The use of ablative lasers in the treatment of facial melasma

Melasma represents a pigmentary disorder that is difficult to treat. This study aims to broadly review the use of ablative lasers (Er:YAG and CO2) in the treatment of melasma, presenting the level of evidence of studies published to date. A total of 75 patients were enrolled in four case series studies (n=39), one controlled clinical trial (n=6) and one randomized controlled clinical trial (n=30). Studies on the Er:YAG laser showed better results with the use of short square-shaped pulses, which determined low rates of post-inflammatory hyperpigmentation and long-lasting maintenance of results. Likewise, studies on the CO2 laser proved the benefits of short pulse duration along with low-density energy. Post-treatment maintenance with the use of antipigmenting creams was necessary and effective to sustain long-term results. Ablative lasers may represent another useful and effective tool against melasma. Postinflammatory hyperpigmentation and difficulty in sustaining long-term results still represent the main limitations to a broader use of ablative lasers. Based on actual evidence, the use of this technology should be restricted to patients with recalcitrant disease. Further studies will help establish optimal laser parameters and treatment regimens.     

The effects of graphene nanostructures on mesenchymal stem cells

We report the effects of two-dimensional graphene nanostructures; graphene nano-onions (GNOs), graphene oxide nanoribbons (GONRs), and graphene oxide nanoplatelets (GONPs) on viability, and differentiation of human mesenchymal stem cells (MSCs). Cytotoxicity of GNOs, GONRs, and GONPs dispersed in distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)] (DSPE-PEG), on adipose derived mesenchymal stem cells (adMSCs), and bone marrow-derived mesenchymal stem cells (bmMSCs) was assessed by AlamarBlue and Calcein AM viability assays at concentrations ranging from 5 to 300 μg/ml for 24 or 72 h. Cytotoxicity of the 2D graphene nanostructures was found to be dose dependent, not time dependent, with concentrations less than 50 μg/ml showing no significant differences compared to untreated controls. Differentiation potential of adMSCs to adipocytes and osteoblasts, – characterized by Oil Red O staining and elution, alkaline phosphatase activity, calcium matrix deposition and Alizarin Red S staining – did not change significantly when treated with the three graphene nanoparticles at a low (10 μg/ml) and high (50 μg/ml) concentration for 24 h. Transmission electron microscopy (TEM) and confocal Raman spectroscopy indicated cellular uptake of only GNOs and GONPs. The results lay the foundation for the use of these nanoparticles at potentially safe doses as ex vivo labels for MSC-based imaging and therapy.     

无水银二氧化碳结合力测定器的研制

本文介绍了测定二氧化碳结合力的一种新型仪器一快速无水银二氧化碳结合力测定器。该测定器安全无污染，测定结果准确，具有一定的科学创新性和实用性。     

Development toxicity of functionalized single-walled carbon nanotubes on rare minnow embryos and larvae

Abstract

Carbon nanotubes (CNTs) are widely used in industrial and commercial applications, but few studies systematically evaluate their developmental toxicity on aquatic organism. Using rare minnow (Gobiocypris rarus) at early life stages as experimental models, developmental toxicity of functionalized single-walled CNTs (SWCNTs) was investigated following exposure to 0–320?mg/L for 144?h. Results revealed that significantly increased in mortality and malformation was only observed after hatching. Decreased body length, heart rate and swimming speed provide a concentration-dependent manner on larvae; values of 144?h LC₅₀ and EC₅₀ were 140.8 and 109.8?mg/L, respectively. Antioxidant enzyme activities (superoxide dismutase, catalase and glutathione S-transferase) and antioxidant enzyme related mRNA expressions were significant changed; cell apoptosis activities (caspase-3, -8, -9) and cell apoptosis related mRNA expressions were significant up-regulated; reactive oxygen species and DNA damage were significantly induced when the concentration of SWCNTs above 100?mg/L. Fluorescence and electron microscopy sliced observation show that SWCNTs were well dispersed in larvae within 0.5?h, eventually cleared from the larvae at 144?h. This is the first study to define uptake kinetics and to focus on behavioral consequences, physiological changes and mRNA expression following SWCNTs exposure in the early life stages of fish. The results obtained in the present study demonstrated that functionalized SWCNTs have the potential to affect aquatic life when released into the aquatic environment and reached high concentration. In the increasing economical context of SWCNTs, complementary studies must be undertaken, especially including mechanistic and environmental investigations.     

Gas geyser syndrome: An important preventable cause of disabling neurological events

To bring to light the greatly hazardous effects of the use of flue less gas geysers in the domestic setting. Over a period of two years (2008 to 2010) twenty six cases were documented as presenting with unexplained neurological events while bathing in an ill ventilated bathroom with a functional flue less gas geyser. The cases were mainly of three distinct prototypes namely seizure like episodes seen in 11 patients, carbon monoxide intoxication in 13 patients with near cardiac arrest in 4, and as a precipitating factor for epilepsy as seen in 2 cases. Out of the 13 cases presenting as carbon monoxide intoxication 4 had subtle cognitive defects and 2 developed early Parkinsonian features on follow up. To increase awareness regarding gas geyser induced epilepsy and associated carbon monoxide intoxication, both of which are entirely preventable conditions. We also wish to emphasize the importance of stringent and universal implementation of gas geyser usage and installation laws.     

Tanshinone IIA protects rat primary hepatocytes against carbon tetrachloride toxicity via inhibiting mitochondria permeability transition

Tanshinone IIA (Tan IIA), one of the key components of Salvia milthorrhiza Bunge (Lamiaceae), is used to treat liver disease. The present study was carried out to investigate the possible mechanisms involved in the hepatoprotective effects of Tan IIA on carbon tetrachloride (CCl₄)-induced hepatocyte toxicity. In cultures treated with 1 or 2 μM CCl₄, Tan IIA (10–75 μM) significantly increased hepatocyte survival rates. However, only at a concentration of 75 μM could Tan IIA partially reverse the CCl₄ (3 μM)-induced decrease of survival rate (34?±?3% vs. 18?±?3%, n?=?8, p?<?0.01). In isolated mitochondria energized with succinate, Tan IIA could inhibit the large swelling effect induced by CCl₄ (1 and 2 μM). Base on these results, Tan IIA could protect rat primary cultured hepatocytes from CCl₄-induced toxicity partially by the inhibitory effect on the opening of mitochondrial permeability transition (MPT).     

Localization of Heme Oxygenase-2 in the Canine Larynx

The localization of heme oxygenase-2 (HO-2) in the larynx of the dog was investigated using immunohistochemistry. HO-2-positive cells were seen among neurons in intralaryngeal ganglia. Nerve fibers positive to HO-2 immunohistochemistry were seen surrounding laryngeal glands and arterioles and also in the adventitia of arterioles. HO-2-positive fibers were also seen running parallel to the mucosa in the lamina propria but no positive fibers were seen in the epithelium. Some of the intramuscular neurons found in the intrinsic laryngeal muscles were HO-2-positive, although no positive motor fibers were seen, and the neuromuscular junctions were also HO-2-negative. The results implicate the participation of HO-2-in the parasympathetic innervation of the larynx.     

Medical gases

Understanding the complex process of production, storage and delivery of medical gases is vitally important to ensure safe and efficient practice by anaesthetists. This article discusses the medical gases commonly used in anaesthesia and intensive care and details the journey of the commonly used medical gases from production to patient delivery. It includes core knowledge for the FRCA.     

Carbon plate shows even distribution of stress,decreases screw loosening,and increases recovery of preoperative daily feed intake amount in a rabbit model of mandibular continuity defects

IntroductionThe aim of this study was to compare a carbon plate (CP) and a titanium mandibular reconstruction plate (TMRP) in finite element analysis and an animal model.Materials and methodsTwelve rabbits were used for this experiment. After a mandible continuity defect was created, either a CP or a TMRP was used for mandibular reconstruction. Postoperatively, daily feed intake amount (DFIA) was measured for 4 weeks. Radiographic images were also acquired to evaluate screw loosening. For the analysis of the stress distribution, a simple continuity defect model was used, and finite element analysis was performed.ResultsThe CP group had 0.80 ± 0.45 lost screws in an animal during the 4 weeks postoperative observation; however, the TMRP group had 1.86 ± 0.69 lost screws (p = 0.014). Overall, the 5 out of 5 of rabbits in the CP group and 3 out of 7 in the TMRP group exhibited preoperative levels of DFIA during the 4 week observation (p = 0.038). The finite element analysis showed that the stress was more evenly distributed in the CP than in the TMRP model.ConclusionsThe CP group showed decreased screw loosening and increased recovery of preoperative DFIA compared to the TMRP group in a rabbit model of mandibular continuity defects. Perfect adaptation of CP during the operation could not be achieved in spite of reshaping to the mandibular curvature. This disadvantage of the CP system can be overcome by the prefabricated technique using a prototype model.