Neurological outcomes in traffic accidents: A propensity score matching analysis of medical and non-medical origin cases of out-of-hospital cardiac arrest.

AIM: This study aimed to comprehensively compare the characteristics of out-of-hospital cardiac arrest (OHCA) with medical and non-medical origins attributed to traffic accidents and explore the potential association between the cases with a medical origin and neurologically favorable outcomes. METHODS: In this retrospective nationwide population-based study, baseline data were collected between January 2018 and December 2020. We analyzed 5091 OHCA associated with traffic accidents on the road scene. Only those encounters involving treatment or transport by prehospital emergency medical technicians were included. The characteristics of OHCA incidents and their outcomes were analyzed by categorizing patients into "medical origin" and "non-medical origin" groups. RESULTS: Medical-origin cases exhibited several distinct characteristics, including higher frequencies of occurrence during the daytime (79.3% [706/890] vs. 68.9% [2895/4201], p < 0.001), a higher prevalence among male (77.8% [692/890] vs. 68.3% [2871/4201], p < 0.001) and younger patients (median [25-75%]: 63 years [42-77] vs. 66 years [50-76], p = 0.003), a higher proportion of shockable initial rhythms(10.5% [93/890] vs. 1.1% [45/4201], p < 0.001), an increased number of cases requiring advanced airway management (33.8% [301/890] vs. 28.5% [1199/4201], p = 0.002) and adrenaline administration by emergency medical teams (26.9% [239/890] vs. 21.7% [910/4201], p < 0.001), and shorter transport times (55.3% [492/890] vs. 60.9% [2558/4201], p = 0.002) compared to non-medical-origin cases. However, medical-origin cases also had lower witness rates (42.8% [381/890] vs. 27.2% [1142/4201], p < 0.001) and were less likely to be transported to higher-level hospitals (55.3% [492/890] vs. 60.9% [2558/4201], p = 0.002). Propensity score matching analysis identified factors associated with favorable neurological outcomes in medical-origin traffic accidents. The adjusted odds ratios were as follows: 8.46 (3.47-20.61) for cases with shockable initial rhythms, 2.36 (1.01-5.52) for cases involving traffic accidents due to medical origin, and 0.09 (0.01-0.67) for cases where advanced airway management was provided. CONCLUSION: In this retrospective study, the occurrence of OHCAs of medical origin involving traffic accidents were associated with favorable neurological outcomes. These cases more frequently demonstrated favorable factors for survival compared to those classified as of non-medical origin. The findings have important implications for public health and EMS professionals, they will guide future research aimed at optimizing prehospital care strategies and improving survival rates for similar cases.

Potential complications of CAD/CAM-produced resin composite crowns on molars: A retrospective cohort study over four years.

PURPOSE: Evaluation of the clinical performance of computer-aided design/computer-aided manufacturing-produced resin composite crowns (CAD/CAM composite crowns) on molars with a particular focus on placement location. METHODS: A retrospective cohort study was performed based on the clinical records of patients with CAD/CAM composite crowns on molars (June 2016 to March 2021). The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated based the Cox proportional hazard model to evaluate the effect of tooth location on complication type and occurrence. Covariates included crown location (maxilla/mandible, distalmost tooth/not distalmost tooth, and first molar/second or third molar) and endodontically treated (nonvital) or untreated (vital) tooth. RESULTS: Overall, 362 crowns were evaluated (mean follow-up: 378 days, median: 286 days), and 106 crowns (29.3%) showed complications, most frequently crown debonding. The cumulative success and survival rates were 70.9% and 93.7%, respectively, after 1 year and 49.5% and 86.5%, respectively, after 3 years. There was no significant difference in the HRs and log-rank tests in the Kaplan-Meier curves based on crown location parameters (P > 0.05). However, placement on vital teeth was associated with higher risks than on nonvital teeth (HR, 1.55; 95% CI, 1.03-2.23). In addition, the cement as a covariate yielded a high HR. CONCLUSIONS: The location of CAD/CAM composite molar crowns is unlikely a risk factor for complications; therefore, these crowns can be clinically applied to all molars. However, the application of such molar crowns to vital teeth and the use of a cement other than adhesive resin cement present risks.

Impact of adhesive primer and light-curing on polymerization kinetics of self-adhesive resin cement in association with free radical reaction.

This study analyzed the impact of adhesive primer and light-curing on the polymerization kinetics of urethane dimethacrylate-based self-adhesive resin cement combined with free radical reaction. Specimens were prepared by mixing the cement paste with or without adhesive primer. Subsequently, specimens were light-cured or set without light-curing. The degree of conversion (DC), Vickers hardness (Hv), and free radical concentrations were repeatedly measured up to 168 h after the curing initiation. Irrespective of the curing procedures, DC, Hv, and free radical concentration rapidly increased during the initial 30 min of curing. The specimens cured with adhesive primer and/or light-curing generally showed higher values of DC, Hv, and radical concentration than those set by chemical curing alone, especially during the initial polymerization phase. Kinetic analysis using a linear mixed model revealed that the adhesive primer had a higher coefficient estimate than light-curing, indicating that the former had a higher impact on the polymerization. Additionally, the adhesive primer alleviated the Hv reduction caused by water and air during the initial polymerization phase, although light-curing hardly prevented the polymerization inhibition. Therefore, we suggest that application of adhesive primer is beneficial to achieve higher degree of conversion and better mechanical properties of self-adhesive resin cements by enhancing free radical reactions.

Serum affects keratinization and tight junctions in three-dimensional cultures of the mouse keratinocyte cell line COCA through retinoic acid receptor-mediated signaling.

Vitamin A, which is found in serum, is known to affect keratinocyte proliferation, epidermal differentiation, and keratinization. In mice, stratified epithelia in the oral cavity, esophagus, and forestomach are keratinized; however, these epithelia are not keratinized in humans. Several studies have reported that three-dimensional (3D) cultures of human keratinocytes in serum-containing medium could form keratinized epithelia. Here, we evaluated the effects of serum on the morphology, expression, and localization of differentiation markers and tight junction proteins, and paracellular permeability in 3D cultures of mouse keratinocytes. We found that only 0.1% calcium-depleted serum inhibited keratinization and induced a change in the expression of differentiation marker proteins from loricrin to keratin 4; the inhibition of retinoic acid receptor-mediated signaling reversed these changes. Furthermore, the serum reduced claudin-1 protein expression and prevented its localization at occludin-positive spots on the surface of 3D cultures. On the other hand, the serum increased the protein expression of claudin-4, occludin, zonula occludens-1, and E-cadherin. These changes may contribute to the reduction of the transepithelial electrical resistance by approximately half. In conclusion, mouse keratinocytes derived from the epidermis formed non-keratinized structures in 3D cultures in response to vitamin A in serum. The results suggest that retinoic acid receptor-mediated signaling may be inhibited in the mouse epithelia in the oral cavity, esophagus, and forestomach as well as the epidermis, leading to the keratinization of these epithelia.