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Selected AbstractsFactors affecting the time of onset of resorption in avulsed and replanted incisor teeth in childrenDENTAL TRAUMATOLOGY, Issue 5 2001M. Donaldson Abstract , Resorption is the main reason for loss of replanted teeth. The outcome examined in this study is the timing of the onset of resorption. The effect of dichotomised dry and wet time intervals as well as the presence of additional crown damage and of contamination were determined. Of 84 replanted teeth, 67.5% developed resorptions. Twenty-eight had detectable additional crown damage with a more rapid onset being seen in these cases (P=0.009). The critical limit for dry time was 15 min (P=0.038) and significant differences persisted for greater limits also. Serial analysis of the association between the time of onset of root resorption and dichotomised wet time variables failed to yield any significant associations. There was visible contamination detected in 32 teeth and these exhibited a more rapid onset of resorption than the other cases (P=0.030). Teeth with inflammatory root resorption (12.8%) had a more rapid onset of resorption than those that developed replacement resorption (54.7%) (P<0.001). It is concluded that the risk of early resorption is increased in teeth that have additional damage or have contamination, or are kept in dry conditions for longer than 15 min. [source] Biodegradation during contaminant transport in porous media: 7.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2005Impact of multiple-degrader community dynamics Abstract The biodegradation and transport of phenanthrene in porous media containing multiple populations of phenanthrene degraders is examined with a series of miscible-displacement experiments. A long-term experiment was conducted with a soil containing an indigenous microbial community comprised of 25 identified phenanthrene-degrading isolates. The rate and magnitude of phenanthrene biodegradation oscillated throughout the six-month experiment. This behavior, at least in part, is attributed to multiple-population dynamics associated with the indigenous community of phenanthrene degraders, the composition of which changed during the experiment. This hypothesis is supported by the results of experiments conducted using sterilized porous media that were inoculated with selected isolates obtained from the indigenous soil community. The results of experiments conducted with sterilized soil inoculated with isolate A exhibited an initial extended period of steady phenanthrene effluent concentrations, followed by a uniform decline. The results of experiments conducted using sterilized sand for single-isolate systems with one of three selected isolates and for systems of two-isolate combinations, indicate the existence of apparent synergistic and antagonistic interactions among the isolates. For example, phenanthrene biodegradation was relatively extensive and occurred without a lag phase for isolate A alone. However, biodegradation was constrained when isolate A and B were combined, indicating an antagonistic interaction. Conversely, whereas extensive lag phases were exhibited by both isolates B and C for the single-isolate experiments, there was minimal lag when isolates B and C were combined, indicating a synergistic interaction. [source] Effects of Ultraviolet Radiation on Locomotion and Orientation in Roughskin Newts (Taricha granulosa)ETHOLOGY, Issue 3 2000Andrew R. Blaustein Environmental changes, including those associated with the atmosphere may significantly affect individual animals and ultimately populations. Ultraviolet (UV) radiation, perhaps increasing due to stratospheric ozone depletion, has been linked to mortality in a number of organisms, including amphibians. The eggs and larvae of certain amphibian species hatch at significantly lower rates when exposed to ambient ultraviolet light. Yet little is known about the sublethal effects of UV radiation. For example, UV radiation may affect specific behaviors of an animal that could alter its ability to survive. To examine if UV radiation affects amphibian behavior, we used roughskin newts (Taricha granulosa) as a model. Newts were exposed to low-level doses of UV in the laboratory and then tested in the field to examine if UV-exposed and control (no UV) newts differed in orientation towards water or in locomotor activity levels. UV-exposed and control newts both exhibited a significant orientation towards water in field tests but there was no significant difference in orientation between treatments. However, UV-exposed newts were significantly more active than control newts. Our results suggest that exposure to short-term low levels of UV radiation alters certain behaviors. Environmentally induced changes in behavior may have significant ecological and evolutionary consequences. [source] Redox Modification of EMACs Through the Tuning of Ligands: Heptametal(II) Complexes of Pyrazine-Modulated Oligo-,-pyridylamido LigandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2009Rayyat Huseyn Ismayilov Abstract Using pyrazine-modulated oligo-,-pyridylamido ligands N2 -(pyrazin-2-yl)- N6 -[6-(pyrazin-2-ylamino)pyridin-2-yl]pyridine-2,6-diamine (H3pzpz) and N2 -(pyrazin-2-yl)- N6 -[6-(pyridin-2-ylamino)pyridin-2-yl]pyridine-2,6-diamine (H3tpz), linear heptametal(II) extended metal atom chains (EMACs) [M7(,7 -L)4X2] [L = pzpz3,, M = NiII, X = Cl, (1), NCS, (2); M = CrII, X = Cl, (3), NCS, (4); L = tpz3,, M = CrII, X = Cl, (5), NCS, (6)] were synthesized and structurally characterized. Electrochemical studies showed that heptanickel(II) complexes can undergo one reversible oxidation at +0.46 V for 1 and +0.52 V for 2. Chromium(II) species 3 exhibited two reversible, one-electron oxidation peaks at +0.61 and +0.88 V, and 5 exhibited three reversible, one-electron oxidation peaks at +0.40, +0.68 and +1.07 V. The redox peaks shifted positively when axial ligands changed from chloride to thiocyanate anions, at +0.67 and +0.92 V for 4 and +0.44, +0.73 and +1.11 V for 6. The introduction of electron-withdrawing pyrazine rings to the spacer ligand retarded oxidation of the heptametal EMACs and stabilized the complexes. In nickel(II) species 1 and 2, both terminal nickel atoms exist in spin state S = 1 whereas all the inner nickel atoms exist in spin state S = 0. Temperature-dependent magnetic research revealed an antiferromagnetic interaction between the two terminal atoms through a superexchange pathway along metal cores with a parameter of about,4 cm,1. Chromium(II) species 3,6 showed a localized structure consisting of three quadruple Cr,Cr bonds and a single terminal CrII atom. Magnetic study revealed a quintet ground state resulting from the isolated, high-spin CrII atom.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Reactivity of the heme,dioxygen complex of the inducible nitric oxide synthase in the presence of alternative substratesFEBS JOURNAL, Issue 1 2006David Lefèvre-Groboillot Single turnover reactions of the inducible nitric oxide synthase oxygenase domain (iNOSoxy) in the presence of several non ,-amino acid N -hydroxyguanidines and guanidines were studied by stopped-flow visible spectroscopy, and compared with reactions using the native substrates l -arginine (l -arg) or N, -hydroxy- l -arginine (NOHA). In experiments containing dihydrobiopterin, a catalytically incompetent pterin, and each of the studied substrates, l -arg, butylguanidine (BuGua), para -fluorophenylguanidine (FPhGua), NOHA, N -butyl- and N -(para -fluorophenyl)- N,-hydroxyguanidines (BuNOHG and FPhNOHG), the formation of a iron(II) heme,dioxygen intermediate (FeIIO2) was always observed. The FeIIO2 species then decayed to iron(III) iNOSoxy at rates that were dependent on the nature of the substrate. Identical reactions containing the catalytically competent cofactor tetrahydrobiopterin (BH4), iNOSoxy and the three N -hydroxyguanidines, all exhibited an initial formation of an FeIIO2 species that was successively converted to an FeIIINO complex and eventually to high-spin iron(III) iNOSoxy. The formation and decay kinetics of the FeIIINO complex did not vary greatly as a function of the N -hydroxyguanidine structure, but the formation of FeIIINO was substoichiometric in the cases of BuNOHG and FPhNOHG. Reactions between BH4 -containing iNOSoxy and BuGua exhibited kinetics similar to those of the corresponding reaction with l -arginine, with formation of an FeIIO2 intermediate that was directly converted to high-spin iron(III) iNOSoxy. In contrast, no FeIIO2 intermediate was observed in the reaction of BH4 -containing iNOSoxy and FPhGua. Multi-turnover reaction of iNOS with FPhGua did not lead to formation of NO or to hydroxylation of the substrate, contrary to reactions with BuGua or l -arg. Our results reveal how different structural and chemical properties of NOS substrate analogues can impact on the kinetics and reactivity of the FeIIO2 intermediate, and support an important role for substrate pKa during NOS oxygen activation. [source] A further study of factors affecting pneumatic-impact ignition of polymersFIRE AND MATERIALS, Issue 6 2006Fu-Yu Hshieh Abstract One likely cause of polymer ignition in high-pressure oxygen systems is the adiabatic-compression heating of polymers caused by pneumatic impact. The previous study showed that pneumatic-impact ignition of polymers could be initiated by a local heterogeneous reaction between the hot oxygen and the oxidation sites of the polymer. This study further investigates other factors that cause pneumatic-impact ignition of polymers in high-pressure oxygen. Because the oxygen concentration has a significant effect on pneumatic-impact ignition, threshold oxygen concentrations for pneumatic-impact ignition of six selected polymers were determined at 20.7 MPa (3000 psia), an expected service pressure in high-pressure oxygen systems. The six polymers investigated were: Teflon PTFE (polytetrafluoroethylene), Neoflon CTFE (polychlorotrifluoroethylene), PEEK (polyetheretherketone), Zytel 42 (nylon 6/6), Buna N (acrylonitrile butadiene rubber), and Viton A (copolymer of vinylidene fluoride and hexafluoropropylene). The results show that PEEK exhibited the highest threshold oxygen concentration (65%) and Zytel 42 exhibited the lowest threshold oxygen concentration (<21%). Copyright © 2006 John Wiley & Sons, Ltd. [source] Neoadjuvant chemotherapy for squamous cell carcinoma of the oral tongue in young adults: A case seriesHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 9 2005Erich M. Sturgis MD Abstract Background. Squamous cell carcinoma of the oral tongue (SCCOT) in the young population has emerged as a growing worldwide health problem. Standard therapies, consisting primarily of surgery with possible adjuvant radiotherapy, have resulted in only modest improvements in survival in recent decades, whereas the treatments for SCCOT continue to impair oral function. With the increased use and improved functional results of neoadjuvant chemotherapy in the treatment of squamous cell carcinoma of other upper aerodigestive tract sites, we have reviewed our experience with neoadjuvant chemotherapy in young patients with SCCOT. Methods. A retrospective review was conducted of all patients younger than 45 years (N = 49) with previously untreated SCCOT evaluated at a comprehensive cancer center from July 1995 to August 2001. Charts were reviewed to obtain demographic data, comorbidities, nutritional status, tumor status, treatment and response information, and follow-up data. Results. Fifteen patients were identified who received neoadjuvant chemotherapy with taxane-based regimens before undergoing glossectomy and neck dissection. Thirteen of these patients (87%) exhibited stage III or IV disease at presentation, and all exhibited at least a partial response at the primary site. Pathologically positive nodes were identified in only six patients (40%), although 13 (87%) had clinically or radiographically suspicious nodes at presentation. Adjuvant radiation therapy was administered to seven patients (47%). With a median follow-up of 39 months, no patient has had local or regional recurrence, although three patients (20%) have had distant metastases develop; one patient with an isolated distant metastasis was successfully salvaged with radiation. By comparison during the same period, 34 young adult patients with SCCOT were treated with surgery with or without postoperative radiotherapy but without the use of chemotherapy. Although these patients had lower T classifications (18% vs 67% T3/T4; p = .0007), incidence of nodal metastases (15% vs 87% N+; p < .0001), and overall disease stage (24% vs 87% stage III/IV; p < .0001) than the neoadjuvant chemotherapy group, the overall survival (82%), disease-specific survival (88%), and recurrence-free survival (82%) of the surgery-first group was similar to that of the neoadjuvant chemotherapy group (87%, 87%, and 80%, respectively). Conclusions. This retrospective investigation demonstrates that neoadjuvant chemotherapy with taxane-based regimens may play a role in the successful treatment of SCCOT in young adult patients. Ultimately, this treatment plan may lead to improved functional outcomes in young patients with SCCOT by allowing function-sparing surgery and avoiding postoperative radiotherapy, without sacrificing disease control and survival, but a prospective trial is needed. We have initiated a prospective clinical trial to further investigate the impact of neoadjuvant chemotherapy in patients younger than 50 with SCCOT. © 2005 Wiley Periodicals, Inc. Head Neck27: XXX,XXX, 2005 [source] Synthesis and Chemical Properties of Diacetylenes with Pyridinium and 4,4,-Bipyridinium GroupsHELVETICA CHIMICA ACTA, Issue 5 2010Isao Yamaguchi Abstract Diacetylenes (DAs) having a dipolar D- , -A structure (D=donor: amino group; ,=, -conjugation core; A=acceptor: pyridinium (Py) and bipyridinium (BPy) groups), i.e., 4 (APBPyDA) and 5 (APPyPyDA), or an A- , -A structure, i.e., 7 (DBPyDA) and 8 (PyDA(Cl)), were obtained by 1,:,1 and 1,:,2 reactions of 4,4,-(buta-1,3-diyne-1,4-diyl)bis[benzenamine] (APDA; 3) with 1-(2,4-dinitrophenyl)-1,-hexyl-4,4,-bipyridinium bromide chloride (1,:,1,:,1) (1), 1-(2,4-dinitrophenyl)-4-(pyridin-4-yl)pyridinium chloride (2), or 1-(2,4-dinitrophenyl)pyridinium chloride (6) (Schemes 1 and 2). The anion-exchange reactions of 8 with NaI and Li(TCNQ) (TCNQ,=2,2,-(cyclohexa-2,5-diene-1,4-diylidene)bis[propanedinitrile] radical ion (1,)) yielded the corresponding I, and TCNQ, salts 9 (PyDA(I)) and 10 (PyDA(TCNQ)). Compounds 10 and 4 exhibited a UV/VIS absorption due to a charge transfer between the TCNQ, and the pyridinium groups and a strong solute,solvent interaction of a dipolar solute molecule in the polar environment, respectively. Compounds 8,10 exhibited photoluminescence in solution, whereas 4 and 7 did not because of the presence of the 4,4,-bipyridinium quenching groups. Differential-scanning-calorimetry (DSC) measurements suggested that the DAs obtained in this study can be converted into poly(diacetylenes) by thermal polymerization. [source] Naproxen in heterocyclic chemistry: Novel syntheses of triazoles, triazolothiadiazines, triazolothiadiazoles, and triazolothiadiazepine bearing an asymmetric carbon atom and radiostability of the biologically active compoundsHETEROATOM CHEMISTRY, Issue 3 2002Y. A. Ammar Several s-triazoles 2, 7a, 10, 12; s-triazolo[3,4-b][1,3,4]thiadiazines (3,5); s-triazolo[3,4-b][1,3,4]thiadiazoles (6, 8, 11, 15); and s-triazolo[3,4-b][1,3,4]thiadiazepine (14) were synthesized starting from 2-(6-methoxy-2-naphthyl)propanoic acid (1) (Naproxen). The structures of the synthesized compounds were elucidated by elemental analyses and spectral data. Compounds 2, 5, 11, 12, 14, and 15 exhibited a remarkable antifungal activity compared with the standard fungicide Mycostatine. Radiosterilization of the biologically active compounds 2, 5, 11, and 14 in the dry state may prove to be applicable (retaining their structures unchanged up to 40 kGy). © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:199,206, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10019 [source] Presence of a cerebral factor showing summer-morph-producing hormone activity in the brain of the seasonal non-polyphenic butterflies Vanessa cardui, V. indica and Nymphalis xanthomelas japonica (Lepidoptera: Nymphalidae)INSECT SCIENCE, Issue 2 2009Ayuki Tanaka Abstract Three species of nymphalid butterflies, Vanessa cardui, V. indica and Nymphalis xanthomelas japonica, do not exhibit seasonal polyphenism in wing coloration. To determine whether seasonal non-polyphenic butterflies possess a cerebral factor affecting wing coloration, we used a Polygonia c-aureum female short-day pupal assay for detection of summer-morph-producing hormone (SMPH) activity in P. c-aureum. When 2% NaCl extracts of 25 brain-equivalents prepared from the pupal brains of V. cardui, V. indica or N. xanthomelas japonica were injected into Polygonia female short-day pupae, all recipients developed into summer-morph adults with dark-yellow wings, and the average grade score (AGS) of summer morphs showing SMPH activity was 3.8, 3.7 and 4.0, respectively. In contrast, when acetone or 80% ethanol extracts prepared from pupal brains were injected into Polygonia pupae, all recipients developed into autumn-morph adults with a dark-brown coloration and each exhibited an AGS of less than 0.5. Our results indicate that a cerebral factor showing SMPH activity is present in the pupal brain of seasonal non-polyphenic nymphalid butterflies, suggesting that a SMPH and cerebral factor showing SMPH activity occur widely among butterfly species. This finding will improve our understanding of the presence of cerebral factors showing interspecific actions of SHPH. [source] On the design of energy,momentum integration schemes for arbitrary continuum formulations.INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 15 2004Applications to classical, chaotic motion of shells Abstract The construction of energy,momentum methods depends heavily on three kinds of non-linearities: (1) the geometric (non-linearity of the strain,displacement relation), (2) the material (non-linearity of the elastic constitutive law), and (3) the one exhibited in displacement-dependent loading. In previous works, the authors have developed a general method which is valid for any kind of geometric non-linearity. In this paper, we extend the method and combine it with a treatment of material non-linearity as well as that exhibited in force terms. In addition, the dynamical formulation is presented in a general finite element framework where enhanced strains are incorporated as well. The non-linearity of the constitutive law necessitates a new treatment of the enhanced strains in order to retain the energy conservation property. Use is made of the logarithmic strain tensor which allows for a highly non-linear material law, while preserving the advantage of considering non-linear vibrations of classical metallic structures. Various examples and applications to classical and non-classical vibrations and non-linear motion of shells are presented, including (1) chaotic motion of arches, cylinders and caps using a linear constitutive law and (2) large overall motion and non-linear vibration of shells using non-linear constitutive law. Copyright © 2004 John Wiley & Sons, Ltd. [source] Competing kinetic pathways in the bromine addition to allylic ethers in 1,2-dichloroethane: Opposite temperature effectsINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 4 2007Alessandro Cecchi The kinetics of the electrophilic bromination of three allylic ethers in a nonprotic solvent, 1,2-dichloroethane, has been investigated. Two of them followed a prevalent second-order pathway, while the third one exhibited a classical, clean third order. The second-order pathway in the first two olefins is attributed to electrophilic assistance of the ethereal oxygen to the attacking bromine molecule. In the molecular bromination of 2,4- cis -dimethyl-8-oxabicyclo[3.2.1]-6-octen-3- cis -ol, opposite temperature dependences were found for the two different kinetic pathways. An exoergonic process for the second-order reaction was explained by the lesser stability of the bromiranium,bromide ionic intermediate, compared to the bromiranium,tribromide in the third-order profile. © 2007 Wiley Periodicals, Inc. 39: 197,203, 2007 [source] Solution and Thin-Film Aggregation Studies of Octasubstituted Dendritic PhthalocyaninesISRAEL JOURNAL OF CHEMISTRY, Issue 1 2009Casey A. Kernag The synthesis and solution and thin-film characterization of eight octasubstituted dendritic phthalocyanines (Pcs) and their zinc complexes are reported. The Pc chromophore was substituted in the 2,3,9,10,16,17,23,24-positions with three generations of benzylaryl ether dendrons with either a benzyl (3a-3c) or 3,5-di- t -butylbenzyl periphery (3d-3f). Visible spectra in solution (CH2Cl2 -EtOH mixtures, toluene, THF, dioxane, acetone, and EtOAc) indicated a varying degree of chromophore aggregation that depended on solvent, dendrimer generation, and whether the Pc was metallated. Variable-concentration visible spectroscopic studies were analyzed using a nonlinear least-squares fitting procedure giving Kd values. These values further quantitated the observations that the t -butyl-substituted den-drimers 3d-3f were all less prone to aggregation in solution than the unsubstituted dendrimers 3a-3c, with a monotonic decrease in Kd across the series 3a , 3b , 3c , 3d , 3e , 3f. Second-generation t -butyl-substituted dendrimer 3f showed little to no aggregation in all solvents studied. Thin-film studies indicated that the largest members of the two dendrimer groups, third-generation 3c and second-generation 3f, were largely monomeric as evidenced by split Q-bands, similar to that seen in dilute CH2Cl2 solution when deposited via spin-coating onto glass slides. The metallated zinc Pcs 4a-4f all exhibited significantly less tendency toward aggregation in both solution and thin-films than their unmetallated analogues. [source] The incidence of killer activity of non- Saccharomyces yeasts towards indigenous yeast species of grape must: potential application in wine fermentationJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2000N.A. Yap Fourteen killer yeasts were assayed for their ability to kill species of yeast that are commonly associated with fermenting grape must and wine. A total of 147 of a possible 364 killer-sensitive interactions were observed at pH 4·5. Of the killer yeasts studied, Pichia anomala NCYC 434 displayed the broadest killing range. At a pH value comparable with those of wine ferments, pH 3·5, the incidence of killer-sensitive interactions was reduced by 70% across all the yeasts. Williopsis saturnus var. mrakii CBS 1707 exhibited the broadest killing range at the lower pH, killing more than half of the tester strains. Intraspecific variation in sensitivity to killer yeasts was observed in all species where more than one strain was tested. Also, in strains of Pichia anomala, Kluyveromyces lactis and Pichia membranifaciens, the three species in which more than one killer yeast was analysed, intraspecific variation in killer activity was observed. [source] Comparison of cytotoxic and inflammatory responses of photoluminescent silicon nanoparticles with silicon micron-sized particles in RAW 264.7 macrophagesJOURNAL OF APPLIED TOXICOLOGY, Issue 1 2009Jonghoon Choi Abstract Photoluminescent silicon nanoparticles have a bright and stable fluorescence and are promising candidates for bio-imaging, cell staining and drug delivery. With increasing development of nanotechnology applications for biomedicine, an understanding of the potential toxicity of nanoparticles is needed to assess safety concerns for clinical applications. The objective of this study was to compare biological responses of silicon nanoparticles (SNs, 3 nm diameter) with silicon microparticles (SMs, ,100,3000 nm diameter) in cultured murine macrophages (RAW 264.7) using standard protocols for assessing cytotoxicity/cell viability and inflammatory responses developed for micron-sized particles. SNs and SMs were exposed to macrophages with and without addition of endotoxin lipopolysaccharide (LPS), a positive inducer of tumor necrosis factor-alpha (TNF- ,), interleukin 6 (IL-6), and nitric oxide (NO). Cytotoxicity was assayed using the dye exclusion and MTT assays. Cell supernatants were assayed for production TNF- ,, IL-6 and NO. SNs at concentrations ,20 µg ml,1 exhibited no cytotoxicity or inflammatory responses; however, SNs and SMs >20 and 200 µg ml,1, respectively, increased cytotoxicity compared with controls. SMs induced concentration-related increases in TNF- , and IL-6 production; in contrast, the production of these cytokines was shown to decrease with increasing concentrations of SNs. NO production was not induced by SNs or SMs alone. Fluorescence microscopy demonstrated that SNs were associated with the macrophages, either internalized or attached to cell membranes. In conclusion, evaluating differences in biological responses for nanoparticles compared with microparticles of the same material may help improve tests to assess biological responses of nanoparticles that may be used in biomedical applications. Copyright © 2008 John Wiley & Sons, Ltd. [source] Bone marrow changes in adolescent girls with anorexia nervosaJOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2010Kirsten Ecklund Abstract Early osteoporosis is common among adolescent girls with anorexia nervosa (AN) and may result from premature conversion of red (RM) to yellow bone marrow. We performed right knee magnetic resonance imaging (MRI) on a 1.0 T extremity scanner in 20 patients and 20 healthy controls, aged 16.2,±,1.6 years (mean,±,SD). Coronal T1 -weighted (T1W) images and T1 maps were generated from T1 relaxometry images. Blinded radiologists visually assessed RM in the distal femoral and proximal tibial metaphyses in T1W images using a scale of signal intensity from 0 (homogeneous hyperintensity, no RM) to 4 (all dark, complete RM). Subjects with AN exhibited nearly twofold lower metaphyseal RM scores in both the femur (0.64 versus 1.22, p,=,.03) and tibia (0.54 versus 0.96, p,=,.08). In relaxometric measurements of four selected regions (femur and tibia amd epiphysis and metaphysis), subjects with AN showed higher mean epiphyseal but lower metaphyseal T1. The net AN-control difference between epiphysis and metaphysis was 70,ms in the femur (+31 versus ,35,ms, p,=,.02) and of smaller magnitude in the tibia. In relaxometry data from the full width of the femur adjacent to the growth plate, AN subjects showed mean T1 consistently lower than in controls by 30 to 50,ms in virtually every part of the sampling region. These findings suggest that adolescents with AN exhibit premature conversion of hematopoietic to fat cells in the marrow of the peripheral skeleton potentially owing to adipocyte over osteoblast differentiation in the mesenchymal stem cell pool. © 2010 American Society for Bone and Mineral Research [source] Expression of phospholipase C beta family isoenzymes in C2C12 myoblasts during terminal differentiation,JOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2004Irene Faenza In the present work, we have analyzed the expression and subcellular localization of all the members of inositide-specific phospholipase C (PLC,) family in muscle differentiation, given that nuclear PLC,1 has been shown to be related to the differentiative process. Cell cultures of C2C12 myoblasts were induced to differentiate towards the phenotype of myotubes, which are also indicated as differentiated C2C12 cells. By means of immunochemical and immunocytochemical analysis, the expression and subcellular localization of PLC,1, ,2, ,3, ,4 have been assessed. As further characterization, we investigated the localization of PLC, isoenzymes in C2C12 cells by fusing their cDNA to enhanced green fluorescent protein (GFP). In myoblast culture, PLC,4 was the most expressed isoform in the cytoplasm, whereas PLC,1 and ,3 exhibited a lesser expression in this cell compartment. In nuclei of differentiated myotube culture, PLC,1 isoform was expressed at the highest extent. A marked decrease of PLC,4 expression in the cytoplasm of differentiated C2C12 cells was detected as compared to myoblasts. No relevant differences were evidenced as regards the expression of PLC,3 at both cytoplasmatic and nuclear level, whilst PLC,2 expression was almost undetactable. Therefore, we propose that the different subcellular expression of these PLC isoforms, namely the increase of nuclear PLC,1 and the decrease of cytoplasmatic PLC,4, during the establishment of myotube differentiation, is related to a spatial-temporal signaling event, involved in myogenic differentiation. Once again the subcellular localization appears to be a key step for the diverse signaling activity of PLC,s. © 2004 Wiley-Liss, Inc. [source] Novel 2-hydrazino-pyrimidin-4(3H)-one derivatives as potential dihydrofolate reductase inhibitorsJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2010Mariam S. Degani Novel substituted 2-hydrazino-pyrimidin-4(3H)-one derivatives were synthesized and examined for their antifolate activity against DHFR from Pneumocystis carinii (pc), Toxoplasma gondii (tg), Mycobacterium avium (ma), and rat liver (rl). A novel, simple, and feasible methodology was developed for the synthesis of the titled compounds. Amongst these, compound 8 6-phenyl-2-(2-(1-(thiophen-2-yl) ethylidene)hydrazinyl) pyrimidin-4(3H)-one exhibited 17.74 ,M activity against pcDHFR. J. Heterocyclic Chem., (2010). [source] Novel 3-benzoyl-2-piperazinylquinoxaline derivatives as potential antitumor agentsJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2006Sandra Piras A series of new benzoylquinoxaline derivatives (7-26) was synthesized and evaluated for antitumor activity against a panel of 60 human cell lines at the NCI of Bethesda. Among the compounds which have passed the preliminary screening, compound 23 exhibited the best profile and growth inhibition activity at 100 - 10 ,M. The compounds were then tested towards a folate-dependent enzymes bio-library including Thymidylate synthases enzymes and human Dihydrofolate reductase at 10 ,M. The most of compounds exhibited a moderate inhibitory activity towards all or some of the enzymes tested with detectable inhibition constants (Ki) values in the range of 0.6-70 ,M. Compounds 21, 23, 24 showed Ki in the range of 10-38 ,M against both hDHFR and hTS. [source] Synthesis and 11C-labelling of (E,E)-1-(3,,4,-dihydroxystyryl)-4-(3,-methoxy-4,-hydroxystyryl) benzene for PET imaging of amyloid deposits,,JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 8 2002Yanming Wang Abstract Carboxylic acid derivatives of the amyloid-binding dye Congo red do not enter the brain well and are thus unable to serve as in vivo amyloid-imaging agents. A neutral amyloid probe, (E,E)-1-(3,,4,-dihydroxystyryl)-4-(3,-methoxy-4,-hydroxystyryl)benzene (3), devoid of any carboxylate groups has been designed and synthesized via a 12-step reaction sequence with a total yield of 30%. The unsymmetric compound 3 has also been labelled with C-11 via [11C]methyl iodide ([11C]CH3I) methylation of a symmetric 4,4,-dimesyl protected precursor followed by deprotection. Preliminary evaluation indicated that compound 3 selectively stained plaques and neurofibrillary tangles in post-mortem AD brain, and exhibited good binding affinity (Ki=38±8 nM) for A,(1,40) fibrils in vitro. In vivo pharmacokinetic studies indicated that [11C]3 exhibited higher brain uptake than its carboxylic acid analogs and good clearance from normal control mouse brain. [11C]3 also exhibited specific in vivo binding to pancreatic amyloid deposits in the NOR-beta transgenic mouse model. These results justify further investigation of 3 and similar derivatives as surrogate markers for in vivo quantitation of amyloid deposits. Copyright © 2002 John Wiley & Sons, Ltd. [source] Recombinant newcastle disease virus capsids displaying enterovirus 71 VP1 fragment induce a strong immune response in rabbitsJOURNAL OF MEDICAL VIROLOGY, Issue 8 2006Lalita Ambigai Sivasamugham Abstract The complete VP1 protein of EV71 was truncated into six segments and fused to the C-terminal ends of full-length nucleocapsid protein (NPfl) and truncated NP (NPt; lacks 20% amino acid residues from its C-terminal end) of newcastle disease virus (NDV). Western blot analysis using anti-VP1 rabbit serum showed that the N-terminal region of the VP1 protein contains a major antigenic region. The recombinant proteins carrying the truncated VP1 protein, VP11,100, were expressed most efficiently in Escherichia coli as determined by Western blot analysis. Electron microscopic analysis of the purified recombinant protein, NPt-VP1,100 revealed that it predominantly self-assembled into intact ring-like structures whereas NPfl-VP1,100 recombinant proteins showed disrupted ring-like formations. Rabbits immunized with the purified NPt-VP1,100 and NPfl-VP1,100 exhibited a strong immune response against the complete VP1 protein. The antisera of these recombinant proteins also reacted positively with authentic enterovirus 71 and the closely related Coxsackievirus A16 when analyzed by an immunofluorescence assay suggesting their potential as immunological reagents for the detection of anti-enterovirus 71 antibodies in serum samples. J. Med. Virol. 78:1096,1104, 2006. © 2006 Wiley-Liss, Inc. [source] Solid-Based Hydrothermal Synthesis and Characterization of Alumina Nanofibers with Controllable Aspect RatiosJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2009Shou-Cang Shen Nanofibers of AlOOH with controllable aspect ratios have been synthesized by a facile steam-assisted solid-phase crystallization route. The morphology and aspect ratios of resulting AlOOH nanofibers were significantly influenced by the alkaline medium used in the preparation of solid precipitates from Al(NO3)3 solution. When tetramethylammonium hydroxide was used for precipitation, straight rod-like nanofibers with aspect ratios of 10,20 were obtained. The use of other tetra-alkylated ammonium hydroxides, such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide or tetrabutylammonium hydroxide, led to the formation of long wire-like nanofibers with aspect ratios up to 150. After thermal treatment at 600°C, the morphologies of the one-dimensional nanostructures were well preserved while the crystal structure was converted to ,-alumina. The wire-like nanofibers of alumina possessed higher thermal stability than alumina nanorods, and both exhibited much higher stability as compared with alumina micropowder. [source] Fabrication of Thick (>10 ,m) GeO2 Ceramic Films by a Facile Liquid Phase Deposition ProcessJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2007Chengbin Jing GeO2 thick (>10 ,m) ceramic films were fabricated by facile liquid-phase deposition. The solubility of hexagonal GeO2 in water was increased ten times on adding aqueous ammonia at 70°C because of the formation of soluble Ge5O112,. With the addition of sulfuric acid, the alkaline GeO2,aqueous ammonia was neutralized, leading to the transformation of Ge5O112, into GeO2 precipitates. When the H2SO4/NH4OH molar ratio was higher than 11.7, immediate precipitation of GeO2 particles took place in the solution with no GeO2 particles deposited on the substrate. When the H2SO4/NH4OH molar ratio was decreased from 5.85 to 0.29, the precipitation process was retarded, leading to the gradual growth of uniform hexagonal GeO2 thick films on the substrates. The compactness of the film increased with a decrease in the H2SO4/NH4OH molar ratio. The growth of the GeO2 crystal film followed the Bravais,Freidel,Donnay,Harker and Hartman,Perdok models, and the cubic GeO2 particles with a size of about 10 ,m were finally formed on the film. No GeO2 precipitate was produced on the substrate when the GeO2,aqueous ammonia had an excessively low H2SO4/NH4OH molar ratio (,0.15) because the GeO2 solute did not reach the saturation level and the nucleation process could not take place on the substrate. The particles on the film surface deposited from the solution with an H2SO4/NH4OH molar ratio of 0.29 exhibited a nanopore structure. An initial study using this film as a support for KNO3 catalyst was carried out and the result revealed that the catalyst showed good catalytic activity of diesel soot oxidation. [source] Plot shape effects on plant species diversity measurementsJOURNAL OF VEGETATION SCIENCE, Issue 2 2005Jon E. Keeley Abstract. Question: Do rectangular sample plots record more plant species than square plots as suggested by both empirical and theoretical studies? Location: Grasslands, shrublands and forests in the Mediterranean-climate region of California, USA. Methods: We compared three 0.1-ha sampling designs that differed in the shape and dispersion of 1-m2 and 100-m2 nested subplots. We duplicated an earlier study that compared the Whittaker sample design, which had square clustered subplots, with the modified Whittaker design, which had dispersed rectangular subplots. To sort out effects of dispersion from shape we used a third design that overlaid square subplots on the modified Whittaker design. Also, using data from published studies we extracted species richness values for 400-m2 subplots that were either square or 1:4 rectangles partially overlaid on each other from desert scrub in high and low rainfall years, chaparral, sage scrub, oak savanna and coniferous forests with and without fire. Results: We found that earlier empirical reports of more than 30% greater richness with rectangles were due to the confusion of shape effects with spatial effects, coupled with the use of cumulative number of species as the metric for comparison. Average species richness was not significantly different between square and 1:4 rectangular sample plots at either 1- or 100-m2. Pairwise comparisons showed no significant difference between square and rectangular samples in all but one vegetation type, and that one exhibited significantly greater richness with squares. Our three intensive study sites appear to exhibit some level of self-similarity at the scale of 400 m2, but, contrary to theoretical expectations, we could not detect plot shape effects on species richness at this scale. Conclusions: At the 0.1-ha scale or lower there is no evidence that plot shape has predictable effects on number of species recorded from sample plots. We hypothesize that for the mediterranean-climate vegetation types studied here, the primary reason that 1:4 rectangles do not sample greater species richness than squares is because species turnover varies along complex environmental gradients that are both parallel and perpendicular to the long axis of rectangular plots. Reports in the literature of much greater species richness recorded for highly elongated rectangular strips than for squares of the same area are not likely to be fair comparisons because of the dramatically different periphery/area ratio, which includes a much greater proportion of species that are using both above and below-ground niche space outside the sample area. [source] Prediction of significant liver fibrosis in kidney transplant patients with chronic hepatitis C virus infection: the TX-3 indexJOURNAL OF VIRAL HEPATITIS, Issue 6 2010L. L. Schiavon Summary., HCV infection is highly prevalent among kidney transplant (KT) recipients. The natural history and management of these patients are controversial. We sought to assess the diagnostic value of noninvasive markers of liver fibrosis in KT HCV-infected patients. This cross-sectional study included 102 KT individuals with positive HCV-RNA. Bivariate and multivariate analyses were used to identify variables associated with significant fibrosis (METAVIR , F2). Significant fibrosis was observed in 20 patients (20%). Time after transplantation, AST level, and platelet count were identified as independent predictors of significant fibrosis. Based on the regression model, a simplified index was devised. The AUROC for the TX-3 model was 0.867 ± 0.081 (0.909, when adjusted by DANA). Values ,4.0 of TX-3 showed a NPV of 97% and scores >9.6 exhibited a PPV of 71%. If biopsy indication was restricted to scores in the intermediate range of TX-3, this could have been correctly avoided in 68% of cases. The APRI score provided a correct diagnosis in only 47 individuals (46%) and exhibited lower diagnostic indices for both cutoffs, as compared to the TX-3 index. Comparison of AUROCs showed a trend towards superior diagnostic accuracy for TX-3 over APRI, although the difference between AUROCs did not reach statistical significance (0.867 ± 0.053 vs 0.762 ± 0.066, respectively, P = 0.064). In conclusion, significant liver fibrosis can be reliably predicted in KT HCV-infected subjects by simple and widely available parameters. If additional studies confirm our results, this model might obviate the requirement for a liver biopsy in a significant proportion of those patients. [source] The linkage disequilibrium between chloroplast DNA and mitochondrial DNA haplotypes in Beta vulgaris ssp. maritima (L.): the usefulness of both genomes for population genetic studiesMOLECULAR ECOLOGY, Issue 2 2000B. Desplanque Abstract The structure and evolution of the plant mitochondrial genome may allow recurrent appearance of the same mitochondrial variants in different populations. Whether the same mitochondrial variant is distributed by migration or appears recurrently by mutation (creating homoplasy) in different populations is an important question with regard to the use of these markers for population genetic analyses. The genetic association observed between chloroplasts and mitochondria (i.e. two maternally inherited cytoplasmic genomes) may indicate whether or not homoplasy occurs in the mitochondrial genome. Four-hundred and fourteen individuals sampled in wild populations of beets from France and Spain were screened for their mitochondrial and chloroplast polymorphisms. Mitochondrial DNA (mtDNA) polymorphism was investigated with restriction fragment length polymorphism (RFLP) and chloroplast DNA (cpDNA) polymorphism was investigated with polymerase chain reaction PCR,RFLP, using universal primers for the amplification. Twenty and 13 variants for mtDNA and cpDNA were observed, respectively. Most exhibited a widespread geographical distribution. As a very strong linkage disequilibrium was estimated between mtDNA and cpDNA haplotypes, a high rate of recurrent mutation was excluded for the mitochondrial genome of beets. Identical mitochondrial variants found in populations of different regions probably occurred as a result of migration. We concluded from this study that mtDNA is a tool as valuable as cpDNA when a maternal marker is needed for population genetics analyses in beet on a large regional scale. [source] Cross-amplification of polymorphic microsatellites reveals extra-pair paternity and brood parasitism in Sturnus vulgarisMOLECULAR ECOLOGY RESOURCES, Issue 1 2005A. LOYAU Abstract We tested the cross-amplification of 37 microsatellites in a population of starlings (Sturnus vulgaris). Twenty-three of them amplified and five exhibited a large number of alleles per locus and high heterozygosity (on average: 14.6 alleles/locus and HE = 0.704). We assessed the occurrence of extra-pair paternity (EPP) and intraspecific brood parasitism (IBP) in this population. The EPP rate was 16% to 18% offspring from 43% to 45% of nests. IBP was very variable between two successive years (14% to 27% chicks from 25% to 64% of clutches). These five polymorphic markers will be of potential use in studies of genetic diversity, population structure and reproductive strategy of this species. [source] EmtA, a rRNA methyltransferase conferring high-level evernimicin resistanceMOLECULAR MICROBIOLOGY, Issue 6 2001Paul A. Mann Enterococcus faecium strain 9631355 was isolated from animal sources on the basis of its resistance to the growth promotant avilamycin. The strain also exhibited high-level resistance to evernimicin, a drug undergoing evaluation as a therapeutic agent in humans. Ribosomes from strain 9631355 exhibited a dramatic reduction in evernimicin binding, shown by both cell-free translation assays and direct-binding assays. The resistance determinant was cloned from strain 9631355; sequence alignments suggested it was a methyltransferase and therefore it was designated emtA for evernimicin methyltransferase. Evernimicin resistance was transmissible and emtA was localized to a plasmid-borne insertion element. Purified EmtA methylated 50S subunits from an evernimicin-sensitive strain 30-fold more efficiently than those from a resistant strain. Reverse transcription identified a pause site that was unique to the 23S rRNA extracted from resistant ribosomes. The pause corresponded to methylation of residue G2470 (Escherichia coli numbering). RNA footprinting revealed that G2470 is located within the evernimicin-binding site on the ribosome, thus providing an explanation for the reduced binding of the drug to methylated ribosomes. [source] O3 impacts on plant development: a meta-analysis of root/shoot allocation and growthPLANT CELL & ENVIRONMENT, Issue 7 2006D. A. GRANTZ ABSTRACT The mechanism of O3 action on plants remains poorly characterized. Symptoms include visible lesions on the leaf surface, reduced growth and a hypothesized reduction in allocation of carbohydrate to roots. The generality of this latter phenomenon has not been demonstrated. Here, a meta-analysis is performed of all available experimental data, to test the hypotheses that O3 exposure of the shoot inhibits biomass allocation below ground (the root/shoot allometric coefficient, k) and inhibits whole-plant growth rate [relative growth rate (RGR)]. Both k and RGR were significantly reduced by O3 (5.6 and 8.2%, respectively). Variability in k was greater than in RGR, and both exhibited some positive as well as mostly negative responses. The effects on k were distinct from the effects on RGR. In some cases, k was reduced while RGR was unaffected. Slow-growing plants (small RGR) exhibited the largest declines in k. These observations may have mechanistic implications regarding O3 phytotoxicity. There were no effects of type of exposure chamber on sensitivity to O3. The analyses indicate that the O3 inhibition of allocation to roots is real and general, but variable. Further experiments are needed for under-represented plant groups, to characterize exceptions to this generalization and to evaluate O3,environment interactions. [source] Clinicopathological features of chronic hypersensitivity pneumonitisRESPIROLOGY, Issue 4 2002HIROSHI HAYAKAWA Objective: Only limited information exists concerning the clinical and pathological features of chronic hypersensitivity pneumonitis (HP) in Japan and elsewhere. We present data on clinicopathological features of chronic HP obtained through a Japanese nationwide survey. Methodology: We studied the clinical and pathological findings in 10 patients with chronic HP who underwent surgical lung biopsy or postmortem examination. Results: There were three types of clinical course: six of the 10 patients had persistent symptoms followed by repeated acute episodes; two showed a subacute onset with persistent symptoms; and two exhibited an insidious onset. Five patients made no attempt to avoid antigen exposure and they all had progressive disease. Pathological findings indicated that lesions were mainly centrilobular with or without epithelioid cell granulomas in specimens obtained during the acute or subacute stage. In contrast, most patients in the chronic stage predominantly showed interstitial fibrosis with a usual interstitial pneumonia pattern. Conclusions: The pathological findings of chronic HP depend on the stage of the disease at tissue sampling. [source] | ||||||||||||||||||||||||||||||||||||||||