Papers by Alexandra Miller
Science of The Total Environment, Jul 1, 2001
The Persian Gulf War resulted in injuries of US Coalition personnel by fragments of depleted uran... more The Persian Gulf War resulted in injuries of US Coalition personnel by fragments of depleted uranium (DU). Fragments not immediately threatening the health of the individuals were allowed to remain in place, based on long-standing treatment protocols designed for other kinds of metal shrapnel injuries. However, questions were soon raised as to whether this approach is appropriate for a metal with the unique radiological and toxicological properties of DU. The Armed Forces Radiobiology Research Institute (AFRRI) is investigating health effects of embedded fragments of DU to determine whether current surgical fragment removal policies remain appropriate for this metal. These studies employ rodents implanted with DU pellets as well as cultured human cells exposed to DU compounds. Results indicate uranium from implanted DU fragments distributed to tissues far-removed from implantation sites, including bone, kidney, muscle, and liver. Despite levels of uranium in the kidney that were nephrotoxic after acute exposure, no histological or functional kidney toxicity was observed. However, results suggest the need for further studies of long-term health impact, since DU was found to be mutagenic, and it transformed human osteoblast cells to a tumorigenic phenotype. It also altered neurophysiological parameters in rat hippocampus, crossed the placental barrier, and entered fetal tissue. This report summarizes AFRRI's depleted uranium research to date.
This paper addresses the importance of diagnostic radiation dose assessment to help develop a tre... more This paper addresses the importance of diagnostic radiation dose assessment to help develop a treatment strategy within days of a catastrophe. The long-range goals of the Armed Forces Radiobiology Research Institute (AFRRI) Biological Dosimetry Team are to develop validated radiation biodosimeters and to equip medical personnel with diagnostic information (clinical signs and symptoms, physical dosimetry, etc.) germane to the medical management of human radiation casualties. Our specific objectives are (a) to establish definitive, rapid, high-throughput clinical bioassays for radiation dose assessments, (b) to develop complementary triage-type radiation dose assessment bioassays, and (c) to transition the Biodosimetry Assessment Tool (BAT) software program to facilitate the collection, integration, and arching of biodosimetry data to support medical treatment decisions of radiation-exposed individuals. The experimental approach involves three steps: (a) to establish a "reach-back reference laboratory" that uses conventional bioassays for definitive analyses of biological samples; (b) to develop a validated and forward-deployable biological dosimetry capability for rapid radiation dose assessment, with an emphasis on the use of molecular biology-based diagnostic platforms; and (c) to integrate the biodosimetry data in a suitable software platform to assist in medical management, for example, BAT software. AFRRI researchers established the conventional lymphocyte metaphase-spread dicentric assay in accordance with international harmonized protocols and have been applying it in order to estimate radiation doses in several overexposure accidents. The researchers seek to validate a novel interphase, cell-based cytological bioassay that detects cells with chromosomal-type aberrations and radiation-responsive molecular biomarkers (e.g., gene expression, protein) and to perfect it for rapid radiation dose assessment applications. The BAT software program was released at the AFRRI website (www.afrri.usuhs.mil) in June 2002. Designed primarily for prompt use after a radiation incident, the user-friendly program facilitates collection, integration, and archiving of data obtained from exposed persons. Data collected in templates, using the Microsoft Windows-compatible, user-friendly software program, are compared with established radiation dose responses obtained from the literature to provide multiparameter dose assessment. The program
Military Medicine, Feb 1, 2002
The health effects of embedded fragments of depleted uranium (DUl are being investigated to deter... more The health effects of embedded fragments of depleted uranium (DUl are being investigated to determine whether current surgical fragment-removal policies are appropriate for this metal. The authors studied rodents implanted with DUpellets as well as cultured human cells exposed to DU compounds. Results indicate that uranium from implanted DU fragments distributes to tissues distant from implantation sites, including bone, kidney, muscle, and liver. Despite levels of uranium in kidney that would be nephrotoxic after acute exposure, no histological or functional kidney toxicity was observed with embedded DU, indicating that the kidney adapts when exposed chronically. Nonetheless, further studies of the long-term health impact are needed. DU is mutagenic and transforms human osteoblastic cells into a tumorigenic phenotype. It alters neurophysiological parameters in rat hippocampus, crosses the placental barrier, and enters fetal tissue. Preliminary data also indicate decreased rodent litter size when animals are bred 6 months or longer after DUimplantation.
Radiation Protection Dosimetry, Jun 1, 2002
Using a model system of in vitro human peripheral blood lymphocytes, the effect of low-dose (0.25... more Using a model system of in vitro human peripheral blood lymphocytes, the effect of low-dose (0.25 to 1.50 Gy) 250-kVp X ray radiation (1 Gy.min-1) on the expression of several proto-oncogenes was examined (c-Haras, c-src, c-met, c-jun, c-fos, and c-myc) and beta-actin from 0.25 to 17 h post-radiation. RNA was extracted from cells harvested at various times after exposure and examined for levels of particular mRNAs by northern blot hybridisation. A progressive time- and dose-dependent increase in mRNA levels was observed for c-Haras mRNA, while the other proto-oncogenes (c-src, c-met, c-fos, c-jun and c-myc) examined were variable during the same time period. beta-actin levels were initially decreased but at 17 h post-radiation had returned to control levels. A comparison of the rate of c-Haras transcription at 5 and 17 h post-irradiation revealed that c-Haras transcription was higher at 5 h than at 17 h. These findings suggest that the level of specific proto-oncogene expression, particularly c-Haras, may be useful early diagnostic molecular biomarkers for biodosimetry applications. The use of real-time PCR technologies to quantify gene expression changes will also be discussed.
Oxidative Medicine and Cellular Longevity, 2020
Human SARS-CoV-2 infection is characterized by a high mortality rate due to some patients develop... more Human SARS-CoV-2 infection is characterized by a high mortality rate due to some patients developing a large innate immune response associated with a cytokine storm and acute respiratory distress syndrome (ARDS). This is characterized at the molecular level by decreased energy metabolism, altered redox state, oxidative damage, and cell death. Therapies that increase levels of (R)-beta-hydroxybutyrate (R-BHB), such as the ketogenic diet or consuming exogenous ketones, should restore altered energy metabolism and redox state. R-BHB activates anti-inflammatory GPR109A signaling and inhibits the NLRP3 inflammasome and histone deacetylases, while a ketogenic diet has been shown to protect mice from influenza virus infection through a protective γδ T cell response and by increasing electron transport chain gene expression to restore energy metabolism. During a virus-induced cytokine storm, metabolic flexibility is compromised due to increased levels of reactive oxygen species (ROS) and re...
The present need to assess radiation dose rapidly in mass-casualty and population-monitoring scen... more The present need to assess radiation dose rapidly in mass-casualty and population-monitoring scenarios prompted an evaluation of potential protein biomarkers that can provide early diagnostic information after exposure. Using an ex vivo model system of human peripheral lymphocytes as well as an in vivo murine model, we demonstrated radiation-responsive changes in the expression of the proto-oncogene proteins ras-p21, raf-1, and DNA repair protein p21Waf1Cip, each with a progressive time-and radiation-dose-dependent increase. In addition, we adopted a methodology to identify, optimize, and validate radiation-responsive molecular biomarkers that employs Luminex™ technology, a microsphere-based multi-analyte assay system. This technology is based on the principles of the sandwich immunoassay and flow-cytometric analysis in a 96well microtiter plate format. Current studies use reagents prepared in-house by conjugating capture antibodies to Luminex™ microspheres, and biotin to detection antibodies. Preliminary results demonstrate that radiation-responsive changes in the level of GADD45 DNA repair protein occurred with a progressive timeand radiation-dose-dependent increase in the range of 0.15 to 6.0 Gy. A robotic analysis system for processing the blood protein bioassay was established at the Armed Forces Radiobiology Research Institute (AFRRI). The system consists of a Qiagen Biorobot-8000 for large-sample liquid handling to work in concert with the Luminex™ platform. This robotic system provides "proof of concept" for high-throughput isolation, detection, and quantification of blood protein biomarkers for radiation-dose assessment. Use of this sandwich immunoassay bioassay approach is compatible with field-deployable and hand-held diagnostic platforms. Use of validated molecular biomarker assays linked with existing AFRRI medical recording software and medical data-recording forms, available at the website www.afrri.usuhs.mil, would provide enhanced tools for the medical community to effectively manage a radiation casualty incident.
Clinical cancer research : an official journal of the American Association for Cancer Research, 1996
Cytotoxic chemotherapies often give rise to multidrug resistance, which remains a major problem i... more Cytotoxic chemotherapies often give rise to multidrug resistance, which remains a major problem in cancer management. In pursuit of alternative treatments for chemoresistant tumor cells, we tested the response of multidrug-resistant (MDR) tumor cell lines to the aromatic fatty acids phenylacetate (PA) and phenylbutyrate (PB), two differentiation inducers currently in clinical trials. Both compounds induced cytostasis and maturation of multidrug-resistant breast, ovarian, and colon carcinoma cells with no significant effect on cell viability. In contrast to their poor response to doxorubicin, the MDR cells were generally more sensitive to growth arrest by PA and PB than their parental counterparts. The aromatic fatty acids, like the differentiation-inducing aliphatic fatty acid butyrate, up-regulated mdr-1 gene expression. However, while butyrate increased multidrug resistance, PA and PB potentiated the cytotoxic activity of doxorubicin against MDR cells. The latter was associated wi...
Radiation Protection Dosimetry, 2001
Chromosome aberration analysis is the conventional means of assessing radiation exposure. The Arm... more Chromosome aberration analysis is the conventional means of assessing radiation exposure. The Armed Forces Radiobiology Research Institute recently established an alternative method to measure radiation-induced chromosome aberrations in interphase cells. The method uses commercially available chemical agents to induce premature chromosome condensation in resting' G0 human peripheral blood lymphocytes. Then specific whole-chromosome DNA probes are used with fluorescence in situ hybridisation to detect aberrant cells rapidly over a broad dose range. In new research, the real-time fluorogenic 5'-nuclease, or TaqMan, polymerase chain reaction assay is being used to identify radiation-responsive molecular biomarkers, including gene expression targets and DNA mutations. The goal is to establish rapid, precise, high-throughput assay systems that are practical in a variety of radiation exposure scenarios. The new methodologies that have a number of other applications, together with diagnostic software now in development, could improve the United States military's emergency response capability and medical readiness.
Mutagenesis, 1998
During the 1991 Persian Gulf War several US military personnel were wounded by shrapnel fragments... more During the 1991 Persian Gulf War several US military personnel were wounded by shrapnel fragments consisting of depleted uranium. These fragments were treated as conventional shrapnel and were not surgically removed to spare excessive tissue damage. Uranium bioassays conducted over a year after the initial uranium injury indicated a significant increase in urine uranium levels above natural background levels. The potential mutagenic effects of depleted uranium are unknown. To assess the potential mutagenic effects of long-term exposure to internalized depleted uranium, Sprague-Dawley rats were implanted with depleted uranium and their urine and serum were evaluated for mutagenic potential at various times after pellet implantation using the Ames Salmonella reversion assay. Tantalum, an inert metal widely used in prosthetic devices was used for comparison. Enhancement of mutagenic activity in Salmonella typhiurium strain TA98 and the Ames II™ mixed strains (TA7001-7006) was observed in urine samples from animals implanted with depleted uranium pellets. In contrast, urine samples from animals implanted with tantalum did not show a significant enhancement of mutagenic activity in these strains. In depleted uranium-implanted animals, urine mutagenicity increased in a dose-and time-dependent manner demonstrating a strong positive correlation with urine uranium levels (r = 0.995, P < 0.001). There was no mutagenic enhancement of any bacterial strain detected in the sera of animals implanted with either depleted uranium or tantalum pellets. The results suggest that uranium content in the urine is correlated with urine mutagenicity and that urinary mutagenicity might be used as a biomarker to detect exposure to internalized uranium.
Advances in Space Research, 2003
The multiparametric dosimetry system that we are developing for medical radiological defense appl... more The multiparametric dosimetry system that we are developing for medical radiological defense applications could be adapted for spaceflight environments. The system complements the internationally accepted personnel dosimeters and cytogenetic analysis of chromosome aberrations, considered the best means of documenting radiation doses for health records. Our system consists of a portable hematology analyzer, molecular biodosimetry using nucleic acid and antigen-based diagnostic equipment, and a dose assessment management software application. A dry-capillary tube reagent-based centrifuge blood cell counter (QBC Autoread Plus, Becton [correction of Beckon] Dickinson Bioscience) measures peripheral blood lymphocytes and monocytes, which could determine radiation dose based on the kinetics of blood cell depletion. Molecular biomarkers for ionizing radiation exposure (gene expression changes, blood proteins) can be measured in real time using such diagnostic detection technologies as miniaturized nucleic acid sequences and antigen-based biosensors, but they require validation of dose-dependent targets and development of optimized protocols and analysis systems. The Biodosimetry Assessment Tool, a software application, calculates radiation dose based on a patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s physical signs and symptoms and blood cell count analysis. It also annotates location of personnel dosimeters, displays a summary of a patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s dosimetric information to healthcare professionals, and archives the data for further use. These radiation assessment diagnostic technologies can have dual-use applications supporting general medical-related care.
Environmental Health Perspectives, 1998
Torres are greatly appreciated and were invaluable to the success of this project. This research ... more Torres are greatly appreciated and were invaluable to the success of this project. This research was supported in part by the Armed Forces Radiobiology Research Institute under work unit numbers AFRRI-98-3 and AFRRI-98-4. The views presented are those of the authors and do not reflect the official views of the Department of Defense or the U.S. government.
Environmental Health Perspectives, 2007
is an easy and informative read. The book tells an important and heretofore untold story about th... more is an easy and informative read. The book tells an important and heretofore untold story about the experiences of Navajo miners and families in the uranium mining industry. With a stirring foreword written by Stewart L. Udall, former U.S. Representative for Arizona and Secretary of the Interior under presidents John F. Kennedy and Lyndon Johnson, the book clearly intends both to be educational and to evoke an emotional response from the reader. The book is informative and thought provoking. The Navajo People and Uranium Mining is a collection of 12 chapters. Seven chapters contain oral histories and narratives that reveal the experiences of the Navajo people from diverse perspectives, including history, psychology, culture, advocacy, and policy. These narratives, obtained through interviews, are told directly by the miners themselves or by their families, and are thus steeped in emotion. They also create a powerful documentary of the experiences of the Navajo miners, which have been largely unknown by most Americans. As with other dangerous industries in the United States, the self-sacrificing stories of the workers are usually the forgotten ones. The other chapters in the book describe the social, cultural, and political aspects of the Navajo people and uranium mining. The authors describe the health effects of uranium and how these medical issues adversely affected the lives of the miners and their families. A lack of proper health care following uranium exposure led to further consequences. Attention is also given to the psychological
Unexpected events like the Fukushima Daiichi incident demonstrated the possibility that military ... more Unexpected events like the Fukushima Daiichi incident demonstrated the possibility that military personnel could potentially be exposed to low dose radiation (LDR). LDR cancer risks are uncertain and research has yet to establish cancer risks at LDRs because LDR epidemiological studies are difficult to conduct. Understanding LDR cancer risks is critical since it is difficult to predict the long-term consequences of Fukushima, or of any future accidental or terrorist-based large-scale radiological event. LDR involves non-targeted radiation effects (NTEs) which occur in unirradiated cells with an unknown effect on radiation risk assessment. A novel in vitro/in vivo NTE model was used to explore the bone marrow microenvironment and induction of leukemia in LDR exposures scenarios including repeated or chronic exposures. In this model, murine hematopoietic myeloid progenitor cells (FDC-P1) are monitored for their neoplastic transformation both in vitro (transformation assay) and in vivo...
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
Oxford Medicine Online
Reactive oxygen and nitrogen species, ROS and RNS, are ubiquitous in living cells. They have bene... more Reactive oxygen and nitrogen species, ROS and RNS, are ubiquitous in living cells. They have beneficial effects but are also the cause of a wide variety of diseases. However adding excessive amounts of reducing agents has a long history of clinical failure. This problem can be overcome by providing a novel ester of D-beta-hydroxybutyrate–R-1,3-butanediol, which is rapidly hydrolyzed to ketone bodies, the metabolism of which leads to the production of NADPH. The free cytosolic [NADP+]/[NADPH] redox potential is the most negative in the cell and sets the potential of the glutathione and ascorbic acid couples. Ketone bodies also act by inhibiting histone deacetylases, activating the transcription factor FOXO3 and increasing the transcription of enzymes involved in the destruction of ROS. Ketone esters would be effective in the treatment of a variety of disparate diseases where ROS play a role, ranging from Parkinson’s disease to radiation sickness and aging.
Radiation Research, 2021
Chartered by the U.S. Congress in 1961, the Armed Forces Radiobiology Research Institute (AFRRI) ... more Chartered by the U.S. Congress in 1961, the Armed Forces Radiobiology Research Institute (AFRRI) is a Joint Department of Defense (DoD) entity with the mission of carrying out the Medical Radiological Defense Research Program in support of our military forces around the globe. In the last 60 years, the investigators at AFRRI have conducted exploratory and developmental research with broad application to the field of radiation sciences. As the only DoD facility dedicated to radiation research, AFRRI's Medical Radiobiology Advisory Team provides deployable medical and radiobiological subject matter expertise, advising commanders in the response to a U.S. nuclear weapon incident and other nuclear or radiological material incidents. AFRRI received the DoD Joint Meritorious Unit Award on February 17, 2004, for its exceptionally meritorious achievements from September 11, 2001 to June 20, 2003, in response to acts of terrorism and nuclear/radiological threats at home and abroad. In Au...
External or internal contamination from radioactive elements during military operations or a terr... more External or internal contamination from radioactive elements during military operations or a terrorist attack is a serious threat to military and civilian populations. External radiation exposure could result from conventional military scenarios including nuclear weapons use and low-dose exposures during radiation accidents or terrorist attacks. Alternatively, internal radiation exposure could result from depleted uranium exposure via DU shrapnel wounds or inhalation. The long-term health effects of these types of radiation exposures are not well known. Furthermore, development of pharmacological countermeasures to low-dose external and internal radiological contamination is essential to the health and safety of both military and civilian populations. The purpose of these studies is to evaluate low-dose radiation or DU-induced carcinogenesis using in vitro and in vivo models, and to test safe and efficacious medical countermeasures. A third goal of these studies is to identify bioma...
Military Medicine, 2002
A reliable, relatively easy method for diagnostic assessment of radiation exposure is needed to s... more A reliable, relatively easy method for diagnostic assessment of radiation exposure is needed to support the triage of radiation casualties and medical treatment decisions in military defense operations. Our strategy is to identify radiation-responsive DNA mutations and gene expression targets that can be analyzed using polymerase chain reaction (PCR) assays and an existing fluorescence-based nucleic acid analysis system designed for forward-deployable laboratory applications. Using an in vitro model system of human peripheral blood lymphocytes, we identified a candidate nucleic acid biomarker (i.e., gene expression target) that is responsive to ionizing radiation. In this report, we describe our preliminary Haras gene expression findings. A dose-dependent elevation in Haras gene expression levels was demonstrated using Northern-blot analysis 17 hours after exposure to a 250-kVp dose of X-rays (25-100 cGy, 1 Gy/minute); c-Haras expression levels at 100 cGy were ninefold higher than those of controls. An alternative protocol to quantify the Haras cDNA target, using the rapid, real-time reverse transcriptase fluorogenic 5'-nuclease PCR assay, is described, along with a preliminary characterization of the dynamic range for detection. Our research shows that the analysis of multitarget nucleic acid biomarkers, using the multiplex fluorogenic 5'-nuclease PCR assay, has beneficial applications in radiation epidemiology, radiation therapy, and biodosimetry.
Military Medicine, 2002
Limited data exist to permit an accurate assessment of risks for carcinogenesis and mutagenesis f... more Limited data exist to permit an accurate assessment of risks for carcinogenesis and mutagenesis from embedded fragments or inhaled particulates of depleted uranium (DU). Ongoing studies have been designed to provide information about the carcinogenic potential of DU using in vitro and in vivo assessments of morphological transformation as well as cytogenetic, mutagenic, and oncogenic effects. For comparison, we also examined tungsten alloys used in military projectiles and the known carcinogen nickel. Quantitative and qualitative in vitro transformation studies were done to assess the carcinogenic potential of radiation and chemical hazards. Using a human osteosarcoma cell model, we demonstrated that soluble and insoluble DU compounds can transform cells to the tumorigenic phenotype, as characterized by morphological, biochemical, and oncogenic changes consistent with tumor cell behavior. Tungsten alloys and nickel were also shown to be neoplastic transforming agents, although at a frequency less than that of DU. Sister chromatid exchange, micronuclei, and alkaline filter elution assays showed DU and tungsten alloys were genotoxic. Exposure to a nontoxic, nontransforming dose of DU induced a small but statistically significant increase in the number of dicentrics formed in cells. These results suggest that long-term exposure to DU or tungsten alloys could be critical to the development of neoplastic disease in humans and that additional studies are needed.
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Papers by Alexandra Miller