Publications by authors named "Anna Kravchenko"

The efficiency of human immunodeficiency virus-1 (HIV-1) inhibition by sulfated polysaccharides isolated from the various families of red algae of the Far East Pacific coast were studied. The anti-HIV-1 activity of kappa and lambda-carrageenans from , original highly sulfated X-carrageenan with low content of 3,6-anhydrogalactose from and i/κ-carrageenan with hybrid structure isolated from was found. The antiviral action of these polysaccharides and its low-weight oligosaccharide was compared with commercial κ-carrageenan.

View Article and Find Full Text PDF

In many applications, artificial neural networks are best trained for a task by following a curriculum, in which simpler concepts are learned before more complex ones. This curriculum can be hand-crafted by the engineer or optimised like other hyperparameters, by evaluating many curricula. However, this is computationally intensive and the hyperparameters are unlikely to generalise to new datasets.

View Article and Find Full Text PDF

Background: The RNA-Recognition motif (RRM) is a protein domain that binds single-stranded RNA (ssRNA) and is present in as much as 2% of the human genome. Despite this important role in biology, RRM-ssRNA interactions are very challenging to study on the structural level because of the remarkable flexibility of ssRNA. In the absence of atomic-level experimental data, the only method able to predict the 3D structure of protein-ssRNA complexes with any degree of accuracy is ssRNA'TTRACT, an ssRNA fragment-based docking approach using ATTRACT.

View Article and Find Full Text PDF

: Data management is fast becoming an essential part of scientific practice, driven by open science and FAIR (findable, accessible, interoperable, and reusable) data sharing requirements. Whilst data management plans (DMPs) are clear to data management experts and data stewards, understandings of their purpose and creation are often obscure to the producers of the data, which in academic environments are often PhD students. : Within the RNAct EU Horizon 2020 ITN project, we engaged the 10 RNAct early-stage researchers (ESRs) in a training project aimed at formulating a DMP.

View Article and Find Full Text PDF

Comparative structural analysis of gelling polysaccharides from and belonging to Phyllophoraceae and the effect of their structural features and molecular weight on human colon cancer cell lines (HT-29, DLD-1, HCT-116) was carried out. According to chemical analysis, IR and NMR spectroscopies, produces kappa/iota-carrageenan with a predominance of kappa units and minor amounts of mu and/or nu units, while the polysaccharide from is iota/kappa-carrageenan (predominance of iota units) and contains negligible amounts of beta- and nu-carrageenans. Iota/kappa- (Afg-OS) and kappa/iota-oligosaccharides (Mp-OS) were obtained from the original polysaccharides through mild acid hydrolysis.

View Article and Find Full Text PDF

Herpes simplex virus (HSV) infections, the incidence of which is still widespread throughout the world, are actualizing the search and development of new, more effective antiherpetic drugs. The development of multifunctional drug delivery systems, including liposome-based ones, has become a relevant and attractive concept in nanotechnology. The ability of complexes of κ- and Σ-carrageenans (CRGs)-sulfated polysaccharides of red algae, with echinochrome A (Ech), as well as the liposomal form of the Σ-CRG/Ech complex-to inhibit different stages of HSV-1 infection in Vero cells was studied.

View Article and Find Full Text PDF

The sulfated polysaccharides from cystocarpic plants of Mazzaella parksii were studied. Fractionation at a given KCl concentration allowed us to assume, and stepwise fractionation to prove, that these polysaccharides consisted of several carrageenans that differed in structure and molecular weight. As a result of stepwise fractionation with KCl, nine gelling (1-9) and one non-gelling (10) fractions were obtained.

View Article and Find Full Text PDF

The anti-inflammatory effects of the CRG/Ech complex in LPS-induced endotoxemia were investigated in vivo in mice and in vitro in LPS-stimulated RAW 264.7 cells and peritoneal macrophages. The results indicated that the CRG/Ech complex suppressed the LPS-induced inflammatory response by reducing the production of ROS and NO in the macrophages.

View Article and Find Full Text PDF

The structural diversity and unique physicochemical properties of sulphated polysaccharides of red algae carrageenans (CRGs), to a great extent, determine the wide range of their antiviral properties. This work aimed to compare the antiviral activities of different structural types of CRGs: against herpes simplex virus type 1 (HSV-1) and enterovirus (ECHO-1). We found that CRGs significantly increased the resistance of Vero cells to virus infection (preventive effect), directly affected virus particles (virucidal effect), inhibited the attachment and penetration of virus to cells, and were more effective against HSV-1.

View Article and Find Full Text PDF

New insights into the structure of the hybrid κ/β-carrageenan (κ/β-CRG) of the red alga have been obtained. Carrageenan oligosaccharides were prepared through the chemical and enzymatic depolymerization of κ/β-CRG with κ-carrageenase and its the enzyme-resistant fraction. The composition and distribution of the repetition units of κ/β- CRG were investigated by using the negative ion tandem MALDI-TOFMS and ESIMS method, which made it possible to prove and characterize the hybrid structure of this polysaccharide.

View Article and Find Full Text PDF

The inhibitory effects of carrageenans (CRGs) on lipopolysaccharide (LPS) induced inflammation in a mouse model of endotoxemia and in complex therapy of patients with enteric infections of Salmonella etiology were studied. The atomic force microscopy (AFM) examination of LPS and its mixture with CRGs showed that the LPS morphology is significantly changed under the action of κ- and κ/β-CRGs. CRGs were able to increase the synthesis of anti-inflammatory interleukin 10 (IL-10) in vitro, and, at low concentrations, their activity in the mixture with LPS was higher.

View Article and Find Full Text PDF

Objective: The aim: Efficacy assessment of herpesvirus infection drug prophylaxis (HVI) manifestations in the mouth of patients with chronic herpes-associated generalized periodontitis (CHGP) of moderate severity during and shortly after closed curettage.

Patients And Methods: Materials and methods: The total of 87 patients with CHGP of moderate severity aged 35-60 years were examined and divided into groups according to the presence of HVI: Group I (main) included 48 patients who had herpesvirus infection; group II (comparison) - 39 patients who were not found herpesvirus infection. Group III was formed based on the data of out-patient medical reports retrospective analysis and was used to compare the number of complication cases.

View Article and Find Full Text PDF

Several in vivo immunotropic effects of κ/β-carrageenan isolated from the red algae Tichocarpus crinitus were studied, by orally administering it at 100 mg/kg/day to mice for 7 days. Serum levels of IFN-γ, IL-12, IL-1β, and IL-4 were measured. Carrageenan's ability to influence development of LPS-induced inflammation was also assessed.

View Article and Find Full Text PDF

The sulfated polysaccharide from sterile alga Mastocarpus pacificus was investigated. Partial reductive hydrolysis and NMR spectroscopy showed that the extracted polysaccharides were only carrageenans. According to FT-IR- and NMR spectroscopy this polysaccharide was a hybrid kappa/iota-carrageenan with a predominance of kappa-type units.

View Article and Find Full Text PDF

The mucoadhesive properties of different types of carrageenan (kappa-, kappa/beta-, iota/kappa- and lambda-CRGs) isolated from red seaweed families Gigartinaceae and Tichocarpaceae collected on the Pacific coast were studied. We examined the interaction between CRGs and pig stomach mucin in dilute aqueous solutions using a set of methods. Measurements of the dynamic light scattering of mucin in the presence of CRG showed that the polysaccharides cause aggregation of mucin particles, as confirmed by microscopy data.

View Article and Find Full Text PDF

Sea urchin pigment echinochrome A (Ech), a water-insoluble compound, is the active substance in the cardioprotective and antioxidant drug Histochrome (PIBOC FEB RAS, Moscow, Russia). It has been established that Ech dissolves in aqueous solutions of carrageenans (CRGs). Herein, we describe the effects of different types of CRGs on some properties of Ech.

View Article and Find Full Text PDF

Inclusion of drugs in liposomes offers the potential for localized and sustained delivery to mucosal surfaces. The inclusion of the carrageenan matrix with echinochrome A ((Ech)-the active substance of the drug Histochrome) in liposomes was studied. According to the spectral characteristics, Ech was not oxidized and retained stability after encapsulation in the liposomes and the lyophilization process.

View Article and Find Full Text PDF

The possibility of using different types of carrageenans (CRG) as matrixes for incorporating of echinochrome A (Ech) was investigated. Ech interacts with carrageenans and is incorporated into the macromolecular structure of the polysaccharide. The inclusion of Ech in carrageenan matrices decreased its oxidative degradation and improved its solubility.

View Article and Find Full Text PDF

Gelling sulfated polysaccharide from the cystocarpic plants of Ahnfeltiopsis flabelliformis was studied. According to FT-IR and NMR spectroscopy data, the polysaccharide was found to be iota/kappa-carrageenan with iota- and kappa-type units in a 2:1 ratio containing beta-carrageenan units and minor amounts of nu- and mu-carrageenans. The HPLC and ESI MS/MS data of enzymatic hydrolysis products revealed that the main components of the polymer chain are iota-carrabiose, iota-carratetraose and hybrid tetra- and hexasaccharides consisting of kappa- and iota-units.

View Article and Find Full Text PDF

KCl-insoluble sulfated polysaccharide from sterile alga Ahnfeltiopsis flabelliformis was investigated. Partial reductive hydrolysis and NMR spectroscopy showed that the polysaccharide comprises disaccharide units of carrabiose only. According to FT-IR-, 1D, 2D NMR spectroscopies and mass-spectrometry this polysaccharide is kappa/beta-carrageenan with ratio of kappa- and beta-types units 3:1 and contains minor amounts of iota- and gamma-carrageenans (precursor of beta-carrageenan).

View Article and Find Full Text PDF