Benchmark Dose Estimation for Cadmium-Induced Renal Effects Based on a Large Sample Population from Five Chinese Provinces

A survey involving 6103 participants from five Chinese provinces was conducted to evaluate the threshold value of urinary cadmium （UCd） for renal dysfunction as benchmark dose low （BMDL）. The urinary N-acetyl-13-D-glucosaminidase （UNAG） was chosen as an effect biomarker. The UCd BMDLs for UNAG ranged from 2.18μg/g creatinine （cr） to 4.26μg/g cr in the populations of different provinces. The selection of the sample population and area affect the evaluation of the BMDL. The reference level of UCd for renal effects was further evaluated based on the data of all 6103 subjects. With benchmark responses （BMR） of 10%/5%, the overall UCd BMDLs for males in the total population were 3.73/2.08 μg/g cr. The BMD was slightly lower in females, thereby indicating that females may be relatively more sensitive to Cd exposure than are males.

Meso-scale Discovery Assay Detects the Changes of Plasma Cytokine Levels in Mice after Low or High LET Ionizing Irradiation

Objective To obtain precise data on the changes in the levels of 29 cytokines in mice after high or low linear energy transfer(LET)irradiation and to develop an accurate model of radiation exposure based on the cytokine levels after irradiation.Methods Plasma samples harvested from mice at different time points after carbon-ion or X-ray irradiation were analyzed using meso-scale discovery(MSD),a high-throughput and sensitive electrochemiluminescence measurement technique.Dose estimation equations were set up using multiple linear regression analysis.Results The relative levels of IL-6 at 1 h,IL-5 and IL-6 at 24 h,and IL-5,IL-6 and IL-15 at 7 d after irradiation with two intensities increased dose-dependently.The minimum measured levels of IL-5,IL-6 and IL-15 were up to 4.0076 pg/mL,16.4538 pg/mL and 0.4150 pg/mL,respectively.In addition,dose estimation models were established and verified.Conclusions The MSD assay can provide more accurate data regarding the changes in the levels of the cytokines IL-5,IL-6 and IL-15.These cytokines could meet the essential criteria for radiosensitive biomarkers and can be used as radiation indicators.Our prediction models can conveniently and accurately estimate the exposure dose in irradiated organism.

Assessment of ESAK and ED for Adult’s Patients Examined by Computed Radiography

This study designed to evaluate the entrance surface air kerma (ESAK) to the patient during X-ray examination to the skull antero-posterior (AP), skull Lateral (LAT), chest postero-anterior (PA), Lumber spine AP/LAT and Pelvis AP. Totally, 408 patients were included in this study using computed radiography (CR) in different three hospitals in Khartoum;five X-ray machines were covered. The entrance surface air kerma (ESAK) was calculated for each patient from the exposure parameters using different peak tube voltages. Patient’s data such as (age and weight) and exposure parameters (kVp) and (mAs) were recorded. The result obtained showed that, the entrance surface air kerma ranged from 0.88 to 3.30 mGy for Skull (AP), 0.588 to 1.87 mGy for skull (LAT), 0.03 to 2 mGy for chest PA, 1.50 to 3.40 mGy Lumbar spine AP, 2.60 to 5.15 mGy for Lumbar spine (LAT), and 1.05 to 4.40 mGy for Pelvis. This study provides additional data that can help the regulatory authority to establish reference dose level for diagnostic radiology in Sudan. This study recommends that the CR operator must be used to optimize the patient dose by using the best strategies available for reducing radiation dose. Computed radiography must be used with high level training for medical staff to reduce the dose;each radiology department should implement a patient dose measurement quality assurance programme. Doses to the patients should be regularly monitored and the proposed national DRLs should be taken as guidance for optimization.