Prevalence of periodontitis and its correlates among tribal population of Attapady block, Palakkad District, Kerala.

BACKGROUND: Periodontal disease is an immunoinflammatory disease characterized by loss of clinical attachment with subsequent tooth loss. It includes periodontitis and gingivitis. The studies regarding the prevalence of periodontitis among the tribal populations are scarce. The periodontal health status of the tribal population of Attapady has not been reported so far. OBJECTIVE: The present study was conducted to assess the prevalence of periodontitis and its association with oral hygiene habits, tobacco usage, and oral health beliefs among tribal population of Attapady. MATERIALS AND METHODS: This population-based cross-sectional survey of periodontal disease consisting of 360 individuals was conducted among the tribal population of three different panchayats of Attapady. A multistage stratified random sampling was used in the selection of hamlets and cluster sampling for selection of study participants. The sociodemographic characteristics, oral hygiene habits, tobacco usage, and oral health beliefs were assessed using a questionnaire, and clinical examination was based on WHO oral health assessment form 2013. RESULTS: The prevalence of periodontal disease among tribal population of Attapady was 87.5% (95% Confidence interval [CI] 78.48, 96.51).73.3% had gingival bleeding and 13.3% had no/mild periodontitis, The proportion of periodontitis was 84.2% (95% CI 75.5, 92.8). Among chronic perioodntitis subjects 22.8% had moderate periodontitis and 61.4% had severe periodontitis. A significant association was observed between tobacco use (Odds ratio [OR] 5.6, CI 2.99, 10.74), bad oral hygiene habits (OR 4.9, CI 2.64, 9.43), unfavorable oral health beliefs (OR 3.21, CI 1.63, 6.32), and periodontitis. CONCLUSIONS: The prevalence of periodontal disease and periodontitis are high among tribal population of Attapady. Unfavorable oral health belief, bad oral hygiene habits, and detrimental habits like tobacco use were the modifiable risk factors identified in this group.

ADAM17 Inhibitors Attenuate Corneal Epithelial Detachment Induced by Mustard Exposure.

PURPOSE: Sulfur mustard, nitrogen mustard (NM), and 2-chloroethyl ethyl sulfide all cause corneal injury with epithelial-stromal separation, differing only by degree. Injury can resolve in a few weeks or develop into chronic corneal problems. These vesicants induce microbullae at the epithelial-stromal junction, which is partially caused by cleavage of transmembranous hemidesmosomal collagen XVII, a component anchoring the epithelium to the stroma. ADAM17 is an enzyme involved in wound healing and is able to cleave collagen XVII. The activity of ADAM17 was inhibited in vesicant-exposed corneas by four different hydroxamates, to evaluate their therapeutic potential when applied 2 hours after exposure, thereby allowing ADAM17 to perform its early steps in wound healing. METHODS: Rabbit corneal organ cultures exposed to NM for 2 hours were washed, then incubated at 37°C for 22 hours, with or without one of the four hydroxamates (dose range, 0.3-100 nmol in 20 µL, applied four times). Corneas were analyzed by light and immunofluorescence microscopy, and ADAM17 activity assays. RESULTS: Nitrogen mustard-induced corneal injury showed significant activation of ADAM17 levels accompanying epithelial-stromal detachment. Corneas treated with hydroxamates starting 2 hours post exposure showed a dose-dependent ADAM17 activity inhibition up to concentrations of 3 nmol. Of the four hydroxamates, NDH4417 (N-octyl-N-hydroxy-2-[4-hydroxy-3-methoxyphenyl] acetamide) was most effective for inhibiting ADAM17 and retaining epithelial-stromal attachment. CONCLUSIONS: Mustard exposure leads to corneal epithelial sloughing caused, in part, by the activation of ADAM17 at the epithelial-stromal junction. Select hydroxamate compounds applied 2 hours after NM exposure mitigated epithelial-stromal separation.

Pyridine-catalyzed addition of diaryl-1,2-diones to dimethyl butynedioate leading to the formation of 1,2-diaroyl dimethyl maleates via an unprecedented rearrangement.

[reaction: see text] Pyridine catalyzes the reaction of 1,2-diaryl diones with dimethyl butynedioate to afford diaroyl maleates. This unprecedented rearrangement involves a unique benzoyl migration and proceeds with complete stereoselectivity.

Engaging the pyridine-DMAD zwitterion in a novel strategy for the selective synthesis of highly substituted benzene and cyclopentenedione derivatives.

[reaction: see text] The pyridine-mediated reaction of dimethyl acetylenedicarboxylate and cyclobutene-1,2-diones affords selective access to either hexasubstituted benzene derivatives or cyclopentenedione derivatives depending on the concentration of pyridine.

A novel biphasic leaching approach for the recovery of Cu and Zn from polymetallic bulk concentrate.

In scale-up biphasic leaching process of polymetallic concentrate, the ferric bioregeneration cycles were performed in 15.0L down flow packed bed reactor; whereas the chemical leaching cycles were done using the biogenerated ferric in an indigenously designed 10.0L stirred tank reactor. The consortium took 25cycles for proper biofilm formation. It showed highest iron oxidation rate (IOR) of 3908.21mg/L/h at 25thcycle under no polymetallic stress. Even under stressed conditions, it was 2650-558mg/L/h. Cu extractions were 86.63-46.51 and Zn extractions were 67.89-14.74% in 1st-4thcycle, respectively. The developed consortium exhibited 17-51times higher IOR compared to original wild type consortium. Extraction isotherm for zinc with 30% Cyanex® 301 indicated that a total of two stages are required for its complete extraction using the phase ratio of 2:1 at equilibrium pH 1.5, leaving behind Fe(II) in the raffinate.

Pyridine-catalyzed stereoselective addition of acyclic 1,2-diones to acetylenic esters: synthetic and theoretical studies of an unprecedented rearrangement.

A systematic study of the addition of various 1,2-acyclic diones to activated acetylenic esters catalyzed by pyridine under mild conditions is described. This reaction provides a new protocol for the stereoselective synthesis of 1,2-diaroyl maleates. The exclusive formation of the cis isomer is especially noteworthy. This reaction occurs through the initial generation of a pyridine-dimethyl acetylene dicarboxylate zwitterion and its addition to the dione followed by an unprecedented benzoyl migration. Pyridine and substituted pyridines, such as 4-dimethylaminopyridine (DMAP) and 3-methoxypyridine, are the best catalysts and anhydrous 1,2-dimethoxyethane is found to be the solvent of choice. Structural, electronic, energetic and mechanistic details of the reaction are also revealed by density functional theory calculations, which strongly support the exclusive formation of the cis isomer of the 1,2-diaroyl maleates.