广东省医学放射工作人员眼晶状体异常影响因素分析

目的 调查广东省医学放射工作人员电离辐射剂量水平和眼晶状体异常现况,分析眼晶状体异常的影响因素。方法 采用方便抽样方法抽取2020年广东省粤中和粤东地区60家医院的 1 501名放射工作人员作为研究对象,回顾性分析其眼晶状体吸收剂量(D_L)和健康检查资料,分析眼晶状体异常的影响因素。结果 研究对象眼晶状体吸收剂量中位数M和第25~75百分位数(P₂₅,P₇₅)为4.86(2.99, 7.90)mGy,其中,男性和女性的剂量M分别为5.14和3.94 mGy; 一、二、三级医疗机构的剂量中位数分别为2.95、3.51、5.06 mGy;放射治疗、诊断放射学、介入放射学、核医学职业类别的剂量M分别为4.05、4.84、5.39、6.71 mGy; 护士、医师、技师岗位的剂量中位数分别为3.48、5.03、5.03 mGy。不同性别、年龄、放射工龄、接触放射起始年龄、医疗机构级别、职业类别、岗位的剂量差异均具有统计学意义(Z=-6.72,H=389.64、511.17、70.29、53.29、49.06、39.89,P<0.05)。研究对象眼晶状体皮质密度增高检出率22.45%(337/1 501),眼晶状体浑浊检出率为8.19%(123/1 501)。 皮质密度增高检出率随着年龄、放射工龄、接触放射起始年龄、医疗机构级别、D_L增加呈线性递增趋势(χ²=366.36、313.77、15.18、21.61、92.13,P<0.05)。眼晶状体浑浊检出率随着年龄、放射工龄、医疗机构级别、剂量增加呈线性递增趋势(χ²=69.64、67.65、67.65、37.37,P<0.05),随着接触放射起始年龄增加呈线性递减趋势(χ²=4.25,P<0.05)。logistic回归分析结果显示,年龄是皮质密度增高的影响因素(χ²=165.98,P<0.05),年龄增加发生皮质密度增高的风险增高(OR=1.33,95%CI: 1.27~1.39)。年龄、放射工龄、职业类别是眼晶状体浑浊的影响因素(χ²=25.78、4.99、6.88,P<0.05)。年龄增加发生眼晶状体浑浊的风险增高 (OR=1.17,95%CI: 1.10~1.24);放射工龄增加发生眼晶状体浑浊的风险增高 (OR=1.06,95%CI: 1.01~1.12);介入放射学工作人员发生眼晶状体浑浊的风险高于放射诊断学、放射治疗与核医学(OR=2.59,95%CI: 1.27~5.25)。结论 长期接触低剂量电离辐射与医学放射工作人员眼晶状体异常检出率具有一定的相关性。年龄、放射工龄、职业类别均是眼晶状体浑浊的影响因素。     

Spatiotemporal Distribution and Epidemiological Characteristics of Hospital Admissions for Carbon Monoxide Poisoning in Guangdong,China, 2013–2020

ObjectiveThis study aimed to determine the spatiotemporal distribution and epidemiological characteristics of hospital admissions for carbon monoxide poisoning (COP) in Guangdong, China, from 2013 to 2020.MethodsData on age- and sex- specific numbers of hospital admissions due to COP in Guangdong (2013–2020) were collected. Daily temperatures were downloaded through the China Meteorological Data Sharing Service System. We analyzed temporal trends through time series decomposition and used spatial autocorrelation analysis to detect spatial clustering. The distributed lag nonlinear model was used to quantify the effects of temperature.ResultsThere were 48,854 COP admissions over the study period. The sex ratio (male to female) was 1:1.74. The concentration ratios (M) ranged from 0.73–0.82. The highest risk occurred in January (season index = 3.59). Most cases were concentrated in the northern mountainous areas of Guangdong with high-high clustering. COP in the study region showed significant spatial autocorrelation, and the global Moran's I value of average annual hospital admission rates for COP was 0.447 (P < 0.05). Low temperatures were associated with high hospital admission rates for COP, with a lag lasting 7 days. With a lag of 0 days, the effects of low temperatures [5th (12 °C)] on COP were 2.24–3.81, as compared with the reference temperature [median (24 °C)].ConclusionCOP in Guangdong province showed significant temporal and spatial heterogeneity. Low temperature was associated with a high risk of COP, and the influence had a lag lasting 7 days.     

LRH1 as a driving factor in pancreatic cancer growth

Liver receptor homolog 1 (LRH1), directs the development and differentiation of embryonic pancreas, and is overexpressed in pancreatic cancer (PC). We hypothesized that LRH1 promotes PC growth. Cell proliferation and tumorigenicity in nude mice were compared between empty vector-transfected (control) and stable LRH1-overexpressed PC cell lines. The subsequent tumor burden, vasculature development, and histologic features were evaluated. LRH1 overexpression enhanced the expression of downstream target genes (cyclin D1/E1) and stimulated cell proliferation in PC cell lines. LRH1 upregulated cyclin E1 truncated T1/T2 isoforms expression which may occur through ERα–calpain1 signaling. Compared with the control, LRH1 overexpressing stable cells generated tumors with increased weight, proliferation index and enhanced angiogenesis. Cyclin D1/E1 and calpain1 were overexpressed in human PC tumors compared to adjacent normal pancreas. These observations demonstrate that LRH1 promotes PC growth and angiogenesis, suggesting that LRH1 is a driving factor in tumorigenesis and may serve as a potential therapeutic target.     

广东省饮用水源水总α和总β放射性水平调查与分析

目的 调查广东省饮用水源水中的总α、总β放射性本底水平,建立水源水放射性水平基线值,为评估核技术应用或人类活动可能所致的饮用水潜在放射风险评估提供基础数据。方法 在全省191个在用水源,分别采集丰水期、枯水期各1次,依照GB/T 5750.13-2006《生活饮用水标准监测方法-放射性指标》要求进行采样、检测分析。按照GB 5749-2006《生活饮用水标准》评价总α、总β放射性水平。结果 丰水期、枯水期共采样382个。用于总α、总β分析的样品为377个,其中丰水期189个,枯水期188个,丰水期与枯水期一一配对样品186个。所有水源水,枯水期总α放射性水平为（0.034±0.060）Bq/L （0.008~0.582 2 Bq/L）、总β放射性水平为（0.108±0.091）Bq/L （0.014~0.637 Bq/L）,丰水期总α放射性水平为（0.045±0.064）Bq/L （0.008~0.402 Bq/L）、总β放射性水平为（0.125±0.128）Bq/L （0.014~0.848 Bq/L）。除汕尾地区响水水库枯水期有1个样品的总α放射性水平（0.582 Bq/L）超过国家饮用水放射性标准指导值外,其他样品总α、总β放射性水平皆远低于国家饮用水放射性标准指导值,丰水期总α放射性水平高于枯水期（t=2.619,P<0.05）。不同水系丰水期、枯水期总α（F_丰水期=1.819,F_枯水期=1.985,P<0.05）、总β（F_丰水期=2.709, F_枯水期=8.461,P<0.05）放射性水平差异均有统计学意义,以粤西诸河为最高。地下水在丰水期的总α、总β放射性水平均高于河流水和湖库水,河流水总α、总β放射性水平高于湖库水,差异均有统计学意义（F_总α=39.323, F_总β=25.911,P<0.05）;枯水期的总α、总β放射性水平高于河流水和湖库水,差异均有统计学意义（F_总α=11.520,F_总β=28.435,P<0.05）;总体上呈现为地下水最高,其次是河流水,最低是湖库水。结论 掌握了广东省全省饮用水源水放射性本底水平分布,低于我国规定的饮用水指导值。粤西诸河水源水放射性水平明显高于其他水系,河流水放射性水平也明显高于湖库水。     

六种固定液对小鼠角膜固定效果的比较

目的观察6种不同固定液固定下,小鼠角膜的组织形态学特征并筛选出适合角膜固定的固定液。方法取60只NIH小鼠眼球,随机分为6组,每组10只,分别固定于6种固定液中,即95%乙醇、10%中性甲醛、Bouin’s液、甲醛-乙酸固定液和Davidson’s液。固定完成后,标本经80%、95%、100%梯度酒精脱水,TO型生物制片透明剂透明,石蜡浸泡,最后石蜡包埋。石蜡切片厚度均为4μm,分别做HE染色,显微镜下观察形态学特征并对角膜各区域厚度进行测量分析。结果不同固定液固定的小鼠角膜组织形态及厚度各具特征,而甲醛-乙酸液固定后的角膜组织细胞形态改变小。结论甲醛-乙酸液固定后组织细胞形态改变小,是比较合适的小鼠角膜固定液。     

Aberrant expression of miR‐451a contributes to 1,2‐dichloroethane‐induced hepatic glycerol gluconeogenesis disorder by inhibiting glycerol kinase expression in NIH Swiss mice

The identification of aberrant microRNA (miRNA) expression during chemical‐induced hepatic dysfunction will lead to a better understanding of the substantial role of miRNAs in liver diseases. 1,2‐Dichloroethane (1,2‐DCE), a chlorinated organic toxicant, can lead to hepatic abnormalities in occupationally exposed populations. To explore whether aberrant miRNA expression is involved in liver abnormalities mediated by 1,2‐DCE exposure, we examined alterations in miRNA expression patterns in the livers of NIH Swiss mice after dynamic inhalation exposure to 350 or 700 mg m^–3 1,2‐DCE for 28 days. Using a microarray chip, we discovered that only mmumiR‐451a was significantly upregulated in the liver tissue of mice exposed to 700 mg m^–3 1,2‐DCE; this finding was validated by quantitative real‐time polymerase chain reaction. In vitro study revealed that it was metabolite 2‐chloroacetic acid, not 1,2‐DCE that resulted in the upregulation of mmu‐miR‐451a in the mouse AML12 cell line. Furthermore, our data showed that the upregulation of mmu‐miR‐451a induced by 2‐chloroacetic acid could suppress the expression of glycerol kinase and lead to the inhibition of glycerol gluconeogenesis in mouse liver tissue and AML12 cells. These observations provide evidence that hepatic mmu‐miR‐451a responds to 1,2‐DCE exposure and might induce glucose metabolism disorders by suppressing the glycerol gluconeogenesis process.     

六种不同混凝土在质子治疗机房屏蔽性能研究

目的 研究6种不同混凝土为主墙时,230 MeV质子治疗室主屏蔽体外的剂量水平,获取6种不同混凝土的屏蔽性能.方法 采用FLUKA程序构建计算模型,将不同混凝土组成引入FLUKA程序,模拟230 MeV质子束流照射情况下关注点周围剂量当量率随混凝土厚度的变化,拟合6种混凝土透射曲线,得到6种不同混凝土的屏蔽性能参数.结...