Identification of two novel fibrinolytic enzymes from Bacillus subtilis QK02

Two fibrinolytic enzymes (QK-1 and QK-2) purified from the supernatant of Bacillus subtilis QK02 culture broth had molecular masses of 42,000 Da and 28,000 Da, respectively. The first 20 amino acids of the N-terminal sequence are AQSVPYGISQ IKAPALHSQG. The deduced protein sequence and its restriction enzyme map of the enzyme QK-2 are different from those of other proteases. The enzyme QK-2 digested not only fibrin but also a subtilisin substrate, and PMSF inhibited its fibrinolytic and amidolytic activities completely; while QK-1 hydrolyzed fibrin and a plasmin substrate, and PMSF as well as aprotinin inhibited its fibrinolytic activity. These results indicated QK-1 was a plasmin-like serine protease and QK-2 a subtilisin family serine protease. Therefore, these enzymes were designated subtilisin QK. The sequence of a DNA fragment encoding subtilisin QK contained an open reading frame of 1149 base pairs encoding 106 amino acids for signal peptide and 257 amino acids for subtilisin QK, which is highly similar with that of a fibrinolytic enzyme, subtilisin NAT (identities 96.8%). Asp32, His64 and Ser221 in the amino acid sequence deduced from the QK gene are identical to the active site of nattokinase (NK) produced by B. subtilis natto.     

两种介入途径治疗急性、亚急性门静脉及肠系膜上静脉血栓的临床疗效分析

目的：评价介入技术治疗急性和亚急性门静脉（portal vein,PV）及肠系膜上静脉（superior mesenterie vein, SMV）血栓形成的临床疗效。方法：对28例治疗急性和亚急性（发病一周至一月）的PV及SMV血栓患者进行介入治疗。按介入治疗途径不同分为下述两组：选择经颈静脉穿刺门静脉（transjugular intrahepatic portosystemic shunt , TIPS途径）置管溶栓（19例）和经皮穿肝内门脉（percutaneous transhepatic）置管溶栓治疗（9例）。结果：所有患者随访一周至三个月,其中治疗成功24例,临床症状明显改善,无严重并发症。经TIPS途径治疗的患者组中,16例随访显示大部分血栓被清除,门静脉系统有血流通过,临床症状缓解。3例SMV及PV恢复部分血流,但临床症状无明显改善。经皮穿肝内门脉直接置管溶栓治疗组中,6例患者的PV及SMV内血栓大部分清除,血流基本改善,2例患者PV及SMV血流部分好转,临床症状无明显改善,严重并发症1例（术后两天死于腹腔出血）。结论：经TIPS途径介入技术和经皮穿肝内门脉直接置管溶栓治疗是治疗急性和亚急性PV及SMV血栓形成的有效方法,前者的疗效及安全性均好于后者。     

Therapeutic applications of ultrasound

Therapeutic applications of ultrasound predate its use in imaging. A range of biological effects can be induced by ultrasound, depending on the exposure levels used. At low levels, beneficial, reversible cellular effects may be produced, whereas at high intensities instantaneous cell death is sought. Therapy ultrasound can therefore be broadly divided into “low power” and “high power” applications. The “low power” group includes physiotherapy, fracture repair, sonophoresis, sonoporation and gene therapy, whereas the most common use of “high power” ultrasound in medicine is probably now high intensity focused ultrasound. Therapeutic effect through the intensity spectrum is obtained by both thermal and non-thermal interaction mechanisms. At low intensities, acoustic streaming is likely to be significant, but at higher levels, heating and acoustic cavitation will predominate. While useful therapeutic effects are now being demonstrated clinically, the mechanisms by which they occur are often not well understood.     

Using F0F1-ATPase motors as micro-mixers accelerates thrombolysis

We have developed a novel micro-mixer using a biological molecular ATP motor. The micro-mixer was constructed from arrays of chromatophore-embedded δ-free F₀F₁-ATPases, where the δ-free F₁ part acted as a rotator to mix solutions, and the F₀ part was driven by light. Confocal microscope studies indicated that the micro-mixer did not touch directly on the fibrin labeled with FITC. The nanomechanical force generated by the motor induced drug movement in the solution and accelerated the fibrinolysis process. All results strongly suggest that the micro-mixers generated a nanomechanical force which accelerated the fibrinolysis process in the presence of lower concentrations of lumbrokinase.     

Flow-induced permeation of non-occlusive blood clots: an MRI study and modelling

The success of clot thrombolysis very much depends on efficient clot permeation with blood plasma carrying the thrombolytic agent. In this paper clot permeation was studied by dynamic magnetic resonance imaging (MRI) on artificial non-occlusive blood clots inserted in an artificial circulation system filled with blood plasma to which an MRI contrast agent was added. The MRI results revealed that clot permeation is much faster and more efficient at the entrance of the flow channel across the clot. Clot permeation with fluid was simulated numerically as well. The simulation was based on numerical solution of Navier-Stokes equations for the flow in the channel and within the clot. The clot was considered as a porous material with known permeability and porosity. Based on the calculated velocity profiles, concentration profiles of fluid in the clot were modelled. These agreed well with the MRI results. The presented model of clot permeation with fluid may also serve as a useful extension to numerical modelling of dissolution of non-occlusive blood clots during thrombolytic therapy.     

腔静脉滤器植入联合导管溶栓术治疗下肢深静脉血栓的疗效分析

目的:探讨腔静脉滤器植入联合导管溶栓术治疗下肢深静脉血栓患者的临床疗效及安全性。方法:回顾性分析2012年10月~2014年10月来我院住院治疗的80例下肢深静脉血栓形成患者的临床资料,根据治疗方式及溶栓途径的差异分为两组,比较两组患者治疗前后下肢周径差变化、静脉通畅率、血栓后综合征情况及治疗后并发症的发生情况。结果:治疗后,两组患者下肢平均周径均有所减少,肿胀明显缓解,静脉通畅度评分显著降低,较治疗前差异有统计学意义(P0.05);其中,观察组患者下肢消肿率更为明显,静脉通畅度更好,较对照组差异有统计学意义(P0.05)。治疗后对照组患者PTS发生例数为9例(23.68%),观察组PTS发生率更低仅为1例(2.38%),差异有统计学意义(P0.05)。两组患者治疗后均出现并发症,但发生率比较无明显统计学意义(P0.05)。结论:采用腔静脉滤器植入联合导管溶栓术治疗下肢深静脉血栓可使静脉阻塞部位尽早恢复通畅,减少瓣膜功能损害,降低PTS等并发症的发生率。     

血清MMP-9水平与急性脑梗死溶栓后出血转化的相关性及其预测意义

目的:研究血清基质金属蛋白酶-9(MMP-9)水平与急性脑梗死(ACI)溶栓后出血转化(HT)的相关性及其预测意义。方法:选择2014年2月到2017年6月在承德医学院附属医院神经内科诊治的ACI患者130例作为研究对象。根据患者是否存在溶栓后HT将其分成HT组(65例)和NHT组(65例),两组均根据患者的实际病情给予个性化的治疗,对比两组患者实验室指标、血清MMP-9水平、美国国立卫生研究院卒中量表(NIHSS)评分,随访6个月后,记录死亡人数及Barthel指数,并分析患者血清MMP-9水平与其NIHSS评分、Barthel指数、低密度脂蛋白胆固醇(LDL-C)及总胆固醇(TC)水平的相关性。结果:HT组LDL-C及TC水平均低于NHT组(P0.05)。HT组患者在溶栓前、溶栓后3 d、溶栓后7 d的血清MMP-9水平、NIHSS评分均高于NHT组(P0.05)。随访6个月后,HT组的死亡率高于NHT组,而Barthel指数低于NHT组(P0.05)。根据Spearman法分析相关性发现,患者血清MMP-9水平与其NIHSS评分呈正相关,而与Barthel指数、LDL-C及TC水平呈负相关(P0.05)。结论:血清MMP-9水平与ACI溶栓后HT具有紧密的关联,有助于更好地预测患者的病情及预后,临床上可考虑在治疗ACI溶栓后HT时监测MMP-9水平,从而获得更加精准的辅助性数据参考。     

急性脑梗死溶栓治疗的临床进展

脑梗死是一种常见的神经系统疾病,具有高发病率、高死亡率和高致残率的特点,给患者及家庭带来巨大的痛苦和经济负担,它已成为当代医学界重要的研究课题。脑梗死的治疗直接影响患者的预后,因此寻找最有效的治疗药物及方法是非常重要的。目前,在急性脑梗死溶栓治疗方面国内外已经开展了大量的实验研究,取得了良好的实验结果。本文就急性脑梗死溶栓治疗的时间窗、溶栓方法、溶栓药物及影响因素等方面进行了总结及展望。     

Different Sodium-Glucose Cotransporter-2 Inhibitors: Can They Prevent Death?

ObjectiveSodium-glucose cotransporter-2 inhibitors (SGLT2is) in cardiovascular outcome trials (CVOTs) demonstrate cardiovascular (CV) safety and benefits. Some dedicated randomized controlled trials (RCTs) demonstrate benefit in terms of renal outcomes and hospitalization due to heart failure (HF). RCTs report differences in the secondary outcomes with respect to mortality (CV and/or all-cause). We undertook a meta-analysis of all SGLT2is for which in addition to CVOT, HF outcome/renal outcome studies are available to establish whether individual SGLT2is were able to prevent death.MethodsWe included available event-driven randomized, placebo-controlled CVOTs and dedicated RCTs of SGLT2is exploring renal outcomes and HF. We included 3 trials of empagliflozin, 3 of dapagliflozin, 2 of canagliflozin, and 2 of sotagliflozin. The efficacy outcomes included all-cause mortality and CV mortality. Hazard ratios (HRs) with 95% CIs were pooled for individual molecules.ResultsThe HR for all-cause mortality including all trials was 0.86 (0.80-0.93). The HRs for all-cause mortality in empagliflozin (N = 16 738), dapagliflozin (N = 26 208), canagliflozin (N = 14 543), and sotagliflozin (N = 11 806) were 0.86 (0.69-1.08), 0.83 (0.72-0.97), 0.86 (0.75-0.97), and 0.95 (0.81-1.11), respectively. The HR for CV mortality including all trials was 0.85 (0.78-0.92). The HRs for CV mortality in empagliflozin, dapagliflozin, sotagliflozin, and canagliflozin were 0.81 (0.63-1.03), 0.88 (0.78-1.00), 0.89 (0.74-1.07), and 0.84 (0.72-0.98), respectively.ConclusionSGLT2is as a class reduce both all-cause mortality and CV mortality. Canagliflozin possibly reduces both all-cause mortality and CV mortality, whereas dapagliflozin may reduce all-cause mortality but not CV mortality. Empagliflozin and sotagliflozin may reduce neither.