Therapeutic effects of stevia aqueous extract alone or in combination with metformin in induced polycystic ovary syndrome rats: Gene expression, hormonal balance, and metabolomics aspects.

OBJECTIVES: This study aimed to assess the individual and combined effects of SAE and Met on the expression of genes related to insulin signaling, oxidative stress, hormonal imbalance, insulin resistance, and dyslipidemia in rats with induced PCOS. METHODS: The estrous cycle of 50 adult Wistar female rats was monitored through vaginal smears. Subsequently, the rats were randomly assigned into five groups of 10, including control (receiving 1ml of carboxymethyl cellulose for 49 days), induction (letrozole at 1mg/kg/d for 21 days), SAE, Met, and SAE/Met. SAE and Met were orally administered at doses of 400mg/kg/d and 250mg/kg/d on day 22 and continued for an additional 28 days. Vaginal smears were analyzed, and gene expression levels of GLUT4, SIRT1, TNF-α, and INSR were evaluated using RT-qPCR. Antioxidant parameters were assessed using detection kits. RESULTS: Treatment with SAE and Met restored a regular estrous cycle pattern in PCOS rats. Furthermore, SAE and Met treatment improved hormonal balance, dyslipidemia, and hyperglycemia in the rats. Administration of SAE and Met significantly elevated levels of antioxidant enzymes SOD and GPx in ovarian tissue (P<0.001). Additionally, mRNA levels of GLUT4, SIRT1, and INSR were significantly increased in ovarian tissue following SAE and Met treatment, while TNF-α gene expression decreased significantly (P<0.0001). CONCLUSION: The findings suggest that SAE and Met aqueous extract exert protective effects on letrozole-induced PCOS in rats by modulating gene expression associated with insulin signaling and oxidative stress.

Development of a three-dimensional in vitro model system to study orthodontic tooth movement.

Few three-dimensional (3-D) models exist to study the cellular aspects and molecular regulation of orthodontic tooth movement (OTM). The aim of this study was to develop a 3-D in vitro model to study mechanical loading of human periodontal ligament (PDL) fibroblasts (hPDLF). hPDLF were seeded within collagen gels to form a PDLF analogue. Characterisation of the seeded collagen gels revealed that the gels supported cell proliferation, viability and the emergence of a possible contractile phenotype, replicating the constrained condition of the human PDL in vivo. We next developed a 3-D model that incorporated a seeded collagen gel interlocked mechanically at two ends to movable end plates. The movable end plates allowed for static tensile or compressive loading of the hPDLF-seeded collagen gels. Preliminary testings showed that this 3-D model mimicked PDL strains similar to those observed during OTM. Our 3-D model of OTM therefore offers promise for use as a model system in future studies to improve our understanding of the effects of OTM on PDLF.

The association between schoolchildren intelligence and refractive error.

PURPOSE: The relationship between refractory errors and intelligence and the importance of genetic, regional and environmental factors in such associations, were investigated in a group of school children. SUBJECTS AND METHODS: One hundred and thirty-seven students (34.3% boys and 65.7% girls) from two primary schools were enrolled in the study. Cycloplegic refraction was performed and a spherical equivalent (SE) > or = 0.5D were determined as hyperopia; <-0.5D myopia and <1 cyl D astigmatism. Demographic factors, parent's education level, teacher based assessment of school performance and average score were also evaluated. RESULTS: Seventy-eight (56.9%) of subjects showed a form of refractory error; 27%, 3% and 2.9% were myope, hyperope or astigmat, respectively, whereas 12.4% of them had both myopia and astigmatism and 10.2% showed hyperopia and astigmatism; 43.1% were normal. CONCLUSIONS: Although our data revealed no distinction of average score between normal group and myopia, hyperopia, astigmatism or hyperopia-astigmatism, there is a statistically significant difference between normal group and those who had both myopia and astigmatism in which the later had a lower mediocre. Our results is somehow in contrast with other parallel studies demonstrating that positive connection between school performance and myopia can be explained by the geographical or racial discrepancies as well as subjects involved in the study and divergent set of cut off limits.