The bactericidal radiation dosages at specific wavelengths in the ultraviolet (UV)-visible spectrum are not well documented. Such information is important for the development of new monochromatic bactericidal devices to be operated at different wavelengths. In this study, radiation dosages required to cause mortality of an Escherichia coli strain, ATCC 25922, ...

We describe variations of three radiation-induced endpoints on the basis of cell genotype: Clonogenic survival, expression of apoptosis and cell-cycle redistribution. Clonogenic survival, apoptosis and cell-cycle redistribution are measured in multiple cell lines after exposure to radiation between 2 and 16 Gy. Cell lines varied in clonogenic radiosensitivity and expression ...

The relative biological effectiveness (RBE) of neutrons and other types of densely ionizing radiation appears to be close to 1.0 for the induction of strand breaks, but considerably higher RBEs have been found for cellular end points such as colony-forming ability. This may be due to differences in the processing ...

PURPOSE: The purpose of the present study was to determine the role of DNA polymerase beta in repair and response after ionizing radiation in different phases of the cell cycle. METHODS AND MATERIALS: Synchronized cells deficient and proficient in DNA polymerase beta were irradiated in different phases of the cell ...

PURPOSE: HER2 is a potential target for radionuclide therapy, especially when HER2 overexpressing breast cancer cells are resistant to Herceptin(R) treatment. Therefore, it is of interest to analyse whether HER2 overexpressing tumour cells have different inherent radiosensitivity. METHODS: The radiosensitivity of three often used HER2 overexpressing cell lines, SKOV-3, SKBR-3 ...

The aim of this study was to investigate the possible relationship between the bystander effect and the low-dose hypersensitivity/increased radio-resistance phenomenon in BJ fibroblast cells taking as response criteria different end points of radiation damage such as cell survival, chromosomal damage (as detected by using micronucleus assay) and double strand ...

Artemis is a recently identified factor involved in V(D)J recombination and nonhomologous end joining (NHEJ) of DNA double-strand break (DSB) repair. Here, we performed targeted disruption of the Artemis gene (ARTEMIS) in the human pre-B cell line Nalm-6. Unexpectedly, we found that cells lacking Artemis exhibit increased sensitivity to low ...

Treatment failure after radiotherapy of head and neck squamous cell carcinoma (HNSCC) could be a significant problem. Our objective is to sensitize SCCVII cells to ionizing radiation in vitro and in vivo through inhibiting ATM expression using antisense oligodeoxynucleotides (AS-ODNs), and investigate the potential mechanism of radiosensitization. We designed and ...

BACKGROUND: Radiation-induced bystander responses, where cells respond to their neighbours being irradiated are being extensively studied. Although evidence shows that bystander responses can be induced in many types of cells, it is not known whether there is a radiation-induced bystander effect in breast cancer cells, where the radiosensitivity may be ...

High energy X-rays are capable of interacting with biological membranes to cause both functional and structural modifications. The goal of the present study was to investigate the effects human fibroblast cells exposed multiple times to 10 Gy over time. Following exposures of 2, 3, or 4 times to 10 Gy/10min ...

PURPOSE: To determine whether exposing hepatocellular carcinoma (HCC) to low dose radiation increases the efficacy of dendritic cell-mediated immunotherapy for HCC. METHODS: Tumour specimens collected from 20 recruited patients with HCC were cultured in primary culture (half successfully) and then exposed to low-dose radiation (0.5 Gy). Immature DCs derived from ...

BACKGROUND: Vinca alkaloids are an important class of anticancer agents and semisynthetic vinca alkaloids are developed to improve the therapeutic index of this class of drugs. In the present study, a direct comparison was made between vinflunine and vinorelbine regarding their radiosensitizing and cell cycle effects. METHODS: Four human tumour ...

To establish immortal human cells, we introduced the cDNA of the human telomere reverse transcriptase (hTERT) gene into skin fibroblast cells obtained from normal and ataxia telangiectasia (AT) individuals of Japanese origin. hTERT-immortalized cells retained their original characteristics and radiosensitivity except for immortalization, suggesting that these cells might be useful ...

Thesis (Ph.D.)--University of Tsukuba, (B), no. 748, 1992.3.25

UVA radiation, the most abundant solar UV radiation reaching Earth's surface, induces oxidative stress through formation of reactive oxygen species (ROS) that can damage different cell components. Because of the broad spectrum of the possible targets of ROS, the cellular response to this radiation is complex. While extensive studies have ...

There is considerable interest at present in low-dose radiation effects in non-human species. In this study gamma radiation-induced adaptive response, a low-dose radiation effect, was examined in three fish cell lines, (CHSE-214 (Chinook salmon), RTG-2 (rainbow trout) and ZEB-2J (zebrafish)). Cell survival after exposure to direct radiation with or without ...

In order to enhance the cytotoxicity of radiation, camptothecin (CPT), an inhibitor of DNA topoisomerase I, was added to the cultured glioma cell lines before irradiation (IR). Radiation responses of five glioblastoma cell lines (U87-MG, U373-MG, GHE, GaMG and SNB-19) treated with CPT were analyzed in terms of cell and ...

Many environmental signals, including ionizing radiation and UV rays, induce activation of Egr-1 gene, thus affecting cell growth and apoptosis. The paucity and the controversial knowledge about the effect of electromagnetic fields (EMF) exposure of nerve cells prompted us to investigate the bioeffects of radiofrequency (RF) radiation on SH-SY5Y neuroblastoma ...

Human cancers have multiple alterations in cell signaling pathways that promote resistance to cytotoxic therapy such as X rays. Parthenolide is a sesquiterpene lactone that has been shown to inhibit several pro-survival cell signaling pathways, induce apoptosis, and enhance chemotherapy-induced cell killing. We investigated whether parthenolide would enhance X-ray-induced cell ...

PURPOSE: To evaluate the proliferation rates of five human uveal melanoma (UM) cell lines after treatment with amfenac, a cyclooxygenase (COX)-2 inhibitor, and subsequent radiation exposure. METHODS: Five human UM cell lines (92.1, SP6.5, MKT-BR, OCM-1, and UW-1) and one human fibroblast cell line (BJ) were incubated with amfenac. Treated ...

The health concerns have been raised following the enormous increase in the use of wireless mobile telephones throughout the world. This investigation had been taken, with the motive to find out whether mobile phone radiations cause any in vivo effects on the frequency of micronucleated exfoliated cells in the exposed ...

PURPOSE: PCI-24781 is a novel broad spectrum histone deacetylase inhibitor that is currently in phase I clinical trials. The ability of PCI-24781 to act as a radiation sensitizer and the mechanisms of radiosensitization were examined. EXPERIMENTAL DESIGN: Exponentially growing human SiHa cervical and WiDr colon carcinoma cells were exposed to ...

Benzo(a)pyrene is an ubiquitous environmental carcinogen produced during incomplete combustion of organic substances, and anti-benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), is the most carcinogenic form of its ultimate metabolites. The goal of this study was to examine the response of human amniotic epithelial FL cells to increasing concentrations of BPDE and to find potential ...

Movements of stomata responding to visible and infrared radiations were analyzed in an intact cucumber leaf by applying an improved heat balance method for evaluation of transpiration rate and leaf conductance. In step response to the visible radiation, photosynthetically active radiation (PAR) induced dynamics of water balance in the whole ...

Genomic instability is considered a hallmark of carcinogenesis, and dysfunction of DNA repair and cell cycle regulation in response to DNA damage caused by ionizing radiation are thought to be important factors in the early stages of genomic instability. We performed cell-based functional screening using an RNA interference library targeting ...

PURPOSE: Vinflunine is an innovative microtubule inhibitor belonging to the vinca alkaloid class that possesses radiosensitising properties, which could lead to promising activity in chemoradiation studies in the clinic. METHOD: In the current study, different incubation times with vinflunine, immediately before radiation and different time intervals between vinflunine treatment and ...

Studying the potential role of tumour necrosis factor (TNF)alpha in the initiation of genomic instability is necessary to understand whether TNFalpha can serve as a signalling mediator of radiation-induced genomic instability in non-irradiated bystander cells. In this study, we examined whether TNFalpha could initiate processes through oxidative stress signalling that ...

Glioblastoma multiform is the most common malignant primary brain tumor in adults, but there remains no effective therapeutic approach. 2-methoxyestradiol (2-ME), which is a naturally occurring metabolite of 17beta-estradiol, was shown to enhance radiotherapeutic effect in certain tumors; however, whether 2-ME can also enhance the sensitivity of glioma cells to ...

AIM: To construct pcDNA3.1-Egr.1p-p16 recombinant plasmid and investigate the expression of p16 in pancreatic cancer JF305 cells induced by radiation and the feasibility of gene radiotherapy for pancreatic carcinoma. METHODS: Human p16 cDNA was ligated to the downstream of Egr-1 promotor to construct pcDNA3.1-Egr.1p-p16 plasmid by restriction enzyme digested. The ...

With aging and cancer there is increased expression or activity of matrix metalloproteinases (MMPs) that degrade and remodel the structural extracellular matrix (ECM). In addition, exposure of skin to ultraviolet (UV) radiation (photoaging) leads to loss of cell viability, membrane damage, and deposition of excessive elastotic material. Lutein has antioxidant, ...

We examined DNA damage responses and repair in four human glioma cell lines (A7, U87, T98G, and U373) and normal human astrocytes (NHAs) after clinically relevant radiation doses to establish whether we could identify differences among them that might suggest new approaches to selective radiosensitization. We used phosphorylation of histone ...

Epidemiological and biological studies indicate that solar UVB radiation is involved in cutaneous malignant melanoma etiology. Indeed, melanocytes are very frequently exposed to solar UV radiation, which induces cell damage and may promote cell transformation. We previously showed that melanocytes and melanoma cells exposed to UVB radiation activates a p53-independent ...

Securin has been shown to regulate genomic stability; nevertheless, the role of securin on the cytotoxicity after radiation is still unclear. Exposure to 1-10 Gy X-ray radiation induced cell death in RKO colorectal cancer cells. The protein levels of securin, p53, and p21 were elevated by radiation. The proteins of ...

Quantitative studies of radiation cytotoxicity have been performed mostly in cells in culture. For a variety of reasons, however, the response of cells in culture may not reflect the response for cells in situ in a whole organism. We describe here an approach for quantification of radiation-induced cell death in ...

Gadd45 genes have been implicated in stress signaling in response to physiological or environmental stressors, which results in either cell cycle arrest, DNA repair, cell survival and senescence, or apoptosis. Evidence accumulated implies that Gadd45 proteins function as stress sensors is mediated by a complex interplay of physical interactions with ...

Ionizing radiation-induced genomic instability has been demonstrated in a variety of endpoints such as delayed reproductive death, chromosome instability and mutations, which occurs in the progeny of survivors many generations after the initial insult. Dependence of these effects on the linear energy transfer (LET) of the radiation is incompletely characterized; ...

The present study was carried out to examine the varietal difference in radiosensitivity of callus cells derived from root-tip segments of six rice varieties. The induced callus cells which were subcultured through three transfers were subjected to X-rays of 2.5 to 15kR at mid log phase of each variety. In ...

The recent years have witnessed a rapid accumulation of experimental data showing that ionizing radiation elicits a plethora of biological effects in unirradiated cells receiving bystander signals from hit cells. This so-called radiation-induced bystander effect (RIBE) manifests in various ways including changes in gene expression, genetic and epigenetic alterations, as ...

Diurnal vertical migration in the water column and the impact of solar radiation on motility were investigated in three marine phytoplankton species: Tetraselmis suecica, Dunaliella salina and Gymnodinium chlorophorum. Cells were exposed to solar radiation either in ultraviolet radiation (UVR, 280-400 nm) transparent Plexiglas tubes (45 cm length, 10 cm ...

Human microvascular endothelial cells (HMEC) were exposed to ionizing radiation at doses ranging from 0 to 16 Gy in either the presence or absence of the active thiol forms of amifostine (WR1065), phosphonol (WR255591), N-acetyl-l-cysteine (NAC), captopril or mesna. Each of these clinically relevant thiols, administered to HMEC at a ...

PURPOSE: In order to identify supportive evidence of radiation exposure to cells, we analyzed the relationship between exposure to ionizing radiation and the induction of deletions in mitochondrial DNA (mtDNA). MATERIALS AND METHODS: Using human hepatoblastoma cell line, HepG2 and its derivatives, HepG2-A, -89 and -400, established after long term ...

Pemetrexed is a new generation antifolate approved for the treatment of mesothelioma and non-small cell lung cancer. Caffeine is known to augment radiation or chemotherapeutic drug-induced cell killing. The current study addresses the impact of caffeine on the activity of pemetrexed in mesothelioma cell lines. Caffeine enhanced pemetrexed activity in ...

Increased expression and activation of receptor tyrosine kinases frequently occur in human brain tumors, mediating a variety of growth-promoting pathways and leading to radioresistance; however, little is known about their motogenic potency relative to one another. In this study, we found co-expression of Insulin like growth factor-1 receptor (IGF-1R) and ...

In order to improve the antenna gain, a composite right/left-handed (CRLH) leaky-wave (LW) antenna composed of symmetrical unit cells with short stubs terminated by vertical vias is designed. The use of symmetrical unit cells suppresses the cross-polarization of radiation to less than 23 dB. By comparing the measured radiation characteristics ...

Radiation-induced bystander mutagenesis at a relatively low dose range was investigated using low LET beta-particles in a three-dimensional cell culture model. CHO cells were labeled with 0, 0.5, 1.0 or 5.0 muCi tritiated thymidine ((3)HdTTP) for 12 h and subsequently incubated with A(L) cells for 24 h at 11 degrees ...

Although extensive information is available on the effect ultraviolet (UV) radiation has on Gram-negative marine bacteria, there is a scarcity of data concerning UV radiation and Gram-positive marine bacteria. The focus of this paper is on Microbacterium maritypicum, with the Gram-negative Vibrio natriegens being used as a standard of comparison. ...

There are a variety of mechanisms and pathways whereby cells safeguard their genomes in the face of environmental insults that damage DNA. Whether each of these pathways is equally robust at specific developmental stages in mammals and whether they are also modulated in a tissue-specific manner, however, are unclear. Here, ...

PURPOSE: The effects of radiofrequency (RF) radiation on cellular ornithine decarboxylase (ODC) activity were studied in fibroblasts, two neural cell lines and primary astrocytes. Several exposure times and exposure levels were used, and the fields were either unmodulated or modulated according to the characteristics of the Global System for Mobile ...

Proteasome activator 200 kDa (PA200) forms nuclear foci after exposure of cells to ionizing radiation and enhances proteasome activity in vitro. Within cells, it is unclear whether PA200 responds to radiation alone or in association with proteasomes. In the present study, we identified three forms of cellular PA200 (termed PA200i, ...

The aim of the study was to investigate the sensitivity of AHH-1 human lymphoblastoid cells to radiation and its relevance to intracellular events, specifically alteration in cellular energy-producing systems. AHH-1 human lymphoblastoid cells were irradiated with 6 Gy of gamma radiation, and then were collected at the indicated time points. ...