Orthograde transport and release of insulin-like growth factor I from the inferior olive to the cerebellum

Insulin-like growth factor I (IGF-I) and its receptor are expressed in functionally related areas of the rat brain such as the inferior olive and the cerebellar cortex. A marked decrease of IGF-I levels in cerebellum is found when inferior olive neurons are lesioned. In addition, Purkinje cells in the cerebellar cortex depend on this growth factor to survive and differentiate in vitro. Thus, we consider it possible that IGF-I forms part of a putative trophic circuitry encompassing the inferior olive and the cerebellar cortex and possibly other functionally connected areas. To test this hypothesis we have studied whether IGF-I may be taken up, transported, and released from the inferior olive to the cerebellum. We have found that ¹²⁵I-IGF-I is taken up by inferior olive neurons in a receptor-mediated process and orthogradely transported to the cerebellum. Thus, radioactivity found in the cerebellar lobe contralateral to the injection site in the inferior olive was immunoprecipitated by an anti-IGF-I antibody, co-eluted with ¹²⁵I-IGF-I in an HPLC column, and co-migrated with ¹²⁵I-IGF-I in an SDS-urea polyacrylamide gel electrophoresis. Time-course studies indicated that orthograde axonal transport is relatively rapid since 30 min after the injection, radiolabeled IGF-I was already detected in the contralateral cerebellum. Furthermore, transport of IGF-i from the inferior olive is specific since when ¹²⁵I-neurotensin was injected in the inferior olive or when ¹²⁵I-IGF-I was injected in the pontine nucleus, no radiactivity was found in the contralateral cerebellum. In addition, no specific transport of ¹²⁵I-IGF-I was found in climbing fiber-deafferented rats or when excess unlabeled IGF-I was co-injected with ¹²⁵I-IGF-I. We next studied whether IGF-I is released by inferior olive neurons. We found that the release of IGF-I from cerebellar slices of normal rats was significantly greater in response to depolarizing stimuli than that from slices obtained of climbing fiber-deafferented animals. Indeed, in vitro release of IGF-I in response to KCI or veratridine was almost completely abolished in the latter. These data suggest that IGF-I is taken up by inferior olive neurons through IGF-I receptors and transported to the cerebellum through their axons without any major modification. Moreover, the release of IGF-I from the cerebellum after depolarization depends on the presence of climbing fiber afferents. Altogether these results indicate that the olivo-cerebellar pathway is able to take up, orthogradely transport, and release IGF-I. Since a similar process has been described in the visual system for basic fibroblast growth factor (bFGF), we propose that IGF-I, bFGF, and possibly other growth factors may constitute afferent trophic signals involved in plastic mechanisms within specific neural circuitries. © 1993 Wiley-Liss, Inc.     

导管射频消融术治疗持续性交界区反复性心动过速2例报告

本文报告两例持续性交界区反复性心动过速(PJRT)患者,应用导管射频消融术治疗,成功地阻断了位于后间隔具有递减传导特性的稳若旁路.随访7～10个月.病人无心动过速发作,提示导管射频消融术是治疗PJRT的有效方法.     

急性冠脉综合征患者强化抗栓治疗研究进展

急性冠脉综合征（ACS）是冠心病的严重类型,ACS患者不仅病死率较高,还存在缺血事件（如缺血性卒中、心肌梗死）复发风险。血小板聚集及血栓形成是导致ACS的重要原因。为降低缺血事件的发生风险,临床推荐ACS患者接受阿司匹林联合强效P2Y12抑制剂的双联抗血小板治疗12个月。然而在标准双联抗血小板治疗下,ACS患者残余缺血风险（经抗栓治疗后仍残留的缺血事件发生风险）仍旧较高。因此为进一步降低缺血事件发生风险,临床对强化抗栓方案的研究也逐渐增多。本文通过总结强化抗栓治疗方案的作用机制及其最新研究进展,发现延长双联抗血小板治疗时间、三联抗血小板治疗、双通道抑制（抗血小板联合抗凝治疗）等强化抗栓治疗方案可降低缺血事件发生风险,为进一步指导临床个体化抗栓治疗及明确最佳抗栓策略提供了参考。     

ACE2基因通过调控Nrf2/HO-1通路改善肾缺血再灌注损伤

目的 探讨血管紧张素转化酶2(ACE2)对缺氧复氧诱导的肾小管上皮细胞HK-2氧化应激、炎症、凋亡及核因子E2相关因子2(Nrf2)/血红素加氧酶1(HO-1)信号通路的影响。 方法 将ACE2慢病毒转染HK-2细胞,按照实验需要分为常氧组(Control组)、缺氧复氧模型组(H/R组)、缺氧复氧转染阴性对照慢病毒组(H/R-NC组)和缺氧复氧转染ACE2慢病毒组(H/R-ACE2组)。细胞经H/R处理后,通过CCK-8法检测细胞活力;RT-PCR及ELISA法检测炎症因子白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)和白介素-1β(IL-1β)水平;比色法检测超氧化物歧化酶(SOD)、丙二醛(MDA)表达水平;Western blotting法检测胱天蛋白酶3(Caspase-3)、B淋巴细胞瘤-2基因(Bcl-2)、Bcl-2关联X蛋白(Bax)、Nrf2、HO-1的蛋白水平。采用Nrf2抑制剂ML385以及HO-1抑制剂SnPPIX抑制Nrf2/HO-1通路,Western blotting法检测Caspase-3、Bcl-2、Bax、Nrf2、HO-1的蛋白表达水平变化,比色法检测SOD和MDA表达变化。 结果 与Control组相比,H/R组细胞活力降低(t=7.58,P<0.001),MDA含量和炎症因子IL-6、TNF-α和IL-1β表达水平以及细胞凋亡相关蛋白Caspase-3、Bax蛋白水平均增加(t_MDA=11.08,P_MDA<0.001;t_PCR-IL-6=5.82,P_PCR-IL6<0.001;t_PCR-TNF-α=7.69,P_PCR-TNF-α<0.001;t_PCR-IL-1β=4.80,P_PCR-IL-1β=0.001;t_ELISA-IL-6=34.11,P_ELISA-IL-6<0.001;t_ELISA-TNF-α=14.12,P_ELISA-TNF-α<0.001;t_ELISA-IL-1β=9.63,P_ELISA-IL-1β<0.001;t_Caspase-3=2.73,P_Caspase-3=0.026;t_Bax=27.75,P_Bax<0.001),SOD活性、Bcl-2和ACE2蛋白水平下降(t_SOD=7.74,P_SOD<0.001;t_Bcl-2=75.49,P_Bcl-2<0.001;t_ACE2=11.41,P_ACE2<0.001)。与H/R组相比,H/R-ACE2组细胞活力增加(t=3.61,P=0.002),MDA含量和炎症因子IL-6、TNF-α和IL-1β表达水平以及细胞凋亡相关蛋白Caspase-3、Bax蛋白水平均下降(t_MDA=6.15,P_MDA<0.001;t_PCR-IL-6=3.34,P_PCR-IL-6=0.006;t_PCR-TNF-α=3.65,P_PCR-TNF-α=0.007;t_PCR-IL-1β=4.06,P_PCR-IL-1β=0.004;t_ELISA-IL-6=14.62,P_ELISA-IL-6<0.001;t_ELISA-TNF-α=10.42,P_ELISA-TNF-α<0.001;t_ELISA-IL-1β=8.65,P_ELISA-IL-1β<0.001;t_Caspase-3=3.74,P_Caspase-3=0.006;t_Bax=30.52,P_Bax<0.001),SOD活性、Bcl-2和ACE2蛋白水平增加(t_SOD=3.58,P_SOD=0.007;t_Bcl-2=63.86,P_Bcl-2<0.001;t_ACE2=58.72,P_ACE2<0.001),Nrf2/HO-1信号通路被激活蛋白水平增加(t_Nrf2=44.55,P_Nrf2<0.001;t_HO-1=14.19,P_HO-1<0.001)。然而ML385和SnPPIX处理会抑制ACE2基因过表达在H/R中HK-2细胞的保护作用(F_Bax=11.02,P_Bax=0.003;F_Bcl-2=21.48,P_Bcl-2<0.001;F_Caspase-3=20.80,P_Caspase-3<0.001;F_SOD=133.49,P_SOD<0.001;F_MDA=14.06,P_MDA=0.001)。 结论 ACE2在HK-2细胞缺氧复氧损伤中具有抑制氧化应激、调节炎症、改善凋亡的作用,Nrf2/HO-1信号通路发挥重要作用。     

基于FAERS的地舒单抗安全警戒信号挖掘与评价

基于FAERS数据库挖掘安全警戒信号,分析评估地舒单抗潜在不良反应信号,为其临床使用提供一定参考依据。方法 通过Openvigil 2.1访问 FAERS 数据库,将地舒单抗作为主要药物,检索自该药首次上市时间（2010年5月—2021年9月）的数据,获得与地舒单抗相关的不良事件报告记录。使用报告比值比法（ROR）和贝叶斯置信度递进神经网络法（BCPNN）筛选地舒单抗安全警戒信号,挖掘潜在的不良反应,并通过工具BioPortal对不良事件信号挖掘结果进行系统分类,通过判断信号间置信区间的变化,发现与药物不良事件关联性较大的信号。结果 从FAERS数据库中收集到270503份不良反应事件（ADE）报告,根据ROR法和BCPNN法共得到343个不良事件信号,通过信号间同义合并、剔除与药物无关的信号后,得到316个不良事件信号。地舒单抗的不良事件系统分类主要为肌肉骨骼和结缔组织疾病、医学检查、胃肠道疾病。FAERS数据库的信号挖掘结果发现,高风险且说明书中未收录的安全警戒信号包括颞下颌关节综合征、下颌脓肿、雌激素缺乏症、血液甲状旁腺激素增加,计算高风险信号的置信区间显示颞下关节综合征较有可能发展成为新的不良反应;另外,也发现种植体周围炎为具有临床意义的可疑警戒信号,但有待进一步观察研究。结论 基于FAERS数据库的信号挖掘结果提示临床应规范使用地舒单抗,治疗期间需警惕患者是否出现颞下颌关节综合征、下颌脓肿、雌激素缺乏症、血液甲状旁腺激素增加等不良反应事件,以便尽早发现尽早处理,从而有效降低临床用药风险     

右美托咪定调控Nrf2/HO-1通路对H2O2诱导心肌细胞氧化应激损伤的作用研究

目的 探讨右美托咪定调控核因子E2相关因子2(Nrf2)/血红素加氧酶1(HO-1)通路对过氧化氢(H₂O₂)诱导心肌细胞氧化应激损伤的作用。方法 体外培养大鼠H9C2心肌细胞,设置对照组、H₂O₂组、1μmol右美托咪定+H₂O₂组、5μmol右美托咪定+H₂O₂组、10μmol右美托咪定+H₂O₂组。CCK-8法检测各组H9C2细胞增殖情况;酶联免疫吸附试验(ELISA)检测各组H9C2细胞丙二醛(MDA)、超氧化物歧化酶(SOD)水平;实时荧光定量聚合酶链反应(q RT-PCR)检测各组H9C2细胞Nrf2、HO-1 mRNA相对表达量;Western blotting检测各组H9C2细胞Nrf2、HO-1蛋白相对表达量。结果 与对照组比较,H₂O₂组H9C2细胞存活率、SOD水平、Nrf2、HO-1 mRNA及蛋白相对...     

格隆溴铵对高氧诱导幼鼠急性肺损伤的影响及其机制研究

目的 探究格隆溴铵对高氧诱导幼鼠急性肺损伤（ALI）的影响及作用机制。方法 从30只SD幼鼠中随机选取10只为对照组,其余幼鼠成功复制高氧诱导的ALI模型,随机分为ALI组、格隆溴铵组,每组10只。格隆溴铵组雾化吸入0.8 mg/（kg·d）格隆溴铵,ALI组、对照组吸入等体积生理盐水,连续给药7 d后,测量幼鼠肺组织湿/干重比值（W/D）、肺指数,检测白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）及肿瘤坏死因子-α（TNF-α）水平及血清活性氧基团（ROS）、超氧化物歧化酶（SOD）水平,比较肺组织病理学变化及Toll样受体4/髓分化因子88（TLR4/MyD88）通路蛋白的表达。结果 与对照组比较,ALI组W/D及肺指数升高（P <0.05）,血清IL-1β、IL-6、TNF-α、SOD水平升高（P <0.05）,ROS水平降低（P <0.05）,TLR4、MyD88蛋白相对表达量上调（P <0.05）;与ALI组比较,格隆溴铵组W/D及肺指数降低（P <0.05）,血清IL-1β、IL-6、TNF-α、SOD水平降低（P <0.05）,ROS水平升高（P <0.05）,TLR4、MyD88蛋白相对表达量下调（P <0.05）。结论 格隆溴铵能改善血清炎症指标及氧化应激指标,降低高氧诱导的ALI,其作用机制可能与TLR4/MyD88通路有关。     

蜥蜴中脑神经通路和起源细胞的形态

本文采用 HRP 法研究了蛤蚧(Gekko gekko)和鳄蜥(Shinisaurus crocodilurus)视顶盖、中脑深核(NPM)与峡核之间的通路和起源细胞的形态。结果指出:1.顶盖与峡核大细胞部(Imc)呈相互区域对应投射;2.同侧顶盖—Imc 投射细胞主要位于第7层,系有径向树突的梨形细胞;同侧 Imc—顶盖投射细胞为小树突域的梨形或多角形细胞;3.顶盖注射标记的 NPM细胞呈纺锤形,染色浅;峡核注射标记的 NPM 细胞,其粗树突往往伸向顶盖;4.NPM 注射标记顶盖细胞和峡核细胞,前者主要位于顶盖第7层,后者散布在峡核大细胞部(Imc)和峡核小细胞部(Ipc)内。     

Recent advances in understanding the pathogenesis of polyglutamine diseases: involvement of molecular chaperones and ubiquitin-proteasome pathway

Polyglutamine diseases consist of a group of familial neurodegenerative disorders caused by expression of proteins containing expanded polyglutamine stretch. Over the past several years, tremendous progress has been made in identifying the molecular mechanisms by which the expanded polyglutamine tract leads to neuronal dysfunction and neurodegeneration. A common feature of most polyglutamine disorders is the occurrence of ubiquitin-positive neuronal intranuclear inclusions. The appearance of ubiquitinated aggregates implies an underline incapability of the cellular chaperones and proteasome machinery that normally functions to prevent the accumulation of misfolded proteins. Here we review the recent studies that have revealed a critical role for molecular chaperones and ubiquitin-proteasome pathway in the pathogenesis of polyglutamine diseases.     

A Study of Early Pregnancy Factor Activity in Preimplantation

PROBLEM and METHOD: Early pregnancy factor (EPF), an Immunosuppressive substance, which appears in pregnant women's sera 48 h after fertilization, is a kind of pregnancy-specific protein. To determine whether the EPF activity could be a super early indicator of pregnancy, we used rosette inhibition assay to detect EPF activity in the sera, collected from 70 women 2–7 days after ovulation intending to conceive monitored by ultrasonography. Simultaneously we selected 40 non-pregnant sera and 12 early-pregnant sera as negative control and positive control, respectively. RESULTS: The results of this study demonstrated that EPF activity is detected in 35 women's sera out of 70 women within 2–7 days after ovulation, and 28 women out of the 35 were pregnant, which was known by follow-up, and 7 were not pregnant, possibly due to either false positive results or embryo loss because of preimplantation failure, thus causing no pregnancy. The other 35 out of 70 had no EPF activity and 34 of them were not pregnant, which was known by follow-up, but one case became pregnant, which was false negative result. Our study showed that diagnosis of the super early pregnancy could be made by detecting EPF activity in maternal serum within the time of preimplantation. The accuracy of pregnancy diagnosis by this method is 88.6%, with a false negative rate of 3.4% and a false positive rate of 17.1%. The β-HCG level was measured from the above 70 women's sera in order to contrast EPF activity. All of the sera collected 2–6 days following ovulation indicated that there were lower β-HCG values in very early pregnancy (≥a5 mIU/ml). On the seventh day after ovulation, EPF activity was detected in 11 out of 15 sera with only 2 of them with a b-HCG level that reached or slightly surpassed that of the early pregnancy diagnosis (5 mIU/ml and 5.4 mIU/ml, respectively). This demonstrated that β-HCG is not the earliest signal of pregnancy; otherwise the EPF activity is one that appears 2–6 days earlier than β-HCG appears. We measured the progesterone level of the 48 sera from the 70 collected above within 2–7 days postovulation and found most of them reached the level of progesterone in the luteal phase (7.5–98.3 nmol/L). This indicated that ovulation had taken place in these women, which was in accordance with observations by ultrasonography. CONCLUSIONS: Our study showed that diagnosis (of 88.6%) of super early pregnancy could be made with an accuracy of 88.6% by detecting EPF activity in maternal serum within 2-days after ovulation. This offers a basis for pregnancy diagnosis for the women who attempt to terminate their pregnancy safely or who conceive unexpectedly, and it contributes to family-planning.