Autism symptoms, functional impairments, and gaze fixation measured using an eye-tracker in 6-year-old children.

Introduction: Autism spectrum disorder (ASD) is a neurodevelopmental disorder clinically characterized by abnormalities in eye contact during social exchanges. We aimed to clarify whether the amount of gaze fixation, measured at the age of 6 years using Gazefinder, which is an established eye-tracking device, is associated with ASD symptoms and functioning. Methods: The current study included 742 participants from the Hamamatsu Birth Cohort Study. Autistic symptoms were evaluated according to the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2), and the functioning of the participating children in real life was assessed using the Japanese version of the Vineland Adaptive Behavior Scales, Second Edition (VABS-II). The Gazefinder system was used for gaze fixation rates; two areas of interest (eyes and mouth) were defined in a talking movie clip, and eye gaze positions were calculated through corneal reflection techniques. Results: The participants had an average age of 6.06 ± 0.14 years (males: 384; 52%). According to ADOS, 617 (83%) children were assessed as having none/mild ASD and 51 (7%) as severe. The average VABS-II scores were approximately 100 (standard deviation = 12). A higher gaze fixation rate on the eyes was associated with a significantly lower likelihood of the child being assigned to the severe ADOS group after controlling for covariates (odds ratio [OR], 0.02; 95% confidence interval [CI], 0.002-0.38). The gaze fixation rate on the mouth was not associated with ASD symptoms. A higher gaze fixation rate on the mouth was associated with a significantly lower likelihood of the child being assigned to the low score group in VABS-II socialization after controlling for covariates (OR, 0.18; 95% CI, 0.04-0.85). The gaze fixation rate on the eyes was not associated with functioning. Conclusion: We found that children with low gaze fixation rates on the eyes were likely to have more ASD symptoms, and children with low gaze fixation rates on the mouth were likely to demonstrate poorer functioning in socialization. Hence, preschool children could be independently assessed in the general population for clinically relevant endophenotypes predictive of ASD symptoms and functional impairments.

Influence of the wettability of different titanium surface topographies on initial cellular behavior.

This study examined the influence of the time-dependent wettability of different surface topographies on initial cellular behavior. Titanium disks with smooth topography (SM) and three kinds of rough topography (sandblasted (SA), microtopography (M) and nanotopography (N)) were prepared. Time-dependent changes in surface wettability were observed in all surfaces as shown in previous studies. On SM surfaces, hydrophobic alteration influenced cell spreading and the activity of RhoA (a small GTPase protein of the Rho family), while no alterations were observed on rough surfaces except for the number of adherent cells. Serum adsorption could recover these functional deteriorations by hydrophobic alteration. These findings suggest that surface topography is a more potent regulator in initial cellular behaviors such as cell spreading and RhoA activation than surface wettability.

Dental resin curing blue light induced oxidative stress with reactive oxygen species production.

Dental resin curing blue light has been used in the treatment of tooth bleaching and to restore teeth with resin-based composite fillings. However, there has been little consideration of its effect on oral tissues such as dental pulp and oral mucosa. The aim of this study was to investigate whether dental resin curing blue light irradiation affects the dental pulp, especially the blood vessels that are known as the first target of reactive oxygen species (ROS), which play an important role in vascular reactivity. We found that blue light irradiation increased the level of lipid peroxidation in isolated rat aorta blood vessels by measuring malondialdehyde. Furthermore, cell proliferative activity was decreased in a time-dependent manner and apoptosis of human aorta vascular smooth muscle cells (VSMCs) was induced. These results indicated that (ROS) such as hydrogen peroxide and hydroxyl radicals were generated in VSMCs by irradiation with blue light, and they induced cytotoxicity associated with oxidative stress, which increased lipid peroxidation and apoptosis. In addition, N-acetyl-l-cysteine, which is a typical intracellular antioxidant, protected VSMCs against cytotoxicity associated with oxidative stress. These findings suggested that antioxidants may be used to prevent oxidative stress in dental pulp by repeated and/or multiple treatments with blue light irradiation in future dental treatments.