Over the past century, ionizing radiation has been known to induce cataracts in crystalline lens of eye, but its mechanistic underpinnings remain incompletely understood. This study is first report clonogenic survival irradiated primary normal human epithelial cells and stimulation proliferation. Here we used two cell strains: HLEC1 WI-38 lung fibroblasts. Both strains were diploid, a replicative lifespan was shorter cells. The colony formation assay demonstrated that both decreases...

Stem cell competition could shed light on the tissue-based quality control mechanism that prevents carcinogenesis. To quantitatively evaluate stem in vitro, we developed a two-color intestinal organoid forming system. First, improved protocol of culturing organoids from leucine-rich-repeat containing G-protein-coupled receptor 5 (Lgr5)- enhanced green fluorescent protein (EGFP)high cells directly sorted Matrigel without embedding. The organoid-forming potential (OFP) was 25% Lgr5-EGFPhigh at...

The attribution of stochastic effects to exposure ionizing radiation has been qualitatively discussed by introducing two distinct concepts provability and probability. This study aims develop a method quantitatively assessing the radiation-related cancers. To this end, 'minimum provable dose' (MPD) was developed applied actual cancer mortality in Japan. background lifetime risk calculated for esophagus, stomach, colon, liver, lungs, skin, breasts, ovaries, bladder, bone marrow as well...

Recently, the question of whether cancer risk is only accelerated but not increased by radiation exposure has been raised. To explore this matter, we analyzed cumulative mortality irradiated mice could be explained x-axis (age) shifted nonirradiated mice. We reanalyzed publicly available data on observed or prevalence in female B6C3F1 that lived their entire lifespan. The results showed curve was well matched to uniformly for all causes death solid tumors and ovarian as is. After adjusting...

In April 2011, the International Commission on Radiological Protection (ICRP) issued statement tissue reactions. This stimulated interest in many countries. The Expert Committee Radiation of Lens Eye was established Japanese Health Physics Society, and 2013, started discussion about international developments recent studies related to dosimetry lens eye. committee now publishes interim report consisting parts I-VI. Of these, this Part I overviews structure eye lens, cataract types scientific...

Intestinal organoids are an in vitro cultured tissue model generated from intestinal stem cells, and they contain a mixture of epithelial cell types. We previously established efficient 'one cell/well' sorting method, defined organoid-forming potential (OFP) as useful index to evaluate the stemness individual cells. In this study, we assessed response radiation dose dose-rate by measuring both OFP percentage cells crypts. After high-dose-rate (HDR, 0.5 Gy/min) irradiation vivo, harvested...

For many Japanese radiation workers in the medical, nuclear and other industrial fields, equivalent dose of lens eye will be sufficiently lower than new ICRP limit. However, for medical staff members who are engaged interventional radiology cardiology may exceed limit, especially when they exposed closely to higher scatter a long time. In addition, dosimetry protection emergency recovery Fukushima Daiichi Nuclear Power Plant (FNPP1) important issues. Thus gathering information related is...

The International Commission on Radiological Protection (ICRP) has classified radiation cataract as tissue reactions (formerly known deterministic effects or non-stochastic effects) for which a threshold dose exists, and recommended an equivalent limit the lens of eye to prevent vision-impairing cataracts. A occupational been 150 mSv/year predicated >8 Sv since 1980 Brighton Statement, but was drastically lowered by 2011 Seoul Statement 20 mSv/year, averaged over defined periods 5 years,...

The system of radiological protection has been functioning well and is sufficiently robust. However, it needs to be further improved by new scientific findings. At low dose rate, which are the main areas protection, carcinogenesis regarded as risk its biological mechanisms need elucidated. Biological effect a given generally decreases with decreasing radiation known ‘dose-rate effect’. Tissue stem cells considered targets for radiation-induced carcinogenesis. In tissues exposed radiation,...

Radiation cataract has been classified as tissue reactions (formerly known deterministic effects or non-stochastic effects) with a threshold dose. In 1984, the International Commission on Radiological Protection (ICRP) suggested dose of >8 Sv for vision-impairing cataracts in highly fractionated protracted exposures. Such was used to recommend an occupational limit lens 150 mSv/year 1990 and 2007, but reduced 0.5 2011 all exposure scenarios irrespective rate delivery. New determined basis...

A cataract is a clouding of the crystalline lens eye. Radiation has been known for over century, but its underlying mechanisms remain incompletely understood. In 2011, International Commission on Radiological Protection (ICRP) issued Seoul Statement to lower dose threshold vision-impairing cataract. ICRP deduced acute from epidemiological evidence demonstrating zero threshold, concluded that tissue reaction with albeit small. This paper first hypothesize there will be early- and late-onset...

A brief review is given of the history and methodology external dosimetry for lens eye. Under 1989 revision to domestic radiological protection regulations, concept on effective dose equivalent limit eye (150 mSv/y) both introduced in ICRP 1977 recommendations has changed nationwide monitoring non-uniform exposure situations trunk a worker. In such situations, which are often created by presence protective apron, worker required use at least two personal dosemeters, one worn under apron...

Background: A comprehensive, traceable, and easy-to-understand radiation risk indicator is desired for radiological protection. The early-onset hypothesis could be used this purpose.Materials Methods: An early death (IED) was developed calculated using the epidemiological dataset from 14th Report of Life Span Study (LSS) Hiroshima Nagasaki. By clarifying calculation process, IED all-cause mortality estimated. In addition, characteristics solid cancer cardiovascular as well those men women,...

Radiation response differs depending on the dose and rate in intestinal stem cells; however, underlying mechanisms are not clear. To understand effects of low-dose low-dose-rate radiation, authors established an organoid system that mimics vivo environment sporadic irradiation conditions vitro. Organoid-forming potential number cells organoids derived from 1 Gy-irradiated were lower than those non-irradiated difference was significant, although exhibited significant growth disadvantage...

While the revised dose limit for lens of eye was presented by International Commission on Radiological Protection (ICRP), measurement standards have been discussed in Organization Standardization (ISO). In Basic Safety Standards Atomic Energy Agency (IAEA), a new ICRP included, and technical document published as guidance implications occupational radiation protection. By Radiation Association (IRPA) Task Group Implementation Revised Dose Limits to Lens Eye, opinions are investigated member...

The International Commission on Radiological Protection (ICRP) and the Radiation Units Measurements (ICRU) have been defined operational quantities protection quantities. Dose limits also recommended by ICRP using These some related values for main radiation such as photons, electrons, neutrons, are summarized in this article with historical considerations. indicated conversion coefficients lens of eye absorbed dose per fluence Equivalent is not used because a quantity that uses weighting...