Mesenchymal stem cells transplantation suppresses inflammatory responses in global cerebral ischemia: contribution of TNF-α-induced protein 6.

AIM: To investigate the effects of mesenchymal stem cells (MSCs) transplantation on rat global cerebral ischemia and the underlying mechanisms. METHODS: Adult male SD rats underwent asphxial cardiac arrest to induce global cerebral ischemia, then received intravenous injection of 5×10(6) cultured MSCs of SD rats at 2 h after resuscitation. In another group of cardiac arrest rats, tumor necrosis factor-α-induced protein 6 (TSG-6, 6 µg) was injected into the right lateral ventricle. Functional outcome was assessed at 1, 3, and 7 d after resuscitation. Donor MSCs in the brains were detected at 3 d after resuscitation. The level of serum S-100B and proinflammatory cytokines in cerebral cortex were assayed using ELISA. The expression of TSG-6 and proinflammatory cytokines in cerebral cortex was assayed using RT-PCR. Western blot was performed to determine the levels of TSG-6 and neutrophil elastase in cerebral cortex. RESULTS: MSCs transplantation significantly reduced serum S-100B level, and improved neurological function after global cerebral ischemia compared to the PBS-treated group. The MSCs injected migrated into the ischemic brains, and were observed mainly in the cerebral cortex. Furthermore, MSCs transplantation significantly increased the expression of TSG-6, and reduced the expression of neutrophil elastase and proinflammatory cytokines in the cerebral cortex. Intracerebroventricular injection of TSG-6 reproduced the beneficial effects of MSCs transplantation in rats with global cerebral ischemia. CONCLUSION: MSCs transplantation improves functional recovery and reduces inflammatory responses in rats with global cerebral ischemia, maybe via upregulation of TSG-6 expression.

[Effects and mechanisms of heme oxygenase-1 on rats with postresuscitation myocardial dysfunction].

OBJECTIVE: To explore the effects and mechanisms of heme oxygenase-1 on rats with postresuscitation myocardial dysfunction. METHODS: Male Sprague-Dawley rats were asphyxiated for 9 minutes and resuscitated. They were randomly divided into 4 groups: sham-operated, cardiopulmonary resuscitation (CPR), hemin and hemin + ZnPP (zinc protoporphyrin IX). Resuscitated groups had 2 observation points: 6 and 24 hours post-CPR (n = 8 for each time point). And the sham-operated group of 12 rats were divided in two observation points, according to 6 or 24 hours post-operation (n = 6 each). Hemodynamic was observed. The expression of heme oxygenase-1 (HO-1) in cardiac tissue was detected by Western blot. And the activity of cardiac homogenate superoxide dismutase (SOD) was determined by xanthine oxidase method and the level of malondialdehyde (MDA) measured by the thiobarbituric acid method. Nitrotyrosine protein expression in cardiac tissue was analyzed by immunohistochemistry. RESULTS: (1) The mean blood pressure (MAP) significantly decreased in resuscitated groups after resuscitation (all P < 0.05). No difference existed between the subgroups. The scores of dP/dt40 and -dP/dt significantly decreased in CPR and hemin + ZnPP groups after resuscitation (all P < 0.05). But dP/dt40 in hemin group did not differ significantly after resuscitation and -dP/dt decreased only 0.5 hour and 1 hour post-resuscitation (3341.60 ± 524.85 and 3711.40 ± 502.39 vs 4284.20 ± 800.87, all P < 0.05). The scores of dP/dt40 and -dP/dt in hemin group at all time points post-resuscitation were significantly higher than those in CPR and hemin + ZnPP groups (all P < 0.05). (2) Compared with the sham-operated group, the HO-1 expression, MDA level and nitrotyrosine protein expression significantly increased while the activities of SOD decreased after resuscitation in the CPR, hemin and hemin + ZnPP groups (all P < 0.05). Compared with the CPR and hemin + ZnPP groups, the expression of HO-1 and the activity of SOD increased, while MDA level and nitrotyrosine protein expression were decreased in group hemin (all P < 0.05). No difference existed in the above indices between the CPR and hemin + ZnPP groups. CONCLUSION: HO-1 can reduce myocardial oxidative stress injury after cardiopulmonary resuscitation and effectively improve post-resuscitation myocardial function in rats.

[The epidemiological characteristic of 97,823 cases of pre-hospital medical care in Guangzhou city].

OBJECTIVE: To investigate the epidemiological information of patients in pre-hospital medical care in Guangzhou city, and to explore the characteristics of the patients. METHODS: The data in the year of 2008 were retrieved from the computer database of Guangzhou Emergency Medical Rescue Command Center. RESULTS: (1)In a total of 969 410 calls received, the time of distribution was found to be mainly between 16:00 and 18:00 [11.78% (114 224)], and least frequently between 04:00 and 06:00 [2.40% (23 237)]. (2)Among 109 682 dispatches of ambulances, Baiyun district received the most [26.77% (29 364)], and followed by Haizhu district [18.30% (20 069)], Tianhe district [18.20% (19 962)], respectively. (3)Among 97 823 cases of pre-hospital medical care, death rate of the male patients was higher than the female [amount: 57.65% (56 394) vs. 38.48% (37 641), mortality: 59.17% (3 269) vs. 33.95% (1 876)]. (4)In 9 7823 cases of pre-hospital medical care, trauma constituted the highest rate [34.57% (33 820)], especially traffic accidents [11.56% (11 307)], and the age of most of the patients ranged between 21 and 50. Disease of the nervous system ranged the second, followed by diseases of circulatory system, respiratory system and digestive system, and most of them were over 51 years old, and most frequently above 70. (5)In 97 823 cases of pre-hospital medical care, there were 5 525 deaths (5.65%), in whom the circulatory system diseases ranged first (especially sudden death) [33.07% (1 827)], followed by unclassified diseases [29.79% (1 646)], trauma [15.67% (866)], respiratory diseases [7.48% (413)], and neurological emergency illnesses [5.95% (329)]. The age of deceased was far older than 51, particularly 70. The age of most of the deceased was above 61, and age of traumatic death was 21-40. CONCLUSION: (1) It is very important to reduce the death rate of the middle-old aged patients by strengthening prevention and timely treatment of cardiovascular and cerebrovascular diseases, and improve the medical strategies in emergency care, in order to lower the death rate during emergency.(2)It is very important to emphasize safely in production lines and to strengthen traffic regulations in order to reduce the incidence of trauma, thus it is especially traffic accident, expect that the death rate of trauma could be lowered.

Carbon Monoxide Improves Neurologic Outcomes by Mitochondrial Biogenesis after Global Cerebral Ischemia Induced by Cardiac Arrest in Rats.

Mitochondrial dysfunction contributes to brain injury following global cerebral ischemia after cardiac arrest. Carbon monoxide treatment has shown potent cytoprotective effects in ischemia/reperfusion injury. This study aimed to investigate the effects of carbon monoxide-releasing molecules on brain mitochondrial dysfunction and brain injury following resuscitation after cardiac arrest in rats. A rat model of cardiac arrest was established by asphyxia. The animals were randomly divided into the following 3 groups: cardiac arrest and resuscitation group, cardiac arrest and resuscitation plus carbon monoxide intervention group, and sham control group (no cardiac arrest). After the return of spontaneous circulation, neurologic deficit scores (NDS) and S-100B levels were significantly decreased at 24, 48, and 72 h, but carbon monoxide treatment improved the NDS and S-100B levels at 24 h and the 3-day survival rates of the rats. This treatment also decreased the number of damaged neurons in the hippocampus CA1 area and increased the brain mitochondrial activity. In addition, it increased mitochondrial biogenesis by increasing the expression of biogenesis factors including peroxisome proliferator-activated receptor-γ coactivator-1α, nuclear respiratory factor-1, nuclear respiratory factor-2 and mitochondrial transcription factor A. Thus, this study showed that carbon monoxide treatment alleviated brain injury after cardiac arrest in rats by increased brain mitochondrial biogenesis.

Changes of end-tidal carbon dioxide during cardiopulmonary resuscitation from ventricular fibrillation versus asphyxial cardiac arrest.

BACKGROUND: Partial pressure of end-tidal carbon dioxide (PETCO2) has been used to monitor the effectiveness of precordial compression (PC) and regarded as a prognostic value of outcomes in cardiopulmonary resuscitation (CPR). This study was to investigate changes of PETCO2 during CPR in rats with ventricular fibrillation (VF) versus asphyxial cardiac arrest. METHODS: Sixty-two male Sprague-Dawley (SD) rats were randomly divided into an asphyxial group (n=32) and a VF group (n=30). PETCO2 was measured during CPR from a 6-minute period of VF or asphyxial cardiac arrest. RESULTS: The initial values of PETCO2 immediately after PC in the VF group were significantly lower than those in the asphyxial group (12.8±4.87 mmHg vs. 49.2±8.13 mmHg, P=0.000). In the VF group, the values of PETCO2 after 6 minutes of PC were significantly higher in rats with return of spontaneous circulation (ROSC), compared with those in rats without ROSC (16.5±3.07 mmHg vs. 13.2±2.62 mmHg, P=0.004). In the asphyxial group, the values of PETCO2 after 2 minutes of PC in rats with ROSC were significantly higher than those in rats without ROSC (20.8±3.24 mmHg vs. 13.9±1.50 mmHg, P=0.000). Receiver operator characteristic (ROC) curves of PETCO2 showed significant sensitivity and specificity for predicting ROSC in VF versus asphyxial cardiac arrest. CONCLUSIONS: The initial values of PETCO2 immediately after CPR may be helpful in differentiating the causes of cardiac arrest. Changes of PETCO2 during CPR can predict outcomes of CPR.