Expectant management of deep cerebral venous thrombosis with intraventricular hemorrhage

Limited randomized clinical trial data favor the use of anticoagulation in patients with cerebral venous thrombosis. We present a patient with deep cerebral venous thrombosis in whom anticoagulation was withheld because of coexistent intraventricular hemorrhage. She had a benign clinical course without anticoagulation, suggesting that close observation may be a management option in these patients.     

Complicated transseptal puncture during intervention catheter ablation on atrial fibrillation concomitant with straight back syndrome

Straight back syndrome (SBS) is a thoracic deformity with absence of upper thoracic spine kyphosis and heart compression. The anatomic abnormity of SBS may raise the difficulty of introcardial operation and increase the complicated risk of intervention performance. Here we report a case of SBS with complicated transseptal puncture during intervention catheter ablation of atrial fibrillation.     

模特征对伴单侧坐骨神经痛的腰椎间盘突出症的诊断价值

目的：介绍与验证一种反映腰椎间盘突出伴单侧坐骨神经痛的体征——模特征。方法：选取72例经腰椎MRI证实有腰椎间盘突出（L4，532例，L5／S1 40例）并伴单侧坐骨神经痛的患者，男49例，女23例，年龄32～68岁，平均50．7岁。每例患者人院当日由两位医师间隔2h分别检查，患者背对检查者，嘱其取最能缓解坐骨神经痛的站立姿势，若患者出现患侧屈髋屈膝、骨盆倾向患侧的姿势，记为“模特征阳性”，否则记为“模特征阴性”。同时行直腿抬高试验（SLR），阳性患者记录诱发下肢放射痛的最小角度。结果：70例患者两检查者结果完全相同，其中阳性60例，阴性10例，敏感性为85．7％；仅2例患者两检查者结果不一致，重复性97．2％。SLR均为阳性。结论：模特征是诊断伴单侧坐骨神经痛腰椎间盘突出症的简单、敏感的临床体征。     

显微镜下直切口锁孔微创治疗高血压性脑出血

目的探讨显微镜下直切口锁孔微创治疗高血压性脑出血的价值。方法根据CT提示血肿在头皮的投影设计手术切口部位，通过4～5cm皮肤直切口，直径2cm的骨窗，切开皮层到达血肿腔清除血肿。结果血肿完全清除17例，18例清除率达到90％，4例清除率达到80％。术后再出血2例。4例术后3周内死亡：2例死于循环呼吸功能衰竭，1例死于脑干功能衰竭，1例死于消化道出血，手术死亡率10．2％（4／39）。35例随访0．5—3年，平均2．1年，术后6个月ADL分级：1级9例，2级12例，3级9例，4级4例，5级1例，死亡4例。结论显微镜下直切口锁孔微创技术是一种快速、有效和安全的治疗高血压性脑出血的手术方法，可以解除血肿的占位压迫效应，有效止血，防止再出血，效果满意。     

人体对预先暴露-1,-0.5,0 Gz之后+Gz时的心血管反应

目的: 评价推拉动作的心血管反应性及推拉效应的发生机制. 方法: 17名健康体检现役歼击机飞行员被分别暴露于9次头高位倾斜(HUT,+1 Gz)→头低位倾斜(HDT,-1 Gz,-0.5 Gz,0 Gz)→HUT,随机顺序. 在下列条件下进行:+90° HUT 2 min,随后转为-90°, -30°, 0° HDT各30 s,随后转为+90° HUT 2 min. 床体旋转速度为45°*s-1. 间隔4 s监测一次血压(收缩压、舒张压和平均动脉压),实时监测心电图. 结果: 在HDT期间,心率和血压较基础HUT明显下降. 随后HUT,心率和血压上升,但与基础HUT比较其速度和幅度变小. -0.5 Gz和0 Gz血压较-1 Gz时明显升高. 结论: 在推拉动作小于+1 Gz时相由于颈动脉窦压力感受器的作用,导致反射性交感神经抑制、副交感神经兴奋,在其后的+Gz时相,这种交感-副交感神经兴奋性转换延迟,导致对其后+Gz的心血管反应性延迟. 这可能是推拉效应的发生机制之一.     

Chronology of the push pull effect on nonhuman primates—shift of the arterial pressure threshold

Fighter pilots are frequently exposed to high Gz acceleration which may induce in-flight loss of consciousness (G-LOC). One factor reducing tolerance to accelerations is a previous exposure to negative accelerations. This phenomenon, which happens during the first few seconds after the onset of the positive plateau, is called the push pull effect. Our goal was to validate a non human primate model in order to study push pull physiological mechanisms and possible changes in arterial pressure, which may occur after the first ten seconds of the positive acceleration plateau. Eight rhesus monkeys were centrifuged in profile runs, including positive Gz accelerations (+1.4, +2 and +3 Gz) with or without previous negative Gz acceleration (–2 and –3 Gz vs. +1.4 Gz). Heart rate, blood pressure and esophageal pressure were recorded during the entire centrifugation run. Results showed that the push pull effect was observed in the non human primate model. Moreover, the reduced tolerance to acceleration lingered longer than that during the first ten seconds after exposure to +Gz acceleration. It was found that, after the fourteenth second, mean blood arterial pressure stabilizes at a lower value, when the positive acceleration is preceded by a negative acceleration (15.8 kPa for –1 Gz and 15.5 for –2 Gz vs. 16.9 for 1.4 Gz). The chronology of the push pull effect seems to involve two periods. One has a short time span. The other one has a longer time span and could be induced by shift of pressure threshold, coming from exposure to previous negative acceleration.     

Enhanced activity of GABA receptors inhibits glutamate release induced by focal cerebral ischemia in rat striatum

Cerebral ischemia causes an excess release of glutamate, which can injure neurons. The striatum is one of the important regions vulnerable to hypoxia and ischemia. Using push–pull perfusion technique, we investigated the regulatory role of γ-aminobutyric acid (GABA) and its receptors in modifying the amount of glutamate in rat striatum with ischemia. Perfusion with exogenous GABA (1 mM) inhibited cerebral ischemia-induced glutamate release by as much as 47%. We further characterized relative roles of subtype receptors of GABA on glutamate release by using pharmacological tools. While baclofen (500 μM), a GABA_B receptor agonist, suppressed ischemia-induced glutamate release by 52%, GABA_B receptor antagonist saclofen (500 μM) failed to produce a significant increase of glutamate release. The GABA_A receptor agonist muscimol (500 μM) also reduced by 38% the release of glutamate induced by cerebral ischemia but the GABA_A receptor antagonist bicuculline (500 μM) had very little effect. The present study demonstrates that the excessive release of glutamate or the overly activated glutamate receptor, triggered by cerebral ischemia, can be down-regulated by exogenous GABA or by increased activity of GABA receptors, especially the presynaptic GABA_B receptors, which might be one of the important mechanisms to protect against striatum neuronal damage from over stimulation by excessive glutamate during ischemia.     

旋转床模拟推拉动作对脑循环功能的影响

目的 探讨推拉动作对脑血管循环功能的影响及推拉效应的＋ＧＺ下降机制。方法１０名被试者在旋转床上经受“直立位－倒立位－直立位”Ｒ 模拟推拉动作,采用网谱勒（ＴＣＤ）技术监测分析旋转床模拟推拉脑血流速度及脉动参数的变化。结果 倒立位时出现收缩期流速增加、舒张期流速降低、脉动参数ＰＩ与ＲＩ升高的阻力增高型频谱,随后直立位时,这些变化更加明显且恢复较慢。在实验过程中平均血流速度没有显著变化。结论在推拉动作     

一种尖牙控轴直丝托槽的结构设计

目的 设计一种用于错畸形的正畸治疗的新型托槽——尖牙控轴直丝托槽,对其结构设计和应用原理进行探讨分析.方法 定性设计矫治器的结构,托槽两个对角旋转翼与另两个对角翼可以通过旋转轴发生转动,能灵活选择放入弓丝前不锈钢丝结扎托槽与放入弓丝后弹性结扎托槽等结扎方式.结果 设计出一种尖牙正畸控轴直丝托槽,其特征是两对角托槽翼与另两个对角翼可以通过旋转轴发生转动,从而改变托槽槽沟的高度及宽度.结论 使用尖牙控轴托槽时,可以通过结扎尖牙控轴托槽的合龈翼来选择采取不同的矫治系统.     

高角安氏Ⅱ类1分类拔牙患者的临床治疗

目的 通过细丝弓技术在高角安氏Ⅱ类1分类拔牙患者直丝弓矫治中的应用,探讨其矫治前后软硬组织的变化,为临床正畸设计和矫治提供参考.方法 本研究采用回顾性的研究方法,以符合纳入标准的17例正畸患者为研究对象矫治前后拍摄头颅侧位定位片,对头影测量结果应用SPSS15.0软件进行统计分析.结果 17例高角安氏Ⅱ类1分类错(牙合)患者矫治结束后,磨牙和尖牙关系中性,覆(牙合)覆盖正常.正畸治疗后矢状向ANB角减小1.18°,U1-NA角减小19.13°,L1-NB角减小6.42°,L1-MP角减小5.28°,颏突度增加0.46mm,颏倾斜度减小3.99°,有统计学意义.垂直向OP-MP角减小0.19°,L6-MP距增加0.98 mm,有统计学意义,而上、下颌切牙和上磨牙垂直变化无统计学意义.矫治后软组织侧貌明显改善,面型角减小4.56°,鼻唇角增加16.48°,上、下唇突点距离审美平面减小4.93 mm和3.99 mm,PosB’-FH角增加6.88°,有统计学意义.结论 高角安氏Ⅱ类1分类患者拔除四颗第一双尖牙,采用直丝弓矫治器矫治,矫治过程中应用细丝弓矫治技术可以对患者矢状向和垂直向达到良好的支抗控制,矫治后软组织侧貌明显改善.