Sleep Deprivation Interferes with JAK/STAT Signaling Pathway and Myogenesis in the Masseter Muscle of Rats.

OBJECTIVES: The aim of the study was to study the Janus kinase/tyrosine kinase-activated transduction factor (JAK/STAT) signaling pathway and myogenesis on the masseter muscle after sleep deprivation and to investigate the role of stress in this scenario. SUBJECTS AND METHODS: A total of 18 male Wistar rats were divided into the following groups: control (n = 6): animals were not submitted to any procedures, and paradoxical sleep deprivation and vehicle (PSD + V; n = 6): animals were subjected to PSD for 96 h and (PSD + MET; n = 6): animals were subjected to PSD for 96 h with administration of metyrapone. Paradoxical sleep deprivation was performed by the modified multiple platforms method. Histopathological analysis, histomorphometry, and immunohistochemistry were performed. RESULTS: The results showed the presence of inflammatory infiltrate in the PSD + V and PSD + MET groups and atrophy. Histomorphometry showed that the cellular profile area decreased, while cellular density increased in both experimental groups. Expression of p-STAT 3, MyoD, and MyoG increased in the PSD + V group, while the PSD + MET group showed increased expression of IL-6 and p-STAT 3. CONCLUSION: Our results suggest that sleep deprivation induces an inflammatory response and atrophy in the masseter muscle of rats.

Evaluation of the antiseptic and wound healing potential of polyhexamethylene guanidine hydrochloride as well as its toxic effects.

The synthetic polyhexamethylene guanidine hydrochloride (PHMGH) polymer presents antifungal and antimicrobial activities in vitro. However, in vivo reports regarding its antiseptic and healing activity are scarce in the scientific literature. Thus, the present study aimed to evaluate the antimicrobial and healing effects, as well as toxicological parameters, of a topical solution containing 0.5% PHMGH (Akwaton®) in the treatment of superficial skin wounds experimentally induced on the dorsum of rodents. In addition, non-clinical safety studies were also conducted for use in human health, such as acute oral toxicity and genotoxicity tests. Animals did clinically not present dermatitis. After two days of topical treatment, PHMGH showed a significant antiseptic effect compared to the untreated group, reducing the number of colony-forming units by 72%, reaching 100% on the fourth day of treatment. The animals treated with PHMGH showed a significant area reduction of the skin lesions in relation to the untreated group, indicating a healing effect of the polymer. Moreover, PHMGH treatment led to a significant increase in fibroblasts when compared to the untreated group, revealing its healing action. No significant differences were observed between the biochemical indicators of hepatoxicity and nephrotoxicity, nor genotoxicity between the PHMGH-treated and the negative control groups. The results of acute oral toxicity showed that PHMGH at 5% presents a lethal dose 50% greater than the 2000 mg/kg. At a concentration of 5%, PHMGH did not show genotoxicity nor cytotoxicity at doses up to 1500 mg/kg through the micronucleus assay in mice. Therefore, 0.5% PHMGH showed an antimicrobial and healing effect, with no toxicity, and could be a promising adjunct in the microbial control of healing wounds.

Paradoxical sleep deprivation induces differential biological response in rat masticatory muscles: Inflammation, autophagy and myogenesis.

BACKGROUND: The aim of this study was to evaluate whether sleep deprivation (SD) induces inflammation, autophagy and myogenesis in the following masticatory muscles: masseter and temporal. METHODS: In this study, 18 animals were randomly distributed into three groups: control group (CTL, n = 6), SD for 96 hours (SD96, n = 6), and SD for 96 hours and more 96 hours of sleep recovery (SD96 + R, n = 6). RESULTS: In the histopathological analysis, SD 96 was able to induce inflammation in masseter and temporal. Nevertheless, the lack of inflammatory process was evidenced to the masseter in the group SD96 + R. Upregulation of TNF-alpha production was detected in the SD96 group, while SD96 + R decreased TNF immunoexpression for both skeletal muscles evaluated. MyoD and myogenin increased in rats submitted to SD96. By contrast, the levels of MyoD decreased in the group SD96 + R. Myogenin pointed out high immunoexpression in SD96 + R groups. In temporal, pAkt decreased in animals submitted to SD96, but it increased in the group SD96 + R. The levels of LC3 protein increased in both skeletal muscles studied, and masseter decreased LC3 protein expression in the SD96 + R. CONCLUSION: In summary, our results demonstrate that SD is able to induce inflammation, atrophy and myogenesis in rat masticatory muscles, being more intense in temporal when compared to masseter.

The use of N-methylpyrrolidone as a cosolvent and oxidant in pharmaceutical stress testing.

The use of N-methylpyrrolidone (NMP) as an oxidant and cosolvent in pharmaceutical stress testing (forced degradation) is examined. Various active pharmaceutical ingredients were heated in NMP-water solutions under nitrogen, air, and oxygen and then analyzed by high-performance liquid chromatography, usually with ultraviolet diode array detection and mass spectrometry detection. In some cases, degradation products were isolated and characterized by nuclear magnetic resonance. The NMP-water-air-heat system provided oxidative and hydrolytic degradation products. The observed oxidation products were consistent with products expected from free radical autoxidation, reactions with hydroperoxides, and possibly singlet oxygen. Oxidative and hydrolytic pathways could be distinguished by comparison of the reactions carried out under air/oxygen and nitrogen. In many cases, the oxidation products observed during stress testing were also observed during formal stability studies of drug products. The NMP-water-air-heat stress condition facilitates various oxidative degradation pathways, which are often relevant to drug product on stability. This approach facilitates stability-indicating method development and helps elucidate degradation pathways.

Proteome analysis of rat polymorphonuclear leukocytes: a two-dimensional electrophoresis/mass spectrometry approach.

The development of a two-dimensional (2-D) map of rat polymorphonuclear (PMN) leukocytes is here reported for the first time. The map is built up by utilizing a wide immobilized pH gradient (IPG), pH 3-10, in the first dimension and also a narrower IPG pH 4.5-8.5 gradient. In addition, the map is constructed by adopting the most recent protocols in 2-D mapping, which call for reduction and alkylation of the sample prior to the start of any electrophoretic step, including the IPG dimension. Fifty-two major protein spots have been so far identified by utilizing both matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) and electrospray quadrupole (Q)-TOF mass spectrometry. A large number of house-keeping and cytoskeleton proteins were detected, together with proteins which are specific to PMN organelles or related to PMN functions such as phagocytosis and chemotaxis. The results obtained demonstrate the possibility of obtaining a single 2-D gel based proteomic map of PMN with representative proteins from different cellular compartments, also including membrane components, allowing the study of PMN protein expression on a proteome-wide scale. The aim of this project is to build an extensive database of such proteins, to be utilized for future studies where the expression of PMN proteins is used as a disease- or drug treatment marker.