Chornobyl radiation—congenital anomalies: A persisting dilemma

We report population prevalence rates of neural tube defects (NDT) and microcephaly (MIC) as well as levels of incorporated Cs137 by pregnant women in two areas of the Rivne Province of Ukraine, a northern half (Polissia) polluted by Chornobyl radiation and not‐Polissia areas. Monitoring of congenital malformations was conducted with adherence to methods adopted by a European surveillance network (EUROCAT). Incorporated Cs137 (Bq/kg) by pregnant women residing in the Polissia and not‐Polissia areas were obtained concurrently with prenatal ultrasound examinations. In Polissia, the incorporated Cs137 levels by pregnant women as well as the prevalence rates of NDTs and MIC are significantly higher than in not‐Polissia. In Polissia, the prevalence rates of NDTs and MIC are among the highest in Europe. The debate concerning the teratogenic impact of chronic exposures to low levels of ionizing radiation was re‐ignited by our 2010 report. Health agencies uphold the notion that exposure to Chornobyl radiation levels are too low to be teratogenic, which is inconsistent with our observations. Further investigations in Rivne by international teams can, we believe, contribute facts to the ongoing debate. Our monitoring system, experience and data can facilitate concurrent investigations of teratogenic risks from exposures to other sources of ionizing radiation, alcohol, folate, and zinc deficiencies, among other risk factors. Study of genomic impacts can likewise be undertaken.     

Vertical profile of Cs in soil

In this paper, a vertical distribution of ¹³⁷Cs in undisturbed soil was investigated experimentally and theoretically. Soil samples were taken from the surroundings of the city of Kragujevac in central Serbia during spring-summer of 2001. The sampling locations were chosen in such a way that the influence of soil characteristics on depth distribution of ¹³⁷Cs in soil could be investigated. Activity of ¹³⁷Cs in soil samples was measured using a HpGe detector and multi-channel analyzer. Based on vertical distribution of ¹³⁷Cs in soil which was measured for each of 10 locations, the diffusion coefficient of ¹³⁷Cs in soil was determined. In the next half-century, ¹³⁷Cs will remain as the source of the exposure. Fifteen years after the Chernobyl accident, and more than 30 years after nuclear probes, the largest activity of ¹³⁷Cs is still within 10 cm of the upper layer of the soil. This result confirms that the penetration of ¹³⁷Cs in soil is a very slow process. Experimental results were compared with two different Green functions and no major differences were found between them. While both functions fit experimental data well in the upper layer of soil, the fitting is not so good in deeper layers. Although the curves obtained by these two functions are very close to each other, there are some differences in the values of parameters acquired by them.     

新疆核试验场周围土壤中90Sr137Cs水平

用放射化学分析方法,对新疆核试验场周围10个调查区和远离核试验场位于上风向的5个对照区采取的土壤样品进行了⁹⁰Sr、¹³⁷Cs分析测定。核试验场周围调查区土壤中⁹⁰Sr累积平均沉降量为1.5×10³Bqm^-2,¹³⁷Cs为4.9×10³Bqm^-2;对照区⁹⁰Sr累积平均沉降量为1.3×10³Bqm^-2,¹³⁷Cs为3.9×10³Bqm^-2。调查区和对照区表层土壤中州⁹⁰Sr,¹³⁷Cs放射性平均水平无显著性差异。通过估算得出了调查区⁹⁰Sr、¹³⁷Cs对居民产生约定有效剂量当量分别为78.3μSv(集体剂量当量负担为23.9人·sv)和270μSv(集体剂量当量负担为82.3人·sv),对照区分别为70.5μSv,(集体剂量当量负担为14.1人·sv)和220μSv(集体剂量当量负担为14.1人·sv)。两个地区居民受到来自核试验产生的⁹⁰Sr和¹³⁷Cs给予人体的内照射剂量当量负担基本上是一样的。可认为⁹⁰Sr、¹³⁷Cs对新疆核试验场周围没有造成严重的局部污染。对居民的身体健康不致于产生不良影响。     

Functional expression of 4-1BB (CD137) in the inflammatory tissue in Crohn's disease

4-1BB ligand (L) expressed on antigen presenting cells (APC) interacts with 4-1BB, expressed on activated T cells and this interaction costimulates T cells to secrete cytokines and to proliferate. We investigated whether 4-1BB/4-1BBL interactions might be involved in the pathogenesis of Crohn's disease (CD). In immunohistochemistry, we found 4-1BB expression on lamina propria (LP) cells in inflamed and to a lesser extend in non-inflamed gut tissue from CD patients. mRNA levels for 4-1BB were also elevated in intestinal CD tissue. In contrast, only few 4-1BB-expressing cells were found in inflamed tissue from ulcerative colitis (UC) patients and almost no positive cells were found in control intestinal tissue. 4-1BB expression was better sustained on in vitro activated lamina propria T cells from CD patients compared to controls. Finally, agonistic anti-4-1BB antibody enhanced interferon-gamma (IFN-gamma) production and proliferation of lamina propria T cells from CD patients. Taken together, our data suggest that 4-1BB/4-1BBL interactions contribute to the persistence of gut inflammation in CD.     

Evidence for the existence of two forms of α2A-adrenoceptors in the rat

Summary The _2A-adrenoceptors in rat spleen, kidney, spinal cord and cerebral cortex were studied using [³H]-RX821002 radioligand binding. In the spleen, spinal cord and cerebral cortex, the ligand bound to saturable sites with a K _d of about 1 nmol/l and capacities of 134, 240 and 290 fmol/mg protein, respectively. Computer modelling competition curves for 39 drugs, including those for _2A-, _2B- or _2C-adrenoceptor selective drugs, indicated that the sites labelled by [³H]-RX821002 in the spleen consisted of a single population of _2A-adrenoceptors. However, the competition curves for guanoxabenz were definitely biphasic and resolved into two site fits, indicating that guanoxabenz was binding to both high affinity (K _d = 35 nmol/1) and low affinity (K _d = 8900 nmol/1) _2A-adrenoceptor sites in the proportions 57% and 43%, respectively. The K _d ^Sfor a number of ₂-adrenoceptor subtype selective drugs, measured in competition with [³H]-RX821002 in cerebral cortex and spinal cord, were highly correlated with those obtained in the spleen indicating their _2A-adrenoceptor nature. However, by contrast to the results with the spleen, the guanoxabenz competition curves for the spinal cord and cerebral cortex were monophasic and resolved only into one site fits, the K _d of guanoxabenz being about 4000 nmol/l for both tissues. Drug K _d ^Sfor kidney _2A-adrenoceptors were also determined using [³H]-RX821002. For nearly all drugs tested, the K _d ^Swere highly correlated with those found for the _2A-adrenoceptors in the other rat tissues. However, for guanoxabenz, the data indicated that it competed with [³H]-RX821002 at a single _2A-adrenoceptor site with a K _d of 39 nmol/1. When the rat _2A-adrenoceptor gene RG20 was transiently expressed in COS-7 cells and its ligand binding properties probed using [³H]-RX821002, the drug K _d ^Sobtained were also highly correlated with those found for the _2A-adrenoceptors in the spleen, cerebral cortex, spinal cord and kidney of the rat. For the RG20 encoded receptor, the guanoxabenz competition curves were steep and monophasic and modelled best into one site fits, with the Kd of guanoxabenz being 5200 nmol/1.It is suggested that guanoxabenz can differentiate between two forms of _2A-adrenoceptors in the rat: _2A1 and _2A2. The _2A1-form is present in the spleen and kidney where it shows a high apparent affinity for guanoxabenz. The _2A2-form shows a low apparent affinity for guanoxabenz and is present in the spleen, cerebal cortex and spinal cord. The _2A2-form of the rat ₂-adrenoceptor appears to be encoded by the RG20 gene. The _2A, and _2A2-adrenoceptor forms do not represent high and low affinity receptor forms for agonists because assays included EDTA, Gpp(NH)p and Na⁺, which eliminated the high affinity receptors for agonists.     

Evaluation of a new fletcher applicator using cesium-137

The improved Fletcher Applicator¹ is a recent modification of the afterloading Fletcher system. Its aluminum construction reduces the weight by 50 % and is more comfortable for the patient. Removable caps contain medially placed tungsten screens that shield tissues anteriorly and posteriorly. When the caps are removed, the colpostats can be used as Delclos mini-ovoids. A method for evaluating the dosimetry of brachytherapy applicators in a water phantom was devised so this applicator could be studied and compared with other gynecologic applicators. The results show that the transmission ratios—the fraction of radiation transmitted through the tungsten shields—differ from those of the preloaded Fletcher colpostat, but are similar to the transmission ratios of the Fletcher-Suit applicator. There is a 10 % to 25 % reduction in the radiation dose to the region of the bladder trigone and anterior rectum with the shield containing cap in place. This percent reduction in dose is in agreement with other Fletcher applicators. Misalignment of the source basket within the colpostat, and motion of the source in the carrier cause variations in the dose rate at specific distances from the colpostat.     

淋巴细胞微核试验用于全血γ射线辐照效果评价

目的探讨淋巴细胞微核试验用于全血γ射线的辐照效果。方法分别用15、25、35Gy射线剂量的137Cs辐照血液,注入含有PHA的RPIM1640培养基的小瓶中培养(37℃,72h),收集淋巴细胞,制片,观察和计算微核细胞率;另分离淋巴细胞,进行淋巴细胞增殖试验。结果与对照组相比,随着辐照剂量的升高,微核细胞率显著升高(P<0.01),而淋巴细胞增殖率显著下降(P<0.01)。微核细胞率与淋巴细胞增值率之间有高度相关性,曲线拟合方程为:^Y=1021.246613-43.872036X 0.825340X2-0.004886X3,R2=0.999999,P<0.01。结论微核试验用于评价γ射线灭活淋巴细胞的效果有一定的应用前景,35Gy剂量的137Csγ射线对淋巴细胞的灭活效果较好。     

长链非编码RNA TUSC8调控miR-137对宫颈癌迁移和侵袭的影响

【摘要】 目的 探讨长链非编码RNA TUSC8调控miR 137对宫颈癌迁移和侵袭的影响及其机制。方法 qPCR检测TUSC8和miR 137在宫颈癌组织和正常宫颈组织中的表达情况及差异,分析TUSC8与宫颈癌患者临床病理学参数之间的相关关系,双荧光素酶报告基因检测TUSC8与miR 137之间的相互作用;Transwell侵袭实验检测抑制TUSC8后宫颈癌细胞侵袭行为的变化情况;划痕愈合实验检测抑制TUSC8后宫颈癌细胞迁移行为的变化情况;裸鼠体内成瘤实验抑制TUSC8后宫颈癌细胞的成瘤能力的变化。结果 与正常宫颈组织相比,宫颈癌组织中TUSC8和miR 137的表达水平均相对上调,差异有统计学意义（P＜005）;TUSC8的表达与宫颈癌的病理分期相关以及淋巴结转移情况有关,分期越高,TUSC8在宫颈癌组织中表达越高,淋巴结转移的患者中TUSC8的表达也相对较高;双荧光素酶实验证实TUSC8能与miR 137的3’ UTR特异性结合,可以调控miR 137的表达与活性;抑制TUSC8的表达后可以抑制宫颈癌细胞的迁移和侵袭能力;抑制TUSC8后宫颈癌细胞的成瘤能力受到相应的抑制。结论 TUSC8可以调控miR 137的表达影响宫颈癌细胞的迁移和侵袭行为。