改良线栓法大鼠大脑中动脉阻塞模型的建立

目的对大鼠大脑中动脉阻塞（MCAO）再灌注模型进行改良,通过比较再灌注24h时大鼠神经功能评分、梗死率、模型制作时间、成功率和死亡率等指标评价改良线栓法大鼠MCAO再灌注模型的有效性。方法12只SD大鼠随机分为对照和模型两组,对照组采用分离结扎翼腭动脉,从颈外动脉插入线栓至大脑中动脉。模型组采用不分离结扎翼腭动脉,从颈总动脉分叉处插入线栓至大脑中动脉。阻断大脑中动脉血供2h后将线栓拔出实现再灌注。于再灌注24h时观察脑组织组织病理学改变,计算比较两组大鼠神经功能评分、模型制作时间、模型成功率和死亡率以及鼠脑切片TTC染色测量脑梗死率。结果两组MCAO模型在再灌注24h后大鼠神经功能评分、梗死率、模型成功率和死亡率等方面没有显著差异;模型组的模型制作时间显著少于对照组（P〈0．05）。结论采用不分离结扎翼腭动脉,由颈总动脉插入线栓的改良线栓法是稳定和可靠的MCAO造模方法。     

视网膜静脉阻塞与颈动脉狭窄的相关性研究

目的:探究视网膜静脉阻塞与颈动脉狭窄的相关性研究,并为其临床检测、治疗与预后提供参考。方法:选择我院55例视网膜静脉阻塞患者(55只眼)为研究组,对其裸眼视力、矫正视力、眼压、眼底血管荧光造影(FFA)等检查资料进行分析,并进行多普勒彩超检查,记录其颈动脉狭窄情况,并对两种疾病之间的关系进行分析。同时选取55例健康人作为对照组。结果:研究组55例患者确诊为视网膜静脉阻塞(RVO),多普勒结果显示患者患侧与健侧劲动脉血流动力学各项差异不明显(P0.05);其IMT值较之对照组显著增高(P0.05);其PSV与EDV值有所降低,差异具有统计学意义(P0.05)。结论:视网膜静脉阻塞患者大多存在颈动脉狭窄,因此检测颈动脉血流动力学对于诊断与预防视网膜静脉阻塞有着重要作用。     

Partial Carotid Occlusion as Treatment for Intracranial Internal Carotid Aneurysms

A study was undertaken to investigate the possibility of using partial carotid occlusion instead of complete carotid ligation for the treatment of intracranial internal carotid aneurysms with a view to avoiding such complications of the latter procedure as neurological deficit resulting from cerebral ischemia, and ascending thrombus formation. The beneficial effect of carotid ligation has been explained by the interruption of pulsatile flow which can cause rupture of an aneurysm by resonance phenomena. Studies on blood flow in the aorta in dogs, as well as in a human carotid artery in vivo and in vitro, showed that the same object could be achieved by the use of constriction by a Poppen clamp. This changed the pulsatile blood flow to a relatively non-pulsatile state with slight diminution in mean flow. Partial occlusion of the common carotid artery is recommended for those cases of intracranial aneurysm in which complete carotid occlusion would not likely be tolerated.     

凝闭双侧椎动脉预处理对大鼠全脑缺血损伤的防护作用

目的：观察凝闭双侧椎动脉与夹闭双侧颈总动脉之间的不同时间间隔对Pulsinelli四血管闭塞法全脑缺血模型的影响、以及在凝闭单侧椎动脉的基础上夹闭双侧颈总动脉后的脑缺血的特点。方法：84只Wistar大鼠．随机分为以下4组：对照组、双侧椎动脉凝闭组、全脑缺血组、单侧椎动脉凝闭＋双侧颈总动脉夹闭组。全脑缺血组中,根据凝闭双侧椎动脉与夹闭双侧颈总动脉之间的时间间隔不同,又分为24h间隔、48h间隔和72h间隔3个亚组。观察大鼠脑缺血过程中的反应包括瞳孔散大、对光反射等情况,脑缺血后恢复翻正反射所需要的时间、以及动物的一般状况,并应用硫堇染色法观察海马CA1区锥体神经元迟发性死亡的情况：结果：全脑缺血72h间隔亚组的大鼠,脑缺血过程中的反应、脑缺血后的一般状况和锥体神经元迟发性死亡程度均明显重于全脑缺血24h间隔亚组及48h间隔亚组,但24h间隔亚组与48h间隔亚组之间无显著差异一单侧椎动脉凝闭＋双侧颈总动脉夹闭组大鼠的凝闭侧瞳孔散大、对光反射消失、海马CA1区神经元大量死亡;而未凝闭侧未见上述相关变化。结论：凝闭双侧椎动脉本身也具有脑缺血预处理样作用,对其后48h内夹闭双侧颈总动脉所致的严重脑缺血具有一定程度的保护作用;大鼠椎动脉对脑干及海马的血液供应均存在明显的同侧优势效应,     

Thermography in Occlusive Cerebrovascular Diseases

Cooling of the skin over the medial supraorbital region in 80% of patients who have an occlusion or severe stenosis of a carotid artery can be demonstrated by facial thermography. Minor stenotic lesions in the carotid arteries do not produce characteristic thermographic changes, while thermography is of no help in the diagnosis of vertebrobasilar arterial disease.Thermographic changes suggestive of carotid arterial lesions are found occasionally in patients whose angiograms are normal, owing to variations in the size of the frontal sinuses, or factors such as fever or inflammatory lesions.It is suggested that facial thermography is of value in the preliminary investigation of patients with occlusive cerebrovascular disease.     

Model of occlusion-reperfusion arrhythmias of the transplanted heart in rats

Rats with heterotopically transplanted heart were used for modeling of occlusion-reperfusion arrhythmias. Heart transplantation was carried out by performing the anastomoses between the recipient carotid artery and jugular vein and innominate artery and pulmonary artery of the transplant respectively. The reversible ischemia of myocardium was achieved through temporal occlusion of recipient carotid artery supplying transplanted heart. The model is characterised by total denervation of the heart, the absence of pump function, total nature of myocardial ischemia during occlusion of supplying artery, high reproducibility of arrhythmias and the opportunity of repeated use of the animals.     

Conjugal disharmony: a hitherto unrecognised cause of strokes.

Two women of reproductive age suffered strokes. Neither was taking oral contraceptives, and investigations showed no other causal factors. The radiological findings were characteristic of traumatic internal carotid artery occlusion, but neither patient gave a history of trauma. Only after further inquiry into the patients'' social circumstances did it emerge that each had survived an attempt at strangulation by her husband. Such a cause of stroke in young women should be considered when other causes of carotid artery occlusion cannot be identified.     

Superficial intimal injury of the rabbit carotid artery induced by distilled water

The study of mechanical injury to the aortic endothelium in experimental animals is important in understanding the pathologic processes in atherogenesis. In this investigation distilled water was used to produced superficial injury to the rabbit carotid artery. Sterilized distilled water was injected into a temporarily isolated segment of rabbit carotid artery measuring 0.5 cm in length. After 4 min blood flow was reestablished by removal of the isolating ligatures. The carotid arteries were examined at time intervals of 5 min, 24 h, 48 h, 1 month, 3 months and 6 months after injury. Five min after injury, the carotid endothelial cells were almost completely removed but no medical injury was present. After 24 and 48 h, a few platelets were adherent to the denuded intimal surface. After 1 month, 3 months and 6 months the injured surface showed a slight intimal thickening consisting of modified smooth muscle cells. Our experimental findings suggested that the extent of the injured area is more important in the repair process than its depth.     

Ischemic Postconditioning Fails to Protect against Neonatal Cerebral Stroke

The lack of efficient neuroprotective strategies for neonatal stroke could be ascribed to pathogenic ischemic processes differentiating adults and neonates. We explored this hypothesis using a rat model of neonatal ischemia induced by permanent occlusion of the left distal middle cerebral artery combined with 50 min of occlusion of both common carotid arteries (CCA). Postconditioning was performed by repetitive brief release and occlusion (30 s, 1 and/or 5 min) of CCA after 50 min of CCA occlusion. Alternative reperfusion was generated by controlled release of the bilateral CCA occlusion. Blood-flow velocities in the left internal carotid artery were measured using color-coded pulsed Doppler ultrasound imaging. Cortical perfusion was measured using laser Doppler. Cerebrovascular vasoreactivity was evaluated after inhalation with the hypercapnic gas or inhaled nitric oxide (NO). Whatever the type of serial mechanical interruptions of blood flow at reperfusion, postconditioning did not reduce infarct volume after 72 hours. A gradual perfusion was found during early re-flow both in the left internal carotid artery and in the cortical penumbra. The absence of acute hyperemia during early CCA re-flow, and the lack of NO-dependent vasoreactivity in P7 rat brain could in part explain the inefficiency of ischemic postconditioning after ischemia-reperfusion.     

Involvement of CCR-2 chemokine receptor activation in ischemic preconditioning and postconditioning of brain in mice

The present study has been designed to investigate the potential role of CCR-2 chemokine receptor in ischemic preconditioning as well as postconditioning induced reversal of ischemia-reperfusion injury in mouse brain. Bilateral carotid artery occlusion of 17min followed by reperfusion for 24h was employed in present study to produce ischemia and reperfusion induced cerebral injury in mice. Cerebral infarct size was measured using triphenyltetrazolium chloride staining. Memory was evaluated using elevated plus-maze test and Morris water maze test. Rota rod test was employed to assess motor incoordination. Bilateral carotid artery occlusion followed by reperfusion produced cerebral infarction and impaired memory and motor co-ordination. Three preceding episodes of bilateral carotid artery occlusion for 1min and reperfusion of 1min were employed to elicit ischemic preconditioning of brain, while three episodes of bilateral carotid artery occlusion for 10s and reperfusion of 10s immediately after the completion of were employed to elicit ischemic postconditioning of brain. Both prior ischemic preconditioning as well as ischemic postconditioning immediately after global cerebral ischemia prevented markedly ischemia-reperfusion-induced cerebral injury as measured in terms of infarct size, loss of memory and motor coordination. RS 102895, a selective CCR-2 chemokine receptor antagonist, attenuated the neuroprotective effect of both the ischemic preconditioning as well as postconditioning. It is concluded that the neuroprotective effect of both ischemic preconditioning as well as ischemic postconditioning may involve the activation of CCR-2 chemokine receptors.     

CEREBRAL ENERGY METABOLISM DURING TRANSIENT ISCHEMIA AND RECOVERY IN THE GERBIL1

Energy metabolism was studied in the cerebral cortex of gerbils during and following ischemia induced by 1 h of unilateral carotid artery occlusion. An aneurysm clip was applied to the right common carotid artery of 50-70 g gerbils under brief halothane anesthesia, and the clip was removed 1 h later. Clinical state (gait, responsiveness, seizures) was evaluated during carotid occlusion, and 40% of the animals showed clinical evidence of stroke. Cortical energy stores (2 ATP + ADP + P-creatine) were more than half depleted in the ipsilateral cortex of clinically-affected gerbils, and glucose fell by 75%; lactate rose over 7-fold in the same specimens. After release of the carotid clip, clinical state improved, and biochemical abnormalities partially resolved. However, even after 24 h, the concentration of ATP and the total pool of adenine nucleotides remained subnormal. Metabolic activity in the ischemic cortex, assessed as the utilization of high-energy phosphates following decapitation, was normal after 1 h of recovery and decreased (-50%) after 24 h but was increased by more than 50% after 4 h. Cerebral glucose utilization, evaluated from autoradiographs prepared after intravenous administration of 2-[1-¹⁴C]deoxyglucose, was also increased in the cortex, hippocampus, and thalamus after 4 h of recovery. This post-ischemic hypermetabolism in tissue damaged by ischemia may identify a critical period for cell repair, when therapy could be decisive.     

兔血管外膜对血管重构及收缩功能影响的初步观察

本文研究血管外膜在血管重塑及功能调控中的作用。实验采用在体去除兔颈动脉外膜的方法,于术后即刻、1周及2周取出动脉作组织学、免疫组织化学染色及血管反应性测定。结果显示：(1)去除颈动脉局部外膜对内皮及中层平滑肌无明显损伤;(2)去除外膜后血管平滑肌细胞增殖,并有新生内膜形成;(3)与对照例比较,去外膜侧血管对去甲肾上腺素的收缩反应在术后即刻及1周时减弱(P＜0．05)。上述研究结果提示：去除动脉外膜可导致血管内膜增殖及血管平滑肌收缩功能的改变,表明外膜可能参与血管重塑及对血管功能的调控。     

Carnitine requirement of vascular endothelial and smooth muscle cells in imminent ischemia

Rats were subjected to bilateral carotid artery occlusion for 30 min, followed by reperfusion for varying time periods. The concentration of reduced and oxidized glutathione, glutathione peroxidase and glutathione reductase were determined in whole brain after varying periods of reperfusion. Lipid peroxidation was also assessed by determining the levels of malondialdehyde (MDA) in the brain. Reperfusion for 1 hr following bilateral carotid artery occlusion resulted in significant decrease in total glutathione (GSH) concentration along with small but significant increase in oxidized glutathione (GSSG) levels. After 4 hr of reperfusion, GSH levels recovered, although GSSG levels remained elevated up to 12 hr of reperfusion. Increase in malondialdehyde levels was also detected in the brain up to 12 hr of reperfusion. Glutathione reductase activity remained significantly low up to 144 hr of reperfusion, while glutathione peroxidase activity remained unaffected. These results demonstrate that oxidative stress is generated in the brain during reperfusion following partial ischemia due to bilateral carotid artery occlusion.     

Modelling the circle of Willis to assess the effects of anatomical variations and occlusions on cerebral flows

Blood flow in the circle of Willis (CoW) is modelled using the 1-D equations of pressure and flow wave propagation in compliant vessels. The model starts at the left ventricle and includes the largest arteries that supply the CoW. Based on published physiological data, it is able to capture the main features of pulse wave propagation along the aorta, at the brachiocephalic bifurcation and throughout the cerebral arteries. The collateral ability of the complete CoW and its most frequent anatomical variations is studied in normal conditions and after occlusion of a carotid or vertebral artery (VA). Our results suggest that the system does not require collateral pathways through the communicating arteries to adequately perfuse the brain of normal subjects. The communicating arteries become important in cases of missing or occluded vessels, the anterior communicating artery (ACoA) being a more critical collateral pathway than the posterior communicating arteries (PCoAs) if an internal carotid artery (ICA) is occluded. Occlusions of the VAs proved to be far less critical than occlusions of the ICAs. The worst scenario in terms of reduction in the mean cerebral outflows is a CoW without the first segment of an anterior cerebral artery combined with an occlusion of the contralateral ICA. Furthermore, in patients without any severe occlusion of a carotid or VA, the direction of flow measured at the communicating arteries corresponds to the side of the CoW with an absent or occluded artery. Finally, we study the effect of partial occlusions of the communicating arteries on the cerebral flows, which again confirms that the ACoA is a more important collateral pathway than the PCoAs if an ICA is occluded.     

Potassium nitrate effect on the development of neurological disorders in experimental brain ischemia

Effect of potassium nitrate (KNO₃) on the dynamics of neurological disorders and lethality in rats as sequelae of brain ischemia induced by a single-step bilateral common carotid artery occlusion were investigated in Wistar rats. KNO₃ at a dose of 5 mg/1000 g administered 60 min prior to the occlusion of the two carotid arteries reliably reduced the severity of neurological disorders and lethality in rats.     

Combined treatment of traumatic aortic transection and Kommerell diverticulum

We present the case of a 41-year-old male trauma patient admitted to the emergency department after being struck in a pedestrian versus a motor vehicle accident. Computed tomography revealed a traumatic transaction of the descending aorta with pseudoaneurysm and an aberrant right subclavian artery with Kommerell diverticulum. Surgical correction was accomplished with bilateral subclavian carotid bypass, with occlusion of both subclavian arteries followed by the placement of endovascular stent grafts to repair the aortic injury.     

Comparative neurohistological observations on the intrinsic innervation of pancreatic artery (blood vessel) in the representative of bird and mammal

The present investigation was undertaken for the study of the comparative neurohistological observations of pancreatic-Artery (blood vessel) in Gallus domesticus (white leghorn) and Suncus murinus (Indian musk shrew) by cholinesterase technique. In Gallus, the innervation of arteries (blood vessel) was by a good number of non-myelinated nerevs, which formed the periarterial plexus in participation with the postganglionic fibres at one end and the fibres of the nerve cells of the other end. In Suncus, the periarterial and AChE-positive ganglia were arranged in chain-like fashion on the periphery of the artery. Periarterial plexus was formed by tortuous, myelinated nerves and the nerve fibres of the ganglia.     

Ascending pathways mediating somatoautonomic reflexes in exercising dogs

The ascending spinal pathways mediating somatocardiovascular reflexes during exercise were studied in unanesthetized dogs by placing lesions in the lumbar spinal cord. After training to run on a treadmill with hindlimbs only, 20 dogs were anesthetized and instrumented using sterile surgical techniques. To chronically record heart rate and arterial blood pressure, the aorta was cannulated via the omocervical artery. To test the intactness of descending spinal sympathetic pathways, reflex pressor responses to baroreceptor hypotension were produced by bilateral carotid arterial occlusion using pneumatic vessel occluders placed around the common carotid arteries. To generate transient ischemic exercise (120 s), a pneumatic occluder was placed around the left iliac artery. Eight to 10 days after instrumentation, blood pressure and heart rate were monitored at rest and during hindlimb running with and without simultaneous iliac arterial occlusion. The modest pressor response and tachycardia elicited by hindlimb exercise were markedly augmented by simultaneous hindlimb ischemia (i.e., iliac arterial occlusion). Lesion placement in the dorsolateral sulcus area and the dorsolateral funiculus at L2 significantly reduced the blood pressure and heart rate responses to simultaneous exercise occlusion. The cardiovascular responses to nonischemic exercise and bilateral carotid arterial occlusion were not altered by such spinal sections. It is concluded that in the dog the ascending spinal pathways mediating cardiovascular responses to ischemic exercise are located in the lateral funiculus, including the dorsolateral sulcus area and dorsolateral funiculus.     

Prevalence and outcome of symptomatic carotid lesions in young adults. National Research Council Study Group.

OBJECTIVE--To estimate the prevalence and outcome of symptomatic internal carotid artery lesions in young adults. DESIGN--Multicentre hospital based observational study with five year follow up. SETTING--Seven neurological departments in northern and central Italy. SUBJECTS--240 patients (115 men) aged 15-44 with a recent transient ischaemic attack or stroke in the carotid territory. MAIN OUTCOME MEASURES--(a) Prevalence of symptomatic internal carotid artery stenosis or occlusion detected by continuous wave Doppler ultrasonography at entry; (b) incidence rates of cerebral, cardiac, and non-vascular death; non-fatal stroke; and non-fatal myocardial infarction. RESULTS--Carotid stenoses of 50-99% and occlusions were found in 38 patients (15.8%). Both conditions were significantly more frequent in patients aged over 35 and in those with hypertension, diabetes mellitus, and stroke at entry. The standardised mortality ratio at five years was 10.5 (95% confidence interval 5.0 to 19.3). Survival of patients with stenoses of 0-49% and occlusions was significantly better than that of patients with stenoses of 50-99%. Carotid stenosis of 50-99% was an independent predictor of death (hazard ratio 7.9; 95% confidence interval 2.2 to 29) and non-fatal stroke (hazard ratio 7.4; 1.5 to 37.4). CONCLUSIONS--The prevalence of carotid stenosis or occlusion in young adults after a cerebrovascular event is low. Though patients with high grade symptomatic carotid stenosis are at risk of non-fetal and fetal events, patients with internal artery occlusion apparently have a benign prognosis.     

The modelling of cerebral ischemia in dogs with pathological kinking and occlusion of the carotid arteries]

An experimental model of brain ischemia in pathological kinking and occlusion of carotid artery has been developed on 40 dogs. Each model was documented angiographically, controlled with radionuclides, evaluated morphofunctionally. Basing on the results, surgical indications for correction of brachiocephalic artery lesions are provided.