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6407 citation(s) found for "Ma, Christopher".

Significance of Necrosis in Grading of Oligodendroglial Neoplasms: A Clinicopathologic and Genetic Study of Newly Diagnosed High-Grade Gliomas
Miller, C. Ryan , Scheithauer, Bernd W., Perry, Arie , Dunham, Christopher P. , Perry, Arie

Journal of Clinical Oncology | November 30, 2006 | Volume: 24 | Issue: 34 | Pages: 5419-5426

10.1200/jco.2006.08.1497 | PMID 17135643 Get It

Purpose High-grade gliomas (HGGs; WHO grades 3-4) are highly diverse, with survival times ranging from months to years. WHO 2000 grading criteria for high-grade oligodendroglial neoplasms [anaplastic oligoastrocytoma (AOA) and anaplastic oligodendroglioma (AO)] remain subjective, and the existence of grade 4 variants is controversial. Patients and Methods Overall survival (OS) of 1,093 adult patients with a cerebral HGG newly diagnosed between 1990 and 2005 was analyzed by univariate and multivariate models for significance of the following factors: patient age, surgery type, year of diagnosis, endothelial proliferation, necrosis, oligodendroglial histology, treatment center, and chromosome 1p, 19q, 7p (EGFR), and 10q (PTEN) abnormalities by fluorescence in situ hybridization (FISH). Results Necrosis was a statistically significant predictor of poor OS on univariate and multivariate analyses in AOA but not in AO. Median OS for patients with necrotic AOA (22.8 months) was significantly worse than for patients with non-necrotic AOA (86.9 months; P < .0001) but was better than conventional glioblastomas (9.8 months; P < .0001). In addition to patient age, the following were significant independent prognostic factors (P ≤ .001): grade and surgery type for the entire HGG cohort; modified grade for AOA (3 v 4); and modified grade, 1p/19q codeletion status, and oligodendroglial histology for the 586 HGGs analyzed by FISH. Conclusion Stratification of AOA, but not of pure AO, into grades 3 and 4 on the basis of necrosis is prognostically justified and is more powerful than the current approach. Both routine histology and genetic testing provide independent, prognostically useful information.
Primary Central Nervous System Lymphoma: The Memorial Sloan-Kettering Cancer Center Prognostic Model
Abrey, Lauren E. , Ben‐Porat, Leah, Panageas, Katherine S. , Curran, Walter J. , Schultz, Christopher J. , Leibel, Steven A., Nelson, Diana F., Mehta, Minesh P. , DeAngelis, Lisa M. , Price, Leah , Yahalom, Joachim , Berkey, Brian A. , Mehta, Minesh P , Price, Leah

Journal of Clinical Oncology | November 21, 2006 | Volume: 24 | Issue: 36 | Pages: 5711-5715

10.1200/jco.2006.08.2941 | PMID 17116938 Get It

Purpose The purpose of this study was to analyze prognostic factors for patients with newly diagnosed primary CNS lymphoma (PCNSL) in order to establish a predictive model that could be applied to the care of patients and the design of prospective clinical trials. Patients and Methods Three hundred thirty-eight consecutive patients with newly diagnosed PCNSL seen at Memorial Sloan-Kettering Cancer Center (MSKCC; New York, NY) between 1983 and 2003 were analyzed. Standard univariate and multivariate analyses were performed. In addition, a formal cut point analysis was used to determine the most statistically significant cut point for age. Recursive partitioning analysis (RPA) was used to create independent prognostic classes. An external validation set obtained from three prospective Radiation Therapy Oncology Group (RTOG) PCNSL clinical trials was used to test the RPA classification. Results Age and performance status were the only variables identified on standard multivariate analysis. Cut point analysis of age determined that patients age ≤ 50 years had significantly improved outcome compared with older patients. RPA of 282 patients identified three distinct prognostic classes: class 1 (patients < 50 years), class 2 (patients ≥50; Karnofsky performance score [KPS] ≥ 70) and class 3 (patients ≥ 50; KPS < 70). These three classes significantly distinguished outcome with regard to both overall and failure-free survival. Analysis of the RTOG data set confirmed the validity of this classification. Conclusion The MSKCC prognostic score is a simple, statistically powerful model with universal applicability to patients with newly diagnosed PCNSL. We recommend that it be adopted for the management of newly diagnosed patients and incorporated into the design of prospective clinical trials.
Cryoelectron Microscopy of Protein IX-Modified Adenoviruses Suggests a New Position for the C Terminus of Protein IX
Marsh, Michael P., Campos, Samuel K. , Baker, Matthew L. , Chen, Christopher Y. , Chiu, Wah , Barry, Michael A. , Barry, Michael A , Campos, Samuel K

Journal of Virology | November 13, 2006 | Volume: 80 | Issue: 23 | Pages: 11881-11886

10.1128/jvi.01471-06 | PMID 16987967 Get It

ABSTRACT Recombinant human adenovirus is a useful gene delivery vector for clinical gene therapy. Minor capsid protein IX of adenovirus has been of recent interest since multiple studies have shown that modifications can be made to its C terminus to alter viral tropism or add molecular tags and/or reporter proteins. We examined the structure of an engineered adenovirus displaying the enhanced green fluorescent protein (EGFP) fused to the C terminus of protein IX. Cryoelectron microscopy and reconstruction localized the C-terminal EGFP fusion between the H2 hexon and the H4 hexon, positioned between adjacent facets, directly above the density previously assigned as protein IIIa. The original assignment of IIIa was based largely on indirect evidence, and the data presented herein support the reassignment of the IIIa density as protein IX.
Parkinsonism, Lrrk2 G2019S, and tau neuropathology
Rajput, Ali H. , Dickson, Dennis W. , Robinson, Christopher A. , Ross, Owen A. , Dächsel, Justus C., Lincoln, S., Cobb, Stephanie A., Rajput, Michele L., Farrer, Matthew J. , Dickson, Dennis W , Ross, Owen A

Neurology | October 24, 2006 | Volume: 67 | Issue: 8 | Pages: 1506-1508

10.1212/01.wnl.0000240220.33950.0c | PMID 17060589 Get It

Intravascular Ultrasound for Intracranial Angioplasty and Stent Placement: Technical Case Report
Wehman, J. Christopher, Holmes, David R. , Hopkins, L. Nelson , Hanel, Ricardó A. , Levy, Elad I.

Operative Neurosurgery | October 18, 2006 | Volume: 59 | Issue: suppl_4 | Pages: ONS-E481-ONS-E483

10.1227/01.neu.0000222825.92929.0c | PMID 17041521 Get It

Abstract OBJECTIVE: Intravascular ultrasound (IVUS) imaging has been used extensively in coronary artery interventions and has provided invaluable information for the understanding and treatment of coronary arterial disease. We present here the first description, to our knowledge, of IVUS-guided intracranial arterial interventions in the clinical setting. CLINICAL PRESENTATION: Two patients underwent intracranial angioplasty and stent placement with the assistance of IVUS for the evaluation of their lesions. One patient underwent stenting to treat an occlusive dissection of the left internal carotid artery that occurred during arteriovenous malformation embolization. Another patient underwent angioplasty and stenting for high-grade restenosis of a basilar artery atherosclerotic lesion. RESULTS: Both patients underwent successful revascularization procedures. The patient with the dissection had a small intraventricular and parenchymal hemorrhage documented by computed tomography 4 hours after treatment, but did not develop hydrocephalus or further hemorrhage. Both patients did well clinically and had no permanent neurological deficits. IVUS provided important information in terms of lesion evaluation, stent selection, and stent placement in each case. CONCLUSION: IVUS of the intracranial circulation may assist the performance of intracranial angioplasty and stenting. It provides useful information that can affect clinical decisions. It may prove to be a valuable tool in clinical use and enhance our understanding of vascular disease of the intracranial circulation, as it has in the coronary circulation.
Characterization of "Peak E," a Novel Amino Acid Associated with Eosinophilia-Myalgia Syndrome
Mayeno, Arthur N., Foote, Christopher S., Loegering, David A., Ames, Matthew M. , Hedberg, Craig W. , Gleich, Gerald J. , Lin, Feng

Science | October 5, 2006 | Volume: 250 | Issue: 4988 | Pages: 1707-1708

10.1126/science.2270484 | PMID 2270484 Get It

Epidemiologic studies strongly associate eosinophilia-myalgia syndrome (EMS) with ingestion of tryptophan containing a contaminant ("peak E"). Prior reports have suggested that peak E is the di-tryptophan Nα-animal of acetaldehyde. Spectral and chemical studies now demonstrate that peak E is 1,1′-ethylidenebis[tryptophan]. This novel amino acid may be the etiological agent responsible for EMS, or it may be a marker of a still unidentified causal agent.
Increased Fibroblast Growth Factor-Inducible 14 Expression Levels Promote Glioma Cell Invasion via Rac1 and Nuclear Factor-κB and Correlate with Poor Patient Outcome
Tran, Nhan L. , McDonough, Wendy S., Savitch, Benjamin A., Ensign, Shannon P. Fortin , Winkles, Jeffrey A. , Symons, Marc , Cunliffe, Heather E. , Hoelzinger, Dominique B. , Rennert, Jessica L., Burkly, Linda C. , Loftus, Joseph C. , Ensign, Shannon P. Fortin , Nakada, Mitsutoshi , Hostetter, Galen H. , Michaelson, Jennifer S. , Lipinski, Christopher A. , Mariani, Luigi , Berens, Michael E. , Tran, Nhan L

Cancer Research | October 3, 2006 | Volume: 66 | Issue: 19 | Pages: 9535-9542

10.1158/0008-5472.can-06-0418 | PMID 17018610 Get It

Abstract Glial tumors progress to malignant grades by heightened proliferation and relentless dispersion throughout the central nervous system. Understanding genetic and biochemical processes that foster these behaviors is likely to reveal specific and effective targets for therapeutic intervention. Our current report shows that the fibroblast growth factor-inducible 14 (Fn14), a member of the tumor necrosis factor (TNF) receptor superfamily, is expressed at high levels in migrating glioma cells in vitro and invading glioma cells in vivo. Forced Fn14 overexpression stimulates glioma cell migration and invasion, and depletion of Rac1 by small interfering RNA inhibits this cellular response. Activation of Fn14 signaling by the ligand TNF-like weak inducer of apoptosis (TWEAK) stimulates migration and up-regulates expression of Fn14; this TWEAK effect requires Rac1 and nuclear factor-κB (NF-κB) activity. The Fn14 promoter region contains NF-κB binding sites, which mediate positive feedback causing sustained overexpression of Fn14 and enduring glioma cell invasion. Furthermore, Fn14 gene expression levels increase with glioma grade and inversely correlate with patient survival. These results show that the Fn14 cascade operates as a positive feedback mechanism for elevated and sustained Fn14 expression. Such a feedback loop argues for aggressive targeting of the Fn14 axis as a unique and specific driver of glioma malignant behavior. (Cancer Res 2006; 66(19): 9535-42)
Modeling Chronic Glycemic Exposure Variables as Correlates and Predictors of Microvascular Complications of Diabetes
Dyck, P. James B. , Davies, Jenny L., Clark, Vicki M., Litchy, William J. , Klein, Christopher J. , Rizza, Robert A., Pach, John M., Larson, Timothy S., Melton, L. Joseph, O’Brien, Peter C. , Klein, Ronald , Klein, Christopher J

Diabetes Care | September 26, 2006 | Volume: 29 | Issue: 10 | Pages: 2282-2288

10.2337/dc06-0525 | PMID 17003307 Get It

OBJECTIVE—The degree to which chronic glycemic exposure (CGE) (fasting plasma glucose [FPG], HbA1c [A1C], duration of diabetes, age at onset of diabetes, or combinations of these) is associated with or predicts the severity of microvessel complications is unsettled. Specifically, we test whether combinations of components correlate and predict complications better than individual components. RESEARCH DESIGN AND METHODS—Correlations and predictions of CGE and complications were assessed in the Rochester Diabetic Neuropathy Study, a population-based, cross-sectional, and longitudinal epidemiologic survey of 504 patients with diabetes followed for up to 20 years. RESULTS—In multivariate analysis, A1C and duration of diabetes (and to a lesser degree age at onset of diabetes but not FPG) were the main significant CGE risk covariates for complications. A derived glycemic exposure index (GEi) correlated with and predicted complications better than did individual components. Composite or staged measures of polyneuropathy provided higher correlations and better predictions than did dichotomous measures of whether polyneuropathy was present or not. Generally, the mean GEi was significantly higher with increasing stages of severity of complications. CONCLUSIONS—A combination of A1C, duration of diabetes, and age at onset of diabetes (a mathematical index, GEi) correlates significantly with complications and predicts later complications better than single components of CGE. Serial measures of A1C improved the correlations and predictions. For polyneuropathy, continuous or staged measurements performed better than dichotomous judgments. Even with intensive assessment of CGE and complications over long times, only about one-third of the variability of the severity of complications is explained, emphasizing the role of other putative risk covariates.
Cytotoxic synergy between the multikinase inhibitor sorafenib and the proteasome inhibitor bortezomib in vitro: induction of apoptosis through Akt and c-Jun NH2-terminal kinase pathways
Yu, Chunrong, Friday, Bret B., Lai, Jin-Ping, Yang, Lin , Carter, Christopher A., Roberts, Lewis R. , Adjei, Alex A. , Sarkaria, Jann N. , Kay, Neil E. , Kaufmann, Scott H. , Roberts, Lewis R

Molecular Cancer Therapeutics | September 19, 2006 | Volume: 5 | Issue: 9 | Pages: 2378-2387

10.1158/1535-7163.mct-06-0235 | PMID 16985072 Get It

Abstract This study was undertaken to characterize preclinical cytotoxic interactions for human malignancies between the multikinase inhibitor sorafenib (BAY 43-9006) and proteasome inhibitors bortezomib or MG132. Multiple tumor cell lines of varying histiotypes, including A549 (lung adenocarcinoma), 786-O (renal cell carcinoma), HeLa (cervical carcinoma), MDA-MB-231 (breast), K562 (chronic myelogenous leukemia), Jurkat (acute T-cell leukemia), MEC-2 (B-chronic lymphocytic leukemia), and U251 and D37 (glioma), as well as cells derived from primary human glioma tumors that are likely a more clinically relevant model were treated with sorafenib or bortezomib alone or in combination. Sorafenib and bortezomib synergistically induced a marked increase in mitochondrial injury and apoptosis, reflected by cytochrome c release, caspase-3 cleavage, and poly(ADP-ribose) polymerase degradation in a broad range of solid tumor and leukemia cell lines. These findings were accompanied by several biochemical changes, including decreased phosphorylation of vascular endothelial growth factor receptor-2, platelet-derived growth factor receptor-β, and Akt and increased phosphorylation of stress-related c-Jun NH2-terminal kinase (JNK). Inhibition of Akt was required for synergism, as a constitutively active Akt protected cells against apoptosis induced by the combination. Alternatively, the JNK inhibitor SP600125 could also protect cells from apoptosis induced by the combination, indicating that both inhibition of Akt and activation of JNK were required for the synergism. These findings show that sorafenib interacts synergistically with bortezomib to induce apoptosis in a broad spectrum of neoplastic cell lines and show an important role for the Akt and JNK pathways in mediating synergism. Further clinical development of this combination seems warranted. [Mol Cancer Ther 2006;5(9):2378–87]
Regression analysis for comparing protein samples with 16O/18O stable-isotope labeled mass spectrometry
Eckel‐Passow, Jeanette E. , Oberg, Ann L. , Therneau, Terry M. , Mason, Christopher J. , Johnson, Kenneth L. , Bergen, H. Robert, Mahoney, Douglas W. , Olson, Janet E.

Bioinformatics | September 6, 2006 | Volume: 22 | Issue: 22 | Pages: 2739-2745

10.1093/bioinformatics/btl464 | PMID 16954138 Get It

Abstract Motivation: Using stable isotopes in global proteome scans, labeled molecules from one sample are pooled with unlabeled molecules from another sample and subsequently subjected to mass-spectral analysis. Stable-isotope methodologies make use of the fact that identical molecules of different stable-isotope compositions are differentiated in a mass spectrometer and are represented in a mass spectrum as distinct isotopic clusters with a known mass shift. We describe two multivariable linear regression models for 16O/18O stable-isotope labeled data that jointly model pairs of resolved isotopic clusters from the same peptide and quantify the abundance present in each of the two biological samples while concurrently accounting for peptide-specific incorporation rates of the heavy isotope. The abundance measure for each peptide from the two biological samples is then used in down-stream statistical analyses, e.g. differential expression analysis. Because the multivariable regression models are able to correct for the abundance of the labeled peptide that appear as an unlabeled peptide due to the inability to exchange the natural C-terminal oxygen for the heavy isotope, they are particularly advantageous for a two-step digestion/labeling procedure. We discuss how estimates from the regression model are used to quantify the variability of the estimated abundance measures for the paired samples. Although discussed in the context of 16O/18O stable-isotope labeled data, the multivariable regression models are generalizable to other stable-isotope labeled technologies. Contact: eckel@mayo.edu