Features of Highly Homologous T-Cell Receptor Repertoire in the Immune Response to Mutations in Immunogenic Epitopes.

CD8+ T-cell immunity, mediated through interactions between human leukocyte antigen (HLA) and the T-cell receptor (TCR), plays a pivotal role in conferring immune memory and protection against viral infections. The emergence of SARS-CoV-2 variants presents a significant challenge to the existing population immunity. While numerous SARS-CoV-2 mutations have been associated with immune evasion from CD8+ T cells, the molecular effects of most mutations on epitope-specific TCR recognition remain largely unexplored, particularly for epitope-specific repertoires characterized by common TCRs.

T-Cell Receptors Cross-Reactive to Coronaviral Epitopes Homologous to the SPR Peptide.

The COVID-19 pandemic caused by the rapid spread of the novel coronavirus SARS-CoV-2, has promoted an interest in studying the T-cell immune response. It was found that the polyclonal and cross-reactive T-cell response against seasonal coronaviruses and other SARS-CoV-2 strains reduced disease severity. We investigated the immunodominant T-cell epitope SPRWYFYYYL from the nucleocapsid protein of SARS-CoV-2.

Carrageenan films as promising mucoadhesive ocular drug delivery systems.

Polymer mucoadhesive films being developed for use in ophthalmology represent a new tool for drug delivery and are considered an alternative to traditional dosage forms. Due to their mucoadhesive properties, carrageenans (CRGs) are widely used in various forms for drug delivery. In this study, films based on CRGs of various structural types (κ/β, κ, x, and λ) for use in ophthalmology were studied.

Data and models for stance and premise detection in COVID-19 tweets: Insights from the Social Media Mining for Health (SMM4H) 2022 shared task.

The COVID-19 pandemic has sparked numerous discussions on social media platforms, with users sharing their views on topics such as mask-wearing and vaccination. To facilitate the evaluation of neural models for stance detection and premise classification, we organized the Social Media Mining for Health (SMM4H) 2022 Shared Task 2. This competition utilized manually annotated posts on three COVID-19-related topics: school closures, stay-at-home orders, and wearing masks.

Physicochemical Properties and Antiherpetic Activity of κ-Carrageenan Complex with Chitosan.

Nanoparticles formation is one of the ways to modulate the physicochemical properties and enhance the activity of original polysaccharides. For this purpose, based on the polysaccharide of red algae, κ-carrageenan (κ-CRG), it polyelectrolyte complex (PEC), with chitosan, were obtained. The complex formation was confirmed by ultracentrifugation in a Percoll gradient, with dynamic light scattering.

Mucoadhesive Marine Polysaccharides.

Mucoadhesive polymers are of growing interest in the field of drug delivery due to their ability to interact with the body's mucosa and increase the effectiveness of the drug. Excellent mucoadhesive performance is typically observed for polymers possessing charged groups or non-ionic functional groups capable of forming hydrogen bonds and electrostatic interactions with mucosal surfaces. Among mucoadhesive polymers, marine carbohydrate biopolymers have been attracting attention due to their biocompatibility and biodegradability, sample functional groups, strong water absorption and favorable physiochemical properties.

Carrageenan gel beads for echinochrome inclusion: Influence of structural features of carrageenan.

Carrageenan (CRG) and carrageenan/chitosan (CH) gel beads (CRG/CH) were prepared as a release delivery system for echinochrome A (Ech). According to spectral data, the Ech was dispersed in the polymer matrix, interacted with CRG, was not oxidised, and remained stable after encapsulation in CRG beads. Carrageenan beads containing Ech were coated with CH by layering.

Current Trend of Marine Carbohydrate-Containing Compounds with Medicinal Properties.

Carbohydrates are most abundant biomolecules on Earth and, also, the most complex biomolecules in terms of structure [...

[AL-amyloidosis with cardiac involvement. Diagnostic capabilities of non-invasive methods].

There are presented the literature data and a description of the clinical course of the disease in isolated/predominant cardiac amyloidosis. Amyloid cardiomyopathy is the most common phenocopy of hypertrophic cardiomyopathy. The modern possibilities of non-invasive diagnostics using osteoscintigraphy for the differential diagnosis between amyloid cardiomyopathy caused by AL- and transthyretin amyloidosis are described in detail.

Anatomy of the Bezymianny volcano merely before an explosive eruption on 20.12.2017.

Strong explosive eruptions of volcanoes throw out mixtures of gases and ash from high-pressure underground reservoirs. Investigating these subsurface reservoirs may help to forecast and characterize an eruption. In this study, we compare seismic tomography results with remote sensing and petrology data to identify deep and subaerial manifestations of pre-eruptive processes at Bezymianny volcano in Kamchatka shortly before its violent explosion on December 20, 2017.

The Comparative Immunotropic Activity of Carrageenan, Chitosan and Their Complexes.

The immunotropic activity of polyelectrolyte complexes (PEC) of κ-carrageenan (κ-CGN) and chitosan (CH) of various compositions was assessed in comparison with the initial polysaccharides in comparable doses. For this, two soluble forms of PEC, with an excess of CH (CH:CGN mass ratios of 10:1) and with an excess of CGN (CH: CGN mass ratios of 1:10) were prepared. The ability of PEC to scavenge NO depended on the content of the κ-CGN in the PEC.

Inhibitory Effects of Carrageenans on Endotoxin-Induced Inflammation.

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.

Effect of carrageenans on some lipid metabolism components in vitro.

The research described here focused on the effect of sulfated red algal polysaccharides (κ-, κ/β-, ι/κ-carrageenan) individually and in combination with lipopolysaccharide (LPS) on the synthesis of prostaglandin E (PGE) and cytokines (interleukin [IL]-1β and IL-6) in whole blood model in vitro. The results demonstrated that, at high concentrations, carrageenans have substantial ability to modulate PGE synthesis and stimulate IL-1β and IL-6 synthesis. A low degree of sulfate and high molecular weight were a prerequisite for the ability of carrageenans to modulate PGE synthesis.

Mucoadhesive properties of sulphated polysaccharides carrageenans from red seaweed families Gigartinaceae and Tichocarpaceae.

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.

Effects of Carrageenans on Biological Properties of Echinochrome.

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.

Liposomal Form of the Echinochrome-Carrageenan Complex.

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.

Morphology, electrokinetic characteristics and the effect on biofilm formation of carrageenan:chitosan polyelectrolyte complexes.

Carrageenan:chitosan (CG:CH) polyelectrolyte complexes (PEC) were obtained and the effect of the initial components ratio on formation was studied by dynamic light scattering, atomic force microscopy (AFM) and electrokinetic measurements. Positively charged PEC particles (average ζ-potential 40.2 mV) were formed, provided that the polycation was present in excess in the complex and was stabilized by chitosan amino groups.

[Transthyretin amyloidosis in a cohort of old and very old patients with chronic heart failure].

Background: Life-time diagnostics of wild type transthyretin amyloidosis (ATTR(wt)-amyloidosis) is virtually absent, even though ATTR(wt)-amyloidosis is an underestimated cause for morbidity and mortality, particularly in the older age group.

Aim: To study incidence, demographic characteristics, and morpho-functional features of ATTR(wt)-amyloidosis in patients with FC IV CHF and LV hypertrophy > 15 mm according to autopsy data.

Materials And Methods: Postmortem reports were retrospectively analyzed for patients (n=141; 19 % males, 81 % females) of cardiology departments aged ≥69 with the underlying CHF syndrome.

Carrageenans-Sulfated Polysaccharides from Red Seaweeds as Matrices for the Inclusion of Echinochrome.

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.

[Cytokine-inducing and anti-inflammatory activity of chitosan and its low-molecular derivative].

A low-molecular derivative of the polysaccharide (5 kDa) was obtained and its cytokine-inducing and anti-inflammatory activity was studied by free radical depolymerization of chitosan (110 kDa). It was shown that high-molecular chitosan in vitro inhibited the synthesis of anti-inflammatory cytokine, the tumor necrosis factor alpha induced by endotoxin. In the case of peroral introduction to experimental animals, high- and low-molecular chitosans stimulated synthesis of the anti-inflammatory cytokine IL-10 in the blood serum of mice; in this case, the activity of the high-molecular derivative was two times higher as compared with the initial polysaccharide.

Carrageenans effect on neutrophils alone and in combination with LPS in vitro.

Influence of sulfated red algal polysaccharides (κ-, λ-, and κ/β-carrageenans) and degraded derivative of κ/β-carrageenan on neutrophils/monocytes activation alone and in combination with lipopolysaccharide was investigated by means of determination of reactive oxygen species production, latex microparticles engulfment, total and extracellular myeloperoxidase induction and the analysis of silhouette and contour two-dimensional images of flattened cells. Carrageenans alone can activate neutrophils with much less potency than lipopolysaccharide (LPS) and the sulfation degree of carrageenans stipulates high activity in this role. On the other hand, carrageenans especially with low contents of sulfate groups are able to interfere with LPS in vitro resulting in reducing inter- and intracellular activation of neutrophils killing mechanisms.

Influence of structural features of carrageenan on the formation of polyelectrolyte complexes with chitosan.

The polyelectrolyte complexes (PEC) of carrageenans (CG)-κ-, κ/β-, λ-and x-CG with chitosan were obtained. The formation of PEC was detected by Fourier-transform infrared (FTIR) spectroscopy and by centrifugation in a Percoll gradient. The influence of the structural peculiarities of CG on its interaction with chitosan was studied.

The supramolecular structure of LPS-chitosan complexes of varied composition in relation to their biological activity.

The complexes of chitosan (Ch) with lipopolysaccharides (LPSs) from Escherichia coli O55:B5 (E-LPS) and Yersinia pseudotuberculosis 1B 598 (Y-LPS) of various weight compositions were investigated using quasi-elastic light scattering, ζ-potential distribution assay and atomic force microscopy. The alteration of ζ-potential of E-LPS-Ch complexes from negative to positive values depending on Ch content was detected. The Y-LPS-Ch complexes had similar positive ζ-potentials regardless of Ch content.

Effect of chitosan on tobacco mosaic virus (TMV) accumulation, hydrolase activity, and morphological abnormalities of the viral particles in leaves of N. tabacum L. cv. Samsun.

The effect of chitosan on the development of infection caused by Tobacco mosaic virus (TMV) in leaves of Nicotiana tabacum L. cv. Samsun has been studied.