bluuebunny/crossref_metadata_2025_split huggingface dataset:
WE‐E‐AUD‐04: Radiation Characteristics and Hypo‐Fractionation Dose Response for the DVS Implantable MOSFET Dosimeter
Authors: Beyer GP , Pursley J , Mann G , Espenhahn E , Fraisse C , Godfrey D , Oldham M 
Published: July 2007

Purpose: Evaluation of the radiation characteristics and performance of the DVS® implantable MOSFET dosimeter for typical and hypo‐fractionated protocols. Method and Materials: The commercially available DVS is calibrated for use in the range of 150–250 cGy per fraction up to 80 Gy. The dosimeter was evaluated to determine its radiation characteristics, including response to energy, angular dependence, temperature, and dose shadowing. Dosimeter performance was also validated in a phantom simulating different radiation treatment conditions. A high dose calibrated dosimeter for use with hypo‐fractionated protocols is introduced. Phantom measurements were performed to validate this dosimeter in the dose per fraction range of 400–1200 cGy. All phantom data was validated using a NIST‐traceable calibrated ion chamber. Results: The DVS was found to have a very small energy dependency (⩽1.5%) in the ‐18 MV range. With kV onboard imaging, an over‐response was only measurable for doses from kV‐CBCT. The radial angular dependence was found to be within 1.4% and the maximum angular dependence (6%) was obtained for beams traveling through the coil and electronics. A dosimeter implanted in close parallel alignment with the sagittal body axis would minimize this effect. Since the DVS is calibrated at 37°C (for use at body temperature), measurements performed at room temperature require a correction factor of approximately 1.033. Phantom measurements (23°C, 37°C) resulted in values well within the specified accuracy of 5%. The dosimeter calibrated for use in hypo‐fractionation applications resulted in an average variability of −0.3% (σ=2.2%) from predicted dose in the range of 400–1200cGy per fraction. Conclusions: This data suggests that DVS can be used, together with current delivery and planning techniques, to optimize radiation treatment by measuring the dose delivered in the treatment area. Testing shows the potential to use the high‐dose calibrated dosimeter with hypo‐fractionated radiation treatments.Research sponsored by Sicel Technologies, Inc.
WE‐E‐BRA‐06: Imaging Linear Accelerator Startup Using a High‐Speed Scintillation Based Electronic Portal Imaging Device (Hi‐EPID)
Authors: Ranade M , Lynch B , Li J , Kim S , Dempsey J 
Published: July 2007

Purpose: Using the high‐speed scintillation based electronic portal imaging device (Hi‐EPID), to analyze the characteristics of the fluence delivered from a commercial clinical linear accelerator (Synergy® S, Elekta). To study the fluence output at short time scales. Method and Materials: The Hi‐EPID consists of a high speed digital camera coupled with a fast terbium‐doped gadolinium‐oxy‐sulfide (Gd2O2S:Tb) scintillator. The camera can record every single radiation pulse out of the accelerator, at up to 500 fps. Both open field and multileaf collimator (MLC) based intensity modulated radiation therapy (IMRT) fields were evaluated. The startup time of linac delivery was recorded. Results: Fluence delivery irregularities were observed with the Hi‐EPID device, within 250 ms. For the open field delivery, the fluence increased with time until it reached a plateau, in approximately 100 to 250 ms, and then remained constant. However, in the case of a six segment IMRT field delivery, the fluence variation differed between segments. For some segments, the fluence increased in the beginning and then reached a plateau. For others, the fluence rose and fell sharply, followed by a slower rise to the plateau. The rapid fluence variation before a plateau was as high as 60% of the maximum. A field size dependence of fluence was observed. An analysis of field shapes showed no unplanned motion of MLC was during step and shoot delivery, as has been reported for other clinical linac. Conclusion: The Hi‐EPID is capable of imaging the fluence out of a linear accelerator with high temporal resolution. The startup characteristics of the accelerator can be studied. For short time IMRT segments, fluence and dose rate varied over a significant portion of the segment. As the dose rate fluctuates during startup, its effect on IMRT delivery can be studied.This work was supported by NCI grant R01‐CA‐100636.
TH‐D‐M100J‐09: Activity Recovery From Dual Radiotracer PET Scans
Authors: Vanderhoek M , Barbee D , Jeraj R 
Published: July 2007

Purpose: Comprehensive assessment of tumor biological substructure requires multiple PET radiotracers resulting in time‐consuming imaging procedures. Ideally, multiple PET scans should be performed during one “imaging session,” resulting in the presence of multiple radiotracers during the later scans. We aim to develop a methodology to recover the activities of two mixed radionuclides present during a PET scan. Method and Materials: A heterogeneous tumor phantom composed of empty acrylic spheres mounted inside a cylindrical “background region” filled with low‐activity solution was scanned for 10‐minutes. Then, high‐activity solution was injected into the spheres while low‐activity solution was mixed into the background region and a 600‐minute dynamic PET scan was acquired. Images containing one radionuclide were subtracted from dual‐radionuclide images, yielding “recovered images” of each radionuclide. Recovered images were compared with single radionuclide reference images.Subsequently, canine subjects with nasopharyngeal tumors were injected with ‐ATSM (hypoxia radiotracer) and scanned 24 hours later, followed immediately by 18FLT injection (cellular proliferation radiotracer) and another scan. Images from ‐ATSM canine scans were subtracted from dual‐radiotracer images. Results: Recovered phantom images closely correlated with reference images. image correlation coefficients were consistently higher than 0.96 and increased as “contamination” decayed. image correlation coefficients were higher than 0.95 for background activities greater than 14% of the total background activity. By image subtraction, the biological distribution of 18FLT in the canine nasopharyngeal tumors was recovered from the dual‐radiotracer images. Conclusions: Radionuclide activities can be effectively recovered from PET scans containing two mixed radionuclides. Subtraction of single radiotracer images from dual‐radiotracer images is a reliable method of activity recovery, provided the pharmacokinetics of one radiotracer is stable during dual‐radiotracer image acquisition. Implications are positive for sequential imaging of different physiological functions using multiple radiotracers during one “multiple PET scan” imaging session.
Identification and Clinical Significance of Mobilized Endothelial Progenitor Cells in Tumor Vasculogenesis of Hepatocellular Carcinoma
Authors: Yu Decai , Sun Xitai , Qiu Yudong , Zhou Jianxing , Wu Yafu , Zhuang Lingyuan , Chen Jun , Ding Yitao 
Published: July 2007

Abstract
Purpose: To investigate the distribution, frequency, and clinical significance of mobilized endothelial progenitor cells (EPC) in hepatocellular carcinoma (HCC).
Experimental Design: In healthy controls and patients with HCC, the frequency of circulating EPCs was determined by colony-forming assays, fluorescence-activated cell sorting, and real-time PCR. One hundred sixty-five–amino acid form of vascular endothelial growth factor and platelet-derived growth factor-BB in plasma and tissue were quantified by ELISA. The distribution and frequency of EPCs were evaluated by immunofluorescence, immunohistochemistry, and real-time PCR in normal liver (n = 8), and tumor tissue (TT), adjacent nonmalignant liver tissue (AT), and tumor-free tissue 5 cm from the tumor edge (TF) from 64 patients with HCC. Clinicopathologic data for these patients were evaluated.
Results: Compared with values for healthy controls, colony-forming unit scores were higher in the peripheral blood of patients with HCC. Plasma 165-amino acid form of vascular endothelial growth factor and platelet-derived growth factor-BB correlated with the expression level of the AC133 gene, which was also higher in the peripheral blood of patients with HCC. Immunohistochemical analysis showed that EPCs were incorporated into the microvessels in cirrhotic and tumor tissue. Compared with normal liver (9.00), increased AC133+ microvessel density (microvessels/0.74 mm2) was found in TT (53.56), AT (84.76), and TF (48.33). The levels of AC133 gene expression and AC133-microvessel density in AT, which were the highest among four groups, correlated with clinicopathologic variables (the absence of tumor capsule, venous invasion, proliferating cell nuclear antigen intensity, and early recurrence).
Conclusions: Mobilized EPCs participate in tumor vasculogenesis of HCC. AC133 gene or antigen in peripheral blood and liver tissue could be used as a biomarker for predicting the progression of HCC.
Immune Signatures of Murine and Human Cancers Reveal Unique Mechanisms of Tumor Escape and New Targets for Cancer Immunotherapy
Authors: Sadun Rebecca E. , Sachsman Suzanne M. , Chen Xiaoying , Christenson Kamilee W. , Morris William Z. , Hu Peisheng , Epstein Alan L. 
Published: July 2007

AbstractPurpose: Despite lymphocyte infiltration of tumors and the activation of tumor-draining lymph nodes, malignant tumors are able to “escape” from both innate and adaptive immune responses. For immunotherapy to be successful, it must reverse these escape mechanisms, which necessitates explicit and tumor-specific elucidation of tumor escape strategies.Research Design: To identify relevant escape mechanisms in murine tumors and in two corresponding human cancers, real-time reverse transcription-PCR was used to measure a panel of genes associated with T-cell activation and inhibition pathways.Results: Comparative analysis of the expression levels of these immunomodulatory genes showed astonishing similarities in expression patterns between murine and human breast cancers but profound variability in the expression of immunomodulatory genes in colorectal cancers. For human ductal adenocarcinoma of the breast, down-regulation of dendritic cell maturation marker CD83 and T-cell activation gene CD28 was observed as well as a notable increase in the expression of the immunoinhibitory gene B7-H4. By contrast, colorectal adenocarcinoma cases showed high variability in tumor escape mechanisms, indicating a need to produce immune signatures for individual patients to identify appropriate immunotherapeutic targets.Conclusions: These results show that certain tumors, such as ductal carcinoma of the breast, show consistent immunologic abnormalities that can be used as targets for immunotherapy. These findings also show the importance and feasibility of determining the immune signatures of patients' tumors to select appropriate immunotherapeutic strategies. Ultimately, these results advocate for the determination of immune signatures as part of the customary repertoire of clinical diagnostics for cancer.
Bevacizumab-Induced Transient Remodeling of the Vasculature in Neuroblastoma Xenografts Results in Improved Delivery and Efficacy of Systemically Administered Chemotherapy
Authors: Dickson Paxton V. , Hamner John B. , Sims Thomas L. , Fraga Charles H. , Ng Catherine Y.C. , Rajasekeran Surender , Hagedorn Nikolaus L. , McCarville M. Beth , Stewart Clinton F. , Davidoff Andrew M. 
Published: July 2007

AbstractPurpose: Dysfunctional tumor vessels can be a significant barrier to effective cancer therapy. However, increasing evidence suggests that vascular endothelial growth factor (VEGF) inhibition can effect transient “normalization” of the tumor vasculature, thereby improving tumor perfusion and, consequently, delivery of systemic chemotherapy. We sought to examine temporal changes in tumor vascular function in response to the anti-VEGF antibody, bevacizumab.Experimental Design: Established orthotopic neuroblastoma xenografts treated with bevacizumab were evaluated at serial time points for treatment-associated changes in intratumoral vascular physiology, penetration of systemically administered chemotherapy, and efficacy of combination therapy.Results: After a single bevacizumab dose, a progressive decrease in tumor microvessel density to &lt;30% of control was observed within 7 days. Assessment of the tumor microenvironment revealed a rapid, sustained decrease in both tumor vessel permeability and tumor interstitial fluid pressure, whereas intratumoral perfusion, as assessed by contrast-enhanced ultrasonography, was improved, although this latter change abated by 1 week. Intratumoral drug delivery mirrored these changes; penetration of chemotherapy was improved by as much as 81% when given 1 to 3 days after bevacizumab, compared with when both drugs were given concomitantly, or 7 days apart. Finally, administering topotecan to tumor-bearing mice 3 days after bevacizumab resulted in greater tumor growth inhibition (36% of control size) than with monotherapy (88% bevacizumab, 54% topotecan) or concomitant administration of the two drugs (44%).Conclusions: Bevacizumab-mediated VEGF blockade effects alterations in tumor vessel physiology that allow improved delivery and efficacy of chemotherapy, although careful consideration of drug scheduling is required to optimize antitumor activity.
Reduced Likelihood of Metastases in Patients with Microsatellite-Unstable Colorectal Cancer
Authors: Malesci Alberto , Laghi Luigi , Bianchi Paolo , Delconte Gabriele , Randolph Ann , Torri Valter , Carnaghi Carlo , Doci Roberto , Rosati Riccardo , Montorsi Marco , Roncalli Massimo , Gennari Leandro , Santoro Armando 
Published: July 2007

Abstract
Purpose: The outcome of patients with colorectal cancer is more favorable when the tumor exhibits high-frequency microsatellite instability (MSI). Although associated with earlier-stage tumors, MSI has been proposed as an independent predictor of survival. We tested the prognostic value of MSI in a large series of patients diagnosed with colorectal cancer in the last decade.
Experimental Design: The survival of 893 consecutive patients with colorectal cancer characterized by microsatellite status was analyzed. The 89 (10%) patients with MSI cancer were classified according to tumor mismatch repair (MMR) defect, MMR germ-line mutation, hMLH1 and p16 promoter methylation, BRAF and K-ras mutations, and frameshifts of target genes.
Results: The colorectal cancer–specific survival was significantly (P = 0.02) better in patients with MSI cancer than in those with stable tumor (MSS). MSI did not predict a significantly lower risk of cancer-related death if tumor stage was included in the multivariate analysis [hazard ratio, 0.72; 95% confidence interval (95% CI), 0.40-1.29; P = 0.27]. Instead, MSI was strongly associated with a decreased likelihood of lymph node (odds ratio, 0.31; 95% CI, 0.17-0.56; P &lt; 0.001) and distant organ (odds ratio, 0.13; 95% CI, 0.05-0.33; P &lt; 0.001) metastases at diagnosis, independently of tumor pathologic features. Molecular predictors of reduced metastatic risk, and then of more favorable prognosis, included TGFβRII mutation for all MSI tumors, hMSH2 deficiency for hereditary non-polyposis colorectal cancer, and absence of p16 methylation for sporadic hMLH1-deficient cancers.
Conclusions: Tumor MSI is a stage-dependent predictor of survival in patients with colorectal cancer. The decreased likelihood of metastases in patients with MSI cancer is associated with specific genetic and epigenetic changes of the primary tumor.
Temperate Mountain Glacier-Melting Rates for the Period 2001–30: Estimates from Three Coupled GCM Simulations for the Greater Himalayas
Authors: Ren Diandong , Karoly David J. , Leslie Lance M. 
Published: July 2007

Abstract
The temperate glaciers in the greater Himalayas (GH) and the neighboring region contribute to the freshwater supply for almost one-half of the people on earth. Under global warming conditions, the GH glaciers may melt more rapidly than high-latitude glaciers, owing to the coincidence of the accumulation and ablation seasons in summer. Based on a first-order energy balance approach for glacier thermodynamics, the possible imposed additional melting rate was estimated from three climate simulations using the Geophysical Fluid Dynamics Laboratory Global Coupled Climate Model version 2.1 (GFDL-CM2.1), the Model for Interdisciplinary Research on Climate 3.2, high-resolution version (MIROC3.2-hires), and the Met Office’s Third Hadley Centre Coupled Ocean–Atmosphere General Circulation Model (HadCM3). The simulations were carried out under the Special Report on Emissions Scenarios (SRES) A1B scenario. For the 30-yr period of 2001–30, all three CGCMs indicate that the glacial regions most sensitive to regional warming are the Tianshan–Altai Mountains to the north and Hengduan Mountains to the south. A map of potential melting was produced and was used to calculate the glacier-melting speed, yielding an additional spatially averaged glacier depth reduction of approximately 2 m for the 2001–30 period for those areas located below 4000 m. Averaged over the entire GH region, the melting rate is accelerating at about 5 mm yr−2. The general circulation over the GH region was found to have clear multidecadal variability, with the 30-yr period of 2001–30 likely to be wetter than the previous 30-yr period of 1971–2000. Considering the possible trend in precipitation from snow to rain, the actual melting rates of the GH glaciers may even be larger than those obtained in this research.
Characteristic Profiles of Instrumental Activities of Daily Living in Chinese Older Persons with Mild Cognitive Impairment
Authors: Woon Chi Tam Cindy , Chiu Wa Lam Linda , Chiu Helen F.K. , Lui Victor W.C. 
Published: July 2007

Increasing evidence suggests that performance of the instrumental activities of daily living (IADL) can be impaired at the mild cognitive impairment (MCI) stage. Our study aimed at investigating the profiles of functional impairment in Chinese subjects with MCI. Subjects with MCI were categorized into single-domain amnestic MCI (a-MCI) (n = 54) and multiple-domain amnestic MCI (md-MCI) (n = 93) groups. Their functional scores of Disability Assessment of Dementia (DAD) were compared with those of cognitively normal elderly controls (NC) (n = 78) and those with mild Alzheimer's disease (AD) (n = 85). Subjects with md-MCI had intermediate performance in IADL between the NC and those with mild AD. Subjects with a-MCI had functional scores similar to those of normal controls. Age, education, and global cognitive test scores were not associated with functional scores in MCI subjects. Our results demonstrated that Chinese older persons with md-MCI had impairment in IADL, as compared to NC and subjects with a-MCI. This finding suggests that assessment of IADL should be incorporated in the clinical evaluation of MCI.
Insights into the mechanism of FTY720 and compatibility with regulatory T cells for the inhibition of graft-versus-host disease (GVHD)
Authors: Taylor Patricia A. , Ehrhardt Michael J. , Lees Christopher J. , Tolar Jakub , Weigel Brenda J. , Panoskaltsis-Mortari Angela , Serody Jonathan S. , Brinkmann Volker , Blazar Bruce R. 
Published: July 2007

Abstract
The immunomodulator FTY720 (FTY) has been shown to be beneficial in experimental models of organ transplantation and autoimmunity. We show that FTY significantly inhibited but did not prevent graft-versus-host disease (GVHD) in lethally irradiated or nonirradiated allogeneic recipients. Although most studies implicate prevention of lymphocyte egress from lymphoid organs as the primary mechanism of action, our data indicate that FTY effects on the host are more likely to be responsible for GVHD inhibition. FTY reduced splenic CD11c+ cells by 50%, and similarly reduced CD4+ and CD8+ T-cell responder frequencies in the spleen early after transplantation. Imaging of GFP+ effectors indicated that FTY modified donor effector T-cell migration to secondary lymphoid organs, but did not uniformly trap T cells in lymph nodes or prevent early effector migration to GVHD parenchymal target organs. Administration of FTY only prior to transplantation inhibited GVHD, indicating that the primary function of FTY may be targeted to host cells. FTY was additive with regulatory T cells for GVHD inhibition. FTY slightly impaired but did not abrogate a graft-versus-leukemia (GVL) effect against C1498, a myeloid leukemia. Our data further define the mechanisms of action and provide insight as to the potential clinical uses of FTY in allogeneic bone marrow transplant recipients.
Theoretical Study of the Change in the Magnetism and Conductivity of Diethylspirobiphenalenyl
Authors: Takenaka Mao , Taniguchi Takeshi , Kawakami Takashi , Kitagawa Yasutaka , Okumura Mitsutaka , Yamaguchi Kizashi 
Published: July 2007

Abstract
The J values of the Heisenberg model and t and Ueff values in the Hubbard model have been evaluated by the Kohn–Sham density functional theory (KS-DFT) for dimeric pairs of diethyl-spirobiphenalenyl. The Quantum Monte Carlo (QMC) simulation has been carried out with the calculated J values to evaluate the magnetic susceptibility for this molecular crystal, reproducing the experimental tendency. The band gaps estimated by using t and Ueff values are also consistent with the experiment on conductivity.
N,N′-Dichlorobis(2,4,6-trichlorophenyl)urea (CC-2): An Efficient Reagent for N-Chlorination of Amino Esters, Amide, and Peptides
Authors: Sathe Manisha , Karade Hitendra , Kaushik Mahabir Parshad 
Published: July 2007

Abstract
A simple, efficient, and rapid protocol for N-chlorination of various protected amino esters, amides, and peptides has been described. N,N′-dichlorobis(2,4,6-trichlorophenyl)urea has been used as a chlorinating agent and transformation takes place rapidly in mild conditions with quantitative yields.
RhCl3/Amine-catalyzed Cyclotrimerization of Alkynes
Authors: Yoshida Kenta , Morimoto Ichiro , Mitsudo Koichi , Tanaka Hideo 
Published: July 2007

Abstract
RhCl3/amine was found to be an efficient catalyst for the cyclotrimerization of alkynes. The [2+2+2] cyclotrimerization of internal alkynes proceeded smoothly to afford hexa-substituted benzenes regioselectively in moderate to high yields.
The Bro1-Domain Protein, EGO-2, Promotes Notch Signaling inCaenorhabditis elegans
Authors: Liu Ying , Maine Eleanor M 
Published: July 2007

AbstractIn Caenorhabditis elegans, as in other animals, Notch-type signaling mediates numerous inductive events during development. The mechanism of Notch-type signaling involves proteolytic cleavage of the receptor and subsequent transport of the receptor intracellular domain to the nucleus, where it acts as a transcriptional regulator. Notch-type signaling activity is modulated by post-translational modifications and endocytosis of ligand and receptor. We previously identified the ego-2 (enhancer of glp-1) gene as a positive regulator of germline proliferation that interacts genetically with the GLP-1/Notch signaling pathway in the germline. Here, we show that ego-2 positively regulates signaling in various tissues via both GLP-1 and the second C. elegans Notch-type receptor, LIN-12. ego-2 activity also promotes aspects of development not known to require GLP-1 or LIN-12. The EGO-2 protein contains a Bro1 domain, which is known in other systems to localize to certain endosomal compartments. EGO-2 activity in the soma promotes GLP-1 signaling in the germline, consistent with a role for EGO-2 in production of active ligand. Another C. elegans Bro1-domain protein, ALX-1, is known to interact physically with LIN-12/Notch. We document a complex phenotypic interaction between ego-2 and alx-1, consistent with their relationship being antagonistic with respect to some developmental processes and agonistic with respect to others.