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1.
Anita M. R. Fisher Kathleen Danenberg Debabrata Banerjee Joseph R. Bertino Peter Danenberg Charles J. Gomer 《Photochemistry and photobiology》1997,66(2):265-270
Loss of p53 function has been correlated with decreased sensitivity to chemotherapy and radiation therapy in a variety of human tumors. Comparable analysis of p53 status with sensitivity to oxidative stress induced by pho-todynamic therapy has not been reported. In the current study we examined photosensitivity in human promye-locytic leukemia HL60 cells exhibiting either wild-type p53, mutated p53 or deleted p53 expression. Experiments were performed using a purpurin, tin ethyl etiopurpurin (SnET2)-, or a porphyrin, Photofrin (PH)-based photo-sensitizer. Total SnET2 accumulation was comparable in all three cell lines. Uptake of PH was highest in cells expressing wild-type p53 but incubation conditions could be adjusted to achieve equivalent cellular PH levels during experiments that analyzed photosensitivity. Survival measurements demonstrated that HL60 cells expressing wild-type p53 were more sensitive to PH- and SnET2-mediated photosensitization, as well as to UVC irradiation, when compared to HL60 cells exhibiting deleted or mutated p53 phenotypes. A rapid apoptotic response was observed following purpurin- and porphyrin-induced photosensitization in all cell lines. Results of this study indicate that photosensitivity is increased in HL60 cells expressing wild-type p53 and that photosensitizer-medi-ated oxidative stress can induce apoptosis through a p53-independent mechanism in HL60 cells . 相似文献
2.
R.J. Bertino B.A.W. Coller G.B. Deacon I.K. Johnson 《Journal of fluorine chemistry》1975,5(4):335-357
The lithium polyfluorobenzenesulphinates, Li O2SR (R = C6F5, -HC6F4, -HC6F4, or -HC6F4), and the dilithium tetrafluorobenzenedisulphinates, - and -(LiO2S)2C6F4, have been prepared by reaction of the appropriate polyfluoroaryllithium compounds with sulphur dioxide. All compounds were isolated as hydrates and gave the corresponding -benzylthiouronium salts on treatment with -benzylthiouronium chloride. From reactions of the lithium sulphinates with suitable mercuric salts in water, generally at room temperature, the derivatives RHgX (R = C6F5, X = Cl, Br, CH3CO2, or PhSO2; R = -HC6F4, X = Cl, Br, or CH3CO2; R = -HC6F4, X = Cl or Br; R = -HC6F4, X = Cl), -(XHg)2C6F4 (X = Cl, Br, or CH3CO2), and -(XHg)2C6X4 (X = Cl or Br) have been prepared. Similarly, the bispolyfluorophenylmercurials R2Hg (R = C6F5, -HC6F4, or -HC6F4) have been prepared from the corresponding lithium sulphinates and either mercuric salts or polyfluorophenylmercuric halides in aqueous -butanol. A possible mechanism for the sulphur dioxide elimination reactions is discussed. 相似文献
3.
M. F. Bertino R. R. Gadipalli L. A. Martin J. G. Story B. Heckman S. Guha N. Leventis 《Journal of Sol-Gel Science and Technology》2006,39(3):299-306
Silica hydrogels and planar substrates were patterned with CdS nanoparticles using a photolithographic method based on the
photo dissociation of thiols and cadmium-thiolate complexes. Silica hydrogels were prepared via a standard base-catalyzed
route. The solvent was exchanged with an aqueous solution of CdSO4 and 2-mercaptoethanol, and the samples were then exposed to a focused ultraviolet beam. Planar substrates were patterned
by illuminating a precursor solution spin coated on the substrates. CdS nanoparticles formed in the illuminated spots, and
had a diameter below about 2 nm. The diameter of the spots illuminated by the UV beam could be varied from a few hundred to
a few μm, on both hydrogels and planar substrates. Samples were characterized with transmission electron microscopy, X-ray
photoelectron spectroscopy, X-ray diffraction, and optical absorption, photoluminescence and Raman spectroscopies. All these
techniques confirmed the chemical identity of the CdS nanoparticles. To investigate the mechanism of nanoparticle formation,
we took absorption spectra of the precursor solution as a function of irradiation time. In unirradiated solutions, we noticed
a maximum at 250 nm, characteristic of Cd-thiolate complexes. The absorption at 250 nm decreased with increasing irradiation
time. A new band appeared at 265 nm for exposures around 5 min, and that band shifted to 290 nm in samples exposed for 10 min.
A yellow precipitate formed after about 30 min. XRD showed that the precipitate was cubic CdS, with a mean particle size of
1.4 nm. We attribute formation of CdS to the photodissociation of the thiols and of the Cd-thiolates. UV irradiation of these
precursors yields a series of species that can react with Cd2+, such as RS·, S2− and H2S. Small CdS nanoparticles form in the initial stages of illumination, and present absorption bands in the 265–290 nm region.
These CdS aggregates grow, coalesce and precipitate for longer irradiation times. 相似文献
4.
Three-dimensional metallic structures are fabricated with high spatial resolution in silica aerogels. In our method, silica hydrogels are prepared with a standard base-catalyzed route, and exchanged with an aqueous solution typically containing Ag+ ions (1 M) and 2-propanol (0.2 M). The metal ions are reduced photolytically with a table-top ultraviolet lamp, or radiolytically, with a focused X-ray beam. We fabricated dots and lines as small as 30 × 70 μm, protruding for several mm into the bulk of the materials. The hydrogels are eventually supercritically dried to yield aerogels, without any measurable change in the shape and spatial resolution of the lithographed structures. Transmission electron microscopy shows that illuminated regions are composed by Ag clusters with a size of several μm, separated by thin layers of silica. 相似文献
5.
High-performance liquid chromatographic method for the simultaneous measurement of floxuridine and fluorouracil in human body fluids. 总被引:2,自引:0,他引:2
J A Smith-Rogers W P Tong M E Duafala M Markman J R Bertino 《Journal of chromatography. A》1991,566(1):147-154
A method for the simultaneous measurement of floxuridine (5-fluorodeoxyuridine) and fluorouracil in human plasma and peritoneal fluid has been developed. This method utilizes high-performance liquid chromatographic analysis with a Zorbax RX column (25 cm x 4.6 mm I.D.) plus a guard cartridge of the same material. The sensitivity limits for this assay are 0.25 mumol/l in a 20-microliters sample. The detection limit at a signal-to-noise ratio of 3 is 2.5 nmol/l. This procedure has been used to quantitatively measure concentration versus time profiles of floxuridine and fluorouracil in plasma and peritoneal fluid of human patients after receiving intraperitoneal administration of floxuridine. 相似文献
6.
Magnetic nanoparticles of nickel ferrite (size: 24±4 nm) have been synthesized by chemical coprecipitation method using stable ferric and nickel salts. Coercivity of nanoparticles has been found to increase with decrease in temperature of the samples. It has been observed that the coercivity follows a simple model of thermal activation of particle’s moment over the anisotropy barrier in the temperature range (10-300 K), in accordance with Kneller’s law for ferromagnetic materials. Saturation magnetization follows the modified Bloch’s law in the temperature range from 300 to 50 K. However, below 50 K, an abrupt increase in magnetization of nanoparticles was observed. This increase in magnetization at lower temperatures was explained with reference to the presence of freezed surface-spins and some paramagnetic impurities at the shell of nanoparticles that are activated at lower temperatures in core-shell nickel ferrite nanoparticles. 相似文献
7.
R. R. Gadipalli L. A. Martin B. Heckman J. G. Story M. F. Bertino P. Fraundorf S. Guha N. Leventis 《Journal of Sol-Gel Science and Technology》2006,40(1):101-107
CdS quantum dots were fabricated photolithographically on the surface and in the bulk of silica hydrogels, as well as on the
surface of planar substrates. Silica hydrogels were prepared with a standard base-catalyzed route, and the solvent was exchanged
with a cold aqueous solution of Cd(NO3)2, NH4OH, thiourea, and a capping agent, e.g., 2-mercaptoethanol. The samples were then exposed to a focused infrared beam produced
by a continuous-wave Nd:YAG laser. The precursors reacted upon heating, and CdS nanoparticles formed in the illuminated regions.
Use of capping agents allowed to control the mean particle size, while focusing of the beam inside hydrogel monoliths generated
nanoparticles in their bulk, but not at the surface. Planar substrates were patterned by illuminating a precursor solution
spin-coated on the substrates. The average size of the CdS nanoparticles could be varied between about 1.5 and 4.5 nm by varying
the type and the concentration of the capping agents. 相似文献
8.
Pillalamarri SK Blum FD Bertino MF 《Chemical communications (Cambridge, England)》2005,(36):4584-4585
Polyaniline-gold nanocomposites containing polyaniline nanostructures attached to well-dispersed uniform-size gold nanoparticles were obtained using a surface initiation approach. 相似文献
9.
S Quaranta M G Giuffrida M Cavaletto C Giunta J Godovac-Zimmermann B Ca?as C Fabris E Bertino M Mombrò A Conti 《Electrophoresis》2001,22(9):1810-1818
The human milk fat globule membrane protein composition is still largely unknown, although it counts for 2-4% of the total milk protein content and contains several important biologically active components. The aim of this work was to create a two-dimensional electrophoresis (2-DE) map of the human milk fat globule membrane proteins, both integral and membrane-associated, and to identify and characterize as many protein components as possible. A new protocol for the solubilization and extraction of the human milk fat globule membrane proteins with a double extraction procedure is presented, and the results compared with the extraction methods reported in the literature. The proteins were separated, in the first dimension, by isoelectric focusing (IEF) in the pH range 3-10 on strips of 13 cm length and, in the second dimension, by Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) on 11.5% T homogeneous gels. A reproducible 2-DE map of integral and membrane-associated proteins was obtained and the first 23 spots, representing the major components, were identified by matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometric analysis and/or by amino acid sequencing. 相似文献
10.
Gounder MK Lin H Stein M Goodin S Bertino JR Kong AN DiPaola RS 《Biomedical chromatography : BMC》2012,26(5):650-654
2‐Deoxyglucose (2‐DG), an analog of glucose, is widely used to interfere with glycolysis in tumor cells and studied as a therapeutic approach in clinical trials. To evaluate the pharmacokinetics of 2‐DG, we describe the development and validation of a sensitive HPLC fluorescent method for the quantitation of 2‐DG in plasma. Plasma samples were deproteinized with methanol and the supernatant was dried at 45°C. The residues were dissolved in methanolic sodium acetate–boric acid solution. 2‐DG and other monosaccharides were derivatized to 2‐aminobenzoic acid derivatives in a single step in the presence of sodium cyanoborohydride at 80°C for 45 min. The analytes were separated on a YMC ODS C18 reversed‐phase column using gradient elution. The excitation and emission wavelengths were set at 360 and 425 nm. The 2‐DG calibration curves were linear over the range of 0.63–300 µg/mL with a limit of detection of 0.5 µg/mL. The assay provided satisfactory intra‐day and inter‐day precision with RSD less than 9.8%, and the accuracy ranged from 86.8 to 110.0%. The HPLC method is reproducible and suitable for the quantitation of 2‐DG in plasma. The method was successfully applied to characterize the pharmacokinetics profile of 2‐DG in patients with advanced solid tumors. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献