Shiwen Chen

Predicting Progressive Hemorrhagic Injury after Traumatic Brain Injury: Derivation and Validation of a Risk Score Based on Admission Characteristics

Previous studies have demonstrated that patients with traumatic brain injury (TBI) who also have progressive hemorrhagic injury (PHI), have a higher risk of clinical deterioration and worse outcomes than do TBI patients without PHI. Therefore, the early prediction of PHI occurrence is useful to evaluate the status of patients with TBI and to improve outcomes. The objective of this study was to develop and validate a prognostic model that uses information available at admission to determine the likelihood of PHI after TBI. Retrospectively collected data were used to develop a PHI prognostic model with a logistic regression analysis. The prediction model was validated in 114 patients from a separate hospital. Eight independent prognostic factors were identified: age ≥ 57 years (5 points), intra-axial bleeding/brain contusion (4 points), midline shift ≥ 5 mm (6 points), platelet (PLT) count<100×10⁹/L (10 points), PLT count ≥ 100 but <150×10⁹/L (4 points), prothrombin time>14 sec (7 points), D-dimer ≥ 5 mg/L (12 points), and glucose ≥ 10 mmol/L (10 points). Each patient was assigned a number of points proportional to the regression coefficient. We calculated risk scores for each patient and defined three risk groups: low risk (0-13 points), intermediate risk (14-22 points), and high risk (23-54 points). In the development cohort, the PHI rates after TBI for these three groups were 10.3%, 47.3%, and 85.2%, respectively. In the validation cohort, the corresponding PHI rates were 10.9%, 47.3%, and 86.9%. The C-statistic for the point system was 0.864 (p=0.509 by the Hosmer-Lemeshow test) in the development cohort, and 0.862 (p=0.589 by the Hosmer-Lemeshow test) in the validation cohort. In conclusion, a relatively simple risk score using admission predictors accurately predicted the risk for PHI after TBI.

A prospective clinical study of routine repeat computed tomography (CT) after traumatic brain injury (TBI)

Purpose: To discuss the repeated CT scanning in patients with traumatic brain injury (TBI) and to identify the conditions under which this approach is necessary. Methods: One hundred and seventy-one patients who suffered TBI but were not surgically treated were divided into two groups: the routine-repeat CT group (n = 89) and the non-routine-repeat CT group (n = 82). The patients’ clinical characteristics were compared. T-tests and stepwise logistic regression were used for analysis. Patients in the routine-repeat CT group were divided into three groups according to GCS scores to determine the need for routinely repeated CT scans. Results: The results revealed statistically significant differences between the two groups in terms of neuro-ICU-LOS and LOS (p < 0.01). No significant differences emerged with respect to hospital charges and GCS scores at discharge (p > 0.05). AGE, international normalized ratio (INR), D-dimer concentration (DD), GCS scores and number of hours between the first CT scan and the injury (HCT1) were influential factors of developing progressive haemorrhage. Conclusion: The routine-repeat CT group fared better than did the non-routine-repeat CT group. Routinely repeated CTs were minimally effective among those with mild TBI, whereas this procedure demonstrated a significant effect on patients with moderate and severe TBI.

Progressive Epidural Hematoma in Patients with Head Trauma: Incidence, Outcome, and Risk Factors

Progressive epidural hematoma (PEDH) after head injury is often observed on serial computerized tomography (CT) scans. Recent advances in imaging modalities and treatment might affect its incidence and outcome. In this study, PEDH was observed in 9.2% of 412 head trauma patients in whom two CT scans were obtained within 24 hours of injury, and in a majority of cases, it developed within 3 days after injury. In multivariate logistic regression, patient gender, age, Glasgow Coma Scale (GCS) score at admission, and skull fracture were not associated with PEDH, whereas hypotension (odds ratio (OR) 0.38, 95% confidence interval (CI) 0.17–0.84), time interval of the first CT scanning (OR 0.42, 95% CI 0.19–0.83), coagulopathy (OR 0.36, 95% CI 0.15–0.85), or decompressive craniectomy (DC) (OR 0.46, 95% CI 0.21–0.97) was independently associated with an increased risk of PEDH. The 3-month postinjury outcome was similar in patients with PEDH and patients without PEDH (χ 2 = 0.07, P = 0.86). In conclusion, epidural hematoma has a greater tendency to progress early after injury, often in dramatic and rapid fashion. Recognition of this important treatable cause of secondary brain injury and the associated risk factors may help identify the group at risk and tailor management of patients with TBI.

Bacterial Cellulose Membranes Used as Artificial Substitutes for Dural Defection in Rabbits

To improve the efficacy and safety of dural repair in neurosurgical procedures, a new dural material derived from bacterial cellulose (BC) was evaluated in a rabbit model with dural defects. We prepared artificial dura mater using bacterial cellulose which was incubated and fermented from Acetobacter xylinum. The dural defects of the rabbit model were repaired with BC membranes. All surgeries were performed under sodium pentobarbital anesthesia, and all efforts were made to minimize suffering. All animals were humanely euthanized by intravenous injection of phenobarbitone, at each time point, after the operation. Then, the histocompatibility and inflammatory effects of BC were examined by histological examination, real-time fluorescent quantitative polymerase chain reaction (PCR) and Western Blot. BC membranes evenly covered the surface of brain without adhesion. There were seldom inflammatory cells surrounding the membrane during the early postoperative period. The expression of inflammatory cytokines IL-1β, IL-6 and TNF-α as well as iNOS and COX-2 were lower in the BC group compared to the control group at 7, 14 and 21 days after implantation. BC can repair dural defects in rabbit and has a decreased inflammatory response compared to traditional materials. However, the long-term effects need to be validated in larger animals.

Dose-Dependent Protective Effect of Bisperoxovanadium against Acute Cerebral Ischemia in a Rat Model of Ischemia/Reperfusion Injury

PTEN (phosphatase and tensin homologue deleted on chromosome 10) is a dual-specificity lipid and protein phosphatase. The loss of PTEN was originally discovered in numerous human cancers. PTEN inhibition by bisperoxovanadium (bpV) reduces neurological damage after ischemic brain injury. The purpose of this study was to identify the optimal neuroprotective dose of bpV when administrated after focal ischemia/reperfusion (I/R) injury in rats. Focal I/R injury was induced using the middle cerebral artery occlusion method. bpV at doses of 0.25, 0.50 and 1.0 mg/kg were injected intraperitoneally just after reperfusion, with saline serving as a vehicle control. A maximal reduction in brain injury was observed with 1.0 mg/kg bpV. This dose of bpV also significantly blocked apoptosis in the penumbral cortex of rats. This beneficial effect was associated with the increasing levels of Akt phosphorylation in the penumbral cortex. These results demonstrate that the pharmacological inhibition of PTEN protects against I/R injury in a dose-dependent manner and the protective effect might be induced through upregulation of the phosphoinositide-3 kinase/Akt pro-survival pathway, suggesting a new therapeutic strategy to combat ischemic brain injury.

Luminal serotonin time‐dependently modulates vagal afferent driven antinociception in response to colorectal distention in rats

Background  Compelling evidence shows that vagal afferents mediate antinociception in response to visceral insults. Our recent findings implied that luminal serotonin (5‐hydroxytryptamine, 5‐HT) might mediate chronic food allergen sensitized visceral hyperalgesia, in which vagal afferents might be implicated. Here, to test this hypothesis, we investigated the effects of luminal infused 5‐HT on visceral nociception and the involvement of vagal antinociceptive pathway.

5-HT 3 receptors mediate the time-dependent vagal afferent modulation of nociception during chronic food allergen-sensitized visceral hyperalgesia in rats

Abstract  Converging lines of evidence demonstrate a vagally mediated antinociceptive pathway in animals undergoing acute visceral insults, the contribution of this system to visceral pain following chronic noxious stimuli is unknown. 5‐HT3 receptor (5‐HT3Rs) on spinal afferents are crucially involved in nociceptive processing, the role of 5‐HT3Rs on vagal afferents is unclear. The aim of the present study was to determine the contribution of vagal afferents to visceral nociception in rats undergoing chronic luminal allergen stimulation and whether it involves vagal 5‐HT3Rs. Sensitized rats received chicken egg albumin (EA, 1 mg mL−1) in drinking water for 2 weeks (day 1–14). Visceromotor response (VMR) to colorectal distension [colorectal distension (CRD), 60 mmHg] and the levels of mRNA encoding 5‐HT3R (including 3A and 3B subunits) in the nodose ganglia (NG) were evaluated on day 2, 4, 8 and 15. Chronic EA challenge induced gradually increased visceral nociception, with a peak on day 15. Subdiaphragmatic vagotomy or functional deafferentation with capsaicin abolished this time‐dependent manner, inducing hyperalgesia from day 2, lasting to day 15. Intraluminal infusion of a 5‐HT3R antagonist (granisetron), whether alone or infused after local mucosa anaesthetic with 1% lidocaine, mimicked the effects of vagotomy. The mRNA levels for 5‐HT3B or 5‐HT3A subunit in the NG showed an opposite time‐course to that of visceral pain, which increased from day 2, then decreased gradually to levels lower than those of controls. Our results demonstrate a time‐dependent vagal afferent modulation of chronic allergen‐sensitized visceral hyperalgesia, which may involve a 5‐HT3R pathway.

Tetranectin knockout mice develop features of Parkinson disease.

Background/Aims: Aggregation of insoluble α-synuclein to form Lewy bodies (LBs) may contribute to the selective loss of midbrain dopaminergic neurons in Parkinson disease (PD). Lack of robust animal models has impeded elucidation of the molecular mechanisms of LB formation and other critical aspects of PD pathogenesis. Methods: We established a mouse model with targeted deletion of the plasminogen-binding protein tetranectin (TN) gene (TN-/-) and measured the behavioral and histopathological features of PD. Results: Aged (15-to 20-month-old) TN-/- mice displayed motor deficits resembling PD symptoms, including limb rigidity and both slower ambulation (bradykinesia) and reduced rearing activity in the open field. In addition, these mice exhibited more numerous α-synuclein-positive LB-like inclusions within the substantia nigra pars compacta (SNc) and reduced numbers of SNc dopaminergic neurons than age-matched wild type (WT) mice. These pathological changes were also accompanied by loss of dopamine terminals in the dorsal striatum. Conclusion: The TN-/- mouse exhibits several key features of PD and so may be a valuable model for studying LB formation and testing candidate neuroprotective therapies for PD and other synucleinopathies.

Endostatin/Collagen XVIII Is Increased in Cerebrospinal Fluid after Severe Traumatic Brain Injury

Recent studies have suggested that endogenous angiogenesis inhibitor endostatin/collagen XVIII might play an important role in the secondary brain injury following traumatic brain injury (TBI). In this study, we measured endostatin/collagen XVIII concentrations serially for 1 week after hospitalization by using the enzyme-linked immunosorbent assay method in the cerebrospinal fluid (CSF) of 30 patients with TBI and a Glasgow Coma Scale (GCS) score of 8 or less on admission. There was a significant trend toward increased CSF levels of endostatin after TBI versus control from 72 h after injury. In patients with GCS score of 3–5, CSF endostatin concentration was substantially higher at 72 h after injury than that in patients with GCS score of 6–8 (P < 0.05) and peaked rapidly at day 5 after injury, but decreased thereafter. The CSF endostatin concentration in 12 patients with an unfavorable outcome was significantly higher than that in 18 patients with a favorable outcome at day 5 (P = 0.043) and day 7 (P = 0.005) after trauma. Receiver operating characteristic curve analysis suggested a reliable operating point for the 7-day CSF endostatin concentration predicting poor prognosis to be 67.29 pg/mL. Our preliminary findings provide new evidence that endostatin/collagen XVIII concentration in the CSF increases substantially in patients with sTBI. Its dynamic change may have some clinical significance on the judgment of brain injury severity and the assessment of prognosis. This trial is registered with the ClinicalTrials.gov Identifier: NCT01846546.

Vagal afferent-dependent cholecystokinin modulation of visceral pain requires central amygdala NMDA-NR2B receptors in rats.

Cholecystokinin (CCK), a gut hormone that is released during feeding, exerts gastrointestinal effects in part through vagal pathway. It is reported to be a potential trigger for increased postprandial visceral sensitivity in healthy subjects and, especially in patients with irritable bowel syndrome. NR2B‐containing N‐methyl‐d‐aspartate (NMDA) receptors in the central amygdala (CeA) participate in pain modulation. Systemically administered CCK activates the CeA‐innervating neurons. Here, we investigated whether CCK modulation of visceral sensitivity is mediated through CeA NMDA‐NR2B receptors and whether this modulation involves vagal pathway.