Toxicity Assessment of 4 Azo Dyes in Zebrafish Embryos.

Azo dyes are used widely as color additives in food, drugs, and cosmetics; hence, there is an increasing concern about their safety and possible health hazards. In the present study, we chose 4 azo dyes tartrazine, Sunset Yellow, amaranth, and Allura red and evaluated their developmental toxicity on zebrafish embryos. At concentration levels of 5 to 50 mM, we found that azo dyes can induce hatching difficulty and developmental abnormalities such as cardiac edema, decreased heart rate, yolk sac edema, and spinal defects including spinal curvature and tail distortion. Exposure to 100 mM of each azo dye was completely embryolethal. The median lethal concentration (LC50), median effective concentration (EC50), and teratogenic index (TI) were calculated for each azo dye at 72 hours postfertilization. For tartrazine, the LC50 was 47.10 mM and EC50 value was at 42.66 mM with TI ratio of 1.10. For Sunset Yellow, the LC50 was 38.93 mM and EC50 value was at 29.81 mM with TI ratio of 1.31. For amaranth, the LC50 was 39.86 mM and EC50 value was at 31.94 mM with TI ratio of 1.25. For Allura red, the LC50 was 47.42 mM and EC50 value was 40.05 mM with TI ratio of 1.18. This study reports the developmental toxicity of azo dyes in zebrafish embryos at concentrations higher than the expected human exposures from consuming food and drugs containing azo dyes.

[Accuracy of three-dimensional camera system based on stereophotography on photographic acquisition of deformity facial images].

OBJECTIVE: To evaluate and analyze the accuracy of three-dimensional camera system acquisition based on stereophotography for the photographic acquisition of images of facial deformities. METHODS: 3D digital models of 45 waxen facial models of patients with facial deformities were obtained via a 3D camera system based on stereophotography. A total of 19 feature lines were measured on each 3D model by using the software. The measurements taken by the coordinate-measuring machine were accepted as standard values. Statistical analysis was performed to evaluate the accuracy of the system and the corresponding factors. RESULTS: Statistical analysis results showed that the measured values of the characteristic distance obtained by 3D camera system were statistically different from the standard values (P<0.001). Convex deformities had significant influence on the measuring error of 3D camera system (P<0.05), while cleft deformities had no significant influence on the measuring error (P>0.05). The facial regions significantly influenced measuring error (P<0.05). The deformities had no significant influence on the percentage of measurement values (P>0.05). The middle facial regions had significant difference with bilateral facial regions on the percentage of measurement values (P<0.05), while the left and right facial regions had no significant difference (P>0.05). CONCLUSIONS: The accuracy of 3D camera system based on stereophotography for the photographic acquisition of facial deformities are influenced by the morphology of the facial deformities and facial regions. Moreover, the measuring error is acceptable in clinical settings.

A novel combination of nano-scaffolds with micro-scaffolds to mimic extracellularmatrices improve osteogenesis.

To improve bone engineering for clinical applications, we coupled nanofiber-peptide hydrogel to nano-hydroxyapatite/collagen to form a bioactive scaffold (cnHAC) that mimics extracellular matrices. In comparison to nano-hydroxyapatite/collagen, we found that cnHAC promoted cell adhesion and spreading, and DNA content measurements, alkaline phosphatase activity assays, and reverse transcriptase-polymerase chain reaction analyses of osteogenic gene expression showed that cnHAC significantly improved cellular attachment, proliferation, and osteogenic differentiation in vitro (P < 0.05). In vivo models based on rat calvarial implants showed that cnHAC significantly enhanced bone regeneration (P < 0.05). In conclusion, we demonstrated that novel cnHAC scaffolds could potentially facilitate future bone regenerative medicine.