Roles of Neuropeptides in Sleep-Wake Regulation.

Sleep and wakefulness are basic behavioral states that require coordination between several brain regions, and they involve multiple neurochemical systems, including neuropeptides. Neuropeptides are a group of peptides produced by neurons and neuroendocrine cells of the central nervous system. Like traditional neurotransmitters, neuropeptides can bind to specific surface receptors and subsequently regulate neuronal activities. For example, orexin is a crucial component for the maintenance of wakefulness and the suppression of rapid eye movement (REM) sleep. In addition to orexin, melanin-concentrating hormone, and galanin may promote REM sleep. These results suggest that neuropeptides play an important role in sleep-wake regulation. These neuropeptides can be divided into three categories according to their effects on sleep-wake behaviors in rodents and humans. (i) Galanin, melanin-concentrating hormone, and vasoactive intestinal polypeptide are sleep-promoting peptides. It is also noticeable that vasoactive intestinal polypeptide particularly increases REM sleep. (ii) Orexin and neuropeptide S have been shown to induce wakefulness. (iii) Neuropeptide Y and substance P may have a bidirectional function as they can produce both arousal and sleep-inducing effects. This review will introduce the distribution of various neuropeptides in the brain and summarize the roles of different neuropeptides in sleep-wake regulation. We aim to lay the foundation for future studies to uncover the mechanisms that underlie the initiation, maintenance, and end of sleep-wake states.

Treatment of Tear Trough Deformity: Fat Repositioning versus Autologous Fat Grafting.

BACKGROUND: Fat-preserving lower blepharoplasty techniques and filling techniques using autologous or non-autologous materials are increasingly used to treat tear trough deformity. However, there has been no definitive comparison of the results of fat repositioning versus autologous fat grafting for this condition. The authors used statistical analysis to compare the results of the two methods. METHODS: From October 2013 to September 2015, a total of 101 patients, aged 20-43 years, underwent fat repositioning or autologous fat grafting in our department. Group 1 (51 patients, 102 eyes) underwent intraorbital fat repositioning with septal reset by transconjunctival lower blepharoplasty. Group 2 (50 patients, 100 eyes) underwent autologous fat grafting by lipoinjection. RESULTS: No significant complications occurred in any patient postoperatively. Four of 102 eyes in Group 1 and seven of 100 eyes in Group 2 had no improvement; the rest had different degrees of improvement. In Grade II and III deformities, fat repositioning resulted in significantly greater improvement of grade compared with autologous fat grafting. The surgical method of Group 1 resulted in better curative effects than that of Group 2. CONCLUSION: In patients with tear trough deformity and without obvious skin or orbicularis oculi muscle laxity, both fat repositioning and autologous fat grafting are acceptable for mild deformity. In patients with higher-grade deformities, fat repositioning produced superior results than autologous fat grafting. LEVEL OF EVIDENCE IV: This journal requires that the authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Adsorption of microcystin-LR from water with iron oxide nanoparticles.

Adsorption of microcystin-LR (MC-LR) from water using iron oxide (alpha-Fe2O3) nanoparticles was investigated in this study. Adsorption of MC-LR adsorption was well-described by a pseudo second order kinetics model and Freundlich and Langmuir isotherm equations at 15 to 35 degrees C. Thermodynamic analysis showed that the Gibbs free energy was negative, whereas standard enthalpy and entropy changes were positive at this temperature range. These findings suggest that the adsorption of MC-LR on iron oxide nanoparticles was spontaneous and endothermic. The effects of initial pH, inorganic cations, and competing compounds with carboxyl groups on absorption of MC-LR were also evaluated. Typically, adsorption efficiency decreased with increasing pH from 2 to 11. Sodium ions did not appear to significantly affect MC-LR adsorption, whereas calcium ions slightly enhanced the MC-LR adsorption capacity of the iron oxide nanoparticles. Moreover, the inhibiting effect of competing organic compounds was increased with increasing numbers of carboxyl groups, as follows: citric acid (3)>oxalic acid (2)>benzoic acid (1).