Take a Swipe at Actinide Bioavailability: Application of a New In Vitro Method.

Filter swipe tests are used for routine analyses of actinides in nuclear industrial, research, and weapon facilities as well as following accidental release. Actinide physicochemical properties will determine in part bioavailability and internal contamination levels. The aim of this work was to develop and validate a new approach to predict actinide bioavailability recovered by filter swipe tests.

Determination of drug efficacy to dissolve cobalt oxide particles in cellular models: Towards a therapeutic approach to decrease pulmonary retention.

Following accidental inhalation of radioactive cobalt particles, the poorly soluble and highly radioactive CoO particles are retained for long periods in lungs. To decrease their retention time is of crucial importance to minimize radiation-induced damage. As dissolved cobalt is quickly transferred to blood and eliminated by urinary excretion, enhancing the dissolution of particles would favor Co elimination.

The evaluation of oral and dental health and behavioural risk among ultra-endurance athletes: a cross-sectional epidemiological study.

This study assessed for the first time the oral and dental health of ultra-trail athletes. We also confirmed and quantified the scale of their exposure to oral health risk factors. This was a cross-sectional study using data from a survey among runners who enlisted in the 2020 edition of the UT4M races ().

DTPA Treatment of Wound Contamination in Rats with Americium: Evaluation of Urinary Profiles Using STATBIODIS Shows Importance of Prompt Administration.

In the nuclear industry, wound contamination with americium is expected to increase with decommissioning and waste management. Treatment of workers with diethylenetriaminepentaacetic acid (DTPA) requires optimization to reduce internal contamination and radiation exposure. This work aimed at evaluating and comparing different DTPA protocol efficacies after wound contamination of rats with americium.

In vitro assessment of cobalt oxide particle dissolution in simulated lung fluids for identification of new decorporating agents.

Inhalation of CoO particles may occur at the work place in nuclear industry. Their low solubility may result in chronic lung exposure to γ rays. Our strategy for an improved therapeutic approach is to enhance particle dissolution to facilitate cobalt excretion, as the dissolved fraction is rapidly eliminated, mainly in urine.

Americium biodistribution in rats after wound contamination with different physicochemical forms in the presence or absence of plutonium: analyses using STATBIODIS.

Americium (Am) biodistribution data obtained after wound contamination in rats were analysed to evaluate and quantify the influence of different physicochemical forms of Am in the presence or absence of plutonium (Pu). The biodistribution data were individual Am daily urinary excretion and tissue retention. The data were analysed with STATBIODIS, a statistical tool developed in the laboratory and based on the R language.

Actinide-contaminated Skin: Comparing Decontamination Efficacy of Water, Cleansing Gels, and DTPA Gels.

Skin contamination by alpha-emitting actinides is a risk to workers during nuclear fuel production and reactor decommissioning. Also, the list of items for potential use in radiological dispersal devices includes plutonium and americium. The actinide chemical form is important and solvents such as tributyl phosphate, used to extract plutonium, can influence plutonium behavior.

Impact of the spectral and spatial properties of natural light on indoor gas-phase chemistry: Experimental and modeling study.

The characteristics of indoor light (intensity, spectral, spatial distribution) originating from outdoors have been studied using experimental and modeling tools. They are influenced by many parameters such as building location, meteorological conditions, and the type of window. They have a direct impact on indoor air quality through a change in chemical processes by varying the photolysis rates of indoor pollutants.

Decorporation Approach after Rat Lung Contamination with Plutonium: Evaluation of the Key Parameters Influencing the Efficacy of a Protracted Chelation Treatment.

While the efficacy of a protracted zinc (Zn)- or calcium (Ca)-diethylenetriaminepentaacetic acid (DTPA) treatment in reducing transuranic body burden has already been demonstrated, questions about therapeutic variables remain. In response to this, we designed animal experiments primarily to assess both the effect of fractionation of a given dose and the effect of the frequency of dose fraction, with the same total dose. In our study, rats were contaminated intravenously with plutonium (Pu) then treated several days later with Ca-DTPA given at once or in various split-dose regimens cumulating to the same total dose and spread over several days.

Skin absorption of actinides: influence of solvents or chelates on skin penetration ex vivo.

Purpose: To evaluate skin penetration and retention of americium (Am) and plutonium (Pu), in different chemical forms relevant to the nuclear industry and to treatment by chelation.

Materials And Methods: Percutaneous penetration of different Am and Pu forms were evaluated using viable pig skin with the Franz cell diffusion system. The behavior of the complex Pu-tributyl phosphate (Pu-TBP), Am or Pu complexed to the chelator Diethylene triamine pentaacetic acid (DTPA) and the effect of dimethyl sulfoxide (DMSO) was assessed.

Forecasting the In Vivo Behavior of Radiocontaminants of Unknown Physicochemical Properties Using a Simple In Vitro Test.

An understanding of the "bioavailability" of disseminated radiocontaminants is a necessary adjunct in order to tailor treatment and to calculate dose. A simple test has been designed to predict the bioavailability of different actinide forms likely to be found after dissemination of radioactive elements by dispersal devices or nuclear reactor incidents. Plutonium (Pu) or Americium (Am) nitrate or MOX (U,PuO2) are immobilized in culture wells using a static gel phase simulating biological compartments (lung, wound, etc.

Penetration and decontamination of americium-241 ex vivo using fresh and frozen pig skin.

Skin contamination is one of the most probable risks following major nuclear or radiological incidents. However, accidents involving skin contamination with radionuclides may occur in the nuclear industry, in research laboratories and in nuclear medicine departments. This work aims to measure the penetration of the radiological contaminant Americium (Am) in fresh and frozen skin and to evaluate the distribution of the contamination in the skin.

Decorporation of Pu/Am Actinides by Chelation Therapy: New Arguments in Favor of an Intracellular Component of DTPA Action.

Diethylenetriaminepentaacetic acid (DTPA) is currently still the only known chelating drug that can be used for decorporation of internalized plutonium (Pu) and americium (Am). It is generally assumed that chelation occurs only in biological fluids, thus preventing Pu/Am deposition in target tissues. We postulate that actinide chelation may also occur inside cells by a mechanism called "intracellular chelation".

Combined drug and surgery treatment of plutonium-contaminated wounds: indications obtained using a rodent model.

There is an important requirement following accidental actinide contamination of wounds to limit the dissemination and retention of such alpha-emitting radionuclides. To reduce wound and systemic contamination, treatment approaches include chelation therapy with or without wound excision. However, it has been hypothesized that wound excision could lead to increased contaminant release and systemic organ retention.

Increased retention of americium in kidneys as compared with plutonium in an actinide wound contamination model in the rat.

Purpose: Americium-241 ((241)Am) presents a potential risk for nuclear industry workers associated with reactor decommissioning and aging combustible materials. The purpose of this study was to investigate Am renal retention after actinide contamination by wounding in the rat.

Materials And Methods: Anesthetized rats were contaminated with Mixed Oxide (MOX) (7.

Actinide handling after wound entry with local or systemic decorporation therapy in the rat.

Background: Treatment of actinide-contaminated wounds may be problematic because of contaminant physicochemical properties, dissemination and anatomical localization. This study investigates different chelation/resection protocols after contamination of rats with americium (Am) or plutonium (Pu) nitrate or mixed oxide (MOX; uranium (U), Pu oxide).

Methods: Anesthetized rats were contaminated with Am or Pu nitrate (moderately soluble) or MOX (insoluble) following wounding of hind leg muscle.

CCD camera response to diffraction patterns simulating particle images.

We present a statistical study of CCD (or CMOS) camera response to small images. Diffraction patterns simulating particle images of a size around 2-3 pixels were experimentally generated and characterized using three-point Gaussian peak fitting, currently used in particle image velocimetry (PIV) for accurate location estimation. Based on this peak-fitting technique, the bias and RMS error between locations of simulated and real images were accurately calculated by using a homemade program.

Digital microscopic holography for micrometer particles in air.

The development of a specific holographic setup designed for providing three-dimensional imaging of micrometer particles in a very small volume inside a large air-flow facility is described. Study of a 1.5 mm(3) volume is made possible with the use of a microscope objective for magnification of the object field.

Contribution of granulosa cells and follicular fluid to ovarian estrogen secretion in rhesus monkey in vivo.

In order to ascertain which ovarian cell type within the follicle is the source of preovulatory estrogen secretion in vivo, ovarian venous, as well as peripheral venous, blood was collected prior to, 5 min, 30 min, and 120 min after the removal of follicular fluid and granulosa cells from 17 monkeys. In addition, estrogen, progesterone, and progestins were measured in the peripheral blood, ovarian venous blood, and follicular fluid of the follicle-containing and contralateral ovary in 24 monkeys, in order to prove that the preovulatory follicle is the principal source of estrogen. Estradiol was the principal estrogen and was secreted in larger amounts by the ovary with the large preovulatory follicle (7-10 mm in diameter) compared with the contralateral ovary.