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)

Bis(tert-butyldimethylsiloxy)- (7), bis(dimethylthexylsiloxy)- (8), bis(tri-n-hexylsiloxy)- (9), and bis(dimethyloctadecylsiloxy)silicon 2,3-naphthalocyanines (10) were prepared via substitution of the bis(hydroxy) precursor with the corresponding chlorosilane ligands and characterized by spectroscopic and combustion analyses. They show strong absorption around 780 nm where tissues exhibit optimal transparency. Compounds 7-10 are capable of producing singlet oxygen. They are relatively photostable although less stable than the analogous phthalocyanine, i.e., the bis-(dimethylthexylsiloxy)silicon phthalocyanine (12). They were evaluated as potential photosensitizers for the photodynamic therapy (PDT) of cancer in vitro against V-79 cells and in vivo against the EMT-6 tumor in Balb/c mice. In vitro all four dyes showed limited phototoxicity combined with substantial dark toxicity. Surprisingly, in vivo (i.v., 0.1 mumol/kg, 24 h prior to the photoirradiation of the tumor with 780-nm light, 190 mW/cm2, 400 J/cm2) all dyes induced tumor regression in at least 50% of mice whereas compound 8 gave a complete tumor response in 80% of mice without apparent systemic toxicity at doses as high as 10 mumol/kg. At 24 h postinjection, compound 8 showed a favorable tumor to muscle ratio of 7, assuring minimal damage to the healthy tissue surrounding the tumor during PDT. Our data confirm the potential of silicon naphthalocyanines as far-red-shifted photosensitizers for the PDT of cancer and indicate the importance of the selection of the two axial silicon ligands for optimal photodynamic efficacy.
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PMID:Synthesis and photodynamic activities of silicon 2,3-naphthalocyanine derivatives. 830 68

The photodynamic therapy (PDT) activity of the bis(dimethylthexylsiloxy)silicon 2,3-naphthalocyanine (SiNc 8) was evaluated against the EMT-6 tumor implanted intradermally in BALB/c mice. The SiNc 8 was formulated in aqueous emulsions based on Cremophor EL or Solutol HS 15. The formulation was shown to affect plasma clearance and overall pharmacokinetics. Compared to Cremophor, Solutol promoted rapid plasma clearance and high liver retention of the dye, combined with a slight increase of dye tumor concentrations. The PDT action spectrum for tumor response of SiNc 8 in Cremophor (190 mW cm-2, 200 J cm-2, 24 h postinjection [p.i.] of 1 mumol kg-1) showed a maximum at 780 nm, which corresponds to the absorption maximum of the monomeric dye as well as the in vivo maximum change in the "diffuse optical density" produced by the dye. The extent of tumor necrosis increased with augmented dye and light doses. Regardless of the formulation, at 1 h p.i. of 0.1 mumol kg-1 SiNc 8, PDT efficiency (190 mW cm-2, 400 J cm-2) was high but accompanied by severe damage to normal tissues, at 24 h p.i. PDT resulted in complete tumor regression in 80% of the animals without adverse effects to adjacent tissues, while at 72 h p.i. PDT induced no tumor response with Cremophor and only a partial response with Solutol. At the latter time point, plasma dye clearance was nearly complete while tumor tissue levels remained high, suggesting that tumor response correlates with plasma rather than tumor dye levels. Skin sensitivity of SKhI mice to solar-simulated radiation was lower with SiNc 8 as compared to Photofrin. Our data suggest the potential of SiNc 8 as a far-red absorbing photosensitizer in clinical PDT.
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PMID:Photodynamic activities and skin photosensitivity of the bis(dimethylthexylsiloxy)silicon 2,3-naphthalocyanine in mice. 857 Jul 40

We investigated the signaling mechanism of stretch-induced cell remodeling in human umbilical vein endothelial cells (HUVECs). Freshly dissociated HUVECs were cultured on an elastic silicon membrane and subjected to uniaxial cyclic stretch (20% in length, 1 Hz). The cells started to change their morphology as early as 15 min after stretch onset, and most cells eventually aligned perpendicularly to the stretch axis within 1 h. This remodeling was dependent on the increase in intracellular calcium concentration ([Ca2+]i) via a Ca(2+)-permeable stretch-activated (SA) channel. During the process of remodeling, extensive rearrangement of stress fibers and focal adhesions was observed, which may be close to the final step in the intracellular signaling cascade. This event was [Ca2+]i-dependent, suggesting the existence of a Ca(2+)-dependent intermediate cascade that links [Ca2+]i to the rearrangement of cytoskeletons and focal adhesions. We found that some proteins, including pp125FAK (focal adhesion kinase) and paxillin, were tyrosine phosphorylated during cyclic stretch in a Ca(2+)-dependent manner. Inhibition of this tyrosine phosphorylation prohibited the stretch-dependent rearrangement of cytoskeletons and focal adhesions as well as the remodeling. Finally the tyrosine kinase src, which could phosphorylate pp125FAK, was found to be activated in a [Ca2+]i-dependent way during stretch. All of the above molecular events were consistently Ca(2+)-dependent, which led us to propose the signaling cascade: SA channel activation-->[Ca2+]i increase-->src activation-->protein tyrosine phosphorylation-->rearrangement of cytoskeletons and focal adhesions-->cell remodeling.
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PMID:Mechanotransduction and intracellular signaling mechanisms of stretch-induced remodeling in endothelial cells. 947 80

In this study, critical signaling pathway required for the stretch induced morphological changes of human umbilical endothelial cells (HUVECs) was investigated. Uniaxial cyclic stretch (1 Hz, 20% in length) of the cells cultured on an elastic silicon membrane induced a gradual morphological change in the cells from a polygonal shape to an elongated spindle-like shape whose long axis was aligned perpendicular to the stretch axis. We found that protein tyrosine phosphorylation of cellular proteins increased and peaked at 20 min in response to cyclic stretch. Either treatment of cells with gadolinium (Gd3+), a potent blocker for stretch-activated channels, or removal of extracellular Ca2+ blocked the tyrosine phosphorylation of the proteins, suggesting that stretch-activated (SA) ion channels regulated stretch specific tyrosine phosphorylation. The major phosphorylated proteins had molecular masses of approximately 120-135 kDa, and 70 kDa. Immunoprecipitation experiments revealed that paxillin, focal adhesion kinase (pp125FAK) and pp130CAS were included in the 70 kDa and 120-135 kDa bands, respectively. The morphological change was inhibited by herbimycin A and genistein, inhibitors of tyrosine kinases, suggesting that tyrosine phosphorylation was required for the morphological change. In addition, the kinase activation of pp125FAK was observed in response to cyclic stretch. Moreover, suppression of pp125FAK expression by the antisense phosphorothioate oligodeoxynucleotides (S-ODN) in HUVECs resulted in inhibition of tyrosine phosphorylation of paxillin and the stretch-dependent morphological changes. These results suggest that an activation of tyrosine kinase(s) by an increase in intracellular Ca2+ and pp125FAK play a critical role in the unique morphological change specifically observed in endothelial cells subjected to uni-axial cyclic stretch.
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PMID:Pp125FAK is required for stretch dependent morphological response of endothelial cells. 969 39

The capabilities of neutron and photon activation analysis (NAA and PAA, respectively) for low-level determination of silicon in biological materials have been examined. Sensitivities of a variety of modes of NAA and PAA with radiochemical separation have been evaluated. Results are presented for silicon in reference materials CSRM 12-2-03 Lucerne, Bowen's Kale, NIST SRM-1571 Orchard Leaves, and NIST SRM-1515 Apple Leaves. The results were obtained by employing the 29Si(n,p)29Al reaction with fast reactor neutrons and the radiochemical procedure developed for aluminium separation. Possibilities of further improvement of the silicon determination limit down to the microg g(-1) level by employing NAA and PAA with radiochemical separation are outlined.
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PMID:Possibilities of low-level determination of silicon in biological materials by activation analysis. 1145 Dec 44

A radiochemical neutron activation analysis procedure has been developed, critically evaluated, and shown to have the necessary sensitivity, chemical specificity, matrix independence, and precision to certify phosphorus at ion implantation levels in silicon. 32P, produced by neutron capture of 31P, is chemically separated from the sample matrix and measured using a beta proportional counter. The method is used here to certify the amount of phosphorus in SRM 2133 (Phosphorus Implant in Silicon Depth Profile Standard) as (9.58 +/- 0.16) x 10(14) atoms x cm(-2). A detailed evaluation of uncertainties is given.
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PMID:Radiochemical neutron activation analysis for certification of ion-implanted phosphorus in silicon. 1463 14

A new beamline (MPW6.2) has been designed and built for the study of materials during processing where three synchrotron techniques, SAXS, WAXS and XAS, are available simultaneously. It has been demonstrated that Rietveld refinable data can be collected from silicon SRM 640b over a 60 degrees range in a time scale of 1 s. The data have been refined to a chi(2) of 2.4, the peaks fitting best to a Pearson VII function or with fundamental parameters. The peak halfwidths have been found to be approximately constant at 0.06 degrees over a 120 degrees angular range indicating that the instrumental resolution function has matched its design specification. A quantitative comparison of data sets collected on the same isotactic polypropylene system on MPW6.2 and DUBBLE at the ESRF shows a 17% improvement in angular resolution and a 1.8 improvement in peak-to-background ratio with the RAPID2 system; the ESRF data vary more smoothly across detector channels. The time-dependent wide-angle XRD was tested by comparing a hydration reaction of gypsum-bassanite-anhydrite with energy-dispersive data collected on the same system on the same time scale. Three sample data sets from the reaction were selected for analysis and gave an average chi(2) of 3.8. The Rietveld-refined lattice parameters are a good match with published values and the corresponding errors show a mean value of 3.3 x 10(-4). The data have also been analysed by the Pawley decomposition phase-modelling technique demonstrating the ability of the station to quickly and accurately identify new phases. The combined SAXS/WAXS capability of the station was tested with the crystallization and spinodal decomposition of a very dilute polymer system. Our measurements show that the crystallization of a high-density co-polymer (E76B38) as low as 0.5% by weight can be observed in solution in hexane. The WAXS and SAXS data sets were collected on the same time scale. The SAXS detector was calibrated using a collagen sample that gave 30 orders of diffraction in 1 s of data collection. The combined XRD and XAS measurement capability of the station was tested by observing the collapse and re-crystallization of zinc-exchanged zeolite A (zeolite Zn/Na-A). Previous studies of this material on station 9.3 at the SRS were compared with those from the new station. A time improvement of 38 was observed with better quality counting statistics. The improved angular resolution from the WAXS detector enabled new peaks to be identified.
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PMID:The new materials processing beamline at the SRS Daresbury, MPW6.2. 1496 Jul 81

We present femtosecond time-resolved pump-probe experiments on iodine molecules enclosed into well-defined cages and channels of different crystalline SiO2 modifications of zeolites. The new experimental results obtained from iodine in TON (Silica-ZSM-22), FER (Silica-Ferrierit), and MFI (Silicalit-1) porosils are compared with data published earlier on the iodine/DDR (Decadodecasil 3R) porosil system [Flachenecker et al., Phys. Chem. Chem. Phys. 5, 865 (2003)]. A summary of all findings is given. The processes analyzed by means of the ultrafast spectroscopy are the vibrational relaxation as well as the dissociation and recombination reactions, which are caused by the interaction of the photo-excited iodine molecules with the cavity walls of the porosils. A clear dependence of the observed dynamics on the geometry of the surrounding lattice structure can be seen. These measurements are supported by temperature-dependent experiments. Making use of a theoretical model which is based on the classical Langevin equation, an analysis of the geometry-reaction relation is performed. The Brownian dynamics simulations show that in contrast to the vibrational relaxation the predissociation dynamics are independent of the frequency of collisions with the surroundings. From the results obtained in the different surroundings, we conclude that mainly local fields are responsible for the crossing from the bound B state to the repulsive a/a' states of the iodine molecules.
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PMID:The elementary steps of the photodissociation and recombination reactions of iodine molecules enclosed in cages and channels of zeolite crystals: a femtosecond time-resolved study of the geometry effect. 1526 45

An instrument for cold neutron prompt gamma-ray activation analysis (PGAA), located at the NIST Center for Neutron Research (NCNR), has proven useful for the measurement of boron in a variety of materials. Neutrons, moderated by passage through liquid hydrogen at 20 K, pass through a (58)Ni coated guide to the PGAA station in the cold neutron guide hall of the NCNR. The thermal equivalent neutron fluence rate at the sample position is 9 x 10(8) cm(-2) s(-1). Prompt gamma rays are measured by a cadmium- and lead-shielded high-purity germanium detector. The instrument has been used to measure boron mass fractions in minerals, in NIST SRM 2175 (Refractory Alloy MP-35-N) for certification of boron, and most recently in semiconductor-grade silicon. The limit of detection for boron in many materials is <10 ng g(-1).
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PMID:Determination of boron in materials by cold neutron prompt gamma-ray activation analysis. 1561 60

Silica gels modified with n-alkyl chains (n = 18, 30) are prepared by two different synthetic routes and are examined by variable temperature FTIR and solid-state NMR spectroscopy. HPLC measurements of SRM 869, cis/trans ss-carotene isomers and xanthophylls isomers confirm the dependence of the separation mechanism on the alkyl chain length and the synthetic routes. The determination of the silane functionality and degree of cross-linking of silane ligands on the silica surface is achieved by 29Si CP/MAS NMR measurements. The structural order and mobility of the alkyl chains are investigated by means of variable temperature 13C CP/MAS NMR measurements. Variable temperature FTIR studies are performed where conformational order and flexibility of the alkyl chains in C18 and C30 phases are monitored through conformational sensitive CH2 symmetric, anti-symmetric stretching and wagging modes. In addition, the chromatographic properties of the C18 and C30 phases are determined. The results derived from the FTIR, NMR and HPLC measurements are discussed in the context of the applied synthetic routes and alkyl chain lengths.
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PMID:Influence of synthetic routes on the conformational order and mobility of C18 and C30 stationary phases. 1647 20


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