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We examined the transcriptome/post-transcriptome for persistent gene expression changes after radiation exposure in a baboon model. Eighteen baboons were irradiated with a whole body equivalent dose of 2.5 or 5 Gy. Blood samples were taken before, 7, 28 and 75–106 days after radiation exposure. Stage I was a whole genome screening for mRNA combined with a qRT-PCR platform for detection of 667 miRNAs. Candidate mRNAs and miRNAs differentially up- or down-regulated in stage I were chosen for validation in stage II using the remaining samples. Only 12 of 32 candidate genes provided analyzable results with two mRNAs showing significant 3–5-fold differences in gene expression over the reference (p < 0.0001). From 667 candidate miRNAs, 290 miRNA were eligible for analysis with 21 miRNAs independently validated using qRT-PCR. These miRNAs showed persistent expression changes on each day and over days 7–106 days after exposure (n = 7). In particular miR-212 involved in radiosensitivity and immune modulation appeared persistently and 48–77-fold up-regulated over the entire time period. We are finally trying to put our results into a context of clinical implications and provide possible hints on underlying molecular mechanisms to be examined in future studies.

The physiological parameters needed for estimating the activity of tritium taken into the body from various tritiated environments are well established experimentally. Less certain is the relation of dose equivalent rate to body burden. A quality factor of unity appears reasonable. For chronic exposures to tritium, isotopic concentrations effects and transmutation effects are unimportant. The choice of body water as the critical organ is conservative since no tissue has a higher proportion of hydrogen. Recommended limiting levels for tritium in drinking water, in air, and in food are also conservative. For acute exposures, the main problem is estimating the dose equivalent from tritium bound to tissue components. One general analysis suggests an upper limit for this of 25% of the dose equivalent from tritium in body water.

This study aimed to investigate body physical parameters as substitutes for water equivalent diameter (Dw) while calculating size-specific dose estimates (SSDEs) during adult chest computed tomography (CT). A retrospective analysis was conducted on 776 patients. Patients were divided into training set (542 patients) and validation set (234 patients) according to a ratio of 7:3. The correlations between physical parameters and Dw were analyzed. The differences between SSDE substitutes and the reference SSDE (SSDE reference ) were compared. Strong positive correlations were observed between body mass index (BMI) and Dw as well as between weight and Dw in overall, male, and female patients (all p  < 0.001). The correlations between BMI and Dw were stronger than those between weight and Dw in overall, male, and female subjects (all p  < 0.001). SSDE weight and SSDE BMI were not significantly different from SSDE reference ( p  > 0.05). The RMSEs of overall patients between SSDE weight and SSDE reference as well as between SSDE BMI and SSDE reference were 0.237 and 0.2, respectively. The use of sex-specific regression equations for BMI caused a slightly reduction in RMSE. Weight and BMI can be used as surrogate parameters for Dw when calculating SSDE in adult chest CT exams, with BMI being the preferred substitute parameter.

Tree shrew (Tupaia belangeri) is a promising experimental animal in biomedical research, but the equivalent doses of drugs between tree shrew and human and other animals has not been explored, which hinders its further application in a wider scope. The main objective of this article is to provide a method of equivalent dose conversion between tree shrews and other species based on body surface area (BSA). BSA of tree shrews were measured by Image J software, and then the average Km value of tree shrews was figured out based on the body weights and BSA, then the conversion coefficients of equivalent dose among tree shrew and other species of experimental animals were calculated based known data. The Km value of tree shrews was 0.105±0.001. Through BSA conversion, the equivalent dose for tree shrews (D-ts) relative to rats was obtained by formula: D-ts = 1.36×D-a (rats weighing 200g as example), and the error was less than 10% when the BW of the tree shrew was 0.09 kg–0.15 kg. The coefficients of equivalent dose transferring from tree shrews to human and other species were calculated in article. These parameters could be used to determine a suitable dosing strategy for tree shrew studies.

The study aimed to compute the effective dose (E) and size-specific dose estimate (SSDE) of routine adult patients undergoing thorax and abdominal computed tomography (CT) imaging and to present their multivariate analysis. All adult thorax and abdominal CT examinations conducted from March 2022 to June 2022 were prospectively included in this study. The Water Equivalent Diameter (Dw) and SSDE of all the examinations were computed from CT dose index volume (CTDIvol) and Dose length product (DLP) displayed on the dose report in the CT console. The multivariate statistical analysis was performed to investigate the correlation of SSDE and E on CTDIvol, Dw area of the region of interest (ROI) (AreaROI), body mass index (BMI), conversion factor (fsize) and hounsfield (HUmean) number in the ROI at 95% level of significance (P < 0.05). The linear regression analysis was performed to investigate the dependence of SSDE and E on other parameters for both abdominal and thorax patients. A total number of 135 (Abdomen = 61 and Thorax = 74) measurements were performed. The mean value of effective dose for abdomen and thorax patients was found to be 7.17 ± 3.94 and 4.89 ± 2.16 mSv, respectively. The SSDE was observed to be 13.24 ± 3.61 and 13.04 ± 3.61 mGy for thorax and abdomen respectively. The multivariate analysis suggests that SSDE for abdominal CT is found significantly dependent on CTDIvol, Dw and fsize with P < 0.05 and E is found to be significantly dependent on DLP, AreaROI, Dw and fsize at 95% level of confidence for abdominal CT imaging. SSDE for thorax CT was found significantly dependent on BMI, CTDIvol, HUmean, Dw and fsize at 95% level of confidence. Furthermore, E was observed dependent on DLP at P < 0.05. The linear regression analysis also shows that E is strongly correlated with DLP (r = 1.0) for both thorax and abdominal CT, further the SSDE was observed strongly correlated with CTDIvol with r = 0.79 and r = 0.86 for abdomen and thorax CT respectively. A strong correlation was observed between BMI and for Dw abdominal CT imaging (r = 0.68). The mean value of SSDE for thorax is slightly greater than abdomen. The average value of effective dose for abdomen and thorax measurements was found to be 7.17 ± 3.94 and 4.89 ± 2.16 mSv and , correspondingly. SSDE for both abdomen and thorax CT is significantly dependent on CTDIvol, Dw and fsize at 95% level of confidence. The strong correlation was also observed E on DLP and SSDE on CTDIvol for both Abdomen and Thorax CT. The strong dependence of Dw on BMI (r = 0.68) is due to the excessive fat concentration around the stomach and abdomen.

INTRODUCTION:Excess weight is an established risk factor of colorectal cancer (CRC). However, evidence is lacking on how its impact varies by polygenic risk at different stages of colorectal carcinogenesis.METHODS:We assessed the individual and joint associations of body mass index (BMI) and polygenic risk scores (PRSs) with findings of colorectal neoplasms among 4,784 participants of screening colonoscopy. Adjusted odds ratios (aORs) for excess weight derived by multiple logistic regression were converted to genetic risk equivalents (GREs) to quantify the impact of excess weight compared with genetic predisposition.RESULTS:Overweight and obesity (BMI 25-<30 and ≥30 kg/m2) were associated with increased risk of any colorectal neoplasm (aOR [95% confidence interval, CI] 1.26 [1.09-1.45] and 1.47 [1.24-1.75]). Obesity was associated with increased risk of advanced colorectal neoplasm (aOR [95% CI] 1.46 [1.16-1.84]). Dose-response relationships were seen for the PRS (stronger for advanced neoplasms than any neoplasms), with no interaction with BMI, suggesting multiplicative effects of both factors. Obese participants with a PRS in the highest tertile had a 2.3-fold (95% CI 1.7-3.1) and 2.9-fold (95% CI 1.9-4.3) increased risk of any colorectal neoplasm and advanced colorectal neoplasm, respectively. The aOR of obesity translated into a GRE of 38, meaning that its impact was estimated to be equivalent to the risk caused by 38 percentiles higher PRS for colorectal neoplasm.DISCUSSION:Excess weight and polygenic risk are associated with increased risk of colorectal neoplasms in a multiplicative manner. Maintaining normal weight is estimated to have an equivalent effect as having 38 percentiles lower PRS.

Background Cardiovascular-kidney-metabolic (CKM) syndrome has become a major global health burden, while physical activity, as an important lifestyle intervention, remains unclear regarding its protective effects on disease risk across different CKM stages. Methods We utilized data from the China Health and Retirement Longitudinal Study (CHARLS), including 7,159 participants. According to the quartile distribution of total weekly metabolic equivalents, all participants were divided into four groups: Q1 group (≤ 1732.5 MET-min/week, reference group), Q2 group (1732.6–4158.0 MET-min/week), Q3 group (4158.1–9744.0 MET-min/week), and Q4 group (> 9744.0 MET-min/week). For CKM analysis, participants were categorized into two groups: low-risk CKM (stages 0–2) and high-risk CKM (stages 3–4), with high-risk CKM progression defined as the risk of being in stages 3–4 versus stages 0–2. We employed three progressively adjusted logistic regression models to assess the associations between physical activity metabolic equivalents and outcomes of heart disease, stroke, diabetes, cardiovascular disease (CVD), cardiometabolic disease (CMD), and cardiometabolic multimorbidity (CMM). Dose-response relationships were evaluated using restricted cubic spline functions, and subgroup analyses and receiver operating characteristic (ROC) curve assessments were conducted to evaluate predictive performance. Results In the fully adjusted model, compared to Q1, Q4 was significantly associated with reduced risks of heart disease (OR = 0.760, 95%CI: 0.631–0.912), stroke (OR = 0.571, 95%CI: 0.376–0.850), diabetes (OR = 0.701, 95%CI: 0.551–0.888), CVD (OR = 0.741, 95%CI: 0.621–0.883), CMD (OR = 0.728, 95%CI: 0.621–0.853), and CMM (OR = 0.529, 95%CI: 0.360–0.762). Similarly, for high-risk CKM progression, the Q4 group demonstrated significant protective effects with a 27.5% risk reduction (OR = 0.725, 95%CI: 0.617–0.850, P  < 0.001), while Q2 and Q3 groups showed no significant associations. Dose-response analysis revealed significant linear relationships for all diseases (P overall < 0.05). Subgroup analyses identified age, gender, and residence as significant effect modifiers, with greater health benefits observed among elderly individuals, males, and urban residents. ROC analysis showed good predictive performance with area under the curve (AUC) values exceeding 0.7 for all diseases, with CMM showing the highest predictive effect (AUC: 0.827). Conclusions Among CKM stage 0–4 populations, high-level physical activity provides significant protective effects against cardiovascular and metabolic diseases. This highlights the important role of physical activity intervention in the prevention of these diseases.

Background Musculoskeletal disease (MSD) is a major cause of disability among older adults, and understanding the role of physical activity (PA) in preventing these conditions is crucial. This study aimed to explore the association between PA levels and MSD risk among adults aged 45 and above, clarify the dose‒response relationship, and provide tailored guidelines. Methods Using data from the China Health and Retirement Longitudinal Study (CHARLS), a cross-sectional analysis was conducted on 15,909 adults aged 45 and over. The study population was divided into MSD ( n  = 7014) and nMSD ( n  = 8895) groups based on musculoskeletal health status. PA levels were assessed using the International Physical Activity Questionnaire and categorized into low intensity physical activity (LIPA), moderate vigorous physical activity (MVPA), and vigorous physical activity (VPA). Multivariable logistic regression models and restricted cubic spline regression were used to examine the relationship between PA levels and MSD risk in middle-aged and older adults. Sensitivity analyses and stratified analyses were also performed. Results The main outcome measures were musculoskeletal diseases prevalence and PA levels. MVPA and VPA reduced MSD risk by 19% [ OR = 0.81 , 95% CI ( 0.72 , 0.90 ), P  < 0.001] and 12% [ OR = 0.88 , 95% CI ( 0.79 , 0.98 ), P  < 0.05], respectively. What’s more, after adjusting for confounding factors, VPA increased risk by 32% [ OR = 1.32 , 95% CI ( 1.04 , 1.66 ), P  < 0.05]. The relationship was nonlinear, showing a U-shaped pattern with age and hypertension status as significant moderators. The optimal PA energy expenditure was identified as approximately 1500 metabolic equivalents of tasks (METs) per week for adults aged 45–74, 1400 METs per week for those aged 75 and above, and 1600 METs per week for hypertensive adults aged 45 and older. Conclusions For adults aged 45 years and older, VPA significantly increases the risk of MSD. Adults aged 45 years and older should adjust their weekly METs based on their age. Additionally, those with hypertension should moderately increase their weekly METs to promote optimal musculoskeletal health.

Background Re-irradiation (re-RT) is a technically challenging task for which few standardized approaches exist. This is in part due to the lack of a common platform to assess dose tolerance in relation to toxicity in the re-RT setting. To better address this knowledge gap and provide new tools for studying and developing thresholds for re-RT, we developed a novel algorithm that allows for anatomically accurate three-dimensional mapping of composite biological effective dose (BED) distributions from nominal doses (Gy). Methods The algorithm was designed to automatically convert nominal dose from prior treatment plans to corresponding BED value maps (voxel size 2.5 mm 3 and α/β of 3 for normal tissue, BED 3 ). Following the conversion of each plan to a BED 3 dose distribution, deformable registration was used to create a summed composite re-irradiation BED 3 plan for each patient who received two treatments. A proof-of-principle analysis was performed on 38 re-irradiation cases of initial stereotactic ablative radiotherapy (SABR) followed by either re-SABR or chemoradiation for isolated locoregional recurrence of early-stage non-small cell lung cancer. Results Evaluation of the algorithm-generated maps revealed appropriate conversion of physical dose to BED at each voxel. Of 14 patients receiving repeat SABR, there was one case each of grade 3 chest wall pain (7%), pneumonitis (7%), and dyspnea (7%). Of 24 patients undergoing repeat fractionated radiotherapy, grade 3 events were limited to two cases each of pneumonitis and dyspnea (8%). Composite BED 3 dosimetry for each patient who experienced grade 2–3 events is provided and may help guide development of precise cumulative dose thresholds for organs at risk in the re-RT setting. Conclusions This novel algorithm successfully created a voxel-by-voxel composite treatment plan using BED values. This approach may be used to more precisely examine dosimetric predictors of toxicities and to establish more accurate normal tissue constraints for re-irradiation.

Purpose To determine the thickness of a soft variable shape tungsten rubber (STR) as a lung compensating filter in total body irradiation. Methods A tough water (TW) phantom and tough lung (TL) phantom were used as water and lung‐equivalent phantoms. The TW with a thickness of 3 cm simulating the thoracic wall was used (upper layer). The TW or TL with a thickness from 1 to 15 cm (1 cm increments) was placed beneath the upper layer (middle layer). The TW with a thickness of 5 cm simulating the mediastinum was placed beneath the middle layer (lower layer), and a farmer ionization chamber was placed beneath this layer. The relative doses of a 10 MV X‐rays were then measured. The TL was compensated in 1 mm increments from 1 to 11 mm of the STR, and the thickness of the STR at the same dose of TW (water equivalent) was obtained. Results The compensating ability of STR increased as the thickness of the TL increased, and an STR with a thickness of 1 mm reduced the dose by 2%–4%, depending on the thickness of lung. The STR thickness as an equivalent dose of TW per cm of TL was approximately linear, and the thickness was 0.62 mm/cm of TL. Conclusion The STR can be used as a lung compensating filter for a water equivalent dose with 0.62 mm of STR per cm of lung.