Extracellular signal regulated kinases 1/2 signal pathway and responses of astrocytes after diffuse brain injury

BACKGROUND: The treatment of diffuse brain injury during an acute period is focused on relieving degrees of secondary brain injury. Generation and development of pathological changes of secondary brain injury depend on signal conduction, so down-regulating over response of astrocyte through interfering a key link of signal conduction pathway may bring a new thinking for the treatment of diffuse brain injury. OBJECTIVE: To observe the effect of over activity of extracellular signal regulated kinases 1/2 (ERK1/2) signal pathway on the response of astrocyte during an acute period of diffuse brain injury. DESIGN: Completely randomized grouping and controlled animal study. SETTINGS: Department of Neurosurgery, the Third Affiliated Hospital, Nanchang University; Department of Neurosurgery, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology. MATERIALS: A total of 158 healthy male SD rats, of 11 weeks old, weighing 320–370 g, were provided by Experimental Animal Faulty, Tongji Medical College, Huazhong University of Science and Technology. Rabbit-anti-phosphorylated ERK1/2 (pERK1/2) polyclonal antibody was provided by R&D Company; rabbit-anti-glial fibrillary acidic protein (GFAP) polyclonal antibody, SP immunohistochemical kit and horseradish peroxidase (HRP)-labeled goat-anti-rabbit IgG by Santa Cruz Company; specific inhibitor U0126 of ERK1/2 signal pathway by Alexis Company. METHODS: The experiment was carried out in the Laboratory of Neurosurgery, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology from September 2004 to March 2006. ① Detection of pERK1/2 expression: A total of 110 rats were randomly divided into sham operation group (n =5), model group (n =35), high-dosage U0126 group (n =35) and low-dosage U0126 group (n =35). Rats in the sham operation group were only treated with incision of epicranium and fixation of backup plate, but not hit. Rats in the model group were used to establish diffuse brain injury models based on Marmarou free falling body without drug intervention. Rats in the high- and low-dosage U0126 groups were injected into caudal vein with 0.1 and 0.05 mg/kg U0126, respectively, and then, rats were hit to establish injured models. Every 5 rats were collected from model, high- and low-dosage U0126 groups at 5, 30 minutes, 3, 12, 24, 72 hours and 7 days after diffuse brain injury to detect pERK1/2 expression in cortex of parietal lobe based on Western blot technique. ② Distribution of pERK1/2 and positive GFAP cells in brain tissue: Another 48 rats were randomly divided into sham operation group (n =3), model group (n =15), high-dosage U0126 group (n =15) and low-dosage U0126 group (n =15). The intervention and administration were dealt as the same as those mentioned above. Every 3 rats were collected from model, high- and low-dosage U0126 groups at 30 minutes, 3, 12, 24 and 72 hours after model establishment to observe the distribution of pERK1/2 and postive GFAP cells in brain tissue which was cut from coronal section at Bregma –4.8 mm layer with immunohistochemical staining. MAIN OUTCOME MEASURES: pERK1/2 expression in cortex of parietal lobe and distribution of pERK1/2 and positive GFAP cells in brain tissues. RESULTS: ① pERK1/2 expression: After diffuse brain injury, pERK1/2 expression in cortex of parietal lobe was rapidly increased in the model group, reached at peak at 5 minutes and then decreased gradually. But the expression was still in a high level until the 72nd hour and fallen to the basic level on the 7th day. pERK1/2 level was lower in high- and low-dosage U0126 groups than that in model group at various time points (P < 0.01); meanwhile, pERK1/2 level was lower in high-dosage U0126 group than that in low-dosage U0126 group. The results showed that there was a certain dosage dependence on pERK1/2 expression. ② Distribution of pERK1/2 and positive GFAP cells in brain tissue: Positive expression of pERK1/2 lasted in brain tissue from 30 minutes to 72 hours after diffuse brain injury (P < 0.05). In addition, from 30 minutes to 3 hours, brown-yellow stained cells were mainly distributed in plasma, but rarely in nucleus. A lot of positive cells had tree-like apophysis, which was similar to neurons. With the time passing by, more and more nuclei manifested positive stains; moreover, nuclei mainly manifested positive staining until 24 hours after diffuse brain injury. Immune-positive pERK1/2 cells were widely distributed in brain tissue, especially mainly in binding site between deep cortex and cerebral white matter, and then in hippocampus. In addition, ependymal cell and vascular endothelial cells of choroids plexus also manifested strongly positive staining. As compared with model group, positive cells were decreased gradually in high- and low-dosage U0126 groups. However, number of positive cells was less in high-dosage U0126 group than that in low-dosage U0126 group. CONCLUSION: Diffuse brain injury strongly induces the activity of ERK1/2 signal pathway and response of astrocyte; in addition, U0126 can inhibit response of glial cells during an acute period, and the effect manifests dosage dependence.     

急性重型脑损伤患者脑组织氧代谢监测及意义

目的　探讨对急性重型脑损伤患者行脑组织氧代谢监测的临床意义。　方法对2 8例急性重型脑损伤患者 (均在全麻下急诊行血肿清除术和 (或 )去骨瓣减压术 )术中及术后持续进行脑组织氧代谢监测 ,观察脑组织氧分压 (PbtO2 )、二氧化碳分压 (PbtCO2 )和pH值 (pHbt)的变化。　结果　 (1) 2 8例脑外伤患者在剪开硬脑膜后PbtO2 、pHbt分别从 (13± 4 )mmHg、(6 .96± 0 .15 )增加至 (2 1± 5 )mmHg、7.0 5± 0 .12 (P <0 .0 5 ) ,PbtCO2 从 (6 1± 6 )mmHg下降至 (5 3± 5 )mmHg(P <0 .0 5 )。(2 )其中 2 4例脑外伤患者在血肿清除后 ,PbtO2 、pHbt值分别从 (2 1± 4 )mmHg、7.0 5± 0 .11增加至 (2 8± 6 )mmHg、7.15± 0 .10 (P <0 .0 5 ) ,PbtCO2 从 (5 2± 6 )mmHg下降至 (4 5± 4 )mmHg(P <0 .0 5 )。 (3)PbtO2 <10mmHg持续 30min以上的患者预后差。　结论　 (1)脑组织氧代谢监测是一种安全、可靠的监测手段 ,能直接动态反映脑组织的病理生理变化 ,及时发现脑组织缺血缺氧 ,以指导治疗。 (2 )持续进行脑组织氧代谢监测可判断重型脑外伤患者的预后。     

大鼠脊髓缺血再灌流时脊髓神经元对躯体和内脏传入刺激的反应

５０只大鼠用乌拉坦麻醉，箭毒制动。通过阻断腹主动脉血流以模拟腰段脊髓的局部缺血和再灌流损伤，玻璃微电极记录Ｌ２节段脊髓单位放电（ＳＣＵＤｓ），观察缺血再灌流时脊髓神经元对腓神经刺激（ＰＮＶ），内脏大神经刺激（ＶＬＮＶ）及两者同时刺激（ＳＶ）的反应。结果在缺血前所记录的１３３个自发放电单位中，对３种刺激均产生兴奋（Ｅ）、抑制（Ｉ）及无反应（ＮＲ）３种形式的反应，表明大鼠Ｌ２节段脊髓存在躯体、内脏和躯体内脏反应性神经元，并有会聚和阻塞现象。在脊髓缺血再灌流时，神经元对ＰＮＶ、ＶＬＮＶ、ＳＶ也产生Ｅ、Ｉ、ＮＲ３种形式的反应，提示脊髓缺血再灌流时神经元对躯体和内脏传入刺激的反应形式不受影响；但缺血时ＳＣＵＤｓ对ＰＮＶ、ＶＬＮＶ产生反应的单位数减少，这表明脊髓缺血损伤时神经元对躯体和内脏传入刺激的反应性减弱，随着缺血损伤加重，脊髓神经元对躯体内脏信号的整合功能下降     

Flexor digitorum profundus tendongrafting (extrasynovial donor tendons)

Although the prevalence of flexor tendon grafting has decreased since the early part of this century, the technique isstill an important part of a hand surgeons armamentarium. Primary and staged flexor tendon grafting are appropriate techniques used to restore digital function after failed or neglected repairs. Appropriate patient selection, meticulous reconstructive techniques, and respect for basic biological principles of healing and repair are essential elements for successful tendon grafting.     

维持肢体正常的运动感觉功能所需最少神经根数的实验研究

目的 研究臂丛神经根单发断，２根切断（不同方式联合）及３根切断后对肢体的影响，为治疗臂丛根性撕脱伤寻找更多的潜在移位神经，方法 ２５２只ＳＤ大鼠随机分为１３组：（１）第１－５组（单根神经根切断组）；每组１２只大鼠。分别切断Ｃ５－８Ｔ１各神经根；（２）第６－１２组（２根神经根切断组）；每组２４只大鼠。分别切断相邻及不相邻２根神经根，即Ｃ５，６，Ｃ６，７，Ｃ７，８，Ｃ８Ｔ１，Ｃ５，７，Ｃ６，８和Ｃ７Ｔ     

重型颅脑损伤持续颅内压及脑灌注压监护与预后关系

作者对５０例重型颅脑损伤患者（ＧＣＳ３－８分），及５０例伤情与诊断和手术方式基本相似的另一组患者进行颅内压（ＩＣＰ）与脑灌注压（ＣＣＰ）连续监测对比研究。结果表明，监护组除８例ＩＣＰ压力＜２．００ｋＰａ，ＣＰＰ＞９．３３ｋＰａ外，余４２例均有不同程度ＩＣＰ增高与ＣＰＰ降低。这些患者分别为创伤性颅内血肿、广泛性脑挫裂伤、继发性脑水肿或脑肿胀等，均采取积极的手术及综合治疗。死亡率为１４％。非监护组治疗方法与监护组相同，预后较差且并发症多，死亡率为２８％。作者认为，对重型颅脑损伤患者施行连续ＩＣＰ、ＣＰＰ监护，是降低并发症和死亡率，提高疗效的有力措施，具有重要的临床应用价值。     

周围性面神经损伤患者对侧神经支配的研究

目的　通过测定面神经损伤患者组及大学生志愿者组面神经各分支对侧神经支配率 ,探讨周围性面肌瘫痪恢复过程中面神经对侧代偿支配的问题。方法　分别测定大学生志愿者 2 2例( 2 2侧 )及 10 8例面神经损伤患者的面神经电图对其对侧神经支配率进行分析其中损伤组又按发病原因不同 ,分为医源性损伤组、Bell氏面瘫组和创伤性损伤组 ,测试损伤支数为Ⅰ支 76支 ,Ⅱ支 81支 ,Ⅲ支 88支 ,Ⅳ支 6 6支。结果　①损伤组 3组间对侧支配率差异无显著性 (P >0 0 5 ) ;②损伤组Ⅰ、Ⅱ支对侧支配率明显高于志愿者组 (P <0 0 0 1) ;③损伤组Ⅰ支对侧支配率明显高于Ⅱ支(P <0 0 0 1)。结论　面神经损伤后 ,存在对侧神经支配功能增强的表现     

Mandibular fracture not shown by axial computed tomography: Benefit of computed reformation

A 36-year-old man was brought to the emergency department after being assaulted. A mandible series showed a nondisplaced fracture through the angle of the mandible extending through the left third molar tooth. Axial slices from a nonhelical computed tomographic (CT) examination of the head as well as a helical CT examination of the mandible failed to demonstrate the fracture. The fracture was well shown, however, on sagittal CT reformations. Although CT is generally regarded as more sensitive than plain radiography for the detection of fractures, fractures may be overlooked by CT if examination in only one plane is performed.     

MR imaging evaluation of knee collateral ligaments and related injuries: Comparison of T1-weighted,T2-weighted,and fat-saturated T2-weighted sequences—correlation with clinical findings

The objectives of this study were to compare the ability of T1-weighted (T1W), proton density/T2-weighted (PD/T2W), and fat saturation (FS) PD/T2W magnetic resonance (MR) sequences for depiction of the knee collateral ligaments and related injuries, and to compare MR findings with clinical findings. Ten subjects with normal knee ligaments and 64 patients with suspected collateral ligament injuries underwent coronal T1W, PD/T2W, and FS PD/T2W imaging. Abnormalities ranged from edema surrounding the collateral ligaments (grade I) to complete disruption of ligamentous fibers (grade III). FS PD/T2W images improved definition of the medial collateral ligament (MCL) and lateral collateral ligament (LCL) compared with other sequences in 78% and 81% of patients, respectively. While the apparent grade of collateral ligament injury was similar with all pulse sequences in most patients, depiction of such injury was usually most conspicuous on FS PD/T2W images (MCL, 92% of patients; LCL, 38% of patients). In no patients were clinically diagnosed collateral ligament injuries undetected or understaged with MR imaging. MR findings indicated higher-grade MCL and LCL injuries than did clinical examination in 24 and 15 patients, respectively.