bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anogenital gland secretions of Lemur catta and Propithecus verreauxi coquereli: A preliminary chemical examination
Authors: Hayes R.A. , Morelli T.L. , Wright P.C. 
Published: June 2004

AbstractAlthough prosimians are greatly olfaction‐oriented, little is known about the specifics of how they use scent to communicate. In this preliminary study we attempted to delineate intra‐ and interspecific differences among the anogenital gland secretions of two lemur species (Lemur catta and Propithecus verreauxi coquereli) using gas chromatography‐mass spectrometry (GC‐MS). The results indicate that the two species are discernible through scent. Furthermore, we were able to identify reproductive status using this technique. The anogenital secretions of the different sexes in L. catta, though perhaps not P. v. coquereli, are chemically distinguishable. Given this information, it appears that at least some lemur species can use scent marks to determine species, sex, and reproductive status. Am J Primatol 63:49–62, 2004. © 2004 Wiley‐Liss, Inc.
Pre‐retirement predator encounters alter the morning behavior of captive marmosets (Callithrix geoffroyi)
Authors: Hankerson Sarah J. , Caine Nancy G. 
Published: June 2004

AbstractLimited data are available on the long‐term effect an encounter with a predator has on its potential prey. Anecdotal reports from field research indicate that even unsuccessful attacks by predators on callitrichids have long‐lasting effects. The subjects for this study were two groups of Geoffroy's marmosets (Callithrix geoffroyi) housed outside, off exhibit, at the Center for Reproduction of Endangered Species at the San Diego Wild Animal Park. Before they retired in the evening, the marmosets were observed under one of three conditions: snake model, cloth control, and no‐stimulus control. Data were collected the following morning for 1 hr after the animals emerged from the sleeping box. Compared to control conditions, exposure to the snake model before retirement the previous evening was associated with significantly more vigilance checks (i.e., inspecting the area where the stimulus was last seen), and a delay in beginning to forage on the ground. These results suggest that callitrichids use recent threatening experiences to guide their vigilance behavior 12 hr after the threat is detected, and that they adjust their early morning behavior in response to potential predatory threats. Am. J. Primatol. 63:75–85, 2004. © 2004 Wiley‐Liss, Inc.
Nonphosphorylated high‐molecular‐weight neurofilament expression suggests early maturation of the monkey subiculum
Authors: Lavenex Pierre , Lavenex Pamela Banta , Amaral David G. 
Published: June 2004

AbstractWe analyzed the distribution of nonphosphorylated high‐molecular‐weight neurofilaments (NF‐H) in the hippocampal formation of infant (3‐week‐old and 3‐month‐old) and adult (9–17‐year‐old) macaque monkeys in order to obtain neuroanatomical evidence of the maturity of these structures shortly after birth. We employed the monoclonal antibody SMI‐32, a well‐characterized antibody raised against nonphosphorylated NF‐H, the expression of which is believed to reflect the maturation of certain neuronal populations. Patterns of SMI‐32 immunoreactivity differed dramatically between infant and adult monkeys. In adults, nonphosphorylated NF‐H expression was prominent in the CA3 and CA2 fields of the hippocampus, in the subiculum and in the entorhinal cortex. In infants, only the subiculum stained heavily for nonphosphorylated NF‐H. These findings suggest that different subregions of the primate hippocampal formation mature at different times during development. The subiculum, the major source of efferent projections from the hippocampal formation toward subcortical structures, matures early during development. In contrast, the entorhinal cortex, the main interface of the hippocampal formation with the neocortex, matures relatively later. These findings have direct implications for the type of information processing that might be subserved by the primate hippocampal formation shortly after birth, as well as for the emergence of particular behavioral and memory processes during postnatal development. © 2004 Wiley‐Liss, Inc.
Biodegradable radiation delivery system utilizing glass microspheres and ethylenediaminetetraacetate chelation therapy
Authors: Conzone Samuel D. , Hall Matthew M. , Day Delbert E. , Brown Roger F. 
Published: June 2004

AbstractDysprosium lithium‐borate (DyLB) glass microspheres have been developed as a biodegradable radiation delivery vehicle for the treatment of rheumatoid arthritis and other diseases. Radioactive microspheres of these glasses are intended to be injected into a joint infected with rheumatoid arthritis to safely deliver a localized dose (100 Gy) of beta radiation. Once injected, the microspheres react nonuniformly with body fluids. The nonradioactive, lithium‐borate component is dissolved from the glass, whereas the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes “chemically” trapped in a solid, dysprosium phosphate reaction product that has the same size as the unreacted microsphere. The glass microspheres lose ≈80% of their weight after nonuniform reaction (<1 day), but the dysprosium phosphate reaction product is slowly metabolized by the body over several months. Ethylenediaminetetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product in vitro in <2 h. The dysprosium phosphate reaction product which formed in vivo in the joint of a Sprague‐Dawley rat was also dissolved by EDTA chelation therapy in <1 week, without causing any detectable joint damage. The combination of DyLB glass microspheres and EDTA chelation therapy provides a unique “tool” for the medical community because it can deliver a large dose (>100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 256–264, 2004
Alterations of cell lipids by metal salts
Authors: Schuster George S. , Caughman Gretchen B. 
Published: June 2004

AbstractMetallic medical devices undergo degradation in vivo and the degradation products affect the chemistry and biological responses of cells and tissues in the immediate vicinity. The responses vary with the metal and cell type. In the current study, we examined the effects of several metals on a human monocytic cell line. Monocytes are important effector cells capable of responding rapidly to inflammatory and immune stimuli in a variety of ways, including production of inflammatory proteins, differential expression of surface adhesion molecules, enhanced phagocytic activity, and activation and differentiation to macrophages. Cells were exposed in the presence of 14C‐acetate to titanium, nickel, chromium, copper, or cobalt or vanadium at concentrations that were subinhibitory or inhibitory based on cellular mitochondrial dehydrogenase activity. Cell lipids were then extracted, separated by thin layer chromatography, and quantitated by liquid scintillation spectrometry. Total cell protein also was measured. Titanium reduced cell protein content at concentrations that were noninhibitory to mitochondrial dehydrogenase activity, whereas neither chromium nor cobalt affected protein amounts at dehydrogenase‐inhibitory concentrations. In cells exposed to vanadium, the protein‐ and dehydrogenase‐inhibitory concentrations were similar. The major effects on cell lipids appeared to occur in the neutral lipids, although chromium, cobalt, and titanium produced changes in some major phospholipids. These results suggest that metals differentially affect various metabolic pathways in THP‐1 cells, perhaps related to their abilities to enter the cells or interact with the membrane. These alterations to the cells may affect the cells' abilities to respond to various stimuli that can damage the tissues. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 347–353, 2004
Characterization of non‐covalent complexes of rutin with cyclodextrins by electrospray ionization tandem mass spectrometry
Authors: Guo Mingquan , Song Fengrui , Liu Zhiqiang , Liu Shuying 
Published: June 2004

AbstractElectrospray ionization tandem mass spectrometry (ESI‐MSn) and the phase solubility method were used to characterize the gas‐phase and solution‐phase non‐covalent complexes between rutin (R) and α‐, β‐ and γ‐cyclodextrins (CDs). The direct correlation between mass spectrometric results and solution‐phase behavior is thus revealed. The order of the 1 : 1 association constants (Kc) of the complexes between R and the three CDs in solution calculated from solubility diagrams is in good agreement with the order of their relative peak intensities and relative collision‐induced dissociation (CID) energies of the complexes under the same ESI‐MSn condition in both the positive and negative ion modes. Not only the binding stoichiometry but also the relative stabilities and even binding sites of the CD–R complexes can be elucidated by ESI‐MSn. The diagnostic fragmentation of CD–R complexes, with a significant contribution of covalent fragmentation of rutin leaving the quercetin (Q) moiety attached to the CDs, provides convincing evidence for the formation of inclusion complexes between R and CDs. The diagnostic fragment ions can be partly confirmed by the complexes between Q and CDs. The gas‐phase stability order of the deprotonated CD–R complexes is β‐CD–R > α‐CD–R > γ‐CD/R; β‐CD seems to bind R more strongly than the other CDs. Copyright © 2004 John Wiley & Sons, Ltd.
Screening for dihydropyridine calcium channel blockers in plasma by automated solid‐phase extraction and liquid chromatography/tandem mass spectrometry
Authors: Mueller Claudia A. , González Ana B. Baranda , Weinmann Wolfgang 
Published: June 2004

AbstractA liquid chromatographic/tandem mass spectrometric (LC/MS/MS) screening method was developed for the screening of 11 calcium channel blockers of the 1,4‐dihydropyridine type in plasma samples for forensic and clinical cases. Plasma samples were extracted by automated solid‐phase extraction. Analysis was performed using a reversed‐phase C18 column, gradient elution and a triple‐quadrupole mass spectrometer with TurboIonSpray source in positive mode and multiple reaction monitoring. This method was found to be selective and sensitive for the detection of the target compounds at their therapeutic plasma concentrations. Copyright © 2004 John Wiley & Sons, Ltd.
Site of alkylation of N‐methyl‐ and N‐ethylaniline in the gas phase: a tandem mass spectrometric study
Authors: Ackloo Suzanne , Harrison Alex G. , Terlouw Johan K. 
Published: June 2004

AbstractN‐Methylaniline (NMA) was ethylated and N‐ethylaniline (NEA) was methylated under chemical ionization conditions using C2H5I and CH3I, respectively, as reagent gases. The structures of the resulting m/z 136 adduct ions have been probed using metastable ion and collision‐induced dissociation (CID) methods. From the similarity of the spectra obtained and from the presence of structure‐diagnostic ions at m/z 59 (CH3NHC2H5+•) and m/z 44 (CH3NHCH2+), it is concluded that predominantly N‐alkylation occurs in both systems. This interpretation was aided by the use of C2D5I and CD3I as reagents. Adduct ions of m/z 136 were also formed by ethylation of the isomeric toluidines and by methylation of the ring‐ethylanilines. The resulting CID mass spectra were distinctly different from those obtained for the m/z 136 ions obtained by alkylation of NMA and NEA. Protonation of N‐ethyl‐N‐methylaniline using CH3C(O)CH3 as Brønsted acid reagent produced an m/z 136 species whose CID mass spectrum also featured intense ion signals at m/z 59 and 44. This observation led to the conclusion that protonation with acetone as reagent results, in this case, in dominant N‐protonation. However, the CID mass spectrum of the m/z 136 ion formed when CH3OH was the protonating agent featured a weak signal at m/z 44 and no signal at m/z 59. Hence it was concluded that the latter m/z 136 ion contains a larger contribution from the ring‐protonated adduct. Copyright © 2004 John Wiley & Sons, Ltd.
Isolation of retinal progenitor cells from post‐mortem human tissue and comparison with autologous brain progenitors
Authors: Klassen Henry , Ziaeian Boback , Kirov Ivan I. , Young Michael J. , Schwartz Philip H. 
Published: June 2004

AbstractThe goal of the present study was threefold: to determine whether viable human retinal progenitor cells (hRPCs) could be obtained from cadaveric retinal tissue, to evaluate marker expression by these cells, and to compare hRPCs to human brain progenitor cells (hBPCs). Retinas were dissected from post‐mortem premature infants, enzymatically dissociated, and grown in the presence of epidermal growth factor and basic fibroblast growth factor. The cells grew as suspended spheres or adherent monolayers, depending on culture conditions. Expanded populations were banked or harvested for analysis by RT‐PCR, immunocytochemistry, and flow cytometry. hBPCs derived from forebrain specimens from the same donors were grown and used for RT‐PCR. Post‐mortem human retinal specimens yielded viable cultures that grew to confluence repeatedly, although not beyond 3 months. Cultured hRPCs expressed a range of markers consistent with CNS progenitor cells, including nestin, vimentin, Sox2, Ki‐67, GD2 ganglioside, and CD15 (Lewis X), as well as the tetraspanins CD9 and CD81, CD95 (Fas), and MHC class I antigens. No MHC class II expression was detected. hRPCs, but not hBPCs, expressed Dach1, Pax6, Six3, Six6, and recoverin. Minority subpopulations of hRPCs and hBPCs expressed doublecortin, β‐III tubulin, and glial fibrillary acidic protein, which is consistent with increased lineage restriction in subsets of cultured cells. Viable progenitor cells can be cultured from the post‐mortem retina of premature infants and exhibit a gene expression profile consistent with immature neuroepithelial cells. hRPCs can be distinguished from hBPC cultures by the expression of retinal specification genes and recoverin. © 2004 Wiley‐Liss, Inc.
Three putative N‐glycosylation sites within the murine 5‐HT3A receptor sequence affect plasma membrane targeting, ligand binding, and calcium influx in heterologous mammalian cells
Authors: Quirk Phillip L. , Rao Suma , Roth Bryan L. , Siegel Ruth E. 
Published: June 2004

AbstractThe serotonin type 3A receptor (5‐HT3AR) is a ligand‐gated ion channel (LGIC) that modulates a diverse set of cognitive and physiological functions. The 5‐HT3AR, as with other LGICs, is a pentameric ion channel comprising five glycoprotein subunits. Although the N‐terminal of the 5‐HT3AR contains three putative N‐linked glycosylation sites, the importance of each glycosylation site has not yet been established. To address this question, we used tunicamycin treatment and site‐directed mutagenesis to inhibit selectively N‐linked glycosylation at each site and then examined the effects of these treatments on receptor expression and function in transiently transfected heterologous cells. We show that the murine 5‐HT3AR is glycosylated and that each N‐linked glycosylation site plays a role in receptor regulation. Our findings suggest that N109 is necessary for receptor assembly, whereas N174 and N190 are important for plasma membrane targeting and ligand binding. Furthermore, we demonstrate that each site is necessary for 5‐HT3AR‐mediated Ca2+ influx. We conclude that N‐glycosylation is a critical step in the maturation, trafficking, and function of the murine 5‐HT3AR. © 2004 Wiley‐Liss, Inc.
Steady plasma concentration of unfractionated heparin reduces infarct volume and prevents inflammatory damage after transient focal cerebral ischemia in the rat
Authors: Cervera Álvaro , Justicia Carles , Reverter Joan C. , Planas Anna M. , Chamorro Ángel 
Published: June 2004

AbstractUnfractionated heparin (UH) decreases the extent of infarction after transient focal brain ischemia in the rat and abridges neuroinflammatory damage in patients with acute stroke. This study was aimed at assessing whether controlled and steady heparinemia in plasma can reduce infarct volume and exert neuroprotective effects after ischemia. Infarct volume was measured at 24 and 7 days following a 1‐hr intraluminal middle cerebral artery (MCA) occlusion in rats treated with UH or with vehicle. After testing several UH administration protocols, we choose to give a bolus of 200 U/kg, which was started 3 hr after the occlusion, followed by a 24‐hr intraperitoneal perfusion of 70 U/kg/hr, which maintained a 24‐hr steady plasma heparinemia (0.3–0.6 U/ml) and caused no CNS or systemic bleeding. In addition, plasma IL‐10 concentration was measured by ELISA, endothelial VCAM‐1 expression was evaluated by i.v. injection of a 125I‐labeled monoclonal antibody against VCAM‐1, and brain hemeoxygenase‐1 (HO‐1) expression was determined by Western blot. UH‐treated rats showed smaller infarctions than rats treated with vehicle, as well as higher IL‐10 plasma levels and HO‐1 brain expression and lower endothelial VCAM‐1 induction. The study shows that a stable plasma concentration of UH given at nonhemorrhagic doses reduces infarct volume after ischemia‐reperfusion in the rat. It also shows that UH prevented the induction of cell adhesion molecules in the cerebral vasculature and increased the expression of molecules with antiinflammatory and prosurvival properties. These findings support further testing of the clinical value of parenteral, adjusted, high‐dose UH in patients with acute stroke. © 2004 Wiley‐Liss, Inc.
Expression and location of mRNAs encoding multiple forms of secretory phospholipase A2 in the rat retina
Authors: Kolko Miriam , Christoffersen Nanna R. , Barreiro Sebastian G. , Bazan Nicolas G. 
Published: June 2004

AbstractLow‐molecular‐weight secretory phospholipases A2 (sPLA2s) are a subgroup of PLA2s, which are secreted, bind to receptors, and may act as intercellular signaling modulators. At least 10 different groups have been characterized in mammals, and there is expanding evidence of the significance of sPLA2s in neuronal signaling and survival [Kolko et al. (1996) J. Biol. Chem. 271: 32722–32728]. To date, no retinal sPLA2s have been cloned or characterized. We evaluated the existence and abundance of sPLA2 subtypes in rat retina and explored their possible involvement in light‐induced retinal damage. We designed primers to identify the sPLA2s in rat retina, based on known sequences of sPLA2‐specific mRNAs in other tissues. RNA was isolated from rat retina, and cDNA was produced and used for PCR cloning to identify the novel subtypes of sPLA2. Our study revealed the presence of mRNAs encoding sPLA2‐IB, ‐X, ‐V, ‐IIE, ‐IIA, and ‐IIF in the retina, and quantification by real‐time PCR revealed different abundances of the sPLA2s. We showed a time‐dependent gene induction of sPLA2‐X, ‐IB, and ‐V in light‐induced retinal damage. We further explored the location of sPLA2‐IB by in situ hybridization and immunohistochemistry. This study is the first to reveal the presence, abundance, and induction of mRNAs encoding sPLA2s in rat retina. We suggest that these enzymes are themselves intercellular signaling modulators of retinal cell function and perhaps also of retinal degeneration. © 2004 Wiley‐Liss, Inc.
Synthesis and photoluminescence of linear and hyperbranched polyethers containing phenylquinoxaline units and flexible aliphatic spacers
Authors: Baek Jong‐Beom , Chien L.‐C. 
Published: June 2004

AbstractUltrahigh‐molecular‐weight linear polyethers were prepared through a reaction between the phenylquinoxaline monomers 2,3‐bis(4‐hydroxyphenyl)‐6‐fluoroquinoxaline and 2,3‐bis(4‐hydroxyphenyl)‐6‐(α,α,α‐trifluoromethyl)quinoxaline and 1,12‐dibromododecane. A new hyperbranched polyether containing a phenylquinoxaline moiety was also prepared from a new self‐polymerizable AB2 monomer, 2,3‐bis(6‐bromohexyloxyphenyl)‐6‐(4‐hydroxyphenyloxy)quinoxaline. All the polyethers were amorphous and soluble in polar aprotic solvents. Their solution‐cast thin films were light yellow, ductile, and optically transparent. The polymers were thermally stable up to 350 °C and had glass‐transition temperatures in the range of 25–83 °C, which depended on the architecture and monomer structure. The monomers and polymers displayed fluorescence maxima in the blue‐light region in the range of 431–449 nm with relatively narrow peak widths; this indicated that they had pure and intense fluorescence. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3587–3603, 2004
Macromolecular surfactants for supercritical carbon dioxide applications: Synthesis and characterization of fluorinated block copolymers prepared by nitroxide‐mediated radical polymerization
Authors: Lacroix‐Desmazes Patrick , Andre Pascal , Desimone Joseph M. , Ruzette Anne‐Valérie , Boutevin Bernard 
Published: June 2004

AbstractPoly(perfluorooctyl‐ethylenoxymethylstyrene) (PFDS) and poly(1,1,2,2‐tetrahydroperfluorodecyl acrylate) (PFDA) homopolymers as well as poly(styrene)‐b‐poly(perfluorooctyl‐ethylenoxymethylstyrene) (PS‐b‐PFDS) and poly(styrene)‐b‐poly(1,1,2,2‐tetrahydroperfluorodecyl acrylate) acrylate) (PS‐b‐PFDA) block copolymers of various chain lengths were synthesized by nitroxide‐mediated radical polymerization in the presence of either 2,2,6,6‐tetramethyl‐1‐piperidinyloxy free radical (TEMPO) in the case of FDS monomer or N‐tert‐butyl‐N‐(1‐diethylphosphono‐2,2‐dimethylpropyl)‐N‐oxyl (DEPN) in the case of the FDA monomer. The molar composition of the block copolymers was determined by elemental analysis and proton NMR while the blocky structure was checked by SEC analysis in trifluorotoluene. Block copolymers PS‐b‐PFDS (3.6K/60K) and PS‐b‐PFDA (3.7K/43K) were soluble in neat CO2 at moderate pressure and temperature, indicating the formation of micelles. Similar block copolymers with a longer PS block such as PS‐b‐PFDA (9.5K/49K), corresponding to a lower CO2‐philic/CO2‐phobic balance, were insoluble in neat CO2 but could be solubilized in the presence of styrene as a cosolvent. Additionally, surface and bulk properties of PS‐b‐PFDA were investigated, indicating the same surface tension as for the PFDA homopolymer (γLV = 10.3 mN/m) and a bulk nanostructured morphology. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3537–3552, 2004
Kinetic modeling studies of ethylene polymerization reactions using supported chromium catalysts
Authors: Matos I. , Zhang Y. , Lemos M. A. N. D. A. , Freire Filipe , Fonseca I. F. , Marques M. M. , Lemos F. 
Published: June 2004

AbstractKinetic models for ethylene polymerization based on a general coordination–insertion mechanism, in which either a monocoordinated species or a bicoordinated species could lead to migratory insertion, were constructed. These models were implemented through the solution of a set of differential equations resulting from the material balances for all the species involved. The application of these kinetic models to monomer consumption for different supported catalysts produced very good fittings and allowed the estimation of the kinetic rate constants of each elementary step. Although the same kinetic scheme was used to describe all the observations, the results of the fitting showed that the supported chromium species behaved very differently according to the support. Only in the case of the silica‐supported catalysts was mechanical fragmentation of the particles observed during the course of the reaction, and this implied the inclusion of a new term in the model. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3464–3472, 2004