RESUMO
Epilepsy is a heterogenous group of disorders defined by recurrent seizure activity due to abnormal synchronized activity of neurons. A growing number of epilepsy cases are believed to be caused by genetic factors and copy number variants (CNV) contribute to up to 5% of epilepsy cases. However, CNVs in epilepsy are usually large deletions or duplications involving multiple neurodevelopmental genes. In patients who underwent seizure focus resection for treatment-resistant epilepsy, whole genome DNA methylation profiling identified 3 main clusters of which one showed strong association with receptor tyrosine kinase (RTK) genes. We identified focal copy number gains involving epidermal growth factor receptor (EGFR) and PDGFRA loci. The dysplastic neurons of cases with amplifications showed marked overexpression of EGFR and PDGFRA, while glial and endothelial cells were negative. Targeted sequencing of regulatory regions and DNA methylation analysis revealed that only enhancer regions of EGFR and gene promoter of PDGFRA were amplified, while coding regions did not show copy number abnormalities or somatic mutations. Somatic focal copy number gains of noncoding regulatory represent a previously unrecognized genetic driver in epilepsy and a mechanism of abnormal activation of RTK genes. Upregulated RTKs provide a potential avenue for therapy in seizure disorders.
Assuntos
Encéfalo/metabolismo , Variações do Número de Cópias de DNA , Metilação de DNA , Epilepsia Resistente a Medicamentos/genética , Receptores ErbB/genética , Adolescente , Adulto , Criança , Epilepsia Resistente a Medicamentos/metabolismo , Receptores ErbB/metabolismo , Feminino , Humanos , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: Both genetic and methylation analysis have been shown to provide insight into the diagnosis and prognosis of many brain tumors. However, the implication of methylation profiling and its interaction with genetic alterations in pediatric low-grade gliomas (PLGGs) are unclear. METHODS: We performed a comprehensive analysis of PLGG with long-term clinical follow-up. In total 152 PLGGs were analyzed from a range of pathological subtypes, including 40 gangliogliomas. Complete molecular analysis was compared with genome-wide methylation data and outcome in all patients. For further analysis of specific PLGG groups, including BRAF p.V600E mutant gliomas, we compiled an additional cohort of clinically and genetically defined tumors from 3 large centers. RESULTS: Unsupervised hierarchical clustering revealed 5 novel subgroups of PLGG. These were dominated by nonneoplastic factors such as tumor location and lymphocytic infiltration. Midline PLGG clustered together while deep hemispheric lesions differed from lesions in the periphery. Mutations were distributed throughout these location-driven clusters of PLGG. A novel methylation cluster suggesting high lymphocyte infiltration was confirmed pathologically and exhibited worse progression-free survival compared with PLGG harboring similar molecular alterations (P = 0.008; multivariate analysis: P = 0.035). Although the current methylation classifier revealed low confidence in 44% of cases and failed to add information in most PLGG, it was helpful in reclassifying rare cases. The addition of histopathological and molecular information to specific methylation subgroups such as pleomorphic xanthoastrocytoma-like tumors could stratify these tumors into low and high risk (P = 0.0014). CONCLUSION: The PLGG methylome is affected by multiple nonneoplastic factors. Combined molecular and pathological analysis is key to provide additional information when methylation classification is used for PLGG in the clinical setting.
Assuntos
Astrocitoma , Neoplasias Encefálicas , Glioma , Neoplasias Encefálicas/genética , Criança , Epigênese Genética , Epigenômica , Glioma/genética , Humanos , MutaçãoRESUMO
BACKGROUND: This study evaluated patient-reported outcomes in patients undergoing primary total hip arthroplasty with a polyethylene liner to determine the influence of cup orientation and other variables on patient-reported outcomes. METHODS: A total of 477 cases were prospectively monitored through average 4.7 years follow-up. Cup position was measured on pelvis radiographs. Patients completed the Western Ontario and McMaster Universities Osteoarthritis Index and Short Form 12 Health Survey questionnaires. RESULTS: Average cup abduction was 43.1° ± 7.5° and anteversion was 13.3° ± 7.5°. Three hundred cups were within the target zone. All outcomes' improvement from baseline and cup position was not an independent risk factor for the Western Ontario and McMaster Universities Osteoarthritis Index or Short Form 12 Health Survey improvement. CONCLUSION: Accurate cup orientation may not be critical to maximizing patient-perceived outcomes if the combined anteversion is within a normal range, the hip joint is properly balanced, and a polyethylene liner is coupled with a metal or ceramic femoral head.
Assuntos
Acetábulo/cirurgia , Artroplastia de Quadril/instrumentação , Prótese de Quadril/estatística & dados numéricos , Idoso , Feminino , Cabeça do Fêmur/cirurgia , Seguimentos , Articulação do Quadril/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , PolietilenoRESUMO
This study examined functional properties and biocompatibility of glutaraldehyde-fixed bovine articular cartilage over several weeks of incubation at body temperature to investigate its potential use as a resurfacing material in joint arthroplasty. In the first experiment, treated cartilage disks were fixed using 0.02, 0.20 and 0.60% glutaraldehyde for 24h then incubated, along with an untreated control group, in saline for up to 28d at 37°C. Both the equilibrium compressive and tensile moduli increased nearly twofold in treated samples compared to day 0 control, and remained at that level from day 1 to 28; the equilibrium friction coefficient against glass rose nearly twofold immediately after fixation (day 1) but returned to control values after day 7. Live explants co-cultured with fixed explants showed no quantitative difference in cell viability over 28d. In general, no significant differences were observed between 0.20 and 0.60% groups, so 0.20% was deemed sufficient for complete fixation. In the second experiment, cartilage-on-cartilage frictional measurements were performed under a migrating contact configuration. In the treated group, one explant was fixed using 0.20% glutaraldehyde while the apposing explant was left untreated; in the control group both explants were left untreated. From day 1 to 28, the treated group exhibited either no significant difference or slightly lower friction coefficient than the untreated group. These results suggest that a properly titrated glutaraldehyde treatment can reproduce the desired functional properties of native articular cartilage and maintain these properties for at least 28d at body temperature.
Assuntos
Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/fisiologia , Fixadores/farmacologia , Fricção/efeitos dos fármacos , Glutaral/farmacologia , Fatores Etários , Animais , Bioprótese , Temperatura Corporal , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Condrócitos/citologia , Condrócitos/efeitos dos fármacos , Força Compressiva/efeitos dos fármacos , Teste de Materiais , Técnicas de Cultura de Órgãos , Osteoartrite/fisiopatologia , Resistência à Tração/efeitos dos fármacos , Suporte de CargaRESUMO
Quantitative measurements of cartilage wear have been challenging, with no method having yet emerged as a standard. This study tested the hypothesis that latest-generation particle analyzers are capable of detecting cartilage wear debris generated during in vitro loading experiments that last 24 h or less, by producing measurable content significantly above background noise levels otherwise undetectable through standard biochemical assays. Immature bovine cartilage disks (4 mm diameter, 1.3 mm thick) were tested against glass using reciprocal sliding under unconfined compression creep for 24 h. Control groups were used to assess various sources of contamination. Results demonstrated that cartilage samples subjected to frictional loading produced particulate volume significantly higher than background noise and contamination levels at all tested time points (1, 2, 6, and 24 h, p < 0.042). The particle counter was able to detect very small levels of wear (less than 0.02% of the tissue sample by volume), whereas no significant differences were observed in biochemical assays for collagen or glycosaminoglycans among any of the groups or time points. These findings confirm that latest-generation particle analyzers are capable of detecting very low wear levels in cartilage experiments conducted over a period no greater than 24 h.