Effects of acute liver injury on blood coagulation

Summary.  The mechanisms leading to the hemostatic changes of acute liver injury are poorly understood. To study these further we have assessed coagulation and immune changes in patients with acute paracetamol overdose and compared the results to patients with chronic cirrhosis and normal healthy controls. The results demonstrate that in paracetamol overdose coagulation factors (F)II, V, VII and X were reduced to a similar degree and were significantly lower than FIX and FXI (mean levels 0.28, 0.16, 0.13, 0.19, 0.51 and 0.72 IU mL⁻¹, respectively). In cirrhosis, by contrast, FII, FV, FVII, FIX and FX were equally reduced whilst FXI was lower than the other factors (mean levels 0.64, 0.69, 0.62, 0.60, 0.66 and 0.40 IU mL⁻¹, respectively). FVIII was raised in paracetamol overdose patients but normal in those with cirrhosis (mean levels 1.95 and 1.01 IU mL⁻¹, respectively). Interleukin-6 and tumor necrosis factor-α levels were raised in both patient groups, but higher levels were found in paracetamol overdose, compared to cirrhosis. Thrombin-antithrombin and soluble tissue factor levels were higher in those with acute liver injury but normal in cirrhosis. Antithrombin levels were reduced in both acute liver injury and cirrhosis. From these data we put forward a novel mechanism for the coagulation changes in acute paracetamol induced liver injury. We propose that immune activation leads to tissue factor-initiated consumption of FII, FV, FVII and FX, but that levels of FIX and FXI are better preserved because antithrombin inhibits the thrombin induced positive feedback loop that activates these latter factors.     

Prediction and Detection of Secondary Hemorrhages after Thrombolytic Therapy in Ischemic Stroke

Abstract It is well established that thrombolytic therapy increases the risk of secondary intracerebral hemorrhage in ischemic stroke patients. However, the term “intracerebral hemorrhage” (ICH) covers a wide spectrum from tiny spots of blood to massive space-occupying hematoma. We will review the etiology and clinical consequences of secondary hemorrhage after thrombolysis in ischemic stroke patients and discuss the ability of magnetic resonance imaging (MRI) to predict this phenomenon. MRI is a highly sensitive tool for detection of hemorrhagic transformation after ischemic stroke. The definitions of a so-called symptomatic hemorrhage after ischemic infarction differ considerably and will also be described. Attributing a causal relationship of a clinical deterioration to a secondary hemorrhage is not easy and should be only addressed when it exceeds at least 30% of the infarct volume. In other patients, secondary hemorrhage might be regarded as side effect of reperfusion within the region with the most severe perfusion deficit. Cerebral microbleeds (CMBs) are a frequent finding in patients with leukoaraiosis and appear to be a general marker of various types of bleeding- prone small vessel disease and a predictor of recurrent vascular events. Current data do not support the hypothesis that the detection of CMBs is a useful diagnostic criterion for the exclusion of patients with CMBs from thrombolytic therapy. However, an increased risk for the rare patients with numerous CMBs can not be ruled out.      

Kinetic modeling of PET-FDG in the brain without blood sampling

The aim in this work is to report a new method to calculate parametric images from a single scan acquisition with positron emission tomography (PET) and fluorodeoxyglucose (FDG) in the human brain without blood sampling. It is usually practical for research or clinical purposes to inject the patient in an isolated room and to start the PET acquisition only for some 10–20 min, about 30 min after FDG injection. In order to calculate the cerebral metabolic rates for glucose (CMRG), usually several blood samples are required. The proposed method considers the relation between the uptake of the tracer in the cerebellum as a reference tissue and the population based input curve. Similar results were obtained for CMRG values with the present method in comparison to the usual autoradiographic and the non-linear least squares fitting of regions of interest.     

丹参注射液治疗老年人急性脑梗塞时间窗的探讨

目的探讨丹参注射液治疗老年人急性脑梗塞的最佳时间窗.方法选择老年人急性脑梗塞患者120例,随机按发病后24～48小时、72～96小时、120～144小时初始给予丹参注射液,分成早治、中治、晚治3组,均给药4周,每日1次,其余常规治疗相同.结果4周和8周后观察疗效、神经功能缺损恢复程度,早治组均明显优于其余两组,但梗塞面积扩大或继发出血3组差异无显著性.结论丹参注射液最有效且安全的时间窗是梗塞后24～48小时内.     

机械通气治疗小儿急性肺损伤

目的：探讨小儿急性肺损伤(ALI)的临床治疗。方法：对本院综合ICU1998年4月至2002年4月发生的22例小儿ALI的临床治疗情况进行回顾性分析。结果：本组22例小儿ALI采用呼吸末正压机械通气(PEEP)联合大剂量甲基强的松龙冲击治疗，有效率为86．36％；3例死亡，死亡率为13．64％，死于多器官功能不全综合征(MODS)。结论：机械通气治疗小儿ALI应选择最佳PEEP，动态监测动脉血气指标和X线胸片，在综合治疗基础上加用大剂量甲基强的松龙冲击治疗能收到较好的疗效。     

移植肝缺血-再灌注损伤程度的评估及其与肝移植患者预后的关系

目的探讨移植肝缺血-再灌注损伤程度的评估方法及其与肝移植患者预后的关系。方法218例良性终末期肝病患者，在移植肝恢复血液灌注后1h采取外周静脉血，测定丙氨酸转氨酶浓度（定义为基础肝功能），同时采用组织气体分析仪测定肝组织的氧分压，并取肝组织活检，计算水变性及坏死细胞百分比，分别对上述3项指标进行评分，再根据各指标得分之和将缺血-再灌注损伤程度划分为5级（0～Ⅳ级），统计围手术期（术后2周内）、术后近期（术后2周至1个月）、术后中远期（1个月以上）的患者死亡率。结果移植肝缺血再灌注损伤程度评为0级者157例（A组），死亡7例（4．5％），71．4％（5／7）死于术后3-6个月；缺血-再灌注损伤程度评为Ⅰ级者25例（B组），死亡5例（20．0％），80．0％（4／5）死于术后2周至3个月；缺血-再灌注损伤程度评为Ⅱ级者23例（C组），死亡5例（21．7％），80．0％（4／5）死于术后2周至3个月；缺血-再灌注损伤程度评为Ⅲ级者8例（D组），死亡7例（87．5％），85．7％（6／7）死于术后1个月内；缺血-再灌注损伤程度评为Ⅳ级者5例（E组），全部死亡，80．0％（4／5）死于术后1个月内。A组各期死亡率明显低于B组、C组（P〈0．05）和D组、E组（P〈0．01）；B组、C组间各期死亡率的差异无统计学意义（P〉0．05）；B组、C组各期死亡率均低于D组、E组（P〈0．05）。结论基础肝功能、组织氧分压以及水变性和坏死细胞百分比三项指标可基本反映移植肝缺血-再灌注损伤程度；缺血-再灌注损伤评级达Ⅲ～Ⅳ级者术后死亡率较高。     

海水浸泡兔脑挫伤后caspase-8及caspase-3表达的研究

目的建立海水浸泡颅脑挫裂伤模型,观察海水浸泡对实验性脑挫裂伤后创伤性脑水肿的影响及研究兔脑挫伤后不同时间caspase-8及caspase-3表达的变化。方法采用立体定向自由落体伤模型进行持续海水浸泡作为实验组,对照组采用同样的方法致伤后不进行海水浸泡。观察创伤组织的病理改变,并通过免疫组化染色和计算机图像分析技术用半定量化的方法检测不同干预不同时程caspase-8和caspase-3的活性表达强弱差异。结果实验组和对照组均发生了创伤性脑水肿,但水肿高峰期出现时间不一致,严重程度也不一致。实验组caspase-8和caspase-3活性表达强度均高于对照组。结论海水浸泡促进了挫裂伤周边缺血水肿区神经细胞凋亡的增加。     

以失用为主要表现的胼胝体梗死

目的探讨胼胝体梗死的临床表现、病因及鉴别诊断特点。方法对2005年7月收治的1例53岁男性胼胝体梗死患者的临床表现、影像学特点、病因机制及其治疗过程进行回顾分析。结果临床主要表现为发作性黑蒙、言语不利,既往有高血压、糖尿病、脑梗死、吸烟、饮酒史,体格检查以失用为主要表现。头部MRI检查可见左侧脑室旁、胼胝体梗死,右侧基底节、脑桥陈旧性腔隙性梗死;脑血管造影检查显示为多发性血管狭窄,其中以左侧大脑中动脉、右侧颈内动脉及基底动脉最为严重。经颈内动脉内膜剥离术及颈内动脉支架植入术治疗,临床症状缓解。结论失用可以是胼胝体梗死的主要表现,其病因是在脑动脉粥样硬化基础上的血流动力学改变,患者预后良好。