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1430 citation(s) found for "Uk, Nathan".

Facile Assembly of Micro- and Nanoarrays for Sensing with Natural Cell Membranes
Wittenberg, Nathan J. , Im, Hyungsoon , Johnson, Timothy W. , Xu, Xiaohua , Warrington, Arthur E. , Rodriguez, Moses , Oh, Sang‐Hyun , Oh, Sang-Hyun , Rodriguez, Moses

ACS Nano | August 12, 2011 | Volume: 5 | Issue: 9 | Pages: 7555-7564

10.1021/nn202554t | PMID 21842844 Get It

The association of bone density and calcified atherosclerosis is stronger in women without dyslipidemia: The multi-ethnic study of atherosclerosis
Jensky, Nicole E., Hyder, Joseph A. , Allison, Matthew , Wong, Nathan D. , Aboyans, Victor , Schreiner, Pamela J. , Carr, J. Jeffrey , Wassel, Christina L. , Criqui, Michael H. , Aboyans, Victor , Blumenthal, Roger S. , Ix, Joachim H. , Wong, Nathan , Allison, Matthew A

Journal of Bone and Mineral Research | August 10, 2011 | Volume: 26 | Issue: 11 | Pages: 2702-2709

10.1002/jbmr.469 | PMID 21834088 Get It

Abstract We tested whether the association between bone mineral density (BMD) and coronary artery calcification (CAC) varies according to dyslipidemia in community-living individuals. Between 2002 and 2005, 305 women and 631 men (mean age of 64 years), who were not taking lipid-lowering medications or estrogen were assessed for spine BMD, CAC, and total (TC), HDL- and LDL-cholesterol and triglycerides. Participants were a random sample from the Multi-Ethnic Study of Atherosclerosis (MESA) without clinical cardiovascular disease. Spine BMD at the L3 vertebrate was performed by computer tomography (CT). CAC prevalence was measured by CT. The total cholesterol to HDL ratio (TC:HDL) ≥ 5.0 was used as the primary marker of hyperlipidemia. The association of BMD with CAC differed in women with TC:HDL < 5.0 versus higher (p-interaction = 0.01). In age- and race-adjusted models, among women with TC:HDL < 5.0, each SD (43.4 mg/cc) greater BMD was associated with a 25% lower prevalence of CAC (prevalence ratio [PR] 0.75, 95% confidence interval [CI] 0.63–0.89), whereas among women with higher TC:HDL, higher BMD was not significantly associated with CAC (PR 1.22, 95% CI 0.82–1.82). Results were similar using other definitions of hyperlipidemia. In contrast, no consistent association was observed between BMD and CAC in men, irrespective of the TC:HDL ratio (p interaction 0.54). The inverse association of BMD with CAC is stronger in women without dyslipidemia. These data argue against the hypothesis that dyslipidemia is the key factor responsible for the inverse association of BMD with atherosclerosis. © 2011 American Society for Bone and Mineral Research
The HIV-1-Specific Protein Casp8p41 Induces Death of Infected Cells through Bax/Bak
Sainski, Amy M., Natesampillai, Sekar, Bren, Gary D., Taylor, Julie , Saenz, Dyana T. , Poeschla, Eric M. , Badley, Andrew D. , Cummins, Nathan W. , Badley, Andrew D

Journal of Virology | June 9, 2011 | Volume: 85 | Issue: 16 | Pages: 7965-7975

10.1128/jvi.02515-10 | PMID 21653671 Get It

ABSTRACT Casp8p41, a novel protein generated when HIV-1 protease cleaves caspase 8, independently causes NF-κB activation, proinflammatory cytokine production, and cell death. Here we investigate the mechanism by which Casp8p41 induces cell death. Immunogold staining and electron microscopy demonstrate that Casp8p41 localizes to mitochondria of activated primary CD4 T cells, suggesting mitochondrial involvement. Therefore, we assessed the dependency of Casp8p41-induced death on Bax/Bak and caspase 9. In wild-type (WT) mouse embryonic fibroblast (MEF) cells, Casp8p41 causes rapid mitochondrial depolarization ( P < 0.001), yet Casp8p41 expression in Bax/Bak double-knockout (DKO) MEF cells does not. Similarly, caspase 9-deficient T cells (JMR cells), which express Casp8p41, undergo minimal cell death, whereas reconstituting these cells with caspase 9 (F9 cells) restores Casp8p41 cytotoxicity ( P < 0.01). The infection of caspase 9-deficient cells with a green fluorescent protein (GFP) HIV-1 reporter virus results in cell death in 32% of infected GFP-positive cells, while the restoration of caspase 9 expression in these cells restores infected-cell killing to 68% ( P < 0.05), with similar levels of viral replication between infections. Our data demonstrate that Casp8p41 requires Bax/Bak to induce mitochondrial depolarization, which leads to caspase 9 activation following either Casp8p41 expression or HIV-1 infection. This understanding allows the design of strategies to interrupt this form of death of HIV-1-infected cells.
Neuronal intracellular transport and neurodegenerative disease
Staff, Nathan P. , Benarroch, Eduardo E. , Klein, Christopher J. , Staff, Nathan P , Klein, Christopher J

Neurology | March 15, 2011 | Volume: 76 | Issue: 11 | Pages: 1015-1020

10.1212/wnl.0b013e31821103f7 | PMID 21403113 Get It

Abstract 904: Obesity is an independent prognostic variable in colon cancer survivors
Foster, Nathan R. , Rankin, Cathyrn, Sinicrope, Frank A. , Sargent, Daniel J. , O’Connell, Michael J.

Cancer Research | February 25, 2011 | Volume: 70 | Issue: 8_Supplement | Pages: 904-904

10.1158/1538-7445.am10-904 Get It

Abstract Purpose: Obesity is associated with an increased risk of colon cancer. However, the influence of body mass index (BMI) upon the prognosis of colon cancer survivors and its relationship to gender remains unknown. Experimental Design: BMI (kg/m2) was categorized in patients with TNM stage II and III colon carcinomas (n= 4,381) enrolled in 7 randomized trials of 5-fluorouracil-based adjuvant chemotherapy. Cox proportional hazards models were used to determine the association of BMI with disease-free (DFS) and overall survival (OS). Results: Among colon cancer patients, 868 (20%) were obese (BMI &gt;30 kg/m2) of which 606 were class 1 (BMI 30-34 kg/m2) and 262 were class 2,3 (BMI &gt;35 kg/m2). Obese versus normal-weight patients were more likely to be younger (p=0.038), have distal tumors (0.058), show intact DNA mismatch repair (MMR) (p=0.035), and have more lymph node metastases (p=0.017). In a multivariate analysis, BMI was significantly associated with both DFS (p=0.030) and OS (p=0.0017). Men with class 2,3 obesity showed reduced OS compared to normal weight men [HR 1.35 (1.02, 1.79); p=0.039]. Women with class I obesity had reduced OS [HR 1.24 (1.01, 1.53), p=0.045] compared to normal weight women. Overweight status was associated with improved OS in men (p= 0.006) and underweight women had significantly worse OS (p= 0.019). BMI was not predictive of therapeutic benefit. Conclusions: Obesity is an independent prognostic variable in colon cancer survivors and shows gender-related differences. These data suggest that obesity-related biological factors can influence clinical outcome. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 904.
Metabolic benefits of resistance training and fast glycolytic skeletal muscle
LeBrasseur, Nathan K. , Walsh, Kenneth , Arany, Zoltan Pierre , LeBrasseur, Nathan K

American Journal of Physiology-Endocrinology and Metabolism | November 3, 2010 | Volume: 300 | Issue: 1 | Pages: E3-E10

10.1152/ajpendo.00512.2010 | PMID 21045171 Get It

Skeletal muscle exhibits remarkable plasticity with respect to its metabolic properties. Recent work has shown that interventions such as resistance training, genetic alterations and pharmacological strategies that increase muscle mass and glycolytic capacity, and not necessarily oxidative competence, can improve body composition and systemic metabolism. We review here recent advances in our understanding of the signaling and transcriptional regulatory pathways of this strategy and review new evidence obtained from mice and humans that supports the notion that increasing muscle mass and glycolytic capacity may effectively counter insulin resistance and type 2 diabetes mellitus.
Postpartum Depression Screening
Wichman, Christina L., Angstman, Kurt B. , Lynch, Brian , Whalen, Denise, Jacobson, Nathan A.

Journal of Primary Care & Community Health | September 30, 2010 | Volume: 1 | Issue: 3 | Pages: 158-163

10.1177/2150131910380055 | PMID 23804604 Get It

Postpartum depression (PPD) has emerged as an important issue for pediatricians and family practitioners because of detrimental effects on children. PPD occurs in 10% to 22% of women who have recently given birth, but fewer than half of cases are recognized. Despite the impact of PPD, many primary care clinicians do not have systemic screening approaches implemented. This paper will review the development of a screening protocol for PPD in a multispecialty clinic, with the implementation utilizing depression care managers and the preliminary results of our process. Of the 333 screened examinations during the 4-month study, 38.1% (n = 127) were performed for the 2-month well child examination; 33.6% (n = 112) were for the 4-month examination, with 28.2% (n = 94) being performed for the 6-month well child examination. Only 15 (4.5%) were positive for possible depression with a screening compliance rate of 47.9%. No significant difference was noted in the timing of the well child visit with a positive screening test result, nor was there any difference in family medicine versus pediatric colleagues in the utilization of the screening or diagnosis of PPD. Implementation of PPD screening in a multispecialty clinic can be effective, given utilization of depression care managers.
Effects of Composite Formulation on Mechanical Properties of Biodegradable Poly(Propylene Fumarate)/Bone Fiber Scaffolds
Liu, Nathan , Yaszemski, Michael J. , Lu, Lichun , Zhu, Xun

International Journal of Polymer Science | July 8, 2010 | Volume: 2010 | Issue: No issue available | Pages: 1-6

10.1155/2010/270273 | PMID 22034584 Get It

The objective of our paper was to determine the effects of composite formulation on the compressive modulus and ultimate strength of a biodegradable, in situ polymerizable poly(propylene fumarate) (PPF) and bone fiber scaffold. The following parameters were investigated: the incorporation of bone fibers (either mineralized or demineralized), PPF molecular weight, N-vinyl pyrrolidinone (NVP) crosslinker amount, benzoyl peroxide (BP) initiator amount, and sodium chloride porogen amount. Eight formulations were chosen based on a resolution III two-level fractional factorial design. The compressive modulus and ultimate strength of these formulations were measured on a materials testing machine. Absolute values for compressive modulus varied from 21.3 to 271 MPa and 2.8 to 358 MPa for dry and wet samples, respectively. The ultimate strength of the crosslinked composites varied from 2.1 to 20.3 MPa for dry samples and from 0.4 to 16.6 MPa for wet samples. Main effects of each parameter on the measured property were calculated. The incorporation of mineralized bone fibers and an increase in PPF molecular weight resulted in higher compressive modulus and ultimate strength. Both mechanical properties also increased as the amount of benzoyl peroxide increased or the NVP amount decreased in the formulation. Sodium chloride had a dominating effect on the increase of mechanical properties in dry samples but showed little effects in wet samples. Demineralization of bone fibers led to a decrease in the compressive modulus and ultimate strength. Our results suggest that bone fibers are appropriate as structural enforcement components in PPF scaffolds. The desired orthopaedic PPF scaffold might be obtained by changing a variety of composite formulation parameters.
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.