bluuebunny/crossref_metadata_2025_split huggingface dataset:
A missing values imputation method for time series data: an efficient method to investigate the health effects of sulphur dioxide levels
Authors: Weerasinghe Swarna 
Published: March 2009

AbstractEnvironmental data contains lengthy records of sequential missing values. Practical problem arose in the analysis of adverse health effects of sulphur dioxide (SO2) levels and asthma hospital admissions for Sydney, Nova Scotia, Canada. Reliable missing values imputation techniques are required to obtain valid estimates of the associations with sparse health outcomes such as asthma hospital admissions. In this paper, a new method that incorporates prediction errors to impute missing values is described using mean daily average sulphur dioxide levels following a stationary time series with a random error. Existing imputation methods failed to incorporate the prediction errors. An optimal method is developed by extending a between forecast method to include prediction errors. Validity and efficacy are demonstrated comparing the performances with the values that do not include prediction errors. The performances of the optimal method are demonstrated by increased validity and accuracy of the β coefficient of the Poisson regression model for the association with asthma hospital admissions. Visual inspection of the imputed values of sulphur dioxide levels with prediction errors demonstrated that the variation is better captured. The method is computationally simple and can be incorporated into the existing statistical software. Copyright © 2009 John Wiley & Sons, Ltd.
Performance evaluation of a nonlinear Winkler‐based shallow foundation model using centrifuge test results
Authors: Raychowdhury Prishati , Hutchinson Tara C. 
Published: March 2009

AbstractWhen a structure supported on shallow foundations is subjected to inertial loading due to earthquake motions, the foundation may undergo sliding, settling and rocking movements. Even if the capacity of the foundation is mobilized, the soil–foundation interface may dissipate significant amounts of vibrational energy, resulting in reduced force demands to the superstructure. If the capacity is not mobilized, these movements introduce additional flexibility to the system, which may shift its period away from the potentially hazardous zone of response spectra for most earthquake ground motions. In either case, transient and permanent deformations will need to be accounted for.To consider the aforementioned benefits and consequences in performance‐based seismic design, robust and reliable numerical modeling tools are needed. In this article, a Winkler‐based modeling framework is proposed to address this issue. The model includes a distributed array of mechanistic nonlinear inelastic springs, dashpots, and gap elements, with backbone curves of the nonlinear springs calibrated against shallow foundation experiments. Model evaluation is conducted by simulating the response of a number of centrifuge experiments. Experiments considered include square and strip footings, bridge and building models, static and dynamic loading, footings on sand and clay, a range of static vertical factors of safety, and a range of aspect ratios. It is observed that the model can reasonably predict measured footing response in terms of moment, shear, settlement and rotational demands. In addition, the general hysteresis shape of the moment–rotation, settlement–rotation and shear–sliding curves is reasonably captured. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of memantine on cognition in patients with moderate to severe Alzheimer's disease: post‐hoc analyses of ADAS‐cog and SIB total and single‐item scores from six randomized, double‐blind, placebo‐controlled studies
Authors: Mecocci Patrizia , Bladström Anna , Stender Karina 
Published: March 2009

AbstractObjectivesThe post‐hoc analyses reported here evaluate the specific effects of memantine treatment on ADAS‐cog single‐items or SIB subscales for patients with moderate to severe AD.MethodsData from six multicentre, randomised, placebo‐controlled, parallel‐group, double‐blind, 6‐month studies were used as the basis for these post‐hoc analyses. All patients with a Mini‐Mental State Examination (MMSE) score of less than 20 were included. Analyses of patients with moderate AD (MMSE: 10–19), evaluated with the Alzheimer's disease Assessment Scale (ADAS‐cog) and analyses of patients with moderate to severe AD (MMSE: 3–14), evaluated using the Severe Impairment Battery (SIB), were performed separately.ResultsThe mean change from baseline showed a significant benefit of memantine treatment on both the ADAS‐cog (p < 0.01) and the SIB (p < 0.001) total score at study end. The ADAS‐cog single‐item analyses showed significant benefits of memantine treatment, compared to placebo, for mean change from baseline for commands (p < 0.001), ideational praxis (p < 0.05), orientation (p < 0.01), comprehension (p < 0.05), and remembering test instructions (p < 0.05) for observed cases (OC). The SIB subscale analyses showed significant benefits of memantine, compared to placebo, for mean change from baseline for language (p < 0.05), memory (p < 0.05), orientation (p < 0.01), praxis (p < 0.001), and visuospatial ability (p < 0.01) for OC.ConclusionMemantine shows significant benefits on overall cognitive abilities as well as on specific key cognitive domains for patients with moderate to severe AD. Copyright © 2009 John Wiley & Sons, Ltd.
Increased C‐reactive protein is not associated with apathy: the Leiden 85‐Plus Study
Authors: Maas D. W. , van der Mast R. C. , de Craen A. J. M. 
Published: March 2009

AbstractBackgroundApathy has recently been recognized as a distinct clinical syndrome although it is difficult to differentiate from late life depression. In old age, apathy as a syndrome in itself and depression may have different etiologies. Inflammatory markers have been associated with depression in the elderly, but the relation with apathy is unknown.ObjectiveTo assess the relation between C‐reactive protein (CRP) and apathy as a syndrome in itself, apart from depression, in subjects aged 85 and older.MethodsAll data come from the Leiden 85‐Plus Study, a prospective, population‐based study of 599 elderly subjects. CRP was measured at baseline. In all subjects with a Mini Mental State Examination (MMSE) ≥19 points (n = 500), apathy and depression were assessed annually from age 85 to 90 using the three apathy and twelve depression questions of the 15‐item Geriatric Depression Scale (GDS‐15). The association between CRP and apathy or depressive symptoms was assessed both at baseline and longitudinally.ResultsAt baseline, no association was found between CRP‐concentration and apathy or depression. In subjects free of apathy and depression at baseline, subjects in the highest CRP‐tertile at baseline had significantly more increase in depressive symptoms but not in apathy symptoms during follow‐up.ConclusionHigher CRP concentrations increased the risk of depression but not apathy in a community‐based cohort of 85 years old subjects. This suggests that apathy and depression in old age have different etiologies. Copyright © 2009 John Wiley & Sons, Ltd.
Comorbidities and FLT3‐ITD abnormalities as independent prognostic indicators of survival in Elderly acute myeloid leukaemia patients
Authors: Breccia Massimo , Frustaci Anna Maria , Cannella Laura , Stefanizzi Caterina , Latagliata Roberto , Cartoni Claudio , Diverio Daniela , Guarini Anna , Nanni Mauro , Rago Angela , Cimino Giuseppe , Alimena Giuliana 
Published: March 2009

AbstractElderly acute myeloid leukaemia (AML) patients have a dismal prognosis due to biological features of disease in itself and to presence of comorbidities. Aim of this study was to evaluate the prognostic impact of comorbidity prognostic score systems applied in our population of patients. as well as other clinical‐biological features. We retrospectively considered the outcome of 120 patients aged >65 years diagnosed as having AML between January 2001 and December 2005. Comorbidities were evaluated by using Charlson comorbidity index (CCI), Hematopoietic cell transplantation comorbidity index (HCTCI) and a score proposed by Dombret et al. in 2007. Median patient age was 67 years. Forty‐six patients were treated with intensive chemotherapy and 23 reached a complete remission. Seventy‐four patients received only supportive therapies or low‐dose chemotherapy. Multivariate analysis showed the effects of leukocytosis (p = 0.0013), antecedent Myelodysplastic syndrome (MDS) (p = 0.011), FLT3 abnormalities (p = 0.032), CCI (p = 0.0037) and Dombret et al. score (p = 0.045) as independent prognostic parameters for survival. Based on these variables we were able to stratify patients in low and high risk, with different median overall survival: patients were considered as low risk if they had none or only one of the above mentioned adverse factors for survival, with a median overall survival of 447 days. Patients with two or more adverse factors were categorized as high risk: this subgroup had a median overall survival of 227 days (p = 0.001). Comorbidities are independent factors that influence survival. Application of CCI and Dombret score may help to better identify patients at diagnosis who can benefit from intensive chemotherapy. Copyright © 2009 John Wiley & Sons, Ltd.
A multicentre phase II trial of gemcitabine for the treatment of patients with newly diagnosed, relapsed or chemotherapy resistant mantle cell lymphoma: SAKK 36/03
Authors: Hitz F. , Martinelli G. , Zucca E. , von Moos R. , Mingrone W. , Simcock M. , Peterson J. , Cogliatti S. B. , Bertoni F. , Zimmermann D. R. , Ghielmini M. 
Published: March 2009

AbstractMantle cell lymphoma (MCL) has a poor prognosis with often short and incomplete remissions. We aimed to test the efficacy and tolerability of gemcitabine in treating MCL. Gemcitabine was given in doses of 1000 mg/m2 as a 30 min infusion on days 1 and 8 of each 3 week cycle for a maximum of nine cycles. Eighteen patients with a median age of 70 years were recruited. MCL was newly diagnosed in half of patients and relapsed in the remainder. Fifteen patients had Ann Arbor stage IV. The best‐recorded responses were 1 CR (complete remission), 4 PRs (partial responses), 8 SDs (stable diseases) and 4 PDs (diseases progression). The response rate (RR) (CR + PR) was 5 (28%; 95% confidence interval: 7.1, 48.5). The patient achieving a CR had stage IV disease. Most haematological adverse events occurred during the first chemotherapy cycle. Three patients developed non‐haematological serious adverse events: dyspnea, glomerular microangiopathy with haemolytic uremic syndrome (HUS) and hyperglycaemia. The median time‐to‐progression and treatment response duration (TRD) was 8.0 (95% confidence interval: 5.5, 9.3) and 10.6 (95% confidence interval: 5.5, 10.9) months, respectively. We conclude that Gemcitabine is well tolerated, moderately active and can induce disease stabilization in patients with MCL. Copyright © 2009 John Wiley & Sons, Ltd.
Analysis of Bcr‐Abl kinase domain mutations in Korean chronic myeloid leukaemia patients: poor clinical outcome of P‐loop and T315I mutation is disease phase dependent
Authors: Kim Soo‐Hyun , Kim Dongho , Kim Dong‐Wook , Goh Hyun‐Gyung , Jang Se‐Eun , Lee Jeong , Kim Wan‐Seok , Kweon Il‐Young , Park Sa‐Hee 
Published: March 2009

AbstractDespite durable responses to imatinib in chronic myeloid leukaemia (CML), mutations in Bcr‐Abl kinase domain (KD) are known to induce imatinib resistance and cause poor clinical outcome. We characterized Bcr‐Abl KD mutations in 137 Korean CML patients with imatinib resistance (n = 111) or intolerance (n = 26) using allele specific oligonucleotide polymerase chain reaction (PCR) and direct sequencing. Seventy (51%) patients harboured 81 mutations of 20 different types with increasing prevalence in advanced phase. Nine (13%) patients had multiple mutations. No mutation was found in intolerant patients. T315I was the most common mutation and P‐loop was the hottest spot in Bcr‐Abl KD. Patients harbouring P‐loop mutation, T315I, or multiple mutations showed poor overall survival and progression free survival compared with patients harbouring other mutations. Survival analysis according to disease phase of mutation being detected and type of mutations provided correlation between P‐loop or T315I mutation and poor overall survival in blast crisis, but not in accelerated phase (AP) or chronic phase (CP), indicating poor clinical outcome of particular mutations depends on disease phase. CML patients with imatinib resistance showed high rate (63%) of mutations in Bcr‐Abl KD and therefore CML patients who do not respond to imatinib should be the candidates for mutation screening as molecular monitoring. Copyright © 2009 John Wiley & Sons, Ltd.
MPL W515L/K mutations in 343 Chinese adults with JAK2V617F mutation‐negative chronic myeloproliferative disorders detected by a newly developed RQ‐PCR based on TaqMan MGB probes
Authors: Ruan Guo‐Rui , Jiang Bin , Li Ling‐Di , Niu Ji‐Hong , Li Jin‐Lan , Xie Min , Qin Ya‐Zhen , Liu Yan‐Rong , Huang Xiao‐Jun , Chen Shan‐Shan 
Published: March 2009

AbstractAcquired mutations in the juxtamembrane region of MPL (W515L or W515K), the receptor for thrombopoietin, have been reported in patients with primary essential thrombocythemia (ET) or primary myelofibrosis (PMF). The mutations were detected by the newly developed real‐time quantitative PCR (RQ‐PCR) with TaqMan MGB probes and followed by the sequencing analysis. DNA samples were from 343 Chinese adults with JAK2V617F mutation‐negative chronic myeloproliferative disorders (cMPDs). Reference curves were obtained using cloned fragments of MPL containing either the wild‐type or MPL W515L or MPL W515K mutated sequence; the predicted sensitivity level was at least 0.5%(0.1–0.5%) for MPL W515L and 0.5%(0.2–0.5%) for MPL W515K mutant allele in a wild‐type background. The detection rates of MPL W515 mutations were 3.5% in 199 ET patients (7/199), 12.5% in 24 PMF patients (3/24) and 5.6% in 36 cMPD‐unclassed patients (2/36), respectively. No MPL W515 mutations were detected in 32 polycythemia vera (PV) patients, 40 chronic myeloid leukaemia (CML) patients, 12 hypereosinophilic syndrome (HES) patients and 29 normal volunteers. The mean calculated burden of MPL mutant alleles using RQ‐PCR for MPL W515L/K was 24.88 ± 14.80% (range, 1.10–56.32%). MPL W515L/K patients presented lower haemoglobin levels, compared with the patients with JAK2V617F mutation‐positive cMPDs (p < 0.01). The results demonstrated that RQ‐PCR was a reliable and sensitive method for large‐scale screening of the MPL W515L/K mutation in patients suspected to have a cMPD. It can also provide a quantitative estimate of mutant allele burden that might be useful for both patient prognosis and monitoring response to therapy. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis, characterization, and cyclic stress‐influenced degradation of a poly(ethylene glycol)‐based poly(beta‐amino ester)
Authors: Keim Terra , Gall Ken 
Published: March 2009

AbstractThis study aims to fundamentally understand the polymer network formed by poly(ethylene glycol) diacrylate (PEGDA) MW 700 and 3‐methoxypropylamine (3MOPA) as well as to characterize the degradation response of this material with and without applied cyclic stress. Macromer reaction chemistry was confirmed by1H NMR measurements. UV calorimetry analysis revealed conditions of network formation were dependent on molecular weight of the PEGDA monomer and light intensity. The glass transition temperature of all networks PEGDA MW 258, 575, and 700 were measured and found to be in the range of −40 to −30°C with a rubbery moduli ranging from 4 to 10 MPa by DMA. Degradation studies were performed with and without applied cyclical stress, and in most cases, elastic modulus decrease and mass loss occurred steadily over a 24‐h period. Unexpected partial crystallization was discovered to occur in the networks containing higher molecular weight PEGDA in the presence of humidity and high frequency cyclic loading. In all materials, high frequency applied cyclic loading duringin situdegradation resulted in catastrophic fracture of the material prior to an appreciable decrease in modulus. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
The application of type II collagen and chondroitin sulfate grafted PCL porous scaffold in cartilage tissue engineering
Authors: Chang Kuo‐Yung , Hung Li‐Han , Chu I‐Ming , Ko Chih‐Shen , Lee Yu‐Der 
Published: March 2009

AbstractThis study investigates a poly(ϵ‐caprolactone)‐graft‐type II collagen‐graft‐chondroitin sulfate (PCL‐g‐COL‐g‐CS) biomaterial as a scaffold for cartilage tissue engineering. Biodegradable polyester, PCL, was utilized to fabricate three‐dimensional (3D) porous scaffolds by particulate leaching. The PCL scaffold was then surface modified by chemical bonding of 1,6‐hexanediamine and the grafting of a bioactive polymer layer of COL and CS with the help of 1‐ethyl‐3‐(3‐dimethyl‐ aminopropyl) carbodiimide (EDC)/N‐hydroxysuccinimide (NHS) on the modified PCL surface to produce PCL‐g‐COL and PCL‐g‐COL‐g‐CS, respectively. The characteristics of these modified and grafted matrices were examined by ESCA, aminolysis, collagen and CS assay, porosity and water‐binding capacity. Grafted COL and CS markedly increased water‐binding capacity, and promoted the spreading and growth of chondrocytes. During a 4‐week culture period, PCL‐g‐COL and PCL‐g‐COL‐g‐CS matrices both provided more cell proliferation, as determined by measuring the DNA assay. Additionally, a larger amount of secreted collagen and glycosaminoglycans (GAGs) appeared in the PCL‐g‐COL‐g‐CS matrices than in the control (PCL) as indicated by the histochemical sections via Hematoxylin and eosin (H&E) stain, Masson trichrome stain and Safranin‐O stain. The chondrocytes were induced to function normally; the cell phenotype was maintained, and the GAGs and collagen in the PCL‐g‐COL‐g‐CS scaffold were secreted in vitro. These results serve as a basis for future studies of the fabrication process and reveal the potential biocompatibility of the biomimetic matrix for regenerating articular cartilage or other organs. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Heterotypic interaction of fibroblasts and endothelial cells on restricted area
Authors: Lamponi S. , Di Canio C. , Forbicioni M. , Barbucci R. 
Published: March 2009

AbstractThe polysaccharide hyaluronic acid (Hyal) was photoimmobilized on glass surfaces to obtain a pattern with squares and rectangles of different dimensions and chemistry. The microstructured surfaces were characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Attenuated Total Reflection Infrared Spectroscopy (ATR FT‐IR), and Time‐of‐Flight Secondary Ion Mass Spectrometry (ToF‐SIMS). Surface analysis revealed the presence of a pattern consisting of alternating glass and Hyal microstructures whose dimensions decreased from the center to the edge of the sample. The behavior of Human Coronary Artery Endothelial Cells (HCAEC) and human tumoral dermal fibroblasts (C54) was studied on these micropatterned surfaces. Neither HCAEC nor C54 adhered to the immobilized Hyal but both adapted their shape to the different sizes of the glass squares and rectangles. The number of adherent HCAEC and C54 depended on the dimensions of both the glass domains and the nuclei of the cells. Co‐cultured C54 on HCAEC patterned surfaces showed a heterotypic cell‐cell interaction in the same chemical and topographic domain for the first time. In comparison to other techniques for patterning two different cell types, our approach was non cytotoxic and allowed arbitrary geometric patterns to form on different biocompatible substrata. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Improving endothelial cell adhesion and proliferation on titanium by sol–gel derived oxide coating
Authors: Chai Feng , Ochsenbein Anne , Traisnel Michel , Busch Ralf , Breme Jürgen , Hildebrand Hartmut F. 
Published: March 2009

AbstractIn‐stent restenosis becomes increasingly prevalent as a difficult‐to‐treat disease. An alternative therapeutic strategy is enhancing endothelialization on metallic stent surfaces. This study attempted to modify surface chemistry and topography of commercial pure titanium (cp‐Ti) by different sol–gel derived oxide coatings (TiO2, SiO2, SiO2/TiO2, and Nb2O5) to improve endothelialization. The physiochemical properties of the modified surfaces were characterized by ellipsometry, atomic force microscope, and sessile‐drop method. The cell adhesion/proliferation quantity, cell adhesion morphology, and focal adhesion protein expression were evaluated with human pulmonary microvascular endothelial cell line. The thickness of oxide coatings approximates to 100 nm; significantly rougher nanoporous structure was found in the TiO2 and Nb2O5 coatings than that of cp‐Ti. SiO2 coating possesses the highest surface energy (75.1 mJ/m2) and the lowest was for cp‐Ti (45.7 mJ/m2). TiO2 coating showed significantly higher endothelial cell adhesion rate than others; TiO2, Nb2O5, and TiO2/SiO2 coatings exhibited higher endothelial proliferation in 3‐day assays than noncoated Ti. In hemocompatible test, they also showed good hemocompatibility. These results offer the insight into that certain oxide coatings on titanium could significantly improve endothelial cell adhesion and proliferation especially in early period, which will favor reaching the endothelialization rapidly and suitable as matrix for “endothelial seeding” stent. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Comparative characterization of cultures of primary human macrophages or dendritic cells relevant to biomaterial studies
Authors: Shankar Sucharita P. , Babensee Julia E. 
Published: March 2009

AbstractMacrophages are central mediators of biomaterial‐associated wound healing. Dendritic cells (DCs) link innate and adaptive immunity and are important in the context of the host response to combination products. Starting with human peripheral blood mononuclear cells (PBMCs), DCs were derived from monocytes upon culture with granulocyte macrophage colony‐stimulating factor and interleukin‐4; macrophages were derived from monocytes upon culture without cytokines. Macrophage or DC cultures were characterized at relevant timepoints in both adherent and nonadherent fractions on control Primaria™ surfaces to characterize and define these inflammatory/immune cells as a prequel to their use in in vitro test biomaterial‐host response studies. At day 10 (typical time for harvesting macrophages for subsequent treatment with test biomaterials), macrophages were CD11c+, macrophage mannose receptor (MMR)+, CD14+, and CD64+. At day 6 (typical time for harvesting of DCs after 24‐h treatment with test biomaterials), DCs were CD1c+, CD11c+, CD123+, MMR+, CD14+, and CD64−. Furthermore, CD3+ and CD4+ T lymphocytes and CD19+ and CD24+ B lymphocytes were present in both cultures at all timepoints, although to different extents. Immature DCs (∼15 μm), were rounded but presented extensive dendritic processes upon maturation with lipopolysaccharide. Alternatively, adherent macrophages (∼15–20 μm) displayed internalized lipids and exhibited few membrane processes. The characterization and comparison of existing techniques to establish reliable, reproducible primary cultures of DCs or macrophages provides an important basis for examining and interpreting complex macrophage/DC‐lymphocyte‐orchestrated host responses in future studies with equivalent cell populations on test biomaterials. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010