天然放射性核素及其化学类似元素从土壤向人体的转移

目的　计算天然放射性核素从土壤经膳食向人体的转移系数 ,和碱土与碱金属元素在转移中的DF(或OR)。方法　依据我国 4个膳食类型地区食品和 5 2例尸体样品元素分析所获成年男子膳食摄入量和器官组织负荷量以及全国土壤背景值 ,按照UNSCEAR环境转移模式计算元素转移系数、DF和OR。结果　2 32 Th、2 38U、2 2 6 Ra、87Rb和4 0 K由土壤向膳食进而向人体转移系数都依此递增 ,范围分别为 ( 0 0 92～ 4 0 7)Bq·a- 1 /Bq·kg- 1 和 ( 3 5 8× 10 - 3～ 6 34)Bq·a- 1 /Bq·kg- 1 。碱土元素与Pb从土壤向骨骼和碱金属元素向全身的OR范围分别为 3 77× 10 - 4～ 2 39× 10 - 2 和 2 5 2× 10 - 2～ 9 39× 10 - 1 。结论　本文所得P34 都比P2 3低。碱土元素从土壤 膳食 骨骼转移DF都小于 1,Pb的DF在Sr和Ba之间。碱金属元素Rb和Cs从土壤向膳食转移DF小于 1,由膳食向肌肉组织或全身转移的DF大于 1,Na则相反     

SELEX实验中两种富集方法的比较

比较指数富集系统进化配体 (SELEX)实验中 ,液相筛选与固 液相筛选方法的差异对筛选富集库亲和力的影响。液相筛选、膜截留结合核酸的技术路线与固 液相筛选、固相中直接获取结合核酸的途径相比较 ,前一种方法更容易富集到与靶目标结合的目的序列。     

89Sr治疗乳腺癌和前列腺癌多发性骨转移的临床观察

目的 探讨放射性核素89Sr治疗乳腺癌和前列腺癌多发性骨转移患者的临床效果.方法 回顾性分析30例乳腺癌和40例前列腺癌多发性骨转移患者接受89Sr治疗的病例资料,采用Karnofsky评分量表和骨显像方法进行疗效评估.结果 乳腺癌组的止痛总有效率为79%,前列腺癌组的止痛总有效率为85%,两组患者之间差异无统计学意义(x2=0.78,P＞0.05).两组患者的生存质量均有明显改善,治疗前后两组患者的Karnofsky评分均有明显提高(t=2.46,P＜0.05;t=2.68,P＜0.05).治疗后两组患者均未见明显骨髓抑制与肝肾功能损伤.结论 89Sr治疗乳腺癌和前列腺癌多发性骨转移止痛效果良好,患者生存质量有明显提高.     

氚在孕鼠体内的分布和向胎鼠转移特点的研究

作者重点研究了氚水在孕鼠和胎体内的分布代谢及母体中的氚通过不同转移方式向仔代转移的特点．实验用Ｃ５７ＢＬ纯种小鼠，１次腹腔注入１．８５×１０４Ｂｑ／ｇ体重的氚水。实验结果表明；氚能通过胎盘向胎鼠转移，在氚注入后的第２天母体中所测组织器官中的氚活度占注入量的５１％，到第２０天时为１％～２％．各组织间的氚分布水平相差不大，转移系数为０．９９．母体氚也能通过乳汁向胎鼠转移，表现于氚在母体组织中的活度分布低于氚在仔鼠相同组织中的活度．使氚自母体向仔鼠的转移系数超过１～２．可认为，母体氚通过乳汁向仔鼠的转移比通过胎盘转移的转移系数大，因此其辐射影响更大．     

广东高本底地区木薯中天然放射性核素含量及其转移规律的研究

本文对广东高本底地区术薯中天然核素含量分析结果表明。块根中天然U、Th为10^-6g/kg数量级; ²²⁸Ra、²²⁸Ra、²¹⁰Pb和²¹⁰Po均为l0^-11Ci/kg数量级。其中²¹⁰Pb含量最高, 达9.30±0.30×10^-11Ci/kg, ²²⁶Ra最底, 为3.09±0.20×10^-11Ci/kg。按我国现行食品卫生标准评价, 块根中天然U, Tb、²²⁶Ra和²¹⁰Po含量低于限制值, 而²¹⁰Pb和²¹⁰Ra含量分别为限制浓度的4.04倍和l0.4倍。自土壤向块根的转移系数, ²¹⁰Pb, ²¹⁰Po为10^-2数量级, 镭同位素为l0^-3数量级, 天然铀、钍为10^-4～l0^-5数量级。     

黏膜黑色素瘤的转移方式和转移部位:一项回顾性研究

正摘要目的黏膜来源的黑色素瘤非常罕见,而且预后极差。本研究目的是提供黏膜黑色素瘤的转移路径、时间间隔、影响肿瘤扩散的因素及容易发生远处转移的器官。材料与方法共有116例不同部位的黏膜黑色素瘤病人入组。时间间     

MR弥散加权成像对脊柱转移瘤的诊断价值

目的 探讨磁共振DWI对脊柱转移瘤的诊断价值.方法 对40例经临床或病理证实的脊柱转移瘤病人进行矢状位T1WI,T2WI,T2WI/FS及DWI检查,研究其在常规序列和DWI上的表现,并将常规MR序列和DWI序列检出率进行比较,计算正常椎体和病变椎体在DWI上的信号衰减率(signal attenuation ratio,SAR)及表观弥散系数(apparent diffusion coefficient,ADC),并进行统计学分析.结果 (1) MR常规序列和DWI序列(b=500 s/mm2)病灶检出率的比较:T1WI、T2WI/FS及DWI序列病灶检出率均高于T2WI序列,其间的差别有显著性意义(P<0.01),T1WI、T2WI/FS及DWI序列病灶检出率之间无显著性差异(P>0.01).(2)ADC值比较:在DWI上,病变椎体与正常椎 体的ADC值分别为:b=300 s/mm2时,(13.68±0.75)×10-4 mm2/s、(5.56±0.54) ×10-4 mm2/s;b=500 s/mm2时,(13.80±0.63)×10-4 mm2/s、(5.06±0.42) ×10-4 mm2/s.成像条件相同时,病变椎体的ADC值明显高于正常椎体(P<0.01).(3)SAR值比较:在DWI上,病变椎体与正常椎体的SAR值分别为:b=300 s/mm2时,(32.43±1.46)%,(14.94±1.34)%; b=500 s/mm2时,(48.04±1.55)%,(21.69±1.60)%.成像条件相同时,病变椎体的SAR值明显高于正常椎体(P<0.01).(4) 溶骨型、混合型及成骨型3组之间ADC值的比较 (b=500 s/mm2):溶骨型、混合型及成骨型转移瘤ADC值分别为(18.83±2.16)×10-4mm2/s、(13.89±4.42)×10-4 mm2/s、(8.77±1.07)×10-4 mm2/s,3型之间有明显的差异(P<0.01).(5) 溶骨型、混合型及成骨型3组之间SAR值的比较 (b=500 s/mm2):溶骨型、混合型及成骨型转移瘤SAR值分别为(58.87±3.99)%、(48.87±1.56)%、(34.48±3.58)%,3型之间有明显的差异(P<0.01).(6)ADC值与SAR值关系:在DWI上,成像条件相同时,相同组织的SAR值和ADC值之间存在正相关,相关性有显著性意义(P<0.01).结论 DWI可较好地反映椎体的弥散特征,SAR值和ADC值作为一个量化指标,可对脊柱转移瘤和正常椎体进行可靠的鉴别.     

MRI扩散加权成像表观弥散系数对肝脏转移瘤的诊断价值

目的 评价表观弥散系数(apparent diffusion coefficient,ADC)在不同组织来源的肝脏转移瘤的诊断价值.方法 回顾性分析45例经1.5T MRI检查的肝脏转移瘤患者的扩散加权图像,采用单因素方差分析276处肝脏转移瘤的ADC值,比较不同肿瘤组间的差异性.结果 来源于胃直肠癌、肝癌、乳腺癌的肝脏转移瘤的平均ADC值间的差异无统计学意义.来源于肺癌的肝脏转移瘤的平均ADC值低于其他来源的肝脏转移瘤,差异有统计学意义(P＜0.05).来源于胰腺癌的肝脏转移瘤的平均ADC值高于其他来源的肝脏转移瘤,差异有统计学意义(P＜0.05).结论 ADC值在肺癌和胰腺癌来源的肝脏转移瘤的诊断中有一定的价值.     

癌浸润和转移机理研究的某些进展

肿瘤的发生和转移是两个既相互关联又各自独立的生物学过程。正常组织细胞为什么会转变为癌细胞？是近年来研究的热点。同样，癌细胞为什么会转移？能不能防止或治疗癌转移也是近年来人们一直关注的课题之一。下面概述这个研究领域的某些进展。１癌浸润转移与粘附分子癌细...     

热损伤对肝细胞肝癌细胞增殖及侵袭转移特性影响的实验研究

目的 体外实验评价热损伤对肝细胞肝癌(HCC)细胞增殖、侵袭转移能力及上皮-间质细胞转化(EMT)等特性的影响,探索热消融与HCC复发转移之间的关系.方法 通过体外加热构建McA-RH7777 HCC细胞热损伤模型.CCK-8法检测热损伤对HCC细胞增殖能力的影响,流式细胞技术检测细胞周期情况.Transwell实验研究热损伤对HCC细胞侵袭能力的影响.荧光定量-聚合酶链反应(RT-PCR)和蛋白印迹(Western blot)分析热损伤对HCC细胞侵袭及EMT相关分子标志物VEGF、MMP-9、Nm23、E-cadherin、vimentin的mRNA和蛋白表达的影响.结果 McA-RH7777 HCC细胞热处理条件为43.5C水浴30 min.热处理后2～5 d细胞增殖能力显著高于对照组(P＜0.05).热处理48 h及72 h后处于G1期细胞比例降低,S+G2期细胞比例增加,差异有统计学意义(P＜0.05).与对照组比较,热处理后24 h后HCC细胞侵袭能力差异不明显,而热处理72 h后细胞侵袭能力显著增加(22.3±2.46对14.2±1.82,P＜0.001).RT-PCR和蛋白印迹分析结果显示,热处理72 h后HCC细胞VEGF、MMP-9和vimentin表达水平显著增加,E-cadherin表达显著降低,差异有统计学意义(P＜0.05).结论 亚致死量热损伤诱导McA-RH7777 HCC细胞发生EMT并增加其增殖和侵袭转移能力,表现出更高的恶性潜能.     

Assessment of the transfer of Cs in three types of vegetables consumed in Hong Kong

A dynamic food chain model has been built for the modeling of the transfer of ¹³⁷Cs in three types of vegetables consumed in Hong Kong, namely, white flowering cabbage (Brassica chinensis), head lettuce (Lactuca sativa) and celery (Apium graveolens). Some parameters have been estimated from the experimental data obtained in this work. The experimental data include the transfer factors of ¹³⁷Cs from soil to the different vegetable species which are determined through high resolution gamma spectrometry, maximum crop biomasses for the vegetable species, the dry-to-fresh ratios for the vegetable species, the bulk density of soil layers and the average concentration of ¹³⁷Cs in air. The derived parameters include the deposition rate and the root uptake rate, information for tillage, the logistic growth model and radionuclide concentrations in vegetables. The dynamic food chain model is solved by the Birchall–James algorithm to give the ¹³⁷Cs concentration in subsurface soil, from the 0.1–25 cm soil layer, and the ¹³⁷Cs concentration in harvested and unwashed vegetables. As validation of the model and parameters, the concentrations obtained experimentally and from the model are compared and are found to be in good agreement.     

Kinetics of isotopic exchange between strontium polymolybdate and strontium ions in aqueous solution

A heterogeneous isotopic exchange reaction of strontium polymolybdate in strontium chloride solution was studied using ⁹⁰Sr as a tracer. The effects of low and high strontium chloride concentration on the rate and mechanism of the isotopic exchange reaction were investigated. It was found that, at high concentrations, the rate is independent of strontium concentration, but, at low concentrations, the rate is proportional to the strontium concentration. These results support a hypothesis that, at low concentrations, the rate is controlled by film diffusion, whereas at high concentrations it is controlled by particle diffusion. Experiments were performed at 293, 303 and 313 K. Activation energy of isotopic exchange reaction and thermodynamic parameters ΔH^*, ΔS^*, and ΔG^* were calculated using the Arrhenius and Eyring equations. The results also indicated that recrystallization is a predominant factor in the present exchange reaction.     

Measurements of the strontium plasma clearance rate in patients receiving 89Sr radionuclide therapy

The total strontium plasma clearance rate due to excretion through the kidneys and gut has an imporant influence on the absorbed does delivered to skeletal metastases and red bone marrow in patients receiving ⁸⁹Sr radionuclide therapy for disseminated prostatic carcinoma. Although a measurement of the renal strontium plasma clearance rate may readily be obtained through a 24-h urine collection, little information is available on the correlation between renal and total clearances. We describe a method of determining total strontium plasma clearance rate from whole body counter measurements of total body strontium retention and measurements of plasma strontium concentration following administration of a ⁸⁵Sr tracer dose at the time of ⁸⁹Sr therapy. Amongst the 26 patients whom we studied, the total clearance rate varied from 1.2–15.0 l/day, renal clearance rate from 0.1–11.5 l/day, and the mean gut clearance rate was 2.0 l/day. A close correlation was found between total and renal clearance, with the renal component accounting for 96% of the variance in total strontium plasma clearance. A weak collection may exist between gut and renal clearance.     

三种溶液持续冲洗预防有创动脉压监测留置导管内血栓形成

对危重患者进行持续的有创动脉压(Invasivearterial blood pressure,IABP)监测有助于提高治疗效果,降低病死率[1],但是该方法的主要缺点是动脉留置导管内血栓形成[2]。为了探索一种对患者凝血机制影响小,并发症少,在IABP监测时预防动脉留置导管内血栓形成的安全有效方法,我科自     

肾小球滤过率评估方程在亲属肾移植供者评估中的适用性比较

目的以99mTc-DTPA血浆清除率为标准,对24 h内生肌酐清除率(Ccr)、Cockcroft-Gault(CG)方程和简化MDRD方程进行比较,评价三种方程在评估亲属肾移植供者肾功能中的应用价值。方法选择2004—2010年在我院进行评估的40例亲属肾移植供者,所有患者同步检测99mTc-GFR、血、尿肌酐等,将Ccr、C-G方程和简化MDRD方程估算的肾小球滤过率(GFR)用体表面积(BSA)标准化,与BSA标准化的99mTc-DTPA测得的GFR(99m Tc-GFR)进行比较。结果 Ccr、MDRD-GFR、CG-GFR与99mTc-GFR相关系数r分别为:0.74、0.81、0.86;三种方程的GFR估算值与99mTc-GFR差异均有显著统计学意义(P<0.01)。结论三种方程的GFR估算值与99mTc-GFR均有较好的相关性,其中以C-G方程最好,其次为简化MDRD方程,Ccr最低,但三种方程估算值与99mTc-GFR测定值差异均存在显著统计学意义。C-G方程较适合应用于亲属肾移植供者肾功能的初步评价。     

不同病理类型肺癌HRCT征象与三种血清肿瘤标志物的相关性

目的：探讨肺腺癌、肺鳞癌和小细胞肺癌的 HRCT 征象与三种血清肿瘤标志物浓度之间的相关性,提高肺癌的诊断水平。方法：选取111例经病理证实的肺癌患者作为观察对象,其中肺腺癌69例,肺鳞癌30例,小细胞肺癌12例。进行 HRCT 扫描和血清肿瘤标志物（CEA、CYFRA21-1及 NSE）检测,分析不同病理类型肺癌的 HRCT 征象与三种血清肿瘤标志物的相关性。结果：111例肺癌中分叶征102例,毛刺征59例,胸膜凹陷征49例,血管集束征26例,空泡征55例。CEA 在肺腺癌中的浓度最高[（13．43±24．81）ng／mL],CYFRA21-1在肺鳞癌中的浓度最高[（17．81±31．21）ng／mL],NSE 在小细胞肺癌中的浓度值最高[（47．48±57．32）ng／mL]。不同 HRCT 征象的肺癌 CEA 浓度和 CY-FRA21-1浓度没有统计学差异。不同病理类型肺癌的 CEA 浓度没有统计学差异。肺鳞癌的 CYFRA21-1浓度高于肺腺癌和小细胞肺癌（P ＜0．05）。小细胞肺癌 NSE 浓度显著高于肺鳞癌和肺腺癌（P ＜0．05）。结论：CEA、CYFRA21-1和NSE 平均浓度值最的依次是肺腺癌、肺鳞癌和小细胞肺癌。CYFRA21-1浓度、NSE 浓度的显著升高分别提示肺鳞癌、小细胞肺癌的可能性较大。有胸膜凹陷征的小细胞肺癌 NSE 的浓度最高。     

3种常见介入诊疗中放射工作人员有效剂量的估算

目的 选取介入放射学中较常见的脑血管、心血管和肝脏介入诊疗,估算以上3种介入诊疗中放射工作人员的有效剂量.方法 通过仿真人体模型实验,了解脑血管、心血管、肝脏介入诊疗中仿真体模内组织、器官的吸收剂量,并根据ICRP 103号出版物中规定的组织权重因子估算3种介入诊疗中放射工作人员的有效剂量.结果 脑血管介入诊疗时,介入放射工作人员的有效剂量分别为高剂量组24.0μSv、中剂量组9.7μSv、低剂量组6.8 μSv;心血管介入诊疗时,放射工作人员的有效剂量分别为高剂量组36.3 μSv、中剂量组29.3 μSv、低剂量组17.8μSv;肝脏介入诊疗时,放射工作人员的有效剂量分别为高剂量组23.9 μSv、中剂量组11.3μSv、低剂量组5.5μSv.结论 心血管介入诊疗中放射工作人员高、中、低3个剂量组的有效剂量分别高于脑血管和肝脏介入诊疗时相应剂量组的有效剂量.

Abstract：

Objective To study and estimate the effective dose of interventional employees in the common cerebralvascular, cardiovascular and liver interventional diagnosis and treatment.Methods The absorbed doses of tissue or organ of anthropomorphic phantom in these three procedures were estimated by the anthropomorphic phantom experiment.The effective doses were calculated by the tissue weight factor which was given by International Commission on Radiological Protection publication 103.Results The effective doses to high, medium and low group were 24.0, 9.7,6.8 μSv for cerebralvascular interventional diagnosis and treatment, and 36.3, 29.3, 17.8 μSv for cardiovascular interventional diagnosis and treatment, and 23.9, 11.3, 5.5 μ Sv for liver interventional diagnosis and treatment, respectively.Conclusions The effective doses of high, medium and low group of interventional employees in cardiovascular interventional procedure are higher than those of cerebralvascular and liver interventional procedures.     

中国人牙齿胶原蛋白中14C浓度测定及评价

目的　测定不同年龄人牙胶原蛋白中的14 C浓度 ,以了解几十年来世界范围内因核试验生成的14 C对中国的环境污染和人体中14 C浓度的影响。方法　从 192 0～ 1977年间出生的上海居民中收集到的牙齿中挑选永久第 8齿 48只 ,经去污、脱钙、提取胶原蛋白 ,再经高温氧化、精制、还原成石墨 ,用加速器质量分析计 (AMS)测定δ14 C ,并用δ13C进行修正 ,求得Δ14 C浓度。结果　δ14 C在 (- 2 9 5 1± 15 0 2 )‰和 (5 75 88± 2 1 0 9)‰之间 ,Δ14 C在 (- 2 7 0 1± 15 32 )‰和 (5 80 34±2 1 5 2 )‰之间 ,且随出生年份不同有显著变化 ,各试料的δ14 C和Δ14 C之差在δ14 C和Δ14 C的标准差的 1/ 3以下。结论　随出生年份不同牙齿胶原蛋白中14 C浓度有显著变化 ,1940年前出生的Δ14 C值属本底水平 ,从 1941年开始呈明显上升趋势 ,至 195 1年前后出生的达最高峰 ,约为 5 80‰ ,以后呈缓慢减少 ,这与以前报道的植物、人体组织中14 C浓度变化有相似倾向 ,与 1990年报道的日本人牙齿中14 C浓度变化相一致 ,并与世界范围内大气层中核试验次数密切相关。     

Massively parallel sequencing of 74 microhaplotypes and forensic characteristics in three Chinese Sino-Tibetan populations

Microhaplotype (MH), as an emerging type of forensic genetic marker in recent years, has the potential to support multiple forensic applications, especially for mixture deconvolution and biogeographic ancestry inference. Herein, we investigated the genotype data of 74 MHs included in a novel MH panel, the Ion AmpliSeq MH-74 Plex Microhaplotype Research Panel, in three Chinese Sino-Tibetan populations (Han, Tibetan, and Yi) using the Ion Torrent semiconductor sequencing. The sequencing performance, allele frequencies, effective number of alleles (A_e), informativeness (I_n), and forensic parameters were subsequently estimated and calculated. In addition, principal component analysis (PCA) and structure analysis were performed to explore the population relationships among the three populations and the ancestry component distribution. Overall, this novel MH panel is robust and reliable, and has an excellent sequencing performance. The A_e values ranged from 1.0126 to 7.0855 across all samples, and 75.68 % of MHs had A_e values >2.0000. Allele frequencies at some loci varied considerably among the three studied populations, and the mean I_n value was 0.0195. Moreover, the genetic affinity between Tibetans and Yis was closer than that between Tibetans and Hans. The aforementioned results suggest that the Ion AmpliSeq MH-74 Plex Microhaplotype Research Panel is highly polymorphic in three investigated populations and could be used as an effective tool for human forensics. Although these 74 MHs have demonstrated the competency in continental population stratification, a higher resolution for distinguishing intracontinental subpopulations and a more comprehensive database with sufficient reference population data still remain to be accomplished.     

Curvilinear increase in methanol concentration after inhibition of oxidation by ethanol: significance for the investigation of endogenous methanol concentration and formation

Endogenous methanol production was assessed over a period of 5 h in subjects given an infusion of ethanol to inhibit methanol oxidation in the liver after a period of fasting and abstinence from alcohol. Ethanol was administered to each of five subjects at rates of 0.35 g/kg per hour and 0.70 g/kg per hour. The rise in methanol concentration was biphasic regardless of the rate of ethanol administration, with a steeper gradient in the first 10–30 min. This may be due to the existence of a deep compartment from which methanol can be displaced by ethanol. This could take the form of loose binding of methanol to the hepatic oxidation enzymes as an enzyme-substrate complex, or a shift of the oxidation-reduction equilibrium between methanol and formaldehyde. The biphasic nature of the increase, with an initial steeper rise, means that the values obtained in the first 30 min should be excluded from the calculations when the rate of endogenous methanol production is determined by linear regression analysis. Endogenous methanol concentrations to be taken into account after ethanol administration are on average 0.4–0.6 mg/kg higher than those detectable in the absence of ethanol due to the additional method displaced from the deep compartment. Received: 20 January 1997 / Received in revised form: 7 August 1997