To establish and validate a method for cell irradiation in 96-well and 6-well plates using a linear accelerator, three irradiation methods(G0 B0 F40,G0 B1.5 F40, and G180 B1.5 F40) were designed to irradiate cell cult...To establish and validate a method for cell irradiation in 96-well and 6-well plates using a linear accelerator, three irradiation methods(G0 B0 F40,G0 B1.5 F40, and G180 B1.5 F40) were designed to irradiate cell culture plasticware simulated with RW3 slab phantom and polystyrene. The difference between the actual physical measured dose and the preset dose was compared among the three methods under the preparatory conditions of 2, 4, 6, 8, and 10 Gy. MDA-MB-231 cells were analyzed by using a cell proliferation assay and a clonogenic assay to verify the difference between the three cell irradiation methods on cell radiosensitivity. For each preset dose, the difference between the actual measured dose and the preset dose was the lowest for Method G0 B1.5 F40, the second lowest for Method G180 B1.5 F40, and the maximum for Method GOB0 F40. The ranges of the differences were-0.28 to 0.02%,-2.17 to-1.80%, and-4.92 to-4.55%, and 0.31 to-0.12%,-3.42 to-2.86%, and-7.31 to-6.92%,respectively, for 96-well and 6-well plates. The cell culture experiments proved that Method G0 B1.5 F40 was an accurate, effective, simple, and practical irradiation method. The most accurate and effective cell irradiation method should always be used, as it will reduce dose differences and instability factors and provide improved accuracy and comparability for laboratories researching cellular radiosensitivity.展开更多
An in vivo-in vitro transformation system was establi-shed in primary rat tracheal epithelial cells(RTE) whichwere cultured in serum-free F12 medium with the additionof growth factors.Carcinogens were given in vivo by...An in vivo-in vitro transformation system was establi-shed in primary rat tracheal epithelial cells(RTE) whichwere cultured in serum-free F12 medium with the additionof growth factors.Carcinogens were given in vivo by subcu-taneous injection or intratracheal instillation.About 7days after carcinogen exposure,RTE cells were cultured inserum-free medium and then selected in serum-containingmedium.Transformed colonies were counted 5-6 weeks afterthe plating of RTE cells.展开更多
The pathogenic effect of Staphylococci is due to extra-cellular factors and properties such as adherence and biofilm production. The nature of the biofilm and the physiological properties of biofilm-producing bacteria...The pathogenic effect of Staphylococci is due to extra-cellular factors and properties such as adherence and biofilm production. The nature of the biofilm and the physiological properties of biofilm-producing bacteria result in an inherent antibiotic resistance and require further investigation. Two hundred and sixty Staphylococcal strains were cultured from 600 clinical specimens obtained from hospitalized patients. Among these, 155 were identified as coagulase-positive (CPS) and 105 as coagulase-negative (CNS) staphylococci. Staphylococcal strains were tested for biofilm production using the tissue culture plate (TCP) method. TCP detection showed that of the 155 CPS, 124 (80%) were biofilm producers, while 63 (60%) of the 105 CNS were biofilm producers. Biofilm-producing strains were scanned by scanning electron microscope (SEM) to confirm biofilm formation, study biofilm production, and examine antibiotic effects on biofilm formation. Disc diffusion method was used to study resistance of planktonic and biofilm-forming cells to antibiotics. Planktonic cells were less resistant to antibiotics than biofilm-forming cells. Microbroth dilution method and a new BioTimer assay were used to determine antibiotic MICs affecting planktonic and biofilm cells. Both methods showed that the MICs for planktonic cells were less than that for biofilm cells. The BioTimer assay was therefore found to be sensitive, accurate, and reliable, with results in agreement with those from the broth dilution method and SEM.展开更多
基金supported by the Hospital Personnel Climbing Plan of the Tenth People's Hospital Affiliated to Tongji University
文摘To establish and validate a method for cell irradiation in 96-well and 6-well plates using a linear accelerator, three irradiation methods(G0 B0 F40,G0 B1.5 F40, and G180 B1.5 F40) were designed to irradiate cell culture plasticware simulated with RW3 slab phantom and polystyrene. The difference between the actual physical measured dose and the preset dose was compared among the three methods under the preparatory conditions of 2, 4, 6, 8, and 10 Gy. MDA-MB-231 cells were analyzed by using a cell proliferation assay and a clonogenic assay to verify the difference between the three cell irradiation methods on cell radiosensitivity. For each preset dose, the difference between the actual measured dose and the preset dose was the lowest for Method G0 B1.5 F40, the second lowest for Method G180 B1.5 F40, and the maximum for Method GOB0 F40. The ranges of the differences were-0.28 to 0.02%,-2.17 to-1.80%, and-4.92 to-4.55%, and 0.31 to-0.12%,-3.42 to-2.86%, and-7.31 to-6.92%,respectively, for 96-well and 6-well plates. The cell culture experiments proved that Method G0 B1.5 F40 was an accurate, effective, simple, and practical irradiation method. The most accurate and effective cell irradiation method should always be used, as it will reduce dose differences and instability factors and provide improved accuracy and comparability for laboratories researching cellular radiosensitivity.
文摘An in vivo-in vitro transformation system was establi-shed in primary rat tracheal epithelial cells(RTE) whichwere cultured in serum-free F12 medium with the additionof growth factors.Carcinogens were given in vivo by subcu-taneous injection or intratracheal instillation.About 7days after carcinogen exposure,RTE cells were cultured inserum-free medium and then selected in serum-containingmedium.Transformed colonies were counted 5-6 weeks afterthe plating of RTE cells.
文摘The pathogenic effect of Staphylococci is due to extra-cellular factors and properties such as adherence and biofilm production. The nature of the biofilm and the physiological properties of biofilm-producing bacteria result in an inherent antibiotic resistance and require further investigation. Two hundred and sixty Staphylococcal strains were cultured from 600 clinical specimens obtained from hospitalized patients. Among these, 155 were identified as coagulase-positive (CPS) and 105 as coagulase-negative (CNS) staphylococci. Staphylococcal strains were tested for biofilm production using the tissue culture plate (TCP) method. TCP detection showed that of the 155 CPS, 124 (80%) were biofilm producers, while 63 (60%) of the 105 CNS were biofilm producers. Biofilm-producing strains were scanned by scanning electron microscope (SEM) to confirm biofilm formation, study biofilm production, and examine antibiotic effects on biofilm formation. Disc diffusion method was used to study resistance of planktonic and biofilm-forming cells to antibiotics. Planktonic cells were less resistant to antibiotics than biofilm-forming cells. Microbroth dilution method and a new BioTimer assay were used to determine antibiotic MICs affecting planktonic and biofilm cells. Both methods showed that the MICs for planktonic cells were less than that for biofilm cells. The BioTimer assay was therefore found to be sensitive, accurate, and reliable, with results in agreement with those from the broth dilution method and SEM.
