Anti-inflammatory effect of low-intensity laser on the healing of third-degree burn wounds in rats

Third-degree burn wounds are considered severe injuries because they destroy all the skin layers and may affect subcutaneous tissues, fasciae, muscles, and bones. To favor the healing process of the injured tissues, it is very useful to diminish the occurrence of the inflammatory process. The present study was aimed at comparing the effect of different energetic densities of AlGaInP laser on the inflammatory process and in the healing of third-degree burn wounds in Wistar rats. This study was approved by the Ethics Committee, in which 36 adult male rats were selected and suffered the induction of third-degree burn injury. These rats were divided as follows: group 1—control (treated with silver sulfadiazine), group 2—received energy density of 3 J/cm², and group 3—received energy density of 6 J/cm². All animals daily received an occlusive bandage with silver sulfadiazine and 8 % papain. The laser therapy was performed alternatively three times a week. The animals were evaluated on the 3rd, 7th, 14th, and 21st days after the initial lesion and euthanized for the macroscopic, histologic, and morphometric analysis. A higher production of collagen was observed at 7 days and a greater re-epithelialization at 21 days in group 3 (6 J/cm²). Furthermore, the latter when compared to the other groups presented macroscopically a better aspect of the scar at 21 days with more granulation tissue and fibrosis. We conclude that the AlGaInP laser used in dosages of 3 and 6 J/cm² favors the healing of third-degree burn wounds induced in rats.     

The Race of 10 Synthetic RNAi-Based Drugs to the Pharmaceutical Market

Ten years after Fire and Melo’s Nobel Prize for discovery of gene silencing by double-stranded RNA, a remarkable progress was achieved in RNA interference (RNAi). Changes in the chemical structure of synthetic oligonucleotides make them more stable and specific, and new delivery strategies became progressively available. The attention of pharmaceutical industry rapidly turned to RNAi, as an opportunity to explore new drug targets. This review addresses nine small-interfering RNAs (siRNAs) and one unique microRNA (miRNA) inhibitor, which entered the phase 2–3 clinical trials. The siRNAs in focus are PF-04523655, TKM-080301, Atu027, SYL040012, SYL1001, siG12D-LODER (phase 2), QPI-1002, QPI-1007, and patisiran (phase 3). Regarding miRNAs, their content can be down- or up-regulated, by using miRNA inhibitors (AntimiRs) or miRNA mimics. Miravirsen is an AntimiR-122 for hepatitis C virus infection. The flexibility of RNAi technology is easily understood taking into account: (i) the different drug targets (i.e. p53, caspase 2, PKN3, β2-adrenergic receptor, mutated KRAS, microRNAs); (ii) therapeutic conditions, including ophthalmic diseases, kidney injury, amyloidosis, pancreatic cancer, viral hepatitis; and (iii) routes of administration (ocular, intravenous, subcutaneous, intratumoral). Although some issues are still matters of concern (delivery, toxicity, cost, and biological barriers), RNAi definitively opens a wide avenue for drug development.     

Effect of Ventilation Systems on Prevalence of Symptoms Associated with “Sick Buildings” in Brazilian Commercial Establishments

In this questionnaire study, the authors compared the prevalence of certain symptoms and signs associated with Sick Building Syndrome and perceptions relative to environmental discomfort of employees in a central-air-conditioned shopping center and in natural-ventilation commercial shops located on the streets of Niteröi, Rio de Janeiro, Brazil. There was a statistically significant higher prevalence of symptoms (e.g., water and itching of eyes, sore throat, nose irritation, difficulty breathing, skin irritation, sneezing) that were characteristic of Sick Building Syndrome in the air-conditioned building than in the naturally ventilated stores. The results indicated that there exists a continuing need for further research in Brazilian work environments.     

Impact of an In-Person Versus Web-Based Practice Standardized Patient Examination on Student Performance on a Subsequent High-Stakes Standardized Patient Examination

Background: Optimal methods of preparing students for high-stakes standardized patient (SP) examinations are unknown. Purposes: The purpose is to compare the impact of two formats of a formative SP examination (Web-based vs. in-person) on scores on a subsequent high-stakes SP examination and to compare students' satisfaction with each formative examination format. Methods: Clustered randomized trial comparing a Web-based module versus in-person formative SP examination. We compared scores on a subsequent high-stakes SP examination and satisfaction. Results: Scores on the subsequent high-stakes SP examination did not differ between the two formative formats but were higher after the formative assessment than without (p < .001). Satisfaction was higher with the in-person than Web-based formative assessment format (4.00 vs. 3.62 on a 5-point scale, p = .01). Conclusions: Two formats of a formative SP examination led to equivalent improvement in scores on a subsequent high-stakes examination. Students preferred an in-person formative examination to online but were satisfied with both.     

Study of 40-year glacier retreat in the northern region of the Cordillera Vilcanota,Peru, using satellite images: preliminary results

In this article, the possibility of using a Landsat image series to calculate the decadal changes in the area of mountain glaciers in the eastern cordillera of Peru is explored. In the pilot study site, changes in the glacier area at different elevation ranges to understand the altitudinal gradients and the directional properties of glacier retreat during the period 1975–2015 were calculated. This approach can be used in the entire tropical Andes, particularly in the outer tropics, depending on the availability of cloud-free images during the dry season. Similar to other regions in the tropical Andes, glaciers situated below 5000 m a.s.l. have lost nearly 81% of the initial area. It is observed that those glaciers directed towards north-east and east shows higher retreat and this may influence the glacier-fed rivers in the Amazon Basin. Future research will estimate the glacier variations in the entire eastern cordilleras and the corresponding changes in the water discharge volume in the Amazon Basin.