G-CSF对外周血树突状细胞亚群比例的影响

目的 :了解G CSF对小鼠外周血树突状细胞 (DC)亚群比例的影响。方法 :以不同剂量 (0、5 .0、10 .0或 15 .0 μg)的G CSF ,分别皮下注射于BALB/c小鼠 ,连续 6d ,每天 1次。第 6天分离外周血DC ,用流式细胞仪检测DC1(CD11c+ CD8a-)和DC2 (CD11c+ CD8a+ )的比例并计算其绝对值。结果 :经不同剂量的G CSF刺激后 ,外周血DC1的绝对值无显著变化 ,而DC2的绝对值增加 5倍 (9.6× 10 6/Lvs 5 5 .1× 10 6/L ,P <0 .0 1) ,DC1/DC2比值降低 (4.2vs 0 .7,P <0 .0 1)。结论 :G CSF在体内可提高外周血DC2的绝对数 ,对DC1的数无明显影响 ,从而使DC1/DC2的比例倒置     

炎症因子对肾小球系膜细胞分泌IL—8的影响

目的：观察炎症因子ＩＬ－１及肿瘤坏死因子（ＴＮＦ）对人肾小球系膜细胞（ＨＭＣ）分泌ＩＬ－８的影响。方法：体外细胞培养技术及ＥＬＩＳＡ夹心法。结果：ＩＬ－１、ＴＮＦ均可诱导ＨＭＣ分泌ＩＬ－８，并呈剂量依赖性。结论：在一些炎症因子刺激下，ＨＭＣ可能通过分泌趋化因子ＩＬ－８参与肾脏炎症反应的启动和维持     

What determines the frequency of fast network oscillations with irregular neural discharges? I. Synaptic dynamics and excitation-inhibition balance

When the local field potential of a cortical network displays coherent fast oscillations ( approximately 40-Hz gamma or approximately 200-Hz sharp-wave ripples), the spike trains of constituent neurons are typically irregular and sparse. The dichotomy between rhythmic local field and stochastic spike trains presents a challenge to the theory of brain rhythms in the framework of coupled oscillators. Previous studies have shown that when noise is large and recurrent inhibition is strong, a coherent network rhythm can be generated while single neurons fire intermittently at low rates compared to the frequency of the oscillation. However, these studies used too simplified synaptic kinetics to allow quantitative predictions of the population rhythmic frequency. Here we show how to derive quantitatively the coherent oscillation frequency for a randomly connected network of leaky integrate-and-fire neurons with realistic synaptic parameters. In a noise-dominated interneuronal network, the oscillation frequency depends much more on the shortest synaptic time constants (delay and rise time) than on the longer synaptic decay time, and approximately 200-Hz frequency can be realized with synaptic time constants taken from slice data. In a network composed of both interneurons and excitatory cells, the rhythmogenesis is a compromise between two scenarios: the fast purely interneuronal mechanism, and the slower feedback mechanism (relying on the excitatory-inhibitory loop). The properties of the rhythm are determined essentially by the ratio of time scales of excitatory and inhibitory currents and by the balance between the mean recurrent excitation and inhibition. Faster excitation than inhibition, or a higher excitation/inhibition ratio, favors the feedback loop and a much slower oscillation (typically in the gamma range).     

中枢神经系统OMgp的研究进展

在中枢神经系统(CNS)和周围神经系统(PNS)的发育过程中,胶质细胞与神经元的相互作用尤为重要。髓鞘的形成对于轴突的保护、神经冲动的传导以及脊髓损伤后神经的再生具有重要作用。OMgp(olyigodendrocyte myelin glycopro-tein)大多分布于CNS近轴突膜的髓鞘的疏松层以及大的投射     

人类胚胎生殖细胞体外分化为心肌细胞的研究

胚胎生殖（EG）细胞是来源于胚胎原始生殖细胞（PGCs）的多潜能干细胞。采用无饲养层细胞、无细胞因子等的基础培养液（DMEM＋20％NBS＋0．1mM 2Me）培养EG细胞，部分在基础培养液添加10μmol／LRA＋0．75％DMSO或10μmol／L 5-氮胞苷（5-AZA）诱导人类EG细胞向心肌细胞分化，以检测其是否具有向心肌细胞自发分化的能力。9例（8．49％，9／106）胎儿EG细胞在体外分化得到20个节律性心脏跳动样细胞团，其搏动节律为20～120次／min，体外维持节律性搏动最短2d，最长至15d，呈PAS，Myoglobin，α-actin阳性；对K^＋、Ca^＋、肾上腺素等具有与在体心脏相似的反应性；透射电镜观察具有心肌细胞样结构。添加DMSO和RA或5-AZA诱导未得到跳动样心肌细胞，但可提高心肌α-actin免疫组织化学染色阳性率；表明人类胚胎生殖细胞具有向心肌细胞分化的潜能。     

The Impact of Positive Youth Development Attributes on Posttraumatic Stress Disorder Symptoms Among Chinese Adolescents Under COVID-19

PurposeThis study examined the prevalence of posttraumatic stress disorder (PTSD) symptoms among adolescents in mainland China under COVID-19. The direct effects of the perceived threat of COVID-19 and positive youth development (PYD) qualities, as well as the moderating effect of PYD qualities on PTSD symptoms, were studied.MethodsFive schools in Chengdu, Sichuan, China, participated in this study. Two waves of data were collected before school lockdown (Wave 1, between December 2019 and January 2020) and after school resumption (Wave 2, between June 2020 and July 2020), respectively. A total of 4,981 adolescents aged above 11 years (Mean age = 13.15, SD = 1.32 at Wave 1, 51.5% girls) completed questionnaires at both waves. Students responded to measures of PYD qualities at both waves and perceived threat and PTSD symptoms at Wave 2.ResultsA total of 517 adolescents (10.4%) could be regarded as having PTSD. Results indicated significant unique main effects of perceived threat (β = .13, p < .001) and Wave 1 PYD qualities (β = ?.16, p < .001) on PTSD symptoms. Besides, results showed a significant moderating effect of PYD qualities in mitigating the negative impact of perceived threat on PTSD symptoms.ConclusionsThis study revealed the protective effect of PYD attributes in reducing the negative influence of traumatic situations such as COVID-19 on adolescent mental health. Results underscore the importance of promoting PYD qualities in adolescents in mainland China via effective PYD programs.     

结直肠锯齿状腺瘤的临床特征及恶变影响因素分析

目的锯齿状腺瘤被公认为结直肠癌的癌前病变,锯齿状通路被认为是可以独立发展成结直肠癌的重要通路,但目前对于锯齿状腺瘤恶变的相关危险因素还知之甚少。本文旨在分析锯齿状腺瘤在结直肠中的分布特点及潜在恶变因素。方法采用病例对照研究方法,回顾性收集2017年4月至2019年7月期间在中国医学科学院肿瘤医院行肠镜检查并经病理诊断为锯齿状腺瘤患者的临床资料,排除同时具有两种及以上病理类型病变的患者。总结锯齿状腺瘤的临床特征,并进行单因素和Logistic多因素回归分析,探讨锯齿状腺瘤发生恶变的影响因素。结果共在28730例行肠镜检查患者中,发现311例(1.08%)锯齿状腺瘤患者,共发现锯齿状腺瘤372枚。按WHO分类,无蒂锯齿状腺瘤/息肉22枚(5.9%),传统锯齿状腺瘤84枚(22.6%),未分类锯齿状腺瘤266枚(71.5%)。病理结果显示:无异型增生病变106枚(28.5%),低级别上皮内瘤变病变228枚(61.3%),高级别上皮内瘤变或癌变38枚(10.2%)。病变长径<10 mm有204枚(54.8%),≥10 mm有168枚(45.2%);病变位于左半结直肠238枚(64.0%),右半结肠134枚(36.0%)。内镜下大体分型:扁平型16枚(4.3%),无蒂型174枚(46.8%),亚蒂型117枚(31.5%),带蒂型59枚(15.9%)。窄带成像国际结直肠内镜(NICE)分型:Ⅰ型85枚(22.8%),Ⅱ型280枚(75.3%),Ⅲ型4枚(1.1%)。单因素分析显示,病变大小、病变位置、病变部位及不同WHO分类与结直肠锯齿状腺瘤发生恶变有关(均P<0.05);不同NICE分型的锯齿状腺瘤,其恶变率的差异亦有统计学差异(P=0.001)。多因素分析结果显示,病变长径≥10 mm(OR=6.699,95%CI:2.843~15.786)以及病变位于左半结直肠(OR=2.657,95%CI:1.042~6.775)是结直肠锯齿状腺瘤发生恶变的独立危险因素。结论锯齿状腺瘤主要位于左半结直肠,当病变长径≥10 mm或病变位于左半结直肠时,易发生恶变。     

北京市一起新型冠状病毒Omicron变异株聚集性疫情特征分析

目的 分析北京市海淀区一起新型冠状病毒肺炎聚集性疫情流行病学特征及传播链。方法 采用描述性流行病学方法分析疫情流行病学特征,应用现场调查和大数据技术分析传播链。结果 2022年4月27日至5月13日, 海淀区发生一起新型冠状病毒肺炎聚集性疫情,全基因组测序系Omicron变异株（BA.2.2进化分支）;涉及感染者38例,确诊病例34例,无症状感染者4例;临床分型以轻型（88.2%）为主,无重型、危重型和死亡病例;早期临床症状以咽部不适（50.0%）、咳嗽（29.4%）为主;17 d内传播7代,涉及3起社区聚集、2起单位聚集和8个家庭内传播;暴露方式以同住（47.6%）、同时空暴露（31.6%）为主;代间距M（Q₁,Q₃）为3（1,6）d;总续发率为1.5%（37/2 482）,其中家庭续发率为36.7%（18/49）。结论 本起Omicron变异株疫情临床症状轻,家庭、社区聚集性明显,疫情传播速度较快,同时空暴露感染风险较高,需利用信息化技术全面摸排密切接触者,以快制快,有效阻断疫情传播。     

慢性常压缺氧和缺氧伴CO_2潴留大鼠红细胞变形能力与膜收缩蛋白的研究

本文测定了慢性常压缺氧（Ⅱ组）、缺氧伴ＣＯ－２潴留（Ⅲ组）及对照组（Ⅰ组）大鼠红细胞变形能力与红细胞膜收缩蛋白二聚体（ＳＰ－Ｄ）和四聚体（ＳＰ－Ｔ）的相对含量。结果表明，Ⅱ、Ⅲ组红细胞变形指数（ＤＩ）和ＳＰ－Ｄ、ＳＰ－Ｔ相对含量与Ⅰ组均有显著差异，且Ⅱ、Ⅲ组的ＤＩ与ＳＰ－Ｄ／ＳＰ－Ｔ比值呈显著负相关。提示膜收缩蛋白的异常，可能是导致慢性缺氧和伴ＣＯ－２潴留大鼠红细胞变形能力降低的重要因素之一。