likely to face evacuation problems during an actual chemical disaster--tend to reside in areas facing significantly greater exposure to high-impact acute events. Our findings emphasize the growing need to examine social inequities in exposure to both chronic and acute pollution risks in future EJ research and policy.
Asunto(s)
Contaminación del Aire , Exposición a Riesgos Ambientales , Análisis Multivariante , Medición de Riesgo , TexasRESUMEN
Drawing on ethnographic data collected in three informal communities, one in Argentina, one in México, and one in Ecuador, we address the long-standing question posed by Larissa Lomnitz's and Carol Stack's now-classic studies of how impoverished people not only survive but what strategies they adopt in an attempt to build a dignified life. By focusing on the diversity of strategies by which the urban poor solve the everyday problems of individual and collective reproduction, we move beyond the macro-level analysis of structural constraint and material deprivation. Our findings show a remarkable continuity in the difficulties residents of these informal communities confronted and the problem-solving strategies they resorted to. We found that networks of kin and friends continue to play a crucial role in how poor people not only survive but attempt to get ahead. Additionally, we highlight the role of patronage networks and collective action as central to strategies by which the urban poor cope with scarcity and improve their life chances, while also paying close attention to ways in which they deal with pressing issues of insecurity and violence. The paper shows that poor people's survival strategies are deeply imbricated in routine political processes.
RESUMEN
Importance: Social and economic contexts shape children's short- and long-term health. Efforts to address contextual risk factors are increasingly incorporated into pediatric health care. Objective: To compare the effectiveness of 2 social risk-related interventions. Design, Setting, and Participants: This randomized clinical trial included English- and/or Spanish-speaking caregiver-child dyads recruited from a pediatric urgent care clinic nested in a large, urban, safety-net hospital. Study recruitment, enrollment, and follow-up were conducted from July 18, 2016, to March 8, 2019. Data analysis was conducted from January 1, 2019, to January 20, 2020. Interventions: Following standardized social risk assessment, caregivers were randomly assigned to receive either written information regarding relevant government and community social services resources or comparable written information plus in-person assistance and follow-up focused on service access. Main Outcomes and Measures: Caregiver-reported number of social risk factors and child health 6 months after enrollment. Results: Among 611 caregiver-child dyads enrolled in the study, 302 dyads were randomized to the written resources group and 309 dyads were randomized to the written resources plus in-person assistance group. The mean (SD) age of children was 6.1 (5.0) years; 483 children (79.1%) were Hispanic; and 315 children (51.6%) were girls. There were no significant differences between groups in the effects of the interventions. In post hoc secondary analyses, the number of reported social risks decreased from baseline to 6-month follow-up in both groups: caregivers who received written resources alone reported a mean (SE) of 1.28 (0.19) fewer risks at follow-up, while those receiving written resources plus in-person assistance reported 1.74 (0.21) fewer risks at follow-up (both P < .001). In both groups, there were small but statistically significant improvements from baseline to follow-up in child health (mean [SE] change: written resources, 0.37 [0.07]; written resources plus in-person assistance, 0.24 [0.07]; both P < .001). Conclusions and Relevance: This randomized clinical trial compared 2 approaches to addressing social risks in a pediatric urgent care setting and found no statistically significant differences in the social risk and child and caregiver health effects of providing written resources at the point of care with vs without in-person longitudinal navigation services. Caregivers in both groups reported fewer social risks and improved child and caregiver health 6 months after the intervention. These findings deepen understanding of effective doses of social risk-related interventions. Trial Registration: ClinicalTrials.gov Identifier: NCT02746393.
Asunto(s)
Cuidadores/psicología , Servicios de Salud del Niño/organización & administración , Salud Infantil , Padres/psicología , Servicio Social/métodos , Adolescente , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Masculino , Estudios RetrospectivosRESUMEN
Resumen Alrededor del 75% de los habitantes de Metlatónoc, Guerrero, viven en pobreza extrema (ENSANUT, 2012), lo que aumenta sus probabilidades de padecer problemas de salud, fundamentalmente en materias de higiene y nutrición. Para proporcionar a esta población herramientas que mejoren el control sobre la toma de decisiones que afectan su salud y prevenir enfermedades, se implementó un programa comunitario basado en habilidades para la vida y en el Marco para Facilitar el Empoderamiento Intrínseco (Pick y Sirkin, 2010). Se impartió un taller para formar a 35 promotores, quienes lo replicaron con la población meta siguiendo una metodología participativa y vivencial, llegando a 4,728 personas -casi todas mujeres-. Para evaluar el efecto del programa se aplicó un cuestionario de autorreporte; con los promotores se utilizó un diseño longitudinal: pre, post y seguimiento, y con la población meta un diseño pre-post con grupo control. Se encontraron efectos favorables y significativos en gran parte de las variables evaluadas (conocimientos, actitudes y conductas meta, habilidades para la vida, barreras psicosociales, agencia personal y empoderamiento intrínseco), en ambos tipos de participantes. Los hallazgos se discuten a la luz de su contribución para disminuir la vulnerabilidad de las personas y potenciar su desarrollo.
Abstract About 75% of the population of Metlatónoc, Guerrero, México, lives in extreme poverty (ENSANUT, 2012), which increases the probability of having health problems, regarding their hygiene and nutrition. In order to facilitate tools which can allow this population to improve their control over their decisions with respect to their health and disease prevention, a community-based program based on life skills and the Framework for Enabling Intrinsic Empowerment (Pick y Sirkin, 2010) was implemented. Thirty five promoters were trained through an experiential workshop, who replicated it with 4,728 people -mostly women-. To evaluate the program effect, a self-report questionnaire was applied; a longitudinal design (pre, post and follow-up) was used with the promoters and a pre-post with control group with the target population. With both groups, positive statistically significant effects were found in most of the variables: knowledge, attitudes and target behaviors, life skills, psychosocial barriers, personal agency and intrinsic empowerment. Findings are discussed in light of their contribution to diminish the vulnerability of this population, and strengthen their potential for development.