High resolution three-dimensional strain mapping of bioprosthetic heart valves using digital image correlation

Transcatheter aortic valve replacement (TAVR) is a safe and effective treatment option for patients deemed at high and intermediate risk for surgical aortic valve replacement. Similar to surgical aortic valves (SAVs), transcatheter aortic valves (TAVs) undergo calcification and mechanical wear over time. However, to date, there have been limited publications on the long-term durability of TAV devices. To assess longevity and mechanical strength of TAVs in comparison to surgical bioprosthetic valves, three-dimensional deformation analysis and strain measurement of the leaflets become an inevitable part of the evaluation. The goal of this study was to measure and compare leaflet displacement and strain of two commonly used TAVs in a side-by-side comparison with a commonly used SAV using a high-resolution digital image correlation (DIC) system. 26-mm Edwards SAPIEN 3, 26-mm Medtronic CoreValve, and 25-mm Carpentier-Edwards PERIMOUNT Magna surgical bioprosthesis were examined in a custom-made valve testing apparatus. A time-varying, spatially uniform pressure was applied to the leaflets at different loading rates. GOM ARAMIS® software was used to map leaflet displacement and strain fields during loading and unloading. High displacement regions were found to be at the leaflet belly region of the three bioprosthetic valves. In addition, the frame of the surgical bioprosthesis was found to be remarkably flexible, in contrary to CoreValve and SAPIEN 3 in which the stent was nearly rigid under a similar loading condition. The experimental DIC measurements can be used to characterize the anisotropic materiel behavior of the bioprosthetic heart valve leaflets and validate heart valve computational simulations.     

Prion Stability and Infectivity in the Environment

The biology of normal prion protein and the property of infectivity observed in abnormal folding conformations remain thinly characterized. However, enough is known to understand that prion proteins stretch traditional views of proteins in biological systems. Numerous investigators are resolving details of the novel mechanism of infectivity, which appears to feature a protein-only, homologous replication of misfolded isoforms. Many other features of prion biology are equally extraordinary. This review focuses on the status of infectious prions in various natural and man-made environments. The picture that emerges is that prion proteins are durable under extreme conditions of environmental exposure that are uncommon in biological phenomena, and this durability offers the potential for environmental reservoirs of persistent infectivity lasting for years. A recurrent theme in prion research is a propensity for these proteins to bind to mineral and metal surfaces, and several investigators have provided evidence that the normal cellular functions of prion protein may include metalloprotein interactions. This structural propensity for binding to mineral and metal ions offers the hypothesis that prion polypeptides are intrinsically predisposed to non-physiological folding conformations that would account for their environmental durability and persistent infectivity. Similarly, the avidity of binding and potency of prion infectivity from environmental sources also offers a recent hypothesis that prion polypeptides bound to soil minerals are actually more infectious than studies with purified polypeptides would predict. Since certain of the prion diseases have a history of epidemics in economically important animal species and have the potential to transmit to humans, urgency is attached to understanding the environmental transmission of prion diseases and the development of protocols for their containment and inactivation. Special issue article in honor of Dr. George DeVries.     

药物依赖临床治疗的研究新进展

随着吸毒人员的剧增,药物依赖极大的危害着人类健康和社会稳定,已经成为目前严重的社会性问题。心瘾是患者复吸的重要原因,心瘾的戒断是治疗成瘾的关键。供临床医生选择的治疗方法有很多,但是根据成瘾者的病情合理的选择治疗措施是目前临床工作中面临的巨大挑战。本文综述了目前物质依赖的药物治疗的作用机制以及临床疗效、各种手术戒毒的效果以及不良反应、心理行为治疗的原因以及具体措施,药物治疗、手术治疗以及中西医联合治疗的最新进展。     

CARD-FISH技术及其在微生物生态学研究中的应用

催化报告沉积荧光原位杂交技术(Catalyzed reporter deposition-fluorescence in situ hybridization,CARDFISH)是基于传统的FISH技术发展而来,由于其较高的灵敏度及稳定性,可以检测微生物的rRNA、mRNA和DNA上的目标基因等,获得环境微生物的群落及功能信息,现已成为微生物生态学研究领域中的重要技术手段。近些年,CARD-FISH与同位素示踪技术、纳米二次离子质谱技术(Nano SIMS)、扫描电子显微镜(SEM)、流式细胞仪等技术方法的联合使用,不仅可以研究复杂环境中微生物的物种组成、数量及其高分辨形态学信息,而且可以获得微生物在单细胞水平的生理代谢信息及其活性,对在单细胞水平认识原位环境微生物的生理生态功能具有重要意义。本文重点介绍了CARD-FISH的技术路线和要点,并探讨CARD-FISH与相关技术联用在环境微生物生态学研究中的应用及进展。     

医院防护用手术服的结构与功能设计

手术服的结构与功能设计决定了手术服的防护性和舒适性。本文基于穿着者在生理与心理上对手术服防护和舒适性的设计要求,从手术服设计要求、手术服结构设计(手术服材料选择、手术服总体结构设计、衣身设计、领口设计、衣袖和袖口设计、手术服缝合结构设计、色彩设计)、手术服尺寸规格等方面作了较全面深入的分析,可为手术服性能的进一步研究提供参考。     

Surgical and anesthetic management of patients with mitochondrial dysfunction

Mitochondrial diseases are primary defects in bio-energy metabolism. They are a heterogeneous group of diseases. The specific constellation of symptoms that will manifest in the effected individual depends on the type of genetic defect in the mitochondria. The goals of medical management, expressed in a highly simplified fashion, are to maintain a normal acid-base balance and to avoid those medical conditions and situations that add extra stress to a compromised bio-energy production system. Infection is a common stress that may cause a crisis in a patient with mitochondrial dysfunction. Treatment and avoidance of infections is a goal of both medical and surgical management. Common childhood illness such as otitis media, tonsillitis and sinusitis are example of such stress inducing infections.     

The mechanism of lipopolysaccharide administration-induced cognitive function impairment caused by glucose metabolism disorder in adult rats

ObjectiveThis essay aims to make investigation on the mechanism of glucose metabolism disorder and Lipopolysaccharide administration-induced cognitive function impairment in adult rats with surgery. Methods: Divide the objects, 40 male Sprague-Dawley rats at the age of 9 months, into 4 groups. Provide unilateral nephrectomy surgery and/or lipopolysaccharide intraperitoneal injection. Postoperative cognitive function evaluation would be tested by the Morris water maze. Rats with Postoperative Cognitive Dysfunction (POCD) were scanned to analyze the brain glucose metabolism by means of 18F-FDG PET/CT. Phosphatidylinositol 3-Kinase (PI3K), Protein Kinase β (AKT), Insulin Substrates Receptor-2 (IRS-2) and Glucose Transporter 4 (GLUT4) were detected as well. Data will be captured through gene expression in POCD rats via Quantitative Real-Time PCR (QRT-PCR). On the other side, Western Blot was used to measure the expression levels of IRS-2, p-IRS-2, p-PI3K, PI3K, p-AKT, AKT, GLUT4, and p-GLUT4. Results: During the Morris water maze test, the staging time (latency) of rats in each group was becoming short gradually as the training progressed. The incubation time of Day 5 of each group was shorter than that of Day 1 (P < 0.05). On the Day 3 after the surgery, the average target quadrant residence time of Group S+L (100 μg/Kg) was shorter, compared with Group C, L and S. Of which, the average number of perforation was reduced greater than that of Group C (P < 0.05). The average swimming speed of the groups is of no distinct difference (P > 0.05). After the operation, there was no great difference shown among the subjects (P > 0.05) in the average residence time of the target quadrant, the mean number of passages, and the mean swimming speed. On Day 3, the average latency of Group S+L (100 μg/Kg) was longer than Group C (P < 0.05) in the working memory test after the operation. The average latency of rats in Group L and S was showed longer than that in Group C, with tiny difference (P > 0.05). In the 7-Day working memory test, the average latency of the rats in Group L, S and S+L (100 μg/Kg) was obviously longer than that in Group C. Comparing to preoperative rats, POCD rats of Group S+L (100 μg/Kg) were scanned by 18F-FDG PET/CT three days later after the operation. Its SUVmax of the frontal and temporal lobe areas were decreased significantly (P < 0.05). However, difference degree was not significantly shown in the SUVmax between Group C and the preoperative rats (P > 0.05). In comparison with the gene expression of of Group C, the PI3K, IRS-2, AKT and GLUT4 mRNA genes are the key genes in the insulin signaling pathways of the hippocampus of the POCD rats. The expression level was reduced. The expression level of all protein of PI3K, IRS-2, GLUT4 and AKT in the POCD rats was of no great contrast with that in Group C. But for IRS-2 protein, the phosphorylation level has increased, and meanwhile decreased for AKT, PI3K and GLUT4 proteins (P < 0.05). Conclusions: Adult SD rats cognitive dysfunction model treated with unilateral nephrectomy combined and 100 μg/kg LPS intraperitoneal injection were led to abnormal both brain glucose metabolism and insulin expression. The proved phenomenal results signal pathway-related proteins PI3K, IRS-2, AKT and GLUT4. It reached the conclusion that surgical trauma, rather than anesthesia, leads to impaired cognitive function. PI3K, IRS-2, AKT, and GLUT4pathway of brain can be partial explanations of the pathogenesis of POCD.     

透脓托毒饮配合西医手术疗法对肛周坏死性筋膜炎患者预后的影响

目的:探究透脓托毒饮配合西医手术疗法对肛周坏死性筋膜炎(Perianal necrotizing fasciitis,PNF)患者预后的影响。方法:选择西安市中医医院肛肠科于2013年10月-2018年10月收治的肛周坏死性筋膜炎患者60例,根据其入院顺序经随机数字表法分为两组,每组各30例。其中,对照组行PNF清创术,研究组在对照组基础上辅助透脓托毒饮进行治疗,对比两组的治疗总有效率、外周血炎症因子水平、住院时间、创面愈合时间、疼痛积分、腐肉脱落时间、复发率和死亡率。结果:治疗后,研究组的总有效率显著高于对照组(93.3%vs. 73.3%,P0.05);两组血清肿瘤坏死因子-α(Tumor necrosis factor-alpha, TNF-α)、白细胞介素-6(Interleukin-6, IL-6)、白细胞介素-10(IL-10)水平均较治疗前显著降低,且研究组以上指标均明显低于对照组(P0.05)。研究组的住院时间、创面愈合时间、疼痛积分、腐肉脱落时间均显著短于(低于)对照组(P0.05)。随访3个月,两组的术后复发率和死亡率比较均无显著差异(P0.05)。结论:透脓托毒饮配合清创术治疗PNF的效果显著优于单用清创术,其可有效改善患者的临床症状和预后,可能与其显著降低血清炎症因子水平有关。     

3D打印技术在周围型肺癌手术规划中的应用

目的:通过比较计算机断层扫描,三维重建图像和3D打印在手术中显示肺动脉分支的能力,探讨3D打印技术在周围型肺癌手术规划中的应用价值。方法:2018年1月-2018年12月,同一胸外科治疗组中接受电视胸腔镜择期右肺上叶切除手术的周围型肺癌患者30例。随机分为3组,每组10例,分别通过计算机断层扫描,三维重建图像和3D打印进行术前手术规划。分别记录每组手术规划中的右肺上叶动脉分支数目,然后将这些记录与术中实际所见进行比较。结果:各组间患者一般资料无统计学差异。所有患者均有完整的CT扫描、三维重建、3D打印和术中动脉分支数据,且都接受了VATS解剖性右肺上叶切除术,术中进行顺利,无中转开胸,无术中大出血,术后无明显并发症和围手术期死亡,皆顺利出院。CT组的右肺上叶动脉分支数量为1.5±0.52,3DI组为2.1±0.57,3DP组为2.2±0.63。CT组、3DI组和3DP组分别与手术中所见比较,CT组存在统计学差异(P=0.025),其他两组无统计学意义。结论:3D打印技术在周围型肺癌手术规划中的效果优于计算机断层扫描,比三维重建图像更加直观,建议推广。     

选择性贲门周围血管离断术治疗门静脉高压症的临床价值

目的：探讨选择性断流术与传统断流术在门静脉高压症手术治疗中的疗效。方法：分析我院从2007 年10 月至2013 年10 月行传统断流术52 例患者与行选择性断流术的34例患者的临床资料,对两组进行回顾性对比分析。结果：选择性断流术术后近 期脾窝积液、发热以及随访期间再出血、门静脉高压性胃病(portal hypertensive gastropathy,PHG)发生率明显减低(P<0.05),食管胃 底静脉曲张程度明显减轻（P<0.05）,肝性脑病发生率未增加(P>0.05)。结论：选择性断流术可以明显改善断流术后再出血和PHG 发病率高的问题,降低术后并发症的发生,近期疗效显著。但术后6-12 月,食管旁静脉均基本闭塞,远期疗效还有待于进一步研 究。