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1.
Artículo en Inglés | MEDLINE | ID: mdl-38527109

RESUMEN

INTRODUCTION: Health systems are constantly evolving in response to existing and emerging health challenges and are increasingly adopting the Quintuple Aim to guide transformation and improvement efforts. Addressing health challenges and achieving the Quintuple Aim (enhancing patient experience, improving healthcare provider experience, promoting population health, optimising the value of healthcare services, and advancing health equity) may be enhanced with the use of a Learning Health Systems approach that fosters the real-time use of data and evidence to inform improvement efforts and harnesses embedded researchers to co-produce timely, relevant evidence to address priorities. Training programs have emerged to build embedded research capacity within health system organisations and have focused predominantly on the postdoctoral career stage, with little attention paid to the early career researcher (ECR) stage. The objective of this study was to understand ECR training and mentorship needs in the embedded research context to inform the creation new or adaptation of existing programs to build embedded ECR capacity. METHODS: This study used a qualitative approach to garner insight from embedded and applied scholars and health systems leaders in Canada from various professional backgrounds and at various career stages using a combination of focus group discussions, key informant interviews, and an online survey. Thematic content analysis was used to examine the responses of study participants within the interview themes. RESULTS: Twenty-six (26) participants were included in the study. Results were organised according to four key themes: (1) key competencies and skills needed by embedded ECRs; (2) additional training and capacity development needs; (3) training delivery approaches; and (4) enablers and challenges faced by embedded ECRs. Results highlight the importance of supporting ECRs to develop their leadership and organisational management capabilities; their knowledge of and ability to use research approaches that are well-suited to real-world, complex, evolving environments; and their opportunities to learn with and from each other and mentors. Results underscore the perceived importance of context, including being embedded in a supportive environment that values research and evidence and of academic incentives that recognise and value real-world research impact. The challenges of responding to shifting organisational and system priorities were identified. Additional insights from health systems leaders were also highlighted. CONCLUSION: This study identified the multifaceted needs of embedded ECRs and the challenges they face within healthcare systems. Designing new programs or tailoring existing ones to address these needs would build their capacity, foster career progression, and ensure their impact as leaders of evidence-informed health system improvement which is crucial for achieving the Quintuple Aim.

2.
Arterioscler Thromb Vasc Biol ; 38(9): 2174-2183, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29930007

RESUMEN

Objective- Vascular fusion represents an important mechanism of vessel enlargement during development; however, its significance in postnatal vessel enlargement is still unknown. During fusion, 2 adjoining vessels merge to share 1 larger lumen. The aim of this research was to identify the molecular mechanism responsible for vascular fusion. Approach and Results- We previously showed that both low shear stress and DAPT ( N-[ N-(3,5-difluorophenacetyl)-L-alanyl]- S-phenylglycine t-butyl ester) treatment in the embryo result in a hyperfused vascular plexus and that increasing shear stress levels could prevent DAPT-induced fusion. We, therefore, investigated vascular endothelial-cadherin (VEC) phosphorylation because this is a common downstream target of low shear stress and DAPT treatment. VEC phosphorylation increases after DAPT treatment and decreased shear stress. The increased phosphorylation occurred independent of the cleavage of the Notch intracellular domain. Increasing shear stress rescues hyperfusion by DAPT treatment by causing the association of the phosphatase vascular endothelial-protein tyrosine phosphatase with VEC, counteracting VEC phosphorylation. Finally, Src (proto-oncogene tyrosine-protein kinase Src) inhibition prevents VEC phosphorylation in endothelial cells and can rescue hyperfusion induced by low shear stress and DAPT treatment. Moesin, a VEC target that was previously reported to mediate endothelial cell rearrangement during lumenization, relocalizes to cell membranes in vascular beds undergoing hyperfusion. Conclusions- This study provides the first evidence that VEC phosphorylation, induced by DAPT treatment and low shear stress, is involved in the process of fusion during vascular remodeling.


Asunto(s)
Antígenos CD/metabolismo , Cadherinas/metabolismo , Estrés Mecánico , Remodelación Vascular , Animales , Membrana Celular/metabolismo , Células Cultivadas , Dipéptidos/farmacología , Embrión de Mamíferos , Células Endoteliales/metabolismo , Endotelio Vascular/metabolismo , Proteínas de Microfilamentos/metabolismo , Fosforilación , Familia-src Quinasas/antagonistas & inhibidores , Familia-src Quinasas/metabolismo
3.
Arterioscler Thromb Vasc Biol ; 34(7): 1468-76, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24764455

RESUMEN

OBJECTIVE: The H2.0-like homeobox transcription factor (HLX) plays an essential role in visceral organogenesis in mice and has been shown to regulate angiogenic sprouting in vitro and in zebrafish embryos. We therefore examined the role of HLX in vascular development in mouse and avian embryos. APPROACH AND RESULTS: In situ hybridization showed that Hlx is expressed in a subset of sprouting blood vessels in postnatal mouse retinas and embryos. Hlx expression was conserved in quail embryos and upregulated in blood vessels at the onset of circulation. In vitro assays showed that Hlx is dynamically regulated by growth factors and shear stress alterations. Proangiogenic vascular endothelial growth factor induces Hlx expression in cultured endothelial cells, whereas signals that induce stalk cell identity lead to a reduction in Hlx expression. HLX was also downregulated in embryos in which flow was ablated, whereas injection of a starch solution, which increases blood viscosity and therefore shear stress, causes an upregulation in HLX. HLX knockdown in vitro resulted in a reduction in tip cell marker expression and in reduced angiogenic sprouting, but Hlx(-/-) embryos showed no defect in vascular sprouting at E8.5, E9.5, or E11.5 in vivo. Vascular remodeling of the capillary plexus was altered in Hlx(-/-) embryos, with a modestly enlarged venous plexus and reduction of the arterial plexus. CONCLUSIONS: Our findings indicate not only that Hlx regulates sprouting in vitro, but that its role in sprouting is nonessential in vivo. We find HLX is regulated by shear stress and a subtle defect in vascular remodeling is present in knockout embryos.


Asunto(s)
Vasos Sanguíneos/metabolismo , Proteínas de Homeodominio/metabolismo , Neovascularización Fisiológica , Factores de Transcripción/metabolismo , Saco Vitelino/irrigación sanguínea , Animales , Vasos Sanguíneos/embriología , Viscosidad Sanguínea , Células Cultivadas , Embrión de Mamíferos/irrigación sanguínea , Embrión no Mamífero , Regulación del Desarrollo de la Expresión Génica , Edad Gestacional , Proteínas de Homeodominio/genética , Humanos , Mecanotransducción Celular , Ratones , Ratones Noqueados , Codorniz , Interferencia de ARN , Flujo Sanguíneo Regional , Estrés Mecánico , Factores de Transcripción/deficiencia , Factores de Transcripción/genética , Transfección
4.
J Biol Chem ; 288(19): 13278-94, 2013 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-23530031

RESUMEN

BACKGROUND: BRIL is a bone-specific membrane protein that is involved in osteogenesis imperfecta type V. RESULTS: Bril transcription is activated by Sp1, Sp3, OSX, and GLI2 and by CpG demethylation. CONCLUSION: Regulation of Bril involves trans-acting factors integrating at conserved promoter elements and epigenetic modifications. SIGNIFICANCE: Identification of the mechanisms governing Bril transcription is important to understand its role in skeletal biology. Bril encodes a small membrane protein present in osteoblasts. In humans, a single recurrent mutation in the 5'-UTR of BRIL causes osteogenesis imperfecta type V. The exact function of BRIL and the mechanism by which it contributes to disease are still unknown. The goal of the current study was to characterize the mechanisms governing Bril transcription in humans, rats, and mice. In the three species, as detected by luciferase reporter assays in UMR106 cells, we found that most of the base-line regulatory activity was localized within ∼250 bp upstream of the coding ATG. Co-transfection experiments indicated that Sp1 and Sp3 were potent inducers of the promoter activity, through the binding of several GC-rich boxes. Osterix was a weak activator but acted cooperatively with Sp1 and GLI2 to synergistically induce the BRIL promoter. GLI2, a mediator of hedgehog signaling pathway, was also a potent activator of BRIL through a single GLI binding site. Correspondingly, agonists of the hedgehog pathway (purmorphamine and Indian hedgehog) in MC3T3 osteoblasts led to increased BRIL levels. The BRIL promoter activity was also found to be negatively modulated through two different mechanisms. First, the ZFP354C zinc finger protein repressed basal and Sp1-induced activity. Second, CpG methylation of the promoter region correlated with an inactive state and prevented Sp1 activation. The data provide the very first analyses of the cis- and trans-acting factors regulating Bril transcription. They revealed key roles for the Sp members and GLI2 that possibly cooperate to activate Bril when the promoter becomes demethylated.


Asunto(s)
Metilación de ADN , Silenciador del Gen , Proteínas de la Membrana/genética , Transcripción Genética , Activación Transcripcional , Células 3T3 , Animales , Secuencia de Bases , Huesos/metabolismo , Diferenciación Celular , Secuencia Conservada , Islas de CpG , Femenino , Células HEK293 , Proteínas Hedgehog/metabolismo , Humanos , Factores de Transcripción de Tipo Kruppel/fisiología , Proteínas de la Membrana/metabolismo , Ratones , Ratones Noqueados , Anotación de Secuencia Molecular , Datos de Secuencia Molecular , Proteínas Nucleares/fisiología , Regiones Promotoras Genéticas , Unión Proteica , Ratas , Proteínas Represoras/metabolismo , Transducción de Señal , Factor de Transcripción Sp1/fisiología , TATA Box , Proteína Gli2 con Dedos de Zinc
5.
Learn Health Syst ; 8(2): e10399, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38633024

RESUMEN

Introduction: The Health System Impact (HSI) Fellowship is an embedded research training program that aims to prepare doctoral trainees and postdoctoral fellows for stronger career readiness and greater impact as emerging leaders within and beyond the academy, including in learning health systems (LHS). The program supports fellows to develop 10 leadership and research competencies that comprise the Enriched Core Competency Framework in Health Services and Policy Research through a combination of experiential learning, mentorship, and professional development training. This study tracks competency development of HSI fellows over time and examines fellows' perspectives on which program design elements support their competency development. Methods: A competency assessment tool developed for the program was independently completed by 95 postdoctoral and 36 doctoral fellows (self-assessments) and their respective 203 dyad (academic and health system) supervisors in the 2017 to 2019 program cohorts, who independently rated the strength of fellows' 10 competencies at baseline and several points thereafter. Competency strength ratings were analyzed to understand change over time and differences in ratings across groups (between fellows' sex, supervisor type, and supervisor vs. fellow). Program design element ratings were examined to understand perspectives on their contribution toward fellows' competency development. Results: Fellows' competency strength significantly improved in all 10 domains over time, based on independent assessments by the fellows and their dyad supervisors. Supervisors tended to rate the fellows' competency strength higher than the fellows did. Differences in competency ratings between male and female fellows (self-assessments) and between academic and health system supervisors were either negligble or not significant. Fellows identified all nine program design elements as enriching their competency development. Conclusion: The HSI Fellowship provides an opportunity for fellows to develop the full suite of enriched core competencies and to prepare a cadre of emerging leaders with the skills and experience to contribute to the advancement of LHS.

6.
Healthc Pap ; 21(4): 64-75, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38482659

RESUMEN

In this paper, we explore what is needed to generate quality research to guide evidence-informed digital health policy and call the Canadian community of patients, clinicians, policy (decision) makers and researchers to action in setting digital health research priorities for supporting underserved communities. Using specific examples, we describe how evidence is produced and implemented to guide digital health policy. We study how research environments must change to reflect and include the communities for whom the policy is intended. Our goal is to guide how future evidence reaches policy makers to help them shape healthcare services and how these services are delivered to underserved communities in Canada. Understanding the pathways through which evidence can make a difference to equitable and sustainable digital health policy is vital for guiding the types of research that attract priority resources.


Asunto(s)
Política de Salud , Calidad de la Atención de Salud , Humanos , Canadá , Práctica Clínica Basada en la Evidencia
7.
Int J Health Policy Manag ; 12: 7333, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37579439

RESUMEN

BACKGROUND: This descriptive study reports the early career outcomes of postdoctoral fellows who completed a novel embedded fellowship training program, the Canadian Institutes of Health Research (CIHR) Health System Impact (HSI) Fellowship. The program was designed to support impact-oriented career paths of doctoral graduates, build research capacity within health system organizations, and help to advance learning health systems in Canada. METHODS: Employment of fellowship alumni upon completion of the program were tracked using internet searches of publicly accessible online sources and complemented with program survey data. RESULTS: Descriptive analyses show that all 87 eligible alumni included in the study are currently employed (100% of 87), with 92% employed in Canada. Their employment spans several sectors, including in academic (37%), public (29%), healthcare delivery (17%), and private (14%) sectors. Altogether, 32% of alumni held hybrid roles with an affiliation in academia and another sector. The most common position types were senior scientist (42%), professorships (18%), and director, manager or administrator roles (12%). Program reporting data indicate that these employment outcomes are generally consistent with the group's career aspirations reported at the start of the fellowship program, and that the program receives high ratings from fellows in the extent it is believed to support their career preparedness and readiness (4.49 out of 5). CONCLUSION: We find that HSI Fellow alumni are employed mostly in research-related roles in a range of sectors including, but not limited to academia, that they positively perceive the program's success in elevating their career readiness and potential to make an impact - suggesting that the program may help equip fellows with the skills, readiness and networks for a broad array of employment sectors and roles. The findings are a promising signal of the demand for research talent and the growing capacity for learning health systems in Canada.


Asunto(s)
Atención a la Salud , Becas , Humanos , Canadá , Programas de Gobierno , Personal de Salud
8.
Healthc Pap ; 20(3): 9-24, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35759481

RESUMEN

The Canadian Institutes of Health Research - Institute of Health Services and Policy Research's (IHSPR's) Strategic Plan 2021-2026: Accelerate Health Care System Transformation through Research to Achieve the Quadruple Aim and Health Equity for All (CIHR IHSPR 2021) outlines the Institute's key priority areas for investment and activity over the next five years. IHSPR used an evidence-informed strategic planning process that was pan-Canadian in scope and designed to elicit the health services and policy research priorities of decision makers, providers, researchers, patients, communities and the public. This paper outlines IHSPR's four key strategic priorities for supporting and optimizing research in transforming Canada's healthcare delivery systems over the next five years.


Asunto(s)
Equidad en Salud , Canadá , Atención a la Salud , Programas de Gobierno , Humanos
9.
Healthc Pap ; 20(3): 78-83, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35759488

RESUMEN

The Canadian Institutes of Health Research - Institute of Health Services and Policy Research's (IHSPR) Strategic Plan 2021-2026 (CIHR IHSPR 2021) aims to accelerate healthcare system transformation to achieve the Quadruple Aim and health equity through research. This special issue features a collection of commentaries from academic and health system leaders who were invited to respond to IHSPR's strategic plan and share insights regarding the opportunities the plan presents and areas where more attention may be needed. The present paper features a response from the IHSPR team and outlines the next steps regarding implementation. IHSPR is deeply grateful to the commentary authors for their insight, advice and recommendations, which will help to inform the implementation of the plan.


Asunto(s)
Atención a la Salud , Investigación sobre Servicios de Salud , Canadá , Política de Salud , Servicios de Salud , Humanos
10.
Nat Commun ; 11(1): 4826, 2020 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-32958757

RESUMEN

DNA replication initiates from multiple genomic locations called replication origins. In metazoa, DNA sequence elements involved in origin specification remain elusive. Here, we examine pluripotent, primary, differentiating, and immortalized human cells, and demonstrate that a class of origins, termed core origins, is shared by different cell types and host ~80% of all DNA replication initiation events in any cell population. We detect a shared G-rich DNA sequence signature that coincides with most core origins in both human and mouse genomes. Transcription and G-rich elements can independently associate with replication origin activity. Computational algorithms show that core origins can be predicted, based solely on DNA sequence patterns but not on consensus motifs. Our results demonstrate that, despite an attributed stochasticity, core origins are chosen from a limited pool of genomic regions. Immortalization through oncogenic gene expression, but not normal cellular differentiation, results in increased stochastic firing from heterochromatin and decreased origin density at TAD borders.


Asunto(s)
ADN/biosíntesis , ADN/química , Origen de Réplica/genética , Animales , Composición de Base , Secuencia de Bases , Carcinogénesis , Diferenciación Celular , Células Cultivadas , Replicación del ADN/genética , Genoma Humano/genética , Heterocromatina/genética , Humanos , Ratones , Motivos de Nucleótidos , Transcripción Genética
11.
Front Pediatr ; 7: 332, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31440489

RESUMEN

Background: In preschool-aged children with, or at elevated risk for, developmental disabilities, challenges and needs arise from vulnerabilities linked to critical and newly emerging cognitive, speech, motor, behavioral, and social skills. For families, this can be a stressful period as they witness the gradual unfolding of their child's differences and await to receive care. Nationally and internationally, service delivery models during this critical period are not standardized nor are they nimble or sufficient enough, leading to long wait times, service gaps and duplications. Given these struggles, there is a need to examine whether "health coaching", a structured educational program that is deliverable by different and more accessible means, can be effective in empowering families, by delivering information, providing social supports, and decreasing the demands on the overwhelmed health and developmental services. The primary objective is to evaluate the feasibility and the effectiveness of a coaching intervention (in comparison to usual and locally available care), for parents of children with emerging developmental delays. Method/Design: A multi-centered pragmatic randomized controlled trial design will be used. Families will be recruited from a representative sample of those awaiting publicly-funded regional child health services for children with developmental delays in four Canadian provinces. The target sample size is 392 families with children aged 1.5 to 4.5 years at recruitment date. Families will be randomly assigned to receive either the BRIGHT Coaching intervention (coach supported, hardcopy and online self-managed educational resources: 14 sessions, 2 sessions every 4 weeks for 6-9 months) or usual care that is locally available. In addition to the feasibility and acceptability measures, outcomes related to family empowerment, parental satisfaction and efficacy with caregiver competency will be evaluated at baseline, post-treatment (8 months), and follow-up (12 months). Discussion: This manuscript presents the background information, design, description of the interventions and of the protocol for the randomized controlled trial on the effectiveness of BRIGHT Coaching intervention for families of children with emerging developmental delays. Trial Registration: ClinicalTrials.gov, U.S. National Library of Medicine, National Institutes of Health #NCT03880383, 03/15/2019. Retrospectively registered.

12.
PLoS One ; 12(9): e0184568, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28880886

RESUMEN

BRIL (bone-restricted IFITM-like), is a short transmembrane protein expressed almost exclusively in osteoblasts. Although much is known about its bone-restricted gene expression pattern and protein biochemical and topological features, little information is available for BRIL physiological function. Two autosomal dominant forms of osteogenesis imperfecta (OI) are caused by distinct, but recurrent mutations in the BRIL gene. Yet, the underlying mechanisms by which those mutations lead to OI are still poorly understood. A previous report indicated that BRIL knockout (KO) mice had bone deformities, shortened long bones, and reproductive problems. Here we generated and systematically analyzed the skeletal phenotype of a new global Bril KO/LacZ knockin mouse model. KO mice reproduced and thrived normally up to 12 month of age. The skeletal phenotype of KO and WT littermates was assessed at embryonic (E13.5 to E18.5) and postnatal (2 days, 3 weeks, 3 months and 8 months) time-points. Embryos from E13.5 through to E18.5 showed significant X-Gal staining in all skeletal elements without any apparent patterning anomalies. Although bone deformities were never observed at any postnatal ages, minor and transient differences were noted in terms of bone length and static uCT parameters, but not systematically across all ages and genders. These changes, however, were not accompanied by significant alteration in bone material properties as assessed by a 3-point bending test. In addition, no changes were detected in circulating serum markers of bone turnover (P1NP, CTX-I, and osteocalcin). Gene expression monitoring also revealed no major impact of the loss of BRIL. Further, when mice were challenged with a surgically-induced fracture in tibia, bones repaired equally well in the KO mice as compared to WT. Finally, we showed that BRIL C-terminus is not a bona fide binding site for calcium. In conclusion, our in depth analysis suggest that skeletal patterning, bone mass accrual and remodeling in mice proceeded independent of BRIL.


Asunto(s)
Proteínas de la Membrana/metabolismo , Osteoblastos/metabolismo , Animales , Desarrollo Óseo/genética , Desarrollo Óseo/fisiología , Calcio/metabolismo , Femenino , Homeostasis/genética , Homeostasis/fisiología , Proteínas de la Membrana/genética , Ratones , Ratones Noqueados , Osteoblastos/citología , Osteogénesis/genética , Osteogénesis/fisiología , Osteogénesis Imperfecta/genética , Osteogénesis Imperfecta/metabolismo , Embarazo , Unión Proteica , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
13.
Sci Rep ; 7: 43817, 2017 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-28272478

RESUMEN

Erythro-myeloid progenitors (EMPs) were recently described to arise from the yolk sac endothelium, just prior to vascular remodeling, and are the source of adult/post-natal tissue resident macrophages. Questions remain, however, concerning whether EMPs differentiate directly from the endothelium or merely pass through. We provide the first evidence in vivo that EMPs can emerge directly from endothelial cells (ECs) and demonstrate a role for these cells in vascular development. We find that EMPs express most EC markers but late EMPs and EMP-derived cells do not take up acetylated low-density lipoprotein (AcLDL), as ECs do. When the endothelium is labelled with AcLDL before EMPs differentiate, EMPs and EMP-derived cells arise that are AcLDL+. If AcLDL is injected after the onset of EMP differentiation, however, the majority of EMP-derived cells are not double labelled. We find that cell division precedes entry of EMPs into circulation, and that blood flow facilitates the transition of EMPs from the endothelium into circulation in a nitric oxide-dependent manner. In gain-of-function studies, we inject the CSF1-Fc ligand in embryos and found that this increases the number of CSF1R+ cells, which localize to the venous plexus and significantly disrupt venous remodeling. This is the first study to definitively establish that EMPs arise from the endothelium in vivo and show a role for early myeloid cells in vascular development.


Asunto(s)
Células Endoteliales/citología , Células Precursoras Eritroides/citología , Células Madre Embrionarias de Ratones/citología , Células Progenitoras Mieloides/citología , Remodelación Vascular , Saco Vitelino/citología , Animales , Células Endoteliales/metabolismo , Células Precursoras Eritroides/metabolismo , Femenino , Hematopoyesis , Lipoproteínas LDL/metabolismo , Masculino , Ratones , Ratones Transgénicos , Microscopía Confocal , Células Madre Embrionarias de Ratones/metabolismo , Células Progenitoras Mieloides/metabolismo , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Saco Vitelino/irrigación sanguínea , Saco Vitelino/embriología
14.
PLoS One ; 8(2): e56790, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23457615

RESUMEN

Bone morphogenetic proteins (BMPs) are recognized for their ability to induce bone formation in vivo and in vitro. Their osteogenic and osteoinductive properties are tightly regulated by the secretion of specific BMP antagonists, which have been shown to physically bind and sometimes be blocked by the extracellular proteoglycan heparan sulphate side chains (from hereon referred to as HS). The purpose of this study was to investigate if local application of 5 µg of HS proteoglycan to a bone regenerate site in a mouse model of distraction osteogenesis (DO) can accelerate bone healing and affect the expression of key members of the BMP signaling pathway. DO was performed on the right tibia of 115 adult male wild-type mice. At mid-distraction (day 11), half the group was injected locally with 5 µg of HS, while the other half was injected with saline. The mice were sacrificed at 2 time-points: mid-consolidation (34 days) and full consolidation (51 days). The distracted tibial zone was then collected for analysis by µCT, radiology, biomechanical testing, immunohistochemistry, and histology. While µCT data showed no statistically significant difference in bone formation, the results of biomechanical testing in stiffness and ultimate force were significantly lower in the HS-injected bones at 51 days, compared to controls. Immunohistochemistry results also suggested a decrease in expression of several key members of the BMP signaling pathway at 34 days. Furthermore, wound dehiscence and infection rates were significantly elevated in the HS group compared to the controls, which resulted in a higher rate of euthanasia in the treatment group. Our findings demonstrate that exogenous application of 5 µg of HS in the distracted gap of a murine model had a negative impact on bone and wound healing.


Asunto(s)
Heparitina Sulfato/farmacología , Osteogénesis por Distracción , Osteogénesis/efectos de los fármacos , Animales , Fenómenos Biomecánicos , Proteínas Morfogenéticas Óseas/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Complicaciones Posoperatorias , Transducción de Señal/efectos de los fármacos , Tibia/citología , Tibia/efectos de los fármacos , Tibia/crecimiento & desarrollo , Tibia/cirugía , Microtomografía por Rayos X
15.
Int J Pediatr ; 2012: 898924, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22548088

RESUMEN

Children with musculoskeletal conditions experience muscle weakness, difficulty walking and limitations in physical activities. Standard treatment includes physiotherapy, casting, and surgery. The use of botulinum toxins appears as a promising treatment on its own, but usually as an adjunct to other treatment modalities and as an alternative to surgery. The objectives were to establish the evidence on the effectiveness, safety and functional outcome of BTX-A in children with musculoskeletal conditions. A literature search using five electronic databases identified 24 studies that met our inclusion criteria. Two randomized clinical trials were included; most studies were case studies with small sample sizes and no control group. Improvements in gait pattern, function, range of motion, reduction of co-contractions, and avoidance of surgical procedures were found following BTX-A injections. Adverse events were not reported in 10 studies, minor adverse events were reported in 13 children and there were no severe adverse events. Additional doses appear safe. BTX-A is a promising treatment adjunct in improving functional outcomes in children with musculoskeletal conditions. Future studies including larger samples, longer follow-up periods and a comparison group are required to provide evidence on the effectiveness and safety of this drug in children with musculoskeletal conditions.

16.
J Histochem Cytochem ; 60(3): 219-28, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22356868

RESUMEN

While the surgical procedure of distraction osteogenesis (DO) is very successful in the treatment of orthopedic conditions, its major limitation of slow bone formation in the distracted gap has prompted numerous attempts to understand and accelerate this slow bone formation. Interestingly, WNT/FZD signaling has been identified as a critical pathway in mediating bone formation and regeneration but has not yet been studied in the context of DO. The objective of this study was to determine the spatial and temporal localization of endogenous WNT signaling proteins at various times of bone formation in a wild-type mouse model of DO. In this study, the DO protocol performed on mice consisted of three phases: latency (5 days), distraction (12 days), and consolidation (34 days). Our immunohistochemical findings of distracted bone specimens show an increased expression of WNT ligands (WNT4 and WNT10A), receptors (FZD1 and 2, LRP5 and 6), ß-catenin, and pathway antagonizers (DKK1; CTBP1 and 2; sFRP1, 2, and 4) during the distraction phase, which were then down-regulated during consolidation. This is the first published report to show an activation of the WNT pathway in DO and could help identify WNT as a potential therapeutic target in accelerating bone regeneration during DO.


Asunto(s)
Regeneración Ósea/fisiología , Huesos/metabolismo , Marcadores Genéticos , Osteogénesis por Distracción , Osteogénesis/fisiología , Proteínas Wnt/metabolismo , Vía de Señalización Wnt/fisiología , Animales , Huesos/citología , Comunicación Celular , Diferenciación Celular , Condrocitos/citología , Condrocitos/metabolismo , Femenino , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Modelos Animales , Osteoblastos/citología , Osteoblastos/metabolismo , Proteínas Wnt/genética
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