Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.2 (focal adhesion kinase)
44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The advantages and disadvantages of neutron activation analysis (NAA) and inductively coupled plasma-source mass spectrometry (ICP-MS) for the analysis of biological materials is reviewed. Comparison is made between NAA (instrumental) and ICP-MS (conventional pneumatic solution nebulization and laser ablation) analysis of the biological reference material National Bureau of Standards (NBS) SRM 1577 Bovine Liver. Relatively good agreement is achieved between the results for the 18 elements analyzed by both techniques and those either certified or reported in the literature. Elemental concentrations for Li, Mg, Al, Ca, Cr, Mn, Fe, Cu, Zn, Br, Rb, and Cs are also reported for IAEA Mixed Human Diet (H9), NBS SRM 909 Human Serum, and NBS SRM 1577a Bovine Liver, analyzed by solution nebulization ICP-MS.
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PMID:Trace elemental content of biological materials. A comparison of NAA and ICP-MS analysis. 170 18

A study was undertaken to determine the average values for elements in normal human brain (11 individuals, age group 65-75). Twelve brain parts were selected from both hemispheres. Determinations were carried out by NAA and ICP-AES. The main elements (Na, K, Mg, Ca, Fe, P, S) and trace elements (Al, B, Co, Cr, Cu, Mn, Ni, Pb, Zn) were investigated. Quality control was ensured by using NBS Bovine Liver SRM. The results obtained with independent methods were compared, and the data show a good correlation. On the basis of these investigations, the regional distribution of elements can be given.
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PMID:Determination of main and trace element contents in human brain by NAA and ICP-AES methods. 170 77

Four environmentally and biologically important arsenic species, dimethylarsenic acid (DMA), monomethylarsonic acid (MMA), As(III) and As(V) are separated by micellar liquid chromatography. Linear dynamic ranges for the four species are three orders of magnitude and detection limits are in the picogram range with inductively coupled plasma mass spectrometric (ICP-MS) detection. This paper discussed in detail the development of the chromatographic conditions. The micellar mobile phase, which consisted of 0.05 M cetyltrimethylammonium bromide, 10% propanol and 0.02 M borate buffer, showed good compatibility with ICP-MS. This method allowed direct injection of urine samples onto the chromatographic system without extensive pretreatment and presented no interference from chlorine in the matrix. Detection limits are comparable with other LC-ICP-MS studies. An SRM urine sample was used to demonstrate the applicability of this technique to "real-life" situations. Results indicated that DMA, MMA and As(V) were present in the urine sample.
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PMID:Arsenic speciation by micellar liquid chromatography with inductively coupled plasma mass spectrometric detection. 753 27

Development of a new method for the determination of Cr(III) and Cr(VI) is described. Anion-exchange high-performance liquid chromatography (HPLC) was used to separate Cr(III) and Cr(VI) with on-line detection by inductively coupled plasma atomic emission spectroscopy (ICP-AES) at 2766 A in preliminary studies, and inductively coupled plasma mass spectrometry (ICP-MS) with single-ion monitoring at m/z 52 and m/z 53 for final work. A mobile phase consisting of ammonium sulfate and ammonium hydroxide was used, and a simple chelation procedure with EDTA was followed to stabilize the Cr(III) species in standard solutions. ICP-MS results indicated the feasibility of using chromium isotope m/z 53 instead of the more abundant m/z 52 isotope due to a high mobile-phase background most significantly from the SO+ polyatomic interference. The absolute detection limits based on peak-height calculations were 40 pg for Cr(III) and 100 pg for Cr(VI) in aqueous media by HPLC-ICP-MS. The linear dynamic range extended from 5 ppb (ng/ml) to 1 ppm (micrograms/ml) for both species. By HPLC-ICP-AES, detection limits were 100 ng for Cr(III) and 200 ng for Cr(VI). Cr(III) was detected in NIST-SRM 1643c (National Institute of Standards and Technology-Standard Reference Material, Trace Elements in Water) by HPLC-ICP-MS at the 20 ppb level.
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PMID:Chromium speciation by anion-exchange high-performance liquid chromatography with both inductively coupled plasma atomic emission spectroscopic and inductively coupled plasma mass spectrometric detection. 758 51

A method was developed to analyze various calcium supplements for Ca and Pb content. The analysis involves a dry ash of the supplements followed by wet digestion. The Pb is determined by graphite furnace atomic absorption spectrophotometry (GFAAS). Analysis of Ca is by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Ca supplements fortified with Pb at levels ranging from 0.25 to 10.0 micrograms/g yielded recoveries ranging from 82.7 +/- 4.2 to 105.0 +/- 1.7%. To test accuracy, the method was applied to National Institute of Standards and Technology standard reference materials (NIST SRMs) 1572 citrus leaves and 1486 bone meal. GFAAS analysis of SRM 1572 averaged 13.1 +/- 0.6 micrograms Pb per g (certificate value, 13.3 +/- 2.4 micrograms Pb per g), and analysis of SRM 1486 averaged 1.34 +/- 0.11 micrograms Pb per g (certificate value, 1.335 +/- 0.014 micrograms Pb per g). ICP-AES analysis of SRM 1572 averaged 3.12 +/- 0.01% Ca (certificate value, 3.15 +/- 0.10% Ca by weight), and analysis of SRM 1486 averaged 27.63 +/- 0.27% Ca (certificate value, 26.58 +/- 0.24% Ca). The method's limit of quantitation (LOQ), on supplement Ca basis and a 1 g sample, averaged 0.75 micrograms Pb per 1 g Ca for supplements containing 9 to 35% Ca by weight. At a Pb level of 0.663 micrograms/g Ca, the reproducibility relative standard deviation (RSDr) averaged 7.3% and the repeatability relative standard deviation (RSDR) averaged 8.0%. It is recommended that the method be studied collaboratively.
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PMID:Analysis of calcium and lead in calcium supplements by inductively coupled plasma-atomic emission spectrometry and graphite furnace atomic absorption spectrophotometry. 795 Apr 30

An on-line anodic stripping voltammetry (ASV) flow system, interfaced with inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICPMS) detectors, has been used for determination of arsenic(III) and selenium(IV) and for elimination of polyatomic interferences which arise from chloride in sample matrices. Details of the working electrode preparation are discussed. Arsenic signals in ICP-AES were enhanced by as much as 10 times through preconcentration of sample volumes up to 5 mL. Using ICP-AES detection, recoveries for analyte spikes in 1:10 diluted urine were 102% for As(III) (matrix-matched standards) and 91% for Se(IV) (standards in electrolyte). Using ICPMS detection, determination of certified Se(IV) and Se(IV) spikes in diluted NIST SRM 2670 elevated urine gave recoveries of 92-103%, while recoveries of As(III) spikes in diluted NIST SRM 2670 urine ranged from 94 to 113%. High levels of chloride matrix exhibited little effect on the arsenic signal with ICP-AES or ICPMS detection. Elimination of the polyatomic interference ArCl+ in ICPMS was very efficient for diluted NIST SRM 2670 urine and for a synthetic matrix of 1000 micrograms/mL chloride.
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PMID:Determination of arsenic(III) and selenium(IV) using an on-line anodic stripping voltammetry flow cell with detection by inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. 829 28

Homogenization with a flat valve homogenizer in combination with high-speed blending was evaluated for the preparation of slurries suitable for the ETAAS determination of cadmium, copper and lead concentrations in six SRMs and in frozen cervine liver and kidney. Fresh tissue (approximately 2 g) or powdered SRM (approximately 0.1 g) was dispersed, at high speed, in 20 ml of ethanol-water (1 + 9 v/v) containing 0.25% m/m tetramethylammonium hydroxide. The resulting suspension was passed through a high-pressure flat valve homogenizer. Determinations performed on the resulting homogenate, provided estimates for Cd, Pb and Cu concentrations that were within 27, 23 and 18% of the certified values, respectively, for the six SRMs. In all instances, the experimental results did not differ significantly from the certified values. For frozen tissues there was good agreement between the concentrations as determined by slurry homogenization-ETAAS and conventional digestion-ICP-MS. In addition, no significant differences were detected between the slopes of the calibration curves for external standards and standard additions to homogenized sample (SRMs or fresh tissue). Moreover, replicate determinations of analyte concentrations in slurries at various times post-preparation did not detect any segregation of the homogenates during 6 d. For these matrices at least, short-term sample storage had no discernible effect on the analyte apparent concentrations. The applicability of the process was limited only by the levels of contaminating Pb and Cu introduced into the sample by the homogenizer.
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PMID:Slurry preparation by high-pressure homogenization for cadmium, copper and lead determination in cervine liver and kidney by electrothermal atomic absorption spectrometry. 863 93

A simple and rapid method for the determination of some trace element impurities in high purity silver, combining the isolation of analytes from the silver matrix with selective precipitation followed by ICP-MS determination was developed. On the basis of an extreme difference in the solubilities of the chlorides of silver and the other accompanying trace elements, silver can be separated completely through the addition of hydrochloric acid. The sample of silver was at first dissolved in 7 M nitric acid followed by addition of hydrochloric acid to remove the silver matrix by formation of a silver chloride precipitate, while leaving the trace element impurities in the solution, which was subsequently analysed by ICP-MS. Eleven elements (Al, Au, Cd, Co, Cu, Fe, Mg, Mn, Ni, Pb and Sn) were determined with good accuracy and precision. The limits of detection (based on the 3 sigma criterion) of these elements were 10(-1)-10(-3) ng g-1. The proposed method was successfully applied to the determination of metal impurities in high-purity silver samples (EM9465 and EM 9343) and validated by the analysis of NIST SRM 8171 (Fine Silver FS 14).
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PMID:Selective precipitation separation and inductively coupled plasma mass spectrometric determination of trace metal impurities in high purity silver. 924 9

Measurement of arsenic (As) in biological samples such as urine has important clinical applications and is being undertaken more frequently in epidemiologic studies because of concern about the carcinogenicity of low to moderate levels of As exposure. The objective of this study was to evaluate and improve the accuracy of As determination in urine by inductively coupled plasma mass spectrometry (ICP-MS). Determination of As in biological samples by ICP-MS is difficult for two reasons: the formation of the molecular ion 40Ar35Cl, which overlaps with monoisotopic As at a mass-to-charge ratio (m/z) of 75 (causing spectral interference), and signal enhancement due to organic matrix (nonspectral interference). Available procedures were examined, including the application of different correction procedures using 40Ar37Cl and 16O35Cl molecular-ion formation; the addition of N2 into plasma or nebulizer gas flows; and the addition of organic molecules to the sample and to calibration standards to eliminate or correct for interference due to molecular-ion formation. The accuracy and precision of determination of As [m/z 75, ionization potential (IP) 9.81 eV] with use of an internal standard was also investigated. Three elements were studied as candidate internal standards: germanium (Ge: m/z 74, IP 7.90 eV), indium (In: m/z 115, IP 5.79 eV), and tellurium (Te: m/z 128, IP 9.01 eV). It was found that these three elements performed more or less equally well with Ar-N2 plasma; it was also found that accuracy was significantly improved when Te was used as the internal standard instead of Ge or In for ethanol-added samples. Our results indicate that accurate and precise measurement of As in urine by ICP-MS can be obtained by either of two methods (< 5% error, approximately 2% RSD, limit of detection 0.1 ng ml-1): (1) the addition of 1% N2 to plasma gas flow or 3% N2 to nebulizer gas flow, along with use of any of the internal standards tested, or (2) the addition of ethanol to the sample and to calibration standards, with use of Te as the internal standard. The most accurate results (< 1% error) for National Institute of Standard and Technology Standard Reference Material (NIST SRM) 2670 (toxic elements in urine) were obtained with Ar-N2 plasma with either Te or In as the internal standard.
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PMID:Determination of the total arsenic concentration in human urine by inductively coupled plasma mass spectrometry: a comparison of the accuracy of three analytical methods. 965 5

Despite opioids are routinely used for analgesia in head injured patients, the effects of such drugs on ICP and cerebral hemodynamics remain controversial. Cerebrovascular autoregulation (CAR) could be an important factor in the ICP increases reported after opioid administration. In order to describe the effects on intracranial pressure of fentanyl and correlated such effects with autoregulation status, we studied 30 consecutive severe head injury patients who received fentanyl (2 micrograms/kg) intravenously over one minute. Prior to study, CAR was assessed. Monitoring included MAP, HR, SaO2, ETCO2, SjO2 and ICP. Changes in cerebral blood flow (CBF) were estimated from relative changes in AVDO2. Patients mean GCS was 5.7 +/- 1.7 (mean +/- STD) and mean ICP on admission was 23.8 +/- 16.3 mmHg. Fentanyl caused significant increases in ICP and decreases in MAP and CPP, but CBF remained unchanged when estimated by AVDO2. In patients with preserved CAR (34.5%), opioid-induced ICP increase was greater (but not statistically significant) than in those with impaired CAR (65.5%). We conclude than fentanyl moderately increased ICP and decreased MAP and CPP. Our data suggests that in patients with preserved CAR, potent opioids could cause greater increases of ICP, probably due to activation of the vasodilatadory cascade.
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PMID:Effects on intracranial pressure of fentanyl in severe head injured patients. 977 29


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