干扰素基因激活因子激动剂对人皮肤黑色素瘤细胞的放射增敏作用研究

目的探讨干扰素基因激活因子(STING)激动剂对皮肤黑色素瘤细胞的放射增敏作用及其机制。方法为检测STING激动剂环二腺苷酸(c-di-AMP)对人皮肤黑色素瘤细胞(A375)辐射后的影响, 将人皮肤黑色素瘤细胞A375分为空白对照组、10 μmol/L c-di-AMP处理组、X射线照射组、照射+c-di-AMP组。通过CCK-8法、乳酸脱氢酶(LDH)释放实验、平板克隆形成实验以及流式细胞术等手段, 检测c-di-AMP对A375细胞的放射增敏作用。采用Western blot检测细胞死亡相关蛋白表达。结果 10 μmol/L的c-di-AMP联合10 Gy X射线照射时可见明显的放射增敏效应, A375细胞活力较X射线照射组显著下降(t=5.11, P<0.05), 细胞毒性显著增加(t=10.15, P<0.05), 细胞凋亡显著增加(t=4.41, P<0.05), 细胞克隆增殖能力显著降低(t=6.30、3.55、5.45、3.55, P<0.05)。c-di-AMP的放射增敏比(SER)为1.88。10 μmol/L的c-di-AMP联合10 Gy...     

中枢神经元间非突触信息传递方式的研究进展

19世纪末期,著名的神经解剖学家Cajal和Golgi就神经元间的连接方式进行了激烈的争论。这个问题的答案毫无疑问对理解信号是如何从神经系统一部分传递到另一部分具有十分重大的意义。高尔基的网络学说认为神经系统是由网状组织组成,神经元胞浆在细胞连接处直接相通。而Cajal利用     

ICRU89号报告的解读——放射物理篇

本篇综述对ICRU89号报告的放射物理相关内容进行了详细解读,希望为从事宫颈癌近距离放射治疗的同仁在放射物理相关方面提供借鉴。     

医科达数字化电子直线加速器控制软件IPV基本原理与应用解读

目的 介绍医科达数字化医用电子直线加速器控制软件里子项目和项目成分值(IPV)的工作原理,并具体说明控制软件通过三类子项目及其项目分项实时监测、控制子系统的运行状态。方法 首先介绍医科达数字化医用电子直线加速器的控制系统组成,然后介绍控制软件里子项目和项目分项的定义和分类,以及各类子项目的基本原理,最后通过分析高功率移相器的运动控制具体说明控制软件的子项目在实时监测、控制子系统运行状态的应用。结果 通过分析原理和举例详细、具体说明了控制软件IPV的工作原理及其应用,使用户尤其是维修人员能掌握相应理论知识,在日常使用和维修时能通过软件快速准确地查找运行参数,并根据相关子系统的控制原理分析问题和解决故障。结论 用户尤其是维修人员掌握这些子项目及其项目分项的工作原理,就能在日常使用或维修、校准时,快速准确地通过控制软件查看、校准运行参数,解决设备故障,并避免错误操作引起事故。     

Test Procedures for Disease Prevalence with Partially Validated Data

Investigating the prevalence of a disease is an important topic in medical studies. Such investigations are usually based on the classification results of a group of subjects according to whether they have the disease. To classify subjects, screening tests that are inexpensive and nonintrusive to the test subjects are frequently used to produce results in a timely manner. However, such screening tests may suffer from high levels of misclassification. Although it is often possible to design a gold-standard test or device that is not subject to misclassification, such devices are usually costly and time-consuming, and in some cases intrusive to the test subjects. As a compromise between these two approaches, it is possible to use data that are obtained by the method of double-sampling. In this article, we derive and investigate four test statistics for testing a hypothesis on disease prevalence with double-sampling data. The test statistics are implemented through both the asymptotic method suitable for large samples and approximate unconditional method suitable for small samples. Our simulation results show that the approximate unconditional method usually produces a more satisfactory empirical type I error rate and power than its asymptotic counterpart, especially for small to moderate sample sizes. The results also suggest that the score test and the Wald test based on an estimate of variance with parameters estimated under the null hypothesis outperform the others. An real example is used to illustrate the proposed methods.     

G3BP1 interacts with YWHAZ to regulate chemoresistance and predict adjuvant chemotherapy benefit in gastric cancer

BACKGROUND A large proportion of gastric cancer patients are susceptible to chemoresistance, while the underlying mechanism remains obscure. Stress granules (SGs) play a self-defence role for tumour cells in inhibiting chemotherapy-induced apoptosis. As an SG assembly effector, G3BP1 (Ras-GTPase-activating protein SH3 domain-binding protein) has been reported to be overexpressed in gastric cancer; thus, here we aim to explore its potent roles in gastric cancer chemoresistance.METHODS Kaplan–Meier analysis was used to compare survival rates in gastric cancer patients with different G3BP1 expression. The influence of G3BP1 on gastric cancer cell chemoresistance and apoptosis were evaluated by in vitro and in vivo approaches. The interaction between G3BP1 and YWHAZ was assessed by immunohistochemistry, immunoprecipitation and immunofluorescence.RESULTS G3BP1 was associated with the poor outcome of gastric cancer patients who received adjuvant chemotherapy. G3BP1 knockdown significantly increased the sensitivity of gastric cancer cells to chemotherapy drugs. Mechanically, cell apoptosis and pro-apoptotic-associated molecules were significantly elevated upon G3BP1 depletion. Gene co-expression network analyses identified YWHAZ as the critical interlayer of G3BP1; as a result, G3BP1 interacted with YWHAZ to sequester Bax into the cytoplasm. Clinically, G3BP1^highYWHAZ^high gastric cancer patients displayed the worst outcome compared with other patients after chemotherapy.CONCLUSIONS The expression of G3BP1 and YWHAZ could predict the adjuvant chemotherapy benefit in gastric cancer patients.Subject terms: Gastric cancer, Cell death     

The anti-arthritic activity of total glycosides from Pterocephalus hookeri,a traditional Tibetan herbal medicine

Context: Pterocephalus hookeri (C. B. Clarke) Hock., a traditional Tibetan herbal medicine rich in glycosides, has been used to treat several diseases including rheumatoid arthritis.

Objective: To evaluate the anti-arthritic activity of total glycosides from P. hookeri, and its possible mechanisms of action.

Materials and methods: Anti-arthritic activity of total glycosides from P. hookeri (oral administration for 30 days at 14–56?mg/kg) was evaluated using paw swelling, arthritis scores and histopathological measurement in adjuvant-induced arthritis (AA) Sprague-Dawley rats. The NF-κB p65 expression in synovial tissues, and serum superoxide dismutase (SOD) activity, malondialdehyde (MDA) and nitric oxide (NO) levels was measured in AA rats, respectively. Further assessment of anti-inflammatory and analgesic activities of these glycosides were carried out using inflammation and hyperalgesia models induced by xylene, carrageenan, agar and acetic acid, respectively.

Results: Total glycosides (56?mg/kg) decreased the paw swelling (38.0%, p?p?p?p?p?p?p?Discussion and conclusion: Our findings confirmed the anti-arthritic property of the total glycosides from P. hookeri, which may be attributed to its inhibition on NF-κB signalling and oxidative stress.