[Efficacy and safety of undenatured type II collagen in patients with knee osteoarthritis: a multicenter, prospective, double-blind, placebo-controlled, randomized trial].

BACKGROUND: Non-pharmacological treatments based on collagen as a dietary supplement are emerging as a new area of interest to support preventive or therapeutic effects in patients with osteoarthritis (OA). AIM: In a multicenter, prospective, double-blind, placebo-controlled, randomized study, to evaluate the effectiveness and safety of the use of the Artneo complex containing undenatured chicken collagen type II in patients with OA of the knee joints. MATERIALS AND METHODS: The study enrolled 212 outpatients from 12 centers in the Russian Federation with knee OA, stages II and III according to the Kellgren-Lawrence classification. The participants included 171 women (80.7%) and 41 men (19.3%), with an average age of 60.2±9.0 years (range: 40 to 75 years). The study population was randomly allocated in equal proportions into two groups using an interactive web response system (IWRS). Group 1 (Artneo) consisted of 106 patients who took one capsule of the drug once daily for 180 days. Group 2 (Placebo) also had 106 patients, with the dosage form and regimen identical to Group 1. During the treatment period, the following outcomes were assessed: WOMAC index, KOOS, pain according to VAS, quality of life using the EQ-5D questionnaire, and the need for NSAIDs. All patients underwent a clinical blood test, general urine analysis, biochemical blood test, and ultrasound examination of the affected knee joint. RESULTS: In a prospective, double-blind, placebo-controlled, randomized study, it was demonstrated that the Artneo combination, containing undenatured chicken collagen type II, has a positive effect on all clinical manifestations of OA: it effectively reduces pain, stiffness, and improves the functional state of joints and quality of life. It has a good safety profile and is superior to placebo in all parameters studied. CONCLUSION: The results of the study confirm the good effectiveness and safety of the Artneo combination in patients with OA of the knee joints.

Synthetic Peptide Fragments of the Wtx Toxin Reduce Blood Pressure in Rats under General Anesthesia.

Previously, it was shown that the non-conventional toxin WTX from the venom of the cobra Naja kaouthia, when administered intravenously, caused a decrease in blood pressure (BP) and an increase in heart rate (HR) in rats [13]. To identify the site of the toxin molecule responsible for these effects, we studied the influence of synthetic peptide fragments of the WTX on BP and HR in normotensive male Sprague-Dawley rats under general anesthesia induced by Telazol and Xylazine. It was found that peptides corresponding to the WTX central polypeptide loop, stabilized by a disulfide bond, at intravenous injection at concentrations from 0.1 to 1.0 mg/mL caused a dose-dependent decrease in BP, with the HR increasing only in the first 5-10 min after administration. Thus, WTX fragments corresponding to the central polypeptide loop reproduce the decrease in blood pressure caused by the toxin.

α-Conotoxin RgIA and oligoarginine R8 in the mice model alleviate long-term oxaliplatin induced neuropathy.

Оligoarginines were recently discovered (Lebedev et al., 2019 Nov) as a novel class of nicotinic acetylcholine receptors (nAChRs) inhibitors, octaoligoarginine R8 showing a relatively high affinity (44 nM) for the α9/α10 nAChR. Since the inhibition of α9/α10 nAChR by α-conotoxin RgIA and its analogs is a possible way to drugs against neuropathic pain, here in a mice model we compared R8 with α-conotoxin RgIA in the effects on the chemotherapy-induced peripheral neuropathy (CIPN), namely on the long-term oxaliplatin induced neuropathy. Tests of cold allodynia, hot plate, Von Frey and grip strength analysis revealed for R8 and α-conotoxin RgIA similar positive effects, expressed most prominently after two weeks of administration. Histological analysis of the dorsal root ganglia sections showed for R8 and RgIA a similar partial correction of changes in the nuclear morphology of neurons. Since α9/α10 nAChR might be not the only drug target for R8, we analyzed the R8 action on rat TRPV1 and TRPA1, well-known nociceptive receptors. Against rTRPV1 at 25 µM there was no inhibition, while for rTRPA1 IC50 was about 20 µM. Thus, involvement of rTRPA1 cannot be excluded, but in view of the R8 much higher affinity for α9/α10 nAChR the latter seems to be the main target and the easily synthesized R8 can be considered as a potential candidate for a drug design.

The association of hemoglobin drop with in-hospital outcomes in COVID-19 patients.

BACKGROUND: Bleeding events can be critical in hospitalized patients with COVID-19, especially those with aggressive anticoagulation therapy. AIM: We aimed to investigate whether hemoglobin drop was associated with increased risk of acute kidney injury (AKI) and in-hospital mortality among patients with COVID-19. DESIGN: Retrospective cohort study. METHODS: This retrospective study was conducted by review of the medical records of 6683 patients with laboratory-confirmed COVID-19 hospitalized in the Mount Sinai Health system between 1st March 2020 and 30th March 2021. We compared patients with and without hemoglobin drop >3 g/dl during hospitalization within a week after admissions, using inverse probability treatment weighted analysis (IPTW). Outcomes of interest were in-hospital mortality and AKI which was defined as serum creatine change of 0.3 mg/dl increase or 1.5 times baseline. RESULTS: Of the 6683 patients admitted due to COVID-19, 750 (11.2%) patients presented with a marked hemoglobin drop. Patients with hemoglobin drop were more likely to receive therapeutic anticoagulation within 2 days after admissions. Patients with hemoglobin drop had higher crude in-hospital mortality (40.8% vs. 20.0%, P < 0.001) as well as AKI (51.4% vs. 23.9%, P < 0.001) compared to those without. IPTW analysis showed that hemoglobin drop was associated with higher in-hospital mortality compared to those without (odds ratio (OR) [95% confidential interval (CI)]: 2.21 [1.54-2.88], P < 0.001) as well as AKI (OR [95% CI]: 2.79 [2.08-3.73], P < 0.001). CONCLUSIONS: Hemoglobin drop during COVID-19 related hospitalizations was associated with a higher risk of AKI and in-hospital mortality.

Encapsulation of Neurotoxins, Blockers of Nicotinic Acetylcholine Receptors, in Nanomaterials Based on Sulfated Polysaccharides.

Three-finger snake neurotoxins are selective antagonists of some nicotinic acetylcholine receptor subtypes and are widely used to study these receptors. The peptide neurotoxin azemiopsin, recently isolated from the venom of Azemipos feae, is a selective blocker of muscle-type nicotinic acetylcholine receptor. In order to reduce their toxicity and increase resistance under physiological conditions, we have encapsulated these toxins into nanomaterials. The study of nanomaterials after interaction with neurotoxins by the methods of transmission electron microscopy and dynamic light scattering revealed an increase in the size of nanoparticles, which indicates the inclusion of neurotoxins in nanomaterials.

Polyarginine Peptides As a New Class of Ligands of Nicotinic Acetylcholine Receptors.

Arginine-containing peptides R3, R8, and R16 were obtained by solid-phase peptide synthesis, and their binding to nicotinic acetylcholine receptors (nAChRs) of muscle and neuronal (α7) types was studied by competitive radioligand assay with the use of 125I-α-bungarotoxin. The resulting peptides exhibited a significantly greater binding activity with respect to the muscle-type nAChRs than to the α7 receptor. Thus, we have discovered a new class of nAChR ligands. The affinity of the synthesized oligoarginines for nAChR depended on the number of amino acid residues in the chain. The highest affinity was exhibited by the R16 peptide, which contained 16 arginine residues.

In the face of pain: The choice of visual cues in pain conditioning matters.

BACKGROUND: Visual cue conditioning is a valuable experimental paradigm to investigate placebo and nocebo effects in pain. However, little attention has been paid to the cues themselves and potential variability of effects (their quantity and quality) stemming from the choice of stimuli. Yet, this seemingly methodological question has important implications for the interpretation of experimental findings in terms of their significance for clinical practice. METHODS: We investigated the effect of heat pain conditioning using different types of visual cues (abstract images, faces and pseudo-words) in a group of 22 healthy volunteers. We analysed conditioning effects calculated as the difference in pain ratings to heat stimuli of identical temperature preceded by conditioned high or low pain cues with (1) subliminal and supraliminal presentation; and (2) immediately after conditioning and following extinction. Awareness manipulation and test following indirect, observational extinction allowed us to assess the strength and robustness of the conditioning effects induced with different cue types. RESULTS: We observed no differences in conditioning effect magnitudes between images, faces and words when all stimuli were presented supraliminally. With subliminal presentation, only face stimuli elicited a significant effect; equally only face cue-induced effect withstood extinction. CONCLUSIONS: Our findings indicate that face-related associations to pain might be stronger than those elicited with other visual cues, as face cues seem to induce stronger subliminal effects and withstand mild extinction. SIGNIFICANCE: We compared different types of neutral cues commonly used in conditioning paradigms and found that faces elicited a stronger, more robust nonconscious effect than abstract images or pseudo-words.

Analysis of binding centers in nicotinic receptors with the aid of synthetic peptides.

We studies the receptor-binding specificity of the synthetic peptide HAP (High Affinity Peptide) and its analogues, which are regarded as a model of the orthosteric site nicotinic acetylcholine receptors (nAChR). Using radioligand analysis, electrophysiology tests, and calcium imaging, we assessed the ability of HAP to interact with nAChR antagonists: long α-neurotoxins and α-conotoxins. A high affinity of HAP for α-bungarotoxin and the absence of its interaction with α-cobratoxin and α-conotoxins was found. The synthesized analogues of HAP in general retained the properties of the original peptide. Thus, HAP cannot be a model of a ligand-binding site.

[SYNTHETIC CONJUGATED ANALOGUES OF CAPSULE POLYSACCHARIDES OF PNEUMOCOCCUS - AN INSTRUMENT FOR DETECTION OF POST-VACCINATION ANTIBODIES].

AIM: Evaluation ofthe ability of capsule polysaccharides (CP) of Streptococcus pneumoniae serotype 3 and 14 and their synthetic structure analogues, conjugated with bovine serum albumin (BSA), to detect antibodies in post-vaccination sera of mice. Materials andmethods. Oligosaccharides correspond- ing to one, one and a half and two repeating links of serotype 3 and 14 S. pneumoniae CP were synthe- sized, their conjugates with BSA were produced by squarate method as well. Ligand content-per BSA molecule was controlled by MALDI-TOF spectrometry. Immune sera were obtained after 2 intraperi- toneal administrations to mice of glucoconjugates adsorbed on aluminum hydroxide or 13-valent pneumococcal conjugated vaccine. Determination of levels of post-vaccination class G antibodies and their sub-isotypes was carried out in EIA. RESULTS: Immunization of mice with neoglucoconjugates resulted in formation of predominantly IgGl recognizing serotype 3 and 14 S. pneumoniae C. IgG1 in mice immunized with a 13-valent conjugated vaccine recognized serotype 3 S. pneumoniae CP, but detected serotype 14 S. pneumoniae CP weakly. All the conjugated synthetic oligosaccharides were characterized by a high ability to bind antibodies in blood of mice immunized with the polysaccharide conjugated vaccine. BSA-tetrasaccharide of serotype 3 S. pneumoniae and BSA-tetrasaccharide of serotype 14 S.pneumoniae were characterized by the highest ability to detect IgG1 against C. CONCLUSION: Synthetic oligosaccharides, conjugated with BSA protein-carrier, may be used to develop diagnostic test-systems for determination of antibodies in post-vaccination sera.

[HYGIENIC JUSTIFICATION OF OPTIMIZATION OF THE INTEGRATED ASSESSMENT OF DRINKING WATER ACCORDING TO THE WATER QUALITY INDEX].

The present study is devoted to theoretical questions of optimization of integrated assessment of the composition and properties of drinking water with the use of the Water Quality Index (WQI) and considering in it all 4 criteria for its hygienic quality-sanitary-toxicological, microbiological, radiation and organoleptic. There is presented a sequence of the analysis of benchmark data of the laboratory study of drinking water, including the selection of priority indices, their distribution into 4 groups according to hygienic criteria, calculations the ratios of real values (C) of indices to their hygiene MPC and the final calculation of the WQI. There is emphasized the importance of classes of hazard of substances, and the need for the special attention to the substances-carcinogens in the integrated assessment of water quality. To overcome the non-equivalence of contributions to the assessment of water quality factors, measured in different units, often disparated in their effect on human health, there are used the principles of combined action at levels below the MCL:C/MPC indices of performance of the unidirectional action are summed (e.g. carcinogenic substances), from indices of the independent action there are selected the most significant ones with the highest values of C/MPC, besides that there are also used counterbalancing factors K determined accordingly to Delphi method, with a maximum values of 5 for carcinogens and the minimum value of 1 for the substances affecting the organoleptic properties ofwater. There is presented the scheme of the final calculation of the value of WQI.

Subthreshold depression is associated with impaired resting-state functional connectivity of the cognitive control network.

Subthreshold depression (StD) is a prevalent condition associated with social morbidity and increased service utilization, as well as a high risk of developing into a major depressive disorder (MDD). The lack of well-defined diagnostic criteria for StD has limited research on this disorder, with very few brain-imaging studies examining the neurobiology of StD. Yet, identifying the neural pathology of StD has the potential to elucidate risk factors and prognostic markers for major depression and is crucial for developing tailored treatments for patients at mild stages of depression. We investigated resting-state functional connectivity (rs-FC) of the cognitive control network (CCN), known to be dysregulated in MDD, using the bilateral dorsolateral prefrontal cortex (DLPFC) as a seed, focusing on two cohorts of StD subjects (young and middle aged) as well as matched controls. Irrespective of age, we found a significant rs-FC decrease in the CCN of the StD subjects, compared with matched controls, particularly between the DLPFC and the brain regions associated with the representation of self and other mental states (temporo-parietal junction (TPJ) and precuneus), as well as salience detection and orienting (insula). The functional connectivity between the DLPFC and the left TPJ was also associated with depressive symptom scores measured by the Center for Epidemiologic Studies Depression Scale. This finding may shed light on the neural pathology of StD, leading to better understanding of mild stages of depression, its diagnosis and the development of new treatments.

[EPITOPIC SPECIFICITY OF A SYNTHETIC DISACCHARIDE, RECURRING LINK OF CAPSULE POLYSACCHARIDE CHAIN OF SEROTYPE 3 STREPTOCCUS PNEUMONIAE].

AIM: Study epitopic specificity of synthetic disaccharide, recurring link of serotype 3 S. pneumoniae, conjugated with bovine serum albumin (BSA). MATERIALS AND METHODS: Conjugate of the synthetic disaccharide with BSA was obtained by squarate method. Antigenic activity of the conjugate was studied in competitive EIA. Titers of IgG against capsule polysaccharide of serotype 3 S. pneumoniae were determined in EIA by using sera of mice immunized twice with disaccharide conjugate sorbed onto aluminum hydroxide. RESULTS: Disaccharide conjugate used as a well-covering antigen (4 µg/well) in EIA was characterized by a high degree of specificity and interacted only with IgG against serotype 3 S. pneumoniae in antimicrobial sera of animals without reacting with antibodies (ABs) against other pneumococcus serotypes (6B, 10A, 19A, 19F, 23F). Disaccharide conjugated with BSA was determined in competitive EIA to inhibit bonding of ABs to disaccharide by 78.8%, bacterial capsule polysaccharide by 56.9%, BSA did not inhibit the sera activity. The study of sera of mice immunized by serotype 3 S. pneumoniae disaccharide conjugate in EIA, where capsule polysaccharide was used as a plate-sorbed antigen, has established the presence of IgG against capsule polysaccharide at a titer of 1:1600. CONCLUSION: The disaccharide that is a single recurring link of serotype 3 S. pneumoniae contains a key epitope of capsule polysaccharide. The synthetic disaccharide could be used as a component of multivalent conjugated pneumococcal vaccines and for development of diagnostic test-systems.

Optimization of the Method of Buccal Epithelial Cell Isolation and Culturing on Collagen Substrate for Ophthalmologic Application.

We performed morphofunctional analysis of cultured rabbit buccal epithelial cells in the primary culture, during passaging, and upon interaction with collagen substrates. Three different morphological types were identified. It was demonstrated that precursors of rabbit buccal epithelium were characterized by high proliferative activity, retain their biological properties throughout long-term culturing, and adhere to various collagen substrates.

[Immunogenic properties of experimental production series of Staphylovac-2 vaccine].

AIM: Study experimental production series of Staphylovac-2 by accumulation of specific IgG and safety. MATERIALS AND METHODS: Experimental production samples of staphylococci vaccines were studied by the accumulation of specific IgG in sera of immunized BALB/c line mice in EIA. Safety was evaluated in tests of acute and chronic toxicity including pathomorphologic and histologic, hematologic and biochemical studies, studies of the effect on central nervous system. RESULTS: A statistically significant (2.6 - 3.0 times) increase of IgG levels in sera of immunized mice compared with control was noted. In the experiments studying acute and chronic toxicity the increase in body mass and mass of internal organs differed from data obtained from control animals at no observation periods. None of the studied methods of safety evaluation showed differences of the studied vaccine series from the control. CONCLUSION: The recommended dose for subcutaneous administration into human of 200 µg is experimentally justified and could be the basis for carrying out clinical studies of staphylococci vaccines in humans.

Protective activity of a glycoconjugate based on a synthetic hexasaccharide related to a fragment of capsular Streptococcus pneumoniae serotype 14 polysaccharide chain.

We studied the effects of immunization with a conjugate of carrier protein and hexasaccharide ligand related to a fragment of capsular of Str. pneumoniae serotype 14 polysaccharide chain on activation of innate and adaptive immunity. It was found that two-fold immunization with the glycoconjugate adsorbed on aluminum hydroxide significantly increased the titer of IgG antibodies to capsular polysaccharide in the blood and protected 100% mice from infection with Str. pneumoniae serotype 14. Enhanced bactericidal activity of peripheral blood lymphocytes of mice was found 4 and 24 h after the first immunization with the immobilized glycoconjugate. Adsorption of the glycoconjugate on aluminum hydroxide resulted in modification of the immune processes at the stage of activation of innate immunity and subsequent strengthening of the adaptive immunity.

[100 years of drinking water regulation. Retrospective review, current situation and prospects].

There is considered the history of the development of legislative requirements to the regulation of the quality of drinking water in different countries and international organizations during the period from 1912 to the present time. In terms of comparative analysis there is analyzed the current state of regulatory frameworks of the Russian Federation, WHO, EU, Finland, the UK, Singapore, Australia, Japan, China, Nigeria, the United States and Canada in the field of providing favorable conditions of population drinking water use. There has been noted the significant progress in standardization of the content of the biogenic elements and chemical pollution of drinking water in the absence of uniform requirements to the composition and properties of drinking water globally, that is bound to the need to take into account the national peculiarities of drinking water supply within the separate countries. As promising directions for improving regulation of drinking water quality there are noted: the development of new standards for prioritized water pollution, periodic review ofstandards after appearance of the new scientific data on the biological action of substances, the use of the concept of risk, the harmonization of the normative values and the assessment of the possibility of introduction into the practice the one more criterion of profitableness of population water use--the bioenergetic state of the water.

[New approaches in the regulation of blood phagocytes and reduction in the formation of oxygen radicals in patients with heart failure].

AIM: The purpose was to study the effect of actovegin on the formation of reactive oxygen species by blood phagocytes of patients with heart failure and on SK-N-SH neuron necrosis. MATERIALS AND METHODS: The generation of superoxide anion (O2-*) were recorded on whole blood samples (50-100 µl). Change lucigenin-dependent hemiluminescence determined on a hemi-luminometer "Biotoks-7". As a stimulator of the phagocyte. phorbol ester (PMA, 1 µm) was used. Necrosis of neurons induced by hydrogen peroxide was determined by fluorescence of propidium iodit. RESULTS: Blood phagocytes of heart failure patients are initially pre-activated (primed). These cells spontaneous generated oxygen radicals. Actovegin dosa-dependent decreased radicals level and radical induced by PMA (1 µm). After PMA maximal inhibitory effect of actovegin observed in doses higher than 2-3 mg/ml. The impact of actovegin on the viability of human SK-N-SH neurons in the presence hydrogen peroxide (100 µm) was studied in vitro. Under these conditions hydrogen peroxide triggered radical-dependent neurons necrosis Actovegin dosa-dependent decreased of neuron death. CONCLUSION: Actovegin inhibits spontaneous and induced formation of reactive oxygen species generated by blood phagocytes of patients with heart failure. Actovegin suppressed necrosis of human SK-N-SH neuroblastoma cells caused by hydrogen peroxide. It is assumed that actovegin protects_cells of arious organs and tissues, including blood cells and neurons that die as a result of ischemia and inflammation by reducing levels of react.ive-oxygenspecies.

[Effect of aluminium hydroxide on innate immunity and immunogenicity of bacterial and synthetic antigens of Streptococcus pneumoniae].

AIM: Study the effect of aluminium hydroxide on molecular-cell mechanisms of innate immunity activation and its adjuvant effect on immunogenicity of natural bacterial and synthetic pneumococci antigens. MATERIALS AND METHODS: Surface markers of dendritic cells (DC), mononuclear leukocytes (ML) and cytokine levels were determined by flow cytometry; IgG titers--by EIA. Protective activity was evaluated in experiments with active protection of mice from infection with virulent pneumococci strains. RESULTS: Aluminium hydroxide increased the ML content of mice spleen expressing TLR2 and TLR4. Its addition into the culture of immature DC induced the appearance of a population of cells with mature DC markers--CD83, CD80, CD86, however, the level of undifferentiated cells (CD34) and cells with adhesion molecules (CD11c, CD38) did not change. DC produced IL-1ß, IL-5, IL-10, IFNγ into the cultivation medium. An increase of cytokine production took place 2 hours after the administration into mice and was retained for the observation period (24 hours). Th1 (IFNγ, TNFα) and Th2 (IL-5, IL-10, GM-CSF) cytokine production gave evidence on immune response polarization by Th1/Th2, type. After 2 administrations of aluminium hydroxide into mice the number of ML with CD19+, CD5+, NK1.1+, CD25+, MHCII+ markers increased during decrease of CD3+, CD4+ and CD8+ T-lymphocytes. Adaptive immunity activation was characterized by high IgG titers to pneumococci capsule polysaccharide and protection of 90 - 100% of the mice against infection with lethal doses of S. pneumoniae strains, was detected during 2-fold immunization of mice with conjugates of synthetic pneumococci oligosaccharides with BSA,sorbed onto aluminium hydroxide, whereas natural bacterial antigens provided 90 - 100% survival of animals during immunization without the adjuvant. CONCLUSION: Data are provided on the effect of aluminium hydroxide on key effectors of innate immunity: DC, ML, TLRs and cytokine production. A reasonable administration of this adjuvant was shown to be in association with conjugates of pneumococci synthetic oligosaccharides with a carrier protein.