401
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McCullagh P, Zheng H, Black N, Davies R, Mawson S, McGlade K. Section 1: Medical Informatics and eHealth. Technol Health Care 2008. [DOI: 10.3233/thc-2008-16507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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402
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Zhou Y, Li HP, Li QH, Zheng H, Zhang RX, Chen G, Baughman RP. Differentiation of sarcoidosis from tuberculosis using real-time PCR assay for the detection and quantification of Mycobacterium tuberculosis. SARCOIDOSIS, VASCULITIS, AND DIFFUSE LUNG DISEASES : OFFICIAL JOURNAL OF WASOG 2008; 25:93-99. [PMID: 19382528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
BACKGROUND The clinical and pathological features of sarcoidosis and tuberculosis may mimic each other, and when the caseous necrosis is not seen in tuberculosis tissue, differentiation is not easy. OBJECTIVE This study evaluates the ability of real-time PCR quantification and sets the quantitive value to differentiate sarcoidosis from TB. METHODS Formalin-fixed and paraffin-embedded sections of biopsy samples, from 104 patients with sarcoidosis, 31 patients with tuberculosis, and 55 controls with other respiratory diseases (26 with nonspecific lymphadenitis and 29 with emphysema bullae), were collected to amplify insertion sequence IS986 of Mycobacterium tuberculosis (MTB) genome by real-time quantitative PCR. The diagnostic performance of qualitative and quantitative analysis of real-time quantitative PCR was assessed by receiver-operating characteristic (ROC) curves. RESULTS MTB DNA was detected in 20 of the 104 sarcoidosis samples and 7 of the 55 control samples, but was detected in all of the 31 tuberculosis samples. The numbers of MTB genomes were 0-4.71x10(3) copies per ml in sarcoidosis samples, 1.58x10(2)-5.43x10(7) copies per ml in tuberculosis samples and 0-1.02x10(3) copies per ml in controls with quantitative analysis. Receiver-operating characteristic (ROC) curves showed that MTB genome quantification had greater diagnostic performance than MTB genome qualitation in discriminating patients with sarcoidosis from those with tuberculosis (area under the ROC curves: 0.994 vs 0.904, P<0.001). The sensitivity and specificity of qualitative analysis were 100% and 80.8% respectively. At cutoff value of 1.14x10(3) copies per ml for MTB genome quantification, the sensitivity was 96.8% and specificity was 98.1%. CONCLUSIONS The real time PCR quantification is a valuable test for differentiation between sarcoidosis and tuberculosis, and the MTB genome copies number of 1.14x10(3) copies per ml should be preferred as quantitative cutoff value for the differentiation.
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403
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Zheng H, Zhu SY, Zubairy MS. Quantum Zeno and anti-Zeno effects: without the rotating-wave approximation. PHYSICAL REVIEW LETTERS 2008; 101:200404. [PMID: 19113320 DOI: 10.1103/physrevlett.101.200404] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Indexed: 05/27/2023]
Abstract
We show that the counterrotating, neglected in the previous studies of the quantum Zeno effect (QZE) in atomic decay, can have a large impact on the short-time evolution. We calculate the electron self-energy, the Lamb shift, and the QZE without making the rotating-wave approximation (RWA) and show that, for hydrogen in free space, the Zeno time is longer by 2 orders of magnitude than that obtained from the RWA. We also show that there is no anti-Zeno effect as the counterrotating terms and rotating terms represent the opposite processes in the higher frequency region. Consequently, the experimental measurement of the QZE may be much easier than what was determined with the RWA results.
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404
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Ew KH, Wee CL, Zhang DG, Zhu KY, Zheng H. Effects of functional electrical stimulation relating to leg movement. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2008; 2005:6203-6. [PMID: 17281682 DOI: 10.1109/iembs.2005.1615912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Functional electrical stimulation (FES) has grown to be an effective and important element in the biomedical industry over the years. Due to this fact, it has become the basis of many researches. However, much work is focused on the theory and control technique with very few relating experiments. In this work, some key experiments were performed on the leg muscles during the leg movement. Some useful results were obtained with regards to muscle reaction, in terms EMG readings. The stimulus of the FES system was also applied to the muscles during the leg movement. The readings of experiments reveal some important muscle properties which are verified accordingly.
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405
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Hurwitz M, Zheng H, Nagaraja G, Bausero M, Manola J, Kaur P, Asea A. Radiation Therapy Induces Circulating Serum Heat Shock Proteins in Prostate Cancer Patients: Clinical Findings and Laboratory Correlates. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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406
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Minor W, Zheng H, Chruszcz M. Metal and small-molecule agent environment in macromolecules. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308095032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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407
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Sledz P, Zheng H, Chruszcz M, Zimmerman M, Joachimiak A, Minor W. The role of protein methylation rescue method for protein crystallization. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308092581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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408
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Zheng H. Is sham acupuncture necessary? Aliment Pharmacol Ther 2008; 28:497-8; author reply 498-9. [PMID: 18715397 DOI: 10.1111/j.1365-2036.2008.03755.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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409
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Zheng H, Sun Y, Lin S, Mao Z, Jiang B. Yersinia enterocolitica infection in diarrheal patients. Eur J Clin Microbiol Infect Dis 2008; 27:741-52. [DOI: 10.1007/s10096-008-0562-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Accepted: 05/25/2008] [Indexed: 11/30/2022]
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410
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Blaszkowsky LS, Zhu AX, Abrams TA, Earle CC, Kwak E, Hezel AF, Meyerhardt JA, Horgan K, Zheng H, Ryan DP. A phase II study of gemcitabine (G), bevacizumab (B), and erlotinib (E) in locally advanced (LAPC) and metastatic adenocarcinoma (MPC) of the pancreas. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.15515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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411
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Henrickson SE, Mempel TR, Mazo IB, Liu B, Artyomov MN, Zheng H, Peixoto A, Flynn M, Senman B, Junt T, Wong HC, Chakraborty AK, von Andrian UH. In Vivo Imaging of T Cell Priming. Sci Signal 2008; 1:pt2. [DOI: 10.1126/stke.112pt2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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412
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Chmaissem O, Zheng H, Huq A, Stephens P, Mitchell J. Formation of Co3+ octahedra and tetrahedra in YBaCo4O8.1. J SOLID STATE CHEM 2008. [DOI: 10.1016/j.jssc.2007.12.016] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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413
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Reay DP, Bilbao R, Koppanati BM, Cai L, O'Day TL, Jiang Z, Zheng H, Watchko JF, Clemens PR. Full-length dystrophin gene transfer to the mdx mouse in utero. Gene Ther 2008; 15:531-6. [PMID: 18273052 DOI: 10.1038/gt.2008.8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In utero gene therapy for genetic diseases, such as muscular dystrophies, offers potential advantages over postnatal treatment including vector delivery at the earliest point in the disease and treatment prior to full maturation of the immune system. This study examines in utero gene delivery of full-length murine dystrophin to the murine mdx model for Duchenne muscular dystrophy using a high-capacity adenoviral vector. We examined dystrophin expression, spread of vector, morphology and specific force production of the tibialis anterior muscle 9 weeks after intramuscular in utero injection. Recombinant dystrophin was expressed in the hindlimb muscles, with the majority of animals having expression in two muscles of the injected hindlimb. The dystrophin-glycoprotein complex was restored in those muscle fibers expressing recombinant dystrophin. Analysis of the percentage of dystrophin-expressing muscle fibers with centrally placed nuclei revealed effective protection from cycles of degeneration and regeneration normally seen in muscle fibers lacking dystrophin. However, due to low levels of muscle gene transfer, further advances in the efficiency of adenoviral vector-mediated gene delivery would be required for clinical applications of in utero gene therapy for primary myopathies such as Duchenne muscular dystrophy.
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414
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Wang G, Dong C, Sun YA, Xie K, Zheng H. Characterization of Volatile Components in Dry Chrysanthemum Flowers Using Headspace--Liquid-Phase Microextraction--Gas Chromatography. J Chromatogr Sci 2008; 46:127-32. [DOI: 10.1093/chromsci/46.2.127] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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415
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McCullagh PJ, Zheng H, Black ND, Davies R, Mawson S, McGlade K. Section 1: medical informatics and eHealth. Technol Health Care 2008; 16:381-397. [PMID: 19126977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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416
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Zhu J, Cao W, Jiang B, Zhang DS, Zheng H, Zhou Q, Shung KK. Nano-structured TiO(2) film fabricated at room temperature and its acoustic properties. JOURNAL OF PHYSICS D: APPLIED PHYSICS 2008; 41:162001. [PMID: 19672322 PMCID: PMC2723960 DOI: 10.1088/0022-3727/41/16/162001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nano-structured TiO(2) thin film has been successfully fabricated at room temperature. Using a quarter wavelength characterization method, we have measured the acoustic impedance of this porous film, which can be adjusted from 5.3 to 7.19 Mrayl by curing it at different temperatures. The uniform microstructure and easy fabrication at room temperature make this material an excellent candidate for matching layers of ultra-high frequency ultrasonic imaging transducers.
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417
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Wakabayashi Y, Upton MH, Grenier S, Hill JP, Nelson CS, Kim JW, Ryan PJ, Goldman AI, Zheng H, Mitchell JF. Surface effects on the orbital order in the single-layered manganite La0.5Sr1.5MnO4. NATURE MATERIALS 2007; 6:972-976. [PMID: 18026106 DOI: 10.1038/nmat2061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Accepted: 10/15/2007] [Indexed: 05/25/2023]
Abstract
The question of how bulk electronic order is terminated at a surface is an intriguing one, and one with possible practical implications--for example in nanoscaled systems that may be characterized by their surface behaviour. One example of such order is orbital order, and in principle it should be possible to probe the termination of this order with surface X-ray scattering. Here, we report the first observation of the scattering arising from the termination of bulk orbital order at the surface of a crystal--so-called 'orbital truncation rods'. The measurements, carried out on a cleaved perovskite, La(0.5)Sr(1.5)MnO(4), reveal that whereas the crystallographic surface is atomically smooth, the orbital 'surface', which is observed through the atomic displacements caused by the orbital order, is much rougher, with a typical scale of the surface roughness of approximately 7 degrees A. Interestingly, the temperature dependence of this scattering shows evidence of a surface-induced second-order transition.
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418
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Bradley A, Ramírez-Solis R, Zheng H, Hasty P, Davis A. Genetic manipulation of the mouse via gene targeting in embryonic stem cells. CIBA FOUNDATION SYMPOSIUM 2007; 165:256-69; discussion 269-76. [PMID: 1516472 DOI: 10.1002/9780470514221.ch15] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Gene targeting applied to totipotent embryonic stem (ES) cells is a very powerful means of creating highly specific mutations of genes in the mouse. The successful application of this technology is however constrained by both the types of mutations that can be generated at a target locus and the ability to reconstruct a germline chimera from the manipulated cells. We have developed two cell lines that can be routinely transmitted through the germline of chimeras after cloning and prolonged selection in tissue culture. We have also established a variety of methods for generating non-selected mutations at the X-linked hprt locus in ES cells. Our observations at this locus have enabled us to generate successfully a subtle mutation at the non-selectable Hox-2.6 locus.
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419
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Yang L, Wang B, Long C, Wu G, Zheng H. Increased asynchronous release and aberrant calcium channel activation in amyloid precursor protein deficient neuromuscular synapses. Neuroscience 2007; 149:768-78. [PMID: 17919826 DOI: 10.1016/j.neuroscience.2007.08.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 08/13/2007] [Accepted: 08/24/2007] [Indexed: 01/06/2023]
Abstract
Despite the critical roles of the amyloid precursor protein (APP) in Alzheimer's disease pathogenesis, its physiological function remains poorly established. Our previous studies implicated a structural and functional activity of the APP family of proteins in the developing neuromuscular junction (NMJ). Here we performed comprehensive analyses of neurotransmission in mature neuromuscular synapse of APP deficient mice. We found that APP deletion led to reduced paired-pulse facilitation and increased depression of synaptic transmission with repetitive stimulation. Readily releasable pool size and total releasable vesicles were not affected, but probability of release was significantly increased. Strikingly, the amount of asynchronous release, a measure sensitive to presynaptic calcium concentration, was dramatically increased, and pharmacological studies revealed that it was attributed to aberrant activation of N- and L-type Ca(2+) channels. We propose that APP modulates synaptic transmission at the NMJ by ensuring proper Ca(2+) channel function.
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420
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Freeland JW, Kavich JJ, Gray KE, Ozyuzer L, Zheng H, Mitchell JF, Warusawithana MP, Ryan P, Zhai X, Kodama RH, Eckstein JN. Suppressed magnetization at the surfaces and interfaces of ferromagnetic metallic manganites. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2007; 19:315210. [PMID: 21694110 DOI: 10.1088/0953-8984/19/31/315210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
What happens to ferromagnetism at the surfaces and interfaces of manganites? With the competition between charge, spin, and orbital degrees of freedom, it is not surprising that the surface behaviour may be profoundly different to that of the bulk. Using a powerful combination of two surface probes, tunnelling and polarized x-ray interactions, this paper reviews our work on the nature of the electronic and magnetic states at manganite surfaces and interfaces. The general observation is that ferromagnetism is not the lowest energy state at the surface or interface, which results in a suppression or even loss of ferromagnetic order at the surface. Two cases will be discussed ranging from the surface of the quasi-2D bilayer manganite (La(2-2x)Sr(1+2x)Mn(2)O(7)) to the 3D perovskite (La(2/3)Sr(1/3)MnO(3))/SrTiO(3) interface. For the bilayer manganite, which is ferromagnetic and conducting in the bulk, these probes present clear evidence for an intrinsic insulating non-ferromagnetic surface layer atop adjacent subsurface layers that display the full bulk magnetization. This abrupt intrinsic magnetic interface is attributed to the weak inter-bilayer coupling native to these quasi-two-dimensional materials. This is in marked contrast to the situation for the non-layered manganite system (La(2/3)Sr(1/3)MnO(3)/SrTiO(3)), whose magnetization near the interface is less than half the bulk value at low temperatures and decreases with increasing temperature at a faster rate than that for the bulk.
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421
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Townsend R, Zheng H, Patterson L, Berthoud HR. Food intake suppression induced by fourth ventricular CCK and MTII but not oxytocin and bombesin is partially mediated by activation of the ERK intracellular signaling cascade. Appetite 2007. [DOI: 10.1016/j.appet.2007.03.202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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422
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Zheng H, Patterson L, Berthoud HR. Food reward: Orexin-signaling in ventral tegmental area contributes to high-fat intake induced by accumbens opioid stimulation. Appetite 2007. [DOI: 10.1016/j.appet.2007.03.220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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423
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Kavanagh JJ, Hu W, Fu S, Deavers M, Moore C, Coleman RL, Levenback CF, Shen D, Zheng H G, YF L, Mueller P, Gershenson DM, Zheng H, Li YF. Anti-tumor activity of letrozole in patients with recurrent advanced low malignant potential or low-grade serous ovarian tumors. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.5582] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
5582 Purpose: To evaluate the clinical activity of oral Letrozole in patients with recurrent and advanced low malignant potential or low grade serous ovarian tumors and to determine the impact of steroid receptor expression on this observed activity. Methods: In a phase II design, we recruited patients with confirmed recurrent advanced stage low malignant potential tumors and recurrent low-grade serous carcinomas. Measurable disease was required. Steroid hormone expression (ER and PR), EGFR, and Her2/neu expression were determined on available pathological material by IHC from the initial surgery or at documentation of recurrent disease and blood was obtained before enrollment and every other month while on therapy. Letrozole was administered orally at a dose of 2.5 mg once a day. The endpoints were objective response rate assessed by Response Evaluation Criteria in Solid Tumor. Adverse events were graded using the National Cancer Institute Common Toxicity Criteria. Results: Thirteen patients meeting eligibility have been enrolled are evaluable for response and toxicity. From objective clinical parameters (RECIST) no patients had a CR or PR; five patients (38%) had disease stabilizations, eight patients had progressive disease. However, using criteria for CA 125 response, we obtained a complete serologic response in 2 of 13 patients (15%), and a partial serologic response in 2 additional patients (15%); marker stabilization was seen in 5 other patients (38%). CA125 increased in four patients (31%). We also detected the presence of ER, PR, EGFR, Her-2/Neu by IHC, and estradiol in the plasma by ELISA. No significant correlation was observed between tumor marker response and ER expression alone. However, when we evaluated the co-expression of ER/PR we found 3 of 5 (60%) patients had a serologic response compared to just 1 of 8 patients with ER+/PR- tumors (P=0.07). We observed no severe adverse events. Conclusion: Our preliminary data suggests that oral Letrozole has some antitumor activity in recurrent advanced low grade or borderline ovarian tumors and is well tolerated. The analysis of correlation between objective response and combined prediction markers including phosphorylated ER, PR, AKT, and IGFR is ongoing (Supported by CTRF). No significant financial relationships to disclose.
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424
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Zavaliche F, Zhao T, Zheng H, Straub F, Cruz MP, Yang PL, Hao D, Ramesh R. Electrically assisted magnetic recording in multiferroic nanostructures. NANO LETTERS 2007; 7:1586-90. [PMID: 17497818 DOI: 10.1021/nl070465o] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We demonstrate the room-temperature control of magnetization reversal with an electric field in an epitaxial nanostructure consisting of ferrimagnetic nanopillars embedded in a ferroelectric matrix. This was achieved by combining a weak, uniform magnetic field with the switching electric field to selectively switch pillars with only one magnetic configuration. On the basis of these experimental results, we propose to use an electric field to assist magnetic recording in multiferroic systems with high perpendicular magnetic anisotropy.
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425
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Zheng H, Blat D, Fridkin M. Novel neuroprotective neurotrophic NAP analogs targeting metal toxicity and oxidative stress: potential candidates for the control of neurodegenerative diseases. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2007:163-72. [PMID: 17447427 DOI: 10.1007/978-3-211-33328-0_18] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A large body of data indicates that a cascade of events contributes to the neurodegeneration in Alzheimer's disease (AD) and Parkinson's disease (PD). Metal (Fe, Cu, Zn) dyshomeostasis and oxidative stress are believed to play a pivotal role in the pathogenesis of these diseases. Accordingly, multifunctional compounds combining metal chelating and antioxidative activity hold a great promise as potential drugs for treating AD and PD. In this study, two novel NAPVSIPQ (NAP) analogs (M98 and M99) with potential antioxidant-metal chelating ability were designed and investigated, aiming to improve the poor metal chelating and antioxidative activity of NAP. Our studies showed that both M98 and M99 formed stable metal (Fe, Cu, Zn) complexes in water and demonstrated good metal (Fe, Cu, Zn) chelating properties as opposed to the poor metal (Fe, Cu, Zn) chelating properties of their parent peptide NAP. M98 and M99 exhibited significant inhibition of iron-induced lipid peroxidation in rat brain homogenates at concentrations of > or = 30 microM, while NAP failed to show any inhibition even at 100 microM. In human neuroblastoma cell (SH-SY5Y) culture, M98 and M99 at 1 microM completely protected against 6-hydroxydopamine (6OHDA) toxicity with potency similar to NAP and desferal (DFO), a strong iron chelator and a highly potent radical scavenger. In PC12 cell culture, M98 at the range of 0.001-1 microM displayed potent protection against 6-OHDA toxicity, comparable to NAP and DFO. These results suggest that M98 and M99 deserve further investigation as potential drug candidates for neuroprotection.
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