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ISSUES: Overdose prevention centres (OPC) are non-residential spaces where people can use illicit drugs (that they have obtained elsewhere) in the presence of staff who can intervene to prevent and manage any overdoses that occur. Many reviews of OPCs exist but they do not explain how OPCs work. APPROACH: We carried out a realist review, using the RAMESES reporting standards. We systematically searched for and then thematically analysed 391 documents that provide information on the contexts, mechanisms and outcomes of OPCs. KEY FINDINGS: Our retroductive analysis identified a causal pathway that highlights the feeling of safety - and the immediate outcome of not dying - as conditions of possibility for the people who use OPCs to build trust and experience social inclusion. The combination of safety, trust and social inclusion that is triggered by OPCs can - depending on the contexts in which they operate - generate other positive outcomes, which may include less risky drug use practices, reductions in blood borne viruses and injection-related infections and wounds, and access to housing. These outcomes are contingent on relevant contexts, including political and legal environments, which differ for women and people from racialised minorities. CONCLUSIONS: OPCs can enable people who live with structural violence and vulnerability to develop feelings of safety and trust that help them stay alive and to build longer term trajectories of social inclusion, with potential to improve other aspects of their health and living conditions.
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Sobredosis de Droga , Confianza , Humanos , Sobredosis de Droga/prevención & control , Seguridad , Trastornos Relacionados con Sustancias/prevención & control , Trastornos Relacionados con Sustancias/psicologíaRESUMEN
Natural killer (NK) cell-based immunotherapy is being explored for treating infectious diseases, including viral infections. Here, we discuss evidence of NK cell responses to different viruses, ongoing clinical efforts to treat such infections with NK cell products, and review platforms to generate NK cell products.
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Inmunoterapia , Células Asesinas Naturales , AntiviralesRESUMEN
Facial expressions are one way in which infants and adults communicate emotion. Infants scan expressions similarly to adults, yet it remains unclear whether they are receptive to the affective information they convey. The current study investigates 6-, 9- and 12-month infants' (N = 146) pupillary responses to the six "basic" emotional expressions (happy, sad, surprise, fear, anger, and disgust). To do this we use dynamic stimuli and gaze-contingent eye-tracking to simulate brief interactive exchanges, alongside a static control condition. Infants' arousal responses were stronger for dynamic compared to static stimuli. And for dynamic stimuli we found that, compared to neutral, infants showed dilatory responses for happy and angry expressions only. Although previous work has shown infants can discriminate perceptually between facial expressions, our data suggest that sensitivity to the affective content of all six basic emotional expressions may not fully emerge until later in ontogeny.
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Expresión Facial , Pupila , Adulto , Ira , Emociones/fisiología , Felicidad , Humanos , LactanteRESUMEN
Despite being inherently dynamic phenomena, much of our understanding of how infants attend and scan facial expressions is based on static face stimuli. Here we investigate how six-, nine-, and twelve-month infants allocate their visual attention toward dynamic-interactive videos of the six basic emotional expressions, and compare their responses with static images of the same stimuli. We find infants show clear differences in how they attend and scan dynamic and static expressions, looking longer toward the dynamic-face and lower-face regions. Infants across all age groups show differential interest in expressions, and show precise scanning of regions "diagnostic" for emotion recognition. These data also indicate that infants' attention toward dynamic expressions develops over the first year of life, including relative increases in interest and scanning precision toward some negative facial expressions (e.g., anger, fear, and disgust).
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Emociones , Expresión Facial , Ira , Cara , Miedo , Humanos , LactanteRESUMEN
Studies with infant siblings of children with Autism Spectrum Disorder have attempted to identify early markers for the disorder and suggest that autistic symptoms emerge between 12 and 24 months of age. Yet, a reliable first-year marker remains elusive. We propose that in order to establish first-year manifestations of this inherently social disorder, we need to develop research methods that are sufficiently socially demanding and realistically interactive. Building on Keemink et al. [2019, Developmental Psychology, 55, 1362-1371], we employed a gaze-contingent eye-tracking paradigm in which infants could interact with face stimuli. Infants could elicit emotional expressions (happiness, sadness, surprise, fear, disgust, anger) from on-screen faces by engaging in eye contact. We collected eye-tracking data and video-recorded behavioural response data from 122 (64 male, 58 female) typically developing infants and 31 infant siblings (17 male, 14 female) aged 6-, 9- and 12-months old. All infants demonstrated a significant Expression by AOI interaction (F(10, 1470) = 10.003, P < 0.001, Åp2 = 0.064). Infants' eye movements were "expression-specific" with infants distributing their fixations to AOIs differently per expression. Whereas eye movements provide no evidence of deviancies, behavioural response data show significant aberrancies in reciprocity for infant siblings. Infant siblings show reduced social responsiveness at the group level (F(1, 147) = 4.10, P = 0.042, Åp2 = 0.028) and individual level (Fischer's Exact, P = 0.032). We conclude that the gaze-contingency paradigm provides a realistically interactive experience capable of detecting deviancies in social responsiveness early, and we discuss our results in relation to subsequent infant sibling development. LAY SUMMARY: We investigated how infant siblings of children with autism spectrum disorder respond to interactive faces presented on a computer screen. Our study demonstrates that infant siblings are less responsive when interacting with faces on a computer screen (e.g., they smile and imitate less) in comparison to infants without an older sibling with autism. Reduced responsiveness within social interaction could potentially have implications for how parents and carers interact with these infants. Autism Res 2021, 14: 973-983. © 2020 International Society for Autism Research and Wiley Periodicals LLC.
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Trastorno del Espectro Autista , Trastorno Autístico , Niño , Desarrollo Infantil , Movimientos Oculares , Femenino , Humanos , Lactante , Masculino , HermanosRESUMEN
Infants show preferential attention toward faces and detect faces embedded within complex naturalistic scenes. Newborn infants are insensitive to race, but rapidly develop differential processing of own- and other-race faces. In the present study, we investigated the development of attentional orienting toward own- and other-race faces embedded within naturalistic scenes. Infants aged six-, nine- and twelve-months did not show differences in the speed of orienting to own- and other race faces, but other-race faces held infants' visual attention for longer. We also found a clear developmental progression in attentional capture and holding, with older infants orienting to faces faster and fixating them for longer. Results are interpreted within the context of the two-process model of face processing.
RESUMEN
Face scanning is an important skill that takes place in a highly interactive context embedded within social interaction. However, previous research has studied face scanning using noninteractive stimuli. We aimed to study face scanning and social interaction in infancy in a more ecologically valid way by providing infants with a naturalistic and socially engaging experience. We developed a novel gaze-contingent eye-tracking paradigm in which infants could interact with face stimuli. Responses (socially engaging/socially disengaging) from faces were contingent on infants' eye movements. We collected eye-tracking and behavioral data of 162 (79 male, 83 female) 6-, 9- and 12-month-old infants. All infants showed a clear preference for looking at the eyes relative to the mouth. Contingency was learned implicitly, and infants were more likely to show behavioral responses (e.g., smiling, pointing) when receiving socially engaging responses. Infants' responses were also more often congruent with the actors' responses. Additionally, our large sample allowed us to look at the ranges of behavior on our task, and we identified a small number of infants who displayed deviant behaviors. We discuss these findings in relation to data collected from a small sample (N = 11) of infants considered to be at-risk for autism spectrum disorders. Our results demonstrate the versatility of the gaze-contingency eye-tracking paradigm, allowing for a more nuanced and complex investigation of face scanning as it happens in real-life interaction. As we provide additional measures of contingency learning and reciprocity, our task holds the potential to investigate atypical neurodevelopment within the first year of life. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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Cara , Fijación Ocular/fisiología , Percepción Social , Percepción Visual/fisiología , Atención/fisiología , Femenino , Humanos , Lactante , MasculinoRESUMEN
BACKGROUND: The mechanism by which natural killer (NK) cell education results in licensed NK cells with heightened effector function against missing self-targets is not known. OBJECTIVE: We sought to identify potential mechanisms of enhanced function in licensed human NK cells. METHODS: We used expanded human NK cells from killer immunoglobulin-like receptor (KIR)/HLA-genotyped donors sorted for single-KIR+ cells to generate pure populations of licensed and unlicensed NK cells. We performed proteomic and gene expression analysis of these cells before and after receptor cross-linking and performed functional and metabolic analysis before and after interference with selected metabolic pathways. We verified key findings using freshly isolated and sorted NK cells from peripheral blood. RESULTS: We confirmed that licensed human NK cells are greater in number in peripheral blood and proliferate more in vitro than unlicensed NK cells. Using high-throughput protein analysis, we found that unstimulated licensed NK cells have increased expression of the glycolytic enzyme pyruvate kinase muscle isozyme M2 and after KIR cross-linking have increased phosphorylation of the metabolic modulators p38-α and 5' adenosine monophosphate-activated protein kinase α. After cytokine expansion and activation, unlicensed NK cells depended solely on mitochondrial respiration for cytolytic function, whereas licensed NK cells demonstrated metabolic reprogramming toward glycolysis and mitochondrial-dependent glutaminolysis, leading to accumulation of glycolytic metabolites and depletion of glutamate. As such, blocking both glycolysis and mitochondrial-dependent respiration was required to suppress the cytotoxicity of licensed NK cells. CONCLUSIONS: Collectively, our data support an arming model of education in which enhanced glycolysis in licensed NK cells supports proliferative and cytotoxic capacity.
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Glucólisis/inmunología , Activación de Linfocitos/inmunología , Modelos Inmunológicos , Regulación de la Expresión Génica/inmunología , Humanos , Proteómica , Receptores KIR/inmunologíaRESUMEN
PRRS is among the diseases with the highest economic impact in pig production worldwide. Different strategies have been developed and applied to combat PRRS at farm level. The broad variety of available intervention strategies makes it difficult to decide on the most cost-efficient strategy for a given farm situation, as it depends on many farm-individual factors like disease severity, prices or farm structure. Aim of this study was to create a simulation tool to estimate the cost-efficiency of different control strategies at individual farm level. Baseline is a model that estimates the costs of PRRS, based on changes in health and productivity, in a specific farm setting (e.g. farm type, herd size, type of batch farrowing). The model evaluates different intervention scenarios: depopulation/repopulation (D/R), close & roll-over (C&R), mass vaccination of sows (MS), mass vaccination of sows and vaccination of piglets (MSâ¯+â¯piglets), improvements in internal biosecurity (BSM), and combinations of vaccinations with BSM. Data on improvement in health and productivity parameters for each intervention were obtained through literature review and from expert opinions. The economic efficiency of the different strategies was assessed over 5 years through investment appraisals: the resulting expected value (EV) indicated the most cost-effective strategy. Calculations were performed for 5 example scenarios with varying farm type (farrow-to-finish - breeding herd), disease severity (slightly - moderately - severely affected) and PRRSV detection (yes - no). The assumed herd size was 1000 sows with farm and price structure as commonly found in Germany. In a moderately affected (moderate deviations in health and productivity parameters from what could be expected in an average negative herd), unstable farrow-to-finish herd, the most cost-efficient strategies according to their median EV were C&R (1'126'807) and MSâ¯+â¯piglets ( 1'114'649). In a slightly affected farrow-to-finish herd, no virus detected, the highest median EV was for MSâ¯+â¯piglets ( 721'745) and MS ( 664'111). Results indicate that the expected benefits of interventions and the most efficient strategy depend on the individual farm situation, e.g. disease severity. The model provides new insights regarding the cost-efficiency of various PRRSV intervention strategies at farm level. It is a valuable tool for farmers and veterinarians to estimate expected economic consequences of an intervention for a specific farm setting and thus enables a better informed decision.
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Sacrificio de Animales/economía , Crianza de Animales Domésticos/métodos , Síndrome Respiratorio y de la Reproducción Porcina/prevención & control , Vacunación/veterinaria , Crianza de Animales Domésticos/economía , Animales , Análisis Costo-Beneficio , Femenino , Alemania , Modelos Teóricos , Sus scrofa , Porcinos , Vacunación/economíaRESUMEN
Relapse has emerged as the most important cause of treatment failure after allogeneic hematopoietic stem cell transplantation (HSCT). To test the hypothesis that natural killer (NK) cells can decrease the risk of leukemia relapse, we initiated a phase 1 dose-escalation study of membrane-bound interleukin 21 (mbIL21) expanded donor NK cells infused before and after haploidentical HSCT for high-risk myeloid malignancies. The goals were to determine the safety, feasibility, and maximum tolerated dose. Patients received a melphalan-based reduced-intensity conditioning regimen and posttransplant cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis. NK cells were infused on days -2, +7, and +28 posttransplant. All NK expansions achieved the required cell number, and 11 of 13 patients enrolled received all 3 planned NK-cell doses (1 × 105/kg to 1 × 108/kg per dose). No infusional reactions or dose-limiting toxicities occurred. All patients engrafted with donor cells. Seven patients (54%) developed grade 1-2 acute GVHD (aGVHD), none developed grade 3-4 aGVHD or chronic GVHD, and a low incidence of viral complications was observed. One patient died of nonrelapse mortality; 1 patient relapsed. All others were alive and in remission at last follow-up (median, 14.7 months). NK-cell reconstitution was quantitatively, phenotypically, and functionally superior compared with a similar group of patients not receiving NK cells. In conclusion, this trial demonstrated production feasibility and safety of infusing high doses of ex vivo-expanded NK cells after haploidentical HSCT without adverse effects, increased GVHD, or higher mortality, and was associated with significantly improved NK-cell number and function, lower viral infections, and low relapse rate posttransplant.
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Transfusión de Componentes Sanguíneos/métodos , Neoplasias Hematológicas/terapia , Interleucinas/metabolismo , Células Asesinas Naturales/trasplante , Adolescente , Adulto , Anciano , Técnicas de Cultivo de Célula , Proliferación Celular , Células Cultivadas , Femenino , Haplotipos , Prueba de Histocompatibilidad/métodos , Humanos , Células K562 , Células Asesinas Naturales/metabolismo , Células Asesinas Naturales/fisiología , Masculino , Proteínas de la Membrana/metabolismo , Persona de Mediana Edad , Donantes de Tejidos , Acondicionamiento Pretrasplante/métodos , Trasplante Homólogo , Resultado del Tratamiento , Adulto JovenRESUMEN
Porcine reproductive and respiratory syndrome (PRRS) is reported to be among the diseases with the highest economic impact in modern pig production worldwide. Yet, the economic impact of the disease at farm level is not well understood as, especially in endemically infected pig herds, losses are often not obvious. It is therefore difficult for farmers and veterinarians to appraise whether control measures such as virus elimination or vaccination will be economically beneficial for their farm. Thus, aim of this study was to develop an epidemiological and economic model to determine the costs of PRRS for an individual pig farm. In a production model that simulates farm outputs, depending on farm type, farrowing rhythm or length of suckling period, an epidemiological model was integrated. In this, the impact of PRRS infection on health and productivity was estimated. Financial losses were calculated in a gross margin analysis and a partial budget analysis based on the changes in health and production parameters assumed for different PRRS disease severities. Data on the effects of endemic infection on reproductive performance, morbidity and mortality, daily weight gain, feed efficiency and treatment costs were obtained from literature and expert opinion. Nine different disease scenarios were calculated, in which a farrow-to-finish farm (1000 sows) was slightly, moderately or severely affected by PRRS, based on changes in health and production parameters, and either in breeding, in nursery and fattening or in all three stages together. Annual losses ranged from a median of 75'724 (90% confidence interval (C.I.): 78'885- 122'946), if the farm was slightly affected in nursery and fattening, to a median of 650'090 (90% C.I. 603'585- 698'379), if the farm was severely affected in all stages. Overall losses were slightly higher if breeding was affected than if nursery and fattening were affected. In a herd moderately affected in all stages, median losses in breeding were 46'021 and 422'387 in fattening, whereas costs were 25'435 lower in nursery, compared with a PRRSV-negative farm. The model is a valuable decision-support tool for farmers and veterinarians if a farm is proven to be affected by PRRS (confirmed by laboratory diagnosis). The output can help to understand the need for interventions in case of significant impact on the profitability of their enterprise. The model can support veterinarians in their communication to farmers in cases where costly disease control measures are justified.
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Granjas/economía , Síndrome Respiratorio y de la Reproducción Porcina/economía , Animales , Costos y Análisis de Costo , Femenino , Síndrome Respiratorio y de la Reproducción Porcina/epidemiología , Virus del Síndrome Respiratorio y Reproductivo Porcino , Reproducción , PorcinosRESUMEN
BackgroundThere is a notable absence of evidence based early interventions for young children with FASD. ObjectiveThis study examines clinicians' perspectives regarding the needs of caregivers of children with FASD and how such perspectives informed the development of a family-centered early intervention for young children with prenatal alcohol exposure. Method19 professionals who work with children with prenatal alcohol exposure and / or in out-of-home care were recruited to participate in focus groups. The facilitator used a semi-structured topic guide to elicit feedback from participants. These data were transcribed, coded, and categorized to reflect themes in a manner informed by a grounded theory approach. A second investigator repeated the process. Codes were chosen and assigned to data by consensus. ResultsThe coded data yielded five distinct perceived challenges faced by caregivers: (1) seeking and possibly receiving a diagnosis; (2) processing emotions and coming to terms with the child's difficulties; (3) seeking support and belonging within a knowledgeable community; (4) developing a new understanding of the child's behavior; and (5) becoming an educator, advocate, and expert on the child and FASD. ConclusionProfessionals believe specific capacities are essential insofar as the human service systems that caregivers engage are perceived to be under-equipped to respond to the distinct set of challenges faced by children with FASD and their families. Findings are discussed in terms of how the proposed intervention was designed to address such challenges and to cultivate those key capacities in order for families to meet their children's needs.
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Cuidadores/psicología , Intervención Educativa Precoz/organización & administración , Trastornos del Espectro Alcohólico Fetal/diagnóstico , Trastornos del Espectro Alcohólico Fetal/terapia , Personal de Salud/psicología , Niño , Trastornos de la Conducta Infantil/terapia , Emociones , Grupos Focales , Humanos , Evaluación de Necesidades , Aceptación de la Atención de Salud , Percepción , Apoyo SocialAsunto(s)
Crimen , Neoplasias , Víctimas de Crimen , Humanos , Células Asesinas Naturales , Factores de TiempoRESUMEN
Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is a lethal muscle-wasting disease that is caused by mutations in the LAMA2 gene, resulting in the loss of laminin-α2 protein. MDC1A patients exhibit severe muscle weakness from birth, are confined to a wheelchair, require ventilator assistance, and have reduced life expectancy. There are currently no effective treatments or cures for MDC1A. Laminin-α2 is required for the formation of heterotrimeric laminin-211 (ie, α2, ß1, and γ1) and laminin-221 (ie, α2, ß2, and γ1), which are major constituents of skeletal muscle basal lamina. Laminin-111 (ie, α1, ß1, and γ1) is the predominant laminin isoform in embryonic skeletal muscle and supports normal skeletal muscle development in laminin-α2-deficient muscle but is absent from adult skeletal muscle. In this study, we determined whether treatment with Engelbreth-Holm-Swarm-derived mouse laminin-111 protein could rescue MDC1A in the dy(W-/-) mouse model. We demonstrate that laminin-111 protein systemically delivered to the muscles of laminin-α2-deficient mice prevents muscle pathology, improves muscle strength, and dramatically increases life expectancy. Laminin-111 also prevented apoptosis in laminin-α2-deficient mouse muscle and primary human MDC1A myogenic cells, which indicates a conserved mechanism of action and cross-reactivity between species. Our results demonstrate that laminin-111 can serve as an effective protein substitution therapy for the treatment of muscular dystrophy in the dy(W-/-) mouse model and establish the potential for its use in the treatment of MDC1A.
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Laminina/uso terapéutico , Distrofias Musculares/tratamiento farmacológico , Animales , Apoptosis/efectos de los fármacos , Línea Celular , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos/métodos , Femenino , Fibrosis , Humanos , Inyecciones Intramusculares , Inyecciones Intraperitoneales , Estimación de Kaplan-Meier , Laminina/administración & dosificación , Laminina/deficiencia , Laminina/metabolismo , Ratones , Actividad Motora/efectos de los fármacos , Fuerza Muscular/efectos de los fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Músculo Esquelético/fisiopatología , Distrofias Musculares/metabolismo , Distrofias Musculares/patología , Distrofias Musculares/fisiopatología , Mioblastos/efectos de los fármacos , Mioblastos/patología , Miositis/prevención & control , Isoformas de Proteínas/administración & dosificación , Isoformas de Proteínas/uso terapéutico , Pérdida de Peso/efectos de los fármacosRESUMEN
Bronchoalveolar lavages (BALs) were performed with a bronchoscope on 5- and 7.5-week-old, anesthetized, high health status pigs (n = 14). At 10 weeks of age, pigs (n = 28) were necropsied, lungs were removed, and BAL samples were collected from the right diaphragmatic lobe with a modified 12-Fr (4-mm) Foley catheter. Peripheral blood was sampled from all pigs (n = 28) before each BAL procedure. Peripheral blood and BAL samples were collected according to a similar study design at 5, 7.5, and 10 weeks of age from 12 low health status pigs, which were raised according to standard farm procedures (n = 6) or as segregated early weaned pigs (n = 6). Bronchoalveolar lavage cytology and hematologic 95% confidence intervals were determined for 5-, 7.5-, and 10-week-old high (group A) and low health status pigs (groups B and C). The results were compared between the different groups. Repeated BALs were easily performed in all pigs, making this an additional tool for evaluation of respiratory health. Total numbers of cells and neutrophils in peripheral blood and BAL samples were greater in low health status pigs than in high health status pigs. Hematologic results paralleled the findings in BAL fluid. Segregated early weaning of low health status pigs in a less challenging environment mainly reduced the number of neutrophils in BAL samples and peripheral blood.
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Lavado Broncoalveolar/veterinaria , Infecciones del Sistema Respiratorio/veterinaria , Enfermedades de los Porcinos/diagnóstico , Factores de Edad , Animales , Animales Recién Nacidos , Broncoscopía/veterinaria , Recuento de Células , Estado de Salud , Pulmón/citología , Neutrófilos/citología , Valores de Referencia , Infecciones del Sistema Respiratorio/diagnóstico , PorcinosRESUMEN
The purpose of this study was to evaluate the effect of longterm exposure to airborne dust and endotoxin on the respiratory system of pigs. A continuous flow exposure chamber was built for the purpose of exposing pigs to selected airborne contaminants. Pigs (n = 6) were exposed to a combination of a very fine corn/soybean meal (40.6 mg/m3) with added lipopolysaccharide (LPS; 12.4 microg/m3) for 8 h/d over 5 d for 15 wk (75 d of exposure). Control pigs (n = 6) were housed in a room with minimal contamination of these airborne contaminants. Surprisingly, dust in the exposure chamber and the control room was highly contaminated with peptidoglycan. Changes in the lung were monitored by collecting bronchoalveolar lavage (BAL) fluid for cytology at 5 different time points throughout the exposure period. Blood samples were collected at the same time for hematology. A non-specific respiratory inflammatory response was found in exposed and control pigs, as suggested by the increased neutrophils in BAL fluid and the small inflammatory areas in the lung tissue. No macroscopic lung lesions were observed in control or exposed pigs. The findings in the control pigs imply that even low dust concentrations and possibly peptidoglycan contamination can induce cellular changes in the BAL fluid and that a true control pig does not exist. In addition, the exposed pigs developed a mild eosinophilia, indicating an allergic response to the airborne contaminants.
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Contaminantes Atmosféricos/toxicidad , Contaminación del Aire Interior , Líquido del Lavado Bronquioalveolar/citología , Polvo , Endotoxinas/toxicidad , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Animales , Endotoxinas/análisis , Vivienda para Animales , Leucocitos/efectos de los fármacos , Leucocitos/fisiología , Linfocitos/efectos de los fármacos , Linfocitos/fisiología , Macrófagos Alveolares/efectos de los fármacos , Macrófagos Alveolares/fisiología , Neutrófilos/efectos de los fármacos , Neutrófilos/fisiología , Peptidoglicano/análisis , Porcinos , Factores de Tiempo , Ventilación/métodosRESUMEN
The main purpose of this study was to investigate the relationship between prevalence of respiratory disease in swine and respiratory health of swine farmers. Fourteen farms were selected based on clinical history and slaughtercheck evidence of respiratory problems in pigs. The farms were divided into two groups with either high (n = 7) or low (n = 7) prevalence of respiratory disease in pigs. Airborne dust, endotoxin and peptidoglycan were measured once in farrowing, gestation, nursery and finishing of each farm. Respiratory health of farmers in participating farms was evaluated by questionnaire and pulmonary function test. A mean of 71% of the pigs in high prevalence farms had pneumonic lesions at slaughter, compared with 7% in low prevalence farms. No significant relationship was found between prevalence of respiratory disease in pigs and airborne dust, endotoxin or peptidoglycan. More farmers in high prevalence farms reported chest tightness (p = 0.038). The percentage predicted FEF 25%-75%; was lower (p = 0.046) in farmers working in high prevalence farms. Significant differences disappeared after adjusting for smoking status. Our study suggests that farmers working on farms with a high prevalence for respiratory disease in pigs may have more respiratory problems than farmers working in farms with low prevalence of such diseases.
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Enfermedades de los Trabajadores Agrícolas/epidemiología , Contaminantes Ocupacionales del Aire/efectos adversos , Infecciones del Sistema Respiratorio/epidemiología , Adulto , Enfermedades de los Trabajadores Agrícolas/etiología , Enfermedades de los Trabajadores Agrícolas/fisiopatología , Animales , Humanos , Illinois/epidemiología , Prevalencia , Infecciones del Sistema Respiratorio/etiología , Infecciones del Sistema Respiratorio/fisiopatología , Espirometría , Porcinos , Enfermedades de los Porcinos/epidemiología , Wisconsin/epidemiologíaRESUMEN
In October 1993 and 1994, respectively, 77 and 76 third-year veterinary students visited a swine farm to work with pigs for 3 h. On both occasions, a large number of students reported flu-like symptoms after the visit. To further investigate this, the students were presented with a questionnaire modeled after the standard questionnaire used for evaluating organic dust exposure. General and/or respiratory symptoms were reported by 103/142 (72.5%) students. General symptoms, such as eye irritation, headache and tiredness were experienced by 60/103 (42.2%) students. Cough, nasal and throat irritation, and sinus trouble were the most prevalent respiratory symptoms and were reported by 94/103 (91%) of the students. Symptoms mostly developed the same day and disappeared within 3 d after exposure. The presence of respiratory and/or general symptoms was not significantly different between students who wore a mask during the lab or those who did not. Students with pre-existing allergies were more likely to develop respiratory symptoms than non-allergic students.
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Enfermedades de los Trabajadores Agrícolas/epidemiología , Crianza de Animales Domésticos , Educación en Veterinaria , Hipersensibilidad/epidemiología , Enfermedades Respiratorias/epidemiología , Estudiantes , Porcinos , Adulto , Enfermedades de los Trabajadores Agrícolas/prevención & control , Animales , Humanos , Máscaras , Encuestas y Cuestionarios , WisconsinRESUMEN
Cross-protection experiments were conducted to determine whether antigenic differences located within the lipopolysaccharides (LPS) of Actinobacillus pleuropneumoniae subtypes 1A and 1B were important with respect to the efficacy of whole cell, formalin-inactivated bacterins. Based on clinical signs, lung lesions scores and mortality rates, pigs immunized with A. pleuropneumoniae subtype 1A were partially protected against severe challenge with both subtypes 1A and 1B. In contrast, 1B vaccinated pigs were not protected against severe challenge with subtype 1A but were partially protected against 1B challenge. Cross-reactive serum antibody levels were measured with an ELISA using outer membranes of subtype 1A or 1B as the coating antigen. Serum antibodies were detected against both subtypes within 2 weeks after the first immunization. Antibody levels increased with time and were generally higher against the homologous subtype coating antigen. We conclude that antigenic variation within a capsular serotype, due to antigenic variation within LPS, can result in the failure of whole cell bacterins to provide protection against challenge with the same capsular serotype. This lack of cross-protection within a capsular serotype provides partial explanation for vaccination failures observed under field conditions.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/inmunología , Anticuerpos Antibacterianos/sangre , Vacunas Bacterianas , Lipopolisacáridos/inmunología , Enfermedades de los Porcinos , Infecciones por Actinobacillus/prevención & control , Actinobacillus pleuropneumoniae/clasificación , Análisis de Varianza , Animales , Formación de Anticuerpos , Proteínas de la Membrana Bacteriana Externa/inmunología , Reacciones Cruzadas , Ensayo de Inmunoadsorción Enzimática , Serotipificación , Porcinos , VacunaciónRESUMEN
Two distinct antigenic subtypes of Actinobacillus pleuropneumoniae serotype 1 were identified via coagglutination (Co-A) and designated as 1A and 1B. The reference strains, ATCC 27088 (1A) and ISU 158 (1B), were used to prepare hyperimmune rabbit sera for Co-A reagents. Of 75 serotype 1 field isolates tested by Co-A, 35 isolates typed as 1A, 12 as 1B and 28 as 1A/1B. Significant cross-reactivity between the 2 subtypes was found in the Co-A and was eliminated in 20/28 1A/1B strains by using Co-A reagents prepared with rabbit sera absorbed with the heterologous reference strain. However, twelve isolates (5 1A and 7 1A/1B; 16%) showed no reaction with Co-A reagents prepared with absorbed sera. Immunoblots of outer membranes (OM) prepared from APP 1A or 1B reference strains and field isolates indicated that antigenic differences between subtypes 1A and 1B were located within the high molecular weight (MW) region of the gels (40-100 kDa). Hyperimmune rabbit sera against 1A or 1B and sera from pigs vaccinated with whole-cell, formalin inactivated 1A or 1B bacterins reacted with the high MW region only in strains of the homologous subtype. In contrast, 4 of 5 sera from 1B infected pigs and 2 of 5 sera from 1A infected pigs reacted with all APP serotype 1 strains regardless of subtype. Apparently, infection exposed cross-reactive antigenic determinants that were not exposed by immunization with killed bacteria preparations. SDS-PAGE gels with LPS purified from APP 1A, 1B, 9 and 11 showed that 1A, 9 and 11 LPS O-antigens had an identical smooth ladder pattern, while 1B LPS was distinctly different. In immunoblots with OM or LPS and in dot-immunobinding assays with LPS, rabbit antiserum against APP 1A reacted with 1A, 9 and 11. In contrast, rabbit antiserum against APP 1B only reacted with APP 1B and weakly with APP 9 in the OM immunoblot and with LPS from APP 1B, 9 and 11 in the LPS immunoblot and dot-immunobinding assay. We conclude that 2 subtypes of APP serotype 1 can be distinguished based on their antigenic differences. These differences are located, at least in part, within the LPS O-antigens. LPS O-antigens from APP 1B appear more antigenically similar to APP 9 LPS than to either APP 1A or APP 11 LPS. There may also be antigenic differences in the capsular polysaccharides of APP 1A and 1B strains.(ABSTRACT TRUNCATED AT 400 WORDS)