From static to dynamic:live observation of the support system after ischemic stroke by two photon-excited fluorescence laser-scanning microscopy

Ischemic stroke is one of the most common causes of mortality and disability worldwide.However,treatment efficacy and the progress of research remain unsatisfactory.As the critical support system and essential components in neurovascular units,glial cells and blood vessels(including the bloodbrain barrier)together maintain an optimal microenvironment for neuronal function.They provide nutrients,regulate neuronal excitability,and prevent harmful substances from entering brain tissue.The highly dynamic networks of this support system play an essential role in ischemic stroke through processes including brain homeostasis,supporting neuronal function,and reacting to injuries.However,most studies have focused on postmortem animals,which inevitably lack critical information about the dynamic changes that occur after ischemic stroke.Therefore,a high-precision technique for research in living animals is urgently needed.Two-photon fluorescence laser-scanning microscopy is a powerful imaging technique that can facilitate live imaging at high spatiotemporal resolutions.Twophoton fluorescence laser-scanning microscopy can provide images of the whole-cortex vascular 3D structure,information on multicellular component interactions,and provide images of structure and function in the cranial window.This technique shifts the existing research paradigm from static to dynamic,from flat to stereoscopic,and from single-cell function to multicellular intercommunication,thus providing direct and reliable evidence to identify the pathophysiological mechanisms following ischemic stroke in an intact brain.In this review,we discuss exciting findings from research on the support system after ischemic stroke using two-photon fluorescence laser-scanning microscopy,highlighting the importance of dynamic observations of cellular behavior and interactions in the networks of the brain’s support systems.We show the excellent application prospects and advantages of two-photon fluorescence laser-scanning microscopy and predict future research developments and directions in the study of ischemic stroke.

原发性闭角型青光眼的发病机制研究新进展

原发性闭角型青光眼(PACG)是临床上最常见的一种青光眼类型,全球发病率高且致盲性大,具有进行性不可逆发展的特点。PACG的发病机制复杂多样,不仅与眼部解剖结构的异常有关,如前房结构出现角膜小、短眼轴和浅前房等特征,近年研究还发现晶状体、虹膜、睫状体及脉络膜异常均与PACG的发病有关。另外PACG的发生与遗传因素和心理应激因素亦有较紧密的关系,本文结合文献报道较为全面地从解剖特征、遗传因素、心理应激三个方面对PACG的发病机制做了简要论述,希望籍此为青光眼的早期诊断和治疗提供有益的理论支撑。

Curcumin protects against acetaminophen-induced apoptosis in hepatic injury

AIM:To explore the effects of curcumin(CMN)on hepatic injury induced by acetaminophen(APAP)in vivo.METHODS:Male mice were randomly divided into three groups:groupⅠ(control)mice received the equivalent volumes of phosphate-buffered saline(PBS)intraperitoneally(ip);GroupⅡ[APAP+carboxymethylcellulose(CMC)]mice received 1%CMC(vehicle)2h before APAP injection;GroupⅢ(APAP+CMN)mice received curcumin(10 or 20 mg/kg,ip)2 h before before or after APAP challenge.In GroupsⅡandⅢ,APAP was dissolved in pyrogen-free PBS and injected at a single dose of 300 mg/kg.CMN was dissolved in 1%CMC.Mice were sacrificed 16 h after the APAP injection to determine alanine aminotransferase(ALT)levels in serum and malondialdehyde(MDA)accumulation,superoxide dismutase(SOD)activity and hepatocyte apoptosis in liver tissues.RESULTS:Both pre-and post-treatment with curcumin resulted in a significant decrease in serum ALT compared with APAP treatment group(10 mg/kg:801.46±661.34 U/L;20 mg/kg:99.68±86.48 U/L vs 5406.80±1785.75 U/L,P<0.001,respectively).The incidence of liver necrosis was significantly lowered in CMN treated animals.MDA contents were significantly reduced in 20 mg/kg CMN pretreatment group,but increased in APAP treated group(10.96±0.87 nmol/mg protein vs 16.03±2.58 nmol/mg protein,P<0.05).The decrease of SOD activity in APAP treatment group and the increase of SOD in 20 mg/kg CMN pretreatment group were also detected(24.54±4.95 U/mg protein vs 50.21±1.93 U/mg protein,P<0.05).Furthermore,CMN treatment efficiently protected against APAPinduced apoptosis via increasing Bcl-2/Bax ratio.CONCLUSION:CMN has significant therapeutic potential in both APAP-induced hepatotoxicity and other types of liver diseases.

Naringenin protects against isoniazid- and rifampicininduced apoptosis in hepatic injury

AIM To explore the protective effects and mechanisms of naringenin(NRG) on hepatic injury induced by isoniazid(INH) and rifampicin(RIF).METHODS Male mice were randomly divided into four groups and treated for 14 d as follows: normal control group was administered intragastrically with normal saline solution alone; model group was administered intragastrically with INH(100 mg/kg) and RIF(100 mg/kg); lowand high-dosage NRG pretreatment groups were administered intragastrically with different doses of NRG(50 or 100 mg/kg) 2 h before INH and RIF challenge. Mice were killed 16 h after the last dose of drug treatment to determine activity of serum transaminases. Oxidative stress was evaluated by measuring hepatic glutathione(GSH) and superoxide dismutase(SOD) and malondialdehyde(MDA) levels. Histopathological changes in hepatic tissue were observed under the optical microscope. Hepatocyte apoptosis was measured by TUNEL assay and caspase-3 activation. Expression of Bcl-2 and Bax in liver was determined by western blot.RESULTS Both low- and high-dosage NRG pretreatment obviously alleviated serum levels of alanine aminotransferase and aspartate aminotransferase, liver index, hepatic MDA content, and increased hepatic GSH content and SOD activity compared with the INH and RIF-treated group(44.71 ± 8.15 U/L, 38.22 ± 6.64 U/L vs 58.15 ± 10.54 U/L; 98.36 ± 14.78 U/L, 92.41 ± 13.59 U/L vs 133.05 ± 19.36 U/L; 5.34% ± 0.26%, 4.93% ± 0.25% vs 5.71% ± 0.28%; 2.76 ± 0.67 nmol/mgprot, 2.64 ± 0.64 nmol/mgprot vs 4.49 ± 1.12 nmol/mgprot; 5.91 ± 1.31 mg/gprot, 6.42 ± 1.42 mg/gprot vs 3.11 ± 0.73 mg/gprot; 137.31 ± 24.62 U/mgprot, 148.83 ± 26.75 U/mgprot vs 102.34 ± 19.22 U/mgprot; all P < 0.01 or 0.05). Histopathological evaluation showed obvious necrosis and inflammatory cell infiltration in liver of mice administered INH and RIF; however, mice pretreated with NRG showed minor hepatic injury. In addition, INH and RIF resulted in hepatocyte apoptosis, and NRG pretreatment dramatically suppressed INHand RIF-induced hepatocytes apoptosis. Furthermore, NRG-mediated anti-apoptotic effects seemed to be in connection with its regulation of Bax and Bcl-2 protein expression in hepatic tissue.CONCLUSION NRG might attenuate INH- and RIF-induced hepatic injury via suppression of oxidative stress and hepatocyte apoptosis.

Apolipoprotein E Gene Polymorphisms Are Risk Factors for Spontaneous Intracerebral Hemorrhage:A Systematic Review and Meta-analysis

Intracerebral hemorrhage(ICH)is a serious clinical disease with high morbidity,whose pathogenesis might be related to apolipoprotein E(APOE)gene polymorphisms.To comprehensively evaluate the risk factors for ICH occurrence,we performed a meta-analysis.We searched online databases to identify eligible studies based on the relationship between APOE genetic polymorphisms and ICH occurrence risk.Specific and pooled odds ratios(ORs)were calculated and by assessing small study bias,we drew the relationship between APOE polymorphisms and ICH risk.We included 15 eligible studies in our study containing a total of 1642 ICH samples and 5545 normal controls.The comparison of e4 andε3 APOE genotypes revealed that specific and pooled ORs showed a significantly increased odds ratio in ICH patients with theε4 genotype,indicating thatε4 gene is a risk factor for ICH occurrence,and the heterogeneity is acceptable.Similarly,it was found that theε2 genotype also contributed to the incidence rate of ICH.However,after the subgroup analysis by ethnicity,this APOE genetic polymorphism acted as a harmful factor only in white populations,but did not show an effect in Asian populations.It was suggested that both 82 andε4 APOE alleles were risk factors for ICH in general.They were risk factors in white populations only,neither had a detectable effect in Asian populations after subgroup analysing by ethnicity.

Improving tensile-shear properties of friction stir lap welded dissimilar Al/Mg joints by eliminating hook defect and controlling interfacial reaction

To improve tensile-shear properties of fiction stir lap welded(FSLW) dissimilar Al/Mg joints, pin-tip profiles were innovatively designed and welding speed was optimized, and effects of them on formation, interface microstructure and mechanical properties of different FSLW joints were investigated. With increasing the welding speed, the tensile-shear load of FSLW joints produced by three pins presents an increasing firstly and then decreasing trend. Compared with Rpin, the hook and hole defect in the joints made by S-pin and T-pin are eliminated owing to additional eccentric force. Moreover, the joints obtained by T-pin at 75 mm/min have the highest tensile-shear load, and a maximum value of 3.425 kN is produced, which increases by 96.8%.Meanwhile, the pin-tip profile improves significantly the interface reaction depending on the welding temperature. For R-pin, thick brittle intermetallic compounds of about 6.9 μm Al3Mg2and 13.3 μm Al12Mg17layers at the welding interface derived from diffusion reaction are formed, resulting in continuous cracks. However, using T-pin can raise the interface temperature, and which makes the interface liquefy locally to generate only 2.2 μm Al3Mg2layer and dispersive(Al12-Mg17+Mg) eutectic structure. This can release high residual stress and remove welding crack, consequently enhancing the interface properties of T-pin joints.

O-GlcNAc修饰与疾病病理学的联系（英文）

O-连接的N-乙酰葡萄糖胺(O-GlcNAc)修饰是一种发生于蛋白质丝氨酸或苏氨酸残基上的蛋白翻译后修饰,它能动态地发生在细胞的任何部位,如细胞质、线粒体、细胞核等。O-GlcNAc修饰的供体尿苷二磷酸-N-乙酰葡萄糖胺(UDP-GlcNAc)是己糖胺生物合成途径(HBP)的终产物。GlcNAc在蛋白上的添加和移除分别需要O-GlcNAc转移酶(OGT)和O-GlcNAc水解酶(OGA)的介导。被O-GlcNAc修饰的蛋白包括转录因子、代谢酶、细胞信号传导因子等。O-GlcNAc通过调控这些蛋白的功能参与到许多重要的生物进程中,如转录、翻译、代谢、信号传导、自噬等。此外,O-GlcNAc修饰的失调还与许多重要疾病息息相关,包括癌症、糖尿病、神经退行性疾病和心血管疾病。更好地了解O-GlcNAc修饰在这些疾病生理病理学进程中所起的作用将有助于开发新的治疗策略。本文介绍了O-GlcNAc与疾病病理联系的最新研究,并揭示O-GlcNAc可作为潜在的临床治疗靶点。

Teaching Reform and Practice of Functional Experiment Based on the Cultivation of Excellent Medical Talents

In order to cultivate excellent clinical medical talents with a solid foundation, strong literacy, refined skills, excellent communication abilities, innovative thinking, and a strong focus on practicality, functional experiments have undergone a series of reforms in areas such as constructing new curriculum systems, improving teaching content, updating teaching equipment, introducing new teaching models, and enhancing teaching evaluation systems.

Single-cell RNA-Seq analysis identified kidney progenitor cells from human urine

Dear Editor,Urine passes through the entire kidney and urinary tract system starting from the glomerulus and ending to the urethra.Cells in the kidney and urinary tract could be exfoliated from the epithelium into the urine,while leukocyte could infiltrate from the local tissue into the urine,which makes the urine a useful subject for clinical evaluation of relevant diseases.

Effects of Prior Antiplatelet Therapy on the Prognosis of Primary Intracerebral Hemorrhage： A Meta-analysis

Background：Antiplatelet therapy （APT） was prevalently being used in the prevention of vascular disease,but the influence of prior APT on the prognosis of patients with intracerebral hemorrhage （ICH） remains controversial.This meta-analysis was to explore the effects of prior APT on the prognosis of patients with primary ICH.Methods：PubMed and Embase were searched to identify the eligible studies.The studies comparing the mortality of ICH patients with or without prior APT were included.The quality of these studies was evaluated by the Newcastle-Ottawa quality assessment scale.The adjusted or unadjusted odds ratio （OR） for mortality between ICH patients with and without prior APT were pooled with 95% confidence interval （95% CI） as the effect of this meta-analysis.Results：Twenty-two studies fulfilled the inclusion criteria and exhibited high qualities.The pooled OR was 1.37 （95% CI：1.13-1.66,P =0.001） for univariate analysis and 1.41 （95% CI：1.05-1.90,P =0.024） for multivariate analysis.The meta-regression indicated that for each 1-day increase in the time of assessment,the adjusted OR for the mortality of APT patients decreased by 0.0049 （95% CI：0.0006-0.0091,P =0.026） as compared to non-APT patients.Conclusion：Prior APT was associated with high mortality in patients with ICH that might be attributed primarily to its strong effect on early time.

Reprogramming rat astrocytes into neurons using small molecules for cell replacement following intracerebral hemorrhage

Astrocytes are promising source cells to replace neurons lost to disease owing to a shared lineage and capacities for dedifferentiation and proliferation under pathological conditions.Reprogramming of astrocytes to neurons has been achieved by transcription factor modulation,but reprogramming in vitro or in vivo using small-molecule drugs may have several advantages for clinical application.For instance,small molecules can be extensively characterized for efficacy,toxicity,and tumorigenicity in vitro;induce rapid initiation and subsequent reversal of transdifferentiation upon withdrawal,and obviate the need for exogenous gene transfection.Here we report a new astrocyte-neuron reprogramming strategy using a combination of small molecules(0.5 m M valproic acid,1μM Rep Sox,3μM CHIR99021,2μM I-BET151,10μM ISX-9,and 10μM forskolin).Treatment with this drug combination gradually reduced expression levels of astroglial marker proteins(glial fibrillary acidic protein and S100),transiently enhanced expression of the neuronal progenitor marker doublecortin,and subsequently elevated expression of the mature neuronal marker Neu N in primary astrocyte cultures.These changes were accompanied by transition to a neuron-like morphological phenotype and expression of multiple neuronal transcription factors.Further,this drug combination induced astrocyte-to-neuron transdifferentiation in a culture model of intracerebral hemorrhage(ICH)and upregulated many transdifferentiation-associated signaling molecules in ICH model rats.In culture,the drug combination also reduced ICH model-associated oxidative stress,apoptosis,and pro-inflammatory cytokine production.Neurons derived from small-molecule reprogramming of astrocytes in adult Sprague-Dawley rats demonstrated long-term survival and maintenance of neuronal phenotype.This small-molecule-induced astrocyte-to-neuron transdifferentiation method may be a promising strategy for neuronal replacement therapy.

Efficacy and safety of percutaneous patent foramen ovale closure devices for recurrent stroke: A systemic review and network meta-analysis

Background:Randomized controlled trials(RCTs)that directly compare the efficacy and safety of percutaneous patent foramen ovale(PFO)closure devices have not been conducted.Thus,we performed a network meta-analysis to identify the efficacy and safety of occluder devices.Methods:From 1 st January,2000 to 1 st May,2018,we searched Embase,PubM ed,and Cochrane Library for RCTs about percutaneous closure devices(such as STARFlex,GORE,and Amplatzer)and medical therapy for cryptogenic cerebral ischemic patients with PFO.The occurrence rate of recurrent stroke,atrial fibrillation(AF),major vascular complication(MVC),headache,transient ischemic attack,and bleeding were compared with the frequentist and Bayesian methods using R statistics.Results:We included 3747 patients from six RCTs.The GORE and Amplatzer occluders were found to be significantly associated with a decreased risk of recurrent stroke[relative risk(RR):0.37 and 0.49;95%confidence interval(CI):0.17–0.81,0.29–0.83,respectively].Moreover,STARFlex was correlated to an increased risk of postoperative AF and MVCs(RR:11.66 and 7.63;95%CI:4.87–21.91,2.34–24.88).Conclusions:Among the three devices,the GORE and Amplatzer occluders are found to be the most effective in preventing secondary stroke in patients with PFO.Meanwhile,STARFlex is the least recommended device because it cannot decrease the risk of recurrent stroke and is the most likely to cause adverse events.