Citations

Mayo Clinic

Clear

7716 citation(s) found for "Ma, Daniel".

MR characterization of hepatic storage iron in transfusional iron overload
Tang, Haiying, Jensen, Jens H. , Sammet, Christina L., Sheth, Sujit , Swaminathan, Srirama V., Hultman, Kristi, Wu, EX , Brown, Truman R. , Brittenham, Gary M. , Kim, Daniel , Kim, Daniel , Kim, Daniel

Journal of Magnetic Resonance Imaging | May 29, 2013 | Volume: 39 | Issue: 2 | Pages: 307-316

10.1002/jmri.24171 | PMID 23720394 Get It

PurposeTo quantify the two principal forms of hepatic storage iron, diffuse, soluble iron (primarily ferritin), and aggregated, insoluble iron (primarily hemosiderin) using a new MRI method in patients with transfusional iron overload.Materials and MethodsSix healthy volunteers and 20 patients with transfusion‐dependent thalassemia syndromes and iron overload were examined. Ferritin‐ and hemosiderin‐like iron were determined based on the measurement of two distinct relaxation parameters: the “reduced” transverse relaxation rate, RR2, and the “aggregation index,” A, using three sets of Carr‐Purcell‐Meiboom‐Gill (CPMG) datasets with different interecho spacings. Agarose phantoms, simulating the relaxation and susceptibility properties of tissue with different concentrations of dispersed (ferritin‐like) and aggregated (hemosiderin‐like) iron, were used for validation.ResultsBoth phantom and in vivo human data confirmed that transverse relaxation components associated with the dispersed and aggregated iron could be separated using the two‐parameter (RR2, A) method. The MRI‐determined total hepatic storage iron was highly correlated (r = 0.95) with measurements derived from biopsy or biosusceptometry. As total hepatic storage iron increased, the proportion stored as aggregated iron became greater.ConclusionThis method provides a new means for noninvasive MRI determination of the partition of hepatic storage iron between ferritin and hemosiderin in iron overload disorders. J. Magn. Reson. Imaging 2014;39:307–316. © 2013 Wiley Periodicals, Inc.
Localized Tongue Amyloidosis: A Single Institutional Case Series
O’Reilly, Ashley G., D’Souza, Anita , Lust, John A., Price, Daniel L. , O'Reilly, Ashley, Price, Daniel L , D'Souza, Anita

Otolaryngology–Head and Neck Surgery | May 29, 2013 | Volume: 149 | Issue: 2 | Pages: 240-244

10.1177/0194599813490896 | PMID 23715681 Get It

ObjectiveReview Mayo Clinic experience of localized tongue amyloidosis.Study DesignCase series with retrospective chart review.SettingAcademic medical center.Subjects and MethodsCases of localized tongue amyloidosis were identified from the dysproteinemia database at the Mayo Clinic in Rochester, Minnesota. Electronic records were reviewed with focus on presenting symptoms, laboratory results (ie, serum or urine immunoelectrophoresis, bone marrow biopsy, and fat aspirate analysis), treatment modality, and status of disease at follow‐up.ResultsSix cases of localized tongue amyloidosis presented to the Mayo Clinic between 1969 and 2011. Mean patient age was 69 years (range, 43‐90). Patients presented with asymptomatic tongue mass(es). Biopsy of the tongue mass in all patients showed amyloid on Congo red stains. Work‐up for systemic amyloidosis, including bone marrow biopsy, fat aspiration, and serum and urine protein immunoelectrophoresis, was negative for all 6 patients, nor was there other organ involvement. Two patients underwent resection of the lesions, and the remaining patients elected for observation. Recurrence requiring repeat excision occurred in 1 of the patients that underwent resection. Repeat evaluation for systemic involvement was performed in 3 patients 1 to 3 years after the initial diagnosis. None of these patients went on to develop systemic involvement.ConclusionsLocalized tongue amyloidosis remains a rare diagnosis and requires exclusion of systemic involvement. Localized lesions may be observed or resected; however, recurrence may occur with resection. Patients with localized tongue amyloidosis do not appear to be at increased risk of developing systemic involvement.
Genetics of Stroke
Woo, Daniel , Meschia, James F.

Stroke | May 24, 2013 | Volume: 44 | Issue: 6_suppl_1 | Pages: No page available

10.1161/strokeaha.112.680041 | PMID 23709714 Get It

Simple Risk Model Predicts Incidence of Atrial Fibrillation in a Racially and Geographically Diverse Population: the CHARGE‐AF Consortium
Alonso, Álvaro , Krijthe, Bouwe P., Aspelund, Thor , Stepas, Katherine A., Pencina, Michael , Moser, Carlee , Sinner, Moritz F. , Sotoodehnia, Nona, Fontes, João D. , Janssens, A. Cecile J.W. , Witteman, Jacqueline C.M., Chamberlain, Alanna M. , Lubitz, Steven A. , Agarwal, Sunil , McManus, David D. , Ellinor, Patrick T. , Larson, Martin G. , Burke, Gregory L. , Hofman, Albert , Levy, Daniel , Gottdiener, John S. , Couper, David , Harris, Tamara B. , Soliman, Elsayed Z. , Stricker, Bruno H. , Guðnason, Vilmundur , Heckbert, Susan R. , Benjamin, Emelia J. , Kronmal, Richard A. , Magnani, Jared W. , Schnabel, Renate B. , Launer, Lenore J. , Kääb, Stefan , Alonso, Alvaro , Chamberlain, Alanna M , Benjamin, Emelia J , Lubitz, Steven A , Ellinor, Patrick T , Levy, Daniel , Couper, David

Journal of the American Heart Association | May 24, 2013 | Volume: 2 | Issue: 2 | Pages: No page available

10.1161/jaha.112.000102 | PMID 23537808 Get It

Background Tools for the prediction of atrial fibrillation ( AF ) may identify high‐risk individuals more likely to benefit from preventive interventions and serve as a benchmark to test novel putative risk factors. Methods and Results Individual‐level data from 3 large cohorts in the U nited S tates (Atherosclerosis Risk in Communities [ ARIC ] study, the Cardiovascular Health Study [ CHS ], and the Framingham Heart Study [ FHS ]), including 18 556 men and women aged 46 to 94 years (19% A frican A mericans, 81% whites) were pooled to derive predictive models for AF using clinical variables. Validation of the derived models was performed in 7672 participants from the Age, Gene and Environment—Reykjavik study ( AGES ) and the Rotterdam Study ( RS ). The analysis included 1186 incident AF cases in the derivation cohorts and 585 in the validation cohorts. A simple 5‐year predictive model including the variables age, race, height, weight, systolic and diastolic blood pressure, current smoking, use of antihypertensive medication, diabetes, and history of myocardial infarction and heart failure had good discrimination (C‐statistic, 0.765; 95% CI , 0.748 to 0.781). Addition of variables from the electrocardiogram did not improve the overall model discrimination (C‐statistic, 0.767; 95% CI , 0.750 to 0.783; categorical net reclassification improvement, −0.0032; 95% CI , −0.0178 to 0.0113). In the validation cohorts, discrimination was acceptable ( AGES C‐statistic, 0.664; 95% CI , 0.632 to 0.697 and RS C‐statistic, 0.705; 95% CI , 0.664 to 0.747) and calibration was adequate. Conclusion A risk model including variables readily available in primary care settings adequately predicted AF in diverse populations from the U nited S tates and E urope.
Phase II trial of panobinostat, an oral pan‐deacetylase inhibitor in patients with primary myelofibrosis, post–essential thrombocythaemia, and post–polycythaemia vera myelofibrosis
Tefferi, Ayalew , Paley, Carole, Wadleigh, Martha , Ritchie, Ellen K. , Snyder, David S., Begna, Kebede H. , Ganguly, Siddhartha , Ondovik, Michael S., Rine, Jessica, Bhalla, Kapil N. , DeAngelo, Daniel J. , Mesa, Ruben A. , Fiskus, Warren C.

British Journal of Haematology | May 23, 2013 | Volume: 162 | Issue: 3 | Pages: 326-335

10.1111/bjh.12384 | PMID 23701016 Get It

SummaryMyelofibrosis (MF) is a Philadelphia chromosome–negative stem cell myeloproliferative neoplasm (MPN) associated with cytopenias, splenomegaly, constitutional symptoms, and poor prognosis. MF patients commonly express JAK2 V617F mutation and activation of Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signalling. Agents targeting the JAK/STAT pathway have demonstrated efficacy in patients with MF. This study evaluated panobinostat, a pan‐deacetylase inhibitor that depletes JAK2 V617F levels and JAK/STAT signalling in MPN cells, in patients with primary MF, post–essential thrombocythaemia MF, and post–polycythaemia vera MF. Patients received panobinostat 40 mg administered three times per week. Dose reductions were permitted for toxicities. The primary endpoint was response rate at 6 months using International Working Group for Myelofibrosis Research and Treatment (IWG‐MRT) consensus criteria. Analyses of peripheral blood cells from treated patients revealed that panobinostat inhibited JAK/STAT signalling, decreased inflammatory cytokine levels, and decreased JAK2 V617F allelic burden. However, panobinostat was poorly tolerated at the dose and schedule evaluated, and only 16 of 35 patients completed ≥2 cycles of treatment. One patient (3%) achieved an IWG‐MRT response. Common adverse events were thrombocytopenia (71·4%) and diarrhoea (80·0%). Although molecular correlative analyses suggested that panobinostat inhibits key intracellular targets, limited clinical activity was observed because of poor tolerance.
In Reply:
Turner, J. , Cole, Daniel J.

Anesthesiology | May 22, 2013 | Volume: 118 | Issue: 6 | Pages: 1484-1484

10.1097/aln.0b013e318291d923 Get It

Level IIB lymph node metastasis in laryngeal and hypopharyngeal squamous cell carcinoma: Single‐institution case series and review of the literature
Gross, Brian C., Olsen, Steven M., Lewis, Jean E., Kasperbauer, Jan L. , Moore, Eric J. , Olsen, Kerry D., Price, Daniel L. , Price, Daniel L

The Laryngoscope | May 20, 2013 | Volume: 123 | Issue: 12 | Pages: 3032-3036

10.1002/lary.24198 | PMID 23686866 Get It

Objectives/HypothesisTo determine the incidence of level IIB lymph node metastasis in patients with laryngeal or hypopharyngeal squamous cell carcinoma and to evaluate the need for elective and therapeutic neck dissection of level IIB.Study DesignRetrospective cohort study and review of the literature.MethodsPatients with laryngeal or hypopharyngeal squamous cell carcinoma (N = 65) were primarily treated with surgery at Mayo Clinic (Rochester, Minnesota) from 2004 through 2010. Neck dissection specimens were analyzed by a pathologist, and metastases to level IIB were reported. In addition, 18 previously published studies, totaling 1,114 neck dissections, were reviewed.ResultsLevel IIB lymph node metastases were present in 4% and 17% of elective and therapeutic neck dissections, respectively. Ipsilateral IIB metastasis was more common than contralateral IIB metastasis in elective and therapeutic neck dissection specimens. Level IIB lymph node metastasis was not significantly associated with level IIA nodal metastasis, level III nodal metastasis, clinical primary tumor stage, clinical nodal stage, or pathologic confirmation of extracapsular spread in either laryngeal or hypopharyngeal squamous cell carcinoma.ConclusionsThe rate of occult IIB metastasis in laryngeal and hypopharyngeal squamous cell carcinoma is exceedingly low. In a clinically node‐negative case, the ipsilateral and contralateral level IIB nodal packet should not be dissected. For clinically node‐positive cases, ipsilateral level IIB dissection should be performed; contralateral IIB dissection should be performed only when indicated.Level of Evidence4. Laryngoscope, 123:3032–3036, 2013
Adaptive adjustment of the randomization ratio using historical control data
Hobbs, Brian P. , Carlin, Bradley P. , Sargent, Daniel J. , Sargent, Daniel J

Clinical Trials | May 20, 2013 | Volume: 10 | Issue: 3 | Pages: 430-440

10.1177/1740774513483934 | PMID 23690095 Get It

Background Prospective trial design often occurs in the presence of ‘acceptable’ historical control data. Typically, these data are only utilized for treatment comparison in a posteriori retrospective analysis to estimate population-averaged effects in a random-effects meta-analysis. Purpose We propose and investigate an adaptive trial design in the context of an actual randomized controlled colorectal cancer trial. This trial, originally reported by Goldberg et al., succeeded a similar trial reported by Saltz et al., and used a control therapy identical to that tested (and found beneficial) in the Saltz trial. Methods The proposed trial implements an adaptive randomization procedure for allocating patients aimed at balancing total information (concurrent and historical) among the study arms. This is accomplished by assigning more patients to receive the novel therapy in the absence of strong evidence for heterogeneity among the concurrent and historical controls. Allocation probabilities adapt as a function of the effective historical sample size (EHSS), characterizing relative informativeness defined in the context of a piecewise exponential model for evaluating time to disease progression. Commensurate priors are utilized to assess historical and concurrent heterogeneity at interim analyses and to borrow strength from the historical data in the final analysis. The adaptive trial’s frequentist properties are simulated using the actual patient-level historical control data from the Saltz trial and the actual enrollment dates for patients enrolled into the Goldberg trial. Results Assessing concurrent and historical heterogeneity at interim analyses and balancing total information with the adaptive randomization procedure lead to trials that on average assign more new patients to the novel treatment when the historical controls are unbiased or slightly biased compared to the concurrent controls. Large magnitudes of bias lead to approximately equal allocation of patients among the treatment arms. Using the proposed commensurate prior model to borrow strength from the historical data, after balancing total information with the adaptive randomization procedure, provides admissible estimators of the novel treatment effect with desirable bias-variance trade-offs. Limitations Adaptive randomization methods in general are sensitive to population drift and more suitable for trials that initiate with gradual enrollment. Balancing information among study arms in time-to-event analyses is difficult in the presence of informative right-censoring. Conclusions The proposed design could prove important in trials that follow recent evaluations of a control therapy. Efficient use of the historical controls is especially important in contexts where reliance on preexisting information is unavoidable because the control therapy is exceptionally hazardous, expensive, or the disease is rare.
Cognitive outcomes of patients undergoing therapeutic hypothermia after cardiac arrest
Fugate, Jennifer E. , Moore, Samuel A., White, Roger D., Knopman, David S. , Claassen, Daniel O. , Wijdicks, Eelco F. M. , Rabinstein, Alejandro A.

Neurology | May 18, 2013 | Volume: 81 | Issue: 1 | Pages: 40-45

10.1212/wnl.0b013e318297ee7e | PMID 23685933 Get It

Level IIB lymph node metastasis in oropharyngeal squamous cell carcinoma
Gross, Brian C., Olsen, Steven M., Lewis, Jean E., Kasperbauer, Jan L. , Moore, Eric J. , Olsen, Kerry D., Price, Daniel L. , Price, Daniel L

The Laryngoscope | May 17, 2013 | Volume: 123 | Issue: 11 | Pages: 2700-2705

10.1002/lary.24129 | PMID 23686577 Get It

Objectives/HypothesisTo determine the incidence of level IIB lymph node metastasis in patients with oropharyngeal squamous cell carcinoma (OPSCC) and to evaluate the necessity of level IIB dissection for elective and therapeutic neck dissections.Study DesignRetrospective cohort study.MethodsPatients with OPSCC (N = 348) were surgically managed at our institution from 2004 through 2010. Neck dissection specimens were reviewed by a pathologist, and level IIB metastases were analyzed with respect to clinical and pathologic data.ResultsLevel IIB lymph node metastases were present in 2.5% and 25% of elective and therapeutic neck dissections, respectively. Level IIA metastasis, clinical tumor stage, clinical nodal stage, extracapsular spread, and primary tumor location in the tonsil were significantly associated with level IIB metastasis.ConclusionsThis study uniquely demonstrated a statistically significant association between clinical tumor stage and tonsil subsite with level IIB metastasis in OPSCC. Considering the predicted incidence of nodal metastasis, we conclude that level IIB neck dissection can be omitted in early stage (T1 or T2) clinically node negative (cN0) OPSCC. In patients with a cN0 neck and advanced OPSCC (T3 or T4), primary tumor in the tonsil, or ipsilateral clinically node positive (cN+) and contralateral cN0 neck, level IIB dissection should be considered. Level IIB dissection should be performed routinely in patients with cN+ OPSCC.Level of Evidence4. Laryngoscope, 123:2700–2705, 2013