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LC
Kinds of LC Terms modified by LC Selected AbstractsThe effect of number of lengthening contractions on rat isometric force production at different frequencies of nerve stimulationACTA PHYSIOLOGICA, Issue 3 2009M. E. T. Willems Abstract Aim:, To test the effect of 3, 10, 60 and 240 lengthening contractions (LC) on maximal isometric force of rat plantar flexor muscles at different stimulation frequencies. Methods:, Using a dynamometer and electrical nerve stimulation, maximally active skeletal muscles were stretched by ankle rotation to produce LC of the plantar flexor muscles in intact female rats. After the lengthening contraction protocols, maximal isometric force was measured at different frequencies of nerve activation to obtain frequency-dependent force deficits (weakness). Results:, The magnitude of the force deficit, measured 1 h after the protocols at 80 Hz, increased as a function of repetition number (three LC, 33.3 ± 1.7%; 10 LC, 37.2 ± 2.3%; 60 LC, 67.6 ± 1.5%; 240 LC, 77.7 ± 1.2%). Force deficits were also measured at each stimulation frequency tested (5:120 Hz). Using a ratio of isometric force at 20:100 Hz stimulation, the relative depression of force at low frequency was determined. The relative depression of isometric force at low frequency was most prominent during the early repetitions. Conclusion:, As low-frequency force depression appears to result primarily from excitation,contraction (E,C) coupling failure, the early LC in a series of repeated contractions probably contribute most to damage of the cellular components involved in E,C coupling. [source] Phase transition behavior and structure of the thermotropic liquid crystal 6-{[(4,-{[(undecyl)carbonyl]oxy}biphenyl-4yl)carbonyl]oxy}-1-hexyneCRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2006Leijing Liu Abstract The phase transition behaviors and corresponding structures of 6-{[(4,-{[(undecyl)carbonyl]oxy}biphenyl-4yl)carbonyl]oxy}-1-hexyne (A4EE11) were investigated using differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and wide angle X-ray diffraction (WAXD). In comparison with the published homologues, 5-{[(4,-heptoxy-biphenyl-4-yl)carbonyl]oxy}-1-pentyne (A3EO7) which shows a monotropic smectic A (SmA) phase and a metastable monotropic smectic C (SmC) phase; 5-{[(4,-heptoxy-biphenyl-4-yl)oxy]carbonyl}- 1-pentyne (A3E'O7) that exhibits three enantiotropic stable liquid crystalline (LC) phases, SmA phase, SmC phase and smectic X (SmX) phase; 5-{[(4,-heptoxy-biphenyl-4-yl)carbonyl]oxy}-1-undecyne (A9EO7) which has a monotropic SmA phase and a metastable crystal phase, A4EE11 integrates the enantiotropy, monotropy and metastability of the LC phases of those three compounds. Upon cooling from isotropic state to room temperature, in the temperature range of 62.0 to 58.5°C, A4EE11 shows an enantiotropic smectic A (SmA) phase with a layer spacing d=32.69Å. Further lowering the temperature, it enters into a metastable monotropic smectic B (SmB) phase with a longer layer spacing d=34.22Å which has a tendency towards crystallization. The metastability of the liquid crystalline phase may associate to the linkage order of the ester bridge between the mesogenic core and the flexible spacer. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Molecular characterization of Ciona sperm outer arm dynein reveals multiple components related to outer arm docking complex protein 2CYTOSKELETON, Issue 10 2006Akiko Hozumi Abstract Using proteomic and immunochemical techniques, we have identified the light and intermediate chains (IC) of outer arm dynein from sperm axonemes of the ascidian Cionaintestinalis. Ciona outer arm dynein contains six light chains (LC) including a leucine-rich repeat protein, Tctex1- and Tctex2-related proteins, a protein similar to Drosophila roadblock and two components related to Chlamydomonas LC8. No LC with thioredoxin domains is included in Ciona outer arm dynein. Among the five ICs in Ciona, three are orthologs of those in sea urchin dynein: two are WD-repeat proteins and the third one, unique to metazoan sperm flagella, contains both thioredoxin and nucleoside diphosphate kinase modules. The remaining two Ciona ICs have extensive coiled coil structure and show sequence similarity to outer arm dynein docking complex protein 2 (DC2) that was first identified in Chlamydomonas flagella. We recently identified a third DC2-like protein with coiled coil structure, Ci-Axp66.0 that is also associated in substoichiometric amounts with Ciona outer arm dynein. In addition, Oda5p, a component of an additional complex required for assembly of outer arm dynein in Chlamydomonas flagella, also groups with this family of DC2-like proteins. Thus, the assembly of outer arm dynein onto doublet microtubules involves multiple coiled-coil proteins related to DC2. Cell Motil. Cytoskeleton 2006. © 2006 Wiley-Liss, Inc. [source] Neural correlates of movement generation in the ,at-risk mental state'ACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2010M. R. Broome Broome MR, Matthiasson P, Fusar-Poli P, Woolley JB, Johns LC, Tabraham P, Bramon E, Valmaggia L, Williams SCR, Brammer MJ, Chitnis X, McGuire PK. Neural correlates of movement generation in the ,at-risk mental state'. Objective:, People with ,prodromal' symptoms have a very high risk of developing psychosis. We examined the neurocognitive basis of this vulnerability by using functional MRI to study subjects with an at-risk mental state (ARMS) while they performed a random movement generation task. Method:, Cross-sectional comparison of individuals with an ARMS (n = 17), patients with first episode schizophreniform psychosis (n = 10) and healthy volunteers (n = 15). Subjects were studied using functional MRI while they performed a random movement generation paradigm. Results:, During random movement generation, the ARMS group showed less activation in the left inferior parietal cortex than controls, but greater activation than in the first episode group. Conclusion:, The ARMS is associated with abnormalities of regional brain function that are qualitatively similar to those in patients who have recently presented with psychosis but less severe. [source] The Attentional Resource Allocation Scale (ARAS): psychometric properties of a composite measure for dissociation and absorption,DEPRESSION AND ANXIETY, Issue 8 2010R. N. Carleton M.A. Abstract Background: Differences in attentional processes have been linked to the development and maintenance of psychopathology. Shifts in such processes have been described by the constructs Dissociation and Absorption. Dissociation occurs when external and/or internal stimuli are excluded from consciousness due to discrepant, rather than unitary, manifestations of cognitive awareness [Erdelyi MH. 1994: Int J Clin Exp Hypnosis 42:379,390]. In contrast, absorption can be conceptualized by a focus on limited stimuli, to the exclusion of other stimuli, because of unifying, rather than discrepant, manifestations of cognitive awareness. The Dissociative Experiences Scale [DES; Bernstein EM, Putnam FW. 1986: J Nerv Ment Dis 174:727,735] and Tellegen Absorption Scale [TAS; Tellegen A, Atkinson G. 1974: J Abnorm Psychol 83:268,277] are common measures of each construct; however, no factor analyses are available for the TAS and despite accepted overlap, no one has assessed the DES and TAS items simultaneously. Previous research suggests the constructs and factor structures need clarification, possibly including more parsimonious item inclusion [Lyons LC, Crawford HJ. 1997: Person Individ Diff 23:1071,1084]. The purpose of this study was to evaluate the factor structure of the DES and TAS and create a psychometrically stable measure of Dissociation and Absorption. Methods: This study included data from an undergraduate (n=841; 76% women) and a community sample (n=233; 86% women) who each completed the DES and TAS. Results: Exploratory factor analyses [Osborne JW (ed). 2008: Best Practices in Quantitative Methods. Los Angeles: Sage Publications Inc.] with all DES and TAS items suggested a 15-item 3-factor solution (i.e., imaginative involvement, dissociative amnesia, attentional dissociation). Confirmatory factor analyses resulted in excellent fit indices for the same solution. Conclusions: The items and factors were conceptualized in line with precedent research as the Attentional Resource Allocation Scale (ARAS). Comprehensive results, implications, and future research directions are discussed. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc. [source] Histological and Clinical Findings in Different Surgical Strategies for Focal Axillary HyperhidrosisDERMATOLOGIC SURGERY, Issue 8 2008FALK G. BECHARA MD INTRODUCTION Although a variety of different surgical strategies for focal axillary hyperhidrosis (FAH) have proven effective, little is known of intraoperative and postoperative histologies of different surgical methods. OBJECTIVE The objective was to use pre-, intra-, and postoperative histologic findings to evaluate different surgical procedures for FAH in establishing a possible correlation between the interventions and clinical outcome. MATERIAL AND METHODS A total of 40 patients underwent surgery with 15 undergoing liposuction-curettage (LC), 14 radical skin excision (RSE) with Y-plasty closure, and 11 a skin-sparing technique (SST). Before surgery, density and ratio of eccrine and apocrine sweat glands were evaluated with routine histology. Further biopsies were taken directly after surgery in the RSE and SST groups and 1 year postoperatively in all patients. Additionally, gravimetry was performed, side effects were documented, and patients were asked to evaluate the aesthetic outcome of the surgical method by using an analogue scale. RESULTS Preoperatively, the mean density of eccrine glands was 11.1/cm2 compared to 16.9/cm2 apocrine glands (apocrine/eccrine ratio, 1.6). Biopsy specimen directly after surgery showed remaining sweat glands in 7/15 (46.7%) LC patients and in 4/11 (36.4%) of the SST patients. One year after surgery, sweat gland density was significantly reduced in the LC (79.1%) and the SST (74.9%) groups. In the RSE group, only scar formation was present. Gravimetry showed significantly reduced sweat rates 12 months after surgery in all groups (LC, 66.4%; SST, 62.9%; RSE, 65.3% [p<.05]). Most frequent side effects were hematoma (LC, n=3; SST, n=2; RSE, n=3), subcutaneous fibrotic bridles (LC, n=8; SST, n=3; RSE, n=0), skin erosion (LC, n=3; SST, n=4; RSE, n=0), focal hair loss (LC, n=9; SST, n=11; RSE, n=14), and paresthesia (LC, n=4; SST, n=3; RSE, n=5). CONCLUSION Histologic distribution and density of sweat glands were comparable to previous studies. All three surgical procedures evaluated are effective in the treatment of FAH. RSE and SST techniques are associated with a higher risk of side effects and cause more extensive scarring. However, one LC patient (n=1; 6.7%) did not respond to treatment. [source] Methods for detecting and identifying retinoids in tissueDEVELOPMENTAL NEUROBIOLOGY, Issue 7 2006Thomas E. Gundersen Abstract Methods for retinoid analysis in tissue include direct spectrophotometry or fluorometry and retinoid responsive reporter constructs in the form of cell reporter assays or transgenic reporter animals, but chromatographic methods dominate and posses several superior features in quantitative analysis. The multitude of extraction protocols used can coarsely be divided into manual liquid-liquid extraction protocols and semi- or fully automated solid phase extraction-based protocols. Liquid chromatographic separation in reversed phase dominates although normal phase is also used. Detection is mainly performed with UV detectors although electrochemical and fluorescence detection is also used. Mass spectrometry in combination with LC is more often used in retinoid analysis and is likely to dominate in the future. © 2006 Wiley Periodicals, Inc. J Neurobiol 66: 631,644, 2006 [source] Neuronal differentiation and long-term survival of newly generated cells in the olfactory midbrain of the adult spiny lobster, Panulirus argusDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2001Manfred Schmidt Abstract The fate of continuously generated cells in the soma clusters of the olfactory midbrain of adult spiny lobsters, Panulirus argus, was investigated by in vivo pulse-chase experiments with the proliferation marker 5-bromo-2,-deoxyuridine (BrdU) combined with immunostainings for neuropeptides of mature neurons. A BrdU injection after a survival time (ST) of 14 h labeled about 100 nuclei in the lateral soma clusters (LC), comprised of projection neurons, and about 30 nuclei in the medial soma clusters (MC), comprised of local interneurons. The BrdU-positive nuclei were confined to small regions at the inside of these clusters, which also contain nuclei in different phases of mitosis and thus represent proliferative zones. After STs of 2 weeks or 3 months, the number of BrdU-positive nuclei was doubled, indicating a mitosis of all originally labeled cells. Dependent on ST, the BrdU-positive nuclei were translocated from the proliferative zones towards the outside of the clusters, where somata of mature neurons reside. Immunostainings with antibodies to the neuropeptides FMRFamide and substance P, both of which label a large portion of somata in the MC and a pair of giant neurons projecting into the LC, revealed that in both clusters the proliferative zones are surrounded by, but are themselves devoid of, labeling. In the MC, some BrdU-positive somata were double-labeled by the FMRFamide antibody after an ST of 3 months, and by the substance P antibody after STs of 6 and 11/14 months, but not after 3 months. In the LC, BrdU-positive somata after an ST of 3 months partially and after 6 and 11/14 months widely overlapped with the arborizations of the giant neurons, indicating the establishment of synaptic input. The experiments show that cells generated in proliferative zones in the LC and MC of adult spiny lobsters after a final mitosis differentiate into neurons within months, survive for at least 1 year, and are integrated into the circuitry of the olfactory midbrain. A new hypothesis about the mechanism of adult neurogenesis in the central olfactory pathway of decapod crustaceans is developed, linking it to neurogenesis during embryonic and larval development. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 181,203, 2001 [source] Differences in endoscopic views during biopsy through the right and left lower biopsy channels of the upper gastrointestinal endoscopeDIGESTIVE ENDOSCOPY, Issue 3 2004Naoki Mantani Background:, It has not been established as to which side the biopsy (instrument) channel should be placed in the tip of a front-viewing upper gastrointestinal (GI) endoscope to allow an en-face approach to lesions on various aspects of the stomach wall. Methods:, Using a front-viewing two-channel endoscope, we identi,ed a difference in endoscopic views during biopsy between lower-right and lower-left channels. Colored marks were distributed on the lesser curvature (LC), greater curvature (GC), anterior wall (AW), and posterior wall (PW) in the ,stomach' of a dummy for mock-performance of upper GI endoscopy. When biopsy forceps through the different channels touched the marks, an endoscopic photograph was taken. Furthermore, when biopsy specimens were obtained from PW lesions in several patients, endoscopic views were compared between the two biopsy channels. Results:, In the dummy study, no remarkable difference was detected in targeting the marks on AW, LC, or GC of the stomach. The dummy and the patient study showed that the lower-right approach could target PW lesions with a more adequate endoscopic view than from the lower left. The lower-left approach targeted PW lesions on the higher body with a nearly blinded endoscopic view. Specimens from PW of the upper body, which could be precisely obtained under direct visual control through the lower-right channel, were no smaller than those obtained using the channel on the lower left. Conclusion:, The present study suggests that the lower-right channel may be preferable to the lower-left channel in the tip of a front-viewing upper GI endoscope. [source] Direct injection horse-urine analysis for the quantification and confirmation of threshold substances for doping control.DRUG TESTING AND ANALYSIS, Issue 8 2009Abstract Levodopa and dopamine have been abused as performance-altering substances in horse racing. Urinary 3-methoxytyramine is used as an indicator of dopaminergic manipulation resulting from dopamine or levodopa administration and is prohibited with a urinary threshold of 4 µg mL,1 (free and conjugated). A simple liquid chromatographic (LC)/mass spectrometric (MS) (LCMS) method was developed and validated for the quantification and identification of 3-methoxytyramine in equine urine. Sample preparation involved enzymatic hydrolysis and protein precipitation. Hydrophilic interaction liquid chromatography (HILIC) was selected as a separation technique that allows effective retention of polar substances like 3-methoxytyramine and efficient separation from matrix compounds. Electrospray ionization (ESI) in positive mode with product ion scan mode was chosen for the detection of the analytes. Quantification of 3-methoxytyramine was performed with fragmentation at low collision energy, resulting in one product ion, while a second run at high collision energy was performed for confirmation (at least three abundant ions). Studies on matrix effects showed ion suppression depending on the horse urine used. To overcome the variability of the results originating from the matrix effects, isotopic labelled internal standard was used and linear regression calibration methodology was applied for the quantitative determination of the analyte. The tested linear range was 1,20 µg mL,1. The relative standard deviations of intra- and inter- assay analysis of 3-methoxytyramine in horse urine were lower than 4.2% and 3.2%, respectively. Overall accuracy (relative percentage error) was less than 6.2%. The method was applied to case samples, demonstrating simplicity, accuracy and selectivity. Copyright © 2009 John Wiley & Sons, Ltd. [source] Contemporary egg size divergence among sympatric grayling demes with common ancestorsECOLOGY OF FRESHWATER FISH, Issue 1 2008F. Gregersen Abstract, This study documents divergence in egg size that has occurred over less than 25 generations among sympatric demes of European grayling (Thymallus thymallus) from Lake Lesjaskogsvatnet in Norway. A cluster analysis identified two clusters of tributaries: one of small, warm tributaries (SW) and the other of large, cold tributaries (LC). Spawning occurs more regularly and up to 4 weeks earlier in SW tributaries compared with that in LC ones. We explored numerous mixed models predicting egg size from year (random effect), basin and tributary (fixed effects), and female length. The most supported model estimated length-adjusted egg size to be larger in SW tributaries compared with that in LC tributaries. Combinations of density-dependent (competition for food/space) and density-independent (temperature) factors along with phenotypic plasticity and maternal effects are discussed as potential differentiation sources. We suggest high temperatures (increased metabolism) to reinforce the selective advantage of large eggs under conditions with highly density-dependent fry interactions. [source] Simultaneous Determination of Dopamine and Ascorbic Acid Using the Nano-Gold Self-Assembled Glassy Carbon ElectrodeELECTROANALYSIS, Issue 10 2009Guangzhi Hu Abstract Electrochemical behavior of dopamine (DA) was investigated at the gold nanoparticles self-assembled glassy carbon electrode (GNP/LC/GCE), which was fabricated by self-assembling gold nanoparticles on the surface of L -cysteine (LC) modified glassy carbon electrode (GCE) via successive cyclic voltammetry (CV). A pair of well-defined redox peaks of DA on the GNP/LC/GCE was obtained at Epa=0.197,V and Epc=0.146,V, respectively. And the peak separation between DA and AA is about 0.2,V, which is enough for simultaneous determination of DA and AA. The peak currents of DA and AA were proportional with their concentrations in the range of 6.0×10,8,8.5×10,5 mol L,1 and 1.0×10,6,2.5×10,3 mol L,1, with the detection limit of 2.0×10,8 mol L,1 and 3.0×10,7 mol L,1 (S/N=3), respectively. The modified electrode exhibits an excellent reproducibility, sensibility and stability for simultaneous determination of DA and AA in human serum with satisfactory result. [source] Liquid chromatography on chipELECTROPHORESIS, Issue 15 2010Karine Faure Abstract LC is one of the most powerful separation techniques as illustrated by its leading role in analytical sciences through both academic and industrial communities. Its implementation in microsystems appears to be crucial in the development of ,-Total Analysis System. If electrophoretic techniques have been widely used in miniaturized devices, LC has faced multiple challenges in the downsizing process. During the past 5 years, significant breakthroughs have been achieved in this research area, in both conception and use of LC on chip. This review emphasizes the development of novel stationary phases and their implementation in microchannels. Recent instrumental advances are also presented, highlighting the various driving forces (pressure, electrical field) that have been selected and their respective ranges of applications. [source] Cationic and anionic lipid-based nanoparticles in CEC for protein separationELECTROPHORESIS, Issue 11 2010Christian Nilsson Abstract The development of new separation techniques is an important task in protein science. Herein, we describe how anionic and cationic lipid-based liquid crystalline nanoparticles can be used for protein separation. The potential of the suggested separation methods is demonstrated on green fluorescent protein (GFP) samples for future use on more complex samples. Three different CEC-LIF approaches for protein separation are described. (i) GFP and GFP N212Y, which are equally charged, were separated with high resolution by using anionic nanoparticles suspended in the electrolyte and adsorbed to the capillary wall. (ii) High efficiency (800,000 plates/m) and peak capacity were demonstrated separating GFP samples from Escherichia coli with cationic nanoparticles suspended in the electrolyte and adsorbed to the capillary wall. (iii) Three single amino-acid-substituted GFP variants were separated with high resolution using an approach based on a physical attached double-layer coating of cationic and anionic nanoparticles combined with anionic lipid nanoparticles suspended in the electrolyte. The soft and porous lipid-based nanoparticles were synthesized by a one-step procedure based on the self-assembly of lipids, and were biocompatible with a large surface-to-volume ratio. The methodology is still under development and the optimization of the nanoparticle chemistry and separation conditions can further improve the separation system. In contrast to conventional LC, a new interaction phase is introduced for every analysis, which minimizes carry-over and time-consuming column regeneration. [source] Cover Picture: Electrophoresis 9'2010ELECTROPHORESIS, Issue 9 2010Article first published online: 26 APR 2010 Issue no. 9 is a special issue on "CEC and EKC" comprising one "Fast Track" article and 21 articles distributed over two distinct parts. "Part I groups 13 contributions on enantioseparations in CE, CEC and capillary LC using various chiral selectors and their applications to a wide range of chiral species, while Part II assembles 8 papers on various methodological aspects and applications of EKC, CEC and CE". The "Fast Track" paper describes enhanced selectivity in CZE with multi-chiral selector systems. [source] Identification of rat urinary glycoproteome captured by three lectins using gel and LC-based proteomicsELECTROPHORESIS, Issue 21 2008Pyong-Gon Moon Abstract Many different types of urine proteome studies have been done, but urine glycoprotein studies are insufficient. Therefore, we studied the glycoproteins from rat urine, which could be used to identify biomarkers in an animal model. First, urinary proteins were prepared by using the dialysis and lyophilizing methods from rat urine. Glycoproteins enriched with lectin affinity purification, concanavalin A, jacalin and wheat germ agglutinin from the urinary proteins were separated by means of reverse-phase fast protein LC (FPLC) or 1-D PAGE. Each FPLC fraction and 1-D PAGE gel band were trypsin-digested and analyzed by means of nanoLC-MS/MS. LC-MS/MS analyses were carried out by using linear ion trap MS. A total of 318 rat urinary glycoproteins were identified from the FPLC fractions and gel bands; approximately 90% of identified proteins were confirmed as glycoproteins in Swiss-Prot. Many glycoproteins, known as biomarkers, including C-reactive protein, uromodulin, amyloid beta A4 protein, alpha-1-inhibitor 3, vitamin D-binding protein, kallikrein 3 and fetuin-A were identified in this study. By studying urinary glycoproteins collected from rat, these results may help to assist in identifying urinary biomarkers regarding various types of disease models. [source] The resistance of metallothionein to proteolytic digestion: An LC-MS/MS analysisELECTROPHORESIS, Issue 16 2007Rongying Wang Abstract Metallothioneins (MTs) are a family of cysteine-rich metalloproteins which strongly bind to heavy metals, such as Cd(II), Zn(II), and Cu(I). Previous works by other group using gel electrophoresis and fluorescence showed MTs were resistant to proteolytic digestion by a variety of enzymes, raising the difficulties in proteomic identification of MTs. The present work was attempted to analyze the resistance of MTs to trypsin using LC with MS/MS (LC-MS/MS), which was able to determine the sequences of the produced peptides and thus precisely characterize the cleavages. The results showed that metal-saturated MTs were completely resistant to trypsin. This resistance problem could be overcome by the addition of EDTA to MT samples, which rendered MTs readily digested into peptides and identified by MS/MS. Interestingly, the partially metal binding MTs were digested into peptides predominantly with miss cleavages which were well dependent on the amount of heavy metals bound to MTs. An explanation for these observations was proposed. The potential applications of the MT's resistance to trypsin in isolation and identification of MTs in complex mixtures such as cultured cells was demonstrated. The preliminary data also showed the same proteomic approach of proteolytic digestion followed by MS/MS analysis may provide information on metal binding status of MTs, along with the identification of MTs in a mixture. [source] Biomarker discovery in rat plasma for estrogen receptor-, actionELECTROPHORESIS, Issue 23 2005Tom G. Holt Dr. Abstract To support in vivo screening efforts for estrogen receptor (ER) subtype selective therapeutic agents, we initiated work to discover surrogate markers (biomarkers) in blood plasma that would change in response to ER subtype-specific action. We used a proteomic approach employing strong anion exchange chromatography (SAX), PAGE, and MS to identify potential plasma markers for selective ER-, action. The methodology was used to compare blood from vehicle-treated rats to blood from rats treated with either 17,-estradiol (an ER-,/ER-, agonist) or compound 1 (17,-ethynyl-[3,2-c]pyrazolo-19-nor-4-androstene-17,-ol, an ER-,-selective agonist). Blood samples were first fractionated by SAX to separate fractions containing dominant common plasma proteins from fractions enriched for less-abundant plasma proteins. 1-D PAGE analysis of fractions depleted of dominant plasma proteins revealed treatment-specific changes in protein profiles. Protein bands that changed reproducibly in response to ER-, action were excised from the gel, separated by capillary LC, and identified by microspray ESI-MS. Using this method, the plasma levels of two proteins, transthyretin and apolipoprotein E, were shown to decrease in response to ER-, agonism. The method lacked the sensitivity to identify the known, 1000-fold less-abundant, estrogenic marker prolactin (PRL). However, using a commercial RIA and immunoblots, we showed that PRL levels increase significantly in response to treatment with the ER-, selective agonist, compound 1. [source] Urtica dioica agglutinin: Separation, identification, and quantitation of individual isolectins by capillary electrophoresis and capillary electrophoresis,mass spectrometryELECTROPHORESIS, Issue 9 2005Markus Ganzera Abstract With benign prostatic hyperplasia (BPH) being a major health problem in ageing men, alternative therapeutic approaches (e.g., with phytopharmaceuticals) are of great interest. Based on pharmacological evidences, one of the most promising options in that respect are the lectins found in Urtica dioica (stinging nettle) roots. In this study the qualitative and quantitative analysis of individual isolectins in U. dioica extracts is described, which is the first report on using capillary electrophoresis (CE) for the analysis of lectins in plant material at all. By utilizing a 200 mM sodium acetate buffer (pH 3.75) a baseline separation and determination of four closely related isolectins was feasible within 20 min in the aqueous plant extracts. The individual compounds were identified based on reference compounds as well as data obtained from CE-mass spectrometry (MS) experiments. After modifying the optimized CE conditions to 100 mM ammonium formate buffer with pH 3.75 and a voltage of 15 kV, the isolectins were clearly assignable in positive electrospray ionization (ESI) mode. The quantitative results obtained by CE (the total lectin content varied from 0 to 0.42% in the samples) were accurate (recovery rates of spiked samples between 92.5 and 96.2%), precise (relative standard deviation < 5%) and in good agreement to those obtained by High-performance liquid chromatography (HPLC). As for peak resolution, assignable compounds and required separation time the newly developed CE method was clearly advantageous over the determination achieved by LC. [source] High-efficiency peptide analysis on monolithic multimode capillary columns: Pressure-assisted capillary electrochromatography/capillary electrophoresis coupled to UV and electrospray ionization-mass spectrometryELECTROPHORESIS, Issue 21 2003Alexander R. Ivanov Abstract High-efficiency peptide analysis using multimode pressure-assisted capillary electrochromatography/capillary electrophoresis (pCEC/pCE) monolithic polymeric columns and the separation of model peptide mixtures and protein digests by isocratic and gradient elution under an applied electric field with UV and electrospray ionization-mass spectrometry (ESI-MS) detection is demonstrated. Capillary multipurpose columns were prepared in silanized fused-silica capillaries of 50, 75, and 100 ,m inner diameters by thermally induced in situ copolymerization of methacrylic monomers in the presence of n -propanol and formamide as porogens and azobisisobutyronitrile as initiator. N -Ethylbutylamine was used to modify the chromatographic surface of the monolith from neutral to cationic. Monolithic columns were termed as multipurpose or multimode columns because they showed mixed modes of separation mechanisms under different conditions. Anion-exchange separation ability in the liquid chromatography (LC) mode can be determined by the cationic chromatographic surface of the monolith. At acidic pH and high voltage across the column, the monolithic stationary phase provided conditions for predominantly capillary electrophoretic migration of peptides. At basic pH and electric field across the column, enhanced chromatographic retention of peptides on monolithic capillary column made CEC mechanisms of migration responsible for separation. The role of pressure, ionic strength, pH, and organic content of the mobile phase on chromatographic performance was investigated. High efficiencies (exceeding 300,000 plates/m) of the monolithic columns for peptide separations are shown using volatile and nonvolatile, acidic and basic buffers. Good reproducibility and robustness of isocratic and gradient elution pressure-assisted CEC/CE separations were achieved for both UV and ESI-MS detection. Manipulation of the electric field and gradient conditions allowed high-throughput analysis of complex peptide mixtures. A simple design of sheathless electrospray emitter provided effective and robust low dead volume interfacing of monolithic multimode columns with ESI-MS. Gradient elution pressure-assisted mixed-mode separation CE/CEC-ESI-MS mass fingerprinting and data-dependent pCE/pCEC-ESI-MS/MS analysis of a bovine serum albumin (BSA) tryptic digest in less than 5 min yielding high sequence coverage (73%) demonstrated the potential of the method. [source] Seasonal dynamics of the hepatotoxic microcystins in various organs of four freshwater bivalves from the large eutrophic lake Taihu of subtropical China and the risk to human consumptionENVIRONMENTAL TOXICOLOGY, Issue 6 2005Jun Chen Abstract So far, little is known on the distribution of hepatotoxic microcystin (MC) in various organs of bivalves, and there is no study on MC accumulation in bivalves from Chinese waters. Distribution pattern and seasonal dynamics of MC-LR, -YR and -RR in various organs (hepatopancreas, intestine, visceral mass, gill, foot, and rest) of four edible freshwater mussels (Anodonta woodiana, Hyriopsis cumingii, Cristaria plicata, and Lamprotula leai) were studied monthly during Oct. 2003,Sep. 2004 in Lake Taihu with toxic cyanobacterial blooms in the summer. Qualitative and quantitative determinations of MCs in the organs were done by LC,MS and HPLC. The major toxins were present in the hepatopancreas (45.5,55.4%), followed by visceral mass with substantial amount of gonad (27.6,35.5%), whereas gill and foot were the least (1.8,5.1%). The maximum MC contents in the hepatopancreas, intestine, visceral mass, gill, foot, and rest were 38.48, 20.65, 1.70, 0.64, 0.58, and 0.61 ,g/g DW, respectively. There were rather good positive correlation in MC contents between intestines and hepatopancreas of the four bivalves (r = 0.75,0.97, p < 0.05). There appeared to be positive correlations between the maximum MC content in the hepatopancreas and the ,13C (r = 0.919) or ,15N (r = 0.878) of the foot, indicating that the different MC content in the hepatopancreas might be due to different food ingestion. A glutathione (GSH) conjugate of MC-LR was also detected in the foot sample of C. plicata. Among the foot samples analyzed, 54% were above the provisional WHO tolerable daily intake (TDI) level, and the mean daily intakes from the four bivalves were 8,23.5 times the TDI value when the bivalves are eaten as a whole, suggesting the high risk of consuming bivalves in Lake Taihu. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 572,584, 2005. [source] A two-step model for Langerhans cell migration to skin-draining LNEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2008Eduardo J. Villablanca Abstract Although the role of Langerhans cells (LC) in skin immune responses is still a matter of debate, it is known that LC require the chemokine receptor CCR7 for migrating to skin-draining LN. A report in the current issue of the European Journal of Immunology unfolds some of the intricacies of LC migration, showing that LC need CXCR4, but not CCR7, for their migration from the epidermis to the dermis. Thus, LC migration to skin-draining LN occurs in two distinct phases: a first step from the epidermis to the dermis regulated by CXCR4 and a second CCR7-dependent step from the dermis to LN. Here we discuss the potential implications of this new two-step LC migration paradigm. [source] TNF-, induces the generation of Langerin/(CD207)+ immature Langerhans-type dendritic cells from both CD14,CD1a, and CD14+CD1a, precursors derived from CD34+ cord blood cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2003Jean-François Arrighi Abstract CD34+ cell-derived hematopoietic precursors amplified with FLT3-ligand, thrombopoietin and stem cell factor became, after a 6-day induction with GM-CSF, IL-4 and TGF-,1, HLA-DR+, CD1a+, CD83,, CD86,, CD80, cells. A fraction of them expressed Langerin, Lag, and E-cadherin, resembling epidermal Langerhans cells (LC). TNF-, addedfor the last 3,days only marginally induced CD83 expression, but strikingly increased the proportion of immature Langerin+CD83, LC. Langerin+CD83+ and Langerin+CD83, cells were functionally distinct, the former internalizing less efficiently Langerin than the latter. Both CD1a,CD14, and CD1a,CD14+ cells sorted from FLT3-ligand, thrombopoietin and stem cell factor cultures responded to TNF-, by an increase of Langerin+ cells. Thus, TNF-, rescued LC precursors irrespective of their commitment to the monocytic lineage. When added to GM-CSF, IL-4 and TGF,,1 containing-cultures, LPS or IL-1, also induced significant numbers of Langerin+CD83, immature cells displaying a low allostimulatory activity, while CD40-ligand largely promoted highly allostimulatory Langerin,CD83+ cells. Altogether, these data show that in contrast to CD40-ligand, which induced LC maturation even in presence of TGF-,1, nonspecific proinflammatory factors such as TNF-,, IL-1, or LPS, essentially induced immature LC generation, and little cell activation in the presence of TGF-,1. [source] Should levodopa dose be reduced when switched to stalevo?EUROPEAN JOURNAL OF NEUROLOGY, Issue 3 2008G. Linazasoro The addition of entacapone to levodopa-carbidopa (LC) or the switch from LC to a tablet containing levodopa,carbidopa,entacapone (LCE) improves the wearing-off phenomenon, increases the ,on' time and decreases the ,off' time, but the appearance or exacerbation of dyskinesias is the more frequent side-effect. Thus, a reduction of the total levodopa dosage would be recommended. However, this could result in a lack of efficacy against the wearing-off. We report on the results of a clinical trial conducted to determine the best way in terms of efficacy, tolerability and safety of switching from LC to LCE in patients with Parkinson's disease (PD) and end of dose wearing-off. 39 patients with PD and wearing-off without or with mild dyskinesias were randomly assigned to either a group receiving the same LC dosage or to a group in which the total LC amount was reduced by 15,25%. Four weeks after the change, both groups showed an increase in daily ,on' time and a reduction in the daily time spent in ,off'. Two patients in each group experienced an increase in basal dyskinesias. No differences in clinical assessment between groups were found. Tolerance was excellent. This study suggests that switching from LC to LCE in patients with mild-to-moderate wearing-off can be done safely with or without reducing the total LD amount, but in the clinical setting it would be more practical to keep the dosage of LC unchanged unless severe dyskinesias are present. [source] Altered presynaptic function in monoaminergic neurons of monoamine oxidase-A knockout miceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2002Catarina Å. Owesson Abstract Monoamine oxidase-A knockout (MAO-A KO) mice have elevated brain serotonin (5-HT) and noradrenaline (NA) levels, and one would therefore anticipate increased monoamine release and compensatory changes in other aspects of presynaptic monoamine function. In this study we used voltammetry in brain slices from the locus coeruleus (LC), dorsal raphe (DRN) and striatum (CPu) in 7-week-old MAO-A KO and C3H control mice to measure stimulated monoamine efflux and its control by amine transporters and autoreceptors. In LC, peak NA efflux on stimulation (99 pulses, 100 Hz) was higher in MAO-A KO than C3H mice (938 ± 58 nm cf. 511 ± 42 nm; P < 0.001). The NA uptake half time (t½) was longer in MAO-A KO than in C3H mice (6.0 ± 0.9 s cf. 1.9 ± 0.3 s; P < 0.001) and the selective NA reuptake inhibitor desipramine (50 nm) had a smaller effect in MAO-A KO mice. NA transporter binding was significantly lower in the LC of MAO-A KO mice compared to C3H controls (P < 0.01) but not in the DRN. The ,2 agonist dexmedetomidine (10 nm) decreased stimulated NA efflux more in C3H than in MAO-A KO mice (73.3% cf. 29.6% inhibition, P < 0.001). In DRN, peak 5-HT efflux on stimulation (99 pulses, 100 Hz) was greater (P < 0.01) in MAO-A KO (262 ± 44 nm) than C3H mice (157 ± 16 nm). Moreover, 5-HT uptake t½ was longer (P < 0.05) in MAO-A KO than in C3H mice (8.8 ± 1.1 s cf. 4.9 ± 0.6 s, P < 0.05) and the effect of citalopram (75 nm) was attenuated in MAO-A KOs. Serotonin transporter binding was also lower in both the DRN and LC of MAO-A KO mice. The 5-HT1A agonist 8-OH-DPAT (1 µm) decreased 5-HT efflux more in C3H than in MAO-A KO mice (38.3% inhibition cf. 21.6%, P < 0.001). In contrast, there were no significant differences between MAO-A KO and C3H mice in CPu dopamine efflux and uptake and the effect of the D2/3 agonist quinpirole was similar in the two strains. In summary, MAO-A KO mice show major dysregulation of monoaminergic presynaptic mechanisms such as autoreceptor control and transporter kinetics. [source] Sealing ability of occlusal resin composite restoration using four restorative proceduresEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 6 2008Danuchit Banomyong The purpose of this work was to investigate fluid flow after restoration using four restorative procedures. Micro-gap, internal dye leakage, and micropermeability of bonded interfaces were also investigated. Each tooth was mounted, connected to a fluid flow-measuring device, and an occlusal cavity was prepared. Fluid flow after cavity preparation was recorded as the baseline measurement, and the cavity was restored using one of four restorative procedures: bonding with total-etch (Single Bond 2) or self-etch (Clearfil SE Bond) adhesives without lining; or lining with resin-modified glass-ionomer cement (GIC) (Fuji Lining LC) or conventional GIC (Fuji IX) and then bonding with the total-etch adhesive. Fluid flow was recorded after restoration and at specific time-points up to 6 months thereafter and recorded as a percentage. Micro-gap formation was analyzed using resin replicas and scanning electron microscopy. Internal leakage of 2% methylene blue dye was observed under a light microscope. In micro-permeability testing, fluorescent-dye penetration was investigated using confocal laser microscopy. None of the restorative procedures provided a perfectly sealed restoration. Glass-ionomer lining did not reduce fluid flow after restoration, and micro-gaps were frequently detected. The self-etch adhesive failed to provide a better seal than the total-etch adhesive, and even initial gap formation was rarely observed for the former. Penetration of methylene blue and fluorescent dyes was detected in most restorations. [source] Crack closure on rehydration of glass-ionomer materialsEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2004Sharanbir K. Sidhu Moisture-sensitivity of immature glass-ionomer cements suggests that hydration-induced volumetric expansion might close and potentially heal established cracks. Crack closure in glass-ionomer cements (GICs) was observed following rehydration. Circular cavities were prepared in 15 teeth: 10 were restored with resin-modified GICs (5 with Fuji II LC and 5 with Photac-Fil) and 5 were restored with a conventional GIC (Fuji IX); all were dehydrated for 1 min with air and imaged immediately by confocal microscopy. Crack formation in each was located, after which water was placed on the surface and observed for 15 min via a CCD camera. Dehydration caused cracks with measurable gaps, while rehydration resulted in varying degrees of closure: closure was limited in the conventional GIC, and complete or near complete along part/s of the crack in the resin-modified GICs. In all, closure movement became imperceptible after the first 10 min. Statistical analysis indicated no significant difference between the closure behavior of all materials. However, the resin-modified GICs appeared to show a greater potential for closure of established cracks than the conventional GIC upon rehydration. [source] Four-year water degradation of a resin-modified glass-ionomer adhesive bonded to dentinEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2004Jan De Munck Glass-ionomers are auto-adhesive to tooth tissue through combined micro-mechanical and chemical bonding. How much each of the two bonding components contributes to the actual bonding effectiveness is, however, not known and there is not much information available on long-term stability. The objective of this study was to assess the bonding effectiveness of a resin-modified glass-ionomer adhesive to dentin after 4 yr of water storage. Fuji Bond LC (GC) was applied without (i) and with pretreatment using (ii) a polyalkenoic acid conditioner and (iii) a 37.5% phosphoric acid etchant. The etchant was used to exclude any chemical interaction with hydroxyapatite. The micro-tensile bond strength (µTBS) to dentin decreased significantly over the 4 yr period in all three experimental groups. After 24 h and 4 yr, the lowest µTBS was recorded when dentin was not pretreated. The highest µTBS was obtained following polyalkenoic acid pretreatment, although this was not significantly different from specimens that were pretreated using phosphoric acid. Pretreating dentin with phosphoric acid intensified micromechanical interlocking at the expense of chemical bonding potential to hydroxyapatite. Nevertheless, correlating the µTBS data with failure analysis through scanning electron microscopy and transmission electron microscopy indicated that combined micro-mechanical and chemical bonding involving pretreatment with the polyalkenoic acid conditioner yielded the most durable bond. [source] Identification of organic eluates from four polymer-based dental filling materialsEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2003Vibeke Barman Michelsen Elution from polymer-based dental filling materials may have a potential impact on the biocompatibility of the materials. Since information from the manufacturers about ingredients in the materials often is incomplete, analyses of eluates from the materials are necessary for a better knowledge about possible harmful compounds. The aim of this study was to identify organic eluates from polymerized samples of two composites, one compomer and one resin-reinforced glass ionomer cement. Samples were immersed in ethanol or Ringer's solution. Organic leachables were analyzed by gas chromatography,mass spectrometry. Identification was confirmed with reference substances, if available. Among components detected were monomers, co-monomers, initiators, stabilizers, decomposition products and contaminants. Thirty-two substances were identified and 17 were confirmed with reference substances. From elution in Ringer's we identified 13 eluates from Tetric Ceram, 10 from Z250, 21 from Dyract and six from Fuji II LC; HEMA, HC and CQ were found in all samples. From elution in ethanol 12 eluates from Tetric Ceram, 18 eluates from Z250, 19 from Dyract and 10 from Fuji II LC were identified. The diversity of eluates from the four materials under study is demonstrated. Owing to variation between the materials, the biocompatibility including the allergenic potential may be different. [source] E-model based comparison of multiple description coding and layered coding in packet networksEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 7 2007Yugang Zhou We examine the performance of multiple description coding (MDC) with and without the use of automatic repeat request (ARQ) protocols for packet network communication, in comparison with layered coding (LC). The rate-distortion lower bound of MDC and LC are incorporated into an E-model based performance measure, which accounts for the additional costs of excess rates and delay incurred from using ARQ. The results show that the relative merits of the schemes depend on the values of the packet loss rates and round-trip-time (RTT). LC is superior for small RTT and unaided MDC is superior for large RTT. For moderate RTT, LC is preferred for small packet loss rates and MDC aided by ARQ is preferred for large packet loss rates. Copyright © 2007 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||||||||||||||