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Abstract Background After traumatic brain injury (TBI), peripheral monocytes infiltrate into the central nervous system due to disruption of the blood–brain barrier, and play an important role in neuroinflammation. However, the mechanisms regulating the movement and function of peripheral monocytes after TBI have not been fully investigated. Methods TBI patients who underwent surgery at our hospital were recruited. CXCR2 expression in CD14+ monocytes from peripheral blood and cerebrospinal fluid (CSF) of TBI patients around surgery was analyzed by flow cytometry and compared with that of patients who suffered TBI 2–24 months prior and underwent cranioplasty. In vitro, serum or CSF from TBI/non-TBI patients were used to treat peripheral monocytes isolated from healthy volunteers to evaluate their effect on CXCR2 expression. Transwell experiments were performed to analyze the role of CXCR2 in monocyte chemotaxis toward the CSF. The role of CXCR2 in monocyte-mediated immunogenic cell death (ICD) of nerve cells was explored in an indirect co-culture system. Results Transient CXCR2 upregulation in monocytes from the peripheral blood and CSF of TBI patients was detected soon after surgery and was associated with unfavorable outcomes. TBI serum and CSF promoted CXCR2 expression in monocytes, and dexamethasone reversed this effect. Peripheral monocytes from TBI patients showed enhanced chemotaxis toward the CSF and increased inflammatory cytokine secretion. The CXCR2 antagonist SB225002 decreased monocyte chemotaxis toward TBI CSF, and lowered pro-inflammatory cytokine secretion in monocytes treated with TBI serum. SB225002 also relieved ICD in nerve cells co-cultured with TBI serum-treated monocytes. Conclusions CXCR2 is transiently overexpressed in the peripheral monocytes of TBI patients post-surgery, and drives peripheral monocyte chemotaxis toward CSF and monocyte-mediated ICD of nerve cells. Therefore, CXCR2 may be a target for monocyte-based therapies for TBI.

Background: Therapeutic hypothermia may need prolonged duration for the patients with severe traumatic brain injury (sTBI). Methods: The Long-Term Hypothermia trial was a prospective, multicenter, randomized, controlled clinical trial to examine the safety and efficacy in adults with sTBI. Eligible patients were 18–65, Glasgow Coma Scale score at 4 to 8, and initial intracranial pressure (ICP) ≥ 25 mm Hg, randomly assigned to the long-term mild hypothermia group (34–35 °C for 5 days) or normothermia group at 37 °C. The primary outcome was the Glasgow outcome scale (GOS) at 6 months. Secondary outcomes included ICP control, complications and laboratory findings, the length of ICU and hospital stay, and GOS at 6 months in patients with initial ICP ≥ 30 mm Hg. This trial is registered with ClinicalTrials.gov, NCT01886222. Findings: 302 patients were enrolled from June 25, 2013, to December 31, 2018, with 6 months follow-up in 14 hospitals, 156 in hypothermia group and 146 in normothermia group. There was no difference in favorable outcome (OR 1·55, 95%CI 0·91–2·64; P = 0·105) and in mortality (P = 0·111) between groups. In patients with an initial ICP ≥ 30 mm Hg, hypothermic treatment significantly increased favorable outcome over normothermia group (60·82%, 42·71%, respectively; OR 1·861, 95%CI 1·031–3·361; P = 0·039). Long-term mild hypothermia did not increase the incidences of complications. Interpretation: Long-term mild hypothermia did not improve the neurological outcomes. However, it may be a potential option in sTBI patients with initial ICP ≥ 30 mm Hg. Funding: : Shanghai municipal government and Shanghai Jiao Tong University/School of Medicine.

The deformation of existing pipelines caused by the tunneling of a shield machine along curved sections has not been sufficiently researched, and a corresponding theoretical prediction formula is lacking. This paper derives a prediction formula for the deformation of an existing pipeline caused by shield machine tunneling along a curved section. Further, a finite difference model (FDM) corresponding to an actual project is built. Finally, the deformation of the surface and existing pipelines caused by shield machine tunneling along the curved section is analyzed. The research results show that the results of theoretical prediction, FDM calculation, and field monitoring data are consistent. In addition, the deformation of the surface and the existing pipeline are asymmetrically distributed when the shield machine tunnels along the curve section instead of symmetrically distributed (for straight line segment). When the pipeline is perpendicular to the tunnel axis, the maximum deformation position of the existing pipeline deviates from the tunnel axis by about 0.5 times the tunnel radius. In addition, as the angle β between the pipeline axis and the tunnel axis increases, the maximum deformation position of the pipeline gradually approaches the tunnel axis.