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Chan R, Stuart-Fox D, Jessop TS. Why are females ornamented? A test of the courtship stimulation and courtship rejection hypotheses. Behav Ecol 2009. [DOI: 10.1093/beheco/arp136] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Eaton KK, Chan R, Howard MA, McLaren-Howard JM. A Comparison of Lactulose Breath Hydrogen Measurements with Gut Fermentation Profiles in Patients with Fungal-type Dysbiosis. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/13590840020030249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Tsai P, Chan R. SU-FF-T-630: Characterizing the Enhance Dynamic Wedge Parameters in the Eclipse Treatment Planning System and Assessing Its Accuracy in Beam Modeling. Med Phys 2009. [DOI: 10.1118/1.3182128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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79
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Zhang Q, Chan R. SU-FF-T-148: Effect of Dose Rate On Gated IMRT Dose Delivery. Med Phys 2009. [DOI: 10.1118/1.3181622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Lee J, Chan R. SU-FF-T-13: Clinical Use of Multi-Lumen Catheter for Accelerated Partial Breast Irradiation. Med Phys 2009. [DOI: 10.1118/1.3181484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Jessop TS, Chan R, Stuart-Fox D. Sex steroid correlates of female-specific colouration, behaviour and reproductive state in Lake Eyre dragon lizards, Ctenophorus maculosus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2009; 195:619-30. [DOI: 10.1007/s00359-009-0437-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 03/16/2009] [Accepted: 03/18/2009] [Indexed: 11/30/2022]
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Leung A, Lefaucheur J, Rollnik J, Donohue M, Xu R, Lee R, André-Obadia N, Khedr E, Saitoh Y, Wallace M, Chan R. RTMS in neuropathic pain management-a meta-analysis. THE JOURNAL OF PAIN 2009. [DOI: 10.1016/j.jpain.2009.01.161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ross JDC, Garcia PJ, Zenilman J, Lewis DA, Chan R, Poder A. Summary of proceedings of the IUSTI Global Challenges Symposium (ISSTDR 2007/10th IUSTI World Congress). Int J STD AIDS 2009; 20:130-4. [PMID: 19182062 DOI: 10.1258/ijsa.2008.008041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Chan R, Park KC, Lee MH, Lee ES, Chang SE, Leow YH, Tay YK, Legarda-Montinola F, Tsai RY, Tsai TH, Shek S, Kerrouche N, Thomas G, Verallo-Rowell V. A randomized controlled trial of the efficacy and safety of a fixed triple combination (fluocinolone acetonide 0.01%, hydroquinone 4%, tretinoin 0.05%) compared with hydroquinone 4% cream in Asian patients with moderate to severe melasma. Br J Dermatol 2008; 159:697-703. [PMID: 18616780 DOI: 10.1111/j.1365-2133.2008.08717.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Melasma is an acquired, chronic hypermelanosis for which therapy remains a challenge. OBJECTIVES To compare the efficacy and safety of a triple combination [TC: fluocinolone acetonide 0.01%, hydroquinone (HQ) 4%, tretinoin 0.05%] vs. HQ 4% after 8 weeks of treatment of moderate to severe facial melasma in Asian patients. METHODS This was a multicentre, randomized, controlled, investigator-blinded, parallel comparison study. East and South-East Asian patients aged 18 years or older, with a clinical diagnosis of moderate to severe melasma, were enrolled in this study. Patients were enrolled at baseline and treated daily for 8 weeks with TC cream (one application at bedtime) or HQ cream (twice daily). There were four study visits: at baseline and weeks 2, 4 and 8. The primary efficacy variable was the melasma global severity score (GSS). Other outcome measures included Melasma Area and Severity Index, global improvement and patient satisfaction. Safety was assessed through the reporting of adverse events. RESULTS TC had superior efficacy to HQ for the primary variable: 77/120 patients (64.2%) on TC had GSS 'none' or 'mild' at week 8 vs. 48/122 patients (39.4%) on HQ (P < 0.001). The secondary efficacy variables confirmed these results. Patient satisfaction was in favour of TC (90/127, 70.8%, vs. 64/129, 49.6%; P = 0.005). More patients had related adverse events on TC (63/129, 48.8%) than on HQ (18/131, 13.7%) but most were mild and none was severe. CONCLUSIONS Efficacy in Asians and patient satisfaction were superior with the fixed TC than with HQ 4%.
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Ozdemir O, Bussière M, Leung A, Gulka I, Lee D, Chan R, Spence JD, Pelz D. Intra-arterial thrombolysis of occluded middle cerebral artery by use of collateral pathways in patients with tandem cervical carotid artery/middle cerebral artery occlusion. AJNR Am J Neuroradiol 2008; 29:1596-600. [PMID: 18524975 DOI: 10.3174/ajnr.a1163] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND PURPOSE Cervical internal carotid artery (ICA) occlusion with middle cerebral artery (MCA) embolic occlusion is associated with a low rate of recanalization and poor outcome after intravenous thrombolysis. Prompt revascularization is required to prevent disabling stroke. We report our experience on acute ischemic stroke patients with tandem ICA or MCA occlusions treated with microcathether navigation and intra-arterial thrombolysis by use of collateral pathways including the posterior or anterior communicating arteries, or both pathways. MATERIALS AND METHODS We retrospectively identified 8 patients with proximal ICA occlusion associated with MCA embolic occlusions treated with intra-arterial thrombolysis (IA rtPA). Access to the occluded MCA was obtained via catheter navigation through intact collateral pathways, including posterior communicating (PcomA) or anterior communicating (AcomA) arteries, without passing a microcathether through the acutely occluded ICA. We assessed clinical outcomes using modified Rankin scale (mRS) and National Institutes of Health Stroke Scale (NIHSS). RESULTS Eight patients with a mean age of 57 +/- 4 years and median NIHSS of 14 were identified. Mean time from stroke onset to intra-arterial thrombolysis was 292 +/- 44 minutes. The MCA was revascularized completely in 5 of the 8 patients via collateral intra-arterial rtPA administration. All of the patients had a favorable outcome defined as a mRS of < or =2 or more at 1 and 3 months' follow-up after thrombolytic therapy. One patient had an asymptomatic petechial hemorrhage. CONCLUSION In this small number of patients with tandem occlusions of the ICA and MCA, intra-arterial thrombolysis and recanalization of the MCA by use of collateral pathways to bypass the occluded ICA is a safe and efficacious therapeutic option.
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Dimitrov V, Heng J, Timp K, Dimauro O, Chan R, Hafez M, Feng J, Sorsch T, Mansfield W, Miner J, Kornblit A, Klemens F, Bower J, Cirelli R, Ferry EJ, Taylor A, Feng M, Timp G. Small-Signal Performance and Modeling of sub-50nm nMOSFETs with f above 460-GHz. SOLID-STATE ELECTRONICS 2008; 52:899-908. [PMID: 20706596 PMCID: PMC2919744 DOI: 10.1016/j.sse.2008.01.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have fabricated and tested the performance of sub-50nm gate nMOSFETs to assess their suitability for mixed signal applications in the super high frequency (SHF) band, i.e. 3-30GHz. For a 30nm×40 μm×2 device, we found f(T) =465GHz at V(ds)=2V, V(g)=0.67V, which is the highest cut-off frequency reported for a MOSFET produced on bulk silicon substrate so far. However, our measurements of f(max) and noise figure indicate that parasitics impose limitations on SHF operation. We also present a high-frequency ac model appropriate to sub-50nm gate length nanotransistors, which incorporates the effects of the parasitics. The model accurately accounts for measurements of the S and Y parameters in the frequency range from 1 to 50GHz.
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Zhang Q, Chan R, Hale D, Tsai P. TU-C-AUD B-07: Effect of Respiratory Gating On Dose Delilvery in a Moving Target. Med Phys 2008. [DOI: 10.1118/1.2962443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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88
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Lee J, Chan R. SU-GG-T-504: Verification of Accuracy of the Monte Carlo Based Electron Treatment Planning System. Med Phys 2008. [DOI: 10.1118/1.2962253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Sen P, Sun YJ, Tan HH, Tan SH, Chan R. Comparison of nested-polymerase chain reaction and virus culture for the diagnosis of genital herpes simplex virus infection. Singapore Med J 2008; 49:466-469. [PMID: 18581019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
INTRODUCTION This study was performed to compare nested-polymerase chain reaction (PCR) with viral culture as a diagnostic tool for genital herpes simplex virus (HSV) infection in a sexually transmitted infection (STI) clinic in Singapore. METHODS 103 consecutive patients presenting with clinical features suggestive of genital herpes were enrolled in the study. Two swabs were obtained from each patient. On one swab, cell culture and typing was performed, and on the second swab, nested-PCR was performed and the infecting viral type was determined by using type-specific primers. RESULTS 63 patients (61.2 percent) had a positive PCR test for HSV. Of these, 13 patients (20.6 percent) had HSV type 1 (HSV-1), 50 patients (79.4 percent) had HSV type 2 (HSV-2). HSV-1 and HSV-2 were detected by viral culture in only six patients and 24 patients, respectively. The sensitivity of cell culture compared to PCR was 46.1 percent for HSV-1 infection and 48 percent for HSV-2 infection. PCR further detected an additional 52.4 percent of HSV cases. The specificity of PCR was 100 percent. CONCLUSION Nested-PCR has been shown in this study to be an effective diagnostic and typing method for HSV infection in a STI clinic in Singapore with its higher sensitivity and specificity to routine viral isolation in cell culture.
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Dawson MI, Hobbs PD, Chan R, Derdzinski K, Helmes CT, Chao W, Meierhenry E, Schiff LJ. Conformational restrictions of the retinoid skeleton. CIBA FOUNDATION SYMPOSIUM 2008; 113:6-28. [PMID: 2411481 DOI: 10.1002/9780470720943.ch2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A series of conformationally restricted retinoids has been synthesized and assayed for biological activity. These compounds have aromatic rings in place of selected double bonds of the tetraene side-chain of retinoic acid and could be considered as analogues of retinoic acid in which some of the double bonds possess s-cis topology. Thus far, analogues in which the bonds corresponding to the (5,7E)-, (7,9E)-, (9,11,13E)- and (11,13E)-double bond systems of retinoic acid are restricted to a cisoid conformation have been studied. Analogues were screened for their ability to reverse keratinization in hamster tracheal organ culture and to inhibit the induction of ornithine decarboxylase in mouse epidermis. Selected compounds were also screened in the antipapilloma assay in mice. The toxicity of some analogues on intraperitoneal injection in mice was determined.
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Waksman R, Pakala R, Roy P, Baffour R, Hellinga D, Seabron R, Chan R, Scheinowitz M, Kolodgie F, Virmani R. Effect of clopidogrel on neointimal formation and inflammation in balloon-denuded and radiated hypercholesterolemic rabbit iliac arteries. CARDIOVASCULAR REVASCULARIZATION MEDICINE 2008. [DOI: 10.1016/j.carrev.2008.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Zhang Q, Lee J, Chan R. SU-DD-A2-06: EPID Portal Dosimetry for IMRT Validation. Med Phys 2007. [DOI: 10.1118/1.2760350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Sun W, Qetin M, Chan R, Reddy V, Holmvang G, Chandar V, Willsky A. Segmenting and tracking the left ventricle by learning the dynamics in cardiac images. ACTA ACUST UNITED AC 2007; 19:553-65. [PMID: 17354725 DOI: 10.1007/11505730_46] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Having accurate left ventricle (LV) segmentations across a cardiac cycle provides useful quantitative (e.g. ejection fraction) and qualitative information for diagnosis of certain heart conditions. Existing LV segmentation techniques are founded mostly upon algorithms for segmenting static images. In order to exploit the dynamic structure of the heart in a principled manner, we approach the problem of LV segmentation as a recursive estimation problem. In our framework, LV boundaries constitute the dynamic system state to be estimated, and a sequence of observed cardiac images constitute the data. By formulating the problem as one of state estimation, the segmentation at each particular time is based not only on the data observed at that instant, but also on predictions based on past segmentations. This requires a dynamical system model of the LV, which we propose to learn from training data through an information-theoretic approach. To incorporate the learned dynamic model into our segmentation framework and obtain predictions, we use ideas from particle filtering. Our framework uses a curve evolution method to combine such predictions with the observed images to estimate the LV boundaries at each time. We demonstrate the effectiveness of the proposed approach on a large set of cardiac images. We observe that our approach provides more accurate segmentations than those from static image segmentation techniques, especially when the observed data are of limited quality.
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Waksman R, Pakala R, Baffour R, Seabron R, Hellinga D, Chan R, Tio F, Wittchow E, Hartwig S, Waldmann KH, Harder C. Effect of pimecrolimus-eluting stent on intimal hyperplasia in porcine coronary arteries. CARDIOVASCULAR REVASCULARIZATION MEDICINE 2007. [DOI: 10.1016/j.carrev.2007.03.111] [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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Waksman R, Pakala R, Okabe T, Baffour R, Seabron R, Hellinga D, Chan R, Tio F, Wittchow E, Hartwig S, Waldmann KH, Harder C. Adjunct vascular brachytherapy further improves efficacy of absorbable metallic stents in porcine coronary arteries. CARDIOVASCULAR REVASCULARIZATION MEDICINE 2007. [DOI: 10.1016/j.carrev.2007.03.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Cole A, Metzger A, Ahmed G, Brescia MR, Chan R, Wen J, Qin LY, Henderson I. Solid-Phase Synthesis of N-9-Substituted 2,8-Diaminopurines. ACTA ACUST UNITED AC 2007. [DOI: 10.1055/s-2007-968224] [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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97
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DuPont F, Chan R, Lopez R. Molar fractions of high-molecular-weight glutenin subunits are stable when wheat is grown under various mineral nutrition and temperature regimens. J Cereal Sci 2007. [DOI: 10.1016/j.jcs.2006.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Tjin Tham Sjin RM, Naspinski J, Birsner AE, Li C, Chan R, Lo KM, Gillies S, Zurakowski D, Folkman J, Samulski J, Javaherian K. Endostatin therapy reveals a U-shaped curve for antitumor activity. Cancer Gene Ther 2006; 13:619-27. [PMID: 16456550 DOI: 10.1038/sj.cgt.7700938] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Developing continuous systemic delivery of endostatin has been a goal of many laboratories. We have employed a method of gene therapy utilizing different viral constructs. Here, we report that a new serotype of adeno-associated viruses, which incorporates canine endostatin, provides dose-dependent transgene expression in the circulation after intramuscular injection in mice. Elevated levels of endostatin remained stable in the circulation for at least 4 months. In vitro assays determined that the protein expressed was biologically active. Antitumor activities of the above construct demonstrated a U-shape curve, where the maximum activity was observed within a certain critical concentration range. These data suggest that an optimum dose range may be required to achieve therapeutic efficacy in large animal models.
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Murphy BD, Fox AJ, Lee DH, Sahlas DJ, Black SE, Hogan MJ, Coutts SB, Demchuk AM, Goyal M, Aviv RI, Symons S, Gulka IB, Beletsky V, Pelz D, Hachinski V, Chan R, Lee TY. Identification of Penumbra and Infarct in Acute Ischemic Stroke Using Computed Tomography Perfusion–Derived Blood Flow and Blood Volume Measurements. Stroke 2006; 37:1771-7. [PMID: 16763182 DOI: 10.1161/01.str.0000227243.96808.53] [Citation(s) in RCA: 201] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND PURPOSE We investigated whether computed tomography (CT) perfusion-derived cerebral blood flow (CBF) and cerebral blood volume (CBV) could be used to differentiate between penumbra and infarcted gray matter in a limited, exploratory sample of acute stroke patients. METHODS Thirty patients underwent a noncontrast CT (NCCT), CT angiography (CTA), and CT perfusion (CTP) scan within 7 hours of stroke onset, NCCT and CTA at 24 hours, and NCCT at 5 to 7 days. Twenty-five patients met the criteria for inclusion and were subsequently divided into 2 groups: those with recanalization at 24 hours (n=16) and those without (n=9). Penumbra was operationally defined as tissue with an admission CBF <25 mL x 100 g(-1) x min(-1) that was not infarcted on the 5- to 7-day NCCT. Logistic regression was applied to differentiate between infarct and penumbra data points. RESULTS For recanalized patients, CBF was significantly lower (P<0.05) for infarct (13.3+/-3.75 mL x 100 g(-1) x min(-1)) than penumbra (25.0+/-3.82 mL x 100 g(-1) x min(-1)). CBV in the penumbra (2.15+/-0.43 mL x 100 g(-1)) was significantly higher than contralateral (1.78+/-0.30 mL x 100 g(-1)) and infarcted tissue (1.12+/-0.37 mL x 100 g(-1)). Logistic regression using an interaction term (CBFxCBV) resulted in sensitivity, specificity, and accuracy of 97.0%, 97.2%, and 97.1%, respectively. The interaction term resulted in a significantly better (P<0.05) fit than CBF or CBV alone, suggesting that the CBV threshold for infarction varies with CBF. For patients without recanalization, CBF and CBV for infarcted regions were 15.1+/-5.67 mL x 100 g(-1) x min(-1) and 1.17+/-0.41 mL x 100 g(-1), respectively. CONCLUSIONS We have shown in a limited sample of patients that CBF and CBV obtained from CTP can be sensitive and specific for infarction and should be investigated further in a prospective trial to assess their utility for differentiating between infarct and penumbra.
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Chan R, Voorhorst C, Hass M, Kondo T, Hashino E. Activating PTPN11 mutants aberrantly promote myelomonocytic differentiation. Leuk Res 2006. [DOI: 10.1016/s0145-2126(06)80014-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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