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

Mechanisms of Protein Kinase PKR-Mediated Amplification of Beta Interferon Induction by C Protein-Deficient Measles Virus
McAllister, Christopher S. , Toth, Ann M. , Devaux, Patricia , Cattaneo, Roberto , Samuel, Charles E. , Zhang, Ping

Journal of Virology | October 22, 2009 | Volume: 84 | Issue: 1 | Pages: 380-386

10.1128/jvi.02630-08 | PMID 19846517 Get It

ABSTRACT The measles virus P gene products V and C antagonize the host interferon (IFN) response, blocking both IFN signaling and production. Using Moraten vaccine strain-derived measles virus and isogenic mutants deficient for either V or C protein production (V ko and C ko , respectively), we observed that the C ko virus was a potent inducer of IFN-β, while induction by V ko virus was an order of magnitude lower than that by the C ko virus. The parental recombinant Moraten virus did not significantly induce IFN-β. The enhanced IFN-inducing capacity of the C ko virus correlated with an enhanced activation of IFN regulatory factor 3 (IRF-3), NF-κB, and ATF-2 in C ko -infected compared to V ko or parental virus-infected cells. Furthermore, protein kinase PKR and mitochondrial adapter IPS-1 were required for maximal C ko -mediated IFN-β induction, which correlated with the PKR-mediated enhancement of mitogen-activated protein kinase and NF-κB activation. Our results reveal multiple consequences of C protein expression and document an important function for PKR as an enhancer of IFN-β induction during measles virus infection.
Whole-Body Sleeping Beauty Mutagenesis Can Cause Penetrant Leukemia/Lymphoma and Rare High-Grade Glioma without Associated Embryonic Lethality
Collier, Lara S. , Adams, David J. , Hackett, Christopher S. , Bendzick, Laura E. , Davies, Michael N., Diers, Miechaleen D., Tieu, Christina, Matise, Ilze , Dupuy, Adam J. , Copeland, Neal G., Jenkins, Nancy A., Weiss, William A. , Jenkins, Robert B. , Largaespada, David A. , Akagi, Keiko , Rodríguez, Fausto J. , Bender, Aaron M. , Hodgson, John , Largaespada, David A.

Cancer Research | October 20, 2009 | Volume: 69 | Issue: 21 | Pages: 8429-8437

10.1158/0008-5472.can-09-1760 | PMID 19843846 Get It

Abstract The Sleeping Beauty (SB) transposon system has been used as a somatic mutagen to identify candidate cancer genes. In previous studies, efficient leukemia/lymphoma formation on an otherwise wild-type genetic background occurred in mice undergoing whole-body mobilization of transposons, but was accompanied by high levels of embryonic lethality. To explore the utility of SB for large-scale cancer gene discovery projects, we have generated mice that carry combinations of different transposon and transposase transgenes. We have identified a transposon/transposase combination that promotes highly penetrant leukemia/lymphoma formation on an otherwise wild-type genetic background, yet does not cause embryonic lethality. Infiltrating gliomas also occurred at lower penetrance in these mice. SB-induced or accelerated tumors do not harbor large numbers of chromosomal amplifications or deletions, indicating that transposon mobilization likely promotes tumor formation by insertional mutagenesis of cancer genes, and not by promoting wide-scale genomic instability. Cloning of transposon insertions from lymphomas/leukemias identified common insertion sites at known and candidate novel cancer genes. These data indicate that a high mutagenesis rate can be achieved using SB without high levels of embryonic lethality or genomic instability. Furthermore, the SB system could be used to identify new genes involved in lymphomagenesis/leukemogenesis. [Cancer Res 2009;69(21):8429–37]
Dose to Radiosensitive Organs During Routine Chest CT: Effects of Tube Current Modulation
Angel, Erin , Yaghmai, Nazanin, Jude, Cecilia M., DeMarco, John J., Cagnon, Christopher H., Goldin, Jonathan , Primak, Andrew N. , Cody, Dianna D. , Stevens, Donna M., Cagnon, Chris H., McCollough, Cynthia H. , McNitt‐Gray, Michael F.

American Journal of Roentgenology | October 20, 2009 | Volume: 193 | Issue: 5 | Pages: 1340-1345

10.2214/ajr.09.2886 | PMID 19843751 Get It

Rosenow’s rabbits and postencephalitic parkinsonism
Claassen, Daniel O. , Boes, Christopher J.

Neurology | October 12, 2009 | Volume: 73 | Issue: 15 | Pages: 1240-1241

10.1212/wnl.0b013e3181bc01bc | PMID 19822874 Get It

Haplotype and Cell Proliferation Analyses of Candidate Lung Cancer Susceptibility Genes on Chromosome 15q24-25.1
Liu, Pengyuan , Wen, Weidong, James, Michael A. , Wang, Yian , Bailey‐Wilson, Joan E. , Pinney, Susan M. , Yang, Ping , Petersen, Gloria M. , Wiest, Jonathan S., Fain, Pamela R., Schwartz, Ann G. , Gazdar, Adi F. , Gaba, Colette , Rothschild, Henry, Mandal, Diptasri , Kupert, Elena, Lee, Juwon , Seminara, Daniela, Anderson, Marshall W., Liu, Yan , Amos, Christopher I. , Andrade, Mariza de , Minna, John Dorrance , You, Ming , Wilson, Richard K , Pinney, Susan M

Cancer Research | September 29, 2009 | Volume: 69 | Issue: 19 | Pages: 7844-7850

10.1158/0008-5472.can-09-1833 | PMID 19789337 Get It

Abstract Recent genome-wide association studies have linked the chromosome 15q24-25.1 locus to nicotine addiction and lung cancer susceptibility. To refine the 15q24-25.1 locus, we performed a haplotype-based association analysis of 194 familial lung cases and 219 cancer-free controls from the Genetic Epidemiology of Lung Cancer Consortium (GELCC) collection, and used proliferation and apoptosis analyses to determine which gene(s) in the 15q24-25.1 locus mediates effects on lung cancer cell growth in vitro. We identified two distinct subregions, hapL (P = 3.20 × 10−6) and hapN (P = 1.51 × 10−6), which were significantly associated with familial lung cancer. hapL encompasses IREB2, LOC123688, and PSMA4, and hapN encompasses the three nicotinic acetylcholine receptor subunit genes CHRNA5, CHRNA3, and CHRNB4. Examination of the genes around hapL revealed that PSMA4 plays a role in promoting cancer cell proliferation. PSMA4 mRNA levels were increased in lung tumors compared with normal lung tissues. Down-regulation of PSMA4 expression decreased proteasome activity and induced apoptosis. Proteasome dysfunction leads to many diseases including cancer, and drugs that inhibit proteasome activity show promise as a form of cancer treatment. Genes around hapN were also investigated, but did not show any direct effect on lung cancer cell proliferation. We concluded that PSMA4 is a strong candidate mediator of lung cancer cell growth, and may directly affect lung cancer susceptibility through its modulation of cell proliferation and apoptosis. [Cancer Res 2009;69(19):7844–50]
Developmental outcomes for neonatal dural arteriovenous fistulas
Johnson, Jonathan N. , Hartman, Tyler, Barbaresi, William J. , Raffel, Corey , Colby, Christopher E.

Journal of Neurosurgery: Pediatrics | September 22, 2009 | Volume: 3 | Issue: 2 | Pages: 105-109

10.3171/2008.11.peds0876 | PMID 19278308 Get It

Large dural arteriovenous malformations (DAVMs) accompanied by cardiac failure usually carry a poor prognosis with a high risk of morbidity and death. The authors report on the case of a male neonate with a massive DAVM who presented at birth with macrocephaly and high-output cardiac failure. The child initially underwent treatment with surgical clipping of the large main feeding artery. Hydrocephalus, thought to be due to venous hypertension, developed when the boy was 8 months old. The condition resolved after interventional embolization treatment. The patient did not require placement of a ventriculoperitoneal shunt. At 21 months of age, the child had near normal development without any focal neurological deficits.
Frequency and Severity of Adverse Effects of Iodinated and Gadolinium Contrast Materials: Retrospective Review of 456,930 Doses
Hunt, Christopher H. , Hartman, Robert P. , Hesley, Gina K. , Hunt, Christopher H

American Journal of Roentgenology | September 21, 2009 | Volume: 193 | Issue: 4 | Pages: 1124-1127

10.2214/ajr.09.2520 | PMID 19770337 Get It

Comonitoring of adenosine and dopamine using the Wireless Instantaneous Neurotransmitter Concentration System: proof of principle
Chang, Su-Youne , Tye, Susannah J. , Kimble, Christopher J., Bennet, Kevin E. , Blaha, Charles D. , Lee, Kendall H. , Shon, Young‐Min , Tye, Susannah J , Blaha, Charles

Journal of Neurosurgery | September 4, 2009 | Volume: 112 | Issue: 3 | Pages: 539-548

10.3171/2009.7.jns09787 | PMID 19731995 Get It

Object The authors of previous studies have demonstrated that local adenosine efflux may contribute to the therapeutic mechanism of action of thalamic deep brain stimulation (DBS) for essential tremor. Real-time monitoring of the neurochemical output of DBS-targeted regions may thus advance functional neurosurgical procedures by identifying candidate neurotransmitters and neuromodulators involved in the physiological effects of DBS. This would in turn permit the development of a method of chemically guided placement of DBS electrodes in vivo. Designed in compliance with FDA-recognized standards for medical electrical device safety, the authors report on the utility of the Wireless Instantaneous Neurotransmitter Concentration System (WINCS) for real-time comonitoring of electrical stimulation–evoked adenosine and dopamine efflux in vivo, utilizing fast-scan cyclic voltammetry (FSCV) at a polyacrylonitrile-based (T-650) carbon fiber microelectrode (CFM). Methods The WINCS was used for FSCV, which consisted of a triangle wave scanned between −0.4 and +1.5 V at a rate of 400 V/second and applied at 10 Hz. All voltages applied to the CFM were with respect to an Ag/AgCl reference electrode. The CFM was constructed by aspirating a single T-650 carbon fiber (r = 2.5 μm) into a glass capillary and pulling to a microscopic tip using a pipette puller. The exposed carbon fiber (the sensing region) extended beyond the glass insulation by ~ 50 μm. Proof of principle tests included in vitro measurements of adenosine and dopamine, as well as in vivo measurements in urethane-anesthetized rats by monitoring adenosine and dopamine efflux in the dorsomedial caudate putamen evoked by high-frequency electrical stimulation of the ventral tegmental area and substantia nigra. Results The WINCS provided reliable, high-fidelity measurements of adenosine efflux. Peak oxidative currents appeared at +1.5 V and at +1.0 V for adenosine, separate from the peak oxidative current at +0.6 V for dopamine. The WINCS detected subsecond adenosine and dopamine efflux in the caudate putamen at an implanted CFM during high-frequency stimulation of the ventral tegmental area and substantia nigra. Both in vitro and in vivo testing demonstrated that WINCS can detect adenosine in the presence of other easily oxidizable neurochemicals such as dopamine comparable to the detection abilities of a conventional hardwired electrochemical system for FSCV. Conclusions Altogether, these results demonstrate that WINCS is well suited for wireless monitoring of high-frequency stimulation-evoked changes in brain extracellular concentrations of adenosine. Clinical applications of selective adenosine measurements may prove important to the future development of DBS technology.
Extracorporeal Membrane Oxygenation for the Treatment of Neonatal Respiratory Failure
Carey, William A., Colby, Christopher E.

Seminars in Cardiothoracic and Vascular Anesthesia | August 27, 2009 | Volume: 13 | Issue: 3 | Pages: 192-197

10.1177/1089253209347948 | PMID 19713207 Get It

This review discusses the use of extracorporeal membrane oxygenation (ECMO) for the treatment of respiratory failure in neonates. After briefly reviewing the early history of neonatal ECMO, the authors describe the respiratory diagnoses most often treated with ECMO and the manner in which affected neonates are deemed to have “failed” conventional therapies and thus require ECMO. After reviewing the most common indications for ECMO, factors that influence the timing of conversion to extracorporeal life support, as well as criteria that may exclude patients from receiving ECMO therapy, are described. At the conclusion of this article, the authors discuss the long-term outcomes of neonates whose respiratory disease was treated with ECMO and the costs associated with that care.
TLR3-Stimulated Dendritic Cells Up-regulate B7-H1 Expression and Influence the Magnitude of CD8 T Cell Responses to Tumor Vaccination
Pulko, Vesna, Krco, Christopher J., Harris, Kimberley J., Frigola, Xavier, Kwon, Eugene D., Dong, Haidong , Liu, Xin , Dong, Haidong

The Journal of Immunology | August 26, 2009 | Volume: 183 | Issue: 6 | Pages: 3634-3641

10.4049/jimmunol.0900974 | PMID 19710456 Get It

Abstract Agonists of TLR have been explored as vaccine adjuvants for tumor immunotherapy. However, their immunological consequences are not fully understood. Although TLR signaling increases the functional potential of dendritic cells (DCs) for priming T cells, coinduction of potentially negative immunoregulatory capacities may impair effector T cell generation. We examined the expression and function of B7 family costimulatory molecules on DCs after activation with the TLR3 agonist, polyinosinic:polycytidylic acid. We demonstrated that polyinosinic:polycytidylic acid consistently up-regulated both B7-2 and B7-H1 molecules on resident, migratory DCs from spleen and lymph nodes. Depletion or blockade of B7-H1 on activated DCs increased the magnitude of effector CD8 T cell expansion. DC-based or protein-based tumor vaccines, in combination with B7-H1 blockade, induced strong effector CD8 T cell responses, resulting in protective immunity against newly established tumors. Our studies suggest that TLR3 signaling has the potential to up-regulate both positive and negative coregulatory molecules on APCs. Selective blockade of negative regulatory molecules in combination with TLR3 agonist may be an effective strategy for increasing the efficacy of tumor vaccines.