К вопросу об оздоровлении воздуха в пассажирских вагонах (1891–1892 годы)

News from the archivesThis material briefly reproduces the main content of the article by Alexander Kritsky in the «Railway Business» journal in 1891 and 1892. The very fact of a multi-issue and very voluminous publication shows how much attention was paid at one time to the issue of air purity in railway passenger cars.The original punctuation, vocabulary and abbreviations adopted at that time are preserved in the text as much as possible.Пресс-архивДанный материал кратко воспроизводит основное содержание статьи А. М. Крицкого в журнале «Железнодорожное дело» в 1891 и 1892 годах. Сам факт растянувшейся на несколько номеров и весьма объёмной публикации показывает, какое внимание было уделено в своё время вопросу чистоты воздуха в железнодорожных пассажирских вагонах. В тексте максимально сохранены оригинальная пунктуация, лексика и сокращения, принятые в то время

Does nitrate reductase play a key role in photoinduction of carotenoid synthesis in Neurospora crassa?

Does nitrate reductase play a key role in photoinduction of caroteniod synthesis in Neurospora crassa

Psychological distress and post-traumatic symptomatology among dental healthcare workers in Russia: Results of a pilot study

The spread of SARS-CoV-2 infection has increased the risk of mental health problems, including post-traumatic stress disorders (PTSD), and healthcare workers (HCWs) are at greater risk than other occupational groups. This observational cross-sectional study aimed to explore the symptoms of depression, anxiety, and PTSD among dental HCWs in Russia during the coronavirus disease 2019 (COVID-19) pandemic. The survey was carried out among 128 dental HCWs from three dental clinics of Ekaterinburg, Russia. The mean age of the sample was 38.6 years. Depression, anxiety, and stress were assessed using the Depression Anxiety and Stress Scale-21 (DASS-21); PTSD was assessed using the PTSD Symptom Scale-Self-Report (PSS-SR); subjective distress was assessed using the Impact of Event Scale-Revised (IES-R). The results indicated that 20.3-24.2% HCWs had mild to extremely severe symptoms of psychological distress, and 7.1-29.7% had clinical symptoms of PTSD. No differences between females and males were revealed. HCWs working directly with patients had significantly higher levels of PTSD symptoms and the risk of PTSD development compared to those working indirectly, whereas older HCWs had significantly higher levels of both psychological distress and PTSD symptoms compared to younger HCWs. Thus, dental HCWs are at high risk for psychological distress and PTSD symptoms during the COVID-19 pandemic. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The study was partly supported by the Government contract of the Institute of Immunology and Physiology (AAAA-A18-118020690020-1) and the HSE University Basic Research Program (funded by the Russian Academic Excellence Project 5-1000)

Comparative MLVA-Analysis of Vibrio cholerae Strains of Classical Biovar, Isolated in the Russian Federation and Abroad

Objective of the study is to determine phylogenetic affinity of the Vibrio cholerae strains of classical biovar, isolated between 1937 and 1969 in Russia, to the strains from near and far abroad countries. Materials and methods. Utilized were 27 Vibrio cholerae strains of classical biovar. PCR was carried out applying “BIS M112” amplifier. Genetic analyzer ABI 3500xl was used for sequencing of the strains. MLVA-analysis was performed by reference to 5 MLVA-loci: VC0147, VC0436-0437, VC1650, VCA0171, and VCA0238. Nutrient requirement and soluble hemagglutinin/protease production was established using plate method. Results and conclusions. Identified have been 8 MLVA-clusters and 21 MLVA-types. It is determined that the strains, isolated during atypical cholera outbreak 1942–1943 in Russia, are inhomogeneous as regards phenotype and genotype and fall into two separate groups, one of which is related to the strain, isolated during cholera outbreak 1938 in Khabarovsk, and another group – to the strains from India and China, isolated in 1946 and 1949, respectively

DEVELOPMENT OF THE ALGORITHM FOR IDENTIFICATION OF THE LEVEL OF VIBRIO CHOLERAE CTXA AND TOXR GENE EXPRESSION USING RT-PCR WITH REAL-TIME HYBRIDIZATION-FLUORESCENT REGISTRATION OF RESULTS

Objective of the study is to design the algorithm for assessment of expression of the structural and regulatory virulence Vibrio cholerae genes by the model of ctxA and toxR genes encoding and controlling biosynthesis of cholera toxin.Materials and methods. Utilized were 10 strains of Vibrio cholerae, classical and El Tor biovars. Cloning of gene fragments was carried out through transformation and ligation. RT-PCR was done in “BIS M112” and “Rotor-GeneQ” amplifiers. Processing of the results was performed by means of the software package in set with Rotor-GeneQ (Software 1.8.17.5).Results and conclusions. Developed has been the algorithm for evaluation of the level of expression of V. cholerae ctxA and toxR genes applying RT-PCR with real-time hybridization-fluorescent registration of results. The stated algorithm allows for rapid and effective statistically significant specification of the expression of structural and regulatory virulence V. cholerae genes and can be used for evaluation of newly discovered cholera vibrio strains

Vibrio cholerae secretion system of the type VI

The review summarizes literature data on the Vibrio cholerae secretion system of the 6th type. This system is a contact-dependent macromolecular mechanism through which bacteria translocate toxic effector proteins into target cells. It is found in many Gram-negative bacteria, including Vibrio cholerae. V. cholerae infects phagocytic amoebae, nematodes, ciliates, bacteria belonging to different species, as well as unrelated strains of V. cholerae using this system. DNA released after lysis of competing bacteria can be taken up by Vibrio cholerae cells, which leads to the acquisition of new genetic material. The type VI secretion system is involved in the infectious process. The destruction of macrophages and microbiota contributes to the active reproduction of the pathogen and colonization of host epitheliocytes, and the production of effector proteins causes the development of diarrhea and intestinal inflammation. Cholera vibrio secretion system of the 6th type has a structure similar to other gram-negative bacteria. The genes encoding the proteins of this system are located in one large region of the second chromosome and in several additional clusters. It has been shown that toxigenic strains of V. cholerae contain an identical set of secretion system genes, while their composition is variable in non-toxigenic isolates. The regulation of secretion system protein expression differs in V. cholerae strains of different toxigenicity, depends on a number of environmental signals, and is associated with other cell regulatory networks. The paper provides experimental data on the analysis of the structure of the global regulatory gene, vasH, of the type VI secretion system in toxigenic and non-toxigenic V. cholerae O1, biovar El Tor strains isolated in the Russian Federation. Thus, the type VI secretion system is an important mechanism that facilitates the survival of V. cholerae in complex communities in vitro, protects against damaging factors of the macroorganism and increases virulence in vivo, and also provides evolutionary transformations of cholera vibrio. Further study of this system will allow a better understanding of the pathogen-host interaction processes, as well as the adaptation mechanisms of V. cholerae in the external environment

Transformation of 6-tetrahydrobiopterin in aqueous solutions under UV-irradiation

© 2017 Elsevier B.V. Melanogenesis disturbance leads to several pathologies, including vitiligo disease. Ultraviolet (UV) narrowband phototherapy (308 or 311nm) is used in treating vitiligo; however, the mechanism of phototherapy is not yet understood. Vitiligo is accompanied by three-fivefold increased de-novo synthesis of (6R)-l-erythro-5,6,7,8-tetrahydrobiopterin (H 4 Bip), its excess and its further oxidation can be considered as significant factors in the pathogenesis of vitiligo. (H 4 Bip), as the phenylalanine 4-hydroxylase coenzyme, catalyzes the oxidation of phenylalanine to tyrosine (a melanin precursor). In this context, photo-transformation of H 4 Bip in aqueous buffer solutions has been studied. HPLC-MS/MS has demonstrated that pterin products of H 4 Bip autoxidation (7,8-dihydropterin (H 2 Ptr), dihydroxanthopterin and pterin) predominate over biopterin products (7,8-dihydrobiopterin (H 2 Bip) and biopterin). We have shown that UV irradiation accelerates the autoxidation while the products of oxidative degradation of H 4 Bip act as photosensitizers. The distinctive feature of photooxidation of H 4 Bip from autoxidation is the formation of dihydropterin (N 2 Ptr) 2 and dihydrobiopterin (N 2 Bip) 2 dimers. By means of HPLC-MS/MS it was found that formation of dihydropterin dimers is the predominant process. The signal of molecular ion of the dimer (N 2 Ptr) 2 (m/z =331) was almost a thousand times higher than the signal of (N 2 Bip) 2 (m/z =479). The key point of the dimerization is photoexcitation (at 310-320nm) of the intermolecular complex (qH 2 Ptr-N 2 Ptr) generated in dark. As a result of the photoreaction azacyclobutane dimers have been formed. In the case of alternation of dark and light intervals H 4 Bip converted into dimers with 96 % yield. The data obtained are discussed in the context of UV-B narrowband vitiligo phototherapy

Comparative Analysis of Survival Capacity among Typical and Genovariant Strains of <i>Vibrio cholerae</i>, Biovar El Tor <i>in vivo</i> and <i>in vitro</i>

Objective of the study was to conduct experiments on survival capacity of toxigenic genovariant strains as compared to typical strains of V. cholerae , biovar El Tor in autoclaved river water and in the organism of laboratory animals. Consequently, it was determined that both, genovariant and typical El Tor vibrios, sustained for a significant period of time (more than 5 months) in the river water, though a number of the bacterial cells in the population of the typical ones gradually decreased, while in the genovariant strains - the growth was observed in between the 7th and 21st day. CFU of the genovariants was 1.5-2.5 and 1.8-3.0 times higher than the amount of typical strain bacteria on the day 7 and day 21, respectively. Selective advantage of genovariants was also confirmed by competitive test in vitro . Furthermore, genovariants dominated over typical strains of V. cholerae , biovar El Tor in the mixed population in vivo (bioassay animals): CFU of the genovariants 1.25-84.0 times exceeded that of the typical strains when seeding out the contents of intestine and gastrointestinal wall homogenate. Put forward was an assumption that one of the factors for genovariant selective advantage might be enhanced adaptation ability affected by changes of cell metabolic activity. Identified capacity of genovariant toxigenic strains - not only to sustain in open water bodies of our country, but also to propagate in there, creates unfavorable epidemiological situation on cholera

Parasite Component Community of Smalltooth Sawfish Off Florida: Diversity, Conservation Concerns, and Research Applications

Compared with that of other charismatic elasmobranchs, the component community of metazoan parasites infecting endangered smalltooth sawfish Pristis pectinata is exceedingly poorly characterized: adults of Dermophthirioides pristidis and Neoheterocotyle inpristi (ectoparasitic flatworms of skin and gill, respectively) were the only confirmed parasites prior to the description, based on specimens reported herein, of Mycteronastes caalusi. Our opportune and directed parasitological examinations of 290 smalltooth sawfish (277 live inspections; 13 necropsies; 671 to 2640 mm stretch total length) in south Florida coastal waters revealed at least 8 species of Platyhelminthes, 9 of Arthropoda, 4 of Annelida, and 1 of Nematoda. This collection includes representatives of an undescribed species of Aporocotylidae (Digenea) and myriad new host records, considerably updating and advancing our understanding of smalltooth sawfish symbionts. We also confirm that D. pristidis and N. inpristi are extant and propose D. pristidis as a reliable biological tag. Some of these parasites are evidently highly host-specific and so vulnerable to extinction

Seroprevalence of sars-cov-2 antibodies in symptomatic individuals is higher than in persons who are at increased risk exposure: The results of the single-center, prospective, cross-sectional study

The present study aimed to assess antibody seropositivity prevalence among symptomatic individuals and individuals with a high risk of occupational exposure to SARS-CoV-2. Participants from Chelyabinsk (Russian Federation) who were at an increased risk of exposure to SARS-CoV-2 (high-risk group, n = 1091) and participants who either had symptoms consistent with COVID-19 or were suspected to have experienced COVID-19 in the past (symptomatic group, n = 692) were enrolled between 28 September and 30 December 2020. Blood samples were tested by enzyme-linked immunosorbent assay D-5501 SARS-Cov-2-IgG-EIA-BEST and D-5502 SARS-Cov-2-IgM-EIA-BEST (AO Vector-Best, Novosibirsk, Russia). The overall seropositivity rate was 28.33–28.53%. SARS-CoV-2 antibodies were detected in 17.23% (adjusted prevalence of 17.17–17.29%) of participants in the high-risk and 45.95% (adjusted prevalence of 45.91–46.24%) in the symptomatic group. Higher IgG and IgM titers were observed in women compared to men, as well as in participants in the symptomatic group compared to those in the high-risk group. The results indicate that the seroprevalence among residents in several Russian regions is low (28.38%) and inadequate to provide herd immunity. The lower seroprevalence among participants in the high-risk group may be attributed to the enforcement of healthcare protocols and the use of adequate personal protective equipment. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The reported study was funded by RFBR and NSFC (project No.20-515-55003), by the NSFC (project No. 82161138003), and partly by the Government contract of the Institute of Immunology and Physiology (AAAA-A21-121012090090-9)