平均血小板体积与心房颤动相关性研究进展

心房颤动(AF)的主要严重危害是局部血栓形成后脱落,并随血流循环到达全身各处血管,引发脑卒中和其他血栓栓塞事件。血小板活化是血栓形成机制中的重要组成部分,其中平均血小板体积(MPV)为血小板活性标志物之一,其检测手段较其他血小板活性标志物更简单、经济,且临床获取更广泛、便捷。国内外多项研究显示MPV与AF、AF的发生及AF相关卒中风险有关,本文拟对该领域相关研究进行综述,旨在为预防AF及其相关卒中提供理论依据。     

间尼索地平的HPLC测定

本文采用ＨＰＬＣ法对间尼索地平原料及片剂进行了定量分析研究。     

Keratograph 5M眼表综合分析仪观察小梁切除术后泪膜的早期变化

目的：运用Keratograph 5 M眼表综合分析仪观察小梁切除术后泪膜的早期变化。方法：收集青光眼患者41例46眼,分别于小梁切除术前1d,术后1d;1wk;1mo 行第一次泪膜破裂时间( first tear break up time,FTBUT)、平均泪膜破裂时间( average tear break up time,ATBUT)、非侵入式泪河高度( non-invasive tear meniscus height,NITMH)、脂质层厚度分级及睑板腺完整度评分检查。结果：与术前1 d 相比,术后1 d;1 wk;1 mo 的 FTBUT、ATBUT缩短(P<0.05),脂质层变薄(P<0.017)。术后1d的NITMH高于术前1d,而术后1wk和1mo的NITMH低于术前1d(P<0.05)。睑板腺完整度评分手术前后差异无统计学意义(P>0.05)。结论：Keratograph 5 M眼表综合分析仪可以快速、精确地评估泪膜的功能。青光眼小梁切除术在术后短期内可对泪膜的稳定性及泪液的分泌量产生不良影响。     

[Gly14]-Humanin Protects Against Amyloid β Peptide-Induced Impairment of Spatial Learning and Memory in Rats

Alzheimer disease（AD）, a progressive neurodegenerative disorder, is characterized by cognitive decline and the accumulation of senile plaques in the brain.Amyloid b protein（Aβ） in the plaques is thought to be responsible for the memory loss in AD patients. [Gly14]-humanin（HNG）, a derivative of humanin（HN）, has much stronger neuroprotective effects than natural HN in vitro.However, clarification of the Aβ active center and the neuroprotective mechanism of HN still need in vivo evidence. The present study first compared the in vivo biological effects of three Aβ fragments（1–42, 31–35, and 35–31） on spatial memory in rats, and investigated the neuroprotective effects and molecular mechanisms of HNG. The results showed that intrahippocampal injection of Aβ_1–42and Aβ_31–35almost equally impaired spatial learning and memory, but the reversed sequence Aβ_35–31 did not have any effect; a high dose of Aβ_31–35（20 nmol） produced a more detrimental response than a low dose（2 nmol）; Aβ_31–35 injection also disrupted gene and protein expression in the hippocampus, with up-regulation of caspase3 and down-regulation of STAT3; pretreatment with HNG not only protected spatial memory but also rescued STAT3 from Aβ-induced disruption; and the neuroprotective effects of HNG were effectively counteracted by genistein, a specific tyrosine kinase inhibitor. These results clearly show that sequence 31–35 in Aβ is the shortest active center responsible for the neurotoxicity of Aβ from molecule to behavior; and HNG protects spatial learning and memory in rats against Aβ-induced insults; and probably involves the activation of tyrosine kinases and subsequent beneficial modulation of STAT3 and caspase3.     

Immune response pattern varies with the natural history of chronic hepatitis B

BACKGROUND Chronic hepatitis B is a highly heterogeneous disease that can be divided into four phases: Immune tolerant(IT), immune active(IA), inactive carrier(IC) and hepatitis B envelope antigen(HBeAg)-negative hepatitis(ENEG).AIM To investigate the immune status of natural killer(NK) and T cells in different phases of chronic hepatitis B.METHODS The frequency, phenotype and function of circulating NK cells, as well as nonantigen-specific and hepatitis B virus(HBV)-specific T cell responses were detected by flow cytometry in healthy and HBV-infected subjects.RESULTS The ability of NK cells to produce IFN-γ was markedly attenuated in HBVinfected patients overall but was less compromised in IC patients. Patients in the IT and IA phases also displayed significantly lower TNF-α production compared to healthy subjects. NK cells were phenotypically activated in the IA and ENEGphases, as evidenced by the upregulation of NKp44 in CD56^bright NK cells and CD69 in CD56^dim NK cells. Furthermore, global T-cells from the ENEG phase displayed a proinflammatory cytokine profile with upregulated IFN-γ and TNF-αexpression, while this profile was suppressed in IT and IA patients. Finally, core and S antigen-specific T cell responses were significantly stronger after in vitro expansion in the IC phase compared to other phases.CONCLUSION Our findings demonstrate the changes in immune response pattern during the natural history of HBV infection. Both NK and T cells are functionally impaired in the IT and IA phases. With the spontaneous clearance of HBeAg and hepatitis B surface antigen decline, NK cell cytokine production and HBV-specific T responses are partially restored in IC phase, and the ENEG phase is dominated by nonantigen-specific T cell responses.     

CD44单克隆抗体A3D8通过抑制ERK1/2上调Bim诱导HL-60细胞早期凋亡

CD44单克隆抗体A3D8可抑制急性髓系白血病(acute myeloid leukemia,AML)细胞的增殖抑制,并诱导其早期凋亡。本研究探讨在此过程中ERK以及BCL-2家族成员的作用机制,为治疗白血病提供新方法和新的药物靶点。用MTT法检测A3D8对HL-60细胞的增殖抑制效应,用流式细胞术检测A3D8对HL-60细胞线粒体膜电位的变化,用实时定量PCR技术检测BIMmRNA表达的变化;用Western blot检测A3D8处理后磷酸化ERK-1/2的表达变化。结果表明:A3D8能显著抑制HL-60细胞的增殖,抑制效率呈现剂量和时间的量效关系,并可进一步诱导HL-60细胞的早期凋亡,而BCL-2家族成员Bim的表达水平也随时间和浓度的变化而改变,磷酸化ERK-1/2的表达水平明显降低。结论 :CD44单克隆抗体A3D8可通过降低磷酸化ERK-1/2的表达来调节Bim,从而诱导HL-60细胞的增殖抑制和早期凋亡。     

抑制钠氢交换蛋白1促进低氧诱导的K562细胞分化

本研究主要探讨低氧微环境对慢性髓系白血病细胞系K562分化的影响及钠氢交换蛋白1(NHE1)在该过程中的作用。利用低氧模拟物CoCl2或于低氧(2%O2、5%CO2和93%N2)环境中培养K562细胞,应用激光共聚焦显微镜测定细胞内pH值(intracellular pH,pHi),瑞氏染色观察细胞形态,实时定量RT-PCR检测基因表达,Western blot技术检测MAPK磷酸化水平的改变。结果表明:与对照组相比,低氧培养的K562细胞表现出成熟相关的形态学改变,并伴随CCAAT/增强子结合蛋白(C/EBPα)的mRNA水平上调;特异性NHE1抑制剂Cariporide预处理能够促进低氧诱导的K562细胞分化,Cariporide处理后K562细胞的P38和ERK5蛋白激酶磷酸化水平显著增强。结论 :低氧及低氧模拟物能够诱导K562细胞系分化,抑制NHE1活性协同促进低氧诱导的K562细胞分化,其机制可能是通过增强细胞内MAPK蛋白激酶磷酸化水平促进分化。     

A simple hydrazone as a multianalyte (Cu2+, Al3+, Zn2+) sensor at different pH values and the resultant Al3+ complex as a sensor for F−

A new colorimetric and fluorescence molecular chemosensor based on triazole hydrazone can be used as a multi-probe for selective detection of Al³⁺, Zn²⁺, and Cu²⁺ by monitoring changes in the absorption and fluorescence spectral patterns. Results show that Al³⁺ and Zn²⁺ ions can induce remarkable fluorescence enhancement at pH 6.0 and pH 10.0, respectively, while the addition of Cu²⁺ ions leads to a significant UV-visible absorption enhancement in the visible range at pH 6.0. In addition, the resultant Al³⁺ complex could act as an ‘on–off’ fluorescence sensor for F⁻. The fluorescence sensor was also used to monitor intracellular Al³⁺, Zn²⁺, and F⁻ in Hela cells.

A fluorescent probe for Al³⁺ and Zn²⁺ was synthesised, and the resultant Al³⁺-complex was used for the detection of F⁻.     

A high-performance trace level acetone sensor using an indispensable V4C3Tx MXene

The development of a stringent sensor to detect low levels of acetone, yielding the potential for the point-of-care clinical diagnosis of diabetes, is still a great challenge but is urgently required. Most studies have focused on Ti₃C₂T_x, yet other types of MXenes with good performance are rare. Herein, an emerging kind of MXene, V₄C₃T_x, has been prepared from V₄AlC₃via the selective etching of the Al layer using aqueous HF at room temperature (RT), and its performance as an acetone sensor is presented. A V₄C₃T_x based acetone sensor delivers good performance, as demonstrated by its low working temperature of 25 °C, low detection limit of 1 ppm (lower than the 1.8 ppm diabetes diagnosis threshold), and high selectivity towards acetone in a mixed gas of acetone and water vapor, hopefully showing promise for application in the much faster and earlier diagnosis of diabetes. V₄C₃T_x MXene is used for the first time in the field of acetone detection in this work, hopefully opening up a path for the investigation of applications of MXene in gas sensors, and such exciting findings distinguish V₄C₃T_x as a comparable material to the well-known Ti₃C₂T_x. In addition, we used DFT calculations to explore the mechanisms that result in the superior selectivity for acetone with respect to water vapor. Hopefully, the proposed mechanisms combining experimental results and theoretical study will shed light on the design and production of new high-performance acetone sensors.

A high-performance acetone sensor utilizing an emerging indispensable V₄C₃T_x MXene is described via combining experimental results with theoretical study.     

Refractive outcomes after vitrectomy combined with phacoemulsification of idiopathic macular holes

AIM:To report the refractive outcomes after vitrectomy combined with phacoemulsification and intraocular lens(IOL)implantation(phaco-vitrectomy)in idiopathic macular holes(IMH).METHODS:A total of 56 eyes with IMH(IMH group)that underwent phaco-vitrectomy and 44 eyes with age-related cataract(ARC group)that underwent cataract surgery were retrospectively reviewed.The best corrective visual acuity(BCVA),predicted refractive error(PRE),actual refractive error(ARE),axial length(AL),were measured in both groups before and 6 mo after operation.The power calculation of IOL and the predicted refractive error(PRE)were calculated according to the SRK/T formula.The difference of PRE and ARE between the two groups were compared and analyzed.RESULTS:In the IMH group,the diameters of macular holes were 271.73±75.85μm,the closure rate was 100%.The pre-and post-operative BCVA were 0.80±0.35 and 0.40±0.35 log MAR.The PRE of A-ultrasound and IOL Master in the IMH group was-0.27±0.25 and 0.10±0.66 D.The postoperative mean absolute prediction error(MAE)was observed to be 0.58±0.65 and 0.53±0.37 D in the IOL Master and A-ultrasound(P=0.758).The PRE and ARE of the IMH group were 0.10±0.66 D and-0.19±0.64 D(P=0.102).The PRE and ARE of the ARC group was-0.43±0.95 and-0.31±0.93 D(P=0.383).The difference between PRE and ARE was-0.33±0.81 and 0.09±0.64 D in the IMH and ARC groups(P=0.021).The proportion of myopic shift was 67.9%in the IMH group and 27.3%in the ARC group(P=0.004).CONCLUSION:The myopic shift can be observed in patients with IMH after phaco-vitrectomy.