Finite element analysis of the biomechanical interaction between coronary sinus and proximal anchoring stent in coronary sinus annuloplasty

Recent clinical studies of the percutaneous transvenous mitral annuloplasty (PTMA) devices have shown a short-term reduction of mitral regurgitation after implantation. However, adverse events associated with the devices such as compression and perforation of vessel branches, device migration and fracture were reported. In this study, a finite element analysis was carried out to investigate the biomechanical interaction between the proximal anchor stent of a PTMA device and the coronary sinus (CS) vessel in three steps including: (i) the stent release and contact with the CS wall, (ii) the axial pull t the stent connector and (iii) the pressure inflation of the vessel wall. To investigate the impact of the material properties of tissues and stents on the interactive responses, the CS vessel was modelled with human and porcine material properties, and the proximal stent was modelled with two different Nitinol materials with one being stiffer than the other. The results indicated that the vessel wall stresses and contact forces imposed by the stents were much higher in the human model than the porcine model. However, the mechanical differences induced by the two stent types were relatively small. The softer stent exhibited a better fatigue safety factor when deployed in the human model than in the porcine model. These results underscored the importance of the CS tissue mechanical properties. Vessel wall stress and stent radial force obtained in the human model were higher than those obtained in the porcine model, which also brought up questions as to the validity of using the porcine model to assess device mechanical function. The quantification of these biomechanical interactions can offer scientific insight into the development and optimisation of the PTMA device design.     

684例胆道感染患者胆汁病原菌分布及耐药性分析

目的研究胆道感染患者胆汁病原菌的分布及其耐药性,为临床合理使用抗菌药物提供依据。方法对684例胆道感染患者胆汁进行培养,应用Micro Scan Walk Away40细菌鉴定及药敏分析系统对分离菌进行鉴定及药敏测定,用WHONET 5.6软件进行数据分析。结果从684例患者胆汁中分离出315株病原菌,革兰阴性杆菌占65.1%,革兰阳性球菌占34.3%,真菌占0.6%。革兰阴性杆菌对亚胺培南、美罗培南、头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、左氧氟沙星、头孢吡肟、庆大霉素耐药率较低。肠球菌属、葡萄球菌属对喹诺酮类耐药率较低,未发现耐万古霉素、利奈唑胺的革兰阳性球菌。结论胆道感染仍以革兰阴性杆菌为主,病原菌分布广泛,耐药情况较严重,治疗使用抗生素需要进行病原菌检测及耐药性分析。     

Comparative histopathology of Opisthorchis felineus and Opisthorchis viverrini in a hamster model: an implication of high pathogenicity of the European liver fluke

European liver fluke (Opisthorchis felineus) and Asian liver fluke (Opisthorchis viverrini) are similar in morphology but comparative pathology of the infections has not been described. We therefore did comparative histopathology of both parasites in an experimental animal model. The study was conducted in 3 groups of 105 Syrian golden hamsters; the first and second groups fed with 50 metacercariae of O. felineus (OF) or O. viverrini (OV) and the last group was uninfected controls. Five hamsters in each group were euthanized on weeks 1, 2, 4, 8, 12 and 24 post-infection. The liver tissue was fixed and processed for routine histopathology and immunohistochemistry for proliferation markers (BrdU or PCNA). Overall, the liver histopathology of O. felineus and O. viverrini infection was generally similar. However, various histopathogical features including intense inflammation, fibrosis, biliary and goblet cell hyperplasia and dysplasia occurred earlier in the OF group. In addition, the existence of precancerous lesions such as cholangiofibrosis in a long-term infection was observed only in this group. O. felineus is larger in size than O. viverrini which, together with its excreted and secreted antigens, likely is crucial in the induction of liver fluke induced disease. The differences in nature and timing of the histopathological profile indicate that opisthorchiasis caused by the European liver fluke O. felineus is more pathogenic than its Asian relative O. viverrini.     

血栓弹力图指导支架内血栓后不稳定心绞痛治疗1 例及文献复习

目的:探讨在血栓弹力图监测血小板抑制率的情况下,调整氯吡格雷及阿司匹林用量,治疗冠心病、PCI术后支架内再发血栓患者的临床意义。方法:报告中国人民解放军总医院1例支架内亚急性血栓患者的临床资料并复习相关文献,对其临床表现、诊断、在血栓弹力图指导下的治疗进行分析。结果:1例支架内亚急性血栓患者经治疗病情好转出院,出院后继续调整氯吡格雷及阿司匹林用量,达到满意血小板抑制率,患者症状消失。结论:冠状动脉介入治疗后发生支架内血栓的患者,应用血栓弹力图指导氯吡格雷及阿司匹林用量,可达到令人满意的血小板抑制率,并防止出血情况发生。     

Food-drug interaction of (-)-epigallocatechin-3-gallate on the pharmacokinetics of irinotecan and the metabolite SN-38

The aim of the present study was to investigate the effect of (-)-epigallocatechin-3-gallate (EGCG) on the pharmacokinetics of irinotecan (CPT-11) and its metabolite SN-38. EGCG was potentially used to modulate the ATPase activity of P-glycoprotein (P-gp). Experimental Sprague-Dawley rats were treated with EGCG (20mg/kg, i.v.) 10min before CPT-11 (10mg/kg, i.v.) administration, whereas the control group received CPT-11 (10mg/kg, i.v.) only. The biological samples were prepared by the protein precipitation and detected by HPLC-fluorescence detection which provided a good separation of CPT-11 and SN-38 within 10min. The pharmacokinetic data indicate that the area under the plasma concentration-time curves (AUC) of CPT-11 and SN-38 were increased by 57.7 and 18.3%, and AUC in bile were decreased by 15.8 and 46.8%, respectively, for the group pretreated with EGCG. The blood to bile distribution ratio (AUC(bile)/AUC(blood)) was significantly reduced after group coadministration of EGCG, it can be seen that the bile efflux transport system of CPT-11 and SN-38 may be markedly reduced by the treatment of EGCG which plays the role of P-gp inhibitor. In conclusion, EGCG was found to inhibit the transport of CPT-11 and SN-38 into the biliary elimination and their half-lives in plasma could be substantially prolonged. Based on the food-drug interaction, persons taking daily nutritional supplements should be warned of this interaction possibility.     

Spray-dried milk supplemented with alpha-linolenic acid or eicosapentaenoic acid and docosahexaenoic acid decreases HMG Co A reductase activity and increases biliary secretion of lipids in rats

In our earlier study, we have shown that rats fed spray-dried milk containing alpha-linolenic acid (LNA 18:3 n-3) or eicosapentaenoic acid (EPA 20:5 n-3) and docosahexaenoic acid (DHA 22:6 n-3) had significantly lower amounts of serum and liver cholesterol. To evaluate the mechanism for hypocholesterolemic effect of n-3 fatty acids containing milk formulation, we fed male Wistar rats with spray-dried milk containing linseed oil (LSO) (source of LNA) or fish oil (FO) (source of EPA+DHA) for 8 weeks. Feeding n-3 fatty acid containing milk formulation lowered the hepatic 3-hydroxy-methylglutaryl coenzyme A (HMG Co A) activity by 17-22% compared to rats given control diet devoid of n-3 fatty acids. The cholesterol level in liver microsomes was found to be decreased by 16% and 20%, respectively, in LSO and FO containing formulation fed rats. The bile flow was enhanced to an extent of 19-23% in experimental groups compared to control animals. The biliary cholesterol and phospholipid secretion was increased to an extent of 49-55% and 140-146%, respectively, in rats fed n-3 fatty acid containing formulation. The increase in the total bile acids secretion in bile was mainly reflected on an increase in the levels of taurine conjugated bile acids. These results indicated that n-3 fatty acid containing spray-dried milk formulation would bring about the hypocholesterolemic effect by lowering HMG Co A reductase activity in liver and by increasing the secretion of bile constituents.     

锦葵目蚬木属和柄翅果属的木材解剖学研究及其系统学意义

蚬木属(Excentrodendron H.T.Chang & R.H.Miau)与柄翅果属(Burretiodendron Rehder)的分离一直未得到广泛认同,二者在锦葵目中的系统地位也还不十分清楚.本文研究了柄翅果、元江柄翅果、滇桐和火绳树的木材解剖.柄翅果和元江柄翅果在木材解剖特征上非常相似,2～3个管孔组成径列复管孔,单管孔较多,导管分子无螺纹加厚,穿孔板单一,轴向薄壁组织稀少,射线异型IIB,单列射线少,多列射线常2～3列,具翅子树属型瓦形细胞;蚬木属单列射线罕见,瓦形细胞榴莲型,单列射线较高,木材解剖特征支持蚬木属和柄翅果属的分离;蚬木属和柄翅果属与滇桐属在木材解剖特征上差异显著,与火绳树属的差异也较明显,但与梧桐科翅子树属比较接近,与其它有关类群,如一担柴属、Luehea、Entelea以及Dombeyeae族等都有明显差异.     

酪酸梭菌活菌胶囊对胆道结石患者术后肠功能紊乱的治疗作用

目的观察酪酸梭菌活菌胶囊(商品名:阿泰宁)对胆道结石患者术后肠功能紊乱的疗效及对术后消化吸收功能的改善作用。方法选取40例行胆总管切开探查术且术后出现腹泻、腹胀、消化不良等肠功能紊乱的胆总管结石患者。随机分为观察组和对照组,每组20例。两组患者均予以生理盐水补液、止泻药止泻和低脂饮食等常规治疗,观察组患者加服酪酸梭菌活菌胶囊,3粒/次,2次/d,连用28d。观察两组患者用药后的临床疗效及不良反应。结果观察组患者临床总有效率(100.0%)显著高于对照组(80.0%)(P0.05);腹泻和腹胀的时间显著短于对照组(P0.01);同时治疗后观察组患者总胆固醇、甘油三酯、球蛋白水平显著高于对照组(P0.05),电解质紊乱发生率低于对照组(P0.05)。治疗期间所有患者未见不良反应。结论酪酸梭菌活菌胶囊治疗胆道结石患者术后肠功能紊乱疗效显著,能够显著改善患者对脂质的消化吸收能力,对患者术后消化吸收功能的改善具有积极的作用,值得临床推广应用。     

药物涂层球囊概述及其在外周动脉疾病治疗中的应用进展

经皮经腔血管成形术(PTA)已广泛用于外周动脉疾病(PAD)的治疗。然而,该技术存在血管壁弹性回缩和内膜增生等不足。PTA术后植入金属裸支架(BMS)虽然可以减少血管壁弹性回缩,但由此引起的支架内再狭窄(ISR)又成为治疗中的一个突出问题。药物洗脱支架(DES)被用来解决狭窄问题,但晚期支架内血栓形成(LST)、内皮化延迟和必须长期抗血小板治疗等问题也随之而来。在这样的背景下,药物涂层球囊(DCB)获得了快速发展。DCB作为非支架方案,可将所携载的活性药物转移至病变段血管壁,对ISR或原发病变均有较好的治疗效果。本文简要介绍了DCB的发展历史,并通过实验室研究、动物实验和临床试验,从机制上阐述涂层技术、涂层药物、赋形剂等对DCB功效和安全性的影响以及DCB在PAD治疗中的应用进展。