Incidence of Chest Tube Malposition in the Critically Ill: A Prospective Computed Tomography Study

Background: Malposition of percutaneously inserted chest tubes is considered as a rare complication in critically ill patients. Its incidence, however, remains uncertain. The aims of the study were to assess the true incidence of chest tube malposition in critically ill patients and to identify predicting factors.

Methods: The authors prospectively studied 122 chest tubes percutaneously inserted in 75 consecutive critically ill patients. For clinical reasons independent of the study, thoracic computed tomography scanning was performed in 63 patients, allowing direct visualization of 106 chest tubes. Based on these findings, chest tube position was classified as intrapleural, intrafissural, or intraparenchymal. Factors predicting chest tube malposition were analyzed by univariate and multivariate analysis.

Results: The mean delay between chest tube placement and thoracic scan was 3.5 +/- 2.9 days. Twenty-two chest tubes were diagnosed as being intrafissural (21%), and 10 were diagnosed as being intraparenchymal (9%). The only predicting factor associated with the risk of malposition was the use of a trocar for the percutaneous insertion of the chest tube (P = 0.032).     

腹腔镜D3淋巴清扫联合保留盆腔自主神经直肠癌根治术对男性性功能的影响

目的 对比分析腹腔镜和开腹联合保留自主神经的D3直肠癌根治术对男性性功能的影响.方法 采用前瞻性研究的方法,将我院2006年6月至2007年10月入选的男性直肠癌患者119例随机分别进行开腹(OS组59例)和腹腔镜(LS组60例)手术,两组病例均采用联合保留自主神经的D3直肠癌根治术.在术前和术后3、6和12个月,分别采用IIEF问卷对男性性功能进行评价,对比两组病例术后性功能情况.结果 术后3次随访结果显示,LS组性功能障碍总发生率分别为23.3%、18.3%和11.6%,OS组分别为32.2%、27.1%和16.9%;两组比较,差异无统计学意义(P>0.05).结论 腹腔镜D3淋巴清扫联合保留自主神经的直肠癌根治术能够达到与开腹手术相同的效果.     

长托宁用于全麻术前用药的效果观察

目的:观察长托宁作为全麻病人麻醉前用药对心血管系统和呼吸道分泌物的影响.方法:随机选择20例需全麻手术病人,在麻醉诱导前静注长托宁0.015 mg/kg,观察注药前、后5、10、20分钟各时点的血压、心率、脉搏氧饱和度及口干程度以及术中术毕口腔和呼吸道分泌物情况.结果:病人使用长托宁后5、10、20分钟的血压、心率与使用前相比有下降趋势,但无统计学意义(P＞0.05),脉搏氧饱和度未见明显改变,用药10分钟病人有轻度口干,术毕拔除气管导管时口腔及呼吸道分泌物较少.结论:长托宁用于全麻病人麻醉前给药效果满意.     

Inhibitory effects of benzoate on chiral inversion and clearance of N(G)-nitro-arginine in conscious rats.

N(G)-nitro-arginine (NNA) is known to exhibit stereoselective pharmacokinetics in which N(G)-nitro-d-arginine (d-NNA) has a faster clearance rate than N(G)-nitro-l-arginine (l-NNA) in anesthetized rats, and d-NNA undergoes unidirectional chiral inversion. It was postulated that chiral inversion of d-NNA was performed in a two-step pathway by d-amino acid oxidase (DAAO) followed by an unidentified transaminase. Such chiral inversion contributes (at least partially) to the pharmacokinetic stereoselectivity of NNA. This study used the selective inhibitor of DAAO, sodium benzoate, to test the above hypothesis. An i.v. bolus injection of d-NNA (32 mg/kg) and l-NNA (16 mg/kg) in conscious rats exhibited biphasic disposition with different pharmacokinetic parameters in a stereospecific manner (approximately 5-10-fold differences). Unidirectional chiral inversion of d-NNA but not l-NNA was found from these animals. In addition to its similar inhibitory effects on the d-NNA conversion and DAAO activity in kidney homogenates, sodium benzoate completely blocked chiral inversion of d-NNA and led to a smaller stereospecific difference, reflected by a nearly 50% reduction of d-NNA clearance and a 2-fold increase in t(1/2) and area under the curve of d-NNA in benzoate-pretreated rats. The results suggest that DAAO plays an essential role in chiral inversion of d-NNA and chiral inversion contributes mostly to the pharmacokinetic stereospecificity of NNA.     

螺旋CT三维重建成像在先天性高肩胛症手术方式选择中的作用

[目的]探讨螺旋CT三维重建技术在先天性高肩胛症分度和手术方式选择中的作用。[方法]22例先天性高肩胛症术前应用螺旋CT对病变部位进行扫描并三维重建，测量以肩胛骨肩胛冈内侧缘为参照点，两侧肩胛骨高度差。根据测量结果依据Cavendish分度将其分类，并根据三维重建成像选择不同的矫形手术术式。[结果]本组22例病人，随访2—4年，外观及功能均有不同程度的改善，未出现神经、血管和椎体等的损伤。[结论]根据螺旋CT扫描和三维重建检查结果，术前即可直观的明确先天性高肩胛症的病变程度，相互关系，伴发畸形，患侧肩胛骨与正常对侧肩胛骨的外观差异等，便于手术操作方案的制定，避免了手术操作的盲目性，减少医源性并发症的发生。     

Glutamate acts at NMDA receptors on fresh bovine and on cultured human retinal pigment epithelial cells to trigger release of ATP

Efficient vesicle membrane recycling at presynaptic terminals is pivotal for preventing depletion and maintaining high firing rates in neuronal networks. We used a new approach, based on the combination of spectrally different optical probes, to investigate how stimulation determines the fate of synaptic vesicles after endocytosis. We found that in the small central synapses of rat hippocampal neurones low frequency stimulation (40 action potentials at 2 Hz) targets vesicles preferentially to vesicle pools that were kinetically faster. Vesicles taken up during endocytosis triggered by high frequency stimulation (400 action potentials, 20 Hz) were also placed in the back of the release queue. We performed a spatial analysis of the recycled vesicles in living hippocampal boutons using two spectrally different FM-dyes (FM1-43 and FM5-95). By using these consecutively, vesicles endocytosed by either stimulation protocol were labelled with a different colour. This revealed that the kinetic arrangement was also reflected in the spatial organization of vesicles within the bouton. Next, we identified the postsynaptic site of the active zone by transfecting the neurones with postsynaptic density protein PSD-95-CFP. The data from these triple colour experiments suggest that retrieval after low frequency stimulation keeps vesicles in a more confined region closer to the active zone as identified by PSD-95-CFP expression at the postsynaptic site.     

血管移植搭桥治疗巨大动脉瘤

目的探讨中、高流量血管搭桥方法对颅内巨大颅内动脉瘤的治疗。方法8例巨大和颅底复杂动脉瘤患者,主要表现头痛发病者5例,视力减退者2例,面部麻木者1例。未破裂动脉瘤6例,2例患者发生动脉瘤破裂,Hunt-Hess分级分别为Ⅰ级和Ⅱ级。血管造影证实：动脉瘤体位于颈内动脉海绵窦段（C4段）4例、床突上段（C1段）2例、大脑中动脉M2～M1段者2例动脉瘤大小为2．5～6．0cm,平均直径3．7cm。其中6例动脉瘤为梭形,2例为宽颈动脉瘤。8例患者均采用额颞开颅,骨瓣要尽可能低到颅底,以缩短搭桥移植血管在颅外走行长度。通常用7-0显微缝线吻合移植血管与颈外动脉,用8-0缝线吻合移植血管与颅内段颈内动脉和大脑中动脉。4例患者利用大隐静脉移植搭桥,4例患者利用桡动脉移植搭桥。颅内、外搭桥完毕后将动脉瘤近心端和远端的供血动脉结扎和夹闭,阻断动脉瘤的全部血供。对3例有压迫脑神经或颅内占位引起颅压高的患者,将动脉瘤切除。结果5例术后头痛消失,1例视力减退者明显改善,1例动眼神经麻痹恢复。5例术后行脑血管造影检查,3例行CT血管造影检查,7例搭桥吻合血管全部畅通,动脉瘤消失。2例术后出现暂时性一侧肢体力弱,肌力在Ⅱ～Ⅲ级之间,术后1个月完全恢复。结论中、高流量颅内外血管搭桥可作为治疗颅内巨大动脉瘤的有效方法。     

C端序列的删除对非出血重组蛇毒纤溶酶的影响

[目的]研究C端序列对非出血重组纤溶酶(rFⅡ)特异性、活性和热敏感性的影响.[方法]通过SOEing PCR方法构建删除C端序列的突变体,突变体和rFⅡ分别在P.pastoris中诱导表达.表达和纯化的蛋白用SDS-PAGE和Westeren blot进行鉴定.之后分析其生化特性.[结果]rFⅡ及突变体通过SDS-PAGE和Westeren blot得到证实.生化分析揭示:①突变体对显色底物N-(p-Tosyl)-Gly-Pro-Lys-pNA的催化效率(Kcat/Km)是rFⅡ的1.9倍;②突变体和rFⅡ对氧化的胰岛素B链拥有共同的优先裂解位点,可是在随后的裂解中开始展现差异;③突变体显示了更高的纤(原)活性;④热处理表明突变体相较r FⅡ对温度的增加更敏感;⑤通过圆二色谱测量,突变体的螺旋比例有所增加.[结论]删除的序列参与rFⅡ的特异性、活性和热敏感性,该序列可作为下一步优化的候选序列.