大鼠肝移植无肝期研究进展

随着肝移植手术器械、方法和技术不断发展,其疗效日益提升,但无肝期时间的长短仍是影响肝移植效果的重要因素。大鼠是肝移植相关基础研究的主要动物模型之一,本文就延长大鼠肝移植无肝期持续时间及缩短大鼠肝移植无肝期操作时间的方法,包括吸入性七氟烷麻醉、颈静脉留置针补液、无肝期前夹闭腹主动脉、无肝期前门静脉注入生理盐水、脾脏皮下转位术、肝食管动脉电凝离断、肝上下腔静脉磁环吻合、肝上下腔静脉套管吻合、肝上下腔静脉支架吻合、门静脉快速连接装置套管、肝下下腔静脉保留肝脏组织环套管进行综述,为延长大鼠无肝期持续时间,提高无肝期操作效率,提升大鼠肝移植成功率提供参考。     

Development of a Hemodynamically Optimized Outflow Cannula for Cardiopulmonary Bypass

The jet of the outflow cannula is a potential risk for patients undergoing cardiopulmonary bypass (CPB), because increased jet velocities lead to altered flow conditions and might furthermore mobilize atherosclerotic plaques from calcified aortas. The cannula jet is therefore among the main reasons for cerebral hypoxia and stroke in CPB patients. In the past, we developed a validated computational fluid dynamics (CFD) model to analyze flow conditions during CPB as dependent on cannulation and support modalities. This model is now applied to develop a novel CPB outflow cannula to reduce the jet effect and increase cerebral blood flow. The Multi‐Module Cannula (MMC) is based on a generic elbow cannula that was iteratively improved. It features an inner wall to smoothly guide the blood as well as an elliptically shaped outlet diffuser. During standard CPB conditions of 5 L/min, the pressure drop over the MMC is 61 mm Hg, compared with 68 mm Hg with a standard cannula. The maximum velocities are decreased from 3.7 m/s to 3.3 m/s. In the cannula jet of the MMC, the velocities are reduced further, down to 1.6 m/s. The cerebral blood flow is typically reduced during CPB. Using the MMC, however, it reaches almost physiological values at 715 mL/min. These results suggest that the MMC outperforms standard CPB cannulas. Further design improvements and improved insertion techniques are under consideration.     

Liposuction: Optimizing factors

Two aspects of liposuction procedures are discussed as ways of improving results. First, to help with the efficiency of fat removal several technical points are considered, especially the freedom and the facility of performing the liposuction procedure with a syringe without the aid of an aspirator. Surgeons are showing a growing interest with this new method. New and practical material that allows a reduced number of necessary manipulations is described. Second, we stress the importance of drainage, especially in relation to the resumption of activity which is much quicker due to the absence of postoperative bruising. When using drainage, the final result can be obtained as early as the second or third day.     

The effect of ribonucleic acid injections upon the maze-learning ability of rats

Rats received intraventricular injections of whole brain ribonucleic acid (RNA) via a cannula over two consecutive days of training. Two tests were conducted 14 and 30 days later. Compared to saline controls, there was a significant treatment by test period interaction for errors. However, there was no reliable difference between groups in terms of errors or time. It is suggested that RNA injections do not reliably decrease the amount of time to complete a complex maze, but do produce an initial enhancement of performance in terms of errors.     

A simple multiple-cannula headpiece for the rat

The construction of a multiple-cannula headpiece, its implantation into the rat brain, and its use in intracranial injections is described. The headpiece is rapidly and cheaply produced from common hospital and laboratory supplies once several machined metal parts have been made, and its construction is easily adapted to changes in injection technique, e.g., infusion by osmotic minipump.     

A cannula system for frequent infusions into the CSF of the cerebral ventricles of the goat

A three-cannula system for infusions into the cerebral ventricular system of the goat is described. The technique offers the following advantage over previous methods. It allows frequent infusions in the non-anesthetized, undisturbed goat and ensures free communication with the CSF over long periods of time.     

Melt Electrospun Bilayered Scaffolds for Tissue Integration of a Suture‐Less Inflow Cannula for Rotary Blood Pumps

Implantation of left ventricular assist devices typically requires cardiopulmonary bypass support, which is associated with postoperative complications. A novel suture‐less inflow cannula, which can be implanted without bypass, uses mild myocardial compression to seal the interface, however, this may lead to necrosis of the myocardium. To circumvent this issue, a bilayered scaffold has been developed to promote tissue growth at the interface between cannula and myocardium. The bilayered scaffold consists of a silicone base layer, which mimics the seal, and a melt electrospun polycaprolactone scaffold to serve as a tissue integration layer. Biocompatibility of the bilayered scaffolds was assessed by analyzing cell viability, morphology, and metabolic activity of human foreskin fibroblasts cultured on the scaffolds for up to 14 days. There was no evidence of cytotoxicity and the cells adhered readily to the bilayered scaffolds, revealing a cell morphology characteristic of fibroblasts, in contrast to the low cell adhesion observed on flat silicone sheets. The rate of cell proliferation on the bilayered scaffolds rose over the 14‐day period and was significantly greater than cells seeded on the silicone sheets. This study suggests that melt electrospun bilayered scaffolds have the potential to support tissue integration of a suture‐less inflow cannula for cardiovascular applications. Furthermore, the method of fabrication described here and the application of bilayered scaffolds could also have potential uses in a diverse range of biomedical applications.     

急性呼吸道传染病患者经鼻高流量氧疗期间医院感染防控的最佳证据总结

目的 总结急性呼吸道传染病患者经鼻高流量氧疗期间医院感染防控的最佳证据。方法 制订文献检索策略,检索BMJ best practice、UpToDate、美国国立指南库、英国国家卫生与临床优化研究所网站、苏格兰院际指南网、世界卫生组织网、美国呼吸治疗协会网、欧洲呼吸学会网、医脉通数据库、Cochrane Library、PubMed、CINAHL、Web of Science、万方数据库、中国知网,检索时限为建库至2022年8月。根据筛选标准选取与本研究相关的文献,进行文献质量评价后提取证据。结果 共纳入11篇文献,包括9篇专家共识、1篇系统评价和1篇原始研究,提取26条证据,包括人员管理、环境管理、医护人员防护、医疗护理操作、终末处理、急救管理6个类别。结论 该研究总结的最佳证据对急性呼吸道传染病患者经鼻高流量氧疗期间的医院感染预防与控制具有指导意义,证据应用时需结合病原体特性、传播性等进行综合评判。