Preventive effects of seat belts on traumatic brain injury in motor vehicle collisions classified by crash severities and collision directions.

PURPOSE: This study aimed to measure the preventive effect of seat belt on traumatic brain injury (TBI) and to compare the effect according to the crash severities and collision directions. METHODS: Korea In-Depth Accident Study (KIDAS) has collected vehicle and demographic data on injured occupants involved in motor vehicle collisions (MVCs) who visited three emergency medical centers for calendar years 2011-2016. Primary and secondary end points were TBI (abbreviated injury score 2+) and in-hospital mortality. Crush extent (CE) was classified into 1-2, 3-4, 5-6, and 7-9 according to the crash severity. We calculated adjusted odds ratios (ORs) of seat belts and CE for study outcomes and developed an interaction model in each collision direction using multivariate logistic regression analysis. RESULTS: Of the 2,245 occupants who were injured in MVCs, 295 (13.1%) occupants sustained TBI. In univariate analysis, old age, unbelted status, lateral collision, and higher CE were factors associated with TBI in MVCs. Occupants with belted status was less likely to have TBI and in-hospital mortality compared with those with unbelted status [AORs (95% CI) 0.48 (0.37-0.62) and 0.49 (0.30-0.81), respectively]. In interaction analysis, preventive effects of seat belts on TBI from MVCs were retained within CE 5-6 in frontal MVCs and within CE 1-2 in near side lateral MVCs, and those of seat belts on in-hospital mortality were reserved within CE 3-4 in frontal and rollover MVCs. CONCLUSIONS: The preventive effects of seat belts on TBI and in-hospital mortality are preserved within a limited crash severity in each collision direction.

Protective effect of helmet use on cervical injury in motorcycle crashes: A case-control study.

INTRODUCTION: Helmet use during motorcycle crashes (MCCs) has been shown to reduce traumatic brain injury and mortality. However, preventive effects of its use on cervical spine injury remain controversial. In this study, we evaluated whether helmet use can reduce cervical spine injury during MCCs. PATIENTS AND METHODS: A case-control study using data from the Emergency Department-based Injury In-depth Surveillance (EDIIS) registry was conducted. Cases were defined as patients with cervical spine injury [≥2 points in the Abbreviated Injury Scale (AIS)] in MCCs from 2011 to 2016. Four controls were matched to one case with strata which included age and sex from the EDIIS registry. Primary outcome was cervical spine injury, secondary outcome was intensive care unit (ICU) admission, and tertiary outcomes was mortality. Multivariable logistic regression analysis was used to calculate odds ratios (OR) with 95% confidence intervals (CIs) to evaluate the associations between helmet use and related outcomes. RESULTS: In total, 2600 patients were analysed; among these, 1145 (44.0%) used helmets at the time of crashes. The helmet group showed lower alcohol consumption and mortality rates than the no helmet group (alcohol: 3.2% vs. 9.2%, respectively, and mortality: 2.4% vs. 7.1%, respectively; p < 0.01). Compared with the no helmet group, the helmet group was less likely to have cervical spine injury [adjusted OR, 0.62 (0.51-0.77)]. In addition, helmet use has been shown to help prevent ICU admission and mortality [adjusted OR, 0.45 (0.36-0.56) and 0.32 (0.21-0.51), respectively]. CONCLUSION: Helmet use was found to have significant preventive effects on cervical spine injury during MCCs.

Differentiation of mouse p19 embryonic carcinoma stem cells injected into an empty zebrafish egg chorion in a microfluidic device.

Mouse P19 embryonic carcinoma (EC) stem cells were xenotransplanted into the emptied chorion, the transparent envelope of a fertilized zebrafish egg (rather than mouse native zona pellucida) combined with a microfluidic device to study P19 EC cell differentiation in the chorion biomaterial. A distilled-water jet was used to remove the innate yolk and perivitelline inner mass from the chorion. P19 EC cells were injected into the emptied chorion using a micropipette, and they were subsequently cultured until the inner space of the chorion became completely occupied by cells. A simple microfluidic device was used for handling convenience and effective experiment. At d15, we found neural cells in the outer layer of the cell mass and beating cardiomyocytes in the inner layer of the large embryoid body. We propose that even though the species are different, the external innate membranes developed for embryo protection represent a useful type of ECM.

Using the chorions of fertilized zebrafish eggs as a biomaterial for the attachment and differentiation of mouse stem cells.

The development of proper biomaterials is critical for the success of cell therapy and modern tissue engineering. Here, we extruded the yolk and remaining inner mass from fertilized zebrafish eggs and used the resulting chorions as a biomaterial for the differentiation and attachment of mouse P19 embryonic carcinoma (EC) cells. Cells inserted into the chorion showed the spontaneous formation of embryoid body due to the repulsive cell adhesion of the chorion and differentiated specifically into neural cells and cardiomyocytes. In contrast, dissolved chorion extracellular matrix (ECM) conferred enhanced cell attachment on it, suggesting that a unique property of the zebrafish chorion with nanoporous structure appears to be responsible for the simple and controllable embryoid formation for stem cell differentiation. These results indicate that chorions from fertilized zebrafish eggs may be used as an extracellular matrix alternative and applied for stem cell differentiation to specific cell lineages.