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Acute Coronavirus Disease 2019 symptoms limit daily activities, but little is known about its association with severe acute respiratory syndrome coronavirus 2 viral burden. In this exploratory analysis of placebo recipients in the ACTIV-2/A5401 platform trial, we showed that high anterior nasal RNA levels and detectable plasma RNA were associated with delayed symptom improvement. Clinical Trials Registration. https://clinicaltrials.gov/ct2/show/NCT04518410.
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COVID-19 , Adulto , Humanos , ARN , SARS-CoV-2 , Carga ViralRESUMEN
Randomized trials are an established method to evaluate the causal effects of interventions. Despite concerted efforts to retain all trial participants, some missing outcome data are often inevitable. It is unclear how best to account for missing outcome data in sample size calculations. A standard approach is to inflate the sample size by the inverse of one minus the anticipated dropout probability. However, the performance of this approach in the presence of informative outcome missingness has not been well-studied. We investigate sample size calculation when outcome data are missing at random given the randomized intervention group and fully observed baseline covariates under an inverse probability of response weighted (IPRW) estimating equations approach. Using M-estimation theory, we derive sample size formulas for both individually randomized and cluster randomized trials (CRTs). We illustrate the proposed method by calculating a sample size for a CRT designed to detect a difference in HIV testing strategies under an IPRW approach. We additionally develop an R shiny app to facilitate implementation of the sample size formulas.
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Modelos Estadísticos , Humanos , Tamaño de la Muestra , Interpretación Estadística de Datos , Ensayos Clínicos Controlados Aleatorios como Asunto , ProbabilidadRESUMEN
This study assessed the impact of structural characteristics on quality rating and improvement systems (QRIS) outcomes in an Australian national study. Data from the Australian Children's Education and Care Quality Authority (ACECQA) repository of National Quality Standard (NQS) ratings were used to identify long day care services that had improved from Working Towards NQS to Meeting or Exceeding NQS or had no change over two assessments. QRIS outcomes were examined for state/territory jurisdiction, urban-rural location, community socio-economic status, type and size of provider organisation, centre size and stability of centre owner/provider using multinomial logistic regression analyses. Controlling for jurisdiction, results showed that improvement to Meeting NQS was more likely for not-for-profit versus for-profit providers and for large multi-site provider organisations versus small, stand-alone providers. Improvement to Exceeding NQS was also associated with not-for-profit and larger provider organisations, as well as larger versus smaller centres, and centres that had stable ownership.
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BACKGROUND: Intra-articular corticosteroids, such as isoflupredone acetate, are commonly used in the treatment of joint inflammation, especially in performance horses. Following administration in a non-inflamed joints blood concentrations of isoflupredone were low and detectable for only a short period of time post-administration compared to synovial fluid concentrations. For some drugs, inflammation can affect pharmacokinetics, therefore, the goal of the current study was to describe the pharmacokinetics of isoflupredone acetate following intra-articular administration using a model of acute synovitis. Secondarily, pharmacodynamic effects, including effects on joint circumference, joint flexion, and lameness following intra-articular administration of isoflupredone acetate in the experimental model were described. METHODS: Sixteen horses received a single intra-articular dose of 8 mg of isoflupredone acetate or saline 12 h post-administration of lipopolysaccharide. Blood and urine samples were collected up to 72 h and synovial fluid for 28 days post-administration, drug concentrations determined by liquid chromatography- mass spectrometry and pharmacokinetic analysis performed. Joint circumference, maximum angle of pain free joint flexion and lameness were evaluated prior to and post-treatment. RESULTS: The maximum isoflupredone plasma concentration was 2.45 ± 0.61 ng/mL at 2.5 ± 0.75 h and concentrations were less than the limit of quantitation by 72 h. Isoflupredone was below detectable concentrations in urine by 72 h post-administration in all horses and no longer detectable in synovial fluid by 96 h post-administration. Joint circumference was significantly decreased in the isoflupredone treatment group compared to the saline group at 24 and 48 h post drug administration. Pain free joint flexion was significantly different between the saline and isoflupredone treatment groups on day 4 post-treatment. CONCLUSIONS: Synovial fluid concentrations and maximum plasma concentrations of isoflupredone differed slightly between the current study and a previous one describing administration into a non-inflamed joint, however, the detection time of isoflupredone in blood was comparable. Effects of isoflupredone on joint circumference and degree of pain free joint flexion suggest a short duration of effect with respect to alleviation of lipopolysaccharide induced synovitis, however, results of this study support future studies of the anti-inflammatory effects of intra-articular isoflupredone acetate.
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Enfermedades de los Caballos , Sinovitis , Caballos , Animales , Lipopolisacáridos , Cojera Animal/inducido químicamente , Cojera Animal/tratamiento farmacológico , Inyecciones Intraarticulares/veterinaria , Sinovitis/inducido químicamente , Sinovitis/tratamiento farmacológico , Sinovitis/veterinaria , Líquido Sinovial , Inflamación/tratamiento farmacológico , Inflamación/veterinaria , Enfermedades de los Caballos/inducido químicamente , Enfermedades de los Caballos/tratamiento farmacológicoRESUMEN
BACKGROUND: Pregnant women with an elevated viral load of hepatitis B virus (HBV) have a risk of transmitting infection to their infants, despite the infants' receiving hepatitis B immune globulin. METHODS: In this multicenter, double-blind clinical trial performed in Thailand, we randomly assigned hepatitis B e antigen (HBeAg)-positive pregnant women with an alanine aminotransferase level of 60 IU or less per liter to receive tenofovir disoproxil fumarate (TDF) or placebo from 28 weeks of gestation to 2 months post partum. Infants received hepatitis B immune globulin at birth and hepatitis B vaccine at birth and at 1, 2, 4, and 6 months. The primary end point was a hepatitis B surface antigen (HBsAg)-positive status in the infant, confirmed by the HBV DNA level at 6 months of age. We calculated that a sample of 328 women would provide the trial with 90% power to detect a difference of at least 9 percentage points in the transmission rate (expected rate, 3% in the TDF group vs. 12% in the placebo group). RESULTS: From January 2013 to August 2015, we enrolled 331 women; 168 women were randomly assigned to the TDF group and 163 to the placebo group. At enrollment, the median gestational age was 28.3 weeks, and the median HBV DNA level was 8.0 log10 IU per milliliter. Among 322 deliveries (97% of the participants), there were 319 singleton births, two twin pairs, and one stillborn infant. The median time from birth to administration of hepatitis B immune globulin was 1.3 hours, and the median time from birth to administration of hepatitis B vaccine was 1.2 hours. In the primary analysis, none of the 147 infants (0%; 95% confidence interval [CI], 0 to 2) in the TDF group were infected, as compared with 3 of 147 (2%; 95% CI, 0 to 6) in the placebo group (P=0.12). The rate of adverse events did not differ significantly between groups. The incidence of a maternal alanine aminotransferase level of more than 300 IU per liter after discontinuation of the trial regimen was 6% in the TDF group and 3% in the placebo group (P=0.29). CONCLUSIONS: In a setting in which the rate of mother-to-child HBV transmission was low with the administration of hepatitis B immune globulin and hepatitis B vaccine in infants born to HBeAg-positive mothers, the additional maternal use of TDF did not result in a significantly lower rate of transmission. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development; ClinicalTrials.gov number, NCT01745822 .).
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Antivirales/uso terapéutico , Virus de la Hepatitis B/aislamiento & purificación , Hepatitis B/transmisión , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Tenofovir/uso terapéutico , Adolescente , Adulto , Alanina Transaminasa/sangre , Antivirales/efectos adversos , ADN Viral/aislamiento & purificación , Método Doble Ciego , Femenino , Hepatitis B/diagnóstico , Hepatitis B/tratamiento farmacológico , Vacunas contra Hepatitis B , Antígenos e de la Hepatitis B/sangre , Virus de la Hepatitis B/genética , Humanos , Lactante , Recién Nacido , Masculino , Embarazo , Tenofovir/efectos adversos , Carga Viral , Adulto JovenRESUMEN
Power calculation for stepped-wedge cluster randomized trials (SW-CRTs) presents unique challenges, beyond those of standard parallel cluster randomized trials, due to the need to consider temporal within cluster correlations and background period effects. To date, power calculation methods specific to SW-CRTs have primarily been developed under a linear model. When the outcome is binary, the use of a linear model corresponds to assessing a prevalence difference; yet trial analysis often employs a nonlinear link function. We propose power calculation methods for cross-sectional SW-CRTs under a logistic model fitted by generalized estimating equations. Firstly, under an exchangeable correlation structure, we show the power based on a logistic model is lower than that from assuming a linear model in the absence of period effects. We then evaluate the impact of background prevalence changes over time on power. To allow the correlation among outcomes in the same cluster to change over time and with treatment status, we generalize the methods to more complex correlation structures. Our simulation studies demonstrate that the proposed power calculation methods perform well with the model-based variance under the true correlation structure and reveal that a working independence structure can result in substantial efficiency loss, while a working exchangeable structure performs well even when the underlying correlation structure deviates from exchangeable. An extension to our methods accounts for variable cluster sizes and reveals that unequal cluster sizes have a modest impact on power. We illustrate the approaches by application to a quality of care improvement trial for acute coronary syndrome.
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Proyectos de Investigación , Análisis por Conglomerados , Estudios Transversales , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Tamaño de la MuestraRESUMEN
We evaluated health-related quality of life (QoL) and self-reported incomplete adherence as predictors of early second-line antiretroviral (ART) virological failure (VF). ACTG A5273 study participants completed the ACTG SF-21 measure which has 8 QoL domains. We used exact logistic regression to assess the association of QoL at baseline and week 4 with early VF adjusted for self-reported adherence. Of 500 individuals (51% women, median age 39 years) in this analysis, 79% and 75% self-reported complete adherence (no missing doses in the past month) at weeks 4 and 24, respectively. Early VF was experienced by 7% and more common among those who self-reported incomplete adherence. Participants with low week 4 QoL scores had higher rates of early VF than participants with high scores. After adjusting for self-reported adherence at week 4, VL and CD4 at baseline, cognitive functioning, pain and mental health domains were significantly associated with subsequent early VF. In this post-hoc analysis, poorer QoL adds to self-reported incomplete adherence after 4 weeks of second-line ART in predicting VF at week 24. Evaluation is needed to assess whether individuals with poorer QoL might be targeted for greater support to reduce risk of VF.Trial registration: ClinicalTrials.gov identifier: NCT01352715.
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Fármacos Anti-VIH , Infecciones por VIH , Adulto , Fármacos Anti-VIH/uso terapéutico , Antirretrovirales/uso terapéutico , Femenino , Infecciones por VIH/tratamiento farmacológico , Humanos , Masculino , Cumplimiento de la Medicación , Calidad de Vida , Autoinforme , Carga ViralRESUMEN
Standard sample size calculation formulas for stepped wedge cluster randomized trials (SW-CRTs) assume that cluster sizes are equal. When cluster sizes vary substantially, ignoring this variation may lead to an under-powered study. We investigate the relative efficiency of a SW-CRT with varying cluster sizes to equal cluster sizes, and derive variance estimators for the intervention effect that account for this variation under a mixed effects model-a commonly used approach for analyzing data from cluster randomized trials. When cluster sizes vary, the power of a SW-CRT depends on the order in which clusters receive the intervention, which is determined through randomization. We first derive a variance formula that corresponds to any particular realization of the randomized sequence and propose efficient algorithms to identify upper and lower bounds of the power. We then obtain an "expected" power based on a first-order approximation to the variance formula, where the expectation is taken with respect to all possible randomization sequences. Finally, we provide a variance formula for more general settings where only the cluster size arithmetic mean and coefficient of variation, instead of exact cluster sizes, are known in the design stage. We evaluate our methods through simulations and illustrate that the average power of a SW-CRT decreases as the variation in cluster sizes increases, and the impact is largest when the number of clusters is small.
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Algoritmos , Proyectos de Investigación , Análisis por Conglomerados , Estudios Transversales , Ensayos Clínicos Controlados Aleatorios como Asunto , Tamaño de la MuestraRESUMEN
In a randomized, double-blind, placebo-controlled trial of tenofovir disoproxil fumarate (TDF) use from 28 weeks gestational age to 2 months postpartum to prevent mother-to-child transmission of hepatitis B virus, there was no significant effect of maternal TDF use on maternal or infant bone mineral density 1 year after delivery/birth. Clinical Trials Registration. NCT01745822.
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Antivirales/uso terapéutico , Densidad Ósea/efectos de los fármacos , Hepatitis B/tratamiento farmacológico , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Tenofovir/uso terapéutico , Adulto , Método Doble Ciego , Femenino , Edad Gestacional , Virus de la Hepatitis B , Humanos , Lactante , Masculino , Periodo Posparto , Embarazo , Complicaciones Infecciosas del Embarazo/prevención & control , Complicaciones Infecciosas del Embarazo/virología , Carga Viral/efectos de los fármacos , Adulto JovenRESUMEN
BACKGROUND: The discovery of potent and broadly neutralizing antibodies (bNAbs) against human immunodeficiency virus (HIV) has made passive immunization a potential strategy for the prevention and treatment of HIV infection. We sought to determine whether passive administration of VRC01, a bNAb targeting the HIV CD4-binding site, can safely prevent or delay plasma viral rebound after the discontinuation of antiretroviral therapy (ART). METHODS: We conducted two open-label trials (AIDS Clinical Trials Group [ACTG] A5340 and National Institutes of Health [NIH] 15-I-0140) of the safety, side-effect profile, pharmacokinetic properties, and antiviral activity of VRC01 in persons with HIV infection who were undergoing interruption of ART. RESULTS: A total of 24 participants were enrolled, and one serious alcohol-related adverse event occurred. Viral rebound occurred despite plasma VRC01 concentrations greater than 50 µg per milliliter. The median time to rebound was 4 weeks in the A5340 trial and 5.6 weeks in the NIH trial. Study participants were more likely than historical controls to have viral suppression at week 4 (38% vs. 13%, P=0.04 by a two-sided Fisher's exact test in the A5340 trial; and 80% vs. 13%, P<0.001 by a two-sided Fisher's exact test in the NIH trial) but the difference was not significant at week 8. Analyses of virus populations before ART as well as before and after ART interruption showed that VRC01 exerted pressure on rebounding virus, resulting in restriction of recrudescent viruses and selection for preexisting and emerging antibody neutralization-resistant virus. CONCLUSIONS: VRC01 slightly delayed plasma viral rebound in the trial participants, as compared with historical controls, but it did not maintain viral suppression by week 8. In the small number of participants enrolled in these trials, no safety concerns were identified with passive immunization with a single bNAb (VRC01). (Funded by the National Institute of Allergy and Infectious Diseases and others; ACTG A5340 and NIH 15-I-0140 ClinicalTrials.gov numbers, NCT02463227 and NCT02471326 .).
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Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Neutralizantes/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , VIH/aislamiento & purificación , Viremia/prevención & control , Adulto , Anciano , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales/farmacocinética , Anticuerpos Neutralizantes/efectos adversos , Anticuerpos ampliamente neutralizantes , Femenino , VIH/genética , Anticuerpos Anti-VIH , Infecciones por VIH/virología , Estudio Históricamente Controlado , Humanos , Masculino , Persona de Mediana Edad , Filogenia , ARN Viral/sangre , Carga ViralRESUMEN
Several post-translational modifications figure prominently in ventricular remodeling. The beta-O-linkage of N-acetylglucosamine (O-GlcNAc) to proteins has emerged as an important signal in the cardiovascular system. Although there are limited insights about the regulation of the biosynthetic pathway that gives rise to the O-GlcNAc post-translational modification, much remains to be elucidated regarding the enzymes, such as O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), which regulate the presence/absence of O-GlcNAcylation. Recently, we showed that the transcription factor, E2F1, could negatively regulate OGT and OGA expression in vitro. The present study sought to determine whether E2f1 deletion would improve post-infarct ventricular function by de-repressing expression of OGT and OGA. Male and female mice were subjected to non-reperfused myocardial infarction (MI) and followed for 1 or 4 week. MI significantly increased E2F1 expression. Deletion of E2f1 alone was not sufficient to alter OGT or OGA expression in a naïve setting. Cardiac dysfunction was significantly attenuated at 1-week post-MI in E2f1-ablated mice. During chronic heart failure, E2f1 deletion also attenuated cardiac dysfunction. Despite the improvement in function, OGT and OGA expression was not normalized and protein O-GlcNAcyltion was not changed at 1-week post-MI. OGA expression was significantly upregulated at 4-week post-MI but overall protein O-GlcNAcylation was not changed. As an alternative explanation, we also performed guided transcriptional profiling of predicted targets of E2F1, which indicated potential differences in cardiac metabolism, angiogenesis, and apoptosis. E2f1 ablation increased heart size and preserved remote zone capillary density at 1-week post-MI. During chronic heart failure, cardiomyocytes in the remote zone of E2f1-deleted hearts were larger than wildtype. These data indicate that, overall, E2f1 exerts a deleterious effect on ventricular remodeling. Thus, E2f1 deletion improves ventricular remodeling with limited impact on enzymes regulating O-GlcNAcylation.
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Factor de Transcripción E2F1/deficiencia , Infarto del Miocardio/metabolismo , Miocardio/metabolismo , Función Ventricular Izquierda , Remodelación Ventricular , Animales , Capilares/metabolismo , Capilares/patología , Vasos Coronarios/metabolismo , Vasos Coronarios/patología , Modelos Animales de Enfermedad , Factor de Transcripción E2F1/genética , Femenino , Eliminación de Gen , Glicosilación , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Infarto del Miocardio/genética , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Miocardio/patología , N-Acetilglucosaminiltransferasas/metabolismo , beta-N-Acetilhexosaminidasas/metabolismoRESUMEN
We assessed tenofovir exposure during pregnancy and postpartum in hepatitis B virus (HBV)-infected HIV-uninfected women receiving tenofovir disoproxil fumarate (TDF) to prevent mother-to-child transmission of HBV. Data from 154 women who received TDF within a randomized controlled trial were included. Individual plasma tenofovir exposures (area under the concentration-time curve from 0 to 24 h [AUC0-24]) were estimated using a population pharmacokinetic approach. The estimated geometric mean tenofovir AUC0-24 was 20% (95% confidence interval [95% CI], 19 to 21%) lower during pregnancy than during postpartum; this modest reduction in the absence of HBV transmission suggests that no dose adjustment is needed.
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Antivirales/farmacocinética , Virus de la Hepatitis B/efectos de los fármacos , Hepatitis B Crónica/tratamiento farmacológico , Hepatitis B Crónica/transmisión , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Tenofovir/farmacocinética , Administración Oral , Adulto , Antivirales/sangre , Antivirales/farmacología , Área Bajo la Curva , Femenino , Antígenos de Superficie de la Hepatitis B/sangre , Virus de la Hepatitis B/crecimiento & desarrollo , Hepatitis B Crónica/virología , Humanos , Periodo Posparto , Embarazo , Tenofovir/sangre , Tenofovir/farmacología , Carga Viral/efectos de los fármacosRESUMEN
We evaluated health-related quality of life (QoL) in HIV infection participants with virologic failure (VF) on first-line antiretroviral therapy (ART) in 9 resource-limited settings (RLS). ACTG SF-21 was completed by 512 participants at A5273 study entry; 8 domains assessed: general health perceptions (GHP), physical functioning (PF), role functioning (RF), social functioning (SF), cognitive functioning (CF), pain (P), mental health (MH), and energy/fatigue (E/F); each was scored between 0 (worst) to 100 (best). Mean QoL scores ranged from 67 (GHP) to 91 (PF, SF, CF). QoL varied by country; high VL and low CD4 were associated with worse QoL in most domains, except RF (VL only), SF (CD4 only) and CF (neither). Number of comorbidities, BMI and history of AIDS were associated with some domains. Relationships between QoL and VL varied among countries for all domains. The association of worse disease status with worse QoL may reflect low QoL when ART was initiated and/or deterioration associated with VF.
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Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/psicología , Calidad de Vida/psicología , Adulto , Femenino , Infecciones por VIH/virología , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Carga ViralRESUMEN
This study explored the longitudinal association between early shared reading and children's later school achievement. We also examined the mediating role of children's academic school readiness and the moderating effect of family socioeconomic status. Data were drawn from the Longitudinal Study of Australian Children (n = 4,768). Frequency of shared reading and academic school readiness were assessed at the ages of 2-3 and 4-5. School achievement was assessed at age 8-9 via standardized national tests of school literacy and mathematics achievement. Results indicated that early shared reading was associated with children's school achievement directly and indirectly through receptive language and early academic skills. The results also showed that frequency of reading predicts the outcome measures, over and above other home activities such as telling child a story or practicing music. The associations were stronger among low and middle SES groups compared to the high SES group. We conclude that shared reading is uniquely associated to indicators of children's cognitive development such as language and early academic skills as well as children's school achievement. This effect is over and above families' socioeconomic status and other activities that parents do. This may be because books offer unique opportunities to teach children new words and concepts in a systematic way, and this is something that most parents would not be able to do otherwise.
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A nested case-cohort study was performed in participants of a clinical trial of first-line human immunodeficiency virus treatments to investigate plasma biomarkers of inflammation and microbial translocation for their association with immune reconstitution inflammatory syndrome (IRIS). Fifty-one of 1452 participants with baseline CD4 count <350 cells/µL developed IRIS. Plasma from 51 IRIS cases, including 6 stratified by preenrollment CD4 count ≤200 cells/µL, were analyzed and compared to 94 non-IRIS controls. At baseline, CXCL10, lipopolysaccharide, soluble CD14, 16S ribosomal DNA, and interferon-α2 were associated with greater risk of IRIS. Systemic inflammation through persistent monocyte activation and microbial translocation appear to be important in IRIS pathogenesis.
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Fármacos Anti-VIH/uso terapéutico , Biomarcadores/sangre , Citocinas/sangre , Infecciones por VIH/tratamiento farmacológico , Síndrome Inflamatorio de Reconstitución Inmune/sangre , Síndrome Inflamatorio de Reconstitución Inmune/inmunología , Translocación Genética/inmunología , Estudios de Cohortes , HumanosRESUMEN
Vietnamese is one of the 20 most commonly spoken languages in the world; however, there are no standardised tools to assess Vietnamese children's speech. This study aimed to validate and norm the Vietnamese version of the Intelligibility in Context Scale (ICS-VN). Data were collected from parents of 181 children (aged 2;0-5;11) living in Ha Noi, Northern Viet Nam. The mean ICS-VN score was 4.43 (out of a maximum of 5), indicating that children were 'usually' to 'always' intelligible; however, item-level scores demonstrated significant differences between communication partners. Children with parental concerns about speech and language had significantly lower mean scores than children without parental concerns. Scores also differed by children's age, parents' occupation and mothers' education level but not by sex of child or fathers' education level. The ICS-VN had good psychometric properties indicating it to be a valid tool for use with Vietnamese-speaking children in Northern Viet Nam.
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Lenguaje Infantil , Psicometría , Inteligibilidad del Habla , Factores de Edad , Preescolar , Femenino , Humanos , Masculino , Padres/psicología , Reproducibilidad de los Resultados , Medición de la Producción del Habla , Encuestas y Cuestionarios , VietnamRESUMEN
We conducted a case-controlled study of the associations of CCR5-Δ32 heterozygosity with human immunodeficiency virus type 1 (HIV-1) reservoir size, lymphocyte activation, and CCR5 expression in 114 CCR5(Δ32/WT) and 177 wild-type CCR5 AIDS Clinical Trials Group participants receiving suppressive antiretroviral therapy. Overall, no significant differences were found between groups for any of these parameters. However, higher levels of CCR5 expression correlated with lower amounts of cell-associated HIV-1 RNA. The relationship between CCR5-Δ32 heterozygosity, CCR5 expression, and markers of HIV-1 persistence is likely to be complex and may be influenced by factors such as the duration of ART.
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Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/genética , VIH-1/aislamiento & purificación , Activación de Linfocitos/fisiología , Receptores CCR5/metabolismo , Estudios de Casos y Controles , ADN Circular , ADN Viral/sangre , ADN Viral/aislamiento & purificación , Femenino , Predisposición Genética a la Enfermedad , VIH-1/genética , Humanos , Masculino , ARN Viral/sangre , ARN Viral/aislamiento & purificación , Receptores CCR5/genética , Linfocitos T/fisiologíaRESUMEN
BACKGROUND: Clenbuterol, a beta2-adrenergic receptor agonist, is used therapeutically to treat respiratory conditions in the horse. However, by virtue of its mechanism of action it has been suggested that clenbuterol may also have repartitioning affects in horses and as such the potential to affect performance. Clenbuterol decreases the percent fat and increases fat-free mass following high dose administration in combination with intense exercise in horses. In the current study, microarray analysis and real-time PCR were used to study the temporal effects of low and high dose chronic clenbuterol administration on differential gene expression of several skeletal muscle myosin heavy chains, genes involved in lipid metabolism and the ß2-adrenergic receptor. The effect of clenbuterol administration on differential gene expression has not been previously reported in the horse, therefore the primary objective of the current study was to describe clenbuterol-induced temporal changes in gene expression following chronic oral administration of clenbuterol at both high and low doses. RESULTS: Steady state clenbuterol concentrations were achieved at approximately 50 h post administration of the first dose for the low dose regimen and at approximately 18-19 days (10 days post administration of 3.2 µg/kg) for the escalating dosing regimen. Following chronic administration of the low dose (0.8 µg/kg BID) of clenbuterol, a total of 114 genes were differentially expressed, however, none of these changes were found to be significant following FDR adjustment of the p-values. A total of 7,093 genes were differentially expressed with 3,623 genes up regulated and 3,470 genes down regulated following chronic high dose administration. Of the genes selected for further study by real-time PCR, down-regulation of genes encoding myosin heavy chains 2 and 7, steroyl CoA desaturase and the ß2-adrenergic receptor were noted. For most genes, expression levels returned towards baseline levels following cessation of drug administration. CONCLUSION: This study showed no evidence of modified gene expression following chronic low dose administration of clenbuterol to horses. However, following chronic administration of high doses of clenbuterol alterations were noted in transcripts encoding various myosin heavy chains, lipid metabolizing enzymes and the ß2-adrenergic receptor.
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Agonistas Adrenérgicos beta/farmacología , Clenbuterol/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Animales , Perfilación de la Expresión Génica , Caballos , Especificidad de Órganos/genética , TranscriptomaRESUMEN
BACKGROUND: Chronic hepatitis B virus (HBV) infection is complicated by cirrhosis and liver cancer. In Thailand, 6-7 % of adults are chronically infected with HBV. The risk of mother-to-child transmission (MTCT) of HBV has been estimated to be about 12 % when mothers have a high hepatitis B viral load, even if infants receive passive-active prophylaxis with HBV immunoglobulin (HBIg) and initiate the hepatitis B vaccine series at birth. We designed a study to assess the efficacy and safety of a short course of maternal tenofovir disoproxil fumarate (TDF) among women with a marker of high viral load for the prevention of MTCT of HBV. METHODS: The study is a phase III, multicenter (17 sites in Thailand), placebo-controlled, double-blind, randomized 1:1, two-arm clinical trial of TDF 300 mg once daily versus placebo among pregnant women from 28 weeks' gestation through 2-month post-partum. All infants receive HBIg at birth, and a hepatitis B (HB) vaccination series according to Thai guidelines: birth, and age 1, 2, 4 and 6 months. Participant women at study entry must be age ≥18 years, hepatitis B surface antigen (HBsAg) and e-antigen (HBeAg) positive, have alanine aminotransferase (ALT) level < 30 IU/L at screening (confirmed < 60 IU/L pre-entry), negative hepatitis C serology, creatinine clearance >50 mL/min, and no history of anti-HBV antiviral treatment. The target sample size of 328 mother/infant pairs assumed 156 evaluable cases per arm to detect a ≥9 % difference in MTCT transmission (3 % experimental arm versus 12 % placebo arm) with 90 % power. Mothers and infants are followed until 12 months after delivery. The primary infant endpoint is detection of HBsAg, confirmed by detection of HBV DNA at six months of age. Secondary endpoints are maternal and infant adverse events, acute exacerbations of maternal hepatitis B disease (ALT >300 IU/L, defined as a "flare") following discontinuation of study treatment, infant HBV infection status and growth up to 12 months of age. DISCUSSION: The results of this randomized trial will clarify the efficacy and safety of a short course of antiviral treatment to prevent mother-to-child transmission of HBV and inform international guidelines. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01745822 .