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4578 citation(s) found for "Xu, Xu Steven".

Real-Time 3-Dimensional Ultrasound-Assisted Infraclavicular Brachial Plexus Catheter Placement: Implications of a New Technology
Clendenen, Steven R. , Robards, Christopher B., Clendenen, Nathan , Freidenstein, James, Greengrass, Roy A.

Anesthesiology Research and Practice | June 1, 2010 | Volume: 2010 | Issue: No issue available | Pages: 1-4

10.1155/2010/208025 | PMID 20700433 Get It

Background. There are a variety of techniques for targeting placement of an infraclavicular blockade; these include eliciting paresthesias, nerve stimulation, and 2-dimensional (2D) ultrasound (US) guidance. Current 2D US allows direct visualization of a “flat” image of the advancing needle and neurovascular structures but without the ability to extensively analyze multidimensional data and allow for real-time manipulation. Three-dimensional (3D) ultrasonography has gained popularity and usefulness in many clinical specialties such as obstetrics and cardiology. We describe some of the potential clinical applications of 3D US in regional anesthesia.Methods. This case represents an infraclavicular catheter placement facilitated by 3D US, which demonstrates 360-degree spatial relationships of the entire anatomic region.Results. The block needle, peripheral nerve catheter, and local anesthetic diffusion were observed in multiple planes of view without manipulation of the US probe.Conclusion. Advantages of 3D US may include the ability to confirm correct needle and catheter placement prior to the injection of local anesthetic. The spread of local anesthetic along the length of the nerve can be easily observed while manipulating the 3D images in real-time by simply rotating the trackball on the US machine to provide additional information that cannot be identified with 2D US alone.
Defective Mismatch Repair As a Predictive Marker for Lack of Efficacy of Fluorouracil-Based Adjuvant Therapy in Colon Cancer
Sargent, Daniel J. , Marsoni, Silvia , Monges, Geneviève, Thibodeau, Stephen N. , Labianca, Roberto , French, Amy J. , Kabat, Brian, Foster, Nathan R. , Torri, Valter , Ribic, Christine, Moore, Malcolm , Zaniboni, Alberto , Seitz, J. F., Sinicrope, Frank, Gallinger, Steven , Hamilton, Stanley R. , Grothey, Axel , Sargent, Daniel J , Marsoni, Silvia

Journal of Clinical Oncology | May 24, 2010 | Volume: 28 | Issue: 20 | Pages: 3219-3226

10.1200/jco.2009.27.1825 | PMID 20498393 Get It

Purpose Prior reports have indicated that patients with colon cancer who demonstrate high-level microsatellite instability (MSI-H) or defective DNA mismatch repair (dMMR) have improved survival and receive no benefit from fluorouracil (FU) -based adjuvant therapy compared with patients who have microsatellite-stable or proficient mismatch repair (pMMR) tumors. We examined MMR status as a predictor of adjuvant therapy benefit in patients with stages II and III colon cancer. Methods MSI assay or immunohistochemistry for MMR proteins were performed on 457 patients who were previously randomly assigned to FU-based therapy (either FU + levamisole or FU + leucovorin; n = 229) versus no postsurgical treatment (n = 228). Data were subsequently pooled with data from a previous analysis. The primary end point was disease-free survival (DFS). Results Overall, 70 (15%) of 457 patients exhibited dMMR. Adjuvant therapy significantly improved DFS (hazard ratio [HR], 0.67; 95% CI, 0.48 to 0.93; P = .02) in patients with pMMR tumors. Patients with dMMR tumors receiving FU had no improvement in DFS (HR, 1.10; 95% CI, 0.42 to 2.91; P = .85) compared with those randomly assigned to surgery alone. In the pooled data set of 1,027 patients (n = 165 with dMMR), these findings were maintained; in patients with stage II disease and with dMMR tumors, treatment was associated with reduced overall survival (HR, 2.95; 95% CI, 1.02 to 8.54; P = .04). Conclusion Patient stratification by MMR status may provide a more tailored approach to colon cancer adjuvant therapy. These data support MMR status assessment for patients being considered for FU therapy alone and consideration of MMR status in treatment decision making.
Topiramate intervention to prevent transformation of episodic migraine: The topiramate INTREPID study
Silberstein, Stephen D., Cady, Roger , Freitag, Fred, Mathew, Ninan T., Biondi, David M., Ascher, Steven, Olson, William H., Hulihan, Joseph, Lipton, Richard B. , Dodick, David W.

Cephalalgia | May 17, 2010 | Volume: 31 | Issue: 1 | Pages: 18-30

10.1177/0333102410372427 | PMID 20974598 Get It

Objective: The study sought to evaluate whether topiramate prevents development of chronic daily headache (CDH, ≥15 headache days per month) in adult subjects with high-frequency episodic migraine (HFEM, 9–14 migraine headache days/month). A secondary objective was to assess the efficacy of topiramate as preventive migraine treatment in this population. Methods: This was a multicenter, randomized, double-blind, placebo-controlled study comparing topiramate 100 mg/day and placebo for 26 weeks. The primary efficacy variable was new-onset CDH at month 6. Secondary efficacy measures included migraine and headache days. Adverse events (AEs) were evaluated. Results: A total of 159 topiramate subjects and 171 placebo subjects were efficacy-evaluable. At month 6, 1.4% of topiramate subjects versus 2.3% of placebo subjects had CDH ( p = .589). Compared with placebo, topiramate treatment was associated with statistically significant reductions in mean number of migraine days (6.6 vs. 5.3/28 days; p = .001) and headache days (6.6 vs 5.3/28 days; p = .001). Most commonly reported AEs in the topiramate versus placebo group included paresthesia (32.4% vs. 7.0%), fatigue (14.8% vs. 8.6%), dizziness (11.4% vs. 7.6%) and nausea (10.8% vs. 9.2%). Conclusion: Topiramate 100 mg/day did not prevent the development of CDH at six months in subjects with HFEM. Topiramate was effective in reducing headache days and migraine headache days and generally well tolerated.
Cholangiocyte Myosin IIB Is Required for Localized Aggregation of Sodium Glucose Cotransporter 1 to Sites ofCryptosporidium parvumCellular Invasion and Facilitates Parasite Internalization
O’Hara, Steven P. , Gajdos, Gabriella B., Trussoni, Christy E. , Splinter, Patrick L., LaRusso, Nicholas F.

Infection and Immunity | May 11, 2010 | Volume: 78 | Issue: 7 | Pages: 2927-2936

10.1128/iai.00077-10 | PMID 20457792 Get It

ABSTRACTInternalization of the obligate intracellular apicomplexan parasite,Cryptosporidium parvum, results in the formation of a unique intramembranous yet extracytoplasmic niche on the apical surfaces of host epithelial cells, a process that depends on host cell membrane extension. We previously demonstrated that efficientC. parvuminvasion of biliary epithelial cells (cholangiocytes) requires host cell actin polymerization and localized membrane translocation/insertion of Na+/glucose cotransporter 1 (SGLT1) and of aquaporin 1 (Aqp1), a water channel, at the attachment site. The resultant localized water influx facilitates parasite cellular invasion by promoting host-cell membrane protrusion. However, the molecular mechanisms by whichC. parvuminduces membrane translocation/insertion of SGLT1/Aqp1 are obscure. We report here that cultured human cholangiocytes express several nonmuscle myosins, including myosins IIA and IIB. Moreover,C. parvuminfection of cultured cholangiocytes results in the localized selective aggregation of myosin IIB but not myosin IIA at the region of parasite attachment, as assessed by dual-label immunofluorescence confocal microscopy. Concordantly, treatment of cells with the myosin light chain kinase inhibitor ML-7 or the myosin II-specific inhibitor blebbistatin or selective RNA-mediated repression of myosin IIB significantly inhibits (P< 0.05)C. parvumcellular invasion (by 60 to 80%). Furthermore ML-7 and blebbistatin significantly decrease (P< 0.02)C. parvum-induced accumulation of SGLT1 at infection sites (by approximately 80%). Thus, localized actomyosin-dependent membrane translocation of transporters/channels initiated byC. parvumis essential for membrane extension and parasite internalization, a phenomenon that may also be relevant to the mechanisms of cell membrane protrusion in general.
Alzheimer's Disease Neuroimaging Initiative biomarkers as quantitative phenotypes: Genetics core aims, progress, and plans
Saykin, Andrew J. , Shen, Li , Potkin, Steven G. , Swaminathan, Shanker , Kim, Sungeun , Risacher, Shannon L. , Huentelman, Matthew J. , Craig, David W. , Thompson, Paul M. , Stein, Jason L. , Moore, Jason H. , Farrer, Lindsay A. , Jack, Clifford R. , Weiner, Michael W. , Initiative, Alzheimer's Disease Neuroimaging, Foroud, Tatiana , Nho, Kwangsik T. , Green, Robert C. , Bertram, Lars , Initiative, Alzheimer's Disease Neuroimaging, Jack, Clifford R , Saykin, Andrew J , Shen, Li , Stein, Jason L , Thompson, Paul M

Alzheimer's & Dementia | May 7, 2010 | Volume: 6 | Issue: 3 | Pages: 265-273

10.1016/j.jalz.2010.03.013 | PMID 20451875 Get It

The role of the Alzheimer's Disease Neuroimaging Initiative Genetics Core is to facilitate the investigation of genetic influences on disease onset and trajectory as reflected in structural, functional, and molecular imaging changes; fluid biomarkers; and cognitive status. Major goals include (1) blood sample processing, genotyping, and dissemination, (2) genome‐wide association studies (GWAS) of longitudinal phenotypic data, and (3) providing a central resource, point of contact and planning group for genetics within the Alzheimer's Disease Neuroimaging Initiative. Genome‐wide array data have been publicly released and updated, and several neuroimaging GWAS have recently been reported examining baseline magnetic resonance imaging measures as quantitative phenotypes. Other preliminary investigations include copy number variation in mild cognitive impairment and Alzheimer's disease and GWAS of baseline cerebrospinal fluid biomarkers and longitudinal changes on magnetic resonance imaging. Blood collection for RNA studies is a new direction. Genetic studies of longitudinal phenotypes hold promise for elucidating disease mechanisms and risk, development of therapeutic strategies, and refining selection criteria for clinical trials.
CHOP and AP-1 cooperatively mediate PUMA expression during lipoapoptosis
Cazanave, Sophie C. , Elmi, Nafisa A., Akazawa, Yuko , Bronk, Steven F., Mott, Justin L. , Gores, Gregory J.

American Journal of Physiology-Gastrointestinal and Liver Physiology | April 30, 2010 | Volume: 299 | Issue: 1 | Pages: G236-G243

10.1152/ajpgi.00091.2010 | PMID 20430872 Get It

Endoplasmic reticulum (ER) stress-mediated apoptosis is a key feature of hepatocyte cytotoxicity by saturated free fatty acids (FFA). This lipoapoptosis is dependent, in part, on the transcriptional upregulation of the BH3-only protein PUMA (p53 upregulated modulator of apoptosis). Although the activator protein (AP)-1 complex facilitates PUMA expression by saturated FFA, the transcription factor CAAT/enhancer binding homologous protein (CHOP) is also induced by ER stress and promotes apoptosis. To integrate the role of these two transcription factors in ER stress-induced apoptosis, we examined the relative contribution of CHOP and AP-1 in mediating PUMA induction by saturated FFA. Our results demonstrate that short-hairpin RNA-targeted knockdown of CHOP attenuates palmitate-induced apoptosis in Huh-7 cells. Loss of CHOP induction also reduced the increase in PUMA mRNA and protein levels as well as Bax activation by palmitate. No functional CHOP binding sites were identified in the PUMA promoter sequence. Rather, we observed that CHOP physically interacts with the AP-1 complex protein c-Jun upon palmitate treatment, and a CHOP:phosphorylated c-Jun heteromeric complex binds to the AP-1 consensus binding sequence within the PUMA promoter region. Finally, loss of function studies suggest that both transcription factors are necessary for maximal PUMA induction. Collectively, these data suggest that CHOP and AP-1 cooperatively mediate PUMA induction during hepatocyte lipoapoptosis.
Impact of Online Primary Care Visits on Standard Costs: A Pilot Study
Rohrer, James E. , Angstman, Kurt B. , Adamson, Steven C., Bernard, Matthew , Bachman, John W., Morgan, Mark E.

Population Health Management | April 25, 2010 | Volume: 13 | Issue: 2 | Pages: 59-63

10.1089/pop.2009.0018 | PMID 20415617 Get It

As medical providers seek new ways to control costs, online visits have begun to receive serious consideration. The purpose of this study was to compare the odds of being a cost outlier during a 6-month period after either an online visit or a standard drop-in visit in a conventional medical office setting. Medical records of primary care patients (both adults and children) seen in a large group practice in Minnesota in 2008 were analyzed for this study. Two groups of patients were studied: those who had an online visit ( N = 390) and a comparison group who had regular office care for same-day, acute visits ( N = 376). Case types were classified as either complex or common, with common being defined as treatment for pinkeye, sore throat, viral illness, bronchitis, or cough. Outliers were defined as patients for whom standard costs exceeded the 75 th percentile during a 6-month period after the index visit. Multiple logistic regression analysis was used to adjust for differences between groups. The percentage of online visitors who were cost outliers was 21.2 (versus 28.5 in the standard visit group). Median standard costs were $161 for online visits and $219 for same-day acute visits. The adjusted odds of being a cost outlier was lower for the online visit group than for the standard visit group (odds ratio [OR] 0.52, 95% confidence interval [95% CI] 0.35–0.77) after adjusting for number of visits in the previous 6 months, age, sex, and case type. Outpatient visits in the previous 6 months were positively related to outlier status (OR 1.23, 95% CI 1.17–1.29). Online visits appeared to reduce medical costs for patients during a 6-month period after the visit. ( Population Health Management 2010;13:59–63)
A commonly carried allele of the obesity-related FTO gene is associated with reduced brain volume in the healthy elderly
Ho, April J., Stein, Jason L. , Hua, Xue , Lee, Suh , Hibar, Derrek P., Leow, Alex , Dinov, Ivo D. , Toga, Arthur W. , Saykin, Andrew J. , Shen, Li , Pankratz, Nathan , Huentelman, Matthew J. , Craig, David W. , Gerber, Jill D., Allen, April N., Corneveaux, Jason J., Stephan, Dietrich A. , DeCarli, Charles , Dechairo, Bryan, Jack, Clifford R. , Weiner, Michael W. , Raji, Cyrus A. , Becker, James T. , Carmichael, Owen , Thompson, Paul M. , Initiative, the Alzheimer's Disease Neuroimaging, Thal, Leon J., Petersen, Ronald C., Jagust, William J. , Trojanowki, John Q., Toga, Arthur W., Gamst, Anthony, Potter, William Z., Montine, Tom, Anders, Dale, Felmlee, Joel P. , Schuff, Norbert, Alexander, Gene E. , Bandy, Dan, Foster, Norm, Reiman, Eric M. , Shaw, Les, Korecka, Magdalena , Toga, Arthur W., Crawford, Karen , Neu, Scott, Kornak, John , Kachaturian, Zaven, Frank, Richard , Molchan, Susan, Vorobik, Remi, Schneider, Lon S. , Pawluczyk, Sonia, Spann, Bryan , Fleisher, Adam , Vanderswag, Helen, Heidebrink, Judith L. , Johnson, Kris , Doody, Rachelle S., Villanueva‐Meyer, Javier , Chowdhury, Munir , Bell, Karen L. , Mintun, Mark A., Schneider, Stacy, Marson, Daniel , Griffith, Randall, Badger, Beverly, Grossman, Hillel, deToledo‐Morrell, Leyla, Bach, Julie , Duara, Ranjan , Isaacson, Richard , Strauman, Silvia, Albert, Marilyn S. , Pedroso, Julia, Toroney, Jaimie, Santi, Susan M De, Doraiswamy, P. Murali , Petrella, Jeffrey R. , Aiello, Marilyn, Clark, Christopher M. , Pham, Cassie, Nuñez, Jessica, Smith, Charles D., Given, Curtis A., Hardy, Peter , DeKosky, Steven T. , Oakley, MaryAnn, Simpson, Donna M., Ismail, M. Saleem , McCallum, Colleen, Cramer, Steven C. , Mulnard, Ruth A., Mc-Adams-Ortiz, Catherine, Martin-Cook, Kristen, Devous, Michael D. , Cellar, Janet S., Anderson, Heather S., Laubinger, Mary M., Bartzokis, George, Lu, Po H. , Fletcher, Rita, Parfitt, Francine, Farlow, Martin R. , Herring, Scott, Hake, Ann Marie , Dyck, Christopher H. van , MacAvoy, Martha G., Bifano, Laurel A., Chertkow, Howard, Bergman, Howard , Hosein, Chris, Graham, Simon J. , Caldwell, Curtis, Assaly, Michele, Hsiung, Ging‐Yuek Robin , Kertesz, Andrew , Trost, Dick, Bernick, Charles , Johnson, Nancy , Sadowsky, Carl, Villena, Teresa, Mesner, Scott, Aisen, Paul, Johnson, Kathleen, Behan, Kelly E., Johnson, Keith A. , Rosen, Allyson , Tinklenberg, Jared, Ashford, Wes, Connor, Donald J., Obradov, Sanja, Jayam‐Trouth, Annapurni , Wang, Paul J. , Auchus, Alexander P. , Huang, Juebin , DeCarli, Charles , Kittur, Smita, Mirje, Seema, Borrie, Michael, Lee, T‐Y, Asthana, Sanjay , Carlsson, Cynthia M., Highum, Diane, Preda, Adrian , Tariot, Pierre N. , Hendin, Barry , Kataki, Maria , Zimmerman, Earl A. , Celmins, Dzintra, Brown, Alice D., Gandy, Sam, Marenberg, Marjorie E., Rovner, Barry W. , Blank, Karen, Anderson, Karen, Santulli, Robert B. , Paré, Nadia, Williamson, Jeff D. , Raj, Balebail Ashok, Giordano, Amy T., Ott, Brian R. , Wu, Chuang‐Kuo, Cohen, Ronald A. , Wilks, Kerri, Lee, Ting‐Yim , Foroud, Tatiana , Potkin, Steven G. , López, Oscar L. , Initiative, the Alzheimer's Disease Neuroimaging, Toga, Arthur W., Beckett, Laurel , Green, Robert C. , Bernstein, Matt A. , Fox, Nick C. , Koeppe, Robert A. , Foster, Norm, Chen, Kewei , Lee, Virginia M.‐Y. , Toga, Arthur W., Harvey, Danielle , Snyder, Peter J. , Kaye, Jeffrey , Quinn, Joseph F. , Lord, Joanne L. , Stern, Yaakov , Honig, Lawrence S. , Morris, John C. , Tang, Cheuk Ying , Stern, Jessica A. , Shah, Raj C. , Duara, Ranjan , Rusinek, Henry , Leon, Mony J. de , Porsteinsson, Anton P. , Diaz‐Arrastia, Ramon , Levey, Allan I. , Lah, James J. , Burns, Jeffrey M. , Silverman, Daniel H.S. , Johnson, Heather K. , Black, Sandra E. , Feldman, Howard , ROGERS, John H. , Gitelman, Darren R. , Mesulam, Marsel M. , Sperling, Reisa Anne , Rentz, Dorene M. , Sabbagh, Marwan Noel , Killiany, Ronald , Norbash, Alexander , Obisesan, Thomas O. , Friedland, Robert P. , Fletcher, Evan M. , Johnson, Sterling C. , Nguyen, Dana R. , Scharre, Douglas W. , Beversdorf, David Q. , Gandy, Sam , Pearlson, Godfrey D. , Sink, Kaycee M. , Potter, Huntington , Jack, Clifford R , Saykin, Andrew J , Shen, Li , Preda, Adrian , Toga, Arthur W , Stein, Jason L , Thompson, Paul M , Hsiung, Gink-Yuek , Pankratz, Nathan

Proceedings of the National Academy of Sciences | April 19, 2010 | Volume: 107 | Issue: 18 | Pages: 8404-8409

10.1073/pnas.0910878107 | PMID 20404173 Get It

A recently identified variant within the fat mass and obesity-associated ( FTO ) gene is carried by 46% of Western Europeans and is associated with an ~1.2 kg higher weight, on average, in adults and an ~1 cm greater waist circumference. With >1 billion overweight and 300 million obese persons worldwide, it is crucial to understand the implications of carrying this very common allele for the health of our aging population. FTO is highly expressed in the brain and elevated body mass index (BMI) is associated with brain atrophy, but it is unknown how the obesity-associated risk allele affects human brain structure. We therefore generated 3D maps of regional brain volume differences in 206 healthy elderly subjects scanned with MRI and genotyped as part of the Alzheimer's Disease Neuroimaging Initiative. We found a pattern of systematic brain volume deficits in carriers of the obesity-associated risk allele versus noncarriers. Relative to structure volumes in the mean template, FTO risk allele carriers versus noncarriers had an average brain volume difference of ~8% in the frontal lobes and 12% in the occipital lobes—these regions also showed significant volume deficits in subjects with higher BMI. These brain differences were not attributable to differences in cholesterol levels, hypertension, or the volume of white matter hyperintensities; which were not detectably higher in FTO risk allele carriers versus noncarriers. These brain maps reveal that a commonly carried susceptibility allele for obesity is associated with structural brain atrophy, with implications for the health of the elderly.
Coordination of Centrosome Homeostasis and DNA Repair Is Intact in MCF-7 and Disrupted in MDA-MB 231 Breast Cancer Cells
Acu, Ilie D., Liu, Tieju , Suino-Powell, Kelly, Mooney, Steven M. , D’Assoro, Antonino B. , Correa, Ricardo G. , Niu, Yun , Kumar, Rajiv , Salisbury, Jeffrey L., Rowland, Nicholas James , Muotri, Alysson Renato , Kumar, Rajiv

Cancer Research | April 13, 2010 | Volume: 70 | Issue: 8 | Pages: 3320-3328

10.1158/0008-5472.can-09-3800 | PMID 20388771 Get It

Abstract When cells encounter substantial DNA damage, critical cell cycle events are halted while DNA repair mechanisms are activated to restore genome integrity. Genomic integrity also depends on proper assembly and function of the bipolar mitotic spindle, which is required for equal chromosome segregation. Failure to execute either of these processes leads to genomic instability, aging, and cancer. Here, we show that following DNA damage in the breast cancer cell line MCF-7, the centrosome protein centrin2 moves from the cytoplasm and accumulates in the nucleus in a xeroderma pigmentosum complementation group C protein (XPC)–dependent manner, reducing the available cytoplasmic pool of this key centriole protein and preventing centrosome amplification. MDA-MB 231 cells do not express XPC and fail to move centrin into the nucleus following DNA damage. Reintroduction of XPC expression in MDA-MB 231 cells rescues nuclear centrin2 sequestration and reestablishes control against centrosome amplification, regardless of mutant p53 status. Importantly, the capacity to repair DNA damage was also dependent on the availability of centrin2 in the nucleus. These observations show that centrin and XPC cooperate in a reciprocal mechanism to coordinate centrosome homeostasis and DNA repair and suggest that this process may provide a tractable target to develop treatments to slow progression of cancer and aging. Cancer Res; 70(8); 3320–8. ©2010 AACR.
The arterial anatomy of the medial femoral condyle and its clinical implications
Jones, David, Moran, Steven L. , Shin, Alexander Y. , Yamamoto, Hiroyuki , Bishop, Allen T. , Shin, Alexander Y

Journal of Hand Surgery (European Volume) | March 17, 2010 | Volume: 35 | Issue: 7 | Pages: 569-574

10.1177/1753193410364484 | PMID 20237188 Get It

The success of vascularized bone grafts from the medial femoral condyle in various clinical applications has sparked renewed interest in the microvascular anatomy of this region. This study describes the arterial supply of the distal medial femoral condyle and its implications in harvesting vascularized bone grafts. The location, branching pattern, internal diameter, and distribution of perforators of the descending genicular artery and superior medial genicular artery in 19 fresh cadaveric lower limbs were recorded. The descending genicular artery was present in 89% and the superior medial genicular artery was present in 100% of specimens with average distances proximal to the articular surface of 13.7 cm and 5.2 cm, respectively. The average number of perforating vessels was greatest in the posterior distal quadrant of the condyle. The blood supply of the medial femoral condyle is plentiful and consistent making it a useful source for free vascularized bone grafts.