Occupational exposure to ionizing radiation has no effect on T‐ and B‐cell total counts or percentages of helper,cytotoxic and activated T‐cell subsets in the peripheral circulation of male radiation workers

Purpose: To investigate changes in immune cell subsets in the peripheral circulation of a male population occupationally exposed to ionizing radiation.

Materials and methods: Peripheral blood samples were taken from 194 male workers with cumulative exposures of >200?mSv (mean exposure 331.5?mSv, mean age 51 years) and from a reference population of 131 male workers with cumulative exposures of <27.5?mSv (mean exposure 13.9?mSv, mean age 47 years). Samples were analysed by flow cytometry for T‐ and B‐cell total counts and for the T‐cell subset percentages of CD4⁺ (helper T‐cells), CD8⁺ (cytotoxic T‐cells) and CD3⁺/HLA‐DR⁺ (activated T‐cells).

Results: Comparison of the >200 and <27.5?mSv exposure groups using linear regression analysis showed no statistically significant differences between the two groups for T‐cell total count, B‐cell total count or for percentages of the T‐cell subsets CD4⁺, CD8⁺ or CD3⁺/HLA‐DR⁺ and CD4⁺:CD8⁺. However, statistically significant increases in both T‐ and B‐cell total counts were observed within the two exposure groups and data pooled from both groups when non‐smokers (never and ex‐smokers) were compared with current smokers. For pooled data T‐cell total count increased in smokers by 35% (p=0.0001) and B‐cell total count increased by 37% (p=0.0004).

Conclusions: No significant immunological effects were observed in male radiation workers with cumulative exposures of >200?mSv when compared with a reference population with cumulative exposures of <27.5?mSv, although highly significant increases in both T‐ and B‐cell total counts were observed in smokers compared with non‐smokers.     

Chronic low-dose gamma-radiation exposure and the alteration of the distribution of lymphocyte subpopulations in residents of radioactive buildings

Purpose : To elucidate the immunological change incurred in a human population by protracted gamma-radiation exposure at home environment. Materials and methods : An examination on the CD3+, CD4+, CD8+ and HLA-DR+ lymphocyte subsets was arranged for 196 exposed subjects with mean excess cumulative dose of 169mSv during 2-13 years of exposure. Another 55 close relatives of the exposed subjects were recruited as the non-exposed reference population. Results : The mean percentages of CD4+ T-lymphocytes, HLA-DR+ lymphocytes and the CD4+/CD8+ ratios in the exposed subjects (35.5, 19.9 and 1.51 respectively) were significantly lower than those of reference individuals (38.0, 22.6 and 1.72; p 0.02, 0.003, and 0.03 respectively), while the CD8 in total counts of the exposed was moderately increased above that of the reference populations (p=0.1). By ANOVA analysis, the percentages of CD4+ and HLA-DR+ subsets were significantly associated with radiation dose (p =0.0046, 0.003), while CD4+/CD8+ ratios were moderately associated with dose (p=0.073). HLA-DR+ counts were significantly and positively associated with duration of relocation from radioactive apartments (p=0.029). Conclusions : Significant immunological effects were observed in those who had received chronic low-dose radiation exposure.     

Chronic low-dose gamma-radiation exposure and the alteration of the distribution of lymphocyte subpopulations in residents of radioactive buildings.

PURPOSE: To elucidate the immunological change incurred in a human population by protracted gamma-radiation exposure at home environment. MATERIALS AND METHODS: An examination on the CD3+, CD4+, CD8+ and HLA-DR+ lymphocyte subsets was arranged for 196 exposed subjects with mean excess cumulative dose of 169 mSv during 2-13 years of exposure. Another 55 close relatives of the exposed subjects were recruited as the non-exposed reference population. RESULTS: The mean percentages of CD4+ T-lymphocytes, HLA-DR+ lymphocytes and the CD4+ /CD8+ ratios in the exposed subjects (35.5, 19.9 and 1.51 respectively) were significantly lower than those of reference individuals (38.0, 22.6 and 1.72; p= 0.02, 0.003, and 0.03 respectively), while the CD8+ in total counts of the exposed was moderately increased above that of the reference populations (p=0.1). By ANOVA analysis, the percentages of CD4+ and HLA-DR+ subsets were significantly associated with radiation dose (p=0.0046, 0.003), while CD4+/CD8+ ratios were moderately associated with dose (p=0.073). HLA-DR+ counts were significantly and positively associated with duration of relocation from radioactive apartments (p = 0.029). CONCLUSIONS: Significant immunological effects were observed in those who had received chronic low-dose radiation exposure.     

The effect of the ratio of CD4 + to CD8 + T-cells on radiation-induced apoptosis in human lymphocyte subpopulations

Purpose: Apoptosis occurs spontaneously in cultured human peripheral blood lymphocytes but is enhanced by exposure to ionizing radiation. Subpopulations of lymphocytes are known to have varying radiosensitivities to radiation-induced apoptosis. The purpose of this study was to examine the radiation-induced apoptotic response of CD4 + and CD8 + T-cells incubated as a complete lymphocyte population. Materials and Methods: Using a four-colour flow-cytometry method, which measures annexin-V binding to phosphatidyl serine and propidium iodide, spontaneous and radiation-induced apoptosis was measured in the total lymphocyte fraction and in CD4 + and CD8 + T-cell subpopulations. Results: It was found that CD8 + T-cells were more sensitive to radiation-induced apoptosis than CD4 + T-cells at doses up to 2 Gy. The yield of radiation-induced apoptosis in the total lymphocyte fraction decreased with increasing ratios of CD4 + to CD8 + T-cells (CD4/CD8 ratio). By manipulating the CD4/CD8 ratio within lymphocyte cultures, it was found that the CD4/CD8 ratio had a dramatic effect on the yield of spontaneous apoptosis of total lymphocytes fraction and CD4 + T-cells but not CD8 + T-cells. Conclusion: The CD4/CD8 ratio affects the apoptotic response of human lymphocytes and CD4 + T-cells.     

Chromosome analysis of workers occupationally exposed to radiation at the Sellafield nuclear facility

Purpose : To investigate the relationship between stable chromosome aberration frequency in peripheral blood lymphocytes and occupational cumulative radiation exposure. Materials and methods : Cytogenetic analysis using G-banding was performed on peripheral blood lymphocyte cultures from 104 workers from the British Nuclear Fuels PLC facility at Sellafield, UK. The study group comprised 61 men with lifetime cumulative doses > 500mSv, 39 men with minimal exposure (i.e. < 50 mSv) who formed a control group and 4 men with intermediate doses. Results : The slope of the dose-response, adjusted for smoking status, for translocations and insertions was 0.55 +/- 0.31 x 10 -2 /cell/Sv. Consideration of chromosome breakpoints for all aberrations combined in the radiation workers revealed an excess in the C group chromosomes and a deficit in the F group chromosomes with breakpoints being concentrated in the terminal regions whereas the distribution in the control group did not deviate from expectation. Conclusions : The dose-response was not significantly different from the parallel FISH analysis (Tucker et al. 1997) and confirms that chronic radiation exposure appears to be substantially less effective at inducing stable chromosome aberrations in comparison with acute exposure.     

Chromosome analysis of workers occupationally exposed to radiation at the Sellafield nuclear facility

PURPOSE: To investigate the relationship between stable chromosome aberration frequency in peripheral blood lymphocytes and occupational cumulative radiation exposure. MATERIALS AND METHODS: Cytogenetic analysis using G-banding was performed on peripheral blood lymphocyte cultures from 104 workers from the British Nuclear Fuels PLC facility at Sellafield, UK. The study group comprised 61 men with lifetime cumulative doses > 500 mSv, 39 men with minimal exposure (i.e. < 50 mSv) who formed a control group and 4 men with intermediate doses. RESULTS: The slope of the dose-response, adjusted for smoking status, for translocations and insertions was 0.55+/-0.31 x 10(-2)/cell/Sv. Consideration of chromosome breakpoints for all aberrations combined in the radiation workers revealed an excess in the C group chromosomes and a deficit in the F group chromosomes with breakpoints being concentrated in the terminal regions whereas the distribution in the control group did not deviate from expectation. CONCLUSIONS: The dose-response was not significantly different from the parallel FISH analysis (Tucker et al. 1997) and confirms that chronic radiation exposure appears to be substantially less effective at inducing stable chromosome aberrations in comparison with acute exposure.     

Assessment of effective dose from concomitant exposures required in verification of the target volume in radiotherapy

The requirement of the Ionising Radiation (Medical Exposure) Regulation 2000 [IR(ME)R] of justifying all exposures to ionizing radiation includes those from radiotherapy double exposure portal images resulting in exposure to normal tissues outside the treatment volume. Typical effective doses were calculated for a range of common sites using CT data to outline those parts of specific organs subject to concomitant radiation and generate dose-volume histograms. The product of the mean dose and the relative probability of inducing a fatal cancer in specific organs was used to determine a representative total effective dose in mSv per monitor unit for each site. A table of representative effective doses, ranging from 0.32 mSv to 2.56 mSv per monitor unit, was produced, which may be used to monitor cumulative effective doses of individual patients from double exposure portal images, in addition to those received from localization procedures.     

Use of a centrifuge-based automated blood cell counter for radiation dose assessment

Hematological changes create early-response biomarkers for assessing radiation doses. Existing dose-prediction models are based on serial blood lymphocyte counts after acute whole-body exposure to gamma-radiation. Measurements of lymphocyte-depletion kinetics after possible exposures are useful for triaging patients and managing medical resources. The small-footprint QBC Autoread Plus System provides cost-effective hematological analyses with reproducibility, accuracy, and a broad dynamic range. QBC analysis measures centrifugally packed, whole blood cells in microhematocrit tubes and reports pooled lymphocyte and monocyte counts. Our objective was to modify this procedure to report pure lymphocyte counts for radiation biodosimetry applications. The CD14 antigen is strongly expressed on most human monocytes. Using anti-CD14-coated Dynabeads, we have devised a rapid method for depleting monocytes from whole blood without altering the lymphocyte viability or count. This simple dry procedure provides reliable lymphocyte counts for results that fall within the normal lymphocyte count range (1-4 x 10(9) cells per L) for radiation exposure assessment using lymphocyte-depletion kinetics.     

A survey of annual radiation dose for radiation workers from occupational and medical exposures in Kyushu]

This study was carried out to determine annual dose equivalents of exposure in workers exposed to medical radiation and occupational radiation in an enterprise associated with nuclear power plants. The results indicated that medical exposure is much higher than occupational exposure. Average annual effective dose equivalents for medical and occupational exposure were 4.0-7.5 mSv and 2.4-3.6 mSv, respectively. Individual occupational exposure limits have been well controlled and maintained at one-fifth of the dose limit for radiation workers (50 mSv/yr). On the other hand, medical exposure in the older workers of this enterprise has been increasing as a result of X-ray diagnosis with barium meal.     

Cumulative radiation exposure from diagnostic imaging in intensive care unit patients

AIM:To quantify cumulative effective dose of intensive care unit(ICU)patients attributable to diagnostic imaging.METHODS:This was a prospective,interdisciplinary study conducted in the ICU of a large tertiary referral and level 1 trauma center.Demographic and clinical data including age,gender,date of ICU admission,primary reason for ICU admission,APACHE Ⅱ score,length of stay,number of days intubated,date of death or discharge,and re-admission data was collected on all patients admitted over a 1-year period.The overall radiation exposure was quantified by the cumulative effective radiation dose(CED)in millisieverts(mS v)and calculated using reference effective doses published by the United Kingdom National Radiation Protection Board.Pediatric patients were selected for subgroupanalysis.RESULTS:A total of 2737 studies were performedin 421 patients.The total CED was 1704 m Sv with a median CED of 1.5 mS v(IQR 0.04-6.6 mS v).Total CED in pediatric patients was 74.6 mS v with a median CED of 0.07 mS v(IQR 0.01-4.7 mS v).Chest radiography was the most commonly performed examination accounting for 83% of all studies but only 2.7% of total CED.Computed tomography(CT)accounted for 16% of all studies performed and contributed 97% of total CED.Trauma patients received a statistically significant higher dose [median CED 7.7 mS v(IQR 3.5-13.8 mS v)] than medical [median CED 1.4 m Sv(IQR 0.05-5.4 m Sv)] and surgical [median CED 1.6 mS v(IQR 0.04-7.5 mS v)] patients.Length of stay in ICU [OR = 1.12(95%CI:1.079-1.157)] was identified as an independent predictor of receiving a CED greater than 15 mS v.CONCLUSION:Trauma patients and patients with extended ICU admission times are at increased risk of higher CEDs.CED should be minimized where feasible,especially in young patients.     

The effect of the ratio of CD4+ to CD8+ T-cells on radiation-induced apoptosis in human lymphocyte subpopulations

PURPOSE: Apoptosis occurs spontaneously in cultured human peripheral blood lymphocytes but is enhanced by exposure to ionizing radiation. Subpopulations of lymphocytes are known to have varying radiosensitivities to radiation-induced apoptosis. The purpose of this study was to examine the radiation-induced apoptotic response of CD4(+) and CD8(+) T-cells incubated as a complete lymphocyte population. MATERIALS AND METHODS: Using a four-colour flow-cytometry method, which measures annexin-V binding to phosphatidyl serine and propidium iodide, spontaneous and radiation-induced apoptosis was measured in the total lymphocyte fraction and in CD4(+) and CD8(+) T-cell subpopulations. RESULTS: It was found that CD8(+) T-cells were more sensitive to radiation-induced apoptosis than CD4(+) T-cells at doses up to 2 Gy. The yield of radiation-induced apoptosis in the total lymphocyte fraction decreased with increasing ratios of CD4(+) to CD8(+) T-cells (CD4/CD8 ratio). By manipulating the CD4/CD8 ratio within lymphocyte cultures, it was found that the CD4/CD8 ratio had a dramatic effect on the yield of spontaneous apoptosis of total lymphocytes fraction and CD4(+) T-cells but not CD8(+) T-cells. CONCLUSION: The CD4/CD8 ratio affects the apoptotic response of human lymphocytes and CD4(+) T-cells.     

Clinical prognosis of patients with early-stage human immunodeficiency virus (HIV) disease: contribution of HIV-1 RNA and T lymphocyte subset quantitation

Systems for the staging of individuals with human immunodeficiency virus type 1 (HIV-1) infection were developed 15 years ago. Subsequently, assays for quantitating HIV-1 RNA and immunophenotyping of lymphocyte subsets have been developed and validated. The utility of these assays for improved staging in early disease was evaluated in 256 HIV-infected adults (52% minority) with CD4 counts > or = 400 cells/microL followed in U.S. military medical centers before the highly active anti-retroviral therapy era. HIV viral load (RNA) was quantitated; the frequencies of select CD4+ immunophenotypes were determined in 112 subjects. The results were analyzed in relation to three outcome measures: death, first acquired immunodeficiency syndrome-defining opportunistic infection, and CD4 count < or = 200 cells/microL. Serum RNA level and CD4 count were each found to be predictive of all three outcomes. In addition, increases in the T-cell subsets CD28-CD4+ and CD29+CD26-CD4+ were found to be independently predictive of more rapid progression. The classification of early-stage HIV patients is improved by the quantitation of both viral RNA and T-lymphocyte subsets.     

急性冠状动脉综合征介入患者辐射剂量分析

目的分析200例急性动脉综合征介入治疗患者受照射剂量,探讨病变部位、狭窄程度、年龄和手术医生等因素对辐射剂量的影响。方法回顾分析我院200例急性动脉综合征行介入治疗(PCI)患者所记录的剂量资料,随机配置的剂量检测系统记录剂量面积乘积(DAP)和累计剂量(CD),根据DAP值估算有效剂量(ED)。根据血管病变受累程度分为单一病变和复杂病变以及患者年龄分组(小于40岁组,40~60岁组及大于60岁组)、左右侧冠状动脉和第一操作医生对患者受辐射剂量的影响。结果①本次收录200例行PCI术者累积剂量CD值191~5524 mGy,平均值(1157±781)mGy;剂量面积乘积DAP值(12714~417228)mGy·cm^2,平均值(100690±63896)mGy.cm^2;有效剂量ED范围1.119~58.411 mSv,平均值(14±9)mSv。②单一病变相比复杂病变辐射剂量少,CD值、DAP值、ED值差异有统计学意义(P<0.05)。③左侧冠状动脉大于右侧冠状动脉(P<0.05)。④3个年龄组间各个剂量值方差分析差异无统计学意义(P>0.05)。⑤2组不同年资操作医生患者所受剂量差异无统计学意义(P>0.05)。结论急性冠状动脉综合征PCI术患者接受辐射剂量差异较大,主要与病变本身(包括病变部位和累计范围及变异等)因素相关。     

多发伤患者住院期间X射线累积有效 剂量研究

目的 研究多发伤患者在院治疗期间的累积医疗X射线检查剂量,探讨其影响因素.方法 回顾性收集2009年6月至2011年4月在本院治疗患者的CT、DR检查记录,CT记录其DLP值,并用各部位转换系数算出有效剂量;DR参照以往研究各部位有效剂量数据.结果 共收集113位患者的X射线检查的累积剂量,剂量范围16.48～153.3 mSv,平均(52.3±26.6)mSv.结论 多发伤患者其累积X射线剂量处于较高的水平.应加强对医疗X射线检查的累积剂量管理,通过建立患者X射线辐射剂量档案管理可能使临床医生、检查技术员重视检查开单的选择以及检查参数的合理设置.     

Immunological changes after cancer treatment and participation in an exercise program

PURPOSE: The purpose of this investigation was to evaluate the impact of undertaking peripheral blood stem cell transplantation (PBST) on T-cell number and function, and to determine the role of a mixed type, moderate intensity exercise program in facilitating the recovery of T-cell number and function. METHODS: Immunological measures of white blood cell, lymphocyte, CD3, CD4, and CD8 counts, and CD3 cell function were assessed pretransplant (PI), immediately posttransplant (PII), and 1 month (I1), 2 months (I2) and 3 months (PIII) posttransplant. After PII, 12 patients were divided equally into a control group (CG) or exercise intervention group (EG). RESULTS: Lower total T-cell, helper T-cell, and suppressor T-cell counts (P< 0.01), as well as lower T-cell function (P< 0.01), when compared with normative data, were found at PI. More specifically, 88% of the group had CD3, CD4, and CD8 counts that were more than 40%, 20%, and 50% below normal at PI, respectively. Undertaking a PBST caused further adverse changes to the total leukocyte, lymphocyte, CD3, CD4 and CD8 count, and the helper/suppressor ratio. Although CD8 counts had returned to normal by PIII, CD3, CD4, and the CD4 /CD8 ratio remained significantly lower than normative data (P< 0.01), with 66%, 100%, and 100% of the subject group reporting counts and ratios, respectively, below the normal range. CONCLUSION: The PBST patients were immunocompromised before undertaking the transplant, and the transplant procedure imposed further adverse changes to the leukocyte and lymphocyte counts. The leukocyte and CD8 counts returned to normal within 3 months posttransplant; however, the other immunological parameters assessed demonstrated a delayed recovery. Although participation in the exercise program did not facilitate a faster immune cell recovery, neither did the exercise program hinder or delay recovery.     

2014-2018年江西省医用放射工作人员外照射个人剂量监测结果分析

目的 分析江西省医疗机构放射工作人员的外照射个人剂量情况,为放射防护工作提供参考.方法 以2014-2018年江西省医疗机构不同工种放射工作人员为调查对象,工种包括诊断放射学、放射治疗、核医学和介入放射学,统计分析江西医用放射工作人员的受照剂量水平.结果 本次共调查23 833人次,平均人均年有效剂量为0.316 mS...     

Analysis of chromosome aberrations in nuclear-power-plant workers considering the lifetime of lymphocytes

Purpose : To analyse chromosome aberrations in nuclear-power-plant workers taking account of the mean lifetime of lymphocytes (MLTL). Materials and methods : Analysis of chromosome aberrations was performed on peripheral lymphocytes from 395 nuclear-power-plant workers and 135 controls. An equivalent acute dose (EAD) was calculated utilizing MLTL values of either 4.3 or 10 years. Results : Using an MLTL value of 10 years produced an EAD range of 0.01 mSv - 182 mSv (mean 46.6 mSv), while using an MLTL of 4.3 years produced results ranging from 0.01 mSv to 86.2 mSv (mean 23.4 mSv). A significant increase of chromosome-type exchange by the equivalent acute dose was observed using an MLTL of either 10 or 4.3 years when including the control in the analysis, but a significant increase was not seen when only the exposed was considered. A significant increase of chromosome-type deletion by EAD was seen even when only the exposed group was considered. Conclusions : EAD values based on an MLTL of either 4.3 or 10 years, as well as cumulative dose, showed no significant association with chromosome aberrations, when radiation workers only were analysed. The narrow dose range examined in this study might have contributed to this finding.     

Analysis of chromosome aberrations in nuclear-power-plant workers considering the lifetime of lymphocytes

PURPOSE: To analyse chromosome aberrations in nuclear-power-plant workers taking account of the mean lifetime of lymphocytes (MLTL). MATERIALS AND METHODS: Analysis of chromosome aberrations was performed on peripheral lymphocytes from 395 nuclear-power-plant workers and 135 controls. An equivalent acute dose (EAD) was calculated utilizing MLTL values of either 4.3 or 10 years. RESULTS: Using an MLTL value of 10 years produced an EAD range of 0.O1 mSv -182mSv(mean 46.6mSv), while using an MLTL, of 4.3 years produced results ranging from 0.01 mSv to 86.2 mSv (mean 23.4 mSv). A significant increase of chromosome-type exchange by the equivalent acute dose was observed using an MLTL of either 10 or 4.3 years when including the control in the analysis, but a significant increase was not seen when only the exposed was considered. A significant increase of chromosome-type deletion by EAD was seen even when only the exposed group was considered. CONCLUSIONS: EAD values based on an MLTL of either 4.3 or 10 years, as well as cumulative dose, showed no significant association with chromosome aberrations, when radiation workers only were analysed. The narrow dose range examined in this study might have contributed to this finding.     

Occupational radiation monitoring at a large medical center in Japan

Occupational radiation dose monitoring is a method of ensuring that radiation levels are within the regulatory limits. Our objective in this study was to evaluate the radiation doses experienced by personnel at a radiology facility between 2001 and 2010. Overall, 2418 annual dose records for workers who were categorized into four occupational groups were analyzed. The groups included: (1) radiologists, (2) radiologic technologists, (3) nurses, and (4) other workers, who belong to other hospital departments, but who participate partially in some radiologic procedures. The dose distribution was found to be skewed, with 76 % of personnel having received no measurable doses and almost 2 % having received doses of more than 2 mSv. The weighted-average annual doses ranged from 0.13 to 0.57, 0.9 to 2.12, 0.01 to 0.19, and 0.01 to 0.09 mSv for the radiologists, radiologic technologists, nurses, and the other workers, respectively. The radiologic technologists received the highest radiation exposure among the four groups. It was found that the average annual doses were decreasing over time for the radiologists, radiologic technologists, and others, whereas they were increasing for the nurses. Nurses play an important role in assisting radiologists and patients during various radiologic procedures, which might have increased their average annual dose. During the 10-year period of this study, there was no incidence of a dose exceeding the annual dose limit of 20 mSv. Furthermore, there was no detectable neutron exposure.     

Analysis of radiation doses in the percutaneous treatment of varicocele in adolescents

PURPOSE: Varicocele is a common clinical condition that affects 15% of the male population and is an important cause of male infertility. Fluoroscopy-guided percutaneous treatment with retrograde sclerosis is a good alternative to surgery. We report our experience in calculating the total radiation dose to patient and the associated risk. MATERIALS AND METHODS: Our study was performed on 67 patients undergoing percutaneous treatment of varicocele with transbrachial approach and retrograde sclerosis. Thirteen dosimeters with two TLD detectors were positioned on the patients' skin. Calculation of the Entrance Surface Dose and application of appropriate transmission coefficients of the depth-dose allowed us to determine the Equivalent Doses for the single organs. Similar studies were conducted during plain abdominal x-ray and urography for comparative purposes. RESULTS: The mean effective dose during percutaneous treatment of varicocele was 18 mSv, whereas the dose for abdominal x-ray was 1.31 mSv and that for urography was 4.6 mSv. DISCUSSION AND CONCLUSIONS: Examinations involving the use of x-rays have been estimated to contribute to half of all the radiation absorbed by the population, and the number of both diagnostic examinations and interventional procedures is steadily rising. Radiation exposure, especially in children, requires special consideration. Percutaneous treatment of varicocele is a valuable alternative to surgery, not least because of reduced exposure. The use of specially-built lead coats and the creation of regional referral centres employing specialised staff are two possible measures that could further reduce radiation doses and dispel concerns about this procedure.