Average Exposure Dose Research Articles

An agent-based study on the airborne transmission risk of infectious disease in a fever clinic during COVID-19 pandemic

Prevention of nosocomial infections is particularly important for the control of COVID-19 pandemic. We conducted a field study and performed extensive numerical simulations of infection transmission in a fever clinic during pandemic through an agent-based model with pedestrian dynamic and an infection transmission model. Furthermore, we evaluated the cross-infection risk of the patients influenced by the patient inject flow, medical service capability and plane layout. The service capability of fever clinic is determined by the least efficient medical session. When patient inject flow exceeded the service capability, the average dwell time, contact time, exposure dose, and risk of infection of patients all increased dramatically. With the patient inject flow exceeding the service capability, the growth rate of the contact time between patients and the cross-infection risk increased by 11.5-fold and 29.5-fold, respectively. The plane layout of the fever clinic affected the exposure dose and risk of infection. The waiting areas in the fever clinic had the highest risk, where the cumulative exposure dose of virus occupied up to 66.5% of the total. Our research will help to evaluate the biosafety of hospital buildings used for the diagnosis and treatment of infectious diseases.

Physiologically based kinetic model for assessing intermittent chronic internal exposure to chemicals: Application for disinfection by-products in swimming pool water

Chronic exposure to disinfection by-products (DBPs) via swimming in chlorinated pools can damage the genetic material and even cause cancers in humans. To assess the intermittent chronic internal exposure to DBPs in swimming pool water, a physiologically based kinetic (PBK) modeling framework was introduced to simulate daily average internal exposure doses of DBPs that can be linked to the corresponding daily average external doses. Biotransfer factor (BTF), i.e., the steady-state concentration ratio between human bodies and swimming pool water, was applied to measure the bioaccumulation potential of chemicals in organs and tissues. The results simulated for the four selected trihalomethanes (THMs) (i.e., chloroform, bromoform, dibromochloromethane, and bromodichloromethane) showed that lungs had the highest simulated BTF among human organs and tissues, with the inhalation route showing the maximum contribution to the overall external dose. In addition, route-specific analysis indicated that chronic internal exposure doses of THMs via oral and dermal routes were negligible compared to the inhalation route. Theoretical simulation using the dissipation coefficient of THMs in the air can help optimize the design and operation of swimming pools to substantially reduce chronic internal exposure doses of THMs. The simulated results for time-dependent chloroform concentration in human blood agreed with the reported data and can be further improved once more information about the THM concentrations in breathing zones of swimmers is obtained, indicating that the proposed model can be used as a practical tool to assess intermittent chronic internal exposure of THMs in swimming pool water. In future studies, human exposure to THMs via other pathways (e.g., drinking water, showering, and bathing) can be incorporated into the proposed model to comprehensively evaluate the internal exposure doses of THMs in humans.

When giants talk; robotic dialog during thoracolumbar and sacral surgery

BackgroundSpinal trauma patients treated in a specialized hybrid operating room (OR) using two robotic systems communicating during surgery.MethodsRetrospective review of patients with thoracolumbar or sacral fractures who underwent surgical fixation between Jan 2017 to Jan 2020 with robotic-guided percutaneous pedicle screw insertion in the specialized hybrid OR with Robotic flat panel 3D C-arm (ArtisZeego) for intraoperative interventional imaging connected with the robotic-guidance platform Renaissance (Mazor Robotics).ResultsTwenty eight surgeries were performed in 27 patients; 23 with traumatic spinal fractures, 4 with multi-level thoracolumbar compression fractures due to severe osteoporosis. Average patient age 49 (range 12–86). Average radiation exposure time 40 s (range 12–114 s). Average radiation exposure dose 11,584 ± SD uGym2 (range 4454–58,959). Lumber levels operated on were between T5 and S2 (shortest three vertebras and longest eight vertebras). 235 (range 5–11) trajectories were performed. All trajectories were accurate in all cases percutaneous pedicle screws placement was correct, without breach noted at the pedicle in any of the cases. No major complications reported. In all cases, follow-up X-rays showed adequate fracture reduction with restoration.ConclusionsMerging of surgical robotics technologies increases patient safety and surgeon and patient confidence in percutaneous spine traumatic procedures.

Pregnancy and neonatal outcomes after periconceptional exposure to isotretinoin in Koreans.

ObjectiveIsotretinoin should not be used during pregnancy because of the risk of birth defects. Most pregnant women exposed to isotretinoin choose voluntary pregnancy termination due to concerns about birth defects. However, birth outcome data supporting the termination of pregnancy are lacking. This study aimed to evaluate pregnancy and neonatal outcomes after periconception exposure to isotretinoin.MethodsThis was a prospective cohort study. We evaluated pregnancy and neonatal outcomes after exposure to isotretinoin in 151 pregnant women. Among 1,026 callers at the Korean Teratology Information Service from 2001 to 2017 exposed to isotretinoin during the periconception period, 151 pregnant women who received counseling on teratogenic risk after visiting the clinic were included.ResultsAmong the 151 participants who visited the clinic, only 42 were evaluated using ultrasonography until approximately 20 weeks of gestation. Ultimately, 23 patients were included in the study. The average gestation period during the last exposure to the drug was 2 weeks, and the average daily exposure dose was 12 mg. There were two cases of major birth defects in the exposure group. Spontaneous abortion rates were 17.7% and 8.7% in the exposure and non-exposure groups, respectively (P=0.035). There was no significant difference between the exposure and non-exposure groups in terms of pregnancy and neonatal outcomes.ConclusionThere was no significant difference in pregnancy and neonatal outcomes, including birth defects, between the exposure and non-exposure groups. Further studies with larger sample sizes are required to validate our findings.

Level of contamination with deoxynivalenol, zearalenone and fumonisins in cereal products - assessment of consumer exposure.

The main aim of this study was to determine the content of mycotoxins, such as: deoxynivalenol (DON), zearalenone (ZEA) and fumonisins (FUM) in cereal products, and such products intended for infants. The secondary objective was to assess consumer exposure to the DON, ZEA and FUM occurring in cereal products, including those intended for infants and young children. The study included cereals and cereal products such as flours, grits, pastas, products of the bakery industry, snacks and cereal products intended for infants and young children, available in retail outlets in the Małopolska Province of Poland. DON content was determined by high-performance liquid chromatography with a DAD detector, while the contents of ZEA and FUM were detected by high-performance liquid chromatography with fluorescence detection. The determined concentration of mycotoxins exceeded the maximum level specified in food law in only two cases. DON level in maize flour was 1511.0 μg kg-1 and exceeded the maximal residue level (MRL) set at 750.0 μg kg-1. The value of MRL for ZEA was over the permissible value of 75.0 μg kg-1 in the maize flour sample only, and was 212.0 μg kg-1. None of the samples examined was beyond the permissible level of FUM. Levels higher than those permissible for the examined cereal products were noted in only two cases. FUMs were the most commonly found Fusarium mycotoxins, followed by DON and ZEA. The mean exposure doses of the assessed mycotoxins, resulting from the consumption of cereal products in the selected populations, were at low levels (reaching a maximum of 6.81%) and did not exceed the tolerable daily intake (TDI) or provisional maximum tolerable daily intake (PMTDI). Therefore, the observed average chronic exposure dose not pose a health risk to consumers.

Health risk assessment of As due to rice ingestion based on iAs distribution and actual consumption patterns for the residents in Beijing: a cross-sectional study.

As a well-known human carcinogen, arsenic (As) could pose various detrimental health effects to humans mainly through the exposure pathway of food ingestion. In comparison with other foods, rice can accumulate more arsenic due to its tissue specificity. Thus, it is of great significance to assess the health risk of As due to rice ingestion. However, the study on risk assessment from exposure to As in rice is still in an early stage and lack accuracy to date. In this study, after obtaining the rice exposure behavior patterns based on a questionnaire survey, a total of 160 rice samples, which consisted of 4 types (i.e., japonica, indica, glutinous and brown rice), rice from 4 areas and consumed by most of the population in Beijing, were collected. On the basis of the actual intake rate and the species weighted average concentration of consumed rice, average daily exposure dose and health risks of inorganic As (iAs) from rice ingestion were assessed for the population among different genders and ages in Beijing. The results show that japonica rice and rice from Northeast China had higher As content, with the same value of 0.064mgkg-1. And, they were the most popular rice consumed by people, with the intake rates of 75.50gd-1, and 67.91gd-1, respectively. The proportion of iAs to total As (tAs) was 58.34%, with a range of 43.18-71.88%. The average daily dose of iAs for the population was 1.15 × 10-4, which mainly came from japonica rice and the rice from Northeast China ingestion. In comparison with the acceptable non-cancer risk, which had a HQ value of 0.38, the carcinogenic risk of the population in Beijing was 1.73 × 10-4 on average. Furthermore, males had higher carcinogenic risk (1.88 × 10-4) than females (1.62 × 10-4), and the people in the age of 45-55 suffered from the highest carcinogenic risk (2.22 × 10-4), which mainly was attributed to the japonica rice and the rice from Northeast China. This study strengthened that appropriate dietary patterns should be paid more attention in order to control the health risk due to As exposure.

Probabilistic Risk Assessment of Arsenic Exposure Through Drinking Water Intake in Chinese Residents

The total arsenic concentrations of the three main drinking water types in China were determined through a systematic literature review. The distribution models of drinking water exposure parameters for different age groups were obtained using the regression method. The carcinogenic and non-carcinogenic risks of different population groups caused by arsenic exposure through different drinking water types were evaluated by a probabilistic risk assessment. The results showed that the geometric mean of total arsenic content in all the drinking water samples in China was (13.0±38.1) μg·L-1. The highest arsenic content was found in the Inner Mongolia Autonomous Region, followed by Guangxi and Shanxi. Based on the relevant standards for drinking water quality, the probability exceeding the threshold value of groundwater and source water is 23.2% and 18.4%, respectively. According to the results of non-carcinogenic risk assessment, the probability of the residents drinking well water and surface water from the water source area exceeding the daily average exposure dose threshold was 24.0% and 19.5%, respectively. According to the carcinogenic risk assessment, the median of carcinogenic risk caused by arsenic in drinking water in China was 3.22×10-5, which is acceptable. The population group of 18-45 years old had the highest risk, and the median LCR was 1.37×10-5. There was still a certain probability that the LCR of drinking well water and surface water would exceed the acceptable risk level recommended by the US EPA. In conclusion, the potential health risks caused by arsenic exposure through drinking water intake exist among Chinese residents. Further control of the arsenic concentration in drinking water is required to reduce the health risk and improve the safety of drinking water. Meanwhile, it is suggested to strengthen the research on risk threshold to provide a scientific basis for the residents' health protection.

Analysis and health risk assessment of phthalate esters (PAEs) in indoor dust of preschool and elementary school centers in city of Tehran, Iran.

Individuals spend a lot of time indoors; thus they are generally exposed to phthalates used in consumer products. Therefore, those exposed to phthalates as indoor contaminants are at high risks. The present study was conducted to evaluate the carcinogenic and non-carcinogenic hazard of phthalate esters (PAEs), like dimethyl phthalate, diethyl phthalate, di(nbutyl) phthalate, butyl benzyl phthalate, dioctyl phthalate, and di(2-ethylhexyl) phthalate in the dust obtained from 21 schools in Tehran, in 2019. A total of 63 indoor dust specimens were obtained by a vacuum cleaner. After transferring dust samples to the laboratory, 100 mg of each sample was centrifuged and mixed with 20 ml acetone and kept through a night and ultrasonicated within 30 min. Eventually, PAEs' contents were measured via gas chromatography-mass spectrometry. Based on the findings, median concentrations of DMP, DEP, DnBP, BBP, DEHP, and DnOP were 0.90, 0.10, 6.0, 0.20, 118.30, and 4.10 mg kg-1 respectively. Moreover, the overall average daily exposure doses (ADD) of phthalate esters via dust ingestion, skin contact, and inhalation were 1.56E-03, 1.70E-06, and 1.56E-07 mg kg-1 day-1, respectively, and the lifetime average daily exposure doses (LADD) were 1.83E-04, 2.34E-08, and 2.46E-08 mg kg-1 day-1, respectively; thus ingestion of dust particles was found to be the main pathway of exposure to phthalate for non-carcinogenic and carcinogenic risks. Although based on the results, the studied samples were below the US Environmental Protection Agency threshold of 1.00E-06, due to the disadvantages of phthalates in human safety, these kinds of investigations are helpful in understanding the main ways of exposure to PAEs and providing a science-based framework for the future attempts for mitigating the PAEs indoor emissions.

Clinical effectiveness of apatinib at different doses in patients with advanced gastric cancer as the third-line or further treatment: Results from a post-marketing phase IV study.

e16037 Background: Apatinib, a highly selective VEGFR2 inhibitor, has shown a clinical benefit as third-line or further-line treatment in patients with gastric cancer in a randomized phase III study with the initial dose of 850mg. However, the study was conducted in a small scale (n = 267) under standardized conditions. Here, we assessed exposure and effectiveness of apatinib at different doses using data collected from a post-marketing phase IV study that included a broader patient population with a larger sample size. Methods: Patients with advanced or metastatic advanced gastric cancer or gastroesophageal junction adenocarcinoma who were aged 18-75 with ECOG performance status of 0-2 and failed at least two lines of chemotherapy were enrolled. Apatinib was recommended with an initial dose of 850 mg q.d orally, while the initial dose was determined at the discretion of the investigators. Administration of apatinib regarding the initial dose, duration of treatment, dose modification, average daily exposure dose (ADED) and its effect on progression-free survival (PFS) and overall survival (OS) were analyzed. Results: A total of 2004 patients were included in the intention-to-treat population. The median age was 59 (range, 19-85) years, 71.8% of patients were male, 84.2% had ECOG performance status of 0-1; 96.4% had stage IV disease, and 98.8% had metastases, among which 34.2% with more than 2 metastases. Five patients did not receive therapy. Compared to 5.5% of patients with the initial dose > 500mg, 94.1% was given at the initial dose≤500mg; 8.6% had ADED > 500mg and 91.1% had ADED ≤500mg. The median duration of treatment was 56 days. Treatment interruption and discontinuation, and dose reduction occurred in 34.4%, 24.5%, and 13.7% of patients due to adverse events, respectively. Survival analyses in the initial dose ≤500mg/ > 500mg subgroups showed median PFS of 2.6 months (95%CI 2.20-2.79) vs 2.7 months (95% CI 1.91-3.32), median OS of 5.6 months (95% CI 5.26-5.95) vs 5.9 months (95% CI 4.40-6.87). In the ADED ≤500mg/ > 500mg subgroups, the median PFS was 2.6 months (95% CI 2.14-2.76) vs 3.0 months (95% CI 2.27-3.61), and median OS was 5.7 months (95% CI 5.32-6.08) vs 6.1 months (95% CI 5.36-7.72). Conclusions: In conclusion, more than 90% of the patients received a lower dose regimen, which indicate dosage of 500mg or lower is a tolerated exposure. Furthermore, dose at 500mg or lower produced similar efficacy to that more than 500mg. Clinical trial information: NCT02426034.

Returning radioactively contaminated territories to normal life: current problems and ways for solution (35 years after the Chernobyl NPP accident)

Relevance. 35 years after the Chernobyl NPP accident, 1.974 settlements remain in the radioactively contaminated areas of the Russian Federation (above 37 kBq/m2 for 137Cs). 90.9 % of these settlements are located in four regions: Bryansk, Kaluga, Tula, Orel. In 137 settlements located in the southwestern districts of the Bryansk region, the average annual exposure doses of residents exceed 1 mSv. This requires measures for their further recovery and return to normal life without radiation-related restrictions.Intention. Generalize data on changes in the radiation and socio-economic situation in radioactively contaminated territories as a result of the Chernobyl accident over the past five years and analyze the remaining problems of returning the population to normal living conditions and economic activities.Methodology. Results of monitoring of the Chernobyl accident affected territories performed by departmental scientific organizations of Emercom, the Russian Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor), the Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet), Ministry of Agriculture, Federal Forestry Agency (Rosleskhoz) were retrospectively analyzed.Results and Discussion. In 98.5 % of settlements with average annual exposure doses above 1 mSv, the internal exposure prevails, mainly due to radionuclides from natural food. Weighted average 137Cs contamination density in the southwestern districts of the Bryansk region decreases as follows: forests > agricultural lands > settlements. Deterioration of demographic indicators in the most radioactively contaminated districts was noted.Conclusion. The need is shown for an integrated approach to return radioactively contaminated territories back to normal via ensuring both the radiation safety of the population and improving the socio-economic conditions in the regions affected by the Chernobyl accident.

Quantitative Microbial Risk Assessment (QMRA) of Workers Exposure to Bioaerosols at MSW Open Dumpsites

AbstractThe bioaerosol exposure data from the study by Akpeimeh, Fletcher, and Evans (2019) was used to compute the risk of infection from the exposure of dumpsite workers to Aspergillus fumigatus and Escherichia coli O157:H7. A stochastic (Markov Chain) model was used to model the transport of the inhaled dose though the human respiratory system and then integrated into the beta‐Poisson dose–response model to estimate workers risks of respiratory and gastrointestinal (GI) infection. The infection risk was computed based on workers exposure to E. coli O157:H7 at 10–50% pathogen ingestion rate and pathogen‐indicator ratio (P:I) of 1:103 and 1:104, while exposure to A. fumigatus was based solely on the average initial exposure dose. The results showed that after 11 hours of exposure, workers engaged in scavenging, waste sorting, and site monitoring were at risk of respiratory and GI infection in the magnitude of 10−1. However, the risk estimates associated with specific areas of the dumpsite showed that, the risk of GI infection at the active area ranged between 3.23 × 10−3–1.56 × 10−2 and 3.25 × 10−4–1.62 × 10−3; dormant area 2.06 × 10−3–1.01 × 10−2 and 2.09 × 10−4–1.04 × 10−3; entrance 1.85 × 10−3–9.09 × 10−3 and 1.87 × 10−4–9.27 × 10−4; boundary 1.82 × 10−3–8.82 × 10−3 and 2.09 × 10−4–8.94 × 10−4 for P:I = 1:103 and 1:104 respectively, while the risk of respiratory infection risks were in the magnitude of 10−1 for all four locations. The estimated risk of workers developing respiratory and gastrointestinal infections were high for all activities assessed at the dumpsite.

An External Dose Assessment of Worker during RadWaste Treatment Facility Decommissioning

Background: Kori unit #1 is permanently shut down after a 40-year lifetime. The Nuclear Safety and Security Commission recommends establishing initial decommissioning plans for all nuclear and radwaste treatment facilities. Therefore, the Korea Atomic Energy Research Institute (KAERI) must establish an initial and final decommissioning plan for radwaste-treatment facilities. Radiation safety assessment, which constitutes one chapter of the decommissioning plan, is important for establishing a decommissioning schedule, a strategy, and cost. It is also a critical issue for the government and public to understand. Materials and Methods: This study provides a method for assessing external radiation dose to workers during decommissioning. An external dose is calculated following each exposure scenario, decommissioning strategy, and working schedule. In this study, exposure dose is evaluated using the deterministic method. Physical characterization of the facility is obtained by both direct measurement and analysis of the drawings, and radiological characterization is analyzed using the annual report of KAERI, which measures the ambient dose every month. Results and Discussion: External doses are calculated at each stage of a decommissioning strategy and found to increase with each successive stage. The maximum external dose was evaluated to be 397.06 man-mSv when working in liquid-waste storage. To satisfy the regulations, working period and manpower must be managed. In this study, average and cumulative exposure doses were calculated for three cases, and the average exposure dose was found to be about 17 mSv/yr in all the cases. Conclusion: For the three cases presented, the average exposure dose is well below the annual maximum effective dose restriction imposed by the international and domestic regulations. Working period and manpower greatly affect the cost and entire decommissioning plan; hence, the chosen option must take account of these factors with due consideration of worker safety.

The Dynamics of the Average Annual and Cumulative Radiation Exposure Doses of the Adult Population of the Russian Federation after the Chernobyl Disaster

The purpose of the study was to study the patterns of forming average annual and cumulative exposure doses. The subject of the study was the dynamics of the average annual and cumulative doses of the adult population of the Russian Federation after the Chernobyl nuclear power plant accident. Results and conclusions. We estimated the contribution of external and internal exposure doses accumulated during the first year after the disaster into the total doses accumulated in 1986–2016 in the population living in the areas with different levels of 137Cs activity in surface soil. The contribution of the exposure doses received during the first year after the accident into the total doses accumulated in 1986–2016 by the population of the regions with different levels of 137Cs activity in surface soil was more than 30%. The contribution of the internal exposure dose received during the first year after the accident into the total exposure dose accumulated in 1986–2016 by the population exceeded that of the external dose. We predicted the average annual and cumulative exposure doses of the population until the year 2056: in 2016, the actual average annual exposure dose for the population exceeded 1.0 mSv/year only in 19 settlements of the Bryansk Region while by 2056 the number of such settlements would be null. In 2016, the average cumulative exposure dose of the population exceeded 70 mSv in 55 settlements of the Bryansk Region, the maximum being 299 mSv. According to the forecast for the year 2056, the total number of settlements in the Bryansk Region with the average cumulative exposure dose of the population equal to or greater than 70 mSv would approach 92. All these settlements are situated only in the Bryansk Region. The maximum expected value of the average cumulative exposure dose would be 374 mSv. We estimated the contribution of the population exposure dose accumulated in 1986–2016 into the exposure dose accumulated during 70 years (a lifetime dose). The contribution of the average accumulated effective exposure dose for 1986–2016 into the dose predicted for 1986–2056 ranged 86% to 94%. This means that the major part of the lifetime dose has been already accumulated by the locals

항공승무원의 우주방사선 피폭 저감에 관한 연구

The purpose of this study is to analyze the radiation dose data of the space crew of the flight crew and to present a plan for the health management of the flight crew on the basis of the analysis. The analysis show that the average exposure dose of the flight attendants continued to rise, and the exposure dose of the flight attendants was five(5) times higher than that of the radiation workers. As a way to reduce the effects of cosmic radiation, this paper suggests appropriate personnel allocation by model, balanced allocation of high and low latitude routes by crew according to the aircraft type, and a low altitude flight plan for high latitude flight. This study will help aviation crew members understand cosmic radiation and trust in the company’s policies. In the future, it will be necessary to enhance the flight safety of the crew by deriving meaningful results by analyzing data related to cosmic radiation of various routes.

External dose evaluation based on detailed air dose rate measurements in living environments

A method was devised to estimate the realistic external doses of residents expected to return to their homes after evacuation orders are lifted. For 196 residents expected to return to six towns and villages, surveys were administered in FY 2014–2016. After interviewing residents about their expected life patterns after their return, detailed air dose rate measurements were taken along their reported personal routes representing patterns of movement in their daily life. The maximum and average annual additional external effective dose were estimated at 4.9 mSv and 0.86 mSv, respectively. Although the mean values and dispersion of external effective doses differed depending on the level of evacuation, for 93.3% of all residents, the estimated annual additional external effective doses were less than 2 mSv. Measuring air dose rates inside houses was found to be important to obtain a realistic evaluation of the external exposure dose because our research revealed that the average time spent indoors was 87% of the total living time. Moreover, the average exposure dose at home accounted for 66.8% of the annual exposure dose.

Receptor-based aggregate exposure assessment of phthalates based on individual's simultaneous use of multiple cosmetic products

To estimate realistic exposure to a chemical, the aggregate exposure from multiple consumer products should be considered. A receptor-based aggregate exposure assessment was conducted according to individuals' exposure factors and simultaneous use patterns including co-use and non-use. A product-based aggregate exposure assessment was conducted by product usage rates of population and users’ exposure factors. Two aggregate exposure assessments were compared. Exposure factors for 31 cosmetic products were collected by face-to-face interviews with 1001 members of the Korean population through national representative sampling. The concentrations of phthalates in 214 cosmetic products were analyzed by GC-MS-MS. The average aggregate exposure dose (AED) determined by the receptor-based method for di(2-ethylhexyl)phthalate (DEHP), di-n-butyl phthalate (DnBP), and diethyl phthalate (DEP) were 0.68 ± 0.87, 1.08 ± 5.71, and 2.47 ± 9.05 μg/kg/day, respectively. The cosmetics that contributed most to the receptor-based AED were skin care and body care products for DEHP, nail care products for DnBP, and fragrance and hair care products for DEP. The young female group showed the highest exposure. The product-based aggregate exposure assessment method underestimated high exposure but overestimated average exposure for DnBP and DEP. The receptor-based aggregate exposure assessment method would be used to determine high exposure groups.

Associations between urate-lowering therapy and the risk of type 2 diabetes mellitus.

BackgroundGout is independently associated with increased risk of type 2 diabetes mellitus (T2DM). Urate-lowering therapy (ULT) might be beneficial in lowering the risks of T2DM. Therefore, we conducted a nested case-control study to evaluate the associations between ULT and T2DM.MethodsThis study retrieved the data of 29,765 gout patients from the period of 1998–2010 by using data from Taiwan’s National Health Insurance Research Database. Controls (n = 59,530) were matched at a 1:2 ratio by age, sex, and region. Multivariate Cox proportional hazards regression were performed to examine the dose-dependent relationship between ULT and T2DM.ResultsThe adjusted Hazard ratio (HR) for the association of T2DM with allopurinol or benzbromarone exposure was 1.17 (95% confidence interval (CI) 1.07–1.28) and1.09 (95% CI 1.03–1.15), respectively. The HR for the cumulative allopurinol dose was 0.87 (95% CI 0.71–1.07) for patients with dose ≤1.3 mg/day and was 1.31 (95% CI 1.13–1.52) for those with a dose >15.2 mg/day. Similarly, the HR for the cumulative benzbromarone dose was 0.85(95% CI 0.75–0.96) for patients with a dose ≤1.3 mg/day and 1.42 (95% CI 1.30–1.55) for patients with a dose>9.4 mg/day, respectively. Moreover, the average exposure dose of >100 mg/day for allopurinol and >100 mg/day for benzbromarone was associated with a 1.28-fold (95% CI 1.11–1.48) and 1.47-fold (95% CI 1.23–1.76) T2DM risk respectively. The HR for patients in aged >50 years group with cumulative dose ≤1.3 mg/day of allopurinol or benzbromarone had lower risk of T2DM (HR = 0.74, 95% CI 0.58–0.94 for allopurinol; HR = 0.79, 95% CI 0.69–0.90 for benzbromarone).ConclusionGout patients with prolonged ULT and a high dose of ULT were associated with a significant increase in T2DM risk. Although gout patients with age greater than 50 years and a lower dose of ULT may be beneficial in lowering T2DM risk, further clinical studies need to be confirmed these associations.

A novel patient-specific three-dimensional-printed external template to guide iliosacral screw insertion: a retrospective study

BackgroundIliosacral screw fixation is a popular method for the management of posterior pelvic ring fractures or dislocations, providing adequate biomechanical stability. Our aim in this study was to describe the use of a new patient-specific external template to guide the insertion of iliosacral screws and to evaluate the efficacy and safety of this technique compared with the conventional fluoroscopy-guided technique.MethodsThis was a retrospective study of patients with incomplete or complete posterior pelvic ring disruptions who required iliosacral screw fixation. For analysis, patients were divided into two groups: the external template group (37 screws in 22 patients) and the conventional group (28 screws in 18 patients). The operative time per screw, radiation exposure time and the rate of screw perforation (accuracy) were compared between groups. In the external template group, the difference between the actual and planned iliosacral screw position was also compared.ResultsIn the conventional group, the average operative time per screw was 39.7 ± 10.6 min, with an average radiation exposure dose of 1904.0 ± 844.5 cGy/cm2, with 4 cases of screw perforation. In the external template group, the average operative time per screw was 17.9 ± 4.7 min, with an average radiation exposure dose of 742.8 ± 230.6 cGy/cm2 and 1 case of screw perforation. In the template group, the mean deviation distance between the actual and planned screw position was 2.75 ± 1.0 mm at the tip, 1.83 ± 0.67 mm in the nerve root tunnel zone and 1.52 ± 0.48 mm at the entry point, with a mean deviation angle of 1.73 ± 0.80°.ConclusionsThe external template provides an accurate and safe navigation tool for percutaneous iliosacral screw insertion that could decrease the operative time and radiation exposure.

Evaluation of Natural Radioactive Dose Levels and Associated Annual Effective Dose Rates in Ingested Foodstuffs at Abuja, Nigeria


 
 
 
 Measurement of radioactive contamination in some commonly consumed foodstuffs within the six area councils of Abuja, Nigeria was conducted in this study by means of a very sensitive and portable 3M/3-X Geiger Müller counter-based environmental radiation dosimeter. Eight different food samples were randomly selected in each of the sample locations making a total of 48 foodstuffs samples surveyed across the six area councils. The results obtained show that, the range of radiation dose levels in the analyzed samples varied from 0.01590.0001 to 0.34070.0002 μSvy-1 at Bwari; 0.14900.0001 to 0.39020.0002 μSvy-1 at AMAC; 0.00950.0001 to 0.02090.0001 μSvy-1 at Gwagwalada; 0.00570.0001 to 0.01330.0002 μSvy-1 at Kuje; 0.02740.0001 to 0.22710.0002 μSvy-1 at Abaji; Kwali was between 0.01820.0001 and 0.35030.0002 μSvy-1, and their corresponding arithmetic mean are 0.16900.0001 μSvy-1, 0.22560.0001 μSvy-1, 0.01330.0001 μSvy-1, 0.00880.0001 μSvy-1, 0.13600.0001 μSvy-1 and 0.12370.0001 μSvy-1, which gives estimated annual effective dose rates of 0.18850.0003 mSvy-1, 0.25760.0001 mSvy-1, 0.11700.0001 mSvy-1, 0.07710.0001 mSvy-1, 0.15530.0002 mSvy-1, and 0.14120.0001 mSvy-1 for Bwari, AMAC, Gwagwalada, Kuje, Abaji and Kwali area councils respectively. This finding reveals that the obtained values were sufficiently less than the maximum recommended global average exposure dose limit for environmental background (2.4 mSvy-1) and general public dose limit (1.0 mSvy-1). The radiation dose levels and dose rates associated with the intake of foodstuffs across the area councils are, therefore, relatively low and may not pose any immediate radiological health hazard to the populace, as deterministic radiation effects occur only in extreme cases.
 
 
 
 

Clinical study of total marrow and lymphatic irradiation in children using helical tomotherapy

Objective To evaluate the feasibility of total marrow and lymphatic irradiation (TMLI) with helical tomotherapy as a conditioning regimen before hematopoietic stem cell transplantation (HSCT). Methods Seven children with acute lymphoblastic leukemia and aplastic anemia were recruited as study subjects. The median age was 7 years old. The prescribed dose was 12 Gy/6 fractions twice daily. The exposure dose of the target and the organs at risk between helical helical tomotherapy-based TMLI regimen and total body irradiation (TBI) regimen were statistically compared, and acute toxicity grading was performed for all patients. Results Compared with the TBI regimen, the average exposure dose reduction for organs at risk after the TMLI regimen was ranged from 4.2% to 40.6%.The average exposure dose reduction for the kidney was the largest among all organs. The acute toxicities experienced by all patients were graded and recorded including 2 cases of nausea, 5 cases of vomiting, 1 case of anorexia, 1 case of eryhema, 3 cases of diarrhea, and 1 case of oral mucositis. Only grade 1-2 toxicities were observed, and no grade 3-4 toxicities occurred. Conclusions The findings in this study confirm the feasibility of helical helical tomotherapy-based TMLI regimen. Compared with the TBI regimen, the mean duration of treatment for the TMLI regimen with an equivalent dose is not increased. The exposure dose experienced by organs at risk is reduced and the predicted incidence rate is decreased when the TMLI regimen is employed, which provides a myeloablative pretreatment strategy. However, the long-term toxicity of TMLI regime remains to be evaluated by clinical trials. Key words: Total body irradiation; Total marrow and lymphatic irradiation; Helical tomotherapy; Acute toxicity