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1.
We describe a microfluidic device that can be used to detect interactions between red blood cells (RBCs) and endothelial cells using a gold pillar array (created by electrodeposition) and an integrated detection electrode. Endothelial cells can release nitric oxide (NO) via stimulation by RBC‐derived ATP. These studies incorporate on‐chip endothelial cell immobilization, direct RBC contact, and detection of NO in a single microfluidic device. In order to study the RBC‐EC interactions, this work used a microfluidic device made of a PDMS chip with two adjacent channels and a polystyrene base with embedded electrodes for creating a membrane (via gold pillars) and detecting NO (at a glassy carbon electrode coated with platinum‐black and Nafion). RBCs were pharmacologically treated with treprostinil in the absence and presence of glybenclamide, and ATP release was determined as was the resultant NO release from endothelial cells. Treprostinil treatment of RBCs resulted in ATP release that stimulated endothelial cells to release on average 1.8±0.2 nM NO per endothelial cell (average±SEM, n=8). Pretreatment of RBCs with glybenclamide inhibited treprostinil‐induced ATP release and, therefore, less NO was produced by the endothelial cells (0.92±0.1 nM NO per endothelial cell, n=7). In the future, this device can be used to study interactions between many other cell types (both adherent and non‐adherent cell lines) and incorporate other detection schemes. 相似文献
2.
Fang Wang Xiaocui Deng Wei Wang Zilin Chen 《Journal of Solid State Electrochemistry》2011,15(4):829-836
A nitric oxide (NO) electrochemical sensor was developed via one-step construction of gold nanoparticles (GNPs)–chitosan (CS)
nanocomposite sensing film on a glassy carbon electrode (GCE) surface. This method is very simple and convenient. The GNPs–CS
film which is controllable and stable exhibits catalytic activity to NO oxidation. The anodic peak potential significantly
shifted negatively compared with that at bare GCE. The high sensitivity and good stability of developed method have been coupled
to a wide linear range from 3.60 × 10−8 to 4.32 × 10−5 M for the quantitative analysis of NO. The detection limit of 7.20 nM is much lower than the vast majority of reported methods.
This NO sensor has been successfully applied to NO measurement in biological and pharmaceutical samples. Real-time amperometric
data show that the addition of L-arginine (L-Arg) can cause a slow release of NO from a whole rat kidney with a maximum concentration
of ca. 150 nM. The concentration of NO monitoring from the drug sample was calculated to be ca. 1.60 μM. 相似文献
3.
Joana P. N. Ribeiro Luís M. Magalhães Marcela A. Segundo Salette Reis José L. F. C. Lima 《Analytical and bioanalytical chemistry》2010,397(7):3005-3014
In the present work, a fluorimetric automatic method based on multisyringe flow injection analysis (MSFIA) was developed for
in vitro evaluation of scavenging capacity against nitric oxide (NO) using 4,5-diaminofluorescein (DAF-2) as an NO-selective
fluorogenic probe. The MSFIA manifold was assembled to perform the in-line generation of NO and the competitive reaction of
putative scavenger molecules and DAF-2 with NO at conditions close to those found in vivo regarding temperature (37°C), pH
(7.4), and concentration of NO (less than 1 μM). This approach allowed the evaluation of scavenging capacity against NO by
endogenous antioxidant molecules, pharmaceutical compounds, and human plasma. IC50 values were calculated for rutin (1.30 ± 0.02 μM, positive control), cysteine (321 ± 8 μM), reduced glutathione (1106 ± 93 μM),
uric acid (134 ± 12 μM), dipyrone (1.36 ± 0.06 μM), and captopril (363 ± 28 μM). A high degree of automation was attained
as the successive dilution of antioxidant standard solutions required for IC50 assessment was performed automatically, in a dilution chamber placed in the flow system. A determination throughput of 16 h-1 and a good precision were attained (relative standard deviation between 1.6 and 9.0%), fostering the application of the proposed
method to routine/screening analysis of scavenging capacity against NO. 相似文献
4.
Glycerol would stimulate the production of poly(γ-glutamic acid) (γ-PGA) and decrease its molecular weight in Bacillus subtilis NX-2. When 20 g/l glycerol was added in the medium, the yield of γ-PGA increased from 26.7 ± 1.0 to 31.7 ± 1.3 g/l, and molecular
weight of γ-PGA decreased from 2.43 ± 0.07 × 106 to 1.86 ± 0.06 × 106 Da. In addition, it was found that the decrease of γ-PGA chain length by glycerol would lead to the decrease of broth viscosity
during the fermentation and enhanced the uptake of substrates, which could not only improve cell growth but also stimulate
γ-PGA production. Moreover, it was also found that glycerol could effectively regulate molecular weight between 2.43 ± 0.07 × 106 and 1.42 ± 0.05 × 106 Da with the concentration ranging from 0 to 60 g/l. This was the first time to discover such contribution of glycerol on
γ-PGA production in Bacillus genus. And the effects of glycerol on molecular weight of γ-PGA would be developed to be an approach for the regulation of
microbial γ-PGA chain length, which is of practical importance for future commercial development of this polymer. 相似文献
5.
The alterations of organic acids citrate, α-ketoglutarate, succinate, fumarate, malate production together with isocitrate
lyase activity as a glyoxalate shunt enzyme, and antibiotic production of Streptomyces sp M4018 were investigated in relation to changes in the glucose, glycerol and starch concentrations (5–20 g/L) after identification
as a strain of Streptomyces hiroshimensis based on phenotypic and genotypic characteristics. The highest intracellular citrate and α-ketoglutarate levels in 20 g/l
of glucose, glycerol, and starch mediums were 399.47 ± 4.78, 426.93 ± 6.40, 355.84 ± 5.38 ppm and 444.81 ± 5.12, 192.96 ± 2.26,
115.20 ± 2.87 ppm, respectively. The highest succinate, malate, and fumarate levels were also determined in 20 g/l of glucose
medium as 548.9 ± 11.21, 596.15 ± 8.26, and 406.42 ± 6.59 ppm and the levels were significantly higher than the levels in
glycerol and starch. Extracellular organic acid levels measured also showed significant correlation with carbon source concentrations
by showing negative correlation with pH levels of the growth medium. The antibiotic production of Streptomyces sp. M4018 was also higher in glucose medium as was the case also for organic acids when compared with glycerol. On the other
hand, there is no production in starch. 相似文献
6.
Huang KJ Zhang M Xie WZ Zhang HS Feng YQ Wang H 《Analytical and bioanalytical chemistry》2007,388(4):939-946
A simple, sensitive, selective, and low-cost method is proposed for rapidly determining nitric oxide (NO) in some rat tissues.
Polymer monolith microextraction (PMME) using a poly(methacrylic acid–ethylene glycol dimethacrylate) (MAA-EGDMA) monolithic
column was combined with derivatization of NO using 1,3,5,7-tetramethyl-8-(3′,4′-diaminophenyl)-difluoroboradiaza-s-indacene (TMDABODIPY), and this was used to analyze the derivatives of NO by high-performance liquid chromatography (HPLC)
with fluorescence detection at λ
ex/λ
em = 498/507 nm. The baseline separation of TMDABODIPY and its NO derivative is performed under simple conditions in which a
C18 column is used and eluted with 50 mmol L−1 ethanolamine and methanol. The conditions for the extraction of NO derivatives were optimized. The limit of detection of
NO was 2 × 10−12 mol L−1 (S/N = 3). The linearity range of the method was 9 × 10−11−4.5 × 10−8 mol L−1. The interday and intraday relative standard deviations were less than 5%. The proposed method was successfully applied to
the determination of NO levels in some rat tissue samples including heart, kidney, and liver with recoveries varying from
87.1 to 95.2%. 相似文献
7.
Valiollah Babaeipour Seyed Abbas Shojaosadati Rasoul Khalilzadeh Nader Maghsoudi Amir Mohammad Farnoud 《Applied biochemistry and biotechnology》2010,160(8):2366-2376
Development of inexpensive and simple culture media and appropriate induction conditions are always favorable for industry.
In this research, chemical composition and stoichiometric data for γ-interferon production and recombinant Escherichia coli growth were used in order to achieve a simple medium and favorable induction conditions. To achieve this goal, the effects
of medium composition and induction conditions on the production of γ-interferon were investigated in batch culture of E. coli BL21 (DE3) [pET3a-ifnγ]. These conditions were considered as suitable conditions for the production of γ-interferon: 2.5× M9 medium, supplemented
with a mixture of amino acids (milligram per liter), including glutamic acid 215, aspartic acid 250, lysine 160, and phenylalanine
90, and induction at late-log phase (OD600 = 4.5). Under these conditions, dry cell weight of 6 ± 0.2 g/l and γ-interferon concentration of 2.15 ± 0.1 g/l were obtained.
Later, without changing the concentration ratio of amino acids and glucose, the effect of increase in the primary glucose
concentration on productivity of γ-interferon was investigated. It was found that 25 g/l glucose will result in maximum attainable
biomass and recombinant human γ-interferon. At improved conditions, a dry cell weight of 14 ± 0.2 g/l, concentration and overall
productivity of γ-interferon 4.2 ± 0.1 g/l and 420 ± 10 mg/l h, respectively, were obtained. 相似文献
8.
Giovannoli C Anfossi L Baggiani C Giraudi G 《Analytical and bioanalytical chemistry》2008,392(3):385-393
Experimental work performed was aimed at the assessment of a competitive capillary electrophoresis immunoassay with laser-induced
fluorescence (CEIA-LIF) detection for the determination of the Cry1Ab endotoxin from Bacillus thuringensis. The binding constant of a monoclonal antibody, raised against the insecticide protein Cry1Ab, was determined on a microplate
by indirect enzyme-linked immunosorbent assay (ELISA) and compared with that obtained in-capillary under nonequilibrium separation
conditions. The two binding constants appear comparable—(5.0 ± 1.2) × 106 M−1 and (9.06 ± 5.7) × 106 M−1—reflecting good preservation of the antibody binding behavior in the capillary electrophoresis format. These results allow
use of a calibration curve possible between 0.2 and 150 nM of endotoxin protein, with a limit of detection of 0.5 nM (33 μg L−1). Preliminary recovery experiments on maize extracts spiked with known amounts of Cry1Ab endotoxin also showed promising
results in detecting the toxin in complex real matrices. 相似文献
9.
Campos-Candel A Llobat-Estellés M Mauri-Aucejo AR 《Analytical and bioanalytical chemistry》2007,387(4):1517-1523
A procedure for the determination of benzene, toluene, ethylbenzene and o-xylene, m-xylene and p-xylene (BTEX) in occupational environments is proposed. These compounds are extracted from activated charcoal using accelerated
solvent extraction. Operational parameters are optimized and quantitative recovery is obtained using acetonitrile as the extraction
solvent and 1-mL extraction cells, a preheat time of 2 min, a temperature of 160 °C, a pressure of 1,500 psi, a static period
of 5 min, a flush volume of 110%, two cycles and a purge time of 90 s. Determination of BTEX compounds is carried out by gas
chromatography using a flame ionization detector. The recoveries, obtained for a confidence level of 95%, are 91 ± 4, 100 ± 3,
104 ± 2, 93 ± 4, 99 ± 2 and 99 ± 2% for benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene, respectively. The detection limits are 0.5 μg for benzene, 0.7 μg for toluene and 1.0 μg for the other compounds.
The proposed procedure has been applied to real samples collected in several workplaces, like a microbiology laboratory, an
analytical chemistry laboratory, a printer’s, a car repair shop and a petrol station. From the results obtained, it can be
concluded that the occupational exposures determined are always acceptable because they are lower than the tenth part of the
recommended exposure limits (VLA-ED and VLA-EC). 相似文献
10.
Krska R Schubert-Ullrich P Josephs RD Emteborg H Buttinger G Pettersson H van Egmond HP Schothorst RC Macdonald S Chan D 《Analytical and bioanalytical chemistry》2007,388(5-6):1215-1226
This paper presents results from the European Commission-funded project Doncalibrant, the objective of which was to produce
calibrators with certified mass fractions of the Fusarium toxins deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-Ac-DON), 15-acetyldeoxynivalenol (15-Ac-DON), and nivalenol (NIV),
in acetonitrile. The calibrators, available in ampoules, were sufficiently homogeneous, with between-bottle variations (s
bb) of less than 2%. Long-term stability studies performed at four different temperatures between −18 and 40 °C revealed no
significant negative trends (at a confidence level of 95%). Molar absorptivity coefficients (in L mol−1 cm−1) were determined for all four toxins (DON: 6805 ± 126, NIV: 6955 ± 205, 3-Ac-DON: 6983 ± 141, 15-Ac-DON: 6935 ± 142) on the
basis of a mini-interlaboratory exercise. The overall uncertainty of the calibrators’ target values for DON and NIV were evaluated
on the basis of gravimetric preparation data and include uncertainty contributions from possible heterogeneity, storage, and
transport. The Doncalibrant project resulted in the production of calibrators for DON (IRMM-315) and NIV (IRMM-316) in acetonitrile
with certified mass fractions of 25.1 ± 1.2 μg g−1 and 24.0 ± 1.1 μg g−1, respectively. Both CRMs became commercially available from the Institute for Reference Materials and Measurements (IRMM,
Geel, Belgium) at the beginning of 2007. 相似文献
11.
Anna M. Clark Kyle M. Sousa Claire N. Chisolm Ormond A. MacDougald Robert T. Kennedy 《Analytical and bioanalytical chemistry》2010,397(7):2939-2947
A three-layer microfluidic device was developed that combined perfusion of cultured cells with on-line chemical analysis for
near real-time monitoring of cellular secretions. Two layers were reversibly sealed to form a cell chamber that allowed cells
grown on coverslips to be loaded directly into the chip. The outlet of the chamber was in fluidic contact with a third layer
that was permanently bonded. Perfusate from the cell chamber flowed into this third layer where a fluorescence enzyme assay
for non-esterified fatty acid (NEFA) was performed on-line. The device was used to monitor efflux of NEFAs from ∼6,200 cultured
adipocytes with 83 s temporal resolution. Perfusion of murine 3T3-L1 cultured adipocytes resulted in an average basal concentration
of 24.2 ± 2.4 μM NEFA (SEM, n = 6) detected in the effluent corresponding to 3.31 × 10−5 nmol cell−1 min−1. Upon pharmacological treatment with a β-adrenergic agonist to stimulate lipolysis, a 6.9 ± 0.7-fold (SEM, n = 6) sustained increase in NEFA secretion was observed. This multilayer device provides a versatile platform that could be
adapted for use with other cell types to study corresponding cellular secretions in near real-time. 相似文献
12.
Cell–cell communication is often achieved via granular exocytosis, as in neurons during synaptic transmission or neuroendocrine
cells during blood hormone control. Owing to its critical role in membrane properties and SNARE function, cholesterol is expected
to play an important role in the highly conserved process of exocytosis. In this work, membrane cholesterol concentration
is systematically varied in primary culture mouse chromaffin cells, and the change in secretion behavior of distinct vesicle
pools as well as pool recovery following stimulation is measured using carbon-fiber microelectrode amperometry. Amperometric
traces obtained from activation of the younger readily releasable and slowly releasable pool (RRP/SRP) vesicles at depleted
cholesterol levels showed fewer sustained fusion pore features (6.1 ± 1.1% of spikes compared with 11.2 ± 1.0% for control),
revealing that cholesterol content influences fusion pore formation and stability during exocytosis. Moreover, subsequent
stimulation of RRP/SRP vesicles showed that cellular cholesterol level influences both the quantal recovery and kinetics of
the later release events. Finally, diverging effects of cholesterol on RRP and the older reserve pool vesicle release suggest
two different mechanisms for the release of these two vesicular pools. 相似文献
13.
The objective of this work was to delineate the effect of hydrophilic and hydrophobic polymeric additives on sol–gel transition
and release profile of timolol maleate (TM) from poly (ethylene glycol)–poly (ε-caprolactone)–poly (ethylene glycol) (PEG–PCL–PEG)-based
thermosensitive hydrogel. Polycaprolactone (hydrophobic additive) and polyvinyl alcohol (PVA) (hydrophilic additive) reduced
critical gel concentration of PEG–PCL–PEG triblock polymer. The effect of PCL on sol–gel transition was more pronounced than
PVA. However, with PCL no statistically significant difference in release profile was observed. The effect of PVA on release
profile was more pronounced, which reduced the cumulative percentage release of TM from 86.4 ± 0.8% to 73.7 ± 1.8% over 316 h.
Moreover, cytotoxicity of the hydrogel was also investigated utilizing rabbit primary corneal epithelial culture cells. No
significant cytotoxicity of hydrogel alone or in presence of additives was observed. So, polymeric additive strategy serves
as a valuable tool for optimizing TM release kinetics from PEG–PCL–PEG hydrogel matrix. 相似文献
14.
Precht JC Ganchev B Heinkele G Brauch H Schwab M Mürdter TE 《Analytical and bioanalytical chemistry》2012,403(1):301-308
Letrozole is an efficient endocrine treatment of postmenopausal breast cancer, however, not all patients benefit from this
treatment, and moreover, severe side-effects like arthralgia frequently lead to discontinuation. To better understand inter-individual
variability in drug response and side-effects, plasma analysis of steady-state concentrations of letrozole and its major metabolites
is crucial. We developed a rapid, sensitive, and specific method for the simultaneous quantification of letrozole and its
metabolites 4,4′-(hydroxymethylene)dibenzonitrile (carbinol) and bis(4-cyanophenyl)methyl hexopyranosiduronic acid (carbinol-gluc)
by UHPLC-ESI-MS/MS using in-house synthesized, stable isotope-labeled internal standards. Following solid-phase extraction
in BondElut C18 96-well plates, the analytes were separated on a ZORBAX Eclipse XDB-C18 column (1.8 μm, 4.6 × 50 mm) with
a gradient of acetonitrile in 0.1% acetic acid in water and detected on a triple quadrupole mass spectrometer with electrospray
ionization in the multiple reaction monitoring mode. Lower limits of quantification were 20, 0.2, and 2 nM for letrozole,
carbinol, and carbinol-gluc, respectively. The assay has been validated according to FDA guidance and applied to the analysis
of 20 plasma samples of postmenopausal breast cancer patients treated with 2.5 mg of letrozole per day. Mean plasma levels
(±SD) were 366 ± 173, 0.38 ± 0.09, and 34 ± 12 nM for letrozole, carbinol, and carbinol-gluc, respectively. Our rapid and
sensitive mass spectrometry based method enables future pharmacokinetic investigations of letrozole outcome. 相似文献
15.
Wanwisa Moon-ai Ploypat Niyomploy Ruethairat Boonsombat Polkit Sangvanich Aphichart Karnchanatat 《Applied biochemistry and biotechnology》2012,166(8):2138-2155
Superoxide dismutase (SOD, EC 1.15.1.1) is a metalloenzyme or antioxidant enzyme that catalyzes the disproportionation of
the harmful superoxide anionic radical to hydrogen peroxide and molecular oxygen. Due to its antioxidative effects, SOD has
long been applied in medicinal treatment, cosmetic, and other chemical industries. Fifteen Zingiberaceae plants were tested
for SOD activity in their rhizome extracts. The crude homogenate and ammonium sulfate cut fraction of Curcuma aeruginosa were found to contain a significant level of SOD activity. The SOD enzyme was enriched 16.7-fold by sequential ammonium sulfate
precipitation, diethylaminoethyl cellulose ion exchange, and Superdex 75 gel filtration column chromatography. An overall
SOD yield of 2.51 % with a specific activity of 812.20 U/mg was obtained. The enriched SOD had an apparent MW of 31.5 kDa,
as judged by sodium dodecyl sulfate polyacrylamide gel electrophoresis, and a pH and temperature optima of 4.0 and 50 °C.
With nitroblue tetrazolium and riboflavin as substrates, the K
m values were 57.31 ± 0.012 and 1.51 ± 0.014 M, respectively, with corresponding V
max values of 333.7 ± 0.034 and 254.1 ± 0.022 μmol min−1 mg protein−1. This SOD likely belongs to the Fe- or Mn-SOD category due to the fact that it was insensitive to potassium cyanide or hydrogen
peroxide inhibition, but was potentially weakly stimulated by hydrogen peroxide, and stimulated by Mn2+and Fe2+ ions. Moreover, this purified SOD also exhibited inhibitory effects on lipopolysaccharide-induced nitric oxide production
in cultured mouse macrophage cell RAW 264.7 in a dose-dependent manner (IC50 = 14.36 ± 0.15 μg protein/ml). 相似文献
16.
Lottmann A Cadé E Geagea ML Delhomme O Grand C Veilleraud C Rizet AL Mirabel P Millet M 《Analytical and bioanalytical chemistry》2007,387(5):1855-1861
In to order increase sensitivity and to reduce the background induced by matrix effects, a method was developed that uses
flash chromatography to separate various compounds present in atmospheric aerosol samples prior to their analysis with different
analytical techniques (GC–MS, GC–FID, HPLC). For this purpose, flash chromatography using a 4 g silica gel column crossed
by eluent at a flow rate of 20 mL min−1 was used. An eluent with enhanced polarity is needed to separate nonpolar (linear and branched alkanes), semipolar (PAH,
nitro-PAH and cholesterol) and polar (methoxyphenols, alkanoic acids, and levoglucosan) compounds. Three combinations of solvents
were used: hexane for the nonpolar fraction (F1), toluene/hexane for the semipolar fraction (F2) and dimethylformamide for
the polar fraction (F3). The use of different eluents for each fraction allows separation of the sample to be accomplished
with good repeatability and satisfying yields [85 ± 5% for F1, 81 ± 8% (PAHs), 89 ± 6% (nitro-PAHs) and 74 ± 7% (cholesterol)
for F2 and 79 ± 7% (n-alkanoic acids), 40 ± 11% (methoxyphenols) and 77 ± 6% (levoglucosan) for F3]. The methoxyphenol yields were low due to losses
during the concentration/evaporation step. This method was then applied to analyse the organic composition of particles collected
at an urban site in Strasbourg (France). 相似文献
17.
Shukor MY Rahman MF Shamaan NA Lee CH Karim MI Syed MA 《Applied biochemistry and biotechnology》2008,144(3):293-300
Molybdenum-reducing activity in the heterotrophic bacteria is a phenomenon that has been reported for more than 100 years.
In the presence of molybdenum in the growth media, bacterial colonies turn to blue. The enzyme(s) responsible for the reduction
of molybdenum to molybdenum blue in these bacteria has never been purified. In our quest to purify the molybdenum-reducing
enzyme, we have devised a better substrate for the enzyme activity using laboratory-prepared phosphomolybdate instead of the
commercial 12-phosphomolybdate we developed previously. Using laboratory-prepared phosphomolybdate, the highest activity is
given by 10:4-phosphomolybdate. The apparent Michaelis constant, K
m for the laboratory-prepared 10:4-phosphomolybdate is 2.56 ± 0.25 mM (arbitrary concentration), whereas the apparent V
max is 99.4 ± 2.85 nmol Mo-blue min−1 mg−1 protein. The apparent Michaelis constant or K
m for NADH as the electron donor is 1.38 ± 0.09 mM, whereas the apparent V
max is 102.6 ± 1.73 nmol Mo-blue min−1 mg−1 protein. The apparent K
m and V
max for another electron donor, NADPH, is 1.43 ± 0.10 mM and 57.16 ± 1.01 nmol Mo-blue min−1 mg−1 protein, respectively, using the same batch of molybdenum-reducing enzyme. The apparent V
max obtained for NADH and 10:4-phosphomolybdate is approximately 13 times better than 12-phoshomolybdate using the same batch
of enzyme, and hence, the laboratory-prepared phosphomolybdate is a much better substrate than 12-phoshomolybdate. In addition,
10:4-phosphomolybdate can be routinely prepared from phosphate and molybdate, two common chemicals in the laboratory. 相似文献
18.
This paper describes the fabrication and characterization of a microfluidic device that utilizes a reservoir-based approach
for endothelial cell immobilization and integrated embedded carbon ink microelectrodes for the amperometric detection of extracellular
nitric oxide (NO) release. The design utilizes a buffer channel to continuously introduce buffer or a plug of stimulant to
the reservoir as well as a separate sampling channel that constantly withdraws buffer from the reservoir and over the microelectrode.
A steel pin is used for both the fluidic connection to the sampling channel and to provide a quasi-reference electrode for
the carbon ink microelectrode. Characterization of the device was performed using NO standards produced from a NONOate salt.
Finally, NO release from a layer of immobilized endothelial cells was monitored and quantified using the system. This system
holds promise as a means to electrochemically detect extracellular NO release from endothelial cells in either an array of
reservoirs or concurrently with fluorescence-based intracellular NO measurements. 相似文献
19.
Gazi E Dwyer J Lockyer NP Gardner P Shanks JH Roulson J Hart CA Clarke NW Brown MD 《Analytical and bioanalytical chemistry》2007,387(5):1621-1631
Prostate cancer (CaP) cells preferentially metastasise to the bone marrow, a microenvironment that plays a substantial role
in the sustenance and progression of the CaP tumour. Here we use a combination of FTIR microspectroscopy and histological
stains to increase molecular specificity and probe the biochemistry of metastatic CaP cells in bone marrow tissue derived
from a limited source of paraffin-embedded biopsies of different patients. This provides distinction between the following
dominant metabolic processes driving the proliferation of the metastatic cells in each of these biopsies: glycerophospholipid
synthesis from triacylglyceride, available from surrounding adipocytes, in specimen 1, through significantly high (p ≤ 0.05) carbohydrate (8.23 ± 1.44 cm−1), phosphate (6.13 ± 1.5 cm−1) and lipid hydrocarbon (24.14 ± 5.9 cm−1) signals compared with the organ-confined CaP control (OC CaP), together with vacuolation of cell cytoplasm; glycolipid synthesis
in specimen 2, through significantly high (p ≤ 0.05) carbohydrate (5.51 ± 0.04 cm−1) and high lipid hydrocarbon (17.91 ± 2.3 cm−1) compared with OC CaP, together with positive diastase-digested periodic acid Schiff staining in the majority of metastatic
CaP cells; glycolysis in specimen 3, though significantly high (p ≤ 0.05) carbohydrate (8.86 ± 1.78 cm−1) and significantly lower (p ≤ 0.05) lipid hydrocarbon (11.67 ± 0.4 cm−1) than OC CaP, together with negative diastase-digested periodic acid Schiff staining in the majority of metastatic CaP cells.
Detailed understanding of the biochemistry underpinning the proliferation of tumour cells at metastatic sites may help towards
refining chemotherapeutic treatment. 相似文献
20.
Radix Scrophulariae (Xuanshen) is one of the famous Chinese herbal medicines widely used to treat rheumatism, tussis, pharyngalgia, arthritis,
constipation, and conjunctival congestion. Harpagoside and cinnamic acid are the main bioactive components of Xuanshen. The
purpose of this study was to develop an HPLC–UV method for simultaneous determination of harpagoside and cinnamic acid in
rat plasma and investigate pharmacokinetic parameters of harpagoside and cinnamic acid after oral administration of Xuanshen
extract (760 mg kg−1). After addition of syringin as internal standard, the analytes were isolated from plasma by liquid–liquid extraction. Separation
was achieved on a Kromasil C18 column, and detection was by UV absorption at 272 nm. The described assay was validated in terms of linearity, accuracy,
precision, recovery, and limit of quantification according to the FDA validation guidelines. Calibration curves for both analytes
were linear with the coefficient of variation (r) for both was greater than 0.999. Accuracy for harpagoside and cinnamic acid ranged from 100.7–103.5% and 96.9–102.9%, respectively,
and precision for both analytes were less than 8.5%. The main pharmacokinetic parameters found for harpagoside and cinnamic
acid after oral infusion of Xuanshen extract were as follows: C
max 1488.7 ± 205.9 and 556.8 ± 94.2 ng mL−1, T
max 2.09 ± 0.31 and (1.48 ± 0.14 h, AUC0–24 10336.4 ± 1426.8 and 3653.1 ± 456.4 ng h mL−1, 11276.8 ± 1321.4 and 3704.5 ± 398.8 ng h mL−1, and t
1/2 4.9 ± 1.3 and 2.5 ± 0.9 h, respectively. These results indicated that the proposed method is simple, selective, and feasible
for pharmacokinetic study of Radix Scrophulariae extract in rats.
Figure Radix Scrophulariae 相似文献