Polyethylene glycol has immunoprotective effects on sciatic allografts, but behavioral recovery and graft tolerance require neurorrhaphy and axonal fusion

Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripheral nerve allografts undergo immunological rejection by the host immune system.In contrast,peripheral nerve injuries repaired by polyethylene glycol fusion of peripheral nerve allografts exhibit excellent behavioral recovery within weeks,reduced immune responses,and many axons do not undergo Wallerian degeneration.The relative contribution of neurorrhaphy and polyethylene glycol-fusion of axons versus the effects of polyethylene glycol per se was unknown prior to this study.We hypothesized that polyethylene glycol might have some immune-protective effects,but polyethylene glycol-fusion was necessary to prevent Wallerian degeneration and functional/behavioral recovery.We examined how polyethylene glycol solutions per se affect functional and behavioral recovery and peripheral nerve allograft morphological and immunological responses in the absence of polyethylene glycol-induced axonal fusion.Ablation-type sciatic nerve injuries in outbred Sprague–Dawley rats were repaired according to a modified protocol using the same solutions as polyethylene glycol-fused peripheral nerve allografts,but peripheral nerve allografts were loose-sutured(loose-sutured polyethylene glycol)with an intentional gap of 1–2 mm to prevent fusion by polyethylene glycol of peripheral nerve allograft axons with host axons.Similar to negative control peripheral nerve allografts not treated by polyethylene glycol and in contrast to polyethylene glycol-fused peripheral nerve allografts,animals with loose-sutured polyethylene glycol peripheral nerve allografts exhibited Wallerian degeneration for all axons and myelin degeneration by 7 days postoperatively and did not recover sciatic-mediated behavioral functions by 42 days postoperatively.Other morphological signs of rejection,such as collapsed Schwann cell basal lamina tubes,were absent in polyethylene glycol-fused peripheral nerve allografts but commonly observed in negative control and loose-sutured polyethylene glycol peripheral nerve allografts at 21 days postoperatively.Loose-sutured polyethylene glycol peripheral nerve allografts had more pro-inflammatory and less anti-inflammatory macrophages than negative control peripheral nerve allografts.While T cell counts were similarly high in loose-sutured-polyethylene glycol and negative control peripheral nerve allografts,loose-sutured polyethylene glycol peripheral nerve allografts expressed some cytokines/chemokines important for T cell activation at much lower levels at 14 days postoperatively.MHCI expression was elevated in loose-sutured polyethylene glycol peripheral nerve allografts,but MHCII expression was modestly lower compared to negative control at 21 days postoperatively.We conclude that,while polyethylene glycol per se reduces some immune responses of peripheral nerve allografts,successful polyethylene glycol-fusion repair of some axons is necessary to prevent Wallerian degeneration of those axons and immune rejection of peripheral nerve allografts,and produce recovery of sensory/motor functions and voluntary behaviors.Translation of polyethylene glycol-fusion technologies would produce a paradigm shift from the current clinical practice of waiting days to months to repair ablation peripheral nerve injuries.

Imbalance of Circulating Follicular Regulatory and Follicular Helper T Cell Subpopulations Is Associated with Disease Progression and Serum CYFRA 21-1 Levels in Patients with Non-small Cell Lung Cancer

Objective This study aimed to investigate the changes of follicular helper T(TFH)and follicular regulatory T(TFR)cell subpopulations in patients with non-small cell lung cancer(NSCLC)and their significance.Methods Peripheral blood was collected from 58 NSCLC patients at different stages and 38 healthy controls.Flow cytometry was used to detect TFH cell subpopulation based on programmed death 1(PD-1)and inducible co-stimulator(ICOS),and TFR cell subpopulation based on cluster determinant 45RA(CD45RA)and forkhead box protein P3(FoxP3).The levels of interleukin-10(IL-10),interleukin-17a(IL-17a),interleukin-21(IL-21),and transforming growth factor-β(TGF-β)in the plasma were measured,and changes in circulating B cell subsets and plasma IgG levels were also analyzed.The correlation between serum cytokeratin fragment antigen 21-1(CYFRA 21-1)levels and TFH,TFR,or B cell subpopulations was further explored.Results The TFR/TFH ratio increased significantly in NSCLC patients.The CD45RA^(+)FoxP3^(int) TFR subsets were increased,with their proportions increasing in stages Ⅱ to Ⅲ and decreasing in stage IV.PD-1^(+)ICOS+TFH cells showed a downward trend with increasing stages.Plasma IL-21 and TGF-β concentrations were increased in NSCLC patients compared with healthy controls.Plasmablasts,plasma IgG levels,and CD45RA^(+)FoxP3^(int) TFR cells showed similar trends.TFH numbers and plasmablasts were positively correlated with CYFRA 21-1 in stages Ⅰ-Ⅲ and negatively correlated with CYFRA 21-1 in stage IV.Conclusion Circulating TFH and TFR cell subpopulations and plasmablasts dynamically change in different stages of NSCLC,which is associated with serum CYFRA 21-1 levels and reflects disease progression.

儿童急性T淋巴细胞白血病预后影响因素分析——CCCG-ALL-2015方案单中心临床研究

目的探讨儿童急性T淋巴细胞白血病(acute T-lymphoblastic leukemia,T-ALL)患儿的临床特征,并分析其与预后的关系。方法回顾性分析2015年11月—2019年12月南京医科大学附属儿童医院血液肿瘤科采用CCCG-ALL-2015方案诊治的50例T-ALL患儿的临床资料及随访结果,运用Kaplan-Meier生存分析、Cox回归分析等方法分析患儿预后的影响因素。结果50例T-ALL患儿中,共复发7例。复发组和非复发组基本临床资料的比较差异无统计学意义(P>0.05)。复发组诱导缓解治疗后第46天微小残留病(minimal residual disease,MRD)阳性率(≥0.01%)高于非复发组,差异有统计学意义(P=0.037)。50例患儿5年总体生存率为(87±5)%,5年无事件生存率为(86±5)%。多因素Cox回归分析显示诱导缓解治疗后第46天MRD水平是预后的独立影响因素(HR=0.104,95%CI:0.015~0.740,P=0.024)。结论MRD对T-ALL患儿的预后有重要意义,临床上需根据MRD水平提供个性化治疗,预防复发、改善预后。

Milk fat globule membrane supplementation protects againstβ-lactoglobul-ininduced food allergy in mice via upregulation of regulatory T cells and enhancement of intestinal barrier in a microbiota-derived short-chain fatty acids manner

Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects and possible underlying mechanisms of MFGM on cow’s milk allergy(CMA)in aβ-lactoglobulin(BLG)-induced allergic mice model.MFGM was supplemented to allergic mice induced by BLG at a dose of 400 mg/kg body weight.Results demonstrated that MFGM alleviated food allergy symptoms,decreased serum levels of lipopolysaccharide,pro-inflammatory cytokines,immunoglobulin(Ig)E,Ig G1,and Th2 cytokines including interleukin(IL)-4,while increased serum levels of Th1 cytokines including interferon-γand regulatory T cells(Tregs)cytokines including IL-10 and transforming growth factor-β.MFGM modulated gut microbiota and enhanced intestinal barrier of BLG-allergic mice,as evidenced by decreased relative abundance of Desulfobacterota,Rikenellaceae,Lachnospiraceae,and Desulfovibrionaceae,while increased relative abundance of Bacteroidetes,Lactobacillaceae and Muribaculaceae,and enhanced expressions of tight junction proteins including Occludin,Claudin-1 and zonula occludens-1.Furthermore,MFGM increased fecal short-chain fatty acids(SCFAs)levels,which elevated G protein-coupled receptor(GPR)43 and GPR109A expressions.The increased expressions of GPR43 and GPR109A induced CD103+dendritic cells accumulation and promoted Tregs differentiation in mesenteric lymph node to a certain extent.In summary,MFGM alleviated CMA in a BLG-induced allergic mice model through enhancing intestinal barrier and promoting Tregs differentiation,which may be correlated with SCFAs-mediated activation of GPRs.These findings suggest that MFGM may be useful as a promising functional ingredient against CMA.

红景天苷促进MC3T3-E1细胞成骨分化能力的体外实验

背景:骨缺损可直接影响牙齿种植的成功率及种植体的长期稳定性。研究显示红景天苷可促进成骨细胞增殖、分化,但对于其成骨分化相关通路具体研究不多。目的:体外细胞实验研究红景天苷对MC3T3-E1细胞增殖和分化的影响,并探究其对相关基因和蛋白表达的影响。方法:采用CCK-8实验和碱性磷酸酶实验筛选红景天苷(0.5,1,5,10,50μmol/L)促进MC3T3-E1细胞增殖和分化的最佳浓度。实验分为4组:对照组、红景天苷组、红景天苷+LY294002组、LY294002组,分别用成骨诱导液、含10μmol/L红景天苷、10μmol/L红景天苷+10μmol/L LY294002、10μmol/L LY294002的成骨诱导液进行培养,观察红景天苷及PI3K/Akt信号通路抑制剂LY294002对成骨相关基因和蛋白表达的影响。结果与结论:①CCK-8实验和碱性磷酸酶实验显示:红景天苷促进MC3T3-E1细胞增殖的作用在10μmol/L时最显著;②与对照组相比,红景天苷可以促进矿化、促进细胞黏附、减少细胞死亡,提高Runx-2、骨钙素、骨桥蛋白的mRNA表达(P<0.01),提高Runx-2和p-Akt蛋白表达(P<0.01);而添加PI3K/Akt信号通路抑制剂LY294002则可逆转以上结果;③结果表明,红景天苷能促进MC3T3-E1细胞矿化,并能促进成骨相关基因、蛋白的表达,这可能与PI3K/Akt信号通路的激活有关。

Preventive effects of Bifidobacterium lactis Probio-M8 on ovalbumin-induced food allergy in mice

Food allergy is a significant public health concern globally.Certain probiotics have been found to enhance food allergy by regulating immune-microbe interactions in animal models and patients.However,the effects of Bifidobacterium lactis Probio-M8 on food allergy have not been thoroughly investigated.The present study examined the anti-allergic properties of Probio-M8,particularly in relation to immune response and gut microbiota composition.Results demonstrate that oral administration of Probio-M8 effectively mitigated the allergy symptoms triggered by ovalbumin(OVA)by ameliorating the morphological damage in the jejunum,reducing OVA-specific IgE and histamine levels in the serum,and suppressing Th2 cytokines(interleukin(IL)4 and IL-13)while increasing Th1 cytokines(interferon(IFN)γ)and regulatory T(Treg)cytokines(IL-10 and transforming growth factor(TGF)β1)in the culture supernatants of splenic cells.Furthermore,Probio-M8 effectively altered the diversity and composition of gut microbiota,particularly the relative abundances of Akkermansia_muciniphila in OVA-induced mice.Compared to the OVA group,the Probio-M8 group showed a decrease in the relative abundance of Akkermansia_muciniphila.In conclusion,Probio-M8 demonstrates the potential to alleviate food allergy by regulating the Th1/Th2 response and modulating gut microbiota,thereby offering a novel therapeutic strategy for patients with food allergy.

Expanding indications for chronic hepatitis B treatment: Is it really desirable to treat everyone?

Chronic viral hepatitis causes an increased risk of progressive liver disease and hepatocellular carcinoma.On the wave of the World Health Organization’s goal to reduce new cases and deaths from hepatitis B and C by 2030,there is an increasing call to expand the indications for treatment of chronic hepatitis B.Currently,the main goal of treatment is to achieve a functional cure due to the inability of current drugs to completely eradicate the virus.There are still many discrepancies between available guidelines in terms of eligibility for treatment as well as an uncertainty about the appropriate treatment duration.This editorial addresses key questions about the topic and whether indications for treatment should be expanded.

2’-Fucosyllactose alleviate immune checkpoint blockade-associated colitis by reshaping gut microbiota and activating AHR pathway

Immune checkpoint blockade(ICB)therapeutics are highly effective in cancer immunotherapy,but gastrointestinal toxicity limited the application.Intestinal microbiota plays a crucial role in ICB-associated colitis.2’-Fucosyllactose(2’FL)is most abundance prebiotic in human milk that can reshape gut microbiota and exert immune regulatory effect.The study aimed to determine the effects of 2’FL on ICB-associated colitis and to uncover the mediating mechanism.ICB-associated colitis was induced by the ipilimumab and dextran sulfate sodium.Oral administration of 2’FL(0.6 g/(kg∙day))ameliorated ICB-induced colitis by enhancing regulatory T cells(Treg)and the M2/M1 ratio of macrophages in colon.2’FL treatment also increased the expression of tight junction proteins(zonula occludens-1(ZO-1)and mucin 2(MUC2))and antioxidant stress indicators(superoxide dismutase(SOD)and catalase(CAT)).In addition,administration of 2’FL increased the abundance of Bifidobacterium and Lactobacillus,and elevated the levels of microbial metabolites,such as indole-3-lactic acid(ILA),which activated the aryl hydrocarbon receptor ligands(AHR)pathway.The protective effect of 2’FL was abolished upon depletion of gut microbiota,and ILA treatment partially simulated the protective effect of 2’FL.Notably,2’FL did not exhibit inhibition of antitumor immunity.These findings suggest that 2’FL could serve as a potential protective strategy for ICB-associated colitis by modulating the intestinal microbiota and bacterial metabolites.

Quintessence anisotropic stellar models in quadratic and Born-Infeld modified teleparallel Rastall gravity

This study aims to discuss anisotropic solutions that are spherically symmetric in the quintessence field,which describe compact stellar objects in the modified Rastall teleparallel theory of gravity.To achieve this goal,the Krori and Barua arrangement for spherically symmetric components of the line element is incorporated.We explore the field equations by selecting appropriate off-diagonal tetrad fields.Born-Infeld function of torsion f(T)=β√λT+1-1 and power law form h(T)=δTn are used.The Born-Infeld gravity was the first modified teleparallel gravity to discuss inflation.We use the linear equation of state pr=ξρto separate the quintessence density.After obtaining the field equations,we investigate different physical parameters that demonstrate the stability and physical acceptability of the stellar models.We use observational data,such as the mass and radius of the compact star candidates PSRJ 1416-2230,Cen X-3,&4U 1820-30,to ensure the physical plausibility of our findings.

All-electron basis sets for H to Xe specific for ZORA calculations:Applications in atoms and molecules

A segmented basis set of quadruple zeta valence quality plus polarization functions(QZP)for H through Xe was developed to be used in conjunction with the ZORA Hamiltonian.This set was augmented with diffuse functions to describe electrons farther away from the nuclei adequately.Using the ZORA-CCSD(T)/QZP-ZORA theoretical model,atomic ionization energies and bond lengths,harmonic vibrational frequencies,and atomization energies of some molecules were calculated.The addition of core-valence corrections has been shown to improve the agreement between theoretical and experimental results for molecular properties.For atomization energies,a similar observation emerges when considering spin-orbit couplings.With the augmented QZP-ZORA set,static mean dipole polarizabilities of a set of atoms were calculated and compared with previously published recommended and experimental values.Performance evaluations of the ZORA and Douglas–Kroll–Hess Hamiltonians were made for each property studied.

黄芪甲苷可缓解MC3T3-E1细胞氧化应激损伤并促进成骨

背景:氧化应激是导致骨质疏松症的主要原因之一,减少氧化应激水平与增加抗氧化防御是治疗骨质疏松症的重要研究方向。研究证实黄芪甲苷具有抗骨质疏松作用,但其作用机制尚不明确。目的:探讨黄芪甲苷对氧化应激条件下MC3T3-E1细胞成骨的作用。方法:将MC3T3-E1细胞分4组培养:对照组加入完全培养基,模型组加入含过氧化氢的完全培养基干预24 h后更换为完全培养基,黄芪甲苷组加入含过氧化氢、黄芪甲苷的完全培养基干预24 h后更换为含黄芪甲苷的完全培养基,抑制剂组加入含过氧化氢、黄芪甲苷、细胞外信号调节激酶(extracellular signal-regulated kinases,ERK)抑制剂的完全培养基干预24 h后更换为含黄芪甲苷、ERK抑制剂的完全培养基。过氧化氢干预48 h后,通过丙二醛含量检测黄芪甲苷对MC3T3-E1细胞氧化应激的缓解作用;过氧化氢干预48 h后进行成骨诱导培养,通过碱性磷酸酶染色、茜素红染色验证MC3T3-E1细胞成骨及矿化能力,通过RT-qPCR检测成骨相关基因的表达,Western blot检测成骨相关蛋白及ERK/腺苷酸激活蛋白激酶(AMP-activated protein kinase,AMPK)信号通路蛋白的表达。结果与结论:(1)模型组细胞内碱性磷酸酶含量与矿化结节形成均少于对照组(P<0.05),黄芪甲苷组细胞内碱性磷酸酶含量与矿化结节形成均多于模型组(P<0.05)。(2)与对照组比较,模型组细胞内丙二醛含量增加(P<0.05),骨钙素、RUNX2、Ⅰ型胶原蛋白的mRNA与蛋白表达均降低(P<0.05),AMPK mRNA与p-AMPK蛋白表达升高(P<0.05);与模型组比较,黄芪甲苷组细胞内丙二醛含量减少(P<0.05),骨钙素、RUNX2、Ⅰ型胶原蛋白的mRNA与蛋白表达均升高(P<0.05),ERK1/2、AMPK mRNA表达升高(P<0.05),p-AMPK、p-ERK1/2蛋白表达均升高(P<0.05);ERK抑制剂可部分抑制黄芪甲苷的上述作用。(3)结果表明,黄芪甲苷可通过激活ERK/AMPK信号通路促进氧化应激条件下MC3T3-E1细胞的成骨分化。

GAS2增强CXCR4蛋白稳定性并促进T-ALL细胞的生长

目的研究生长抑制特异蛋白GAS2(growth arrest-specific 2)在急性T淋巴细胞白血病(T-cell acute lymphoblastic leukemia,T-ALL)细胞体内外生长和迁移中的功能,并初探其作用机制。方法(1)以MOLT-4细胞为模型,研究过表达GAS2对这些细胞的生长、集落生成、迁移和体内成白血病能力的影响;(2)利用RT-qPCR、Western blot和流式细胞术研究GAS2对CXCR4表达的影响;(3)在过表达GAS2的MOLT-4细胞中沉默CXCR4,研究CXCR4在GAS2促进T-ALL细胞生长功能中的作用。结果(1)过表达GAS2显著增强MOLT-4细胞的生长、集落生成和迁移能力;(2)过表达GAS2增强MOLT-4细胞在免疫缺陷小鼠体内的成白血病的能力;(3)GAS2增强CXCR4的蛋白表达、细胞膜表达和稳定性,但不影响它的mRNA表达;(4)CXCR4沉默能逆转过表达GAS2所导致的MOLT-4细胞生长增快。结论GAS2可部分通过增强CXCR4的蛋白稳定性而促进T-ALL细胞的生长。该研究增进了对T-ALL分子致病机制的认知,有望为疾病治疗提供新思路。

T cell interactions with microglia in immune-inflammatory processes of ischemic stroke

The primary mechanism of secondary injury after cerebral ischemia may be the brain inflammation that emerges after an ischemic stroke,which promotes neuronal death and inhibits nerve tissue regeneration.As the first immune cells to be activated after an ischemic stroke,microglia play an important immunomodulatory role in the progression of the condition.After an ischemic stroke,peripheral blood immune cells(mainly T cells)are recruited to the central nervous system by chemokines secreted by immune cells in the brain,where they interact with central nervous system cells(mainly microglia)to trigger a secondary neuroimmune response.This review summarizes the interactions between T cells and microglia in the immune-inflammatory processes of ischemic stroke.We found that,during ischemic stroke,T cells and microglia demonstrate a more pronounced synergistic effect.Th1,Th17,and M1 microglia can co-secrete proinflammatory factors,such as interferon-γ,tumor necrosis factor-α,and interleukin-1β,to promote neuroinflammation and exacerbate brain injury.Th2,Treg,and M2 microglia jointly secrete anti-inflammatory factors,such as interleukin-4,interleukin-10,and transforming growth factor-β,to inhibit the progression of neuroinflammation,as well as growth factors such as brain-derived neurotrophic factor to promote nerve regeneration and repair brain injury.Immune interactions between microglia and T cells influence the direction of the subsequent neuroinflammation,which in turn determines the prognosis of ischemic stroke patients.Clinical trials have been conducted on the ways to modulate the interactions between T cells and microglia toward anti-inflammatory communication using the immunosuppressant fingolimod or overdosing with Treg cells to promote neural tissue repair and reduce the damage caused by ischemic stroke.However,such studies have been relatively infrequent,and clinical experience is still insufficient.In summary,in ischemic stroke,T cell subsets and activated microglia act synergistically to regulate inflammatory progression,mainly by secreting inflammatory factors.In the future,a key research direction for ischemic stroke treatment could be rooted in the enhancement of anti-inflammatory factor secretion by promoting the generation of Th2 and Treg cells,along with the activation of M2-type microglia.These approaches may alleviate neuroinflammation and facilitate the repair of neural tissues.

Analysis of the anti-T2DM components in dichloromethane fraction of Schisandra sphenanthera and its mechanism

Background:The type 2 diabetes mellitus(T2DM)pharmacodynamic study of various parts of Schisandra sphenanthera was conducted in the previous stage,and it was found that dichloromethane extracted part(SDP)had a significant hypoglycemic effect.Therefore,the components of SDP were analyzed,and the specific mechanism of its anti-T2DM was explored.Methods:We used a high-fat,high-sugar diet in combination with streptozotocin to induce a T2DM rat model,and the model rats were divided into two groups according to body weight and blood glucose.Triglyceride,oral glucose tolerance test,fasting blood glucose,low density lipoprotein cholesterol,superoxide dismutase,insulin,glycated hemoglobin,total cholesterol,nonesterified free fatty acids,alanine aminotransferase,high-density lipoprotein cholesterol,aspartate aminotransferase,malondialdehyde,and glutathione peroxidase were measured,organ indices were calculated,and pathological sections of pancreas and liver were observed.The 16S rRNA V3–V4 region of intestinal flora was sequenced to explore the effect of SDP on biochemical indicators and intestinal flora.Based on the above indicators,the anti-T2DM mechanism of SDP in Schisandra sphenanthera was analyzed.Results:After six weeks of administration,the biochemical indices of diabetic rats were diminished compared to the control group.And SDP could significantly increase the gut microbialα-diversity index,resulting in significant changes in the flora of T2DM rats,with increased richness and diversity,reduced harmful flora,and significantly back-regulated the levels of acetic acid,propionic acid,and butyric acid.Conclusion:SDP can improve the symptoms associated with elevated blood glucose,dyslipidemia,elevated fasting insulin levels,and damaged glucose tolerance in rats.SDP against T2DM may be through the control of intestinal flora to normalize and exert anti-diabetic effect;its main active components may be lignans and terpenoids.

初级纤毛介导成骨前体细胞系MC3T3-E1传代衰老减低成骨分化能力

背景:在大段骨缺损修复中,由于种子细胞传代等多种因素可引起成骨类细胞衰老,造成组织工程骨植入体内后成骨分化活性降低。近年来,初级纤毛介导细胞衰老的机制已被广泛研究,但“传代衰老-成骨活性减低”的初级纤毛相关机制尚未完全明了。目的:探讨初级纤毛调控成骨性MC3T3-E1细胞传代衰老的可能机制。方法:成骨前体细胞系MC3T3-E1细胞传代至第10代(早期传代)及第40代(晚期传代),同时使用siRNA沉默IFT88阻碍初级纤毛生成,即将细胞分为第10代组、第40代组、第10代+siRNA IFT88-组、第40代+siRNA IFT88-组。各组细胞成骨诱导3 d,采用RT-PCR和Western blot检测衰老标志物CDKN2A(P16)的表达、成骨活性标志物骨形态发生蛋白2和碱性磷酸酶的表达、Hedgehog通路IHH的表达;茜素红染色和初级纤毛免疫荧光染色分析初级纤毛形态;对初级纤毛阳性率与IHH、骨形态发生蛋白2的表达进行Spearman相关性分析。结果与结论:①成骨诱导3 d,第40代组MC3T3-E1细胞的CDKN2A(P16)表达显著高于第10代组,而在siRNA IFT88-干预后差异消失;②第10代组的初级纤毛细胞阳性率高于第40代组,siRNA IFT88-则显著性抑制第10代与第40代细胞的初级纤毛表达;③第10代组MC3T3-E1细胞的碱性磷酸酶及骨形态发生蛋白2的转录活性和蛋白表达均高于第40代组,通过siRNA抑制初级纤毛表达后,上述差异减低或者消失;④初级纤毛细胞阳性率与IHH蛋白表达及骨形态发生蛋白2蛋白表达呈正相关。结果表明:初级纤毛介导了成骨性MC3T3-E1细胞的传代衰老,可调控成骨分化能力。

雷帕霉素逆转T-ALL Jurkat细胞对糖皮质激素耐药(英文)

目的探讨雷帕霉素能否有效逆转T细胞急性淋巴细胞白血病(T-ALL)Jurkat细胞对糖皮质激素(GC)的耐药。方法用10 nmol/L雷帕霉素(Rap组)、1μmol/L地塞米松(Dex组)、10 nmol/L雷帕霉素联合1μmol/L地塞米松(Rap+Dex组)和0.05%DMSO和0.01%乙醇(对照组)分别处理Jurkat细胞。MTT法检测细胞增殖;流式细胞术检测细胞周期和凋亡;Western blot法分析mTOR及细胞周期、凋亡相关蛋白表达情况。结果10 nmol/L雷帕霉素能有效抑制mTOR信号通路,逆转Jurkat细胞对GC耐药。雷帕霉素和地塞米松协同作用可有效上调细胞周期抑制蛋白p21和p27的表达,并协同下调细胞周期素D1的表达,从而阻抑细胞在G1期。雷帕霉素协同地塞米松,通过上调Bim表达,活化caspase-3,促进Jurkat细胞凋亡。结论雷帕霉素可有效逆转T-ALL Jurkat细胞对GC耐药。包含雷帕霉素和地塞米松的化疗方案有望成为治疗耐药T-ALL的有效方案。

T-ALL及T细胞株相关TCR Vβ基因谱系和克隆性分析

目的 了解T细胞 急性淋巴细胞白血病 (T ALL)患者外周血中的T细胞及T细胞株的TCRVβ基因谱系及其克隆性增殖情况。方法 利用RT PCR方法扩增 6个不同的T细胞株和 6例初发未治T ALL病人外周血单个核细胞中 2 4个TCRVβ基因的互补决定区 3(CDR3) ,PCR产物进一步经荧光标记和基因扫描分析CDR3长度而确定T细胞的克隆性 ,部分T细胞株的单克隆PCR产物进一步进行序列分析。结果 与正常人外周血表达全部 2 4个Vβ亚家族不同 ,6例T ALL病人分别表达 5～ 12个Vβ亚家族。 6例病人均存在 1个或多个Vβ亚家族的寡克隆或双克隆增殖T细胞 ,另外 ,还有一些Vβ亚家族多克隆模式发生改变 ,呈现寡克隆性增殖的趋势。T细胞株多显示为表达一个Vβ亚家族的单克隆T细胞 ,不同T细胞株的CDR3长度和序列不尽相同。结论 T ALL患者外周血T细胞的TCRVβ谱系出现限制性改变 ,均可检测到克隆性增殖T细胞 ,尚需进一步鉴定其性质 (肿瘤性或抗原特异性增殖 ) 。

Microstructures and mechanical properties of extruded and aged Mg-Zn-Mn-Sn-Y alloys

The microstructures and mechanical properties of Mg-6Zn-1Mn-4Sn and Mg-6Zn-1Mn-4Sn-0.5Y alloys under extrusion and T6 aging conditions were investigated by optical microscopy（OM）, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and tensile test. The results show that Y element refines the grains and improves the comprehensive mechanical properties of ZMT614-0.5Y both in as-extruded and T6 states. The phase compositions of Mg-6Zn-1Mn-4Sn-0.5Y are α-Mg, Mg Zn2, Mn, Mg2 Sn and Mg Sn Y phases. After T6 treatment, the ultimate tensile strength（UTS） and yield strength（YS） increase while the elongation decreases severely. For both of these alloys, the theoretical results combined with the experimental values demonstrate that the grain boundary strengthening and solid solution strengthening play an important role in enhancing the YS in the as-extruded state, while the precipitation strengthening is the key factor for the enhancement of YS in the T6 state.

B-ALL病人TCR Vβ基因谱系和克隆性分析

目的 了解B ALL病人外周血T细胞的TCRVβ基因谱系及其克隆性增殖情况。 方法 利用RT PCR方法扩增 13例初发未治B ALL病人外周血单个核细胞中 2 4个TCRVβ基因的互补决定区 3(CDR3) ,PCR产物进一步经荧光标记和基因扫描分析CDR3长度而确定T细胞的克隆性。结果 13例B ALL病人分别表达 2～ 18个Vβ亚家族。 13例病人均存在 1个或多个Vβ亚家族的克隆增殖T细胞 ,增殖形式包括寡克隆及寡克隆增殖趋势、双克隆和单克隆。Vβ2 1和Vβ2 3亚家族出现克隆增殖性T细胞的频率较高。结论 B ALL病人外周血T细胞的TCRVβ谱系呈现优势利用的特点 ,并存在克隆性增殖的T细胞 ,这可能是机体对白血病相关抗原产生的特异性免疫反应 ;Vβ2 1和Vβ2 3亚家族T细胞发生克隆增殖改变的趋向性比较明显 ,可能与B

Effects of T9I6 thermo-mechanical process on microstructure, mechanical properties and ballistic resistance of 2519A aluminum alloy

The effects of T916 thermo-mechanical process on microstructures, mechanical properties and ballistic resistance of 2519A aluminum alloy were investigated by optical microscopy （OM）, transmission electron microscopy （TEM）, tensile tests and ballistic resistance test. After T916 treatment, the yield strength, tensile strength and elongation rate of 2519A aluminum alloy reach 501 MPa, 540 MPa and 14%, respectively. And the ballistic limit velocity of 2519A-T916 alloy （30 mm in thickness） is 715 rn/s. The microstructure varies near the sidewalls of crater. The interrupted ageing contributes to these excellent properties of the alloy. During T916 process, the precipitation of Guinier Preston （GP） zone is finer and denser during the interrupted ageing, thus resulting in well precipitated strengthening phase.