bluuebunny/crossref_metadata_2025_split huggingface dataset:
Systèmes aromatiques à 10 électrons π dérivés de l'aza‐3a penlalène. VIII. Recherches dans la série du pyrazolo[3,2‐c]‐s‐triazole
Authors: Claramunt Rosa‐Maria , Fabregà José‐Maria , Elguero José 
Published: April 2009

AbstractOn montre que l'action des β‐cétoesters sur les diamino‐1,2 triazoles‐1,3,4 permet d'obtenir des pyrazolo[3,2‐c]‐s‐triazoles: en function de ce résultat on propose une structure dihydro‐7,8 9H‐.s‐triazolo[4,3‐b] [1,2,4]triazepinone‐8 pour le produit intermédiaire de cette synthèse.
Substituted chromans and tetrahydrofuro[2,3‐b]benzofurans (trapped tetrahedral intermediates) from 3‐phenyl‐2‐benzofuranones
Authors: Zaugg H. E. , Leonard J. E. , Denet R. W. , Arendsen D. L. 
Published: April 2009

AbstractThe previously discovered neighboring group reaction has been extended to the synthesis of chroman derivatives (i.e., 4, 5, 6) containing geminal methyls in the 2‐position, a feature common to certain physiologically active natural chromans. In two instances, cyclic ortho ester by‐products (8), not observed in previous work, were formed as a result of the intramolecular trapping of tetrahedral intermediates. Reasons for the incursion of this unexpected side reaction are discussed.
Diazo‐, azo‐ and azidoazoles, and related compounds. 1. Synthesis of naphthoazolo‐as‐triazines from diazoazoles and 2‐naphthol
Authors: Vilarrasa J. , Granados R. 
Published: April 2009

AbstractAzo derivatives prepared by coupling 2‐diazoimidazole, 3(5))diazopyrazole, 3(5)diazo‐s‐triazole, 4(5)diazo‐v‐triazole and diazotetrazole with β‐naphthol have been cyclized to the corresponding naphthoazolo‐as‐triazines, an heterocyclic system related to azasteroids. The structure of the products have been elucidated. A consistent mechanism for the cyclization is proposed.
Synthesis and configuration of trans‐1‐amino‐4‐benzyl‐2,6‐dimethylpiperazine as an intermediate of semi‐synthetic rifamycins
Authors: Cignarella Giorgio , Gallo Gian Gualberto 
Published: April 2009

AbstractThe synthesis of trans‐1‐amino‐4‐benzyl‐2,6‐dimethylpiperazine (1b), trans‐4‐benzyl‐2,6‐dimethylpiperazine (VIIb) and trans‐2,6‐dimethylpiperazine (IIb) are described, by condensation of N‐benzyl‐1,2‐propanediamine with α‐bromopropionate and successive thermal cyclization and reduction with lithium aluminum hydride.The assignment of the cis, trans configuration to the isomers was based on a thorough examination of the ring proton nmr signals of the two isomers of 4‐benzyl‐2,6‐dimethylpiperazine (VIIa and VIIb) interpreted in terms of conformational considerations.
New heterocyclic compounds derived from 1,4‐dihydro‐3(2H)‐cinnolinone. Cyclic hydrazides. Note I
Authors: Winters G. , Aresi V. , Nathansohn G. 
Published: April 2009

AbstractThe question concerning the synthesis of the 1,4‐dihydro‐3(2H)cinnolinone was solved and some new tetracyclic derivatives are described. The structure and the synthesis of the two isomers 2‐(2‐carbomethoxymethylphenyl)phthalazine‐1(2H),4(3H)dione and 1‐(2‐carbomethoxybenzoyl)‐1,2‐dihydrocinnolin‐3(4H)one are discussed.
Approche théorique de la réactivité chimique des azaindènes: 2.imidazo[1,2]azines
Authors: Arriau J. , Dargelos A. , Chalvet O. , Maury G. 
Published: April 2009

AbstractPlusieurs modèles théoriques ont été appliqués à l'étude de la réactivité de quatre systèmes hélérocycliques du type imidazo [1,2]azine, et les résultats obtenus ont été comparés.
Neonatal and adult O4+ oligodendrocyte lineage cells display different growth factor responses and different gene expression patterns
Authors: Lin Grace , Mela Angeliki , Guilfoyle Eileen M. , Goldman James E. 
Published: April 2009

AbstractOligodendrocytes are the myelinating cells of the central nervous system. Although the CNS possesses the ability to repair demyelinating insults, in certain cases, such as the chronic lesions found in multiple sclerosis, remyelination fails. Cycling cells capable of becoming oligodendrocytes have been identified in both the developing and the adult mammalian forebrain. Many studies have focused on differences in gene expression profiles as oligodendrocyte progenitors differentiate into myelinating oligodendrocytes by isolating cells at different developmental stages from animals at a single age. However, few have studied the differences that exist between the progenitors of the neonatal CNS and those of the adult CNS. This study examined the response of neonatal and adult O4+ cells to platelet‐derived growth factor‐AA, basic fibroblast growth factor, and insulin‐like growth factor‐1 and revealed marked differences. Whereas adult cells readily differentiated in vitro, the majority of neonatal progenitors remained immature. Microarray analysis was used to examine differences between acutely isolated neonatal and adult progenitors further. Gene expression profiles showed that the adult O4+ cells are more developmentally mature than neonatal cells. Neonatal cells expressed higher levels of genes involved in proliferation. Adult O4+ cells expressed higher levels of transcripts for genes involved in cell death and survival. Therefore, O4+ cells from the adult differ greatly from those of the neonate, and the developmental stage of the animal models utilized must be taken into consideration when applying principles from neonatal systems to the adult. © 2009 Wiley‐Liss, Inc.
Histone deacetylase inhibitors promote neurosteroid‐mediated cell differentiation and enhance serotonin‐stimulated brain‐derived neurotrophic factor gene expression in rat C6 glioma cells
Authors: Morita Kyoji , Gotohda Takako , Arimochi Hideki , Lee Mi‐Sook , Her Song 
Published: April 2009

AbstractProgesterone treatment has previously been reported to promote the differentiation of glial cells probably through the production of 5α‐reduced neurosteroids, resulting in the enhancement of serotonin‐stimulated brain‐derived neurotrophic factor (BDNF) gene expression, which is considered to contribute to the survival, regeneration, and plasticity of neuronal cells in the brain and hence has been suggested to improve mood disorders and other symptoms in depressive patients. Based on these previous observations, the effects on glial cells of histone deacetylase (HDAC) inhibitors, which are known as agents promoting cell differentiation, were examined using rat C6 glioma cells as a model for in vitro studies. Consequently, trichostatin A (TSA), sodium butyrate (NaB), and valproic acid (VPA) stimulated glial fibrillary acidic protein (GFAP) gene expression, and their stimulatory effects on GFAP gene expression were inhibited by treatment of these cells with finasteride, an inhibitor of the enzyme producing 5α‐reduced neurosteroids. In addition, HDAC inhibitors enhanced serotonin‐stimulated BDNF gene expression, the enhancement of which could be abolished by the inhibition of 5α‐reduced neurosteroid production in the glioma cells. These results suggest that HDAC inhibitors may be able to promote the differentiation of rat C6 glioma cells through the production of 5α‐reduced neurosteroids, resulting in the enhancement of serotonin‐stimulated BDNF gene expression as a consequence of promoting their differentiation, indicating the possibility that differentiated glial cells may be implicated in preserving the integrity of neural networks as well as improving the function of neuronal cells in the brain. © 2009 Wiley‐Liss, Inc.
Blockade of NMDA receptors and nitric oxide synthesis in the dorsolateral periaqueductal gray attenuates behavioral and cellular responses of rats exposed to a live predator
Authors: Aguiar Daniele Cristina , Guimarães Francisco Silveira 
Published: April 2009

AbstractInnate fear stimulus induces activation of neurons containing the neuronal nitric oxide synthase enzyme (nNOS) in defensive‐related brain regions such as the dorsolateral periaqueductal gray (dlPAG). Intra‐dlPAG administration of nitric oxide synthase (NOS) inhibitors and glutamate antagonists induce anxiolytic‐like responses. We investigated the involvement of nitric oxide (NO) and glutamate neurotransmission in defensive reactions modulated by dlPAG. We tested if intra‐dlPAG injections of the selective nNOS inhibitor, N‐propyl‐L‐arginine (NP), or the glutamate antagonist, AP7 (2‐amino‐7‐phosphonoheptanoic acid), would attenuate behavioral responses and cellular activation induced by predator exposure (cat). Fos‐like immunoreactivity (FLI) was used as a marker of neuronal functional activation, whereas nNOS immunohistochemistry was used to identify NOS neurons. Cat exposure induced fear responses and an increase of FLI in the dlPAG and dorsal premammillary nucleus (PMd). NP and AP7 attenuated the cat‐induced behavioral responses. Whereas NP tended to attenuate FLI in the dlPAG, AP7 induced a significant reduction in cellular activation of this region. The latter drug, however, increased FLI and double‐labeled cells in the PMd. Cellular activation of this region was significantly correlated with time spent near the cat (r = 0.7597 and 0.6057 for FLI and double‐labeled cells). These results suggest that glutamate/NO‐mediated neurotransmission in the dlPAG plays an important role in responses elicit by predator exposure. Blocking these neurotransmitter systems in this brain area impairs defensive responses. The longer time spent near the predator that follows AP7 effect could lead to an increased cellular activation of the PMd, a more rostral brain area that has also been related to defensive responses. © 2009 Wiley‐Liss, Inc.
Gap junction inhibitors modulate S100B secretion in astrocyte cultures and acute hippocampal slices
Authors: Leite Marina Concli , Galland Fabiana , de Souza Daniela F. , Guerra Maria Cristina , Bobermin Larissa , Biasibetti Regina , Gottfried Carmem , Gonçalves Carlos‐Alberto 
Published: April 2009

AbstractAstrocytes sense, integrate, and respond to stimuli generated by neurons or neural injury; this response involves gap junction (GJ) communication. Neuronal vulnerability to injury increased when cocultures of astrocytes and neurons were exposed to GJ inhibitors. However, GJ uncoupling could limit the extension of a lesion. We investigated a possible link between GJ communication and S100B secretion. S100B is a calcium‐binding protein of 21 kDa that is predominantly expressed and secreted by astrocytes, which has trophic paracrine activity on neurite growth, glial proliferation, and neuronal survival. GJ inhibitors were analyzed in isolated astrocytes in primary cultures from hippocampus, acute hippocampal slices, and C6 glioma cells, which were used as a negative control. Our data indicate that GJ blocking stimulates S100B secretion in astrocyte cultures and acute hippocampal slices. Different assays were used to confirm cell integrity during exposure to GJ inhibitors. S100B secretion was observed with different types of GJ inhibitors; the resulting event was dependent on time, the nature of the inhibitor, its putative molecular target of GJ blocking, and/or the cell preparation used. Only carbenoxolone induced a fast and persistent increase in S100B secretion in both preparations. Endothelin‐1 increased S100B secretion in astrocyte cultures at 1 hr, but a decrease was observed at 6 hr or in acute hippocampal slices. Physiologically, a local GJ closure associated with release of S100B in injury conditions favors the idea of a common mechanism available to limit the extension of lesion and increase the chances of cell survival. © 2009 Wiley‐Liss, Inc.
Use of MEKC for the analysis of reactant and product of Baylis–Hillman reaction
Authors: Qi Li , Cui Kai , Qiao Juan , Yang Gengliang , Chen Yi 
Published: April 2009

AbstractA facile, fast and high efficiency micellar EKC has been explored for the analysis and UV detection of p‐nitrobenzaldehyde and 2‐[hydroxy(4‐nitrophenyl)methyl]‐2‐cyclopenten‐1‐one with a buffer electrolyte of 30.0 mM tetraborate and 50.0 mM sodium taurodeoxycholate at pH 9.3. Under the optimal conditions, a linear range from 7.8×10–2 to 5.0×102 mM for those analytes (r2 > 0.99) was achieved. The LOD was 3.9 μM for 2‐[hydroxy(4‐nitrophenyl)methyl]‐2‐cyclopenten‐1‐one and 7.8 μM for p‐nitrobenzaldehyde, respectively (S/N = 3). The applicability of this new method for the analysis of reactants (p‐nitrobenzaldehyde and cyclopent‐2‐enone), catalysts (imidazole or N‐methyl imidazole or 1‐benzyl‐imidazole) and product (2‐[hydroxy(4‐nitrophenyl)methyl]‐2‐cyclopenten‐1‐one) on offline Baylis–Hillman reaction was examined. The relationship between the reaction time and the amount of product has been studied. Meanwhile, three different kinds of catalysts were investigated for getting the desired moderate to good amount products. It was found that comparing with N‐methyl imidazole or 1‐benzyl‐imidazole catalyst, imidazole‐catalyzed reaction could produce more products within the same reaction time. Furthermore, the results indicated that the rate law for the investigated Baylis–Hillman reaction was second‐order reaction. The rate constant for the reaction is 1.34 (±0.01)×10–3 mol–1 m3/s.
Repeatability of peptide identifications in shotgun proteome analysis employing off‐line two‐dimensional chromatographic separations and ion‐trap MS
Authors: Delmotte Nathanaël , Lasaosa Maria , Tholey Andreas , Heinzle Elmar , van Dorsselaer Alain , Huber Christian G. 
Published: April 2009

AbstractThe repeatability of peptide identifications in shotgun proteome analyses employing strong cation‐exchange‐×ion‐pair RP HPLC hyphenated to ESI MS/MS was compared to an alternative scheme, comprising high‐pH RP chromatography combined with low‐pH ion‐pair RP chromatography. Equivalent results were obtained with both methods in proteome analysis of Corynebacterium glutamicum. From a total number of 1350 to 1850 peptides identified in triplicate analyses of five consecutive fractions chosen from the first‐dimension separation, 41–45% of the peptides were identified three times, whereas 16–22 and 37–39% of the peptides were identified only twice or once, respectively. A comparison of the repeatability of peptide identifications from complex samples upon 1‐ or 2‐D chromatographic separation revealed that an additional separation dimension decreases the repeatability by approximately 25%.
Highly sensitive and accurate profiling of carotenoids by supercritical fluid chromatography coupled with mass spectrometry
Authors: Matsubara Atsuki , Bamba Takeshi , Ishida Hiroki , Fukusaki Eiichiro , Hirata Kazumasa 
Published: April 2009

AbstractWe attempted to establish a high‐speed and high‐resolution profiling method for a carotenoid mixture as a highly selective and highly sensitive detection method; the analysis was carried out by supercritical fluid chromatography (SFC) coupled with mass spectrometry (MS). When an octadecyl‐bonded silica (ODS) particle‐packed column was used for separation, seven carotenoids including structural isomers were successfully separated within 15 min. This result indicated not only improved separation but also improved throughput compared to the separation and throughput in RP‐HPLC. The use of a monolithic ODS column resulted in additional improvement in both the resolution and the throughput; the analysis time was reduced to 4 min by increasing the flow rate. Furthermore, carotenoids in biological samples containing the complex matrices were separated effectively by using several monolithic columns whose back pressure was very low. The mass spectrometer allowed us to perform a more sensitive analysis than UV detection; the detection limit of each carotenoid was 50 pg or below. This is the first report of carotenoid analysis carried out by SFC‐MS. The profiling method developed in this study will be a powerful tool for carrying out accurate profiling of biological samples.
Development and validation of stir bar sorptive extraction of polar phenols in water followed by HPLC separation in poly(vinylpyrrolididone‐divinylbenzene) monolith
Authors: Huang Xiaojia , Qiu Ningning , Yuan Dongxing 
Published: April 2009

AbstractAn effective and simple method for polar phenols in water matrix was developed by using stir bar sorptive extraction (SBSE) based on a hydrophilic poly(vinylpyrrolididone‐divinylbenzene) (VPDB) monolithic material and HPLC analysis. To achieve optimum extraction performance for phenols, several parameters, including extraction and desorption time, desorption solvent, pH value, and ionic strength of sample matrix, were investigated. Under the optimized experimental conditions, eight phenols were directly enriched from water samples and analyzed by HPLC‐DAD. The detection limits (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target compounds were achieved within the range of 0.72–1.37 and 2.40–4.27 ng/mL from spiked water, respectively. Recoveries of eight phenolic compounds were found in the range of 55.2–95.9%. The calibration curves showed the linearity ranging from 5 to 150 ng/mL with linear regression coefficient R2 values above 0.98. Method repeatability presented as intra‐ and interday precisions were also found with the RSDs less than 4.10 and 7.61%, respectively. The distribution coefficients between VPDB and water (KVPDB/W) for phenolic compounds were also calculated and compared with KO/W. Finally, the proposed method was successfully applied to the determination of the target compounds in tap water, sea water and wastewater samples.
No somatic genetic change in the paxillin gene in nonsmall‐cell lung cancer
Authors: Pallier Karine , Houllier Anne‐Marie , Le Corre Delphine , Cazes Aurélie , Laurent‐Puig Pierre , Blons Hélène 
Published: April 2009

AbstractThe paxillin gene (PXN) encodes a focal adhesion associated protein that could be involved in the progression of lung cancer through its interactions with the actin cytoskeleton and key signal transduction oncogenes. PXN mutations and PXN amplifications were recently identified in nonsmall‐cell lung cancer (NSCLC) and amplifications were associated with MET increased copy number. The description of tumors with two to three mutations in the PXN gene and the overrepresentation of GC to AT transitions were unexpected and needed confirmation. The aim of this study was to validate the incidence of PXN somatic alterations in NSCLC and to correlate them to other common genetic alterations. PXN mutations and copy number changes at PXN, EGFR, and MET loci were analyzed on DNAs from frozen tumor samples (n = 159) that had been previously screened for mutations at EGFR, KRAS, BRAF, ERBB2, STK11, PIK3CA, and TP53. We found PXN polymorphisms including nonsynonymous ones but no PXN amplification and only 1/159 (<1%) somatic tumor mutation F416L. In conclusion, we do not deny the possible involvement of PXN in cancer but our findings do not support a major role for PXN somatic changes in lung carcinogenesis. © 2009 Wiley‐Liss, Inc.
Gender differences in the association between antidepressant use and restless legs syndrome
Authors: Baughman Kristin R. , Bourguet Claire C. , Ober Scott K. 
Published: April 2009

AbstractContradictory results have been reported for the association between antidepressant use and Restless Legs Syndrome (RLS). Our aim was to clarify the relationship and examine possible gender differences. We interviewed 1,693 veterans receiving primary care from the Cleveland VA Medical Center and obtained prescription drug information from their medical records. Overall, use of an antidepressant was associated with RLS for men (RR = 1.77, CI = 1.26, 2.48) but not for women (RR = 0.79, CI = 0.43, 1.47). Analyses of individual antidepressants revealed an association between RLS and fluoxetine for women (RR = 2.47, CI = 1.33, 4.56), and associations between RLS and citalopram, (RR = 2.09, CI = 1.20, 3.64), paroxetine (RR = 1.97, CI = 1.02, 3.79), and amitriptyline (RR = 2.40, CI = 1.45, 4.00) for men. We conclude that RLS may be associated with antidepressant use, but the association varies by gender and type of antidepressant. Antidepressant use is more strongly associated with RLS in men than in women. © 2009 Movement Disorder Society
Hyposmia and executive dysfunction as predictors of future Parkinson's disease: A prospective study
Authors: Ponsen Mirthe M. , Stoffers Diederick , Twisk Jos W.R. , Wolters Erik Ch. , Berendse Henk W. 
Published: April 2009

AbstractOlfactory deficits and executive dysfunction are early and common symptoms in Parkinson's disease (PD). Previous studies have shown that hyposmia can be a first sign of PD. The aim of the present study was to determine which of three olfactory tests and two selected tests of executive function would be the best predictor of future PD over a 5 year period. In a cohort of 361 nonparkinsonian, nondemented first‐degree relatives of PD patients, in whom alternative causes of olfactory dysfunction were excluded, we measured baseline performance on three olfactory and two executive function tasks. Five years from baseline, clinical neurological evaluation and/or a screening questionnaire, sensitive to the presence of Parkinsonism, were used to detect individuals developing clinical PD. Our results show that in first degree relatives of PD patients worse performance on each of three olfactory processing tasks was associated with an increased risk of developing PD within 5 years, whereas performance on selected tests of executive dysfunction was not associated with an increased risk of developing PD. Interestingly, impaired odor discrimination was the best predictor for future PD. © 2009 Movement Disorder Society
A basic tool for risk assessment: A new method for the analysis of ergot alkaloids in rye and selected rye products
Authors: Müller Carola , Kemmlein Sabine , Klaffke Horst , Krauthause Werner , Preiß‐Weigert Angelika , Wittkowski Reiner 
Published: April 2009

AbstractAs a basis for the collection of occurrence and exposure data of ergot alkaloids in food, an HPLC method coupled with fluorimetric detection (HPLC‐FLD) for the determination of 12 pharmacologically active ergot alkaloids in rye and rye products was developed. Samples were extracted with a mixture of ethyl acetate, methanol, and aqueous ammonia, followed by centrifugation and purification by solid phase filtration (SPF) with basic alumina. After solvent adjustment, the samples were analyzed by HPLC‐FLD using a phenyl–hexyl‐column. Recoveries for five major alkaloids were between 89.3% (ergotamine) and 99.8% (α‐ergokryptine) with a maximum LOQ of 3.3 μg/kg (ergometrine). Precision expressed as RSD ranged from 2.8% (ergocristine) to 12.4% (α‐ergokryptine) for repeatability, and from 6.5% (ergocornine) to 14.9% (ergotamine) for within‐laboratory reproducibility, respectively. In a survey of 39 rye product samples, ergocristine and ergotamine were found to be the major alkaloids in commercially available rye products with contents of 127 μg/kg (ergocristine), and 134 μg/kg (ergotamine) in rye flour, and 152.5 and 117.8 μg/kg in coarse meal, respectively.
Rapid water and lipid imaging with T2 mapping using a radial IDEAL‐GRASE technique
Authors: Li Zhiqiang , Graff Christian , Gmitro Arthur F. , Squire Scott W. , Bilgin Ali , Outwater Eric K. , Altbach Maria I. 
Published: April 2009

AbstractThree‐point Dixon methods have been investigated as a means to generate water and fat images without the effects of field inhomogeneities. Recently, an iterative algorithm (IDEAL, iterative decomposition of water and fat with echo asymmetry and least squares estimation) was combined with a gradient and spin‐echo acquisition strategy (IDEAL‐GRASE) to provide a time‐efficient method for lipid–water imaging with correction for the effects of field inhomogeneities. The method presented in this work combines IDEAL‐GRASE with radial data acquisition. Radial data sampling offers robustness to motion over Cartesian trajectories as well as the possibility of generating high‐resolution T2 maps in addition to the water and fat images. The radial IDEAL‐GRASE technique is demonstrated in phantoms and in vivo for various applications including abdominal, pelvic, and cardiac imaging. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.