[Objective] This study aimed to investigate the effect of zearalenone (ZEN) on DNA damage of porcine leydig cells. [Method] Porcine leydig cells cultured in vitro were collected to determine the median lethal dose (LD...[Objective] This study aimed to investigate the effect of zearalenone (ZEN) on DNA damage of porcine leydig cells. [Method] Porcine leydig cells cultured in vitro were collected to determine the median lethal dose (LD50) of ZEN with tetrazolium-based colorimetric assay (MTT assay). Comet assay was carried out to detect the DNA damage of porcine leydig cells exposed to at 0 (negative group), 1, 5, 10, 20, 40 μmol/L of ZEN. [Result] The percentage of cell tail was 16.67%, 34.00%, 40.67%, 52.00% and 64.67% under 0, 1, 5, 10 and 20 μmol/L of ZEN, respectively; the differences between the percentages of cell tail in various experimental groups had extremely significant statistical significance compared with the negative group (P<0.01), showing a significant dose-effect relationship; Tail length in various groups was 57.60±4.78, 57.75±6.25, 78.97±5.83, 100.50±6.94 and 146.83±12.31 μm, respectively; Tail DNA % in various groups was 21.29±2.25%, 22.24±2.43%, 31.21±6.27%, 37.45±4.33% and 60.68±9.83%, respectively; Tail length and Tail DNA % in experimental groups with ZEN concentration above 5 μmol/L showed significant differences (P<0.05) compared with the negative group, which showed an upward trend with the increase of ZEN concentration. [Conclusion] ZEN has genotoxic effect on porcine leydig cells, which can cause DNA damage, with a significant dose-effect relationship.展开更多
The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was ...The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was confirmed by N-terminal peptide sequencing. Two groups of bioassays, artificial diet incorporation assay and contact insecticidal effect assay, were carried out separately to verify the toxicity of this recombinant toxin. At the end of a 24 h experimental period, more than 60% of the testing diamondback moth (Plutella xylostella) larvae were killed in both groups with LC50 value of 18.4 microM and 0.70 microM respectively. Cytotoxicity assay using cultured Sf9 insect cells and MCF-7 human cells demonstrated that the toxin AaIT had specific toxicity against insect cells but not human cells. Only 0.13 microM recombinant toxin was needed to kill 50% of cultured insect cells while as much as 1.3 microM toxin had absolutely no effect on human cells. Insect cells produced obvious intrusions from their plasma membrane before broken up. We infer that toxin AaIT bind to a putative sodium channel in these insect cells and open the channel persistently, which would result in Na+ influx and finally cause destruction of insect cells.展开更多
Objective: To evaluate retrospectively the effect of general anesthesia on DNA damage in the blood mononuclear cells (PBMCs) of surgical patients in order to provide evidence for a better nursing care during the proce...Objective: To evaluate retrospectively the effect of general anesthesia on DNA damage in the blood mononuclear cells (PBMCs) of surgical patients in order to provide evidence for a better nursing care during the procedure. Methods: Clinical charts of 76 patients who underwent operation under general anesthesia and 76 healthy control subjects with documented results of DNA damage extent in PBMCs from the single-cell gel electrophoresis (SCGE) or comet assay and serum contents of superoxide dismutase (SOD) and malondialdehyde (MDA) from biochemical analyses were reviewed. The percentage of comet PBMCs and tail DNA and serum contents of SOD and MAD were analyzed by student t-test. Results: Compared with healthy control subjects, generally anesthetized surgical patients had significantly higher % comet PBMCs and % tail DNA (P < 0.05) and significantly lower serum concentrations of SOD (P < 0.05) and significantly higher serum concentrations of MAD (P < 0.05). Compared with levels before general anesthesia in surgical patients, % comet PBMCs, % tail DNA, and serum levels of MAD were significantly higher (P < 0.05 or 0.01), and serum levels of SOD were significantly lower (P < 0.05), after general anesthesia. Conclusions: General anesthesia during surgery causes a certain degree of hypoxia and PBMC damage. Particular attention should be paid to monitoring and maintenance of blood oxygen saturation in patients undergoing surgery under general anesthesia.展开更多
Obejctive To assess the genotoxic effects of X ray radiation on human populations Methods The single cell gel electrophoresis (SCGE) and cytokinesis blocked micronucleus (CBMN) test were applied as biological dos...Obejctive To assess the genotoxic effects of X ray radiation on human populations Methods The single cell gel electrophoresis (SCGE) and cytokinesis blocked micronucleus (CBMN) test were applied as biological dosimeters to detect DNA damage and abnormalities in human peripheral lymphocytes of subpopulation exposed to X ray radiation The subjects were divided into four groups: 12 radiation patients; 13 intervention radiation therapy doctors; 32 radiation diagnostians; 28 controls Results The average comet lengths of the four groups were 128 17±4 49?μm, 88 09±5 39?μm, 72 68±2 57?μm and 32 87±0 57?μm, respectively The difference in average comet length between any two groups was highly significant ( P <0 01) The average micronucleated cell (MNC) rates (‰) of the four groups were 12 33±0 85, 9 75±1 02, 8 48±0 66 and 3 18±0 36, respectively The difference of MNC rates of Group 1 vs 3, 1 vs 4, 2 vs 4 and 3 vs 4 was highly significant ( P <0 01), and the difference of Group 1 vs 2 was significant ( P <0 05), but there was no difference of MNC rate in Group 2 vs 3 ( P >0 05) Conclusions This study showed that both the comet assay and the CBMN test could be used to monitor populations exposed to X ray radiation, but the comet assay seems to be more sensitive than the CBMN test展开更多
Postmortem interval(PMI)estimation is a recurring problem in the field of forensic medicine.Conventional methods are effective but are insufficient to estimate accurate and precise time of death or PMI.In addition,deg...Postmortem interval(PMI)estimation is a recurring problem in the field of forensic medicine.Conventional methods are effective but are insufficient to estimate accurate and precise time of death or PMI.In addition,degradation of biological samples is another major problem in forensic science which affects the investigation process and misleads the result.Some previous studies reported that DNA fragmentation has strong correlation with PMI.DNA fragmentation increased with prolonged PMI.Comet assay is a rapid sensitive,versatile,reliable and cost effective technique that is specifically used for qualitative and quantitative estimation of nuclear DNA fragmentation.Due to this attribute,comet assay can help to estimate accurate and precise time of death for some extent that is for early PMI estimation.In addition,two confounding factors are responsible for DNA fragmentation:(1)micro-organism;(2)environmental condition.Here,comet assay plays a dual role:(1)partially degraded samples get repaired using repair enzyme;(2)accurate time since deposition can be measured without using repair enzyme.Furthermore,this assay can also help to identify potential exposures of environmental-released chemicals/toxicants and its deleterious effects on human population.In this way,comet assay shows its versatile applications that could be useful for forensic investigation.Therefore,with the help of this review,an attempt was made to explore the versatility of comet assay technique for forensic applications and its future perspective.展开更多
文摘[Objective] This study aimed to investigate the effect of zearalenone (ZEN) on DNA damage of porcine leydig cells. [Method] Porcine leydig cells cultured in vitro were collected to determine the median lethal dose (LD50) of ZEN with tetrazolium-based colorimetric assay (MTT assay). Comet assay was carried out to detect the DNA damage of porcine leydig cells exposed to at 0 (negative group), 1, 5, 10, 20, 40 μmol/L of ZEN. [Result] The percentage of cell tail was 16.67%, 34.00%, 40.67%, 52.00% and 64.67% under 0, 1, 5, 10 and 20 μmol/L of ZEN, respectively; the differences between the percentages of cell tail in various experimental groups had extremely significant statistical significance compared with the negative group (P<0.01), showing a significant dose-effect relationship; Tail length in various groups was 57.60±4.78, 57.75±6.25, 78.97±5.83, 100.50±6.94 and 146.83±12.31 μm, respectively; Tail DNA % in various groups was 21.29±2.25%, 22.24±2.43%, 31.21±6.27%, 37.45±4.33% and 60.68±9.83%, respectively; Tail length and Tail DNA % in experimental groups with ZEN concentration above 5 μmol/L showed significant differences (P<0.05) compared with the negative group, which showed an upward trend with the increase of ZEN concentration. [Conclusion] ZEN has genotoxic effect on porcine leydig cells, which can cause DNA damage, with a significant dose-effect relationship.
基金This work was supported by a grant from 863High Technology Program,Chinese Ministry of Sci-ence and Technology
文摘The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was confirmed by N-terminal peptide sequencing. Two groups of bioassays, artificial diet incorporation assay and contact insecticidal effect assay, were carried out separately to verify the toxicity of this recombinant toxin. At the end of a 24 h experimental period, more than 60% of the testing diamondback moth (Plutella xylostella) larvae were killed in both groups with LC50 value of 18.4 microM and 0.70 microM respectively. Cytotoxicity assay using cultured Sf9 insect cells and MCF-7 human cells demonstrated that the toxin AaIT had specific toxicity against insect cells but not human cells. Only 0.13 microM recombinant toxin was needed to kill 50% of cultured insect cells while as much as 1.3 microM toxin had absolutely no effect on human cells. Insect cells produced obvious intrusions from their plasma membrane before broken up. We infer that toxin AaIT bind to a putative sodium channel in these insect cells and open the channel persistently, which would result in Na+ influx and finally cause destruction of insect cells.
文摘Objective: To evaluate retrospectively the effect of general anesthesia on DNA damage in the blood mononuclear cells (PBMCs) of surgical patients in order to provide evidence for a better nursing care during the procedure. Methods: Clinical charts of 76 patients who underwent operation under general anesthesia and 76 healthy control subjects with documented results of DNA damage extent in PBMCs from the single-cell gel electrophoresis (SCGE) or comet assay and serum contents of superoxide dismutase (SOD) and malondialdehyde (MDA) from biochemical analyses were reviewed. The percentage of comet PBMCs and tail DNA and serum contents of SOD and MAD were analyzed by student t-test. Results: Compared with healthy control subjects, generally anesthetized surgical patients had significantly higher % comet PBMCs and % tail DNA (P < 0.05) and significantly lower serum concentrations of SOD (P < 0.05) and significantly higher serum concentrations of MAD (P < 0.05). Compared with levels before general anesthesia in surgical patients, % comet PBMCs, % tail DNA, and serum levels of MAD were significantly higher (P < 0.05 or 0.01), and serum levels of SOD were significantly lower (P < 0.05), after general anesthesia. Conclusions: General anesthesia during surgery causes a certain degree of hypoxia and PBMC damage. Particular attention should be paid to monitoring and maintenance of blood oxygen saturation in patients undergoing surgery under general anesthesia.
基金ThisresearchwassupportedbytheNaturalScienceFoundationofZhejiangProvince China (No 396 490 )
文摘Obejctive To assess the genotoxic effects of X ray radiation on human populations Methods The single cell gel electrophoresis (SCGE) and cytokinesis blocked micronucleus (CBMN) test were applied as biological dosimeters to detect DNA damage and abnormalities in human peripheral lymphocytes of subpopulation exposed to X ray radiation The subjects were divided into four groups: 12 radiation patients; 13 intervention radiation therapy doctors; 32 radiation diagnostians; 28 controls Results The average comet lengths of the four groups were 128 17±4 49?μm, 88 09±5 39?μm, 72 68±2 57?μm and 32 87±0 57?μm, respectively The difference in average comet length between any two groups was highly significant ( P <0 01) The average micronucleated cell (MNC) rates (‰) of the four groups were 12 33±0 85, 9 75±1 02, 8 48±0 66 and 3 18±0 36, respectively The difference of MNC rates of Group 1 vs 3, 1 vs 4, 2 vs 4 and 3 vs 4 was highly significant ( P <0 01), and the difference of Group 1 vs 2 was significant ( P <0 05), but there was no difference of MNC rate in Group 2 vs 3 ( P >0 05) Conclusions This study showed that both the comet assay and the CBMN test could be used to monitor populations exposed to X ray radiation, but the comet assay seems to be more sensitive than the CBMN test
文摘Postmortem interval(PMI)estimation is a recurring problem in the field of forensic medicine.Conventional methods are effective but are insufficient to estimate accurate and precise time of death or PMI.In addition,degradation of biological samples is another major problem in forensic science which affects the investigation process and misleads the result.Some previous studies reported that DNA fragmentation has strong correlation with PMI.DNA fragmentation increased with prolonged PMI.Comet assay is a rapid sensitive,versatile,reliable and cost effective technique that is specifically used for qualitative and quantitative estimation of nuclear DNA fragmentation.Due to this attribute,comet assay can help to estimate accurate and precise time of death for some extent that is for early PMI estimation.In addition,two confounding factors are responsible for DNA fragmentation:(1)micro-organism;(2)environmental condition.Here,comet assay plays a dual role:(1)partially degraded samples get repaired using repair enzyme;(2)accurate time since deposition can be measured without using repair enzyme.Furthermore,this assay can also help to identify potential exposures of environmental-released chemicals/toxicants and its deleterious effects on human population.In this way,comet assay shows its versatile applications that could be useful for forensic investigation.Therefore,with the help of this review,an attempt was made to explore the versatility of comet assay technique for forensic applications and its future perspective.
