| Background:Aneurysm subarachnoid hemorrhage(a SAH)is a critical neurological disease with high rates of mortality and morbidity.The average age of these patients is lower than other types of stroke patients,causing heavy economic burden to the society.Recently,the improving identification and early management of the bleeding source,management of patients in the neurocritical care unit with oral nimodipine,decrease the mortality of SAH patients.Recently,the concept of early brain injury(EBI)was put forward,which was caused by the pathophysiologic changes during the first 72 h following SAH.EBI is the major factor which is closely related to prognosis.Early intervention can improve the treatment and lead to better outcomes.It's important to get early diagnosis and timely treatment for early brain injury.It's difficult to get early diagnosis for specific biomarker is lacked.So it's urgent to find a specific biomarker.Objective:To build an ear artery-intracranial shunt SAH model.To investigate the expression of Ngb?LCN-2 of brain tissue and CSF of rabbit after SAH.Method:1 The rabbits were randomly divided into a sham group(n=16)and SAH group(n=25).SAH model was performed using bleeding driving technique.The ear central artery was punctured and the blood was shunt into chiasmatic cistern.Intracranial pressure(ICP),regional cerebral blood flow(r CBF)were monitored.Brain water content and blood brain barrier(BBB)permeability were evaluated after the SAH was performed.The head of the rabbits were scanned by CT,and the histological of the brain was stained with HE and Nissl.2 76 rabbits were randomly divided into sham group,SAH3 h group,SAH6 h group,SAH12 h group?SAH24h group,SAH48 h group,SAH72 h group(each group n=8),CSF group(n=20).Sham group and each SAH group,brains were taken out.The levels of Ngb and LCN-2 in brain tissue were evaluated by western blot analysis.And the concentration of Ngb,LCN-2,TNF-? and IL-6 in cerebral spinal fluid was also tested by Elisa.Result:1 The ear central artery-chiasmatic cistern SAH rabbit model was built.The r CBF decreased dramatically after the onset of SAH.Then reached at the lowest spot after 3 minutes,whose value was 42.5% of baseline.Before SAH model was performed,the neurological and behavior score was 2.And it increased to4.9±0.47 at 24 h.Then the rabbit's food intake was reduced.And rabbits had symptoms such as depression,hair messy.As for 48 h and 72 h,the scores were5.4±1.02 and 5.6±0.8.Then the food intake was lesser.Some rabbits even became unconsciousness.Brain water content at 24 h was higher than the sham group.The CT scan showed some bubble shadow in chiasmatic cistern,which means the shunt tube had being put accurately.2 western blot analysis showed that SAH resulted in increased ratio of Ngb level,which peaked at 24 h after SAH.Elisa test showed that the concentration of Ngb in CSF also increased after SAH.The peak is also at 24 h.LCN-2 level of brain tissue increased at 24 h,and peaked at 48 h after SAH.The concentration of LCN-2in CSF also increased after SAH.Elisa test showed that the concentration of TNF-? and IL-6 in CSF increased after SAH,peaked at 72 h after SAH.Conclusion: 1 A novel SAH model was established in this research.Monitoring ICP,r CBF,brain water content,BBB permeability,we can conclude that the ear central arterychiasmatic cistern model can be used as a EBI model after SAH,for it can stimulate the conditions of EBI.The conditions include the elevation of ICP,cerebral perfusion disruption,BBB damage and cerebral edema.2 The level of Ngb or LCN-2 in brain tissue increased and peaked at 24 h or 48 h after SAH.the concentration of Ngb in CSF also increased after SAH.The peak is also at 24 h or 48 h,which mean that using Ngb and LCN-2 as a EBI biomarker is convenient and practicable. |
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