氨氯地平联合ALT-711对自发性高血压大鼠大动脉硬化的干预作用

目的:观察氨氯地平联合晚期糖基化终末产物交联蛋白裂解剂(ALT-711)对高血压治疗作用以及探索防治高血压大动脉硬化的优化方案。方法:选用10周龄的雄性自发性高血压大鼠(SHR)18只,随机分为3组每组6只:SHR对照组(A组):生理盐水1 ml/(kg.d)灌胃;氨氯地平治疗组(B组):1 mg/(kg.d)氨氯地平灌胃。ALT-711+氨氯地平干预组(C组):10 mg/(kg.d)ALT-711+1 mg/(kg.d)氨氯地平灌胃。共给药8周。8周后麻醉处死动物,取大动脉切片Masson染色,图像分析测定胶原容积分数,免疫组化法检测三组SHR大鼠大动脉晚期糖基化终末产物(AGEs)、整合素β1和纤维连接蛋白(FN)的表达率。结果:与对照组比较,治疗组B组和C组SHR大鼠的血压显著降低,且AGEs、整合素β1和FN的阳性表达率降低差异有统计学意义(P<0.05)。结论:ALT-711联合氨氯地平能促进SHR主动脉细胞外基质的降解,提示ALT-711联合氨氯地平治疗SHRs在降压治疗同时防治大动脉硬化方面较单用氨氯地平更优。     

顺铂脂质体腹腔注射对S180荷瘤小鼠的治疗作用

目的 探讨顺铂脂质体腹腔注射对S180荷瘤小鼠的抗肿瘤作用.方法 采用昆明种小鼠腹腔内注射S180细胞形成腹水瘤模型,40只小鼠肿瘤种植24 h后随机分为4组,分别为生理盐水组、空白脂质体组、顺铂注射液组、顺铂脂质体组,分别给予生理盐水、空白脂质体、顺铂注射液和顺铂脂质体腹腔注射,共给药4次,给药时间间隔72 h.结果...     

miR-147a靶向MCM3抑制脉络膜黑色素瘤细胞增殖、迁移和侵袭

目的:研究miR-147a对脉络膜黑色素瘤细胞增殖、迁移和侵袭的影响,并探究其作用机制。方法:采用脂质体转染人脉络膜黑色素瘤MUM-2B细胞,设置miR-NC、miR-147a mimics、inhibitor-NC、miR-147a inhibitor四组。采用EDU染色法检测细胞增殖;Transwell实验检测细胞迁移、侵袭;Targetscan生物信息学网站预测分析miR-147a下游靶基因;双荧光素酶报告基因实验验证miR-147a是否靶向结合MCM3 mRNA 3' UTR区;蛋白质印迹法（Western Blot）检测靶基因MCM3蛋白表达。结果:过表达miR-147a可显著降低MUM-2B细胞的增殖数、迁移数和侵袭数,相反,敲减miR-147a提高细胞增殖数、迁移数和侵袭数。miR-147a直接靶向并负向调控MCM3蛋白表达。沉默MCM3可抑制MUM-2B细胞增殖、迁移和侵袭。结论:miR-147a通过直接靶向MCM3抑制脉络膜黑色素瘤MUM-2B细胞的增殖、迁移和侵袭。miR-147a/MCM3轴可能是治疗脉络膜黑色素瘤的新靶标。     

Dynamic allostery governs cyclophilin A–HIV capsid interplay

Host factor protein Cyclophilin A (CypA) regulates HIV-1 viral infectivity through direct interactions with the viral capsid, by an unknown mechanism. CypA can either promote or inhibit viral infection, depending on host cell type and HIV-1 capsid (CA) protein sequence. We have examined the role of conformational dynamics on the nanosecond to millisecond timescale in HIV-1 CA assemblies in the escape from CypA dependence, by magic-angle spinning (MAS) NMR and molecular dynamics (MD). Through the analysis of backbone ¹H-¹⁵N and ¹H-¹³C dipolar tensors and peak intensities from 3D MAS NMR spectra of wild-type and the A92E and G94D CypA escape mutants, we demonstrate that assembled CA is dynamic, particularly in loop regions. The CypA loop in assembled wild-type CA from two strains exhibits unprecedented mobility on the nanosecond to microsecond timescales, and the experimental NMR dipolar order parameters are in quantitative agreement with those calculated from MD trajectories. Remarkably, the CypA loop dynamics of wild-type CA HXB2 assembly is significantly attenuated upon CypA binding, and the dynamics profiles of the A92E and G94D CypA escape mutants closely resemble that of wild-type CA assembly in complex with CypA. These results suggest that CypA loop dynamics is a determining factor in HIV-1''s escape from CypA dependence.Cyclophilin A (CypA), a peptidyl-prolyl isomerase, is a host factor critical in the regulation of the HIV-1 infection, involving a direct interaction with the capsid (CA) protein (1–3). The mechanism by which CypA modulates the viral infectivity is complex and poorly understood, being dependent on the CA protein primary sequence and the host cell type (4–6). For example, it is known that mutations in the CypA-binding loop of the CA protein dramatically reduce virus infectivity (7, 8). The A92E and G94D escape mutants bind CypA with similar affinity to wild-type CA, but exhibit only 10% of the activity of wild-type CA in the presence of CypA, and full infectivity can be restored if CypA is inhibited with cyclosporin A in the host cells (8), as shown schematically in SI Appendix, Fig. S1. Alas, the molecular mechanisms underlying CypA escape remain elusive, despite numerous virological, biochemical, and structural–biological studies.The present study investigates the internal conformational dynamics of a CA protein assembly. Although static structures of HIV-1 proteins and complexes with host factors provide important clues into their assembly architecture and conformational details of the interactions, structures alone are insufficient for understanding molecular mechanisms. It is well known that biological functions can be dynamically regulated, at multiple levels of organization, from internal dynamics of individual protein molecules (9) to entire cells. This dynamic regulation certainly also applies to HIV-1 because numerous dynamic processes are associated with HIV-1 assembly, disassembly, release, and maturation (10, 11). For example, we previously demonstrated that internal conformational dynamics of the CA protein and its structural plasticity determine its ability to assemble into pleiomorphic conical capsids (12, 13) (Fig. 1). We also uncovered that, in the HIV-1 CA-SP1 maturation intermediate, dynamic disorder in the SP1 peptide plays an important role in the final step of virus maturation, permitting condensation of CA into the cores of infectious virions (14).Open in a separate windowFig. 1.(A, Left) All-atom MD-derived model of mature HIV-1 capsid constructed on the basis of cryo-electron tomography (cryo-ET) and solution NMR studies (13). The capsid comprises 216 hexamers (orange) and 12 pentamers (blue) [Protein Data Bank (PDB) ID 3J3Y]. Structural organization of a hexamer of hexamers (HOH) building block is illustrated in the expansion. Color coded are individual hexameric units comprising the HOH building block. (A, Right) The 3D structure of CA monomer [HXB2 sequence polymorph [PDB file 3NTE (42)]. (B) Cosedimentation assay of CA with CypA illustrating the efficiency of cosedimentation for different CA/CypA molar ratios. S, supernatant; P, pellet. (C) Transmission electron microscopy (TEM) images of tubular assemblies of CA and CA/CypA. (C, Upper) CA NL4-3 (Left), CA NL4-3 A92E (Center), and CA NL4-3 G94D (Right). (C, Lower) HXB2 (Left) and CA HXB2/CypA (Right). (D) Expansions around the aliphatic region for 2D NCA and combined R2-driven (CORD) MAS NMR spectra for CA HXB2 (black) and CA HXB2/CypA (orange), illustrating the multiple chemical shift perturbations observed upon formation of the complex. These perturbations are mapped onto the structure of CA monomer (A) and are confined to flexible loops and residue variation sites. The spectra are recorded at 20.0 T and the MAS frequency of 14 kHz. (E) Expansions of glycine regions for 2D NCA MAS NMR spectra for (from left to right): HXB2, HXB2/CypA, NL4-3, NL4-3 A92E, and NL4-3 G94D. Dashed lines indicate the G89 cross-peaks associated with cis- and trans-P90.In this study, we examined the residue-specific mobility of CA protein from HXB2 and NL4-3 sequence polymorphs (SI Appendix, Fig. S2) in tubular assemblies on the nanoseconds to milliseconds timescales. In particular, we compared wild-type and A92E and G94D escape mutants of the NL4-3 strain as well as wild-type HXB2 CA alone and in complex with CypA. As discussed previously (14, 15), tubular assemblies recapitulate the hexameric lattice, the predominant symmetry arrangement of the conical HIV-1 capsid core, illustrated in Fig. 1A. Dipolar tensors and resonance intensities extracted from a series of 2D and 3D homonuclear and heteronuclear magic-angle spinning (MAS) NMR experiments revealed that certain regions in both HXB2 and NL4-3 wild-type CA are unusually dynamic on all timescales. These motions are significantly attenuated upon CypA binding. Most remarkably, the dynamic profiles of the A92E and G94D escape mutants closely resemble that of CA when bound by CypA. To gain further understanding of the sequence-dependent dynamics profiles of CA assemblies, we performed extensive molecular dynamics (MD) simulations. The motionally averaged dipolar tensors extracted from the MD trajectories are in remarkable quantitative agreement with the NMR results. Together, our results suggest that changes in the sequence-dependent conformational dynamics may be a key determinant in the escape mechanism of HIV-1 CA capsid mutants from CypA dependence.     

疼痛与心理护理共同应用于晚期肿瘤癌痛患者的效果研究

目的:探讨疼痛与心理护理共同应用于晚期肿瘤癌痛患者的效果。方法:选取郑州大学附属肿瘤医院2019年3月至2020年3月收治的晚期肿瘤癌痛患者80例。以简单随机化法分为对照组和观察组,40例每组。对照组男∶女=19∶21,年龄（59.22±7.36）岁,肺癌9例、肠癌13例、胃癌12例、其他6例;观察组男∶女=18∶22...     

基于血浊理论探讨风痰瘀阻型中风的发病机制及治疗思路

风痰瘀阻证是临床缺血性脑卒中急性期的证型之一,传统中医治法疗效欠佳,预后不良,致残率高,因此寻求新的治疗思路对于改善患者预后具有重大意义。文章基于血浊理论对其发病机制进行探讨,阐述了血浊致脏腑虚、脑髓伤为发病之基,致风痰瘀阻、脑络伤为核心病机;结合现代研究证实血浊为该病的病理枢纽,提出在传统治则加用化浊行血中药治疗风痰瘀阻型中风,以期提高临床疗效。     

GC-MS法同时测定盐酸决奈达隆中的3种甲磺酸酯

目的：建立同时测定盐酸决奈达隆中甲磺酸甲酯,甲磺酸乙酯,甲磺酸异丙酯含量的方法.方法：采用柱前衍生技术,利用GC-MS法,测定盐酸决奈达隆中三种甲磺酸酯的含量.结果：甲磺酸甲酯的检测限为0.003 75 ng·ml-1,线性范围为2.0 ～ 625.0ng·ml-1,r =0.999 4,甲磺酸乙酯的检测限为0.0375 ng·ml-1,线性范围为2.0 ～625.0 ng·ml-1,r=0.999 8,甲磺酸异丙酯的检测限为0.375 ng·ml-1,线性范围为2.0 ～625.0 ng·ml-1,r=0.999 8.回收率分别为99.89％,98.98％,100.36％,RSD分别为3.67％,2.82％,3.47％（n=9）.结论：该方法简便,准确,快速,适用于盐酸决奈达隆质量控制和检测.     

用Ames点试验法对日用化工品致突变性的研究(附30种分析报告)

本文对30种日用化工品进行了Ames′试验研究。结果表明:洗衣粉、洗发膏有致突变作用,染发剂和治疗性化妆品大部分有致突变作用;一些护肤营养类化妆品则无。实验中发现的大部分致突变物质在高浓度时有抑制环,诱变作用不明显,经稀释到合适浓度后才有明显的致突变作用。