bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave assisted extraction of drugs of abuse from human urine
Authors: Fernández Purificación , Lago Marta , Lorenzo Rosa Antonia , Carro Antonia María , Bermejo Ana María , Tabernero María Jesús 
Published: February 2007

AbstractMicrowave assisted extraction (MAE) was used to extract drugs of abuse from urine samples for the simultaneous determination of morphine, codeine, 6‐acetylmorphine (6AM), cocaine, cocaethylene, benzoylecgonine (BEG), methadone and 2‐ethylidene‐1,5‐dimethyl‐3,3‐diphenylpyrrolidine (EDDP) by high performance liquid chromatography with diode array detector (HPLC‐DAD). The working wavelengths used were 285 nm for morphine, codeine and 6AM; 233 nm for cocaine, cocaethylene and BEG; and 292 nm for methadone and EDDP. The mobile phase was a gradient of acetonitrile and phosphate buffer at pH 6.5. A full factorial design was used to identify the most suitable extraction conditions as regards pH, solvent and time of extraction. The optimum conditions thus established provided analyte recoveries from 61% to 109%. The detector response was linear over the drug concentration range 0.1–4.0 µg ml−1 in urine. The within‐ and between‐day precision and accuracy were less than 8% and 6.5%, respectively. The method was applied successfully to samples obtained from Galician hospitals and courts. Copyright © 2007 John Wiley & Sons, Ltd.
Enhanced wear resistance of modified cross‐linked polyethylene by grafting with poly(2‐methacryloyloxyethyl phosphorylcholine)
Authors: Kyomoto Masayuki , Moro Toru , Konno Tomohiro , Takadama Hiroaki , Yamawaki Noboru , Kawaguchi Hiroshi , Takatori Yoshio , Nakamura Kozo , Ishihara Kazuhiko 
Published: February 2007

AbstractWe developed a cross‐linked polyethylene (CLPE) modified with a phospholipid polymer in order to address the serious problem of osteolysis caused by wear particles derived from the polyethylene components of artificial hip joints. Our goal of preventing aseptic loosening could be achieved by avoiding any formation of CLPE wear particles or suppressing the activation of cell systems by the wear particles. We investigated the surface and wear resistance properties of 2‐methacryloyloxyethyl phosphorylcholine (MPC) polymer grafted onto the surface of CLPE (CLPE‐g‐MPC). The relative density of MPC polymer chains was determined by the PO group index. Generally, polymerization times correspond to the number of polymer chains in radical polymerization. After 3.0 × 106 cycles in a hip joint simulator test, the steady wear rates of the untreated CLPE and CLPE‐g‐MPC cups with a low PO group index were as high as 4 mg/106 cycles; those of the CLPE‐g‐MPC cups with high PO group indexes, that is, 0.46 and 0.48, markedly decreased to −1.12 and 0.16 mg/106 cycles, respectively. Therefore, the grafting of an MPC polymer with high density would be essential in order to maintain the long‐term wear resistance of CLPE‐g‐MPC as an orthopedic bearing material. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Mechanical stress‐mediated Runx2 activation is dependent on Ras/ERK1/2 MAPK signaling in osteoblasts
Authors: Kanno Takahiro , Takahashi Tetsu , Tsujisawa Toshiyuki , Ariyoshi Wataru , Nishihara Tatsuji 
Published: February 2007

AbstractThe sequence of biochemical events involved in mechanical stress‐induced signaling in osteoblastic cells remains unclear. Runx2, a transcription factor involved in the control of osteoblast differentiation, has been identified as a target of mechanical stress‐induced signaling in osteoblastic cells. In this study, uniaxial sinusoidal stretching (15% strain, 115% peak‐to‐peak, at 1/12 Hz) stimulated the differentiation of osteoblast‐like MC3T3‐E1 cells and rat primary osteoblastic cells by activating Runx2. We examined the involvement of diverse mitogen‐activated protein kinase (MAPK) pathways in the activation of Runx2 during mechanical stress. Mechanical stress increased alkaline phosphatase activity, a marker of osteoblast differentiation, increased the expression of the osteoblast‐specific extracellular matrix (ECM) protein osteocalcin, and induced Runx2 activation, along with increased osterix expression. Furthermore, activation of ERK1/2 and p38 MAPKs increased significantly. U0126, a selective inhibitor of ERK1/2, completely blocked Runx2 activation during periods of mechanical stress, but the p38 MAPK‐selective inhibitor SB203580 did not alter nuclear phosphorylation of Runx2. Small interfering RNA (siRNA) targeting Rous sarcoma kinase (RAS), an upstream regulator of both ERK1/2 and p38 MAPKs, inhibited stretch‐induced ERK1/2 activation, but not mechanically induced p38 MAPK activity. Furthermore, mechanically induced Runx2 activation was inhibited by Ras depletion, using siRNA. These findings indicate that mechanical stress regulates Runx2 activation and favors osteoblast differentiation through the activation of MAPK signal transduction pathways and Ras/Raf‐dependent ERK1/2 activation, independent of p38 MAPK signaling. J. Cell. Biochem. 101:1266–1277, 2007. © 2007 Wiley‐Liss, Inc.
L‐NAME reverses quinolinic acid‐induced toxicity in rat corticostriatal slices: Involvement of src family kinases
Authors: Mallozzi Cinzia , Martire Alberto , Domenici Maria Rosaria , Metere Alessio , Popoli Patrizia , Di Stasi A.M. Michela 
Published: February 2007

AbstractQuinolinic acid (QA) is an endogenous excitotoxin acting on N‐methyl‐d‐aspartate receptors (NMDARs) that leads to the pathologic and neurochemical features similar to those observed in Huntington's disease (HD). The mechanism of QA toxicity also involves free radicals formation and oxidative stress. NMDARs are particularly vulnerable to the action of reactive oxygen species (ROS) and reactive nitrogen species (RNS) that can act as modulators of the activity of protein tyrosine kinases (PTKs) and phosphotyrosine phosphatases (PTPs). Because QA is able to activate neuronal nitric oxide synthase (nNOS) as well as to stimulate the NMDARs, we evaluated the effect of Nω‐Nitro‐l‐arginine‐methyl ester (l‐NAME), a selective nNOS inhibitor, on QA‐induced neurotoxicity in rat corticostriatal slices. In electrophysiologic experiments we observed that slice perfusion with QA induced a strong reduction of field potential (FP) amplitude, followed by a partial recovery at the end of the QA washout. In the presence of l‐NAME the recovery of FP amplitude was significantly increased with respect to QA alone. In synaptosomes, prepared from corticostriatal slices after the electrophysiologic recordings, we observed that l‐NAME pre‐incubation reversed the QA‐mediated inhibitory effects on protein tyrosine phosphorylation pattern, c‐src, lyn, and fyn kinase activities and tyrosine phosphorylation of NMDAR subunit NR2B, whereas the PTP activity was not recovered in the presence of l‐NAME. These findings suggest that NO plays a key role in the molecular mechanisms of QA‐mediated excitotoxicity in experimental model of HD. © 2007 Wiley‐Liss, Inc.
Microenvironment regulation of PRG4 phenotype of chondrocytes
Authors: Blewis Megan E. , Schumacher Barbara L. , Klein Travis J. , Schmidt Tannin A. , Voegtline Michael S. , Sah Robert L. 
Published: February 2007

AbstractArticular cartilage is a heterogeneous tissue with superficial (S), middle (M), and deep (D) zones. Chondrocytes in the S zone secrete the lubricating PRG4 protein, while chondrocytes from the M and D zones are more specialized in producing large amounts of the glycosaminoglycan (GAG) component of the extracellular matrix. Soluble and insoluble chemicals and mechanical stimuli regulate cartilage development, growth, and homeostasis; however, the mechanisms of regulation responsible for the distinct PRG4‐positive and negative phenotypes of chondrocytes are unknown. The objective of this study was to determine if interaction between S and M chondrocytes regulates chondrocyte phenotype, as determined by coculture in monolayer at different ratios of S:M (100:0, 75:25, 50:50, 25:75, 0:100) and at different densities (240,000, 120,000, 60,000, and 30,000 cells/cm2), and by measurement of PRG4 secretion and expression, and GAG accumulation. Coculture of S and M cells resulted in significant up‐regulation in PRG4 secretion and the percentage of cells expressing PRG4, with simultaneous down‐regulation of GAG accumulation. Tracking M cells with PKH67 dye in coculture revealed that they maintained a PRG4‐negative phenotype, and proliferated less than S cells. Taken together, these results indicate that the up‐regulated PRG4 expression in coculture is a result of preferential proliferation of PRG4‐expressing S cells. This finding may have practical implications for generating a large number of phenotypically normal S cells, which can be limited in source, for tissue engineering applications. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:685–695, 2007
Immunohistochemical localization of bone morphogenetic proteins (BMPs) 2, 4, 6, and 7 during induced heterotopic bone formation
Authors: McCullough Kirk A. , Waits Chad A. , Garimella Rama , Tague Sarah E. , Sipe Joseph B. , Anderson H. Clarke 
Published: February 2007

AbstractThe distribution and staining intensity of bone morphogenetic proteins (BMPs) 2, 4, 6, and 7 were assessed by immunohistochemistry in ectopic bone induced in Nu/Nu mice by Saos‐2 cell derived implants. Devitalized Saos‐2 cells or their extracts can induce endochondral bone formation when implanted subcutaneously into Nu/Nu mice. BMP staining was mostly cytoplasmic. The most intense BMP staining was seen in hypertrophic and apoptotic chondrocytes, osteoprogenitor cells such as periosteal and perivascular cells, and osteoblasts. BMP staining in osteocytes and osteoclasts was variable, ranging from undetectable to intensely stained, and from minimal to moderately stained in megakaryocytes of the induced bone marrow. BMP‐2, 4, 6, and 7 staining in Saos‐2 implant‐induced bone indicates the following: (1) Saos‐2 cell products promote expression of BMPs by host osteoprogenitor cells, which in turn, leads to bone and marrow formation at ectopic sites; (2) strong BMP staining is seen in maturing chondrocytes, and thus may play a role in chondrocyte differentiation and/or apoptosis; (3) BMP expression in perivascular and periosteal cells indicates that osteoprogenitor cells also express BMP; (4) BMP release by osteoclasts may promote osteoblastic differentiation at sites of bone remodeling. These new data can be useful in understanding the role of BMPs in promoting clinical bone repair and in various pathologic conditions. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:465–472, 2007
Adenosquamous/squamous cell carcinoma of the gallbladder
Authors: Chan Kun‐Ming , Yu Ming‐Chin , Lee Wei‐Chen , Jan Yi‐Yin , Chen Miin‐Fu 
Published: February 2007

AbstractBackground and ObjectivesAdenosquamous/squamous cell carcinoma is a rare histopathologic subtype of gallbladder malignancy. Its clinical features have rarely been described, and its differences from the major histopathologic subtype, adenocarcinoma, remain uncertain.MethodsAll patients with gallbladder carcinoma were retrospectively reviewed. Patients with a histopathologic subtype of either adenosquamous (n = 12) or squamous cell (n = 2) carcinoma were categorized to group I, and patients with adenocarcinoma were categorized to group II. The clinical characteristics and outcomes of these two groups were compared.ResultsThe two groups were generally no different in clinical features. However, tumor stages of group I patients were significantly advanced (P = 0.048) and included liver involvement (P = 0.008). The outcomes of advanced‐stage patients in group II were not different from group I (P = 0.413). Nevertheless, patients in both groups with advanced stage pT who had undergone curative resection showed significantly better survival curves than patients who had undergone non‐curative resection (P = 0.003).ConclusionsPatients with adenosquamous/squamous cell carcinoma of the gallbladder were generally similar to those with adenocarcinoma in clinical characteristics, but had a tendency for liver infiltration. Although the two histopathologic subtypes of the gallbladder carcinoma had similar poor outcomes, better survival could be obtained by performing curative resection for these patients. J. Surg. Oncol. 2007;95:129–134. © 2007 Wiley‐Liss, Inc.
Prediction of sites of recurrence in gastric carcinoma using immunohistochemical parameters
Authors: Saito Hiroaki , Osaki Tomohiro , Murakami Daiki , Sakamoto Teruhisa , Kanaji Shingo , Ohro Shotaro , Tatebe Shigeru , Tsujitani Shunichi , Ikeguchi Masahide 
Published: February 2007

AbstractBackground and ObjectivesTo improve prognosis of patients with gastric cancer, it is important to detect recurrences at an early stage following surgery. If the site of recurrence can be predicted, recurrent disease can be easier detected at an early stage. However, this is difficult to achieve using normal clinicopathological factors. We aimed to predict sites of recurrence in patients with advanced gastric carcinoma who underwent curative resection.MethodsExpressions of vascular endothelial growth factor (VEGF), transforming growth factor (TGF)‐ß1, and p53, together with density of microvessels (MVs), and dendritic cell (DC) infiltration were examined by immunohistochemistry to evaluate their relationships with recurrence patterns in patients with advanced gastric carcinoma (n = 92).ResultsAll immunohistochemical parameters closely correlated with prognosis (TGF‐ß1, P = 0.008; VEGF, P < 0.001; p53, P = 0.028; MV, P < 0.001; DC, P < 0.001). Multivariate analysis showed that DC infiltration (P = 0.02; HR, 2.52; 95%CI, 1.16–5.48), MV density (P = 0.023; HR, 2.48; 95%CI, 1.13–5.44), VEGF expression (P = 0.002; HR, 3.27; 95%CI, 1.52–7.05), and lymph node metastasis (P < 0.0001; HR, 2.09; 95%CI, 1.49–2.93) were independent prognostic factors. A multivariate logistic regression analysis indicated that DC infiltration (P = 0.004; Odds ratio, 4.25; 95%CI, 1.51–11.96) and lymph node metastasis (P = 0.01; Odds ratio, 3.37; 95%CI, 1.31–8.66) provided significant estimates of relative risks for development of peritoneal recurrence. Upon development of hematogenous recurrence, VEGF expression significantly indicated relative risks (P < 0.001; Odds ratio, 7.26; 95%CI, 1.41–37.3). Moreover, p53 expression closely correlated with lymph node recurrence (P = 0.042; Odds ratio, 11; 95%CI, 1.26–95.7).ConclusionsAssessment of immunohistochemical parameters can predict sites of recurrence in gastric carcinomas, and thus contributes to improve prognosis. J. Surg. Oncol. 2007;95:123–128. © 2007 Wiley‐Liss, Inc.
Preoperative chemoradiation and flap reconstruction provide high local control and low wound complication rates for patients undergoing limb salvage surgery for upper extremity tumors
Authors: Temple C.L.F. , Ross D.C. , Magi E. , DiFrancesco L.M. , Kurien E. , Temple W.J. 
Published: February 2007

AbstractBackground and ObjectivesNeoadjuvant protocols in the management of upper extremity sarcoma have improved local control rates but have been associated with high complication rates. We present a refinement of the Eilber protocol using judicious preoperative chemoradiation, limb salvage surgery, and flap coverage to achieve high local control rates with acceptable wound healing complications.MethodsPatients presenting with upper extremity neoplasms from 1986 to 2002 were treated with a modified Eilber protocol, consisting of 3 days of adriamycin (30 mg/day) and sequential radiotherapy (300 cGy/day for 10 days). Limb salvage surgery with flap coverage where needed was performed 4–8 weeks later. Patients were followed prospectively for recurrence.ResultsFifty‐three consecutive patients with upper extremity tumors were treated and followed for a mean of 6.1 years. This cohort included 44 sarcomas and nine non‐metastasizing, locally aggressive tumors. There were two local recurrences (3.8%). Limb salvage was achieved in all patients. Flaps were required in 43.4% of patients. Major complications occurred in 11%, were all flap related (partial flap loss, venous congestion), and went on to heal promptly with treatment.ConclusionThis modified Eilber protocol achieved 96% local control for upper extremity tumors with a wound complication rate of 11%. The liberal use of flaps of resulted in healed, stable wounds in all patients. J. Surg. Oncol. 2007;95:135–141. © 2007 Wiley‐Liss, Inc.
Identification and determination of glycosides in tobacco leaves by liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry
Authors: Pang Tao , Yuan Zhongyi , Dai Yongsheng , Wang Chang , Yang Jun , Peng Liming , Xu Guowang 
Published: February 2007

AbstractHPLC‐atmospheric pressure chemical ionization MS (HPLC‐APCI‐MS) was used to screen and identify glycosides in tobacco leaf. MS/MS and MS3 and photodiode array (PDA) detection were also used in the characterization. A total of 12 glycosides were found and four of them were identified based on their abundant [M + H]+ ions, UV spectra, and MS/MS analysis and they are scopolin, rutin, quercetin‐3‐glycoside, and kaempferol‐3‐rutinoside. Analytical characteristics of the method were investigated. The contents of these glycosides were obtained and compared based on the relative peak area to the internal standard in seven kinds of tobacco leaf.
An alternative multiple‐trapping LC‐SPE‐NMR system
Authors: Wilson Steven Ray , Malerød Helle , Petersen Dirk , Rise Frode , Lundanes Elsa , Greibrokk Tyge 
Published: February 2007

AbstractIn this paper, we describe approaches that make RP LC‐SPE‐NMR simpler, and in our opinion, result in more reliable methods for trapping and subsequent transfer of separated trace‐level compounds to the NMR. An SPE unit based on a commercially available, low dead‐volume 10 port high‐pressure column selector gives the possibility of trapping compounds on nine individual SPEs that have standard fittings. This allows the operator to employ specific stationary phases that are not available as SPEs in commercially available LC‐SPE‐NMR systems. Multiple trappings of small compounds like monuron, 1‐(4‐chlorophenyl)‐3‐methylurea, and 4‐chlorophenylurea were easily performed employing a porous‐carbon SPE material. The system was optimized to elute the SPE‐trapped compounds to the NMR probes in as small a volume as possible using back‐flushing. The proper match of NMR probe volume and SPE column inner diameter and elution volume was discussed, as well as the necessity of drying loaded SPEs prior to NMR transfer when using porous‐carbon SPE material.
Pharmaceutical determination in surface and wastewaters using high‐performance liquid chromatography‐(electrospray)‐mass spectrometry
Authors: Pedrouzo Marta , Reverté Sandra , Borrull Francesc , Pocurull Eva , Marcé Rosa Maria 
Published: February 2007

AbstractA method was developed to determine 11 pharmaceutical compounds in water samples. The method uses SPE and HPLC coupled to MS (LC/MS) using ESI in both positive and negative modes. Three different sorbents were compared for the extraction of analytes from river and sewage treatment plant (STP) waters and OASIS HLB provided the best results. For the solid‐phase extraction of 500 mL of river water samples, the recoveries were between 41 and 101% with the exception of acetaminophen, salicylic acid and naproxen. The LODs were between 3 and 5 ng/L for all the compounds, except naproxen which had an LOD of 15 ng/L. Acetaminophen, caffeine, carbamazepine, bezafibrate and ibuprofen were found in three of the tested river samples at ng/L levels and among them, the highest values were for caffeine and bezafibrate with 305 and 363 ng/L, respectively. For the influent and effluent water samples of the STP, volumes of 100 and 250 mL were used, respectively, to obtain acceptable recoveries. All the compounds showed recoveries between 33 and 91% for effluent samples and 33–72% for influent samples, with the exception of acetaminophen, salicylic acid and bezafibrate, which had lower recoveries. The method developed enabled pharmaceuticals in the influent and effluent sewage waters to be determined in five campaigns carried out between February 2004 and June 2005. Several pharmaceuticals were found in the influent samples: for instance, maximum concentrations of ibuprofen and caffeine were 6 and 40 μg/L, respectively.
Effect of experimental conditions on the metal dusting phenomenon in several commercial nickel‐base alloys
Authors: Di Gabriele F. , Stott F. H. , Liu Z. 
Published: February 2007

AbstractThe corrosion phenomenon, metal dusting, has been observed in many high‐temperature industrial plants, such as ammonia, syngas and steam‐reforming industries. An experimental research programme has been carried out into the degradation resistance of wrought and cast commercial high‐temperature nickel‐base alloys in H2/CO gas mixtures at 650 °C.The results in this paper are focused on the effect of the experimental set‐up on the response of the alloy during exposure to the gas mixture; in particular, the specimen holders had an important role on the onset of carbon transfer from the gas to the alloy surfaces. Specimens of most alloys exposed to the gas mixture while suspended from quartz hangers were shown to have good resistance to the environment for periods up to 5000 h. On the other hand, specimens of these alloys, exposed while located in porous refractory ceramic holders, gained large amounts of coke and underwent severe damage. A series of short tests were carried out in order to ascertain the main factors influencing the alloy reactivities in the experimental rig. The presence of specimens of a less‐resistant alloy and slight variations in gas composition (with the addition of CO2) were observed to have a marked impact on the alloy reactivities. Factors such as catalysts, contaminants and gas composition were considered and are discussed.
Fluorescence Turn‐On Detection of Nitric Oxide in Aqueous Solution Using Cationic Conjugated Polyelectrolytes
Authors: Xing Chengfen , Yu Minghui , Wang Shu , Shi Zhiqiang , Li Yuliang , Zhu Daoben 
Published: February 2007

AbstractA fluorescent turn‐on detection for nitric oxide in aqueous solution is developed using cationic conjugated polymers. The assay benefits from the sensitivity of optical signals from conjugated polymers and the simplicity of fluorescence measurement techniques. The assay contains three elements: a cationic conjugated polymer that contains imidazole moieties, Cu2+ ions, and the target nitric oxide. The highly fluorescent conjugated polymer coordinates to Cu2+ ions through weak N · · · Cu interactions, and its fluorescence is efficiently quenched by a photo‐induced electron transfer process (‘off’ state). In the presence of nitric oxide, the transformation of the paramagnetic Cu2+ ion into a diamagnetic Cu1+ ion inhibits the quenching and, therefore, the fluorescence of the conjugate polymer is recovered (‘on’ state). Other biologically relevant reactive nitrogen species, such as NOBF4, NaNO2, and NaNO3 don't exhibit the fluorescence recovery of the conjugated polymer under the same conditions as nitric oxide. The cationic conjugated polymer/Cu2+ complex can thus be used as a platform to detect nitric oxide in aqueous solution with high sensitivity and selectivity.magnified image