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Cell-free DNA (cfDNA) is increasingly recognized as a promising biomarker candidate for disease monitoring. However, its utility in neurodegenerative diseases, like amyotrophic lateral sclerosis (ALS), remains underexplored. Existing biomarker discovery approaches are tailored to a specific disease context or are too expensive to be clinically practical. Here, we address these challenges through a new approach combining advances in molecular and computational technologies. First, we develop statistical tools to select tissue-informative DNA methylation sites relevant to a disease process of interest. We then employ a capture protocol to select these sites and perform targeted methylation sequencing. Multi-modal information about the DNA methylation patterns are then utilized in machine learning algorithms trained to predict disease status and disease progression. We applied our method to two independent cohorts of ALS patients and controls (n=192). Overall, we found that the targeted sites accurately predicted ALS status and replicated between cohorts. Additionally, we identified epigenetic features associated with ALS phenotypes, including disease severity. These findings highlight the potential of cfDNA as a non-invasive biomarker for ALS.
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Objective: To investigate changes in immune markers and frequencies throughout disease progression in patients with amyotrophic lateral sclerosis (ALS). Methods: In this longitudinal study, serial blood samples were collected from 21 patients with ALS over a time period of up to 16 months. Flow cytometry was used to quantitate CD14, HLA-DR, and CD16 marker expression on monocyte subpopulations and neutrophils, as well as their cell population frequencies. A Generalized Estimating Equation model was used to assess the association between changes in these immune parameters and disease duration and the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R). Results: CD14 expression on monocyte subpopulations increased with both disease duration and a decrease in ALSFRS-R score in patients with ALS. HLA-DR expression on monocyte subpopulations also increased with disease severity and/or duration. The expression of CD16 did not change relative to disease duration or ALSFRS-R. Finally, patients had a reduction in non-classical monocytes and an increase in the classical to non-classical monocyte ratio throughout disease duration. Conclusion: The progressive immunological changes observed in this study provide further support that monocytes are implicated in ALS pathology. Monocytic CD14 and HLA-DR surface proteins may serve as a therapeutic target or criteria for the recruitment of patients with ALS into clinical trials for immunomodulatory therapies.
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Esclerosis Amiotrófica Lateral , Antígenos HLA-DR , Receptores de Lipopolisacáridos , Monocitos , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Biomarcadores/metabolismo , Citometría de Flujo , Antígenos HLA-DR/metabolismo , Humanos , Receptores de Lipopolisacáridos/metabolismo , Estudios Longitudinales , Monocitos/metabolismoRESUMEN
BACKGROUND: Swallowing therapy is commonly provided as a treatment to lessen the risk or severity of dysphagia secondary to radiotherapy (RT) for head and neck cancer (HNC); however, best practice is not yet established. This trial will compare the effectiveness of prophylactic (high and low intensity) versus reactive interventions for swallowing in patients with HNC undergoing RT. METHODS: This multi-site, international randomized clinical trial (RCT) will include 952 adult patients receiving radiotherapy for HNC and who are at high risk for post-RT dysphagia. Participants will be randomized to receive one of three interventions for swallowing during RT: RE-ACTIVE, started promptly if/when dysphagia is identified; PRO-ACTIVE EAT, low intensity prophylactic intervention started before RT commences; or, PRO-ACTIVE EAT+EXERCISE, high intensity prophylactic intervention also started before RT commences. We hypothesize that the PRO-ACTIVE therapies are more effective than late RE-ACTIVE therapy; and, that the more intensive PRO-ACTIVE (EAT + EXERCISE) is superior to the low intensive PRO-ACTIVE (EAT). The primary endpoint of effectiveness is duration of feeding tube dependency one year post radiation therapy, selected as a pragmatic outcome valued equally by diverse stakeholders (e.g., patients, caregivers and clinicians). Secondary outcomes will include objective measures of swallow physiology and function, pneumonia and weight loss, along with various patient-reported swallowing-related outcomes, such as quality of life, symptom burden, and self-efficacy. DISCUSSION: Dysphagia is a common and potentially life-threatening chronic toxicity of radiotherapy, and a priority issue for HNC survivors. Yet, the optimal timing and intensity of swallowing therapy provided by a speech-language pathologist is not known. With no clearly preferred strategy, current practice is fraught with substantial variation. The pragmatic PRO-ACTIVE trial aims to specifically address the decisional dilemma of when swallowing therapy should begin (i.e., before or after a swallowing problem develops). The critical impact of this dilemma is heightened by the growing number of young HNC patients in healthcare systems that need to allocate resources most effectively. The results of the PRO-ACTIVE trial will address the global uncertainty regarding best practice for dysphagia management in HNC patients receiving radiotherapy. TRIAL REGISTRATION: The protocol is registered with the US Patient Centered Outcomes Research Institute, and the PRO-ACTIVE trial was prospectively registered at ClinicalTrials.gov , under the identifier NCT03455608 ; First posted: Mar 6, 2018; Last verified: Jun 17, 2021. Protocol Version: 1.3 (January 27, 2020).
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Trastornos de Deglución/prevención & control , Deglución , Neoplasias de Cabeza y Cuello/radioterapia , Traumatismos por Radiación/complicaciones , Adulto , Toma de Decisiones , Deglución/fisiología , Deglución/efectos de la radiación , Trastornos de Deglución/etiología , Trastornos de Deglución/terapia , Nutrición Enteral/instrumentación , Humanos , Medición de Resultados Informados por el Paciente , Calidad de Vida , Neumonitis por Radiación , Autoeficacia , Método Simple Ciego , Factores de Tiempo , Pérdida de PesoRESUMEN
BACKGROUND: The BETTER (Building on Existing Tools to Improve Chronic Disease Prevention and Screening in Primary Care) intervention was designed to integrate the approach to chronic disease prevention and screening in primary care and demonstrated effective in a previous randomized trial. METHODS: We tested the effectiveness of the BETTER HEALTH intervention, a public health adaptation of BETTER, at improving participation in chronic disease prevention and screening actions for residents of low-income neighbourhoods in a cluster randomized trial, with ten low-income neighbourhoods in Durham Region Ontario randomized to immediate intervention vs. wait-list. The unit of analysis was the individual, and eligible participants were adults age 40-64 years residing in the neighbourhoods. Public health nurses trained as "prevention practitioners" held one prevention-focused visit with each participant. They provided participants with a tailored prevention prescription and supported them to set health-related goals. The primary outcome was a composite index: the number of evidence-based actions achieved at six months as a proportion of those for which participants were eligible at baseline. RESULTS: Of 126 participants (60 in immediate arm; 66 in wait-list arm), 125 were included in analyses (1 participant withdrew consent). In both arms, participants were eligible for a mean of 8.6 actions at baseline. At follow-up, participants in the immediate intervention arm met 64.5% of actions for which they were eligible versus 42.1% in the wait-list arm (rate ratio 1.53 [95% confidence interval 1.22-1.84]). CONCLUSION: Public health nurses using the BETTER HEALTH intervention led to a higher proportion of identified evidence-based prevention and screening actions achieved at six months for people living with socioeconomic disadvantage. TRIAL REGISTRATION: NCT03052959 , registered February 10, 2017.
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Tamizaje Masivo , Salud Pública , Adulto , Enfermedad Crónica , Humanos , Persona de Mediana Edad , Ontario , Atención Primaria de SaludRESUMEN
BACKGROUND: Preoperative anaemia is associated with elevated risks of postoperative complications. This association may be explained by confounding related to poor cardiopulmonary fitness. We conducted a pre-specified substudy of the Measurement of Exercise Tolerance before Surgery (METS) study to examine the associations of preoperative haemoglobin concentration with preoperative cardiopulmonary exercise testing performance (peak oxygen consumption, anaerobic threshold) and postoperative complications. METHODS: The substudy included a nested cross-sectional analysis and nested cohort analysis. In the cross-sectional study (1279 participants), multivariate linear regression modelling was used to determine the adjusted association of haemoglobin concentration with peak oxygen consumption and anaerobic threshold. In the nested cohort study (1256 participants), multivariable logistic regression modelling was used to determine the adjusted association of haemoglobin concentration, peak oxygen consumption, and anaerobic threshold with the primary endpoint (composite outcome of death, cardiovascular complications, acute kidney injury, or surgical site infection) and secondary endpoint (moderate or severe complications). RESULTS: Haemoglobin concentration explained 3.8% of the variation in peak oxygen consumption and anaerobic threshold (P<0.001). Although not associated with the primary endpoint, haemoglobin concentration was associated with moderate or severe complications after adjustment for peak oxygen consumption (odds ratio=0.86 per 10 g L-1 increase; 95% confidence interval, 0.77-0.96) or anaerobic threshold (odds ratio=0.86; 95% confidence interval, 0.77-0.97). Lower peak oxygen consumption was associated with moderate or severe complications without effect modification by haemoglobin concentration (P=0.12). CONCLUSION: Haemoglobin concentration explains a small proportion of variation in exercise capacity. Both anaemia and poor functional capacity are associated with postoperative complications and may therefore be modifiable targets for preoperative optimisation.
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Anemia , Tolerancia al Ejercicio , Estudios de Cohortes , Estudios Transversales , Prueba de Esfuerzo , Hemoglobinas , Humanos , Consumo de OxígenoRESUMEN
RATIONALE: Targeted temperature management (TTM) improves survival with good neurological outcome after out-of-hospital cardiac arrest (OHCA), but is delivered inconsistently and often with delay. OBJECTIVE: To determine if prehospital cooling by paramedics leads to higher rates of 'successful TTM', defined as achieving a target temperature of 32-34°C within 6h of hospital arrival. METHODS: Pragmatic RCT comparing prehospital cooling (surface ice packs, cold saline infusion, wristband reminders) initiated 5min after return of spontaneous circulation (ROSC) versus usual resuscitation and transport. The primary outcome was rate of 'successful TTM'; secondary outcomes were rates of applying TTM in hospital, survival with good neurological outcome, pulmonary edema in emergency department, and re-arrest during transport. RESULTS: 585 patients were randomized to receive prehospital cooling (n=279) or control (n=306). Prehospital cooling did not increase rates of 'successful TTM' (30% vs 25%; RR, 1.17; 95% confidence interval [CI] 0.91-1.52; p=0.22), but increased rates of applying TTM in hospital (68% vs 56%; RR, 1.21; 95%CI 1.07-1.37; p=0.003). Survival with good neurological outcome (29% vs 26%; RR, 1.13, 95%CI 0.87-1.47; p=0.37) was similar. Prehospital cooling was not associated with re-arrest during transport (7.5% vs 8.2%; RR, 0.94; 95%CI 0.54-1.63; p=0.83) but was associated with decreased incidence of pulmonary edema in emergency department (12% vs 18%; RR, 0.66; 95%CI 0.44-0.99; p=0.04). CONCLUSIONS: Prehospital cooling initiated 5min after ROSC did not increase rates of achieving a target temperature of 32-34°C within 6h of hospital arrival but was safe and increased application of TTM in hospital.
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Servicios Médicos de Urgencia/métodos , Hipotermia Inducida/métodos , Hielo , Paro Cardíaco Extrahospitalario/terapia , Cloruro de Sodio/administración & dosificación , Anciano , Anciano de 80 o más Años , Temperatura Corporal , Reanimación Cardiopulmonar , Frío , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Paro Cardíaco Extrahospitalario/mortalidad , Factores de Tiempo , Resultado del TratamientoRESUMEN
Overweight and obesity in preschool-aged children are major health concerns. Accurate and reliable estimates of prevalence are necessary to direct public health and clinical interventions. There are currently three international growth standards used to determine prevalence of overweight and obesity, each using different methodologies: Center for Disease Control (CDC), World Health Organization (WHO) and International Obesity Task Force (IOTF). Adoption and use of each method were examined through a systematic review of Australian population studies (2006-2017). For this period, systematically identified population studies (N = 20) reported prevalence of overweight and obesity ranging between 15 and 38% with most (n = 16) applying the IOTF standards. To demonstrate the differences in prevalence estimates yielded by the IOTF in comparison to the WHO and CDC standards, methods were applied to a sample of N = 1,926 Australian children, aged 3-5 years. As expected, the three standards yielded significantly different estimates when applied to this single population. Prevalence of overweight/obesity was WHO - 9.3%, IOTF - 21.7% and CDC - 33.1%. Judicious selection of growth standards, taking account of their underpinning methodologies and provisions of access to study data sets to allow prevalence comparisons, is recommended.
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Obesidad Infantil/epidemiología , Australia/epidemiología , Desarrollo Infantil , Preescolar , Humanos , Prevalencia , Estándares de ReferenciaRESUMEN
BACKGROUND: The role of fathers in shaping their child's eating behaviour and weight status through their involvement in child feeding has rarely been studied. This study aims to describe fathers' perceived responsibility for child feeding, and to identify predictors of how frequently fathers eat meals with their child. METHODS: Four hundred and thirty-six Australian fathers (M age = 37 years, SD = 6 years; 34% university educated) of a 2-5-year-old child (M age = 3.5 years, SD = 0.9 years; 53% boys) were recruited via contact with mothers enrolled in existing research projects or a university staff and student email list. Data were collected from fathers via a self-report questionnaire. Descriptive and hierarchical linear regression analyses were conducted. RESULTS: The majority of fathers reported that the family often/mostly ate meals together (79%). Many fathers perceived that they were responsible at least half of the time for feeding their child in terms of organizing meals (42%); amount offered (50%) and deciding if their child eats the 'right kind of foods' (60%). Time spent in paid employment was inversely associated with how frequently fathers ate meals with their child (ß = -0.23, P < 0.001); however, both higher perceived responsibility for child feeding (ß = 0.16, P < 0.004) and a more involved and positive attitude toward their role as a father (ß = 0.20, P < 0.001) were positively related to how often they ate meals with their child, adjusting for a range of paternal and child covariates, including time spent in paid employment. CONCLUSIONS: Fathers from a broad range of educational backgrounds appear willing to participate in research studies on child feeding. Most fathers were engaged and involved in family meals and child feeding. This suggests that fathers, like mothers, should be viewed as potential agents for the implementation of positive feeding practices within the family.
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Dieta , Relaciones Padre-Hijo , Conducta Alimentaria , Adulto , Australia , Preescolar , Estudios Transversales , Femenino , Humanos , Masculino , Obesidad/prevención & control , Obesidad Infantil/prevención & control , Percepción , Responsabilidad Social , Encuestas y CuestionariosRESUMEN
A range of chemicals found in the aquatic environment have the potential to influence endocrine function and affect sexual development by mimicking or antagonizing the effects of hormones, or by altering the synthesis and metabolism of hormones. The aim of this study was to evaluate whether the effects of chemicals interfering with sex hormone synthesis may affect the regulation of early ovarian development via the modulation of sex steroid and insulin-like growth factor (IGF) systems. To this end, ex vivo ovary cultures of juvenile brown trout (Salmo trutta fario) were exposed for 2 days to either 1,4,6-androstatriene-3,17-dione (ATD, a specific aromatase inhibitor), prochloraz (an imidazole fungicide), or tributyltin (TBT, a persistent organic pollutant). Further, juvenile female brown trout were exposed in vivo for 2 days to prochloraz or TBT. The ex vivo and in vivo ovarian gene expression of the aromatase (CYP19), responsible for estrogen production, and of IGF1 and 2 were compared. Moreover, 17ß-estradiol (E2) and testosterone (T) production from ex vivo ovary cultures was assessed. Ex vivo exposure to ATD inhibited ovarian E2 synthesis, while T levels accumulated. However, ATD did not affect ex vivo expression of cyp19, igf1, or igf2. Ex vivo exposure to prochloraz inhibited ovarian E2 production, but did not affect T levels. Further prochloraz up-regulated igf1 expression in both ex vivo and in vivo exposures. TBT exposure did not modify ex vivo synthesis of either E2 or T. However, in vivo exposure to TBT down-regulated igf2 expression. The results indicate that ovarian inhibition of E2 production in juvenile brown trout might not directly affect cyp19 and igf gene expression. Thus, we suggest that the test chemicals may interfere with both sex steroid and IGF systems in an independent manner, and based on published literature, potentially lead to endocrine dysfunction and altered sexual development.
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Disruptores Endocrinos/toxicidad , Ovario/efectos de los fármacos , Trucha , Contaminantes Químicos del Agua/toxicidad , Androstatrienos/toxicidad , Animales , Aromatasa/genética , Inhibidores de la Aromatasa/toxicidad , Estradiol/metabolismo , Femenino , Fungicidas Industriales/toxicidad , Expresión Génica/efectos de los fármacos , Imidazoles/toxicidad , Factor I del Crecimiento Similar a la Insulina/genética , Factor II del Crecimiento Similar a la Insulina/genética , Ovario/metabolismo , Testosterona/metabolismo , Compuestos de Trialquiltina/toxicidad , Trucha/genética , Trucha/metabolismoRESUMEN
UNLABELLED: We conducted a cluster randomized trial evaluating the effect of a centralized coordinator who identifies and follows up with fracture patients and their primary care physicians about osteoporosis. Compared with controls, intervention patients were five times more likely to receive BMD testing and two times more likely to receive appropriate management. INTRODUCTION: To determine if a centralized coordinator who follows up with fracture patients and their primary care physicians by telephone and mail (intervention) will increase the proportion of patients who receive appropriate post-fracture osteoporosis management, compared to simple fall prevention advice (attention control). METHODS: A cluster randomized controlled trial was conducted in small community hospitals in the province of Ontario, Canada. Hospitals that treated between 60 and 340 fracture patients per year were eligible. Patients 40 years and older presenting with a low trauma fracture were identified from Emergency Department records and enrolled in the trial. The primary outcome was 'appropriate' management, defined as a normal bone mineral density (BMD) test or taking osteoporosis medications. RESULTS: Thirty-six hospitals were randomized to either intervention or control and 130 intervention and 137 control subjects completed the study. The mean age of participants was 65 ± 12 years and 69% were female. The intervention increased the proportion of patients who received appropriate management within 6 months of fracture; 45% in the intervention group compared with 26% in the control group (absolute difference of 19%; adjusted OR, 2.3; 95% CI, 1.3-4.1). The proportion who had a BMD test scheduled or performed was much higher with 57% of intervention patients compared with 21% of controls (absolute difference of 36%; adjusted OR, 4.8; 95% CI, 3.0-7.0). CONCLUSIONS: A centralized osteoporosis coordinator is effective in improving the quality of osteoporosis care in smaller communities that do not have on-site coordinators or direct access to osteoporosis specialists.
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Manejo de Caso/organización & administración , Prestación Integrada de Atención de Salud/organización & administración , Osteoporosis/diagnóstico , Fracturas Osteoporóticas/prevención & control , Adulto , Anciano , Conservadores de la Densidad Ósea/uso terapéutico , Utilización de Medicamentos/estadística & datos numéricos , Servicio de Urgencia en Hospital , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ontario , Osteoporosis/tratamiento farmacológico , Evaluación de Resultado en la Atención de Salud , Atención Primaria de Salud/organización & administración , Factores SexualesRESUMEN
A variety of natural and synthetic environmental substances have been shown to disrupt vertebrate reproduction through mimicking or modifying the regulation of the endocrine system. Tests to screen for any such chemicals that directly interact with the steroid hormone receptors are widely available; however, few tests have been developed to identify chemicals that affect endocrine function through non-receptor mediated mechanisms. The aim of this study was, therefore, to develop an assay for the identification of substances that disrupt the activity of enzymes involved in the sex steroid biosynthesis cascade, in particular the aromatase enzyme, CYP19, that catalyses the final conversion of androgens to estrogens. A gonad ex vivo assay was developed using gonad explants harvested from juvenile brown trout and cultured in a modified Leibovitz medium. Effects on sex steroid biosynthesis were quantified through measurement of 17ß-estradiol (E2) and testosterone (T) concentrations in the medium after 2 days incubation. Exposure of ovary explants to 100 ng/mL 1,4,6-androstatriene-3,17-dione (ATD), a potent pharmaceutical aromatase inhibitor, reduced E2 concentrations and elevated T concentrations confirming that CYP19 activity could be inhibited in the assay. Exposure of ovary explants to 250 ng/mL prochloraz, an imidazole fungicide, also reduced E2 concentrations but did not affect T levels, consistent with reports that in addition to inhibiting CYP19 activity, prochloraz also inhibits enzymes in the steroidogenic pathway upstream of the CYP19 enzyme. Exposure to a third chemical, tributyltin (TBT), did not affect T or E2 concentrations, further supporting previous evidence that the CYP19 modulating effects of this chemical are not mediated through direct inhibition of CYP19 activity. These results demonstrate that the gonad ex vivo assay developed here can be successfully used to identify substances that disrupt sex steroid biosynthesis and further that it has the potential to inform on their specific mode of action.
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Aromatasa/metabolismo , Técnicas de Cultivo de Célula/métodos , Hormonas Esteroides Gonadales/biosíntesis , Gónadas/citología , Trucha , Androstatrienos/farmacología , Animales , Inhibidores de la Aromatasa/farmacología , Estradiol/metabolismo , Femenino , Fungicidas Industriales/toxicidad , Gónadas/metabolismo , Imidazoles/toxicidad , Masculino , Testosterona/metabolismo , Compuestos de Trialquiltina/toxicidadRESUMEN
The CANUSA investigators reported a near doubling of the risk of death in peritoneal dialysis patients treated at U.S. sites compared to Canadian centers. Recently, evidence has suggested that background mortality rates in the general population might be responsible for differences in death rates on dialysis. The objective of this study was to determine if differences in background mortality in the general population were responsible for the increased risk of death observed in American patients in the CANUSA study. The CANUSA study was a prospective cohort study of 680 consecutive peritoneal dialysis patients at 14 centers in the U.S. and Canada. Extensive baseline data were available for all patients. The expected mortality rate of an individual of the same age, sex, and country of residence was determined at the time of enrollment in the CANUSA study. Cox proportional hazards models were used to determine if background mortality rates were responsible for the observed differences in survival between the two countries. Background mortality rate in the general population was associated with an increased risk of death on peritoneal dialysis, but after adjustment for other baseline factors, it was no longer significant. The adjusted, relative hazard of dying in the U.S. compared to Canada was unchanged after further adjusting for background mortality rate in statistical models (HR = 1.93; 95% confidence interval: 1.13 - 3.28). In conclusion, the increased risk of mortality in U.S. patients enrolled in the CANUSA study was not explained by differences in the background mortality rate in the general population.
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Diálisis Peritoneal/mortalidad , Factores de Edad , Canadá/epidemiología , Humanos , Selección de Paciente , Modelos de Riesgos Proporcionales , Sistema de Registros , Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Estados Unidos/epidemiología , Listas de EsperaRESUMEN
BACKGROUND: Evidence suggests that increasing intensity of rehabilitation results in better motor recovery. Limited evidence is available on the effectiveness of an interactive virtual reality gaming system for stroke rehabilitation. EVREST was designed to evaluate feasibility, safety and efficacy of using the Nintendo Wii gaming virtual reality (VRWii) technology to improve arm recovery in stroke patients. METHODS: Pilot randomized study comparing, VRWii versus recreational therapy (RT) in patients receiving standard rehabilitation within six months of stroke with a motor deficit of > or =3 on the Chedoke-McMaster Scale (arm). In this study we expect to randomize 20 patients. All participants (age 18-85) will receive customary rehabilitative treatment consistent of a standardized protocol (eight sessions, 60 min each, over a two-week period). OUTCOME MEASURES: The primary feasibility outcome is the total time receiving the intervention. The primary safety outcome is the proportion of patients experiencing intervention-related adverse events during the study period. Efficacy, a secondary outcome measure, will be measured by the Wolf Motor Function Test, Box and Block Test, and Stroke Impact Scale at the four-week follow-up visit. From November, 2008 to September, 2009 21 patients were randomized to VRWii or RT. Mean age, 61 (range 41-83) years. Mean time from stroke onset 25 (range 10-56) days. CONCLUSIONS: EVREST is the first randomized parallel controlled trial assessing the feasibility, safety, and efficacy of virtual reality using Wii gaming technology in stroke rehabilitation. The results of this study will serve as the basis for a larger multicentre trial. ClinicalTrials.gov registration# NTC692523.
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Rehabilitación de Accidente Cerebrovascular , Juegos de Video , Actividades Cotidianas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Canadá , Cuidadores , Protocolos Clínicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Destreza Motora , Selección de Paciente , Proyectos Piloto , Desempeño Psicomotor/fisiología , Proyectos de Investigación , Resultado del Tratamiento , Extremidad Superior , Adulto JovenRESUMEN
1. Understanding why invading populations sometimes fail to establish is of considerable relevance to the development of strategies for managing biological invasions. 2. Newly arriving populations tend to be sparse and are often influenced by Allee effects. Mating failure is a typical cause of Allee effects in low-density insect populations, and dispersion of individuals in space and time can exacerbate mate-location failure in invading populations. 3. Here we evaluate the relative importance of dispersal and sexual asynchrony as contributors to Allee effects in invading populations by adopting as a case study the gypsy moth (Lymantria dispar L.), an important insect defoliator for which considerable demographic information is available. 4. We used release-recapture experiments to parameterize a model that describes probabilities that males locate females along various spatial and temporal offsets between male and female adult emergence. 5. Based on these experimental results, we developed a generalized model of mating success that demonstrates the existence of an Allee threshold, below which introduced gypsy moth populations are likely to go extinct without any management intervention.
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Migración Animal/fisiología , Mariposas Nocturnas/fisiología , Animales , Simulación por Computador , Femenino , Masculino , Dinámica Poblacional , Reproducción/fisiología , Conducta Sexual Animal/fisiología , Factores de TiempoRESUMEN
OBJECTIVE: To predict death or neurodevelopmental impairment (NDI) in extremely low birth weight infants by classification trees with recursive partitioning and automatic selection of optimal cut points of variables. STUDY DESIGN: Data from the Trial of Indomethacin Prophylaxis in Preterms were randomly divided into development (n=784) and validation sets (n=262). Three models were developed for the combined outcome of death (8 days to 18 months) or NDI (cerebral palsy, cognitive delay, deafness, or blindness at 18 months corrected age): antenatal: antenatal data; early neonatal: antenatal+first 3 days data; and first week: antenatal, first 3 days, and 4th to 8th days data. Decision trees were tested on the validation set. RESULTS: Variables associated with death/NDI in each model were: Antenatal: Gestation
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Árboles de Decisión , Viabilidad Fetal , Recien Nacido Prematuro , Recién Nacido de muy Bajo Peso , Discapacidades del Desarrollo/epidemiología , Discapacidades del Desarrollo/prevención & control , Femenino , Humanos , Mortalidad Infantil , Recién Nacido , Enfermedades del Prematuro/epidemiología , Enfermedades del Prematuro/mortalidad , Enfermedades del Prematuro/prevención & control , Masculino , Valor Predictivo de las Pruebas , Pronóstico , Sensibilidad y EspecificidadAsunto(s)
Antagonistas Adrenérgicos beta/uso terapéutico , Antiarrítmicos/uso terapéutico , Fibrilación Atrial/prevención & control , Metoprolol/uso terapéutico , Complicaciones Posoperatorias/prevención & control , Método Doble Ciego , Humanos , Tiempo de Internación , Cuidados Preoperatorios , Estudios ProspectivosRESUMEN
BACKGROUND: Although observational studies suggest that IVF is more effective than no treatment for women with Fallopian tube patency, this has not been tested rigorously in a randomized controlled trial (RCT). METHODS: Eligible consenting couples planning their first treatment cycle in five Canadian fertility clinics received either IVF, within 90 days of randomization, or a period of 90 days with no treatment. Random allocation was stratified by female age and sperm quality, and administered using numbered, opaque, sealed envelopes. Follow-up assessed live birth and associated morbidity. RESULTS: Sixty-eight couples were randomized to a first cycle of IVF and 71 couples had 3 months without treatment. The live birth rates were 20/68 (29%) and 1/71 (1%), respectively. The single delivery in the untreated group was of twins, as were six of the 20 IVF deliveries (30%). An average of 2.0 embryos were transferred and no triplet pregnancies resulted. The relative likelihood of delivery after allocation to IVF was 20.9-fold higher than after allocation to no treatment [95% confidence interval (CI) 2.8-155]. The presence of abnormal sperm did not reduce this likelihood. Treating four women (95% CI 3-6) with one cycle of IVF is required to achieve a single additional birth. CONCLUSIONS: This study provides a valid and up-to-date comparison for policy makers and patients as they make choices around IVF, accurately measuring and confirming a major benefit from treatment.
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Pruebas de Obstrucción de las Trompas Uterinas , Trompas Uterinas/fisiología , Fertilización In Vitro , Infertilidad Femenina/terapia , Resultado del Embarazo , Tasa de Natalidad , Femenino , Fertilidad , Humanos , EmbarazoRESUMEN
BACKGROUND: Today, women have an enlightened view towards their life cycles, which is evidence of their healing potential. Women need to share their insights about their healing potential gained through self-reflective processes. Their voices must be heard so that we can benefit from their collective wisdom. The process of healing through self-reflection has begun as a group of nurses share their insights. Documenting the perspectives of these nurses provides the opportunity for other women to learn from and apply this knowledge to their lives. METHOD: Through purposive sampling, eight registered nurses, all women, were selected to participate in in-depth, personal, semi-structured interviews. The purposes in this paper are to describe a three-stage (i.e. awareness, critical analysis, and new perspective) reflective-thinking model and discuss the application of this model to women's expressed inner knowledge and wisdom across personal and professional life cycles. RESULTS: Three themes, signifying their ability to heal themselves, were labelled: Spirituality, Be-ing Versus Do-ing, and Eustress Versus Distress. CONCLUSIONS: Essentially, self-reflection results from both personal and professional stimuli and signifies the need for change so that healing can begin. Recommendations are offered for nurse educators and researchers.
Asunto(s)
Adaptación Psicológica , Modelos Psicológicos , Enfermeras y Enfermeros/psicología , Autoimagen , Pensamiento , Salud de la Mujer , Mujeres/psicología , Adulto , Actitud , Concienciación , Femenino , Identidad de Género , Desarrollo Humano , Humanos , Conocimiento , Acontecimientos que Cambian la Vida , Lógica , Investigación Metodológica en Enfermería , Solución de Problemas , Terapia por Relajación , Religión y Psicología , Encuestas y Cuestionarios , Carga de TrabajoRESUMEN
Experiments were conducted to assess the in vivo potency of binary mixtures of estrogenic chemicals using plasma vitellogenin (VTG) concentrations in juvenile rainbow trout (Oncorhynchus mykiss) as the endpoint. The estrogenic potencies of estradiol-17beta (E2), 4-tertnonylphenol (NP), and methoxychlor (MXC) were determined following 14 day exposures to the individual chemicals and binary mixtures of these chemicals. E2, NP, and MXC all induced concentration dependent increases in plasma VTG, with lowest observed effect concentrations of 4.7 and 7.9 ng L(-1) for E2, 6.1 and 6.4 microg L(-1) for NP, and 4.4 and 6.5 microg L(-1) for MXC. Concentration-response curves for fixed ratio binary mixtures of E2 and NP (1:1000), E2 and MXC (1:1000), and NP and MXC (1:1) were compared to those obtained for the individual chemicals, using the model of concentration addition. Mixtures of E2 and NP were additive at the concentrations tested, but mixtures of E2 and MXC were less than additive. This suggests that while NP probably acts via the same mechanism as E2 in inducing VTG synthesis, MXC may be acting via a different mechanism(s), possibly as a result of its conversion to HPTE which is an estrogen receptor alpha agonist and an estrogen receptor beta antagonist. It was not possible to determine whether mixtures of MXC and NP were additive using VTG induction, because the toxicity of MXC restricted the effect range forwhich the expected response curve forthe binary mixture could be calculated. The data presented illustrate that the model of concentration addition can accurately predict effects on VTG induction, where we know that both chemicals act via the same mechanism in mediating a vitellogenic response.