Classification of spatiotemporal hemodynamics from brain perfusion MR images using expectation-maximization estimation with finite mixture of multivariate gaussian distributions.

The ability to cluster different perfusion compartments in the brain is critical for analyzing brain perfusion. This study presents a method based on a mixture of multivariate Gaussians (MoMG) and the expectation-maximization (EM) algorithm to dissect various perfusion compartments from dynamic susceptibility contrast (DSC) MR images so that each compartment comprises pixels of similar signal-time curves. This EM-based method provides an objective way to 1) delineate an area to serve as the in-plane arterial input function (AIF) of the feeding artery for adjacent tissues to better quantify the relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and mean transit time (MTT); 2) demarcate regions with abnormal perfusion derangement to facilitate diagnosis; and 3) obtain parametric maps with supplementary information, such as temporal scenarios and recirculation of contrast agent. Results from normal subjects show that perfusion cascade manifests (in order of appearance) the arteries, gray matter (GM), white matter (WM), veins and sinuses, and choroid plexus mixed with cerebrospinal fluid (CSF). The averaged rCBV, rCBF, and MTT ratios between GM and WM are in good agreement with those in the literature. Results from a patient with cerebral arteriovenous malformation (CAVM) showed distinct spatiotemporal characteristics between perfusion patterns, which allowed differentiation between pathological and nonpathological areas.     

经皮穿刺腰椎间盘切吸术治疗腰椎间盘突出症的远期疗效

目的 观察X线电视引导下经皮穿刺腰椎间盘切吸术治疗腰椎间盘突出症的远期疗效。方法 32例经CT扫描证实的腰椎间盘突出症患者，其中，膨出型29例，游离型2例，以及突出型1例，均经X线电视引导下经皮穿刺腰椎间盘切吸术治疗，术后均经随访0.5～11.0a。结果 术后1周～3个月，32例中的24例临床症状与体征得到有效控制或明显减轻，随访5～11a观察表明，症状完全消失和明显减轻者分别见于23例和6例，总有效率90.6%，预后极好和较好者均见于膨出型腰椎间盘突出症患者。结论 游离型和突出型腰椎间盘突出症的疗效均不理想，因此，术前认真选择适应证是获得理想疗效的关键性因素。     

Influence of bradykinin B1 and B2 receptors in the immune response triggered by renal ischemia–reperfusion injury

Bradykinin B1 receptors are exclusively expressed in inflamed tissues. For this reason, they have been related with the outcomes of several pathologies. Ischemia–reperfusion injury is caused by the activation of inflammatory and cytoprotective genes, such as macrophage chemoattractant protein-1 and heme oxygenase-1, respectively. This study was aimed to analyze the involvement of bradykinin B1 and B2 receptors (B1R and B2R) in tissue response after renal ischemia–reperfusion injury. For that, B1R (B1−/−), B2R (B2−/−) knockout animals and its control (wild-type mice, B1B2+/+) were subjected to renal bilateral ischemia, followed by 24, 48 and 120 h of reperfusion. At these time points, blood serum samples were collected for creatinine and urea dosages. Kidneys were harvested for histology and molecular analyses by real-time PCR. At 24 and 48 h of reperfusion, B1−/− group resulted in the lowest serum creatinine and urea levels, indicating less renal damage, which was proved by renal histology. Renal protection associated with B1−/− mice was also related with higher expression of HO-1 and lower expression of MCP-1. In conclusion, the absence of B1R had a protective role against inflammatory responses developed after renal ischemia–reperfusion injury.     

舒张功能障碍对冠心病的诊断价值

目的应用超声多普勒方法评价冠心病患者的左室整体舒张功能及舒张功能障碍的发生率，探讨舒张功能障碍在冠心病无创诊断中的价值。方法对入选病人行常规检查，同时进行二尖瓣血流频谱、肺静脉血流频谱及二尖瓣环组织多普勒检查，对比临床标准与舒张功能障碍标准对冠心病的诊断率。结果舒张功能障碍标准对冠心病的检出率显著高于临床标准。结论舒张功能检查可作为冠心病诊断的初筛检查。     

兔膝关节持续被动活动对前交叉韧带重建术后切口局部组织血氧饱和度的影响

目的 探讨膝关节持续被动活动（continuous passive motion, CPM）对兔前交叉韧带重建术后切口局部组织血氧饱和度的影响. 方法 20 只八月龄雄性新西兰大白兔右侧后肢膝关节行自体双股半腱肌腱移植重建前交叉韧带手术,术后随机分为2组：自由活动组（n＝10）和CPM组（n＝10）.自由活动组笼内自由活动;CPM组应用兔膝关节持续被动活动器运动.术后第2天,近红外光技术装置ODISseyTM 局部组织血氧监护仪测量每一来回（屈曲30°～110°）不同CPM速度（分别为2.35°/s、3.2°/s 、8°/s）时的切口局部组织血氧饱和度（tissue oxygen saturation ,StO2）变化,选择最好的CPM范围和速度.分别在术前和术后第2、4、6、8、10、14天观察膝关节CPM不同角度时切口局部组织StO2的变化. 结果 与自由活动组相比,3种速度的CPM在不同屈曲角度下均保持较高的StO2,且有显著性差异（P＜0.05）,不同CPM速度之间StO2有显著性差异（P＜0.05）.每一来回（屈曲30°～110°）运动速度为3.2°/s时保持最高的StO2.在术前和术后第2、4、6、8、10、14天等各时间点,膝关节屈曲30°、60°、90°、110°时StO2均无显著性差异（P＞0.05）,不同的时间点（术前和术后第2、4、6、8、10、14天）切口的StO2差别均有显著统计学意义（P＜0.05）.术后第2～4天最低,然后逐渐上升.术后第2周拆线后,切口愈合良好,没有感染、血肿和切口裂开. 结论 兔膝前交叉韧带重建术后第2天开始进行膝关节CPM（屈曲30°～110°）,可增加切口局部组织血氧饱和度,以3.2°/s的CPM速度最佳.     

An automated on-line method for simultaneous analysis of phenothiazines in human serum by high-performance liquid chromatography/sonic spray ionization mass spectrometry using backflush column switching

An automated on-line method for simultaneous analysis of five phenothiazine drugs by high-performance liquid chromatography (HPLC)/sonic spray ionization mass spectrometry (SSI-MS) has been established, using backflush column switching. A 400-μl portion of serum sample diluted 81-fold with distilled water was subjected to the on-line system. In the system, an Oasis HLB cartridge was used as the precolumn for extraction; large molecules such as proteins in serum were discarded by use of distilled water containing 0.1% formic acid as a mobile phase. After switching a valve, the analytes trapped in the precolumn were eluted in the backflush mode and separated by a Chromolith Performance RP-18e column, which is composed of C₁₈-bonded monolithic silica. The column effluents were then introduced into the SSI-MS. The present method provided successful separation and determination of six phenothiazines including an internal standard. Satisfactory linearities, reproducibility, and sensitivity were obtained at concentration levels that matched the toxic levels of phenothiazines. All drug peaks appeared within 18 min, and the system could be reequilibrated in only about 8 min for the next run. Because of the simplicity and rapidness of the method, it is likely to be useful in the fields of emergency medicine and forensic toxicology.     

退变腰椎间盘髓核细胞立体培养与单层培养的生物活性比较

目的：比较体外单层培养和旋转微载体立体培养人退变腰椎间盘髓核细胞的生物学活性指标,探讨更加有效的椎间盘髓核细胞体外培养方法.方法：对获取的腰椎间盘突出症患者的24个椎间盘按年龄分为A组（20～25 岁）、B组（26～30 岁）、C组（36～45 岁）及D组（＞45岁）,分别利用酶消化法进行单层细胞培养和旋转微载体立体培养系统进行立体培养,观察细胞生长形态,检测细胞生长曲线及速度、细胞生长活性、细胞分裂指数及胶原含量.结果：单层培养的髓核细胞贴壁后为多角形或梭形,伸出伪足;立体培养的细胞在微载体上呈梭形或不规则形,呈立体状生长.立体培养的细胞生长速度较快,1周内两种培养方法各时间点及各组间比较均具有统计学意义（P＜0.05）.立体培养的髓核细胞活性提高,随年龄增加细胞活性下降;指数生长期细胞分裂指数与单层培养相比有统计学意义（P＜0.05）;Ⅰ、Ⅱ型胶原含量与单层培养相比有统计学意义（P＜0.05）,A组分别与B组、C组及D组比较均有统计学意义（P＜0.05）.结论：旋转立体培养人退变椎间盘髓核细胞的活性保持良好,较单层培养能够大量、优质收集种子细胞,可用于椎间盘组织工程中种子细胞的研究.     

术前无创正压通气治疗对脊柱侧凸患者围手术期肺功能的影响

目的:研究术前使用呼吸机无创正压通气治疗对脊柱侧凸患者围手术期肺功能的影响。方法:将40例Cobb角≥60°、肺功能存在中度以上限制性通气功能障碍、行脊柱侧凸矫形术的脊柱侧凸患者,随机分成A组和B组,每组20例。A组在术前采用BiPAP呼吸机,经用面罩无创正压通气(NIPPV)治疗1个月;B组常规术前准备。观察A组患者治疗前后肺功能的改善及两组患者围手术期肺功能的差异。结果:两组患者性别、年龄、身高、体重、Cobb角度、手术时间、手术径路、融合椎体数等基本情况比较无统计学差异(P>0.05);A组患者经NIPPV治疗后肺活量(VC)、肺活量占预计值的百分比(VC%)、用力肺活量(FVC)、第一秒最大呼气量(FEV1.0)、最大通气量(MVV)和最大通气量占预计值的百分比(MVV%)较治疗前明显改善(P<0.01);两组患者术中氧合指数、术后拔管时间、拔管后15min动脉血气PO2、PCO2比较有显著性差异(P<0.05)。结论:术前无创正压通气治疗可改善脊柱侧凸患者围手术期的肺功能,可缩短手术后气管插管的拔管时间,改善术后通气功能,有助于脊柱侧凸患者手术后早期恢复。     

SOLIS在颈椎前路融合术中的应用

目的 探讨新型颈椎前路融合器(SOLIS)在颈椎前路融合术中的应用效果.方法 对18例脊髓型颈椎病、12例颈椎间盘突出症采用颈椎前路减压融合术,小切口入路(3～4 cm),椎间盘及部分椎体后缘切除后保留椎体终板,植人带自体松质骨的SOLIS.以手术前后X线片及JOA评分评价疗效.结果 30例随访6～18个月,平均12.5个月.置人的SOLIS位置良好,无移动及脱出迹象;病变椎间隙高度恢复正常,未见椎间高度丢失;所有节段均于术后3～8个月骨性融合.术前JOA评分平均10.4分,术后平均14.9分,两者有统计学意义(P＜0.01).结论 颈椎前路融合器SOLIS具有良好的生物相容性,手术创伤小,能有效地恢复颈椎高度,融合率高,融合后稳定性好,神经功能改善优良率高.