Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 306
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Nature ; 576(7786): 237-242, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31802007

RESUMEN

During the solar minimum, when the Sun is at its least active, the solar wind1,2 is observed at high latitudes as a predominantly fast (more than 500 kilometres per second), highly Alfvénic rarefied stream of plasma originating from deep within coronal holes. Closer to the ecliptic plane, the solar wind is interspersed with a more variable slow wind3 of less than 500 kilometres per second. The precise origins of the slow wind streams are less certain4; theories and observations suggest that they may originate at the tips of helmet streamers5,6, from interchange reconnection near coronal hole boundaries7,8, or within coronal holes with highly diverging magnetic fields9,10. The heating mechanism required to drive the solar wind is also unresolved, although candidate mechanisms include Alfvén-wave turbulence11,12, heating by reconnection in nanoflares13, ion cyclotron wave heating14 and acceleration by thermal gradients1. At a distance of one astronomical unit, the wind is mixed and evolved, and therefore much of the diagnostic structure of these sources and processes has been lost. Here we present observations from the Parker Solar Probe15 at 36 to 54 solar radii that show evidence of slow Alfvénic solar wind emerging from a small equatorial coronal hole. The measured magnetic field exhibits patches of large, intermittent reversals that are associated with jets of plasma and enhanced Poynting flux and that are interspersed in a smoother and less turbulent flow with a near-radial magnetic field. Furthermore, plasma-wave measurements suggest the existence of electron and ion velocity-space micro-instabilities10,16 that are associated with plasma heating and thermalization processes. Our measurements suggest that there is an impulsive mechanism associated with solar-wind energization and that micro-instabilities play a part in heating, and we provide evidence that low-latitude coronal holes are a key source of the slow solar wind.

2.
BMC Psychiatry ; 23(1): 499, 2023 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-37438722

RESUMEN

BACKGROUND: Alcohol use disorder (AUD) is highly prevalent and commonly co-occurs with other psychiatric disorders among Veterans. Provisional evidence supports the use of Approach Avoidance Training (AAT) - a form of computer-delivered cognitive bias modification designed to target implicit approach bias for alcohol-related cues - as an adjunctive program to treat AUD. However, the extent to which AAT is effective for improving AUD recovery outcomes in outpatient Veteran samples and those with psychiatric comorbidities has been understudied to date. Here we describe a double-blind randomized controlled trial of AAT versus a comparison condition (Sham) being conducted in Veterans with comorbid psychiatric conditions completing outpatient standard care. METHODS: One hundred thirty-six Veterans currently receiving outpatient treatment for AUD will be recruited for this randomized controlled trial with parallel group assignment. Participants will be randomized to either 6 weeks of AAT (n = 68) or Sham (n = 68) training in conjunction with usual care. Assessments will occur at baseline and 6 weeks, 3 months, and 6 months post-baseline. Primary outcome variables will include functional consequences of drinking. Secondary outcome variables will include alcohol consumption, and behavioral indicators of alcohol approach bias. A subset of participants (n = 51) will also complete functional magnetic resonance imaging (fMRI) to assess neural response during an alcohol approach bias assessment. DISCUSSION: This study is the first randomized controlled trial of AAT administered as an adjunctive treatment to standard care in Veterans with AUD and comorbid psychiatric disorders. Additionally, behavioral and neuroimaging data will be used to determine the extent to which AAT targets approach bias for alcohol cues. If effective, AAT may be a promising low-cost adjunctive treatment option for individuals with AUD. REGISTRY NAME: AAT for Alcohol Use Disorder in Veterans. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05372029; Date of Registration: 5/9/2022.


Asunto(s)
Alcoholismo , Veteranos , Humanos , Alcoholismo/terapia , Etanol , Atención Ambulatoria , Consumo de Bebidas Alcohólicas , Ensayos Clínicos Controlados Aleatorios como Asunto
3.
J Endocrinol Invest ; 45(11): 2149-2156, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35831586

RESUMEN

PURPOSE: Thyroid dysfunction in COVID-19 carries clinical and prognostic implications. In this study, we developed a prediction score (ThyroCOVID) for abnormal thyroid function (TFT) on admission amongst COVID-19 patients. METHODS: Consecutive COVID-19 patients admitted to Queen Mary Hospital were prospectively recruited during July 2020-May 2021. Thyroid-stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) were measured on admission. Multivariable logistic regression analysis was performed to identify independent determinants of abnormal TFTs. ThyroCOVID was developed based on a clinical model with the lowest Akaike information criteria. RESULTS: Five hundred and forty six COVID-19 patients were recruited (median age 50 years, 45.4% men, 72.9% mild disease on admission). 84 patients (15.4%) had abnormal TFTs on admission. Patients with abnormal TFTs were more likely to be older, have more comorbidities, symptomatic, have worse COVID-19 severity, higher SARS-CoV-2 viral loads and more adverse profile of acute-phase reactants, haematological and biochemical parameters. ThyroCOVID consisted of five parameters: symptoms (malaise), comorbidities (ischaemic heart disease/congestive heart failure) and laboratory parameters (lymphocyte count, C-reactive protein, and SARS-CoV-2 cycle threshold values). It was able to identify abnormal TFT on admission with an AUROC of 0.73 (95% CI 0.67-0.79). The optimal cut-off of 0.15 had a sensitivity of 75.0%, specificity of 65.2%, negative predictive value of 93.5% and positive predictive value of 28.1% in identifying abnormal TFTs on admission amongst COVID-19 patients. CONCLUSION: ThyroCOVID, a prediction score to identify COVID-19 patients at risk of having abnormal TFT on admission, was developed based on a cohort of predominantly non-severe COVID-19 patients.


Asunto(s)
COVID-19 , Triyodotironina , Proteína C-Reactiva , COVID-19/diagnóstico , COVID-19/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , SARS-CoV-2 , Pruebas de Función de la Tiroides , Glándula Tiroides , Tirotropina , Tiroxina
4.
Eur Cell Mater ; 41: 216-232, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33644848

RESUMEN

Conventional root canal treatment replaces the infected pulp with defined materials. Alternative cell-based tissue engineering strategies aim to regenerate a fully functional pulp within the root canal. Despite recent advances in this area, however, the regeneration of an innervated pulp remains a major challenge in the field. Both graphene (2DG) and pulsed electromagnetic fields (PEMFs) independently have been shown to promote diverse cellular developmental programs. The present study showed that 2DG promoted the neurogenic induction of human dental pulp stem cells (hDPSCs) by upregulating and accelerating the expression of mature neuronal markers. Notably, 2DG induced the highest expression of transient receptor potential canonical cation channel type 1 (TRPC1) during early neurogenesis. As brief PEMF exposure promotes in vitro differentiation by activating a TRPC1-mitochondrial axis, an opportunity to combine 2DG with developmentally targeted PEMF exposure for synergistic effects was realizable. Neurogenic gene expression, neurotransmitter release, and reactive oxygen species (ROS) production were greatly enhanced by a brief (10 min) and low amplitude (2 mT) PEMF exposure timed to coincide with the highest TRPC1 expression from hDPSCs on 2DG. In contrast, hDPSCs on glass were less responsive to PEMF exposure. The capacity of PEMFs to promote neurogenesis was precluded by the administration of penicillin/streptomycin, mirroring previous studies demonstrating that aminoglycoside antibiotics block TRPC1-mediated calcium entry and verifying the contribution of TRPC1 in this form of magnetoreception. Hence, graphene created a more conducive environment for subsequent PEMF-stimulated neurogenic induction of hDPSCs through their mutual capacity to activate TRPC1with subsequent ROS production.


Asunto(s)
Pulpa Dental/citología , Grafito/química , Neurogénesis/fisiología , Células Madre/citología , Canales Catiónicos TRPC/metabolismo , Diferenciación Celular/fisiología , Línea Celular , Proliferación Celular/fisiología , Pulpa Dental/metabolismo , Campos Electromagnéticos , Humanos , Regeneración/fisiología , Células Madre/metabolismo , Ingeniería de Tejidos/métodos
5.
J Endocrinol Invest ; 44(3): 523-530, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32602078

RESUMEN

PURPOSE: Findings on trabecular bone score (TBS), an index of bone quality, have been reported in prediabetes defined by impaired fasting glucose or HbA1c. Here, we assessed the bone mineral density (BMD) and TBS in prediabetes individuals with impaired glucose tolerance (IGT), and investigated the association of these bone parameters with serum levels of fibroblast growth factor 21 (FGF21), a hormone implicated in bone metabolism and with higher levels in IGT. METHODS: Chinese postmenopausal women aged 55-80 years, without diabetes, were recruited from the Hong Kong Cardiovascular Risk Factor Prevalence Study in 2016-2018. Normal glucose tolerance (NGT) was defined by fasting glucose < 5.6 mmol/L and 2-h plasma glucose (2hG) < 7.8 mmol/L, and IGT by 2hG 7.8-11 mmol/L. Serum levels of FGF21 and other bone metabolism regulators were measured. Insulin sensitivity was assessed by the Matsuda index. Independent determinants of TBS were evaluated using multivariable stepwise linear regression. RESULTS: 173 individuals with NGT and 73 with IGT were included. TBS was lower in those with IGT compared to those with NGT, while BMD was comparable. Individuals with IGT had significantly higher serum FGF21 levels, which in turn showed an independent inverse relationship with TBS, attenuated after inclusion of the Matsuda index. Serum FGF21 levels, however, did not correlate with BMD. CONCLUSION: Among Chinese postmenopausal women, bone quality was worse in IGT, despite comparable bone density. FGF21 levels showed a significant independent inverse relationship with TBS, partly attributed to insulin resistance. Whether FGF21 contributes to the impaired bone quality in IGT remains speculative.


Asunto(s)
Biomarcadores/metabolismo , Glucemia/análisis , Densidad Ósea , Factores de Crecimiento de Fibroblastos/metabolismo , Fracturas Óseas/patología , Intolerancia a la Glucosa/complicaciones , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Estudios Transversales , Femenino , Estudios de Seguimiento , Fracturas Óseas/etiología , Fracturas Óseas/metabolismo , Prueba de Tolerancia a la Glucosa , Humanos , Resistencia a la Insulina , Persona de Mediana Edad , Pronóstico
6.
Neuroimage ; 223: 117383, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32949710

RESUMEN

Resting state fMRI (rsfMRI) is frequently used to study brain function, including in clinical populations. Similarity of blood-oxygen-level-dependent (BOLD) fluctuations during rsfMRI between brain regions is thought to reflect intrinsic functional connectivity (FC), potentially due to history of coactivation. To quantify similarity, studies have almost exclusively relied on Pearson correlation, which assumes linearity and can therefore underestimate FC if the hemodynamic response function differs regionally or there is BOLD signal lag between timeseries. Here we show in three cohorts of children, adolescents and adults, with and without autism spectrum disorders (ASDs), that measuring the similarity of BOLD signal fluctuations using non-linear dynamic time warping (DTW) is more robust to global signal regression (GSR), has higher test-retest reliability and is more sensitive to task-related changes in FC. Additionally, when comparing FC between individuals with ASDs and typical controls, more group differences are detected using DTW. DTW estimates are also more related to ASD symptom severity and executive function, while Pearson correlation estimates of FC are more strongly associated with respiration during rsfMRI. Together these findings suggest that non-linear methods such as DTW improve estimation of resting state FC, particularly when studying clinical populations whose hemodynamics or neurovascular coupling may be altered compared to typical controls.


Asunto(s)
Trastorno del Espectro Autista/fisiopatología , Mapeo Encefálico/métodos , Encéfalo/fisiopatología , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética , Adolescente , Adulto , Trastorno del Espectro Autista/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Niño , Interpretación Estadística de Datos , Femenino , Humanos , Masculino , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/fisiopatología , Dinámicas no Lineales , Adulto Joven
7.
Osteoporos Int ; 31(10): 1955-1964, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32385660

RESUMEN

Type 2 diabetes is associated with an increased risk of hip fractures. We hypothesize that long-term glycemic variability predicts incident hip fractures. We demonstrated that HbA1c variability predicted incident hip fractures independent of mean HbA1c, suggesting the potential benefits of minimizing glycemic variability in addition to optimizing mean glycemia for bone health. INTRODUCTION: Type 2 diabetes is associated with an increased risk of hip fractures, and a linear relationship between HbA1c levels and hip fracture incidence has been observed. We hypothesize that HbA1c variability also predicts incident hip fractures in type 2 diabetes. METHODS: Chinese individuals with type 2 diabetes aged ≥ 60 years were identified from electronic health records in Hong Kong between 2008 and 2012 and observed for incident hip fractures. Hip fracture was defined by the International Classification of Diseases (Ninth Revision) code 820. HbA1c variability was determined using standard deviation, adjusted standard deviation, and coefficient of variation of HbA1c measurements in the 5 years preceding the entry date. Multivariable Cox regression analysis was used to evaluate associations between HbA1c variability and incident hip fractures. RESULTS: A total of 83,282 participants were included. Their mean age was 71.3 ± 7.5 years, duration of diabetes 11.7 ± 7.7 years, baseline HbA1c 56.6 ± 13.5 mmol/mol (7.33 ± 1.23%), and median follow-up 6.8 years. All indices of HbA1c variability were significant independent predictors of incident hip fractures, with an adjusted hazard ratio of up to 1.29 (all p < 0.001), and remained to be independent predictors across groups of different intensity of glycemic control. Mean HbA1c ≥ 64 mmol/mol (8.0%) was associated with a 25% increase in incident hip fractures compared with mean HbA1c < 53 mmol/mol (7.0%). CONCLUSION: HbA1c variability is an independent positive predictor of hip fracture in type 2 diabetes, across the spectrum of varying degree of glycemic control, while a high HbA1c is also not advisable from the perspective of bone health.


Asunto(s)
Diabetes Mellitus Tipo 2 , Fracturas de Cadera , Anciano , Glucemia , China/epidemiología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/epidemiología , Hemoglobina Glucada/análisis , Fracturas de Cadera/epidemiología , Fracturas de Cadera/etiología , Humanos , Persona de Mediana Edad , Factores de Riesgo
8.
Clin Radiol ; 75(1): 77.e15-77.e22, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31668796

RESUMEN

AIM: To evaluate the microstructural abnormalities of the white matter tracts (WMT) using diffusion tensor imaging (DTI) in children with global developmental delay (GDD). MATERIALS AND METHODS: Sixteen children with GDD underwent magnetic resonance imaging (MRI) and cross-sectional DTI. Formal developmental assessment of all GDD patients was performed using the Mullen Scales of Early Learning. An automated processing pipeline for the WMT assessment was implemented. The DTI-derived metrics of the children with GDD were compared to healthy children with normal development (ND). RESULTS: Only two out of the 17 WMT demonstrated significant differences (p<0.05) in DTI parameters between the GDD and ND group. In the uncinate fasciculus (UF), the GDD group had lower mean values for fractional anisotropy (FA; 0.40 versus 0.44), higher values for mean diffusivity (0.96 versus 0.91×10-3 mm2/s) and radial diffusivity (0.75 versus 0.68×10-3 mm2/s) compared to the ND group. In the superior cerebellar peduncle (SCP), mean FA values were lower for the GDD group (0.38 versus 0.40). Normal myelination pattern of DTI parameters was deviated against age for GDD group for UF and SCP. CONCLUSION: The UF and SCP WMT showed microstructural changes suggestive of compromised white matter maturation in children with GDD. The DTI metrics have potential as imaging markers for inadequate white matter maturation in GDD children.


Asunto(s)
Cerebelo/anomalías , Cerebelo/diagnóstico por imagen , Discapacidades del Desarrollo/fisiopatología , Imagen por Resonancia Magnética/métodos , Corteza Prefrontal/anomalías , Corteza Prefrontal/diagnóstico por imagen , Sustancia Blanca/anomalías , Sustancia Blanca/diagnóstico por imagen , Anisotropía , Preescolar , Estudios Transversales , Imagen de Difusión por Resonancia Magnética , Estudios de Factibilidad , Femenino , Humanos , Lactante , Masculino
9.
J Endocrinol Invest ; 43(3): 347-355, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31529391

RESUMEN

PURPOSE: Accurate subtyping of the primary aldosteronism into aldosterone-producing adenoma (APA) and idiopathic adrenal hyperplasia (IAH) is important to direct for specific treatment modalities. The objective of the study was to compare the clinical and biochemical parameters of APA and IAH patients to derive a Clinical Prediction Score reliably predicting APA from IAH. METHODS: This was a retrospective multi-centre study recruiting 38 APA patients and 42 IAH patients from four major hospitals in Hong Kong using database from Surgical Outcomes Monitoring and Improvement Programme and Clinical Data Analysis and Reporting System. Their clinical and biochemical parameters were evaluated. RESULTS: Patients in APA group were younger than IAH group (mean age 48.6 ± 9.2 vs. 57.1 ± 7.3 years old, p < 0.001), had more suppressed renin before saline infusion in saline infusion test (SIT) (median 0.19 [IQR 0.15-0.37] vs. 0.39 [IQR 0.19-0.69] ng/mL/h, p = 0.01), and higher aldosterone level after saline infusion in SIT (median 674 [IQR 498-1000] vs. 327 [IQR 242-483] pmol/L, p < 0.001). A clinical prediction score using three parameters was devised, comprising age at diagnosis < 50 years, PRA before saline infusion in SIT ≤ 0.26 ng/mL/h, and aldosterone level after saline infusion in SIT ≥ 424 pmol/L. A score of 2 would predict APA with a sensitivity of 84.2% and specificity of 88.1%, and a score of 3 would predict APA with a sensitivity of 31.6% and specificity of 100%. CONCLUSIONS: Clinical Prediction Score based on the combination of age at diagnosis, PRA, and aldosterone level in the saline infusion tests could reliably predict APA from IAH.


Asunto(s)
Neoplasias de la Corteza Suprarrenal/complicaciones , Adenoma Corticosuprarrenal/complicaciones , Aldosterona/sangre , Hiperaldosteronismo/etiología , Neoplasias de la Corteza Suprarrenal/sangre , Adenoma Corticosuprarrenal/sangre , Adulto , Factores de Edad , Femenino , Humanos , Hiperaldosteronismo/sangre , Hiperplasia/complicaciones , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
12.
Surg Endosc ; 32(12): 4999-5005, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29959522

RESUMEN

INTRODUCTION: Laparoscopic ventral hernia repair (VHR) is associated with decreased morbidity and shorter length of stay (LOS) when compared to open VHR. Despite evidence of the benefits of laparoscopy, its utilization in VHR has lagged behind that of other complex surgical procedures. We hypothesized that utilization is further reduced in emergency cases. The aim of this study was to evaluate the utilization of laparoscopy in emergent VHR and to assess 30-day outcomes for patients undergoing laparoscopic emergent ventral hernia repair (LEVHR) versus open emergent ventral hernia repair (OEVHR). METHODS: We used the ACS-NSQIP database for years 2006-2015 to compare LEVHR versus OEVHR. Inclusion required two factors: (1) classification as an emergency case and (2) primary procedure documented as laparoscopic or open repair of incarcerated umbilical, ventral, or incisional hernia. LOS and 30-day morbidity and mortality were assessed. RESULTS: A total of 13,126 patients underwent emergent repair of initial or recurrent umbilical, ventral, or incisional hernia. 1130 (8.6%) underwent LEVHR repair and 11,996 (91.4%) underwent OEVHR. Patient demographic data display a trend toward decreased utilization of laparoscopy in patients with more significant comorbidities. LEVHR was associated with decreased operative time and postoperative LOS. LEVHR was associated with decreased superficial surgical site infection (SSI), deep SSI, and 30-day mortality. Subgroup analysis displays decreased incidence of superficial SSI, deep SSI, wound disruption, pneumonia, and postoperative sepsis for patients ASA1-3 undergoing LEVHR versus OEVHR. CONCLUSION: Utilization of laparoscopy in VHR is low in emergency cases. Patients who did undergo LEVHR had decreased postoperative LOS and decreased infectious and wound-related morbidity. Increased utilization in emergency VHR could significantly improve patient outcomes. Further study is warranted.


Asunto(s)
Herniorrafia , Laparoscopía , Complicaciones Posoperatorias , Anciano , Bases de Datos Factuales , Servicio de Urgencia en Hospital/estadística & datos numéricos , Femenino , Mal Uso de los Servicios de Salud , Hernia Ventral/cirugía , Herniorrafia/efectos adversos , Herniorrafia/métodos , Humanos , Laparoscopía/efectos adversos , Laparoscopía/métodos , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Evaluación de Procesos y Resultados en Atención de Salud , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Estados Unidos
13.
Hong Kong Med J ; 29(4): 366-367, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37599407
14.
Osteoarthritis Cartilage ; 25(12): 1969-1979, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28011099

RESUMEN

OBJECTIVE: The primary aim was to evaluate the effect of a dosed walking program on knee pain for patients with severe knee osteoarthritis (OA). Secondary aims evaluated the effects on cardiovascular health, function and quality of life. DESIGN: Participants with severe knee OA and increased cardiovascular risk were randomly assigned to a 12-week walking program of 70 min/week of at least moderate intensity, or to usual care. The primary outcome was knee pain (0-10). Secondary outcomes were of cardiovascular risk including physical activity, blood pressure, blood lipid and glucose levels, body mass index and waist circumference; WOMAC Index scores; physical function; and quality of life. RESULTS: Forty-six participants (23 each group) were recruited. Sixteen participants (70%) adhered to the walking program. Intention to treat analysis showed no between-group difference in knee pain. The walking group had increased odds of achieving a healthy systolic blood pressure (OR = 5.7, 95% CI 1.2-26.9), and a faster walking speed (Mean Difference (MD) = 0.12 m/s, 95% CI 0.02-0.23). Per protocol analysis based on participant adherence showed the walking group had more daily steps (MD = 1345 steps, 95% CI 365-2325); more time walking (MD = 18 min/day, 95% CI 5-31); reduced waist circumference (MD = -5.3 cm, 95% CI -10.5 to -0.03); and increased knee stiffness (MD = 0.9 units, 95% CI 0.07-1.8). CONCLUSIONS: Patients with severe knee OA prescribed a 12-week walking program of 70 min/week may have had cardiovascular benefits without decreasing knee pain. Australian New Zealand Clinical Trials Registry ACTRN12615000015549.


Asunto(s)
Artralgia/fisiopatología , Glucemia/metabolismo , Enfermedades Cardiovasculares/metabolismo , Terapia por Ejercicio , Osteoartritis de la Rodilla/terapia , Caminata , Anciano , Anciano de 80 o más Años , Artralgia/etiología , Australia/epidemiología , Presión Sanguínea , Índice de Masa Corporal , Enfermedades Cardiovasculares/epidemiología , HDL-Colesterol/metabolismo , LDL-Colesterol/metabolismo , Comorbilidad , Dislipidemias/epidemiología , Dislipidemias/metabolismo , Ejercicio Físico , Femenino , Intolerancia a la Glucosa/epidemiología , Intolerancia a la Glucosa/metabolismo , Humanos , Hipertensión/epidemiología , Hipertensión/metabolismo , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Obesidad/metabolismo , Osteoartritis de la Rodilla/complicaciones , Osteoartritis de la Rodilla/epidemiología , Osteoartritis de la Rodilla/fisiopatología , Dimensión del Dolor , Calidad de Vida , Índice de Severidad de la Enfermedad , Método Simple Ciego , Resultado del Tratamiento , Triglicéridos/metabolismo , Circunferencia de la Cintura
15.
Clin Radiol ; 71(2): 170-7, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26688549

RESUMEN

AIM: To determine whether lesion size affects the diagnostic performance of apparent diffusion coefficient (ADC) in the evaluation of breast masses. MATERIALS AND METHODS: Consecutive breast lesions detected at magnetic resonance imaging (MRI) from June 2010 to July 2013 were retrospectively reviewed. Differences in the ADCs of benign and malignant mass lesions were compared. Receiver operating characteristics analysis was performed to evaluate diagnostic performance of ADC regarding lesion size (≤ 1 cm or >1 cm) and their T2W signal intensities. RESULTS: Seventy-four malignant lesions (77.9%) and 21 (22.1%) benign lesions were included. Twenty-two of the 95 (23.2%) masses measured ≤ 1 cm (mean 0.73 ± 0.4; range 0.51-0.8 cm) and 73/95 (76.9%) masses measured >1 cm (mean 2.11 ± 0.1; range 1.1-3.3 cm). The mean ADC was significantly lower for malignant than for benign lesions (mean for malignant lesion, 0.89 ± 0.29 × 10(-3) mm(2)/s; mean for benign lesions, 1.27 ± 0.42 × 10(-3) mm(2)/s; p<0.01). The optimal ADC cut-off for differentiating benign and malignant lesion was 1.088 × 10(-3) mm(2)/s with a sensitivity of 85.9% and specificity of 77% for lesions >1 cm. The sensitivity and specificity were lowered to 60% and 50%, respectively, for lesions of size ≤ 1. Maximal sensitivity and specificity were reached when the ADC value was used to evaluate T2-dark lesions. CONCLUSION: Diffusion-weighted MRI is useful for characterizing masses that are hypointense on T2-weighted images. Lower sensitivity and specificity were found for breast lesions ≤ 1 cm.


Asunto(s)
Neoplasias de la Mama/patología , Mama/patología , Imagen de Difusión por Resonancia Magnética , Adulto , Anciano , Medios de Contraste , Diagnóstico Diferencial , Femenino , Humanos , Aumento de la Imagen , Persona de Mediana Edad , Curva ROC , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad
16.
Mol Genet Metab ; 114(4): 599-603, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25724074

RESUMEN

PURPOSE: To describe a diagnostic protocol, surveillance and treatment guidelines, genetic counseling considerations and long-term follow-up data elements developed in preparation for X-linked adrenoleukodystrophy (X-ALD) newborn screening in New York State. METHODS: A group including the director from each regional NYS inherited metabolic disorder center, personnel from the NYS Newborn Screening Program, and others prepared a follow-up plan for X-ALD NBS. Over the months preceding the start of screening, a series of conference calls took place to develop and refine a complete newborn screening system from initial positive screen results to long-term follow-up. RESULTS: A diagnostic protocol was developed to determine for each newborn with a positive screen whether the final diagnosis is X-ALD, carrier of X-ALD, Zellweger spectrum disorder, acyl CoA oxidase deficiency or D-bifunctional protein deficiency. For asymptomatic males with X-ALD, surveillance protocols were developed for use at the time of diagnosis, during childhood and during adulthood. Considerations for timing of treatment of adrenal and cerebral disease were developed. CONCLUSION: Because New York was the first newborn screening laboratory to include X-ALD on its panel, and symptoms may not develop for years, long-term follow-up is needed to evaluate the presented guidelines.


Asunto(s)
Adrenoleucodistrofia/diagnóstico , Tamizaje Neonatal , Acil-CoA Oxidasa/deficiencia , Insuficiencia Suprarrenal/diagnóstico , Algoritmos , Asesoramiento Genético , Humanos , Recién Nacido , Masculino , New York , Trastorno Peroxisomal/diagnóstico , Proteína-2 Multifuncional Peroxisomal/deficiencia , Síndrome de Zellweger/diagnóstico
17.
Osteoarthritis Cartilage ; 23(8): 1285-93, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25882926

RESUMEN

OBJECTIVE: To determine how much physical activity, in the form of walking, can be safely and feasibly tolerated for people with severe knee osteoarthritis (OA). DESIGN: Phase I dose response trial with escalating walking doses of 10, 20, 35, 50, 70, and 95 min over 1 week, were prescribed non-randomly to people with severe knee OA. The primary stopping rule was a substantial increase in knee pain. The primary outcomes were an estimation of the maximum tolerated dose of walking; and the proportion of people who did not complete the dose for feasibility reasons. The secondary outcomes were pain, stiffness and activity limitation Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). RESULTS: Twenty-four participants (13 women) aged 53-83 years, and average body mass index (BMI) of 34 kg/m(2) (SD 9) were recruited. Three participants were assigned to each dose between 10 and 70 min, and nine participants assigned to the 95-min dose. The trial was stopped at 95 min due to the maximum number of adverse events occurring at this dose. Therefore, the maximum tolerated dose was 70 min. No participant stopped due to reasons related to feasibility. There was a moderate association between dose and increased activity (linear R(2) = 0.31, cubic R(2) = 0.69) and reduced stiffness (linear R(2) = 0.20, cubic R(2) = 0.52), with increased benefits at moderate to higher doses. CONCLUSIONS: There is preliminary evidence that 70 min per week of moderate intensity supervised walking was safe and feasible for people with severe OA of the knee; for higher doses there was a risk of exacerbating knee pain levels.


Asunto(s)
Tolerancia al Ejercicio/fisiología , Osteoartritis de la Rodilla/fisiopatología , Osteoartritis de la Rodilla/terapia , Caminata/fisiología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Índice de Severidad de la Enfermedad , Factores de Tiempo
18.
Diabet Med ; 32(9): 1207-11, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25594838

RESUMEN

AIMS: To investigate the usefulness of the additional measurement of HbA1c , compared with performing only the oral glucose tolerance test (OGTT), in identifying participants at increased cardiometabolic risk, in an urban Chinese population. METHODS: All participants from the fourth visit of the population-based Hong Kong Cardiovascular Risk Factors Prevalence Study, without known diabetes, were included. All had their glycaemic status assessed by OGTT and HbA1c , according to American Diabetic Association 2010 criteria. RESULTS: Based on OGTT criteria alone, 3.5% of the study cohort (N = 1300) had diabetes and 19.2% had prediabetes. Based on HbA1c criteria only, 6.2% had diabetes and 61.2% had prediabetes. The measurement of HbA1c , in addition to the OGTT, increased the proportion of participants with diabetes to 7.8% and with prediabetes to 65.3%. Subjects with prediabetes having raised HbA1c but normal glycaemia (N = 600) had waist circumference, systolic blood pressure, fasting glucose, insulin resistance index (HOMA-IR), Gutt Index and Framingham 10-year cardiovascular risk scores intermediate between those with both normal HbA1c and glycaemia (N = 350), and those with impaired fasting glucose and/or impaired glucose tolerance (N = 249; all P < 0.01). CONCLUSION: The measurement of HbA1c in our population, in addition to the OGTT, results in the detection of a large number of participants with prediabetes having raised HbA1c but normal glycaemia who have a cardiometabolic risk profile intermediate between impaired fasting glucose and/or impaired glucose tolerance and normal participants, and would benefit from early lifestyle intervention.


Asunto(s)
Angiopatías Diabéticas/diagnóstico , Hemoglobina Glucada/metabolismo , Enfermedades Metabólicas/diagnóstico , Estado Prediabético/diagnóstico , Análisis de Varianza , Glucemia/metabolismo , China/etnología , Angiopatías Diabéticas/sangre , Ayuno/sangre , Femenino , Prueba de Tolerancia a la Glucosa , Hong Kong/etnología , Humanos , Masculino , Enfermedades Metabólicas/sangre , Persona de Mediana Edad , Estado Prediabético/sangre , Factores de Riesgo , Salud Urbana , Circunferencia de la Cintura/fisiología
19.
Horm Metab Res ; 47(11): 833-8, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26267327

RESUMEN

Identification of germline mutation in patients with apparently sporadic pheochromocytomas and paragangliomas is crucial. Clinical indicators, which include young age, bilateral or multifocal, extra-adrenal, malignant, or recurrent tumors, predict the likelihood of harboring germline mutation in Caucasian subjects. However, data on the prevalence of germline mutation, as well as the applicability of these clinical indicators in Chinese, are lacking. We conducted a cross-sectional study at a single endocrine tertiary referral center in Hong Kong. Subjects with pheochromocytomas and paragangliomas were evaluated for the presence of germline mutations involving 10 susceptibility genes, which included NF1, RET, VHL, SDHA, SDHB, SDHC, SDHD, TMEM 127, MAX, and FH genes. Clinical indicators were assessed for their association with the presence of germline mutations. Germline mutations, 2 being novel, were found in 24.4% of the 41 Chinese subjects recruited and 11.4% among those with apparently sporadic presentation. The increasing number of the afore-mentioned clinical indicators significantly correlated with the likelihood of harboring germline mutation in one of the 10 susceptibility genes. (r=0.757, p=0.026). The presence of 2 or more clinical indicators should prompt genetic testing for germline mutations in Chinese subjects. In conclusion, our study confirmed that a significant proportion of Chinese subjects with apparently sporadic pheochromocytoma and paraganglioma harbored germline mutations and these clinical indicators identified from Caucasians series were also applicable in Chinese subjects. This information will be of clinical relevance in the design of appropriate genetic screening strategies in Chinese populations.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/genética , Pueblo Asiatico/genética , Predisposición Genética a la Enfermedad , Paraganglioma/genética , Feocromocitoma/genética , Adulto , China , Mutación de Línea Germinal/genética , Humanos , Persona de Mediana Edad , Curva ROC
20.
Nat Commun ; 15(1): 2871, 2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38605019

RESUMEN

The development of van der Waals heterostructures has introduced unconventional phenomena that emerge at atomically precise interfaces. For example, interlayer excitons in two-dimensional transition metal dichalcogenides show intriguing optical properties at low temperatures. Here we report on room-temperature observation of interface excitons in mixed-dimensional heterostructures consisting of two-dimensional tungsten diselenide and one-dimensional carbon nanotubes. Bright emission peaks originating from the interface are identified, spanning a broad energy range within the telecommunication wavelengths. The effect of band alignment is investigated by systematically varying the nanotube bandgap, and we assign the new peaks to interface excitons as they only appear in type-II heterostructures. Room-temperature localization of low-energy interface excitons is indicated by extended lifetimes as well as small excitation saturation powers, and photon correlation measurements confirm antibunching. With mixed-dimensional van der Waals heterostructures where band alignment can be engineered, new opportunities for quantum photonics are envisioned.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA