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1.
Artigo em Inglês | MEDLINE | ID: mdl-38085178

RESUMO

OBJECTIVES: Evidence for the comparative cost-effectiveness of intra-articular corticosteroid injection in people with hip osteoarthritis (OA) remains unclear. This study investigated the cost-effectiveness of best current treatment (BCT) comprising advice and education plus a single ultrasound-guided intra-articular hip injection (USGI) of 40 mg triamcinolone acetonide and 4 ml 1% lidocaine hydrochloride (BCT+US-T) versus BCT alone. METHODS: A trial-based cost-utility analysis of BCT+US-T compared with BCT was undertaken over 6 months. Patient-level cost data were obtained, and effectiveness was measured in terms of quality-adjusted life years (QALYs), allowing the calculation of cost per QALY gained from a United Kingdom (UK) National Health Service (NHS) perspective. RESULTS: BCT+US-T was associated with lower mean NHS costs (BCT+US-T minus BCT: £-161.6, 95% CI: £-583.95 to £54.18) and small but significantly higher mean QALYs than BCT alone over 6 months (BCT+US-T minus BCT: 0.0487, 95% CI: 0.0091, 0.0886). In the base case, BCT+US-T was the most cost-effective and dominated BCT alone. Differences in total costs were driven by number of visits to NHS consultants, private physiotherapists, and chiropractors, and hip surgery, which were more common with BCT alone than BCT+US-T. CONCLUSION: Intra-articular corticosteroid injection plus BCT (BCT+US-T) for patients with hip OA results in lower costs and better outcomes, and is highly cost-effective, compared with BCT alone. TRIAL REGISTRATION: EudraCT: 2014-003412-37 (August 8, 2015) and registered with Current Controlled Trials: ISRCTN 50550256 (July 28, 2015). TRIAL PROTOCOL: Full details of the trial protocol can be found in the Supplementary Appendix, available with the full text of this article at https://bmcmusculoskeletdisord.biomedcentral.com/articles/10.1186/s12891-018-2153-0#citeas. DOI: doi.org/10.1186/s12891-018-2153-0.

2.
PLoS One ; 18(10): e0293576, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37903120

RESUMO

BACKGROUND: Oesophageal cancer has significant morbidity and mortality but late diagnosis is common since early signs of disease are frequently misinterpreted. Project DELTA aims to enable earlier detection and treatment through targeted screening using a novel risk prediction algorithm for oesophageal cancer (incorporating risk factors of Barrett's oesophagus including prescriptions for acid-reducing medications (CanPredict)), together with a non-invasive, low-cost sampling device (CytospongeTM). However, there are many barriers to implementation, and this paper identifies key ethical and legal challenges to implementing these personalised prevention strategies for Barrett's oesophagus/oesophageal cancer. METHODS: To identify ethical and legal issues relevant to the deployment of a risk prediction tool for oesophageal cancer into primary care, we adopted an interdisciplinary approach, incorporating targeted informal literature reviews, interviews with expert collaborators, a multidisciplinary workshop and ethical and legal analysis. RESULTS: Successful implementation raises many issues including ensuring transparency and effective risk communication; addressing bias and inequity; managing resources appropriately and avoiding exceptionalism. Clinicians will need support and training to use cancer risk prediction algorithms, ensuring that they understand how risk algorithms supplement rather than replace medical decision-making. Workshop participants had concerns about liability for harms arising from risk algorithms, including from potential bias and inequitable implementation. Determining strategies for risk communication enabling transparency but avoiding exceptionalist approaches are a significant challenge. Future challenges include using artificial intelligence to bolster risk assessment, incorporating genomics into risk tools, and deployment by non-health professional users. However, these strategies could improve detection and outcomes. CONCLUSIONS: Novel pathways incorporating risk prediction algorithms hold considerable promise, especially when combined with low-cost sampling. However immediate priorities should be to develop risk communication strategies that take account of using validated risk algorithms, and to ensure equitable implementation. Resolving questions about liability for harms arising should be a longer-term objective.


Assuntos
Esôfago de Barrett , Neoplasias Esofágicas , Humanos , Esôfago de Barrett/diagnóstico , Inteligência Artificial , Detecção Precoce de Câncer/efeitos adversos , Neoplasias Esofágicas/complicações , Fatores de Risco
3.
Front Digit Health ; 5: 1139210, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36999168

RESUMO

Introduction: Ethical and legal factors will have an important bearing on when and whether automation is appropriate in healthcare. There is a developing literature on the ethics of artificial intelligence (AI) in health, including specific legal or regulatory questions such as whether there is a right to an explanation of AI decision-making. However, there has been limited consideration of the specific ethical and legal factors that influence when, and in what form, human involvement may be required in the implementation of AI in a clinical pathway, and the views of the wide range of stakeholders involved. To address this question, we chose the exemplar of the pathway for the early detection of Barrett's Oesophagus (BE) and oesophageal adenocarcinoma, where Gehrung and colleagues have developed a "semi-automated", deep-learning system to analyse samples from the CytospongeTM TFF3 test (a minimally invasive alternative to endoscopy), where AI promises to mitigate increasing demands for pathologists' time and input. Methods: We gathered a multidisciplinary group of stakeholders, including developers, patients, healthcare professionals and regulators, to obtain their perspectives on the ethical and legal issues that may arise using this exemplar. Results: The findings are grouped under six general themes: risk and potential harms; impacts on human experts; equity and bias; transparency and oversight; patient information and choice; accountability, moral responsibility and liability for error. Within these themes, a range of subtle and context-specific elements emerged, highlighting the importance of pre-implementation, interdisciplinary discussions and appreciation of pathway specific considerations. Discussion: To evaluate these findings, we draw on the well-established principles of biomedical ethics identified by Beauchamp and Childress as a lens through which to view these results and their implications for personalised medicine. Our findings are not only relevant to this context but have implications for AI in digital pathology and healthcare more broadly.

4.
J Community Genet ; 9(3): 195-199, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29470710

RESUMO

Risk prediction models have a key role in stratified disease prevention, and the incorporation of genomic data into these models promises more effective personalisation. Although the clinical utility of incorporating genomic data into risk prediction tools is increasingly compelling, at least for some applications and disease types, the legal and regulatory implications have not been examined and have been overshadowed by discussions about clinical and scientific utility and feasibility. We held a workshop to explore relevant legal and regulatory perspectives from four EU Member States: France, Germany, the Netherlands and the UK. While we found no absolute prohibition on the use of such data in those tools, there are considerable challenges. Currently, these are modest and result from genomic data being classified as sensitive data under existing Data Protection regulation. However, these challenges will increase in the future following the implementation of EU Regulations on data protection which take effect in 2018, and reforms to the governance of the manufacture, development and use of in vitro diagnostic devices to be implemented in 2022. Collectively these will increase the regulatory burden placed on these products as risk stratification tools will be brought within the scope of these new Regulations. The failure to respond to the challenges posed by the use of genomic data in disease risk stratification tools could therefore prove costly to those developing and using such tools.

5.
BMC Med Genomics ; 9(1): 57, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27586379

RESUMO

BACKGROUND: Genomic testing has reached the point where, technically at least, it can be cheaper to undertake panel-, exome- or whole genome testing than it is to sequence a single gene. An attribute of these approaches is that information gleaned will often have uncertain significance. In addition to the challenges this presents for pre-test counseling and informed consent, a further consideration emerges over how - ethically - we should conceive of and respond to this uncertainty. To date, the ethical aspects of uncertainty in genomics have remained under-explored. DISCUSSION: In this paper, we draft a conceptual and ethical response to the question of how to conceive of and respond to uncertainty in genomic medicine. After introducing the problem, we articulate a concept of 'genomic uncertainty'. Drawing on this, together with exemplar clinical cases and related empirical literature, we then critique the presumption that uncertainty is always problematic and something to be avoided, or eradicated. We conclude by outlining an 'ethics of genomic uncertainty'; describing how we might handle uncertainty in genomic medicine. This involves fostering resilience, welfare, autonomy and solidarity. CONCLUSIONS: Uncertainty will be an inherent aspect of clinical practice in genomics for some time to come. Genomic testing should not be offered with the explicit aim to reduce uncertainty. Rather, uncertainty should be appraised, adapted to and communicated about as part of the process of offering and providing genomic information.


Assuntos
Ética Médica , Genômica , Incerteza , Feminino , Testes Genéticos/ética , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/genética
6.
J Pers Med ; 5(2): 191-212, 2015 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-26068647

RESUMO

There is growing evidence that inclusion of genetic information about known common susceptibility variants may enable population risk-stratification and personalized prevention for common diseases including cancer. This would require the inclusion of genetic testing as an integral part of individual risk assessment of an asymptomatic individual. Front line health professionals would be expected to interact with and assist asymptomatic individuals through the risk stratification process. In that case, additional knowledge and skills may be needed. Current guidelines and frameworks for genetic competencies of non-specialist health professionals place an emphasis on rare inherited genetic diseases. For common diseases, health professionals do use risk assessment tools but such tools currently do not assess genetic susceptibility of individuals. In this article, we compare the skills and knowledge needed by non-genetic health professionals, if risk-stratified prevention is implemented, with existing competence recommendations from the UK, USA and Europe, in order to assess the gaps in current competences. We found that health professionals would benefit from understanding the contribution of common genetic variations in disease risk, the rationale for a risk-stratified prevention pathway, and the implications of using genomic information in risk-assessment and risk management of asymptomatic individuals for common disease prevention.

7.
BMC Res Notes ; 7: 370, 2014 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-24938650

RESUMO

BACKGROUND: Our aim, having previously investigated through a qualitative study involving extensive discussions with experts and patients the issues involved in establishing and maintaining a disease specific brain and tissue bank for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), was to develop a protocol for a UK ME/CFS repository of high quality human tissue from well characterised subjects with ME/CFS and controls suitable for a broad range of research applications. This would involve a specific donor program coupled with rapid tissue collection and processing, supplemented by comprehensive prospectively collected clinical, laboratory and self-assessment data from cases and controls. FINDINGS: We reviewed the operations of existing tissue banks from published literature and from their internal protocols and standard operating procedures (SOPs). On this basis, we developed the protocol presented here, which was designed to meet high technical and ethical standards and legal requirements and was based on recommendations of the MRC UK Brain Banks Network. The facility would be most efficient and cost-effective if incorporated into an existing tissue bank. Tissue collection would be rapid and follow robust protocols to ensure preservation sufficient for a wide range of research uses. A central tissue bank would have resources both for wide-scale donor recruitment and rapid response to donor death for prompt harvesting and processing of tissue. CONCLUSION: An ME/CFS brain and tissue bank could be established using this protocol. Success would depend on careful consideration of logistic, technical, legal and ethical issues, continuous consultation with patients and the donor population, and a sustainable model of funding ideally involving research councils, health services, and patient charities. This initiative could revolutionise the understanding of this still poorly-understood disease and enhance development of diagnostic biomarkers and treatments.


Assuntos
Encéfalo/patologia , Cadáver , Síndrome de Fadiga Crônica/patologia , Bancos de Tecidos , Humanos
8.
J Med Ethics ; 40(3): 163-7, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23454719

RESUMO

Increased knowledge of the gene-disease associations contributing to common cancer development raises the prospect of population stratification by genotype and other risk factors. Individual risk assessments could be used to target interventions such as screening, treatment and health education. Genotyping neonates, infants or young children as part of a systematic programme would improve coverage and uptake, and facilitate a screening package that maximises potential benefits and minimises harms including overdiagnosis. This paper explores the potential justifications and risks of genotyping children for genetic variants associated with common cancer development within a personalised screening programme. It identifies the ethical and legal principles that might guide population genotyping where the predictive value of the testing is modest and associated risks might arise in the future, and considers the standards required by population screening programme validity measures (such as the Wilson and Jungner criteria including cost-effectiveness and equitable access). These are distinguished from the normative principles underpinning predictive genetic testing of children for adult-onset diseases-namely, to make best-interests judgements and to preserve autonomy. While the case for population-based genotyping of neonates or young children has not yet been made, the justifications for this approach are likely to become increasingly compelling. A modified evaluative and normative framework should be developed, capturing elements from individualistic and population-based approaches. This should emphasise proper communication and genuine parental consent or informed choice, while recognising the challenges associated with making unsolicited approaches to an asymptomatic group. Such a framework would be strengthened by complementary empirical research.


Assuntos
Testes Genéticos/ética , Testes Genéticos/legislação & jurisprudência , Genótipo , Programas de Rastreamento/ética , Princípios Morais , Neoplasias/genética , Adulto , Pré-Escolar , Europa (Continente) , Feminino , Predisposição Genética para Doença , Humanos , Lactente , Masculino , Consentimento dos Pais , Medicina de Precisão/ética , Valor Preditivo dos Testes , Medição de Risco , Fatores de Risco
9.
Eur J Hum Genet ; 22(5): 575-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24129434

RESUMO

With the development and increasing accessibility of new genomic tools such as next-generation sequencing, genome-wide association studies, and genomic stratification models, the debate on genetic discrimination in the context of life insurance became even more complex, requiring a review of current practices and the exploration of new scenarios. In this perspective, a multidisciplinary group of international experts representing different interests revisited the genetics and life insurance debate during a 2-day symposium 'Life insurance: breast cancer research and genetic risk prediction seminar' held in Quebec City, Canada on 24 and 25 September 2012. Having reviewed the current legal, social, and ethical issues on the use of genomic information in the context of life insurance, the Expert Group identified four main questions: (1) Have recent developments in genomics and related sciences changed the contours of the genetics and life insurance debate? (2) Are genomic results obtained in a research context relevant for life insurance underwriting? (3) Should predictive risk assessment and risk stratification models based on genomic data also be used for life insurance underwriting? (4) What positive actions could stakeholders in the debate take to alleviate concerns over the use of genomic information by life insurance underwriters? This paper presents a summary of the discussions and the specific action items recommended by the Expert Group.


Assuntos
Testes Genéticos , Seguro de Vida , Medição de Risco , Canadá , Testes Genéticos/ética , Testes Genéticos/legislação & jurisprudência , Estudo de Associação Genômica Ampla , Genômica , Humanos , Seguro de Vida/ética , Seguro de Vida/legislação & jurisprudência , Medição de Risco/legislação & jurisprudência
10.
Nat Genet ; 45(4): 349-51, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23535723

RESUMO

The PHG Foundation led a multidisciplinary program, which used results from COGS research identifying genetic variants associated with breast, ovarian and prostate cancers to model risk-stratified prevention for breast and prostate cancers. Implementing such strategies would require attention to the use and storage of genetic information, the development of risk assessment tools, new protocols for consent and programs of professional education and public engagement.


Assuntos
Neoplasias da Mama/diagnóstico , Detecção Precoce de Câncer , Neoplasias Ovarianas/diagnóstico , Neoplasias da Próstata/diagnóstico , Saúde Pública , Neoplasias da Mama/genética , Comportamento Cooperativo , Feminino , Humanos , Masculino , Neoplasias Ovarianas/genética , Neoplasias da Próstata/genética , Medição de Risco
11.
Genet Med ; 15(6): 423-32, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23412607

RESUMO

Individual risk prediction and stratification based on polygenic profiling may be useful in disease prevention. Risk-stratified population screening based on multiple factors including a polygenic risk profile has the potential to be more efficient than age-stratified screening. In this article, we summarize the implications of personalized screening for breast and prostate cancers. We report the opinions of multidisciplinary international experts who have explored the scientific, ethical, and logistical aspects of stratified screening. We have identified (i) the need to recognize the benefits and harms of personalized screening as compared with existing screening methods, (ii) that the use of genetic data highlights complex ethical issues including discrimination against high-risk individuals by insurers and employers and patient autonomy in relation to genetic testing of minors, (iii) the need for transparency and clear communication about risk scores, about harms and benefits, and about reasons for inclusion and exclusion from the risk-based screening process, and (iv) the need to develop new professional competences and to assess cost-effectiveness and acceptability of stratified screening programs before implementation. We conclude that health professionals and stakeholders need to consider the implications of incorporating genetic information in intervention strategies for health-care planning in the future.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Detecção Precoce de Câncer , Testes Genéticos , Genômica , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/genética , Detecção Precoce de Câncer/ética , Detecção Precoce de Câncer/métodos , Feminino , Privacidade Genética , Testes Genéticos/ética , Testes Genéticos/legislação & jurisprudência , Testes Genéticos/métodos , Genômica/ética , Genômica/legislação & jurisprudência , Genômica/métodos , Humanos , Masculino , Opinião Pública , Medição de Risco
12.
J Neurosci ; 27(50): 13770-80, 2007 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-18077689

RESUMO

Pain hypersensitivity is a cardinal sign of tissue damage, but how molecules from peripheral tissues affect sensory neuron physiology is incompletely understood. Previous studies have shown that activin A increases after peripheral injury and is sufficient to induce acute nociceptive behavior and increase pain peptides in sensory ganglia. This study was designed to test the possibility that the enhanced nociceptive responsiveness associated with activin involved sensitization of transient receptor potential vanilloid I (TRPV1) in primary sensory neurons. Activin receptors were found widely distributed among adult sensory neurons, including those that also express the capsaicin receptor. Whole-cell patch-clamp recording from sensory neurons showed that activin acutely sensitized capsaicin responses and depended on activin receptor kinase activity. Pharmacological studies revealed that the activin sensitization of capsaicin responses required PKCepsilon signaling, but not PI3K (phosphoinositide 3-kinase), ERK (extracellular signal-regulated protein kinase), PKA, PKCalpha/beta, or Src. Furthermore, activin administration caused acute thermal hyperalgesia in wild-type mice, but not in TRPV1-null mice. These data suggest that activin signals through its own receptor, involves PKCepsilon signaling to sensitize the TRPV1 channel, and contributes to acute thermal hyperalgesia.


Assuntos
Ativinas/farmacologia , Gânglios Espinais/metabolismo , Hiperalgesia/metabolismo , Neurônios/metabolismo , Canais de Cátion TRPV/metabolismo , Receptores de Ativinas/genética , Receptores de Ativinas/metabolismo , Animais , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Gânglios Espinais/citologia , Gânglios Espinais/efeitos dos fármacos , Hiperalgesia/induzido quimicamente , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/citologia , Neurônios/efeitos dos fármacos , Medição da Dor/efeitos dos fármacos , Técnicas de Patch-Clamp , Proteína Quinase C-épsilon/antagonistas & inibidores , Proteína Quinase C-épsilon/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Canais de Cátion TRPV/genética
13.
Ann Neurol ; 62(3): 288-300, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17696121

RESUMO

OBJECTIVE: To determine the role of bone morphogenetic proteins (BMPs) in stimulating glial scar formation in demyelinating lesions of the adult spinal cord. METHODS: The dorsal columns of adult rats were injected with lysolecithin to induce a local demyelinating lesion. Levels of BMP4 and BMP7 proteins were assayed and compared with glial fibrillary acidic protein expression in the injury area. BMP-responsive cells were identified by expression of phosphorylated Smad1/5/8. Cultures of mature spinal cord astrocytes were treated with BMP4, and levels of chondroitin sulphate proteoglycans (CSPGs) were measured. The effect of BMP4 on CSPG gene regulation was determined by real-time polymerase chain reaction for CSPG core proteins. RESULTS: BMP4 and BMP7 increase rapidly at the site of demyelination, and astrocytes surrounding the lesion increase expression of phosphorylated Smad1/5/8. Cultured mature astrocytes respond directly to BMPs with Smad1 translocation to the nucleus, increased phosphorylated Smad1/5/8, and increases in glial fibrillary acidic protein and CSPG expression. BMP treatment also increased CSPG messenger RNA for CSPG core proteins, including aggrecan and neurocan. Increases in CSPG expression in astrocytes by BMPs were blocked by the inhibitor noggin. Injections of BMP4 or BMP7 into the dorsal columns in the absence of demyelination led to increases in CSPG expression. INTERPRETATION: Local increases in BMPs at the site of a demyelinating lesion causes upregulation of gliosis, glial scar formation, and heightened expression of CSPGs such as neurocan and aggrecan that may inhibit remyelination.


Assuntos
Proteínas Morfogenéticas Ósseas/fisiologia , Doenças Desmielinizantes/patologia , Gliose/patologia , Doenças da Medula Espinal/patologia , Animais , Apoptose/fisiologia , Western Blotting , Proteína Morfogenética Óssea 4 , Proteína Morfogenética Óssea 7 , Proteínas Morfogenéticas Ósseas/metabolismo , Proliferação de Células , Células Cultivadas , Sulfatos de Condroitina/metabolismo , DNA/biossíntese , DNA/genética , Doenças Desmielinizantes/induzido quimicamente , Feminino , Proteína Glial Fibrilar Ácida/biossíntese , Imuno-Histoquímica , Lisofosfatidilcolinas , Neuroglia/patologia , Fosforilação , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Smad/biossíntese , Doenças da Medula Espinal/induzido quimicamente , Regulação para Cima/genética , Regulação para Cima/fisiologia
14.
J Neurosci ; 25(40): 9227-35, 2005 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-16207882

RESUMO

Calcitonin gene-related peptide (CGRP) is a sensory neuropeptide important in inflammatory pain that conveys pain information centrally and dilates blood vessels peripherally. Previous studies indicate that activin A increases CGRP-immunoreactive (IR) sensory neurons in vitro, and following wound, activin A protein increases in the skin and more neurons have detectable CGRP expression in the innervating dorsal root ganglion (DRG). These data suggest some adult sensory neurons respond to activin A or other target-derived factors with increased neuropeptide expression. This study was undertaken to test whether activin contributes to inflammatory pain and increased CGRP and to learn which neurons retained plasticity. After adjuvant-induced inflammation, activin mRNA, but not NGF or glial cell line-derived neurotrophic factor, increased in the skin. To examine which DRG neurons increased CGRP immunoreactivity, retrograde tracer-labeled cutaneous neurons were characterized after inflammation. The proportion and size of tracer-labeled DRG neurons with detectable CGRP increased after inflammation. One-third of CGRP-IR neurons that appear after inflammation also had isolectin B4 binding, suggesting that some mechanoreceptors became CGRP-IR. In contrast, the increased proportion of CGRP-IR neurons did not appear to come from RT97-IR neurons. To learn whether central projections were altered after inflammation, CGRP immunoreactivity in the protein kinase Cgamma-IR lamina IIi was quantified and found to increase. Injection of activin A protein alone caused robust tactile allodynia and increased CGRP in the DRG. Together, these data support the hypothesis that inflammation and skin changes involving activin A cause some sensory neurons to increase CGRP expression and pain responses.


Assuntos
Ativinas , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Inflamação/metabolismo , Subunidades beta de Inibinas , Doenças do Sistema Nervoso Periférico/metabolismo , Tato , Animais , Tornozelo/inervação , Tornozelo/fisiopatologia , Peptídeo Relacionado com Gene de Calcitonina/genética , Feminino , Adjuvante de Freund , Gânglios Espinais/citologia , Regulação da Expressão Gênica/fisiologia , Hiperestesia/induzido quimicamente , Hiperestesia/fisiopatologia , Imuno-Histoquímica/métodos , Inflamação/induzido quimicamente , Fator de Crescimento Neural/farmacologia , Neurônios Aferentes/efeitos dos fármacos , Neurônios Aferentes/metabolismo , Doenças do Sistema Nervoso Periférico/induzido quimicamente , RNA Mensageiro , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Pele/efeitos dos fármacos , Pele/inervação , Pele/metabolismo , Fatores de Tempo
15.
J Neurosci Res ; 76(1): 9-19, 2004 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-15048926

RESUMO

Oligodendrocyte precursors (OPCs) initially arise in the motor neuron domain of the ventral ventricular zone of the developing spinal cord. After dispersal throughout gray and white matter, OPCs differentiate in a characteristic ventral to dorsal sequence. The spatial localization of OPC induction is in part a result of both positive local sonic hedgehog signaling and dorsally derived inhibitory cues. One component of dorsal inhibitory signals seems to be members of the transforming growth factor beta (TGFbeta) superfamily such as the bone morphogenetic proteins (BMPs). We show that during the initial appearance and subsequent maturation of OPCs, BMP4 was expressed specifically in the dorsal midline and its expression was correlated spatially and temporally with phospho-Smad 1+, BMP4-responsive cells. Implantation of sonic hedgehog (Shh)-coated beads adjacent to dorsal spinal cord in Xenopus embryos induced ectopic dorsal OPCs whereas BMP4-coated beads inhibited OPC appearance. More importantly, blocking endogenous dorsal BMP4 with anti-BMP4-coated beads locally induced ectopic OPCs. Similar results were obtained using soluble ligands on slice preparations of rodent spinal cord in vitro. In dissociated cell cultures of embryonic rat spinal cord, Shh and BMP4 had antagonistic effects on OPC development and the sensitivity of oligodendrocyte lineage cells to BMP4 increased with maturation. These data suggest that BMP4 contributes to the pattern of spinal cord oligodendrogenesis by regulating both induction and maturation of spinal cord OPCs.


Assuntos
Proteínas Morfogenéticas Ósseas/fisiologia , Oligodendroglia/fisiologia , Medula Espinal/citologia , Animais , Western Blotting , Proteína Morfogenética Óssea 4 , Proteínas Morfogenéticas Ósseas/biossíntese , Proteínas Morfogenéticas Ósseas/genética , Diferenciação Celular/fisiologia , Células Cultivadas , Eletroforese em Gel de Poliacrilamida , Regulação da Expressão Gênica/fisiologia , Proteínas Hedgehog , Imuno-Histoquímica , Técnicas de Cultura de Órgãos , Ratos , Células-Tronco/fisiologia , Transativadores/genética , Transativadores/fisiologia , Xenopus , Proteínas de Xenopus
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