bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell adhesion resistance mechanisms using arrays of dextran‐derivative layers
Authors: Monchaux Emmanuelle , Vermette Patrick 
Published: October 2007

AbstractTo control interactions at the cell–material interface, low‐fouling polymer coatings are used to prevent nonspecific interactions. Subsequent biosignals may be grafted on these low‐fouling layers to induce specific biological responses. A polymer array technology was developed to study structural diversity of carboxy‐methyl‐dextran (CMD) grafted layers in connection with their cell repulsion ability. Arrays of CMD layers were exposed to fibroblasts to screen for cell resistant layers according to the immobilization conditions used to produce these surfaces. Cell cytoskeleton and fibronectin matrix deposition and reorganization were labeled in short‐term (4 and 12 h) and long‐term (3 days of cell confluence) cell adhesion assays. Results suggest that CMD layers that were resistant to cell adhesion were dense, flexible, and presented a regular (i.e., defect‐free) hydrated surface. Cell‐resistant CMD layers prevented cell matrix deposition and assembly, affecting cell–substrate adhesion and cytoskeletal organization. Finally, an optimized CMD layer was chosen and proved to be as resistant as a poly(ethylene glycol) layer. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Investigation of epidermal growth factor containing liposome formulation effects on burn wound healing
Authors: Alemdaroğlu Ceren , Degim Zelihagül , Celebi Nevin , Şengezer Mustafa , Alömeroglu Melih , Nacar Ahmet 
Published: October 2007

AbstractIt was aimed to develop liposome formulations containing epidermal growth factor (EGF) and to investigate the healing effects of these formulations on second‐degree burn wounds in rats. Multilamellar type liposomes containing EGF were prepared by film formation method. In vitro releases of EGF from liposome formulations were determined using spectrofluorometer. Second‐degree standard burn wounds were formed on rats and liposome formulations containing 10 μg/mL EGF (ELP group), EGF solution (ES group), liposome without containing EGF (LP group), and Silverdine® ointment (SIL group) were applied daily. Untreated control groups [unburned (S) and untreated (Y) rats] were also evaluated. Biopsies were taken at the 3rd, 7th, and 14th day of the treatment from the wounds and histological observations were performed under transmission electron microscope. Bromodeoxyuridine (BrdU) staining technique was used for immunohistochemical analysis. After trichrome stainings, the thicknesses of the epidermis and the areas of the fibroblast nucleus were measured using a light microscope and Vision Screening Analysis Program. It was observed that the healing in the ELP group was the fastest among all groups (p < 0.05) at the 14th day of therapy. The healing effect in order from highest to lowest efficacy was found to be ELP>SIL>ES groups, respectively, at the 14th day. All results indicated that the EGF‐liposome formulation is effective and can be used for the treatment of burn wounds. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Inverse opal hydrogel‐collagen composite scaffolds as a supportive microenvironment for immune cell migration
Authors: Stachowiak Agnieszka N. , Irvine Darrell J. 
Published: October 2007

AbstractImmunotherapies harness the inherent potential of the body to destroy foreign or infected cells, and are currently being investigated as treatments for cancer. One way to boost native immune responses might be to engineer ectopic lymphoid tissue, providing a supportive microenvironment for immune cell priming, and/or bringing together immune cells at a desired location (e.g., solid tumor sites). Here we describe the development and in vitro testing of composite macroporous poly(ethylene glycol) (PEG) hydrogel scaffolds infused with collagen as a tissue engineering platform for immunotherapy. The PEG hydrogel with ordered, interconnected pores provided mechanical stability and the potential to depot supporting cytokines/chemokines, while an infused collagen matrix supported intra‐scaffold migration of loaded T cells and dendritic cells. Rapid, nearly unconstrained T cell migration through scaffolds was achieved by using inverse opal supporting structures with 80 μm macropores. In addition, we demonstrated that the lymphoid tissue chemokine CCL21 could be bound to the inverse opal gel walls of these scaffolds, to provide motility‐inducing cues for T cells within these structures. This hybrid scaffold approach combines the strengths of the synthetic and biopolymer hydrogels used in a highly synergistic fashion, allowing each material to compensate for limiting properties of its partner. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Macrophage depletion diminishes implant‐wear‐induced inflammatory osteolysis in a mouse model
Authors: Ren Weiping , Markel David C. , Schwendener Reto , Ding Yunhong , Wu Bin , Wooley Paul H. 
Published: October 2007

AbstractThe purpose of this study was to determine whether macrophage depletion using clodronate liposomes diminishes wear‐debris‐induced inflammatory osteolysis in a murine osteolysis model. Ultra high molecular weight polyethylene (UHMWPE) particles were introduced into established air pouches on BALB/c mice, followed by implantation of calvaria bone from syngeneic littermates. Macrophages were depleted by the intraperitoneal injection of clodronate liposome (2 mg) 2 days before bone implantation and re‐injection every 3 days (1 mg) until the sacrifice of the mice. Mice without clodronate liposome therapy or treated with empty liposome as well as mice injected with saline alone were included in this study as controls. Pouch tissues were collected 14 days after bone implantation for molecular and histology analysis. Our findings indicated that (1) macrophage depletion in clodronate‐liposome‐treated mice was achieved, as illustrated by F4/80 immunostaining in both pouch and spleen tissues; (2) clodronate‐liposome treatment significantly reduced UHMWPE‐induced tissue inflammation, with diminished pouch membrane thickness, reduced inflammatory cellular infiltration, and lowered interleukin 1β (IL‐1β) and tumor necrosis factor α (TNFα) expression; (3) clodronate‐liposome treatment markedly reduced the number of TRAP+cells in pouch tissues and protected against bone collagen depletion. In conclusion, this study demonstrates that macrophage depletion using clodronate‐liposome reduces UHMWPE particle‐induced inflammatory osteolysis. This observation supports the hypothesis that macrophages contribute to the severity of UHMWPE particles induced inflammatory osteolysis, and suggest that macrophage depletion represents a viable therapeutic approach to the prevention and treatment of patients with aseptic loosening. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Growth of keratinocytes on porous films of poly(3‐hydroxybutyrate) and poly(4‐hydroxybutyrate) blended with hyaluronic acid and chitosan
Authors: Peschel Gundela , Dahse Hans‐Martin , Konrad Anke , Wieland Gerhard Dieter , Mueller Peter‐Juergen , Martin David P. , Roth Martin 
Published: October 2007

AbstractThe objective of this study was to develop novel absorbable films suitable for use as a tissue‐engineering scaffold for keratinocytes as a therapy for replacement of damaged skin. Poly(4‐hydroxybutyrate) (P(4HB)) and poly (3‐hydroxybutyrate) (P(3HB)) were blended with small amounts of the polysaccharides hyaluronic acid (HA), chitosan (CH), pectin and alginic acid, and were solution cast to produce porous films. The resulting composites had favorable mechanical properties, and these films were compared with two commercially available implantable films made of poly(L‐lactide‐co‐D,L‐lactide) (PLA copolymer) and HA benzyl ester. Tensile testing demonstrated that a high level of flexibility of P(4HB) was retained in the P(4HB)‐polysaccharide composite films, whereas the P(3HB) film and its polysaccharide composites were stiffer and more brittle. The proliferation kinetics of adherent HaCaT keratinocytes on the films was examined in vitro. The porous surface of the P(4HB) and P(3HB) films blended with HA or CH promoted the growth of keratinocytes significantly. The order of maximum cell numbers on these films was P(4HB)/HA > P(4HB)/CH > P(3HB)/HA > P(3HB)/CH > P(3HB)/pectin > P(3HB)/alginic acid. Scanning electron microscopy and confocal laser scanning microscopy revealed differences in cell growth. Cells formed clusters on P(3HB) and its composites, while the cells grew as a confluent layer on P(4HB) and its composites. HaCaT cells formed large numbers of filaments only on P(4HB) films, indicating the excellent biocompatibility of this material. For the nonporous PHB films, the proliferation rate of cells was found to increase with decreasing hydrophobicity in the order: P(4HB) > P(3HB)/P(4HB) blend > P(3HB). © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Transformations in CDHA/OCP/β‐TCP scaffold during ageing in simulated body fluid at 36.5°C
Authors: Morejón‐Alonso Loreley , García Carrodeguas Raúl , Delgado García‐Menocal José A. 
Published: October 2007

AbstractThe transformations that took place in a scaffold composed of CDHA/OCP/β‐TCP by ageing in SBF at 36.5° during 14 days were studied. A carbonated‐apatite layer was formed during immersion in SBF on the surface of the scaffold and part of the OCP present in the inner core of the material was also transformed into apatite. The precipitated apatite layer exhibited the typical globular morphology characteristic of bioactive materials. The content of CDHA increased from 14 to 29 wt % at the expense of the content of OCP that decreased from 39 to 29 wt %. β‐TCP content dropped slightly from 47 to 42 wt %. Total porosity (from 56.1% ± 0.6% to 62.4% ± 0.5%) and real density (from 2.58 ± 0.01 to 2.79 ± 0.01 g/cm3) increased, and diametral tensile (from 2.1 ± 0.3 to 0.9 ± 0.1 MPa) and compressive strengths (from 8.5 ± 1.0 to 6.8 ± 0.6 MPa) decreased during ageing. The in vitro results showed that the scaffold composed of CDHA, OCP, and β‐TCP is bioactive and partially resorbable. It seems to be suitable for in situ bone regeneration procedures. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Examining the influence of short‐term implantation on oxidative degradation in retrieved highly crosslinked polyethylene tibial components
Authors: Willie B. M. , Foot L. J. , Prall M. W. , Bloebaum R. D. 
Published: October 2007

AbstractConcerns remain regarding the oxidative resistance of highly crosslinked polyethylene (PE). The study investigated the in vivo performance of Durasul highly crosslinked PE by comparing the oxidation index, density, and percent crystallinity in the weightbearing and nonweightbearing region of retrieved components with unused time zero tibial components. Retrieved and unused Sulene conventional PE tibial components were examined for comparison and the effects of shelf age, in vivo duration, and ex vivo duration were also investigated. The oxidation index was not significantly different between unused time zero and retrieved Durasul PE components. Regression analysis data supported these findings in that neither shelf age, in vivo duration, nor ex vivo duration was a significant predictor of oxidation index in the retrieved Durasul PE components. In contrast, the retrieved conventional PE components had significantly greater oxidation index, density, and percent crystallinity compared with unused time zero PE components. Regression data suggested that in vivo and ex vivo duration, but not shelf aging, influenced the changes observed in the conventional PE components. These data also showed that in vivo loading did not significantly affect the oxidation index, density, or percent crystallinity in either the retrieved Durasul or conventional PE tibial components. This investigation demonstrates that changes in oxidation index, density, and percent crystallinity of retrieved Durasul PE components after short‐term in vivo durations are likely not a clinical concern. These data should be used as a benchmark to compare with future studies examining the long‐term oxidative resistance of Durasul highly crosslinked PE tibial components. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Comparative study of poly(vinyl alcohol)‐based support materials for the immobilization of glucose oxidase
Authors: Wong Fui‐Ling , Abdul‐Aziz Azila 
Published: October 2007

AbstractBACKGROUND: The performances of four types of glucose oxidase (GOD) immobilization materials based on poly(vinyl alcohol) (PVA) were compared. The matrices of interest were chemically‐linked PVA, freeze‐thawed PVA cryogel, tetramethoxysilane (TMOS) sol‐gel‐PVA hybrid material, and alumina sol‐gel‐PVA hybrid material.RESULTS: Overall, the membranes showed good sensitivity except for the chemically cross‐linked PVA. However, the main differences with the enzyme immobilization methods were enzyme leakage and values of Kmapp.CONCLUSION: Freeze‐thawed PVA‐GOD membranes and TMOS‐PVA, which showed satisfactory sensitivity and adequate value of Kmapp, were quite promising as support materials for immobilizing GOD. Copyright © 2007 Society of Chemical Industry
Benzene removal with vertical‐flow constructed treatment wetlands
Authors: Eke Paul E. , Scholz Miklas 
Published: October 2007

AbstractBACKGROUND: Twelve vertical‐flow experimental wetlands have been constructed using different compositions, and were operated in batch‐flow mode to reduce pumping costs. Six wetlands were located indoors and six outdoors. Benzene was used as a representative example substance to assess the removal of low molecular weight petroleum compounds.RESULTS: Findings indicate that the constructed wetlands remove benzene (inflow of approximately 1.3 g L−1) from hydrocarbon‐contaminated wastewater streams with better indoor (controlled environment) than outdoor treatment performances. Overall mean removal efficiencies for the experimental rig placed outside were as follows: benzene 85%, chemical oxygen demand (COD), 70%; ammonia‐nitrogen, 83%; nitrate‐nitrogen, 88%; ortho‐phosphate‐phosphorus, 58%. In comparison, removal efficiencies for the experimental rig placed indoors were higher: benzene 95%, COD, 80%; ammonia‐nitrogen, 90%; nitrate‐nitrogen, 94%; ortho‐phosphate‐phosphorus, 66%. Benzene removal was predominantly due to volatilization after 1 day of retention time.CONCLUSION: The use of aggregates (sand and gravel) and the presence of Phragmites australis (Cav.) Trin. ex Steud. resulted in no significant difference in terms of benzene, redox potential, dissolved oxygen, 5‐day at 20 °C N‐allylthiourea biochemical oxygen demand, COD and nutrients removal. Statistical differences were assessed by analysis of variance and Tukey HSD tests (P < 0.05). Copyright © 2007 Society of Chemical Industry
Effect of sludge retention time in sludge holding tank on excess sludge production in the oxic‐settling‐anoxic (OSA) activated sludge process
Authors: Ye Fen‐Xia , Zhu Rui‐Fen , Li Ying 
Published: October 2007

AbstractThe activated sludge process is a core technology in wastewater treatment plants. Excess sludge produced in the process must be treated and disposed of properly and may account for up to 60% of total plant operating cost. Therefore, it is necessary to develop new biological concepts to minimize excess sludge production. The oxic‐settling‐anoxic process (OSA process), a modified activated sludge process, may produce less excess sludge than the conventional activated sludge process. The effect of sludge retention time in the sludge holding tank of the OSA process on excess sludge yield has been studied. Four pilot‐scale activated sludge systems were employed, one of which was a conventional activated sludge process, and was used as the control system. The other three were OSA systems operated with different sludge retention times (5.5 h, 7.6 h, and 11.5 h) in the sludge holding tank. All systems were operated with synthetic wastewater for 7 months. Results showed that the three OSA processes with 5.5 h, 7.6 h, and 11.5 h sludge retention time reduced the excess sludge by 33%, 23% and 14%, respectively. Compared to the control process, chemical oxygen demand (COD) removal efficiency and effluent NH3–N concentration were not significantly influenced, but total nitrogen (TN) removal efficiency decreased by 0–9%. Total phosphorus (TP) removal efficiency of OSA processes with 7.6 h and 11.5 h sludge retention time increased by 19%. Sludge settleability was excellent in the three OSA processes. No distinct shift in the diversity of the predominant species was found in microbial populations. We conclude that the OSA system could reduce excess sludge production. Results suggest 6–7 h sludge retention time would be optimal. Copyright © 2007 Society of Chemical Industry
Optimization of cordycepin extraction from cultured Cordyceps militaris by HPLC‐DAD coupled with uniform design
Authors: Song Jiang‐Feng , Liu Chun‐Quan , Li Da‐Jing , Jin Bang‐Quan 
Published: October 2007

AbstractBACKGROUND: Uniform design was used to optimize the ultrasonic‐assisted extraction of cordycepin from cultured Cordyceps militaris. The peak area of cordycepin identified using high performance liquid chromatography (HPLC) at a detection wavelength of 260 nm was considered the detection index. Three factors, ethanol concentration, extraction time and volume ratio of solvent to sample were studied. Optimal quadric polynomial step by step regression was applied to process the experimental results.RESULTS: Results show that the main factors affecting cordycepin extraction yield were the volume ratio of solvent to sample, extraction time and ethanol concentration, in that order. Cordycepin extraction yield reached a peak with ethanol concentration 20.21%, extraction time 101.88 min, and volume ratio of solvent to sample 33.13 mL g−1. An extraction model was developed based on the findings.CONCLUSION: A direct, reliable and accurate assay has been developed for the quantification of cordycepin in cultured Cordyceps militaris by a HPLC‐DAD method. The validation procedure confirmed that this method is appropriate for the quality control of cordycepin. Results show that the uniform experimental design approach is useful for finding polynomial functions describing the relationships between variables and responses and to find the best experimental conditions for the extraction of cordycepin in the experimental domain considered. Copyright © 2007 Society of Chemical Industry
Comparative study of nitrification performances of immobilized cell fluidized bed reactor and contact oxidation biofilm reactor in treating high strength ammonia wastewater
Authors: Qiao Xiang L , Chen Qing X , Zhang Zhen J 
Published: October 2007

AbstractBACKGROUND: The immobilized cell fluidized bed reactor and contact oxidation biofilm reactor are two common choices for high strength ammonia wastewater treatment, however, comparative study of the nitrification performance of the two reactors has not been thoroughly studied. The nitrification performance of the two bioreactors when treating strong synthetic ammonia wastewater was investigated and compared.RESULTS: Results demonstrated that the immobilized cell fluidized bed reactor had a shorter acclimation period, and possessed several advantages over the contact oxidation biofilm reactor, in the form of complete oxidation of 150–360 mg L−1 ammonia wastewater in a shorter time, higher ammonia removal rates (from 9.6 to 4.32 × 102 mgN L−1 d−1) over the temperature range 8 to 32 °C, irrespective of organic load. In contrast, a large reduction in ammonia removal was found in the contact oxidation biofilm reactor with chemical oxygen demand (COD) load. The immobilized cell fluidized bed reactor exhibited stable and high rates of nitrification in the long term.CONCLUSION: These facts demonstrated that the immobilized cell fluidized bed reactor is a suitable selection for high strength ammonia wastewater treatment. Copyright © 2007 Society of Chemical Industry
Intraoperative sonography in patients with colorectal cancer and resectable liver metastases on preoperative FDG‐PET‐CT
Authors: Wildi Stephan M. , Gubler Christoph , Hany Thomas , Petrowsky Henrik , Clavien Pierre A. , Jochum Wolfram , Gerlach Tilman , Fried Michael , Mullhaupt Beat 
Published: October 2007

AbstractBackgroundCombined fluorine 18‐fluorodeoxyglucose–positron emission tomography–CT imaging has been shown to be of good diagnostic value in the preoperative evaluation of patients with colorectal cancer and liver metastases. The adjunctive use of intraoperative sonography (IOUS) may have a limited impact on treatment selection in these patients.PurposeTo compare the diagnostic performance of preoperative positron emission tomography (PET)‐CT alone and PET‐CT combined with IOUS in the evaluation of patients who are considered for curative resection of hepatic metastases from colorectal carcinoma.Materials and MethodsPatients with colorectal cancer who underwent resection of hepatic metastases and preoperative PET‐CT (with or without contrast‐enhanced CT) and IOUS were identified. The performance of the imaging techniques was evaluated through review of the radiologic reports, correlation with surgical and histopathologic findings, and clinical follow‐up.ResultsThirty‐one patients (mean age, 63.5 years [range, 53–82 years]) were analyzed. Fifteen patients had received preoperative chemotherapy. The mean interval between PET‐CT and IOUS was 22.6 days (range, 1–56 days). In 4 cases, neither PET‐CT nor IOUS correctly diagnosed the liver metastases. In all 31 patients, the sensitivity of PET‐CT alone and PET‐CT combined with IOUS was 63% (95% CI 44–80%) and 93% (95% CI 78–98%), respectively; the positive predictive value was 81% and 89%, respectively. In patients without preoperative chemotherapy (n = 16), the sensitivity of PET‐CT alone and PET‐CT combined with IOUS was 77% (95% CI 49–94%) and 100% (95% CI 79–100%), respectively. In 11 cases (35%), IOUS altered the surgical strategy.ConclusionIn patients with colorectal carcinoma and potentially resectable liver metastases on preoperative PET‐CT, IOUS can provide additional information that may alter decision making with regard to surgical technique. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Phase inversion harmonic imaging improves assessment of renal calculi: A comparison with fundamental gray‐scale sonography
Authors: Özdemir Hüseyin , Demir Mustafa Kemal , Temizöz Osman , Genchellac Hakan , Unlu Ercument 
Published: October 2007

AbstractPurposeTo compare phase inversion harmonic imaging (PIHI) with fundamental imaging (FI) in the evaluation of renal calculi.MethodsThirty adult patients with renal calculi (17 men, 13 women; mean age 44 years [range, 25–71]) underwent transabdominal sonographic examination of the urinary system. Both kidneys and renal calculi were examined with PIHI and FI. Overall renal conspicuity, calculus visibility, and clarity of posterior shadowing were assessed subjectively using a 4‐point scale (0 being the worst, 3 being the best). The maximum diameter of the calculi was measured using both techniques. The effect of body mass index on qualitative scoring and quantitative measurements was evaluated.ResultsPIHI improved overall renal conspicuity compared with FI (p < 0.001). The visibility of the calculi and clarity of posterior shadowing were significantly better with PIHI than with FI (p < 0.001 for both parameters). The maximum diameter of calculi was larger with PIHI than with FI (p < 0.001). The superiority of PIHI over FI regarding overall conspicuity of the kidney, visibility of the calculus, and clarity of posterior shadowing scores increased in the obese group (p < 0.001 for all 3 parameters). The mean calculus diameter difference between the 2 techniques was significantly higher in the obese group.ConclusionThe routine use of PIHI is recommended in the evaluation of renal calculi. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008