Influence of Different Undercut Depths of Clasp Fabricated by Selective Laser Melting on Retentive Force

INTRODUCTION

The purpose of this study was to investigate the influence of undercut depths on abutment teeth regarding the retentive force of clasps fabricated through selective laser melting (SLM), and to compare them with conventional cast clasps.

METHODS

Akers clasps made of cobalt chromium alloy were fabricated using the SLM method (SLM), and the retentive forces were compared with clasps made with the conventional cast method (Cast). Three undercut amounts (0.25 mm, 0.15 mm, and 0 mm) were applied on the abutment tooth. The specimens were subjected to 10,000 repetitive insertion/removal cycles.

RESULTS

SLM-0.15 showed slightly lower initial retentive force than the Cast specimens, it remained within an acceptable range. During insertion/removal test, the SLM-0.15 specimen showed a significant difference between the initial retentive force and the retentive force after 5,000 cycles, indicating that SLM-0.15 was the least likely to change in retentive force within the parameters established in this study. The inner clasp surface on the SLM groups had higher surface roughness before testing compared to the Cast specimen.

CONCLUSIONS

Akers clasps fabricated by SLM demonstrated optimal initial retentive forces with smaller undercuts than conventional Cast clasps, and the retentive forces changed less with repetitive insertion/removal.

Continuing Steady Challenges Involved in the Lifting of Evacuation Orders after the Fukushima Daiichi Nuclear Power Plant Accident

ABSTRACT

Steady efforts for recovery and reconstruction after the accident at the Fukushima Daiichi Nuclear Power Plant have been underway for 12.5 y. The present study reports on the world's first-ever efforts for a gradual and safe return to areas contaminated with radiation fallout and reconstruction support by providing an overview of the actual situation regarding the strategy for return, especially with the transition after the lifting of the evacuation order by the Japanese government. A stage-by-stage progression of the evacuation order and lifting strategy is summarized chronologically in the following three phases: the Emergency Phase in 2011, the Reconstruction Phase from 2013 to 2020, and the Challenging Phase for Lifting All the Evacuation Zones from 2023. Through the lifting strategy of the government, the number of evacuees decreased significantly, especially during the Reconstruction Phase, from 152,113 in May 2013 to 37,826 in May 2020. It is crucial to strengthen support for reconstruction and convey an unbiased and accurate understanding of Fukushima Prefecture by developing a concrete strategy for community development and increasing the size of the exchange population.

Characteristics and immune checkpoint status of radioiodine-refractory recurrent papillary thyroid carcinomas from Ukrainian Chornobyl Tissue Bank donors

Introduction

The radioiodine-refractory (RAI-R) recurrent papillary thyroid carcinomas (PTCs) are more frequent in elderly patients and have an unfavorable prognosis. Data on the prevalence and characteristics of RAI-R recurrent PTCs in patients of young and middle age with or without a history of radiation exposure in childhood are poorly described. The aim of the current study was: i) to determine the frequency of RAI-R recurrent PTCs among donors of the Chornobyl Tissue Bank (CTB) and analyze the clinicopathological features of primary tumors (PTs), primary metastases (PMTSs), recurrent metastases (RMTSs) and risk factors for RMTS, and ii) to determine the immune checkpoint status (ICS) of the RAI-R recurrent PTCs and to assess the factors associated with ICS positivity.

Methods

Sixty RAI-R recurrent PTCs (46 exposed to radiation and 14 non-exposed, 2.5% of all cases registered with the CTB) from the Ukrainian patients aged up to 48 years were identified.

Results

The clinicopathological characteristics of the PTs moderately to weakly resembled those of the PMTS and RMTS from the same patients while the metastatic tissues were highly similar. The multivariate model of RMTS included the dominant solid-trabecular growth pattern of the PT, cystic changes, N1b metastases, and the probability of a causation (POC) of PTC by radiation as risk factors. Among these factors, the lateral PMTS (N1b) had the strongest effect. The longer period of latency (a POC component) was the second statistically significant characteristic. ICS percent agreement between the PT and RAI-R RMTS was 91.5%; 23.7% of PTs and 28.8% of RMTSs had positive ICS (positive PD-L1 tumor epithelial cells (TECs) and positive PD-L1/PD1 tumor-associated immune cells). ICS positivity of PTs was associated with pronounced oncocytic changes and high density of the p16INK4A-positive TECs in the invasive areas of PTs. In RMTSs, ICS positivity was associated with pronounced oncocytic changes and Ki-67 labeling index ≥ 4.5% of PTs, and the dominant solid-trabecular growth pattern, Ki-67 labeling index ≥ 7.6% and p16INK4A-positivity of RMTS.

Discussion

The findings are of clinical relevance and may be useful for developing individual treatment approaches for patients with RAI-R recurrent PTCs possibly involving immunotherapy.

No evidence of thyroid consequences in seven nuclear workers at the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant accident: 10-year follow-up results of thyroid status

Seven emergency nuclear workers, who had internal exposure due to an intake of radionuclides, mainly I-131, during the emergency response operation in March 2011, after the accident at the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi Nuclear Power Plant (FDNPP), visited the National Institute of Radiological Sciences (NIRS) outpatient clinic for medical evaluation. They were followed up after their first visit for 10 years. The estimated committed equivalent doses to the thyroid were distributed between 3.2 to 1.2 × 10 Sv. This group thought to be received highest exposure at the accident. None of the workers had symptoms related to abnormal thyroid function. The examinations, including thyroid function tests and ultrasound, detected no abnormalities related to radiation exposure. However, there is a need for continuous monitoring of their thyroid status for longer periods in the future.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Anti-CENP-C Antibody-Based Immunofluorescence Dicentric Assay: Radiation Dose-Response, Validation Studies, and Radiation Dose-Dependency on Sister Centromere Fluorescence

Dicentric chromosome assay (DCA) is the most accepted cytological technique for the purpose of biological dosimetry in radiological and nuclear accidents, however, it is not always easy to evaluate dicentric chromosomes because of the technical difficulty in identifying dicentric chromosomes on Giemsa-stained metaphase chromosome samples. Here, we applied an antibody recognizing centromere protein (CENP) C, CENP-C, whose antigenicity is resistant to the fixation with Carnoy's solution. Normal human diploid cells were irradiated with various doses of 137Cs γ rays at 1 Gy/ min, treated with hypotonic solution, fixed with Carnoy's fixative, and metaphase chromosome spreads were stained with anti-CENP-C antibody. Dose-dependent induction of dicentric chromosomes was confirmed between 1 and 10 Gy of γ rays, and the results were compatible with those obtained by the conventional Giemsa-stained chromosome samples. The CENP-C assay also uncovered the difference in the fluorescence from the sister centromeres on the same chromosome, which was more pronounced after radiation exposure. Although the underlying mechanism is still to be determined, the result suggests a novel effect of radiation on centromeres. The innovative protocol for CENP-C-based DCA, which enables ideal visualization of centromeres, is simple, effective and reliable. It does not require skilled examiners, so that it may be an alternative method, avoiding uneasiness of the current DCA using Giemsa-stained metaphase chromosome samples.

Relation of lymphopenia to comorbidity burden and its prognostic value in patients with acute decompensated heart failure with preserved left ventricular ejection fraction: a multicentre study

Background

Systemic inflammation resulting from comorbidities is postulated to play a central role in the pathophysiology of heart failure (HF) with preserved ejection fraction (HFpEF). Lymphopenia is a common manifestation of systemic inflammation and a prognostic factor in patients with HF. However, the association of lymphopenia with the comorbidity burden is unknown, and its prognostic value in patients with HFpEF admitted due to acute decompensated heart failure (ADHF) also remains elusive.

Purpose

We sought to clarify the relation of lymphopenia with the comorbidity burden, as well as its prognostic value and complementarity with the Get with the Guidelines-Heart Failure (GWTG-HF) risk score in ADHF patients with HFpEF.

Methods

Patients' data were extracted from the Prospective mUlticenteR obServational stUdy of patIenTs with Heart Failure with Preserved Ejection Fraction (PURSUIT-HFpEF), which is a prospective multicentre registry for patients with ADHF with a LVEF ≥50%. We analysed data of patients admitted between June 2016 and December 2020 who survived to discharge. The total lymphocyte count (per μL) and GWTG-HF risk score were obtained on admission, as previously reported. Comorbidity burden was defined as the number of comorbidities from the following: atrial fibrillation, hypertension, diabetes mellitus, coronary artery disease, chronic kidney disease, chronic obstructive pulmonary disease, anaemia, and obesity. The study endpoint was all-cause death.

Results

Over a median follow-up of 417 days, 181 of the 1013 included patients died. The proportion of patients with a total lymphocyte count in the lowest tertile was increasing with the increase in comorbidity burden (Figure 1). In the multivariate Cox analysis, a total lymphocyte count in the intermediate (hazard ratio [HR] 1.55, 95% confidence interval [CI] 1.00–2.41, p=0.0486) and lowest tertile (HR 2.23, 95% CI 1.47–3.38, p=0.0002) was independently associated with all-cause death. There was a significant difference in the all-cause death rate among the groups stratified by total lymphocyte count tertile (Figure 2). The total lymphocyte count had a higher C-statistic value (0.627) for the prediction of all-cause death than the GWTG-HF risk score, and the C-statistic value of the GWTG-HF risk score was improved when the total lymphocyte count was added (0.613 to 0.636, p=0.0260).

Conclusions

Lymphopenia was significantly associated with comorbidity burden. Furthermore, it was a useful marker of poor prognosis in hospitalised patients with acute HFpEF and was shown to be complementary to the contemporary HF prognostic score.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Roche Diagnostics K.K.Fuji Film Toyama Chemical Co. Ltd.

Absence of the Anterior Communicating Artery on Selective MRA is Associated with New Ischemic Lesions on MRI after Carotid Revascularization

BACKGROUND AND PURPOSE

ICA-selective MRA using a pencil beam presaturation pulse can accurately visualize anterior communicating artery flow. We evaluated the impact of anterior communicating artery flow on the perioperative hemodynamic status and new ischemic lesions after carotid revascularization.

MATERIALS AND METHODS

Eighty-three patients with carotid artery stenosis were included. We assessed anterior communicating artery flow using ICA-selective MRA. The preoperative hemodynamic status was measured using SPECT. We also measured the change in regional cerebral oxygen saturation after temporary ICA occlusion. New ischemic lesions were evaluated by DWI on the day after treatment.

RESULTS

Anterior communicating artery flow was detected in 61 patients, but it was not detected in 22 patients. Preoperative cerebrovascular reactivity was significantly higher in patients with (versus without) anterior communicating artery flow with a mean peak systolic velocity of ≥200 cm/s (39.6% [SD, 23.8%] versus 25.2% [SD, 16.4%]; P = .030). The decrease in mean regional cerebral oxygen saturation was significantly greater in patients without (versus with) anterior communicating artery flow (8.5% [SD, 5.6%] versus 3.7% [SD, 3.8%]; P = .002). New ischemic lesions after the procedure were observed in 23 patients. The multivariate logistic regression analysis revealed that anterior communicating artery flow (OR, 0.07; 95% CI, 0.012-0.45; P = .005) was associated with new ischemic lesions.

CONCLUSIONS

The absence of anterior communicating artery flow influenced the perioperative hemodynamic status in patients with carotid stenosis and was associated with an increased incidence of new ischemic lesions after carotid revascularization.

Clinicopathological Implications of the BRAF V600E Mutation in Papillary Thyroid Carcinoma of Ukrainian Patients Exposed to the Chernobyl Radiation in Childhood: A Study for 30 Years After the Accident

With time after the Chernobyl accident, the number of papillary thyroid carcinomas (PTCs) driven by the BRAF^V600E oncoprotein is growing in patients exposed to radiation at a young age. Clinicopathological associations of BRAF^V600E in PTCs from patients with internal radiation history have not been sufficiently studied so far. This work analyzes the structural characteristics, proliferative activity, invasive features, clinical information, and dosimetric data in the BRAF^V600E-positive and BRAF^V600E-negative PTCs from the Ukrainian patients exposed to Chernobyl radiation and treated over 30 years after the accident. The study included 428 PTCs from patients aged 4-49 years at surgery who lived in the six northern regions of Ukraine most contaminated by ¹³¹I, were ≤18 years of age at the time of exposure, and were operated on from 1990 to 2017. Immunohistochemical staining for BRAF^V600E was performed with the VE1 antibody. The probability of causation (POC) of a tumor due to radiation was determined using an interactive online NIH/NCI software. BRAF^V600E was detected in 136/428 (31.8%) PTCs. In comparison with the BRAF^V600E-negative PTCs, the BRAF^V600E-positivity was associated with older patient age at the accident and at surgery, a longer period of latency, and lower POC. The BRAF^V600E-positive PTCs were characterized by smaller tumor size, higher Ki67 labeling index, more frequent oncocytic changes, multifocality, and dominant papillary growth pattern. Tumor invasive features were less frequent in the BRAF^V600E-positive PTCs and did not change with POC level. Despite a less aggressive tumor phenotype, BRAF^V600E was a risk factor for recurrence, namely radioiodine-refractory (RAI-R) recurrent metastases. Multivariate models of RAI-R included BRAF^V600E and/or histopathological parameters closely correlating with BRAF^V600E such as tumor size, multifocality, dominant papillary growth pattern, or oncocytic changes. Thus, the BRAF^V600E-positive PTCs from patients from a high-risk group for radiogenic thyroid cancer diagnosed in the 30 years after the Chernobyl accident did not display higher invasiveness regardless of POC level, but in view of the prognostic impact of this genetic alteration, knowledge of the BRAF status may be beneficial for middle-aged patients with radiogenic PTC considered for RAI therapy, and suggests more careful follow-up of patients with the BRAF^V600E-positive tumors.

The high degree of similarity in histopathological and clinical characteristics between radiogenic and sporadic papillary thyroid microcarcinomas in young patients

The potential overtreatment of patients with papillary thyroid microcarcinoma (MPTC) has been an important clinical problem in endocrine oncology over the past decade. At the same time, current clinical guidelines tend to consider prior radiation exposure as a contraindication to less extensive surgery, even for low-risk thyroid carcinomas, which primarily include microcarcinomas. This study aims to determine whether there are differences in the behavior of MPTC of two etiological forms (radiogenic and sporadic), including invasive properties, clinical data, and recurrence in patients aged up to 30 years. For this purpose, 136 radiogenic (from patients aged up to 18 years at the time of the Chornobyl accident) and 83 sporadic (from patients born after the Chornobyl accident) MPTCs were selected and compared using univariate and multivariate statistical methods in a whole group and in age and tumor size subgroups. No evidence of more aggressive clinical and histopathological behavior of radiogenic MPTCs as compared to sporadic tumors for basic structural, invasive characteristics, treatment options, and postoperative follow-up results was found. Moreover, radiogenic MPTCs were characterized by the lower frequencies of oncocytic changes (OR = 0.392, p = 0.004), nodal disease (OR = 0.509, p = 0.050), and more frequent complete remission (excellent response) after radioiodine therapy (OR = 9.174, p = 0.008). These results strongly suggest that internal irradiation does not affect tumor phenotype, does not associate with more pronounced invasive properties, and does not worsen prognosis in pediatric or young adult patients with MPTC, implying that radiation history may be not a pivotal factor for determining treatment strategy in such patients.

The relationship of the clinicopathological characteristics and treatment results of post-Chornobyl papillary thyroid microcarcinomas with the latency period and radiation exposure

INTRODUCTION

A worldwide increase in the incidence of thyroid cancer during the last decades is largely due to papillary thyroid microcarcinomas (MPTCs), which are mostly low-risk tumors. In view of recent clinical recommendations to reduce the extent of surgery for low-risk thyroid cancer, and persisting uncertainty about the impact of radiation history, we set out to address whether clinicopathological characteristics and prognosis of post-Chornobyl MPTCs were changing with regard to: i) the latency period, ii) probability of causation (POC) of a tumor due to radiation, and iii) tumor size.

METHODS

Patients (n = 465) aged up to 50 years at diagnosis who lived in April, 1986 in six northern, most radiocontaminated regions of Ukraine were studied.

RESULTS

Latency period was statistically significantly associated with the reduction of POC level, tumor size and the frequency of fully encapsulated MPTCs. In contrast, the frequency of oncocytic changes and the BRAF^V600E mutation increased. Invasive properties and clinical follow-up results did not depend on latency except for a lower frequency of complete remission after postsurgical radioiodine therapy. The POC level was associated with more frequent extrathyroidal extension, and lymphatic/vascular invasion, less frequent oncocytic changes and BRAF^V600E , and did not associate with any clinical indicator. Tumor size was negatively associated with the latency period and BRAF^V600E , and had a statistically significant effect on invasive properties of MPTCs: both the integrative invasiveness score and its components such as lymphatic/vascular invasion, extrathyroidal extension and lymph node metastases increased. The frequency of total thyroidectomy, neck lymph node dissection and radioiodine therapy also increased with the larger tumor size. The duration of the latency period, POC level or tumor size did not associate with the chance of disease recurrence.

DISCUSSION

In summary, we did not observe overall worsening of the clinicopathological features or treatment results of radiogenic MPTCs that could be associated with the latency period or POC level, suggesting that radiation history did not strongly affect those in the analyzed MPTC patients. However, the increase in the invasive properties with tumor size indicates the need for individual risk stratification for each MPTC patient, regardless of radiation history, for treatment decision-making.

The BRAFV600E Mutation Is Not a Risk Factor for More Aggressive Tumor Behavior in Radiogenic and Sporadic Papillary Thyroid Carcinoma at a Young Age

Simple Summary

Analysis of the groups of young Ukrainian patients (aged ≤28 years) with radiogenic and sporadic papillary thyroid carcinomas (PTCs) showed that the frequency of BRAF^V600E was increasing with patient age, consistently remaining lower in radiogenic PTCs. In both etiopathogenic groups, the BRAF^V600E-positive PTCs more frequently had a dominant papillary growth pattern, smaller tumor size, higher Ki67 labeling index, and a frequency of the major indicators of tumor invasiveness that is lower than or equal to that of the BRAF^V600E-negative tumors. Comparison of the BRAF^V600E-positive PTCs across the groups found a virtual absence of differences, while the BRAF^V600E-negative tumors differed markedly and displayed a higher frequency of invasive tumor features in the radiogenic PTCs. Hence, there is evidence that BRAF^V600E does not confer a more aggressive course of PTC in young patients regardless of tumor etiology.

Abstract

Histopathological changes in the fusion oncogene-driven papillary thyroid carcinomas (PTCs) from children and adolescents exposed to Chernobyl fallout have been extensively studied. However, characteristics of the radiogenic BRAF^V600E-positive PTCs, whose proportion is growing with time, are not well described yet. We analyzed the relationship between the BRAF^V600E status (determined immunohistochemically with the VE1 antibody) and the clinicopathological features of 247 radiogenic and 138 sporadic PTCs from young Ukrainian patients aged ≤28 years. The frequency of BRAF^V600E was increasing with patient age, consistently remaining lower in radiogenic PTCs. In both etiopathogenic groups, the BRAF^V600E-positive PTCs more frequently had a dominant papillary growth pattern, smaller tumor size, higher Ki67 labeling index, and a frequency of the major indicators of tumor invasiveness that is lower than or equal to that of the BRAF^V600E-negative tumors. Comparison of the BRAF^V600E-positive PTCs across the groups found a virtual absence of differences. In contrast, the BRAF^V600E-negative radiogenic PTCs displayed less frequent dominant papillary and more frequent solid growth patterns, lower Ki67 labeling index, and higher invasiveness than the BRAF^V600E-negative sporadic tumors. Thus, BRAF^V600E is not associated with a more aggressive course of PTC in young patients regardless of etiology. The major clinicopathological differences between the radiogenic and sporadic PTCs are observed among the BRAF^V600E-negative tumors.

Bone-destructive osseous arteriovenous fistula at the jugular bulb mimicking a glomus jugular tumor

BACKGROUND

Some reports have described intraosseous arteriovenous fistulas showing osteolytic changes, but an osseous arteriovenous fistula (AVF) at the jugular bulb showing extensive bone destruction is a very rare disease.

CASE DESCRIPTION

A 60-year-old man presented with pulsatile tinnitus and right facial nerve palsy. Radiological imaging showed a large homogenously enhanced osteolytic lesion at the right jugular foramen. A cerebral angiogram showed a high-flow vascular lesion of the jugular bulb associated with retrograde sinus reflux, resulting in venous congestion of the deep venous system. These findings led us to misdiagnose this lesion as a glomus jugular tumor. However, combined arterial and venous angiography after transarterial embolization revealed the precise angioarchitecture, and we finally diagnosed this lesion as a high-flow osseous AVF at the jugular bulb. We performed transvenous embolization using a triple catheter technique. The lesion was successfully obliterated, and the 6-months angiogram showed no recurrence.

CONCLUSION

A rare case of high flow osseous AVF at the jugular bulb associated with osteolytic changes in the surrounding bony structure is reported. Although many hypervascular lesions at the jugular bulb are glomus tumors, bone destructive osseous AVF at the jugular bulb should be considered.

Papillary Thyroid Carcinoma in Ukraine After Chernobyl and in Japan After Fukushima: Different Histopathological Scenarios

Background: A significant increase in the incidence of papillary thyroid carcinoma (PTC) in subjects exposed to radiation at a young age is a well-documented health consequence of the Chernobyl accident. The ongoing Thyroid Ultrasound Examination (TUE) program in children and adolescents of Fukushima Prefecture in Japan also indicated a high prevalence of PTC although its attribution to radiation exposure is a subject of debate. The objective of this study was to perform histopathological analysis of tumor architecture and invasive properties in (i) radiogenic post-Chernobyl and sporadic PTCs from Ukraine, and (ii) PTCs in patients from Fukushima and other Prefectures of Japan of comparable age groups. Methods: The Ukrainian radiogenic PTCs included 245 PTCs from patients who resided in three highly ¹³¹I-contaminated regions and 165 sporadic PTCs diagnosed in residents of the same regions who were born after the accident and therefore not exposed to radioiodine. The Japanese series included 115 PTCs detected during the preliminary and the first full-scale surveys of the TUE in Fukushima and 223 PTCs from patients resident in other Prefectures. All of the subjects were included in the main statistical analysis. Three additional analyses were performed limiting the subjects to children, adolescents, and adults. Results: Ukrainian radiogenic PTC was characterized by the higher frequency of tumors with a dominant solid-trabecular growth pattern and higher invasiveness, more frequent extrathyroidal extension, lymphatic/vascular invasion, regional and distant metastases when compared with sporadic Ukrainian PTC. The integrative "invasiveness score," based on five cancer characteristics, was also higher in the radiogenic group. The differences were most pronounced in children. In contrast, no significant differences in tumor morphology or invasiveness were observed between the two Japanese groups or the three age subgroups. The only statistically significant findings were the higher proportion of male patients, smaller mean tumor size, and higher frequency of T1b tumors in the Fukushima group. Conclusions: The difference in morphological features that indicate biological behavior of PTC between the radiation-related and sporadic groups from Ukraine, together with the lack of such in the two groups from Japan, strongly suggest a nonradiogenic etiology of PTC from Fukushima and other Prefectures.

Radiomics analysis of myocardial perfusion SPECT images in patients with cardiomyopathy and heart failure

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI Grants

Background

Although myocardial perfusion heterogeneity due to focally damaged cardiomyocytes is observed in single−photon emission computed tomography (SPECT) imaging, a current perfusion defect scoring system does not allow us to provide sufficient diagnostic information for heterogeneity.

Purpose

The aim of this study was to perform radiomics analysis of myocardial perfusion SPECT (MPS) images to investigate the potential to detect myocardial perfusion heterogeneity.

Methods

Patients with hypertrophic cardiomyopathy (n = 3), heart failure (n = 9), and with a low likelihood of coronary artery disease (n =15) (Figure 1), who underwent a rest 99mTc-MIBI myocardial perfusion SPECT, were assessed using a LIFEx software. Four shape−based features, 6 histogram−based features, and 32 textural features were computed. The relevant features for the classification of the patients were selected using the Boruta algorithm, and hierarchical clustering of the selected features using the Spearman correlation coefficient was also performed for the feature reduction. The receiver operating characteristics (ROC) analysis was performed by the support vector machine to calculate the area under the ROC curve (AUC) for the selected features.

Results

Of 40 features, 17 were selected by the classification analysis, and these features were classified into 7 classes by the correlation analysis (Figure 2). The ROC AUCs for 7 features extracted from each class were 0.99, 0.97, 0.96, 0.92, 0.90, 0.86, and 0.83 for the contrast of NDGLDM, the entropy of histogram, ZLNU of GLZLM, the energy of GLCM, the energy of histogram, SZLGE of GLZLM, and the correlation of GLCM, respectively, as compared to 0.39 for a summed rest score.

Conclusions

Radiomics analysis successfully determined the myocardial perfusion heterogeneity in patients with cardiomyopathy and heart failure. It might be promising for the evaluation of myocardial damages that cannot be analyzed by the conventional scoring method.

Major Oncogenic Drivers and Their Clinicopathological Correlations in Sporadic Childhood Papillary Thyroid Carcinoma in Belarus

Childhood papillary thyroid carcinoma (PTC) diagnosed after the Chernobyl accident in Belarus displayed a high frequency of gene rearrangements and low frequency of point mutations. Since 2001, only sporadic thyroid cancer occurs in children aged up to 14 years but its molecular characteristics have not been reported. Here, we determine the major oncogenic events in PTC from non-exposed Belarusian children and assess their clinicopathological correlations. Among the 34 tumors, 23 (67.6%) harbored one of the mutually exclusive oncogenes: 5 (14.7%) BRAFV600E, 4 (11.8%) RET/PTC1, 6 (17.6%) RET/PTC3, 2 (5.9%) rare fusion genes, and 6 (17.6%) ETV6ex4/NTRK3. No mutations in codons 12, 13, and 61 of K-, N- and H-RAS, BRAFK601E, or ETV6ex5/NTRK3 or AKAP9/BRAF were detected. Fusion genes were significantly more frequent than BRAFV600E (p = 0.002). Clinicopathologically, RET/PTC3 was associated with solid growth pattern and higher tumor aggressiveness, BRAFV600E and RET/PTC1 with classic papillary morphology and mild clinical phenotype, and ETV6ex4/NTRK3 with follicular-patterned PTC and reduced aggressiveness. The spectrum of driver mutations in sporadic childhood PTC in Belarus largely parallels that in Chernobyl PTC, yet the frequencies of some oncogenes may likely differ from those in the early-onset Chernobyl PTC; clinicopathological features correlate with the oncogene type.

Experiences of crisis communication during radiation emergency and risk communication for recovery of the community in Fukushima

Since 2011, Nagasaki University (Nagasaki, Japan) has been assisting the reconstruction efforts of Kawauchi Village (Fukushima Prefecture), which was the first village to decide to return to their home town after the evacuation due to the accident at the Fukushima Daiichi Nuclear Power Station. In April 2013, Nagasaki University and the Kawauchi Government Office concluded an agreement concerning comprehensive cooperation toward the reconstruction of the village. Furthermore, we began comprehensive support for the residents of Tomioka who returned to their hometown in 2017, and of Ohkuma town in 2020. On the basis of the experiences in Kawauchi, Tomioka and Ohkuma, it is clear that the cooperation of residents, local authorities and specialists is essential for the recovery of areas affected by the accident at the Fukushima Daiichi Nuclear Power Station. Accumulated experiences and practices should be carefully evaluated and recorded to prepare for unexpected nuclear disasters in the future.

Cell competition between anaplastic thyroid cancer and normal thyroid follicular cells exerts reciprocal stress response defining tumor suppressive effects of normal epithelial tissue

The microenvironment of an early-stage tumor, in which a small number of cancer cells is surrounded by a normal counterpart milieu, plays a crucial role in determining the fate of initiated cells. Here, we examined cell competition between anaplastic thyroid cancer cells and normal thyroid follicular cells using co-culture method. Cancer cells were grown until they formed small clusters, to which normal cells were added to create high-density co-culture condition. We found that co-culture with normal cells significantly suppressed the growth of cancer cell clusters through the activation of Akt-Skp2 pathway. In turn, cancer cells triggered apoptosis in the neighboring normal cells through local activation of ERK1/2. A bi-directional cell competition provides a suppressive mechanism of anaplastic thyroid cancer progression. Since the competitive effect was negated by terminal growth arrest caused by radiation exposure to normal cells, modulation of reciprocal stress response in vivo could be an intrinsic mechanism associated with tumor initiation, propagation, and metastasis.

Cellular Mechanism Underlying Highly-Active or Antiretroviral Therapy-Induced Lipodystrophy: Atazanavir, a Protease Inhibitor, Compromises Adipogenic Conversion of Adipose-Derived Stem/Progenitor Cells through Accelerating ER Stress-Mediated Cell Death in Differentiating Adipocytes

Lipodystrophy is a common complication in human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy (HAART) or antiretroviral therapy (ART). Previous studies demonstrated that endoplasmic reticulum (ER) stress-mediated unfolded protein response (UPR) is involved in lipodystrophy; however, the detailed mechanism has not been fully described in human adipogenic cell lineage. We utilized adipose tissue-derived stem cells (ADSCs) obtained from human subcutaneous adipose tissue, and atazanavir (ATV), a protease inhibitor (PI), was administered to ADSCs and ADSCs undergoing adipogenic conversion. Marked repression of adipogenic differentiation was observed when ATV was administered during 10 days of ADSC culture in adipogenic differentiation medium. Although ATV had no effect on ADSCs, it significantly induced apoptosis in differentiating adipocytes. ATV treatment also caused the punctate appearance of CCAAT-enhancer-binding (C/EBP) protein homologous protein (CHOP), and altered expression of CHOP and GRP78/Bip, which are the representation of ER stress, only in differentiating adipocytes. Administration of UPR inhibitors restored adipogenic differentiation, indicating that ER stress-mediated UPR was induced in differentiating adipocytes in the presence of ATV. We also observed autophagy, which was potentiated in differentiating adipocytes by ATV treatment. Thus, adipogenic cell atrophy leads to ATV-induced lipodystrophy, which is mediated by ER stress-mediated UPR and accelerated autophagy, both of which would cause adipogenic apoptosis. As our study demonstrated for the first time that ADSCs are unsusceptible to ATV and its deleterious effects are limited to the differentiating adipocytes, responsible target(s) for ATV-induced lipodystrophy may be protease(s) processing adipogenesis-specific protein(s).

Comparison of artificial tooth position in dentures fabricated by heat curing and additive manufacturing

BACKGROUND

The purpose of this study was to compare the displacement of tooth arrangement in dentures fabricated by additive manufacturing (AM) and heat curing.

METHODS

Three-dimensional (3D) scanning was performed for edentulous jaw models. After the teeth were arranged, 3D scanning for the wax denture was performed. Heat-cured dentures were fabricated with heat-cure polymer resin. Based on data obtained by subtracting the model data from wax denture data, AM dentures were fabricated from ultraviolet-cured acrylic resin. Accuracy was verified by superimposing heat-cured and AM dentures on the tooth region data from the wax dentures and measuring displacement of the tooth arrangement.

RESULTS

In the maxillary dentures, the amount of tooth displacement for the heat-cured dentures and for the AM dentures ranged from -0.08 to +0.06 mm and from -0.25 to +0.06 mm respectively. A significant difference was observed between two dentures. In the mandibular dentures, the amount of tooth displacement for the heat-cured dentures and for the AM dentures ranged from -0.09 to +0.07 mm and from -0.03 to +0.07 mm respectively. No significant difference was observed between two dentures.

CONCLUSIONS

The artificial teeth of the maxillary dentures fabricated by AM showed a greater displacement compared to those by heat curing.

The Clinicopathological Results of Thyroid Cancer With BRAFV600E Mutation in the Young Population of Fukushima

BACKGROUND

Thyroid ultrasound screening for children aged 0 to 18 years was performed in Fukushima following the accident at the Fukushima Daiichi Nuclear Power Plant. As a result, many thyroid cancer cases were detected. To explore the carcinogenic mechanisms of these cancers, we analyzed their clinicopathological and genetic features.

METHODS

We analyzed 138 cases (52 males and 86 females) who had undergone surgery between 2013 and 2016 at Fukushima Medical University Hospital. Postoperative pathological diagnosis revealed 136 (98.6%) cases of papillary thyroid cancer (PTC).

RESULTS

The BRAFV600E mutation was detected using direct DNA sequencing in 96 (69.6%) of the thyroid cancer cases. In addition, oncogenic rearrangements were detected in 23 cases (16.7%). Regarding chromosomal rearrangements, 8 (5.8%) RET/PTC1, 6 (4.3%) ETV6(ex4)/NTRK3, 2 (1.4%) STRN/ALK, and 1 each of RET/PTC3, AFAP1L2/RET, PPFIBP/RET, KIAA1217/RET, ΔRFP/RET, SQSTM1/NTRK3 and TPR/NTRK1 were detected. Tumor size was smaller in the BRAFV600E mutation cases (12.8 ± 6.8 mm) than in wild-type BRAF cases (20.9 ± 10.5 mm). In the BRAFV600E mutation cases, 83 (86.5%) showed lymph node metastasis, whereas 26 (61.9%) of the wild-type BRAF cases showed lymph node metastasis.

CONCLUSIONS

The BRAFV600E mutation was mainly detected in residents of Fukushima, which was different from post-Chernobyl PTC cases with RET/PTC3 rearrangement. PTC with the BRAFV600E mutation was smaller but was shown in the high rate of central cervical lymph node metastasis than the wild-type BRAF PTC in the young population of Fukushima.

Hypothyroidism after radiation exposure: brief narrative review

The thyroid gland is among the organs at the greatest risk of cancer from ionizing radiation. Epidemiological evidence from survivors of radiation therapy, atomic bombing, and the Chernobyl reactor accident, clearly shows that radiation exposure in childhood can cause thyroid cancer and benign thyroid nodules. Radiation exposure also may induce hypothyroidism and autoimmune reactions against the thyroid, but these effects are less well-documented. The literature includes only a few, methodologically weak animal studies regarding genetic/molecular mechanisms underlying hypothyroidism and thyroid autoimmunity after radiation exposure. Rather, evidence about radiation-induced hypothyroidism and thyroid autoimmunity derives mainly from follow-up studies in patients treated with external beam radiotherapy (EBRT) or iodine-131, and from epidemiological studies in the atomic bombing or nuclear accident survivors. Historically, hypothyroidism after external irradiation of the thyroid in adulthood was considered not to develop below a 10-20 Gy dose threshold. Newer data suggest a 10 Gy threshold after EBRT. By contrast, data from patients after iodine-131 "internal radiation therapy" of Graves´ disease indicate that hypothyroidism rarely occurs below thyroid doses of 50 Gy. Studies in children affected by the Chernobyl accident indicate that the dose threshold for hypothyroidism may be considerably lower, 3-5 Gy, aligning with observations in A-bomb survivors exposed as children. The reasons for these dose differences in radiosensitivity are not fully understood. Other important questions about the development of hypothyroidism after radiation exposure e.g., in utero, about the interaction between autoimmunity and hypofunction, and about the different effects of internal and external irradiation still must be answered.

The outcome of ablation for non-paroxysmal atrial fibrillation targeting spatiotemporal electrogram dispersion compared with ganglionated plexi ablation

Background

Although catheter ablation targeting ganglionated plexi (GP) playing an important role in formation of triggers and substrates of atrial fibrillation (AF) has been reported as one of the effective ablation strategies in non-paroxysmal AF (non-PAF) patients, its effectiveness varies among the study groups. More recently, ablation targeting spatiotemporal electrogram dispersion (STED) areas, assumed to contain AF drivers in forms of rotational activation is proposed. However, the optimal ablation strategy for non-PAF is still controversial since the exact mechanisms of non-PAF are not well understood.

Purpose

To investigate the effectiveness of GP ablation for autonomic modification and STED ablation for modulation of AF drivers.

Methods

Consecutive 149 non-PAF patients who underwent STED ablation in our center were enrolled. We detected STED areas within the whole left and right atrium during AF using PentaRay®, and ablated them. If AF was terminated during STED ablation, we finished the procedure without burning the remaining STED areas. If not, electrical cardioversion was applied. The outcome was compared with that in consecutive 156 non-PAF patients undergoing GP ablation previously in our center.

Results

(1) The clinical characteristics were comparable between two groups (see Table). (2) A Kaplan-Meier curve showed that there was no significant difference between the freedom rates from non-PAF/non-paroxysmal atrial tachycardia (non-PAT) after single procedure in STED group and GP group (Figure, left). (3) However, the freedom rates from non-PAT in STED group was significantly lower than that GP group (Figure, right).

Conclusions

The recurrence type of atrial arrhythmia after ablation was remarkably different between ablation of STED and GP. STED ablation might eliminate fibrillatory conduction and control AF driver in patients with non-PAF.

Freedom from atrial arrhythmia

Funding Acknowledgement

Type of funding source: None

Panel of novel urine biomarkers for incident microalbuminuria in people with type 2 diabetes mellitus

AIM

The need to identify novel biomarkers for early diagnosis and treatment of diabetic nephropathy is widely recognized. However, only a few studies have investigated the association between biomarkers and the onset of albuminuria. In this study, we aimed to investigate a panel of biomarkers suitable for predicting microalbuminuria.

METHODS

Some 346 Japanese people with type 2 diabetes exhibiting normoalbuminuria were studied. The endpoint was defined as the onset of microalbuminuria. Thirty biomarkers were selected from among urinary biomarkers described in previous studies. A panel of biomarkers was selected using least absolute shrinkage and selection operator (LASSO). The prognostic performance of the developed panel was evaluated.

RESULTS

During a mean follow-up of 6.2 years, 45 people progressed to microalbuminuria. A composite panel of six biomarkers (monocyte chemoattractant protein-1, osteopontin, soluble human tumour necrosis factor receptor-1, tenascin C, vascular endothelial growth factor-A and kidney injury molecule-1) was developed using LASSO. Compared with the basal model comprising estimated GFR and urinary albumin-to-creatinine ratio, addition of these six biomarkers significantly increased the overall C index from 0.773 to 0.824 (P = 0.019). Net reclassification improvement and integrated discrimination improvement were estimated to be 0.412 (P = 0.049) and 0.040 (P = 0.040), respectively. Decision curve analysis also showed that the model with the six novel biomarkers had a better prognostic value for predicting the onset of microalbuminuria. The optimism was moderate or negligible according to measures.

CONCLUSIONS

The panel consisting of six novel urinary biomarkers effectively predicted incident microalbuminuria in people with type 2 diabetes.

Arterial stiffness could reflect increased cardiac load and reduced pulmonary function in the general population

Background

Pulmonary function is known to decrease with age and reduced pulmonary function has been reported to be associated with all-cause mortality and cardiovascular death. The association between pulmonary impairment and atherosclerosis was reported previously but has not been investigated sufficiently in the general population.

Purpose

We hypothesized that arterial stiffness could reflect increase of cardiac load and reduced pulmonary function. The present study aimed to investigate whether increased cardiac load and reduced pulmonary function could affect arterial stiffness in the general population.

Methods

Subjects undergoing their health check-up were enrolled. Plasma B-type natriuretic peptide (BNP) levels and serum high-sensitivity cardiac troponin I (hs-cTnI) levels were measured to evaluate cardiac load and myocardial damage. Radial augmentation index (rAI) was measured to investigate arterial stiffness using HEM-9000AI device. Subjects with an ST-T segment abnormality on the electrocardiogram, renal insufficiency, cancer, active inflammatory disease, or a history of cardiovascular events and pulmonary disease were excluded. Pulmonary function was assessed using spirometry by calculating forced vital capacity (FVC) as a percentage of predicted value (FVC%-predicted), forced expiratory volume in 1 second (FEV1) as a percentage of predicted value (FEV1%-predicted), and the ratio of FEV1 to FVC (FEV1/FVC).

Results

A total of 1100 subjects aged 57 years were enrolled and their median values of BNP and hs-cTnI were 15.5 and 2.3 pg/ml. The levels of rAI were significantly associated with the levels of BNP after adjustment for possible confounders in multivariate regression analysis, but were not with the levels of hs-TnI. While the parameters of pulmonary function were inversely associated with the levels of rAI and hs-cTnI after adjustment for possible confounders in the multivariate regression analysis, but not with the levels of BNP. The other multivariate regression analyses where BNP, hs-cTnI, parameters of pulmonary function, and the other possible factors were simultaneously included as independent variables revealed that the BNP levels and the FVC%-predicted or FEV1%-predicted, besides age, gender, smoking status, body mass index, blood pressure, heart rate, creatinine, fasting plasma glucose, and triglyceride, were significantly associated with the levels of rAI.

Conclusions

The significant associations of rAI with BNP and pulmonary function were revealed in the general population. These findings support that arterial stiffness could reflect increased cardiac load and reduced pulmonary function, in apparently healthy individuals.

Funding Acknowledgement

Type of funding source: None

Influence of post-disaster evacuation on incidence of hyperuricemia in residents of Fukushima Prefecture: the Fukushima Health Management Survey

Aim

After the Great East Japan Earthquake, over 160,000 residents in Fukushima Prefecture were forced to evacuate the area around the Fukushima Daiichi power plant following nuclear accident there. Health problems in these evacuees have since become a major issue. We have examined the association between evacuation and incidence of hyperuricemia among residents in Fukushima.

Methods

We conducted a cohort study of residents aged 40–90 years without hyperuricemia at the time of the Fukushima disaster. Among 8173 residents who met the inclusion criteria before the disaster, 4789 residents (men: 1971, women: 2818; follow-up duration: 1.38 years; and follow-up rate: 58.6%) remained available for follow-up examinations at the end of March 2013. The main endpoint was incidence of hyperuricemia, defined by the Japanese committee guidelines, using local health data from before and after the disaster. We divided participants by evacuation status and compared outcomes between groups. Using a logistic regression model, we estimated the odds ratio for incidence of hyperuricemia, adjusting for potential confounders, age, gender, waist circumference, physical activity, and alcohol consumption.

Results

Incidence of hyperuricemia was higher in evacuees (men 10.1%; women 1.1%) than in non-evacuees (men 7.4%, women 1.0%). Evacuees had higher body mass index, waist circumference, triglycerides, LDL-cholesterol, fasting plasma glucose, HbA1c, and lower HDL-cholesterol after the disaster than non-evacuees. We found that evacuation was associated with incidence of hyperuricemia (adjusted odds ratio: 1.38; 95% confidence interval: 1.03–1.86).

Conclusion

This is the first study to demonstrate an association between evacuation after a disaster and increased incidence of hyperuricemia.

Factors Influencing the Proportion of Non-examinees in the Fukushima Health Management Survey for Childhood and Adolescent Thyroid Cancer: Results From the Baseline Survey

BACKGROUND

After the Fukushima Daiichi Nuclear Power Plant accident, a preliminary ultrasound-based screening for thyroid cancer was conducted to establish a baseline for subsequent evaluations. In this survey, we assessed the relationship between the proportion of non-examinees and characteristics of the target populations.

METHODS

After summarizing a regional difference of non-examinees among the population of 359,200 (primary evaluation) and 2,246 (confirmatory testing) individuals who were living in Fukushima Prefecture on March 11, 2011, we estimated odds ratios (ORs) for each characteristic, including age, sex, area of residence, and moving after the accident, based on the proportion of non-examinees for the primary examination and the confirmatory testing, using a multivariate logistic regression model.

RESULTS

The dataset included 64,117 non-examinees (primary evaluation) and 194 (confirmatory testing). The logistic regression result indicated that girls were not likely to be non-examinees compared to boys, with adjusted OR of 0.80 (95% confidence interval [CI], 0.78-0.81) for the primary evaluation. Odds were lowest for children 6-10 years old (OR 0.26; 95% CI, 0.25-0.27), and higher for those 11-15 years old (OR 1.28; 95% CI, 1.25-1.32) and over 16 years old (OR 5.30; 95% CI, 5.16-5.43) when compared to children 0-5 years old. Individuals residing in the western part of the prefecture showed higher ORs. There was a higher proportion of non-examinees among those who moved after the accident compared to those who did not in the primary evaluation (OR 1.72; 95% CI, 1.64-1.79).

CONCLUSIONS

In addition to demographic characteristics, a change of residence could be a potential factor that influenced the proportion of non-examinees. Our results will help proper interpretation of reports and prospective management of the survey.

"Living in Contaminated Areas"-Consideration of Different Perspectives

Following large-scale nuclear power plant accidents such as those that occurred at Chernobyl (Ukraine) in 1986 and Fukushima Daiichi (Japan) in 2011, large populations are living in areas containing residual amounts of radioactivity. As a key session of the ConRad conference, experts were invited from different disciplines to provide state-of-the-art information on the topic of "living in contaminated areas." These experts provided their different perspectives on a range of topics including radiation protection principles and dose criteria, environmental measurements and dose estimation, maintaining decent living and working conditions, evidence of health risks, and social impact and risk communication. A short summary of these different perspectives is provided in this paper.

Determination of the Kinetic Parameters for 123I Uptake by the Thyroid, Thyroid Weights, and Thyroid Volumes in Present-day Healthy Japanese Volunteers

The purpose of this study was to evaluate the kinetic parameters that determine the uptake rate of radioiodide in the thyroid over 24 h after administration and to estimate thyroid volumes/masses of present-day Japanese. Methods: We determined the thyroid uptake rate of I in healthy male Japanese after oral administration (4.5-8.0 MBq) without iodine restriction. Masses of thyroid glands were collected in 2012-2016 during autopsies of 7,651 male and 3,331 female subjects. Volumes of thyroid glands were estimated by ultrasonography and magnetic resonance imaging in 52 male subjects. Results: The thyroid uptake rate of I for 24 h was 16.1 ± 5.4%. Kinetic model analysis was conducted to obtain the clearances (L h) for thyroid uptake and urinary excretion of I (0.499 ± 0.258 and 2.10 ± 0.39 L h, respectively). The masses of thyroid glands were on average 19.8 g (95% confidence interval of 18.3-19.5 g) and 15.5 g (95% confidence interval of 14.7-16.2 g) in male and female subjects aged 19-52 y, respectively. Volumes of thyroid glands estimated by ultrasonography and magnetic resonance imaging were 17.5 ± 5.2 and 14.2 ± 5.3 mL, respectively. In healthy Japanese, there has been no significant change for at least 50 y in the thyroid uptake of radioiodide over 24 h or in its kinetic parameters. These Japanese-specific kinetic parameters will allow quantitative estimation of the radiation exposure from the Fukushima accident and its variance during the individual's evacuation from or stay in Fukushima.

The Contribution of Genetic Variants to the Risk of Papillary Thyroid Carcinoma in the Kazakh Population: Study of Common Single Nucleotide Polymorphisms and Their Clinicopathological Correlations

OBJECTIVE

Risk for developing papillary thyroid carcinoma (PTC), the most common endocrine malignancy, is thought to be mediated by lifestyle, environmental exposures and genetic factors. Recent progress in the genome-wide association studies of thyroid cancer leads to the identification of several genetic variants conferring risk to this malignancy across different ethnicities. We set out to elucidate the impact of selected single nucleotide polymorphisms (SNPs) on PTC risk and to evaluate clinicopathological correlations of these genetic variants in the Kazakh population for the first time.

METHODS

Eight SNPs were genotyped in 485 patients with PTC and 1,008 healthy control Kazakh subjects. The association analysis and multivariable modeling of PTC risk by the genetic factors, supplemented with rigorous statistical validation, were performed.

RESULT

Five of the eight SNPs: rs965513 (FOXE1/PTCSC2, P = 1.3E-16), rs1867277 (FOXE1 5'UTR, P = 7.5E-06), rs2439302 (NRG1 intron 1, P = 4.0E-05), rs944289 (PTCSC3/NKX2-1, P = 4.5E-06) and rs10136427 (BATF upstream, P = 9.8E-03) were significantly associated with PTC. rs966423 (DIRC3, P = 0.07) showed a suggestive association. rs7267944 (DHX35) was associated with PTC risk in males (P = 0.02), rs1867277 (FOXE1) conferred the higher risk in subjects older than 55 years (P = 7.0E-05), and rs6983267 (POU5F1B/CCAT2) was associated with pT3-T4 tumors (P = 0.01). The contribution of genetic component (unidirectional independent effects of rs965513, rs944289, rs2439302 and rs10136427 adjusted for age and sex) to PTC risk in the analyzed series was estimated to be 30-40%.

CONCLUSION

Genetic factors analyzed in the present work display significant association signals with PTC either on the whole group analysis or in particular clinicopathological groups and account for about one-third of the risk for PTC in the Kazakh population.

Incidence of Thyroid Cancer Among Children and Young Adults in Fukushima, Japan, Screened With 2 Rounds of Ultrasonography Within 5 Years of the 2011 Fukushima Daiichi Nuclear Power Station Accident

Importance

Ultrasonographic (US) screening for thyroid cancer was performed in the Fukushima Health Management Survey after the 2011 Fukushima Daiichi nuclear power station accident. Clinical characteristics of thyroid cancers screened by US among children and young adults during the first 5 years after the accident were analyzed.

Objectives

To evaluate the number of detected thyroid cancers by age group within 5 years of the Fukushima Daiichi nuclear power station accident and to compare the basic clinical characteristics and demographic patterns in first- and second-round examinations.

Design, Setting, and Participants

In this observational study, 324 301 individuals 18 years or younger at the time of accident were included. Patients received a cytologic diagnosis of malignant or suspected malignant thyroid cancer during the first (fiscal years 2011-2013) or second round (fiscal years 2014-2015) of screening. Number of detected cases of cancer was evaluated, correcting for the number of examinees by age group at the time of the accident and for the incidence of detected cancers according to age group at the time of the screening (age groups were divided into 3-year intervals). Results were compared using the age-specific incidence of unscreened cancers from a national cancer registry.

Main Outcomes and Measures

Clinical baseline characteristics of the patients and the age-specific number and incidence of thyroid cancers detected during the second round.

Results

Among 299 905 individuals screened in the first round (50.5% male; mean [SD] age at screening, 14.9 [2.6] years), malignant or suspected thyroid cancer was diagnosed in 116. Among 271 083 individuals screened in the second round (50.4% male; age at screening, 12.6 [3.2] years), malignant or suspected thyroid cancer was diagnosed in 71. The most common pathologic diagnosis in surgical cases was papillary thyroid cancer (149 of 152 [98.0%]). The distribution pattern by age group at the time of the accident, where the number of detected thyroid cancer cases was corrected by the number of examinees, increased with older age in both screening rounds. This demographic pattern was similar between the first and second examinations. The distribution pattern of the incidence rate by age group at the time of screening in the second round also increased with older age. The incidence rate detected by screening was 29 cases per 100 000 person-years for those aged 15 to 17 years, 48 cases per 100 000 person-years for those aged 18 to 20 years, and 64 cases per 100 000 person-years for those aged 21 to 22 years.

Conclusions and Relevance

Large-scale mass US screening of young people resulted in the diagnosis of a number of thyroid cancers, with no major changes in overall characteristics within 5 years of the 2011 Fukushima nuclear power station accident. These results suggest that US screening can identify many detectable cancers from a large pool of nonclinical and subclinical thyroid cancers among individuals of a relatively young age, in an age-dependent manner.

Childhood leukemia in Ukraine after the Chornobyl accident

This population-based ecological study analyzes the prevalence of childhood leukemia in Ukraine before and after the Chornobyl nuclear power plant accident, based on the contamination status of the territory, time period, gender, and age. Three regions-Zhytomyr, Kyiv (except Kyiv city), and Chernihiv were included as areas contaminated by radioactive ¹³⁷Cs from 1 to 15 Ci/km² with annual effective doses exceeding 1.0 mSv, and Sumy region as the control (non-contaminated) area with ¹³⁷Cs contamination less than 1 Ci/km² and effective doses less than 0.5 mSv per year. The integrated database of the National Research Centre for Radiation Medicine used in the present study included 1085 childhood leukemia cases. Two aggregated periods were used for analysis: 1980-1986 (pre-accident) and 1987-2000 (post-accident). ICD-9 codes for leukemia (204-208.9) were used to perform analyses according to the extent of leukemic cells maturity (acute, chronic, and maturity unspecified leukemia), leukemic cell lineage (lymphoid, myeloid and lineage unspecified leukemia) and all leukemia cases in different age subgroups (1-4, 5-9, 10-14, and 15-19 years). Standard methods of descriptive epidemiology were used to calculate the prevalence of disease and frequency ratio in regression models. A statistically significant increase in frequency ratio for acute leukemia (1.44; 95% confidence interval (CI), 1.22-1.71), myeloid leukemia (2.93; 95% CI, 1.71-5.40), cell lineage unspecified leukemia (II) (1.48; 95% CI, 1.18-1.87) and all forms of leukemia (1.59; 95% CI, 1.36-1.86) was found for the post-accident period in highly contaminated areas. The results indicate that the frequency of childhood leukemia (and of some of its types) increased in contaminated areas during the post-accident period, suggesting that radiation exposure after the Chornobyl accident might be the cause of the increase. However, further analytical studies, with individual or at least group dose estimates, are needed to confirm a link between childhood leukemia and the Chornobyl accident.

Thyroid Cancer after Exposure to Radioiodine in Childhood and Adolescence: 131I-Related Risk and the Role of Selected Host and Environmental Factors

In this study, we expanded on a previously published population-based case-control study on subjects exposed to iodine-131 (131I) from Chernobyl fallout at age ≤18 years using improved individual 131I absorbed thyroid doses. We further studied the impact of iodine deficiency and other selected host risk factors on 131I-related thyroid cancer risk after childhood exposure. We included 298 thyroid cancer cases and 1934 matched controls from the most contaminated regions of Belarus and the Russian Federation. We performed statistical analysis using conditional logistic regression models. We found a statistically significant linear quadratic dose-effect association between thyroid cancer and 131I thyroid dose in the range up to 5 grays (Gy). Self-reported personal history of benign nodules, any thyroid disease except thyroid cancer, family history of thyroid cancer, increased body mass index, and deficient stable iodine status at the time of the accident were statistically significant risk factors (p < 0.05 for each factor) for thyroid cancer after adjustment for thyroid 131I dose effect. Subjects who received stable iodine supplementation in the years after the accident had a significantly lower 131I-related risk of thyroid cancer. Our findings are important for thyroid cancer prevention, and for further improvement of medical surveillance in the affected populations.