Arrhythmogenesis Toxicity of Aconitine Is Related to Intracellular Ca2+ Signals

Aconitine is a well-known arrhythmogenic toxin and induces triggered activities through cardiac voltage-gated Na⁺ channels. However, the effects of aconitine on intracellular Ca²⁺ signals were previously unknown. We investigated the effects of aconitine on intracellular Ca²⁺ signals in rat ventricular myocytes and explored the possible mechanism of arrhythmogenic toxicity induced by aconitine. Ca²⁺ signals were evaluated by measuring L-type Ca²⁺ currents, caffeine-induced Ca²⁺ release and the expression of NCX and SERCA2a. Action potential and triggered activities were recorded by whole-cell patch-clamp techniques. In rat ventricular myocytes, the action potential duration was significantly prolonged by 1 µM aconitine. At higher concentrations (5 µM and 10 µM), aconitine induced triggered activities and delayed after-depolarizations (6 of 8 cases), which were inhibited by verapamil. Aconitine (1 µM) significantly increased the I_Ca-L density from 12.77 ± 3.12 pA/pF to 18.98 ± 3.89 pA/pF (n=10, p<0.01). The activation curve was shifted towards more negative potential, while the inactivation curve was shifted towards more positive potential by 1 μM aconitine. The level of Ca²⁺ release induced by 10 mM caffeine was markedly increased. Aconitine (1 µM) increased the expression of NCX, while SERCA2a expression was reduced. In conclusion, aconitine increased the cytosolic [Ca²⁺]_i by accelerating I_Ca-L and changing the expression of NCX and SERCA2a. Then, the elevation of cytosolic [Ca²⁺]_i induced triggered activities and delayed after-depolarizations. Arrhythmogenesis toxicity of aconitine is related to intracellular Ca²⁺ signals.     

Pelvic lipomatosis with cystitis glandularis managed with cyclooxygenase-2 inhibitor: A case report

BACKGROUNDPelvic lipomatosis (PL) is a rare benign condition with characteristic overgrowth of histologically benign fat and invasion and compression of pelvic organs, often leading to non-specific lower urinary tract symptoms (LUTS). Approximately 40% of patients with PL have cystitis glandularis (CG). The cause of PL combined with CG is poorly understood, and there is currently no effective treatment. Refractory CG with upper urinary tract obstruction even requires partial or radical bladder resection. CASE SUMMARYIn this case, a patient suffering from PL with CG was treated by transurethral resection of bladder tumour (TUR-BT) and oral administration of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor. The LUTS were alleviated, and the cystoscopy results improved significantly. Immunohistochemistry showed up-regulated COX-2 expression in the epithelium of TUR-BT samples, suggesting that COX-2 may participate in the pathophysiological process of PL combined with CG. CONCLUSIONWe report for the first time that celecoxib may be an effective treatment strategy for PL combined with refractory CG.     

Effects of the calcineurin dependent signaling pathway inhibition by cyclosporin A on early and late cardiac remodeling following myocardial infarction

BACKGROUND: The calcineurin-mediated signaling pathway has been implicated as one of the crucial pathways in cardiac hypertrophy. However, the role of calcineurin pathway on cardiac remodeling after myocardial infarction (MI) has not been well defined. METHODS: Infarcted rats (n = 45) were randomized into calcineurin inhibitor, cyclosporin A (CsA) or vehicle groups, 3 days after MI and treated for 2 weeks (early post-MI cardiac remodeling stage), or randomized 17 days after MI and treated for 2 weeks (late remodeling stage). RESULTS: Calcineurin pathway inhibition during the early cardiac remodeling stage attenuated the myocardial hypertrophy after MI (P < 0.05). However, left ventricular dimensions were further increased and fractional shortening deteriorated with calcineurin inhibition during this stage (P < 0.05, each). During late remodeling stage, CsA treatment did not affect myocardial hypertrophy and cardiac dilation following MI. CONCLUSION: Our results strongly support the hypothesis that calcineurin pathway mediates compensatory myocardial hypertrophy during the early remodeling stage after MI. However, the calcineurin pathway does not seem to affect the late remodeling after MI.     

Antigen-recognition sites of micromanipulated T cells in patients with acquired aplastic anemia

OBJECTIVE: Acquired aplastic anemia (AA) is a rare disorder characterized by pancytopenia and hypocellular bone marrow. Though experimental and clinical data suggest that AA represents a T cell-mediated disease, neither the immune response nor the nature of inciting antigen(s) have been characterized so far. The identification of a restricted T cell repertoire by PCR techniques in total lymphocyte populations supports an antigen-driven T cell response. In order to investigate the clonal composition, we analyzed the gene rearrangements of the T cell receptor (TCR) variable beta chain (Vbeta) at the single-cell level. PATIENTS AND METHODS: CD3(+) T lymphocytes were micromanipulated from peripheral blood and bone marrow samples of 8 AA patients and healthy controls. Subsequently amplified VDJ gene segments of the TCRVbeta chain were analyzed for functional rearrangements. More than 500 functionally rearranged TCR loci were studied for Vbeta/Jbeta gene segment usage and molecular composition of the complementary-determining region 3 (CDR3). RESULTS: In comparison to healthy controls, the Vbeta sequences confirmed a highly restricted T cell repertoire in AA patients at the single-cell level. Both in bone marrow and peripheral blood a predominance of Vbeta13 and Jbeta2S7 was observed. Furthermore, individual clonal T-cell expansion was identified in the majority of patients. However, deduced CDR3 amino acid sequences revealed a high variability without common motifs among the 8 patients. CONCLUSION: Individual clonal T-cell expansion with high diversity of the antigen-binding sites among the analyzed patients argues for the predominance of private inciting epitopes in AA.     

PCSK9 regulates apoptosis in human neuroglioma u251 cells via mitochondrial signaling pathways

Proprotein convertase subtilisin/kexin type 9 (PCSK9), belongs to a family of proprotein convertases (PCs), encodes a neural apoptosis-regulated convertase 1. However, the precise role of PCSK9 during glioma cells apoptosis has not been reported. Therefore, we examined the effects of knockdown and overexpression of PCSK9 on apoptosis of human neuroglioma U251 cells, and investigated the underlying mechanisms of apoptosis. We found that PCSK9 regulated cells proliferation as determined by CCK-8 and Hoechst staining analysis. In addition, western blot results showed that PCSK9 siRNA promote apoptosis via activation of caspase-3 and down-regulation of the anti-apoptotic proteins, XIAP and p-Akt, while PCSK9 overexpression inhibited apoptosis. Moreover, PCSK9 siRNA improved the ratio of Bax/Bcl-2 which leads to the release of cytochrome c, while PCSK9 overexpression decreased it. Taken together, these data demonstrate that PCSK9 may regulate apoptosis through mitochondrial pathway and is expected to be a promising therapeutic strategy for the malignant glioma.     

颅内外血栓在系统性红斑狼疮患儿中的发生情况比较*

目的 通过回顾性比较儿童系统性红斑狼疮（SLE）患者发生颅内、外血栓的情况,旨在发现SLE合并不同部位血栓的危险因素。方法 选取2006年1月—2019年12月首都医科大学附属北京儿童医院收治的SLE患儿,收集患儿人口学资料、临床表现、活动度评估及治疗、病程及随访资料等,并收集实验室检查数据及血栓相关数据等,根据血栓部位将患儿分为颅内血栓组及颅外血栓组,对两组资料进行比较。结果 27例SLE合并血栓患儿中,6例（22.22%）发生颅内血栓,21例（77.78%）患儿发生颅外血栓。颅内血栓以颅内静脉窦血栓形成（CVST）更为多见,横窦是CVST最常见的受累部位。颅外血栓常见受累部位依次为股总静脉、髂外静脉及股深浅静脉。颅外血栓组合并肾脏受累比例较颅内血栓组高（P?<0.05）,颅内血栓组合并神经系统受累比例较颅外血栓组高（P?<0.05）。颅外血栓组的Hb、C3、C4水平较颅内血栓组低,尿蛋白水平较颅内血栓组高（P?<0.05）。治疗后两组血栓均有一定程度的好转,其中颅内血栓组1例（16.7%）患儿血栓消失再通,颅外血栓组11例（52.4%）患儿血栓消失再通。结论 SLE合并颅内、外血栓形成有不同的特点,神经系统症状是颅内血栓最常见的症状,肾脏受累的患儿更易发生颅外血栓。早期诊断,积极治疗可明显改善SLE合并血栓患儿的预后。     

新型冠状病毒肺炎疫情期间北京市某医联体的应对措施及实施评价

背景　北京市出台多项新型冠状病毒肺炎（新冠肺炎）疫情防控措施,而医联体作为推动医疗资源优化配置的重要举措,在疫情中发挥了重要作用,通过评价医联体在此期间各项措施的实施情况,为医联体应对突发公共卫生事件时可采取的措施和作用等提供参考。目的　本研究以北京市某医联体作为案例,对于该医联体在新冠肺炎疫情期间采取的主要应对措施的实施情况进行评价,了解医联体在疫情期间如何发挥作用。方法　采用典型抽样和目的抽样,从北京市某医联体中的核心医院和3家社区卫生服务中心选取受访者17例,包括1例核心医院管理人员、4例社区卫生服务中心管理人员、2例社区卫生服务中心护士长、4例全科医生、6例患者。采用个人深度半结构式访谈,于2020年3月对17例受访者进行面对面访谈。访谈主要内容包括新冠肺炎疫情期间医联体采取的应对措施,并基于规范化过程理论和复杂干预过程评价整合出评价框架,从措施与现有工作价值一致性、措施实施覆盖程度、措施实施效果、措施实施阻碍和/或促进因素及对医联体发展的影响这5个维度对各个措施进行评价。访谈经知情同意后录音、记录,访谈资料在NVivo软件的协助下,采用主题分析法进行分析。结果　该医联体在疫情期间采取的主要措施为培训、加强社区转诊预约、核心医院患者输液下转。疫情期间共举办培训2次,加强了医联体成员单位对新冠肺炎的认知、诊疗和防护水平;但需对社区卫生服务中心更有针对性和实用性。社区转诊预约在此期间覆盖16个社区卫生服务中心,共接收转诊患者50例,筛查出246例建议到发热门诊就诊的可疑人员;更多患者在此期间倾向社区就诊,促进了分级诊疗的实施;但转诊标准需更明确。核心医院输液患者下转380例,缓解了核心医院急诊输液压力,也为患者提供了更便利、安全的输液环境,增强了医联体内部的凝聚和协作;但信息共享需加强。结论　疫情期间该医联体各成员单元团结协作,体现出医联体分级诊疗的重要作用。同时发现医联体培训、转诊标准的明确及信息共享三方面仍需完善,为医联体的进一步发展提供了参考。