机械应力对幼鼠髋臼发育影响的实验研究

目的阐明异常机械应力对髋臼发育和髋臼软骨生长板内软骨细胞增殖的影响,探讨髋臼发育不良的修复方法。方法将60只3周龄的雌性Wistar大鼠分成3组,每组20只,左侧髋关节为实验侧,右侧为对照侧。A组:在2周内反复将髋关节手法脱位后再复位;B组:膝关节伸直位钢针固定,制作髋臼发育不良的动物模型,2周后拔出钢针;C组:持续伸直位固定膝关节。三组动物分别于第5、7、9、12周时进行钼靶软X线、组织形态学及透射电镜观察。结果A组第5周时唇缘变钝,髋臼角比对侧增大约5°,软骨生长板内增殖层软骨细胞极向紊乱,SO染色无差异,圆韧带有淋巴细胞浸润,第7、9、12周时变化小,两侧无差异;B组第5周时髋臼角比对侧明显增大,第7周时唇缘变钝、内翻,纤维增生,柱状细胞极性紊乱,肥大细胞层增多,第9、12周时接近正常,12周时髋臼角为23.4°,髋臼入口最短径为5.0mm;C组髋臼角比对侧持续增大,没有任何改善倾向,第12周时唇缘内翻、扁平,无明显柱状细胞排列,细胞核变小,细胞器减少,空泡形成,髋臼角为71.3°,髋臼入口最短径为2.9mm。结论在髋臼发育旺盛期解除异常机械应力、恢复头臼同心,髋臼发育不良有治愈倾向。造成髋臼发育不良的直接原因是软骨生长板内增殖层软骨细胞代谢功能发生改变,骨化延迟。     

Mechanobiology and force transduction in scars developed in darker skin types

BACKGROUND: Scarring is a complex process involving many cell types, cytokines and biological pathways including mechanobiology. Some subtle mechanical properties of skin can be assessed by measuring the speed of ultrasound shear wave propagation. The orientation of abnormal skin tension forces can be visualized, particularly in darker skin types, using dermoscopy showing distinct patterns of rete ridges' conformation. AIM: To assess some mechanobiological features of scars in darker skin types. PATIENTS AND METHODS: Large atrophic and hypertrophic surgical scars were examined on the trunk of 35 darker skin subjects. The surrounding skin was used as a comparator. Dermoscopic aspects were recorded. Resonance running time measurements (RRTM) were performed using a shear wave propagation device (Reviscometer). They were performed in four specific directions at given angles with regard to the long axis of the scar. The minimum, maximum and mean RRTM values were recorded at each site. RESULTS: Dermoscopy revealed patterns of melanin deposits in scars distinct from the normal honeycomb network seen in the surrounding skin. Hypertrophic scars showed a patchy pattern of large macular melanoderma dispersed in a lighter background. In these cases, low RRTM values were obtained with little variations according to the orientation of the measurements. By contrast, atrophic scars showed a streaky laddering melanotic pattern under dermoscopy. Higher RRTM values were often obtained, particularly in the transversal direction of the scars. Mechanical anisotropy was greater in the atrophic scars compared with the normal skin. DISCUSSION: Darker skin types represent a model for visualizing the main orientation of the epidermal rete ridges. A correlation was found between the pattern of melanized rete ridges of scars and the main orientation of the intrinsic forces in the skin.     

Symptoms, diagnosis and endoscopic management of common bile duct stones

Symptomatic BDS commonly cause significant morbidity and attempt at stone removal should be attempted if possible. Complications of CBDS include biliary colic, jaundice, cholangitis and pancreatitis. Investigations aimed to predict the presence of stones within the bile duct include serum bilirubin, AST, ALP, common bile duct diameter and age as independent predictors of choledocholithiasis. TUS is a sensitive test in detecting bile duct dilatation but the sensitivity is reduced in its ability to detect choledocholithiasis. A NIH consensus statement found that ERC, MRC and EUS were comparable in their sensitivities, specificities and accuracy rates for detection of choledocholithiasis. ERC and stone removal using a balloon or basket is often performed following EST. EBD may be performed if patients have uncorrected coagulopathies but the risk of pancreatitis is higher than for EST (although the risk of bleeding complications is lower for EBD). ML is often required in difficult to remove CBDS and using this device, CBDS can be removed in 90–95% of cases. Other forms of lithotripsy including laser lithotripsy and EHL are confined to specialised centres and the evidence for their use is based on small studies. ESWL may clear stones from the bile duct in up to 93% of patients but frequently ERC and stone fragment removal is required post ESWL. The role of medical therapy in difficult to remove CBDS (or in CBDS in patients with severe co-morbid illness preventing ERC + stone removal) is still currently uncertain due to a lack of large randomised control trials.     

肠内营养在慢性阻塞性肺病机械通气治疗与护理中的作用

目的　探讨肠内营养对慢性阻塞性肺病 (COPD)机械通气治疗与护理中的作用。方法　行机械通气的2 8例患者随机分为 2组 ,治疗组 14例给予安素营养 4周 ,对照组 14例给予一定量糖、脂肪、氨基酸等常规输液 ,上述两组病人每周常规测定血清蛋白 (ALB)、IgA、IgG、IgM、FEV1、PaO2 、PaCO2 及一次脱机成功率。结果　治疗 2周末实验组ALB、IgA、IgG、IgM均显著高于对照组 (P <0 0 5 ) ;治疗 4周末治疗组所有指标均显著高于对照组 (P <0 0 5 )。结论　肠内营养是COPD机械通气患者的一项重要治疗措施 ,良好细致的护理是保证其成功实施的关键     

机械通气患者体位改变插入胃管效果与分析

目的提高有创机械通气患者插入胃管的成功率,减少因反复插管所致的并发症,减轻患者痛苦,提高护士的工作效率。方法把有创机械通气的60例患者,随机分为观察组30例和对照组30例,观察组采取改变常规的“去枕头后仰位”为“抬高床头70°~80°角,头正位”插入胃管,对照组采取常规的去枕头后仰卧位的体位方法插入胃管。结果对照组一次插管成功率为6.66%,观察组一次插管成功率为90%,经统计学分析,差异有显著意义(P<0.01)。结论有创机械通气患者改变常规的“去枕头后仰位”为“抬高床头70°~80°角,头正位”后一次插入胃管成功率明显提高。     

应用联合减压术治疗中晚期脑疝疗效观察

目的　观察联合减压术治疗特重型颅脑损伤合并嵌顿性脑疝的效果。方法　将 97例格拉斯哥昏迷评分 (GCS) 3～ 5分的特重型颅脑损伤合并嵌顿性脑疝患者随机分为两组 ,分别采用联合减压术 (46例 )与常规骨瓣开颅术 (5 1例 )治疗 ,术后两组均经常规治疗。随访 1～ 32个月 ,平均 7个月。比较两组患者临床疗效、颅内压变化及并发症发生率。结果　联合减压治疗组有效率为 80 .4 % (37/ 4 6例 ) ,其中恢复良好、中残2 7例 (占 5 8.7% ) ,重残 10例 (占 2 1.7% ) ,死亡 9例 (占 19.6 % ) ;常规骨瓣开颅术对照组有效率为 33.4 %(17/ 5 1例 ) ,其中恢复良好、中残 6例 (占 11.8% ) ,重残 11例 (占 2 1.6 % ) ,死亡 34例 (占 6 6 .6 % ) ,两组有效率和病死率比较差异均有显著性 (P均 <0 .0 1)。联合减压治疗组患者颅内压下降速度和程度优于常规骨瓣开颅术对照组 (P<0 .0 5 )。联合减压治疗组患者的急性脑膨出、切口疝、切口脑脊液漏、外伤性癫疒间及术后枕叶脑梗死发生率均明显低于常规骨瓣开颅术对照组 (P<0 .0 5或 P<0 .0 1) ,但两组术后颅内感染发生率差异无显著性 (P>0 .0 5 )。结论　联合减压术治疗特重脑损伤合并嵌顿性脑疝患者的疗效优于常规骨瓣开颅术。     

高频喷射通气结合胸壁挤压对组胺致肺损伤犬呼吸循环功能的影响

以高频喷射通气结合胸壁挤压（ＨＦＪＶ＋ＣＷＣ）为通气模式，观察其对组胺致肺损伤犬呼吸循环功能的影响，并与单纯高频喷射通气（ＨＦＪＶ）进行比较。结果表明：与ＨＦＪＶ相比，ＨＦＪＶ＋ＣＷＣ时的功能残气量（ＦＲＣ）、ＰａＣＯ＿２和ＰＣＯ＿２均显著降低（Ｐ＜０．０１），肺泡通气量（Ｖ＿Ａ）和二氧化碳排出量（ＣＯ＿２）均显著增高（Ｐ＜０．０１），每分呼出气量（Ｖ＿Ｅ）、ＰａＯ＿２、ＰＣＯ＿２、吸气峰压（ＰＩＰ）、平均气道压（Ｐａｗ）、呼气末压（ＥＥＰ）、ＨＲ、平均动脉压（ＭＡＰ）、肺动脉压（ＰＡＰ）和肺毛细血管楔压（ＰＣＷＰ）均无显著变化（Ｐ＞０．０５）。提示：ＨＦＪＶ＋ＣＷＣ除保留单纯ＨＦＪＶ时气道开放、气道低压、良好的血液氧合、不影响循环功能等特点外，还具有增加呼气动力，改善肺泡通气，显著促进ＣＯ＿２排除等优点。     

复合树脂预热的研究现状和临床应用

复合树脂作为临床常用牙科充填材料存在耐磨性差、聚合收缩大和牙本质边缘适应性不佳等问题。近年有研究发现预热可以改善复合树脂的性能,本文就预热复合树脂对其单体转化率、边缘微渗漏、机械性能以及牙髓的影响等方面进行探讨,以供临床参考。     

Automatic jet ventilation in children anaesthetized by the T-piece circuit

Investigation was carried out in ten children aged between one month and six years, who were anaesthetized by the T-piece circuit. The volume of the reservoir tubing of the T-piece was 250 ml. Ventilation was controlled automatically by oxygen jets which were delivered via an injector attached to the reservoir tubing. The oxygen jets were regulated by an electronically-controlled solenoid valve. The children were ventilated by a tidal volume about 12 ml±kg^?1 at a rate of 12-20 per min depending on their age, while the FGF varied between 3 and 6 l min^?1 depending on their body weight. The resulting FIO₂ ranged between 0.32 and 0.34 which was expected from the oxygen:nitrous oxide mixture (1:2), denoting no mixing of the oxygen jets with the anaesthetic mixture. The PA_co2 was ventilation-dependent, and ranged between 4±6-5±3 kPa (35-41 mmHg). The results suggest that automatic jet ventilation facilitates controlled ventilation in children anaesthetized by the T-piece circuit, while maintaining the original simplicity of the T-piece.;     

高频喷射通气时麻醉犬动脉血二氧化碳分压的估计

作用测定５－８次常频呼吸后呼气末二氧化碳分压的方法，探讨了高频喷射通气时麻醉犬动脉脉血二氧化碳分压与Ｐｅｔｃｏ２的关系，结果表明，在通气频率分别为６０，１００及２００次／ｍｉｎ时，Ｐｅｔｃｏ２和Ｐａｃｏ２均无显性差异，Ｐｅｔｃｏ２呈显相关（ｒ＝０．８３，Ｐ＜０．０１）。结果提示，测定５－８次常频呼吸后的Ｐｅｔｃｏ２可较准确地评估ＨＦＪＶ时麻醉犬的Ｐａｃｏ２。