bluuebunny/crossref_metadata_2025_split huggingface dataset:
A method of estimating conceptus doses resulting from multidetector CT examinations during all stages of gestation
Authors: Damilakis John , Tzedakis Antonis , Perisinakis Kostas , Papadakis Antonios E. 
Published: December 2010

Purpose:Current methods for the estimation of conceptus dose from multidetector CT (MDCT) examinations performed on the mother provide dose data for typical protocols with a fixed scan length. However, modified low‐dose imaging protocols are frequently used during pregnancy. The purpose of the current study was to develop a method for the estimation of conceptus dose from any MDCT examination of the trunk performed during all stages of gestation.Methods:The Monte Carlo N‐Particle (MCNP) radiation transport code was employed in this study to model the Siemens Sensation 16 and Sensation 64 MDCT scanners. Four mathematical phantoms were used, simulating women at 0, 3, 6, and 9 months of gestation. The contribution to the conceptus dose from single simulated scans was obtained at various positions across the phantoms. To investigate the effect of maternal body size and conceptus depth on conceptus dose, phantoms of different sizes were produced by adding layers of adipose tissue around the trunk of the mathematical phantoms. To verify MCNP results, conceptus dose measurements were carried out by means of three physical anthropomorphic phantoms, simulating pregnancy at 0, 3, and 6 months of gestation and thermoluminescence dosimetry (TLD) crystals.Results:The results consist of Monte Carlo‐generated normalized conceptus dose coefficients for single scans across the four mathematical phantoms. These coefficients were defined as the conceptus dose contribution from a single scan divided by the CTDI free‐in‐air measured with identical scanning parameters. Data have been produced to take into account the effect of maternal body size and conceptus position variations on conceptus dose. Conceptus doses measured with TLD crystals showed a difference of up to 19% compared to those estimated by mathematical simulations.Conclusions:Estimation of conceptus doses from MDCT examinations of the trunk performed on pregnant patients during all stages of gestation can be made using the method developed in the current study.
Failure mode and effect analysis‐based quality assurance for dynamic MLC tracking systems
Authors: Sawant Amit , Dieterich Sonja , Svatos Michelle , Keall Paul 
Published: December 2010

Purpose:To develop and implement a failure mode and effect analysis (FMEA)‐based commissioning and quality assurance framework for dynamic multileaf collimator (DMLC) tumor tracking systems.Methods:A systematic failure mode and effect analysis was performed for a prototype real‐time tumor tracking system that uses implanted electromagnetic transponders for tumor position monitoring and a DMLC for real‐time beam adaptation. A detailed process tree of DMLC tracking delivery was created and potential tracking‐specific failure modes were identified. For each failure mode, a risk probability number (RPN) was calculated from the product of the probability of occurrence, the severity of effect, and the detectibility of the failure. Based on the insights obtained from the FMEA, commissioning and QA procedures were developed to check (i) the accuracy of coordinate system transformation, (ii) system latency, (iii) spatial and dosimetric delivery accuracy, (iv) delivery efficiency, and (v) accuracy and consistency of system response to error conditions. The frequency of testing for each failure mode was determined from the RPN value.Results:Failures modes with were recommended to be tested monthly. Failure modes with were assigned to be tested during comprehensive evaluations, e.g., during commissioning, annual quality assurance, and after major software/hardware upgrades. System latency was determined to be . The system showed consistent and accurate response to erroneous conditions. Tracking accuracy was within 3%–3 mm gamma (100% pass rate) for sinusoidal as well as a wide variety of patient‐derived respiratory motions. The total time taken for monthly QA was , while that taken for comprehensive testing was .Conclusions:FMEA proved to be a powerful and flexible tool to develop and implement a quality management (QM) framework for DMLC tracking. The authors conclude that the use of FMEA‐based QM ensures efficient allocation of clinical resources because the most critical failure modes receive the most attention. It is expected that the set of guidelines proposed here will serve as a living document that is updated with the accumulation of progressively more intrainstitutional and interinstitutional experience with DMLC tracking.
An automatic and accurate x‐ray tube focal spot/grid alignment system for mobile radiography: System description and alignment accuracya)
Authors: Gauntt David M. , Barnes Gary T. 
Published: December 2010

Purpose:A mobile radiography automatic grid alignment system (AGAS) has been developed by modifying a commercially available mobile unit. The objectives of this article are to describe the modifications and operation and to report on the accuracy with which the focal spot is aligned to the grid and the time required to achieve the alignment.Methods:The modifications include an optical target arm attached to the grid tunnel, a video camera attached to the collimator, a motion control system with six degrees of freedom to position the collimator and x‐ray tube, and a computer to control the system. The video camera and computer determine the grid position, and then the motion control system drives the x‐ray focal spot to the center of the grid focal axis. The accuracy of the alignment of the focal spot with the grid and the time required to achieve alignment were measured both in laboratory tests and in clinical use.Results:For a typical exam, the modified unit automatically aligns the focal spot with the grid in less than 10 s, with an accuracy of better than 4 mm. The results of the speed and accuracy tests in clinical use were similar to the results in laboratory tests. Comparison patient chest images are presented—one obtained with a standard mobile radiographic unit without a grid and the other obtained with the modified unit and a 15:1 grid. The 15:1 grid images demonstrate a marked improvement in image quality compared to the nongrid images with no increase in patient dose.Conclusions:The mobile radiography AGAS produces images of significantly improved quality compared to nongrid images with alignment times of less than 10 s and no increase in patient dose.
Human Cytomegalovirus Tegument Protein pUL71 Is Required for Efficient Virion Egress
Authors: Womack Andrew , Shenk Thomas 
Published: December 2010

ABSTRACT
The human cytomegalovirus virion is composed of a DNA genome packaged in an icosahedral capsid, surrounded by a tegument of protein and RNA, all enclosed within a glycoprotein-studded envelope. Achieving this intricate virion architecture requires a coordinated process of assembly and egress. We show here that pUL71, a component of the virion tegument with a previously uncharacterized function, is required for the virus-induced reorganization of host cell membranes, which is necessary for efficient viral assembly and egress. A mutant that did not express pUL71 was able to efficiently accumulate viral genomes and proteins that were tested but was defective for the production and release of infectious virions. The protein localized to vesicular structures at the periphery of the viral assembly compartment, and during infection with a pUL71-deficient virus, these structures were grossly enlarged and aberrantly contained a cellular marker of late endosomes/lysosomes. Mutant virus preparations exhibited less infectivity per unit genome than wild-type virus preparations, due to aggregation of virus particles and their association with membrane fragments. Finally, mutant virus particles accumulated within the cytoplasm of infected cells and were localized to the periphery of large structures with properties of lysosomes, whose formation was kinetically favored in mutant-virus-infected cells. Together, these observations point to a role for pUL71 in the establishment and/or maintenance of a functional viral assembly compartment that is required for normal virion trafficking and egress from infected cells.

IMPORTANCE
In addition to causing disease in immunocompromised individuals, human cytomegalovirus is the leading known infectious cause of birth defects. To induce these pathologies, the virus must spread from its site of introduction to various organs and tissues in the body. The processes of viral assembly and egress, which underlie the spread of infection, are incompletely understood. We elucidate a role for a virus-coded protein, pUL71, in these processes and demonstrate the importance of maintaining an intricate, virus-induced reorganization of host cell membranes for efficient virus spread.
Intrinsic risk factors of non-contact quadriceps and hamstring strains in soccer: a prospective study of 100 professional players
Authors: Fousekis Konstantinos , Tsepis Elias , Poulmedis Peter , Athanasopoulos Spyros , Vagenas George 
Published: December 2010

ObjectivesTo identify the intrinsic risk factors of non-contact strains in the hamstrings and quadriceps muscles of professional soccer players via a cohort prospective design.MethodsA total of 100 professional soccer players (aged 19.4–27.8 years) from four professional teams underwent a composite musculoskeletal assessment at preseason. Intrinsic risk factors included dichotomies of asymmetries in muscle strength, flexibility, proprioception, anthropometry and knee joint stability, and of previous injuries. Muscle strains were prospectively monitored during the subsequent season using questionnaires. The data were analysed via binary logistic regression.ResultsThirty-eight percent of the players sustained one or more lower-extremity muscle strains. Sixteen (42.1 %) and seven (18.4 %) of them were clinically diagnosed as having non-contact muscle strains at their hamstrings and quadriceps, respectively. Players with eccentric hamstring strength asymmetries (OR=3.88; 95% CI 1.13 to 13.23), functional leg length asymmetries (OR=3.80; 95% CI 1.08 to 13.33) and no previous hamstrings injuries (OR=0.15; 95% CI 0.029 to 0.79) were at greater risk of sustaining a hamstring muscle strain. Players with eccentric strength (OR=5.01; 95% CI 0.92 to 27.14) and flexibility asymmetries (OR=4.98; 95% CI 0.78 to 31.80) in their quadriceps as well as heavier (OR=10.70; 95% CI 0.73 to 156.37) and shorter players (OR=0.08; 95% CI 0.00 to 1.35) were at greater risk of sustaining a strain in this muscle group.ConclusionsProfessional soccer players with functional asymmetries possess a higher risk of sustaining hamstring strains. Previous injury seems not to constitute a risk factor. The systematic isokinetic evaluation of the lower extremities during the preseason period can provide therapists and trainers with valuable data regarding the predictive elements of non-contact hamstring strains in professional soccer players.
Axial-cones
Authors: Taguchi Yuichi , Agrawal Amit , Veeraraghavan Ashok , Ramalingam Srikumar , Raskar Ramesh 
Published: December 2010

Catadioptric imaging systems are commonly used for wide-angle imaging, but lead to multi-perspective images which do not allow algorithms designed for perspective cameras to be used. Efficient use of such systems requires accurate geometric ray modeling as well as fast algorithms. We present accurate geometric modeling of the multi-perspective photo captured with a spherical catadioptric imaging system usingaxial-cone cameras:multiple perspective cameras lying on an axis each with a different viewpoint and a different cone of rays. This modeling avoids geometric approximations and allows several algorithms developed for perspective cameras to be applied to multi-perspective catadioptric cameras.We demonstrate axial-cone modeling in the context of rendering wide-angle light fields, captured using a spherical mirror array. We present several applications such as spherical distortion correction, digital refocusing for artistic depth of field effects in wide-angle scenes, and wide-angle dense depth estimation. Our GPU implementation using axial-cone modeling achieves up to three orders of magnitude speed up over ray tracing for these applications.
Genomic Instability in Mice Is Greater in Fanconi Anemia Caused by Deficiency of Fancd2 than Fancg
Authors: Reliene Ramune , Yamamoto Mitsuko L. , Rao P. Nagesh , Schiestl Robert H. 
Published: December 2010

Abstract
Fanconi anemia (FA) results from mutations in the FANC genes and is characterized by bone marrow failure, birth defects, and a high incidence of cancer. FANCG is a part of the FA core complex that is responsible for monoubiquitination of FANCD2 and FANCI. The precise role of the FA pathway is not well understood, although it may be involved in homologous recombination (HR), nonhomologous end joining, and translesion synthesis (TLS). Fancd2−/– mice have a more severe phenotype than Fancg−/–, and other FA core complex–deficient mice, although both Fancg and Fancd2 belong to the same FA pathway. We hypothesized that Fancd2 deficiency results in a more severe phenotype because Fancd2 also has a FA pathway-independent function in the maintenance of genomic integrity. To test this hypothesis, we determined the level of DNA damage and genomic instability in Fancd2−/−, Fancg−/–, and wild-type controls. Fancd2−/− mice displayed a higher magnitude of chromosomal breakage and micronucleus formation than the wild-type or Fancg−/− mice. Also, DNA strand breaks were increased in Fancd2−/− but not in Fancg−/− mice. In addition, Fancd2−/– mice displayed an elevated frequency of DNA deletions, resulting from HR at the endogenous pun locus. In contrast, in Fancg−/– mice, the frequency of DNA deletions was decreased. Thus, Fancd2 but not Fancg deficiency results in elevated chromosomal/DNA breakage and permanent genome rearrangements. This provides evidence that Fancd2 plays an additional role in the maintenance of genomic stability than Fancg, which might explain the higher predisposition to cancer seen in the Fancd2−/− mice. Cancer Res; 70(23); 9703–10. ©2010 AACR.
Increase of Plasma VEGF after Intravenous Administration of Bevacizumab Is Predicted by a Pharmacokinetic Model
Authors: Stefanini Marianne O. , Wu Florence T. H. , Mac Gabhann Feilim , Popel Aleksander S. 
Published: December 2010

AbstractVascular endothelial growth factor (VEGF) is one of the most potent cytokines targeted in antiangiogenic therapies. Bevacizumab, a recombinant humanized monoclonal antibody to VEGF, is being used clinically in combination with chemotherapy for colorectal, non–small cell lung and breast cancers, and as a single agent for glioblastoma and is being tested for other types of cancer in numerous clinical trials. It has been reported that the intravenous injection of bevacizumab leads to an increase of plasma VEGF concentration in cancer patients. The mechanism responsible for this counterintuitive increase has not been elucidated, although several hypotheses have been proposed. We use a multiscale systems biology approach to address this problem. We have constructed a whole-body pharmacokinetic model comprising three compartments: blood, normal tissue, and tumor tissue. Molecular interactions among VEGF-A family members, their major receptors, the extracellular matrix, and an anti-VEGF ligand are considered for each compartment. Diffusible molecules extravasate, intravasate, are removed from the healthy tissue through the lymphatics, and are cleared from the blood. Cancer Res; 70(23); 9886–94. ©2010 AACR.
Sphingosine-1-Phosphate Activates the AKT Pathway to Protect Small Intestines from Radiation-Induced Endothelial Apoptosis
Authors: Bonnaud Stéphanie , Niaudet Colin , Legoux François , Corre Isabelle , Delpon Gregory , Saulquin Xavier , Fuks Zvi , Gaugler Marie-Hélène , Kolesnick Richard , Paris François 
Published: December 2010

Abstract
A previous in vitro study showed that sphingosine-1-phosphate (S1P), a ceramide antagonist, preserved endothelial cells in culture from radiation-induced apoptosis. We proposed to validate the role of S1P in tissue radioprotection by inhibiting acute gastrointestinal (GI) syndrome induced by endothelial cell apoptosis after high dose of radiation. Retro-orbital S1P was injected in mice exposed to 15 Gy, a dose-inducing GI syndrome within 10 days. Overall survival and apoptosis on intestines sections were studied. Intestinal cell type targeted by S1P and early molecular survival pathways were researched using irradiated in vitro cell models and in vivo mouse models. We showed that retro-orbital S1P injection before irradiation prevented GI syndrome by inhibiting endothelium collapse. We defined endothelium as a specific therapeutic target because only these cells and not intestinal epithelial cells, or B and T lymphocytes, were protected. Pharmacologic approaches using AKT inhibitor and pertussis toxin established that S1P affords endothelial cell protection in vitro and in vivo through a mechanism involving AKT and 7-pass transmembrane receptors coupled to Gi proteins. Our results provide strong pharmacologic and mechanistic proofs that S1P protects endothelial cells against acute radiation enteropathy. Cancer Res; 70(23); 9905–15. ©2010 AACR.
Integrity of SOS1/EPS8/ABI1 Tri-Complex Determines Ovarian Cancer Metastasis
Authors: Chen Huijun , Wu Xufeng , Pan Zhixing K. , Huang Shuang 
Published: December 2010

Abstract
Ovarian cancer is mainly confined in peritoneal cavity and its metastasis is often associated with the formation of malignant ascites. As lysophosphatidic acid (LPA) is present at high levels in ascites of ovarian cancer patients and potently stimulates cell migration, we reason that LPA-stimulated cell migration may play an important role in ovarian cancer metastasis. Here, we show that only ovarian cancer cell lines with LPA migratory response undergo peritoneal metastatic colonization. LPA-stimulated cell migration is required for metastatic colonization because knockdown of LPA receptor subtype 1 (LPAR1) abolishes this event. However, the difference in metastatic potentials is not caused by the absence of LPAR1 because both metastatic and nonmetastatic lines express similar levels of LPAR1. Instead, we find that LPA can activate Rac only in metastatic cells and that metastatic colonization of ovarian cancer cells necessitates Rac activity. These results thus suggest that LPA-induced Rac activation is a prerequisite for ovarian cancer metastasis. In metastatic cells, Rac activation is facilitated by SOS1/EPS8/ABI1 tri-complex and the integrity of this tri-complex is essential for LPA-stimulated cell migration and metastatic colonization. We show that at least 1 member of SOS1/EPS8/ABI1 tri-complex is absent in nonmetastatic ovarian cancer cells and reexpressing the missing one conferred them with metastatic capability. Importantly, coexpression of SOS1, EPS8, and ABI1, but not of any individual member of SOS1/EPS8/ABI1 tri-complex, correlates with advanced stages and shorter survival of ovarian cancer patients. Our study implicates that the integrity of SOS1/EPS8/ABI1 tri-complex is a determinant of ovarian cancer metastasis. Cancer Res; 70(23); 9979–90. ©2010 AACR.
MEK1/2 Inhibitors AS703026 and AZD6244 May Be Potential Therapies for KRAS Mutated Colorectal Cancer That Is Resistant to EGFR Monoclonal Antibody Therapy
Authors: Yoon Juyong , Koo Kyoung-Hwa , Choi Kang-Yell 
Published: December 2010

Abstract
Epidermal growth factor receptor (EGFR) monoclonal antibodies (mAb) are used widely to treat metastatic colorectal cancer (mCRC) patients, but it is now clear that patients harboring K-ras mutation are resistant to EGFR mAbs such as cetuximab (Erbitux) and panitumumab (Vectibix). For this reason, current recommendations for patient care involve diagnosing the K-ras mutational status of patients prior to EGFR mAb therapy. In this study, we investigated the ability of two MEK inhibitors currently in clinical trials, AS703026 and AZD6244, to address the challenge posed by the resistance of K-ras mutated colorectal cancers to EGFR mAb. AS703026 and AZD6244 were tested in various cell-based assays and tumor xenograft studies, focusing on isogenic human colorectal tumor cell lines that expressed only WT or mutant K-Ras (D-WT or D-MUT). The EGFR mAb cetuximab inhibited the Ras-ERK pathway and proliferation of D-WT cells in vitro and in vivo, but it did not inhibit proliferation of D-MUT cells in either setting. In contrast, AS703026 and AZD6244 effectively inhibited the growth of D-MUT cells in vitro and in vivo by specific inhibition of the key MEK downstream target kinase ERK. Inhibition of MEK by AS703026 or AZD6244 also suppressed cetuximab-resistant colorectal cancer cells attributed to K-ras mutation both in vitro and in vivo. Our findings offer proof-of-concept for the use of MEK inhibitors as an effective therapy in K-ras mutated CRC. Cancer Res; 71(2); 445–53. ©2010 AACR.
Effect of Emphysema on Lung Cancer Risk in Smokers: A Computed Tomography–Based Assessment
Authors: Li Yan , Swensen Stephen J. , Karabekmez Leman Günbey , Marks Randolph S. , Stoddard Shawn M. , Jiang Ruoxiang , Worra Joel B. , Zhang Fang , Midthun David E. , de Andrade Mariza , Song Yong , Yang Ping 
Published: December 2010

Abstract
The contribution of emphysema to lung cancer risk has been recognized, but the effect size needs to be further defined. In this study, 565 primary lung cancer cases were enrolled though a prospective lung cancer cohort at Mayo Clinic, and 450 controls were smokers participating in a lung cancer screening study in the same institution using spiral computed tomography (CT). Cases and controls were frequency matched on age, gender, race, smoking status, and residential region. CT imaging using standard protocol at the time of lung cancer diagnosis (case) or during the study (control) was assessed for emphysema by visual scoring CT analysis as a percentage of lung tissue destroyed. The clinical definition of emphysema was the diagnosis recorded in the medical documentation. Using multiple logistic regression models, emphysema (≥5% on CT) was found to be associated with a 3.8-fold increased lung cancer risk in Caucasians, with higher risk in subgroups of younger (&lt;65 years old, OR = 4.64), heavy smokers (≥40 pack-years, OR = 4.46), and small-cell lung cancer (OR = 5.62). When using &gt;0% or ≥10% emphysema on CT, lung cancer risk was 2.79-fold or 3.33-fold higher than controls. Compared with CT evaluation (using criterion ≥5%), the sensitivity, specificity, positive and negative predictive values, and the accuracy of the clinical diagnosis for emphysema in controls were 19%, 98%, 73%, 84%, and 83%, respectively. These results imply that an accurate evaluation of emphysema could help reliably identify individuals at greater risk of lung cancer among smokers. Cancer Prev Res; 4(1); 43–50. ©2010 AACR.
The Relevance of Environmental Justice for the Legal Framework in the European Union
Authors: Vanheusden Bernard 
Published: December 2010

AbstractEnvironmental justice is a relatively new and unknown notion in European environmental law. The notion originally comes from the US. Environmental justice is the fair treatment and meaningful involvement of all people. The protection of environmental justice plays a prominent role in the US environmental policy. This contribution examines, after a brief history of environmental justice, the relevance of environmental justice for the legal framework in the EU. It includes the results of an empirical research and a test of the EU legal framework. It concludes that environmental justice is not yet something that goes without saying within the EU.