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1.
OPTICAL PROPERTIES OF EXPERIMENTAL PROSTATE TUMORS in vivo 总被引:2,自引:0,他引:2
M. R. Arnfield J. D. Chapman J. Tulip M. C. Fenning M. S. McPhee 《Photochemistry and photobiology》1993,57(2):306-311
The optical properties of tumor tissue provide important information for optimizing treatment plans in photodynamic therapy, especially when intertitial application by multiple fibers is planned. Near infrared light, required to activate novel photosensitizers, should facilitate improved light penetrance of tumor tissue compared with 630 nm light used for activating Photofrin II. We have measured light energy fluence rates for 630 and 789 nm light along radial tracks from a single laterally diffusing optical fiber centrally implanted into Dunning R3327-AT and R3327-H rat tracks from a single laterally diffusing optical fiber centrally implanted into Dunning R3327-AT and R3327-H rat prostate tumors in anesthetized rats. A total of 20 R3327-AT and 10 R3327-H tumors were used in this study with volumes from 2.6 to 13.3 cm3. Light track data were analyzed by an empirical model that described light attenuation. At 630 nm, light attenuation coefficients (LAC) were T1.9 × higher than those at 789 nm for both tumors with the well-differentiated, well-perfused tumor (R3327-H) attenuating to a greater extent than did the rapidly growing anaplastic tumor (R3327-AT). The intertumor variation of LAC was greater than the spatial variations observed within individual tumors. LAC were a function of tumor volume for only 630 nm light in the R3327-AT tumors. 相似文献
2.
Abstract— Radioactivity from [3 H]-guanosine-3',5'-monophosphate was shown to become stably linked to proteins in testis extracts during ultraviolet irradiation. Adenosine-3',5'-monophosphate competitively inhibited incorporation into these proteins. Guanosine-3',5'-monophosphate had a lower affinity for binding sites than did adenosine-3',5'-monophosphate. Similar peptides were photo-labeled with [3 H]-guanosine-3',5'-monophosphate and [3H]-adenosine-3',5'-monophosphate. Guanosine-3',5'-monophosphate was more efficiently incorporated than was adenosine-3',5'-monophosphate. Extracts from a number of tissues incorporated both cyclic nucleotides photochemically. 相似文献
3.
Abstract— Ceramide, a stress-induced second messenger, has been associated with apoptosis in several malignant and non-malignant cell lines. We have shown that photodynamic treatment (PDT), using the phthalocyanine photosensitiz-er Pc 4 (HOSiPcOSi[CH3 ]2 [CH2 ]3 N[CH3 ]2 ), causes increased ceramide generation and subsequent induction of apoptosis in L5178Y-R (LY-R) mouse lymphoma cells. To test further if ceramide generation accompanies photocytotoxicity, we treated various cell lines with a PDT dose producing a 99-99.9% loss of clonogenicity. Like LY-R cells, human leukemia (U937) cells underwent rapid DNA fragmentation initiating within 1 h after PDT. Similarly, Chinese hamster ovary (CHO) cells showed rapid DNA laddering, beginning 1 h following the treatment. In contrast, mouse radiation-induced fibrosarcoma (RIF-1) cells showed no apoptosis within 24 h post-PDT, as judged by the absence of 50 kbp and oligonucleosome-size DNA fragments, as well as no annexin V binding to cells with preserved membrane integrity. Using the same doses of PDT, we observed a time-dependent ceramide accumulation in all three cell lines. While a significant increase in ceramide levels was reached within 1 and 10 min in U937 and CHO cells, respectively, elevated ceramide production was measured only after 30 min in RIF-1 cells. In addition, exogenous N-acetyl-sphingosine was able to mimic PDT-induced apoptosis in U937 and CHO cells. We suggest that ceramide accumulation is associated with PDT-induced apoptosis and photocytotox-icity. 相似文献
4.
Tadashi Mizoguchi Shun Sakamoto Yasushi Koyama Kenji Ogura Fuyuhiko Inagaki 《Photochemistry and photobiology》1998,67(2):239-248
5.
UV irradiation of rabbit muscle phosphofructokinase (PFK) in the presence of adenosine 3',5'-cyclic phosphate (cAMP) resulted in the covalent attachment of this ligand molecule to the enzyme protein. Irradiation in the frozen ice state enhanced the rate of this incorporation more than 10-fold above that achieved in aqueous solution, without significantly affecting the rate of photodestruction of the protein. [3 H]-cAMP and [32 P]-cAMP were each incorporated into PFK at identical rates in the frozen state. Rates of photoincorporation in the frozen and liquid states were both half-maximal at a free ligand concentration approximately equal to the dissociation constant of cAMP and PFK. Adenosine diphosphate (ADP) and adenosine monophosphate (AMP), both of which are known to compete for cAMP binding to PFK, inhibited photoincorporation of cAMP. Guanosine monophosphate (GMP), inosine monophosphate (IMP), and guanosine 3',5'-cyclic phosphate (cGMP), which do not compete for cAMP binding, had no effect on photoincorporation of cAMP. Irradiation of [3 H]-AMP or [3 H]-ADP resulted in photoincorporation into PFK at 0°C, with enhancement at — 77°C similar to that noted with cAMP. 相似文献
6.
Abstract— When [3 H]-cyclic adenosine 3',5'-monophosphate and [3 H]-cyclic guanosine 3',5'-monophos-phate are irradiated at varying UV wavelengths in the presence of cyclic nucleotide receptor proteins, photo-incorporation is maximal in the region of 280 nm. This suggests that covalent coupling occurs by means of photo-activation of an entity other than the ligand cyclic nucleotide. The action spectra more closely resemble the absorbtion spectrum of the reacting protein, making it likely that absorhtion of radiant energy by components of the protein receptor leads to photo-affinity labeling. 相似文献
7.
Abstract— Laser flash photolysis of trans -[Rh(dppe)2 X2 ][PF6 ] (X=Br and I; dppe=bis(diphenylphosphino)ethane) in CH2 Cl2 or CH3 CN produces the d7 Rh(II) radicals, [Rh(dppe)2 X]+ , and halogen atoms. The kinetics of the disappearance of [Rh(dppe)2 X]+ radicals in CH2 Cl2 or CH3 CN were mixed order: H-atom abstraction from solvent to produce the rhodium hydrides, [RhH(dppe)2 X][PF6 ], and Rh/X recombination. In the poor H-atom donor solvent, benzonitrile, Rh/Br recombination was observed to be uncomplicated by competing H-atom abstraction. The hydride complexes [RhH(dppe)2 X][PF6 ], formed by H-atom abstraction were completely characterized by 31 P{1 H}-NMR, 1 H-NMR, and mass specrometry. Cyclohexene was used as an effective trap for photogenerated Br atoms and yielded bromocyclohexane and 3-bromocyclohexene in a relative yield, 1:9. The photochemical mechanism is discussed in light of the transient absorbance and trapping studies. 相似文献
8.
Yuki Hirai Hitoshi Tamiaki Shigenori Kashimura Yoshitaka Saga 《Photochemistry and photobiology》2009,85(5):1140-1146
Demetalation kinetics of bacteriochlorophylls (BChls) c, d and e from green sulfur photosynthetic bacteria were studied under weakly acidic conditions. Demetalation rate constants of BChl e possessing a formyl group at the 7-position were significantly smaller than those of BChls c and d , which had a methyl group at this position. The activation energy of demetalation of 31 R -8,12-diethyl([E,E])-BChl e was 1.5-times larger than that of 31 R -[E,E]-BChl c . 15 N-labeled 31 R -[E,E]-BChls c and e were purified from cells of green sulfur bacteria grown in a medium containing 15 NH4 Cl, and their 15 N NMR spectra were measured. The chemical shifts of N21 , N22 and N23 atoms of 31 R -[E,E]-BChl e were lower-field shifted than those of 31 R -[E,E]-BChl c , respectively, and especially the difference in chemical shifts of N22 was significantly large. These results suggest that the electron-withdrawing formyl group at the 7-position of BChl e affected an electronic state of the chlorin macrocycle and caused BChl e to be more tolerant for removal of the central magnesium compared with BChls c and d . 相似文献
9.
Mary E. Rampey Carrie E. Halkyard Angela R. Williams April J. Angel Douglas R. Hurst Jessica D. Townsend Anne E. Finefrock Charles F. Beam Shannon L. Studer-Martinez 《Photochemistry and photobiology》1999,70(2):176-183
Abstract. The carbomethoxyhydrazone of 2'-hydroxyacetophenone was trilithiated with excess lithium diisopropylamide and C-acylated with a variety of benzoate esters followed by acid cyclization of the intermediates to 2-(5-aryl-l-car-bomethoxy-lHpyrazol-3-yl)phenols [3-(2-hydroxyphen-yl)-lH-pyrazoles]. The products were characterized by Fourier transform-IR, l H NMR, 13 C NMR, UV-visible absorption and fluorescence. All the derivatives in n -heptane have an absorption maximum at ˜304 nm and an extremely weak (φr = 10 4 ) fluorescence with maxima in the range of 335–460 nm. The broad range of fluorescence maxima and fluorescence quantum yields is attributed to varying contributions of charge transfer that are dependent on both the identity of the substituent and solvent polarity. A phenomenally large Stokes-shifted fluorescence maximum at 620 nm was observed for 2-(l-car-bomethoxy-5-[4-dimethylaminophenyl]-lff-pyrazol-3-y1)phenol in n-heptane and attributed to excited-state intramolecular proton transfer. As a result, competitive excited-state proton/charge transfer properties have been observed in the pyrazoles studied, of which the spectral properties can be fine tuned by substituent as well as solvent effects. 相似文献
10.
S. W. Young K. W. Woodburn M. Wright T. D. Mody Q. Fan J. L. Sessler W. C. DOW R. A. Miller 《Photochemistry and photobiology》1996,63(6):892-897
Lutetium texaphyrin, PCI-0123, is a pure, water-soluble photosensitizer with a large broad absorption band centered at 732 nm. The compound was tested for photodynamic therapy (PDT) effectiveness in a murine mammary cancer model. The texaphyrin macrocycle as illustrated by magnetic resonance imaging and 14 C-radiolabeled texaphyrin studies was shown to be tumor selective; a tumor-to-muscle ratio of 10.55 was seen after 5 h. Lutetium texaphyrin, at a drug dose of 20 μmol/kg with irradiation 5 h postinjection at 150 J/cm2 and 150 mW/cm2 , had significant efficacy (P < 0.0001) in treating neoplasms of moderate size (40 ± 14 mm3 ) and also had significant efficacy ( P < 0.0001) in treating larger neoplasms (147 ± 65 mm3 ). The PDT efficacy was correlated with the time interval between PCI-0123 administration and light exposure. A 100% cure rate was achieved when photoirradiation took place 3 h postinjection compared to 50% for 5 h using 10 μmol/kg and 150 J/cm2 at 150 mW/cm2 . The PDT efficacy was attributable to the selective uptakehetention of the texaphyrin photosensitizer in addition to the depth of light penetration achievable at the 732 nm laser irradiation. 相似文献
11.
Michael Price Stanley R. Terlecky David Kessel 《Photochemistry and photobiology》2009,85(6):1491-1496
Although the first reactive oxygen species (ROS) formed during irradiation of photosensitized cells is almost invariably singlet molecular oxygen (1 O2 ), other ROS have been implicated in the phototoxic effects of photodynamic therapy (PDT). Among these are superoxide anion radical (• O2 − ), hydrogen peroxide (H2 O2 ) and hydroxyl radical (• OH). In this study, we investigated the role of H2 O2 in the pro-apoptotic response to PDT in murine leukemia P388 cells. A primary route for detoxification of cellular H2 O2 involves the peroxisomal enzyme catalase. Inhibition of catalase activity by 3-amino-1,2,4-triazole led to an increased apoptotic response. PDT-induced apoptosis was impaired by addition of an exogenous recombinant catalase analog (CAT- skl) that was specifically designed to enter cells and more efficiently localize in peroxisomes. A similar effect was observed upon addition of 2,2'-bipyridine, a reagent that can chelate Fe+2 , a co-factor in the Fenton reaction that results in the conversion of H2 O2 to • OH. These results provide evidence that formation of H2 O2 during irradiation of photosensitized cells contributes to PDT efficacy. 相似文献
12.
M. Holmberg 《Photochemistry and photobiology》1983,37(3):293-295
Pretreatment of human cells with near UV radiation (UVA) in fluences exceeding 5 × 104 Jm−2 caused a decrease in the amount of the unscheduled DNA synthesis induced by far UV radiation (UVC). The DNA repair synthesis, as measured by the incorporation of [3 H] -thymidine, is reduced by nearly a factor of 2 for a UVA radiation exposure of 1.5 × 105 Jm−2 . Since solar UVA fluence rate is rather independent of latitude, this figure corresponds to a UVA exposure time of 50-60 min from noon sunlight in the summer time. 相似文献
13.
Syed I. A. Zaidi Rajesh Agarwal Guido Eichler Boris D. Rihter Malcolm E. Kenney Hasan Mukhtar 《Photochemistry and photobiology》1993,58(2):204-210
Abstract— Photodynamic therapy (PDT) of cancer is a modality that relies upon the irradiation of tumors with visible light following selective uptake of a photosensitizer by the tumor tissue. There is considerable emphasis to define new photosensitizers suitable for PDT of cancer. In this study we evaluated six phthalocyanines (Pc) for their photodynamic effects utilizing rat hepatic microsomes and human erythrocyte ghosts as model membrane sources. Of the newly synthesized Pc, two showed significant destruction of cytochrome P-450 and monooxygenase activities, and enhancement of lipid peroxidation, when added to microsomal suspension followed by irradiation with ∼ 675 nm light. These two Pc named SiPc IV (HOSiPcOSi[CH3 ]2 [CH2 ]3 N[CH3 ]2 ) and SiPc V (HOSiPcOSi[CH3 ]2 [CH2 ]3 N[CH3 ]3 1 I) showed dose-dependent photodestruction of cytochrome P-450 and monooxygenase activities in liver microsomes, and photoenhancement of lipid peroxidation, lipid hydroperoxide formation and lipid fluorescence in rnicrosomes and erythrocyte ghosts. Compared to chloroaluminum phthalocyanine tetrasulfonate, SiPc IV and SiPc V produced far more pronounced photodynamic effects. Sodium azide, histidine, and 2,5-dimethylfuran, the quenchers of singlet oxygen, afforded highly significant protection against SiPc IV- and SiPc V-mediated photodynamic effects. However, to a lesser extent, the quenchers of superoxide anion, hydrogen peroxide and hydroxyl radical also showed some protective effects. These results suggest that SiPc IV and SiPc V may be promising photosensitizers for the PDT of cancer. 相似文献
14.
Abstract The effects of long—term applications of tretinoin(retinoic acid; RA) on acute responses to UVB radiation were examined in hairless mouse skin in vivo. The skin was examined histologically and the radioactive tracer [3 H]-thymidine was used to study premitotic semiconservative DNA synthesis in the epidermal basal cells. Ten and 23 wk applications of a 0.05% RA solution (3 times a wk) induced epidermal acanthosis, hypertrophy of the individual cells and an increased number of [3 H]-thymidine-labelled basal cells. At both time periods there was a distinct reduction in the expected inhibition of DNA synthesis at 4 h and the expected acceleration of DNA synthesis at 48 h after a single exposure to UVB radiation. In addition, the histologic morphology was unchanged at 48 h post irradiation. Thus, the repeated RA applications had a definitive influence on at least two aspects of the cutaneous response to UVB energy. 相似文献
15.
The steady-state UVA (350 nm) photolysis of ( E )-β-ionone ( 1 ) in aerated toluene solutions was studied by 1 H NMR spectroscopy. The formation of the 1,2,4-trioxane ( 2 ) and 5,8-endoperoxide ( 5 ) derivatives in the ratio of 4:1 was observed. Time-resolved laser induced experiments at 355 nm, such as laser-flash photolysis, photoacoustic and singlet oxygen 1 O2 phosphorescence detection, confirmed the formation of the excited triplet state of 1 with a quantum yield Φ T = 0.50 as the precursor for the generation of singlet oxygen 1 O2 ( Φ Δ = 0.16) and the isomeric α-pyran derivative ( 3 ), which was a reaction intermediate detected by NMR. In turn, the reaction of 1 O2 with 1 and 3 occurred with rate constants of 1.0 × 106 and 2.5 × 108 m −1 s−1 to yield the oxygenated products 5 and 2 , respectively, indicating the relevance of the fixed s-cis configuration in the α-pyran ring in the concerted [2+4] cycloaddition of 1 O2 . 相似文献
16.
Abstract— We have determined the dimerization and monomerization cross sections of the Thy < > Thy (cyclobutyl dimer of thymine and thymine) and the Cyt < > Thy (cyclobutyl dimer of cytosine and thymine) dimers in Escherichia coti [3 H]-DNA ([3 H]-thymine labeled DNA) at five wavelengths in the range 240–300 nm. It may be concluded from the dimerization action spectra for the two dimers that the excitation of Thy (thymine) is mainly responsible for the photochemical dimerization reaction in both cases. The calculated quantum yields of dimerization and monomerization are also presented in this paper and several questions, raised by the results obtained at 300 nm, are discussed. 相似文献
17.
INTRODUCTION OF PYRIMIDINE DIMERS INTO DIFFERENT INTRACELLULAR FORMS OF SIMIAN VIRUS 40 总被引:1,自引:0,他引:1
We examined the production of pyrimidine dimers by UV radiation in different intracellular forms of simian virus 40 DNA. Virus and chromatin or previrions were selectively labeled with [l4 C]-thymidine and [3 H]-thymidine, respectively, in the same monolayer of infected cells. Viral DNA was extracted immediately after irradiation, and pyrimidine dimers were detected as sites sensitive to the UV-endonuclease encoded by bacteriophage T4. No difference in the number of dimers introduced into chromatin, previrions. or virions was detected. 相似文献
18.
D. Georgescauld J. P. Desmasèz R. Lapouyadej A. Babeau H. Richard Mitchell Winnik§ 《Photochemistry and photobiology》1980,31(6):539-545
Abstract— The molecule (1,1'-dipyrenyl)-methyl ether [dipyme] shows intramolecular excimer fluorescence in competition with fluorescence from the locally excited pyrene chromophore. This intensity ratio Ic /Im is sensitive to solvent viscosity. The molecule is soluble in synthetic phospholipid membranes. 1 H NMR studies suggest that the molecule is localized in the hydrocarbon region of the membrane. Fluorescence measurements at various temperatures of dipyme dissolved in these membranes show that Ic /Im is exceedingly sensitive to fluidity changes accompanying both the pretransitions and the gel to liquid crystalline transitions of the membrane. These studies can be carried out at a mole ratio of probe to lipid 102 -103 smaller than that necessary to observe bimolecular pyrene excimer formation. 相似文献
19.
S. Nakajima H. Hayashi K. OHSHIMA K. Yamazaki Y. Kubo N. Samejima Y. Kakiuchi Y. Shindoh H. Koshimizu I. Sakata H. Yamauchi 《Photochemistry and photobiology》1987,46(5):783-788
Abstract Mono-DPTA-ethyleneglycol-Ga-deuteroporphyrin (MDEGD) was synthesized, by coordinating non-radioactive Ga in the porphyrin ring and connecting DTPA (diethylene-triamine-N,N,N,N,N,-pentaacetic acid) to its side chain. By labeling with 111In , chemicals for scintigraphy were developed. They were applied to Syrian golden hamsters with implanted pancreatic gland cancers and C57-black mice with Lewis lung cancer to enable tumor imaging and biodistribution examination. A comparative study was also conducted with [67 Ga]citrate. In the resultant data, [111 In]MDEGD showed larger tumor/lung, tumor/kidney and tumor/blood ratio with [67 Ga]citrate. The affinity of [n In]MDEGD in inflammatory tissue was much lower than that of 67 Ga citrate. [111 In]MDEGD lost its photosensitivity. 相似文献
20.
Abstract— The near-UV induced photoreactions of 1-phenyl-1,3,5-heptatriyne (PHT) with undecylenic(10-undecenoic) acid methyl ester (UAME) and 1-hexene have been investigated in n-hexane. Four major photoadducts have been isolated in both cases and purified by normal and reverse phase liquid chromatography. The structures of these adducts were determined by mass, UV absorption, FT-IR, 1 H-and 13 C-NMR spectral analyses, one-and two-dimensional nuclear Overhauser effect studies, and 1 H-1 H homo-correlation spectroscopy. All the data indicate that the adducts are cyclobutenes resulting from the [2+2] photocycloaddition of PHT to UAME and 1-hexene. 相似文献