Michele Ellender

Michele Ellender
Public Health England | HPA · Centre for Radiation, Chemical and Environmental Hazards (CRCE)

PhD, MIBiol

About

55
Publications
7,286
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
850
Citations
Additional affiliations
April 2013 - present
Public Health England
Position
  • Principal Radiation Protection Scientist
April 1998 - March 2013
Health Protection Agency
Position
  • Principal Radiation Protection Scientist
Education
October 1993 - October 1998
University of Surrey
Field of study
  • Studies of the distribution, retention and toxicological effects of uranium, plutonium and americium in CBA/H mice

Publications

Publications (55)
Article
Full-text available
The aim of this review is to investigate the literature pertaining to the potential risks of low-dose ionizing radiation to Lynch syndrome patients by use of computed tomography (CT), either diagnostic CT colonography (CTC), standard staging CT or CT surveillance. Furthermore, this review explores the potential risks of using radiotherapy for treat...
Article
Full-text available
Purpose The aim of this brief personal, high level review is to consider the state of the art for biological dosimetry for radiation routine and emergency response, and the potential future progress in this fascinating and active field. Four areas in which biomarkers may contribute to scientific advancement through improved dose and exposure charac...
Article
Full-text available
Purpose: Epidemiological evidence regarding the radiosensitivity of the lens of the eye and radiation cataract development has led to changes in the EU Basic Safety Standards for protection of the lens against ionizing radiation. However, mechanistic details of lens radiation response pathways and their significance for cataractogenesis remain uncl...
Article
The radiosensitive nature of the lens has been increasingly reported, although the exact mechanistic details of the radiation response pathways for cataractogenesis are unclear. Radiation-induced DNA damage and the subsequent impairment of repair pathways within the lens epithelium are involved. Here, two distinct regions of the murine lens epithel...
Article
Full-text available
Risk estimates for radiation-induced cancer in humans are based on epidemiological data largely drawn from the Japanese atomic bomb survivor studies, which received an acute high dose rate (HDR) ionising radiation. Limited knowledge exists about the effects of chronic low dose rate (LDR) exposure, particularly with respect to the application of the...
Article
The discovery of DNA damage response proteins such as γH2AX, ATM, 53BP1, RAD51, and the MRE11/RAD50/NBS1 complex, that accumulate and/or are modified in the vicinity of a chromosomal DNA double-strand break to form microscopically visible, subnuclear foci, has revolutionized the detection of these lesions and has enabled studies of the cellular mac...
Article
To compare the development of intestinal adenomas following neutron and X-ray exposure of Apc(Min/+) mice (Apc - adenomatous polyposis coli; Min - multiple intestinal neoplasia). Adult mice were exposed to acute doses of X-rays or fission neutrons. Tumour counting was undertaken 200 days later and samples were taken for Loss of Heterozygosity (LOH)...
Article
Full-text available
From studies of the atomic bomb survivors, it is well known that ionizing radiation causes several forms of leukemia. However, since the specific mechanism behind this process remains largely unknown, it is difficult to extrapolate carcinogenic effects at acute high-dose exposures to risk estimates for the chronic low-dose exposures that are import...
Article
Full-text available
Purpose: To analyse the temporal change in microdistribution of 239Pu, 241Am and 233U in mouse femur and to compare the calculated radiation doses with regions of the bone marrow thought to contain target cells for osteosarcoma and leukaemia with relative risk for those diseases. Materials and methods: Neutron-induced and alpha-track autoradiograph...
Article
To assess the sensitivity of ApcMin/+ mice (adenomatous polyposis coli Apc, multiple intestinal neoplasia, Min) to the development of intestinal adenomas after x-irradiation in utero, as neonates, or as young adults. CHB6 ApcMin/+ mice were exposed to an acute dose of 2 Gy x-rays either in utero on day 7 or 14 post-conception, as 2-day or 10-day ne...
Article
Full-text available
Data on the induction of small intestinal tumors, predominantly adenomas, by X radiation in Apc(Min/+) mice are reported. Comparison of these incidences with estimates of radiation-induced direct single gene mutation frequencies taken from the literature support the hypothesis that direct mutational loss of Apc+ is the sole requirement for initiati...
Article
Pathbase (http://www.pathbase.net) is a web accessible database of histopathological images of laboratory mice, developed as a resource for the coding and archiving of data derived from the analysis of mutant or genetically engineered mice and their background strains. The metadata for the images, which allows retrieval and interoperability with ot...
Article
Full-text available
Pathbase is a database that stores images of the abnormal histology associated with spontaneous and induced mutations of both embryonic and adult mice including those produced by transgenesis, targeted mutagenesis and chemical mutagenesis. Images of normal mouse histology and strain‐dependent background lesions are also available. The database and...
Article
Values for the absorption parameters were compared after inhalation or intratracheal installation of 1.5 µm mass median aerodynamic diameter (MMAD) ²³³U3O8 particles into the lungs of HMT strain rats. The two sets of parameter values were similar, as were the calculated dose coefficients and predicted biokinetics for workers. Hence the inhalation a...
Article
Full-text available
Ionizing radiation (IR) is a well-characterized carcinogen in humans and mice. The BALB/c mouse strain is unusually sensitive to IR-induced tissue damage and cancer development in a range of organs, suggestive of a partial defect in DNA damage response. This has been confirmed by finding BALB/c-specific functional polymorphism in Prkdc, a gene on m...
Article
Full-text available
Values for the absorption parameters were compared after inhalation or intratracheal instillation of 1.5 microm mass median aerodynamic diameter (MMAD) 233U3O8 particles into the lungs of HMT strain rats. The two sets of parameter values were similar, as were the calculated dose coefficients and predicted biokinetics for workers. Hence the inhalati...
Article
Full-text available
To study the temporal change in microdistribution of plutonium-239, americium-241 and uranium-233 in the mouse distal femur and to compare and combine calculated radiation doses with those obtained previously for the femoral shaft. Also, to relate doses to relative risks of osteosarcoma and acute myeloid leukaemia. Computer-based image analysis of...
Article
Purpose : To study the temporal change in microdistribution of plutonium-239, americium-241 and uranium-233 in the mouse distal femur and to compare and combine calculated radiation doses with those obtained previously for the femoral shaft. Also, to relate doses to relative risks of osteosarcoma and acute myeloid leukaemia. Materials and methods :...
Article
To compare tumour induction in CBA/H mice, principally osteosarcoma and acute myeloid leukaemia, resulting from exposure to the alpha-emitting nuclides, uranium-233, plutonium-239 and americium-241, and to relate differences between the three nuclides to the pattern of dose delivery within tissues. Each nuclide was administered intraperitoneally in...
Article
Min (multiple intestinal neoplasia) mice carry a mutant allele of the murine Apc (adenomatous polyposis coli) locus and are predisposed to intestinal adenoma formation in the intestinal tract. Early studies have shown complete loss of function of Apc by whole chromosome loss on the tumor-sensitive C57BL/6J genetic background and in AKR x B6 F1 hybr...
Article
Full-text available
To analyse the temporal change in microdistribution of 239Pu, 241Am and 233U in mouse femur and to compare the calculated radiation doses with regions of the bone marrow thought to contain target cells for osteosarcoma and leukaemia with relative risk for those diseases. Neutron-induced and alpha-track autoradiographs were prepared from femora of t...
Article
Purpose: To analyse the temporal change in microdistribution of Pu-239, Am-241 and U-233 in mouse femur and to compare the calculated radiation doses with regions of the bone marrow thought to contain target cells for osteosarcoma and leukaemia with relative risk for those diseases. Materials and methods: Neutron-induced and alpha-track autoradiogr...
Article
The microdistributions of the alpha-particle-emitting bone surface-seeking radionuclides (239)Pu, (241)Am and (233)U in the mouse femoral shaft have been studied using computer-based image analysis of neutron-induced and alpha-particle track autoradiographs, prepared from femora of CBA/H mice which had been injected with 40 kBq kg(-1) of radionucli...
Article
Full-text available
Neutron-induced autoradiographs of femoral bone shafts taken from mice injected with 40 kBq.kg-1 239Pu, 241Am or 233U, 1, 28 or 224 days previously, were analysed morphometrically in order to present a comparison of the changing radionuclide distribution patterns. Microdosimetric methods were used to calculate localised dose rates throughout the bo...
Article
The absorption kinetics for uranium into blood after deposition as tri-n-butylphosphate (UTBP) in the rat lung were combined with human data on particle deposition and clearance from the ICRP Publication 66 respiratory tract model and information from the most recent ICRP biokinetic model for uranium to predict the consequences for exposure of work...
Article
Full-text available
Groups of male and female CBA/H mice were given intraperitoneal injections of 40 kBq kg-1 of 239Pu, 241Am and 233U citrate solutions and the retention and distribution of the three radionuclides compared at times up to 448 days. Similar results were obtained for males and females and showed that: 1. Whole body retention at 448 days was very similar...
Article
The biokinetics of 239Pu and 241Am present in three dust samples obtained from the former nuclear weapons test site were investigated after their deposition in the rat lung. For the different dusts the rates of transfer of the actinides to blood varied up to 100-fold. The most transportable dust had 25% class W and 75% class Y characteristics as de...
Article
This study has examined the efficacy of ZnDTPA administered in drinking water for removing 238Pu and 241Am from the rat after their simultaneous inhalation as nitrates; the dosage used was 95 mumol kg-1d-1. The continuous administration of ZnDTPA over a 14 d interval, commencing 1 h after exposure, reduced the lung and total body contents of 238Pu...
Article
The biokinetics of 239Pu and 241Am present in three dust samples obtained from Maralinga were investigated after their deposition in the rat lung. Results were used as an experimental basis for assessing the radiological implications for human exposure. The transfer rates of these actinides to blood in the various dusts differed by 50-fold. The mos...
Article
Accidental intakes of Plutonium-238(238Pu) and Americium-241 (241Am) nitrates which occur by inhalation will result in partial deposition in the nose. In these experiments nasal clearance was examined in rats after instillation of a 3μl aliquot of the nitrate solution at three different sites in the nose (6, 12, 18mm beyond the nares), and after li...
Article
With DTPA as a comparison, the siderophore analogue code named 3,4,3-LIHOPO has been tested for its ability to remove 238Pu and 241Am from rats after their inhalation or intravenous injection as nitrate. The most effective treatment regimen for inhaled Pu was the repeated administration of 30 mumol kg-1 3,4,3-LIHOPO. By 7 days after exposure, the P...
Article
Full-text available
Hamsters were exposed to an aerosol of fused aluminosilicate particles (FAP) labeled with 57Co. Three groups of animals were given bronchopulmonary lavage, beginning at either 1 week, 1 month, or 6 months after exposure. Each treated group was lavaged eight times over a period of 25 days. Each lavage involved 10 saline washes of the lungs. For each...
Article
Tiron (sodium 4,5-dihydroxybenzene-1,3-disulphonate) has been suggested as a possible antidote for acute uranium poisoning. In this study, the compound has been administered intraperitoneally to rats in dosages of 30, 300 or 1000 mumols kg-1 at 20, 60 and 180 min after the intratracheal instillation of uranyl nitrate. The amounts of uranium deposit...
Article
The efficacy of CaDTPA and ZnDTPA, the chelating agents of choice for several actinide elements, have been evaluated after the deposition of thorium in the rat lung in widely different amounts. The results showed that: 1 When the initial mass concentration of thorium simulated human exposure to four times the annual limits on intake for ²³² Th, the...
Article
The pure carboxylated catechoyl amide LICAM(C) and the calcium and zinc salts of diethylenetriaminepenta-acetic acid (DTPA), were tested for efficacy for removing 238Pu and 241Am from rats after inhalation of the nitrate or intravenous injection of the citrate. The results were compared with the efficacy of methylated LICAM(C) used in previous expe...
Article
After the inhalation of 238Pu and 241Am as nitrate, the repeated administration of DTPA is far superior to that of LICAM(C) for enhancing their elimination from the body. The therapeutic efficacies of these chelating agents are however similar after intravenous injection of 238Pu as citrate. It is concluded that DTPA should remain the agent of choi...
Article
The biokinetics of 238 + 239Pu, 241Am, 144Ce and 137Cs, present in a source of airborne contamination that can be inhaled as a consequence of the pond storage of irradiated magnox fuels, have been examined after their deposition in the rat lung and predictions made of their behaviour in humans. The results show that the most toxic radionuclides pre...
Article
Lung retention was followed for up to 640 days in groups of rats that had inhaled different amounts of a mixed actinide oxide containing 239Pu and 241Am, and/or fused aluminosilicate particles (FAP) labelled with 57Co. Lung retention of 239Pu in the rats exposed at the lowest level (initial lung deposit 0.1 kBq, total alpha activity) was greater th...
Article
This study investigated the tissue distribution and excretion of uranium after its deposition as either the nitrate or bicarbonate in the three regions of the respiratory system of the rat. Results confirm the recommendations of ICRP that uranyl nitrate and bicarbonate should be treated as class D compounds; but imply that some of the parameters us...
Article
Aerosols produced from two commercially available ore concentrates in which the uranium was present essentially in the one as ammonium diuranate (ADU) and in the other as uranium octoxide (U 3 O 8 ) were administered to rats. The results show that: 1 uranium in the ADU bearing material was cleared rapidly from the lungs, mainly to the blood, such t...
Article
Fhe efficacies of N ¹ , N ⁵ , N ¹⁰ , N ¹⁴ -tetrakis (2,3-dihydroxy-4-carboxybenzoyl)-tetra-azatetradecane LICAM(C)] and diethylenetriaminepenta-acetic acid (DTPA) (30 μmol/kg body wt.) have been nvestigated for plutonium (Pu) decorporation after inhalation as the nitrate or tributyl phosphate TBP) complexes and the data compared with those obtained...
Article
Unlabelled: Uranium trioxide, produced industrially, was administered to rats either by inhalation or direct injection of an aqueous suspension into the lungs. The results: show that uranium was cleared rapidly from the lungs, mainly to the blood; show that distribution of uranium among body tissues, and the fraction of the systemic content excr...
Article
Animal experiments have suggested that Puchel, a lipophilic derivative of DTPA may be of use in removing plutonium from humans after an accidental intake. This study reports toxicological findings in mice. After the administration of Puchel, as single or repeated doses of the pentasodium salt, an LD50/ld value of 530 +/- 44 mg kg-1 was obtained.
Article
It is possible, using aerosols of the chelating agent DTPA to remove the transportable fraction of inhaled 238PuO2 as it is formed in the lungs. It has also been shown that concomitant intravenous adminstration of DTPA can produce a worthwhile reduction in extrapulmonary deposits of plutonium. It should be borne in mind, however, that the treatment...
Article
The effects of bronchopulmonary lavage with isotonic NaCl have been investigated in the hamster, and methods are described for separating pulmonary surfactant from cells in lavage fluid and for the quantitative isolation of surfactant from lung. It has been shown that hamsters almost invariably survived a lavage which consisted of ten successive wa...

Network

Cited By

Projects

Projects (6)