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1.
Maturitas ; 172: 23-31, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37084589

RESUMEN

OBJECTIVES: The Women's Health Initiative study reported an increased risk of venous thromboembolism among menopausal women treated with conjugated equine estrogens/medroxyprogesterone acetate (CEE/MPA) versus placebo. Newer hormone therapies may have a lower venous thromboembolism risk. The study compared the risk of venous thromboembolism between women treated with the combined oral product 17ß-estradiol/micronized progesterone (E2/P4) and those treated with oral CEE/MPA regimens. STUDY DESIGN: In a retrospective longitudinal study using real-world claims data from April 2019 to June 2021, women aged 40 years or more treated with oral E2/P4 or oral CEE/MPA who did not have a venous thromboembolism diagnosis before first dispensing claim of CEE/MPA or E2/P4 identified on or after May 1st 2019 (index date) were observed for 6 months or more after the index date. Oral E2/P4 and oral CEE/MPA had been prescribed by the treating physician in real-world practice and were observed through pharmacy dispensing records. MAIN OUTCOME MEASURES: Venous thromboembolism risk was compared between women receiving oral E2/P4 versus oral CEE/MPA. RESULTS: The study included 36,061 women treated with oral E2/P4 or oral CEE/MPA. In the analyses weighted by the inverse probability of treatment for control of potential confounding factors, the incidence of venous thromboembolism was significantly lower for oral E2/P4 compared with oral CEE/MPA (37/10,000 women-years for oral E2/P4 vs 53/10,000 women-years for oral CEE/MPA; incidence rate ratio 0.70, 95 % confidence interval: 0.53-0.92). CONCLUSIONS: Real-world evidence suggests that the risk of venous thromboembolism is significantly lower among women treated with oral E2/P4 compared with oral CEE/MPA.


Asunto(s)
Estrógenos Conjugados (USP) , Tromboembolia Venosa , Femenino , Humanos , Estrógenos Conjugados (USP)/efectos adversos , Progesterona/efectos adversos , Acetato de Medroxiprogesterona/efectos adversos , Estradiol , Tromboembolia Venosa/inducido químicamente , Tromboembolia Venosa/epidemiología , Estudios Longitudinales , Estudios Retrospectivos , Terapia de Reemplazo de Estrógeno/efectos adversos
2.
Osteoporos Int ; 34(5): 977-991, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36872338

RESUMEN

The study results indicate that women with osteoporosis initiated on gastro-resistant risedronate have a lower risk of fracture than those initiated on immediate release risedronate or alendronate. A large proportion of women discontinued all oral bisphosphonate therapies within 1 year of treatment start. PURPOSE: Using a US claims database (2009-2019), we compared risk of fractures between women with osteoporosis initiated on gastro-resistant (GR) risedronate and those initiated on (a) immediate release (IR) risedronate or (b) immediate release alendronate. METHODS: Women aged ≥ 60 years with osteoporosis who had ≥ 2 oral bisphosphonate prescription fills were followed for ≥ 1 year after the first observed bisphosphonates dispensing (index date). Fracture risk was compared between the GR risedronate and IR risedronate/alendronate cohorts using adjusted incidence rate ratios (aIRRs), both overall and in subgroups with high fracture risk due to older age or comorbidity/medications. Site-specific fractures were identified based on diagnosis codes recorded on medical claims using a claims-based algorithm. Persistence on bisphosphonate therapy was evaluated for all groups. RESULTS: aIRRs generally indicated lower fracture risk for GR risedronate than IR risedronate and alendronate. When comparing GR risedronate to IR risedronate, statistically significant aIRRs (p < 0.05) were observed for pelvic fractures in the full cohorts (aIRRs = 0.37), for any fracture and pelvic fractures among women aged ≥ 65 years (aIRRs = 0.63 and 0.41), for any fracture and pelvic fractures among women aged ≥ 70 years (aIRRs = 0.69 and 0.24), and for pelvic fracture among high-risk women due to comorbidity/medications (aIRR = 0.34). When comparing GR risedronate to alendronate, statistically significant aIRRs were observed for pelvic fractures in the full cohorts (aIRR = 0.54), for any fracture and wrist/arm fractures among women aged ≥ 65 years (aIRRs = 0.73 and 0.63), and for any fracture, pelvic, and wrist/arm fractures among women aged ≥ 70 years (aIRRs = 0.72, 0.36, and 0.58). In all cohorts, ~ 40% completely discontinued oral bisphosphonates within 1 year. CONCLUSIONS: Discontinuation rates of oral bisphosphonate therapy were high. However, women initiated on GR risedronate had a significantly lower risk of fracture for several skeletal sites than women initiated on IR risedronate/alendronate, particularly those aged ≥ 70 years.


Asunto(s)
Conservadores de la Densidad Ósea , Fracturas Óseas , Osteoporosis Posmenopáusica , Osteoporosis , Femenino , Humanos , Alendronato/uso terapéutico , Ácido Risedrónico/uso terapéutico , Ácido Etidrónico/uso terapéutico , Osteoporosis/complicaciones , Osteoporosis/tratamiento farmacológico , Osteoporosis/epidemiología , Difosfonatos/uso terapéutico , Fracturas Óseas/tratamiento farmacológico , Conservadores de la Densidad Ósea/uso terapéutico , Osteoporosis Posmenopáusica/complicaciones , Osteoporosis Posmenopáusica/tratamiento farmacológico , Osteoporosis Posmenopáusica/epidemiología
3.
BMC Dermatol ; 20(1): 24, 2020 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-33341118

RESUMEN

BACKGROUND: An estimated 50% of children in the US are Medicaid-insured. Some of these patients have poor health literacy and limited access to medications and specialty care. These factors affect treatment utilization for pediatric patients with atopic dermatitis (AD), the most common inflammatory skin disease in children. This study assesses and compares treatment patterns and healthcare resource utilization (HCRU) between large cohorts of Medicaid and commercially insured children with AD. METHODS: Pediatric patients with AD were identified from 2 large US healthcare claims databases (2011-2016). Included patients had continuous health plan eligibility for ≥6 months before and ≥12 months after the first AD diagnosis (index date). Patients with an autoimmune disease diagnosis within 6 months of the index date were excluded. Treatment patterns and all-cause and AD-related HCRU during the observation period were compared between commercially and Medicaid-insured children. RESULTS: A minority of children were evaluated by a dermatology or allergy/immunology specialist. Several significant differences were observed between commercially and Medicaid-insured children with AD. Disparities detected for Medicaid-insured children included: comparatively fewer received specialist care, emergency department and urgent care center utilization was higher, a greater proportion had asthma and non-atopic morbidities, high- potency topical corticosteroids and calcineurin inhibitors were less often prescribed, and prescriptions for antihistamines were more than three times higher, despite similar rates of comorbid asthma and allergies among antihistamine users. Treatment patterns also varied substantially across physician specialties. CONCLUSIONS: Results suggest barriers in accessing specialty care for all children with AD and significant differences in management between commercially and Medicaid-insured children. These disparities in treatment and access to specialty care may contribute to poor AD control, especially in Medicaid-insured patients.


Asunto(s)
Dermatitis Atópica/terapia , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Disparidades en Atención de Salud/estadística & datos numéricos , Seguro de Salud/estadística & datos numéricos , Medicaid/estadística & datos numéricos , Adolescente , Niño , Preescolar , Dermatitis Atópica/diagnóstico , Dermatitis Atópica/economía , Femenino , Alfabetización en Salud , Accesibilidad a los Servicios de Salud/economía , Disparidades en Atención de Salud/economía , Humanos , Lactante , Recién Nacido , Seguro de Salud/economía , Masculino , Medicaid/economía , Aceptación de la Atención de Salud/estadística & datos numéricos , Estudios Retrospectivos , Factores Socioeconómicos , Estados Unidos
4.
J Am Acad Dermatol ; 82(3): 651-660, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31400453

RESUMEN

BACKGROUND: Real-world evidence on treatment patterns of pediatric patients with atopic dermatitis (AD) is sparse. OBJECTIVE: To assess current treatment patterns in pediatric AD patients. METHODS: Retrospective observational analysis of commercial insurance and Medicaid administrative claims data (January 2011-December 2016) for pediatric AD patients, stratified by age and provider type. RESULTS: The analytic sample comprised 607,258 pediatric AD patients. Median observation period was 30.3 months. Overall, 78.6% were prescribed ≥1 AD medication; 86.7% were prescribed topical corticosteroids, and 5.4% were prescribed a calcineurin inhibitor. Systemic corticosteroids (SCSs) were prescribed for 24.4% of patients, 51.8% of whom did not have asthma or allergic comorbidities. Of the 46.6% prescribed an antihistamine and 16.2% prescribed montelukast, 62.0% and 41.3%, respectively, did not have asthma or allergic comorbidities. Systemic immunosuppressants were rarely prescribed (<0.5%). Higher potency topical corticosteroid and SCS use increased with age. Treatment patterns varied by provider type; specialists were more likely to prescribe higher potency topicals and/or systemics, regardless of patient age. A minority of patients were treated by or referred to a specialist. LIMITATIONS: Identification of AD patients relied on billing diagnoses; the disease severity was proxied by the treatment prescribed. CONCLUSION: Results indicate that SCSs, despite known risks, and other medications with disproven efficacy in AD are frequently prescribed, suggesting a need for safer and more effective alternatives.


Asunto(s)
Dermatitis Atópica/tratamiento farmacológico , Dermatología , Pediatría , Pautas de la Práctica en Medicina , Niño , Preescolar , Análisis de Datos , Femenino , Humanos , Lactante , Seguro de Salud/estadística & datos numéricos , Masculino , Estudios Retrospectivos
5.
Int J Hematol Oncol ; 5(2): 63-75, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30302205

RESUMEN

AIM: To assess the 5-year healthcare resource utilization (HRU) and direct payer costs following allogeneic hematopoietic stem cell transplants (HSCTs) in acute lymphoblastic leukemia pediatric patients using data from two large US administrative databases. PATIENTS & METHODS: Among the 209 patients with acute lymphoblastic leukemia, HRU and costs were described over the up to 5 years after the HSCT. RESULTS: HRU and costs following the HSCTs were substantial. The highest average costs and most intensive HRU were observed within the first year following the HSCTs (49 outpatient visits; 29 laboratory service visits; 68 inpatient days), with a first year cost of US$683,099 and substantial costs over the following years. CONCLUSION: HRU and direct costs associated with allogeneic HSCTs are substantial.

6.
Curr Med Res Opin ; 31(8): 1611-20, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26086788

RESUMEN

OBJECTIVE: To describe real-world treatment patterns of patients receiving colchicine or other treatments during a gout-related emergency room or acute care facility (ER/ACF) visit. METHODS: An online physician-administered questionnaire was used to collect chart data on 500 patients with a gout-related ER/ACF visit after 16 October 2009; 250 patients receiving colchicine (Colchicine Cohort) and 250 receiving NSAIDs, systemic corticosteroids, narcotics, allopurinol, febuxostat, pegloticase, probenecid, or sulfinpyrazone (Other Cohort). Patient characteristics and treatment received/prescribed during the ER/ACF visit (Period 1 [P1]), at discharge (P2), and at the first follow-up visit (P3) are reported. RESULTS: A total of 45 rheumatologists and 63 primary care physicians participated in the study. Patient mean age was 51 years and 74.8% were male. The most common treatments in the Other Cohort were NSAIDs (59.6%), systemic corticosteroids (45.2%), and narcotics (33.6%). The 500 patients contributed 307 distinct treatment patterns from P1 to P3. Of the 20.6% patients not prescribed a treatment in P2, 60.2% were restarted on a treatment in P3. Of the 78.6% treated patients in P2, 27.0% had a treatment adjustment (dose increase, treatment add-on, or initiation of a different gout-related treatment - not with a urate lowering therapy only) in P3; for 72.6% of these patients, physicians justified the treatment adjustment by inadequacy of the treatment for maintenance therapy, insufficient dosage, or inadequate response. In the Colchicine Cohort, 60.8% of patients were prescribed colchicine consistently from P1 to P3, while 26.8% and 17.7% of patients in the Other Cohort were prescribed consistently NSAIDs and systemic corticosteroids from P1 to P3, respectively. LIMITATIONS: Specific nature of the acute gout-related symptoms or potential attack/flare during the ER/ACF visit was not recorded. CONCLUSION: Real-world clinical practice reveals a substantial number of distinct treatment patterns and frequent treatment adjustments by treating physicians for patients with a gout-related ER/ACF visit.


Asunto(s)
Colchicina/uso terapéutico , Supresores de la Gota/uso terapéutico , Gota/tratamiento farmacológico , Corticoesteroides/uso terapéutico , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
7.
Stat Med ; 33(7): 1205-21, 2014 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-24167024

RESUMEN

Evaluating the impacts of clinical or policy interventions on health care utilization requires addressing methodological challenges for causal inference while also analyzing highly skewed data. We examine the impact of registering with a Family Medicine Group, an integrated primary care model in Quebec, on hospitalization and emergency department visits using propensity scores to adjust for baseline characteristics and marginal structural models to account for time-varying exposures. We also evaluate the performance of different marginal structural generalized linear models in the presence of highly skewed data and conduct a simulation study to determine the robustness of alternative generalized linear models to distributional model mis-specification. Although the simulations found that the zero-inflated Poisson likelihood performed the best overall, the negative binomial likelihood gave the best fit for both outcomes in the real dataset. Our results suggest that registration to a Family Medicine Group for all 3 years caused a small reduction in the number of emergency room visits and no significant change in the number of hospitalizations in the final year.


Asunto(s)
Funciones de Verosimilitud , Modelos Lineales , Atención Primaria de Salud/estadística & datos numéricos , Puntaje de Propensión , Anciano , Anciano de 80 o más Años , Simulación por Computador , Servicio de Urgencia en Hospital , Hospitalización , Humanos , Masculino , Quebec
8.
Can J Psychiatry ; 59(11): 597-608, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25565476

RESUMEN

OBJECTIVE: To assess treatment patterns, health care resource utilization (HRU), and costs among previously stimulant-treated children and adolescents with attention-deficit hyperactivity disorder (ADHD) receiving atypical antipsychotic (AAP) prescriptions in Quebec. METHODS: Health care claims data extracted from Quebec's provincial health plan database between March 2007 and February 2012 were analyzed. Children and adolescents (6 to 17 years) with ADHD who were taking a stimulant and either switched to, or augmented with, an AAP (with the first AAP defined as the index AAP) without a documented diagnosis for which AAPs are Health Canada-approved were included. Discontinuation, augmentation, and switching of the index AAP during the 12-month, follow-up period were estimated using Kaplan-Meier survival analysis. HRU and costs for the 6 months before (baseline period) and after initiation of the index AAP were compared. RESULTS: A total of 453 children and adolescents with ADHD, mostly male (74.6%) and aged 6 to 12 years (73.7%), met the inclusion criteria. The 12-month discontinuation, augmentation, and switching rates were 45.5%, 68.2%, and 80.7%, respectively. Patients had, on average, more all-cause prescription fills (22.2, compared with 13.3) and incurred more all-cause pharmacy ($889, compared with $710), total medical ($1096, compared with $644), and total health care ($1985, compared with $1354) costs during the 6-month study period than during the 6-month baseline period (all P < 0.05). Similarly, ADHD-related total health care costs were higher during the study period ($1269, compared with $835; P < 0.05); all-cause and ADHD-related total health care costs increased by 46.6% and 52.0%, respectively. CONCLUSION: Use of an AAP among stimulant-treated children and adolescents with ADHD in Quebec was associated with high rates of therapy changes and increased HRU and costs.


Asunto(s)
Antipsicóticos/economía , Antipsicóticos/uso terapéutico , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad/economía , Costos de la Atención en Salud/estadística & datos numéricos , Recursos en Salud/economía , Recursos en Salud/estadística & datos numéricos , Pautas de la Práctica en Medicina/economía , Pautas de la Práctica en Medicina/estadística & datos numéricos , Adolescente , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Niño , Sustitución de Medicamentos/economía , Sustitución de Medicamentos/estadística & datos numéricos , Utilización de Medicamentos/economía , Utilización de Medicamentos/estadística & datos numéricos , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Programas Nacionales de Salud/economía , Programas Nacionales de Salud/estadística & datos numéricos , Quebec , Revisión de Utilización de Recursos
9.
Ann Biomed Eng ; 42(2): 269-79, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24043605

RESUMEN

Coronary atheroma develop in local sites that are widely variable among patients and are considerably variable in their vulnerability for rupture. This article summarizes studies conducted by our collaborative laboratories on predictive biomechanical modeling of coronary plaques. It aims to give insights into the role of biomechanics in the development and localization of atherosclerosis, the morphologic features that determine vulnerable plaque stability, and emerging in vivo imaging techniques that may detect and characterize vulnerable plaque. Composite biomechanical and hemodynamic factors that influence the actual site of development of plaques have been studied. Plaque vulnerability, in vivo, is more challenging to assess. Important steps have been made in defining the biomechanical factors that are predictive of plaque rupture and the likelihood of this occurring if characteristic features are known. A critical key in defining plaque vulnerability is the accurate quantification of both the morphology and the mechanical properties of the diseased arteries. Recently, an early IVUS based palpography technique developed to assess local strain, elasticity and mechanical instabilities has been successfully revisited and improved to account for complex plaque geometries. This is based on an initial best estimation of the plaque components' contours, allowing subsequent iteration for elastic modulus assessment as a basis for plaque stability determination. The improved method has also been preliminarily evaluated in patients with successful histologic correlation. Further clinical evaluation and refinement are on the horizon.


Asunto(s)
Enfermedad de la Arteria Coronaria , Elasticidad , Hemodinámica , Modelos Cardiovasculares , Placa Aterosclerótica , Fenómenos Biomecánicos , Enfermedad de la Arteria Coronaria/patología , Enfermedad de la Arteria Coronaria/fisiopatología , Humanos , Placa Aterosclerótica/patología , Placa Aterosclerótica/fisiopatología
10.
Am J Physiol Heart Circ Physiol ; 301(3): H1097-106, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21685261

RESUMEN

Coronary bifurcations represent specific regions of the arterial tree that are susceptible to atherosclerotic lesions. While the effects of vessel compliance, curvature, pulsatile blood flow, and cardiac motion on coronary endothelial shear stress have been widely explored, the effects of myocardial contraction on arterial wall stress/strain (WS/S) and vessel stiffness distributions remain unclear. Local increase of vessel stiffness resulting from wall-strain stiffening phenomenon (a local process due to the nonlinear mechanical properties of the arterial wall) may be critical in the development of atherosclerotic lesions. Therefore, the aim of this study was to quantify WS/S and stiffness in coronary bifurcations and to investigate correlations with plaque sites. Anatomic coronary geometry and cardiac motion were generated based on both computed tomography and MRI examinations of eight patients with minimal coronary disease. Computational structural analyses using the finite element method were subsequently performed, and spatial luminal arterial wall stretch (LW(Stretch)) and stiffness (LW(Stiff)) distributions in the left main coronary bifurcations were calculated. Our results show that all plaque sites were concomitantly subject to high LW(Stretch) and high LW(Stiff), with mean amplitudes of 34.7 ± 1.6% and 442.4 ± 113.0 kPa, respectively. The mean LW(Stiff) amplitude was found slightly greater at the plaque sites on the left main coronary artery (mean value: 482.2 ± 88.1 kPa) compared with those computed on the left anterior descending and left circumflex coronary arteries (416.3 ± 61.5 and 428.7 ± 181.8 kPa, respectively). These findings suggest that local wall stiffness plays a role in the initiation of atherosclerotic lesions.


Asunto(s)
Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico , Vasos Coronarios/patología , Imagen por Resonancia Magnética , Contracción Miocárdica , Placa Aterosclerótica/diagnóstico , Tomografía Computarizada por Rayos X , Adulto , Anciano , Fenómenos Biomecánicos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/patología , Enfermedad de la Arteria Coronaria/fisiopatología , Vasos Coronarios/fisiopatología , Elasticidad , Femenino , Análisis de Elementos Finitos , Hemodinámica , Humanos , Interpretación de Imagen Asistida por Computador , Masculino , Persona de Mediana Edad , Modelos Cardiovasculares , Dinámicas no Lineales , Placa Aterosclerótica/diagnóstico por imagen , Placa Aterosclerótica/patología , Placa Aterosclerótica/fisiopatología , Valor Predictivo de las Pruebas , Estrés Mecánico , Factores de Tiempo
11.
Mol Imaging Biol ; 12(1): 2-8, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-19898904

RESUMEN

PURPOSE: A newly developed synthetic alpha v beta 3 integrin targeted optical probe (ITOP) has been demonstrated to target cancer cells, in vivo. Compared to the commercially available cyclic peptide c[RGDfv], this optical probe has at least 20 times better binding affinity for the alpha v beta 3 receptor. The present in vitro study was designed to investigate the possibility of detecting early atherosclerotic plaque by using this ITOP. PROCEDURES: Experiments were performed on five Watanabe heritable hyperlipidemic rabbits and two New Zealand White rabbits for control. Our ITOP was used for detecting the presence of alpha v beta 3 receptors in vitro. RESULTS: Segments of plaque accumulation from two distinct regions of ascending and descending aortas were labeled in Watanabe rabbits. The signal was found principally in the adventitia and proximal intima of the aortic vessel, corresponding directly to the expression of integrin alpha v beta 3 as determined by antibody assay. Moreover, there was a close association between the level of labeling with the alpha v beta 3 targeted probe and the thickness of the adventitia. CONCLUSIONS: This high-affinity ITOP identifies the site and extent of alpha v beta 3 expression and correlates with adventitial thickness. Recent evidence associates alpha v beta 3 expression with the inflammatory process in early vulnerable plaque, making this compound a promising potential biomarker for early atherosclerotic disease.


Asunto(s)
Aterosclerosis/diagnóstico , Diagnóstico por Imagen/métodos , Integrina alfaVbeta3/metabolismo , Sondas Moleculares , Fenómenos Ópticos , Animales , Biomarcadores/metabolismo , Tejido Conectivo/patología , Diagnóstico Precoz , Microscopía Fluorescente , Conejos , Coloración y Etiquetado
12.
Magn Reson Med ; 62(2): 292-9, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19526488

RESUMEN

To enhance the clinical value of coronary magnetic resonance angiography (MRA), high-relaxivity contrast agents have recently been used at 3T. Here we examine a uniform bilateral shadowing artifact observed along the coronary arteries in MRA images collected using such a contrast agent. Simulations were performed to characterize this artifact, including its origin, to determine how best to mitigate this effect, and to optimize a data acquisition/injection scheme. An intraluminal contrast agent concentration model was used to simulate various acquisition strategies with two profile orders for a slow-infusion of a high-relaxivity contrast agent. Filtering effects from temporally variable weighting in k-space are prominent when a centric, radial (CR) profile order is applied during contrast infusion, resulting in decreased signal enhancement and underestimation of vessel width, while both pre- and postinfusion steady-state acquisitions result in overestimation of the vessel width. Acquisition during the brief postinfusion steady-state produces the greatest signal enhancement and minimizes k-space filtering artifacts.


Asunto(s)
Algoritmos , Artefactos , Angiografía Coronaria/métodos , Vasos Coronarios/anatomía & histología , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Angiografía por Resonancia Magnética/métodos , Meglumina/análogos & derivados , Compuestos Organometálicos , Medios de Contraste , Humanos
13.
Am J Physiol Heart Circ Physiol ; 295(2): H717-27, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18586893

RESUMEN

Fibrous cap thickness is often considered as diagnostic of the degree of plaque instability. Necrotic core area (Core(area)) and the arterial remodeling index (Remod(index)), on the other hand, are difficult to use as clinical morphological indexes: literature data show a wide dispersion of Core(area) thresholds above which plaque becomes unstable. Although histopathology shows a strong correlation between Core(area) and Remod(index), it remains unclear how these interact and affect peak cap stress (Cap(stress)), a known predictor of rupture. The aim of this study was to investigate the change in plaque vulnerability as a function of necrotic core size and plaque morphology. Cap(stress) value was calculated on 5,500 idealized atherosclerotic vessel models that had the original feature of mimicking the positive arterial remodeling process described by Glagov. Twenty-four nonruptured plaques acquired by intravascular ultrasound on patients were used to test the performance of the associated idealized morphological models. Taking advantage of the extensive simulations, we investigated the effects of anatomical plaque features on Cap(stress). It was found that: 1) at the early stages of positive remodeling, lesions were more prone to rupture, which could explain the progression and growth of clinically silent plaques and 2) in addition to cap thickness, necrotic core thickness, rather than area, was critical in determining plaque stability. This study demonstrates that plaque instability is to be viewed not as a consequence of fibrous cap thickness alone but rather as a combination of cap thickness, necrotic core thickness, and the arterial remodeling index.


Asunto(s)
Enfermedad de la Arteria Coronaria/patología , Vasos Coronarios/patología , Simulación por Computador , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Progresión de la Enfermedad , Fibrosis , Humanos , Modelos Cardiovasculares , Necrosis , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Medición de Riesgo , Rotura , Estrés Mecánico , Ultrasonografía Intervencional
14.
J Aerosol Med ; 15(2): 141-8, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12184864

RESUMEN

Cystic fibrosis patients demonstrate an increased susceptibility to bacterial lung infections. Airway infiltration by neutrophils will then lead to an increase in human leukocyte elastase (HLE) within the extracellular compartment, thereby producing deleterious effects. Here, we investigated the properties and tissue distribution of an unglycosylated, recombinant form of the HLE inhibitor alpha-1-proteinase inhibitor (alpha(1)-antitrypsin rhalpha1PI) when it is administered to the airway surface. We produced rhalpha1PI using a bacterial expression system and found the purified protein to be indistinguishable from blood-purified, glycosylated alpha1PI at inhibiting elastase in vitro. In contrast to intravenous administration, direct delivery of either alpha1PI or rhalpha1PI to the airway surface of CD-1 mice by nasal instillation produced similar highly detectable levels of protein in bronchoalveolar lavage at all time points, suggesting that glycosylation of alpha1PI does not play the same critical role in determining protein stability at the respiratory surface as it does in the vascular compartment. Interestingly, this unglycosylated rhalpha1PI was also highly protective against elastase-mediated injury 24 h after rhalpha1PI instillation and was consistently found to be significantly more protective than glycosylated blood-derived alpha1PI. Thus, these results provide evidence that aerosol delivery of rhalpha1PI could be an effective strategy for controlling HLE-dependent pathophysiology associated with cystic fibrosis lung disease.


Asunto(s)
Fibrosis Quística/metabolismo , Elastasa de Leucocito/efectos de los fármacos , Elastasa de Leucocito/metabolismo , alfa 1-Antitripsina/farmacología , Animales , Fibrosis Quística/fisiopatología , Glicosilación , Inyecciones Intravenosas , Instilación de Medicamentos , Ratones , Ratones Endogámicos C57BL , Distribución Tisular , alfa 1-Antitripsina/metabolismo
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