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  • NLM标题： Br J Cancer Suppl
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  • 1.

    【2hr】Hypoxia-induced tetraploidisation of a diploid human melanoma cell line in vitro.

    包量

    机译 低氧诱导的二倍体人黑素瘤细胞系的四倍体化。
    摘要：Many human tumours are hyperdiploid, particularly in advanced stages of growth. The purpose of the present work was to investigate whether exposure to hypoxia followed by reoxygenation might induce hyperploidisation of diploid human tumour cells in vitro. The investigation was performed by using the diploid melanoma cell line BEX-c (median chromosome number, 46; DNA index, 1.10 +/- 0.04) as test line and the hyperdiploid melanoma cell line SAX-c (median chromosome number, 61; DNA index, 1.42 +/- 0.03) as control line. Cell cultures kept in glass dishes in air-tight steel chambers were exposed to hypoxia (O2 concentrations < 10 p.p.m. or < 100 p.p.m.) at 37 degrees C for 24 h. DNA content was measured by flow cytometry. Metaphase spreads banded with trypsin-Versene-Giemsa were examined to determine the number of chromosomes per cell. An electronic particle counter was used to measure cell volume. The expression of p53 and pRb was studied by Western blot analysis. Transient exposure to hypoxia was found to induce a doubling of the number of chromosomes in BEX-c but not in SAX-c. The fraction of the BEX-c metaphase spreads with 92 chromosomes was approximately 10% at 18 h after reoxygenation, decreased to approximately 2% at 7 days after reoxygenation and then increased gradually with time. The whole cell population became tetraploid within 25 weeks. BEX-c and SAX-c behaved differently during the 24 h hypoxia exposure. Cell volume and fraction of cells in G2 + M increased with time in BEX-c but remained essentially unchanged in SAX-c. On the other hand, the expression of p53 and pRb was similar for the two lines; hypoxia induced increased expression of p53 and hypophosphorylation of pRb.
  • 2.

    【2hr】Decreased ability of cells overexpressing MYC proteins to reduce peroxide and hydroperoxides.

    包量

    机译 细胞过表达MYC蛋白的能力降低，以减少过氧化物和氢过氧化物。
    摘要：Hydroperoxides are reduced in mammalian cells by a coupled enzyme pathway involving glutathione peroxidase, glutathione reductase and the oxidative limb of the pentose cycle. Oxidation of glucose-6-phosphate by the pentose cycle yields two molecules of NADPH, which can reduce two hydroperoxide molecules to the corresponding alcohol. Rat embryo fibroblasts (REF) transfected with v-myc reduce hydroperoxides slower than the primary REF cell line-measured both as real time peroxide loss and as increased glucose oxidation via the pentose cycle. The v-myc transfected cell line is 50-fold more sensitive to the toxic effects of tBu-OOH. The decreased reduction of peroxides by v-myc transfected cells is not due to changes in the activities of GSH reductase or the enzymes of the oxidative pentose cycle, since diamide stimulates PC activity equally in both cell lines. In addition, the activities of these enzymes, measured in cell homogenates do not differ significantly between the cell lines. Also total GSH peroxidase activity, assayed in cell homogenates, is not significantly different between the cell lines. Two human tumour cell lines which overexpress myc family proteins: NCI-H69, a small-cell lung cancer line which expresses elevated levels of N-myc, and HL-60 cells which overexpress c-myc, also exhibit low levels of pentose cycle stimulation in the presence of tBu-OOH, and a decreased capacity to reduce hydrogen peroxide by peroxide electrode.
  • 3.

    【2hr】Role of the HAP1 protein in repair of oxidative DNA damage and regulation of transcription factors.

    包量

    机译 HAP1蛋白在氧化DNA损伤修复和转录因子调节中的作用。
    摘要：
  • 4.

    【2hr】Vascular endothelial growth factor: environmental controls and effects in angiogenesis.

    包量

    机译 血管内皮生长因子：环境控制和血管生成的影响。
    摘要：
  • 5.

    【2hr】Tempol prevents impairment of the endothelial cell wound healing response caused by ionising radiation.

    包量

    机译 Tempol防止了电离辐射引起的内皮细胞伤口愈合反应的损害。
    摘要：It is known that radiation therapy results in some form of damage to the microcirculation. In support of this view, we found that capillary endothelial cells (EC) treated with X-rays (8 Gy) were defective in their ability to recover a denuded area. A scrape wound of 2 mm width was produced in monolayers 30 min after X-ray or sham treatment. After 48 h, the number of cells migrating into each of five successive 125 microns zones from both sides of the original wound were determined. Greater numbers of sham-treated EC entered zones 3 and 4, compared with irradiated cultures, and only sham-treated EC entered the most distant zone 5. We examined actin fibre orientation within migrating irradiated and sham-treated EC using 2-(D-2-aminobutanoic acid)-7-(N6-((((3,6-bis(dimethylamino)xanthylium-9-yl) carboxyphenyl) amino)thioxomethyl)-L-lysine), chloride (NBD)-phalloidin, immunofluorescent microscopy and computer image analysis. After 48 h, sham-treated, but not irradiated EC, contained actin which was orientated perpendicular to the original wound edge. After 6-9 days, only sham-treated EC closed the wounds. Tempol (4 hydroxy-2,2,6,6-tetra methylpiperidine-1-oxyl)(0.5 or 2 mM)), included in the media during irradiation, prevented this wound healing delay, when measured within the first 24 h. In conclusion, radiation treatment of capillary EC results in a wound healing defect. This defect appears to be related to the EC's inability to realign actin. Tempol protects EC from exhibiting a wound healing delay.
  • 6.

    【2hr】Tumour blood flow modification by endothelin-related peptides in the rat HSN fibrosarcoma.

    包量

    机译 大鼠HSN纤维肉瘤中内皮素相关肽对肿瘤血流的修饰作用。
    摘要：Modification of tissue blood flow and tissue vascular resistance was examined in the female CBH rat, bearing a HSN fibrosarcoma, following bolus intravenous administration of 1 nM kg-1 endothelin-1 (ET-1) or 1 nM kg-1 sarafotoxin S6c (SX6c), selective agonists for endothelin A (ETA) and B (ETB) receptors respectively. Blood flow was measured 15 min after drug administration by the tissue uptake of 125I-labelled-iodoantipyrine. ET-1 and SX6c produced increases in mean arterial blood pressure (MABP) of 52 mmHg and 42 mmHg respectively. Blood flow to the tumour was unaffected by ET-1 treatment, whereas blood flow to normal tissues was reduced, the exception being the heart and the brain in which flow was increased. In contrast, tumour blood flow following SX6c was significantly increased, whereas blood flow in normal tissues was either unaltered or reduced. Vascular resistance was increased in all tissues and the tumour by ET-1 demonstrating that the tumour vasculature was constricting via ETA receptor activation. SX6c however, did not modify tumour vascular resistance, whereas it increased vascular resistance in all normal tissues, suggesting that the tumour lacks a functional population of ETB receptors. This discrepancy may provide a means for selectively modifying tumour blood flow.
  • 7.

    【2hr】Changes in coagulation and permeability properties of human endothelial cells in vitro induced by TNF-alpha or 5,6 MeXAA.

    包量

    机译 TNF-α或5,6 MeXAA诱导的人内皮细胞凝血和通透性变化。
    摘要：5,6 dimethyl xanthenone acetic acid (5,6 MeXAA), an analogue of flavone acetic acid (FAA), has been shown to be more active against murine tumours than FAA. As both drugs have a vascular component in their mechanism of action similar to that observed for TNF-alpha, we have studied the effects of 5,6 MeXAA alone and in combination with TNF-alpha on endothelial function in vitro. The changes induced by the drugs on procoagulant activity and permeability were determined under tumour-simulated conditions of low oxygen tension and the presence of tumour-secreted factors. Procoagulant activity was assayed by measuring the time taken for human umbilical vein endothelial cells (HUVECs) to clot normal human plasma, increased activity resulting in reduced clotting times. HUVECs incubated under aerobic conditions were more sensitive to TNF-alpha than cells incubated at < or = 0.2% oxygen. Culture medium conditioned by the human breast adenocarcinoma cell line MDA-MB-231 strongly upregulated procoagulant activity under both aerobic and hypoxic conditions; clotting times were further reduced by TNF-alpha. Both 5,6 MeXAA and FAA potentiated the effect of TNF-alpha on normal hypoxic endothelial cells; however, under all other conditions, neither drug in combination with TNF-alpha upregulated clotting activity. The presence of tumour-secreted factors had a far greater effect on upregulating procoagulant activity than did oxygen tension. In contrast to procoagulant activity, permeability was insensitive to TNF-alpha and low concentrations of 5,6 MeXAA also caused no change in permeability.
  • 8.

    【2hr】Effect of nitro-L-arginine on blood flow, oxygenation and the activity of hypoxic cell cytotoxins in murine tumours.

    包量

    机译 硝基-L-精氨酸对小鼠肿瘤中血流，氧合和缺氧细胞毒素活性的影响。
    摘要：This study was an investigation into the ability of nitro-L-arginine to change blood flow, oxygenation status and the activity of hypoxic cell cytotoxic agents in two different transplanted murine tumours. The tumour models were the C3H mammary carcinoma grown in the feet of female CDF1 mice and the SaF grown on the backs of CBA mice. Treatments were carried out in restrained non-anaesthetised animals when tumours were about 100 to 200 mm3 in size. Blood flow was monitored using laser Doppler flowmetry; oxygen partial pressure (pO2) distributions were obtained with an Eppendorf oxygen electrode; and response to treatment with hyperthermia (43.5 degrees C; 30 min) and RB6145 (250 mg kg-1;i.p.) assessed using a tumour growth delay assay. Nitro-L-arginine (10 mg kg-1; i.v.) significantly reduced blood flow by around 40-60% within 15 min after injection in C3H tumour and by 30 min in the SaF. However, nitro-L-arginine had absolutely no effect on tumour pO2 measured at the time of maximal blood flow reduction in both tumour types. It also failed to enhance the response of the C3H tumour to heat, but did produce a small yet significant increase in the response of the SaF tumour to RB6145.
  • 9.

    【2hr】Nitric oxide involvement in the toxicity of hydroxyguanidine in leukaemia HL60 cells.

    包量

    机译 一氧化氮参与羟基胍对白血病HL60细胞的毒性作用。
    摘要：The free-radical intermediates and the stable products formed on one-electron oxidation of hydroxyguanidine (HOG) were investigated in order to suggest a mechanistic basis for HOG-induced cytotoxicity and cytostasis in leukaemia HL60 cells. The azide radical (generated radiolytically) reacted with HOG to produce a carbon-centred radical which in the absence of oxygen decays by a first-order process (k = 3.2 x 10(3) s-1) to yield nitric oxide (NO) and urea. Although the HOG radical reacts rapidly with oxygen (rate constant for O2 addition, k = 4.2 x 10(8) dm3 mol-1 s-1) this neither prevented the elimination of NO. nor generated alternative nitrogen oxides (e.g. peroxynitrite) capable of contributing to cellular oxidative stress. The detection of NO. in HL60 cells corroborated mechanistic studies that oxidative denitrification of HOG does not require catalysis by nitric oxide synthase. Quantitation of NO. by electron paramagnetic resonance (EPR) spectroscopy (utilising a NO. -selective probe) shows higher amounts of NO. under anoxic conditions, reflecting competition for NO. with molecular oxygen in oxic cells. Inhibition of cytochrome P450 and myeloperoxidase activity decreased NO. production thereby identifying these enzyme systems as capable of oxidizing HOG in vitro. A correlation exists between the intracellular levels of NO. with both the cytotoxic and cytostatic effects of HOG within HL60 cells. A higher toxicity was observed with hypoxic than with oxic cells. The lower levels of NO. associated with aerobic conditions caused a G1 --> S block in the cell cycle which under anoxia potentiated NO. -induced apoptotic cell death.
  • 10.

    【2hr】Changes in energy metabolism and X-ray sensitivity in murine tumours by the nitric oxide donor SIN-1.

    包量

    机译 一氧化氮供体SIN-1在鼠肿瘤中能量代谢和X射线敏感性的变化。
    摘要：The effect of the nitric oxide (NO) donor SIN-1 on energy metabolism was examined in three murine transplantable tumours in vivo using 31P MRS. SIN-1 at 2 mg kg-1 i.v. reduced Pi/total by 40-50% in SCCVII/Ha and KHT tumours within 5 min of injection, returning to control levels by 20 min. However, this dose of SIN-1 did not consistently alter Pi/total in RIF-1 tumours. Reduction in Pi/total in SCCVII/Ha tumours 10 min after 5 mg kg-1 i.v. SIN-1 was similar to that for 2 mg kg-1. SIN-1 at 10 mg kg-1 had no effect on Pi/total at 10 min after injection, but increased this ratio 2-fold over control at 60 min, at which time no effect of the lower doses of SIN-1 were observed. SIN-1 effects on SCCVII/Ha tumour response to X-rays were also examined, using an in vivo/in vitro clonogenic assay 24 h after treatment. SIN-1 at 0.5-2 mg kg-1 i.v. given immediately before irradiation increased tumour cell killing 2-4-fold over that for 15 Gy X-rays alone, while higher SIN-1 doses were ineffective. The results indicate that NO donors can alter tumour energy metabolism and X-ray response in a manner consistent with increased oxygenation. However, these responses are dependent upon dose, timing and tumour type.
  • 11.

    【2hr】Radiation sensitisation by nitric oxide releasing agents.

    包量

    机译 一氧化氮释放剂引起的辐射敏化。
    摘要：Previous studies have shown that nitric oxide (NO) sensitises hypoxic cells to ionising radiation. In the present study, four different nitric oxide (NO) donor agents were evaluated for both NO release and hypoxic radiosensitisation. The S-nitrosothiol NO donor agents, S-nitrosoglutathione (GSNO) and S-nitroso-N-acetylpenicillamine (SNAP), were shown to release sustained NO concentrations (microM) and significantly radiosensitise hypoxic cells. The extent of hypoxic radiosensitisation by both of these agents at 1.0 mM concentration was similar to that obtained with molecular oxygen. In contrast, neither 3-morpholinosydnonimine (SIN-1) nor sodium nitroprusside (SNP) released detectable NO concentrations and neither agent enhanced the hypoxic radiation response to the extent of that observed for GSNO or SNAP. NO-mediated hypoxic cell radiosensitisation by NO donor drugs may offer a new approach for clinical consideration, particularly if such agents can be selectively delivered to hypoxic cells.
  • 12.

    【2hr】Oxygen distributions partly explain the radiation response of human squamous cell carcinomas.

    包量

    机译 氧气的分布部分解释了人类鳞状细胞癌的放射反应。
    摘要：The oxygen tension of human tumours has often been thought to alter tumour response to radiation therapy. The purpose of this analysis is to determine to what extent the observed results of radiotherapy fit predictions based on in situ human tumour pO2 distributions. The radiation dose-response curve for patients treated with radiation alone for squamous cell cancers of the cervix and oropharynx were calculated based on published data. pO2 histograms were obtained from 30 women with cervical cancer and 11 patients with neck nodes from head and neck cancers. An average of 76 +/- 35 (range 28-174) measurements were made from each patient. Hypoxia was assumed to be a purely dose-modifying factor with a maximum OER of 2.5. Assuming patients are treated with daily radiation doses of 2 Gy, the squamous cell carcinoma alpha/beta ratio is 10 Gy, and that tumours have a mean of 10(8) clonogens, it was possible to estimate tumour control probability. Tumour oxygenation was an extremely important modifier of the slope of the dose-response curve and alone was sufficient to account for the slope of the clinically observed dose-response curve for neck nodes. The response curve for uterine cervical cancers is very shallow, and the oxygen distribution did not completely account for heterogeneity of response of these tumours. The results support the conclusion that oxygen tension distribution is an important modifier of human radiation treatment response.
  • 13.

    【2hr】Heterogeneity in human tumour hypoxic fraction using the comet assay.

    包量

    机译 使用彗星分析检测人类肿瘤缺氧分数的异质性。
    摘要：The alkaline comet assay has previously been used to estimate the fraction of radiobiologically hypoxic cells in tumours from patients undergoing palliative radiotherapy for advanced breast and head and neck cancer. Results obtained from fine needle aspirate biopsies (FNABs) using this method indicate considerable heterogeneity in hypoxic fraction between tumours. Heterogeneity between 3 aspirates taken from the same 10 tumours immediately following single doses of 3.5 to 5 Gy is now examined. Results indicate that a single fine needle aspirate is reasonably representative for DNA damage and DNA content. However, difficulties were encountered in obtaining an adequate sample of tumour cells after the final radiation treatment. The average hypoxic fraction decreased from 14% after the first dose to 9% after the last dose, and in 3 tumours which could be evaluated after both the first and last fraction, the hypoxic fraction decreased in two but increased in the third. Rejoining of DNA strand breaks was observed between sequential aspirates indicating that pooling of samples for analysis may not be advisable using this method.
  • 14.

    【2hr】Influence of topoisomerase II on the formation of oxygen-dependent radiation-induced DNA damage.

    包量

    机译 拓扑异构酶II对氧依赖性辐射诱导的DNA损伤形成的影响。
    摘要：Several laboratories have recently demonstrated the feasibility of using radiation-induced DNA strand breaks (SBs) and DNA-protein cross-links (DPCs) to detect and quantify hypoxic cells in tumours and normal tissues. However, if radiation-induced SBs and DPCs are going to provide reasonable estimates of the hypoxic fraction or fractional hypoxic volume of tumours and normal tissues, their formation as a function of the oxygen concentration must be relatively independent of biological factors such as cell type, proliferative status or the composition and properties of proteins that are intimately associated with the DNA. In the present study, the shape of the oxygen dependence curves and the K(m) values for radiation-induced SBs and DPCs were measured by alkaline elution for two human leukaemia cell lines, CEM and CEM/VM-1, whose nuclear matrix-associated topoisomerase II varied substantially in quantity, activity and binding properties. The sigmoidal shape of the oxygen dependence curves, the K(m) for sB formation (approximately 0.027 mM), and the K(m) for DPC formation (approximately 0.064 mM) were identical for both of these human leukaemia cell lines. Consequently, the quantity and properties of topoisomerase II had no measurable influence on the oxygen-dependent formation of radiation-induced SBs and DPCs. These data suggest that varying levels of nuclear matrix-associated proteins and DNA binding proteins will not be a complicating factor when using radiation-induced SBs and DPCs for estimating the hypoxic fraction or fractional hypoxic volume of tumours and normal tissues.
  • 15.

    【2hr】Immunocytochemical labelling of aerobic and hypoxic mammalian cells using a platinated derivative of EF5.

    包量

    机译 使用EF5的铂衍生物对有氧和低氧的哺乳动物细胞进行免疫细胞化学标记。
    摘要：The monoclonal antibody ELK3-51 was previously developed to detect adducts of the 2-nitroimidazole EF5. Direct immunofluorescence was used to detect adducts of EF5 or of a platinated derivative cis-[PtCl2(NH3)EF5] in SCCVII cells treated under aerobic or hypoxic conditions. Fluorescence measurements of these cells using both image and flow cytometric methods were compared, giving similar profiles. Platination significantly decreased immunofluorescence levels (approximately 4-fold less than EF5) after 3 h in hypoxia, but also increased levels after exposure in air (approximately 1.5 x) such that the hypoxic ratio decreased from approximately 50 to approximately 13. Platinated EF5 also showed significantly greater cytotoxicity than its parent in both aerobic and hypoxic cells. These results are consistent with targeting of EF5 to DNA, which was confirmed qualitatively by confocal microscopy.
  • 16.

    【2hr】Prediction of tumour hypoxia and radioresistance with nuclear medicine markers.

    包量

    机译 用核医学标记物预测肿瘤的缺氧和放射抗性。
    摘要：Second-generation nuclear medicine markers of tumour hypoxia have been synthesised and screened for hypoxic marking activity in cell cultures and in mouse tumours (EMT-6). Markers of the iodinated azomycin nucleoside class with greater water solubility and faster plasma clearance rates relative to iodoazomycin arabinoside (IAZA) were of particular interest. The test systems used to characterise hypoxic marking activity of compounds included (1) covalent linkage of radiolabelled markers to cells in suspension culture equilibrated with specific O2 concentrations; (2) biodistribution of radiolabelled markers in EMT-6 tumour-bearing mice; and (3) biodistribution in R3327-AT tumour-bearing rats by nuclear medicine procedures. Of the iodinated azomycin nucleosides produced to date, beta-D-iodoazomycin galactoside (beta-D-IAZG) and beta-D-iodoazomycin xylopyranoside (beta-D-IAZXP) exhibited high metabolism-dependent hypoxic cell uptake, rapid clearance kinetics from the blood and excellent tumour marking activity in vivo. Tumour-blood (T/B) ratio (a measure of tumour hypoxic fraction) was dependent upon EMT-6 tumour size and implantation site. The radioresistance of individual tumours was measured by in vivo/in vitro assay and correlated well with the T/B ratio of hypoxic marker. These studies have identified beta-D-IAZG and beta-D-IAZXP as effective hypoxic markers for planar and single photon emission computerised tomography (SPECT) imaging studies of tumour oxygenation.
  • 17.

    【2hr】Measurement of hypoxia in human tumours by non-invasive spect imaging of iodoazomycin arabinoside.

    包量

    机译 通过碘阿霉素阿糖胞苷的非侵入性斑点成像测量人类肿瘤中的缺氧。
    摘要：Tumour oxygenation status in individual patients may be assessed using the bioreduction and linkage of 2-nitroimidazole markers to viable hypoxic cells in vivo with subsequent detection by conventional nuclear medicine techniques. Iodoazomycin arabinoside (IAZA) was radiolabelled with Iodine-123 and administered i.v. to 51 patients with newly diagnosed malignancies whose tumours were subsequently imaged by planar and single-photon emission computed tomographic (SPECT) procedures. Quantitative analyses of radiotracer avidity were performed at 24 h post-injection and tumour-normal tissue ratios of greater than 1.10 were deemed positive for tumour hypoxia. By this criterion, the frequencies of hypoxia in small-cell lung cancer, squamous cell carcinomas of head and neck and malignant gliomas were 60% (9/15), 40% (6/15) and 0% (0/11) respectively. The correlation of positive IAZA scans with tumour control and survival in patients with lung cancer and head and neck tumours is currently under study. Preliminary observations in neck metastases from squamous cell carcinoma of head and neck tumours indicates decreased local control at 3 months post-treatment in tumours with IAZA avidity. This study concludes that: (1) 123I-IAZA can be administered safely and repeatedly as an outpatient routine imaging procedure in cancer patients during initial work-up and follow-up; (2) that retained drug can be detected by conventional nuclear medicine procedures in inaccessible deep-seated tumours; and (3) that this technique could prove useful for identifying those patients for whom hypoxia-directed therapy is indicated.
  • 18.

    【2hr】Marking hypoxic cells for complement and cytotoxic T lymphocyte-mediated lysis: using pimonidazole.

    包量

    机译 标记缺氧细胞补体和细胞毒性T淋巴细胞介导的裂解：使用pimonidazole。
    摘要：Artificial antigens are created when 2-nitroimidazoles bind to hypoxic cells. These antigens have been used in the immunodetection of tumour hypoxia but they might also serve to stimulate immune lysis of hypoxic tumour cells by complement- and cell-mediated processes. In order to test this hypothesis, lymphocytes isolated from the spleens of C3H/HeN mice that had been immunised with pimonidazole-labelled 3152-PRO cells were subcultured and tested for their ability to lyse chromium-51 loaded, pimonidazole-labelled 3152-PRO cells in an in vitro assay. In a parallel study, commercially available, rabbit complement was tested for its ability to lyse pimonidazole-labelled V79-4 cells in the presence of monoclonal antibodies which recognise protein adducts of reductively activated pimonidazole. Complement-mediated cell lysis was measured by means of an MTT assay. Complement-mediated and cell-mediated lysis was observed at pimonidazole concentrations which, in themselves, do not produce cell killing.
  • 19.

    【2hr】Tumour pO2 can be increased markedly by mild hyperthermia.

    包量

    机译 轻度体温过高可使肿瘤pO2明显增加。
    摘要：We have studied the feasibility of improving tumour oxygenation with hyperthermia at modest temperatures which are achievable with the use of presently available clinical hyperthermia machines. FSaII tumours grown s.c. in the leg of C3H mice and R3230 AC tumours grown s.c. in the leg of Fischer rats were heated with a water bath and the tumour pO2 was determined with an Eppendorf pO2 histograph. The median pO2 in 7-8 mm diameter control FSaII tumours was 6.5 +/- 0.5 mmHg and it increased to 16.6 +/- 1.1 mmHg when the tumours were heated at 41.5 degrees C for 1 h. The median pO2 in 10 mm diameter control R3230 AC tumours was 3.7 +/- 0.3 mmHg. Heating at 42.5 degrees C for 30 min increased the median pO2 in the R3230 AC tumours to 12.2 +/- 1.8 mmHg. The pO2 in FSaII tumours measured 24 h after heating at 41.5 degrees C for 1 h was still higher than the pO2 before heating. The % frequency of pO2 values lower than 5 mmHg decreased markedly when the tumours were heated at the modest temperatures mentioned above. Modest temperature hyperthermia (MTH) may be an efficient and useful means to improve the oxygenation of human tumours.
  • 20.

    【2hr】The importance of choice of anaesthetics in studying radiation effects in the 9L rat glioma.

    包量

    机译 选择麻醉药以研究9L大鼠神经胶质瘤的放射效应的重要性。
    摘要：In the present study we demonstrate that the glycolysis of the tumour 9L glioma, in vivo, may be manipulated with ketamine/xylazine combinations of anaesthetics. Xylazine alone or in combination with ketamine causes hyperglycaemia which is enhanced by glucose injections. Intracellular tumour pH is acidified when glucose is administered with ketamine/xylazine. However, the combination of inorganic phosphate and insulin with ketamine/xylazine and glucose caused an alkaline shift in the tumour pH as measured by 31P NMR. The anaesthetic combination of ketamine/acepromazine did not produce alterations in blood glucose or in tumour pH status as detected by 31P NMR spectroscopy. These results demonstrate dramatic effects of ketamine/xylazine on the acidification or alkalinisation of the cells of 9L glioma. These altered metabolic states are of potential therapeutic importance. The choice of xylazine alone would be useful for chemotherapy and hyperthermia modalities, both known to be dependent upon glucose metabolism and resultant acidification.
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