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961.
Chaves AR Silva SM Queiroz RH Lanças FM Queiroz ME 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,850(1-2):295-302
A sensitive and reproducible stir bar sorptive extraction and liquid chromatography (SBSE/LC-UV) method is described for the determination of sertraline, mirtazapine, fluoxetine, citalopram, paroxetine, imipramine, nortriptyline, amitriptyne, and desipramine in plasma samples. Important factors in the optimization of SBSE efficiency are discussed, such as extraction time, pH, ionic strength, influence of plasma proteins, and desorption conditions: solvents, modes (magnetic stir, ultrasonic), time, and number of desorption steps. The SBSE/LC-UV method showed to be linear in a concentration ranging from the limit of quantification (LOQ) to 1000.0 ng mL(-1). The LOQ values ranged from 10.0 ng mL(-1) to 40.0 ng mL(-1). The inter-day precision of the SBSE/LC-UV method presented coefficient of the variation lower than 15%. Based on figures of the merit results, the SBSE/LC-UV methodology showed to be adequate to the antidepressants analyses from therapeutic to toxic therapeutic levels. In order to evaluate the proposed method for clinical use, the SBSE/LC-UV method was applied to the analysis of plasma samples from elderly depressed patients. 相似文献
962.
This work presents a biosensor for organophosphorus pesticides based on immobilisation of a highly sensitive genetically engineered acetylcholinesterase (B394) by affinity interactions on metal chelate-functionalised magnetic microbeads. The developed sensor has been compared with those based on the widely used Electric eel cholinesterase and a classical entrapment procedure in a polyvinylalcohol-based matrix. The use of the B394 enzyme allowed lowering both IC50 and LOD by a factor of 100 when compared with Electric eel enzyme sensor. The oriented and site-specific immobilisation combined with the high specificity of the B349 mutant allows a more sensitive detection of insecticides, concentrations as low as 1.31(-11)M (IC10) being detected for both pesticides chlorpyriphos-oxon and chlorfenvinphos. 相似文献
963.
Vaisburg A Paquin I Bernstein N Frechette S Gaudette F Leit S Moradei O Raeppel S Zhou N Bouchain G Woo SH Jin Z Gillespie J Wang J Fournel M Yan PT Trachy-Bourget MC Robert MF Lu A Yuk J Rahil J Macleod AR Besterman JM Li Z Delorme D 《Bioorganic & medicinal chemistry letters》2007,17(24):6729-6733
A variety of N-(2-amino-phenyl)-4-(heteroarylmethyl)-benzamides were designed and synthesized. These compounds were shown to inhibit recombinant human HDAC1 with IC50 values in the sub-micromolar range. In human cancer cells growing in culture these compounds induced hyperacetylation of histones, induced the expression of the tumor suppressor protein p21WAF1/Cip1, and inhibited cellular proliferation. Certain compounds of this class also showed in vivo activity in various human tumor xenograft models in mice. 相似文献
964.
van Koningsbruggen S Straasheijm KR Sterrenburg E de Graaf N Dauwerse HG Frants RR van der Maarel SM 《Chromosoma》2007,116(1):53-64
FRG1 is considered a candidate gene for facioscapulohumeral muscular dystrophy (FSHD) based on its location at chromosome 4qter
and its upregulation in FSHD muscle. The FRG1 protein (FRG1P) localizes to nucleoli, Cajal bodies (and speckles), and has
been suggested to be a component of the human spliceosome but its exact function is unknown. Recently, transgenic mice overexpressing
high levels of FRG1P in skeletal muscle were described to present with muscular dystrophy. Moreover, upregulation of FRG1P
was demonstrated to correlate with missplicing of specific pre-mRNAs. In this study, we have combined colocalization studies
with yeast two-hybrid screens to identify proteins that associate with FRG1P. We demonstrate that artificially induced nucleolar
aggregates of VSV-FRG1P specifically sequester proteins involved in pre-mRNA processing. In addition, we have identified SMN,
PABPN1, and FAM71B, a novel speckle and Cajal body protein, as binding partners of FRG1P. All these proteins are, or seem
to be, involved in RNA biogenesis. Our data confirm the presence of FRG1P in protein complexes containing human spliceosomes
and support a potential role of FRG1P in either splicing or another step in nuclear RNA biogenesis. Intriguingly, among FRG1P-associated
proteins are SMN and PABPN1, both being involved in neuromuscular disorders, possibly through RNA biogenesis-related processes. 相似文献
965.
Gerbino A Fistetto G Colella M Hofer AM Debellis L Caroppo R Curci S 《The Journal of biological chemistry》2007,282(18):13477-13486
The mechanisms for the formation of the osmotic gradient driving water movements in the gastric gland and its modulation via the extracellular Ca(2+)-sensing receptor (CaR) were investigated. Real time measurements of net water flux in the lumen of single gastric glands of the intact amphibian stomach were performed using ion-selective double-barreled microelectrodes. Water movement was measured by recording changes in the concentration of impermeant TEA(+) ions ([TEA(+)](gl)) with TEA(+)-sensitive microelectrodes inserted in the lumen of individual gastric glands. Glandular K(+) (K(+)(gl)) and H(+) (pH(gl)) were also measured by using K(+)- and H(+)-sensitive microelectrodes, respectively. Stimulation with histamine significantly decreased [TEA](gl), indicating net water flow toward the gland lumen. This response was inhibited by the H(+)/K(+)-ATPase inhibitor, SCH 28080. Histamine also elicited a significant and reversible increase in [K(+)](gl) that was blocked by chromanol 293B, a blocker of KCQN1 K(+) channels. Histamine failed to induce net water flow in the presence of chromanol 293B. In the "resting state," stimulation of CaR with diverse agonists resulted in significant increase in [TEA](gl). CaR activation also significantly reduced histamine-induced water secretion and apical K(+) transport. Our data validate the strong link between histamine-stimulated acid secretion and water transport. We also show that cAMP-dependent [K(+)](gl) elevation prior to the onset of acid secretion generates the osmotic gradient initially driving water into the gastric glands and that CaR activation inhibits this process, probably through reduction of intracellular cAMP levels. 相似文献
966.
Doriana Triggiani Donatella Ceccarelli Antonio Tiezzi Tommaso Pisani Silvana Munzi Carlo Gaggi Stefano Loppi 《Biologia》2009,64(1):59-62
In the present study we report some preliminary results concerning the evaluation of antiproliferative activity on murine
myeloma cells (P3X63-Ag8.653) of crude extracts of two common lichen species, Evernia prunastri and Xanthoria parietina.
The results were evaluated by means of the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] test, which
is commonly used to assess the activity of living cells through mitochondrial dehydrogenases. They indicated that extracts
of E. prunastri had no effect, while those of X. parietina significantly affected murine myeloma cell proliferation, with a reduction down to 75% for methanolic extracts. This opens
perspectives for deeper investigations extended also to other mammalian cell lines. 相似文献
967.
Anelise S. Todeschin Maria Helena Vianna Jacob Silvana Jacobs Maria Flavia Marques Ribeiro Aldo Bolten Lucion 《Hormones and behavior》2009,56(1):93-325
Early-life environmental events can induce profound long-lasting changes in several behavioral and neuroendocrine systems. The neonatal handling procedure, which involves repeated brief maternal separations followed by experimental manipulations, reduces stress responses and sexual behavior in adult rats. The purpose of this study was to analyze the effects of neonatal handling on social behaviors of male and female rats in adulthood, as manifest by the results of social memory and social interaction tests. The number of oxytocin (OT) and vasopressin (VP) neurons in the paraventricular (PVN) and supraoptic (SON) nuclei of hypothalamus were also analyzed. The results did not demonstrate impairment of social memory. Notwithstanding, handling did reduce social investigative interaction and increase aggressive behavior in males, but did not do so in females. Furthermore, in both males and females, handling was linked with reduced number of OT-neurons in the parvocellular region of the PVN, while no differences were detected in the magnocellular PVN or the SON. On the other hand, handled males exhibited increased number of VP-neurons in the magnocellular zone of the PVN. We may conclude that the repeated brief maternal separations can reduce affiliative social behavior in adult male rats. Moreover, the disruption of the mother-infant relationship caused by the handling procedure induced long-lasting morphological changes in critical neuroendocrine areas that are involved in social bonding in mammals. 相似文献
968.
Amal Wahhab David Smil Alain Ajamian Martin Allan Yves Chantigny Eric Therrien Natalie Nguyen Sukhdev Manku Silvana Leit Jubrail Rahil Andrea J. Petschner Ai-Hua Lu Alina Nicolescu Sylvain Lefebvre Samuel Montcalm Marielle Fournel Theresa P. Yan Zuomei Li Jeffrey M. Besterman Robert Déziel 《Bioorganic & medicinal chemistry letters》2009,19(2):336-340
The sulfamide moiety has been utilized to design novel HDAC inhibitors. The potency and selectivity of these inhibitors were influenced both by the nature of the scaffold, and the capping group. Linear long-chain-based analogs were primarily HDAC6-selective, while analogs based on the lysine scaffold resulted in potent HDAC1 and HDAC6 inhibitors. 相似文献
969.
Marina M. A. Campos Henry Tonuci Silvana M. Silva Bruna de S. Altoé Dermeval de Carvalho Eloisa A. M. Kronka Ana M. S. Pereira Bianca W. Bertoni Suzelei de C. França Carlos E. S. Miranda 《Phytochemical analysis : PCA》2009,20(6):445-449
Introduction – Although medicinal plants are widely used throughout the world, few studies have been carried out concerning the levels of heavy metal contaminants present. Such metals are highly toxic to living organisms even in low concentrations owing to their cumulative effect. The present paper describes the the development of a pre‐concentration flow injection analysis‐flame atomic absorption spectrometric system to determine the lead content in medicinal plants at the ppb level. Objective – To develop a pre‐concentration flow injection analysis‐flame atomic absorption spectrometric system to determine the lead content in medicinal plants at the ppb level. Methodology – A pre‐concentration flow system was coupled to a flame atomic absorption spectrometer. The plant samples were analysed after nitroperchloric digestion. The proposed system was optimised by evaluating the following parameters: nature, concentration and volume of the eluent solution, elution flow rate, elution efficiency, pre‐concentration flow rate and pre‐concentration time. Results – The proposed system exhibited good performance with high precision and repeatability (RSD ≤ 2.36%), excellent linearity (r = 0.9999), low sample consumption (10.5 mL per determination) and an analytical throughput of 55 samples/h. Lead concentrations ranged from 3.37 ± 0.25 to 7.03 ± 0.51 μg/g in dry material. This concentration interval is greater than that previously published in the literature. Conclusion – The inclusion of a pre‐concentration column in the flow manifold improved the sensitivity of the spectrometer. Thus, it was possible to determine the analyte at the ng/mL level in sample solutions of medicinal plants. This is a very important accomplishment, especially when the cumulative effect of heavy metals in living organisms is considered. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
970.
Davide Serruto Tiziana Spadafina Maria Scarselli Stefania Bambini Maurizio Comanducci Sonja Höhle Mogens Kilian Esteban Veiga Pascale Cossart Marco R. Oggioni Silvana Savino Ilaria Ferlenghi Anna Rita Taddei Rino Rappuoli Mariagrazia Pizza Vega Masignani Beatrice Aricò 《Cellular microbiology》2009,11(7):1044-1063
The Oca (Oligomeric coiled-coil adhesin) family is a subgroup of the bacterial trimeric autotransporter adhesins, which includes structurally related proteins, such as YadA of Yersinia enterocolitica and NadA of Neisseria meningitidis . In this study, we searched in silico for novel members of this family in bacterial genomes and identified HadA ( Haemophilus adhesin A), a trimeric autotransporter expressed only by Haemophilus influenzae biogroup aegyptius causing Brazilian purpuric fever (BPF), a fulminant septicemic disease of children. By comparative genomics and sequence analysis we predicted that the hadA gene is harboured on a mobile genetic element unique to BPF isolates. Biological analysis of HadA in the native background was limited because this organism is not amenable to genetic manipulation. Alternatively, we demonstrated that expression of HadA confers to a non-invasive Escherichia coli strain the ability to adhere to human cells and to extracellular matrix proteins and to induce in vitro bacterial aggregation and microcolony formation. Intriguingly, HadA is predicted to lack the typical N-terminal head domain of Oca proteins generally associated with cellular receptor binding. We propose here a structural model of the HadA coiled-coil stalk and show that the N-terminal region is still responsible of the binding activity and a KGD motif plays a role. Interestingly, HadA promotes bacterial entry into mammalian cells. Our results show a cytoskeleton re-arrangement and an involvement of clathrin in the HadA-mediated internalization. These data give new insights on the structure-function relationship of oligomeric coiled-coil adhesins and suggest a potential role of this protein in the pathogenesis of BPF. 相似文献