Effects Of Local Mild Hypothermia On Vascular Endothelial Cell Of Cerebral Infarction

Research purpose Cerebral infarction is a common type of stroke, and has very high incidence rate, disability rate and death rate. Although various countries make research on prevention and cure of cerebral infarction actively, it is still lack of effective therapy measures up to now. At present, therapy of cerebral infarction is made by two main routes:One is venous thrombolysis therapy; the other is to avoid a series of pathologic and biochemical reactions of brain tissue caused by ischemia and to prevent neuron from death, i.e.nerve protection therapy. Although large quantity of manpower and material resources are invested, clinic trial of neuroprotective agent doesn't obtain expected results. Application of sub-hypothermia provides an effective means for therapy of cerebral infarction, and large quantity of animal test and clinical data in the 1990's prove the positive protective function of sub-hypothermia on cerebral infarction. The subject mainly compares change of contents of serum nitrogen monoxidum (NO) and endothelin (ET) between patients with local sub-hypothermia therapy and common medication, and National Institutes of Health Stroke cale (NIHSS), Fugl Meyer Assessment Method and Bathel Index (BI) are used to assess recovery situation of nerve function defect of patients after using different therapy methods so as to observe and compare curative effect of local sub-hypothermia therapy on cerebral infarct, and to discuss the protective mechanism of local sub-hypothermia on cerebral ischemia.Research method All cases meet cerebral infarct diagnosis standard stipulated by The 4th China National Conference on Cerbralvascular Disease in 1995, and are proven by head CT or MRI; onset time is within 24h;the patients age range is 45-88 years; the first onset patients or recurrence patients without sequelae; the patients with membra paralysis and the MS of paralytic membra were below gradeⅢ. Removing standards:①Large area cerebral infarct history and cerebral hemorrhage history;②Injury or tumor cerebral hemorrhage, and cerebral hemorrhage caused by vascular malformation;③Removing the patients with hypertensive cerebral disease, infectious disease, immune disease and hematological system disease;④Severe hepatic and renal function disorder, alimentary tract hemorrhage, heart failure and multiple organ failure. Case grouping:66 acute cerebral infarct patients were selected from hospital from May,2009 to September,2010 (35 males and 31 females).The patients were divided into two groups randomly:33 patients (17 males and 16 females) with a mean age of (63.54±13.26) years (ranges 45-86) were given local sub-hypothermia therapy, mean time from onset to therapy is (12±9)h, and mark of America National Institutes of Health Stroke Scale (NIHSS) is (17.22±1.91); 33 patients (18 males and 15 females) with a mean age of (62.76±13.68) years (range 46-88) were given common therapy; Mean time from onset to therapy is (13±8)h, and mark of NIHSS is (17.37±2.44). Differences of the age, sex ratio, disease severity, concomitant disease and therapy starting time between the two groups were not significant (P>0.05) through statistic analysis. Drug treatment:Both sub-hypothermia group and control group, which were identified, were given common dehydration for decreasing intracranial pressure, antiplatelet aggregation drug or anticoagulant, symptomatic and supportive treatment. Sub-hypothermia treatment:Besides common drug treatment, sub-hypothermia group was given local sub-hypothermia treatment applying SDL-V type double control cerebral temperature lowering instrument (produced in Tangshan) after hospitalization for 5-7 days; measure tympanic membrane temperature applying OMRON infrared ear type thermometer (Dalian Omron Limited Company), and keep tympanic membrane temperature at about 33-35℃. treatment time was 48～72h, following the standard of brain temperature=tympanic membrane temperature±0.5℃; Monitoring ECG, blood pressure, respiration, pulse, eye pupil and blood potassium, etc. Rewarming:Rise temperature slowly by recovering 1℃=every 1-2 days, recovering temperature not exceeding 0.1℃per hour. Observation index:Applying National Institutes of Health Stroke Scale (NIHSS) for clinic nerve function failure evaluation, full marks was 22; applying Fugl Meyer Assessment (FMA) method for motor function assessment, full marks was 100; applying Bathel index (BI) for capacity of activities of daily living (ADL) evaluation, full marks was 100. The two groups are assessed before therapy and 30 days after therapy; and measure levels of serum NO and ET of patients using nitric acid reduction method and radioimmunoassay differently on the 1st day,3rd day,7th day and 14th day after onset.Results Serum NO levels of local mild hypothermia treatment group are higher than common treatment group (P<0.01) on the 3rd,7th,14th day after onset. Serum ET levels of local mild hypothermia treatment group are lower than common treatment group (P<0.05) on the 7th day after onset,and are significantly lower than common treatment group (P<0.01) on the 3rd,14th day. Differences of NIHSS, Bathel index and Fugl Meyer assessment between the two groups were not significant (P>0.05) before treatment.1 month after therapy, NIHSS assessment of mild hypothermia treatment group were lower than those of control group,while Bathel index and Fugl Meyer assessment of mild hypothermia treatment group were higher than those of control group, and the differences were significant (P<0.01). The results show that combination of mild hypothermia treatment and common drug treatment gives better brain protection.Conclusion Local mild hypothermia therapy can keep dynamical balance of NO and ET, protect vascular endothelial cell, and play its brain protective function, so as to obtain better recovery of the defect of patients' neuro-function.