Construction and Application of the Big Data Research Platform for Biological Sample Information Resources in a Large Com-prehensive Hospital / 医学信息学杂志

Purpose/Significance By integrating clinical and biological sample information,a big data research platform for biologi-cal sample information resources is built to provide one-stop data retrieval,integration and analysis services for researchers,and a data governance system is established,so as to improve the level of hospital clinical research infrastructure construction.Method/Process Common data model and data governance technology are adopted to integrate data sources from different vendors through extraction,trans-formation,loading and other steps to provide a unified data access portal.Result/Conclusion The big data research platform for biologi-cal sample information resources has the advantages of multi-dimensional data screening and rapid integrated analysis,which can pro-vide support for clinical research.

Evaluation of the Impact of Subspecialty Reform on the Core Medical Operation Indicators of a Clinical Department / 中国医院管理

Objective To evaluate the impact of hepatobiliary surgery in a tertiary public hospital on its core medical operation indicators after the implementation of subspecialty reform.Methods The Department of Hepatobiliary Sur-gery,which implemented the subspecialty reform,was the experimental group,and six surgical departments with-out subspecialties were the control group.Seven indicators in the dimensions of medical quality,medical efficiency,and rational use of medication were collected from September to December 2022,and the difference between the experimental group and the control group was analyzed by the differences-in-differences method using the Septem-ber data before the implementation of sub-specialty reform as the baseline value.Results After the subspecialty re-form,the changes of the indicators of the percentage of discharged patients for surgery,intensity of antimicrobial drug use and average hospital stay in hepatobiliary surgery were better than those of the control group;the percentage of discharged patients for minimally invasive surgery and the percentage of medical service revenue were inferior to those of the control group;the intergroup differences of the two indicators of the percentage of discharged patients for level IV surgery and the case-mix index were not significant.Conclusion By setting up similar control departments in the same period and excluding the influence of external confounding factors on the study results,overall,the core medical operation indexes of hepatobiliary surgery were slightly better than those of the control group,but the advantage was not obvious,which might be related to the short observation time after the subspecialty reform,and its long-term effects need to be continuously followed up and analyzed.

Information support practice for anti-COVID-19 consortium composed of multi-medical institutions’ staff / 西安交通大学学报(医学版)

In the emergency of the outbreak of COVID-19 in December 2019, Shaanxi Provincial Health Committee mobilized several medical teams from major hospitals in the province, and, by relying on Xi’an Chest Hospital, jointly established an anti COVID-19 consortium to control and eradicate the epidemic in a short time. Information support is an important guarantee for winning this battle. In order to realize the efficient cooperation among multiple medical teams, we have carried out some exploratory and innovative information support services on the basis of the original information system of the chest hospital. In this process, we have gone through some detours. Some compromises were made on some problems that could not be solved in the short term. Finally, in an environment full of uncertainty, a set of information support management system with basically smooth operation was built through rapid trial and error adjustment. The system mainly includes the following aspects: support of the organizational structure and operation process of the anti-epidemic consortium, support for medical collaboration related businesses of multiple medical teams, and support for statistical reports and online meetings. Information support has played a very important role in this action, and this practice has also accumulated experience for us to deal with similar situations in the future.

International collaboration to promote global health: the 2017 Belt and Road Initiative Global Health International Congress & 2017 Chinese Preventive Medicine Association—Chinese Society on Global Health Annual Meeting / 《全球健康杂志（英文）》

With the rapid development of new technologies and global trade and increasing collaboration among countries worldwide,public health has become a global issue.Global health,as a new discipline,has been drawing more attention from both academia and governments.The Belt and Road (B&R) Initiative,proposed by China in 2013,aims to promote trade and resource exchange,including education,research,and health issues,with over 60 countries in Asia,Africa,and Europe.The B&R Initiative provides good opportunities for involved countries to address health problems jointly as well.In response to the B&R Initiative and to promote international collaboration on global health issues,"The 2017 Belt and Road Initiative Global Health International Congress & 2017 Chinese Preventive Medicine Association-Chinese Society on Global Health Annual Meeting" was held on September 24-27,2017 in Xi'an,China.Thus far,this is the largest high-quality international conference held in China that focused on the B&R Initiative global health issues.This article summarizes the background,key sessions and topics covered during the congress,important events and highlights different perspectives of the B&R Initiative and global health by invited experts from China and abroad.The conference included 17 sessions (3 keynote speech forums and 10 scientific sessions,3 young scholar forums,and a research poster session) and about 100 speakers,around 40 of which were leading experts outside of China.All the major sessions were held in English.More than 40 leaders and experts of health sectors from 13 countries presented their work in the congress.Approximately 400 delegates from 29 countries attended the congress.Delegates had extensive discussions about global health related issues,future cooperation and development in global health.The congress fostered international exchange and collaboration.

"Joint military exercise""Peace friendship-2015""and""Mission harmony-2015""aboard hospital ship" / 军事医学

During the mission of Peace friendship-2015, between September 2015 and January 2016,the Chinese Navy hospital ship respectively participated in the Harmony-2015joint military exercise in Malaysia and with the local military of Polynesia and Barbados .The article summarized the relevant background of the joint military exercise and the main practices in various stages .This article also suggests that the emergency platform be moved forward , the function of the triage area be expanded, basic life support(BLS),advanced cardiovascular life support (ACLS),and advanced trauma life support(ATLS) training programs be introduced, the training model and the test system be innovated , and realistic traumatic conditions be designed in order to guarantee the success of the joint exercise .

The significance, development and prospects of healthcare data integration in new drug clinical trials / 药学学报

With the deployment of electronic medical records systems, more and more routine clinical data are recorded electronically, which become a potential data source for new drug clinical trials. In this paper, we summarized the opportunities, challenges, obstacles and the latest development in this field.

Surgical pathology of revision after knee and hip arthroplasty / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate clinical characteristics and pathological changes of tissue surrounding prosthesis after hip and knee arthroplasty.</p><p><b>METHODS</b>A total of 67 patients receiving hip and knee arthroplasty were included in the study and pathological changes of the revision specimens were evaluated by microscopic examination.</p><p><b>RESULTS</b>Of 67 patients, there were 25 males and 42 females (ratio of 0.6) with a mean age of 64 years. There were 42 cases of revision hip prosthesis and 25 cases of knee prosthesis. The primary causes for the revision varied, including 20 cases of infection (29.9%, within 3 months in 9 cases,3 to 24 months in 3 cases and over 24 months in 8 cases), 14 cases of pain (20.9%), 13 cases of loosening of the prosthesis (19:4%), 9 cases of joint stiffness (13.4%), 8 cases of prosthetic dislocation (11.9%), and 3 cases of prosthesis fracture (4.5%). Pathological findings in the tissue surrounding the prostheses included debris reaction, histiocytes, acute inflammatory, chronic non-specific inflammation, pigmented villonodular synovitis (PVNS), "pseudomembranous", calcification, necrosis, sequestrum, etc. These histological changes were frequently admixed.</p><p><b>CONCLUSIONS</b>Various reasons may lead to hip and knee revision arthroplasty. The main pathological findings include infection, debris granulomas, chronic non-specific inflammatory changes, PVNS. The surgical pathology of the prosthesis provids guidances for clinical treatment and basic research.</p>

Different stimulant intensity of abdominal operation on the expression of tumor necrosis factor α and surfactant protein-A in lung of the rats / 中南大学学报(医学版)

OBJECTIVE@#To determine the influence of different stimulation of abdominal operation on lung.@*METHODS@#We randomly divided 100 SD male rats into 5 groups(n=20): An anesthesia control group (Group A), an abdominal skin 2 cm incision group (Group B), an abdominal skin+ muscle 2 cm incision group (Group C ), an abdominal skin+muscle+peritoneum 2 cm incision group (Group D), and an abdominal skin+muscle+peritoneum 2 cm incision+2 min laparoscopy in abdomen+pull exploration bowel group (Group E). Propofol was used for induction of anaesthesia by rat tail vein with 10 mg/kg, with 35-45 mg/(kg.h) during the operation. Anesthesia depth was maintained during moderate sedation without obvious analgesia action level. According to the postoperative specimens at different time, each group was divided into 4 sub groups, including 6-hour group, 1-day group, 3-day group, and 7-day group(n=5). Immunohistochemical method was used to examine tumor necrosis factor (TNF-α) and lung tissue lung surface active substances related proteins A (SP-A) of rats at different points after surgery.@*RESULTS@#There was no significant differences in the expression of TNF-α at 6 hours, 3 days, and 7 days after surgery in the 5 groups (P>0.05). The expression of TNF-α in Group D, and E was significantly higher than that in Group A at 1 day after surgery (P Group D > Group C > Group B at 1 day, 3 days after surgery, there was no significant difference among the 4 groups. There was no significant differences in the expression of SP-A at 6 hours, 3 days, and 7 days after surgery in the 5 groups (P>0.05). The expression of SP-A in Group D and E was significantly higher than that in Group A at 1 day after surgery (P0.05).@*CONCLUSION@#The greater the stimulant intensity of abdominal operation on rats, the more impact on postoperative lung. The postoperative pulmonary effect of intraperitoneal operation is greater than non-intraperitoneal operation, but in the compensation.

Treatment of life threatening head and neck space infection:A retrospective analysis of 32 cases / 实用口腔医学杂志

Objective:To review the treatment of life threatening head and neck space infection.Methods:Retrospective was con-ducted to analyse the patient characterization,signs and symptoms at the time of presentation,presence of concomitant systemic co-morbidities,treatment,prognosis and bacteriology.Results:32 patients from 2007.01 to 2013.01(mean age was 57.71 years)were included.The cases were increased year by year.1 1 (34.37%)patients had breathing difficulty requiring tracheostomy and 19 (59.3%)had concomitant systemic comorbidities.23 cases recovered completely,8 with severe mediastinal infection were trans-ferred to the department of thoracic surgery or the department of respiratory medicine.1 patient died.Pus submission rate was 96.87%,the bacteria detection rate was 37.50%.Pus culture showed mixed infection dominated by streptococci.Staphylococcus au-reus,pseudomonas aeruginosa,enterococcus faecalis,prevotella and neisseria were detected.Conclusion:Annually incidence of life threatening head and neck space infection is increasing.Treatment of the infection should include:①Ensuring the airway patency;②Surgical incision and drainage as early as possible;③ Hypoglycemic control,maintenance of hemodynamic,nutritional support,and multi-disciplinary approach are the key points in the management of such infections;④ Systemic antibiotics.

Effects of remifentanil on the proliferation and apoptosis of human liver carcinoma cell line HepG2 in vitro / 中国医师杂志

Objective To evaluate the effects of remifentanil on the proliferation,the cell cycle and apoptosis of human liver carcinoma cell line HepG2 in vitro.Methods Human liver carcinoma cells HepG2 were cultured in vitro.The HepG2 cells of the test group were incubated in the RPMI-1640 medium with remifentanil at different concentration(0.001,0.01,0.1,1,10,100,200 μmol/L).The HepG2 cells of the control group were incubated in the RPMI-1640 medium for 48 hours.The level of the cell proliferation was evaluated with methylthiazolyldiphenyl-tetrazolium bromide (MTT) method.The cell cycle was detected with flow cytometry (FCM).The morphological change of apoptosis cell was observed by fluorescence microscopy after staining by Hoechst33258.Results Remifentanil inhibited the proliferation of the HepG2 cells with a dose-dependent effect.Compared with control group,the cell proliferation capability was apparently decreased in the test group (P ＜ 0.05) when the concentration of remifentanil was over 1 μmol/L (P ＜0.05).However,no significant difference in cell proliferation was found when remifentanil was 100 and 200 μmol/ L.The ratio of G0/G1 phase of HepG2 cells was significantly enhanced and the ratio of S phase of HepG2 cells was significantly decreased when remifentanil was over 1 μmol/L.The fluorescent microscopy stained by the Hoechst33258 showed part of HcpG2 cells apoptosis in test group,and the apoptotic rate was significantly increased when remifentanil was over 1 μmol/L (P ＜ 0.05).Conclusions The data suggest that remifentanil would inhibit the proliferation of HepG2 cells and induce apoptosis when remifentanil was over 1 μmol/L.

Ultrastructural changes of genital tract Chlamydia trachomatis after treatment with azithromycin in vitro / 中华皮肤科杂志

ObjectiveTo observe the ultrastructural changes of Chlamydia trachomatis after treatment with azithromycin.Methods The Chlamydia trachomatis laboratory strain (D/UW-3/Cx) was cultured in McCoy cells with or without the presence of azithromycin of 0.0667,0.1340,0.1900,0.2680 and 0.3330 mg/L for 48 hours.The ultrastructural changes of host cells andChlamydia trachomatis were observed by transmission electron microscopy.ResultsAfter 48-hour culture,vesicles increased in number both inside and outside of the inclusion bodies with the rise in azithromycin concentration; there were abnormally large reticulate bodies,some of which experienced abnormal division and even necrosis or breakdown; the number of elementary bodies was decreased,while their size was enlarged,with a more wrinkled outer membrane.No inclusionbodieswereseenwhentheconcentrationofazithromycinwas0.333mg/L. Conclusions Azithromycin can induce an increment in the outer membrane of Chlamydia trachomatis,formation of vesicles,abnormal enlargement or breakdown of reticulate bodies,and a decrease in elementary bodies.

Effect of hemorrhage on cell apoptosis in hippocampal CA1 region of rats under controlled hypotension / 中南大学学报(医学版)

Objective To explore the effect of hemorrhage on cell apoptosis in the hippocampal CA1 region of rats under controlled hypotension (CH).Methods A total of 36 Sprague Dawley rats were randomly divided into 2 groups: Group C (with no CH) and Group H (with CH).According to different ratios of blood loss to total blood volume, Group C and Group H were redivided into 6 subgroups (6 in each group):C_1,H_1(10%);C_2,H_2(20%);C_3,H_3 (30%). Induced by so-dium nitroprusside and esmolol, the mean aterial pressure in Group H was decreased to 50～55 mmHg and kept for 10 minutes, and then blood loss was started, keeping the pump speed. Without CH, the same style of hemorrhage was performed in Group C. The aterial pressure was increased 60 minutes later after the hemorrhage.Expression of bcl-2 and caspase-3 protein was detected by immunohistochemical method, and apoptosis cells were detected by TUNEL staining. Results The average optical density of bcl-2 and caspase-3 was higher in Group H_3 than that in Group C_3(P＜0.05). There were more apoptosis cells examined by TUNEL in Group H_3 than in Group C_3(P＜0.05).Conclusion Thirty percent blood loss under controlled hypotension can induce cell apoptosis in hippocampal CA1 region in rats.

Effect of different tidal volume ventilation on apoptosis and the expression of Bax and Bcl-2 in rat lungs / 中南大学学报(医学版)

OBJECTIVE@#To determine the effect of different tidal volume(Vt) ventilation on apoptosis and the expression of Bax and Bcl-2 in rat lungs.@*METHODS@#Twenty-four healthy SD rats were randomly divided into 4 groups: a control group, a low Vt ventilation group (LV), a middle Vt ventilation group (MV), and a high Vt ventilation group (HV). Rats were subjected to different tidal volumes (10,20,and 40 mL/kg) for 2 h except the control group, which kept their own breath. We determined the lung histopathology score, W/D ratio and WBC in bronchoalceolar lavage fluid (BALF) to evaluate the lung injury and examine the apoptotic cell death, Bax and Bcl-2 protein expression by using TUNEL technique and immunohistochemistry 24 h after the operation.@*RESULTS@#Compared with the control group, MV and HV increased lung histopathology score, W/D ratio, WBC in BALF, apoptosis index (AI )and Bax protein expression, but decreased Bcl-2 protein expression (P0.05).@*CONCLUSION@#Low Vt ventilation contributed little to apoptosis. Higher Vt ventilation can improve Bax while inhibit Bcl-2 expression to aggravate apoptosis in rat lungs.

The effect of hypercapnic acidosis preconditioning on rabbit myocardium / 华中科技大学学报（医学）（英德文版）

This study observed the protective effect of hypercapnic acidosis preconditioning on rabbit heart suffered from ischemia-reperfusion injury. Hypercapnic acidosis was established in animals with mechanical hypoventilation before ischemia-reperfusion. Thirty-two rabbits were randomly divided into 4 groups, with each having 8 animals in term of the degree of acidification: hypercapnic acidosis group A (group A), hypercapnic acidosis group B (group B), hypercapnic acidosis group C (group C), ischemia and reperfusion group (group IR). Animals in group IR were ventilated normally (tidal volume: 15 mL/kg, breathing rate 35 bpm). The PETCO(2) was maintained at the level of 40-50 mmHg for 30 min. Animals in groups A, B, C received low-frequency, low-volume ventilation to achieve hypercarbonic acidosis and the target levels of PETCO(2) were 75-85,65-75, 55-65 mmHg, respectively, with levels being maintained for 5 min. The animals then were ventilated normally to lower PETCO(2) to 40-50 mmHg. The left anterior branch artery of all the animals was ligated for 30 min and reperfused for 180 min. Then the infarct size was calculated. The cardiomyocytes were morphologically observed and ECG and hemodynamics were monitored on continuous basis. Acid-base balance was measured during procedure. Our results showed that the infarct size was (48.5+/-11.5)% of the risk area in the control group and (42.4+/-7.9)% in group C (P>0.05). Mean infarct size was significantly smaller in group B (34.5%+/-9.4%) (P<0.05 vs control group) and group A (31.0%+/-9.1%) (P<0.01 vs control group). It is concluded that HA-preconditioning can effectively protect the myocardium.

Effects of low tidal-volume ventilation on blood gases and respiratory mechanics in childran during open heart surgery / 中华麻醉学杂志

Objective To evaluate the effects of low tidal-volume ventilation on blood gases and respiratory mechanics during open heart surgery in children with acyanotic congenital heart disease. Methods Forty NYHA class Ⅰ-Ⅱ patients with atrial or ventricular septal defect aged 3-6 yrs weighing 12-18 kg undergoing open heart surgery were randomly divided into 2 groups according to the tidal volume of mechanical ventilation: group A low tidal volume(V_r=7ml?kg~(-1),n=20) and group B conventional tidal volume(V_T=9 ml?kg~(-1), n=20). The respiratory rate(RR) was 21-23 bpm, I: E ratio 1:2 and FiO_2 100% in both groups. The patients were premedicated with intramuscular morphine 0.1 mg?kg~(-1) and scopolamine 0.01 mg?kg~(-1). Anesthesia was induced with midazolam 0.1 mg?kg~(-1), fentanyl 10 ?g?kg~(-1) and vecuronium 0.1 mg?kg~(-1) and maintained with infusion of fentanyl 4 ?g?kg~(-1)?h~(-1) and vecuronium 80 ?g?kg?h~(-1) supplemented with isoflurane inhalation(

Influence of sodium ferulate on MDA, SOD, ET and NO during myocardial ischemia and reperfusion injury / 中华麻醉学杂志

Objective:To observe the protective effects of sodium ferulate (SF) on rabbit myocardial ischemia reperfusion injury. Method: Sixteen rabbits were divided randomly into three groups: group A undergoing all procedures except for ischemia-reperfusion and treatment, group B given the routine treatment after ischemia-reperfusion, and group C receiving the routine treatment combined with the intravenous infusion of SF 40mg?kg~(-1) after ischemiareperfusion. Result: Group C showed a significant reduction in myocardial MDA content and plasma ET level (P

Study on gene expression of Chk1 after cerebral ischemia-reperfusion in rats / 中华麻醉学杂志

Objective To investigate the gene expression of Chk1 gene in cerebrum after brain ischemia-reperfusion, trying to provide evidence to elucidate the molecular mechanism of brain injury.Methods Eighty-five male Wistar rats were divided into 3 groups.Group Ⅰ served as normal control.In group Ⅱ (non-ischemia group) animals underwent the whole experimental procedures except the occlusion of the bilateral vertebro-arteries and common carotid arteries.In group Ⅲ (ischemia-reperfusion group) animals were further divided into 3 subgroups according to the duration of ischemia: 10min, 30min and 60min.Each subgroup was again further divided based on the duration of reperfusion: 30min,2h and 6h.The cerebrum was immediately removed from rats after complete brain ischemia-reperfusion. The RNA was isolated and the reverse-transcription-polymerase chain reaction (RT-PCR) was carried out .The cDNA was analyzed by automatic system and the parameters were assessed to define the status of Chk1 mRNA expression in different ischemia and reperfusion groups.Results The quantity of Chk1 mRNA expression in the cerebral cortex of normal adult rat was about half of the glyceraldehyde-3-phosphate-dehydrogenase. When reperfused for 30min, 2h or 6h following 10min, 30 min cerebral ischemia and reperfused for 30min or 2h following 60 min cerebral ischemia, the expression of Chk1 mRNA was not significantly different from that in non-ischemia group.Only reperfused for 6h following 60 min cerebral ischemia, Chk1 mRNA expression decreased significantly.Conclusions The results indicate that Chk1 gene might be involved in molecular mechanism of cerebrum damage during complete global brain ischemia-reperfusion.

Effects of selective mild cerebral hypothermia on endogenous anti-injury mechanism in brain tissue after cardiac arrest and resuscitation / 中华麻醉学杂志

Objective To study the effects of selective mild cerebral hypothermia on endogenous anti-injury mechanism in brain tissue after cardiac arrest and resuscitation. Methods Fifteen healthy mongrel dogs of both sexes were anesthetized and intubated. Cardiac arrest was induced by potassium cardioplegia and cross-clamping of aorta, vena cava superior and inferior and azygos vein and maintained for 18min. The animals were randomly divided into 3 groups: group A, in which no cardiac arrest was induced, served as control ( n = 4) ; in group B animals received routine cerebral resuscitation ( n = 5) ; in group C animals received selective mild cerebral hypothermia (34℃?0.5℃) and routine cerebral resuscitation ( n = 6) . After successful resuscitation, the animals were observed for 8 hours. At the end of the experiment the parietal cerebral cortex was removed for determination of MDA, GSH, LA, FFA content and activities of SOD(T-SOD, Mn-SOD, Cu-ZnSOD) and GSH-Px. Results FFA and LA content of brain tissue in group B was significantly higher than those in group A (P

The Effect of Low Tidal Volume Ventilation on Pulmonary and Cardiac Function before and after Mitral Valve Replacement / 中国医师杂志

Objective To investigate the effects of low tidal volume ventilation on pulmonary and cardiac function before and after mitral valve replacement. Methods Thirty patients with mitral valve diseases were randomly divided into traditional tidal volume ventilation (groupⅠ), low tidal volume ventilation with conventional respiratory rate (group Ⅱ), and low tidal volume ventilation with high respiratory rate (group Ⅲ). Mean arterial pressure (MAP), cardiac output(CO), cardiac index(CI), mean pulmonary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), systemic vascular resistance index (SVRI), and pulmonary vascular resistance index (PVRI) were monitored. Arterial oxygen tension (PaO_2), carbon dioxide tension (PaCO_2), oxygen saturation index(PaO_2/FiO_2), alveolar-arterial PO_2 gradient (PA-aO_2), and Q_S/Q_T were measured. Results Before CPB, CO in group Ⅰ was significantly lower than that in group Ⅲ (P

Study on gene expression of Chk1 after cerebral ischemia-reperfusion in rats / 中华麻醉学杂志

ObjectiveTo investigate the gene expression of Chk1 gene in cerebrum after brain ischemia-reperfusion,trying to provide evidence to elucidatethe molecular mechanism of brain injury. MethodsEighty-five male Wistar rats were divided into 3 groups. Group Ⅰ served as normal control. In group Ⅱ (non-ischemia group) animals underwent the whole experimental procedures except the occlusion of the bilateral vertebro-arteries and common carotid arteries. In group Ⅲ(ischemiareperfusion group) animals were further divided into 3 subgroups according to the duration of ischemia: 10min, 30min and 60min. Each subgroup was again further divided based on the duration of reperfusion: 30min, 2h and 6h. The cerebrum was immediately removed from rats after complete brain ischemiareperfusion. The RNA was isolated and the reverse-transcription-polymerase chain reaction (RT-PCR) was carried out . The cDNA was analyzed by automatic system and the parameters were assessed to define the status of Chk1 mRNA expression in different ischemia and reperfusion groups. ResultsThe quantity of Chk1 mRNA expression in the cerebral cortex of normal adult rat was about half of the glyceraldehyde-3-phosphatedehydrogenase. When reperfused for 30min, 2h or 6h following 10min, 30 min cerebral ischemia and reperfused for 30min or 2h following 60 min cerebral ischemia, the expression of Chk1 mRNA was not significantly different from that in non-ischemia group. Only reperfused for 6h following 60 min cerebral ischemia, Chk1 mRNA expression decreased significantly. ConclusionsThe results indicate that Chk1 gene might be involved in molecular mechanism of cerebrum damage during complete global brain ischemia- reperfusion.