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1.
The increase of environmental radiation dose rate during rainfall at environmental monitoring posts (MPs) was calculated by using the correlation relationship with the dose rate at the neighboring MP. The calculated dose rate agreed with the observed one within less than 20% of the maximum increase height of the observed one for each rainfall. Furthermore, when the dose rate increased due to Krypton-85 (85Kr) discharged from the Tokai Reprocessing Plant (TRP) at the environmental monitoring station (MS) downwind of the stack during rainfall, the dose rate due to the 85Kr was tried to discriminate. The discriminated dose rate agreed with that calculated by the atmospheric dispersion calculation code system, SIERRA-II, using stack monitor data and local meteorological observation data.  相似文献   

2.
The 2-phenyl benzothiazole pharmacophore is known to have high affinity for amyloid beta (Aβ) and is therefore derivatized, to [N-(4′-benzothiazol-pyridin-2-yl-methyl-amino)-acetic acid (BTPAA)] for radiolabeling with [99mTc(CO)3(H2O)3]+ precursor. The radiotracer, 99mTc(CO)3–BTPAA is evaluated in vitro and in vivo to determine its binding with the Aβ and ability to cross the blood brain barrier. The radiotracer prepared in >95 % radiochemical yield, showed ~25 % inhibition in presence of thioflavin-T, indicating its specificity towards aggregated Aβ protein. The radiotracer also showed brain uptake of 0.25 ± 0.04 % injected dose/g at 2 min post injection, indicating its ability to cross the blood brain barrier.  相似文献   

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4.
Bisphosphonates can be labeled with Technetium-99m (99mTc) and are used for bone imaging because of their good localization in the skeleton and rapid clearance from soft tissues. Over the last decades bone scintigraphy has been used extensively in the evaluation of oncological patients to provide information about the sites of bone lesions, their prognosis and the effectiveness of therapy by showing the sequential changes in tracer uptake. Since the lesion visualization and lesion/bone ratio are important utilities for a bone scanning radiopharmaceutic; in this study incorporation of 99mTc labeled alendronate sodium (99mTc–ALD) was evaluated in U2OS (human bone osteosarcoma) and NCI-H209 (human bone carcinoma) cell lines. ALD was directly labeled by 99mTc, radiochemical purity and stability of the complex were analyzed by radioactive thin layer chromatography and radioactive high performance liquid chromatography studies. For cell incorporation study, NCI-H209 and U2OS cell lines were used with standard cell culture methods. The six well plates were used for all experiments and the integrity of each cell monolayer was checked by measuring its transepithelial electrical resistance (TEER) with an epithelial voltammeter. Results confirmed that ALD was successfully radiolabeled with 99mTc. 99mTc–ALD incorporated with NCI-H209 and U2OS cells. The uptake percentages of 99mTc–ALD in NCI-H209 and U2OS cell lines were found significantly different. Since 99mTc–ALD highly uptake in cancer cell line, the results demonstrated that radiolabeled ALD may be a promising agent for bone cancer diagnosis.  相似文献   

5.
Increasing evidence suggests that Cyclin A-Cdk2 activity is required in the apoptosis process induced by various stimuli. To determine a specific substrate of Cyclin A-Cdk2 for apoptosis, in this study, we carried out anin vitro kinase assay using immunoprecipitated complex Cyclin A-Cdk2 as an enzyme source, and recombinant protein GST-Bad as a substrate. Our study showed that Bad was clearly phosphorylated by Cyclin A-Cdk2 in vitro. To examine whether protein Bad can also be phosphorylated by Cyclin A-Cdk2 kinase in vivo, we transiently overexpressed protein Bad with Cyclin A or Cdk2-dn, a dominant negative version of Cdk2, in Hela cells and determined the phosphorylation status of protein Bad. The test showed that protein Bad was clearly phosphorylated in Cyclin A overexpressed cells,but not in Cdk2-dn or mock transfectent. Moreover, etoposide also caused the phosphorylation of endogenetic Bad. In conclusion, here we provide first time evidence that protein Bad can be a substrate of Cyclin A-Cdk2 apoptosis for in vitro and in vivo.  相似文献   

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Classical antifolates containing L-glutamic acid moiety in molecule have shortcomings such as drug resistance which is originated from the defective cell transport by mutation, and toxicity to the host which is due to unnecessarily long retention inside normal cells.[1] One strategy to overcome these shortcomings is to design nonclassical lipophilic inhibitors of folate requiring enzymes by deleting or modifying L-glutamic acid component from the folate analogues.  相似文献   

8.
Metabolism study was carried out on 12b-hydroxylveratroylzygadenine(VOG) that is a cevine-type alkaloid existing in Veratrum nigrum L. and a neurotoxic component. In order to better understand the potential mechanism of neurotoxicity of VOG, this study measured VOG-induced DNA damage in the cerebellum and cerebral cortex of mice after 7 days repetitive oral dose by using single-cell gel electrophoresis(Comet assay). High performance liquid chromatography-tandem mass spectrometry(LC–MS/MS) was developed and applied to separate and identify in vitro and in vivo metabolites of VOG for investing the possible relationship of metabolism and neurotoxicity. In vitro experiment was carried out using rat liver microsomes, while the in vivo study was conducted on rats. The obtained results indicated that VOG might cause DNA damage in cerebellum and cerebral cortex of mice in a dosedependent manner. Hydrolysis of ester bond and O-demethylation were proposed to be the main in vivo metabolic pathways of VOG, while the major in vitro metabolic pathways were proposed as methyl oxidation to aldehyde, dehydrogenation, hydrolysis of ester bond, hydrolysis of ester bond together with acetylation, and methoxylation. O-Demethylation reaction was likely to be associated with reactive oxygen species production, leading to the DNA damage.  相似文献   

9.
Phytochemical screening of air-dried leaves and fruit juice of certain Ficus and Morus spp. have been studied. In an in?vitro study, the ethanol and hexane extracts of the investigated plants were evaluated against hyperlipidaemia by estimating the rate limiting enzyme of cholesterol biothenysis; β-hydroxy-β-methylglutaryl coenzyme A reductase (HMG-CoA reductase). The antioxidant activity was evaluated by reduction of DPPH(-) free radical. Extra phytochemical screening of Ficus extracts was undertaken, which recorded potent hypolipidaemic and antioxidant activities. The more pronounced extract, Ficus mysorensis (hexane extract), was evaluated in?vivo by estimation of the lipid profile and certain antioxidant parameters in hypercholesterolemic rats. The hexane fraction was chromatographed and six isolated compounds were identified. Furthermore, its saponifiable fraction was identified by a MS/MS technique. In conclusion, F. mysorensis recorded hypolipidaemic and antioxidant effects. Detailed studies of the isolated compounds must be undertaken for an evaluation against hypercholesterolemia and free radical elevation.  相似文献   

10.
In this work, histidine derivatives bearing an acetic acid or a propyl amine substituent on the Nε-atom are conjugated to the b-acid, c-acid and d-acid moiety of cyanocobalamin (vitamin B12) via amide formation. Four different derivatives were prepared with different sites of conjugation (b-, c- or d-acid) and different spacer lengths between histidine and the acid moiety. These conjugates can be efficiently labeled with [99mTc(OH2)3(CO)3]+ at yields higher than 95% under mild conditions (50 °C, 30 min, 10−4 M). The biodistribution of the 99mTc(CO)3 labeled conjugates is determined in mice bearing B16-F10 melanoma tumors. The organ distribution varies significantly for each of the derivatives with the percentage injected dose per gram of tumor tissue ranging from 4.4 ± 0.9 to 9.2 ± 2.0.  相似文献   

11.
An industrial chromatographic 99Mo–99mTc generator has been developed with the aid of chromatographic alumina to obtain 99mTc in a non-aqueous medium. This generator system takes advantage of tributyl phosphate to extract 99mTc selectively with appreciable yield and in high radiochemical and radionuclidic purity. This facile, versatile and efficient approach provides 99mTc at industrial sites in a medium soluble in hydrocarbon solvents, for radiotracer applications.  相似文献   

12.
The preparation of99mTc-Sn-EBV and99mTC-Sn-EBA is described. Different parameters affecting the labeling efficiency (ligand concentration, pH, molar ligand: reducing agent ratio) as well as the time-dependent stability of labeled compounds were investigated. Preliminary biodistribution studies in Wistar rats showed accumulation of the above mentioned compounds in kidneys.  相似文献   

13.
An amphiphilic dendrimer bearing a hydrophobic alkyl chain and hydrophilic poly(amidoamine) dendrons is able to combine the advantageous features of lipid and dendrimer vectors to deliver a heat shock protein?27 siRNA and produce potent gene silencing and anticancer activity in?vitro and in?vivo in a prostate cancer model. This dendrimer can be used alternatively for treating various diseases.  相似文献   

14.
The chemical consequences following β decay of 99Mo in Mo(CO)6 have been investigated. The yields of 99mTc species in solid state and in solution of n-pentane were determined by various separation methods. The 99mTc species are identified as 99mTc(CO)5 radicals, 99mTc2(CO)10 and 99mTc2+ ions. The product yields were 73,7 and 7% respectively for the solid and 31, 0 and 39% respectively for the solution. These results are discussed on the basis of the energy distribution of recoiling 99mTc atoms and the charge effects owing to perturbation of electron shells.  相似文献   

15.
Nirmatrelvir (NRV), a 3C-like protease or Mpro inhibitor of SARS-CoV-2, is used for the treatment of COVID-19 in adult and paediatric patients. The present study was accomplished to investigate the comprehensive metabolic fate of NRV using in vitro and in vivo models. The in vitro models used for the study were microsomes (human liver microsomes, rat liver microsomes, mouse liver microsomes) and S9 fractions (human liver S9 fractions and rat liver S9 fractions) with the appropriate cofactors, whereas Sprague–Dawley rats were used as the in vivo models. Nirmatrelvir was administered orally to Sprague–Dawley rats, which was followed by the collection of urine, faeces and blood at pre-determined time intervals. Protein precipitation was used as the sample preparation method for all the samples. The samples were then analysed by liquid chromatography–quadrupole time-of-flight tandem mass spectrometry (LC-Q-ToF-MS/MS) using an Acquity BEH C18 column with 0.1% formic acid and acetonitrile as the mobile phase. Four metabolites were found to be novel, which were formed via amide hydrolysis, oxidation and hydroxylation. Furthermore, an in silico analysis was performed using Meteor Nexus software to predict the probable metabolic changes of NRV. The toxicity and mutagenicity of NRV and its metabolites were also determined using DEREK Nexus and SARAH Nexus.  相似文献   

16.
The proligands of the series tetramethylenebis(N-n-alkylbenzimidazolium bromide) (where n = 3–10) (1–8) as N-heterocyclic carbene (NHC) precursors have been prepared by reacting the initially synthesized N-n-alkyl benzimidazole with 1,4-dibromobutane in 2 : 1 M ratio. A reaction of Ag2O with 1–8 resulted in the formation of Ag(I) complexes tetramethylenebis{(N-n-alkylylbenzimidazol-2-ylidene)silver(I)hexafluorophosphate} (9–16), respectively. All the synthesized compounds were characterized by FT-IR, 1H NMR, 13C NMR, atomic absorption and elemental analysis. Single-crystal X-ray diffraction study on tetramethylenebis{(N-n-octylbenzimidazol-2-ylidene)silver(I)hexafluorophosphate} (14) has revealed that the complex exists as a dinuclear compound. All compounds were assessed for their antiproliferation test on human colorectal cancer cell line (HCT 116). Interestingly, increasing the n-alkyl chain length from n = 3 to 10 of the proligands and their respective complexes showed trends in increased cytotoxicity against human colon cancer cell line. Cytotoxicity data showed that tetramethylene linked bis-benzimidazolium salts and their respective dinuclear Ag(I)–NHC complexes can be useful therapeutic agents against colon cancer.  相似文献   

17.
A simple chromatographic procedure for clean separation of the important radionuclide,99m Tc, in the equilibrium mixture,99Mo−99mTc, has been demonstrated. Separation of pure99mTc has been achieved by preferential extraction of the radioisotope through an anion exchange resin column of Amberlite IRA-410 using Na-ascorbate solution at pH 7 as an eluent. The radiochemical purity of the separated radiotracer has been verified by taking recourse to γ-ray spectrometry. The potentiality of the developed procedure lies in the facts that the eluting agent, ascorbic acid, itself h got its own biomedical importance as Vitamin C and the concerned radioisotope can be obtained in both Tc(IV) and Tc(VII) states as per requirement for diagnostic purposes.  相似文献   

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19.
In a patient with Serratia marcescens bacteraemia, a variant resistant to cefotaxime and amikacin was isolated in a blood culture under combined treatment with cefotaxime and amikacin. In addition, in vitro selection on cefotaxime and/or amikacin yielded resistant mutants from the sensitive parent strain. These mutants displayed the same type of cross-resistance as the clinical strain to all β-lactam and aminoglycoside antibiotics. The mechanisms for this resistance was a decrease in the permeability of the cell. To our knowledge, the isolation of such strains from blood cultures and the mechanism responsible for this ⪡ broad-spectrum resistance ⪢ have not been previously described.  相似文献   

20.
The functionalised cluster Os3(CO)10(CH3CN)2 reacts at room temperature with trimethylsilylacetylene to afford the orange derivative Os3(CO)10(Me3SiC2H) which undergoes decarbonylation and hydrogen migration to give the cluster HOs3(CO)9(CCSiMe3), which has been fully characterised by an X-ray diffraction study.  相似文献   

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