Diastereoselective synthesis of tetrahydropyrrolo[1,2-d]oxadiazoles from functionalized Δ1-pyrrolines and in situ generated nitrile oxides.

Tetrahydropyrrolo[1,2-d]oxadiazoles have been synthesized in good-to-excellent yields via the cycloaddition of nitrile oxides (in situ generated from aldoximes) to readily accessible functionalized Δ1-pyrrolines. The reaction proceeds smoothly at room temperature in a two-phase system in the presence of sodium hypochloride as an oxidant to diastereoselectively afford pharmaceutically prospective 1,2,4-oxadiazolines fused with a five-membered ring. The reaction tolerates a broad range of substrates, including those with oxidant-sensitive functional groups and competitive reaction sites.

Ground Rules for Preschooler Exposure to the Digital Environment: A Review of Studies.

Background: The range of digital technologies that children use from an early age has expanded significantly. Most studies demonstrate that preschoolers now spend substantially longer on digital devices and start using them at a younger age. Finding a solution for this challenge has research merits and relevance, as the data on benefits and harm of early preschoolers' exposure to digital devices is contradictory. This poses a need to determine theoretically sound and practically validated criteria that could guide the duration and quality of children's exposure to the digital environment. Objective: To review studies that contain recommendations on preschoolers' exposure to the digital environment, namely, exposure limits and evidence to justify the limitation of preschoolers' time on digital media. Design: The analysis starts by identifying theoretical foundations that researchers use in their studies of children's behavior in the digital environment. This is followed by an overview of 40 studies that include research papers, official reports, and methodological recommendations made by healthcare and governmental organizations. Results: The review identified the following ground rules for children's exposure to the digital environment: to provide for child's interaction with a digital device, to use educational applications that will develop skills appropriate to the child's age, to ensure mandatory supervision of children's engagement by an adult who limits the exposure according to child's age-related capabilities and creates conditions for active exploration of the real rather than a virtual world. Children's cognitive development suffers the most from passive intake of digital content. Conclusion: The data herein can help to develop strategies to promote healthy and educational engagement of children with digital devices and media; however, the review highlights the insufficiency of psychophysiological research that would make it possible to practically validate the recommendations on the duration of preschoolers' exposure to the digital environment.

Hydrazides in the reaction with hydroxypyrrolines: less nucleophilicity - more diversity.

Expedient protocols for the synthesis of three types of highly functionalized azaheterocyclic scaffolds (dihydropyridazines, tetrahydropyridazines, and partially saturated tricyclic systems) from readily available hydroxypyrrolines and hydrazides are described. The directions of the transformation of a common initial intermediate, namely a Brønsted acid-activated hydroxypyrroline, depend on the reaction conditions and the structure of the hydrazides.

Authoritative subspecies diagnosis tool for European honey bees based on ancestry informative SNPs.

BACKGROUND: With numerous endemic subspecies representing four of its five evolutionary lineages, Europe holds a large fraction of Apis mellifera genetic diversity. This diversity and the natural distribution range have been altered by anthropogenic factors. The conservation of this natural heritage relies on the availability of accurate tools for subspecies diagnosis. Based on pool-sequence data from 2145 worker bees representing 22 populations sampled across Europe, we employed two highly discriminative approaches (PCA and FST) to select the most informative SNPs for ancestry inference. RESULTS: Using a supervised machine learning (ML) approach and a set of 3896 genotyped individuals, we could show that the 4094 selected single nucleotide polymorphisms (SNPs) provide an accurate prediction of ancestry inference in European honey bees. The best ML model was Linear Support Vector Classifier (Linear SVC) which correctly assigned most individuals to one of the 14 subspecies or different genetic origins with a mean accuracy of 96.2% ± 0.8 SD. A total of 3.8% of test individuals were misclassified, most probably due to limited differentiation between the subspecies caused by close geographical proximity, or human interference of genetic integrity of reference subspecies, or a combination thereof. CONCLUSIONS: The diagnostic tool presented here will contribute to a sustainable conservation and support breeding activities in order to preserve the genetic heritage of European honey bees.

Recessive myotonia congenita caused by a homozygous splice site variant in CLCN1 gene: a case report.

BACKGROUND: Myotonia congenita is a rare neuromuscular disease, which is characterized by a delay in muscle relaxation after evoked or voluntary contraction. Myotonia congenita can be inherited in a dominant (Thomsen disease) and recessive form (Becker disease) and both are caused by pathogenic variants in the CLCN1 gene. Noncanonical splice site variants are often classified as variants of uncertain significance, due to insufficient accuracy of splice-predicting tools. Functional analysis using minigene plasmids is widely used in such cases. Moreover, functional analysis is very useful in investigation of the disease pathogenesis, which is necessary for development of future therapeutic approaches. To our knowledge only one noncanonical splice site variant in the CLCN1 gene was functionally characterized to date. We further contribute to this field by evaluation the molecular mechanism of splicing alteration caused by the c.1582 + 5G > A in a homozygous state. CASE PRESENTATION: We report a clinical case of an affected 6-y.o boy with athletic appearance due to muscle hypertrophy, calf muscle stiffness, cramping and various myotonic signs in a consanguineous family with no history of neuromuscular disorders. The neurological examination showed percussion-activated myotonia in the hands and legs. Plasma creatine kinase enzyme and transaminases levels were normal. Electromyography at the time of examination shows myotonic runs in the upper and lower extremities. CONCLUSIONS: Functional analysis of the variant in a minigene system showed alteration of splicing leading to loss of function, thereby confirming that the variant is pathogenic.

Pathomechanisms of a CLCN1 Mutation Found in a Russian Family Suffering From Becker's Myotonia.

Objective: Myotonia congenita (MC) is a rare muscle disease characterized by sarcolemma over-excitability inducing skeletal muscle stiffness. It can be inherited either as an autosomal dominant (Thomsen's disease) or an autosomal recessive (Becker's disease) trait. Both types are caused by loss-of-function mutations in the CLCN1 gene, encoding for ClC-1 chloride channel. We found a ClC-1 mutation, p.G411C, identified in Russian patients who suffered from a severe form of Becker's disease. The purpose of this study was to provide a solid correlation between G411C dysfunction and clinical symptoms in the affected patient. Methods: We provide clinical and genetic information of the proband kindred. Functional studies include patch-clamp electrophysiology, biotinylation assay, western blot analysis, and confocal imaging of G411C and wild-type ClC-1 channels expressed in HEK293T cells. Results: The G411C mutation dramatically abolished chloride currents in transfected HEK cells. Biochemical experiments revealed that the majority of G411C mutant channels did not reach the plasma membrane but remained trapped in the cytoplasm. Treatment with the proteasome inhibitor MG132 reduced the degradation rate of G411C mutant channels, leading to their expression at the plasma membrane. However, despite an increase in cell surface expression, no significant chloride current was recorded in the G411C-transfected cell treated with MG132, suggesting that this mutation produces non-functional ClC-1 chloride channels. Conclusion: These results suggest that the molecular pathophysiology of G411C is linked to a reduced plasma membrane expression and biophysical dysfunction of mutant channels, likely due to a misfolding defect. Chloride current abolition confirms that the mutation is responsible for the clinical phenotype.

Efficacy of covert closed-circuit television monitoring of the hand hygiene compliance of health care workers caring for patients infected with multidrug-resistant organisms in an intensive care unit.

BACKGROUND: To compare covert closed-circuit television (CCTV) monitoring to standard overt observation in assessing the hand hygiene (HH) conduct of health care workers (HCWs) caring for patients infected with multidrug-resistant organisms (MDROs). This was a cross-sectional study in a general intensive care unit of a 1,000-bed university hospital. METHODS: Forty-six general intensive care unit HCWs (staff physicians, registered nurses, and auxiliary workers) caring for contact isolation MDRO-infected patients. The study incorporated the following 3 phases: phase 1, establishment of interrater reliability between 2 simultaneous observers using the overt observation method; phase 2, establishment of interrater reliability between 2 simultaneous observers using the CCTV method; and phase 3, simultaneous monitoring of HH by both methods to evaluate the suitability of CCTV as an alternative to direct observation of the HH conduct of HCWs caring for MDRO-infected patients. RESULTS: Overall, 1,104 opportunities to perform HH were documented during 49 observation sessions. The compliance rate observed by the overt method (37.3%) was significantly higher than that observed when only the covert method was used (26.5%). However, simultaneous overt-covert observations were found to have intraclass correlation coefficients of >0.85. CONCLUSIONS: Covert CCTV observation of HCW HH compliance appears to provide a truer and more realistic picture than overt observation, probably because of its ability to neutralize the Hawthorne effect of overt observation. The high intraclass correlation coefficients between covert observation and overt observation supports this conclusion.

Allozyme polymorphism and phylogenetic relationships in Apis mellifera subspecies selectively reared in Poland and Bulgaria.

The genetic variability of honey bee populations of three subspecies selectively reared in Poland (A. m. carnica and A. m. caucasica) and Bulgaria (A. m. macedonica-type rodopica) was studied using isoenzyme analysis of six enzyme systems (MDH-1, ME, EST-3, ALP, PGM and HK) corresponding to 6 loci. All loci were found to be polymorphic in the studied populations. Three alleles were detected at each locus: MHD-1 (MDH65, MDH80 and MDH100), Me (ME90, ME100 and ME106), EST-3 (EST94, EST100 and EST118), ALP (ALP80 ALP90 and ALP100), PGM (PGM80, PGM100 and PGM114) and HK (HK87, HK100 and HK110). The observed and expected heterozygosities (Ho and He) ranged from 0.196 (A. m. macedonica SM) to 0.265 (A. m. carnica MV) and from 0.224 (A. m. macedonica SM) to 0.273 (A. m. carnica GR), respectively. Allele frequencies of all loci were used to estimate Nei's (1972) genetic distance, which was found to range from 0.003 (between A. m. macedonica TR and SM and between A. m. carnica GR and MV populations) to 0.057 (between A. m. macedonica SM and A. m. caucasica populations). The estimated mean F(ST) value from allozyme data was 0.0364. A UPGMA dendrogram was obtained by genetic distance matrix methods; A. m. macedonica (type rodopica), A. m. carnica and A. m. caucasica populations represented different clades.