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

Phase III Study of Adjuvant Chemotherapy and Radiation Therapy Compared With Chemotherapy Alone in the Surgical Adjuvant Treatment of Colon Cancer: Results of Intergroup Protocol 0130
Martenson, James A., Willett, Christopher G. , Sargent, Daniel J. , Mailliard, James A., Donohue, John H., Gunderson, Leonard L., Thomas, Charles R., Fisher, Barbara, Benson, Al B. , Myerson, Robert J., Goldberg, Richard M. , Sargent, Daniel J

Journal of Clinical Oncology | July 13, 2004 | Volume: 22 | Issue: 16 | Pages: 3277-3283

10.1200/jco.2004.01.029 | PMID 15249584 Get It

Purpose Some patients with colon cancer have a high risk of local recurrence postoperatively. This trial was undertaken to determine whether radiation therapy added to an adjuvant chemotherapy regimen improves outcome in high-risk patients. Patients and Methods Patients with resected colon cancer with tumor adherence or invasion of surrounding structures, or with T3N1 or T3N2 tumors of the ascending or descending colon were randomly assigned to receive fluorouracil and levamisole therapy with or without radiation therapy. Patients who received chemotherapy and radiation therapy (chemoRT) received 45 to 50.4 Gy in 25 to 28 fractions beginning 28 days after starting chemotherapy. Patient enrollment was terminated because of slow accrual after 222 patients enrolled (original goal was 700 patients); 187 patients were assessable. Results Overall 5-year survival was 62% for chemotherapy patients and 58% for chemoRT patients (P > .50); 5-year disease-free survival was 51% for both groups (P > .50). Toxicity (≥ grade 3) occurred in 42% of chemotherapy patients and 54% of chemoRT patients (P = .04). Leukopenia (≥ grade 3) occurred in 10% of chemotherapy patients and 22% of chemoRT patients (P = .02). No significant difference in nonhematologic toxicity (≥ grade 3) was observed between chemoRT and chemotherapy patients (35% v 44%; P = .26). Conclusion Patients who received chemotherapy or chemoRT had similar overall survival and disease-free survival. Toxicity was higher among chemoRT patients. These results must be interpreted with caution because of the high number of ineligible patients and the limited power of the study to detect potentially meaningful differences.
Evaluation and Clinical Implications of Aortic Valve Calcification Measured by Electron-Beam Computed Tomography
Messika–Zeitoun, David , Aubry, Marie-Christine, Détaint, Delphine, Bielak, Lawrence F. , Peyser, Patricia A. , Sheedy, Patrick F. , Breen, Jerome F., Scott, Christopher G. , Tajik, A. Jamil , Turner, Stephen T. , Enriquez‐Sarano, Maurice , Scott, Christopher , Enriquez-Sarano, Maurice , Messika-Zeitoun, David

Circulation | July 12, 2004 | Volume: 110 | Issue: 3 | Pages: 356-362

10.1161/01.cir.0000135469.82545.d0 | PMID 15249504 Get It

Background— Electron-beam computed tomography (EBCT) is used to measure coronary calcification but not for aortic valve calcification (AVC). Its accuracy, association with aortic stenosis (AS) severity, and diagnostic and prognostic value with respect to AVC are unknown. Methods and Results— In 30 explanted aortic valves, the AVC score by EBCT (1125±1294 Agatston units [AU]) showed a strong linear correlation ( r =0.96, P <0.0001) with valvular calcium weight (653±748 mg) by pathology that allowed estimation of calcium weight as AVC score/1.7, with a small standard error of the estimate (53 mg). In 100 consecutive clinical patients, we measured AVC by EBCT and AS severity by echocardiographic aortic valve area (AVA). The AVC score was 1316±1749 AU (range 0 to 7226 AU). Intraobserver and interobserver variabilities were excellent (4±4% and 4±10%, respectively). AVC and AVA were strongly associated ( r =0.79, P <0.0001) but had a curvilinear relationship that suggested that AVC and AVA provide complementary information. AVC score ≥1100 AU provided 93% sensitivity and 82% specificity for diagnosis of severe AS (AVA <1 cm 2 ), with a receiver operator characteristic curve area of 0.89. AVC assessment by echocardiography was often more severe than by EBCT ( P <0.0001). During follow-up, 22 patients either died, developed heart failure, or required surgery. With adjustment for age, sex, symptoms, ejection fraction, and AVA, the AVC score was independently predictive of event-free survival (risk ratio 1.06 per 100-AU increment [1.02 to 1.10], P <0.001), even after adjustment for echocardiographic calcifications. Conclusions— AVC is accurately and reproducibly measured by EBCT and shows a strong association and diagnostic value for severe AS. The curvilinear relationship between AVC and AVA suggests these measures are complementary, and indeed, AVC provides independent outcome information. Thus, AVC is an important measurement in the evaluation of patients with AS.
Identification of Transthyretin Variants by Sequential Proteomic and Genomic Analysis
Bergen, H. Robert, Zeldenrust, Steven R., Butz, Malinda L., Snow, Denise S., Dyck, P. James B. , Klein, Christopher J. , Thibodeau, Stephen N. , Muddiman, David C. , O’Brien, John F. , Klein, Christopher J

Clinical Chemistry | June 25, 2004 | Volume: 50 | Issue: 9 | Pages: 1544-1552

10.1373/clinchem.2004.033266 | PMID 15217993 Get It

Abstract Background: Transthyretin-associated hereditary amyloidosis (ATTR) is an inherited disease in which variants in the primary structure of transthyretin (TTR; prealbumin) lead to the extracellular polymerization of insoluble protein fibrils, causing organ failure and ultimately death when major organs are involved. We have developed an integrated approach to molecular diagnosis with initial analysis of intact plasma TTR by electrospray ionization mass spectrometry (MS) and referral of positive samples for DNA sequence analysis and real-time PCR to confirm the common Gly6Ser polymorphism. Methods: Samples from 6 patients previously diagnosed with ATTR and from 25 controls with (n = 15) or without (n = 10) polyneuropathy were analyzed in a blinded fashion for the presence of variant TTR. TTR protein was extracted with an immunoaffinity resin from 20 μL of archived plasma samples. The purified TTR was reduced with tris(2-carboxyethyl)phosphine and analyzed by MS. The appearance of two peaks (or a single peak shifted in mass indicative of a homozygous variant), including the wild-type mass of 13 761 Da, was indicative of the presence of a variant, and the individual was referred for DNA sequence analysis. Results: MS analysis of intact reduced TTR correctly identified each of six samples known to contain variant TTR. These results were corroborated by subsequent DNA sequence analysis. Additionally, all Gly6Ser polymorphisms were correctly called based on the +30 mass shift and an equal relative abundance of the +30 polymorphism relative to wild-type TTR. No false-positive results were seen. Conclusions: This referral method eliminates the necessity of sequencing most samples and allows screening for the familial forms of amyloidosis in a broad patient population in a timely fashion. This method correctly identified all previously known variants and also identified a novel variant, Val94Ala.
Substitution of Oral Fluoropyrimidines for Infusional Fluorouracil With Radiotherapy: How Much Data Do We Need?
Crane, Christopher H. , Sargent, Daniel J. , Sargent, Daniel J

Journal of Clinical Oncology | June 22, 2004 | Volume: 22 | Issue: 15 | Pages: 2978-2981

10.1200/jco.2004.04.953 | PMID 15210736 Get It

Detection of Genetic Variants of Transthyretin by Liquid Chromatography–Dual Electrospray Ionization Fourier-Transform Ion-Cyclotron-Resonance Mass Spectrometry
Nepomuceno, Angelito I., Mason, Christopher J. , Muddiman, David C. , Bergen, H. Robert, Zeldenrust, Steven R.

Clinical Chemistry | June 18, 2004 | Volume: 50 | Issue: 9 | Pages: 1535-1543

10.1373/clinchem.2004.033274 | PMID 15205369 Get It

AbstractBackground: One of the numerous proteins causing amyloidosis is transthyretin (TTR), a protein usually responsible for the transport of thyroxine and retinol-binding protein. Variants within TTR cause it to aggregate and form insoluble fibers that accumulate in tissue, leading to organ dysfunction.Methods: TTR was immunoprecipitated from serum by use of a polyclonal antibody and subsequently reduced with tris(2-carboxyethyl)phosphine. The purified TTR was then analyzed by fast-gradient liquid chromatography–dual-electrospray ionization Fourier-transform ion-cyclotron-resonance (FT-ICR) mass spectrometry. DNA sequencing was performed on all samples used in this study.Results: Because of the inherent limitations in achieving high mass measurement accuracy based on the most abundant isotopic mass, we applied a fitting procedure that allowed determination of monoisotopic mass. Wild-type TTR (mean molecular mass, 13 761 Da) and its associated variant forms could be distinguished because of the high molecular mass accuracy afforded by FT-ICR (≤3 ppm) except for instances involving isobaric species or when isotopic distributions overlapped significantly. The [M + 11 H+]11+ charge state for all samples was used to determine the mass accuracies for both wild-type and variant forms of the protein. We correctly assigned seven of seven TTR variants. Moreover, using a combination of proteomic and genomic technologies, we discovered and characterized a previously unreported cis double mutation with a mass only 2 Da different from wild-type TTR. Furthermore, DNA sequencing of the TTR gene for all individuals in this study completely agreed with the intact protein measurements.Conclusions: FT-ICR mass spectrometry has sufficient mass accuracy to identify genetic variants of immunoaffinity-purified TTR. We believe that 91% of known TTR variants could be detected by this technique.
Management of Insulin Therapy in Urban Diabetes Patients Is Facilitated by Use of an Intelligent Dosing System
Mann, Linda J., King, Esther C., New, Katina M., Vaughn, Pamela S., Dames, Faye, Dunbar, Virginia G., Caudle, J., Tsui, Circe, McMichael, John , Cook, Curtiss B. , George, Christopher D.

Diabetes Technology & Therapeutics | June 4, 2004 | Volume: 6 | Issue: 3 | Pages: 326-335

10.1089/152091504774198016 | PMID 15198835 Get It

Reconstruction of in vivo time-evolving neuroendocrine dose–response properties unveils admixed deterministic and stochastic elements
Keenan, Daniel M., Irvine, C. H. G., Clarke, Iain J. , Scott, Christopher , Turner, Anne I. , Tilbrook, A.J. , Canny, Benedict J., Veldhuis, Johannes D. , Alexander, Susan

Proceedings of the National Academy of Sciences | April 16, 2004 | Volume: 101 | Issue: 17 | Pages: 6740-6745

10.1073/pnas.0300619101 | PMID 15090645 Get It

Homeostasis in the intact organism is achieved implicitly by repeated incremental feedback (inhibitory) and feedforward (stimulatory) adjustments enforced via intermittent signal exchange. In separated systems, neurohormone signals act deterministically on target cells via quantifiable effector-response functions. On the other hand, in vivo interglandular signaling dynamics have not been estimable to date. Indeed, experimentally isolating components of an interactive network definitionally disrupts time-sensitive linkages. We implement and validate analytical reconstruction of endogenous effector-response properties via a composite model comprising ( i ) a deterministic basic feedback and feedforward ensemble structure; ( ii ) judicious statistical allowance for possible stochastic variability in individual biologically interpretable dose–response properties; and ( iii ) the sole data requirement of serially observed concentrations of a paired signal (input) and response (output). Application of this analytical strategy to a prototypical neuroendocrine axis in the conscious uninjected horse, sheep, and human ( i ) illustrates probabilistic estimation of endogenous effector dose–response properties; and ( ii ) unmasks statistically vivid (2- to 5-fold) random fluctuations in inferred target-gland responsivity within any given pulse train. In conclusion, balanced mathematical formalism allows one to ( i ) reconstruct deterministic properties of interglandular signaling in the intact mammal and ( ii ) quantify apparent signal-response variability over short time scales in vivo . The present proof-of-principle experiments introduce a previously undescribed means to estimate time-evolving signal-response relationships without isotope infusion or pathway disruption.
Impact of T and N Stage and Treatment on Survival and Relapse in Adjuvant Rectal Cancer
Gunderson, Leonard L., Sargent, Daniel J. , Tepper, Joel E. , Begovič, Mirsada, Allmer, Cristine, Colangelo, Linda H., Smalley, Steven R., Haller, Daniel G. , Martenson, James A., Rich, Tyvin A. , Macdonald, John S., Willett, Christopher G. , Goldberg, Richard M. , Wolmark, Norman , O’Connell, Michael J. , Mayer, Robert J. , Ajani, Jaffer A. , Sargent, Daniel J

Journal of Clinical Oncology | April 6, 2004 | Volume: 22 | Issue: 10 | Pages: 1785-1796

10.1200/jco.2004.08.173 | PMID 15067027 Get It

Purpose To determine survival and relapse rates by T and N stage and treatment method in five randomized phase III North American rectal adjuvant studies. Patients and Methods Data were pooled from 3,791 eligible patients enrolled onto North Central Cancer Treatment Group (NCCTG) 79-47-51, NCCTG 86-47-51, US Gastrointestinal Intergroup 0114, National Surgical Adjuvant Breast and Bowel Project (NSABP) R01, and NSABP R02. Surgery alone (S) was the treatment arm in 179 patients. The remaining patients received adjuvant treatment as follows: irradiation (RT) alone (n = 281), RT + fluorouracil (FU) ± semustine bolus chemotherapy (CT; n = 779), RT + protracted venous infusion CT (n = 325), RT + FU ± leucovorin or levamisole bolus CT (n = 1,695), or CT alone (n = 532). Five-year follow-up was available in 94% of surviving patients, and 8-year follow-up, in 62%. Results Overall (OS) and disease-free survival were dependent on TN stage, NT stage, and treatment method. Even among N2 patients, T substage influenced 5-year OS (T1-2, 67%; T3, 44%; T4, 37%; P < .001). Three risk groups of patients were defined: (1) intermediate (T1-2/N1, T3/N0), (2) moderately high (T1-2/N2, T3/N1, T4/N0), and (3) high (T3/N2, T4/N1, T4/N2). For intermediate-risk patients, those receiving S plus CT had 5-year OS rates of 85% (T1-2/N1) and 84% (T3/N0), which was similar to results with S plus RT plus CT (T1-2/N1, 78% to 83%; T3/N0, 74% to 80%). For moderately high-risk lesions, 5-year OS ranged from 43% to 70% with S plus CT, and 44% to 80% with S plus RT plus CT. For high-risk lesions, 5-year OS ranged from 25% to 45% with S plus CT, and 29% to 57% with S plus RT plus CT. Conclusion Different treatment strategies may be indicated for intermediate-risk versus moderately high- or high-risk patients based on differential survival rates and rates of relapse. Use of trimodality treatment for all patients with intermediate-risk lesions may be excessive, since S plus CT resulted in 5-year OS of approximately 85%; however, 5-year disease-free survival rates with S plus CT were 78% (T1-2/N1) and 69%(T3/N0), indicating room for improvement.
Prognostication of survival using cardiac troponins and N-terminal pro-brain natriuretic peptide in patients with primary systemic amyloidosis undergoing peripheral blood stem cell transplantation
Dispenzieri, Angela , Kyle, Robert A. , Lacy, Martha Q. , Burritt, Mary F., Therneau, Terry M. , McConnell, Joseph P., Litzow, Mark R. , Gastineau, Dennis A., Tefferi, Ayalew , Inwards, David J. , Micallef, Ivana N. , Ansell, Stephen M. , Porrata, Luis F. , Elliott, Michelle A. , Rajkumar, S. Vincent , Fonseca, Rafaël , Greipp, Philip R., Lust, John A., Zeldenrust, Steven R., Snow, Denise S., Hayman, S. R., McGregor, Christopher G.A. , Jaffe, Allan S. , Gertz, Morie A. , Hogan, William J. , Witzig, Thomas E. , Jaffe, Allan S. , Rajkumar, S Vincent , Dispenzieri, Angela , Fonseca, Rafael

Blood | March 30, 2004 | Volume: 104 | Issue: 6 | Pages: 1881-1887

10.1182/blood-2004-01-0390 | PMID 15044258 Get It

AbstractPrimary systemic amyloidosis (AL) is a fatal plasma cell disorder. Pilot data suggest survival is better in patients undergoing peripheral blood stem cell transplantation (PBSCT), but the selection process makes the apparent benefit suspect. We have reported that circulating cardiac biomarkers are the best predictors of survival outside of the transplantation setting. We now test whether cardiac troponins (cTnT and cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are prognostic in transplant recipients. In 98 patients with AL undergoing PBSCT, serum cardiac biomarkers were measured (cTnT, 98 patients; cTnI, 65 patients; and NT-proBNP, 63 patients). Elevated levels of cTnT, cTnI, and NT-proBNP were present in 14%, 43%, and 48% of patients, respectively. At 20 months median follow-up, median survival has not been reached for patients with values below the thresholds; in patients with values above the thresholds, median survival is 26.1 months, 66.1 months, and 66.1 months, respectively. Our previously reported risk systems incorporating these markers were also prognostic, notably the cTnT/NT-proBNP staging. Using this system, 49%, 38%, and 13% of patients were in stage I, stage II, and stage III, respectively. Determining levels of circulating biomarkers may be the most powerful tool for staging patients with AL undergoing PBSCT.
A Historical Perspective on Use of the Laryngoscope as a Tool in Anesthesiology
Burkle, Christopher M. , Zepeda, Fernando A., Bacon, Douglas R. , Rose, Steven H.

Anesthesiology | March 23, 2004 | Volume: 100 | Issue: 4 | Pages: 1003-1006

10.1097/00000542-200404000-00034 | PMID 15087639 Get It