Relationship between glutathione and malonaldehyde levels in erythrocytes and the deformation index of erythrocyte in patients at various periods following acute cerebral infarction

BACKGROUND： Glutathione, as an in vivo free radical scavenger, plays an important role in the anti-oxidation defense mechanism in patients with acute cerebral infarction. OBJECTIVE： To observe the relationship between the levels of glutathione （GSH） and malonaldehyde （MDA）, the metabolite of lipid peroxidation, in erythrocyte and deformation index of erythrocyte in patients at various periods following acute cerebral infarction. DESIGN： Controlled observation.SETTING： Qilu Hospital of Shandong University and Institute of Cerebrovascular Disease of Qingdao Medical College. PARTICIPANTS： We chose 98 inpatients with acute cerebral infarction from Department of Neurology, Qilu Hospital of Shandong University from January to December 2000 , serving as cerebral infarction group, including 50 male and 48 female, with mean age of （62±7）years. There were 23 cases found on the 1^st day after onset; 25 cases on the 3^rd day after onset; 25 cases on the 7^th day after onset; 25 cases on the 14th days after onset, and they were all confirmed by craniocerebral CT or MRI. Another 30 homeochronous inpatients with neurosis, cervical syndrome, lumbar intervertebral disc herniation and motor neuron disease were chosen as control group, including 20 male and 10 female, with mean age of （52±8）years . There was no significant difference in age and gender distribution between two groups （P 〉 0.05）. Patients in the two groups were informed of detected index.METHODS：①Ulnar venous blood was chosen from the patients who were fasted on the 1^st, 3^rd,7^th and 14^th days after onset. Deformation index of erythrocyte was measured with BL88-CKX laser diffraction erythrocyte deformeter and photographing was performed. GSH level in erythrocyte was measured with DTNB assay introduced by Beu-tler. MDA level in erythrocyte was measured with modified thiobarbituric acid colorimetric method.②At each sample collecting , according to the criteria accepted by the Fourth National Conference of Cerebrovascular Disease, intergrant of neurologic impairment 〈 15 points was regarded as mild （n=46）, 15 to 30 points as moderate （n=40）and, 〉 30 points as severe （n=12）. ③ t test was used to compare data between two groups , and linear correlation analysis was used in relationship analysis among indexes. MAIN OUTCOME MEASURES ：① Comparison of erythrocyte GSH and MDA levels and deformation index of erythrocyte at various periods between patients with acute cerebral infarction and controls. ②Correlation of erythrocyte GSH level with erythrocyte MDA level and with deformation index of erythrocyte in patients with cerebral infarction . ③ Relationship between erythrocyte GSH level and severity of disease in patients with acute cerebral infarction. RESULTS： Totally 98 patients with acute cerebral infarction and 30 controls all entered the stage of result analysis. ① Erythrocyte GSH level and deformation index of erythrocyte were lower on the 1^st, 3^rd, 7^th and 14^th days after onset in cerebral infarction group than in control group （P 〈 0.05-0.01）, and erythrocyte MDA level was significantly higher in cerebral infarction group than in control group （P 〈 0.05-0.01）. The three indexes changed most significantly on day 3 after onset in patients, and began to recover or decrease on day 7 after onset and inclined to be normal on day 14 after onset. ② Erythrocyte GSH level was significantly negatively correlated with erythrocyte MDA level in patients with acute cerebral infarction on the 1^st, 3^rd, 7^th and 14^th days after onset （r=-0.534, -0.713, -0.645, -0.656, respectively, P 〈 0.05-0.01 ） ,and significantly positively correlated with erythrocyte deformation index （t-=0.502, 0.560, 0.455, 0.504, respectively, P 〈 0.05）. ③Erythrocyte GSH level was significantly lower in moderate or severe patients with acute cerebral infarction than in mild patients[（0.215±0.088）,（0.192±0.102）, （0.281±0.090） g/L, P〈 0.05]. CONCLUSION：①Erythrocyte GSH and MDA levels and deformation index of erythrocyte change significantly on the 3^rd day following acute cerebral infarction. Index detection results gradually tended to be normal on from the 7^th day to 14^th days day after onset. ② Change of erythrocyte GSH level can reflect the severity of disease of patients with acute cerebral infarction.③Decrease of erythrocyte GSH level in patients with acute cerebral infarction is one of reasons that result in the decrease of deformation ability of erythrocyte.

Field of vertical crustal deformation in North China and the feature of its dynamic evolution

Based on the data of precise leveling surveys for 30-odd years and using unified adjustment method unified starting point of calculation and unified network,contour maps of the vertical crustal deformation rate in North China during the periods of 1965-1975,1975-1979,1979-1983 and 1983 1988 have been drawn.Meanwhile,the evolution of vertical crustal deformations has also been studied from a dynamic viewpoint. The results of analysis show that there is an obvious correspondence between the regular variations of the vertical crustal deformation field and the seismic cycles.Furthermore,the paper has also inferred that this correspondence might be related to the micro-variations of the regional stress/strain field. Finally,some problems related to the vertical deformation field and earthquake prediction have been discussed.

Inhibiting bulging deformation of liquid metal free surface by magnetic pressure

A new method was presented to inhibit bulging deformation and fluctuation of free surface by magnetic pressure.A research combined with numerical and experimental methods was conducted to investigate the feasibility and inhibition efficiency.The parameters including magnetic flux density,frequency and action area of magnetic pressure were analyzed.The results show that the method is feasible,and the bulged free surface is fully inhibited by the proper magnetic pressure.The inhibition efficiency increases as the increase in magnetic flux density and frequency,which shows a linear rela-tionship with the magnetic flux density.The frequency has a great influence on the inhibition efficiency when the frequency is changed from 0.15 to 5.00 kHz.However,the frequency more than 5.00 kHz has little influence on the inhibition efficiency and is recommended in application process.When the ratio of the action area to the area of bulged free surface is 0.8,the best inhibition is achieved.However,when the ratio is more than 1.2,a distinct W-shaped free surface is observed.The surficial and internal flow is strengthened with proper magnetic pressure imposed.Moreover,under the action of magnetic pressure,the fluctuation amplitude of free surface decreases from 4.0 to 1.2 mm and the main fluctuation with frequency of 2.34 Hz is dispersed into several minor fluctuations with frequency of 0.4-4.3 Hz.