Selenium Protects Mouse Hypothalamic Cells from Glucocorticoid-Induced Endoplasmic Reticulum Stress Vulnerability and Insulin Signaling Impairment

The use of glucocorticoid medications is known to cause metabolic side effects such as overeating, excess weight gain, and insulin resistance. The hypothalamus, a central regulator of feeding behavior and energy expenditure, is highly responsive to glucocorticoids, and it has been proposed that it plays a role in glucocorticoid-induced metabolic defects. Glucocorticoids can alter the expression and activity of antioxidant enzymes and promote the accumulation of reactive oxygen species. Recent evidence indicates that selenium can counter the effects of glucocorticoids, and selenium is critical for proper hypothalamic function. This study sought to determine whether selenium is capable of protecting hypothalamic cells from dysfunction caused by glucocorticoid exposure. We treated mHypoE-44 mouse hypothalamic cells with corticosterone to study the effects on cellular physiology and the involvement of selenium. We found that corticosterone administration rendered cells more vulnerable to endoplasmic reticulum stress and the subsequent impairment of insulin signaling. Supplementing the cell culture media with additional selenium alleviated endoplasmic reticulum stress and promoted insulin signaling. These findings implicate a protective role of selenium against chronic glucocorticoid-induced hypothalamic dysfunction

Dental plaque score reduction with an oscillating‐rotating power toothbrush and a high‐frequency sonic power toothbrush: a systematic review and meta‐analysis of single‐brushing exercises

Aim: To establish the effect of a single-brushing exercise on dental plaque removal using an oscillating-rotating power toothbrush (OR-PTB) as compared to a high-frequency sonic power toothbrush (HFS-PTB). Materials and Methods: The MEDLINE-PubMed and Cochrane-CENTRAL databases were searched up to September 2019. The inclusion criteria contained (randomized) controlled clinical trials involving healthy adult participants brushing with an OR-PTB as compared to an HFS-PTB. Plaque index (PI) scores were evaluated after a single-brushing exercise. Results: A total of 15 publications were included, representing 34 comparisons, of which 8 were professional brushing exercises and 26 participant brushing exercises. The potential risk of bias was estimated to be low. In the overall descriptive analysis of 34 comparisons, 19 comparisons showed a statistically significant difference in favour of the OR-PTB and 4 in favour of the HFS-PTB. The meta-analysis using the professional brushing study design showed a significant difference of means (DiffM) in favour of the OR-PTB (PI score) (DiffM 0.19; P <.0001) (95% CI [013; 0.25]). In those studies where the participants brushed themselves, the data were inconclusive. PI scores showed no difference between the two brushes (P =.15), while one plaque index (the Rustogi Modified Navy plaque index) indicated significant favour for the OR-PTB (DiffM 0.06; P =.002) (95% CI [0.02; 0.09]). Conclusion: Based on the estimated evidence profile, there is moderate certainty of evidence of a very small but significant beneficial effect on plaque removal after a single-brushing exercise with the OR-PTB over the HFS-PTB

The Experimental Design as Practical Approach to Develop and Optimize a Formulation of Peptide-Loaded Liposomes

To investigate the encapsulation of Print 3G, a peptidic agent that could reduce the angiogenic development of breast tumors, pegylated liposomes used as intravenous vectors were studied and characterized. Recently, the path of liposomes has been explored with success to improve the pharmacological properties of peptidic drugs and to stabilize them. In this study, loaded unilamellar vesicles composed of SPC:CHOL:mPEG2000-DSPE (47:47:6) were prepared by the hydration of lipid film technique. An HPLC method was developed and validated for the determination of Print 3G to calculate its encapsulation efficiency. Observed Print 3G adsorption on different materials employed during liposome preparation (such as glass beads, tubing, and connections for extrusion) led to the modification of the manufacturing method. The freeze-thawing technique was used to enhance the amount of Print 3G encapsulated into blank liposomes prepared using the hydration of lipid film procedure. Many factors may influence peptide entrapment, namely the number of freeze-thawing cycles, the lipid concentration, the peptide concentration, and the mixing time. Consequently, a design of experiments was performed to obtain the best encapsulation efficiency while minimizing the number of experiments. The lipid concentration and the number of freeze-thawing cycles were identified as the positive factors influencing the encapsulation. As a result of the optimization, an optimum was found and encapsulation efficiencies were improved from around 30% to 63%. Liposome integrity was evaluated by photon correlation spectroscopy and freeze-fracture electron microscopy to ensure that the selected formulation possesses the required properties to be a potential candidate for further in vitro and in vivo experiments