ASCORBIС ACID DEGRADATION IN N, N-DIMETHYLFORMAMIDE SOLUTIONS

Objective: Investigate the mechanisms of L-ascorbic acid transforтmation and formation of coloured enamines in N, N-dimethyl-formamide solutions. Methods: An automatic polarimeter Atago POL-1/2 was used for polarimetric investigation. Electronic spectra were recorded by UV-spectrometer Cary 60 (Agilent). The statistical analysis was carried out using the OriginPro 9.1 packages. Results: The Biot’s law violation was found in below 0.1% solutions of L-ascorbic acid (AA) in N, N-dimethylformamide (DMF). During the day, the specific rotation   of 1% AA solution varied from+37 to-1.0. Gradually, the solution acquired the red colour, and its intensity depended on the AA concentration. Spectrophotometrically, it was shown that after 15 min AA was absent in the n·10-3% solutions. The decomposition followed the first-order kinetics (k1=1.83·10-2с-1). At the same time, new absorption bands appeared at 273, 390, 533 nm. Model solutions containing dimethylamine (DMA) had a similar spectrum, and the intensity of the absorption bands increased in proportion to the concentration of DMA. Conclusion: The results show that the first step in the decomposition of ascorbic acid AA in DMF follows first-order kinetics. Numerous decomposition products are optically active compounds and reverse the sign of the optical rotation of the solution. The water resulting from the decomposition of AA is involved in the hydrolysis of the solvent. The hydrolysis product, the secondary amine DMA, interacts with the carbonyl groups of the AA decomposition products to form coloured enamines. Magnesium (II) accelerates the formation of coloured products

Morphological and functional criteria for the effectiveness of recreational activities in children

Objective. The study aimed to perform a comprehensive morphofunctional assessment of the effectiveness of recreational activities in children aged 9–12 years in the summer of 2019.Materials and methods. The study was conducted by the “Problem scientific laboratory of physical methods of diagnosis and treatment” of RostGMU in the children’s health and recreation camp “Mir” (Krasnyi Desant village, Gulf of Taganrog). Procedures and time of the study: somatometry, bioimpedance analysis, сardiointervalography, stabilometrics on the 2nd day of stay and 2.5 weeks after. Two groups were formed: Group I included overweight children (OW), n = 15 (boys, n = 9; girls, n = 6); Group II included children with normal physical development (NPD), n = 37 (boys, n = 17; girls, n = 20). The children received a non-drug complex of camp resource provision for 3 weeks.Results. Health measures did not lead to significant changes in the somatometric parameters. According to the results of the сardiointerval recording, an authentic increase in the variational range and vegetative rhythm index was found in children with NPD, which indicates an increase in the parasympathetic activity of regulation. The stress index decreased by 30% in the case of NPD, and by 6% in the case of OW. Data from the stabilometric “Balls” simulator showed that after the recovery, the regulation of postural control was optimized, and decision-making processes were accelerated, especially in children with NPD.Conclusion. The study showed that in order to assess the effectiveness of recreational activities, along with “mandatory” methods, it is advisable to use functional methods such as cardiointervalography and stabilometrics, which can be recommended for use in health and rehabilitation institutions to assess the adaptive capabilities of the organism

Detection of rifampicin and izoniazid resistance in Mycobacterium tuberculosis strains from Samara Region (Central Russia)

Recently high rates of tuberculosis incidence and prevalence are observed in civilian and prisons sectors in Russia. One of the main reasons for high morbidity levels and ineffectiveness of treatment is wide spreading of drug resistant Mycobacterium tuberculosis strains, but accurate and comprehensive information on levels of drug resistance among strains circulating in Central Russia is unavailable. Rifampicin and izoniazid resistance detection in TB isolates from Samara (Central Russia) civilian and prison TB hospitals and dispensaries in 2000–2002 by revealing mutations in rpoB, katG and inhA genes using Macroarray technique. Methods: A total of 342 M. tuberculosis isolates were tested using Macroarray method. It is based on multiplex amplification of rpoB, katG and inhA genes fragments (with three pairs of biotin labeled primers) following by dothybridization with normal and mutant oligonucleotide probes (fragments of rpoB, katG and inhA genes in which mutations occur) immobilized on nylon membrane strips. Mycobacterial DNA was extracted by heating of cell suspensions following by chloroform extraction. Streptavidin-alkaline phosphatase color development system was used for visualization of results

Genetic diversity of Escherichia coli in gut microbiota of patients with Crohn's disease discovered using metagenomic and genomic analyses

© 2018 The Author(s). Background: Crohn's disease is associated with gut dysbiosis. Independent studies have shown an increase in the abundance of certain bacterial species, particularly Escherichia coli with the adherent-invasive pathotype, in the gut. The role of these species in this disease needs to be elucidated. Methods: We performed a metagenomic study investigating the gut microbiota of patients with Crohn's disease. A metagenomic reconstruction of the consensus genome content of the species was used to assess the genetic variability. Results: The abnormal shifts in the microbial community structures in Crohn's disease were heterogeneous among the patients. The metagenomic data suggested the existence of multiple E. coli strains within individual patients. We discovered that the genetic diversity of the species was high and that only a few samples manifested similarity to the adherent-invasive varieties. The other species demonstrated genetic diversity comparable to that observed in the healthy subjects. Our results were supported by a comparison of the sequenced genomes of isolates from the same microbiota samples and a meta-analysis of published gut metagenomes. Conclusions: The genomic diversity of Crohn's disease-associated E. coli within and among the patients paves the way towards an understanding of the microbial mechanisms underlying the onset and progression of the Crohn's disease and the development of new strategies for the prevention and treatment of this disease

Change in time of spectral characteristics of drug substances (nir region)

The changes in NIR spectra of substances resulting from the processes of natural aging were investigated. The method of discriminant analysis was used for statistical evaluation of differences between two groups of spectra - for initial and aged substances. The values obtained for the spectral range of each substance can limit the possible dispersion of the samples arisen during their aging

Determination of Active Pharmaceutical Substances Dissolution Rate by Laser Light Diffraction Method

Introduction. The strategy of quality control of drugs provides for compliance with the requirements of regulatory documentation methods and critical quality indicators that determine its effectiveness. Special attention should be paid to the properties of the initial pharmaceutical substance (lipophilicity logP, area of the topological polar surface of TPSA, particle size, polymorphism), which determine the solubility and dissolution rate of the active pharmaceutical substance (APS) in terms of their impact on the bioavailability of the finished drug in vivo [1–3]. Since the assessment of pharmacopoeia solubility of APS is reduced to a visual procedure and the use of approximate terms, we have developed an original method for determining the dissolution rate of substances using the laws of chemical kinetics. Validation of the analytical method is carried out at introduction of the new method, and also at change of conditions of analysis of medicines carried out during the life cycle (product lifecycle) of a pharmaceutical product and its manufacturing process [4]. The proposed technique for laser determination of the dissolution rate in water of a medicinal substance of fluoroquinolone group has been tested; elements have been included in validation studies: repeatability, precision, linearity and range.Aim. Development of the method for determining the dissolution rate of active pharmaceutical substances by laser light diffraction with validation elements.Materials and methods. Determination of the dissolution rate of moxifloxacin hydrochloride was carried out in water for laboratory analysis of purity level 1 (ultra-pure water) obtained on the Milli-Q® Integral, the quality of which corresponds to ISO 3696:1987. To achieve this goal, a pharmacopoeia method of research was used – low-angle scattering of laser light (laser diffraction method); instrument equipment – laser dispersion meter Malvern 3600 EC.Results and discussion. An additional analytical method for determination of API dissolution rate by laser light diffraction method was developed. Validation studies on parameters: precision (repeatability, intra-laboratory/intermediate), linearity, analytical region. Precision was estimated based on the results of 18 measurements, the coefficient of variation was 8 %, the relative error of average 4 %. Linearity was determined (correlation coefficient R = 0.992). The range of application of the analytical technique depends on its purpose, is determined in the linearity analysis and ranges from 5 · 10-3 g/ml to 5 · 10-2 g/ml.Conclusion. The proposed methodology can be used as an independent test of the properties of pharmaceutical substances both at the stage of their development and preclinical studies, and in the process of quality control in addition to the existing pharmacopoeia test to assess the solubility of pharmaceutical substances, expressed in terms of conditional