Atorvastatin combined with low-dose dexamethasone for vascular endothelial cell dysfunction induced by chronic subdural hematoma

Atorvastatin has been shown to be a safe and effective non-surgical treatment option for patients with chronic subdural hematoma.However,treatment with atorvastatin is not effective in some patients,who must undergo further surgical treatment.Dexamethasone has anti-inflammatory and immunomodulatory effects,and low dosages are safe and effective for the treatment of many diseases,such as ankylosing spondylitis and community-acquired pneumonia.However,the effects of atorvastatin and low-dose dexamethasone for the treatment of chronic subdural hematoma remain poorly understood.Hematoma samples of patients with chronic subdural hematoma admitted to the General Hospital of Tianjin Medical University of China were collected and diluted in endothelial cell medium at 1:1 as the hematoma group.Atorvastatin,dexamethasone,or their combination was added to the culture medium.The main results were as follows:hopping probe ion conductance microscopy and permeability detection revealed that the best dosages to improve endothelial cell permeability were 0.1μM atorvastatin and 0.1μM dexamethasone.Atorvastatin,dexamethasone,or their combination could markedly improve the recovery of injured endothelial cells.Mice subcutaneously injected with diluted hematoma solution and then treated with atorvastatin,dexamethasone,or their combination exhibited varying levels of rescue of endothelial cell function.Hopping probe ion conductance microscopy,western blot assay,and polymerase chain reaction to evaluate the status of human cerebral endothelial cell status and expression level of tight junction protein indicated that atorvastatin,dexamethasone,or their combination could reduce subcutaneous vascular leakage caused by hematoma fluid.Moreover,the curative effect of the combined treatment was significantly better than that of either single treatment.Expression of Krüppel-like factor 2 protein in human cerebral endothelial cells was significantly increased,as was expression of the tight junction protein and vascular permeability marker vascular endothelial cadherin in each treatment group compared with the hematoma stimulation group.Hematoma fluid in patients with chronic subdural hematoma may damage vascular endothelial cells.However,atorvastatin combined with low-dose dexamethasone could rescue endothelial cell dysfunction by increasing the expression of tight junction proteins after hematoma injury.The effect of combining atorvastatin with low-dose dexamethasone was better than that of atorvastatin alone.Increased expression of Krüppel-like factor 2 may play an important role in the treatment of chronic subdural hematoma.The animal protocols were approved by the Animal Care and Use Committee of Tianjin Medical University of China on July 31,2016(approval No.IRB2016-YX-036).The study regarding human hematoma samples was approved by the Ethics Committee of Tianjin Medical University of China on July 31,2018(approval No.IRB2018-088-01).

Differences in pathological changes between two rat models of severe traumatic brain injury

The rat high-impact free weight drop model mimics the diffuse axonal injury caused by severe traumatic brain injury in humans,while severe controlled cortical impact can produce a severe traumatic brain injury model using precise strike parameters.In this study,we compare the pathological mechanisms and pathological changes between two rat severe brain injury models to identify the similarities and differences.The severe controlled cortical impact model was produced by an electronic controlled cortical impact device,while the severe free weight drop model was produced by dropping a 500 g free weight from a height of 1.8 m through a plastic tube.Body temperature and mortality were recorded,and neurological deficits were assessed with the modified neurological severity score.Brain edema and bloodbrain barrier damage were evaluated by assessing brain water content and Evans blue extravasation.In addition,a cytokine array kit was used to detect inflammatory cytokines.Neuronal apoptosis in the brain and brainstem was quantified by immunofluorescence staining.Both the severe controlled cortical impact and severe free weight drop models exhibited significant neurological impairments and body temperature fluctuations.More severe motor dysfunction was observed in the severe controlled cortical impact model,while more severe cognitive dysfunction was observed in the severe free weight drop model.Brain edema,inflammatory cytokine changes and cortical neuronal apoptosis were more substantial and blood-brain barrier damage was more focal in the severe controlled cortical impact group compared with the severe free weight drop group.The severe free weight drop model presented with more significant apoptosis in the brainstem and diffused blood-brain barrier damage,with higher mortality and lower repeatability compared with the severe controlled cortical impact group.Severe brainstem damage was not found in the severe controlled cortical impact model.These results indicate that the severe controlled cortical impact model is relatively more stable,more reproducible,and shows obvious cerebral pathological changes at an earlier stage.Therefore,the severe controlled cortical impact model is likely more suitable for studies on severe focal traumatic brain injury,while the severe free weight drop model may be more apt for studies on diffuse axonal injury.All experimental procedures were approved by the Ethics Committee of Animal Experiments of Tianjin Medical University,China(approval No.IRB2012-028-02)in Febru ary 2012.

Decreased numbers of circulating endothelial progenitor cells are associated with hyperglycemia in patients with traumatic brain injury

Hyperglycemia reduces the number of circulating endothelial progenitor cells, accelerates their senescence and impairs their function.However, the relationship between blood glucose levels and endothelial progenitor cells in peripheral blood of patients with traumatic brain injury is unclear. In this study, 101 traumatic brain injury patients admitted to the Department of Neurosurgery, Tianjin Medical University General Hospital or the Department of Neurosurgery, Tianjin Huanhu Hospital, China, were enrolled from April 2005 to March 2007. The number of circulating endothelial progenitor cells and blood glucose levels were measured at 1, 4, 7, 14 and 21 days after traumatic brain injury by flow cytometry and automatic biochemical analysis, respectively. The number of circulating endothelial progenitor cells and blood sugar levels in 37 healthy control subjects were also examined. Compared with controls, the number of circulating endothelial progenitor cells in traumatic brain injury patients was decreased at 1 day after injury, and then increased at 4 days after injury,and reached a peak at 7 days after injury. Compared with controls, blood glucose levels in traumatic brain injury patients peaked at 1 day and then decreased until 7 days and then remained stable. At 1, 4, and 7 days after injury, the number of circulating endothelial progenitor cells was negatively correlated with blood sugar levels(r =-0.147, P < 0.05). Our results verify that hyperglycemia in patients with traumatic brain injury is associated with decreased numbers of circulating endothelial progenitor cells. This study was approved by the Ethical Committee of Tianjin Medical University General Hospital, China(approval No. 200501) in January 2015.

Risk factors for corticosteroid insufficiency during the sub-acute phase of acute traumatic brain injury

Hypothalamic-pituitary-adrenal axis dysfunction may lead to the occurrence of critical illness-related corticosteroid insufficiency.Critical illness-related corticosteroid insufficiency can easily occur after traumatic brain injury,but few studies have examined this occurrence.A multicenter,prospective,cohort study was performed to evaluate the function of the hypothalamic-pituitary-adrenal axis and the incidence of critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury.One hundred and forty patients with acute traumatic brain injury were enrolled from the neurosurgical departments of three tertiary-level hospitals in China,and the critical illness-related corticosteroid insufficiency incidence,critical-illness-related corticosteroid insufficiency-related risk factors,complications,and 28-day mortality among these patients was recorded.Critical illness-related corticosteroid insufficiency was diagnosed in patients with plasma total cortisol levels less than 10μg/dL(275.9 nM)on post-injury day 4 or when serum cortisol was insufficiently suppressed(less than 50%)during a dexamethasone suppression test on post-injury day 5.The results demonstrated that critical illness-related corticosteroid insufficiency occurred during the sub-acute phase of traumatic brain injury in 5.6%of patients with mild injury,22.5%of patients with moderate injury,and 52.2%of patients with severe injury.Traumatic brain injury-induced critical illness-related corticosteroid insufficiency was strongly correlated to injury severity during the sub-acute stage of traumatic brain injury.Traumatic brain injury patients with critical illness-related corticosteroid insufficiency frequently presented with hemorrhagic cerebral contusions,diffuse axonal injury,brain herniation,and hypotension.Differences in the incidence of hospital-acquired pneumonia,gastrointestinal bleeding,and 28-day mortality were observed between patients with and without critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury.Hypotension,brain-injury severity,and the types of traumatic brain injury were independent risk factors for traumatic brain injury-induced critical illness-related corticosteroid insufficiency.These findings indicate that critical illness-related corticosteroid insufficiency is common during the sub-acute phase of traumatic brain injury and is strongly associated with poor prognosis.The dexamethasone suppression test is a practical assay for the evaluation of hypothalamic-pituitary-adrenal axis function and for the diagnosis of critical illness-related corticosteroid insufficiency in patients with traumatic brain injury,especially those with hypotension,hemorrhagic cerebral contusions,diffuse axonal injury,and brain herniation.Sub-acute infection of acute traumatic brain injury may be an important factor associated with the occurrence and development of critical illness-related corticosteroid insufficiency.This study protocol was approved by the Ethics Committee of General Hospital of Tianjin Medical University,China in December 2011(approval No.201189).

Stability of rat models of fluid percussion-induced traumatic brain injury: comparison of three different impact forces

Fluid percussion-induced traumatic brain injury models have been widely used in experimental research for years. In an experiment, the stability of impaction is inevitably affected by factors such as the appearance of liquid spikes. Management of impact pressure is a crucial factor that determines the stability of these models, and direction of impact control is another basic element. To improve experimental stability, we calculated a pressure curve by generating repeated impacts using a fluid percussion device at different pendulum angles. A stereotactic frame was used to control the direction of impact. We produced stable and reproducible models, including mild, moderate, and severe traumatic brain injury, using the MODEL01-B device at pendulum angles of 6°, 11° and 13°, with corresponding impact force values of 1.0 ± 0.11 atm（101.32 ± 11.16 k Pa）, 2.6 ± 0.16 atm（263.44 ± 16.21 k Pa）, and 3.6 ± 0.16 atm（364.77 ± 16.21 k Pa）, respectively. Behavioral tests, hematoxylin-eosin staining, and magnetic resonance imaging revealed that models for different degrees of injury were consistent with the clinical properties of mild, moderate, and severe craniocerebral injuries. Using this method, we established fluid percussion models for different degrees of injury and stabilized pathological features based on precise power and direction control.

Role of Regulatory T cell in Clinical Outcome of Traumatic Brain Injury

Background： Traumatic brain injury （TBI） is a life-threatening disease worldwide. Regulatory T cells （Treg ceils） were involved in the immunological system in central nervous system. It is defined as a subpopulation of CD4＋ cells that express CD25 and transcription lactor forkhead box P3. The level of circulating Treg cells increases in a variety of pathologic conditions. The purpose of this study was to uncover the role of circulating Treg cells in TBI. Methods： A clinical study was conducted in two neurosurgical intensive care units of Tianjin Medical University General Hospital and Second Hospital of Tianjin Medical University （Tianjin, China）. Forty patients and 30 healthy controls were recruited t＇rom August 2013 to November 2013. Circulating Treg cells was detected on the follow-up period of 1,4, 7, 14, and 21 days alter TBI. Blood sample （ 1 ml） was withdrawn in the morning and processed within 2 h. Results： There was no significant difference in the level of circulating Treg cells between TBI patients and normal controls during follow-up. TBI patients exhibited higher circulating Treg level than normal controls on the 1st day after TBI. Treg level was decreased on the 4th day, climbed tip on the 7th day and peaked on 14th day after TBI. Treg cells declined to the normal level on 21th day alter TBI. The level of circulating Treg cells was significantly higher in survival TBI patients when compared to nonsurvival TBI patients. TBI patients with improved conditions exhibited significantly higher circulating Treg level when compared to those with deteriorated conditions. The circulating Treg level was correlated with neurologic recovery after TBI. A better neural recovery and lower hospital mortality were found in TBI patients with circulating Treg cells more than 4.91% in total CD4＋ inononuclear cells as compared to those with circulating Treg cells less than 4.91% in total CD4 mononuclear cells in the first 14 days. Conclusions： The level of circulating Treg cells is positively correlated with clinical outcome of TBI. The level of Treg cells predicts the progress for TBI patients and may be a target in TBI treatment.