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.     

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。     

Viscoelasticity of repaired sciatic nerve by poly（lactic-co-glycolic acid） tubes

Medical-grade synthetic poly（lactic-co-glycolic acid） polymer can be used as a biomaterial for nerve repair because of its good biocompatibility, biodegradability and adjustable degradation rate. The stress relaxation and creep properties of peripheral nerve can be greatly improved by repair with poly（lactic-co-glycolic acid） tubes. ＂Fen sciatic nerve specimens were harvested from fresh corpses within 24 hours of death, and were prepared into sciatic nerve injury models by creating a 10 mm defect in each specimen. Defects were repaired by anastomosis with nerve autografts and poly（lactic-co-glycolic acid） tubes. Stress relaxation and creep testing showed that at 7 200 seconds the sciatic nerve anastomosed by poly（lactic-co-glycolic acid） tubes exhibited a greater decrease in stress and increase in strain than those anastomosed by nerve autografts. These findings suggest that poly（lactic-co-glycolic acid） exhibits good viscoelasticity to meet the biomechanical require- ments for a biomaterial used to repair sciatic nerve injury.