宫颈癌顺铂耐药研究进展

顺铂（DDP）作为第一个被发现的金属抗癌药物，是目前最有潜力和应用最广泛的抗肿瘤药物。顺铂在宫颈癌的治疗中尤为重要，目前已被推荐为同步放化疗的首选药物。但随着广泛的使用，顺铂的耐药性逐渐显露出来，并成为限制临床疗效和部分患者肿瘤治疗进展的主要原因之一。顺铂的耐药机制复杂，发生环节较多，但具体耐药机制尚不明确，目前按照顺铂耐药发生的环节可分为:①顺铂在血液循环过程中产生耐药；②顺铂通过细胞膜的流入或流出产生耐药；③顺铂在胞质中产生耐药；④顺铂与DNA结合后产生耐药。本文综述了宫颈癌顺铂耐药可能发生的四个环节及克服耐药常用的手段，为提高顺铂对宫颈癌的疗效提供依据。     

单味中药降尿酸作用机制概述※

降尿酸是治疗痛风和高尿酸血症的基本方法，目前降尿酸作用途径主要是通过抑制黄嘌呤氧化酶、腺苷脱氨酶等合成酶的活性，或（且）影响肾脏尿酸转运蛋白（OAT1、OAT3、URAT1、GLUT9）等的表达，进而降低尿酸的水平。由于中药治疗高尿酸血症及痛风的作用机制尚不明确，因此本文通过检索中国知网、维普、万方、pubMed、Embase等数据库，对相关文献进行筛选，总结了具有明确降尿酸作用机制的单味中药，并进行功效归类，有助于对其作用机制进一步研究，为防治痛风和高尿酸血症提供更可靠、更安全的中医治疗依据。     

A Model for the Origin of Motion Direction Selectivity in Visual Cortex

Motion perception is a vital part of our sensory repertoire in that it contributes to navigation, awareness of moving objects, and communication. Motion sense in carnivores and primates originates with primary visual cortical neurons selective for motion direction. More than 60 years after the discovery of these neurons, there is still no consensus on the mechanism underlying direction selectivity. This paper describes a model of the cat''s visual system in which direction selectivity results from the well-documented orientation selectivity of inhibitory neurons: inhomogeneities in the orientation preference map for inhibitory neurons leads to spatially asymmetric inhibition, and thus to direction selectivity. Stimulation of the model with a drifting grating shows that direction selectivity results from the relative timing of excitatory and inhibitory inputs to a neuron. Using a stationary contrast-reversing grating reveals that the inhibitory input is spatially displaced in the preferred direction relative to the excitatory input, and that this asymmetry leads to the timing difference. More generally, the model yields physiologically realistic estimates of the direction selectivity index, and it reproduces the critical finding with contrast-reversing gratings that response phase advances with grating spatial phase. It is concluded that a model based on intracortical inhibition can account well for the known properties of direction selectivity in carnivores and primates.SIGNIFICANCE STATEMENT Motion perception is vital for navigation, communication, and the awareness of moving objects. Motion sense depends on cortical neurons that are selective for motion direction, and this paper describes a model for the physiological mechanism underlying cortical direction selectivity. The essence of the model is that intracortical inhibition of a direction-selective cell is spatially inhomogeneous and therefore depends on whether a stimulus generates inhibition before or after reaching the cell''s receptive field: the response is weaker in the former than in the latter case. If the model is correct, it will contribute to the understanding of motion processing in carnivores and primates.     

基于网络药理学和分子对接法探索复方一枝蒿颗粒治疗新型冠状病毒肺炎的潜在分子机制

目的 通过网络药理学及分子对接技术探寻复方一枝蒿颗粒治疗新型冠状病毒肺炎的作用机制。方法 应用TCMSP数据库、BATMAN-TCM数据库及文献收集复方一枝蒿颗粒活性成分及潜在靶点。通过TTD、GeneCards和OMMI数据库检索新型冠状病毒肺炎相关的靶点。将复方一枝蒿颗粒药物靶点和新型冠状病毒肺炎相关基因取交集，使用String数据库构建靶蛋白相互作用（PPI）网络。通过Cytoscape构建“药物–活性成分–靶点基因–疾病”网络。对交集靶点进行GO功能、KEGG通路富集分析。利用Autodock_vina软件对活性成分和靶点进行分子对接。结果 共筛选92个活性成分，1 627个靶点，新型冠状病毒肺炎疾病靶点464个，两者取交集筛选出87个潜在靶点。GO功能富集得到2 040个条目（P＜0.05），与病毒过程、参与共生相互作用的生物过程、活性氧代谢过程的调节、与宿主相互作用的生物过程、病毒生命周期、炎症反应的调节等生物学过程有关。KEGG通路分析共得到150条通路，与新冠肺炎密切相关的有人巨细胞病毒感染、结核、COVID-19、IL-17信号通路等。分子对接结果证实，筛选的靶点受体蛋白与活性成分可以较好地结合。结论 复方一枝蒿颗粒可通过多组分、多靶点和多途径的方式对新型冠状病毒肺炎产生治疗作用。     

金黄色葡萄球菌异质性耐药机制及实验室检测技术

 异质性耐药是一种特殊的细菌耐药类型，常表现为同一克隆来源的不同细菌亚群对某种抗菌药物表现出不一致的耐药特征，大多数亚群对某种抗菌药物敏感，而少部分亚群对其耐药或高度耐药。异质性耐药分离株常会导致特定抗菌药物抗感染治疗失败。针对异质性耐药菌较为深入的研究主要集中于革兰阴性菌，革兰阳性球菌的相关报道较少。近年有研究报道万古霉素、利奈唑胺、苯唑西林等多种类型抗菌药物异质性耐药金黄色葡萄球菌分离株出现，但其实际临床意义尚待进一步评估。此文对金黄色葡萄球菌异质性耐药机制和检测技术最新进展进行综述，为细菌异质性耐药机制研究和新型检测技术研发提供新的思路。     

Go-Ichi-Ni-San 2: A potential biomarker and therapeutic target in human cancers

Cancer incidence and mortality are increasing globally, leading to its rising status as a leading cause of death. The Go-Ichi-Ni-San (GINS) complex plays a crucial role in DNA replication and the cell cycle. The GINS complex consists of four subunits encoded by the GINS1, GINS2, GINS3, and GINS4 genes. Recent findings have shown that GINS2 expression is upregulated in many diseases, particularly tumors. For example, increased GINS2 expression has been found in cervical cancer, gastric adenocarcinoma, glioma, non-small cell lung cancer, and pancreatic cancer. It correlates with the clinicopathological characteristics of the tumors. In addition, high GINS2 expression plays a pro-carcinogenic role in tumor development by promoting tumor cell proliferation and migration, inhibiting tumor cell apoptosis, and blocking the cell cycle. This review describes the upregulation of GINS2 expression in most human tumors and the pathway of GINS2 in tumor development. GINS2 may serve as a new marker for tumor diagnosis and a new biological target for therapy.     

Disengagement of tibial insert locking pin in total knee arthroplasty - A rare failure case report

Total Knee Arthroplasty (TKA) has seen many advancements over the years. One such advancement is development of locking mechanism for polyethylene insert in modular implants. It aims to reduce micro motion and wear problems. Disengagement of locking pin from insert after primary TKA without trauma is rare complication. The author describes a rare case of disengagement of the polyethylene insert locking pin in primary total knee arthroplasty. Disengagement of the locking clip was observed 8 months after index operation without any trauma.