Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Neurosci ; 37(40): 9632-9644, 2017 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-28871032

RESUMO

Neurons in the adult mammalian CNS decrease in intrinsic axon growth capacity during development in concert with changes in Krüppel-like transcription factors (KLFs). KLFs regulate axon growth in CNS neurons including retinal ganglion cells (RGCs). Here, we found that knock-down of KLF9, an axon growth suppressor that is normally upregulated 250-fold in RGC development, promotes long-distance optic nerve regeneration in adult rats of both sexes. We identified a novel binding partner, MAPK10/JNK3 kinase, and found that JNK3 (c-Jun N-terminal kinase 3) is critical for KLF9's axon-growth-suppressive activity. Interfering with a JNK3-binding domain or mutating two newly discovered serine phosphorylation acceptor sites, Ser106 and Ser110, effectively abolished KLF9's neurite growth suppression in vitro and promoted axon regeneration in vivo These findings demonstrate a novel, physiologic role for the interaction of KLF9 and JNK3 in regenerative failure in the optic nerve and suggest new therapeutic strategies to promote axon regeneration in the adult CNS.SIGNIFICANCE STATEMENT Injured CNS nerves fail to regenerate spontaneously. Promoting intrinsic axon growth capacity has been a major challenge in the field. Here, we demonstrate that knocking down Krüppel-like transcription factor 9 (KLF9) via shRNA promotes long-distance axon regeneration after optic nerve injury and uncover a novel and important KLF9-JNK3 interaction that contributes to axon growth suppression in vitro and regenerative failure in vivo These studies suggest potential therapeutic approaches to promote axon regeneration in injury and other degenerative diseases in the adult CNS.


Assuntos
Axônios/fisiologia , Encéfalo/fisiologia , Fatores de Transcrição Kruppel-Like/metabolismo , Proteína Quinase 10 Ativada por Mitógeno/metabolismo , Regeneração Nervosa/fisiologia , Fatores Etários , Animais , Sequência de Bases , Células Cultivadas , Sistema Nervoso Central/fisiologia , Feminino , Fatores de Transcrição Kruppel-Like/deficiência , Fatores de Transcrição Kruppel-Like/genética , Masculino , Camundongos , Proteína Quinase 10 Ativada por Mitógeno/genética , Traumatismos do Nervo Óptico/genética , Traumatismos do Nervo Óptico/metabolismo , Técnicas de Cultura de Órgãos , Ligação Proteica/fisiologia , Ratos , Células Ganglionares da Retina/fisiologia
2.
Exp Eye Res ; 171: 54-61, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29526794

RESUMO

Optic neuropathies such as glaucoma are characterized by the degeneration of retinal ganglion cells (RGCs) and the irreversible loss of vision. In these diseases, focal axon injury triggers a propagating axon degeneration and, eventually, cell death. Previous work by us and others identified dual leucine zipper kinase (DLK) and JUN N-terminal kinase (JNK) as key mediators of somal cell death signaling in RGCs following axonal injury. Moreover, others have shown that activation of the DLK/JNK pathway contributes to distal axonal degeneration in some neuronal subtypes and that this activation is dependent on the adaptor protein, sterile alpha and TIR motif containing 1 (SARM1). Given that SARM1 acts upstream of DLK/JNK signaling in axon degeneration, we tested whether SARM1 plays a similar role in RGC somal apoptosis in response to optic nerve injury. Using the mouse optic nerve crush (ONC) model, our results show that SARM1 is critical for RGC axonal degeneration and that axons rescued by SARM1 deficiency are electrophysiologically active. Genetic deletion of SARM1 did not, however, prevent DLK/JNK pathway activation in RGC somas nor did it prevent or delay RGC cell death. These results highlight the importance of SARM1 in RGC axon degeneration and suggest that somal activation of the DLK/JNK pathway is activated by an as-yet-unidentified SARM1-independent signal.


Assuntos
Proteínas do Domínio Armadillo/fisiologia , Axônios/metabolismo , Proteínas do Citoesqueleto/fisiologia , Modelos Animais de Doenças , Traumatismos do Nervo Óptico/metabolismo , Receptores do Fator de Necrose Tumoral/fisiologia , Degeneração Retiniana/metabolismo , Células Ganglionares da Retina/metabolismo , Animais , Apoptose/fisiologia , Axônios/patologia , Contagem de Células , Sobrevivência Celular , Eletrofisiologia , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Compressão Nervosa , Traumatismos do Nervo Óptico/patologia , Degeneração Retiniana/patologia , Células Ganglionares da Retina/patologia
3.
J Surg Oncol ; 115(2): 122-130, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28054348

RESUMO

BACKGROUND: The impact of surgical treatment on outcomes in breast cacner in very young women remains unclear. We sought to determine the effect of surgery type on risk of recurrence and survival in a population-based cohort. METHODS: All women diagnosed with breast cancer aged ≤35 (1994-2003) were identified from the Ontario Cancer Registry. Patient, tumor, and treatment variables, including primary surgery, recurrences, and death were abstracted from chart review. Cox regression models were fit to determine the effect of surgery type on recurrence and overall survival. RESULTS: We identified 1,381 patients with 11-year median follow-up of which 793 (57%) had BCS. Of the remaining mastectomy patients, 52% had postmastectomy radiation. Overall, 41% of patients sustained a recurrence of any type and 31% died. Controlling for known confounders, there was no association between type of surgery and death from any cause (HR = 0.98, 95% CI = 0.78, 1.25) or first recurrence (HR = 0.93, 95% CI = 0.75, 1.14). Distant recurrence was most common (13% in BCS; 25.3% in mastectomy) with local recurrence 12.4% after BCS and 7.5% after mastectomy. CONCLUSIONS: In this cohort of very young women who were selected for treatment with BCS and mastectomy, we found similar oncologic outcomes. J. Surg. Oncol. 2017;115:122-130. © 2017 Wiley Periodicals, Inc.


Assuntos
Neoplasias da Mama/mortalidade , Carcinoma Ductal de Mama/mortalidade , Carcinoma Lobular/mortalidade , Mastectomia Segmentar/mortalidade , Mastectomia/mortalidade , Recidiva Local de Neoplasia/mortalidade , Adolescente , Adulto , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/cirurgia , Carcinoma Lobular/patologia , Carcinoma Lobular/cirurgia , Feminino , Seguimentos , Humanos , Gradação de Tumores , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
4.
Exp Eye Res ; 146: 370-385, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26474494

RESUMO

The inner surface of the retina contains a complex mixture of neurons, glia, and vasculature, including retinal ganglion cells (RGCs), the final output neurons of the retina and primary neurons that are damaged in several blinding diseases. The goal of the current work was two-fold: to assess the feasibility of using computer-assisted detection of nuclei and random forest classification to automate the quantification of RGCs in hematoxylin/eosin (H&E)-stained retinal whole-mounts; and if possible, to use the approach to examine how nuclear size influences disease susceptibility among RGC populations. To achieve this, data from RetFM-J, a semi-automated ImageJ-based module that detects, counts, and collects quantitative data on nuclei of H&E-stained whole-mounted retinas, were used in conjunction with a manually curated set of images to train a random forest classifier. To test performance, computer-derived outputs were compared to previously published features of several well-characterized mouse models of ophthalmic disease and their controls: normal C57BL/6J mice; Jun-sufficient and Jun-deficient mice subjected to controlled optic nerve crush (CONC); and DBA/2J mice with naturally occurring glaucoma. The result of these efforts was development of RetFM-Class, a command-line-based tool that uses data output from RetFM-J to perform random forest classification of cell type. Comparative testing revealed that manual and automated classifications by RetFM-Class correlated well, with 83.2% classification accuracy for RGCs. Automated characterization of C57BL/6J retinas predicted 54,642 RGCs per normal retina, and identified a 48.3% Jun-dependent loss of cells at 35 days post CONC and a 71.2% loss of RGCs among 16-month-old DBA/2J mice with glaucoma. Output from automated analyses was used to compare nuclear area among large numbers of RGCs from DBA/2J mice (n = 127,361). In aged DBA/2J mice with glaucoma, RetFM-Class detected a decrease in median and mean nucleus size of cells classified into the RGC category, as did an independent confirmation study using manual measurements of nuclear area demarcated by BRN3A-immunoreactivity. In conclusion, we have demonstrated that histology-based random forest classification is feasible and can be utilized to study RGCs in a high-throughput fashion. Despite having some limitations, this approach demonstrated a significant association between the size of the RGC nucleus and the DBA/2J form of glaucoma.


Assuntos
Contagem de Células/métodos , Técnicas de Diagnóstico Oftalmológico , Glaucoma/classificação , Células Ganglionares da Retina/citologia , Células Amácrinas , Animais , Núcleo Celular/patologia , Diagnóstico por Computador/métodos , Modelos Animais de Doenças , Estudos de Viabilidade , Glaucoma/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA
5.
CMAJ ; 188(4): E67-E72, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26622006

RESUMO

BACKGROUND: Comprehensive systems for surveilling prescription opioid-related harms provide clear evidence that deaths from prescription opioids have increased dramatically in the United States. However, these harms are not systematically monitored in Canada. In light of a growing public health crisis, accessible, nationwide data sources to examine prescription opioid-related harms in Canada are needed. We sought to examine the performance of 5 algorithms to identify prescription opioid-related deaths from vital statistics data against data abstracted from the Office of the Chief Coroner of Ontario as a gold standard. METHODS: We identified all prescription opioid-related deaths from Ontario coroners' data that occurred between Jan. 31, 2003, and Dec. 31, 2010. We then used 5 different algorithms to identify prescription opioid-related deaths from vital statistics death data in 2010. We selected the algorithm with the highest sensitivity and a positive predictive value of more than 80% as the optimal algorithm for identifying prescription opioid-related deaths. RESULTS: Four of the 5 algorithms had positive predictive values of more than 80%. The algorithm with the highest sensitivity (75%) in 2010 improved slightly in its predictive performance from 2003 to 2010. INTERPRETATION: In the absence of specific systems for monitoring prescription opioid-related deaths in Canada, readily available national vital statistics data can be used to study prescription opioid-related mortality with considerable accuracy. Despite some limitations, these data may facilitate the implementation of national surveillance and monitoring strategies.


Assuntos
Analgésicos Opioides/efeitos adversos , Overdose de Drogas/mortalidade , Prescrições de Medicamentos/estatística & dados numéricos , Algoritmos , Analgésicos Opioides/uso terapêutico , Canadá/epidemiologia , Humanos , Ontário/epidemiologia , Sensibilidade e Especificidade , Estatísticas Vitais
6.
Exp Eye Res ; 141: 42-56, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26116903

RESUMO

While all forms of glaucoma are characterized by a specific pattern of retinal ganglion cell death, they are clinically divided into several distinct subclasses, including normal tension glaucoma, primary open angle glaucoma, congenital glaucoma, and secondary glaucoma. For each type of glaucoma there are likely numerous molecular pathways that control susceptibility to the disease. Given this complexity, a single animal model will never precisely model all aspects of all the different types of human glaucoma. Therefore, multiple animal models have been utilized to study glaucoma but more are needed. Because of the powerful genetic tools available to use in the laboratory mouse, it has proven to be a highly useful mammalian system for studying the pathophysiology of human disease. The similarity between human and mouse eyes coupled with the ability to use a combination of advanced cell biological and genetic tools in mice have led to a large increase in the number of studies using mice to model specific glaucoma phenotypes. Over the last decade, numerous new mouse models and genetic tools have emerged, providing important insight into the cell biology and genetics of glaucoma. In this review, we describe available mouse genetic models that can be used to study glaucoma-relevant disease/pathobiology. Furthermore, we discuss how these models have been used to gain insights into ocular hypertension (a major risk factor for glaucoma) and glaucomatous retinal ganglion cell death. Finally, the potential for developing new mouse models and using advanced genetic tools and resources for studying glaucoma are discussed.


Assuntos
Glaucoma/genética , Pressão Intraocular , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Células Ganglionares da Retina/metabolismo , Células Ganglionares da Retina/patologia
7.
Br J Clin Pharmacol ; 80(4): 662-9, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25980448

RESUMO

AIMS: Clopidogrel and angiotensin converting enzyme (ACE) inhibitors are commonly co-prescribed drugs. Clopidogrel inhibits carboxylesterase 1 (CES1), the enzyme responsible for converting prodrug ACE inhibitors (such as ramipril and perindopril) to their active metabolites. The clinical implications of this potential drug interaction are unknown. The clinical consequences of the potential drug interaction between clopidogrel and prodrug ACE inhibitors were examined. METHODS: We conducted a nested case-control study of Ontarians aged 66 years and older treated with clopidogrel between September 1 2003 and March 31 2013 following acute myocardial infarction. Cases were subjects who died or were hospitalized for reinfarction or heart failure in the subsequent year, and each was matched with up to four controls. The primary outcome was a composite of reinfarction, heart failure or death. The primary analysis examined whether use of the prodrug ACE inhibitors ramipril or perindopril was more common among cases than use of lisinopril, an active ACE inhibitor. RESULTS: Among 45 918 patients treated with clopidogrel following myocardial infarction, we identified 4203 cases and 14 964 controls. After adjustment, we found no association between the composite outcome and use of perindopril (adjusted odds ratio (aOR) 0.94, 95% confidence interval (CI) 0.76, 1.16) or ramipril (aOR 0.97, 95% CI 0.80, 1.18), relative to lisinopril. Secondary analyses of each element of the composite outcome yielded similar findings. CONCLUSIONS: Following myocardial infarction, use of clopidogrel with ACE inhibitors activated by CES1 is not associated with an increased risk of adverse cardiovascular outcomes relative to lisinopril. These findings suggest that the recently described drug interaction between clopidogrel and prodrug ACE inhibitors is of little clinical relevance.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Lisinopril/farmacologia , Perindopril/farmacologia , Ramipril/farmacologia , Ticlopidina/análogos & derivados , Idoso , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Estudos de Casos e Controles , Clopidogrel , Bases de Dados Factuais , Interações Medicamentosas , Quimioterapia Combinada , Feminino , Insuficiência Cardíaca , Humanos , Lisinopril/uso terapêutico , Masculino , Infarto do Miocárdio/tratamento farmacológico , Perindopril/uso terapêutico , Inibidores da Agregação Plaquetária/farmacologia , Ramipril/uso terapêutico , Recidiva , Ticlopidina/farmacologia , Ticlopidina/uso terapêutico , Resultado do Tratamento
8.
Pharmacoepidemiol Drug Saf ; 24(12): 1281-5, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26448559

RESUMO

PURPOSE: Ticagrelor increases serum adenosine concentrations, slowing conduction and possibly leading to bradycardia. Clinical trial data have shown numerically, though not statistically significantly, higher rates of bradyarrhythmias with ticagrelor versus clopidogrel. Additionally, recent case reports have further raised concerns for this adverse effect. We explored the association between ticagrelor and hospitalization for bradycardia in a real-world setting. METHODS: We conducted a population-based, nested case-control study of Ontario residents, 66 years of age or older, discharged after a first acute coronary syndrome by linking multiple healthcare databases. Cases included patients hospitalized for bradycardia within 1 year of starting a P2Y12 inhibitor. For each case, we identified 4 controls matched on age, sex, index date, and current use of a P2Y12 inhibitor. The exposure of interest was a prescription for ticagrelor within 90 days, with clopidogrel use as the reference group. RESULTS: From April 2012 to March 2014, we identified 140 cases and 560 controls who met the study criteria. We found no significant association between bradycardia and exposure to ticagrelor relative to clopidogrel in the previous 90 days prior to the index date (adjusted odds ratio 1.06, 95% confidence interval 0.65-2.21). Further adjustment for potential confounders also did not identify a significant association. CONCLUSIONS: Among older patients with a first acute coronary syndrome, use of ticagrelor was not associated with a greater risk of admission for bradycardia relative to clopidogrel.


Assuntos
Adenosina/análogos & derivados , Bradicardia/epidemiologia , Antagonistas do Receptor Purinérgico P2Y/efeitos adversos , Adenosina/efeitos adversos , Sistemas de Notificação de Reações Adversas a Medicamentos , Idoso , Idoso de 80 Anos ou mais , Bradicardia/induzido quimicamente , Estudos de Casos e Controles , Feminino , Serviços de Saúde para Idosos , Hospitalização , Humanos , Masculino , Ontário/epidemiologia , Ticagrelor
9.
Neurobiol Dis ; 69: 108-16, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24878510

RESUMO

Injury to retinal ganglion cell (RGC) axons triggers rapid activation of Jun N-terminal kinase (JNK) signaling, a major prodeath pathway in injured RGCs. Of the multiple kinases that can activate JNK, dual leucine kinase (Dlk) is known to regulate both apoptosis and Wallerian degeneration triggered by axonal insult. Here we tested the importance of Dlk in regulating somal and axonal degeneration of RGCs following axonal injury. Removal of DLK from the developing optic cup did not grossly affect developmental RGC death or inner plexiform layer organization. In the adult, Dlk deficiency significantly delayed axonal-injury induced RGC death. The activation of JUN was also attenuated in Dlk deficient retinas. Dlk deficiency attenuated the activation of the somal pool of JNK but did not prevent activation of the axonal pool of JNK after axonal injury, indicating that JNK activation in different cellular compartments of an RGC following axonal injury is regulated by distinct upstream kinases. In contrast to its robust influence on somal degeneration, Dlk deficiency did not alter RGC axonal degeneration after axonal injury as assessed using physiological readouts of optic nerve function.


Assuntos
Axônios/enzimologia , MAP Quinase Quinase Quinases/deficiência , Traumatismos do Nervo Óptico/enzimologia , Células Ganglionares da Retina/enzimologia , Degeneração Walleriana/enzimologia , Animais , Axônios/patologia , Morte Celular/fisiologia , Sobrevivência Celular/fisiologia , Modelos Animais de Doenças , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , MAP Quinase Quinase Quinases/genética , Camundongos Transgênicos , Traumatismos do Nervo Óptico/patologia , Fosforilação/fisiologia , Retina/enzimologia , Retina/crescimento & desenvolvimento , Retina/patologia , Células Ganglionares da Retina/patologia , Transdução de Sinais , Técnicas de Cultura de Tecidos , Degeneração Walleriana/patologia
10.
J Neuroinflammation ; 11: 194, 2014 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-25407441

RESUMO

BACKGROUND: Glaucoma is an optic neuropathy that is characterized by the loss of retinal ganglion cells (RGCs) initiated by damage to axons in the optic nerve. The degeneration and death of RGCs has been thought to occur in two waves. The first is axogenic, caused by direct insult to the axon. The second is somatic, and is thought to be caused by the production of inflammatory cytokines from the activated retinal innate immune cells. One of the cytokines consistently linked to glaucoma and RGC damage has been TNFα. Despite strong evidence implicating this protein in neurodegeneration, a direct injection of TNFα does not mimic the rapid loss of RGCs observed after acute optic nerve trauma or exposure to excitotoxins. This suggests that our understanding of TNFα signaling is incomplete. METHODS: RGC death was induced by optic nerve crush in mice. The role of TNFα in this process was examined by quantitative PCR of Tnfα gene expression, and quantification of cell loss in Tnfα (-/-) mice or in wild-type animals receiving an intraocular injection of exongenous TNFα either before or after crush. Signaling pathways downstream of TNFα were examined by immunolabeling for JUN protein accumulation or activation of EGFP expression in NFκB reporter mice. RESULTS: Optic nerve crush caused a modest increase in Tnfα gene expression, with kinetics similar to the activation of both macroglia and microglia. A pre-injection of TNFα attenuated ganglion cell loss after crush, while ganglion cell loss was more severe in Tnfα (-/-) mice. Conversely, over the long term, a single exposure to TNFα induced extrinsic apoptosis in RGCs. Müller cells responded to exogenous TNFα by accumulating JUN and activating NFκB. CONCLUSION: Early after optic nerve crush, TNFα appears to have a protective role for RGCs, which may be mediated through Müller cells.


Assuntos
Compressão Nervosa , Fármacos Neuroprotetores/uso terapêutico , Traumatismos do Nervo Óptico/tratamento farmacológico , Traumatismos do Nervo Óptico/patologia , Células Ganglionares da Retina/patologia , Fator de Necrose Tumoral alfa/uso terapêutico , Animais , Relação Dose-Resposta a Droga , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/farmacologia , Traumatismos do Nervo Óptico/metabolismo , Células Ganglionares da Retina/efeitos dos fármacos , Células Ganglionares da Retina/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
11.
Global Health ; 10: 83, 2014 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-25498958

RESUMO

BACKGROUND: We describe trends in participation by investigators from low- and middle-income countries (LMCs) in publications describing oncology randomized control trials (RCTs) over a decade. METHODS: We used Medline to identify RCTs published in English from 1998 to 2008 evaluating treatment in lung, breast, colorectal, stomach and liver cancers. Data on author affiliations, authorship roles, trial characteristics, funding and interventions were extracted from each article. Countries were stratified as low-, middle- or high-income using World Bank data. Interventions were categorized as requiring basic, limited, enhanced or maximal resources as per the Breast Health Global Initiative classification. Logistic regression was used to identify factors associated with authorship by investigators from LMCs. RESULTS: 454 publications were identified. Proportion of articles with at least one LMC author increased over time from 20% in 1998 to 29% in 2008 (p = 0.01), but almost all LMC authors were from middle-income countries. Proportion of articles with at least one LMC author was higher among articles that explicitly reported recruitment in at least one LMC vs those that did not (76% vs 13%). Among 87 articles (19%) that involved authors from LMCs, 17% had LMC authors as first or corresponding authors, and 67% evaluated interventions requiring enhanced or maximal resources. Factors associated with LMC authorship included industry funding (OR = 3.54, p = 0.0001), placebo comparator arm (OR = 2.57, p = 0.02) and palliative intent treatment (OR = 4.00, p = 0.0003). CONCLUSION: An increasing number of publications describing oncology RCTs involve authors from LMC countries but primarily in non-leadership roles in industry-funded trials.


Assuntos
Bibliometria , Países em Desenvolvimento , Neoplasias/terapia , Publicações Periódicas como Assunto/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Humanos
12.
Exp Eye Res ; 112: 106-17, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23648575

RESUMO

The AP1 family transcription factor JUN is an important molecule in the neuronal response to injury. In retinal ganglion cells (RGCs), JUN is upregulated soon after axonal injury and disrupting JUN activity delays RGC death. JUN is known to participate in the control of many different injury response pathways in neurons, including pathways controlling cell death and axonal regeneration. The role of JUN in regulating genes involved in cell death, ER stress, and regeneration was tested to determine the overall importance of JUN in regulating RGC response to axonal injury. Genes from each of these pathways were transcriptionally controlled following axonal injury and Jun deficiency altered the expression of many of these genes. The differentially expressed genes included, Atf3, Ddit3, Ecel1, Gadd45α, Gal, Hrk, Pten, Socs3, and Sprr1a. Two of these genes, Hrk and Atf3, were tested for importance in RGC death using null alleles of each gene. Disruption of the prodeath Bcl2 family member Hrk did not affect the rate or amount of RGC death after axonal trauma. Deficiency in the ATF/CREB family transcription factor Atf3 did lessen the amount of RGC death after injury, though it did not provide long term protection to RGCs. Since JUN's dimerization partner determines its transcriptional targets, the expression of several candidate AP1 family members were examined. Multiple AP1 family members were induced by axonal injury and had a different expression profile in Jun deficient retinas compared to wildtype retinas (Fosl1, Fosl2 and Jund). Overall, JUN appears to play a multifaceted role in regulating RGC response to axonal injury.


Assuntos
Apoptose , Axônios/patologia , Regeneração Nervosa/fisiologia , Traumatismos do Nervo Óptico/genética , Proteínas Proto-Oncogênicas c-jun/fisiologia , Células Ganglionares da Retina/patologia , Fator de Transcrição AP-1/genética , Fator 3 Ativador da Transcrição/genética , Fator 3 Ativador da Transcrição/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Contagem de Células , Sobrevivência Celular , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Compressão Nervosa , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Traumatismos do Nervo Óptico/metabolismo , Traumatismos do Nervo Óptico/fisiopatologia , Reação em Cadeia da Polimerase em Tempo Real , Ativação Transcricional
13.
Mol Cell Neurosci ; 51(1-2): 53-9, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22836101

RESUMO

The Bcl-2 family is responsible for regulating cell death pathways in neurons during development, after injury and in disease. The activation of the pro-death family member BAX is often the final step before cell death in neurons. Pro-survival family members such as BCL-X (BCL2L1) act to inhibit BAX activation. Overexpression studies have suggested that BCL-X could play an important physiological role in mediating neuronal viability. Loss-of-function studies performed in vivo have implicated BCL-X as a mediator of neuronal survival during the early stages of neurodevelopment. To assess whether BCL-X is needed to promote the survival of neurons in the central nervous system throughout life, Bcl-x was conditionally removed from the optic cup or throughout the adult mouse. During development BCL-X was required for the survival of differentiating retinal ganglion cells (RGCs) leading up to their normal window of developmental death. Despite its expression in adult RGCs, BCL-X was not required for maintaining RGC viability in adult retinas. However, the loss of BCL-X in adult RGCs did significantly increase the rate of death of RGCs after axonal injury. Thus, in developing and injured RGCs there appears to be an active cell survival program preventing neuronal death.


Assuntos
Células Ganglionares da Retina/fisiologia , Proteína bcl-X/fisiologia , Animais , Apoptose/genética , Sobrevivência Celular/genética , Regulação da Expressão Gênica , Camundongos , Neurogênese/genética , Células Ganglionares da Retina/metabolismo , Proteína bcl-X/genética
14.
Neurobiol Dis ; 46(2): 393-401, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22353563

RESUMO

Glaucoma is a neurodegenerative disease characterized by the apoptotic death of retinal ganglion cells (RGCs). The primary insult to RGCs in glaucoma is thought to occur to their axons as they exit the eye in the optic nerve head. However, pathological signaling pathways that exert central roles in triggering RGC death following axonal injury remain unidentified. It is likely that the first changes to occur following axonal injury are signal relay events that transduce the injury signal from the axon to the cell body. Here we focus on the c-Jun N-terminal kinase (JNK1-3) family, a signaling pathway implicated in axonal injury signaling and neurodegenerative apoptosis, and likely to function as a central node in axonal injury-induced RGC death. We show that JNK signaling is activated immediately after axonal injury in RGC axons at the site of injury. Following its early activation, sustained JNK signaling is observed in axonally-injured RGCs in the form of JUN phosphorylation and upregulation. Using mice lacking specific Jnk isoforms, we show that Jnk2 and Jnk3 are the isoforms activated in injured axons. Combined deficiency of Jnk2 and Jnk3 provides robust long-term protection against axonal injury-induced RGC death and prevents downregulation of the RGC marker, BRN3B, and phosphorylation of JUN. Finally, using Jun deficient mice, we show that JUN-dependent pathways are important for axonal injury-induced RGC death. Together these data demonstrate that JNK signaling is the major early pathway triggering RGC death after axonal injury and may directly link axon injury to transcriptional activity that controls RGC death.


Assuntos
Axônios/enzimologia , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 10 Ativada por Mitógeno/fisiologia , Proteína Quinase 9 Ativada por Mitógeno/fisiologia , Células Ganglionares da Retina/enzimologia , Animais , Axônios/patologia , Morte Celular , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Traumatismos do Nervo Óptico/enzimologia , Traumatismos do Nervo Óptico/genética , Traumatismos do Nervo Óptico/patologia , Células Ganglionares da Retina/patologia , Ativação Transcricional/fisiologia
15.
BJU Int ; 110(7): 980-6, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22372862

RESUMO

UNLABELLED: Study Type - Prognosis (cohort) Level of Evidence 2b. What's known on the subject? and What does the study add? ADIPOSE tissue secretes various endocrine and paracrine mediators. Some authors have begun to consider whether peri-prostatic fat (PPF) may interact with the prostate and play a role in carcinogenesis. It has recently been shown that the PPF quantity measured by CT is associated with more aggressive disease in patients undergoing radiation therapy. Our group studied a population not yet diagnosed with prostate cancer. By doing so we were able to identify PPF thickness on transrectal ultrasonography as a risk factor for prostate cancer detection upon biopsy, and as a risk factor for high-grade disease. Our study also raises interesting questions about the underlying mechanisms of the association between PPF quantity and prostate cancer. OBJECTIVE: To determine if the amount of peri-prostatic fat (PPF) on transrectal ultrasonography (TRUS) is a risk factor for incident prostate cancer overall and high-grade prostate cancer (Gleason ≥4). PATIENTS AND METHODS: A prospectively maintained database of patients undergoing prostate biopsy at Princess Margaret Hospital for cancer suspicion was used. • All TRUS examinations were retrospectively reviewed upon 'blinding' to outcome. • PPF thickness, measured as the distance between the prostate and the pubic bone, was used as an index of the quantity of PPF. • PPF measurements, together with other prostate cancer risk factors, were evaluated against prostate cancer and high-grade prostate cancer detection upon biopsy with univariable and multivariable logistic regression and area under the receiver operating characteristic curve (AUC) analysis. RESULTS: Of the 931 patients, 434 (47%) were diagnosed with prostate cancer and 218 (23%) were diagnosed with high-grade prostate cancer. • The mean (range) PPF thickness was 5.3 (0-15) mm. • Increasing PPF thickness was associated with prostate cancer and high-grade prostate cancer diagnosis, with graded effect. When adjusting for other variables, the odds of detecting any prostate cancer and high-grade prostate cancer increased 12% (odds ratio [OR] 1.12, 95% confidence interval [CI] 1.02-1.23) and 20% (OR 1.20, 95% CI 1.07-1.34), respectively, for each millimetre increase in PPF thickness. • The AUCs for the association of PPF with prostate cancer and high-grade prostate cancer were 0.58 (95% CI 0.54-0.62) and 0.59 (95% CI 0.55-0.64), respectively. CONCLUSION: The amount of PPF can be estimated with TRUS and is a predictor of prostate cancer and high-grade prostate cancer at biopsy. To our knowledge, this study is the first to investigate PPF quantity in patients without prior prostate cancer diagnosis.


Assuntos
Tecido Adiposo/patologia , Próstata/patologia , Neoplasias da Próstata/patologia , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Próstata/ultraestrutura , Neoplasias da Próstata/diagnóstico por imagem , Estudos Retrospectivos , Fatores de Risco , Ultrassonografia/métodos
16.
J Urol ; 186(4): 1218-22, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21849182

RESUMO

PURPOSE: We examined the growth of tissue proven renal oncocytoma on serial imaging to improve our understanding of its natural history. MATERIALS AND METHODS: We reviewed the charts of 69 patients with oncocytoma diagnosed by biopsy or surgery between 2004 and 2010. A total of 29 cases were managed by active surveillance for at least 12 months and had 3 or more imaging events. Tumor size was documented and the average tumor growth rate was calculated using a random coefficient model. Interaction terms were used to investigate correlations between variables of interest, including age at diagnosis, gender, symptom status, laterality, initial tumor size, surveillance duration and number of imaging events. RESULTS: At a mean surveillance duration of 40 months 80% of oncocytomas increased in size. Based on the random coefficient model the estimated average growth rate was 0.16 mm monthly (95% CI 0.097-0.228, p <0.0001). We identified no variables that significantly correlated with growth. CONCLUSIONS: Despite its low metastatic potential renal oncocytoma appears to progress locally with a growth rate similar to that of RCC. Thus, absent tumor growth on serial imaging is not a robust prognostic factor for benign histology. Biopsy remains the mainstay of diagnosis. At centers where it can be performed safely and accurately, active surveillance of tissue proven oncocytoma appears to be safe in the short term. Alternative management includes partial nephrectomy and minimally invasive approaches. To our knowledge this is the largest study of oncocytoma natural history.


Assuntos
Adenoma Oxífilo/patologia , Neoplasias Renais/patologia , Adenoma Oxífilo/diagnóstico , Adenoma Oxífilo/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Neoplasias Renais/diagnóstico , Neoplasias Renais/cirurgia , Masculino , Pessoa de Meia-Idade
17.
BJU Int ; 108(8 Pt 2): E237-44, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21507190

RESUMO

OBJECTIVE: •To compare the Prostate Cancer Prevention Trial Risk Calculator (PCPT-RC) and European Randomized Study of Screening for Prostate Cancer Risk Calculator (ERSPC-RC) in a single-institution Canadian cohort. PATIENTS AND METHODS: •At Princess Margaret Hospital, 982 consecutive patients with PCPT-RC and ERSPC-RC covariables were prospectively catalogued before prostate biopsy for suspicion of prostate cancer (PCa). •Receiver-operating characteristic (ROC) curves were generated for each calculator and prostate-specific antigen (PSA). •Comparisons by area under the curve (AUC) and calibration plots were performed. •Predictors of PCa were identified by univariable and multivariable logistic regression. RESULTS: •PCa was detected in 46% and high-grade (HG) PCa (Gleason ≥4) in 23% of subjects with a median PSA level of 6.02 ng/mL. • Multivariable analysis identified transrectal ultrasonography nodule, prostate volume and PSA as the most important predictors of PCa and HG PCa. •ROC curve analysis showed that the ERSPC-RC (AUC = 0.71) outperformed the PCPT-RC (AUC = 0.63) and PSA (AUC = 0.55), for PCa prediction, P < 0.001. •The PCPT-RC was better calibrated in the higher prediction range (40-100%) than the ERSPC-RC, whereas the ERSPC-RC had better calibration and avoided more biopsies in the lower risk range (0-30%). •Discrimination of the ERSPC-RC continued to be superior to the PCPT-RC when the cohort was stratified by different clinical variables. CONCLUSIONS: •The ERSPC-RC had better discrimination for predicting PCa compared to the PCPT-RC in this Canadian cohort. •Calibration would need to be improved to allow routine use of the ERSPC-RC in Canadian practice.


Assuntos
Neoplasias da Próstata/epidemiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco
18.
AIDS Care ; 23(2): 245-51, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21259138

RESUMO

Understanding the neighbourhood perceptions of individuals living with HIV in urban and non-urban areas may help identify potential barriers to uptake and effectiveness of therapy. We evaluate how neighbourhood perceptions are influenced by socio-economic factors, such as food security and stable housing and other explanatory variables, among individuals receiving highly active antiretroviral therapy (HAART) in British Columbia. Neighbourhood perceptions, quality of life and socio-demographic information were collected in an interviewer-administered survey with study participants. Perception of neighbourhood problems, perception of neighbourhood cohesion and perception of relative standard of living were evaluated using previously defined scales. Bivariate and multivariate analyses were carried out to determine associations with neighbourhood perceptions, food security and stable housing. Our analyses were based on 457 participants, of whom 133 (29%) were food secure and 297 (65%) had stable housing. Mean scores for perceptions of neighbourhood problems and cohesion were 35 (IQR 15-58) and 57 (IQR 46-69), respectively. Being food secure and having stable housing was associated with a 9% and 11% decrease in perception of neighbourhood problems, respectively, and a 6% increase in the perception of neighbourhood cohesion in both cases. Food security and stable housing are related to neighbourhood perceptions among individuals on HAART. The results point to potential targets for intervention, involving improvements to living conditions such as housing and food security, which may promote treatment success for HAART, especially in marginalized communities.


Assuntos
Abastecimento de Alimentos , Infecções por HIV , Habitação , Qualidade de Vida , Características de Residência , Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Síndrome da Imunodeficiência Adquirida/epidemiologia , Síndrome da Imunodeficiência Adquirida/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Antirretroviral de Alta Atividade , Colúmbia Britânica/epidemiologia , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Infecções por HIV/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Meio Social , Fatores Socioeconômicos , Adulto Jovem
19.
Lancet ; 373(9679): 1987-92, 2009 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-19501746

RESUMO

Human-rights treaties indicate a country's commitment to human rights. Here, we assess whether ratification of human-rights treaties is associated with improved health and social indicators. Data for health (including HIV prevalence, and maternal, infant, and child [<5 years] mortalities) and social indicators (child labour, human development index, sex gap, and corruption index), gathered from 170 countries, showed no consistent associations between ratification of human-rights treaties and health or social outcomes. Established market economy states had consistently improved health compared with less wealthy settings, but this was not associated with treaty ratification. The status of treaty ratification alone is not a good indicator of the realisation of the right to health. We suggest the need for stringent requirements for ratification of treaties, improved accountability mechanisms to monitor compliance of states with treaty obligations, and financial assistance to support the realisation of the right to health.


Assuntos
Saúde Global , Indicadores Básicos de Saúde , Violação de Direitos Humanos , Direitos Humanos , Cooperação Internacional , Saúde Pública/estatística & dados numéricos , Criança , Mortalidade da Criança , Direitos Civis/legislação & jurisprudência , Direitos Civis/estatística & dados numéricos , Países Desenvolvidos/estatística & dados numéricos , Países em Desenvolvimento/estatística & dados numéricos , Feminino , Infecções por HIV/epidemiologia , Direitos Humanos/legislação & jurisprudência , Violação de Direitos Humanos/legislação & jurisprudência , Violação de Direitos Humanos/prevenção & controle , Humanos , Lactente , Expectativa de Vida , Modelos Logísticos , Masculino , Mortalidade Materna , Análise Multivariada , Saúde Pública/legislação & jurisprudência , Fatores Socioeconômicos , Estatísticas não Paramétricas , Nações Unidas
20.
AIDS Care ; 22(7): 816-26, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20635245

RESUMO

A patient's understanding and use of healthcare information can affect their decisions regarding treatment. Better patient understanding about HIV resistance may improve adherence to therapy, decrease population viral load and extend the use of first-line HIV therapies. We examined knowledge of developing HIV resistance and explored treatment outcomes in a cohort of HIV+ persons on highly active antiretroviral therapy (HAART). The longitudinal investigations into supportive and ancillary health services (LISA) cohort is a prospective study of HIV+ persons on HAART. A comprehensive interviewer-administrated survey collected socio-demographic variables. Drug resistance knowledge was determined using a three-part definition. Clinical markers were collected through linkage with the Drug Treatment Program (DTP) at the British Columbia Centre for Excellence in HIV/AIDS. Categorical variables were compared using Fisher's Exact Test and continuous variables using the Wilcoxon rank-sum test. Proportional odds logistic regression was performed for the adjusted multivariable analysis. Of 457 LISA participants, less than 4% completely defined HIV resistance and 20% reported that they had not discussed resistance with their physician. Overall, 61% of the cohort is >or=95% adherent based on prescription refills. Owing to small numbers pooling was preformed for analyses. The model showed that being younger (OR=0.97, 95% CI: 0.95-0.99), having greater than high school education (OR=1.64, 95% CI: 1.07-2.51), discussing medication with physicians (OR=3.67, 95% CI: 1.76-7.64), having high provider trust (OR=1.02, 95% CI: 1.01-1.03), and receiving one-to-one counseling by a pharmacist (OR=2.14, 95% CI: 1.41-3.24) are predictive of a complete or partial definition of HIV resistance. The probability of completely defining HIV resistance increased from 15.8 to 63.9% if respondents had discussed HIV medication with both a physician and a pharmacist. Although the understanding of HIV resistance showed no differences in treatment outcomes in this cohort, overall adherence and complete understanding of HIV resistance were low. If patient understanding could be improved through discussions with physicians and pharmacists, potential exists to enhance overall adherence and treatment outcomes.


Assuntos
Compreensão , Farmacorresistência Viral , Soropositividade para HIV/tratamento farmacológico , HIV/efeitos dos fármacos , Adulto , Terapia Antirretroviral de Alta Atividade/psicologia , Colúmbia Britânica , Feminino , Soropositividade para HIV/psicologia , Educação em Saúde/métodos , Humanos , Modelos Logísticos , Masculino , Adesão à Medicação/estatística & dados numéricos , Pessoa de Meia-Idade , Inquéritos e Questionários , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA