人工食管植入术后影像学检查的实验研究

目的 探讨影像学检查方法在人工食管实验研究中的应用价值。方法 对10只植入胸段记忆合金组合式人工食管的实验动物模型术后所进行X线平片和食管造影检查结果进行观察分析研究。结果 X线平片清晰显示胸内植入记忆合金组合式人工食管植入的位置原位固定〉9个月3只；2—3月内脱管3只；〉3个月内脱管4只；管体全部滑至胃内，食管造影连续摄片显示重度新生食管狭窄3只；轻度新生食管狭窄4只，同期介入安放食管支架2只．全组仅见1只发生吻合口细小瘘。无发现其它胸内并发症。结论 ①X线检查是进行人工食管动物实验研究简单且实用的检查方法．②食管造影连续摄片检查方法可为已建立植入人工食管的猪实验动物模型术后的观察研究及介入治疗提供多方面的支持帮助。     

大黄提取液对脱矿釉质中钙溶出量的影响

目的 观察大黄提取液对脱矿釉质中钙溶出量的影响.方法 用不同浓度的大黄提取液和去离子水处理牙面后进行脱矿,ASCA生化分析仪对釉质脱矿后的脱矿液进行钙离子浓度的检测.结果 2 mg/ml和4 mg/ml大黄提取液处理后釉质钙溶出量<去离了水(P<0.01)、<1 mg/ml大黄提取液组(P<0.05),>2%氟化钠组但差异无统计学意义(P>0.05).1 mg/ml大黄提取液处理后釉质钙溶出量>2%氟化钠组(P<0.01),<去离子水组但差异无统计学意义(P>0.05).结论 2mg/ ml和4 mg/ml大黄提取液具有抑制脱矿釉质中钙溶出作用:2mg/ml大黄提取液为抑制钙溶出的起始有效浓度.     

CO2气腹对结肠癌细胞侵袭能力影响的体外研究

目的研究不同压强持续性CO2气腹处理对结肠癌细胞侵袭能力的影响。方法建立体外气腹模型,选用人结肠癌细胞株SW1116,分别在不同压强(6、9、12及15mmHg)99.5%医用CO2气体以及常规培养条件下暴露1h,取各压强组处理后0h和72h细胞,使用体外细胞侵袭实验模型进行体外侵袭实验。结果气腹处理后即刻(0h),15mmHg压强组结肠癌细胞侵袭荧光强度(11.36±0.861)明显低于处理前(13.43±1.113),差异有统计学意义(P=0.019),且明显低于其他各组(6mmHg组:15.58±1.015,P=0.000;9mmHg组:13.49±0.750,P=0.011;12mmHg组:13.37±0.949,P=0.016;常规培养组:13.43±2.027,P=0.014);6mmHg压强组处理后细胞侵袭荧光强度(15.58±1.015)高于处理前(14.42±1.491),但差异尚未达到统计学意义(P=0.056),且显著高于其他各压强组(9mmHg组:P=0.013;12mmHg组:P=0.009;15mmHg组:P=0.000;常规培养组:P=0.011)。气腹处理后72h,各压强组处理前、后的结肠癌细胞侵袭荧光强度差异无统计学意义(P>0.05);处理后各压强组间的结肠癌细胞侵袭荧光强度差异亦无统计学意义(P>0.05)。结论CO2气腹能对结肠癌细胞的侵袭能力产生一过性影响,随着CO2气腹压强的增高,结肠癌细胞的侵袭能力可能受到抑制。     

A Tissue-Engineered Artificial Bile Duct Grown to Resemble The Native Bile Duct

The aim of this study was to fabricate an artificial bile duct for the development of a new treatment for biliary diseases. Eighteen hybrid pigs were implanted with a bile duct organoid unit (BDOU) made of a bioabsorbable polymer. Twelve of the transplanted BDOUs had been seeded with autologous bone marrow cells (BMCs) in advance. Six animals, the controls, were grafted with the scaffold alone with no BMCs seeded. The common bile duct was cut, the hepatic cut end of the native common bile duct was anastomosed to the BDOU and the other end was anastomosed to the duodenum. The controls underwent a similar operation. The neo-bile duct was removed at pre-determined time points and investigated histologically. All 18 recipient pigs survived until their sacrifice at 6 weeks, 10 weeks or 6 months. Histological examination revealed incomplete epithelialization of the neo-bile duct at 6 weeks and 10 weeks after transplantation. At 6 months, the organoid exhibited a morphology almost identical to that of the native common bile duct. No differences were found between the controls and BMC-seeded pigs. These results show that the artificial bile duct thus fabricated can serve as a substitute for the native bile duct.     

血浆置换治疗97例重型肝炎并发症的防治

目的探讨血浆置换治疗重型肝炎时并发症的发生原因及防治措施。方法回顾血浆置换治疗97例重型肝炎时出现的并发症的有关资料，分析各种并发症发生的原因。结果26．6次治疗中共出现并发症131次，发生率达49.3％。按发生率高低依次为皮疹、麻木和（或）搐搦、血压下降、胸闷、失衡综合征、置管处渗血、体外循环凝血及置管处渗液。结论血浆置换治疗重型肝炎时并发症的发生率高，但经处理均能缓解，可以在严密监护下实施。     

应用颈椎椎间融合器27例的临床分析

目的分析颈椎椎间融合器（CFC）临床应用的疗效。方法对27例植入CFC的脊髓型颈椎病随访3个月～3年，平均1．8年，观察CFC临床应用疗效。结果本组术后均无发生严重的并发症。影像学资料证实脊髓和神经根减压明显，椎间融合器（Cage）融合良好。术后JOA评分均恢复至15分以上，无症状恶化或复发者。结论Cage融合固定术治疗颈椎病有手术创伤小、无供区并发症、术后恢复快及手术成功率高等优点。     

Detection of electrocardiographic ‘left ventricular strain’ using neural nets

The use of artificial neural networks for classification of ST-T abnormalities of the electrocardiogram (ECG) was investigated. A training set of 356 lateral leads selected from 105 ECGs was visually classified as exhibiting one particular ST-T morphology (left ventricular (LV) strain) or not. Selected measurements, together with the classification, were fed as input to a three-layer software-based network during the learning process. The performance of the network was evaluated by comparing the results obtained from the network with conventional criteria, using two test sets. Set 1 comprised 63 lateral leads from 32 ECGs with ST-T changes showing atypical forms of LV strain. Set 2 consisted of 80 lateral leads from 20 ECGs containing normal and abnormal T-waves. For set 1, the network outperformed conventional criteria, having a higher sensitivity (96 per cent against 85 per cent) and specificity (67 per cent against 50 per cent). With test set 2, both network and conventional criteria were 100 per cent sensitive and 100 per cent specific. For sets 1 and 2 combined, the network had a higher overall sensitivity (97 per cent agaisst 89 per cent) and specificity (88 per cent against 82 per cent). The results suggest that neural networks may be useful in selected areas of electrocardiography, but care is required when selecting patterns for use in the training process.     

New approaches to QSAR: Neural networks and machine learning

Summary Neural networks and machine learning are two methods that are increasingly being used to model QSARs. They make few statistical assumptions and are nonlinear and nonparametric. We describe back-propagation from the field of neural networks, and GOLEM from machine learning, and illustrate their learning mechanisms using a simple expository problem. Back-propagation and GOLEM are then compared with multiple linear regression (using the parameters and their squares) on two real drug design problems: the inhibition ofEscherichia coli dihydrofolate reductase (DHFR) by pyrimidines and the inhibition of rat/mouse tumour DHFR by triazines.     

An Intrapleural Lung Prosthesis: Rationale, Design, and Testing

Abstract: Extracorporeal life support (ECLS or ECMO) is standard treatment for severe respiratory failure but poses many contraindications to future lung transplantation. The solution to this dilemma is the implantable gas exchange device (IGED) or artificial lung. Preliminary efforts to create such an artificial lung have been made since 1970 and include designs involving single devices, intravascular devices (i. e., IVOX), and combination heart–lung devices, Stringent requirements govern the design of such a device, the most important of which are high gas exchange efficiency, low resistance to blood flow, and size. This paper describes such a device. It incorporates large diameter inflow and outflow ports in close proximity and a low resistance wound hollow fiber core encapsulated in a compliant outer shell which conserves the work of the right ventricle. In a large animal model (adult sheep) this device was connected in line with the main pulmonary artery in series with the native lungs. This configuration has the advantages of using the lungs as an embolic filter, perfusing the lungs with fully oxygenated blood, and maintaining the integrity of the anatomy necessary for transplant. Laboratory experiments have run >8 h. Preliminary data show that the animals have remained hemodynamically stable while the devices have supported the animals completely by supplying 100% O₂ saturation with PO₂ values ranging from 250–350 mm Hg. Additionally, this model makes possible the study of respiratory failure without introducing other variables such as extracorporeal circuits or pumps. The other metabolic, endocrine, and reticuloendothelial functions of normal and injured lungs can now be studied more precisely by excluding these variables. Further studies are needed to evaluate this device in chronic (long–term implantation) experiments before clinical application.     

Segmental Uterine Horn Replacement in the Rat Using a Biodegradable Microporous Synthetic Tube

To investigate the possible use of a biodegradable microporous synthetic tube for fallopian tube replacement, polyetherurethane/poly-L-lactide (PU/PLLA) grafts in the uterine horn of the rat were studied and their patency and healing characteristics compared with those of nonbiodegradable polytetrafluoroethylene (PTFE; Teflon) grafts as well as with those of reanastomosed uterine horns. Regarding the healing characteristics, the PU/PLLA grafts were superior to the PTFE graft, as was indicated by the regeneration of endometrium and the extensive perigraft tissue ingrowth. However, the graft/uterine anastomoses of the PU/PLLA and PTFE grafts became obstructed by a plug of mucosal folds, all reanastomosed, uterine horns in the control experiments remaining open. In conclusion, although biodegradable microporous PU/PLLA uterine horn grafts have better healing characteristics than PTFE grafts, they easily obstruct at the graft/uterine junction. Mucosal suturing and/or the use of splints may contribute to the feasibility of biodegradable microporous artificial fallopian tubes in tubal surgery.