Efficacy of Papain Gel—A Smart Alternative to Conventional Methods of Carious Dentin Removal: An <i>In Vitro</i> Study

Aim: The study was aimed at finding out the efficacy of the caries removal ability of a chemomechanical agent (papain gel) and comparing it with that of conventional slow-speed rotary carbide burs and mechanical hand excavators in deciduous extracted molars. Materials and methods: A total of 30 extracted teeth that were used for the present study were distributed equally among two major categories (15 each) by simple random sampling technique. The teeth were sectioned into two halves mesiodistally in a longitudinal plane through the center of the caries. In each category, the corresponding halves were sectioned off randomly but in equal numbers further into two groups as follows: Category 1: Group I hand excavators and group II carbide burs. Category 2: Group III hand excavator group and group IV Papacarie group. Parameters recorded included total time taken for caries removal and residual caries remaining using caries detection dye in each group and category, which were estimated and observed under a stereomicroscope (magnification 12.5×). The data was computed and statistically analyzed to find out and compare the efficacy of caries removal of three different methods used. Results: As per the critical difference (CD), the results of the study showed the caries removal mean time for group IV (Papacarie group) when compared to other groups was significantly higher (p p p p < 0.05). Conclusion: From the results of this study, it was found that papain gel can be used as an effective alternative method compared to conventional methods for caries removal, especially in pediatric patients, owing to its lesser time commitment and better outcome

Adverse Outcome Pathway Networks II: Network Analytics.

Toxicological responses to stressors are more complex than the simple one biological perturbation to one adverse outcome model portrayed by individual adverse outcome pathways (AOPs). Consequently, the AOP framework was designed to facilitate de facto development of AOP networks that can aid understanding and prediction of pleiotropic and interactive effects more common to environmentally realistic, complex exposure scenarios. The present paper introduces nascent concepts related to the qualitative analysis of AOP networks. First, graph theory-based approaches for identifying important topological features are illustrated using two example AOP networks derived from existing AOP descriptions. Second, considerations for identifying the most significant path(s) through an AOP network from either a biological or risk assessment perspective are described. Finally, approaches for identifying interactions among AOPs that may result in additive, synergistic, or antagonistic responses, or previously undefined emergent patterns of response, are introduced. Along with a companion article (Knapen et al. part I), these concepts set the stage for development of tools and case studies that will facilitate more rigorous analysis of AOP networks, and the utility of AOP network-based predictions, for use in research and regulatory decision-making. Collectively, this work addresses one of the major themes identified through a SETAC Horizon Scanning effort focused on advancing the AOP framework. This article is protected by copyright. All rights reserved

A novel AhR ligand, 2AI, protects the retina from environmental stress

Various retinal degenerative diseases including dry and neovascular age-related macular degeneration (AMD), retinitis pigmentosa, and diabetic retinopathy are associated with the degeneration of the retinal pigmented epithelial (RPE) layer of the retina. This consequently results in the death of rod and cone photoreceptors that they support, structurally and functionally leading to legal or complete blindness. Therefore, developing therapeutic strategies to preserve cellular homeostasis in the RPE would be a favorable asset in the clinic. The aryl hydrocarbon receptor (AhR) is a conserved, environmental ligand-dependent, per ARNT-sim (PAS) domain containing bHLH transcription factor that mediates adaptive response to stress via its downstream transcriptional targets. Using in silico, in vitro and in vivo assays, we identified 2,2′-aminophenyl indole (2AI) as a potent synthetic ligand of AhR that protects RPE cells in vitro from lipid peroxidation cytotoxicity mediated by 4-hydroxynonenal (4HNE) as well as the retina in vivo from light-damage. Additionally, metabolic characterization of this molecule by LC-MS suggests that 2AI alters the lipid metabolism of RPE cells, enhancing the intracellular levels of palmitoleic acid. Finally, we show that, as a downstream effector of 2AI-mediated AhR activation, palmitoleic acid protects RPE cells from 4HNE-mediated stress, and light mediated retinal degeneration in mice