bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of human papillomavirus types in cervical cancers in Hong Kong: Current situation and changes over the last decades
Authors: Chan Paul K.S. , Ho Wendy C.S. , Yu Mei‐Yung , Pong Wai‐Mei , Chan Alexander C.L. , Chan Amanda K.C. , Cheung Tak‐Hong , Wong Martin C.S. , To Ka‐Fai , Ng Ho‐Keung 
Published: April 2009

AbstractHuman papillomavirus (HPV) type distribution among cervical cancers and its possible changes over time are key issues that determine the cost‐effectiveness of HPV vaccines. Cervical cancers diagnosed during 3 periods (1997–2007, N = 280; 1984–1986, N = 74; 1972–1973, N = 81) in Hong Kong were examined for HPV type distribution using sensitive broad‐catching methods. The results showed a variation in HPV distribution between histological groups. Among cervical squamous cell carcinoma (SCC) cases diagnosed over the past 10 years, HPV16 was most commonly found (61.2%), followed by HPV18 (17.7%), HPV52 (14.7%) and HPV58 (9.9%), whereas adeno/adenosquamous cell carcinoma was dominated by HPV18 (56.3%) and HPV16 (50.0%). The proportion of HPV16‐positive SCC showed a significant linear trend of increase with time (45.2% for 1972–1973, 58.8% for 1984–1986, 61.2% for 1997–2007; pTrend = 0.023), whereas HPV52‐positive SCC decreased with time (30.1% for 1972–1973; 29.4% for 1984–1986, 14.7% for 1997–2007; pTrend = 0.001). Vaccines comprising HPV16/18 cover 62.6% of SCC and 93.8% of adeno/adenosquamous carcinoma in Hong Kong, and inclusion of HPV52 and HPV58 can increase the coverage by 18.4% for SCC and 4.1% for adeno/adenosquamous cell carcinoma. HPV type distribution may change over time. Further investigations to reveal the determinants for such changes and continuous monitoring for possible type replacement as a result of widespread long‐term use of HPV vaccines are warranted. Multiple infections are commonly revealed by sensitive broad‐catching methods such as those used in this study. However, their implication on vaccine efficacy and cost‐effective analyses should be taken cautiously. © 2009 UICC
Profiles of carbohydrate ligands associated with adsorbed proteins on self‐assembled monolayers of defined chemistries
Authors: Shankar Sucharita P. , Chen Inn Inn , Keselowsky Benjamin G. , García Andrés J. , Babensee Julia E. 
Published: April 2009

AbstractConserved protein–carbohydrate–lipid pathogen‐associated molecular patterns (PAMPs) interact with cells of the innate immune system to mediate antigen recognition and internalization and activation of immune cells. We examined if analogous “biomaterial‐associated molecular patterns” composed of proteins, specifically their carbohydrate modifications, existed on biomaterials, which can play a role in mediating the innate immune response to biomaterials. To probe for these carbohydrates in the adsorbed protein layer, as directed by the underlying biomaterial chemistry, self‐assembled monolayers (SAMs) presenting CH3, OH, COOH, or NH2 were preincubated with serum/plasma, and the presence of carbohydrate ligands of C‐type lectin receptors (CLRs) was investigated using lectin probes in an enzyme‐linked lectin assay (ELLA). Presentation of CLR ligands was detected on control tissue culture polystyrene (TCPS). Absorbances of mannose or N‐acetylglucosamine increased with decreasing incubating serum concentration, whereas absorbances of sialylated epitopes or fucose remained unchanged. Absorbances of α‐galactose or N‐acetylgalactosamine decreased with decreasing incubating serum concentration; β‐galactose was undetectable. Among SAM endgroups, preincubation with 10% serum resulted in differential presentation of CLR ligands: higher α‐galactose on COOH SAMs than NH2 or CH3 SAMs, highest complex mannose on NH2 SAMs, and higher complex mannose on OH SAMs than CH3 SAMs. Least sialylated groups were detected on CH3 SAMs. In summary, biomaterial chemistry may regulate protein adsorption and hence unique presentation of associated carbohydrates. The ultimate goal is to identify the effects of protein glycosylations associated with biomaterials in stimulating innate immune responses. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Enhanced polarization of embryonic hippocampal neurons on micron scale electrospun fibers
Authors: Lee Jae Young , Bashur Chris A. , Gomez Natalia , Goldstein Aaron S. , Schmidt Christine E. 
Published: April 2009

AbstractElectrospun fibers have been fabricated for wide use as artificial tissue engineering scaffolds. In particular, fibers smaller than a cell body have been extensively employed to mimic natural extracellular matrix (ECM) and to explore specific responses by various cell types. We investigated the effects of various poly(lactic acid‐co‐glycolic acid) (PLGA) fiber features on embryonic hippocampal neurons in the early developmental stages in terms of initial axon formation (i.e., polarization) and axon orientation. We produced PLGA fibers that have average diameters ranging from 0.44 μm to 2.2 μm and different degrees of fiber alignment (16–58° in angular standard deviation). After 22 h in culture, embryonic hippocampal neurons grown on PLGA fibers exhibited more axon formation with a 30–50% increase over those on spin‐coated smooth PLGA films. This improvement was independent of fiber diameter and alignment; however, slightly more polarization was observed on the smaller fibers and the more aligned fibers. In addition, average axon length of the polarized embryonic hippocampal neurons was not significantly different among the PLGA fibers when compared with cells grown on spin‐coated PLGA films. These findings suggest that fibers of subcellular diameters stimulate initial axon establishment and guide the direction of axonal extension; however, these fibers do not appear to affect the overall axon length. This information will be valuable in understanding the roles of subcellular features on neuron development and for the design of biomaterials for neural tissue interfacing. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Design and characterization of a biodegradable composite scaffold for ligament tissue engineering
Authors: Hayami James W. S. , Surrao Denver C. , Waldman Stephen D. , Amsden Brian G. 
Published: April 2009

AbstractHerein we report on the development and characterization of a biodegradable composite scaffold for ligament tissue engineering based on the fundamental morphological features of the native ligament. An aligned fibrous component was used to mimic the fibrous collagen network and a hydrogel component to mimic the proteoglycan‐water matrix of the ligament. The composite scaffold was constructed from cell‐adherent, base‐etched, electrospun poly(ϵ‐caprolactone‐co‐D,L‐lactide) (PCLDLLA) fibers embedded in a noncell‐adherent photocrosslinked N‐methacrylated glycol chitosan (MGC) hydrogel seeded with primary ligament fibroblasts. Base etching improved cellular adhesion to the PCLDLLA material. Cells within the MGC hydrogel remained viable (72 ± 4%) during the 4‐week culture period. Immunohistochemistry staining revealed ligament ECM markers collagen type I, collagen type III, and decorin organizing and accumulating along the PCLDLLA fibers within the composite scaffolds. On the basis of these results, it was determined that the composite scaffold design was a viable alternative to the current approaches used for ligament tissue engineering and merits further study. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Temperature evaluation during PMMA screw augmentation in osteoporotic bone—An in vitro study about the risk of thermal necrosis in human femoral heads
Authors: Boner Vanessa , Kuhn Philipp , Mendel Thomas , Gisep Armando 
Published: April 2009

AbstractThe use of polymethylmethacrylate (PMMA) bone cement to augment hip screws reduces cut‐out risk but is associated with an exothermic reaction. This in vitro investigation evaluated the risk of thermal necrosis when augmenting the implant purchase with PMMA. A pilot study analyzed the effects of different PMMA layer thicknesses on temperatures around an implant. The main study used either 3.0 or 6.0 cc PMMA for hip screw augmentation in human femoral heads. The risk of thermal necrosis was estimated according to critical values reported in literature. Highest temperatures were measured inside the PMMA with a significant drop of average maximum temperatures from the center of the PMMA to the PMMA/bone interface. Risk of thermal necrosis exists with PMMA layer thicknesses greater than 5.0 mm. In the main study, we found no risk of thermal necrosis at the PMMA/bone interface or in the surrounding bone, neither with 3.0 nor 6.0 cc PMMA. The results of the two studies were consistent regarding average peak temperatures related to associated cement layer thicknesses. The results of this in vitro study reduce objections concerning the risk of thermal necrosis when augmenting cancellous bone around hip screws with up to 6.0 cc PMMA. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009
Preparation of surface‐modified poly(butylene terephthalate) nonwovens and their application as leukocyte removal filters
Authors: Kim Eun Jin , Yeo Gwu‐Dong , Pai Chaul‐Min , Kang Inn‐Kyu 
Published: April 2009

AbstractBlood transfusion‐related adverse reactions have been reported to be caused by leukocytes in blood products. It is now generally accepted that it would be highly desirable to reduce leukocytes level as low as possible. In this study, melt‐blown poly(butylene terephthalate) nonwoven (PBT‐NW) was treated with a hydroxyapatite (HA) surface‐modification method for removal of leukocytes from blood components. Acrylic acid was graft‐polymerized onto the surface of the PBT‐NW after oxygen plasma glow discharge treatment. The PBT‐NW surface was covered with a thin layer of HA produced by immersing the polymer surface in an aqueous solution containing high concentrations of PO43− and Ca2+ after graft‐polymerization of acrylic acid, which provided the nucleus for HA crystallization. The surface was characterized using water contact angles, attenuated total reflection‐Fourier transform infrared (ATR‐FT‐IR), and electron spectroscopy for chemical analysis. When filtration was performed with a unit of red blood cell concentrates, HA‐deposited PBT‐NW (PBT‐HA) removed 98.5% of the leukocytes and recovered 99.5% of the erythrocytes, suggesting that HA‐deposited PBT‐NW is a very promising blood filter for selective removal of leukocytes. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Bacterial adhesion to diamond‐like carbon as compared to stainless steel
Authors: Soininen Antti , Tiainen Veli‐Matti , Konttinen Yrjö T. , van der Mei Henny C. , Busscher Henk J. , Sharma Prashant K. 
Published: April 2009

AbstractRecent studies suggest that diamond‐like carbon (DLC) coatings are suitable candidates for application on biomedical devices and implants, due to their high hardness, low friction, high wear and corrosion resistance, chemical inertness, smoothness, and tissue and blood compatibility. However, most studies have neglected the potential susceptibility of DLC coatings to bacterial adhesion, which is the first step in the development of implant‐related infections. This study compares adhesion of seven bacterial strains, commonly implicated in implant‐related infections, to tetrahedral amorphous carbon, with their adhesion to AISI 316L surgical steel. The results show that bacterial adhesion to DLC was similar to the adhesion to commonly used stainless steel. This suggests that DLC coating can be advantageously used on implants made of AISI 316L or other materials without increasing the risk to implant‐related infections. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Development, characterization, and validation of porous carbonated hydroxyapatite bone cement
Authors: Tang Pei‐Fu , Li Gang , Wang Ji‐Fang , Zheng Qiu‐Jian , Wang Yan 
Published: April 2009

AbstractCarbonated hydroxyapatite (CHA) bone cement is capable of self‐setting and forming structures similar to mineralized bone. Conventional CHA leaves little room for new bone formation and delays remodeling. The purposes of this study were to develop porous CHA (PCHA) bone cement and to investigate its physicochemical properties, biocompatibility, biodegradation, and in vivo bone repair potential. Vesicants were added to modify CHA, and the solidification time, porosity, and pore size of the PCHA cements were examined. The cytotoxicity and bone repair potential of PCHA were tested in a rabbit bone defect model and assessed by x‐ray, histological examination, and mechanical testing. The porosity of the modified PCHA was 36%; 90.23% of the pores were greater than 70 μm, with a calcium/phosphate ratio of 1.64 and a solidification time of 15 minutes. The PCHA did not affect bone cell growth in vitro, and the degrading time of the PCHA was two and four times faster in vitro and in vivo when compared to CHA. In the bone defect model, the amount of new bone formation in the PCHA‐treated group was eight times greater than that of the CHA group; the compressive strength of the PCHA setting was relatively weak in the first weeks but increased significantly at 8 to 16 weeks compared to the CHA group. The PCHA has stable physicochemical properties and excellent biocompatibility; it degrades faster than CHA, provides more porous spaces for new bone ingrowths, and may be a new form of bone cement for the management of bone defects. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009
Cytotoxic effects of different concentrations of a carbamide peroxide bleaching gel on odontoblast‐like cells MDPC‐23
Authors: de Lima Adriano Fonseca , Lessa Fernanda Campos Rosetti , Gasparoto Mancini Maria Nadir , Hebling Josimeri , de Souza Costa Carlos Alberto , Marchi Giselle Maria 
Published: April 2009

AbstractThis study evaluated the cytotoxic effects of a carbamide peroxide (CP) bleaching gel at different concentrations on odontoblast‐like cells. Immortalized cells of the MDPC‐23 cell line (30,000 cells/cm2) were incubated for 48 h. The bleaching gel was diluted in DMEM culture medium originating extracts with different CP concentrations. The amount (μg/mL) of hydrogen peroxide (H2O2) released from each extract was measured by the leukocrystal violet/horseradish peroxidase enzyme assay. Five groups (n = 10) were formed according to the CP concentration in the extracts: G1‐DMEM (control); G2‐0.0001% CP (0.025 μg/mL H2O2); G3‐0.001% CP (0.43 μg/mL H2O2); G4‐0.01% CP (2.21 μg/mL H2O2); and G5‐0.1% CP (29.74 μg/mL H2O2). MDPC‐23 cells were exposed to the bleaching gel extracts for 60 min and cell metabolism was evaluated by the MTT assay. Data were analyzed statistically by one‐way ANOVA and Tukey's test (α = 0.05). Cell morphology was examined by scanning electron microscopy. The percentages of viable cells were as follows: G1, 100%; G2, 89.41%; G3, 82.4%; G4, 61.5%; and G5, 23.0%. G2 and G3 did not differ significantly (p > 0.05) from G1. The most severe cytotoxic effects were observed in G3 and G4. In conclusion, even at low concentrations, the CP gel extracts presented cytotoxic effects. This cytotoxicity was dose‐dependent, and the 0.1% CP concentration caused the most intense cytopathic effects to the MDPC‐23 cells. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009
Complex molecular assemblies at hand via interactive simulations
Authors: Delalande Olivier , Férey Nicolas , Grasseau Gilles , Baaden Marc 
Published: April 2009

AbstractStudying complex molecular assemblies interactively is becoming an increasingly appealing approach to molecular modeling. Here we focus on interactive molecular dynamics (IMD) as a textbook example for interactive simulation methods. Such simulations can be useful in exploring and generating hypotheses about the structural and mechanical aspects of biomolecular interactions. For the first time, we carry out low‐resolution coarse‐grain IMD simulations. Such simplified modeling methods currently appear to be more suitable for interactive experiments and represent a well‐balanced compromise between an important gain in computational speed versus a moderate loss in modeling accuracy compared to higher resolution all‐atom simulations. This is particularly useful for initial exploration and hypothesis development for rare molecular interaction events. We evaluate which applications are currently feasible using molecular assemblies from 1900 to over 300,000 particles. Three biochemical systems are discussed: the guanylate kinase (GK) enzyme, the outer membrane protease T and the soluble N‐ethylmaleimide‐sensitive factor attachment protein receptors complex involved in membrane fusion. We induce large conformational changes, carry out interactive docking experiments, probe lipid–protein interactions and are able to sense the mechanical properties of a molecular model. Furthermore, such interactive simulations facilitate exploration of modeling parameters for method improvement. For the purpose of these simulations, we have developed a freely available software library called MDDriver. It uses the IMD protocol from NAMD and facilitates the implementation and application of interactive simulations. With MDDriver it becomes very easy to render any particle‐based molecular simulation engine interactive. Here we use its implementation in the Gromacs software as an example. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2009
Molecular dynamics simulations of the detoxification of paraoxon catalyzed by phosphotriesterase
Authors: Zhang Xin , Wu Ruibo , Song Lingchun , Lin Yuchun , Lin Menghai , Cao Zexing , Wu Wei , Mo Yirong 
Published: April 2009

AbstractCombined QM(PM3)/MM molecular dynamics simulations together with QM(DFT)/MM optimizations for key configurations have been performed to elucidate the enzymatic catalysis mechanism on the detoxification of paraoxon by phosphotriesterase (PTE). In the simulations, the PM3 parameters for the phosphorous atom were reoptimized. The equilibrated configuration of the enzyme/substrate complex showed that paraoxon can strongly bind to the more solvent‐exposed metal ion Znβ, but the free energy profile along the binding path demonstrated that the binding is thermodynamically unfavorable. This explains why the crystal structures of PTE with substrate analogues often exhibit long distances between the phosphoral oxygen and Znβ. The subsequent SN2 reaction plays the key role in the whole process, but controversies exist over the identity of the nucleophilic species, which could be either a hydroxide ion terminally coordinated to Znα or the μ‐hydroxo bridge between the α‐ and β‐metals. Our simulations supported the latter and showed that the rate‐limiting step is the distortion of the bound paraoxon to approach the bridging hydroxide. After this preparation step, the bridging hydroxide ion attacks the phosphorous center and replaces the diethyl phosphate with a low barrier. Thus, a plausible way to engineer PTE with enhanced catalytic activity is to stabilize the deformed paraoxon. Conformational analyses indicate that Trp131 is the closest residue to the phosphoryl oxygen, and mutations to Arg or Gln or even Lys, which can shorten the hydrogen bond distance with the phosphoryl oxygen, could potentially lead to a mutant with enhanced activity for the detoxification of organophosphates. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2009
Correction of carotid intima‐media thickness for adaptive dependence on tensile stress: Implication for cardiovascular risk assessment
Authors: Chironi Gilles N. , Simon Alain , Bokov Plamen , Levenson Jaime 
Published: April 2009

AbstractPurpose.Early artery wall‐thickening detected by ultrasound‐assessed increased carotid intima‐media thickness (IMT) may reflect atherosclerosis or represent an adaptive response to keep homeostasis tensile stress that is related inversely to wall thickness by Laplace's equation. We attempted to discriminate between both mechanisms by correcting IMT for its inverse association with tensile stress.Methods.Common carotid IMT and lumen diameter (D) where determined in 40 healthy controls and 119 never‐treated asymptomatic patients with ≥1 traditional cardiovascular risk factor. The cross‐sectional area (CSA) was calculated as π × IMT × (IMT + D). Tensile stress was approximated by [mean blood pressure × (D/2 × IMT)], and wall shear stress by [(blood viscosity) × 4 × (mean blood velocity/D)]. Inverse regression line relating IMT and tensile stress in controls (p < 0.001) was used as a reference to determine in an individual at‐risk patient the IMT deviation, defining ΔIMT from the regression line of controls at the measured patient's tensile stress.Results.ΔIMT correlated positively with age (p < 0.05), body mass index (p < 0.05), blood pressure (p < 0.001), and glucose (p < 0.001). In multivariate analysis, ΔIMT was independently associated with age (p < 0.01), male gender (p < 0.001), and blood pressure (p < 0.001). IMT showed positive association with age (p < 0.001) but not with other risk factors. Also, ΔIMT, like CSA, correlated positively with tensile stress (p < 0.001) and negatively with wall shear stress (p < 0.05, p < 0.01), whereas IMT correlated negatively with tensile stress (p < 0.001) but not with wall shear stress.Conclusion.Correcting IMT for adaptive association with tensile stress may give more strength to carotid evaluation for assessing cardiovascular risk. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Prenatal diagnosis by 3D ultrasound and MRI of an unusual malformation of cortical development with brain‐in‐brain appearance
Authors: Valsecchi Luca , Cavoretto Paolo , Di Piazza Lara , Smid Maddalena , Pontesilli Silvia , Scotti Roberta , Spagnolo Daniele , Baldoli Cristina 
Published: April 2009

AbstractA 31‐year‐old pregnant woman was referred for isolated mild ventriculomegaly and failure to visualize the left lateral ventricle's anterior horn on second trimester sonography (US). Three‐dimensional US suspected a frontal lesion deviating the midline. MRI revealed a mass compressing the ventricle. Follow‐up MRI described a “brain‐in‐brain” malformation: infolded microgyric cortex and white matter in frontal lobe extending to frontal horn and midline, irrorated by hypertophic Heubner artery. Conservative approach was chosen. Neurodevelopment at 1 year is normal. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Measuring microenvironment mechanical stress of rat liver during diethylnitrosamine induced hepatocarcinogenesis by atomic force microscope
Authors: Gang Zhao , Qi Qin , Jing Cui , Wang Chunyou 
Published: April 2009

AbstractWe developed a highly sensitive method to detect liver tissue stiffness with atomic force microscopy (AFM), and investigated the physical features of hepatocarcinogenesis. Wistar rats received weekly intraperitoneal injections of diethylnitrosamine (DEN) or saline (control) followed by a 2‐week wash‐out period. Liver samples were harvested at 10, 14, or 18 weeks for pathological examination and stress detection. Previously normal liver tissues developed fibrosis and carcinoma after DEN administration. Although the elastic modulus (E) values of the normal (saline; 0.18 ± 0.04 MPa), fibrotic (8 weeks DEN; 0.25 ± 0.06 MPa) and cirrhotic (12 weeks DEN; 0.39 ± 0.06 MPa) tissues were significantly different, there was no significant difference between the E values of the cirrhotic and the hepatic cell carcinoma (16 weeks DEN; 0.42 ± 0.07 MPa) tissues. Thus, tissue stiffness quantitatively increases during hepatocarcinogenesis, and AFM can be used to sensitively and precisely detect liver stiffness at the microscopic level. Microsc. Res. Tech. 2009. © 2009 Wiley‐Liss, Inc.