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1.
N Engl J Med ; 385(16): 1462-1473, 2021 10 14.
Artículo en Inglés | MEDLINE | ID: mdl-34644471

RESUMEN

BACKGROUND: Experimental studies and small clinical trials have suggested that treatment with intranasal oxytocin may reduce social impairment in persons with autism spectrum disorder. Oxytocin has been administered in clinical practice to many children with autism spectrum disorder. METHODS: We conducted a 24-week, placebo-controlled phase 2 trial of intranasal oxytocin therapy in children and adolescents 3 to 17 years of age with autism spectrum disorder. Participants were randomly assigned in a 1:1 ratio, with stratification according to age and verbal fluency, to receive oxytocin or placebo, administered intranasally, with a total target dose of 48 international units daily. The primary outcome was the least-squares mean change from baseline on the Aberrant Behavior Checklist modified Social Withdrawal subscale (ABC-mSW), which includes 13 items (scores range from 0 to 39, with higher scores indicating less social interaction). Secondary outcomes included two additional measures of social function and an abbreviated measure of IQ. RESULTS: Of the 355 children and adolescents who underwent screening, 290 were enrolled. A total of 146 participants were assigned to the oxytocin group and 144 to the placebo group; 139 and 138 participants, respectively, completed both the baseline and at least one postbaseline ABC-mSW assessments and were included in the modified intention-to-treat analyses. The least-squares mean change from baseline in the ABC-mSW score (primary outcome) was -3.7 in the oxytocin group and -3.5 in the placebo group (least-squares mean difference, -0.2; 95% confidence interval, -1.5 to 1.0; P = 0.61). Secondary outcomes generally did not differ between the trial groups. The incidence and severity of adverse events were similar in the two groups. CONCLUSIONS: This placebo-controlled trial of intranasal oxytocin therapy in children and adolescents with autism spectrum disorder showed no significant between-group differences in the least-squares mean change from baseline on measures of social or cognitive functioning over a period of 24 weeks. (Funded by the National Institute of Child Health and Human Development; SOARS-B ClinicalTrials.gov number, NCT01944046.).


Asunto(s)
Trastorno del Espectro Autista/tratamiento farmacológico , Oxitocina/administración & dosificación , Conducta Social , Administración Intranasal , Adolescente , Trastorno del Espectro Autista/psicología , Niño , Preescolar , Método Doble Ciego , Femenino , Humanos , Análisis de los Mínimos Cuadrados , Masculino , Oxitocina/efectos adversos , Oxitocina/uso terapéutico , Habilidades Sociales , Insuficiencia del Tratamiento
2.
Lancet ; 399(10322): 359-371, 2022 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-35065784

RESUMEN

BACKGROUND: For young children with peanut allergy, dietary avoidance is the current standard of care. We aimed to assess whether peanut oral immunotherapy can induce desensitisation (an increased allergic reaction threshold while on therapy) or remission (a state of non-responsiveness after discontinuation of immunotherapy) in this population. METHODS: We did a randomised, double-blind, placebo-controlled study in five US academic medical centres. Eligible participants were children aged 12 to younger than 48 months who were reactive to 500 mg or less of peanut protein during a double-blind, placebo-controlled food challenge (DBPCFC). Participants were randomly assigned by use of a computer, in a 2:1 allocation ratio, to receive peanut oral immunotherapy or placebo for 134 weeks (2000 mg peanut protein per day) followed by 26 weeks of avoidance, with participants and study staff and investigators masked to group treatment assignment. The primary outcome was desensitisation at the end of treatment (week 134), and remission after avoidance (week 160), as the key secondary outcome, were assessed by DBPCFC to 5000 mg in the intention-to-treat population. Safety and immunological parameters were assessed in the same population. This trial is registered on ClinicalTrials.gov, NCT03345160. FINDINGS: Between Aug 13, 2013, and Oct 1, 2015, 146 children, with a median age of 39·3 months (IQR 30·8-44·7), were randomly assigned to receive peanut oral immunotherapy (96 participants) or placebo (50 participants). At week 134, 68 (71%, 95% CI 61-80) of 96 participants who received peanut oral immunotherapy compared with one (2%, 0·05-11) of 50 who received placebo met the primary outcome of desensitisation (risk difference [RD] 69%, 95% CI 59-79; p<0·0001). The median cumulative tolerated dose during the week 134 DBPCFC was 5005 mg (IQR 3755-5005) for peanut oral immunotherapy versus 5 mg (0-105) for placebo (p<0·0001). After avoidance, 20 (21%, 95% CI 13-30) of 96 participants receiving peanut oral immunotherapy compared with one (2%, 0·05-11) of 50 receiving placebo met remission criteria (RD 19%, 95% CI 10-28; p=0·0021). The median cumulative tolerated dose during the week 160 DBPCFC was 755 mg (IQR 0-2755) for peanut oral immunotherapy and 0 mg (0-55) for placebo (p<0·0001). A significant proportion of participants receiving peanut oral immunotherapy who passed the 5000 mg DBPCFC at week 134 could no longer tolerate 5000 mg at week 160 (p<0·001). The participant receiving placebo who was desensitised at week 134 also achieved remission at week 160. Compared with placebo, peanut oral immunotherapy decreased peanut-specific and Ara h2-specific IgE, skin prick test, and basophil activation, and increased peanut-specific and Ara h2-specific IgG4 at weeks 134 and 160. By use of multivariable regression analysis of participants receiving peanut oral immunotherapy, younger age and lower baseline peanut-specific IgE was predictive of remission. Most participants (98% with peanut oral immunotherapy vs 80% with placebo) had at least one oral immunotherapy dosing reaction, predominantly mild to moderate and occurring more frequently in participants receiving peanut oral immunotherapy. 35 oral immunotherapy dosing events with moderate symptoms were treated with epinephrine in 21 participants receiving peanut oral immunotherapy. INTERPRETATION: In children with a peanut allergy, initiation of peanut oral immunotherapy before age 4 years was associated with an increase in both desensitisation and remission. Development of remission correlated with immunological biomarkers. The outcomes suggest a window of opportunity at a young age for intervention to induce remission of peanut allergy. FUNDING: National Institute of Allergy and Infectious Disease, Immune Tolerance Network.


Asunto(s)
Alérgenos/administración & dosificación , Arachis/inmunología , Desensibilización Inmunológica , Hipersensibilidad al Cacahuete/prevención & control , Administración Oral , Alérgenos/inmunología , Niño , Preescolar , Método Doble Ciego , Femenino , Humanos , Tolerancia Inmunológica , Masculino , Hipersensibilidad al Cacahuete/inmunología , Resultado del Tratamiento
3.
Pediatr Allergy Immunol ; 32(5): 971-979, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33606312

RESUMEN

BACKGROUND: Nasal allergen challenge (NAC) could be a means to assess indication and/or an outcome of allergen-specific therapies, particularly for perennial allergens. NACs are not commonly conducted in children with asthma, and cockroach NACs are not well established. This study's objective was to identify a range of German cockroach extract doses that induce nasal symptoms and to assess the safety of cockroach NAC in children with asthma. METHODS: Ten adults (18-37 years) followed by 25 children (8-14 years) with well-controlled, persistent asthma and cockroach sensitization underwent NAC with diluent followed by up to 8 escalating doses of cockroach extract (0.00381-11.9 µg/mL Bla g 1). NAC outcome was determined by Total Nasal Symptom Score (TNSS) and/or sneeze score. Cockroach allergen-induced T-cell activation and IL-5 production were measured in peripheral blood mononuclear cells. RESULTS: 67% (6/9) of adults and 68% (17/25) of children had a positive NAC at a median response dose of 0.120 µg/mL [IQR 0.0380-0.379 µg/mL] of Bla g 1. Additionally, three children responded to diluent alone and did not receive any cockroach extract. Overall, 32% (11/34) were positive with sneezes alone, 15% (5/34) with TNSS alone, and 21% (7/34) with both criteria. At baseline, NAC responders had higher cockroach-specific IgE (P = .03), lower cockroach-specific IgG/IgE ratios (children, P = .002), and increased cockroach-specific IL-5-producing T lymphocytes (P = .045). The NAC was well tolerated. CONCLUSION: We report the methodology of NAC development for children with persistent asthma and cockroach sensitization. This NAC could be considered a tool to confirm clinically relevant sensitization and to assess responses in therapeutic studies.


Asunto(s)
Asma , Cucarachas , Alérgenos , Animales , Asma/tratamiento farmacológico , Niño , Humanos , Leucocitos Mononucleares , Pruebas de Provocación Nasal
4.
J Allergy Clin Immunol ; 146(4): 875-883, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32745556

RESUMEN

BACKGROUND: In 2017, the Addendum Guidelines for the Prevention of Peanut Allergy were published with recommendations on early introduction of peanut-containing foods based on infants' clinical history. OBJECTIVE: We sought to conduct a nationwide US survey to assess Guidelines implementation among allergists and immunologists who manage infants for food allergy. METHODS: Survey invitations were delivered to 3281 nonretired, US members of the American Academy of Asthma, Allergy & Immunology, board certified in allergy and immunology. The survey assessed awareness and implementation of the Guidelines and barriers to implementation. Descriptive statistics were generated. RESULTS: Twenty-nine percent (946 of 3281) of surveyed allergists/immunologists responded, and 87.1% (825 of 946) of responders met eligibility criteria. Among eligible responders, 97.1% were aware of the Guidelines. Of these, 64.5% reported full implementation of the Guidelines as published, 34.4% reported partial implementation, and 1.1% reported using none of the Guidelines. Barriers to Guidelines use included parental (47.6%) and self (21.8%) concerns about allergic reactions, lack of referrals (33.6%), parents uninterested in early feeding (28.2%), and lack of clinic time (20.9%). The 2 most common deviations from the Guidelines were considering additional factors not specified in the Guidelines such as family history (50.2%) and conducting skin prick testing in non-high-risk children (43.9%). Of respondents using the Guidelines, 45.7% indicated they needed more education or training. CONCLUSIONS: Essentially all allergists/immunologists who responded to the survey reported full or partial Guidelines implementation. Parental concerns and lack of referrals are major identifiable barriers. Improved Guidelines messaging to parents and referring physicians is warranted.


Asunto(s)
Alergólogos , Implementación de Plan de Salud , Hipersensibilidad al Cacahuete/epidemiología , Hipersensibilidad al Cacahuete/prevención & control , Desensibilización Inmunológica , Personal de Salud , Encuestas Epidemiológicas , Humanos , National Institute of Allergy and Infectious Diseases (U.S.) , Estados Unidos/epidemiología
5.
J Allergy Clin Immunol ; 145(6): 1585-1597, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32169380

RESUMEN

BACKGROUND: The direct-instillation nasal allergen challenge (NAC) and the environmental exposure chamber (EEC) are 2 methods of conducting controlled allergen provocations. The clinical and biological comparability of these methods has not been thoroughly investigated. OBJECTIVE: We sought to compare clinical and immunologic responses to cat allergen in NAC versus EEC. METHODS: Twenty-four participants were randomized to receive either NAC followed by a 2-day challenge in an EEC or a 2-day challenge in an EEC followed by NAC. Challenges were separated by 28-day washout periods. We measured total nasal symptom scores, peak nasal inspiratory flow, nasal (0-8 hours) and serum cytokines, serum antibodies, peripheral blood antigen-specific T lymphocytes, and gene expression in nasal scrapings. The primary outcome was the total nasal symptom score area under the curve for the first 3 hours after allergen exposure in NAC or after initiation of exposure in EEC. RESULTS: Both challenges increased IL-5 and IL-13 in nasal fluids and serum and resulted in altered nasal cell expression of gene modules related to mucosal biology and transcriptional regulation. Changes in gene modules, more so than cytokine measurements, showed significant associations with total nasal symptom score and peak nasal inspiratory flow. Overall, EEC exposure generated larger responses and more early terminations compared with NAC. Although the 2 challenges did not correlate in symptom magnitude or temporality, striking correlations were observed in cytokine levels. CONCLUSIONS: Although clinical outcomes of NAC and EEC were temporally different and nonequivalent in magnitude, immunologic responses were similar. Selection of a particular allergen challenge method should depend on considerations of study objectives and cost.


Asunto(s)
Alérgenos/inmunología , Gatos/inmunología , Exposición a Riesgos Ambientales/efectos adversos , Mucosa Nasal/inmunología , Administración Intranasal/métodos , Adulto , Animales , Anticuerpos/inmunología , Citocinas/inmunología , Femenino , Humanos , Inhalación/inmunología , Masculino , Persona de Mediana Edad , Pruebas de Provocación Nasal/métodos , Pruebas Cutáneas/métodos , Transcripción Genética/inmunología , Adulto Joven
6.
Int J Mol Sci ; 22(14)2021 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-34299271

RESUMEN

Magnetic nanoparticles (MNPs) have a wide range of applications; an area of particular interest is magnetic particle imaging (MPI). MPI is an imaging modality that utilizes superparamagnetic iron oxide particles (SPIONs) as tracer particles to produce highly sensitive and specific images in a broad range of applications, including cardiovascular, neuroimaging, tumor imaging, magnetic hyperthermia and cellular tracking. While there are hurdles to overcome, including accessibility of products, and an understanding of safety and toxicity profiles, MPI has the potential to revolutionize research and clinical biomedical imaging. This review will explore a brief history of MPI, MNP synthesis methods, current and future applications, and safety concerns associated with this newly emerging imaging modality.


Asunto(s)
Medios de Contraste/química , Diagnóstico por Imagen/métodos , Nanopartículas Magnéticas de Óxido de Hierro/química , Animales , Enfermedades Cardiovasculares/diagnóstico por imagen , Enfermedades Cardiovasculares/patología , Diagnóstico por Imagen/tendencias , Humanos , Neoplasias/diagnóstico por imagen , Neoplasias/patología , Enfermedades del Sistema Nervioso/diagnóstico por imagen , Enfermedades del Sistema Nervioso/patología
7.
Nucleic Acids Res ; 46(12): 5977-5995, 2018 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-29722878

RESUMEN

Replication of mitochondrial DNA is strictly regulated during differentiation and development allowing each cell type to acquire its required mtDNA copy number to meet its specific needs for energy. Undifferentiated cells establish the mtDNA set point, which provides low numbers of mtDNA copy but sufficient template for replication once cells commit to specific lineages. However, cancer cells, such as those from the human glioblastoma multiforme cell line, HSR-GBM1, cannot complete differentiation as they fail to enforce the mtDNA set point and are trapped in a 'pseudo-differentiated' state. Global DNA methylation is likely to be a major contributing factor, as DNA demethylation treatments promote differentiation of HSR-GBM1 cells. To determine the relationship between DNA methylation and mtDNA copy number in cancer cells, we applied whole genome MeDIP-Seq and RNA-Seq to HSR-GBM1 cells and following their treatment with the DNA demethylation agents 5-azacytidine and vitamin C. We identified key methylated regions modulated by the DNA demethylation agents that also induced synchronous changes to mtDNA copy number and nuclear gene expression. Our findings highlight the control exerted by DNA methylation on the expression of key genes, the regulation of mtDNA copy number and establishment of the mtDNA set point, which collectively contribute to tumorigenesis.


Asunto(s)
Metilación de ADN , Regulación de la Expresión Génica , Genoma Mitocondrial , Glioblastoma/genética , Línea Celular Tumoral , Núcleo Celular/genética , Variaciones en el Número de Copia de ADN , ADN Mitocondrial/biosíntesis , ADN Mitocondrial/metabolismo , Genes Mitocondriales , Humanos , Inmunoprecipitación/métodos , Transcripción Genética , Secuenciación Completa del Genoma/normas
8.
J Head Trauma Rehabil ; 34(1): 1-10, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30169439

RESUMEN

OBJECTIVE: To investigate effects of cognitive rehabilitation with mobile technology and social support on veterans with traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD). PARTICIPANTS: There were 112 dyads, comprised by a veteran and a family member or friend (224 participants in total). DESIGN: Dyads were randomized to the following: (1) a novel intervention, Cognitive Applications for Life Management (CALM), involving goal management training plus mobile devices for cueing and training attentional control; or (2) Brain Health Training, involving psychoeducation plus mobile devices to train visual memory. MAIN MEASURES: Executive dysfunction (disinhibition, impulsivity) and emotional dysregulation (anger, maladaptive interpersonal behaviors) collected prior to randomization and following intervention completion at 6 months. RESULTS: The clinical trial yielded negative findings regarding executive dysfunction but positive findings on measures of emotion dysregulation. Veterans randomized to CALM reported a 25% decrease in anger over 6 months compared with 8% reduction in the control (B = -5.27, P = .008). Family/friends reported that veterans randomized to CALM engaged in 26% fewer maladaptive interpersonal behaviors (eg, aggression) over 6 months compared with 6% reduction in the control (B = -2.08, P = .016). An unanticipated result was clinically meaningful change in reduced PTSD symptoms among veterans randomized to CALM (P < .001). CONCLUSION: This preliminary study demonstrated effectiveness of CALM for reducing emotional dysregulation in veterans with TBI and PTSD.


Asunto(s)
Lesiones Traumáticas del Encéfalo/rehabilitación , Terapia Cognitivo-Conductual , Computadoras de Mano , Apoyo Social , Trastornos por Estrés Postraumático/rehabilitación , Veteranos/psicología , Adulto , Regulación Emocional , Función Ejecutiva , Femenino , Humanos , Masculino , Estados Unidos
9.
Brain Inj ; 32(12): 1484-1491, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30036112

RESUMEN

OBJECTIVE: Frontal lobe deficits resulting from traumatic brain injury (TBI) and/or posttraumatic stress disorder (PTSD) have been linked to impulsive behaviour. We sought to examine whether neuropsychological performance predicted self-reported impulsivity and informant-reported maladaptive behaviour. METHOD: We administered the Delis-Kaplan Executive Function System (D-KEFS) to 116 Iraq/Afghanistan-era veterans diagnosed with a history of TBI and PTSD. RESULTS: Poorer performance on D-KEFS Stroop Task (both colour and word, separately) and Trail making (letter sequencing and motor speed) tasks and higher PTSD symptom severity were associated with higher self-reported impulsivity. Trail making letter sequencing performance was negatively associated with informant-reported maladaptive behaviour. Regression analyses revealed PTSD symptom severity and Trail making letter sequencing best predicted self-reported impulsivity, even when accounting for age, sex, and education. Only Trail making letter sequencing predicted informant-reported maladaptive behaviour when accounting for other variables in the model. CONCLUSIONS: Attention and processing speed impairments and PTSD symptom severity appear to be important predictors of impulsivity and problematic behaviour among veterans. Findings have implications for theoretical models of aggression and violence and inform the assessment and treatment of individuals with TBI and PTSD.


Asunto(s)
Agresión/fisiología , Lesiones Traumáticas del Encéfalo/psicología , Trastornos de Combate/psicología , Conducta Impulsiva/fisiología , Trastornos por Estrés Postraumático/psicología , Lóbulo Temporal/lesiones , Veteranos/psicología , Adulto , Campaña Afgana 2001- , Anciano , Agresión/psicología , Alcoholismo/psicología , Lesiones Traumáticas del Encéfalo/diagnóstico , Lesiones Traumáticas del Encéfalo/fisiopatología , Trastornos de Combate/diagnóstico , Trastornos de Combate/fisiopatología , Femenino , Humanos , Guerra de Irak 2003-2011 , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Estudios Retrospectivos , Trastornos por Estrés Postraumático/diagnóstico , Trastornos por Estrés Postraumático/fisiopatología , Lóbulo Temporal/fisiopatología , Índices de Gravedad del Trauma , Adulto Joven
10.
Psychosom Med ; 79(2): 201-212, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27669431

RESUMEN

OBJECTIVE: To examine the role of psychosocial factors in mediating the relationship between African American (AA) race and both increased pain sensitivity and blunted stress reactivity. METHODS: Participants included 133 AA and non-Hispanic white (nHW) individuals (mean [SD] age, 37 [9]) matched for age, sex, and socioeconomic status. Participants underwent mental stress testing (Trier Social Stress Test) while cardiovascular, hemodynamic, and neuroendocrine reactivity were measured. Participants completed questionnaires assessing potential sources of psychosocial stress and were tested for pain responses to cold pain and the temporal summation of heat pulses. Mediation analyses were used to determine the extent to which exposure to psychosocial stress accounted for the observed racial differences in stress reactivity and pain. RESULTS: Chronic stress exposure and reactivity to mental stress was largely similar among AAs and nHWs; however, AAs exhibited heightened pain to both cold (p = .012) and heat (p = .004). Racial differences in the relationship between stress reactivity and pain were also observed: while greater stress reactivity was associated with decreased pain among nHWs, reactivity was either unrelated to or even positively associated with pain among AAs (e.g., r = -.21 among nHWs and r = .41 among AAs for stroke volume reactivity and cold pressor intensity). Adjusting for minor racial differences in chronic psychosocial stress did not change these findings. CONCLUSIONS: Accounting for psychosocial factors eliminated racial differences in stress reactivity but not racial differences in sensitivity to experimental pain tasks. Increased exposure to chronic stress may not explain AAs' increased pain sensitivity in laboratory settings.


Asunto(s)
Negro o Afroamericano/etnología , Umbral del Dolor/etnología , Estrés Psicológico/etnología , Población Blanca/etnología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad
11.
Depress Anxiety ; 34(10): 908-917, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28715852

RESUMEN

BACKGROUND: Although traditionally dosed combined oral contraceptives (COCs) (21 days of active pills, 7 days of inactive pills) have not been demonstrated as superior to placebo for the treatment of premenstrual dysphoria (PMD), some randomized controlled trials (RCTs) indicate that oral contraceptives administered with a shortened or eliminated hormone-free interval are superior to placebo. However, results of such trials are mixed, and no existing studies have directly compared continuous and intermittent dosing schedules of the same oral contraceptive. The present study compared placebo, intermittent dosing of oral contraceptives, and continuous dosing of contraceptives for the treatment of PMD. METHODS: Fifty-five women with prospectively confirmed PMD completed a three-arm, RCT in which they were randomized to 3 months of placebo (n = 22), intermittent drospirenone/ethinyl estradiol dosed on a 21-7 schedule (n = 17), or continuous drospirenone/estradiol (n = 16) following a baseline assessment month. RESULTS: All three groups demonstrated similar, robust reductions in premenstrual symptoms over time. A marked placebo response was observed. CONCLUSIONS: The study fails to replicate a uniquely beneficial effect of continuous COC on PMD. Additional work is needed to understand the psychosocial context bolstering the placebo response in women with PMD.


Asunto(s)
Androstenos/farmacología , Anticonceptivos Orales Combinados/farmacología , Etinilestradiol/farmacología , Trastorno Disfórico Premenstrual/tratamiento farmacológico , Adolescente , Adulto , Androstenos/administración & dosificación , Anticonceptivos Orales Combinados/administración & dosificación , Esquema de Medicación , Etinilestradiol/administración & dosificación , Femenino , Humanos , Resultado del Tratamiento , Adulto Joven
12.
Inorg Chem ; 56(16): 10078-10089, 2017 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-28776991

RESUMEN

This paper discusses the fluorination characteristics of phases related to FeSb2O4, by reporting the results of a detailed study of Mg0.50Fe0.50Sb2O4 and Co0.50Fe0.50Sb2O4. Reaction with fluorine gas at low temperatures (typically 230 °C) results in topotactic insertion of fluorine into the channels, which are an inherent feature of the structure. Neutron powder diffraction and solid state NMR studies show that the interstitial fluoride ions are bonded to antimony within the channel walls to form Sb-F-Sb bridges. To date, these reactions have been observed only when Fe2+ ions are present within the chains of edge-linked octahedra (FeO6 in FeSb2O4) that form the structural channels. Oxidation of Fe2+ to Fe3+ is primarily responsible for balancing the increased negative charge associated with the presence of the fluoride ions within the channels. For the two phases studied, the creation of Fe3+ ions within the chains of octahedra modify the magnetic exchange interactions to change the ground-state magnetic symmetry to C-type magnetic order in contrast to the A-type order observed for the unfluorinated oxide parents.

13.
Inorg Chem ; 56(1): 594-607, 2017 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-27977159

RESUMEN

The structure of the mineral schafarzikite, FeSb2O4, has one-dimensional channels with walls comprising Sb3+ cations; the channels are separated by edge-linked FeO6 octahedra that form infinite chains parallel to the channels. Although this structure provides interest with respect to the magnetic and electrical properties associated with the chains and the possibility of chemistry that could occur within the channels, materials in this structural class have received very little attention. Here we show, for the first time, that heating selected phases in oxygen-rich atmospheres can result in relatively large oxygen uptakes (up to ∼2% by mass) at low temperatures (ca. 350 °C) while retaining the parent structure. Using a variety of structural and spectroscopic techniques, it is shown that oxygen is inserted into the channels to provide a structure with the potential to show high one-dimensional oxide ion conductivity. This is the first report of oxygen-excess phases derived from this structure. The oxygen insertion is accompanied not only by oxidation of Fe2+ to Fe3+ within the octahedral chains but also Sb3+ to Sb5+ in the channel walls. The formation of a defect cluster comprising one 5-coordinate Sb5+ ion (which is very rare in an oxide environment), two interstitial O2- ions, and two 4-coordinate Sb3+ ions is suggested and is consistent with all experimental observations. To the best of our knowledge, this is the first example of an oxidation process where the local energetics of the product dictate that simultaneous oxidation of two different cations must occur. This reaction, together with a wide range of cation substitutions that are possible on the transition metal sites, presents opportunities to explore the schafarzikite structure more extensively for a range of catalytic and electrocatalytic applications.

14.
Am J Public Health ; 105(4): 750-6, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25713940

RESUMEN

OBJECTIVES: We examined the impact of a change in New York tax law on the numbers of untaxed cigarettes bootlegged from Native American reservations and resold in the South Bronx. METHODS: Discarded cigarette packs were systematically collected in 30 randomized South Bronx census tracks before and after the amended tax law went into effect in 2011. Also, administrative data were gathered on the number of taxed cigarettes sold in New York State, including sales to Native American reservations. RESULTS: Before the tax amendment, 42% of discarded cigarette packs collected in the South Bronx had no tax stamp. After the tax law went into effect, the percentage of cigarette packs without tax stamps declined to 6.2%. Simultaneously, the percentage of packs with out-of-state tax stamps rose from 18.3% to 66.3%. The percentage of packs with a combined New York State and New York City tax stamp did not change after the tax amendment. CONCLUSIONS: After the tax amendment, the supply of contraband cigarettes appears to have quickly shifted from one lower-priced jurisdiction to another without a change in the overall prevalence of contraband cigarettes.


Asunto(s)
Comercio/legislación & jurisprudencia , Comercio/estadística & datos numéricos , Impuestos/legislación & jurisprudencia , Impuestos/estadística & datos numéricos , Productos de Tabaco/estadística & datos numéricos , Humanos , Indígenas Norteamericanos/estadística & datos numéricos , Ciudad de Nueva York/epidemiología , Fumar/epidemiología
15.
Stat Med ; 34(27): 3531-45, 2015 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-26089186

RESUMEN

We used theoretical and simulation-based approaches to study Type I error rates for one-stage and two-stage analytic methods for cluster-randomized designs. The one-stage approach uses the observed data as outcomes and accounts for within-cluster correlation using a general linear mixed model. The two-stage model uses the cluster specific means as the outcomes in a general linear univariate model. We demonstrate analytically that both one-stage and two-stage models achieve exact Type I error rates when cluster sizes are equal. With unbalanced data, an exact size α test does not exist, and Type I error inflation may occur. Via simulation, we compare the Type I error rates for four one-stage and six two-stage hypothesis testing approaches for unbalanced data. With unbalanced data, the two-stage model, weighted by the inverse of the estimated theoretical variance of the cluster means, and with variance constrained to be positive, provided the best Type I error control for studies having at least six clusters per arm. The one-stage model with Kenward-Roger degrees of freedom and unconstrained variance performed well for studies having at least 14 clusters per arm. The popular analytic method of using a one-stage model with denominator degrees of freedom appropriate for balanced data performed poorly for small sample sizes and low intracluster correlation. Because small sample sizes and low intracluster correlation are common features of cluster-randomized trials, the Kenward-Roger method is the preferred one-stage approach.


Asunto(s)
Sesgo , Análisis por Conglomerados , Mejoramiento de la Calidad , Distribución Normal , Mejoramiento de la Calidad/estadística & datos numéricos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Proyectos de Investigación/normas , Proyectos de Investigación/estadística & datos numéricos
16.
Hum Psychopharmacol ; 30(6): 425-34, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26193781

RESUMEN

OBJECTIVE: Premenstrual dysphoric disorder (PMDD), a more severe form of premenstrual syndrome (PMS), afflicts 5-8% of reproductive age women and results in significant functional impairment. We conducted a double-blind, placebo-controlled trial of adjunctive quetiapine in patients with PMS/PMDD who had inadequate response to selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitor therapy for their symptoms. METHODS: A PMS/PMDD diagnosis was confirmed by 2-month prospective diagnostic assessment of PMS/PMDD using the Prospective Record of the Impact and Severity of Premenstrual Symptoms (PRISM) calendar. Women were randomized equally to receive quetiapine sustained-release (SR) or placebo (25-mg starting dose) during the luteal phase for 3 months. Outcome variables included the Hamilton Depression and Anxiety Scales, Clinical Global Impression Scale, and PRISM. RESULTS: Twenty women were enrolled in the treatment phase. Although the study was underpowered, greater reductions in luteal phase mood ratings were observed in the quetiapine group on the 17-item Hamilton Depression Rating Scale, Clinical Global Impression improvement rating, and PRISM daily score. The quetiapine group showed most improvement in symptoms of mood lability, anxiety, and irritability. CONCLUSION: This small double-blind study suggests that adjunctive treatment with quetiapine SR may be a useful addition to selective serotonin reuptake inhibitor therapy in women with PMS/PMDD by reducing symptoms and improving quality of life.


Asunto(s)
Antipsicóticos/uso terapéutico , Trastorno Disfórico Premenstrual/tratamiento farmacológico , Síndrome Premenstrual/tratamiento farmacológico , Fumarato de Quetiapina/uso terapéutico , Adulto , Antipsicóticos/administración & dosificación , Preparaciones de Acción Retardada , Método Doble Ciego , Quimioterapia Combinada , Femenino , Humanos , Proyectos Piloto , Trastorno Disfórico Premenstrual/fisiopatología , Síndrome Premenstrual/fisiopatología , Estudios Prospectivos , Escalas de Valoración Psiquiátrica , Calidad de Vida , Fumarato de Quetiapina/administración & dosificación , Inhibidores Selectivos de la Recaptación de Serotonina/administración & dosificación , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
17.
J Head Trauma Rehabil ; 30(5): E3-13, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25310290

RESUMEN

OBJECTIVE: To examine how pre-traumatic brain injury (TBI) variables and TBI-related characteristics predict post-TBI criminal arrest, using longitudinal data from the Traumatic Brain Injury Model System National Database. SETTINGS: Medical hospitals; rehabilitation facilities. PARTICIPANTS: Participants with documented TBI and nonmissing Traumatic Brain Injury Model System data, resulting in N = 6315 at 1 year post-TBI, N = 4982 at 2 years post-TBI, and N = 2690 at 5 years post-TBI. DESIGN: Prospective cohort study with secondary data analysis of the relationship between pre-TBI/TBI factors and post-TBI criminal arrest as measured at 3 time points. MAIN MEASURES: Self-report of post-TBI criminal arrest. RESULTS: Post-TBI criminal arrest was associated with gender, age, marital status, educational attainment, pre-TBI felony, pre-TBI drug abuse, pre-TBI alcohol abuse, and violent cause of TBI. Frontal, temporal, parietal, or occipital lobe lesions from computed tomographic scans did not predict post-TBI criminal arrests. Higher numbers of post-TBI arrests were predicted by loss of consciousness (≥24 hours), combined with retention of motor function. CONCLUSION: Premorbid variables, especially pre-TBI felonies, were strongly linked to post-TBI criminal arrests. The relationship between TBI and arrest was complex, and different brain functions (eg, physical mobility) should be considered when understanding this association. Findings highlight that for post-TBI criminal behavior, many risk factors mirror those of the non-TBI general population.


Asunto(s)
Lesiones Encefálicas/psicología , Conducta Criminal , Prisioneros/psicología , Prisioneros/estadística & datos numéricos , Adulto , Alcoholismo/psicología , Lesiones Encefálicas/diagnóstico , Lesiones Encefálicas/rehabilitación , Estudios de Cohortes , Bases de Datos Factuales , Femenino , Escala de Coma de Glasgow , Humanos , Incidencia , Puntaje de Gravedad del Traumatismo , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Medición de Riesgo , Trastornos Relacionados con Sustancias/psicología , Factores de Tiempo , Estados Unidos , Adulto Joven
18.
Prostate ; 74(5): 451-7, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24449207

RESUMEN

BACKGROUND: Prostate-specific membrane antigen (PSMA) remains an important target for diagnostic and therapeutic application for human prostate cancer. Model cell lines have been recently developed to study canine prostate cancer but their PSMA expression and enzymatic activity have not been elucidated. The present study was focused on determining PSMA expression in these model canine cell lines and the use of fluorescent small-molecule enzyme inhibitors to detect canine PSMA expression by flow cytometry. METHODS: Western blot and RT-PCR were used to determine the transcriptional and translational expression of PSMA on the canine cell lines Leo and Ace-1. An endpoint HPLC-based assay was used to monitor the enzymatic activity of canine PSMA and the potency of enzyme inhibitors. Flow cytometry was used to detect the PSMA expressed on Leo and Ace-1 cells using a fluorescently tagged PSMA enzyme inhibitor. RESULTS: Canine PSMA expression on the Leo cell line was confirmed by Western blot and RT-PCR, the enzyme activity, and flow cytometry. Kinetic parameters Km and Vmax of PSMA enzymatic activity for the synthetic substrate (PABGγG) were determined to be 393 nM and 220 pmol min(-1) mg protein(-1) , respectively. The inhibitor core 1 and fluorescent inhibitor 2 were found to be potent reversible inhibitors (IC50 = 13.2 and 1.6 nM, respectively) of PSMA expressed on the Leo cell line. Fluorescent labeling of Leo cells demonstrated that the fluorescent PSMA inhibitor 2 can be used for the detection of PSMA-positive canine prostate tumor cells. Expression of PSMA on Ace-1 was low and not detectable by flow cytometry. CONCLUSIONS: The results described herein have demonstrated that PSMA is expressed on canine prostate tumor cells and exhibits similar enzymatic characteristics as human PSMA. The findings show that the small molecule enzyme inhibitors currently being studied for use in diagnosis and therapy of human prostate cancer can also be extended to include canine prostate cancer. Importantly, the findings demonstrate that the potential of the inhibitors for use in diagnosis and therapy can be evaluated in an immunocompetent animal model that naturally develops prostate cancer before use in humans.


Asunto(s)
Adenocarcinoma/metabolismo , Antígenos de Superficie/metabolismo , Glutamato Carboxipeptidasa II/metabolismo , Neoplasias de la Próstata/metabolismo , Adenocarcinoma/patología , Animales , Línea Celular Tumoral , Perros , Inhibidores Enzimáticos/farmacología , Citometría de Flujo , Masculino , Próstata/efectos de los fármacos , Próstata/metabolismo , Próstata/patología , Neoplasias de la Próstata/patología
19.
Stat Med ; 33(5): 812-27, 2014 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-24122945

RESUMEN

The complexity of system biology means that any metabolic, genetic, or proteomic pathway typically includes so many components (e.g., molecules) that statistical methods specialized for overall testing of high-dimensional and commensurate outcomes are required. While many overall tests have been proposed, very few have power and sample size methods. We develop accurate power and sample size methods and software to facilitate study planning for high-dimensional pathway analysis. With an account of any complex correlation structure between high-dimensional outcomes, the new methods allow power calculation even when the sample size is less than the number of variables. We derive the exact (finite-sample) and approximate non-null distributions of the 'univariate' approach to repeated measures test statistic, as well as power-equivalent scenarios useful to generalize our numerical evaluations. Extensive simulations of group comparisons support the accuracy of the approximations even when the ratio of number of variables to sample size is large. We derive a minimum set of constants and parameters sufficient and practical for power calculation. Using the new methods and specifying the minimum set to determine power for a study of metabolic consequences of vitamin B6 deficiency helps illustrate the practical value of the new results. Free software implementing the power and sample size methods applies to a wide range of designs, including one group pre-intervention and post-intervention comparisons, multiple parallel group comparisons with one-way or factorial designs, and the adjustment and evaluation of covariate effects.


Asunto(s)
Interpretación Estadística de Datos , Proyectos de Investigación , Tamaño de la Muestra , Biología de Sistemas/métodos , Aminoácidos/metabolismo , Humanos , Programas Informáticos , Deficiencia de Vitamina B 6/metabolismo
20.
Phys Chem Chem Phys ; 16(20): 9538-45, 2014 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-24727860

RESUMEN

The electrochemical reaction of FeSb2 with Na is reported for the first time. The first discharge (sodiation) potential profile of FeSb2 is characterized by a gentle slope centered at 0.25 V. During charge (Na removal) and the subsequent discharge, the main reaction takes place near 0.7 V and 0.4 V, respectively. The reversible storage capacity amounts to 360 mA h g(-1), which is smaller than the theoretical value of 537 mA h g(-1). The reaction, studied by ex situ and in situ X-ray diffraction, is found to proceed by the consumption of crystalline FeSb2 to form an amorphous phase. Upon further sodiation, the formation of nanocrystalline Na3Sb domains is evidenced. During desodiation, Na3Sb domains convert into an amorphous phase. The chemical environment of Fe, probed by (57)Fe Mössbauer spectroscopy, undergoes significant changes during the reaction. During sodiation, the well-resolved doublet of FeSb2 with an isomer shift around 0.45 mm s(-1) and a quadrupole splitting of 1.26 mm s(-1) is gradually converted into a doublet line centered at about 0.15 mm s(-1) along with a singlet line around 0 mm s(-1). The former signal results from the formation of a Fe-rich FexSb alloy with an estimated composition of 'Fe4Sb' while the latter signal corresponds to superparamagnetic Fe due to the formation of nanosized pure Fe domains. Interestingly the signal of 'Fe4Sb' remains unaltered during desodiation. This mechanism is substantially different than that observed during the reaction with Li. The irreversible formation of a Fe-rich 'Fe4Sb' alloy and the absence of full desodiation of Sb domains explain the lower than theoretical practical storage capacity.

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