Biomarkers for translational oncology - Peggy Olive's contribution.

Purpose: Peggy Olive of the BC cancer research center (BCCRC), Vancouver, Canada, dedicated her career to improving the efficiency of radiation in the treatment of cancer. Keenly interested in the study of hypoxic cell radiosensitizers, she recognized the importance of DNA repair in improving the efficacy of radiotherapy. At the BCCRC she developed two methods for clinical practice that detect and quantitate DNA damage in mammalian cells.

Peggy Louise Olive: A journey through the 'comet' and beyond.

Peggy Olive from the British Columbia Cancer Research Center in Canada is credited with the development of a method to measure DNA damage in individual cells based on the technique of microelectrophoresis that she named the 'comet assay'; a well-accepted method to measure DNA damage, hypoxia and apoptosis. A multifaceted person and an ardent campaigner of environmental issues, Peggy has contributed significantly to several areas of radiobiology related to the treatment of cancer, her expertise being tumor hypoxia and gamma H2AX foci as a biomarker in radiotherapy.

Gene expression in Catla catla (Hamilton) subjected to acute and protracted doses of gamma radiation.

Studies on transcriptional modulation after gamma radiation exposure in fish are limited. Cell cycle perturbations and expression of apoptotic genes were investigated in the fish, Catla catla after acute and protracted exposures to gamma radiation over a 90day period. Significant changes in gene expression were observed between day 1 and 90 post-exposure.

Nucleoplasmic bridges and tailed nuclei are signatures of radiation exposure in Oreochromis mossambicus using erythrocyte micronucleus cytome assay (EMNCA).

Gamma radiation-induced genetic perturbations in aquatic vertebrates is largely unknown at low-dose rate, especially in the wake of a nuclear disaster and/or other environmental outbreaks. Freshwater fish, Oreochromis mossambicus subjected to low-dose rate (2 mGy/min) at 2.5-, 5-, and 10-Gy doses, were analyzed for "exposure signatures" in blood samples drawn on days 3, 6, 12, 18, and 30, respectively.

Relative biological effectiveness of radon: An in vitro study using chromosome aberrations as a biomarker.

Purpose: The need to determine a reliable relative biological effectiveness (RBE) value for alpha exposures has become important as reports remain controversial. Although a radiation-weighting factor of 20 has been designated for alpha particles, uncertainty exists on realistic value of the RBE of alpha radiation. The aim of this study was to estimate RBE values for radon using chromosome aberrations as the endpoint in respect to various dose rates of gamma radiation.

Gamma radiation induced cell cycle perturbations and DNA damage in Catla Catla as measured by flow cytometry.

Gamma radiation induced cell cycle perturbations and DNA damage in Catla catla were analyzed in erythrocytes at different time points using flow cytometry (FCM). Protracted exposure to radiation induced damage between days 12 and 45. Disturbances in cell cycle machinery, i.

Cytogenotoxicity assessment of monocrotophos and butachlor at single and combined chronic exposures in the fish Catla catla (Hamilton).

Cytogenotoxic effects in the form of micronuclei and deformed nucleus, nuclear buds, binucleated cells, vacuolated nucleus, vacuolated cytoplasm, echinocytes, and enucleus induced by two compounds belonging to two different chemical classes of agrochemicals (monocrotophos and butachlor) at sublethal concentrations (0.625, 1.3, and 2.

Synergistic effect of radon in blood cells of smokers - an in vitro study.

Epidemiological studies indicate that the risk of lung cancer among smokers increases with exposure to residential radon. The present study aimed to investigate the synergetic effect between smoking and radon. Blood samples from smokers and non-smokers were exposed to different concentrations of radon ranging from 0 to 189MBq/m(3) corresponding to doses ranging from 0.

Gamma radiation induced micronuclei and erythrocyte cellular abnormalities in the fish Catla catla.

Ionizing radiation induced DNA damage in fishes is a scarcely studied topic and very few studies are available in fishes exposed to ionizing radiation using the erythrocyte micronucleus assay under laboratory conditions. Since radionuclides released accidentally or during a nuclear disaster can contaminate inland water bodies, biomonitoring methods are required for assessing the impacts of high and low levels of radiation that may ultimately result in ionizing radiation exposure to both humans and non-human biota. Fresh water fish, Catla catla were subjected to protracted (0.

Cytogenetic damage in human blood lymphocytes exposed in vitro to radon.

The effect of radon in inducing DNA damage was investigated in vitro by two well-established cytogenetic assays. Blood samples were irradiated with radon using a novel irradiation assembly. Doses varied between 0 and 127 mGy for chromosome aberration (CA) assay and 0 and 120 mGy for cytokinesis blocked micronucleus (CBMN) assay.

A simple method to irradiate blood cells in vitro with radon gas.

The design and dosimetry of a novel in vitro radon irradiation facility to investigate cytogenetic damage induced by radon and progeny is described. The system offers a 4pi geometry for uniform irradiation, proving a versatile and convenient facility for irradiation of whole blood cells in suspension or media. Doses can be controlled as exact volumes of the gas can be dispensed and measured by the Lucas cell.

Dose-rate effect on the induction of HPRT mutants in human G0 lymphocytes exposed in vitro to gamma radiation.

The influence of dose rate on expression time, cell survival and mutant frequency at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus was evaluated in human G(0) peripheral blood lymphocytes exposed in vitro to gamma rays at low (0.0014 Gy/min) and high (0.85 Gy/min) dose rates.

Studies on the HPRT mutant frequency in T lymphocytes from healthy Indian male population as a function of age and smoking.

Mutant frequency at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene in the peripheral blood lymphocytes obtained from 44 healthy individuals (23 non-smokers and 21 smokers) of an Indian male population was studied using T-lymphocyte cloning assay. It was found that lnMF increased with age at a rate of 2.5% per year (P <0.

DNA damage and integrity of UV-induced DNA repair in lymphocytes of smokers analysed by the comet assay.

DNA damage was assessed in smoker lymphocytes by subjecting them to the single cell gel electrophoresis (SCGE) assay. In addition to the appearance of comet tails, smoker cells exhibited enlarged nuclei when analysed by the comet assay. On comparing basal DNA damage among smokers and a non-smoking control group, smoker lymphocytes showed higher basal DNA damage (smokers, 36.