Effect of insulin levels and plasma fasting glucose on refractive status in the United States population aged 12-19 years.

Purpose: The causes of myopia are varied, and both genetic and environmental influences play an essential role. The prevalence of myopia is increasing among adolescents and is expected to be more than one-third the global population by 2050. Some animal studies suggest that hyperinsulinemia may be a cause of myopia. In this context, the purpose of this paper is to investigate the potential effects of insulin levels and plasma fasting glucose on the refractive status of adolescents. Methods: Data were collected from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2008. Weighted multivariable linear regression models were used to assess the effect of insulin levels, plasma fasting glucose on refractive status. We used a smooth curve fit to reveal the nonlinear relationship between the variables. Results: In the multivariate regression model, as insulin levels increased, there was a shift towards myopia in refractive status (ß = -0.013, 95% CI: -0.023 to -0.004). This correlation was also evident in the male adolescent subgroup (ß = -0.021, 95% CI: -0.035 to -0.007). Similar findings indicated that in Mexican Americans, there was a myopic shift in refractive status as insulin levels increased (ß = -0.018, 95% CI: -0.033 to -0.002). However, grouping by differences in insulin measurement showed no significant correlation in Mexican-Americans. At the same time, there was no significant correlation between plasma fasting glucose and refractive status (ß = -0.041, 95% CI: -0.174 to 0.091). Conclusion: The present cross-sectional study demonstrated that higher insulin levels may promote the development of myopia in adolescents, but there may be variations across gender and ethnicity. More basic research is needed to reveal the mechanistic reasons for the association.

Association between serum vitamin D and refractive status in United States adolescents: A cross-sectional study.

Purpose: We performed this study to determine the relationship between serum vitamin D levels and refractive status in adolescents aged 12-19 years. Methods: Cross-sectional study using the National Health and Nutrition Examination Survey (NHANES) database from 2001 to 2006. We used weighted multivariate linear regression models to assess the association between serum vitamin levels and adolescent refractive status and then built a smooth curve fitting to investigate their internal non-linear relationships. Finally, subgroup analysis was performed according to gender, and the threshold effect of serum vitamin D levels on spherical equivalent degree was analyzed using a two-piecewise linear regression model. Result: A total of 5,901 adolescents aged 12 to 19 years were included in this study. After adjusting for all confounding factors, the multiple linear regression model showed no significant correlation between adolescent spherical equivalent degree and serum vitamin D [0.0019 (-0.0018, 0.0046)]. However, smooth curve fitting analysis showed an inverted U-shaped curve relationship between spherical equivalent degree and serum vitamin D levels in adolescents (turning point: 58.1 nmol/L). In analyses by gender subgroup, this inverted U-shaped relationship was found to be more pronounced in female adolescents (turning point: 61.6 nmol/L). Conclusion: Our results suggest that the correlation between refractive status and serum vitamin D in adolescents differs by gender. When serum vitamin D concentrations were <61.6 nmol/L in female adolescents and <53.2 nmol/L in male adolescents, the spherical equivalent degree showed a positive correlation with serum vitamin D levels. However, there was no significant correlation when adolescent vitamin levels exceeded this threshold.

Generating a geometric structure light field from a digital laser by specifying a laser cavity phase boundary with a Gaussian-convoluted target field.

This research proposed a simple method to design the projected phase boundary of the SLM (spatial light modulator) of the digital laser for the generation of a structure light field of geometric shape. In the proposed method, the phase boundary of the digital laser was designed to match the convolution field of the specified geometric structure field and Gaussian field instead of matching the specified geometric structure field. The phase boundary design suppressed the light reflected from the SLM of a high-inclination angle that is difficult to achieve stable oscillation in the laser resonator. Using the proposed phase boundary design, the laser output with energy distribution closed to geometric structures such as a quadrangular pyramid, triangular pyramid, cone, and multi-ring was produced through experiments. The geometric structure light field generated in this research will be beneficial to the related applications of photolithography and photopolymerization for making micro-elements.

The design and synthesis of redox-responsive oridonin polymeric prodrug micelle formulation for effective gastric cancer therapy.

Advanced gastric cancer (GC) is a significant threat to human health. Oridonin (ORI), isolated from the Chinese herb Rabdosia rubescens, has demonstrated great potential in GC therapy. However, the application of ORI in the clinic was greatly hindered by its poor solubility, low bioavailability, and rapid plasma clearance. Herein, a simple and novel redox-sensitive ORI polymeric prodrug formulation was synthesized by covalently attaching ORI to poly(ethylene glycol)-block-poly(l-lysine) via a disulfide linker, which can self-assemble into micelles (P-ss-ORI) in aqueous solutions and produce low critical micelle concentrations (about 10 mg L-1), characterized by small size (about 80 nm), negative surface charge (about -12 mV), and high drug loading efficiency (18.7%). The in vitro drug release study showed that P-ss-ORI can rapidly and completely release ORI in a glutathione (GSH)-rich environment and under low pH conditions. Moreover, in vitro and in vivo investigations confirmed that P-ss-ORI could remarkably extend the blood circulation time of ORI, enrich in tumor tissue, be effectively endocytosed by GC cancer cells, and quickly and completely release the drug under high intracellular GSH concentrations and low pH conditions, all these characteristics ultimately inhibit the growth of GC. This redox and pH dual-responsive P-ss-ORI formulation provides a useful strategy for GC treatment.