Microspectrophotometric determination of nerve cell respiration at high potassium concentration.
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Biomedical subjects
Publications and source records attributed to R Hultborn.
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In a prospective multicenter study, 186 patients with squamous cell esophageal carcinoma, who after evaluation were considered suitable for surgery, were randomized to 4 treatment groups: Group 1, surgery alone; Group 2, pre-operative chemotherapy (cisplatin and bleomycin) and surgery; Group 3, pre-operative irradiation (35 Gy) and surgery; Group 4, pre-operative chemotherapy, radiotherapy, and surgery. Three-year survival was significantly higher in the pooled groups receiving radiotherapy as compared with the pooled groups not receiving radiotherapy. Comparison of the groups having pre-operative chemotherapy with those not having chemotherapy showed no significant difference in survival. Female patients had a significantly better survival than males. The results indicate that pre-operative irradiation had a beneficial effect on intermediate term survival, whereas the chemotherapy regime used did not influence survival.
PURPOSE: To evaluate the efficacy of pamidronate 60 mg i.v. q 4 weeks in women with advanced breast cancer with skeletal metastases. PATIENTS AND METHODS: 404 woman with skeletal metastases from breast cancer in Sweden and Norway were included in a randomized, placebo-controlled, multicenter study. Except for the study medication, other palliative treatment was chosen at the discretion of the physician. Skeletal related events, i.e. increased pain, treatment of hypercalcemia, pathologic fractures of long bones or pelvis, paralyses due to vertebral compression, palliative radiotherapy for skeletal metastases, surgery on bone and change of antitumor therapy were recorded every third month as well as a self-estimated pain-score using visual Analog Scales and analgesic consumption. RESULTS: There was a significantly increased time to progression of pain (p < 0.01), to hypercalcemic events (p < 0.05) as well as for the cumulative number of skeletal related events (p < 0.01) in favor for the pamidronate group. No statistically significant reduction of pathologic fractures of long bones or pelvis, or pareses due to vertebral compression occurred. No statistically significant differences were found for the need of radiotherapy and surgery on bone. The pamidronate group faired better regarding performance status (p < 0.05). There was a statistically not significant lower consumption of opioid analgesics in the pamidronate group (p = 0.14). CONCLUSION: Pamidronate 60 mg i.v. q 4 weeks reduces skeletal events and improves the quality of life in women with bone metastases from breast cancer.
A study of the feasibility of gradually increased epirubicin and cyclophosphamide dosage in an FEC regimen with G-CSF (granulocyte colony stimulating factor) support in 18 high-risk breast cancer patients as adjuvant treatment was carried out. The FEC regimen was initiated with 5-fluorouracil 600 mg/m2, epirubicin 75 mg/m2 and cyclophosphamide 900 mg/m2 together with G-CSF 5 micrograms/kg subcutaneously on days 2-15 q 3 weeks for nine cycles, increasing individually through four dose levels to a maximum of 5-FU 600 mg/m2 (not escalated), epirubicin 120 mg/m2 and cyclophosphamide 1800 mg/m2. Transient cytopenias were regularly observed without major clinical complications. Rapid recovery and a biphasic overshoot of granulocytes required individualization of G-CSF support. During the 6-month treatment period, a general decline in granulocytes, platelets and haemoglobin was observed, resulting in maximal dose intensity in the middle of the treatment period. Compared to a conventional FEC regimen (5-Fluorouracil 600 mg/m2, Epirubicin 60 mg/m2, Cyclophosphamide 600 mg/m2 q 3 w) without dose reductions, it was feasible to increase the dose of epirubicin by more than 50 per cent with an increased dose intensity between 25 and 70 per cent. The dose of cyclophosphamide was increased by more than 100 per cent. All patients suffered from complete alopecia and moderate nausea, but there was no acute cardiac or severe mucosal toxicity. It was concluded that intensified, G-CSF supported FEC therapy can be safely administered in an outpatient setting, provided the patients are thoroughly informed and adequately monitored. High-risk patients are enrolled in a study comparing the described regimen and a myeloablative regimen including peripheral stem-cell support. Breast cancer seems to respond to chemotherapy in a dose dependent manner, suggesting the use of dose intensified regimens (1,8,9,11). This approach is currently under investigation in studies comparing standard regimens with myelo-ablative regimens in high-risk primary breast cancer (3,10). In a Scandinavian multicenter study (2), two high dose regimens, G-CSF supported dose-escalated FEC and myeloablative cyclophosphamide-thiotepacarboplatin with peripheral stem cell support, are compared as adjuvant therapy in operable high-risk breast cancer. This phase I study was performed to assess the feasibility and achievable dose intensity of an individually dose-escalated FEC regimen not in previous use.
The influence of hypothermia (2 degrees, 15 degrees and 28 degrees C) upon the effect of X-irradiation on chromatin from human diploid fibroblast cells (AG1518) was studied using the fluorescent halo assay. Rewinding of supercoils was inhibited in a dose-dependent manner when cells were irradiated with 4, 8 or 16 Gy. This inhibition of rewinding was reduced when cells were irradiated at subnormal temperatures compared with cells irradiated at 37 degrees C. One hour's preincubation at low temperature did not influence rewinding. When AG1518 cells were irradiated at 37 degrees C in the presence of the radical scavenger DMSO (0.5 M), the radiation-induced damage was reduced. No additional protection of DMSO in hypothermic cells (2 degrees C) was found, possibly indicating that OH-radical-mediated effects are more temperature dependent. These results are similar to those recently found for the malignant MCF-7 cell line.
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.
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.
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.
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.
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.
The effect of chlorpromazine on tumour progression and survival, when used as a modifier of chemotherapy response and toxicity, was studied in mice. The dosage was 15 mg/kg i.p., tested to produce rectal hypothermia within 1 hour, lasting for at least 8 hours, at an ambient temperature of 28 degrees C. The drug or saline was given to inbred C57Bl/6J mice four days previously inoculated i.v. with MCG101-AA sarcoma cells. Little acute toxicity, except for the intended hypothermia, was observed. No influence on survival could be discerned, nor any influence upon distribution of tumour deposits. In this tumour model system, chlorpromazine can be used as a chemotherapy response modifier without significant effects per se.
A double fluorescent staining technique for visualisation of blood vessels was applied to rat mammary tumours. Rats were exposed to noradrenaline or saline and the stained vascular area was recorded. In tumours exposed to noradrenaline, vascular staining was different from that in those exposed to saline, reflecting the possible closure of part of the vasculature in response to the drug.