Genomic and Non-Genomic Actions of Glucocorticoids on Adipose Tissue Lipid Metabolism.

Glucocorticoids (GCs) are hormones that aid the body under stress by regulating glucose and free fatty acids. GCs maintain energy homeostasis in multiple tissues, including those in the liver and skeletal muscle, white adipose tissue (WAT), and brown adipose tissue (BAT). WAT stores energy as triglycerides, while BAT uses fatty acids for heat generation. The multiple genomic and non-genomic pathways in GC signaling vary with exposure duration, location (adipose tissue depot), and species. Genomic effects occur directly through the cytosolic GC receptor (GR), regulating the expression of proteins related to lipid metabolism, such as ATGL and HSL. Non-genomic effects act through mechanisms often independent of the cytosolic GR and happen shortly after GC exposure. Studying the effects of GCs on adipose tissue breakdown and generation (lipolysis and adipogenesis) leads to insights for treatment of adipose-related diseases, such as obesity, coronary disease, and cancer, but has led to controversy among researchers, largely due to the complexity of the process. This paper reviews the recent literature on the genomic and non-genomic effects of GCs on WAT and BAT lipolysis and proposes research to address the many gaps in knowledge related to GC activity and its effects on disease.

Evaluation of the marginal fit of metal copings fabricated by using 3 different CAD-CAM techniques: Milling, stereolithography, and 3D wax printer.

STATEMENT OF PROBLEM: Digital systems have been developed as substitutes for the traditional fabrication of wax patterns and definitive restorations, but the accuracy of these systems is unclear. PURPOSE: The purpose of this in vitro study was to evaluate and compare the marginal fit of metal copings fabricated from milling, stereolithography (SLA), and 3D wax printer (PolyJet) patterns. MATERIAL AND METHODS: A standard machined brass die model was designed and prepared. To fabricate metal copings of standardized shape and dimensions, the die was scanned and nickel-chromium (Ni-Cr) copings were designed by using a dental designer software program. By using the same CAD data to fabricate 30 patterns through milling, SLA, and PolyJet techniques, 10 resin patterns were milled by using a 5-axis milling machine, 10 resin patterns were produced by using a NextDent 5100 3D Printer, and 10 wax patterns were printed by using a Solidscape 3D printer. The patterns were invested and cast in Ni-Cr alloy. Each coping was evaluated by using a digital microscope on 16 points around the finish line on the metal die at ×230 magnification. The mean marginal discrepancy was calculated. The mean differences among the groups were compared by using 1-way ANOVA, and post hoc analysis was used for pairwise comparison of the groups (α=.05). RESULTS: The mean value of marginal discrepancy was 93.1 ±25 µm in the milling, 71.1 ±25 µm in the SLA, and 41.3 ±6 µm in the PolyJet group. No statistically significant difference was found between the milling and SLA groups (P=.158), while the PolyJet group showed significantly lower mean marginal discrepancy than the 2 other groups (P<.05). CONCLUSIONS: The PolyJet method produces metal copings with better marginal fit than the SLA or milling techniques. However, the marginal fit was clinically acceptable in metal copings made with all the 3 methods.