10 research outputs found

    Role of the Endocannabinoid System in Cardiac Remodeling

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    The endocannabinoid system and CB1 and CB2 cannabinoid receptors have been implicated in cardiac remodeling with CB1 inhibition and CB2 activation reported to be beneficial. However, the role of these receptors in cardiac remodeling secondary to hypertension is not known. Moreover, the functions of the CB1 and CB2 cannabinoid receptors in cardiac ventricular fibroblasts and their downstream fibrotic pathways has not yet been elucidated. This study was designed to determine the temporal myocardial expression pattern of CB1 and CB2 receptors in cardiac remodeling secondary to pressure overload (PO) induced hypertension at 3, 5, 14 and 28 days. The expression of the cannabinoid CB1 and CB2 receptors on human ventricular fibroblasts and the effects of their direct modulation on the fibrotic responses were also investigated. Rat model of pressure overload induced by abdominal aortic constriction was used for the in vivo study while the human ventricular fibroblast cell line was used for the in vitro study. The presence of CB1 and CB2 receptors was demonstrated on rat fibroblasts in left ventricular cross-sections and on human ventricular fibroblasts for the first time. Myocardial CB1 receptor levels were transiently increased at 3 days before showing decreased expression at the 14 and 28 day time points in the PO groups as compared to sham values. Myocardial CB2 receptor levels were significantly increased at the 3, 5 and 14 day time points in the PO groups as compared to sham values. Thus, the endocannabinoid system was found to be responsive to the pathophysiological changes occurring in cardiac remodeling with temporal alterations in the expression of cannabinoid receptors. CB1 receptor antagonism on human ventricular fibroblasts was found to decrease their collagen expression and production, thus having an anti-fibrotic effect while CB2 receptor antagonism was found to promote their collagen expression and production, thus having a profibrotic effect. Thus, CB1 antagonism and CB2 agonism seem to be involved in mediating a protective effect against fibrotic responses of the human ventricular fibroblasts. Modulation of these receptors could thus offer an exciting new avenue for development of anti-fibrotic therapies and attenuating adverse remodeling changes

    Global Retinoblastoma Presentation and Analysis by National Income Level.

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    Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs

    Models of care in tele-ophthalmology: a scoping review

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    The objective of this review was to identify and describe telehealth models of care for ophthalmic services. We conducted a scoping review of the literature to identify how ophthalmic care can be delivered by telehealth. We searched the PubMed database to identify relevant articles which were screened based on pre-defined inclusion criteria. For included articles, data were extracted, categorised and analysed. Synthesis of findings was performed narratively. The scoping review included 78 articles describing 62 discrete tele-ophthalmic models of care. Tele-ophthalmic models of care can be used for consultative service, screening, triage and remote supervision. The majority of services were for general eye care and triage (n = 17; 26%) or emergency services (n = 8; 12%). The most common conditions for disease-specific models of care were diabetic retinopathy (n = 14; 21%), and glaucoma (n = 8; 12%). Most models of care involved local clinicians capturing images and transmitting them to an ophthalmologist for assessment. This scoping review demonstrated tele-ophthalmology to be feasible for consultation, screening, triage and remote supervision applications across a broad range of ophthalmic conditions. A large number of models of care have been identified and described in this review. Considerable collaboration between patient-end clinicians and substantial infrastructure is typically required for tele-ophthalmology

    Nanoscale Patterning of Extracellular Matrix Alters Endothelial Function under Shear Stress

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    The role of nanotopographical extracellular matrix (ECM) cues in vascular endothelial cell (EC) organization and function is not well-understood, despite the composition of nano- to microscale fibrillar ECMs within blood vessels. Instead, the predominant modulator of EC organization and function is traditionally thought to be hemodynamic shear stress, in which uniform shear stress induces parallel-alignment of ECs with anti-inflammatory function, whereas disturbed flow induces a disorganized configuration with pro-inflammatory function. Since shear stress acts on ECs by applying a mechanical force concomitant with inducing spatial patterning of the cells, we sought to decouple the effects of shear stress using parallel-aligned nanofibrillar collagen films that induce parallel EC alignment prior to stimulation with disturbed flow resulting from spatial wall shear stress gradients. Using real time live-cell imaging, we tracked the alignment, migration trajectories, proliferation, and anti-inflammatory behavior of ECs when they were cultured on parallel-aligned or randomly oriented nanofibrillar films. Intriguingly, ECs cultured on aligned nanofibrillar films remained well-aligned and migrated predominantly along the direction of aligned nanofibrils, despite exposure to shear stress orthogonal to the direction of the aligned nanofibrils. Furthermore, in stark contrast to ECs cultured on randomly oriented films, ECs on aligned nanofibrillar films exposed to disturbed flow had significantly reduced inflammation and proliferation, while maintaining intact intercellular junctions. This work reveals fundamental insights into the importance of nanoscale ECM interactions in the maintenance of endothelial function. Importantly, it provides new insight into how ECs respond to opposing cues derived from nanotopography and mechanical shear force and has strong implications in the design of polymeric conduits and bioengineered tissues

    The Global Retinoblastoma Outcome Study: a prospective, cluster-based analysis of 4064 patients from 149 countries

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    Background Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. Methods We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1,2017, and Dec 31,2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. Findings The cohort included 4064 children from 149 countries. The median age at diagnosis was 23.2 months (IQR 11.0-36.5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0.8%) of 636 children from high-income countries, 55 (5.4%) of 1027 children from upper-middle-income countries, 342 (19. 7%) of 1738 children from lower-middle-income countries, and 196 (42.9%) of 457 children from low-income countries. Enudeation surgery was available for all children and intravenous chemotherapy was available for 4014 (98.8%) of 4064 children. The 3-year survival rate was 99.5% (95% CI 98.8-100.0) for children from high-income countries, 91.2% (89.5-93.0) for children from upper-middle-income countries, 80.3% (78.3-82.3) for children from lower-middle-income countries, and 57.3% (524-63-0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16.67; 95% CI 4.76-50.00), cT4 advanced tumour compared to cT1 (8.98; 4.44-18.18), and older age at diagnosis in children up to 3 years (1.38 per year; 1.23-1.56). For children aged 3-7 years, the mortality risk decreased slightly (p=0.0104 for the change in slope). Interpretation This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd.Y

    Global Retinoblastoma Presentation and Analysis by National Income Level

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    This cross-sectional analysis reports the retinoblastoma stage at diagnosis across the world during a single year, investigates associations between clinical variables and national income level, and investigates risk factors for advanced disease at diagnosis. Key PointsQuestionIs the income level of a country of residence associated with the clinical stage of presentation of patients with retinoblastoma? FindingsIn this cross-sectional analysis that included 4351 patients with newly diagnosed retinoblastoma, approximately half of all new retinoblastoma cases worldwide in 2017, 49.1\% of patients from low-income countries had extraocular tumor at time of diagnosis compared with 1.5\% of patients from high-income countries. MeaningThe clinical stage of presentation of retinoblastoma, which has a major influence on survival, significantly differs among patients from low-income and high-income countries, which may warrant intervention on national and international levels. ImportanceEarly diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. ObjectivesTo report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and ParticipantsA total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and MeasuresAge at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. ResultsThe cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4\%) were female. Most patients (n=3685 {[}84.7\%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n=2638 {[}62.8\%]), followed by strabismus (n=429 {[}10.2\%]) and proptosis (n=309 {[}7.4\%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5\%) patients having intraocular retinoblastoma and 2 (0.3\%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1\%) having extraocular retinoblastoma and 94 of 498 (18.9\%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 {[}95\% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 {[}95\% CI, 4.30-7.68]). Conclusions and RelevanceThis study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs
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