Introduction The artificial geochemical land where all organisms lived and will live under the conditions of increased level of radiation was set up due to the Chernobyl disaster in 1986. An urgent necessity for studying the various biological effects of chronic influence of low intensity radiation on both individual organisms and populations arose. Combined cytogenetic and radioecological inve...

Checkpoints of DNA integrity are conserved throughout evolution, as are the kinases ATM (Ataxia Telangiectasia mutated) and ATR (Ataxia- and Rad-related), which are related to phosphatidylinositol (PI) 3-kinase [1] [2] [3]. The ATM gene is not essential, but mutations lead to ataxia telangiectasia (AT), a pleiotropic disorder characterised by radiation sensitivity and cellular checkpoint defect...

An unexpected high level of acute lethality has been documented following Photofrin II-mediated photodynamic therapy (PDT) treatments which were localized to the hind leg of normal and tumor-bearing mice. Doses of PDT which induced lethality (10 mg/kg Photofrin II, 200-500 J/cm2) were in the range of doses required to obtain murine tumor cures. The percentage of lethality was proportional to th...

CYTOGENETIC ANALYSES OF LOW DOSE HYPER-RADIOSENSITIVITY INHUMAN LYMPHOBLASTOID CELLS IRRADIATED WITH COBALT-60 GAMMARADIATION byGNANADA S. JOSHIDecember 2014Advisor: Dr. James D. TuckerMajor: Biological ScienceDegree: Doctor or PhilosophyChapter 2:The dose-effect relationships of cells exposed to ionizing radiation are frequentlydescribed by linear qu...

The p53 tumor suppressor acts as a guardian of the genome by preventing the propagation of DNA damage-induced breaks and mutations to subsequent generations of cells. We have previously shown that phosphorylation of the Mdm2 oncoprotein at Ser394 by the ATM kinase is required for robust p53 stabilization and activation in cells treated with ionizing radiation, and that loss of Mdm2 Ser394 phosp...

Both cell lethality and neoplastic transformation were assessed for C3H10T1/2 cells exposed to neutrons with energies from 0.040 to 13.7 MeV. Monoenergetic neutrons with energies from 0.23 to 13.7 MeV and two neutron energy spectra with average energies of 0.040 and 0.070 MeV were produced with a Van de Graaff accelerator at the Radiological Research Accelerator Facility (RARAF) in the Center f...

Manipulations of lethally-irradiated animals, such as for administration of pharmaceuticals, blood sampling, or other laboratory procedures, have the potential to induce stress effects that may negatively affect morbidity and mortality. To investigate this in a murine model of the hematopoietic acute radiation syndrome, 20 individual survival efficacy studies were grouped based on the severity ...

We previously concluded, from our analysis of the published data of other investigators, that the yield of germ-line and somatic mutations after exposure to ionizing radiation is parabolically related to the logarithm of the dose-rate at which a given dose is administered. Here we show that other data reveal a similarly parabolic relationship for other ionizing radiation-associated phenomena, n...

Vitamin A and its derivatives have recently reported to be implicated in synaptic plasticity. The possible effect of vitamin A and its precursor, ?-carotene, on seizure acquisition was tested in PTZ kindling model of epilepsy. Vitamin A and ?-carotene were tested for their ability to 1) suppress seizures (clonic and tonic) and lethality induced by PTZ in PTZ-kindled mice (anticonvulsant effect)...

the immunomodulatory activity of cod liver oil (clo) was evaluated by mice lethality test, carbon clearance assay, neutrophil adhesion test, cyclophosphamide-induced neutropenia, indirect haemagglutination test and effect on serum immunoglobulin levels. clo was administered orally at a dose of 0.5 g/kg or 1 g/kg body weight. in mice lethality test, low dose of clo (0.5 g/kg, po) produced 40% de...