Involvement of N-6 adenine-specific DNA methyltransferase 1 (N6AMT1) in arsenic biomethylation and its role in arsenic-induced toxicity.

BackgroundIn humans, inorganic arsenic (iAs) is metabolized to methylated arsenical species in a multistep process mainly mediated by arsenic (+3 oxidation state) methyltransferase (AS3MT). Among these metabolites is monomethylarsonous acid (MMAIII), the most toxic arsenic species. A recent study in As3mt-knockout mice suggests that unidentified methyltransferases could be involved in alternative iAs methylation pathways. We found that yeast deletion mutants lacking MTQ2 were highly resistant to iAs exposure. The human ortholog of the yeast MTQ2 is N-6 adenine-specific DNA methyltransferase 1 (N6AMT1), encoding a putative methyltransferase.ObjectiveWe investigated the potential role of N6AMT1 in arsenic-induced toxicity.MethodsWe measured and compared the cytotoxicity induced by arsenicals and their metabolic profiles using inductively coupled plasma-mass spectrometry in UROtsa human urothelial cells with enhanced N6AMT1 expression and UROtsa vector control cells treated with different concentrations of either iAsIII or MMAIII.ResultsN6AMT1 was able to convert MMAIII to the less toxic dimethylarsonic acid (DMA) when overexpressed in UROtsa cells. The enhanced expression of N6AMT1 in UROtsa cells decreased cytotoxicity of both iAsIII and MMAIII. Moreover, N6AMT1 is expressed in many human tissues at variable levels, although at levels lower than those of AS3MT, supporting a potential participation in arsenic metabolism in vivo.ConclusionsConsidering that MMAIII is the most toxic arsenical, our data suggest that N6AMT1 has a significant role in determining susceptibility to arsenic toxicity and carcinogenicity because of its specific activity in methylating MMAIII to DMA and other unknown mechanisms

Methodological approaches to assessing economic security in foreign trade

Economic security of foreign trade can be measured through a set of different special indicators with no standardised composition and regulations. The purpose of the study is to analyse the existing methods for assessing the level of economic security in the sphere of foreign trade and to develop an optimal system of indicators for its identification. The research involved scientific publications by national and foreign scholars, official statistical data in the field of Russian export and import as well as the following methods – monography, observation, comparison, economic analysis, analogue and hypothetical modelling. The article assesses various indicators for assessing economic security in foreign trade, applied in Russia and abroad. The authors identified the most informative indicators, proposed a number of threshold requirements for them; included two additional indicators (increment rate of counterfeit goods, share of counterfeit goods in imports), developed a rating-based approach to identify high, average, low, critical and catastrophic levels of economic security in the sphere of export/import operations. Foreign trade is an important activity for any state; however, it involves a number of risks and threats to be carefully assessed and minimised. Therefore, it is necessary to select efficient ways of assessing economic security in foreign trade transactions

Vaccine-induced toxic epidermal necrolysis: A case and systematic review

Background: Erythema multiforme (EM), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are cutaneous hypersensitivityreactions that develop in response to specific triggers such as medications and certain infections. Vaccines, which undergo rigorous safety testing prior to use in humans, are a rare cause of SJS/TEN and little is known about the frequency of such events and corresponding pathogenesis.Objective: Herein, we discuss a case of suspected TEN in a 19-year-old woman who received the meningococcal B vaccine (the first report of such an association) and conduct a systematic review of the associated literature. We also discuss management of this patient with a single dose of etanercept.Methods: Relevant literature was searched using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method.Results: A total of 29 articles reporting EM, SJS, or TEN following vaccination were included from >5 countries. Of the 29, 22 articles reported EM, 6/29 reported SJS, and 4/29 reported TEN (3 articlesreported cases of both EM and SJS/TEN).Conclusions: We suggest consideration of vaccines as an etiology for cases of SJS or TEN that begin with an EM-like presentation, and provide further evidence for the use of etanercept as a viable treatment for TEN

Lamellar ichthyosis in a female neonate without a collodion membrane

The term, autosomal recessive congenital ichthyosis (ARCI), describes a group of rare genetic skin diseases of cornification involving hyperkeratotic scaling at birth. The defective skin barrier function may lead to dehydration, body temperature instability, and high susceptibility to infections. In most cases of ARCI, neonates are born with a collodion membrane covering the body, often presenting with ectropion and eclabium. We report a premature female neonate presenting with hyperkeratotic scaling at birth without a collodion membrane. She was managed with placement in a humidified isolette, prophylactic antibiotics, dilute bleach baths, petrolatum ointment, and artificial eye drops. By the fourth week of life, there was marked improvement in her skin with the large, brown, plate-like scales on the trunk and extremities becoming lighter in color and finer in appearance. The ichthyosis genetic panel showed mutations in the ABCA12 gene resulting in the lamellar ichthyosis phenotype of ARCI. Our literature review revealed at least 28 patients with ARCI who were not born as collodion babies. Although collodion babies are a hallmark of most ARCI cases, clinicians should be aware of neonates with ARCI born without a collodion membrane and expedite appropriate workup and treatment