Asymmetric dimethylarginine blocks nitric oxide-mediated alcohol-stimulated cilia beating.

The airway epithelium is exposed to alcohol during drinking through direct exhalation of volatized ethanol from the bronchial circulation. Alcohol exposure leads to a rapid increase in the cilia beat frequency (CBF) of bronchial epithelial cells followed by a chronic desensitization of cilia stimulatory responses. This effect is governed in part by the nitric oxide regulation of cyclic guanosine and adenosine monophosphate-dependent protein kinases (PKG and PKA) and is not fully understood. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is implicated in the pathogenesis of several pulmonary disorders. We hypothesized that the inhibition of nitric oxide synthase by ADMA blocks alcohol-stimulated increases in CBF. To test this hypothesis, ciliated primary bovine bronchial epithelial cells (BBEC) were preincubated with ADMA (100  µM) and stimulated with 100 mM ethanol. CBF was measured and PKA assayed. By 1 hr, ethanol activated PKA, resulting in elevated CBF. Both alcohol-induced PKA activation and CBF were inhibited in the presence of ADMA. ADMA alone had no effect on PKA activity or CBF. Using a mouse model overexpressing the ADMA-degrading enzyme, dimethylarginine dimethylaminohydrolase (DDAH), we examined PKA and CBF in precision-cut mouse lung slices. Alcohol-stimulated increases in lung slice PKA and CBF were temporally enhanced in the DDAH mice versus control mice

Review of recent progress in wastewater treatment using carbon nanotubes

Background: Clean and clear water is an essential element in our life. Finding new and innovative approaches to purify water is a critical topic in research and development. Carbon nano-tubes are promising adsorbent for many stable organic compounds. The ability of wastewater treatment using carbon nanotubes was studied in this review article. Methods: Adsorption mechanism was discussed based on several research studies. Kinetics and thermodynamics of sorption were reviewed using carbon nanotubes. This review has discussed the approach of removing dyes and heavy metal ions from wastewater using nanomaterials as adsorbent. Furthermore, the paper provides several essential parameters involved in the adsorption mechanism of carbon nanotubes for wastewater applications. Results: The results of this review show that carbon nanotubes are an advantageous source of the ad-sorbent for wastewater applications. High thermal and chemical stability make carbon nanotubes more attractive for the wastewater treatment application. It is observed that both kinetics and equilibrium studies are essential to understand the adsorption phenomena. The adsorption rate constant is considered an important factor to study the adsorption. Conclusion: Nanomaterials in the adsorption process make the process more effortless compared to other types of adsorbents. Carbon nanotubes have several properties that help in surface modification, which make them an effective and environmentally friendly material for wastewater treatment. © 2021 Bentham Science Publishers