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3499 citation(s) found for "Xu, Timothy".

Embryonic Stem Cell Therapy of Heart Failure in Genetic Cardiomyopathy
Nelson, Timothy J. , Crespo‐Diaz, Ruben , Pérez-Terzic, Carmen, Liu, Xiaoke , Seino, Susumu , Behfar, Atta , Yamada, Satsuki , Miki, Takashi , Terzic, André , Behfar, Atta , Nelson, Timothy J , Liu, Xiaoke

Stem Cells | August 1, 2008 | Volume: 26 | Issue: 10 | Pages: 2644-2653

10.1634/stemcells.2008-0187 | PMID 18669912 Get It

Abstract Pathogenic causes underlying nonischemic cardiomyopathies are increasingly being resolved, yet repair therapies for these commonly heritable forms of heart failure are lacking. A case in point is human dilated cardiomyopathy 10 (CMD10; Online Mendelian Inheritance in Man #608569), a progressive organ dysfunction syndrome refractory to conventional therapies and linked to mutations in cardiac ATP-sensitive K+ (KATP) channel subunits. Embryonic stem cell therapy demonstrates benefit in ischemic heart disease, but the reparative capacity of this allogeneic regenerative cell source has not been tested in inherited cardiomyopathy. Here, in a Kir6.2-knockout model lacking functional KATP channels, we recapitulated under the imposed stress of pressure overload the gene-environment substrate of CMD10. Salient features of the human malignant heart failure phenotype were reproduced, including compromised contractility, ventricular dilatation, and poor survival. Embryonic stem cells were delivered through the epicardial route into the left ventricular wall of cardiomyopathic stressed Kir6.2-null mutants. At 1 month of therapy, transplantation of 200,000 cells per heart achieved teratoma-free reversal of systolic dysfunction and electrical synchronization and halted maladaptive remodeling, thereby preventing end-stage organ failure. Tracked using the lacZ reporter transgene, stem cells engrafted into host heart. Beyond formation of cardiac tissue positive for Kir6.2, transplantation induced cell cycle activation and halved fibrotic zones, normalizing sarcomeric and gap junction organization within remuscularized hearts. Improved systemic function induced by stem cell therapy translated into increased stamina, absence of anasarca, and benefit to overall survivorship. Embryonic stem cells thus achieve functional repair in nonischemic genetic cardiomyopathy, expanding indications to the therapy of heritable heart failure. Disclosure of potential conflicts of interest is found at the end of this article.
Comparison between Immunoturbidimetry, Size-Exclusion Chromatography, and LC-MS to Quantify Urinary Albumin
Shaikh, Aisha , Seegmiller, Jesse C. , Borland, Timothy M., Burns, Bradley E., Ladwig, Paula M. , Kumar, Rajiv , Larson, Timothy S., Singh, Ravinder J. , Lieske, John C. , Kumar, Rajiv

Clinical Chemistry | July 11, 2008 | Volume: 54 | Issue: 9 | Pages: 1504-1510

10.1373/clinchem.2008.107508 | PMID 18617580 Get It

Abstract Background: The accurate and precise measurement of urinary albumin is critical, since even minor increases are diagnostically sensitive indicators of renal disease, cardiovascular events, and risk for death. To gain insights into potential measurement biases, we systematically compared urine albumin measurements performed by LC-MS, a clinically available immunoturbidimetric assay, and size-exclusion HPLC. Methods: We obtained unused clinical urine samples from 150 patients who were stratified by degrees of albuminuria (<20 mg/L, 20–250 mg/L, >250 mg/L) as determined by the immunoturbidimetric assay used in our clinical laboratory (Roche Hitachi 912). Urine albumin was then remeasured via LC-MS and HPLC (Accumin™) assays. Results: The immunoturbidimetric assay, calibrated using manufacturer-supplied serum-derived calibrators (Diasorin), underestimated albumin compared with LC-MS. After calibration with purified HSA, this immunoturbidimetric assay correlated well with LC-MS. HPLC overestimated albumin compared with both LC-MS and immunoturbidimetry. The current LC-MS and HPLC assays both performed poorly at concentrations <20 mg/L. Conclusions: Efforts are needed to establish gold-standard traceable calibrators for clinical assays. LC-MS is a specific method to quantify albumin in native urine when concentrations exceed 20 mg/L, and therefore could be employed for standardization among assays.
Toxicology Study of Repeat Intracerebral Administration of a Measles Virus Derivative Producing Carcinoembryonic Antigen in Rhesus Macaques in Support of a Phase I/II Clinical Trial for Patients with Recurrent Gliomas
Myers, Rae, Harvey, Mary, Greiner, Suzanne , Krempski, James , Raffel, Corey , Shelton, Steven E., Soeffker, Diane, Zollman, Paula J., Federspiel, Mark J. , Blanco, Michael, Kaufmann, Timothy J. , Galanis, Evanthia , Krempski, James W

Human Gene Therapy | June 24, 2008 | Volume: 19 | Issue: 7 | Pages: 690-698

10.1089/hum.2008.035 | PMID 18576918 Get It

Elevation of cAMP in Mesenchymal Stem Cells Transiently Upregulates Neural Markers Rather than Inducing Neural Differentiation
Rooney, Gemma E., Howard, Linda , O’Brien, Timothy , Windebank, Anthony J. , Barry, Frank

Stem Cells and Development | June 13, 2008 | Volume: 18 | Issue: 3 | Pages: 387-398

10.1089/scd.2008.0080 | PMID 18554089 Get It

The aims of this research were to examine the neural expression profile of undifferentiated mesenchymal stem cells (MSCs), to define a serum-free environment that would support the survival of MSCs, and to assess the effects of elevated cyclic adenosine monophosphate (cAMP) levels on MSC morphology and expression of neural markers. The neural profile of MSCs was assessed using immunocytochemistry and real-time polymerase chain reaction (PCR) techniques. These MSCs were then cultured in varying serum-free environments, with flow cytometry analysis of cell viability and apoptosis. The effects of forskolin and 8 bromo-cAMP treatment on MSC morphology and expression of neural markers were assessed using light microscopy, immunocytochemistry and real-time PCR analysis. Expression of the neural markers nestin, vimentin, β III tubulin, glial fibrillary acidic protein, and the tropomyosin-related kinases was demonstrated in normal undifferentiated MSCs. Furthermore, MSCs cultured in serum-free conditions containing ascorbic acid 2-phosphate demonstrated greater long-term survival and reduced apoptosis. In contrast, forskolin increased the percentage of cells undergoing apoptosis. Culture in the presence of forskolin induced a 6-fold increase in β III tubulin expression after a 6-h exposure time, which was accompanied by dramatic changes in morphology. However, this effect was transient, with the cells reverting to their normal morphology by 24 h. Treatment with 8 bromo-cAMP induced similar increases in β III tubulin expression without such dramatic morphological changes. Factors which increase the concentration of cAMP induce transient changes in expression of neural markers that appear to be the result of cellular adaptation to changes in culture conditions rather than a real process of neural differentiation.
Sacral Neuromodulation for the Dysfunctional Elimination Syndrome: A Single Center Experience With 20 Children
Roth, Timothy J., Vandersteen, David R. , Hollatz, Pam, Inman, Brant A. , Reinberg, Yuri, Inman, Brant A

Journal of Urology | May 22, 2008 | Volume: 180 | Issue: 1 | Pages: 306-311

10.1016/j.juro.2008.03.033 | PMID 18499169 Get It

Diagnostic Cerebral Angiography: Archaic and Complication-Prone or Here to Stay for Another 80 Years?
Kallmes, David F. , Kaufmann, Timothy J.

American Journal of Roentgenology | May 20, 2008 | Volume: 190 | Issue: 6 | Pages: 1435-1437

10.2214/ajr.07.3522 | PMID 18492888 Get It

Gene-Modified Mesenchymal Stem Cells Express Functionally Active Nerve Growth Factor on an Engineered Poly Lactic Glycolic Acid (PLGA) Substrate
Rooney, Gemma E., Moran, Cathal J., McMahon, Siobhán S. , Ritter, Thomas , Maenz, Martin, Flügel, Alexander , Dockery, Peter , O’Brien, Timothy , Howard, Linda , Windebank, Anthony J. , Barry, Frank

Tissue Engineering Part A | April 11, 2008 | Volume: 14 | Issue: 5 | Pages: 681-690

10.1089/tea.2007.0260 | PMID 18402551 Get It

The Effects of Survey Mode and Asking About Future Intentions on Self-Reports of Colorectal Cancer Screening
Beebe, Timothy J. , Jenkins, Sarah M. , Anderson, Kari J., Davern, Michael E., Rockwood, Todd

Cancer Epidemiology, Biomarkers & Prevention | April 8, 2008 | Volume: 17 | Issue: 4 | Pages: 785-790

10.1158/1055-9965.epi-07-2622 | PMID 18381470 Get It

Abstract Colorectal cancer (CRC) screening rates are often ascertained via self-reports but can be subject to overreporting bias. Asking about intention to get screened before asking about past screening may minimize overreporting of cancer screening. In a statewide survey conducted from July through October of 2005, we embedded an experiment that tested the effect of question ordering (asking about future intention to get screened before or after asking about past screening; “future first” and “future second,” respectively), crossed with survey mode (mail versus telephone), on CRC screening rates. Weighted analysis focused on 752 respondents who were ages 50 years or older. We found (a) that asking about future intentions to get screened before asking about past screening (future first) statistically significantly lowers reports of past CRC screening [70.9% future second versus 58.0% future first; odds ratio (OR), 1.83; 95% confidence interval (95% CI), 1.08-3.13]; (b) that there was no main effect of survey mode; and (c) that the effect of the ordering of the future intentions item varies by survey mode. In the mailed survey, the odds of reporting past CRC screening were almost thrice greater in the future second condition compared with the future first condition (72.4% versus 49.0%, respectively; OR, 2.74; 95% CI, 1.22-6.17). In the telephone condition, the odds of reporting were only 28% higher in the future second (69.5%) condition than in the future first condition (63.9%; OR, 1.28; 95% CI, 0.64-2.57). The results suggest that asking about future intentions to get screened before the actual behavior elicits lower, and arguably more truthful reports of CRC screening but mainly in mailed surveys. (Cancer Epidemiol Biomarkers Prev 2008;17(4):785–90)
Missed Opportunities: Commentary on “The Sentinel”
Moynihan, Timothy J. , Gunten, Charles F. von

Journal of Clinical Oncology | March 29, 2008 | Volume: 26 | Issue: 10 | Pages: 1762-1763

10.1200/jco.2008.16.5027 | PMID 18375909 Get It