GENETIC (RAPD-PCR) VARIABILITY OF STAPHYLOCOCCUS AUREUS STRAINS EXTRACTED FROM LOCUS MORBI AND INTAKT SKIN OF PATIENTS WITH ALLERGODERMATOSIS

The article presents data on the study of genetic relatedness of S. aureus strains growing on the skin and nasal passages of patients with allergodermatoses. A study of the possible correlation between the genotype of the pathogen and the burden of allergodermatoses using the RAPD-PCR method was done. The aim of the research: determination by RAPD-PCR analysis (Random Amplified Polymorphic DNA) of genetic variability and affinity of S. aureus strains extracted from locus morbi, intact areas of skin and nasal mucosa of patients with allergodermatoses (AD and IE). Materials and methods. RAPD-PCR was used to genotype 111 strains of Staphylococcus aureus extracted from the skin and nasal passages of patients with allergodermatoses (AD and IE), as well as 11 strains isolated from the skin of almost healthy individuals to identify genetic links between these strains. These strains were removed from patients with AD and IE who sought medical help in the dermatological department of the State Institution "Institute of Dermatology and Venereology of the National Academy of Medical Sciences of Ukraine" during 2016-2019. Results. When comparing the RAPD spectra of strains extracted from the affected and intact areas of the skin of patients with mild and severe AD, the degree of genetic relatedness of the strains was 75.1±4.4 % and 98.8±0.8 %, (P˂0,001), respectively, indicating a high level of affinity of the strains. Strains of S. aureus removed from the nasal passages of patients with AD had a high level of genetic affinity with strains removed from the affected areas of the skin – 79.5±1.6 %, which indicates the auto-origin of strains growing on the skin of patients. The affinity of strains isolated from patients with IE with the reference culture of S. aureus ATCC 25923 was 27.4±1.8 % and 52.0±5.2 % for strains isolated from patients with AD, indicating their low genetic relatedness. Conclusions. In the study of RAPD spectra of S. aureus strains isolated from patients with both AD and IE, no genotype was identified that would be associated with the disease or its severity. A high level of genetic affinity of strains extracted from locus morbi with strains extracted from the nasal passages of patients with AD, indicating the auto-origin of strains that grow on the skin of patients. It is shown that with increasing severity of AD, the genetic monotype of isolated pathogens increased: in patients with mild AD, 3 genetic clusters of the microorganism were identified, with moderate – 2, and with severe only one

Measurements of group velocity of light in the lake Baikal water

The results of direct measurements of group velocity of light in the lake Baikal water at the depth of 1100 m are presented. The lake Baikal water dispersion has been measured at three wavelengths: 370 nm, 470 nm and 525 nm. The results are in a rather good agreement with theoretical predictions.Comment: 4 pages, 5 figures, talk presented at RICH2002, to be published in NIMA; misprints corrected in formula at page

Stability of magnetic vortex in soft magnetic nano-sized circular cylinder

Stability of magnetic vortex with respect to displacement of its center in a nano-scale circular cylinder made of soft ferromagnetic material is studied theoretically. The mode of vortex displacement producing no magnetic charges on the cylinder side is proposed and the corresponding absolute single-domain radius of the cylinder is calculated as a function of its thickness and the exchange length of the material. In cylinders with the radii less than the single-domain radius the vortex state is unstable and is absolutely prohibited (except if pinned by material imperfections), so that the distribution of the magnetization vector in such cylinders in no applied magnetic field is uniform (or quasi-uniform). The phase diagram of nano-scale cylinders including the stability line and the metastability region obtained here is presented.Comment: 3 pages, 2 figures, RevTex 4, presented at JEMS'01, accepted to JMM

Suppression of density effect in the polarization bremsstrahlung for relativistic charged particles crossing a thin target

The peculiarities of polarization bremsstrahlung emitted when a relativistic charged particle penetrates a thin layer of an amorphous medium are consideredyesBelgorod State Universit

Evolution and stability of a magnetic vortex in small cylindrical ferromagnetic particle under applied field

The energy of a displaced magnetic vortex in a cylindrical particle made of isotropic ferromagnetic material (magnetic dot) is calculated taking into account the magnetic dipolar and the exchange interactions. Under the simplifying assumption of small dot thickness the closed-form expressions for the dot energy is written in a non-perturbative way as a function of the coordinate of the vortex center. Then, the process of losing the stability of the vortex under the influence of the externally applied magnetic field is considered. The field destabilizing the vortex as well as the field when the vortex energy is equal to the energy of a uniformly magnetized state are calculated and presented as a function of dot geometry. The results (containing no adjustable parameters) are compared to the recent experiment and are in good agreement.Comment: 4 pages, 2 figures, RevTe

Anti-blastocystis activity of hop extracts in vitro.

Blastocystis sp. are the most common, unicellular, anaerobic parasites of the intestinal tract of many animal and human species that can cause various digestive diseases. Metronidazole has long been used as a first-line treatment for blastocystosis, but recent clinical and in vitro studies have demonstrated its low efficacy against Blastocystis sp. The aim of this study was to determine the in vitro sensitivity of Blastocystis sp. clinical isolates to carbonic acid hop extracts and alcohol hop extracts in comparison with metronidazole. Five cultures of Blastocystis sp. were isolated from faecal samples from patients with irritable bowel syndrome with predominant diarrhoea (IBS-D, Rome IV). The parasites were identified by microscopy of faecal smears permanently stained with trichrome, Wheatley’s modification and Heidenhain’s iron-haematoxylin. Blastocystis sp. was cultivated at 37°C under anaerobic conditions on RPMI-1640 with antibiotics and horse serum, taking into account their growth characteristics. To detect the antiblastocystic activity hop extracts and metronidazole were tested in the range from 1000 μg/ml to 1 μg/ml.The presence and number of viable Blastocystis sp. cells were determined after 24, 48, 72 and 96 hours. Blastocystis sp. cells were counted in a hemocytometer using the trypan blue dye exclusion test. All experiments were performed in triplicate. According to the results of in vitro sensitivity of 5 clinical isolates of Blastocystis sp. to the action of carbonic acid hop extract, alcohoicl hop extract and metronidazole, a direct positive pattern in the dose-response and contact time-response effects was established. Alcoholic hop extract showed the highest level of antiblastocystic activity with indicators (for 72- hour parasite cultures) of the minimum inhibitory concentration (which inhibits the parasite cultures growth by 50%) (2.8±0,8) μg/ml and the minimum lethal concentration (which destroys parasite cells by 100%) – 8 μg/ml, being 2.4 and 4.5 times lower than the minimum inhibitory concentration and 8 and 62.5 times lower, than the minimum lethal concentration for hop extract and metronidazole, respectively (p<0.05). It has been shown that alcoholic hop extract (≥16 μg/ml) causes gradual morphological changes in Blastocystis sp. cells, leading to their complete destruction.In contrast to metronidazole, subinhibitory concentrations of hop extract (<2 μg/ml) do not stimulate the proliferation of Blastocystis sp. cells in vitro

Anti-blastocystis activity of hop extracts in vitro

Blastocystis sp. are the most common, unicellular, anaerobic parasites of the intestinal tract of many animal and human species that can cause various digestive diseases. Metronidazole has long been used as a first-line treatment for blastocystosis, but recent clinical and in vitro studies have demonstrated its low efficacy against Blastocystis sp. The aim of this study was to determine the in vitro sensitivity of Blastocystis sp. clinical isolates to carbonic acid hop extracts and alcohol hop extracts in comparison with metronidazole. Five cultures of Blastocystis sp. were isolated from faecal samples from patients with irritable bowel syndrome with predominant diarrhoea (IBS-D, Rome IV). The parasites were identified by microscopy of faecal smears permanently stained with trichrome, Wheatley’s modification and Heidenhain’s iron-haematoxylin. Blastocystis sp. was cultivated at 37°C under anaerobic conditions on RPMI-1640 with antibiotics and horse serum, taking into account their growth characteristics. To detect the anti­blastocystic activity hop extracts and metronidazole were tested in the range from 1000 μg/ml to 1 μg/ml.The presence and number of viable Blastocystis sp. cells were determined after 24, 48, 72 and 96 hours. Blastocystis sp. cells were counted in a hemocytometer using the trypan blue dye exclusion test. All experiments were performed in triplicate. According to the results of in vitro sensitivity of 5 clinical isolates of Blastocystis sp. to the action of carbonic acid hop extract, alcohoicl hop extract and metronidazole, a direct positive pattern in the dose-response and contact time-response effects was established. Alcoholic hop extract showed the highest level of antiblastocystic activity with indicators (for 72-hour parasite cultures) of the minimum inhibitory concentration (which inhibits the parasite cultures growth by 50%) (2.8±0,8) μg/ml and the minimum lethal concentration (which destroys parasite cells by 100%) – 8 μg/ml, being 2.4 and 4.5 times lower than the minimum inhibitory concentration and 8 and 62.5 times lower, than the minimum lethal concentration for hop extract and metronidazole, respectively (p<0.05). It has been shown that alcoholic hop extract (≥16 μg/ml) causes gradual morphological changes in Blastocystis sp. cells, leading to their complete destruction.In contrast to metronidazole, subinhibitory concentrations of hop extract (<2 μg/ml) do not stimulate the proliferation of Blastocystis sp. cells in vitro

Geometrical pinning of magnetic vortices induced by a deficit angle on a surface: anisotropic spins on a conic space background

We study magnetic vortex-like excitations lying on a conic space background. Two types of them are obtained. Their energies appear to be linearly dependent on the conical aperture parameter, besides of being logarithmically divergent with the sample size. In addition, we realize a geometrical-like pinning of the vortex, say, it is energetically favorable for it to nucleate around the conical apex. We also study the problem of two vortices on the cone and obtain an interesting effect on such a geometry: excitations of the same charge, then repealing each other, may nucleate around the apex for suitable cone apertures. We also pay attention to the problem of the vortex pair and how its dissociation temperature depends upon conical geometry.Comment: 13 pages, 06 figures, Latex. Version accepted for PHYSICS LETTERS

The Tunka Experiment: Towards a 1-km^2 Cherenkov EAS Array in the Tunka Valley

The project of an EAS Cherenkov array in the Tunka valley/Siberia with an area of about 1 km^2 is presented. The new array will have a ten times bigger area than the existing Tunka-25 array and will permit a detailed study of the cosmic ray energy spectrum and the mass composition in the energy range from 10^15 to 10^18 eV.Comment: 3 pages, 2 figures, to be published in IJMP

Induced four fold anisotropy and bias in compensated NiFe/FeMn double layers

A vector spin model is used to show how frustrations within a multisublattice antiferromagnet such as FeMn can lead to four-fold magnetic anisotropies acting on an exchange coupled ferromagnetic film. Possibilities for the existence of exchange bias are examined and shown to exist for the case of weak chemical disorder at the interface in an otherwise perfect structure. A sensitive dependence on interlayer exchange is found for anisotropies acting on the ferromagnet through the exchange coupling, and we show that a wide range of anisotropies can appear even for a perfect crystalline structure with an ideally flat interface.Comment: 7 pages, 7 figure