DNA损伤在衰老相关疾病中的研究进展

DNA损伤是衰老相关疾病领域的研究热点, 可引起细胞周期停滞、凋亡, 加快个体衰老速度、增加衰老相关疾病的患病风险。本文将从细胞衰老和个体衰老两个层面阐述其与衰老之间的研究进展, 并综述其与衰老常见相关疾病(肿瘤、心血管疾病、阿尔茨海默病)及早衰综合征的关系, 为抗衰老研究和临床干预衰老相关疾病提供理论依据。     

二维斑点追踪显像技术评估窒息新生儿左心室纵向收缩功能与心肌损害的相关性

【摘要】目的 探讨二维斑点追踪显像技术(2D-STI)评估新生儿窒息合并心肌损害后左心室整体及局部心肌的纵向收缩功能在早期诊断窒息新生儿心肌损害中的临床价值。方法 选择2019年07月至2020年12月期间在右江民族医学院附属医院新生儿科住院的足月窒息新生儿61例，经临床确诊合并心肌损害，根据Apgar评分分为轻度组31例和重度组30例，选择同期住院出生的正常足月新生儿30例作为对照组。检测受检者的血清肌酸激酶同工酶（CK-MB）、肌钙蛋白（cTnT）、左室舒张期前后径（LVDId）、左室射血分数（LVEF）、左室短轴缩短率（LVFS）、辛普森法左室射血分数（Simpson EF）、左室三腔心整体应变（GLS-LAX）、左室四腔心整体应变（GLS-A4C）、左室两腔心整体应变（GLS-A2C）、左室整体应变（GLS-AVG）,分析GLS-AVG和CK-MB、cTnT三者的相关性。结果 三组间CK-MB和cTnT比较差异有统计学意义（P<0.05）。三组间性别、体重、胎龄均无统计学差异（P>0.05）。三组间LVDId、LVEF、LVFS、Simpson EF比较差异无统计学意义（P>0.05）。GLS-AVG与CK-MB呈负性相关（r=-0.515，P=0.000），GLS-AVG与cTnT呈负性相关（r=-0.912，P=0.000）。结论 GLS-AVG与CK-MB、cTnT具有相关性，GLS-AVG可作为窒息新生儿心肌损害早期诊断指标。     

RNA相关的低剂量辐射响应标志物

电离辐射会对人体造成损伤,根据受照剂量、时间等因素的不同可诱发多种生物效应。目前对于低剂量辐射产生的健康效应仍有争议,筛选对低剂量敏感的辐射响应生物标志物,对于完善低剂量辐射生物效应机制、拓宽低剂量辐射在临床中的应用均具有重要理论意义。综述探讨各核糖核酸(RNA)在低剂量辐射反应中的变化及其对辐射敏感性的调节作用,同时评估各RNA作为低剂量辐射响应标志物的潜力。     

European consensus on patient contact shielding

Patient contact shielding has been in use for many years in radiology departments in order to reduce the effects and risks of ionising radiation on certain organs. New technologies in projection imaging and CT scanning such as digital receptors and automatic exposure control (AEC) systems have reduced doses and improved image consistency. These changes and a greater understanding of both the benefits and the risks from the use of shielding have led to a review of shielding use in radiology. A number of professional bodies have already issued guidance in this regard. This paper represents the current consensus view of the main bodies involved in radiation safety and imaging in Europe: European Federation of Organisations for Medical Physics, European Federation of Radiographer Societies, European Society of Radiology, European Society of Paediatric Radiology, EuroSafe Imaging, European Radiation Dosimetry Group (EURADOS), and European Academy of DentoMaxilloFacial Radiology (EADMFR). It is based on the expert recommendations of the Gonad and Patient Shielding (GAPS) Group formed with the purpose of developing consensus in this area. The recommendations are intended to be clear and easy to use. They are intended as guidance, and they are developed using a multidisciplinary team approach. It is recognised that regulations, custom and practice vary widely on the use of patient shielding in Europe and it is hoped that these recommendations will inform a change management program that will benefit patients and staff.     

Dose Rate Simulation of the Urine Collection Bag of Patients Undergoing Bone Scintigraphy

ObjectiveThe objective of the study was to estimate the determined dose rate in the urine collection bag of patients undergoing bone scintigraphy.MethodThe ^99m Tc-methylene diphosphonate accumulated activity eliminatedin urine was estimated and calculated by the Committee on Medical Internal Radiation Dose 14 method. This allowed the calculation of the dose rate emitted at distances of 10, 50, and 100 cm and the creation of a simulation collection bag to validate the calculations by means of measurements carried out with a Geiger Müller counter in the same situations. A linear regression test was performed to verify the significant difference between the measurements and validate the dose rate estimate.ResultsThe calculated and measured dose rates showed the highest values at a distance of 10 cm up to 3 hours after administering the radiopharmaceutical to the patient. After this period, as the collection bag was emptied for image acquisition, the dose rate was close to the background radiation.ConclusionThe maximum accumulated activity in the urine collection bag, and consequently, the maximum dose rate, occurs at the time of emptying the bag for image acquisition. Therefore, in addition to exposure to radiation, there is a considerable risk of contamination by ionizing radiation for the professional who performs the procedure. To minimize this risk and the exposure, the recommendation is to use personal protective equipment and to consider radiological protection factors, which are shorter exposure time, longer distance, and greater barrier between the professional and the radioactive source.     

Magnetron Sputtered CsPbCl3 Perovskite Detectors as Real-Time Dosimeters for Clinical Radiotherapy

The aim of this study is to investigate the feasibility of manufacturing thin real-time relative dosimeters for clinical radiotherapy (RT) with potential applications for transmission monitoring in vivo dosimetry and pre-treatment dose verifications. Thin (≈1 μm) layers of a high sensitivity, wide bandgap semiconductor, the inorganic perovskite CsPbCl₃, have been grown for the first time by magnetron sputtering on plastic substrates equipped with electrode arrays. Prototype devices have been tested in real-time configuration to evaluate the dose delivered by a 6 MV photon beam from a linear accelerator. Linearity of the charge with the dose has been verified over three order of magnitudes, linearity of the current signal with the dose rate has been also successfully tested in the range 0.5-4.3 Gy/min. The combination of high sensitivity per unit volume and wide bandgap provides high signal-to-noise ratios, up to 70, even at moderate applied voltages. The Schottky diode configuration allows the detector to operate without bias voltage (null bias).The blocking-barrier structure allows to confine the active volume within sub-millimetric sizes, a quite attractive feature in view to increase granularity and achieve the high spatial resolutions required in modern RT techniques. All the above-mentioned features indeed pave the way to a novel generation of flexible, transmission, real time dosimeters for clinical radiotherapy.     

尿酸性肾病中医分型与氧化应激指标的相关性研究

目的：探讨尿酸性肾病中医分型与氧化应激相关性。方法：采用回顾性分析方法对2017年12月至2019年9月北京中医药大学第三附属医院收治的尿酸性肾病患者105例进行研究，选择同时期正常健康者105例作为对照，参考《中药新药临床研究指导原则》将105例尿酸性肾病和临床常见证型相结合，分成脾肾气虚18例、气阴两虚证19例、肝肾阴虚16例、阴阳两虚12例、湿热蕴结19例、瘀血阻滞17例、痰浊内阻13例，均在入院次日清晨空腹抽取静脉血，检测氧化应激氧化应激、肾功能损害指标，比较不同组别在氧化应激指标含量水平变化情况，比较中医分型和氧化应激、肾功能损害指标水平变化。结果：1）尿酸性肾病组总抗氧化能力（T-ACO）、晚期蛋白氧化物（AOPP）、血清丙二醇（MDA）、超氧化物歧化酶（SOD）含量水平分别为（19.45±3.42）U/mL、（42.45±3.53）μmol/L、（4.52±1.23）nmol/L、（76.78±5.64）U/mL，正常对照组则分别为（10.76±1.31）U/mL、（20.84±1.28）μmol/L、（2.13±0.76）nmol/L、（130.85±16.75）U/mL，尿酸性肾病组T-ACO、AOPP、MDA较正常对照组显著偏高，SOD显著偏低（P<0.05）。2）虚证中阴阳两虚证SOD含量上较其他证型均偏低，而MDA、T-AOC、AOPP、胱抑素C（CysC）、β2微球蛋白、尿微量白蛋白（UMALB）、蛋白尿发生率则较其他证型均偏高，差异均有统计学意义（P<0.05），实证中瘀血阻滞证SOD含量较其他证型均偏低，而MDA、T-AOC、AOPP则较其他证型均偏高，差异均有统计学意义（P<0.05）。结论：尿酸性肾病中医分型的阴阳两虚证、瘀血阻滞证氧化应激水平、肾损害指标均显著升高，可结合该实验室检查进行临床干预。