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1.
Echo Res Pract ; 11(1): 7, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38424646

RESUMEN

INTRODUCTION: Athletic training can result in electrical and structural changes of the right ventricle that may mimic phenotypical features of arrhythmogenic right ventricular cardiomyopathy (ARVC), such as T-wave inversion and right heart dilatation. An erroneous interpretation may have consequences ranging from false reassurance in an athlete vulnerable to cardiac arrhythmias, to unnecessary sports restriction in a healthy individual. The primary aim of this study was to define normal RV dimension reference ranges for academy adolescent footballers of different ethnicities. Secondary aims include analysis of potential overlap between this adolescent group with ARVC criteria and comparison with normal adult ranges. RESULTS: Electrocardiographic (ECG) and echocardiographic data of 1087 academy male footballers aged between 13 and 18 years old (mean age 16.0 ± 0.5 years), attending mandatory cardiac screening were analysed. Ethnicity was categorised as white (n = 826), black (African/Caribbean; n = 166) and mixed-race (one parent white and one parent black; n = 95). Arrhythmogenic right ventricular cardiomyopathy major criteria for T-wave inversion was seen in 3.3% of the cohort. This was more prevalent in black footballers (12%) when compared to mixed race footballers (6.3%) or white footballers (1%), P < 0.05. Up to 59% of the cohort exceeded adult reference ranges for some of the right ventricular parameters, although values were similar to those seen in adult footballers. There were no differences in right ventricular dimensions between ethnicities. In particular, the right ventricular outflow tract diameter would fulfil major criteria for ARVC dimension in 12% of footballers. Overall, 0.2% of the cohort would fulfil diagnosis for 'definite' arrhythmogenic right ventricular cardiomyopathy and 2.2% would fulfil diagnosis for 'borderline' arrhythmogenic right ventricular cardiomyopathy for RV dimensions and ECG changes. This was seen more frequently in black footballers (9.9%) than mixed race footballers (3.9%) or white footballer (0.6%), P < 0.05. Among athletes meeting definite or borderline arrhythmogenic right ventricular cardiomyopathy criteria, no cardiomyopathy was identified after comprehensive clinical assessment, including with cardiac magnetic resonance imaging, exercise testing, ambulatory electrocardiograms and familial evaluation. CONCLUSION: Right heart sizes in excess of accepted adult ranges occurred in as many as one in two adolescent footballers. Structural adaptations in conjunction with anterior T-wave inversion may raise concern for ARVC, highlighting the need for evaluation in expert settings.

2.
J Chem Phys ; 160(2)2024 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-38193556

RESUMEN

The phase behavior of binary blends of AB diblock copolymers of compositions f and 1 - f is examined using field-theoretic simulations. Highly asymmetric compositions (i.e., f ≈ 0) behave like homopolymer blends macrophase separating into coexisting A- and B-rich phases as the segregation is increased, whereas more symmetric diblocks (i.e., f ≈ 0.5) microphase separate into an ordered lamellar phase. In self-consistent field theory, these behaviors are separated by a Lifshitz critical point at f = 0.2113. However, its lower critical dimension is believed to be four, which implies that the Lifshitz point should be destroyed by fluctuations. Consistent with this, it is found to transform into a tricritical point. Furthermore, the highly swollen lamellar phase near the mean-field Lifshitz point disorders into a bicontinuous microemulsion (BµE), consisting of large interpenetrating A- and B-rich microdomains. BµE has been previously reported in ternary blends of AB diblock copolymer with its parent A- and B-type homopolymers, but in that system the homopolymers have a tendency to macrophase separate. Our alternative system for creating BµE is free of this macrophase separation.

3.
J Chem Phys ; 158(4): 044904, 2023 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-36725530

RESUMEN

This study examines the ultraviolet (UV) divergence in field-theoretic simulations (FTSs) of block copolymer melts, which causes an unphysical dependence on the grid resolution, Δ, used to represent the fields. Our FTSs use the discrete Gaussian-chain model and a partial saddle-point approximation to enforce incompressibility. Previous work has demonstrated that the UV divergence can be accounted for by defining an effective interaction parameter, χ=z∞χb+c2χb 2+c3χb 3+⋯, in terms of the bare interaction parameter, χb, used in the FTSs, where the coefficients of the expansion are determined by a Morse calibration. However, the need to use different grid resolutions for different ordered phases generally restricts the calibration to the linear approximation, χ ≈ z∞χb, and prevents the calculation of order-order transitions. Here, we resolve these two issues by showing how the nonlinear calibration can be translated between different grids and how the UV divergence can be removed from free energy calculations. By doing so, we confirm previous observations from particle-based simulations. In particular, we show that the free energy closely matches self-consistent field theory (SCFT) predictions, even in the region where fluctuations disorder the periodic morphologies, and similarly, the periods of the ordered phases match SCFT predictions, provided the SCFT is evaluated with the nonlinear χ.

4.
J Dent Res ; 100(2): 163-170, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33030089

RESUMEN

Propranolol is a nonselective ß-adrenergic receptor antagonist that is efficacious in reducing facial pain. There is evidence that its analgesic efficacy might be modified by variants of the catechol-O-methyltransferase (COMT) gene. We tested the hypothesis in a subset of 143 non-Hispanic Whites from a randomized controlled trial of patients with painful temporomandibular disorder (TMD). Patients were genotyped for rs4680, a single nucleotide polymorphism of COMT, and randomly allocated to either propranolol 60 mg twice daily or placebo. During the 9-wk follow-up period, patients recorded daily ratings of facial pain intensity and duration; the product was computed as an index of facial pain. Postbaseline change in the index at week 9 (the primary endpoint) was analyzed as a continuous variable and dichotomized at thresholds of ≥30% and ≥50% reduction. Mixed models for repeated measures tested for the genotype × treatment group interaction and estimated means, odds ratios (ORs), and 95% confidence limits (95% CLs) of efficacy within COMT genotypes assuming an additive genetic model. In secondary analysis, the cumulative response curves were plotted for dichotomized reductions ranging from ≥20% to ≥70%, and genotype differences in area under the curve percentages (%AUC) were calculated to signify efficacy. Mean index reduction did not differ significantly (P = 0.277) according to genotype, whereas the dichotomized ≥30% reduction revealed greater efficacy among G:G homozygotes (OR = 10.9, 95%CL = 2.4, 50.7) than among A:A homozygotes (OR = 0.8, 95%CL = 0.2, 3.2) with statistically significant interaction (P = 0.035). Cumulative response curves confirmed greater (P = 0.003) efficacy for G:G homozygotes (%AUC difference = 43.7, 95%CL = 15.4, 72.1) than for A:A homozygotes (%AUC difference = 6.5, 95%CL = -30.2, 43.2). The observed antagonistic effect of the A allele on propranolol's efficacy was opposite the synergistic effect hypothesized a priori. This unexpected result highlights the need for better knowledge of COMT's role in pain pathogenesis if the gene is to be used for precision-medicine treatment of TMD (ClinicalTrials.gov NCT02437383).


Asunto(s)
Catecol O-Metiltransferasa , Trastornos de la Articulación Temporomandibular , Catecol O-Metiltransferasa/genética , Dolor Facial/tratamiento farmacológico , Dolor Facial/genética , Genotipo , Humanos , Polimorfismo de Nucleótido Simple/genética , Propranolol/uso terapéutico , Trastornos de la Articulación Temporomandibular/tratamiento farmacológico , Trastornos de la Articulación Temporomandibular/genética
7.
Nature ; 577(7788): 39-41, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31894143

RESUMEN

Galaxy clusters are the most massive virialized structures in the Universe and are formed through the gravitational accretion of matter over cosmic time1. The discovery2 of an evolved galaxy cluster at redshift z = 2, corresponding to a look-back time of 10.4 billion years, provides an opportunity to study its properties. The galaxy cluster XLSSC 122 was originally detected as a faint, extended X-ray source in the XMM Large Scale Structure survey and was revealed to be coincident with a compact over-density of galaxies2 with photometric redshifts of 1.9 ± 0.2. Subsequent observations3 at millimetre wavelengths detected a Sunyaev-Zel'dovich decrement along the line of sight to XLSSC 122, thus confirming the existence of hot intracluster gas, while deep imaging spectroscopy from the European Space Agency's X-ray Multi-Mirror Mission (XMM-Newton) revealed4 an extended, X-ray-bright gaseous atmosphere with a virial temperature of 60 million Kelvin, enriched with metals to the same extent as are local clusters. Here we report optical spectroscopic observations of XLSSC 122 and identify 37 member galaxies at a mean redshift of 1.98, corresponding to a look-back time of 10.4 billion years. We use photometry to determine a mean, dust-free stellar age of 2.98 billion years, indicating that star formation commenced in these galaxies at a mean redshift of 12, when the Universe was only 370 million years old. The full range of inferred formation redshifts, including the effects of dust, covers the interval from 7 to 13. These observations confirm that XLSSC 122 is a remarkably mature galaxy cluster with both evolved stellar populations in the member galaxies and a hot, metal-rich gas composing the intracluster medium.

8.
Philos Trans A Math Phys Eng Sci ; 377(2156): 20190099, 2019 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-31474204

RESUMEN

The Hashin-Shtrikman formalism for the static response of a composite is first summarized, in a form applicable to anisotropic media and arbitrary two-point correlations. Its extension to dynamic response is then explained and in particular the extra coupling, for stress with velocity as well as strain, and momentum density with strain as well as velocity that inevitably follows, is highlighted. The more recent dynamical formulations which incorporate extra flexibility through the use of a weighted mean displacement also receive mention. The article is concluded with an explicit analysis of a simple model random composite and some lessons are drawn from the solution, which exposes at least one clear gap in existing knowledge and requires further research. This article is part of the theme issue 'Modelling of dynamic phenomena and localization in structured media (part 1)'.

9.
Free Radic Biol Med ; 143: 252-259, 2019 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-31369841

RESUMEN

Post-exercise hypotension (PEH) is a common physiological phenomenon leading to lower blood pressure after acute exercise, but it is not fully understood how this intriguing response occurs. This study investigated whether the nitrate-reducing activity of oral bacteria is a key mechanism to trigger PEH. Following a randomized, double blind and crossover design, twenty-three healthy individuals (15 males/8 females) completed two treadmill trials at moderate intensity. After exercise, participants rinsed their mouth with antibacterial mouthwash to inhibit the activity of oral bacteria or a placebo mouthwash. Blood pressure was measured before, 1h and 2 h after exercise. The microvascular response to a reactive hyperaemia test, as well as blood and salivary samples were taken before and 2 h after exercise to analyse nitrate and nitrite concentrations and the oral microbiome. As expected, systolic blood pressure (SBP) was lower (1 h: -5.2 ±â€¯1.0 mmHg; P < 0.001); 2 h: -3.8 ±â€¯1.1 mmHg, P = 0.005) after exercise compared to baseline in the placebo condition. This was accompanied by an increase of circulatory nitrite 2 h after exercise (2h: 100 ±â€¯13 nM) compared to baseline (59 ±â€¯9 nM; P = 0.013). Additionally, an increase in the peak of the tissue oxygenation index (TOI) during the reactive hyperaemia response was observed after exercise (86.1 ±â€¯0.6%) compared to baseline levels (84.8 ±â€¯0.5%; P = 0.010) in the placebo condition. On the other hand, the SBP-lowering effect of exercise was attenuated by 61% at 1 h in the recovery period, and it was fully attenuated 2 h after exercise with antibacterial mouthwash. This was associated with a lack of changes in circulatory nitrite (P > 0.05), and impaired microvascular response (peak TOI baseline: 85.1 ±â€¯3.1%; peak TOI post-exercise: 84.6 ±â€¯3.2%; P > 0.05). Diversity of oral bacteria did not change after exercise in any treatment. These findings show that nitrite synthesis by oral commensal bacteria is a key mechanism to induce the vascular response to exercise over the first period of recovery thereby promoting lower blood pressure and greater muscle oxygenation.


Asunto(s)
Bacterias/crecimiento & desarrollo , Ejercicio Físico , Hiperemia/fisiopatología , Boca/microbiología , Músculo Esquelético/metabolismo , Nitratos/farmacología , Hipotensión Posejercicio/fisiopatología , Adulto , Bacterias/efectos de los fármacos , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Hiperemia/tratamiento farmacológico , Hiperemia/metabolismo , Hiperemia/microbiología , Masculino , Boca/efectos de los fármacos , Antisépticos Bucales/farmacología , Músculo Esquelético/efectos de los fármacos , Hipotensión Posejercicio/tratamiento farmacológico , Hipotensión Posejercicio/metabolismo , Hipotensión Posejercicio/microbiología , Saliva/efectos de los fármacos , Saliva/microbiología
10.
J Chem Phys ; 150(20): 204906, 2019 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-31153196

RESUMEN

The Morse calibration is applied to a lattice model designed for efficient simulations of two-component polymer melts of high molecular weight. The model allows multiple occupancy per site, which results in high invariant polymerization indices, and interactions are limited to monomers within the same site, which enhances the computational speed. The calibration maps the interaction parameter of the lattice model, α, onto the Flory-Huggins χ parameter of the standard Gaussian-chain model, by matching the disordered-state structure function, S(k), of symmetric diblock copolymers to renormalized one-loop predictions. The quantitative accuracy of the calibration is tested by comparing the order-disorder transition of symmetric diblock copolymer melts to the universal prediction obtained from previous simulations. The model is then used to confirm the universality of fluctuation corrections to the critical point of symmetric binary homopolymer blends.

11.
Space Sci Rev ; 215(1): 12, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30880848

RESUMEN

By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars' surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking's Mars seismic monitoring by a factor of ∼ 2500 at 1 Hz and ∼ 200 000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars' surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of M w ∼ 3 at 40 ∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11214-018-0574-6) contains supplementary material, which is available to authorized users.

12.
Ann Oncol ; 29(10): 2061-2067, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-30412224

RESUMEN

Background: Gene expression-based profiling of colorectal cancer (CRC) can be used to identify four molecularly homogeneous consensus molecular subtype (CMS) groups with unique biologic features. However, its applicability to colorectal premalignant lesions remains unknown. Patients and methods: We assembled the largest transcriptomic premalignancy dataset by integrating different public and proprietary cohorts of adenomatous and serrated polyps from sporadic (N = 311) and hereditary (N = 78) patient populations and carried out a comprehensive analysis of carcinogenesis pathways using the CMS random forest (RF) classifier. Results: Overall, transcriptomic subtyping of sporadic and hereditary polyps revealed CMS2 and CMS1 subgroups as the predominant molecular subtypes in premalignancy. Pathway enrichment analysis showed that adenomatous polyps from sporadic or hereditary cases (including Lynch syndrome) displayed a CMS2-like phenotype with WNT and MYC activation, whereas hyperplastic and serrated polyps with CMS1-like phenotype harbored prominent immune activation. Rare adenomas with CMS4-like phenotype showed significant enrichment for stromal signatures along with transforming growth factor-ß activation. There was a strong association of CMS1-like polyps with serrated pathology, right-sided anatomic location and BRAF mutations. Conclusions: Based on our observations made in premalignancy, we propose a model of pathway activation associated with CMS classification in colorectal carcinogenesis. Specifically, while adenomatous polyps are largely CMS2, most hyperplastic and serrated polyps are CMS1 and may transition into other CMS groups during evolution into carcinomas. Our findings shed light on the transcriptional landscape of premalignant colonic polyps and may help guide the development of future biomarkers or preventive treatments for CRC.


Asunto(s)
Adenoma/diagnóstico , Biomarcadores de Tumor/genética , Pólipos del Colon/diagnóstico , Neoplasias Colorrectales/clasificación , Neoplasias Colorrectales/diagnóstico , Mutación , Lesiones Precancerosas/diagnóstico , Adenoma/genética , Pólipos del Colon/genética , Neoplasias Colorrectales/genética , Femenino , Estudios de Seguimiento , Perfilación de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Fenotipo , Lesiones Precancerosas/genética , Valor Predictivo de las Pruebas , Pronóstico , Transcriptoma
13.
Respir Care ; 63(7): 907-912, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29739856

RESUMEN

BACKGROUND: Transcutaneous monitors are utilized to monitor a patient's respiratory status. Some patients have similar values when comparing transcutaneous carbon dioxide (PtcCO2 ) values with blood gas analysis, whereas others show extreme variability. A retrospective review of data was performed to determine how accurately PtcCO2 correlated with CO2 values obtained by arterial blood gas (ABG) or capillary blood gas. METHODS: To determine whether PtcCO2 values correlated with ABG or capillary blood gas values, subjects' records were retrospectively reviewed. Data collected included the PtcCO2 value at the time of blood gas procurement and the ABG or capillary blood gas PCO2 value. Agreement of pairs of methods (ABG vs PtcCO2 and capillary blood gas vs PtcCO2 ) was assessed with the Bland-Altman approach with limits of agreement estimated with a mixed model to account for serial measurements per subject. RESULTS: A total of 912 pairs of ABG/PtcCO2 values on 54 subjects and 307 pairs of capillary blood gas/PtcCO2 values on 34 subjects were analyzed. The PCO2 range for ABG was 24-106 mm Hg, and PtcCO2 values were 27-133 mm Hg. The PCO2 range for capillary blood gas was 29-108 mm Hg, and PtcCO2 values were 30-103 mm Hg. For ABG/PtcCO2 comparisons, the Pearson correlation coefficient was 0.82, 95% CI was 0.80-0.84, and P was <.001. For capillary blood gas/PtcCO2 comparisons, the Pearson correlation coefficient was 0.77, 95% CI was 0.72-0.81, and P was <.001. For ABG/PtcCO2 , the estimated difference ± SD was -6.79 ± 7.62 mm Hg, and limits of agreement were -22.03 to 8.45. For capillary blood gas/PtcCO2 , the estimated difference ± SD was -1.61 ± 7.64 mm Hg, and limits of agreement were -16.88 to 13.66. The repeatability coefficient was about 30 mm Hg. CONCLUSIONS: Based on these data, capillary blood gas comparisons showed less variation and a slightly lower correlation with PtcCO2 than did ABG comparisons. After accounting for serial measurements per patient, due to the wide limits of agreement and poor repeatability, the utility of relying on PtcCO2 readings for this purpose is questionable.


Asunto(s)
Análisis de los Gases de la Sangre/estadística & datos numéricos , Monitoreo de Gas Sanguíneo Transcutáneo/estadística & datos numéricos , Arterias , Análisis de los Gases de la Sangre/métodos , Capilares , Femenino , Humanos , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Masculino , Reproducibilidad de los Resultados , Estudios Retrospectivos
16.
Respir Care ; 62(3): 259-267, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28028189

RESUMEN

BACKGROUND: Respiratory therapist (RT)-driven protocols have been in use for over 30 years. Protocols have been reported to decrease unnecessary or harmful therapy, health-care costs, and hospital stay. This study represents the evaluation of an original respiratory care protocol in the pediatric ICU at Arkansas Children's Hospital for ß-agonist and airway clearance interventions where one did not exist. METHODS: This project was composed of 2 parts: a survey administered to RTs and licensed independent practitioners and a retrospective review of outcome data comparing a therapist-driven ß-agonist/airway clearance protocol with physician-directed respiratory care ordering in a patient population admitted for acute respiratory failure. RESULTS: Acceptance of the protocol was evident in the survey responses because overall perceptions surrounding the implementation of the ß-agonist/airway clearance protocol were positive, and responders perceived that the protocol implementation elevated the status and increased the value of respiratory therapists. For the comparison of physician-directed orders with therapist-driven protocols, there were no significant differences between pre- and post-intervention groups for mean age, sex, mean daily acuity, or mean weighted daily acuity (P = .33, .19, >.99, and .79, respectively). There were also no differences in pediatric index of mortality 2, pediatric index of mortality 2 rate of mortality, pediatric risk of mortality 3 probability of death, and pediatric risk of mortality 3 scores (P = .63, .56, .19, and .44, respectively) between the 2 groups. When comparing physician-directed orders to therapist-driven protocols, all outcome measures (length of stay, ß-agonist therapies, airway clearance therapies, and ventilator days) showed statistically and clinically important reductions, adjusting for subject characteristics (P < .001) for the therapist-driven protocol group. CONCLUSIONS: In this institution, implementation of a ß-agonist/airway clearance protocol resulted in significant reductions of subject interventions and improved outcomes by decreasing length of stay and ventilator days as well as contributing information where clinical evidence is scant, specifically the pediatric ICU.


Asunto(s)
Protocolos Clínicos/normas , Implementación de Plan de Salud , Unidades de Cuidado Intensivo Pediátrico/normas , Insuficiencia Respiratoria/terapia , Terapia Respiratoria/métodos , Niño , Preescolar , Femenino , Humanos , Tiempo de Internación , Masculino , Terapia Respiratoria/normas , Estudios Retrospectivos , Resultado del Tratamiento
17.
Echo Res Pract ; 2016 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-27686556

RESUMEN

INTRODUCTION: Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is an inherited pathology that can increase the risk of sudden death. Current Task Force Criteria for echocardiographic diagnosis do not include new, regional assessment tools which may be relevant in a phenotypically diverse disease. We adopted a systematic review and meta-analysis approach to highlight echocardiographic indices that differentiated ARVC patients and healthy controls. METHODS: Data was extracted and analysed from prospective trials that employed a case-control design meeting strict inclusion and exclusion as well as a-priori quality criteria. Structural indices included proximal RV outflow tract(RVOT1) and RV diastolic area(RVDarea). Functional indices included RV fractional area change (RVFAC), Tricuspid Annular Systolic Excursion(TAPSE), peak systolic and early diastolic myocardial velocities (S' and E' respectively) and myocardial strain. RESULTS: Patients with ARVC had larger RVOT1 (mean  SD; 34 vs. 28 mm P<0.001) and RVDarea (23 vs. 18 cm2 P<0.001) compared to healthy controls. ARVC patients also had lower RVFAC (38 vs. 46 % P<0.001), TAPSE(17 vs. 23 mm P<0.001), S' (9 vs. 12 cm.s-1 P<0.001), E' (9 vs. 13 cm.s-1 P<0.001) and myocardial strain (-17 vs. -30% P<0.001). CONCLUSION: The data from this meta-analysis support current Task Force criteria for the diagnosis of ARVC. In addition, other RV measures that reflect the complex geometry and function in ARVC clearly differentiated between ARVC and healthy controls and may provide additional diagnostic and management value. We recommend that future working groups consider this data when proposing new / revised criteria for the echocardiographic diagnosis of ARVC.

18.
J Neurosci Methods ; 271: 160-8, 2016 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-27378028

RESUMEN

BACKGROUND: One of the barriers to studying the behavioral and emotional effects of pain using functional Magnetic Resonance Imaging (fMRI) is the absence of a commercially available, MRI-compatible, pressure-based algometer to elicit pain. The present study sought to address this barrier through creation and validation of a novel MRI-safe apparatus capable of delivering incremental, measurable amounts of pressure inside a scanning bore. NEW METHOD: We introduced an MR-safe device used to administer pressure-based pain. To test against a commercially available, MRI-incompatible algometer (AlgoMed), 199 participants reported their pain tolerance for both devices. A second experiment tested the validity of pressure-based pain in an MRI environment by comparing brain activation with established neural networks for pain. 10 participants performed an identical procedure to test for pain tolerance while being scanned in a 7T MRI scanner. RESULTS: Results support the validity and reliability of our novel device. In Study 1, pain tolerance with this device was strongly correlated with pain tolerance as measured by a commercially available algometer (r=0.78). In Study 2, this device yielded BOLD activation within the insula (BA 13) and anterior cingulate gyrus (BA 24); as pressure increased, activation in these areas parametrically increased. COMPARISON WITH EXISTING METHOD: These findings correspond to other studies using thermal, electrical, or mechanical pain applications. Behavioral and functional data demonstrate that this new device is a valid method of administering pressure-related pain in MRI environments. CONCLUSIONS: Our novel MRI-safe device is a valid instrument to measure and administer pressure-based pain.


Asunto(s)
Imagen por Resonancia Magnética/instrumentación , Dimensión del Dolor/instrumentación , Dolor/diagnóstico , Dolor/fisiopatología , Presión , Adulto , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Mapeo Encefálico/instrumentación , Diseño de Equipo , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Adulto Joven
19.
Respir Care ; 60(10): 1424-30, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25969513

RESUMEN

BACKGROUND: Optimization of factors affecting aerosol delivery during mechanical ventilation in the pediatric population is important. We hypothesized that increasing the tidal volume (V(T)), using a vibrating mesh nebulizer, and placing the nebulizer at the ventilator would increase lung dose/delivery efficiency. METHODS: Continuous-output jet and vibrating mesh nebulizers loaded with albuterol (2.5 mg/3 mL) were compared when placed before the Y-piece and at the ventilator. The model consisted of a ventilator operated in pressure-regulated volume control ventilation mode at a breathing frequency of 20 breaths/min, PEEP of 5 cm H2O, FIO2 of 0.4, inspiratory time of 0.75 s, and bias flow of 0.5 L/min with a humidifier (37 ± 1.5°C) and an adult heated-wired circuit. V(T) values of 100, 150, 200, and 300 mL were studied. The circuit was connected in series to a 5.5-mm inner diameter endotracheal tube with a filter (lung dose) interposed between them. Delivery efficiency was calculated as a percentage of the nominal dose captured on the filter. Albuterol content was analyzed by spectrophotometry (276 nm). RESULTS: No differences in lung dose/delivery efficiency were found at different V(T) values for the jet nebulizer (both positions) and the vibrating mesh nebulizer (ventilator). Lung dose/delivery efficiency was higher (P < .02) at a VT of 100 mL compared with the other volumes tested. The vibrating mesh nebulizer had higher lung dose/delivery efficiency compared with the jet nebulizer only when placed before the Y-piece. Moving the nebulizers from before the Y-piece to the ventilator increased lung dose/delivery efficiency for all conditions tested except the vibrating mesh nebulizer at a V(T) of 100 mL (P = .36). CONCLUSIONS: Optimization of inhaled drug delivery during pediatric mechanical ventilation should include careful selection of the type of delivery device and its placement in the ventilator circuit. Increasing V(T) during nebulization did not increase lung dose/delivery efficiency.


Asunto(s)
Albuterol/administración & dosificación , Broncodilatadores/administración & dosificación , Sistemas de Liberación de Medicamentos/instrumentación , Nebulizadores y Vaporizadores , Respiración Artificial/instrumentación , Volumen de Ventilación Pulmonar/efectos de los fármacos , Administración por Inhalación , Albuterol/análisis , Broncodilatadores/análisis , Niño , Sistemas de Liberación de Medicamentos/métodos , Diseño de Equipo , Humanos , Intubación Intratraqueal/instrumentación , Modelos Teóricos , Pediatría/instrumentación , Respiración Artificial/métodos , Frecuencia Respiratoria , Ventiladores Mecánicos
20.
J Hum Nutr Diet ; 28(1): 72-84, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24527991

RESUMEN

BACKGROUND: Accurate assessment of energy expenditure and anthropometry in older people is important for targeted nutritional support. The present study aimed to compare measured and calculated resting metabolic rate (m-RMR and c-RMR) and measured, calculated and estimated weight and height in older people aged ≥70 years. METHODS: Participants were healthy older people aged ≥70 years. Indirect calorimetry using a ventilated hood calorimeter was performed for 30 min on fasted participants, and was compared with c-RMR, as calculated using six commonly used equations. Measured, calculated and estimated height and weight were compared. RESULTS: Subjects comprised 14 males and 20 females and mean (SD) m-RMR was 5243 (845) kJ day(-1) [1253 (202) kcal day(-1) ]. The Mifflin St-Jeor equation was the most consistently accurate, with the smallest mean difference between m-RMR and c-RMR of 58 (553) kJ day(-1) [14 (132) kcal day(-1) ] and c-RMR was within 10% of m-RMR in the greatest number of participants (n = 24; 70%). The Schofield equation was among the least accurate in this age group. In older males, self-reported height and weight were accurate, whereas, in females or those unable to self-report height, ulna length was the most accurate alternative to measured height. CONCLUSIONS: Current equations used to calculate RMR in older people have inaccuracies, although the Mifflin St-Jeor equation was most accurate. Future studies should investigate the validity, reliability, cost and practicality of using fat free mass as an item in novel equations to calculate RMR in this age group. Self-reported height and weight in males, and height calculated from ulna length in females, were the most accurate alternatives to measured values in the present study.


Asunto(s)
Metabolismo Basal , Peso Corporal , Anciano , Anciano de 80 o más Años , Estatura , Índice de Masa Corporal , Calorimetría Indirecta/métodos , Metabolismo Energético , Femenino , Humanos , Masculino , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Autoinforme
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