Protein kinase C in focal ischemic rat brain: dual autoradiographic analysis of [C]iodoantipyrine (IAP) and [H]phorbol-12,13-dibutyrate (PDBu)

Protein kinase C (PKC) activity was measured in rat brain with 2 h of middle cerebral artery (MCA) and common carotid artery (CCA) occlusion, using dual autoradiography of [¹⁴C]iodoantipyrine (IAP) and [³H]phorbol-12,13-dibutyrate (PDBu). In the ischemic brain, it required more than 120 min of incubation to obtain a plateau in PDBu binding. In contrast, the binding of PDBu in non-ischemic brain reached a plateau with incubation for 60 min. This delay of PDBu binding in the ischemic brain suggests that the affinity of this ligand is reduced due to a change in structure of the cell membrane caused by ischemia. PDBu binding in the ischemic brain increased significantly compared to the non-ischemic brain. This finding provides further evidence that excessive activation of PKC in the ischemic brain may play an important role in ischemic neuronal damage. ©1997 Elsevier Science B.V. All rights reserved.     

Semipermeable Hollow Fiber Membranes in Hepatocyte Bioreactors: A Prerequisite for a Successful Bioartificial Liver?

Abstract: Recent studies have shown that liver support systems based on viable hepatocytes can prolong life in animal models of acute liver failure. Now the time has come to elucidate the design characteristics that are essential to construct an efficient bioreactor. The gold standard remains the intact liver. Despite the very high cell density in this organ, individual cell perfusion is guaranteed resulting in low diffusional gradients which are essential for optimal mass transfer. These conditions are not met in bioreactors based on hollow fiber membranes. Moreover, the semipermeable membranes can foul and act as a diffusional barrier between the hepatocytes and the blood or plasma of the recipient. We devised a novel bioreactor for use as a bioartificial liver that does not include hollow fiber membranes for blood or plasma perfusion. The device is based on an integral oxygenator and a nonwoven polyester matrix material for hepatocyte culture as small aggregates. The efficacy of this original design was tested in rats with liver ischemia. Preliminary results show statistically significantly improved survival; life was prolonged 100% compared to the control experiments.     

易卒中型肾血管性高血压大鼠的脑血流自动调节下限与最低耐受压

目的　研究易卒中型肾血管性高血压大鼠 (RHRSP)的脑血流 (CBF)自动调节下限及其最低耐受压。　　方法　用氢清除法测定RHRSP和正常SD大鼠在不同低血压水平时 ,一侧顶枕交界区皮质和海马的局部CBF(rCBF) ;72小时后计算RHRSP和SD大鼠海马CA1 区神经细胞 (CA1 NC)线粒体的体密度 (Vv)、比表面 (δ)、平均体积 ( V)和数密度 (Nv) ,　　 结果　正常SD大鼠在平均动脉压 (MABP)为 1 0 67kPa、9 3 3kPa和 8kPa时 ,rCBF值无显著减少。在MABP为 1 0 67kPa时 ,RHRSP的rCBF值显著减少 ;超微结构观察发现CA1 NC无明显缺血改变 ,当MABP为 9 3 3kPa时 ,CA1 NC缺血明显 ;细胞形态分析发现 9 3 3kPa组与 1 0 67kPa组比较 ,前者线粒体的Vv和 V显著增大 ,δ和Nv显著减小。　　结论　RHRSP的CBF自动调节下限上移至 1 0 67kPa,并与其最低耐受压十分接近 ,表明RHRSP是一种研究高血压脑血管损害较理想的动物模型     

电针对沙鼠急性脑缺血再灌注后神经原损伤的保护作用

本实验利用沙鼠急性脑缺血再灌注模型，研究电针对脑缺血及再灌注各期脑电活动的影响及组织病理学的改变。结果表明：缺血１０ｍｌｎ，脑电幅度受到严重抑制，甚至变平坦，总功率大大下降，再灌注后总功率难以恢复，在１２０ｍｉｎ时仅恢复到缺血前的２７．３９±１１．３１％，以后即不再进一步恢复，电针组动物缺血１０ｍｉｎ再灌注后，脑电的恢复明显比对照组快，１２０ｍｉｎ时恢复至缺血前的７１．４５±１６．４６％（Ｐ＜０．０１），２４０ｍｉｎ时继续恢复至缺血前的７５．２７±１８．４３％。同时电针能明显减轻缺血１０ｍｉｎ后再灌注２４小时的神经原缺血性损伤。结果提示：电针对急性脑缺血引起的神经原损伤具有保护作用，并能促进脑功能的恢复。     

Effect of temperature in focal ischemia of rat brain studied by 31P and 1H spectroscopic imaging

³¹P, ¹H and lactate spectroscopic imaging was used to evaluate the effects of hypothermia on focal cerebral ischemia produced by middle cerebral artery occlusion. The effects on high energy phosphate metabolism, pH, lactate and NAA were investigated in 24 spontaneously hypertensive rats subjected to either permanent or transient ischemia. Under either normothermic (37.5°C) or hypothermic (32°C) conditions, with permanent 6-h occlusion, there was little difference between groups in either the NMR measurements or the volume of infarction. In animals that underwent 3 h of ischemia followed by 12 h of reperfusion, the ischemic changes in lactate, pH, NAA, and high-energy phosphate returned toward control values, and there was a protective effect of hypothermia (infarct volume of 211 ± 26 and 40 ± 14 mm³ in normothermic and hypothermic groups, respectively). Thus, hypothermia did not ameliorate the changes in lactate, pH, NAA, or high energy phosphate levels occurring during ischemia, however, during reperfusion there was an improvement in both the recovery of these metabolites and pathological outcome in hypothermic compared with normothermic animals.     

Post-ischemic release of nucleosides and oxypurines in isolated rat hearts. Possible involvement of ventricular fibrillation

Summary In isolated perfused rat hearts global ischemia for 2, 5, and 15 min was produced. Depending on the duration of the ischemia, postischemic reperfusion led to the release of adenosine and its catabolites, and to more or less severe ventricular tachyarrhythmias. When ventricular fibrillation occurred, a highly significant increase in the purine release was observed compared with non-fibrillating hearts. Prevention of fibrillation by antiarrhythmic drugs decreased the purine release in a highly significant way. After only 2 min of ischemia, reperfusion did not lead to ventricular fibrillation. Electrical induction of fibrillation during the reperfusion in these hearts provoked the release of very high amounts of the purine compounds. A similar effect of electrically-induced fibrillation was also obtained in hearts without a previous ischemic period. The findings suggest that ventricular fibrillation is able to induce the release of purine derivatives from the heart.     

心痛灵喷雾剂抗心肌缺血的实验观察

①目的　观察心痛灵喷雾剂对心肌缺血大鼠的药理作用。②方法　通过结扎大鼠冠状动脉前降支制备大鼠心肌缺血模型 ,观察心痛灵喷雾剂对心肌缺血面积和血清磷酸肌酸激酶 (CK)、乳酸脱氢酶 (LDH)、谷草转氨酶 (GOT)的影响 ;静脉注射垂体后叶素制备大鼠心肌缺血模型 ,观察心痛灵喷雾剂对心电图改变的影响。③结果　心痛灵喷雾剂可减少心肌缺血大鼠心肌梗死面积 ,降低血清CK、LDH、GOT活性 ,并减轻静脉注射垂体后叶素引起的缺血性心电图改变 (tD=1.2 2 3～ 13.890 ,P <0 .0 5、0 .0 1)。④结论　心痛灵喷雾剂具有抗心肌缺血的作用     

香烟烟雾吸入对大鼠局灶性脑缺血后梗死灶的影响

目的 观察香烟烟雾吸入对大鼠局灶性脑缺血后梗死灶的影响，探讨其机制。方法 建立吸烟大鼠模型。用TTC染色法测定梗死灶体积，检测大鼠局灶性脑缺血后神经功能缺陷评分及梗死灶体积占同侧半球百分比。结果 除戒烟组外各吸烟组大鼠神经功能缺陷评分及梗死灶体积与对照组相比显著增加，吸烟4周、8周及12周依次增加。戒烟组神经功能评分及梗死体积明显低于吸烟4周组，与对照组无显著差别。结论 吸烟可加重大鼠局灶性脑缺血后脑组织损害，且随着吸烟时间增加而加重，戒烟可使这种脑损害得到一定程度的恢复。     

缺血性脑血管病患者的血脂水平

目的分析缺血性脑血管病（ICVD）患者的血脂水平，为今后预防保健及康复干预决策的制定提供依据。方法在佛山市第一人民医院病案数据库中检索1991-2004年诊断为ICVD的病例共2886例，其中2000-2004年ICVD患者共1430例为一亚组，以我院同时期保健科随机选取的400名健康体检人群为对照组，记录血脂情况，进行对照分析。结果血TC、TG和LDL—C水平ICVD患者组明显高于健康体检人群，差异有统计学意义。男女两性血脂水平均随年龄增加而逐渐增高，50岁以上女性血脂水平明显高于同龄组男性。血脂代谢异常患病率随着年代的推移呈逐步上升趋势，总胆固醇从1991—1994年的24．5％到2001-2004年的38．1％（男性）和22．3％到38．5％（女性），且明显高于国内2000-2001年普查人群高脂血症的患病率。结论佛山地区血脂异常是ICVD的重要原因之一。