RESUMO
BACKGROUND: Fragile X-associated tremor/ataxia syndrome is a neurodegenerative disease of late onset developed by carriers of the premutation in the fragile x mental retardation 1 (FMR1) gene. Pathological features of neurodegeneration in fragile X-associated tremor/ataxia syndrome include toxic levels of FMR1 mRNA, ubiquitin-positive intranuclear inclusions, white matter disease, iron accumulation, and a proinflammatory state. OBJECTIVE: The objective of this study was to analyze the presence of cerebral microbleeds in the brains of patients with fragile X-associated tremor/ataxia syndrome and investigate plausible causes for cerebral microbleeds in fragile X-associated tremor/ataxia syndrome. METHODS: We collected cerebral and cerebellar tissue from 15 fragile X-associated tremor/ataxia syndrome cases and 15 control cases carrying FMR1 normal alleles. We performed hematoxylin and eosin, Perls and Congo red stains, ubiquitin, and amyloid ß protein immunostaining. We quantified the number of cerebral microbleeds, amount of iron, presence of amyloid ß within the capillaries, and number of endothelial cells containing intranuclear inclusions. We evaluated the relationships between pathological findings using correlation analysis. RESULTS: We found intranuclear inclusions in the endothelial cells of capillaries and an increased number of cerebral microbleeds in the brains of those with fragile X-associated tremor/ataxia syndrome, both of which are indicators of cerebrovascular dysfunction. We also found a suggestive association between the amount of capillaries that contain amyloid ß in the cerebral cortex and the rate of disease progression. CONCLUSION: We propose microangiopathy as a pathologic feature of fragile X-associated tremor/ataxia syndrome. © 2021 International Parkinson and Movement Disorder Society.
Assuntos
Síndrome do Cromossomo X Frágil , Doenças Neurodegenerativas , Ataxia/complicações , Ataxia/genética , Hemorragia Cerebral/complicações , Hemorragia Cerebral/diagnóstico por imagem , Células Endoteliais , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/complicações , Síndrome do Cromossomo X Frágil/genética , Humanos , Tremor/complicações , Tremor/genéticaRESUMO
Vascular Ehlers-Danlos syndrome (vEDS) is a connective tissue disorder due to defective type III collagen production and is associated with arterial rupture, spontaneous intestinal perforation, and gravid uterine rupture. Spontaneous pneumothorax and/or hemothorax (P/HTX) also occurs in vEDS patients. The temporal relation of pulmonary manifestations to arterial and intestinal complications in vEDS has not been well described. This was investigated in a multi-institutional retrospective case series of vEDS patients with confirmatory testing for COL3A1 mutation between 2000 and 2012. Data abstracted included demographics, family histories, presentation, and management of associated complications. Ninety-six cases (39% males, mean age 38.6 ± 15.5 years, range 8-79) had confirmatory testing for vEDS. P/HTX was documented in 17 (17.7%) cases. Most P/HTX preceded the diagnosis of vEDS (81%). Diagnosis of vEDS was made after arterial or intestinal complications at a mean of 7 years (range 0-26) post the initial P/HTX. In conclusion, spontaneous P/HTX is an early manifestation of vEDS frequently preceding an arterial complication or intestinal perforation. Thus, a spontaneous P/HTX in a young patient should trigger a differential diagnosis that includes vEDS. This should lead to an investigation of other vEDS features and subsequent genetic testing if vEDS features are present.
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Síndrome de Ehlers-Danlos/complicações , Síndrome de Ehlers-Danlos/genética , Hemotórax/etiologia , Fenótipo , Pneumotórax/etiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Colágeno Tipo III/genética , Estudos Transversais , Síndrome de Ehlers-Danlos/diagnóstico , Feminino , Estudos de Associação Genética , Testes Genéticos , Hemotórax/diagnóstico , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Pneumotórax/diagnóstico , Prevalência , Adulto JovemRESUMO
Latino Americans are a rapidly growing ethnic group in the United States but studies of glioblastoma in this population are limited. We have evaluated characteristics of 21,184 glioblastoma patients from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute. This SEER data from 2001 to 2011 draws from 28% of the U.S. POPULATION: Latinos have a lower incidence of GBM and present slightly younger than non-Latino Whites. Cubans present at an older age than other Latino sub-populations. Latinos have a higher incidence of giant cell glioblastoma than non-Latino Whites while the incidence of gliosarcoma is similar. Despite lower rates of radiation therapy and greater rates of sub-total resection than non-Latino Whites, Latinos have better 1 and 5 year survival rates. SEER does not record chemotherapy data. Survivals of Latino sub-populations are similar with each other. Age, extent of resection, and the use of radiation therapy are associated with improved survival but none of these variables are sufficient in a multivariate analysis to explain the improved survival of Latinos relative to non-Latino Whites. As molecular data is not available in SEER records, we studied the MGMT and IDH status of 571 patients from a UCLA database. MGMT methylation and IDH1 mutation rates are not statistically significantly different between non-Latino Whites and Latinos. For UCLA patients with available information, chemotherapy and radiation rates are similar for non-Latino White and Latino patients, but the latter have lower rates of gross total resection and present at a younger age.
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Neoplasias Encefálicas , Glioblastoma , Adulto , Idoso , Neoplasias Encefálicas/epidemiologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Estudos de Coortes , Metilases de Modificação do DNA/genética , Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Conjuntos de Dados como Assunto/estatística & dados numéricos , Feminino , Glioblastoma/epidemiologia , Glioblastoma/genética , Glioblastoma/mortalidade , Glioblastoma/patologia , Hispânico ou Latino , Humanos , Incidência , Isocitrato Desidrogenase/genética , Masculino , Pessoa de Meia-Idade , Mutação/genética , Análise de Sobrevida , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Estados Unidos/epidemiologiaRESUMO
BACKGROUND: Vesicourethral anastomosis stenosis (VUAS) refers to the diameter narrowing of a vesicourethral anastomosis (VUA). It is a known complication after radical prostatectomy that nowadays presents in less than 1% of these cases. When the lumen narrows sufficiently to impede urine flow, obstructive symptoms arise. While the incidence of VUAS used to be notably higher prior to the widespread use of the robotic approach, traditional procedures still fail in up to 42% of cases. Initial management typically involves endoscopic procedures, such as dilation, incision, or resection. If these approaches prove ineffective, VUA reconstruction is warranted. Following the resection of the unhealthy urethra, a potential drawback is the insufficient length of the healthy proximal urethral to reach the bladder without tension. In such cases, urinary diversion with an ileal conduit is an option. However, when the patient prefers to maintain an orthotopic urinary tract configuration, there is limited guidance in the literature regarding surgical techniques. OBJECTIVE: To outline the indications, describe the step-by-step technique, and evaluate the outcomes of transperineal urethral advancement to facilitate a tension-free VUA. MATERIALS: We first discuss the indications to identify which patients are candidates for this procedure. Then, a step-by-step description of the robotic VUA revision assisted by transperineal urethral mobilization is presented. Detailed steps and helpful hints are included. Finally, we outline the postoperative pathway and expected outcomes. RESULTS: This technique allows patients with VUAS to preserve the orthotopic configuration of the urinary tract when a tension-free anastomosis proves challenging. Although urinary incontinence is expected, an artificial urinary sphincter could be placed in the following months. CONCLUSION: The robotic management of complex vesicourethral anastomosis stenosis with transperineal urethral advancement is a feasible and safe procedure that requires the interdisciplinary management of robotic and reconstructive urologists.
Assuntos
Procedimentos Cirúrgicos Robóticos , Uretra , Masculino , Humanos , Uretra/cirurgia , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Procedimentos Cirúrgicos Urogenitais , Anastomose CirúrgicaRESUMO
Frozen tissue, a gold standard biospecimen, can yield well preserved nucleic acids and proteins after over a decade but is vulnerable to thawing and has substantial fiscal, spatial, and environmental costs. A long-term room temperature biospecimen storage alternative that preserves broad analytical utility can potentially empower tissue-based research. As there is scant data on the analytical utility of lyophilized brain tumor biospecimens, we evaluated lyophilized (freeze-dried) samples stored for 1 year at room temperature. Lyophilized tumor tissue processed into paraffin sections produced good histology. Yields of extracted DNA, RNA, and protein approximated those of frozen tissue. After 1 year, lyophilized samples yielded high molecular weight DNA that permitted copy number variation analysis, IDH 1 mutation detection, and MGMT promoter methylation PCR. A 27 % decrease in RIN scores over the 1 year suggests that RNA degradation was inhibited though incompletely. Nevertheless, RT-PCR studies on lyophilized tissue performed similarly to frozen tissue. In contrast to FFPE tissues where protein bands were absent or shifted to a lower molecular weight, lyophilized samples showed similar protein bands as frozen tissue on SDS-PAGE analysis. Lyophilized tissue performed similarly to frozen tissue for Western blots and enzyme activity assays. Immunohistochemistry of lyophilized tissue that were processed into FFPE blocks often required longer incubation times for staining than standard FFPE samples but generally provided robust antigen detection. This preliminary study suggests that lyophilization has promise for long-term room temperature storage while permitting varied tests; however, further work is required to better stabilize nucleic acids particularly RNA.
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Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , DNA de Neoplasias/análise , Liofilização , Proteínas de Neoplasias/análise , RNA Neoplásico/análise , Western Blotting , Neoplasias Encefálicas/genética , Metilação de DNA , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Humanos , Técnicas Imunoenzimáticas , Isocitrato Desidrogenase/genética , Mutação/genética , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Temperatura , Fatores de Tempo , Fixação de Tecidos , Proteínas Supressoras de Tumor/genéticaRESUMO
Current methods to monitor cellular ATP do not provide spatial or temporal localization of ATP in single cells in real time or they display imperfect specificity to ATP. Here, we have developed a single cell, Enhanced Acceptor Fluorescence (EAF)-based ATP biosensor to visualize ATP in real time. This biosensor utilizes a modified mimic of the ε-subunits of the Bacillus subtilis F(0)F(1) synthase and is coupled to the EAF fluorophores pairs, GFP and YFP. The sensor was then used to monitor ATP in a heterogeneous glioblastoma multiform cancer cell population. We anticipate that this innovative technology and our better understanding of the ATP machinery will have substantial influence on future translational studies.
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Trifosfato de Adenosina/análise , Técnicas Biossensoriais/métodos , Técnicas Citológicas/métodos , Glioblastoma/fisiopatologia , Bacillus subtilis/enzimologia , Fluorescência , Humanos , ATPases Translocadoras de Prótons/metabolismoRESUMO
INTRODUCTION: We utilized an eConsult program to assess the appropriateness and completeness of hematuria evaluation among one of the largest Medicaid networks in California, the Inland Empire Health Plan. METHODS: We retrospectively reviewed all hematuria consults from May 2018 to August 2020. Patient demographic and clinical data were extracted from the electronic health record and dialogues between primary care provider and specialist including laboratory results and imaging. We calculated the proportions of imaging types and the outcome of the eConsults among patients. χ2 and Fisher's exact tests were used for statistical analysis. RESULTS: A total of 106 hematuria eConsults were submitted. Primary care provider evaluation for risk factors rates were low: 37% gross hematuria, 29% voiding symptoms/dysuria, 49% other urothelial risk factors or benign etiology, and 63% smoking. Only 50% of all referrals were deemed appropriate based on a history of gross hematuria or ≥3 red blood cells/high-power field on urinalysis without evidence of infection or contamination. Thirty-one percent of patients received a renal ultrasound, 2.8% received CT urography, 5.7% received other cross-sectional imaging, and 64% received no imaging. By the conclusion of the eConsult only 54% of patients were referred for a face-to-face visit. CONCLUSIONS: The use of eConsults allows for urological access in the safety-net population and presents a means to assess the urological needs in the community. Our findings suggest eConsults represent an opportunity to reduce the morbidity and mortality associated with hematuria among safety-net patients who are otherwise less likely to receive a proper evaluation.
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Hematúria , Medicaid , Estados Unidos/epidemiologia , Humanos , Estudos Retrospectivos , Hematúria/diagnóstico , Atenção Primária à Saúde/métodos , Encaminhamento e ConsultaRESUMO
Disparities in urology are well-documented but less is known about the role of translational research within existing interventional models to address inequalities. In this narrative review, we utilize an accepted framework of the process of translational research in mitigating disparities to investigate current translational and interventional urologic programs that bridge the gap. Three established, disparity-focused urologic interventional programs were identified and are highlighted in depth. Finally, we extrapolate from these findings to provide 10 policy relevant implications to help move urologic disparities research from evidence synthesis to translational research.
Assuntos
Pesquisa Translacional Biomédica , Urologia , HumanosRESUMO
This case documents the co-occurrence of the fragile X-associated tremor ataxia syndrome (FXTAS) and Alzheimer-type neuropathology in a 71-year-old premutation carrier with 85 CGG repeats in the fragile X mental retardation 1 (FMR1) gene, in addition to an apolipoprotein E (APOE) ε4 allele. FXTAS and Alzheimer's Disease (AD) are late-onset neurodegenerative diseases that share overlapping cognitive deficits including processing speed, working memory and executive function. The prevalence of coexistent FXTAS-AD pathology remains unknown. The clinical picture in this case was marked with rapid cognitive decline between age 67 and 71 years in addition to remarkable MRI changes. Over the 16 months between the two clinical evaluations, the brain atrophied 4.12% while the lateral ventricles increased 26.4% and white matter hyperintensities (WMH) volume increased 15.6%. Other regions atrophied substantially faster than the whole brain included the thalamus (-6.28%), globus pallidus (-10.95%), hippocampus (-6.95%), and amygdala (-7.58%). A detailed postmortem assessment included an MRI with confluent WMH and evidence of cerebral microbleeds (CMB). The histopathological study demonstrated FXTAS inclusions in neurons and astrocytes, a widespread presence of phosphorylated tau protein and, amyloid ß plaques in cortical areas and the hippocampus. CMBs were noticed in the precentral gyrus, middle temporal gyrus, visual cortex, and brainstem. There were high amounts of iron deposits in the globus pallidus and the putamen consistent with MRI findings. We hypothesize that coexistent FXTAS-AD neuropathology contributed to the steep decline in cognitive abilities.
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Multicellular animals have evolved conserved signaling pathways that translate cell polarity cues into mitotic spindle positioning to control the orientation of cell division within complex tissue structures. These oriented cell divisions are essential for the development of cell diversity and the maintenance of tissue homeostasis. Despite intense efforts, the molecular mechanisms that control spindle orientation remain incompletely defined. Here, we describe a role for the Hippo (Hpo) kinase complex in promoting Partner of Inscuteable (Pins)-mediated spindle orientation. Knockdown of Hpo, Salvador (Sav), or Warts (Wts) each result in a partial loss of spindle orientation, a phenotype previously described following loss of the Pins-binding protein Mushroom body defect (Mud). Similar to orthologs spanning yeast to mammals, Wts kinase localizes to mitotic spindle poles, a prominent site of Mud localization. Wts directly phosphorylates Mud in vitro within its C-terminal coiled-coil domain. This Mud coiled-coil domain directly binds the adjacent Pins-binding domain to dampen the Pins/Mud interaction, and Wts-mediated phosphorylation uncouples this intramolecular Mud interaction. Loss of Wts prevents cortical Pins/Mud association without affecting Mud accumulation at spindle poles, suggesting phosphorylation acts as a molecular switch to specifically activate cortical Mud function. Finally, loss of Wts in Drosophila imaginal disc epithelial cells results in diminished cortical Mud and defective planar spindle orientation. Our results provide new insights into the molecular basis for dynamic regulation of the cortical Pins/Mud spindle positioning complex and highlight a novel link with an essential, evolutionarily conserved cell proliferation pathway.
Assuntos
Divisão Celular/genética , Proteínas de Drosophila/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Quinases/metabolismo , Fuso Acromático/metabolismo , Transativadores/metabolismo , Animais , Polaridade Celular/fisiologia , Drosophila , Drosophila melanogaster , Inibidores de Dissociação do Nucleotídeo Guanina/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Fosforilação , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Fuso Acromático/genética , Proteínas de Sinalização YAPRESUMO
UNLABELLED: Frozen biospecimens are crucial for translational research and contain well-preserved nucleic acids and protein. However, the risks of freezer failure as well as space, cost, and environmental concerns of frozen biospecimens are substantial. OBJECTIVE: The purpose of the study was to review the current status of room temperature biospecimen storage. METHODS: We searched Pubmed and vendor websites to identify relevant information. RESULTS: Formalin-fixed paraffin embedded (FFPE) tissues have great value but their use is limited by cross-linking and fragmentation of nucleic acids, as well as loss of enzymatic activity. Stabilization solutions can now robustly preserve fresh tissue for up to 7days at room temperature. For longer term storage, commercial vendors of chemical matrices claim real time stability of nucleic acids of over 2 years and their accelerated aging studies to date suggest stability for 12years for RNA and 60years for DNA. However, anatomic pathology biorepositories store mostly frozen tissue rather than nucleic acids. Small quantities of tissue can be directly placed on some chemical matrices to stabilize DNA, however RNA and proteins are not preserved. Current lyophilization approaches can preserve histomorphology, DNA, RNA, and proteins though RNA shows moderate degradation after 1-2years. Formalin-free fixatives show improved but varying abilities to preserve nucleic acids and face validation as well as cost barriers in replacing FFPE specimens. The paraffin embedding process can degrade RNA. CONCLUSION: Development of robust long-term room temperature biospecimen tissue storage technology can potentially reduce costs for the biomedical community in the face of growing targeted therapy needs and decreasing budgets.
Assuntos
Bancos de Espécimes Biológicos/organização & administração , Pesquisa Biomédica/organização & administração , Manejo de Espécimes/normas , Preservação de Tecido/métodos , Fixadores/química , Liofilização , Humanos , Inclusão em Parafina , Estabilidade Proteica , Controle de Qualidade , Estabilidade de RNA , Manejo de Espécimes/economia , Manejo de Espécimes/métodos , Temperatura , Fatores de Tempo , Preservação de Tecido/economia , Preservação de Tecido/instrumentaçãoRESUMO
BACKGROUND: The optimal timing to initiate bevacizumab (BV) therapy for recurrent glioblastoma (GBM) is currently unclear. To address this issue, we examined progression-free survival (PFS) and survival time (ST) in a large retrospective cohort of GBM patients treated with BV at different recurrences. METHODS: We identified 468 primary GBM patients who underwent biopsy or surgery followed by radiation therapy and temozolomide (RT/TMZ), and then received BV. PFS and ST were compared between patients stratified by the recurrence that BV was initiated (upfront, first recurrence, second recurrence, or 3+ recurrences). We also examined the effect on PFS and ST of the addition of chemotherapy to BV. In a larger cohort of GBM patients, we determined overall treatment continuation rates at each recurrence and identified variables predictive of inability to continue treatment. RESULTS: BV PFS was similar for all 3 recurrence groups (median, 4.1 months). There were no differences in BV ST (median, 9.8 months). The addition of chemotherapy to BV improved PFS but not ST. Analysis of treatment continuation rates indicated that the number of patients unable to undergo further treatments is modest, and that patients unable to tolerate BV delay can be identified by age ≥60 years and low extent of resection. CONCLUSIONS: Deferred use of bevacizumab is not associated with diminished efficacy. Analysis of treatment continuation rates identified patients who may be unable to delay BV therapy. Our findings suggest that there is a fixed survival after BV initiation and that delayed BV treatment is preferable for most patients.
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Inibidores da Angiogênese/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Adulto , Idoso , Inibidores da Angiogênese/administração & dosagem , Anticorpos Monoclonais Humanizados/administração & dosagem , Bevacizumab , Estudos de Coortes , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Análise de Sobrevida , Resultado do TratamentoRESUMO
An autofluorescence lifetime wide-field imaging system that can generate contrast in underlying tissue structures of normal and malignant brain tissue samples with video rate acquisition and processing time is presented. Images of the investigated tissues were acquired with high resolution (â¼35 µm) using an algorithm to produce contrast based on differences in relative lifetimes. Sufficient contrast for delineation was produced without the computation of fluorescence decay times or Laguerre coefficients. The imaged tissues were sent for histological analysis that confirmed the detected imaged tissues morphological findings and correlations between relative lifetime maps and histology identified.
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Neoplasias Encefálicas/patologia , Encéfalo/patologia , Glioma/patologia , Microscopia de Fluorescência/métodos , Microscopia de Vídeo/instrumentação , Microscopia de Vídeo/métodos , Algoritmos , Neoplasias Encefálicas/diagnóstico , Calibragem , Desenho de Equipamento , Glioma/diagnóstico , Humanos , Processamento de Imagem Assistida por Computador , Luz , Manejo de Espécimes , Tomografia de Coerência ÓpticaRESUMO
BACKGROUND: Promoter methylation of the DNA repair gene, O-6-methylguanine-DNA methyltransferase (MGMT), is associated with improved treatment outcome for newly diagnosed glioblastoma (GBM) treated with standard chemoradiation. To determine the prognostic significance of MGMT protein expression as assessed by immunohistochemistry (IHC) and its relationship with methylation, we analyzed MGMT expression and promoter methylation with survival in a retrospective patient cohort. METHODS: We identified 418 patients with newly diagnosed GBM at University of California Los Angeles Kaiser Permanente Los Angeles, nearly all of whom received chemoradiation, and determined MGMT expression by IHC, and MGMT promoter methylation by methylation-specific PCR (MSP) and bisulfite sequencing (BiSEQ) of 24 neighboring CpG sites. RESULTS: With use of the median percentage of cells staining by IHC as the threshold, patients with <30% staining had progression-free survival (PFS) of 10.9 months and overall survival (OS) of 20.5 months, compared with PFS of 7.8 months (P < .0001) and OS of 16.7 months (P < .0001) among patients with ≥30% staining. Inter- and intrareader correlation of IHC staining was high. Promoter methylation status by MSP was correlated with IHC staining. However, low IHC staining was frequently observed in the absence of promoter methylation. Increased methylation density determined by BiSEQ correlated with both decreased IHC staining and increased survival, providing a practical semiquantitative alternative to MSP. On the basis of multivariate analysis validated by bootstrap analysis, patients with tandem promoter methylation and low expression demonstrated improved OS and PFS, compared with the other combinations. CONCLUSIONS: Optimal assessment of MGMT status as a prognostic biomarker for patients with newly diagnosed GBM treated with chemoradiation requires determination of both promoter methylation and IHC protein expression.
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Neoplasias Encefálicas/mortalidade , Metilação de DNA , Metilases de Modificação do DNA/genética , Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Glioblastoma/mortalidade , Regiões Promotoras Genéticas/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Adulto , Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Quimiorradioterapia , DNA de Neoplasias/genética , Dacarbazina/análogos & derivados , Dacarbazina/uso terapêutico , Feminino , Seguimentos , Glioblastoma/genética , Glioblastoma/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Reação em Cadeia da Polimerase , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , TemozolomidaRESUMO
BACKGROUND: Mutations in isocitrate dehydrogenase 1 (IDH1) and associated CpG island hypermethylation represent early events in the development of low-grade gliomas and secondary glioblastomas. To identify candidate tumor suppressor genes whose promoter methylation may contribute to gliomagenesis, we compared methylation profiles of IDH1 mutant (MUT) and IDH1 wild-type (WT) tumors using massively parallel reduced representation bisulfite sequencing. METHODS: Reduced representation bisulfite sequencing was performed on ten pathologically matched WT and MUT glioma samples and compared with data from a methylation-sensitive restriction enzyme technique and data from The Cancer Genome Atlas (TCGA). Methylation in the gene retinol-binding protein 1 (RBP1) was identified in IDH1 mutant tumors and further analyzed with primer-based bisulfite sequencing. Correlation between IDH1/IDH2 mutation status and RBP1 methylation was evaluated with Spearman correlation. Survival data were collected retrospectively and analyzed with Kaplan-Meier and Cox proportional hazards analysis. All statistical tests were two-sided. RESULTS: Methylome analysis identified coordinated CpG island hypermethylation in IDH1 MUT gliomas, consistent with previous reports. RBP1, important in retinoic acid metabolism, was found to be hypermethylated in 76 of 79 IDH1 MUT, 3 of 3 IDH2 MUT, and 0 of 116 IDH1/IDH2 WT tumors. IDH1/IDH2 mutation was highly correlated with RBP1 hypermethylation (n = 198; Spearman R = 0.94, 95% confidence interval = 0.92 to 0.95, P < .001). The Cancer Genome Atlas showed IDH1 MUT tumors (n = 23) to be RBP1-hypermethylated with decreased RBP1 expression compared with WT tumors (n = 124). Among patients with primary glioblastoma, patients with RBP1-unmethylated tumors (n = 102) had decreased median overall survival compared with patients with RBP1-methylated tumors (n = 22) (20.3 months vs 36.8 months, respectively; hazard ratio of death = 2.48, 95% confidence interval = 1.30 to 4.75, P = .006). CONCLUSION: RBP1 promoter hypermethylation is found in nearly all IDH1 and IDH2 mutant gliomas and is associated with improved patient survival. Because RBP1 is involved in retinoic acid synthesis, our results suggest that dysregulation of retinoic acid metabolism may contribute to glioma formation along the IDH1/IDH2-mutant pathway.
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Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Metilação de DNA , Glioma/genética , Isocitrato Desidrogenase/genética , Mutação , Proteínas Celulares de Ligação ao Retinol/genética , Adulto , Idoso , Western Blotting , Neoplasias Encefálicas/química , Ilhas de CpG/genética , Análise Mutacional de DNA/métodos , Feminino , Perfilação da Expressão Gênica , Glioma/química , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas/genética , Modelos de Riscos Proporcionais , Reação em Cadeia da Polimerase em Tempo Real , Mapeamento por Restrição , Proteínas Celulares de Ligação ao Retinol/análise , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sulfitos/metabolismo , Tretinoína/metabolismoRESUMO
La Insulinoresistencia se define como un estado metabólico en el cual los efectos periféricos titulares de la insulina se encuentran disminuidos. La resistencia a la acción de esta hormona se compensa mediante un aumento en su secreción por parte de la célula β, resultando en la llamada hiperinsulinemia compensadora. Desde hace varios años se ha acumulado suficiente evidencia de que la insulinoresistencia y la hiperinsulinemia están involucradas en el desarrollo de hipertensión arterial, obesidad y diabetes. Igualmente, la hiperinsulinemia esta altamente relacionada con el desarrollo de de dislipidemia caracterizada por aumento de las VLDL y TAG y una disminución de las HDL favoreciendo la aparición de ateroesclerosis. Otra de las patologías que se ha encontrado fuertemente relacionada con la hiperinsulinemia y la insulinoresistencia es la isquemia miocárdica, tanto en su génesis como en su evolución, ya que se ha demostrado que las posibilidades de supervivencia del miocito se ven reducidas por la disminución de la captación de glucosa durante el período isquémico. La hiperinsulinemia también se relaciona con la hipertrofia miocárdica, probablemente debido al efecto directo de la insulina sobre la elevación de la presión arterial, bien por incremento en la reabsorción de Na+ o por hiperactividad simpática. Finalmente, la resistencia a la insulina es muy prevalente en pacientes no diabéticos que han padecido TIA o ACV sin secuelas. Este hallazgo tiene importantes implicaciones terapéuticas si el tratamiento de esta condición es capaz de reducir la prevalencia de enfermedad cerebro-vascular y enfermedad coronaria.