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| 2. |
- Elmroth, Kerstin, 1970, et al.
(författare)
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Effect of hypothermic irradiation of the growth characteristics of two human cell lines
- 2000
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Ingår i: Anticancer Res. - 0250-7005. ; 20:5B, s. 3429-33
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Tidskriftsartikel (refereegranskat)abstract
- The effect of hypothermic irradiation on the growth characteristics of two human cell lines was investigated. Low temperature (2 degrees C) X-irradiation of MCF-7 cells (2, 3 and 4 Gy) resulted in higher surviving fractions compared to irradiation at 37 degrees C as assessed by the colony forming assay. The ratios for the surviving fraction between the two temperatures were 1.2, 1.5 and 1.7 at 2, 3 and 4 Gy, respectively. Correspondingly, the dose modifying factor was 1.23. The distribution of colony sizes (of those with more than 50 cells) was different with proportionally more small-sized colonies from cells irradiated at 2 degrees C. Colonies from diploid fibroblasts (HS27) were ill-defined and could not be counted. In conclusion, hypothermia during irradiation seems to influence the radioresponse in MCF-7 cells. The growth in multiwell plates of MCF-7 cells and human diploid fibroblasts (HS27) after irradiation with 3 and 4 Gy, respectively, at 2 degrees C or 37 degrees C was assessed by using the crystal violet growth assay. No difference between 2 degrees C or 37 degrees C irradiation was found for either of the two cell lines.
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| 3. |
- Lundgren-Eriksson, L., et al.
(författare)
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Hypothermic modulation of doxorubicin, cisplatin and radiation cytotoxicity in vitro
- 2001
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Ingår i: Anticancer Res. - 0250-7005. ; 21:5, s. 3275-80
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The influence of hypothermia on doxorubicin, cisplatin and radiation cytotoxicity was investigated in vitro. MATERIALS AND METHODS: A human glioma cell line (251MG) in early exponential growth was exposed to doxorubicin or cisplatin at various concentrations for 4 hours, or X-irradiation at 28 degrees C or 37 degrees C. The cells continued growing in multi-well plates at 37 degrees C and were counted every third day until the end of the logarithmic phase, on day 13. RESULTS: Exposure to doxorubicin 0.05-0.5 microg/ml or cisplatin 1-10 microg/ml caused a dose-dependent inhibition of cell growth with a significantly reduced toxicity when exposed at 28 degrees C as compared to 37 degrees C. Irradiation with 4 Gy also resulted in less toxicity during hypothermia. Chlorpromazine 0.01-10 microg/ml, used to induce hypothermia in vivo (1), neither influenced, cellular growth itself nor interacted with doxorubicin, cisplatin or irradiation. CONCLUSION: Moderate hypothermia (28 degrees C) appears to protect against the cellular insult of doxorubicin, cisplatin and ionising irradiation and their consequences.
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| 4. |
- Lundgren-Eriksson, L., et al.
(författare)
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Radio-and chemotoxicity in mice during hypothermia
- 2001
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Ingår i: Anticancer Res. - 0250-7005. ; 21:5, s. 3269-74
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The influence of hypothermia induced by chlorpromazine (10-15 mg/kg given intra-peritoneally) on the survival from radiation and chemotherapy exposure in C57B1-mice, with or without tumour inoculation, was studied. MATERIALS AND METHODS: The mice were exposed to either whole body irradiation (8 Gy), or doxorubicin (15 or 17.5 mg/kg i.p.), or cisplatin (20 mg/kg i. p.) and followed to ensuing death. The control mice maintained a rectal temperature of 38 degres C while those receiving chlorpromazine developed moderate hypothermia of 28 degrees C or 36 degrees C, dependent on the ambient temperature. RESULTS: Hypothermia of 28 degrees C protected the mice from radiation-induced death and acute doxorubicin toxicity, with males gaining more protection than females. The effects appeared dependent on temperature, not on chlorpromazine. Hypothermia protected the mice from acute cisplatin toxicity and increased the anti-tumour effects in both genders. Chlorpromazine itself did not cause toxicity, neither did it change the natural course of tumour progression. CONCLUSION: Hypothermia of 28 degrees C induced by chlorpromazine profoundly reduces radiation, doxorubicin-and cisplatin-induced toxicity in mice with males benefiting more than females. The hypothermia itself, not the chlorpromazine, was responsible for these effects. The anti-neoplastic activity was not compromised; rather, it was enhanced, particularly for cisplatin.
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| 5. |
- Palm, Stig, 1964, et al.
(författare)
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Cell growth kinetics of the human cell line Colo-205 irradiated with photons and astatine-211 alpha-particles
- 2000
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Ingår i: Anticancer Res. - 0250-7005. ; 20:3A, s. 1807-12
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Tidskriftsartikel (refereegranskat)abstract
- Cell growth kinetics following Astatine-211 (211At, alpha-particle emitter) and photon irradiation were studied for the human colorectal cell line Colo-205. A growth assay using 96-well plates was chosen. The growth kinetics could be simulated by assuming certain fractions of cells with various proliferative capacities, i.e. from none up to 5 cell doublings, in addition to the defined survivors with remaining unlimited clonogenic capacity. No significant difference in cell growth characteristics was seen between 211At and photon irradiation. The cell doubling time, as calculated from the increment in optical density, was compared with the results from BrdU experiments in the early phases of growth (Tpot = 18.5 +/- 0.6 h for LDR (low dose rate) photon irradiated and 20.3 +/- 0.8 hours for sham-irradiated cells 40-45 hours post-irradiation) confirming the transient accelerated growth of irradiated cells. No statistically significant difference in growth was found between LDR, MDR (medium dose rate) and HDR (high dose rate) photon irradiation.
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| 6. |
- Palm, Stig, 1964, et al.
(författare)
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In vitro effects of free 211At,211At-albumin and 211At-monoclonal antibody compared to external photon irradiation on two human cancer cell lines
- 2000
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Ingår i: Anticancer Res. - 0250-7005. ; 20:2A, s. 1005-12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to perform various 211At irradiations of importance for the evaluation of 211At-radioimmunotherapy, and compare the effect with that of low linear energy transfer (LET) radiation. MATERIALS AND METHODS: All irradiations were performed on low-concentration single-cell suspensions. Growth assays using 96-well plates were used to estimate apparent cell survival. Centrifuge tube filters were used to estimate the cell uptake and binding of 211At. RESULTS: A relative biological effect (RBE) of 12 +/- 2 (Colo-205) and 5.3 +/- 0.7 (OVCAR-3) was found from 211At-albumin irradiations. There was a 174 +/- 28 times higher free 211At concentration in the cell fraction than in the surrounding medium. For 211At-MAb, an 8,000-30,000 times higher concentration in the cell fraction was achieved, compared to the medium. Corrected for the uptake, an average of 31 +/- 2 ([211At]-astatine) or 26 +/- 5 ([211At]-MAb) decays per cell were required for 37% survival of Colo-205 cells. An average of 19 +/- 3 decays ([211At]-astatine) were required per OVCAR-3 cell. CONCLUSIONS: Cell uptake and binding of 211At was unexpectedly high, possibly favouring its therapeutic use. The binding is probably to the cell surface. The RBE is 5.3 +/- 0.7 for OVCAR-3 and 12 +/- 2 for Colo-205 cells.
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| 7. |
- Palm, Stig, 1964, et al.
(författare)
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Single-cell irradiation from [211At] astatine-labeled C215 monoclonal antibody: improved estimates of radiosensitivity from measurements on cellular uptake and retention
- 2003
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Ingår i: Anticancer Res. - 0250-7005. ; 23:2B, s. 1219-21
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Tidskriftsartikel (refereegranskat)abstract
- New data on the biological effect of 211At-C215 monoclonal antibody in a slowly rotating, widely dispersed single-cell suspension of the human cancer cell line Colo-205 is presented. Cell growth curves of each experiment were used to calculate an apparent cell survival after irradiation. Uptake measurements provided the data needed to calculate the average number of 211At decays per cell in the cell suspension. The results from each experiment were then fit to a mono-exponential function. From the exponential fit, an average of 35 +/- 2 (SD) astatine-211 decays per cell are required for 37% apparent cell survival (D0).
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