Angiotensin II stimulates calcineurin activity in proximal tubule epithelia through AT-1 receptor-mediated tyrosine phosphorylation of the PLC-gamma1 isoform

Angiotensin II (AngII) contributes to the maintenance of extracellular fluid volume by regulating sodium transport in the nephron. In nonepithelial cells, activation of phospholipase C (PLC) by AT-1 receptors stimulates the generation of 1,4,5-trisphosphate (IP(3)) and the release of intracellular calcium. Calcineurin, a serine-threonine phosphatase, is activated by calcium and calmodulin, and both PLC and calcineurin have been linked to sodium transport in the proximal tubule. An examination of whether AngII activates calcineurin in a model of proximal tubule epithelia (LLC-PK1 cells) was performed; AngII increased calcineurin activity within 30 s. An examination of whether AngII activates PLC in proximal tubule epithelia was also performed after first showing that all three families of PLC isoforms are present in LLC-PK1 cells. Application of AngII increased IP(3) generation by 60% within 15 s, which coincided with AngII-induced tyrosine phosphorylation of the PLC-gamma1 isoform also observed at 15 s. AngII-induced tyrosine phosphorylation was blocked by the AT-1 receptor antagonist, Losartan. Subsequently, an inhibitor of tyrosine phosphorylation blocked the AngII-induced activation of calcineurin, as did coincubation with an inhibitor of PLC activity and with an antagonist of the AT-1 receptor. It is therefore concluded that AngII stimulates calcineurin phosphatase activity in proximal tubule epithelial cells through a mechanism involving AT-1 receptor-mediated tyrosine phosphorylation of the PLC isoform.     

尿液端粒酶活性在膀胱癌诊断和监测复发中的意义

目的　探讨检测尿液中端粒酶活性在膀胱癌诊断和监测复发中的意义。　方法　采用PCR ELISA法检测 4 6例膀胱癌患者尿液中的端粒酶活性 ,并观察其中 2 0例术后尿液端粒酶活性变化及与复发的关系。　结果　膀胱癌患者术前尿液端粒酶活性 0 .6 0± 0 .5 6 ,明显高于对照组 0 .18± 0 .0 8,P <0 .0 0 1,肿瘤切除后恢复正常 ,肿瘤复发前再次上升 ;端粒酶活性随肿瘤恶性程度的增加逐渐升高 ;术前端粒酶活性与早期复发无关。　结论　尿液端粒酶活性检测在膀胱癌诊断中有参考价值 ,与膀胱癌恶性程度相关 ,可能成为监测肿瘤复发的重要辅助手段。     

人精子质膜孕激素受体研究

目的 :观察人精子表面孕激素受体 (PR)的定位及阳性表达率。　方法 :精子体外获能后 ,应用异硫氰酸荧光素标记的牛血清白蛋白 孕酮复合物 (P BSA FITC)染色 ,荧光显微镜观察及流式细胞术 (FCM )定量分析法 ,分别观察与孕酮 (P)结合精子形态及标记精子所占比例。　结果 :P BSA FITC染色精子的形态主要表现为 2种类型 :整个顶体区域或仅赤道区呈绿色荧光 ,顶体后区及尾部不着色。与P结合精子的百分率为 (30 2± 2 4 ) %。　结论 :人精子顶体表面有PR表达 ,且这种表达呈选择性     

Combined Application of Blocking Antibodies and MicroRNA Interference in Inhibiting CD44 Expression

Background

We sought to explore the effect of CD44 targeting on the tolerance to memory cell-mediated graft rejection.

Methods

We developed a cardiac transplantation model in nude mice and administered anti-CD44 monoclonal antibodies (mAbs) to these mice. Then, we used anti-CD44 mAb and CD44-interfering microRNA (miRNA) to inhibit CD44 expression in vitro.

Results

The median survival time (MST) associated with multiple intraperitoneal injections was >100 days, whereas that associated with CD4⁺ Tm cells blocked CD44 and that associated with a single intraperitoneal injection of anti-CD44 mAb was 11 and 10.3 days, control group was 5.5 days. The inhibition effect of the anti-CD44 mAb in 3T3 cells significantly reduced with cell proliferation. Used CD44 miRNA in 3T3 cells, the most obvious inhibition effect of mRNA appeared at 48 hours after transfection and the inhibition decreased subsequently. In combination, antibody-mediated blocking and miRNA showed some synergistic effects.

Conclusion

The inhibition of CD44 can significantly prolong the MST in memory models. The inhibition effect of combined application showed limitations with regard to cell proliferation and duration of action, but the short-term synergistic effect of the combined approach was stronger than the effects of individual approaches.     

32例十二指肠外瘘的营养支持

目的 总结十二指肠外瘘的营养治疗经验.方法 对1999年1月至2009年12月间收治的32例十二指肠外瘘患者的临床资料进行回顾性分析.结果 32例患者平均接受35.6（8～82） d的营养支持疗法,其中8例接受全肠外营养支持（TPN）,2例接受全肠内营养支持（TEN）,22例接受肠外肠内联合营养支持（PN加EN）.11例患者进行了肠液回输;28例予以谷氨酰胺强化;22例肠瘘初期加用了生长抑素.本组24例十二指肠外瘘患者经非手术治愈,自然愈合率为75.0%;8例接受手术,治愈6例,死亡2例（分别死于严重腹腔感染和多系统器官衰竭）;共计30例患者痊愈出院.结论 肠外肠内营养支持结合肠液回输、强化谷氨酰胺、生长抑素等措施,可促进十二指肠外瘘愈合.     

前交叉韧带重建术后骨隧道扩大的产生及转归的MRI随访结果

目的 观察前交叉韧带重建术后骨隧道扩大的发生及随时间的演变。方法 对58例（58膝）接受自体胭绳肌腱移植、挤压螺钉固定的前交叉韧带重建病例进行了2年随访。于术后1、3、6、12和24个月分别进行患肢MRI检查,测量矢状位股骨隧道和胫骨隧道的宽度并与术后1个月数值进行比较,增宽≥2mm为隧道扩大。记录骨隧道扩大出现的时间及不同时间段隧道宽度的改变。结果9膝（15．5％）出现股骨隧道扩大,12膝（20．7％）出现胫骨隧道扩大。2膝术后3个月内出现扩大,16膝3～6个月出现扩大,3膝6～12个月出现扩大。隧道扩大的病例术后1、3个月隧道宽度比较差异无统计学意义（P〉0．05）,术后6、12、24个月隧道宽度大于1、3个月（P〈0．05）,而6、12和24个月之间隧道宽度比较差异无统计学意义（P〉0．05）。结论 前交叉韧带重建术后骨隧道扩大主要出现于术后3～6个月之间,并在术后12～24个月保持稳定。     

增加胫骨平台后倾角度、后交叉韧带部分松解对全膝关节置换术后膝关节运动影响的实验研究

目的通过增加胫骨平台后倾角度或后交叉韧带（PCL）部分松解对全膝关节置换术（TKA）中屈曲间隙过紧进行处理,分析这两种方法对TKA术后膝关节运动学的影响。方法测量6例新鲜尸体膝关节标本在完整状态下、正常TKA、屈曲间隙过紧、增加胫骨平台后倾角以及PCL部分松解TKA术后膝关节屈曲0°、30°、60°、90°、120°时的前后松弛度、内外翻松弛度、旋转松弛度及最大屈曲度。结果屈曲过紧TKA与正常TKA相比,在屈曲30°、60°、90°和120°时前后松弛度、内外翻松弛度及旋转松弛度均显著较小（P〈0．05）。与屈曲过紧TKA相比,增加胫骨后倾角后,在屈曲30°、60°、90°和120°时前后松弛度、内外翻松弛度和旋转松弛度均明显增大（P〈0．05）。PCL部分松解与屈曲过紧TKA相比,在屈曲30°、60°、90°和120°时前后松弛度明显增加（P〈0．05）;旋转松弛度在屈曲30°、60°、90°时明显增加（P〈0．05）。与PCL部分松解相比,增加胫骨后倾角的内外翻松弛度在屈曲30°、60°、90°时明显较大（P〈0．05）;旋转松弛度在屈曲0°、30°、60°和90°时明显较大（P〈0．05）。屈曲过紧TKA的最大屈曲度（120．4°）与正常TKA（130．3°）及增加胫骨后倾角（131．1°）相比明显较小（P〈0．05）。增加后倾角与PCL部分松解（124．0°）相比,最大屈曲度较大,但差异无统计学意义（P=0．0816）。结论屈曲间隙过紧TKA术后膝关节的前后松弛度、内外翻松弛度、旋转松弛度和最大屈曲度均减小;增加胫骨平台后倾角后,前后松弛度、内外翻松弛度、旋转松弛度和最大屈曲度均明显增大;PCL部分松解仅能明显增大前后松弛度。因此对于TKA术中屈曲紧张的膝关节,增加胫骨平台后倾角比PCL部分松解能更好地改善膝关节的运动学。     

60岁以上男性多支冠状动脉病变旁路移植术后血流动力学研究

目的研究60岁以上男性多支冠状动脉病变旁路移植术后早期血流动力学的变化。方法对20例60岁以上男性体外循环下多支冠状动脉病变旁路移植术患者术前及术后血流动力学变化进行监测。结果术后2～6小时心脏指数（CI）、每搏指数（SVI）明显降低（P〈0.05）,肺循环指数（PVRI）、体循环指数（SVRI）明显升高（P〈0.05）;24～48小时后心功能明显改善,CI、左室每搏做功指数（LVSWI）明显增高（P〈0.05）。结论多支冠状动脉病变旁路移植术后早期CI明显下降,术后24小时内应有效降低体循环阻力,以降低左心室后负荷并以此增强左心室收缩功能及心排出量     

Factors associated with early mortality after cervical spinal cord injury

Background

A relatively high early mortality rate (<30 days post-injury) for cervical spinal cord injury (SCI) has been observed.

Objective

To investigate this early mortality rate observed after cervical SCI and analyze the associated influential factors.

Methods

Medical records for 1163 patients with cervical SCI were reviewed, and the number of patients with early mortality was documented. Through logistic regression analysis, the effects of age, gender, occupation, cause of injury, severity of injury, highest involved spinal cord segment, nutritional condition during hospitalization, surgical treatment, tracheotomy, etc., on early mortality were assessed. Implementation of early treatment (i.e. surgery, tracheotomy, and nutritional support) and its effect on patient prognosis were also analyzed.

Results

Early mortality occurred in 109 of 1163 patients (9.4%). Four factors affected the early mortality rate, including level and severity of SCI, whether or not surgery was performed, the time interval between SCI and surgery, malnutrition, and tracheotomy. Patients with an American Spinal Injury Association grade of A, a high cervical SCI (C1–C3), and/or no surgical intervention were statistically more likely to have early mortality (P < 0.001).

Conclusion

Severe cervical SCI, upper-level cervical cord injury, malnutrition, and inappropriate tracheotomy are risk factors for early mortality in patients with cervical SCI. Surgery can reduce early mortality. Early tracheotomy should be performed in patients with complete upper-level cervical SCI, but patients with incomplete cervical SCI or complete low-level cervical SCI should initially be treated surgically to maintain smooth airway flow.     

Performance evaluation of microPET: a high-resolution lutetium oxyorthosilicate PET scanner for animal imaging.

A new dedicated PET scanner, microPET, was designed and developed at the University of California, Los Angeles, for imaging small laboratory animals. The goal was to provide a compact system with superior spatial resolution at a fraction of the cost of a clinical PET scanner. METHODS: The system uses fiberoptic readout of individually cut lutetium oxyorthosilicate (LSO) crystals to achieve high spatial resolution. Each microPET detector consists of an 8 x 8 array of 2 x 2 x 10-mm LSO scintillation crystals that are coupled to a 64-channel photomultiplier tube by optical fibers. The tomograph consists of 30 detectors in a continuous ring with a 17.2-cm diameter and fields of view (FOVs) of 11.25 cm in the transaxial direction and 1.8 cm in the axial direction. The system has eight crystal rings and no interplane septa. It operates exclusively in the three-dimensional mode and has an electronically controlled bed that is capable of wobbling with a radius of 300 microm. We describe the performance of the tomograph in terms of its spatial, energy and timing resolution, as well as its sensitivity and counting-rate performance. We also illustrate its overall imaging performance with phantom and animal studies that demonstrate the potential applications of this device to biomedical research. RESULTS: Images reconstructed with three-dimensional filtered backprojection show a spatial resolution of 1.8 mm at the center of the FOV (CFOV), which remains <2.5 mm for the central 5 cm of the transaxial FOV. The resulting volumetric resolution of the system is <8 microL. The absolute system sensitivity measured with a 0.74 MBq (20 microCi) 68Ge point source at the CFOV is 5.62 Hz/kBq. The maximum noise equivalent counting rate obtained with a 6.4-cm diameter cylinder spanning the central 56% of the FOV is 10 kcps, whereas the scatter fraction is 37% at the CFOV for an energy window of 250-650 keV and the same diameter cylinder. CONCLUSION: This is the first PET scanner to use the new scintillator LSO and uses a novel detector design to achieve high volumetric spatial resolution. The combination of imaging characteristics of this prototype system (resolution, sensitivity, counting-rate performance and scatter fraction) opens up new possibilities in the study of animal models with PET.