bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response characteristics of an aquatic biomonitor used for rapid toxicity detection
Authors: van der Schalie W. H. , Shedd T. R. , Widder M. W. , Brennan L. M. 
Published: October 2004

AbstractThe response characteristics of an aquatic biomonitor that detects toxicity by monitoring changes in bluegill (Lepomis macrochirus Raﬁnesque) ventilatory and movement patterns were evaluated in single chemical laboratory studies at concentrations near the 96‐h LC50 concentration and at the EILATox‐Oregon Workshop in sequential tests of multiple unknown samples. Baseline data collected prior to exposure allows each ﬁsh to serve as its own control. When at least 70% of exposed ﬁsh exhibit ventilatory or movement parameters signiﬁcantly different from baseline observations, a group alarm is declared. In the laboratory studies, the aquatic biomonitor responded to the majority of chemicals at the 96‐h lc50 within an hour or less, although substantially higher response times were found for malathion and pentachlorophenol. Workshop tests of single chemical concentrations presented as blind samples were consistent with the laboratory test results. There were no alarms under control conditions in any test. Although data are limited, the aquatic biomonitor appears to respond more rapidly to chemicals causing membrane irritation, narcosis or polar narcosis than to acetylcholinesterase inhibitors or oxidative phosphorylation uncouplers. All four monitored parameters (ventilatory rate, cough rate, ventilatory depth and movement) contributed to identiﬁcation of ﬁrst alarms at acutely toxic levels. Understanding these response patterns can be useful in data interpretation for biomonitor applications such as surface water monitoring for watershed protection, wastewater treatment plant efﬂuent monitoring or source water monitoring for drinking water protection. Copyright © 2004 John Wiley & Sons, Ltd.
Monitoring genotoxicity during the photocatalytic degradation of p‐nitrophenol
Authors: Sekler M. Shani , Levi Y. , Polyak B. , Novoa A. , Dunlop P. S. M. , Byrne J. A. , Marks R. S. 
Published: October 2004

Abstractp‐Nitrophenol is a common structural unit of many pesticides and was chosen as a model compound to monitor genotoxicity during photocatalytic degradation. The genotoxicity of p‐nitrophenol (PNP) and its breakdown products was measured using a bioluminescent bacterial bioassay, Vitotox™. The genotoxic potential decreased with the concomitant photocatalytic degradation of the parent PNP concentration. The rate of genotoxicity reduction was slower than the rate of removal of the parent PNP, due to the formation of genotoxic by‐products. After 6 h of photocatalytic treatment the total genotoxicity was removed. These results indicate that bioassays can be used as a simple and highly sensitive method for monitoring the general toxicity of chemical pollutants before, during and after photocatalytic treatment or other destructive processes. Copyright © 2004 John Wiley & Sons, Ltd.
Responses of fish chromatophore‐based cytosensor to a broad range of biological agents
Authors: Dierksen Karen P. , Mojovic Ljiljana , Caldwell Bruce A. , Preston R. Ryan , Upson Rosalyn , Lawrence Jeannine , McFadden Philip N. , Trempy Janine E. 
Published: October 2004

AbstractA cytosensor based on living chromatophores from Betta splendens Siamese ﬁghting ﬁsh was used to test several classes of biologically active agents. Tested agents include neurotransmitters, adenyl cyclase activators, cytoskeleton effectors, cell membrane effectors and protein synthesis inhibitors. Characteristic cell responses were analyzed, and potential cytosensor applications were considered. Streptococcus pyogenes toxins streptolysin S and streptolysin O, Clostridium tetani tetanolysin, Staphylococcus aureus alpha‐toxin and Vibrio parahemolyticus hemolysin, all bacterial toxins that act on cell membranes, elicited a strong response from chromatophores. A comparison of puriﬁed toxin to actual bacterial culture from Vibrio parahemolyticus demonstrated a nearly identical chromatophore cell response pattern. This suggests that the cytosensor response is reﬂective of bacterial toxin production. Copyright © 2004 John Wiley & Sons, Ltd.
3D real time methodology monitoring cement failures in THA
Authors: Qi Gang , Li Jihui , Mann Kenneth A. , Mouchon W. Paul , Hamstad Marvin A. , Salehi Abraham , Whitten Stephen A. 
Published: October 2004

AbstractThe present work proposed a methodology to monitor cement microcrack formation in the cemented femoral stem construct using the acoustic emission technique. This technique provides a unique means to automatically tally the number of microcracks, to visualize microcrack distribution, and to animate the progress of crack formation in a given time window of a fatigue test. In this work, the formulation of microcrack source location was derived and a computer program was developed specifically for the proposed application. The program was validated using computer simulation and standard pencil lead break tests. It was found that the mathematical errors complied with the acceptable minimal error. Based on the pencil lead break tests, the average technical error used to estimate the resolution of this technique was 4.7 mm at the present stage. The program was then used to monitor the fatigue damage in precoated cemented femoral hip constructs loaded for a total of more than five million cycles. Two types of microcrack activities were observed in the experiments: Type I and Type II microcracks. A Type I microcrack was a crack that was captured by four or more sensors, and therefore its location was defined uniquely by a set of coordinates. A Type II microcrack was a crack that was captured by three or less sensors, therefore it was unlocatable. Both counts of Type I and Type II microcrack were tallied with respect to the day of fatigue tests. Acoustic emission microcrack graphs were used to visualize the distribution of Type I microcracks in the construct. It was found that the Type I microcracks distributed mainly over the proximal third of the stem. The amount of microcrack events decreased significantly as the number of loading cycles increased. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 391–402, 2004
Preparation and characterization of a highly macroporous biodegradable composite tissue engineering scaffold
Authors: Guan Limin , Davies John E. 
Published: October 2004

AbstractA unique composite scaffold for bone‐tissue engineering applications has been prepared by combining biodegradable poly(lactide‐co‐glycolide) (PLGA) with bioresorbable calcium phosphate (CaP) cement particles through the process of particle fusion and phase separation/particle leaching. The scaffold is characterized by a highly interconnected macroporosity, with macropores of 0.8–1.8 mm and porosities ranging from 81% to 91%, and improved mechanical properties with respect to the polymer alone, producing excellent dimensional stability. The scaffold properties were controlled by adjusting the processing parameters, including PLGA molar mass and concentration, CaP/PLGA ratio, and porogen size. The differences in mechanical properties between dry, wet/room temperature, and wet/37°C testing conditions, of which the latter are more relevant for materials to be employed in a biological milieu, were investigated. Thus, a scaffold made from PLGA IV 1.13, PLGA concentration 12.5%, and CaP/PLGA ratio 2:1 exhibited significantly different compressive strengths of 0.16 MPa and 0.04 MPa when tested under dry and wet/37°C conditions, respectively. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 480–487, 2004
Bone morphogenetic protein‐2 decorated silk fibroin films induce osteogenic differentiation of human bone marrow stromal cells
Authors: Karageorgiou Vassilis , Meinel Lorenz , Hofmann Sandra , Malhotra Ajay , Volloch Vladimir , Kaplan David 
Published: October 2004

AbstractBone morphogenetic protein (BMP)‐2 has a critical role in bone formation and regeneration. Therefore, the ability to immobilize this molecule in certain matrices may be crucial in bone tissue engineering. Using carbodiimide chemistry, BMP‐2 was directly immobilized on silk fibroin films. Whereas human bone marrow stromal cells cultured on unmodified silk fibroin films in the presence of osteogenic stimulants exhibited little if any osteogenesis, the same cells cultured on BMP‐2 decorated films in the presence of osteogenic stimulants differentiated into an osteoblastic lineage as assessed by their significantly elevated alkaline phosphatase activity, calcium deposition, and higher transcript levels of collagen type I, bone sialoprotein, osteopontin, osteocalcin, BMP‐2, and cbfa1. Using cell culture inserts, it was demonstrated that differentiation was induced by the immobilized protein and not by protein released into the culture medium. Comparison with a similar amount of medium‐supplemented BMP‐2, where no additional protein was added with medium changes, showed that delivery of BMP‐2 immobilized on the biomaterial surface was more efficient than soluble delivery. The results illustrate that BMP‐2 covalently coupled on silk biomaterial matrices retains biological function in vitro based on the induction of osteogenic markers in seeded bone marrow stromal cells. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 528–537, 2004
Carboxy‐terminal fragment of osteogenic growth peptide regulates myeloid differentiation through RhoA
Authors: Mattii Letizia , Fazzi Rita , Moscato Stefania , Segnani Cristina , Pacini Simone , Galimberti Sara , D'Alessandro Delfo , Bernardini Nunzia , Petrini Mario 
Published: October 2004

AbstractThe carboxy‐terminal fragment of osteogenic growth peptide, OGP(10–14), is a pentapeptide with bone anabolic effects and hematopoietic activity. The latter activity appears to be largely enhanced by specific growth factors. To study the direct activity of OGP(10–14) on myeloid cells, we tested the pentapeptide proliferating/differentiating effects in HL60 cell line. In this cell line, OGP(10–14) significantly inhibited cell proliferation, and enhanced myeloperoxidase (MPO) activity and nitroblue tetrazolium reducing ability. Moreover, it induced cytoskeleton remodeling and small GTP‐binding protein RhoA activation. RhoA, which is known to be involved in HL60 differentiation, mediated these effects as shown by using its specific inhibitor, C3. Treatment with GM‐CSF had a comparable OGP(10–14) activity on proliferation, MPO expression, and RhoA activation. Further studies on cell proliferation and RhoA activation proved enhanced activity by association of the two factors. These results strongly suggest that OGP(10–14) acts directly on HL60 cells by activating RhoA signaling although other possibilities cannot be ruled out. © 2004 Wiley‐Liss, Inc.
Unique precipitation and exocytosis of a calcium salt of myo‐inositol hexakisphosphate in larval Echinococcus granulosus
Authors: Irigoín Florencia , Casaravilla Cecilia , Iborra Francisco , Sim Robert B. , Ferreira Fernando , Díaz Alvaro 
Published: October 2004

AbstractThe ubiquitous intracellular molecule myo‐inositol hexakisphosphate (IP6) is present extracellularly in the hydatid cyst wall (HCW) of the parasitic cestode Echinococcus granulosus. This study shows that extracellular IP6 is present as its solid calcium salt, in the form of deposits that are observed, at the ultrastructural level, as naturally electron dense granules some tens of nanometers in diameter. The presence of a calcium salt of IP6 in these structures was determined by two different electron microscopy techniques: (i) the analysis of the spatial distribution of phosphorus and calcium in the outer, acellular layer of the HCW (the laminated layer, LL) through electron energy loss spectroscopy, and (ii) the observation, by transmission electron microscopy, of HCW that were selectively depleted of IP6 by treatment with EGTA or phytase, an enzyme that catalyses the dephosphorylation of IP6. The deposits of the IP6‐Ca(II) salt are also observed inside membrane vesicles in cells of the germinal layer (the inner, cellular layer of the HCW), indicating that IP6 precipitates with calcium within a cellular vesicular compartment and is then secreted to the LL. Thus, much as in plants (that produce vesicular IP6 deposits), the existence of transporters for IP6 or its precursors in internal membranes is needed to explain the compound's cellular localisation in E. granulosus. © 2004 Wiley‐Liss, Inc.
Ferulic acid inhibits endothelial cell proliferation through NO down‐regulating ERK1/2 pathway
Authors: Hou YongZhong , Yang Jie , Zhao GuangRong , Yuan YingJin 
Published: October 2004

AbstractThe aim of this study was to determine the antiproliferative mechanism of ferulic acid (FA) on serum induced ECV304 cell, a human umbilical vein endothelial line. The results suggest that FA significantly suppressed ECV304 cells proliferation and blocked the cell cycle in G0/G1phase. Treatment of the cells with FA increased nitric oxide (NO) production and inactivated the extracellular signal‐regulated kinase (EERK1/2), and the NO donor, sodium nitroprusside, inhibited both ECV304 cells proliferation and phosphorylation of ERK1/2. However, the NO synthase inhibitor,Nω‐nitro‐L‐arginine methyl ester, caused ECV304 cells proliferation. PD 98059, the inhibitor of ERK1/2, had no effect on the NO production. These results indicate that NO suppressed ECV304 cells proliferation through down‐regulating ERK1/2 pathway. Moreover, the inhibition of cell cycle progression was associated with the decrement of cyclin D1 expression and phosphorylation of retinoblastoma protein (pRb) by increment of p21 level. The findings not only present the first evidence that FA is a potent inhibitor on ECV304 cells proliferation, but also reveal the potential signaling molecules involved in its action. © 2004 Wiley‐Liss, Inc.
Mechanism of LIGHT/interferon‐γ‐induced cell death in HT‐29 cells
Authors: Chang Ying‐Hsin , Chao Yee , Hsieh Shie‐Liang , Lin Wan‐Wan 
Published: October 2004

AbstractLIGHT is a member of tumor necrosis factor (TNF) superfamily, and previous studies have indicated that in the presence of interferon‐γ (IFN‐γ), LIGHT through LTβR signaling can induce cell death with features unlike classic apoptosis. In present study, we investigated the mechanism of LIGHT/IFN‐γ‐induced cell death in HT‐29 cells, where the cell death was profoundly induced when sub‐toxic concentrations of LIGHT and IFN‐γ were co‐treated. LIGHT/IFN‐γ‐induced cell death was accompanied by DNA fragmentation and slight LDH release. This effect was not affected by caspase, JNK nor cathepsin B inhibitors, but was partially prevented by p38 mitogen‐activated protein kinase (MAPK) and poly (ADP‐ribose) polymerase (PARP) inhibitors, and abolished by aurintricarboxylic acid (ATA), which is an inhibitor of endonuclease and STATs signaling of IFN‐γ. Immunobloting reveals that LIGHT/IFN‐γ could induce p38 MAPK activity, Bak and Fas expression, but down‐regulate Mcl‐1. Besides, LIGHT/IFN‐γ could not activate caspase‐3 and ‐9, but decreased mitochrondrial membrane potential. Although LIGHT could not affect IFN‐γ‐induced STAT1 phosphorylation and transactivation activity, which was required for the sensitization of cell death, survival NF‐κB signaling of LIGHT was inhibited by IFN‐γ. These data suggest that co‐presence of LIGHT and IFN‐γ can induce an integrated interaction in signaling pathways, which lead to mitochondrial dysfunction and mix‐type cell death, not involving caspase activation. © 2004 Wiley‐Liss, Inc.
Controlled synthesis of labelled 3‐L‐chlorotyrosine‐[ring‐13C6] and of 3,5‐L‐dichlorotyrosine‐[ring‐13C6]
Authors: Allevi Pietro , Olivero Paola , Anastasia Mario 
Published: October 2004

AbstractPure 3‐L‐chlorotyrosine‐[ring‐13C6] is prepared by chlorination of the 5‐oxazolidinone of L‐tyrosine‐[ring‐13C6] with SO2Cl2 in CH3COOH‐Et2O and successive one‐pot regeneration of the protected aminoacidic functions by BCl3 in dichloromethane. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of 6‐chloro‐3‐((2‐(S)‐azetidinyl)methoxy)‐5‐(2‐[18F]fluoropyridin‐4‐yl)pyridine ([18F]NIDA 522131), a novel potential radioligand for studying extrathalamic nicotinic acetylcholine receptors by PET
Authors: Zhang Yi , Horti Andrew G. 
Published: October 2004

Abstract6‐Chloro‐3‐((2‐(S)‐azetidinyl)methoxy)‐5‐(2‐[18F]fluoropyridin‐4‐yl)pyridine ([18F]NIDA 522131), a potential radioligand for studying extrathalamic nicotinic acetylcholine receptors by positron‐emission tomography, was synthesized via no‐carrier‐added nucleophilic [18F]fluorination of 6‐chloro‐3‐((1‐(tert‐butoxycarbonyl)‐2‐(S)‐azetidinyl)methoxy)‐5‐(2‐iodopyridin‐4‐yl)vinyl)pyridine, followed by acidic deprotection. The overall radiochemical yield of the radiosynthesis was 4–8% (non‐decay‐corrected), the specific radioactivity was in the range of 167–335 GBq/µmol (4500–9000 mCi/µmol) and the radiochemical purity was greater than 99%. Preparation of [18F]NIDA522131 via corresponding bromo‐derivative 2 is also described. Copyright © 2004 John Wiley & Sons, Ltd.
Utility of azetidinium methanesulfonates for radiosynthesis of 3‐[18F]fluoropropyl amines
Authors: Kiesewetter Dale O. , Eckelman William C. 
Published: October 2004

Abstract3‐Methanesulfonyloxypropyl tertiary amines were observed to cyclize to form azetidinium methanesulfonate moieties. Heat‐induced cyclization of 3‐methanesulfonyloxypropyl amines was utilized for preparation of azetidinium methanesulfonates. The azetidinium methanesulfonates were found to incorporate radioactive [18F]fluoride (decay‐corrected yields >60%) efficiently, resulting in an efficient synthesis of 3‐[18F]fluoropropyl tertiary amines. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of [O‐methyl‐11C]‐4‐(1,3‐dimethoxy‐2‐propylamino)‐2,7‐dimethyl‐8‐(2,4‐dichlorophenyl)[1,5‐a]pyrazolo‐1,3,5‐triazine ([11C]DMP696): a potential PET ligand for CRF1 receptors
Authors: Kumar J. S. Dileep , Majo Vattoly J. , Simpson Norman R. , Prabhakaran Jaya , Van Heertum Ronald L. , Mann J. John 
Published: October 2004

AbstractSynthesis of [O‐methyl‐11C]‐4‐(1,3‐dimethoxy‐2‐propylamino)‐2,7‐dimethyl‐8‐(2,4‐dichlorophenyl)[1,5‐a]pyrazolo‐1,3,5‐triazine ([11C]DMP696), a highly selective CRF1 antagonist has been achieved. The total time required for the synthesis of [11C]DMP696 is 30 min from EOB using [11C]methyl triflate in THF, with a 16% yield (EOS) and >99% chemical and radiochemical purities along with a specific activity of >2000 Ci/mmol (EOS). Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of tritium labelled [2′,6′]‐L‐tyrosine
Authors: Augustyniak W. , Kański R. , Kańska M. 
Published: October 2004

AbstractThe synthesis of a specifically ring labelled isotopomer of L‐tyrosine, (L‐Tyr), using a combination of chemical and enzymatic methods is reported. The tritium labelled [2′,6′]‐L‐Tyr has been synthesized via catalytic exchange of phenol with tritiated water in the presence of K2PtCl4, reverse acid catalysed removal of tritium from the o‐ and p‐positions of phenol, and subsequent condensation of the resulting [3′,5‐3H2]‐phenol with S‐methyl‐L‐cysteine using the enzyme β‐tyrosinase from Citrobacter freundii. Copyright © 2004 John Wiley & Sons, Ltd.
Real‐time monitoring of tritium gas reactions using Raman spectroscopy
Authors: Heys J. Richard , Powell Mark E. , Pivonka Don E. 
Published: October 2004

AbstractThe utility of Raman spectroscopy for noninvasive, real‐time monitoring of a range of tritium gas labeling reactions has been investigated, using deuterium gas as a model in most cases. Reaction types include organoiridium‐catalyzed heteroatom‐directed exchange (HDE), olefin hydrogenation and catalytic aryl dehalogenation. Five examples of HDE reactions with several different substrate types were monitored by observation of Raman vibrational bands sensitive to the isotopic substitutions. Changes in peak intensities and/or frequencies associated with the course of labeling are clearly observable at concentrations and reaction scales typical of tritium gas reactions. Similarly, Raman bands sensitive to the chemical changes that occur during catalytic deuterogenation of an olefin and to catalytic deuterium–bromine exchange of an aryl bromide were successfully monitored. This methodology can provide unprecedented real‐time information, otherwise difficult to obtain, over the course of such reactions. Copyright © 2004 John Wiley & Sons, Ltd.
Morphological observation of antler regeneration in red deer (Cervus elaphus)
Authors: Li Chunyi , Suttie James M. , Clark Dawn E. 
Published: October 2004

AbstractDeer antler offers a unique opportunity to explore how nature solves the problem of mammalian appendage regeneration. Annual antler renewal is an example of epimorphic regeneration, which is known to take place through initial blastema formation. Detailed examination of the early process of antler regeneration, however, has thus far been lacking. Therefore, we conducted morphological observations on antler regeneration from naturally cast and artificially created pedicle/antler stumps. On the naturally cast pedicle stumps, early antler regeneration underwent four distinguishable stages (with the Chinese equivalent names): casting of previous hard antlers (oil lamp bowl), early wound healing (tiger eye), late wound healing and early regeneration (millstone), and formation of main beam and brown tine (small saddle). Overall, no cone‐shaped regenerate, a common feature to blastema‐based regeneration, was observed. Taken together with the examination on the sagittal plane of each regenerating stage sample, we found that there are considerable overlaps between late‐stage wound healing and the establishment of posterior and anterior growth centers. Observation of antler regeneration from the artificially created stumps showed that the regeneration potential of antler remnants was significantly reduced compared with that of pedicle tissue. Interestingly, the distal portion of a pedicle stump had greater regeneration potential than the proximal region, although this differential potential may not be constitutive, but rather caused by whether or not pedicle antlerogenic tissue becomes closely associated with the enveloping skin at the cut plane. Antler formation could take place from the distal peripheral tissues of an antler/pedicle stump, without the obvious participation of the entire central bony portion. Overall, our morphological results do not support the notion that antler regeneration takes place through the initial formation of a blastema; rather, it may be a stem cell‐based process. J. Morphol. 262:731–740, 2004. © 2004 Wiley‐Liss, Inc.