Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 153
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Eur Heart J ; 45(3): 181-194, 2024 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-37634192

RESUMEN

BACKGROUND AND AIMS: Coronary flow capacity (CFC) is associated with an observed 10-year survival probability for individual patients before and after actual revascularization for comparison to virtual hypothetical ideal complete revascularization. METHODS: Stress myocardial perfusion (mL/min/g) and coronary flow reserve (CFR) per pixel were quantified in 6979 coronary artery disease (CAD) subjects using Rb-82 positron emission tomography (PET) for CFC maps of artery-specific size-severity abnormalities expressed as percent left ventricle with prospective follow-up to define survival probability per-decade as fraction of 1.0. RESULTS: Severely reduced CFC in 6979 subjects predicted low survival probability that improved by 42% after revascularization compared with no revascularization for comparable severity (P = .0015). For 283 pre-and-post-procedure PET pairs, severely reduced regional CFC-associated survival probability improved heterogeneously after revascularization (P < .001), more so after bypass surgery than percutaneous coronary interventions (P < .001) but normalized in only 5.7%; non-severe baseline CFC or survival probability did not improve compared with severe CFC (P = .00001). Observed CFC-associated survival probability after actual revascularization was lower than virtual ideal hypothetical complete post-revascularization survival probability due to residual CAD or failed revascularization (P < .001) unrelated to gender or microvascular dysfunction. Severely reduced CFC in 2552 post-revascularization subjects associated with low survival probability also improved after repeat revascularization compared with no repeat procedures (P = .025). CONCLUSIONS: Severely reduced CFC and associated observed survival probability improved after first and repeat revascularization compared with no revascularization for comparable CFC severity. Non-severe CFC showed no benefit. Discordance between observed actual and virtual hypothetical post-revascularization survival probability revealed residual CAD or failed revascularization.


Asunto(s)
Enfermedad de la Arteria Coronaria , Humanos , Radioisótopos de Rubidio , Estudios Prospectivos , Tomografía de Emisión de Positrones/métodos , Angiografía Coronaria/métodos
2.
Prev Med ; 184: 107975, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38685533

RESUMEN

INTRODUCTION: The synergistic negative effects of type 2 diabetes (T2DM) and hypertension increases all-cause mortality and the medical complexity of management, which disproportionately impact Hispanics who face barriers to healthcare access. The Salud y Vida intervention was delivered to Hispanic adults living along the Texas-Mexico Border with comorbid poorly controlled T2DM and hypertension. The Salud y Vida multicomponent intervention incorporated community health workers (CHWs) into an expanded chronic care management model to deliver home-based follow-up visits and provided community-based diabetes self-management education. METHODS: We conducted multivariable longitudinal analysis to examine the longitudinal intervention effect on reducing systolic and diastolic blood pressure among 3806 participants enrolled between 2013 and 2019. Participants were compared according to their program participation as either higher (≥ 10 combined educational classes and CHW visits) or lower engagement (<10 encounters). Data was collected between 2013 and 2020. RESULTS: Baseline mean systolic and diastolic blood pressure were 138 and 81 mmHg respectively. There were overall improvements in systolic (-6.49; 95% CI = [-7.13, -5.85]; p < 0.001) and diastolic blood pressure (-3.97; 95% CI = [-4.37, -3.56]; p < 0.001). The higher engagement group had greater systolic blood pressure reduction at 3 months (adjusted mean difference = -1.8 mmHg; 95% CI = [-3.2, -0.3]; p = 0.016) and at 15 month follow-up (adjusted mean difference = -2.3 mmHg; 95% CI = [-4.2, -0.39]; p = 0.0225) compared to the lower engagement group. CONCLUSION: This intervention, tested and delivered in a real-world setting, provides an example of how CHW integration into an expanded chronic care model can improve blood pressure outcomes for individuals with co-morbidities.


Asunto(s)
Agentes Comunitarios de Salud , Diabetes Mellitus Tipo 2 , Hispánicos o Latinos , Hipertensión , Humanos , Texas , Masculino , Femenino , Diabetes Mellitus Tipo 2/terapia , Persona de Mediana Edad , Hispánicos o Latinos/estadística & datos numéricos , Hipertensión/terapia , Hipertensión/etnología , Estudios Longitudinales , Afecciones Crónicas Múltiples/terapia , Adulto , Presión Sanguínea , Anciano
3.
Int J Mol Sci ; 24(16)2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37629024

RESUMEN

The CRISPR-based genome editing technology, known as clustered regularly interspaced short palindromic repeats (CRISPR), has sparked renewed interest in gene therapy. This interest is accompanied by the development of single-guide RNAs (sgRNAs), which enable the introduction of desired genetic modifications at the targeted site when used alongside the CRISPR components. However, the efficient delivery of CRISPR/Cas remains a challenge. Successful gene editing relies on the development of a delivery strategy that can effectively deliver the CRISPR cargo to the target site. To overcome this obstacle, researchers have extensively explored non-viral, viral, and physical methods for targeted delivery of CRISPR/Cas9 and a guide RNA (gRNA) into cells and tissues. Among those methods, liposomes offer a promising approach to enhance the delivery of CRISPR/Cas and gRNA. Liposomes facilitate endosomal escape and leverage various stimuli such as light, pH, ultrasound, and environmental cues to provide both spatial and temporal control of cargo release. Thus, the combination of the CRISPR-based system with liposome delivery technology enables precise and efficient genetic modifications in cells and tissues. This approach has numerous applications in basic research, biotechnology, and therapeutic interventions. For instance, it can be employed to correct genetic mutations associated with inherited diseases and other disorders or to modify immune cells to enhance their disease-fighting capabilities. In summary, liposome-based CRISPR genome editing provides a valuable tool for achieving precise and efficient genetic modifications. This review discusses future directions and opportunities to further advance this rapidly evolving field.


Asunto(s)
Edición Génica , Liposomas , ARN Guía de Sistemas CRISPR-Cas , Biotecnología , Señales (Psicología)
4.
Int J Mol Sci ; 24(18)2023 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-37762009

RESUMEN

G-protein-coupled receptors (GPCRs) are critical regulators of cardiac physiology and a key therapeutic target for the treatment of heart disease. Ectopic olfactory receptors (ORs) are GPCRs expressed in extra-nasal tissues which have recently emerged as new mediators in the metabolic control of cardiac function. The goals of this study were to profile OR gene expression in the human heart, to identify ORs dysregulated by heart failure caused by ischemic cardiomyopathy, and to provide evidence suggestive of a role for those altered ORs in the pathogenesis of heart failure. Left ventricular tissue from heart failure patients (n = 18) and non-failing heart samples (n = 4) were subjected to a two-step transcriptome analysis consisting of the quantification of 372 distinct OR transcripts on real-time PCR arrays and simultaneous determination of global cardiac gene expression by RNA sequencing. This strategy led to the identification of >160 ORs expressed in the human heart, including 38 receptors differentially regulated with heart failure. Co-expression analyses predicted the involvement of dysregulated ORs in the alteration of mitochondrial function, extracellular matrix remodeling, and inflammation. We provide this dataset as a resource for investigating roles of ORs in the human heart, with the hope that it will assist in the identification of new therapeutic targets for the treatment of heart failure.


Asunto(s)
Cardiopatías , Insuficiencia Cardíaca , Receptores Odorantes , Humanos , Receptores Odorantes/genética , Corazón , Insuficiencia Cardíaca/genética , Perfilación de la Expresión Génica
5.
Cerebrovasc Dis ; 49(4): 419-426, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32694259

RESUMEN

INTRODUCTION: White matter hyperintensity (WMH) burden is a critically important cerebrovascular phenotype related to the diagnosis and prognosis of acute ischemic stroke. The effect of WMH burden on functional outcome in large vessel occlusion (LVO) stroke has only been sparsely assessed, and direct LVO and non-LVO comparisons are currently lacking. MATERIAL AND METHODS: We reviewed acute ischemic stroke patients admitted between 2009 and 2017 at a large healthcare system in the USA. Patients with LVO were identified and clinical characteristics, including 90-day functional outcomes, were assessed. Clinical brain MRIs obtained at the time of the stroke underwent quantification of WMH using a fully automated algorithm. The pipeline incorporated automated brain extraction, intensity normalization, and WMH segmentation. RESULTS: A total of 1,601 acute ischemic strokes with documented 90-day mRS were identified, including 353 (22%) with LVO. Among those strokes, WMH volume was available in 1,285 (80.3%) who had a brain MRI suitable for WMH quantification. Increasing WMH volume from 0 to 4 mL, age, female gender, a number of stroke risk factors, presence of LVO, and higher NIHSS at presentation all decreased the odds for a favorable outcome. Increasing WMH above 4 mL, however, was not associated with decreasing odds of favorable outcome. While WMH volume was associated with functional outcome in non-LVO stroke (p = 0.0009), this association between WMH and functional status was not statistically significant in the complete case multivariable model of LVO stroke (p = 0.0637). CONCLUSION: The burden of WMH has effects on 90-day functional outcome after LVO and non-LVO strokes. Particularly, increases from no measurable WMH to 4 mL of WMH correlate strongly with the outcome. Whether this relationship of increasing WMH to worse outcome is more pronounced in non-LVO than LVO strokes deserves additional investigation.


Asunto(s)
Isquemia Encefálica/terapia , Leucoencefalopatías/diagnóstico por imagen , Imagen por Resonancia Magnética , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/terapia , Anciano , Anciano de 80 o más Años , Isquemia Encefálica/complicaciones , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/fisiopatología , Evaluación de la Discapacidad , Femenino , Humanos , Leucoencefalopatías/complicaciones , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Recuperación de la Función , Sistema de Registros , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/fisiopatología , Factores de Tiempo , Resultado del Tratamiento
6.
Echocardiography ; 35(9): 1271-1276, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29756358

RESUMEN

BACKGROUND: Sickle cell disease (SCD) affects millions of people and causes chronic hemolytic anemia leading to vasculopathies such as pulmonary hypertension and abnormalities in cardiac function that increase complications and mortality. It is therefore crucial to identify cardiac abnormalities in SCD. We aimed to assess the prevalence of echocardiographic parameters in SCD to help identify cardiopulmonary risk. METHODS: Ninety-one patients (53% male), median age of 30, body surface area (BSA) of 1.79 m2 , hemoglobin of 8.8 g/dL, and creatinine of 0.7 mg/dL identified. We retrospectively measured laboratory and echocardiographic parameters in patients with SCD : left ventricular (LV) dimensions, LV ejection fraction (LVEF), LV Myocardial Performance Index (MPI), LV Mass Index (MI), Left Atrial Volume Index (LAVI), Tricuspid Regurgitation Velocity (TRV), tricuspid annular plane systolic excursion (TAPSE), right heart dimensions. RESULTS: Prevalence of left heart abnormalities was 32%: increased LV end-diastolic diameter (EDD), 78%: LV MPI, 21%: diastolic dysfunction, 38%: decreased LVEF, 24%: increased LVMI, and 47%: increased LAVI. Right heart abnormalities were 39%: TAPSE, 38%: increased TRV, and 59%: increased pulmonary systolic pressure (PASP). Multivariate logistic regression analysis was significant for increased LVMI and LAVI in those with hemoglobin ≤8 g/dL (odds ratio (OR) 7.4, 95% confidence interval (CI) 2.23-24.6, P = .001) and (OR 3.32, 95% CI 1.18-9.33, P = .023). CONCLUSIONS: We confirmed increased prevalence of abnormal LVEDD, LVMI, diastolic function, LAVI, and PASP in SCD. In addition, we identified abnormal LV MPI (78%), TAPSE (29%). These parameters may be useful and readily accessible echocardiographic prognostic tools in this population.


Asunto(s)
Anemia de Células Falciformes/complicaciones , Ecocardiografía/métodos , Cardiopatías/complicaciones , Cardiopatías/diagnóstico por imagen , Adulto , Femenino , Humanos , Masculino , Estudios Retrospectivos
7.
Rapid Commun Mass Spectrom ; 31(1): 1-8, 2017 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-27689777

RESUMEN

RATIONALE: We have produced a liposomal formulation of xenon (Xe-ELIP) as a neuroprotectant for inhibition of brain damage in stroke patients. This mandates development of a reliable assay to measure the amount of dissolved xenon released from Xe-ELIP in water and blood samples. METHODS: Gas chromatography/mass spectrometry (GC/MS) was used to quantify xenon gas released into the headspace of vials containing Xe-ELIP samples in water or blood. In order to determine blood concentration of xenon in vivo after Xe-ELIP administration, 6 mg of Xe-ELIP lipid was infused intravenously into rats. Blood samples were drawn directly from a catheterized right carotid artery. After introduction of the samples, each vial was allowed to equilibrate to 37°C in a water bath, followed by 20 minutes of sonication prior to headspace sampling. Xenon concentrations were calculated from a gas dose-response curve and normalized using the published xenon water-gas solubility coefficient. RESULTS: The mean corrected percent of xenon from Xe-ELIP released into water was 3.87 ± 0.56% (SD, n = 8), corresponding to 19.3 ± 2.8 µL/mg lipid, which is consistent with previous independent Xe-ELIP measurements. The corresponding xenon content of Xe-ELIP in rat blood was 23.38 ± 7.36 µL/mg lipid (n = 8). Mean rat blood xenon concentration after intravenous administration of Xe-ELIP was 14 ± 10 µM, which is approximately 15% of the estimated neuroprotective level. CONCLUSIONS: Using this approach, we have established a reproducible method for measuring dissolved xenon in fluids. These measurements have established that neuroprotective effects can be elicited by less than 20% of the calculated neuroprotective xenon blood concentration. More work will have to be done to establish the protective xenon pharmacokinetic range. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Cromatografía de Gases y Espectrometría de Masas/métodos , Liposomas/química , Fármacos Neuroprotectores/análisis , Xenón/sangre , Animales , Límite de Detección , Modelos Lineales , Liposomas/sangre , Liposomas/farmacocinética , Masculino , Ratas , Ratas Sprague-Dawley , Reproducibilidad de los Resultados , Xenón/química , Xenón/farmacocinética
8.
Int J Audiol ; 56(8): 525-537, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28388853

RESUMEN

OBJECTIVE: This study identified, digitally recorded, edited and evaluated 89 bisyllabic Vietnamese words with the goal of identifying homogeneous words that could be used to measure the speech recognition threshold (SRT) in native talkers of Vietnamese. DESIGN: Native male and female talker productions of 89 Vietnamese bisyllabic words were recorded, edited and then presented at intensities ranging from -10 to 20 dBHL. Logistic regression was used to identify the best words for measuring the SRT. Forty-eight words were selected and digitally edited to have 50% intelligibility at a level equal to the mean pure-tone average (PTA) for normally hearing participants (5.2 dBHL). STUDY SAMPLE: Twenty normally hearing native Vietnamese participants listened to and repeated bisyllabic Vietnamese words at intensities ranging from -10 to 20 dBHL. RESULTS: A total of 48 male and female talker recordings of bisyllabic words with steep psychometric functions (>9.0%/dB) were chosen for the final bisyllabic SRT list. Only words homogeneous with respect to threshold audibility with steep psychometric function slopes were chosen for the final list. CONCLUSIONS: Digital recordings of bisyllabic Vietnamese words are now available for use in measuring the SRT for patients whose native language is Vietnamese.


Asunto(s)
Prueba del Umbral de Recepción del Habla , Adolescente , Adulto , Femenino , Humanos , Masculino , Psicometría , Vietnam/etnología , Adulto Joven
9.
J Liposome Res ; 26(1): 47-56, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25865025

RESUMEN

CONTEXT: Bevacizumab (BEV) is a monoclonal antibody to vascular endothelial growth factor (VEGF) that ameliorates atheroma progression by inhibiting neovascularization. OBJECTIVE: We aimed to determine whether BEV release from echogenic liposomes (BEV-ELIP) could be enhanced by color Doppler ultrasound (US) and whether the released BEV inhibits VEGF expression by endothelial cells in vitro. MATERIALS AND METHODS: BEV-ELIP samples were subjected to 6 MHz color Doppler ultrasound (MI = 0.4) for 5 min. We assessed release of BEV with a direct ELISA and with fluoresceinated BEV (FITC-BEV) loaded into ELIP by the same method. Human umbilical vein endothelial cell (HUVEC) cultures were stimulated to express VEGF by 10 nM phorbol-12-myristate 13-acetate (PMA). Cell-associated VEGF levels were determined using a cell-based ELISA. RESULTS: Overall, US caused an additional 100 µg of BEV to be released or exposed per BEV-ELIP aliquot within 60 min BEV-ELIP treated with US inhibited VEGF expression by 90% relative to non-treated controls and by 70% relative to BEV-ELIP without US. Also, US-treated BEV-ELIP inhibited HUVEC proliferation by 64% relative to untreated controls and by 45% relative to BEV-ELIP without US. DISCUSSION AND CONCLUSION: We have demonstrated that BEV-ELIP retains its VEGF-binding activity in a liposomal formulation and that clinical Doppler US can significantly increase that activity, both by releasing free BEV and by enhancing the surface exposure of the immunoreactive antibody.


Asunto(s)
Bevacizumab/administración & dosificación , Bevacizumab/uso terapéutico , Placa Aterosclerótica/tratamiento farmacológico , Ondas Ultrasónicas , Bevacizumab/farmacología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Ensayo de Inmunoadsorción Enzimática , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Humanos , Liposomas , Relación Estructura-Actividad , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Factor A de Crecimiento Endotelial Vascular/biosíntesis
10.
J Thromb Thrombolysis ; 40(2): 144-55, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25829338

RESUMEN

Echogenic liposomes (ELIP), that can encapsulate both recombinant tissue-type plasminogen activator (rt-PA) and microbubbles, are under development to improve the treatment of thrombo-occlusive disease. However, the enzymatic activity, thrombolytic efficacy, and stable cavitation activity generated by this agent has yet to be evaluated and compared to another established ultrasound-enhanced thrombolytic scheme. A spectrophotometric method was used to compare the enzymatic activity of the rt-PA incorporated into ELIP (t-ELIP) to that of rt-PA. An in vitro flow model was employed to measure the thrombolytic efficacy and dose of ultraharmonic emissions from stable cavitation for 120-kHz ultrasound exposure of three treatment schemes: rt-PA, rt-PA and the perfluorocarbon-filled microbubble Definity(®), and t-ELIP. The enzymatic activity of rt-PA incorporated into t-ELIP was 28 % that of rt-PA. Thrombolytic efficacy of t-ELIP or rt-PA and Definity(®) was equivalent when the dose of t-ELIP was adjusted to produce comparable enzymatic activity. Sustained bubble activity was nucleated from Definity but not from t-ELIP exposed to 120-kHz ultrasound. These results emphasize the advantages of encapsulating a thrombolytic and the importance of incorporating an insoluble gas required to promote sustained, stable cavitation activity.


Asunto(s)
Medios de Contraste , Microburbujas , Terapia Trombolítica/métodos , Trombosis/diagnóstico por imagen , Trombosis/tratamiento farmacológico , Activador de Tejido Plasminógeno , Medios de Contraste/química , Medios de Contraste/farmacología , Humanos , Liposomas , Proteínas Recombinantes , Activador de Tejido Plasminógeno/química , Activador de Tejido Plasminógeno/farmacología , Ultrasonografía
11.
J Acoust Soc Am ; 137(4): 1693-703, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25920822

RESUMEN

An optical characterization method is presented based on the use of the impulse response to characterize the damping imparted by the shell of an air-filled ultrasound contrast agent (UCA). The interfacial shell viscosity was estimated based on the unforced decaying response of individual echogenic liposomes (ELIP) exposed to a broadband acoustic impulse excitation. Radius versus time response was measured optically based on recordings acquired using an ultra-high-speed camera. The method provided an efficient approach that enabled statistical measurements on 106 individual ELIP. A decrease in shell viscosity, from 2.1 × 10(-8) to 2.5 × 10(-9) kg/s, was observed with increasing dilatation rate, from 0.5 × 10(6) to 1 × 10(7) s(-1). This nonlinear behavior has been reported in other studies of lipid-shelled UCAs and is consistent with rheological shear-thinning. The measured shell viscosity for the ELIP formulation used in this study [κs = (2.1 ± 1.0) × 10(-8) kg/s] was in quantitative agreement with previously reported values on a population of ELIP and is consistent with other lipid-shelled UCAs. The acoustic response of ELIP therefore is similar to other lipid-shelled UCAs despite loading with air instead of perfluorocarbon gas. The methods described here can provide an accurate estimate of the shell viscosity and damping for individual UCA microbubbles.


Asunto(s)
Liposomas/química , Ondas Ultrasónicas , Acústica , Medios de Contraste , Microburbujas , Viscosidad
12.
J Med Biol Eng ; 35(1): 104-112, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25750606

RESUMEN

Parachute mitral valves (PMVs) and parachute-like asymmetric mitral valves (PLAMVs) are associated with congenital anomalies of the papillary muscles. Current imaging modalities cannot provide detailed biomechanical information. This study describes computational evaluation techniques based on three-dimensional (3D) echocardiographic data to determine the biomechanical and physiologic characteristics of PMVs and PLAMVs. The closing and opening mechanics of a normal mitral valve (MV), two types of PLAMV with different degrees of asymmetry, and a true PMV were investigated. MV geometric data in a patient with a normal MV was acquired from 3D echocardiography. The pathologic MVs were modeled by altering the configuration of the papillary muscles in the normal MV model. Dynamic finite element simulations of the normal MV, PLAMVs, and true PMV were performed. There was a strong correlation between the reduction of mitral orifice size and the degree of asymmetry of the papillary muscle location. The PLAMVs demonstrated decreased leaflet coaptation and tenting height. The true PMV revealed severely wrinkled leaflet deformation and narrowed interchordal spaces, leading to uneven leaflet coaptation. There were considerable decreases in leaflet coaptation and abnormal leaflet deformation corresponding to the anomalous location of the papillary muscle tips. This computational MV evaluation strategy provides a powerful tool to better understand biomechanical and pathophysiologic MV abnormalities.

13.
Biomed Eng Online ; 13(1): 31, 2014 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-24649999

RESUMEN

BACKGROUND: Computational simulation using numerical analysis methods can help to assess the complex biomechanical and functional characteristics of the mitral valve (MV) apparatus. It is important to correctly determine physical contact interaction between the MV apparatus components during computational MV evaluation. We hypothesize that leaflet-to-chordae contact interaction plays an important role in computational MV evaluation, specifically in quantitating the degree of leaflet coaptation directly related to the severity of mitral regurgitation (MR). In this study, we have performed dynamic finite element simulations of MV function with and without leaflet-to-chordae contact interaction, and determined the effect of leaflet-to-chordae contact interaction on the computational MV evaluation. METHODS: Computational virtual MV models were created using the MV geometric data in a patient with normal MV without MR and another with pathologic MV with MR obtained from 3D echocardiography. Computational MV simulation with full contact interaction was specified to incorporate entire physically available contact interactions between the leaflets and chordae tendineae. Computational MV simulation without leaflet-to-chordae contact interaction was specified by defining the anterior and posterior leaflets as the only contact inclusion. RESULTS: Without leaflet-to-chordae contact interaction, the computational MV simulations demonstrated physically unrealistic contact interactions between the leaflets and chordae. With leaflet-to-chordae contact interaction, the anterior marginal chordae retained the proper contact with the posterior leaflet during the entire systole. The size of the non-contact region in the simulation with leaflet-to-chordae contact interaction was much larger than for the simulation with only leaflet-to-leaflet contact. CONCLUSIONS: We have successfully demonstrated the effect of leaflet-to-chordae contact interaction on determining leaflet coaptation in computational dynamic MV evaluation. We found that physically realistic contact interactions between the leaflets and chordae should be considered to accurately quantitate leaflet coaptation for MV simulation. Computational evaluation of MV function that allows precise quantitation of leaflet coaptation has great potential to better quantitate the severity of MR.


Asunto(s)
Cuerdas Tendinosas/patología , Insuficiencia de la Válvula Mitral/patología , Válvula Mitral/patología , Algoritmos , Ingeniería Biomédica/métodos , Simulación por Computador , Electrocardiografía/métodos , Humanos , Imagenología Tridimensional , Insuficiencia de la Válvula Mitral/terapia , Modelos Anatómicos , Programas Informáticos , Estrés Mecánico
14.
Echocardiography ; 31(10): E300-3, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25109487

RESUMEN

Clinical long-term outcomes have shown that partial leaflet resection followed by ring annuloplasty is a reliable and reproducible surgical repair technique for treatment of mitral valve (MV) leaflet prolapse. We report a 61-year-old male for three-dimensional transesophageal echocardiography (3DTEE)-based virtual posterior leaflet resection and ring annuloplasty. Severe mitral regurgitation was found and computational evaluation demonstrated substantial leaflet malcoaptation and high stress concentration. Following virtual resection and ring annuloplasty, posterior leaflet prolapse markedly decreased, sufficient leaflet coaptation was restored, and high stress concentration disappeared. Virtual MV repair strategies using 3DTEE have the potential to help optimize MV repair.


Asunto(s)
Ecocardiografía Tridimensional , Anuloplastia de la Válvula Mitral/métodos , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Prolapso de la Válvula Mitral/diagnóstico por imagen , Cirugía Asistida por Computador/métodos , Interfaz Usuario-Computador , Ecocardiografía Transesofágica/métodos , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/etiología , Insuficiencia de la Válvula Mitral/cirugía , Prolapso de la Válvula Mitral/complicaciones , Prolapso de la Válvula Mitral/cirugía , Valor Predictivo de las Pruebas , Resultado del Tratamiento
15.
J Liposome Res ; 24(3): 216-22, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24597467

RESUMEN

Thermodynamic analysis of ligand-target binding has been a useful tool for dissecting the nature of the binding mechanism and, therefore, potentially can provide valuable information regarding the utility of targeted formulations. Based on a consistent coupling of antibody-antigen binding and gel-liquid crystal transition energetics observed for antibody-phosphatidylethanolamine (Ab-PE) conjugates, we hypothesized that the thermodynamic parameters and the affinity for antigen of the Ab-PE conjugates could be effectively predicted once the corresponding information for the unconjugated antibody is determined. This hypothesis has now been tested in nine different antibody-targeted echogenic liposome (ELIP) preparations, where antibody is conjugated to dipalmitoylphosphatidylethanolamine (DPPE) head groups through a thioether linkage. Predictions were satisfactory (affinity not significantly different from the population of values found) in five cases (55.6%), but the affinity of the unconjugated antibody was not significantly different from the population of values found in six cases (66.7%), indicating that the affinities of the conjugated antibody tended not to deviate appreciably from those of the free antibody. While knowledge of the affinities of free antibodies may be sufficient to judge their suitability as targeting agents, thermodynamic analysis may still provide valuable information regarding their usefulness for specific applications.


Asunto(s)
Reacciones Antígeno-Anticuerpo/inmunología , Liposomas/química , Fosfatidiletanolaminas/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Portadores de Fármacos , Humanos , Ratones , Transición de Fase , Termodinámica
16.
Ann Biomed Eng ; 52(2): 414-424, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37957528

RESUMEN

The impact of aortic valve stenosis (AS) extends beyond the vicinity of the narrowed leaflets into the left ventricle (LV) and into the systemic vasculature because of highly unpredictable valve behavior and complex blood flow in the ascending aorta that can be attributed to the strong interaction between the narrowed cusps and the ejected blood. These effects can become exacerbated during exercise and may have implications for disease progression, accurate diagnosis, and timing of intervention. In this 3-D patient-specific study, we employ strongly coupled fluid-structure interaction (FSI) modeling to perform a comprehensive biomechanical evaluation of systolic ejection dynamics in a stenosed aortic valve (AV) during increasing LV contraction. Our model predictions reveal that the heterogeneous ∆P vs. Q relationship that was observed in our previous clinical study can be attributed to a non-linear increase (by ~ 1.5-fold) in aortic valve area as LV heart rate increases from 70 to 115 bpm. Furthermore, our results show that even for a moderately stenotic valve, increased LV contraction during exercise can lead to high-velocity flow turbulence (Re = 11,700) in the aorta similar to that encountered with a severely stenotic valve (Re ~ 10,000), with concomitant greater viscous loss (~3-fold increase) and elevated wall stress in the ascending aorta. Our FSI predictions also reveal that individual valve cusps undergo distinct and highly non-linear increases (>100%) in stress during exercise, potentially contributing to progressive calcification. Such quantitative biomechanical evaluations from realistic FSI workflows provide insights into disease progression and can be integrated with current stress testing for AS patients to comprehensively predict hemodynamics and valve function under both baseline and exercise conditions.


Asunto(s)
Estenosis de la Válvula Aórtica , Válvula Aórtica , Humanos , Prueba de Esfuerzo , Hemodinámica/fisiología , Modelos Cardiovasculares , Progresión de la Enfermedad
17.
J Clin Transl Sci ; 8(1): e33, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38384924

RESUMEN

Translation is the process of turning observations in the research laboratory, clinic, and community into interventions that improve people's health. The Clinical and Translational Science Awards (CTSA) program is a National Center for Advancing Translational Sciences (NCATS) initiative to advance translational science and research. Currently, 64 "CTSA hubs" exist across the nation. Since 2006, the Houston-based Center for Clinical Translational Sciences (CCTS) has assembled a well-integrated, high-impact hub in Texas that includes six partner institutions within the state, encompassing ∼23,000 sq. miles and over 16 million residents. To achieve the NCATS goal of "more treatments for all people more quickly," the CCTS promotes diversity and inclusion by integrating underrepresented populations into clinical studies, workforce training, and career development. In May 2023, we submitted the UM1 application and six "companion" proposals: K12, R25, T32-Predoctoral, T32-Postdoctoral, and RC2 (two applications). In October 2023, we received priority scores for the UM1 (22), K12 (25), T32-Predoctoral (20), and T32-Postdoctoral (23), which historically fall within the NCATS funding range. This report describes the grant preparation and submission approach, coupled with data from an internal survey designed to assimilate feedback from principal investigators, writers, reviewers, and administrative specialists. Herein, we share the challenges faced, the approaches developed, and the lessons learned.

18.
Pharmaceutics ; 16(3)2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38543237

RESUMEN

Liposomes as carriers for CRISPR/Cas9 complexes represent an attractive approach for cardiovascular gene therapy. A critical barrier to this approach remains the efficient delivery of CRISPR-based genetic materials into cardiomyocytes. Echogenic liposomes (ELIP) containing a fluorescein isothiocyanate-labeled decoy oligodeoxynucleotide against nuclear factor kappa B (ELIP-NF-κB-FITC) were used both in vitro on mouse neonatal ventricular myocytes and in vivo on rat hearts to assess gene delivery efficacy with or without ultrasound. In vitro analysis was then repeated with ELIP containing Cas9-sg-IL1RL1 (interleukin 1 receptor-like 1) RNA to determine the efficiency of gene knockdown. ELIP-NF-κB-FITC without ultrasound showed limited gene delivery in vitro and in vivo, but ultrasound combined with ELIP notably improved penetration into heart cells and tissues. When ELIP was used to deliver Cas9-sg-IL1RL1 RNA, gene editing was successful and enhanced by ultrasound. This innovative approach shows promise for heart disease gene therapy using CRISPR technology.

19.
Biochem Biophys Res Commun ; 430(3): 975-80, 2013 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-23261466

RESUMEN

High density lipoprotein (HDL) associated paraoxonase-1 (PON1) is crucial for the anti-oxidant, anti-inflammatory, and anti-atherogenic properties of HDL. Discoidal apolipoprotein (apo)A-I:1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) complex has been shown to be the most effective in binding PON1, stabilizing it, and enhancing its lactonase and inhibitory activity of low density lipoprotein oxidation. Based on our earlier study demonstrating that apoA-I mimetic peptide 4F forms discoidal complex with 1,2-dimyristoyl-sn-glycero-3-phosphocholine, we hypothesized that lipid complexes of 4F would be able to bind PON1 and enhance its activity and stability. To test our hypothesis, we have expressed and purified a recombinant PON1 (rPON1) and studied its interaction with 4F:POPC complex. Our studies show significant increase, compared to the control, in the paraoxonase activity and stability of rPON1 in the presence of 4F:POPC complex. We propose that 4F:POPC complex is a novel platform for PON1 binding, increasing its stability, and enhancing its enzyme activity. We propose a structural model for the 4F:POPC:PON1 ternary complex that is consistent with our results and published observations.


Asunto(s)
Apolipoproteína A-I/metabolismo , Arildialquilfosfatasa/metabolismo , Péptidos/metabolismo , Fosfatidilcolinas/metabolismo , Secuencia de Aminoácidos , Apolipoproteína A-I/química , Arildialquilfosfatasa/genética , Estabilidad de Enzimas , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Péptidos/química , Unión Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
20.
Rheumatology (Oxford) ; 52(6): 1101-8, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23382361

RESUMEN

OBJECTIVE: To evaluate telomere length (TL) between patients with SLE and healthy controls and to test if TL is associated with carotid plaque. METHODS: A pilot study of 154 patients with SLE and 152 controls was performed from the SOLVABLE (Study of Lupus Vascular and Bone Long-Term Endpoints) cohort. Demographic and cardiovascular disease (CVD) factors were collected at baseline. The presence or absence of plaque was evaluated by B-mode US. Genomic DNA was isolated from whole peripheral blood. TL was quantified using real-time quantitative PCR. RESULTS: SLE women had a short TL compared with healthy controls (4.57 vs 5.44 kb, P = 0.03). SLE women showed shorter TL than controls across all age groups: <35 years (4.38 vs 6.37 kb), 35-44 years (4.52 vs 5.30 kb), 45-54 years (4.77 vs 5.68 kb) and ≥55 years (4.60 vs 4.71 kb). Among patients with SLE and carotid plaque there was a trend towards shorter TL at a younger age and it was significantly lower in the 35- to 44-year age group when compared with controls (P = 0.025). Multiple logistic regression analysis indicated a risk of carotid plaque with older age [odds ratio (OR) 1.09; 95% CI 1.06, 1.12] but not with TL (OR 1.05; 95% CI 0.97, 1.13). CONCLUSION: SLE women had significantly shorter TL than controls. SLE women trended towards shorter TL at a younger age. When carotid plaque was identified, the younger SLE women had shorter TL. Only older age but not shorter TL was independently associated with carotid plaque. Additional studies are needed to confirm if TL is a novel biomarker for cardiovascular disease in SLE.


Asunto(s)
Estenosis Carotídea/complicaciones , Lupus Eritematoso Sistémico/complicaciones , Placa Aterosclerótica/complicaciones , Telómero , Adulto , Factores de Edad , Anciano , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/genética , Femenino , Humanos , Lupus Eritematoso Sistémico/diagnóstico por imagen , Lupus Eritematoso Sistémico/genética , Masculino , Persona de Mediana Edad , Proyectos Piloto , Placa Aterosclerótica/diagnóstico por imagen , Placa Aterosclerótica/genética , Factores de Riesgo , Índice de Severidad de la Enfermedad , Ultrasonografía
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA