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
The current study was conducted primarily to investigate and estimate 137Cs activity concentrations and the external dose rate due to fallout radionuclide 137Cs. Soil samples were collected from different 25 locations...The current study was conducted primarily to investigate and estimate 137Cs activity concentrations and the external dose rate due to fallout radionuclide 137Cs. Soil samples were collected from different 25 locations at Riyadh Province and analyzed using low level γ-spectrometry equipped with HPGe-detector. 137Cs activity concentrations and calculated dose rate were found in the range of 0.8 - 3.1 Bq·kg–1 and 0.05 to 0.8 nSv·h–1 with an average value of 1.70 ± 0.7 Bq·kg–1 and 0.11 ± 0.05 nSv·h–1 respectively. The measured 137Cs activity concentration range was compared with the reported ranges in the literature from some of the other locations in the world. Results obtained in this study show that 137Cs concentration is of a lower level in the investigated area. However, the range of 137Cs concentrations observed in this study is significantly high relative to similar data reported from Libya. The average value of estimated external effective dose rate is found far below the dose rate limit of of 1.0 mSv·y–1 for members of the general public recom-mended by ICRP as well as the external gamma radiation dose of 0.48 mSv·y–1 received per head from the natural sources of radiation assessed by (UNSCEAR, 2000). It is concluded that 137Cs soil contamination does not pose radia-tion hazards to the population in the investigated areas.展开更多
The second most important cause of lung cancer after smoking is radon gas. Thus, the determination of indoor radon concentrations in residential buildings and workplaces is an important public health concern. The purp...The second most important cause of lung cancer after smoking is radon gas. Thus, the determination of indoor radon concentrations in residential buildings and workplaces is an important public health concern. The purpose of this research was to measure the concentration of radon gas in the offices of the Institute of Science and Technology and to evaluate the effective dose in the lungs and the risk of cancer. This study used Corentium’s AIR THINGS digital radon detector to determine the radon concentration in sixteen (16) offices. The digital radon detector air Things of Corentium was placed in each office for a minimum period of one week and the concentration values were recorded every 24 hours. The values recorded in each office were the short-term average and the long-term average during seven days of measurement. The short-term radon concentrations vary between 5.286 Bq/m<sup>3</sup> and 192.714 Bq/m3</sup> with an average of 48.01 Bq/m3</sup> and those in the long-term were between 6.143 Bq/m3</sup> and 172.571 Bq/m3</sup> with an average of 52.46 Bq/m3</sup>. The measurements in office N°6 and 13 were above the lower limit of 100 Bq/m3</sup> proposed by the WHO. The short-term and long-term effective doses in the lungs for offices N°6 and 13 were above the “normal” background level of 1.1 mSv/year proposed by UNSCEAR-2000. The short-term effective dose in the lungs for office N°6 was above the lower limit of 3 mSv per the ICRP-23 recommendation. The average number of lung cancer cases per year per million people was 15.展开更多
The activity concentrations of the natural radionuclides namely 238U, 232Th, 40K and 137Cs are measured for soil samples collected from different locations of Tulkarem district in West Back-Palestine. High-resolution ...The activity concentrations of the natural radionuclides namely 238U, 232Th, 40K and 137Cs are measured for soil samples collected from different locations of Tulkarem district in West Back-Palestine. High-resolution gamma spectrometry (HPGe detector) was used to determine the activity concentration of these radionuclides in 72 surface soil samples taken from areas in and surrounding Tulkarem city. The concentration of 238U varied in the range 9.7 - 83.5 Bq kg–1 with an average value of 34.5 Bq kg–1, 232Th in the range 5.3 - 44.8 Bq kg–1 with an average value of 23.8 Bq kg–1, 40K in the range 10.2 - 404.0 Bq kg–1 with an average value of 120.0 Bq kg–1 and 137Cs in the range 1.0 - 24.5 Bq kg–1 with an average value of 7.8 Bq kg–1. The results have been compared with those of different countries of the world and Palestine. To assess the radiological hazard of the natural radioactivity, the absorbed dose rate (Dr), the radium equivalent activity (Raeq), the effective dose rate (Eeff), the annual effective dose equivalent (AEDE), Excess Lifetime Cancer Risk (ELCR), the radioactivity level index (Iγ), and the external (Hex) and internal (Hin) hazard indices were calculated .It can be concluded that no risk may threat the residents around and center of Tulkarem city except some areas which activity due to fallout 137Cs were high concentration levels. Hence the probability of occurrence of any of the health effects of radiation is low. Hence, measurements have been taken as representing baseline values of these radionuclides in the soil in studying area.展开更多
OBJECTIVE: To evaluate the anti-hepatoma effect of Calmodulin antagonist 0 - 4-ethoxyl-butyl-Berbamine (EBB), one of the berbamine derivatives. METHODS: Monotetrazolium (MTT) method was used to analyze the effect of E...OBJECTIVE: To evaluate the anti-hepatoma effect of Calmodulin antagonist 0 - 4-ethoxyl-butyl-Berbamine (EBB), one of the berbamine derivatives. METHODS: Monotetrazolium (MTT) method was used to analyze the effect of EBB on the proliferation and growth inhibition effect. Of a hepatoma cell line in vitro. A mouse hepatoma model was induced by injection of hepatoma cells (H22) in the abdominal cavity. The effect of EBB on survival at different concentrations as well as in combination with 5-FU were investigated in vivo. Flow cytometry analysis, dot blot hybridization, western blot, immunochemistry, enzyme-linked lectin assay (ELISA), trifluoperazine (TFP) and electron microscopic observation were used to study the effect of EBB on cell cycle process, P53 mRNA and protein levels, calmodulin content and ultrastractural changes of hepatoma cells. RESULTS: EBB exerts a very strong inhibitory effect on human hepatoma cell line 7402 and mouse hepatoma cell line H22 in vitro. The IC(50) value of EBB for the two cell lines are 3.312 microg/ml and 1.167 microg/ml, respectively. The sensitivity of H22 cells to 5-FU can be markedly enhanced: The IC(50) dosage of 5-Fu can be decreased from 0.75 microg/ml down to 0.15 microg/ml, when jointly administered with nontoxic dosages of EBB (IC(10)). In vivo, EBB can prolong the lifespan of mice with ascites H22 to more than three months. 64% of mice survived, while all animals in the control group died by the 18th day. When EBB (5 mg x kg(-1) x d(-1)) is jointly used with 5-FU (25 mg x ml(-1) x d(-1)), 73% of mice with ascites H22 survived, much higher than 27% in the 5-FU treated group. EBB can enhance the anti-hepatoma ability of 5-Fu treatment. EBB mechanism against hepatoma: P53 expression in the EBB treated group is substantially higher than that in the control group. EBB increased the translation of P53. As a calmodulin antagonist, EBB decreases amount of the CaM in hepatoma cells and blocked the hepatoma cell proliferation cycle at the G(2)M phase. Before the G(0)/G(1) phase, a 展开更多
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The current study was conducted primarily to investigate and estimate 137Cs activity concentrations and the external dose rate due to fallout radionuclide 137Cs. Soil samples were collected from different 25 locations at Riyadh Province and analyzed using low level γ-spectrometry equipped with HPGe-detector. 137Cs activity concentrations and calculated dose rate were found in the range of 0.8 - 3.1 Bq·kg–1 and 0.05 to 0.8 nSv·h–1 with an average value of 1.70 ± 0.7 Bq·kg–1 and 0.11 ± 0.05 nSv·h–1 respectively. The measured 137Cs activity concentration range was compared with the reported ranges in the literature from some of the other locations in the world. Results obtained in this study show that 137Cs concentration is of a lower level in the investigated area. However, the range of 137Cs concentrations observed in this study is significantly high relative to similar data reported from Libya. The average value of estimated external effective dose rate is found far below the dose rate limit of of 1.0 mSv·y–1 for members of the general public recom-mended by ICRP as well as the external gamma radiation dose of 0.48 mSv·y–1 received per head from the natural sources of radiation assessed by (UNSCEAR, 2000). It is concluded that 137Cs soil contamination does not pose radia-tion hazards to the population in the investigated areas.
文摘The second most important cause of lung cancer after smoking is radon gas. Thus, the determination of indoor radon concentrations in residential buildings and workplaces is an important public health concern. The purpose of this research was to measure the concentration of radon gas in the offices of the Institute of Science and Technology and to evaluate the effective dose in the lungs and the risk of cancer. This study used Corentium’s AIR THINGS digital radon detector to determine the radon concentration in sixteen (16) offices. The digital radon detector air Things of Corentium was placed in each office for a minimum period of one week and the concentration values were recorded every 24 hours. The values recorded in each office were the short-term average and the long-term average during seven days of measurement. The short-term radon concentrations vary between 5.286 Bq/m<sup>3</sup> and 192.714 Bq/m3</sup> with an average of 48.01 Bq/m3</sup> and those in the long-term were between 6.143 Bq/m3</sup> and 172.571 Bq/m3</sup> with an average of 52.46 Bq/m3</sup>. The measurements in office N°6 and 13 were above the lower limit of 100 Bq/m3</sup> proposed by the WHO. The short-term and long-term effective doses in the lungs for offices N°6 and 13 were above the “normal” background level of 1.1 mSv/year proposed by UNSCEAR-2000. The short-term effective dose in the lungs for office N°6 was above the lower limit of 3 mSv per the ICRP-23 recommendation. The average number of lung cancer cases per year per million people was 15.
文摘The activity concentrations of the natural radionuclides namely 238U, 232Th, 40K and 137Cs are measured for soil samples collected from different locations of Tulkarem district in West Back-Palestine. High-resolution gamma spectrometry (HPGe detector) was used to determine the activity concentration of these radionuclides in 72 surface soil samples taken from areas in and surrounding Tulkarem city. The concentration of 238U varied in the range 9.7 - 83.5 Bq kg–1 with an average value of 34.5 Bq kg–1, 232Th in the range 5.3 - 44.8 Bq kg–1 with an average value of 23.8 Bq kg–1, 40K in the range 10.2 - 404.0 Bq kg–1 with an average value of 120.0 Bq kg–1 and 137Cs in the range 1.0 - 24.5 Bq kg–1 with an average value of 7.8 Bq kg–1. The results have been compared with those of different countries of the world and Palestine. To assess the radiological hazard of the natural radioactivity, the absorbed dose rate (Dr), the radium equivalent activity (Raeq), the effective dose rate (Eeff), the annual effective dose equivalent (AEDE), Excess Lifetime Cancer Risk (ELCR), the radioactivity level index (Iγ), and the external (Hex) and internal (Hin) hazard indices were calculated .It can be concluded that no risk may threat the residents around and center of Tulkarem city except some areas which activity due to fallout 137Cs were high concentration levels. Hence the probability of occurrence of any of the health effects of radiation is low. Hence, measurements have been taken as representing baseline values of these radionuclides in the soil in studying area.
文摘OBJECTIVE: To evaluate the anti-hepatoma effect of Calmodulin antagonist 0 - 4-ethoxyl-butyl-Berbamine (EBB), one of the berbamine derivatives. METHODS: Monotetrazolium (MTT) method was used to analyze the effect of EBB on the proliferation and growth inhibition effect. Of a hepatoma cell line in vitro. A mouse hepatoma model was induced by injection of hepatoma cells (H22) in the abdominal cavity. The effect of EBB on survival at different concentrations as well as in combination with 5-FU were investigated in vivo. Flow cytometry analysis, dot blot hybridization, western blot, immunochemistry, enzyme-linked lectin assay (ELISA), trifluoperazine (TFP) and electron microscopic observation were used to study the effect of EBB on cell cycle process, P53 mRNA and protein levels, calmodulin content and ultrastractural changes of hepatoma cells. RESULTS: EBB exerts a very strong inhibitory effect on human hepatoma cell line 7402 and mouse hepatoma cell line H22 in vitro. The IC(50) value of EBB for the two cell lines are 3.312 microg/ml and 1.167 microg/ml, respectively. The sensitivity of H22 cells to 5-FU can be markedly enhanced: The IC(50) dosage of 5-Fu can be decreased from 0.75 microg/ml down to 0.15 microg/ml, when jointly administered with nontoxic dosages of EBB (IC(10)). In vivo, EBB can prolong the lifespan of mice with ascites H22 to more than three months. 64% of mice survived, while all animals in the control group died by the 18th day. When EBB (5 mg x kg(-1) x d(-1)) is jointly used with 5-FU (25 mg x ml(-1) x d(-1)), 73% of mice with ascites H22 survived, much higher than 27% in the 5-FU treated group. EBB can enhance the anti-hepatoma ability of 5-Fu treatment. EBB mechanism against hepatoma: P53 expression in the EBB treated group is substantially higher than that in the control group. EBB increased the translation of P53. As a calmodulin antagonist, EBB decreases amount of the CaM in hepatoma cells and blocked the hepatoma cell proliferation cycle at the G(2)M phase. Before the G(0)/G(1) phase, a
