Gastrointestinal dysfunction is a common peripheral organ complication after traumatic brain injury (TBI), yet the underlying mechanism remains unknown. TBI has been demonstrated to cause gut microbiota dysbiosis in animal models, although the impacts of gut microbiota dysbiosis on gastrointestinal dysfunction were not examined. Bile acids are key metabolites between gut microbiota and host interactions. Therefore, the aim of this study was to investigate the mechanistic links between them by detecting the alterations of gut microbiota and bile acid profile after TBI. For that, we established TBI in mice using a lateral fluid percussion injury model. Gut microbiota was examined by 16S rRNA sequencing, and bile acids were profiled by ultra-performance liquid chromatography-tandem mass spectrometry. Our results showed that TBI caused intestinal inflammation and gut barrier impairment. Alterations of gut microbiota and bile acid profile were observed. The diversity of gut microbiota experienced a time dependent change from 1 h to 7 days post-injury. Levels of bile acids in feces and plasma were decreased after TBI, and the decrease was more significant in secondary bile acids, which may contribute to intestinal inflammation. Specific bacterial taxa such as Staphylococcus and Lachnospiraceae that may contribute to the bile acid metabolic changes were identifed. In conclusion, our study suggested that TBI-induced gut microbiota dysbiosis may contribute to gastrointestinal dysfunction via altering bile acid profile. Gut microbiota may be a potential treatment target for TBI-induced gastrointestinal dysfunction.

DAI is a leading cause of the patient's death or lasting vegetable state following severe TBI, and up to now the detailed mechanism of axonal injury after head trauma is still unclear. Inflammatory responses have been proved to be an important mechanism of neural injury after TBI. However, most of these studies are concerned with focal cerebral injury following head trauma. In contrast to focal injury, studies on the inflammatory reaction following DAI are only beginning. And in this article, we aimed to review such studies. From the studies reviewed, immune response cells would become reactive around the sites of axonal injury after DAI. Besides, the concentrations of several important inflammatory factors, such as IL-1 family, IL-6 and TNF-ɑ, increased after DAI as well, which implies the participation of inflammatory responses. It can be concluded that inflammatory responses probably participate in the neural injury in DAI, but at present the study of inflammatory responses following DAI is still limited and the clear effects of inflammatory response on axonal injury remain to be more explored.

Refractory intracranial hypertension is a leading cause of poor neurological outcomes in patients with severe traumatic brain injury. Decompressive craniectomy has been used in the management of refractory intracranial hypertension for about a century, and is presently one of the most important methods for its control. However, there is still a lack of conclusive evidence for its efficacy in terms of patient outcome. In this article, we focus on the technical aspects of decompressive craniectomy and review different methods for this procedure. Moreover, we review technical improvements in large decompressive craniectomy, which is currently recommended by most authors and is aimed at increasing the decompressive effect, avoiding surgical complications, and facilitating subsequent management. At present, in the absence of prospective randomized controlled trials to prove the role of decompressive craniectomy in the treatment of traumatic brain injury, these technical improvements are valuable.

The mutations in the SARS-CoV-2 virus genome during COVID-19 dissemination are unclear. In 788 COVID-19 patients from Zhejiang province, we observed decreased rate of severe/critical cases compared with patients in Wuhan. For mechanisms exploration, we isolated one strain of SARS-CoV-2 (ZJ01) from a mild COVID-19 patient. Thirty-five specific gene mutations were identified. Phylogenetic and relative synonymous codon usage analysis suggested that ZJ01 may be a potential evolutionary branch of SARS-CoV-2. We classified 54 global virus strains based on the base (C or T) at positions 8824 and 28247 while ZJ01 has T at both sites. The prediction of the Furin cleavage site (FCS) and sequence alignment indicated that the FCS may be an important site of coronavirus evolution. ZJ01 mutations identified near the FCS (F1-2) caused changes in the structure and electrostatic distribution of the S surface protein, further affecting the binding capacity of Furin. Single-cell sequencing and ACE2-Furin co-expression results confirmed that the Furin expression was especially higher in glands, liver, kidneys, and colon. The evolutionary pattern of SARS-CoV-2 towards FCS formation may result in its clinical symptom becoming closer to HKU-1 and OC43 caused mild flu-like symptoms, further showing its potential in differentiating into mild COVID-19 subtypes.

Aims: To evaluate the efficacy of our methods for decreasing the incidence of post-operative central nervous system infections (PCNSI) and to assess the type of microbiology and risk factors associated with PCNSI. Methods: This prospective study was performed at First Affiliated Hospital, College of Medicine, Zhejiang University, which is a major medical centre in eastern China. The study included adult patients who underwent cranial surgery from January 2014 to October 2015 at this institution and survived for more than 7 days . The demographic information and clinical data of the patients were recorded for every operation and the incidence of PCNSI and the type of microbiology were analysed separately for patients undergoing craniotomy and those undergoing cranial burr-hole surgery. Prior to initiation of the study, our research team had developed and implemented a series of methods for reducing infection rates in our department. Results: A total of 1,616 cranial surgery procedures were assessed in the present study; 1,236 craniotomy/craniectomy operations and 380 cranial burr-hole surgery operations. Of these procedures, 29 were complicated by PCNSI (27 cases with meningitis/ventriculitis and two with intracranial abscess/empyema). The overall incidence of PCNSI was 1.8%, while the incidence of craniotomy/craniectomy operations was 2.0% (25 cases) and that of burr-hole surgery operations was 1.1% (four cases); the most common microorganism was Staphylococcus. Of the patients who underwent cranial burr-hole surgery, the only independent risk factor for PCNSI was the absence of prophylactic antibiotics. There were no independent risk factors for craniotomy/craniectomy operations. Conclusions: In the present large-sample study, the incidence of PCNSI was 1.8%, which was dramatically lower than that of a previous study performed by our research group.

Background: A large cranial defect combined with hydrocephalus is a frequent sequela of decompressive craniectomy (DC) performed to treat malignant intracranial hypertension. Currently, many neurosurgeons perform simultaneous cranioplasty and shunt implantation on such patients, but the safety of this combined procedure remains controversial. Methods: We retrospectively evaluated 58 patients treated via cranioplasty and shunt implantation after DC. Twenty patients underwent simultaneous procedures (simultaneous operation group) and 38 underwent staged procedures (staged operation group). We collected and analysed demographic data, information on disease histories, and clinical findings. Results: The overall complication rate was 19%. The two groups did not significantly differ regarding the all-complication (30% vs. 13%), bleeding complication (0% vs. 5%), or treatment failure (15% vs. 3%) rates. However, the rate of surgical site infection/incision healing problems (25% vs. 3%) and the re-operation rate (20% vs. 3%) were significantly higher in the simultaneous operation group. Conclusion: Patients undergoing simultaneous cranioplasty/shunt implantation may be at a higher risk of infectious complications than those undergoing staged operations.