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Objective To develop an unmanned aerial vehicle (UAV)-borne radiation monitoring system with high detection efficiency and nuclide identification ability for airborne monitoring in nuclear emergency. Methods The UAV-borne CeBr3 radiation monitoring system was composed of four cerium bromide (CeBr3) crystal detectors coupled with silicon photomultipliers (SiPMs) and other components including integrated modules, intelligent electronic devices, and new composite materials. Results According to various performance tests on the system, the crystal energy resolution was better than 5% (@0.662 MeV), the peak drift of the energy spectrum was within ±1 channel, the linear fit of energy was 0.99997, the change in the count rate of each energy window during 12 h long-term measurement was less than 5%, and the detection efficiency was higher compared with that of NaI (Tl) detectors of the same volume. Conclusion Through ground point source testing and theoretical calculation, the system has reliable ability to identify radionuclides, which can be used in nuclide identification and the preparedness and response for nuclear and radiation emergencies.
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Objective:To establish a method for automatic determination of iodine level in salt by arsenic-cerium catalytic spectrophotometry using an iodine element detector (hereinafter referred to as this method), and to provide reference for in-depth study of salt iodine detection technology.Methods:This method was used to determine the iodine level in salt, and the linear range, detection limit, precision, and accuracy (determination of salt iodine standard substance GBW10006y and GBW10007y, and addition recovery experiment) of this method were determined. The iodine level of 35 salt samples was determined by this method and redox titration method recommended by the national standard, and the results were compared.Results:This method had a good linear relationship within the range of 50 - 600 μg/L standard curve, the absolute value of the correlation coefficients was > 0.999 0, and the detection limit was 5.0 mg/kg. The relative standard deviation of iodine concentration in salt samples with low, medium and high iodine concentrations were all < 6.0%. The determination results of salt iodine standard substance GBW10006y and GBW10007y were within the given value ranges; three iodine concentrations (6.0, 10.0 and 30.0 mg/kg) were added to the salt samples, with an average recovery rate of 96.7% to 105.0%, and a total average recovery rate of 100.9%. The method comparison experiment showed that there was no statistically significant difference between the salt iodine determination results of this method and the redox titration method ( t = - 1.54, P = 0.132). Conclusion:This method has the advantages of high accuracy, good precision and wide linear range in determining salt iodine, and is suitable for the detection of large quantities of samples in salt iodine monitoring.
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Drought is a common limiting factor affecting rice yield and quality. Cerium oxide nanoparticles(nanoceria) have been widely reported to improve crop stress tolerance. However, the effects and mechanisms of nanoceria on rice drought tolerance are still unknown. The aim of this study is to investigate whether nanoceria can improve rice drought tolerance by modulating reactive oxygen species(ROS) homeostasis and nitric oxide(NO) levels. Our results showed that compared with no-nanoparticle treatment, nanoceria significantly increased the fresh weight of rice seedlings under drought stress(19%, P < 0. 05). Also, under drought stress, the ROS level of rice leaves treated with nanoceria was significantly lower(82%, P < 0. 05) than leaves treated with buffer. The leaf NO level after nanoceria treatment, however, is significantly higher(46%, P < 0. 05) than that with no-nanoparticle treatment under drought stress. Moreover, compared with control plants, nanoceria maintained better membrane integrity in rice leaf cells under drought stress, showing a 70% decrease(P < 0. 05) in dead leaf cells. This study explores the mechanisms underlying nanoceria’s improved rice drought tolerance by affecting ROS and NO levels, which not only further enriches our knowledge about the interaction between nanoparticles and crops under abiotic stress but also gives more support on the sustainable development of nano-enabled agriculture.
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The typical hallmark of tumor evolution is metabolic dysregulation. In addition to secreting immunoregulatory metabolites, tumor cells and various immune cells display different metabolic pathways and plasticity. Harnessing the metabolic differences to reduce the tumor and immunosuppressive cells while enhancing the activity of positive immunoregulatory cells is a promising strategy. We develop a nanoplatform (CLCeMOF) based on cerium metal-organic framework (CeMOF) by lactate oxidase (LOX) modification and glutaminase inhibitor (CB839) loading. The cascade catalytic reactions induced by CLCeMOF generate reactive oxygen species "storm" to elicit immune responses. Meanwhile, LOX-mediated metabolite lactate exhaustion relieves the immunosuppressive tumor microenvironment, preparing the ground for intracellular regulation. Most noticeably, the immunometabolic checkpoint blockade therapy, as a result of glutamine antagonism, is exploited for overall cell mobilization. It is found that CLCeMOF inhibited glutamine metabolism-dependent cells (tumor cells, immunosuppressive cells, etc.), increased infiltration of dendritic cells, and especially reprogrammed CD8+ T lymphocytes with considerable metabolic flexibility toward a highly activated, long-lived, and memory-like phenotype. Such an idea intervenes both metabolite (lactate) and cellular metabolic pathway, which essentially alters overall cell fates toward the desired situation. Collectively, the metabolic intervention strategy is bound to break the evolutionary adaptability of tumors for reinforced immunotherapy.
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Objective:To establish a method for determination of iodine in salt by arsenic-cerium catalytic spectrophotometry.Methods:The content of iodine in salt was detected by arsenic-cerium catalytic spectrophotometry with an automatic iodine analyzer. The standard curve linearity, detection limit, precision and accuracy of the method were evaluated. The iodine content of 20 edible salt samples was detected by the newly established method and direct titration, and the results were compared.Results:In the range of 0 - 150 μg/L standard curve, the correlation coefficient ( r) = - 0.999 9, and the detection limit was 1.4 mg/kg. The average iodine contents of iodine composition analysis standard materials GBW10006z and GBW10007z were 12.2 and 22.8 mg/kg ( n = 6), respectively, which were all within the given standard value ranges, and the relative standard deviations ( RSD) were 2.04% and 2.33%, respectively. Iodine composition analysis standard materials GBW10006b, GBW10007b, GBW10006v, GBW10007v, GBW10006z and GBW10007z measurement results (12.0, 24.6, 12.6, 22.8, 12.3, 23.2 mg/kg, n = 2) were all within the given standard value ranges, with good quality control. The iodine content of 20 edible salt samples was detected by arsenic-cerium catalytic spectrophotometry and direct titration, respectively, and the difference was not statistically significant ( t = 1.99, P = 0.060). Conclusion:Arsenic-cerium catalytic spectrophotometry has the characteristics of good linear relationship, low detection limit, good precision and high accuracy in determination of salt iodine content, which is suitable for popularization and application.
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Objective: To develop and validate new, selective spectrophotometric colorimetric analytical methods for the quantification of methimazole in its pure form and in its pharmaceutical preparations. Methods: Method A is based on the oxidation of methimazole with potassium permanganate in alkaline medium, the manganate ion produced was measured at λmax= 610 nm. Method B is a kinetic determination of methimazole using fixed-time method based on the oxidation of methimazole using known excess of cerium (IV) nitrate in acidic medium and assessing the unreacted Ce (IV) by adding a fixed amount of methyl orange and measuring the absorbance of the resultant solution at λmax=507 nm which is equivalent to the unreacted methyl orange. The reaction conditions and analytical parameters are investigated and optimized. Method validation was carried out according to ICH guidelines in terms of linearity, LOD, LOQ, precision, and accuracy. Results: Beer’s law is obeyed in the range of 1.50–15.00 μg/ml for method A and 0.25–3.00 μg/ml for method B. The developed methods were subjected to the detailed validation procedure. The proposed spectrophotometric methods were applied for the determination of the methimazole in its pure form and in its pharmaceutical formulation. The percentage recoveries were found to be 100.82 % and 99.85 % in the pharmaceutical formulation for the two proposed methods, respectively. Conclusion: Both developed spectrophotometric methods, considered as green analytical chemistry, were found to be novel, highly selective and can be applied for the quality control of methimazole in its pure form and in its pharmaceutical formulation based on the simplicity, applicability of the parameters, accessibility of the reagents employed and reasonably low time of analysis.
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OBJECTIVE: To study the effect of nano-cerium oxide on the early development of zebrafish embryos. METHODS: The well-developed zebrafish embryos were randomly divided into the control group and the 50, 100, 200, 400 and 800 mg/L dose groups, with 40 embryos in each group. The dose groups were treated with nano-cerium oxide at the corresponding mass concentration for 5 days. The control group received no treatment. The death and malformation of embryos were observed. The heart rate of zebrafish embryos was recorded using confocol microscope. The protein expression of microtubule-associated protein 1 light chain 3(LC3) and cleaved Caspase-3 and were observed by Western blot technology. RESULTS: The death and embryonic malformation rate of zebrafish embryos increased with the increase of doses, showing statistical significance(P<0.01). The heart rate of the 800 mg/L dose group was decreased compared with the control group [(77±8) vs(93±4) beats/min, P<0.01]. There was no statistical significant difference in LC3-Ⅱ protein expression in each groups(P>0.05). The cleaved Caspase-3 protein expression increased in all dose groups compared with the control group(P<0.05). The cleaved Caspase-3 protein expression in the 200 mg/L dose group was higher than that in the 50 mg/L dose group(P<0.05). CONCLUSION: The nano-cerium oxide may induce cell apoptosis, causing toxic effect in early development of zebrafish embryos.
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Objective To investigate the effects of cerium oxide nanoparticles of different sizes on the number and constructions of immune cells in peripheral blood of mice after X-ray irradiation. Methods Mice were randomly divided into 4 groups according to body weight layer and the weight of each mouse was weighed. All mice were divided into 6 groups according to weight from high to low, and there were 4 mice in each group. Then 1 mouse was randomly taken from each group to form the control group. Model group, 5 nm and 25 nm cerium oxide nanoparticles groups were formed in turn. There were 6 mice in each group. The mice in model group and cerium oxide nanoparticles administration groups were irradiated once with 3 Gy of X-rays. The mice in cerium oxide nanoparticles groups began to be intraperitoneally administrated once a day with 10 μg 5 nm or 25 nm cerium oxide nanoparticles per kilogram body weight on the 4th day before irradiation and once every other 2 days after irradiation. The mice in the control group and model group were intraperitoneally administrated with 0.9 % saline. The mice were killed on the 10th days after irradiation. White cells count (WBC) and classification in peripheral blood were detected by using automatic globulimeter, and lymphocyte subsets were analyzed by using flow cytometry. Results Compared with the control group, the number of WBC, neutrophil granulocytes, monocytes, lymphocytes, total T lymphocytes, CD4+and CD8+T lymphocytes and the percentages in the model group were decreased (all P＜0.05), and percentages of the lymphocytes, B cells and NK cells and ratio of CD4 to CD8 were increased in model group (all P＜ 0.05). Compared with the model group, the above parameters except percentages of T lymphocytes, CD4+and CD8+T lymphocytes were improved in mice of 5 nm cerium oxide nanoparticle group (all P ＜0.05). Compared with the control group, the number of WBC and lymphocytes were decreased in the 5 nm cerium oxide nanoparticle group (P＜0.05), and there were no significances in other parameters compared with the control group (all P ＞0.05). Compared with the control group, the number of WBC and lymphocytes, the number and percentages of T lymphocytes, CD4+and CD8+T lymphocytes and the percentages were decreased (all P＜ 0.05), and percentage of NK cells and ratio of CD4 to CD8 were significantly increased in 25 nm cerium oxide nanoparticles group (all P＜ 0.05). The number of lymphocytes and CD8+T lymphocytes in 25 nm cerium oxide nanoparticles group was lower than that in 5 nm cerium oxide nanoparticles group (all P ＜ 0.05). Conclusions The effects of cerium oxide nanoparticles of different sizes on the immune cells of mice after X-ray irradiation are different, and 5 nm cerium oxide nanoparticle is superior to 25 nm cerium oxide nanoparticle.
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Objective To screen the suitable sample digestion method for measuring iodine in serum by arsenic cerium catalytic spectrophotometric method , and to carry out the methodology test for the newly developed arsenic cerium catalytic spectrophotometry for determination of iodine in serum .Methods Methodology evaluation.Experimentswere on the sample on the sample digestion method of serum iodine with several common digestive agents . After digestion treatment , the concentration of iodine in serum was determined by arsenic cerium catalytic spectrophotometry .The linearity and linear range of the standard curve, detection limit, precision, recovery rate and anti -interference ability of the newlydeveloped arsenic cerium catalytic spectrophotometry were tested .Results Sample pretreatment method included in the newly developed arsenic cerium catalytic spectrophotometry was selected as follows: perchloric acid -sodium chlorate solution was used as the digestive agent to digest 120 min at 130℃.The calibration relation of C =a+blgA( C: iodine concentration ,A: measuring absorbance ) of the newly developed method existed when arsenic ceriumcatalytic reaction was kept at a certain stable temperature range from 13℃ to 30℃ and in certain stable reacting time .The linear range of the calibration curvewas 0 -300 μg/Land the linear correlative coefficient was -0.9996 --0.9999.The intra assay coefficients of variation ( CVs ) were 0.70%,0.70%and 0.74%(n=6), and the inter assay CVs were 0.57%, 0.51% and 0.57% (n=6) for 3 serum samples.The average recovery was 97.9% with a range from 92.3% to 105.8% for 3 serum samples.Conclusions The newly developed arsenic cerium catalytic spectrophotometry has good precision and accuracy .The sample digestion agent is easy to be prepared and reserved , and the instrument is simple and easy to be operated .The method can be widely used as a reliable technique for measuring iodine in serum.
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Objective To establish a arsenic cerium catalytic rate method for determination of urinary iodine,and increase the linear range of urinary iodine determination.Methods Standard series and urine samples after digestion treatment,were tested using dynamics function of spectrophotometer to record the curve of absorbance value (A) change with time (t) during arsenic cerium catalytic reaction for each measurement system,choice (A1,t1) and (A 2,t2) on this curve and calculating the reaction rate (v),v =(lgA1-lgA2)/(t2-t1).Through the determination of the standard series it could calculate regression equation of iodine concentration (C) with X:C =a ± bX,X =1 000 (v-v0),and the v0 is the reaction rate of reagent blank.Results (① C and X were positively correlated.The standard series linear range was 0-1 200 pμg/L and correlation coefficient r was higher than 0.999 1.The minimum detection limit was 3.9 μg/L (0.25 ml urine).②)Precision:5 urine samples (A,B,C,D,E) were selected within the range of 0-1 200 μg/L and the measured value were (72.3 ± 2.7),(148.2 ± 5.2),(210.5 ± 4.4),(562.7 ± 6.8),and (899.3 ± 8.0) μg/L.The relative standard deviation (RSD) was between 0.9％-3.8％.(③)Accuracy:4 samples (A,B,C,D) were measured for standard addition recovery test,recovery was between 94.2％-107.2％;urinary iodine standard material [the given values were (67.9 ± 9.0),(142.0 ± 10.0),(195.0 ± 10.0),(558.0 ± 17.0),(885.0 ± 28.0) μg/L] were determined and the results were in the range of uncertainty of the standard material.④Method contrast:with the national health standard method (method for determination of iodine in urine by arsenic cerium catalytic spectrophotometry) to determinate 120 urine samples,the results showed that there were 60 urine samples within 0-300 μg/L,60 urine samples were more than 300 μg/L.Then rate method was used to test the 120 urine samples.For the 60 samples within the scope of 0-300 μg/L,the determination results of the two methods were positively correlated (r =0.994,P ＜ 0.01);the results of the rate method were lower than those of the standard method and the difference was statistically significant (t =2.047,P ＜ 0.05).But the average deviation was only 2.1 μg/L,for the determination of urine iodine there was no practical significance;for the 60 samples higher than 300 μg/L,the determination results of the two methods were positively correlated (r =0.993,P ＜ 0.01) and the difference was not statistically significant (t =-1.092,P ＞ 0.05).Conclusions Arsenic cerium catalytic rate method has increased the linear range of urinary iodine determination.Using this method,the vast majority samples can be tested directly without dilution,thereby reducing the workload for determination of urine iodine.
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Objective By studying the variation of individual urinary iodine concentration due to different ways of urine sample collection to optimize it for standard clinical evaluation.Methods Totally 20 healthy adults were recruited and their urine samples were collected as a random urine sample within 1 day,the 24 hour urine and morning urine samples within 5 successive days,respectively.The coefficient of variation in each group was calculated.Paired t test was used to compare the results of 24 hour urine with the results of random urine and that of morning urine samples,respectively.Results The range of individual coefficient of variation for random urine sample within one day was 12.5％-57.4％,while most of the coefficients of variation were around 30.39％.In contrast,the individual coefficients of variation of morning urine sample and 24 hour urine results within 5 days were 5.4％-26.0％ and 3.4％-16.6％ and most of them were at about 11.74％ and 7.91％.The paired t test showed that the results of random urine sample were significantly different compared with that of 24 hour urine (t =-4.231,P ＜ 0.05).On the other hand,there was also significant difference for the results of morning urine compared with that of 24 hour urine (t =3.884,P ＜ 0.05).Conclusion This study suggests that 24 hour urine is the most appropriate way of sample collection for individualized detection of urinary iodine.
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Objective To establish a catalytic spectrophotometric method for determination of iodine in water using the same arsenious acid solution and ceric ammonium sulfate solution as those used in the 2016 version standard method for determination of urinary iodine,and to meet the needs of wide concentration range of water iodine detection.Methods After pretreatment of the water sample with the effective chlorine of sodium dichloroisocyanurate solution for eliminating the interference of reducing substances at room temperature,the concentration of iodine in water was determined by arsenic cerium catalytic spectrophotometry using the same 0.025 mol/L arsenious acid solution and 0.025 mol/L ceric ammonium sulfate solution as those used in the 2016 version standard method for determination of urinary iodine.The linear relationship of the standard curve and the linear rang of different iodine concentration range (0-100,0-400,0-800μg/L),the detection limit,the precision and the accuracy of the sample were tested.Results The calibration relation of C =a + blgA (C:iodine concentration,A:measuring absorbance) in the new method existed when arsenic cerium catalytic reaction was kept at a certain stable temperature ranging from 15 ℃ to 30 ℃ in certain stable reacting time.The linear correlative coefficients absolute value of different iodine concentration range (0-100,0-400,0-800 μg/L) were all greater than 0.999 0,corresponding to the water iodine detection limits were 0.3 μ,g/L (sample volume of 0.80 ml),1.2 μg/L (sample volume of 0.20 ml),and 2.2.μg/L (sample volume of 0.10 ml),respectively.The coefficients of variation (CV) of the three different iodine concentration range were all below 1.0％ (n =6).The iodine recovery rate range of a total of 10 different water samples in these three different concentration range was 95.8％-98.7％,98.3％-103.7％ and 98.5％-104.5％,and the average recovery rate was 97.6％,100.4％ and 102.4％,respectively.In the range of these three different standard curves,water iodine standard materials GBW09114c,GBW09114a and GBW09113c were measured.The relative errors between the results and the given values were ＜ 3.0％,which were in the range of uncertainty of the given value.Conclusion This method verified by methodology experiments has wide linear range,high precision,accuracy,and anti-interference ability,good reproducibility,and is easy to operate,with reduced amount of arsenic waste,reduced environmental pollution,and is suitable for application in different areas to determine water iodine.
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OBJECTIVE: To observe the in vivo metabolism and distribution characteristics of nano-cerium oxide( nanoCeO_2) in rats,and to explore the radio-protective effect of nano-CeO_2. METHODS: i) A total of 18 specific pathogen free( SPF) SD rats were randomly divided into 3 groups. Rats of experiment group and CeO_2 blood group were gavaged with1. 0 g/kg body weight( bw) nano-CeO_2 suspension. Rats of control group were gavaged with double distilled water( DDW)in equal volume. At different time-points after treatment,venous blood was collected from the rats' eye socket in CeO_2 blood group,meanwhile urine and excrement of rats of experiment group were also collected. Organ and tissue samples of experiment group and control group were collected 24. 0 hours after treatment. The concentrations of cerium in biological samples were detected by inductively coupled plasma mass spectrometry. ii) A total of 72 SPF BALB/c mice were randomly divided into 6 groups. Mice of low-,medium-and high-dose groups were gavaged with 100,300 and 900 mg/kg bw nano-CeO_2 suspension respectively. Mice of negative control group,irradiation control group and drug positive control group were gavaged with DDW in equal volume once daily. After 14 days,mice of the other 5 groups were exposed by60Coγ-rays once with 3. 5 Gy( 1 Gy/min) except the negative control group. Mice of drug positive control group were given intraperitoneal injection with 200 mg/kg bw amifostine half an hour before irradiation. After exposure,mice were treated by the above gavages once daily. After 3 and 8 days,6 mice were randomly selected to collect the peripheral blood for the count of white blood cell( WBC) and lymph cell measuring. RESULTS: i) The cerium concentration in blood reached peak value in 4. 0 hours after exposure of nano-CeO_2,and the cerium concentration of urine and excrement reached maximum in8. 0 hours after exposure. After 24. 0 hours of exposure,the cerium concentration of brain in experiment group was higher than that of control group( P < 0. 05). Among the experiment group,the cerium concentrations of sternum,duodenum and brain were higher than that of kidney and heart( P < 0. 05),meanwhile the cerium concentrations of thymus and lung were higher than that of kidney( P < 0. 05). ii) There was no statistical difference in interactive effect of WBC count and lymph cell counts between nano-CeO_2 exposure ways and time( P > 0. 05). The WBC counts of the low-and medium-dose groups were lower than those of the negative control group and the drug positive control group( P < 0. 05). The WBC count of high-dose group was lower than those of irradiation control group,drug positive control group and medium-dose group( P <0. 05). The lymph cell counts of the 3 dose groups were lower than that of drug positive control group( P < 0. 05).CONCLUSION: The nano-CeO_2 is mainly cumulated in organs such as sternum,duodenum,brain,thymus and lung. After induced by radiation,nano-CeO_2 has a certain degree of promotion role in increasing the WBC counts.
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During the previous years, with the emerging of nanotechnology, the enormous capabilities of nanoparticles have drawn great attention from researchers in terms of their potentials in various aspects of pharmacology. Cerium oxide nanoparticles (nanoceria), considered as one of the most widely used nanomaterials, due to its tempting catalytic antioxidant properties, show a promising potential in diverse disorders, such as cerebral ischemic stroke (CIS), cancer, neurodegenerative and inflammatory diseases. Overwhelming generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) during cerebral ischemia and reperfusion periods is known to aggravate brain damage via sophisticated cellular and molecular mechanisms, and therefore exploration of the antioxidant capacities of nanoceria becomes a new approach in reducing cerebral ischemic injury. Furthermore, utilizing nanoceria as a drug carrier might display the propensity to overcome limitations or inefficacy of other conceivable neuroprotectants and exhibit synergistic effects. In this review, we emphasize on the principle features of nanoceria and current researches concerning nanoceria as a potential therapeutic agent or carrier in improving the prognosis of CIS.
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Humans , Antioxidants , Therapeutic Uses , Brain Ischemia , Drug Therapy , Cerium , Chemistry , Therapeutic Uses , Nanoparticles , Chemistry , Therapeutic Uses , Neuroprotective Agents , Therapeutic Uses , Oxidative Stress , Reactive Nitrogen Species , Metabolism , Reactive Oxygen Species , Stroke , Drug Therapy , PathologyABSTRACT
Objective To study the impact of different low concentrations of cerium oxide for hepatocellular carcinoma cell prolifera-tion.Methods Three different types of hepatoma cells (Huh7, HepG2,7721) were cultured,and added different concentrations of cerium oxide (0.005,0.01,0.05,0.1,1 μg/mL),of which the cell proliferation was detected by CCK8.The apoptosis-related genes was detected by qRT-PCR technology.The cell cycle was analyzed by flow cytometry.And the effect of low concentration cerium oxide on hepatocellular carci-noma cells tumorigenicity was confirmed by the nude mice experiments.Results CCK8 experiment showed that low concentrations of cerium oxide could promote proliferation of hepatocellular carcinoma cell, especially in concentration of 0.01μg/mL.The qRT-PCR showed that low concentration of cerium oxide could inhibit the apoptosis of hepatocellular carcinoma cell.The flow cytometry analysis had not found any effect of cerium oxide on cell cycle.The tumorigenicity experiments confirmed that low concentrations of cerium oxide could enhance the tumorigenic ability of hepatocellular carcinoma cell.Conclusion Low concentration of cerium oxide can significantly improve the proliferation of liver cancer cells.
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Objective: The correlation of baicalin-metal (Y3+, La3+, and Ce3+) complexes (BMC) anti-tumor activity and the interactional ability of BMC binding with hepatoma SMMC-7721 cell DNA was investigated. Methods: Hepatoma SMMC-7721 cells DNA was extracted as a target, cyclic voltammetry and AC impedance were utilized to study the interaction between BMC and DNA, and the interaction mechanism between BMC and DNA was explored. Results: BMC and hepatoma SMMC-7721 cell DNA formed a non-electroactive supramolecular compounds through mixed-mode of electrostatic interaction, binding number m = 1, binding constant βBC = 1.27 × 105 L/mol, βBC-Y = 3.46 × 105 L/mol, βBC-La = 6.24 × 105 L/mol, and βBC-Ce = 7.29 × 106 L/mol. After BC binding with metal ions, its ability of binding to DNA significantly enhanced, and the strength order: BC-Ce > BC-La > BC-Y > BC. Conclusion: The ability of BMC binding with DNA consists with its cytotoxicity. After BMC binding with SMMC-7721 cell DNA, it could inhibit the cell proliferation and lead to the cell apoptosis, which illustrates the BMC exhibits an anti-tumor activity. The relevant results have given a reference for the study on the new anti-tumor complexes of Chinese materia medica.
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OBJECTIVES: With recent advances in nanoparticle manufacturing and applications, potential exposure to nanoparticles in various settings is becoming increasing likely. No investigation has yet been performed to assess whether respiratory tract exposure to cerium oxide (CeO2) nanoparticles is associated with alterations in protein signaling, inflammation, and apoptosis in rat lungs. METHODS: Specific-pathogen-free male Sprague-Dawley rats were instilled with either vehicle (saline) or CeO2 nanoparticles at a dosage of 7.0 mg/kg and euthanized 1, 3, 14, 28, 56, or 90 days after exposure. Lung tissues were collected and evaluated for the expression of proteins associated with inflammation and cellular apoptosis. RESULTS: No change in lung weight was detected over the course of the study; however, cerium accumulation in the lungs, gross histological changes, an increased Bax to Bcl-2 ratio, elevated cleaved caspase-3 protein levels, increased phosphorylation of p38 MAPK, and diminished phosphorylation of ERK-1/2-MAPK were detected after CeO2 instillation (p<0.05). CONCLUSIONS: Taken together, these data suggest that high-dose respiratory exposure to CeO2 nanoparticles is associated with lung inflammation, the activation of signaling protein kinases, and cellular apoptosis, which may be indicative of a long-term localized inflammatory response.
Subject(s)
Animals , Male , Rats , Apoptosis/drug effects , Caspase 3/metabolism , Cerium/chemistry , Inflammation , Lung/drug effects , Metal Nanoparticles/chemistry , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Mitogen-Activated Protein Kinases/metabolism , Phosphorylation/drug effects , Proto-Oncogene Proteins c-bcl-2/metabolism , Rats, Sprague-Dawley , Signal Transduction/drug effects , bcl-2-Associated X Protein/metabolism , p38 Mitogen-Activated Protein Kinases/metabolismABSTRACT
Objective To investigate the cytotoxicity on normal cell lines of cerium nitrate, the inhibitory effect on tumor cell lines and the effect on cell cycle in vitro. Methods The cytotoxicity of cerium nitrate on FL, L929 and inhibition rate on Hela, SGC-7901, B16, Lewis, K562, and H_(22) in vitro were detected with the method of MTT. The effect of cerium nitrate on cell cycle of SGC-7901 was studied by one-fluorescence dying method on flow cytometer. Results Cerium nitrate did not show the toxic activities on FL and L929 cell lines when the dose of cerium nitrate was it could noticeably inhibit the growth and proliferation of tumor cells nitrate inhibited the growth and proliferation of tumer cells including HeLa, SGC-7901, B16 and K562; cerium nitrate had a noticeably inhibitory effect on the growth and proliferation of H_(22) cell lines in vitro on Conclusion Cerium nitrate has the property of low toxicity and high selectivity on normal cells, but it can inhibit growth and proliferation of many kinds of tumor cell lines by adjusting cell cycle.
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Objective To study the protective effect of cerium on changes of MDA content and DNA damage induced by cadmium in loach liver.Methods The loaches were randomly divided into control group and low (0.025 mg/L),moderate(0.25 mg/L),high(2.5 mg/L)Cd~(2+) exposed group and low(0.025 mg/L Cd~(2+)+0.025 Ce~(3+)),moderate(0.25 mg/L Cd~(2+)+0.25 mg/L Ce~(3+)),high (2.5 mg/L Cd~(2+)+2.5 mg/L Ce~(3+))CdE~(2+)+Ce~(3+) exposed group,the MDA content in loach liver was determined at 1d,2d,3d,5d,7d and 10 d of exposure with the method of TBA,the MDA damage in loach liver was detected at 7 d with the method of agarose gel electrophoresis.Results The MDA content of low Cd~(2+) exposed group was higher than that in the control at ld and 2 d (P
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OBJECTIVE: To establish spectrophotometry and HPLC methods for the determination of ferrous succinate tablet and to compare the results of above two methods with that of cerium sulphate method.METHODS: Ferrous reacted with 1,10-phenanthroline to form colored complex and spectrophotometry was applied to measure its absorbance.The detection wavelength was set at 510 nm.HPLC method was performed on C18 column with mobile phase consisted of 0.05 mol?L-1 KH2PO4 (pH=2.5) at detection wavelength of 215 nm.The method was quantified by an external standard mode.RESULTS: The linear range of ferrous in spectrophotometry was 0.042 44～2.546 4 mg?L-1 (r=0.999 8) with an average recovery of 99.5% (RSD