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Terms modified by Alternate Selected AbstractsStep-by-Step Build-Up of Biologically Active Cell-Containing Stratified Films Aimed at Tissue EngineeringADVANCED MATERIALS, Issue 6 2009Laurent Grossin Alginate gel layers containing viable cells with adjacent bioactive polyelectrolyte multilayers are fabricated, and their bioactivity is shown to originate mainly from the degradation of the cells. Alternate biofunctionalized multilayers and cell-containing layers are shown to be an essential step toward fabrication of stratified architectures, and tuning the cellular activity is possible by controlling the position of active molecules. [source] Nicotinic acetylcholine receptor structure and function in the efferent auditory systemTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 4 2006Lawrence R. Lustig Abstract This article reviews and presents new data regarding the nicotinic acetylcholine receptor subunits ,9 and ,10. Although phylogentically ancient, these subunits have only recently been identified as critical components of the efferent auditory system and medial olivocochlear pathway. This pathway is important in auditory processing by modulating outer hair cell function to broadly tune the cochlea and improve signal detection in noise. Pharmacologic properties of the functionally expressed ,9,10 receptor closely resemble the cholinergic response of outer hair cells. Molecular, immunohistochemical, and knockout mice studies have added further weight to the role this receptor plays in mediating the efferent auditory response. Alternate and complementary mechanisms of outer hair cell efferent activity might also be mediated through the nAChR ,9,10, either through secondary calcium stores, second messengers, or direct protein-protein interactions. We investigated protein-protein interactions using a yeast-two-hybrid screen of the nAChR ,10 intracellular loop against a rat cochlear cDNA library. Among the identified proteins was prosaposin, a precursor of saposins, which have been shown to act as neurotrophic factors in culture, can bind to a putative G0-coupled cell surface receptor, and may be involved in the prevention of cell death. This study and review suggest that nAChR ,9,10 may represent a potential therapeutic target for a variety of ear disorders, including preventing or treating noise-induced hearing loss, or such debilitating disorders as vertigo or tinnitus. Anat Rec Part A, 2006. © 2006 Wiley-Liss, Inc. [source] Islet Allograft Rejection by Contact-Dependent CD8+ T cells: Perforin and FasL Play Alternate but Obligatory Roles,AMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2007M. Sleater Though CD8+ T lymphocytes are important cellular mediators of islet allograft rejection, their molecular mechanism of rejection remains unidentified. Surprisingly, while it is generally assumed that CD8+ T cells require classic cytotoxic mechanisms to kill grafts in vivo, neither perforin nor FasL (CD95L) are required for acute islet allograft rejection. Thus, it is unclear whether such contact-dependent cytotoxic pathways play an essential role in islet rejection. Moreover, both perforin and CD95L have been implicated in playing roles in peripheral tolerance, further obscuring the role of these effector pathways in rejection. Therefore, we determined whether perforin and/or FasL (CD95L) were required by donor MHC-restricted (,direct') CD8+ T cells to reject islet allografts in vivo. Islet allograft rejection by primed, alloreactive CD8+ T cells was examined independently of other lymphocyte subpopulations via adoptive transfer studies. Individual disruption of T-cell-derived perforin or allograft Fas expression had limited impact on graft rejection. However, simultaneous disruption of both pathways prevented allograft rejection in most recipients despite the chronic persistence of transferred T cells at the graft site. Thus, while there are clearly multiple cellular pathways of allograft rejection, perforin and FasL comprise alternate and necessary routes of acute CD8+ T-cell-mediated islet allograft rejection. [source] Imidazolium based ionic liquid crystals: structure, photophysical and thermal behaviour of [Cnmim]Br·xH2O (n = 12, 14; x=0, 1)CRYSTAL RESEARCH AND TECHNOLOGY, Issue 11 2008A. Getsis Abstract The long chain imidazolium halides [Cnmim]Br·xH2O (n = 10, 12; x = 0, 1) have been synthesized and their structural and thermal behaviour together with their photophysical properties characterized. X-ray structure analyses of the monohydrates ([C12mim]Br·H2O: triclinic, P1, no. 2, Z = 2, Pearson code aP112, a = 550.0(5) pm, b = 779.4(5) pm, c = 2296.1(5) pm, , = 81.89(5)°, , = 83.76(5)°, , = 78.102(5)°, 3523 unique reflections with Io > 2,(Io), R1 = 0.0263, wR2 = 0.0652, GooF = 1.037, T = 263(2) K; [C14mim]Br,H2O: triclinic, P1, no. 2, Z = 12, Pearson code aP11, a = 549.86(8) pm, 782.09(13) pm, c = 2511.3(4) pm, , = 94.86(2)°, , = 94.39(2)°, , = 101.83(2)°, 2063 unique reflections with Io > 2,(Io), R1 = 0.0429, wR2 = 0.0690, GooF = 0.770, T = 293(2) K) show for both compounds similar bilayered structures. Sheets composed of hydrophilic structure regions constituted by positively charged imidazolium head groups, bromide anions and hydrogen bonded water alternate with hydrophobic areas formed by interdigitated long alkyl chains belonging to imidazolium cations with different orientation. Combined differential scanning calorimetry and polarizing optical microscopy shows that the monohydrates as well as the anhydrous imidazolium salts are thermotropic liquid crystals which adopt smectic mesophases. The mesophase region is larger in case of the monohydrates when compared to the anhydrous compounds indicating that water obviously stabilizes the mesophase. All compounds show an intense whitish photoluminescence with short lived (1,,1,*) and long lived (1,,3,*) transitions. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Utility of esophageal biopsy in the diagnosis of nonerosive reflux diseaseDISEASES OF THE ESOPHAGUS, Issue 3 2003R. I. Narayani SUMMARY This study evaluated the accuracy of esophageal biopsy for the diagnosis of nonerosive reflux disease (NERD) in adults. Thirty-five patients with reflux symptoms and a normal endoscopy were prospectively evaluated using esophageal biopsies, 24-h ambulatory pH monitoring and symptomatic response 4 weeks after an increase in antireflux therapy. Biopsies were scored for the total number of typical histologic reflux features seen. Patients were considered to have NERD if both pH-metry was positive and step-up therapy was successful. Biopsies were then compared to this predefined gold standard. Biopsy was most sensitive (62%) but poorly specific (27%) when one or more histologic reflux features were seen. A threshold of three or more histologic features improved the specificity (91%) but reduced sensitivity (31%). Response to step-up therapy was associated with 100% sensitivity and 100% negative predictive value when compared to biopsy and pH-metry as an alternate combined gold standard. In conclusion, biopsy is insensitive in diagnosing NERD but reasonably specific if three or more typical histologic reflux features are present. [source] Caloric restriction for longevity: I. Paradigm, protocols and physiological findings in animal researchEUROPEAN EATING DISORDERS REVIEW, Issue 5 2004Kelly M. Vitousek Abstract The initial article in this series reviews basic findings in the field of caloric restriction for longevity (CRL). To eating disorder specialists, the data are disconcerting. The chronic dieting and subnormal weight we endeavour to prevent and treat in humans appear highly beneficial when imposed on animals. In the laboratory, organisms from nematodes to monkeys thrive when forced to undereat, as long as they receive sufficient micronutrients. The most remarkable results are obtained through the most extreme measures: mice, for example, do best if limited to a third of expected caloric intake, beginning soon after weaning and continuing throughout adulthood. Deprivation can be achieved through an ,anorexic' protocol of steady underconsumption or a ,bulimic' pattern in which periods of fasting alternate with bouts of binge eating. The benefits of such regimens include delayed senescence, postponement and/or attenuation of age-related disease and dramatic increases in average and maximum lifespan. Although some biological functions are impaired (including growth, reproduction and perhaps resistance to certain stressors), the cost/benefit ratio clearly favours CRL when calculated on the basis of physical outcomes in late age. Advocacy of comparable regimens for people, however, is ill-considered. Enthusiasm for CRL can be sustained only by detaching deprivation from the context of daily life, ignoring psychological effects, and dismissing data on human semi-starvation and eating disorders. The experiences of participants in Biosphere 2 and individuals with anorexia nervosa suggest that the price of CRL is unacceptably high when a wider range of outcome variables is examined. Copyright © 2004 John Wiley & Sons, Ltd and Eating Disorders Association. [source] Tetracyanoquinodimethanido Derivatives of (Terpyridine)- and (Phenanthroline)metal Complexes , Structural and Magnetic Studies of Radical-Ion SaltsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2005Cristina Alonso Abstract Several derivatives of formulae [M(terpy)2](TCNQ)2 or [M(terpy)2](TCNQ)3 (M = Ni, Cu, Zn; terpy = 2,2,:6,,2"-terpyridine; TCNQ= 7,7,8,8-tetracyanoquinodimethane) and [M(phen)3](TCNQ)2 or [M(phen)3](TCNQ)4 (M = Fe, Ni; phen = 1,10-phenanthroline) have been obtained. The crystal structures of [M(terpy)2](TCNQ)2 (M = Ni, Cu) show that the metal is surrounded by the terpyridine nitrogen atoms in a closed octahedral environment and the TCNQ anions are dimerised by , overlap. The cationic [M(terpy)2]2+ and the anionic [TCNQ]22, groups alternate in the crystal. For the derivatives with three TCNQ groups, the existence of a stack of trimeric [TCNQ]32, ions having electronic delocalisation is proposed. The compound [Fe(phen)3](TCNQ)2, which shows a strong interaction between TCNQ anions, led to the formation of a , bond in the diamagnetic species [TCNQ,TCNQ], while the nickel analogue is expected to have a localised structure formed by alternation of cationic metal complexes and dimeric [TCNQ]22, anions similar to those observed in the analogous terpy derivatives. The derivatives having four TCNQ groups also show electronic delocalisation and a 1D stack based on the magnetic data is proposed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Neuroanatomical correlates of the near response: voluntary modulation of accommodation/vergence in the human visual systemEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2000Hans O. Richter Abstract This study identifies brain regions participating in the execution of eye movements for voluntary positive accommodation (VPA) during open-loop vergence conditions. Neuronal activity was estimated by measurement of changes in regional cerebral blood flow (rCBF) with positron emission tomography and 15O-water. Thirteen naive volunteers viewed a checkerboard pattern with their dominant right eye, while a lens interrupted the line of gaze during alternate 1.5 s intervals. Three counterbalanced tasks required central fixation and viewing of a stationary checkerboard pattern: (i) through a 0.0 diopter (D) lens; (ii) through a ,5.0-D lens while avoiding volitional accommodation and permitting blur; and (iii) through a ,5.0-D lens while maintaining maximal focus. The latter required large-amplitude, high-frequency VPA. As an additional control, seven of the subjects viewed passively a digitally blurred checkerboard through a 0.0-D lens as above. Optometric measurements confirmed normal visual acuity and ability to perform the focusing task (VPA). Large-amplitude saccadic eye movements, verified absent by electro-oculography, were inhibited by central fixation. Image averaging across subjects demonstrated multifocal changes in rCBF during VPA: striate and extrastriate visual cortices; superior temporal cortices; and cerebellar cortex and vermis. Decreases in rCBF occurred in the lateral intraparietal area, prefrontal and frontal and/or supplementary eye fields. Analysis of regions of interest in the visual cortex showed systematic and appropriate task dependence of rCBF. Activations may reflect sensorimotor processing along the reflex arc of the accommodation system, while deactivations may indicate inhibition of systems participating in visual search. [source] Synthesis and Conformation Analysis of New Perphosphorylated Calix[4]resorcinarenesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 23 2004Vera I. Maslennikova Abstract The octaphosphorylation of calix[4]resorcinarenes 1 by 2-dialkylamino-1,3,2-diheterophosphorinanes 2 is described, and the effect of different factors on the structures of the resulting perphosphorylated products 3,5 was studied. Conformation analysis of these compounds by correlated 2D NMR spectroscopy and X-ray diffraction analysis was performed, and it was found that compounds 3,5, like the initial resorcinarenes 1, each have the all - cis configuration of the R groups in the methylidene bridges of the calixarene system, but different orientations of benzene rings and phosphorinane fragments with respect to one another and to the macrocycle plane. Perphosphorylated resorcinarenes 3a,c, 4a and 5a with R = alkyl exist in flattened cone conformations with the phosphorinane fragments on the same side of the macrocycle plane. The conformations of the perphosphorylated resorcinarenes 3d, 4b and 5b with R = Ph change to forms intermediate between flattened cone and 1,3 - alternate. The phosphorus fragments in these compounds are located on opposite sides of the macrocycle plane. It was shown that the oxidation and sulfurisation of phosphocalixarenes 3 proceed without any change in the spatial organisation of the macrocyclic system. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Synthesis of the Cyclopentyl Nucleoside (,)-Neplanocin A from D -Glucose via Zirconocene-Mediated Ring ContractionHELVETICA CHIMICA ACTA, Issue 6 2005Two approaches for the conversion of d- glucose to (,) -neplanocin A (2), both based on the zirconocene-promoted ring contraction of a vinyl-substituted pyranoside, are herein evaluated (Scheme,1). In the first pathway (Scheme,2), the substrate possesses the , - d- allo configuration (see 6) such that ultimate introduction of the nucleobase would require only an inversion of configuration. However, this precursor proved unresponsive to Cp2Zr (=[ZrCl2(Cp)2]), an end result believed to be a consequence of substantive nonbonded steric effects operating in a key intermediate (Scheme,5). In contrast, the C(2) epimer (see 7) experienced the desired metal-promoted conversion to an enantiomerically pure polyfunctional cyclopentane (see 5 in Scheme,3). The substituents in this product are arrayed in a manner such that conversion to the target nucleoside can be conveniently achieved by a double-inversion sequence (Scheme,4). Recourse to palladium(0)-catalyzed allylic alkylation did not provide an alternate means of generating 2. [source] MOF,Graphite Oxide Composites: Combining the Uniqueness of Graphene Layers and Metal,Organic FrameworksADVANCED MATERIALS, Issue 46 2009Camille Petit Nanocomposites containing graphite oxide (GO) and metal,organic frameworks (MOFs) are prepared. They have a well-defined structure, in which graphene layers from GO alternate with layers of MOF via linkages between epoxy groups from GO and zinc oxide from the MOF (see image). The enhanced porosity and dispersive forces of the composites compared to the precursors provide views for applications in gas adsorption. [source] BRCA1-IRIS activates cyclin D1 expression in breast cancer cells by downregulating the JNK phosphatase DUSP3/VHRINTERNATIONAL JOURNAL OF CANCER, Issue 1 2007Lu Hao Abstract Cyclin D1 plays an important role in cell cycle progression. In breast cancer, Cyclin D1 expression is deregulated by several mechanisms. We previously showed that in breast cancer cells, overexpression of BRCA1-IRIS induces Cyclin D1 overexpression and increases cell proliferation. BRCA1-IRIS alone or in complex with steroid receptor co-activators was targeted to the cyclin D1 promoter pre-bound by the c-Jun/AP1 and activated its transcription, which could explain the co-overexpression of BRCA1-IRIS and Cyclin D1 in breast cancer cells coupled with their increased proliferation. We report here an alternate or a complementary pathway by which BRCA1-IRIS activates Cyclin D1 expression. BRCA1-IRIS overexpression decreases the expression of the dual specificity phosphatase, DUSP3/VHR, an endogenous inhibitor of several MAPKs, including c-Jun N-terminal kinase. Although, the mechanism by which BRCA1-IRIS overexpression accomplishes that is not yet known, it is sufficient to induce Cyclin D1 overexpression in a human mammary epithelial cell model. Cyclin D1 overexpression could be blocked by co-overexpression of VHR in those cells. Furthermore, in 2 breast cancer cell lines that overexpress both BRCA1-IRIS and Cyclin D1 (MCF-7 and SKBR3) depletion of BRCA1-IRIS by RNA interference attenuated the expression of Cyclin D1 by elevating the expression level of VHR. These data demonstrate a critical role for BRCA1-IRIS in human breast cancer cell-cycle control and suggest that deregulated expression of BRCA1-IRIS is likely to reduce dependence on normal physiological growth stimuli, thereby providing a growth advantage to tumor cells and a potential mechanism of resistance to endocrine therapy. © 2007 Wiley-Liss, Inc. [source] Molecular magnetism via resonating valence bonds for conjugated radicals and selected transition metal complexesINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4-5 2001D. J. Klein Abstract Currently there is considerable interest in the nature of exchange interactions leading to unpaired electrons in molecular and cluster magnets. Here, the focus is largely at a qualitative level, via a novel "mean-field" resonance-theoretic view, to deal with exchange couplings, so as to allow unpaired electrons in either (or both of) the ,- and ,-parts of a (largely organic) bipartite (or alternate) molecular network. The (quantitative) number and (qualitative) location of unpaired spins are dealt with by this simple approach, which also offers some (qualitative) information on the occurrence of low-lying higher-spin states. To illustrate the approach it is applied to a variety of systems where the spin sources are conjugated ,-network molecules and polymers, carbenes, variously defected graphites, and a few species involving transition metals, especially Cu. The discussion deals not only with traditional conjugated organics compounds but also with selected inorganic species. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001 [source] Why are maximizers less happy than satisficers?JOURNAL OF BEHAVIORAL DECISION MAKING, Issue 2 2010Because they maximize positive, negative outcomes Abstract Although extant research suggests maximizing is related to objectively positive outcomes (e.g., job offers), I propose maximizing may be simultaneously and positively related to objectively negative outcomes (e.g., job rejections). Specifically, I argue maximizers bear more instances of positive and negative outcomes than satisficers, and that in spite of their positive outcomes,yet because of their negative outcomes,maximizers are less happy than satisficers. In Study 1, participants took the alternate uses test; as expected, maximizing was related to seeking alternatives, yet, maximizing was also related to seeking low-quality alternatives. Moreover, the number of low-quality alternatives partially mediated the relationship between maximizing and negative affect. In Study 2, the impact of maximizing on experiencing negative affect was further assessed by examining whether maximizing is related to seeking and choosing low-quality alternatives. Participants played the Iowa Gambling Task; it was found maximizing was related to alternating among decks, and in particular, sampling bad decks; ultimately, maximizing was related to winning less money, and experiencing more negative affect. Finally, in Study 3, participants responded to questionnaires about positive and negative life outcomes; it was found that maximizing was simultaneously related to experiencing more positive and more negative outcomes, and that negative outcomes predicted happiness to a greater degree than positive outcomes. These findings suggest an irony of maximizing: It produces both positive and negative outcomes, contributing to literature explaining why maximizers are less happy than satisficers, and ultimately whether happiness is a matter of choice. Copyright © 2009 John Wiley & Sons, Ltd. [source] Wear in molded tibial inserts: Knee simulator study of H1900 and GUR1050 polyethylenesJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2008Riichiro Tsukamoto Abstract Hi-fax 1900Ô tibial inserts were used in the IB-1 total knee replacement (TKR) beginning 1978, soon followed by the AGC design. Such direct compression molded (DCM) inserts was relatively immune to oxidation. Unfortunately the Hi-fax 1900Ô resin (H1900) was taken off the market in year 2004. As an alternate, GUR1050 was introduced in the VanguardÔ TKR. However there appeared to be little or no wear comparisons of molded inserts. Therefore the study aim was to compare wear performance of GUR1050 to the historical H1900. The hypothesis was that Hi-fax and GUR1050 would show comparable wear performance. The VanguardÔ was a posterior-cruciate sacrificing design (Biomet Inc.). All tibial inserts were sterilized by gamma-radiation (3.2 Mrad) under argon. A 6-channel, displacement,controlled knee simulator was used with serum lubricant (protein concentration 20 mg/mL). Wear assessments were by gravimetric methods and linear regression techniques. The gross weight-loss trends over 2.5 Mc duration demonstrated excellent linear behavior with good agreement between TKR sets (<±10%). Fluid sorption artifacts in control represented less than 5% of gross wear magnitudes. Thus suitable corrections could be made in determining net wear. The H1900 and GUR1050inserts demonstrated net wear-rates of 3.6 and 3.4 mm3/Mc, respectively. This difference was not found to be statistically significant. This wear study demonstrated that GUR1050 inserts were indistinguishable from the Hi-fax 1900 in terms of laboratory wear performance, proving our hypothesis. Given the excellent clinical history of DCM Hi-fax 1900, the GUR1050 should be an ideal candidate for TKR. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Supercritical CO2 extraction of accumulated capsidiol from biotic elicitor-activated Capsicum annuum L fruit tissuesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2005ur Salg Abstract This work investigates the supercritical CO2 extraction of capsidiol from pepper fruit tissues activated with Alternaria alternate (Fr) Keissler suspension culture as a biotic elicitor. Capsidiol production in the fruit tissue was markedly increased by the treatment with a biotic elicitor and reached its maximum level after 4 days of elicitation. The effects of separation parameters such as temperature, pressure, supercritical solvent flow rate, particle diameter and also initial capsidiol concentration were investigated on solubility, initial extraction rate and extraction yield. The optimal extraction conditions were obtained at the temperature of 40 °C, the pressure of 400 bar, the supercritical CO2 flow rate of 2 cm3 min,1, and the average particle diameter of 116 µm. The results showed that the ratio of the supercritical CO2 extraction yield to the organic solvent extraction yield was changed from 84 to 97 wt-% depending on the initial capsidiol concentration. Copyright © 2004 Society of Chemical Industry [source] Facial Soft Tissue Depths in Craniofacial Identification (Part I): An Analytical Review of the Published Adult Data,JOURNAL OF FORENSIC SCIENCES, Issue 6 2008Carl N. Stephan Ph.D. Abstract:, With the ever increasing production of average soft tissue depth studies, data are becoming increasingly complex, less standardized, and more unwieldy. So far, no overarching review has been attempted to determine: the validity of continued data collection; the usefulness of the existing data subcategorizations; or if a synthesis is possible to produce a manageable soft tissue depth library. While a principal components analysis would provide the best foundation for such an assessment, this type of investigation is not currently possible because of a lack of easily accessible raw data (first, many studies are narrow; second, raw data are infrequently published and/or stored and are not always shared by some authors). This paper provides an alternate means of investigation using an hierarchical approach to review and compare the effects of single variables on published mean values for adults whilst acknowledging measurement errors and within-group variation. The results revealed: (i) no clear secular trends at frequently investigated landmarks; (ii) wide variation in soft tissue depth measures between different measurement techniques irrespective of whether living persons or cadavers were considered; (iii) no clear clustering of non-Caucasoid data far from the Caucasoid means; and (iv) minor differences between males and females. Consequently, the data were pooled across studies using weighted means and standard deviations to cancel out random and opposing study-specific errors, and to produce a single soft tissue depth table with increased sample sizes (e.g., 6786 individuals at pogonion). [source] Floral Ontogeny of Two Species in Magnolia L.JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 10 2006Feng-Xia Xu Abstract Floral ontogeny is described in two species of genus Magnolia (Magnoliaceae), Magnolia albosericea Chun et C. Tsoong, and M. amoena Cheng, representing subgenus Magnolia and subgenus Yulania in Magnolia, by using scanning electron microscope (SEM). The sequence of initiation of floral organs is from proximal to distal. The three distinct outermost and middle organs are initiated in sequence, but ultimately form a single whorl, thus their ontogeny is consistent with a sepal interpretation. The last three tepals (petals) alternate with the preceding tepal whorl. The members of androecium and gynoecium arise spirally, although the androecium shows some intermediacy between a spiral and whorled arrangement. The carpel primordia initiate in group of four to five. The order of stamen initiation within each tier is not determined. The floral ontogeny is remarkably homogeneous between the subgenus Magnolia and subgenus Yulania that does not support the resuming of genus Yulania. (Managing editor: Wei Wang) [source] The turnover of the H3 deuterons from (2- 13C) glutamate and (2- 13C) glutamine reveals subcellular trafficking in the brain of partially deuterated ratsJOURNAL OF NEUROCHEMISTRY, Issue 2009Sebastián Cerdán Abstract We investigated by 13C NMR the turnover of the H3 deuterons of (2- 13C) glutamate and (2- 13C) glutamine in the brain of partially deuterated rats. Adult animals (150,200 g) fed ad libitum received 50%2H2O or tap water 9 days before infusing (1- 13C) glucose or (2- 13C) acetate for 5, 10, 15, 30, 60, or 90 min. The brains were then funnel-frozen and acid extracts were prepared and analyzed by high-resolution 13C NMR. The deuteration of one or the two H3 hydrogens of (2- 13C) glutamate or glutamine resulted in single (,0.07 ppm) or double (,0.14 ppm) isotopic shifts upfield of the corresponding C2 perprotonated resonance, demonstrating two sequential deuteration steps. The faster monodeuteration generated 3R or 3S (2- 13C, 3- 2H) glutamate or glutamine through the alternate activities of cerebral aconitase or isocitrate dehydrogenase, respectively. The slower process produced bideuterated (2- 13C, 3,3,- 2H2) glutamate or glutamine through the consecutive activity of both enzymes. The kinetics of deuteration was fitted to a Michaelis,Menten model including the apparent Km, and Vmax, values for the observed deuterations. Our results revealed different kinetic constants for the alternate and consecutive deuterations, suggesting that these processes were caused by the different cytosolic or mitochondrial isoforms of aconitase and isocitrate dehydrogenase, respectively. The deuterations of (2- 13C) glutamate or glutamine followed also different kinetics from (1- 13C) glucose or (2- 13C) acetate, revealing distinct deuteration environments in the neuronal or glial compartments. [source] Role of fibroblasts and fibroblast-derived growth factors in periprosthetic angiogenesisJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 10 2007Miklos Tunyogi-Csapo Abstract The periprosthetic granulomatous soft tissue [designated iterfacial membrane (IFM) in this study] exhibits heterogeneous histopathological features, in which highly vascularized areas with dense cellularity alternate with fibrotic and pseudocapsule-like tissue structures. Although macrophage/monocyte activation is a prominent event in the periprosthetic environment, fibroblasts also phagocytose particulate wear debris both in vivo and in vitro. Particulate wear debris and/or cytokines/growth factors alone or in combination (e.g., in conditioned media of explant cultures of IFMs) stimulated normal synovial and IFM fibroblasts to express inflammatory mediators and growth factors such as interleukin (IL)-1,, IL-6, IL-8, three isoforms of vascular endothelial growth factor (VEGF), monocyte/macrophage chemoattractant protein-1 (MCP-1), macrophage-colony-stimulating factor (M-CSF), cycloxygenases (Cox-1 and Cox-2), acid- and basic-fibroblast growth factors (FGF-1 and FGF-2), leukemia inhibitory factor-1 (LIF-1), transforming growth factor ,-1 (TGF-,1), receptor activator of nuclear factor-kappa B ligand (RANKL), and osteoprotegerin (OPG). Thus, the fibroblast is capable of expressing a wide array of angiogenic and osteoclastogenic factors which are involved in the detrimental processes of the periprosthetic osteolysis. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1378,1388, 2007 [source] Alterations in Brain Glucose Utilization Accompanying Elevations in Blood Ethanol and Acetate Concentrations in the RatALCOHOLISM, Issue 2 2010Robert J. Pawlosky Background:, Previous studies in humans have shown that alcohol consumption decreased the rate of brain glucose utilization. We investigated whether the major metabolite of ethanol, acetate, could account for this observation by providing an alternate to glucose as an energy substrate for brain and the metabolic consequences of that shift. Methods:, Rats were infused with solutions of sodium acetate, ethanol, or saline containing 13C-2-glucose as a tracer elevating the blood ethanol (BEC) and blood acetate (BAcC) concentrations. After an hour, blood was sampled and the brains of animals were removed by freeze blowing. Tissue samples were analyzed for the intermediates of glucose metabolism, Krebs' cycle, acyl-coenzyme A (CoA) compounds, and amino acids. Results:, Mean peak BEC and BAcC were approximately 25 and 0.8 mM, respectively, in ethanol-infused animals. Peak blood BAcC increased to 12 mM in acetate-infused animals. Both ethanol and acetate infused animals had a lower uptake of 13C-glucose into the brain compared to controls and the concentration of brain 13C-glucose-6-phosphate varied inversely with the BAcC. There were higher concentrations of brain malonyl-CoA and somewhat lower levels of free Mg2+ in ethanol-treated animals compared to saline controls. In acetate-infused animals the concentrations of brain lactate, ,-ketoglutarate, and fumarate were higher. Moreover, the free cytosolic [NAD+]/[NADH] was lower, the free mitochondrial [NAD+]/[NADH] and [CoQ]/[CoQH2] were oxidized and the ,G, of ATP lowered by acetate infusion from ,61.4 kJ to ,59.9 kJ/mol. Conclusions:, Animals with elevated levels of blood ethanol or acetate had decreased 13C-glucose uptake into the brain. In acetate-infused animals elevated BAcC were associated with a decrease in 13C-glucose phosphorylation. The co-ordinate decrease in free cytosolic NAD, oxidation of mitochondrial NAD and Q couples and the decrease in ,G, of ATP was similar to administration of uncoupling agents indicating that the metabolism of acetate in brain caused the mitochondrial voltage dependent pore to form. [source] Optical and electrochemical properties of copoly(aryl ether)s consisting of alternate 2,5-distyrylbenzene and electron-transporting oxadiazole or triazole derivativesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 21 2005Shinn-Horng Chen Abstract New copoly(aryl ether) P1 consisting of alternate electron-transporting 2-(3-(trifluoromethyl)phenyl)-5-(4-(5-(3-(trifluoromethyl)phenyl)-1,3,4-oxadiazol-2-yl)-2,5-bis(hexyloxy)phenyl)-1,3,4-oxadiazole and hole-transporting 2,5-distyrylbenzene (DSB) was synthesized via nucleophilic substitution polymerization. We investigated the optical and electrochemical properties of alternate copoly(aryl ether)s P1,P6, which contain the same hole-transporting DSB segments, but with different electron transporting segments. The effect of trifluoromethyl groups in electron transporting segments is also discussed. Referencing to the spectra of their model compounds M1,M4, the emissions of P1,P3 are dominated exclusively by the hole-transporting fluorophores with longer emissive wavelength about 452,453 nm via efficient excitation energy transfer. Furthermore, P1,P3 also exhibit unique variations in energy transfer in acidic media and solvatochromism in organic solvents. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of P1,P4, estimated from electrochemical data, are ,5.12, ,5.15, ,5.18, ,5.00 eV and ,2.93, ,3.39, ,3.49, ,2.76 eV, respectively. The electron and hole affinity of P1,P6 can be enhanced simultaneously by introducing isolated hole- and electron-transporting segments in backbone. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5083,5096, 2005 [source] Systematic review: endoscopic and imaging-based techniques in the assessment of portal haemodynamics and the risk of variceal bleedingALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 10 2009S. N. SGOUROS Summary Background, Invasive measurement of the hepatic venous pressure gradient (HVPG) is regarded as the gold standard for risk stratification and the evaluation of pharmaceutical agents in patients with portal hypertension. Aim, To review the techniques for endoscopic and imaging-based assessment of portal haemodynamics, with particular emphasis on trials where the results were compared with HVPG or direct portal pressure measurement. Methods, Systematic search of the MEDLINE electronic database with keywords: portal hypertension, variceal bleeding, variceal pressure, endoscopic ultrasound, Doppler ultrasonography, magnetic resonance angiography, CT angiography, hepatic venous pressure gradient. Results, Computed tomography angiography and endoscopic ultrasound (EUS) have been both employed for the diagnosis of complications of portal hypertension and for the evaluation of the efficacy of endoscopic therapy. Colour Doppler ultrasonography and magnetic resonance angiography has given discrepant results. Endoscopic variceal pressure measurements either alone or combined with simultaneous EUS, correlate well with HVPG and risk of variceal bleeding and have a low interobserver variability. Conclusions, Endoscopic and imaging-based measurements of portal haemodynamics provide an alternate means for the assessment of complications of portal hypertension. Further studies are required to validate their use in risk stratification and the evaluation of drug therapies in patients with portal hypertension. [source] Pigment pattern formation in zebrafish: A model for developmental genetics and the evolution of formMICROSCOPY RESEARCH AND TECHNIQUE, Issue 6 2002Ian K. Quigley The zebrafish Danio rerio is an emerging model organism for understanding vertebrate development and genetics. One trait of both historical and recent interest is the pattern formed by neural crest,derived pigment cells, or chromatophores, which include black melanophores, yellow xanthophores, and iridescent iridophores. In zebrafish, an embryonic and early larval pigment pattern consists of several stripes of melanophores and iridophores, whereas xanthophores are scattered widely over the flank. During metamorphosis, however, this pattern is transformed into that of the adult, which comprises several dark stripes of melanophores and iridophores that alternate with light stripes of xanthophores and iridophores. In this review, we place zebrafish relative to other model and non-model species; we review what is known about the processes of chromatophore specification, differentiation, and morphogenesis during the development of embryonic and adult pigment patterns, and we address how future studies of zebrafish will likely aid our understanding of human disease and the evolution of form. Microsc. Res. Tech. 58:442,455, 2002. © 2002 Wiley-Liss, Inc. [source] In the Wake of Things: Speculating in and about Sapphires in Northern MadagascarAMERICAN ANTHROPOLOGIST, Issue 2 2004ANDREW WALSH ABSTRACT This article discusses the interrelatedness of two sorts of speculation undertaken by Malagasy sapphire miners and traders involved in the northern Malagasy sapphire trade: first, the speculating that these people do in sapphires, and, second, the speculating that they do about the uses to which sapphires are put by foreigners. Although Malagasy people involved in the local trade know a great deal about how sapphires might be profitably traded, most of them do not know why foreigners are so interested in these stones. Dubious of foreign traders' assurances that sapphires are used in the production of jewelry, they speculate a variety of alternate, secret uses for them. In this article, it is argued that these speculations emerge out of a variety of locally developed assumptions about how the sapphire trade works, and specifically, the significant roles that deception and knowledge differentials play in its operation. [source] The morphogenesis of lobed plant cells in the mesophyll and epidermis: organization and distinct roles of cortical microtubules and actin filamentsNEW PHYTOLOGIST, Issue 3 2005Emmanuel Panteris Summary The morphogenesis of lobed plant cells has been considered to be controlled by microtubule (MT) and/or actin filament (AF) organization. In this article, a comprehensive mechanism is proposed, in which distinct roles are played by these cytoskeletal components. First, cortical MT bundles and, in the case of pavement cells, radial MT arrays combined with MT bundles determine the deposition of local cell wall thickenings, the cellulose microfibrils of which copy the orientation of underlying MTs. Cell growth is thus locally prevented and, consequently, lobes and constrictions are formed. Arch-like tangential expansion is locally imposed at the external periclinal wall of pavement cells by the radial arrangement of cellulose microfibrils at every wall thickening. Whenever further elongation of the original cell lobes occurs, AF patches assemble at the tips of growing lobes. Intercellular space formation is promoted or prevented by the opposite or alternate, respectively, arrangement of cortical MT arrays between neighboring cells. The genes that are possibly involved in the molecular regulation of the above morphogenetic procedure by MT and AF array organization are reviewed. [source] A new genus of Sapindaceae from SomaliaNORDIC JOURNAL OF BOTANY, Issue 5 2004Mats Thulin The new genus Hirania (Sapindaceae), with the single species H. rosea from south-central Somalia, is decribed and illustrated. It is a shrub with simple, entire leaves, alternate or crowded on short-shoots, and without stipules. The inflorescences are branched with monochasially arranged, unisexual flowers. The flowers (only male ones known) are zygomorphic with five sepals with gland-tipped hairs along margins, four pink, subequal, clawed petals without appendages, and eight, glabrous stamens. The dark purple disk is narrow and tubular and consists of an upper broader segment partly enclosing a lower narrower segment. The closest relative is believed to be the Australian genus Diplopeltis. [source] Noninvasive ventilation in the pediatric intensive care unit for children with acute respiratory failure,,PEDIATRIC PULMONOLOGY, Issue 6 2003W. Gerald Teague MD Abstract Noninvasive ventilation, a novel treatment to increase alveolar ventilation, is accomplished with either subatmospheric or positive pressure administered via an external interface. In adults with acute respiratory failure, noninvasive positive pressure ventilation (NPPV) is superior to standard therapy in preventing intubation and reducing mortality. The role of NPPV in pediatric-age patients with acute respiratory distress is not as well established. Early case reports showed that NPPV treatment does acutely improve both the clinical manifestations of respiratory distress and respiratory gas exchange in children with respiratory distress. However, it is not clear whether NPPV in this setting can prevent vs. delay endotracheal intubation. Other uses of NPPV in the pediatric intensive care unit include the treatment of upper airway obstruction, atelectasis, and exacerbations of neuromuscular disorders, and to facilitate weaning from invasive mechanical ventilation. Successful use of NPPV in young infants with respiratory distress is impeded by the lack of suitable size interfaces, and the response characteristics of commercially available bilevel ventilators. Despite these challenges, NPPV is a promising alternate to standard therapies in the treatment of acute respiratory distress in the pediatric-age patient. Pediatr Pulmonol. 2003; 35:418,426. © 2003 Wiley-Liss, Inc. [source] Optimizing DNA yield from buccal swabs in the elderly: Attempts to promote buccal cell growth in cultureAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 5 2003David J. Vandenbergh Participation in genetic studies is often limited by a volunteer's reluctance to donate blood samples. We wished to determine if alternate, less painful, methods to venipuncture could be used to collect cells to provide DNA for genotyping, and whether the cells could be grown in culture for extraction of DNA. Volunteers in the study were comprised of two groups. Nine individuals from a university campus were recruited to provide samples for initial experiments. A second group of 710 twins and singletons from North Carolina and of African-American descent were a part of an ongoing study of age-related traits and participated in collection of buccal swabs via the mail. A protocol was generated that maximizes the recovery of DNA from buccal swabs, which are easier to handle than saline rinses. The DNA recovered is stable over several years, allowing genotype tests at a future date. Attempts to encourage growth of buccal epithelial cells recovered from swabs in tissue culture proved unsuccessful. Buccal swabs work well for the collection of DNA, especially from nonclinic-based volunteers, and can be sent via the mail to the laboratory for DNA extraction. Thus, an inexpensive and efficient method exists for genetic studies of population-based samples. Am. J. Hum. Biol. 15:637,642, 2003. © 2003 Wiley-Liss, Inc. [source] The OD interpretation of the crystal structure of kettnerite CaBiOFCO3ACTA CRYSTALLOGRAPHICA SECTION A, Issue 6 2009í Hybler The mineral kettnerite, CaBi(OFCO3), is a rare example of an order,disorder (OD) structure with a quadratic net. The lattice parameters of the simplest possible 1O polytype are a = 5.3641,(1), b = 5.3641,(1), c = 13.5771,(2),Ĺ, and the space group is Pbaa. There are three kinds of OD layers, identical to structure-building layers. Two of them are non-polar: the Bi,O and Ca,F at z = 0 and z = 1/2, respectively, with the layer-group symmetry C2/m2/m(4/a,b)21/m21/m. The third kind of OD layer of CO3 groups (located between the Bi,O and Ca,F layers) is polar, with alternating sense of polarity. The layer group is Pba(4)mm. Triangular CO3 groups are parallel to (110) or () planes with one O atom oriented towards the Bi,O layer and the remaining two O atoms oriented towards the Ca,F layer. The orientations of CO3 groups alternate along the [110] and [] directions. As a result, each group parallel to (110) is surrounded by four nearest neighbors parallel to () and vice versa. These positions can be interchanged by an (a + b)/2 shift or by ,/2 rotation; thus stacking of the layer onto adjacent ones is ambiguous. Instead of OD layers, the polytypes are generated by stacking of OD packets, comprising the whole CO3 layers and adjacent halves of the Bi,O and Ca,F layers. They are polar, with alternating sense of polarity; the layer group is Pba(4)mm. Stacking sequences are expressed by ball-and-stick models, with the aid of symbolic figures, and by sequences of orientational characters. There are two maximum-degree-of-order (MDO) polytypes, 1O (really found and described, see lattice parameters and space group above) and 2O, with doubled c parameter and space group Ibca (not yet found). The derivation of the MDO generating operations of both polytypes is presented in this paper. The stacking rule also allows another, non-MDO, polytype with doubled c, i.e. the 2Q polytype, space group P42bc (tetragonal, not yet found). Various kinds of domains can exist: (i) out-of-step domains shifted by (a + b)/2, (ii) twin domains rotated by ,/2 around local tetrads of odd or even packets, and (iii) upside-down domains in the polar 2Q polytype. Stacking sequences of 16 possible domains of the polytypes mentioned above are listed. Also 60 domains of four distinct six-packet polytypes are theoretically possible. [source] | |||||||||||||||||||||||||||||||||||||