A5015571650- Effects of Radiation Exposure
- Molecular Biology Techniques and Applications
- Radiation Therapy and Dosimetry
- Carcinogens and Genotoxicity Assessment
- Adipose Tissue and Metabolism
- Radiopharmaceutical Chemistry and Applications
- Heat shock proteins research
- DNA Repair Mechanisms
- DNA and Nucleic Acid Chemistry
- RNA Research and Splicing
- Radiation Effects and Dosimetry
- Metabolomics and Mass Spectrometry Studies
- Mitochondrial Function and Pathology
- Cancer, Hypoxia, and Metabolism
- Advanced Radiotherapy Techniques
- Genital Health and Disease
- bioluminescence and chemiluminescence research
- Salivary Gland Disorders and Functions
- FOXO transcription factor regulation
- Nuclear Physics and Applications
- Radioactivity and Radon Measurements
- dental development and anomalies
- Cell death mechanisms and regulation
- IL-33, ST2, and ILC Pathways
- Nuclear Structure and Function
Columbia University Irving Medical Center
2008-2024
City College of New York
2002-2022
The Graduate Center, CUNY
2002-2022
Columbia University
2010-2021
Medical Radiological Research Center
2012
Hong Kong University of Science and Technology
2002
University of Hong Kong
2002
Centre for Cellular and Molecular Biology
1994
The effects of dose-rate and its implications on radiation biodosimetry methods are not well studied in the context large-scale radiological scenarios. There significant health risks to individuals exposed an acute dose, but a realistic scenario would include exposure both high low dose-rates, from external internal radioactivity. It is important therefore, understand biological response prolonged exposure; further, discover biomarkers that can be used estimate damage low-dose rate exposures...
Abstract Background The existence of a radiation bystander effect, in which non-irradiated cells respond to signals from irradiated cells, is now well established. It raises concerns for the interpretation risks arising exposure low doses ionizing radiation. However, regulatory mechanisms involved response have not been elucidated. To provide insight into signaling pathways responding bystanders, we measured global gene expression four hours after and direct alpha particle primary human lung...
Although radiation-induced bystander effects have been confirmed using a variety of endpoints, the mechanism(s) underlying these are not well understood, especially for in vivo study. A 1-cm2 area (1 cm × 1 cm) lower abdominal region gpt delta transgenic mice was irradiated with 5 Gy 300 keV X-rays, and changes out-of-field lung liver were observed. Compared sham-treated controls, Spi− mutation frequency increased 2.4-fold non-targeted tissues at 24 h after partial body irradiation (PBIR)....
Abstract Large-scale radiation emergency scenarios involving protracted low dose rate exposure (e.g. a hidden radioactive source in train) necessitate the development of high throughput methods for providing rapid individual estimates. During RENEB (Running European Network Biodosimetry) 2019 exercise, four EDTA-blood samples were exposed to an Iridium-192 (1.36 TBq, Tech-Ops 880 Sentinal) at varying distances and geometries. This resulted doses ranging between 0.2 2.4 Gy using rates 1.5–40...
Early and high-throughput individual dose estimates are essential following large-scale radiation exposure events. In the context of Running European Network for Biodosimetry Physical Dosimetry (RENEB) 2021 exercise, gene expression assays were conducted their corresponding performance dose-assessment is presented in this publication. Three blinded, coded whole blood samples from healthy donors exposed to 0, 1.2 3.5 Gy X-ray doses (240 kVp, 1 Gy/min) using source Yxlon. These exposures...
Tools for radiation exposure reconstruction are required to support the medical management of victims in radiological or nuclear incidents. Different biological and physical dosimetry assays can be used various scenarios estimate dose ionizing a person has absorbed. Regular validation techniques through inter-laboratory comparisons (ILC) is essential guarantee high quality results. In current RENEB comparison, performance established cytogenetic [dicentric chromosome assay (DCA),...
Abstract Background The radiation bystander effect is an important component of the overall biological response tissues and organisms to ionizing radiation, but signaling mechanisms between irradiated non-irradiated cells are not fully understood. In this study, we measured a time-series gene expression after α-particle irradiation applied Feature Based Partitioning around medoids Algorithm (FBPA), new clustering method suitable for sparse time series, identify modules that act in concert...
Cesium-137 is a radionuclide of concern in fallout from reactor accidents or nuclear detonations. When ingested inhaled, it can expose the entire body for an extended period time, potentially contributing to serious health consequences ranging acute radiation syndrome increased cancer risks. To identify changes gene expression that may be informative detecting such exposure, and begin examining molecular responses involved, we have profiled global blood male C57BL/6 mice injected with...
The mouse (Mus musculus) is an extensively used model of human disease and responses to stresses such as ionizing radiation. As part our work developing gene expression biomarkers radiation exposure, dose, injury, we have found many genes are either up-regulated (e.g. CDKN1A, MDM2, BBC3, CCNG1) or down-regulated TCF4 MYC) in both species after irradiation at ~4 8 Gy. However, also that consistently humans mice DDB2, PCNA, GADD45A, SESN1, RRM2B, KCNN4, IFI30, PTPRO). Here test a...
The incidence of asbestos-induced human cancers is increasing worldwide, and considerable evidence suggests that reactive oxygen species (ROS) are important mediators these diseases. Our previous studies suggested mitochondria might be involved in the initiation oxidative stress asbestos-exposed mammalian cells.We investigated whether a potential cytoplasmic target asbestos using mitochondrial DNA-depleted (ρ(0)) small airway epithelial (SAE) cell model: ρ(0) SAE cells lack capacity to...
Downstream factors that regulate the decision between senescence and cell death have not been elucidated. Cells undergo through three pathways, replicative (RS), stress-induced premature (SIPS) oncogene-induced senescence. Recent studies suggest ataxia telangiectasia mutant (ATM) kinase is only a key protein mediating cellular responses to DNA damage, but also regulates induced by telomere end exposure (in RS) or persistent damage SIPS). Here, we show expression of secretory clusterin...
We investigated the cytogenetic and gene expression responses of peripheral blood cells non-human primates (NHP, Macaca mulatta) that were whole-thorax irradiated with a single dose 10 Gy. In this model, partial irradiation NHPs in thoracic region (Whole Thorax Lung Irradiation, WTLI) allows study late radiation-induced lung injury, while avoiding acute radiation syndromes related to hematopoietic gastrointestinal injury. A transient drop circulating lymphocytes platelets was seen by 9 days,...
Abstract Background The existence of a radiation bystander effect, in which non-irradiated cells respond to signals from irradiated cells, is well established. To understand early signaling and gene regulation we used bio-informatics approach, measuring global expression at 30 minutes pathways between 4 hours after exposure α-particles IMR-90 fibroblasts. Methods We whole human genome microarrays real time quantitative PCR measure validate expression. Microarray analysis was done using...
The radioactive isotope Strontium-90 (90Sr) may be released as a component of fallout from nuclear accidents, or in the event radiological incident such detonation an improvised device, and if ingested poses significant health risk to exposed individuals. In order better understand response 90Sr, using easily attainable standard biodosimetry sample fluid, we analyzed global transcriptomic blood cells vivo model system. We injected C57BL/6 mice with solution 90SrCl2 followed them over 30-day...
In a nuclear or radiological event, an early diagnostic prognostic tool is needed to distinguish unexposed from low- and highly exposed individuals with the latter requiring intensive medical care. Radiation-induced gene expression (GE) changes observed within hours days after irradiation have shown potential serve as biomarkers for either dose reconstruction (retrospective dosimetry) prediction of consecutively occurring acute chronic health effects. The advantage GE markers lies in their...
Abstract Cellular senescence is a terminal growth phase characteristic of normal human diploid fibroblasts. Altered gene expression during cellular numerous compared to that younger proliferative cells in culture. We have previously reported the levels and activities hnRNP A1 A2 RNA binding proteins are decreased senescent Both multifunctional may influence mRNA isoforms development. In this study, we tested whether overexpression either protein could modulate INK4a locus, specifically p14...
Abstract In the event of a nuclear attack or large-scale radiation event, there would be an urgent need for assessing dose to which hundreds thousands individuals were exposed. Biodosimetry approaches are being developed address this need, including transcriptomics. Studies have identified many genes with potential biodosimetry, but, date most focused on classification samples by exposure levels, rather than reconstruction. We report here proof-of-principle study applying new methods select...
In the event of an improvised nuclear device or "dirty bomb" in a highly populated area, potentially hundreds thousands people will require screening to ensure that exposed individuals receive appropriate treatment. For this reason, there is need develop tools for high-throughput radiation biodosimetry. Gene expression represents emerging approach biodosimetry and could provide estimate both absorbed dose individual radiation-induced injury. Since approximately 2-4% humans are thought be...
The homologue of cold shock gene cspA Escherichia coli was detected in various isolates Antarctic psychrotrophs representing both Gram-positive and Gram-negative bacteria. Northern hybridization study indicated that the transcript size psychrotrophic bacterium Arthrobacter protophormiae Pseudomonas fluorescens similar to E. homologues these two were expressed constitutively at a low level 4°C 22°C. In P. fluorescens, expression mRNA inducible after shift temperature from 22 maximum induction...
Using microarrays to analyze differential gene expression as a function of p53 status and radiation quality, we observed downregulation large set histone genes in wild-type TK6 cells 24 h after exposure equitoxic doses high-LET (1.67 Gy 1 GeV/amu 56Fe ions) or low-LET (2.5 γ rays) radiation. Quantitative real-time PCR specific subtypes core (H2A, H2B, H3 H4) linker (H1) histones confirmed this result. DNA synthesis are tightly coordinated during the S phase cell cycle, both processes...
In the possible event of a detonation an improvised nuclear device (IND), immediate radiation would consist both photons (gamma rays) and neutrons. Since neutrons generally have high relative biological effectiveness (RBE) for most physiological end points, it is important to understand effect that on biodosimetry methods are being developed medical triage purposes. We previously compared transcriptomic response in human blood after neutron photon irradiation. this study, we analyzed...
Abstract Isolation of RNA from whole saliva, a non-invasive and easily accessible biofluid that is an attractive alternative to blood for high-throughput biodosimetry radiological/nuclear victims might be clinical significance prediction diagnosis disease. In previous analysis 12 human samples we identified two challenges measuring gene expression total RNA: (1) the fraction in saliva was low (2) bacterial contamination overwhelming. To overcome these challenges, performed selective cDNA...
Radiation induced bystander effects are an important component of the overall response cells to irradiation and associated with human health risks. The mechanism responsible includes intra-cellular inter-cellular signaling by which is propagated. However, details not well defined.We measured Mrad9+/+ Mrad9-/- mouse embryonic stem cells, as H1299 inherent or RNA interference-mediated reduced RAD9 levels after exposure 1 Gy α particles, scoring chromosomal aberrations micronuclei formation,...
ABSTRACT A cDNA encoding a eukaryotic translation initiation factor 5A (eIF-5A) homolog in heterotrophic dinoflagellate Crypthecodinium cohnii (CceIF-5A) was isolated through random sequencing of library. The predicted amino acid sequence possesses the 12 strictly conserved acids around lysine 52 (equivalent to 50 or 51 other eukaryotes). single 1.2-kb band detected Northern blot analysis. In synchronized C. cells, transcript level peaked at early G 1 and decreased dramatically on entry S...