Radiolytic Inactivation of Cochlodinium polykrikoides and Alexandrium catenella at Low Absorbed Doses

2020 ◽  
Vol 54 (5) ◽  
pp. 363-367
Author(s):  
Yuri Kim ◽  
A. V. Ponomarev
Keyword(s):  
Cochlodinium Polykrikoides ◽  
Alexandrium Catenella ◽  
Absorbed Doses

A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

1974 ◽  
Vol 13 (02) ◽  
pp. 193-206
Author(s):  
L. Conte ◽  
L. Mombelli ◽  
A. Vanoli
Keyword(s):  
Nuclear Medicine ◽  
Close Agreement ◽  
Whole Body ◽  
Simple Method ◽  
Rapid Estimation ◽  
Absorbed Doses ◽  
The Mean ◽  
The Individual ◽  
Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

scholarly journals Comparison of 90Y SIRT predicted and delivered absorbed doses using a PSF conversion method

2021 ◽  
Vol 89 ◽  
pp. 1-10
Author(s):  
Allison J. Craig ◽  
Iain Murray ◽  
Ana M. Denis-Bacelar ◽  
Bruno Rojas ◽  
Jonathan I. Gear ◽  
...  
Keyword(s):  
Absorbed Doses ◽  
Conversion Method

scholarly journals α-Particle-induced DNA damage tracks in peripheral blood mononuclear cells of [223Ra]RaCl2-treated prostate cancer patients

2021 ◽  
Author(s):  
S. Schumann ◽  
U. Eberlein ◽  
C. Lapa ◽  
J. Müller ◽  
S. Serfling ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Dna Damage ◽  
Cancer Patients ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Absorbed Dose ◽  
Peripheral Blood Mononuclear ◽  
Absorbed Doses ◽  
Blood Mononuclear Cells

Abstract Purpose One therapy option for prostate cancer patients with bone metastases is the use of [223Ra]RaCl2. The α-emitter 223Ra creates DNA damage tracks along α-particle trajectories (α-tracks) in exposed cells that can be revealed by immunofluorescent staining of γ-H2AX+53BP1 DNA double-strand break markers. We investigated the time- and absorbed dose-dependency of the number of α-tracks in peripheral blood mononuclear cells (PBMCs) of patients undergoing their first therapy with [223Ra]RaCl2. Methods Multiple blood samples from nine prostate cancer patients were collected before and after administration of [223Ra]RaCl2, up to 4 weeks after treatment. γ-H2AX- and 53BP1-positive α-tracks were microscopically quantified in isolated and immuno-stained PBMCs. Results The absorbed doses to the blood were less than 6 mGy up to 4 h after administration and maximally 16 mGy in total. Up to 4 h after administration, the α-track frequency was significantly increased relative to baseline and correlated with the absorbed dose to the blood in the dose range < 3 mGy. In most of the late samples (24 h – 4 weeks after administration), the α-track frequency remained elevated. Conclusion The γ-H2AX+53BP1 assay is a potent method for detection of α-particle-induced DNA damages during treatment with or after accidental incorporation of radionuclides even at low absorbed doses. It may serve as a biomarker discriminating α- from β-emitters based on damage geometry.

scholarly journals Distribution of Growth-Inhibiting Bacteria against the Toxic Dinoflagellate Alexandrium catenella (Group I) in Akkeshi-Ko Estuary and Akkeshi Bay, Hokkaido, Japan

2020 ◽  
Vol 11 (1) ◽  
pp. 172
Author(s):  
Yuka Onishi ◽  
Akihiro Tuji ◽  
Atsushi Yamaguchi ◽  
Ichiro Imai
Keyword(s):  
Surface Waters ◽  
Seagrass Bed ◽  
Bacterial Strains ◽  
Toxic Dinoflagellate ◽  
Sequence Analyses ◽  
Alexandrium Catenella ◽  
Group I ◽  
Colony Forming Units ◽  
Rrna Sequences ◽  
Growth Inhibiting

The distribution of growth-inhibiting bacteria (GIB) against the toxic dinoflagellate Alexandrium catenella (Group I) was investigated targeting seagrass leaves and surface waters at the seagrass bed of Akkeshi-ko Estuary and surface waters of nearshore and offshore points of Akkeshi Bay, Japan. Weekly samplings were conducted from April to June in 2011. GIBs were detected from surface of leaves of the seagrass Zostera marina in Akkeshi-ko Estuary (7.5 × 105–4.7 × 106 colony-forming units: CFU g−1 wet leaf) and seawater at the stations in Akkeshi Bay (6.7 × 100–1.1 × 103 CFU mL−1). Sequence analyses revealed that the same bacterial strains with the same 16S rRNA sequences were isolated from the surface biofilm of Z. marina and the seawater in the Akkeshi Bay. We therefore strongly suggested that seagrass beds are the source of algicidal and growth-inhibiting bacteria in coastal ecosystems. Cells of A.catenella were not detected from seawaters in Akkeshi-ko Estuary and the coastal point of Akkeshi Bay, but frequently detected at the offshore point of Akkeshi Bay. It is suggested that A.catenella populations were suppressed by abundant GIBs derived from the seagrass bed, leading to the less toxin contamination of bivalves in Akkeshi-ko Estuary.

scholarly journals Radiopharmacokinetic modelling and radiation dose assessment of 223Ra used for treatment of metastatic castration-resistant prostate cancer

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Vera Höllriegl ◽  
Nina Petoussi-Henss ◽  
Kerstin Hürkamp ◽  
Juan Camilo Ocampo Ramos ◽  
Wei Bo Li
Keyword(s):  
Prostate Cancer ◽  
Radiological Protection ◽  
Bolus Administration ◽  
Time Activity ◽  
Biokinetic Model ◽  
Castration Resistant ◽  
Absorbed Doses ◽  
Red Marrow ◽  
Dose Coefficients ◽  
Modelling Study

Abstract Purpose Ra-223 dichloride (223Ra, Xofigo®) is used for treatment of patients suffering from castration-resistant metastatic prostate cancer. The objective of this work was to apply the most recent biokinetic model for radium and its progeny to show their radiopharmacokinetic behaviour. Organ absorbed doses after intravenous injection of 223Ra were estimated and compared to clinical data and data of an earlier modelling study. Methods The most recent systemic biokinetic model of 223Ra and its progeny, developed by the International Commission on Radiological Protection (ICRP), as well as the ICRP human alimentary tract model were applied for the radiopharmacokinetic modelling of Xofigo® biodistribution in patients after bolus administration. Independent kinetics were assumed for the progeny of 223Ra. The time activity curves for 223Ra were modelled and the time integrated activity coefficients, $$ \overset{\sim }{a}\left({r}_S,{T}_D\right), $$ a ~ r S T D , in the source regions for each progeny were determined. For estimating the organ absorbed doses, the Specific Absorbed Fractions (SAF) and dosimetric framework of ICRP were used together with the aforementioned $$ \overset{\sim }{a}\left({r}_S,{T}_D\right) $$ a ~ r S T D values. Results The distribution of 223Ra after injection showed a rapid plasma clearance and a low urinary excretion. Main elimination was via faeces. Bone retention was found to be about 30% at 4 h post-injection. Similar tendencies were observed in clinical trials of other authors. The highest absorbed dose coefficients were found for bone endosteum, liver and red marrow, followed by kidneys and colon. Conclusion The biokinetic modelling of 223Ra and its progeny may help to predict their distributions in patients after administration of Xofigo®. The organ dose coefficients of this work showed some variation to the values reported from clinical studies and an earlier compartmental modelling study. The dose to the bone endosteum was found to be lower by a factor of ca. 3 than previously estimated.

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