脑出血患者血肿周围组织病理及超微结构变化的动态观察

目的观察脑出血患者血肿周围组织普通病理及超微结构的动态变化。方法对30例脑出血患者采取非功能区人颅直视手术，清除血肿前于血肿旁约1cm处取少许脑组织作为实验组，按发病到手术的时间分为6h以内组6例，6～12h组7例，12～24h组5例，24～48h组3例，48～72h组3例，3～4d组3例，5d组2例，8d组1例。从12h以内组中的7例患者于手术入颅路径上远离血肿处取少许脑组织作为对照组。应用光镜_硐J电镜观察脑组织普通病理及超微结构的动态变化。结果对照组脑组织形态和结构基本正常。实验组6h以内脑组织有轻微损伤。6h以后脑组织损伤逐渐加重。24～48h损伤达高峰，光镜显示脑细胞和纤维水肿明显，细胞形态不完整，核固缩，炎性细胞侵润明显；电镜显示神经元细胞核变空染色质聚集，线粒体肿胀，嵴变短或消失，核糖体减少，次级溶酶体增加，细胞变空，细胞膜不完整，胶质细胞核固缩。72h以后损伤逐渐好转，5d时损伤与6～12h组相似，8d时基本好转，与6h以内组基本接近。结论脑出血后血肿周围脑组织继发性损伤早期就有病理改变，损伤高峰在24～72h，与一般脑出血临床神经功能损害的变化规律基本一致。     

负荷量苯巴比妥预防新生儿缺氧缺血性脑病及颅内出血

观察重度窒息儿静注苯巴比妥预防新生儿缺氧缺血性脑病及颅内出血的效果。方法：选择本院产科出生的重度窦息儿６０例为观察对象,随机分为用药组和对照组各３０例。用药组转入我科后即给予苯巴比妥钠荷量２０ｍｇ／ｋｇ,１２小时后给予维持量５ｍｇ／ｋｇ．ｄ,共７天。     

大鼠脑出血后体感诱发电位的改变与脑水肿的形成

目的:使用体感诱发电位(SEP)对脑出血(ICH)模型进行评价,并观察ICH后不同时期脑水肿的形成过程。方法:采用脑立体定向术制备大鼠脑内囊出血的模型。观察大鼠在手术前及手术后不同时期内神经系统功能、SEP、脑组织形态学及脑组织含水量的改变。结果:与假手术组相比,实验组(6h、12h、1d、5d)、各波潜伏期延长(P<0.05),脑组织含水量增多(P<0.05);实验组(2d、3d)各波潜伏期明显延长(P<0.01),脑组织含水量明显增多(P<0.01);实验组(7d)各波潜伏期缩短(P>0.05),脑组织含水量减少(P>0.05)。脑组织形态学与神经系统功能呈现相应的改变。结论:SEP是评价脑立体定向术制备大鼠脑内囊出血模型的最客观指标,脑出血后脑水肿的形成是一个动态过程,SEP的改变与脑水肿的形成有直接的关系     

Higher Annual Operator Volume Is Associated With Better Reperfusion Rates in Stroke Patients Treated by Mechanical Thrombectomy: The ETIS Registry

Objectives

The aim of this study was to determine whether individual operator characteristics have an impact on reperfusion and procedural complication rates.

Medical Rehabilitation: Guidelines to Advance the Field With High-Impact Clinical Trials

The purpose of this Special Communication is to summarize guidelines and recommendations stemming from an expert panel convened by the National Institutes of Health, National Center for Medical Rehabilitation Research (NCMRR) for a workshop entitled The Future of Medical Rehabilitation Clinical Trials, held September 29-30, 2016, at the NCMRR offices in Bethesda, Maryland. The ultimate goal of both the workshop and this summary is to offer guidance on clinical trials design and operations to the medical rehabilitation research community, with the intent of maximizing the effect of future trials.     

The development and validation of methods for evaluating the immune system in preweaning piglets

The preweaning piglet has been found to be a valuable research model for testing ingredients used in infant formula. As part of the safety assessment, the neonates' immune system is an important component that has to be evaluated. In this study three concurrent strategies were developed to assess immune system status. The methods included (1) immunophenotying to assess circulating innate immune cell populations, (2) monitoring of circulating cytokines, particularly in response to a positive control agent, and (3) monitoring of localized gastrointestinal tissue cytokines using immunohistochemistry (IHC), particularly in response to a positive control agent. All assays were validated using white papers and regulatory guidance within a GLP environment. To validate the assays precision, accuracy and sample stability were evaluated as needed using a fit for purpose approach. In addition animals were treated with proinflammtory substances to detect a positive versus negative signal. In conclusion, these three methods were confirmed to be robust assays to evaluate the immune system and GIT-specific immune responses of preweaning piglets.     

Direct Oral Anticoagulants: New Drugs and New Concepts

Direct oral anticoagulants (DOACs) are approved for multiple thromboembolic disorders and provide advantages over existing agents. As with all anticoagulants, management protocols for the eventuality of bleeding are important. Randomized phase III studies generally show that DOACs have a similar risk of clinically relevant bleeding compared with standard anticoagulants, with reductions in major bleeding in some cases. This may be particularly important in patients with atrial fibrillation, for whom the rate of intracranial hemorrhage was approximately halved with DOACs compared with warfarin. Conversely, the risk of gastrointestinal bleeding may be increased. Specific patient characteristics, such as renal impairment, comedications, and particular aspects of each drug, including the proportion eliminated by the kidneys, must be taken into account when assessing the risk of bleeding. Although routine coagulation monitoring of DOACs is not required, it may be useful under some circumstances. Of the traditional clotting assays, a sensitive and calibrated prothrombin time may be useful for detecting the presence or absence of clinically relevant factor Xa inhibitor concentrations (rivaroxaban or apixaban), but specific anti–factor Xa assays can measure drug levels quantitatively. For dabigatran, the results of an activated partial thromboplastin time test may exclude a clinically relevant pharmacodynamic effect, but a calibrated dilute thrombin time assay can be used for quantification of drug levels. In the event of mild or moderate bleeding, normal hemostatic support measures are recommended. For life-threatening bleeding, use of nonspecific prohemostatic agents may be considered, although clinical evidence is scarce. Specific antidotes are in development.     

Comparison of the effect of edoxaban,a direct factor Xa inhibitor,with a direct thrombin inhibitor,melagatran, and heparin on intracerebral hemorrhage induced by collagenase in rats

Introduction

Intracerebral hemorrhage (ICH) is a major clinical concern with anticoagulation therapy. The effect of a new oral direct FXa inhibitor, edoxaban, was determined in a rat model of ICH and compared with a direct thrombin inhibitor, melagatran, and heparin.

Methods

To induce ICH, 0.1 U collagenase type VII was injected into the striatum of male Wistar rats under anesthesia with thiopental or halothane. Immediately after ICH induction, edoxaban, melagatran, or heparin were infused intravenously. Five hours after ICH induction, the brain was removed and ICH size was measured. To estimate the margin of safety, antithrombotic effects were evaluated in a rat venous thrombosis model.

Results

Edoxaban at 6 mg/kg/h significantly increased ICH volume (1.8-fold) and prolonged prothrombin time (PT) 2.8-fold compared to the vehicle group. No deaths were observed with edoxaban. Melagatran at 1 mg/kg/h increased ICH volume at 1 mg/kg/h (2.8-fold) with 6.1-fold PT prolongation. At 3 mg/kg/h, all rats died due to severe ICH (3.9-fold). Heparin at both 100 and 500 U/kg/h significantly increased ICH. At 500 U/kg/h, 5 out of 8 rats died. The doses required for 50% inhibition of thrombosis of edoxaban, melagatran, and heparin were 0.045 mg/kg/h, 0.14 mg/kg/h, and 55 U/kg/h, respectively. The safety margins between antithrombotic and ICH exacerbation effects of these anticoagulants were 133, 7.1, and 1.8, respectively.

Conclusion

The safety margin of edoxaban was wider than that of melagatran or heparin. These results suggest that edoxaban may be preferable from the perspective of ICH exacerbation risk.     

Lower dosage of recombinant tissue-type plasminogen activator (rt-PA) in the treatment of acute pulmonary embolism: A systematic review and meta-analysis

Background and Objective

According to US Food and Drugs Administration (FDA), 2 hour recombinant tissue plasminogen activator (rt-PA) 100 mg infusion is recommended for eligible patients with acute pulmonary embolism (PE). However,there exists evidence implying that a lower dosage of rt-PA can be equally effective but potentially safer compared with rt-PA 100 mg regimen. The aim of this systematic review and meta-analysis is to assess the efficacy and safety of low dose rt-PA in the treatment of acute PE.

Material and Method

We searched Pubmed, EMBASE, the Cochrane library and CBM Literature Database for randomized controlled trials (RCT) focusing on low dose rt-PA for acute PE. Outcomes were described in terms of changes of image tests and echocardiography, major bleeding events, all-cause death, and recurrence of PE.

Results

Five studies (440 patients) were included, three of which compared low dose rt-PA (0.6 mg/kg, maximum 50 mg or 50 mg infusion 2 h) with standard dose (100 mg infusion 2 h). There were more major bleeding events in standard dose rt-PA group than in low dose group (OR 0.33, 95%CI 0.12-0.91;P = 0.94,I² = 0%), while there were no statistical differences in recurrent PE or all cause mortality between these two groups. Two studies compared low dose (0.6 mg/kg, maximum 50 mg/2 min bolus or 10 mg bolus, ≤ 40 mg/2 h) with heparin. There was no significant difference in major bleeding events (OR 0.73, 95% CI 0.14-3.98;P = 0.72), recurrent PE or all cause mortality. No dose-related heterogeneity was found for all the included studies.

Conclusions

The results of this meta-analysis were hypothesis-generating. Based on the limited data, our systematic review suggested that low dose rt-PA had similar efficacy but was safer than standard dose of rt-PA. In addition, compared with heparin, low dose rt-PA didn’t increase the risk of major bleeding for eligible PE patients.