Flavin mononucleotide in visible light photoinitiating systems for multiple-photocrosslinking and photoencapsulation strategies.

Visible light-induced photocrosslinking techniques have attracted significant attention for their flexibility, controllability, safety, and energy conservation, especially in tissue engineering and biofabrication, compared to UV photocrosslinking. Despite these advantages, current photoinitiators are constrained by various challenges, including inadequate photoinitiation efficiency, low biocompatibility, poor water solubility, and limited compatibility with diverse crosslinking systems. Here, a water-soluble derivative of riboflavin, flavin mononucleotide (FMN-), was used to assess its potential as an initiator in multiple-photocrosslinking systems, including radical photopolymerization, dityrosine, and ditryptophan coupling crosslinking, under blue light irradiation. Blue light irradiation facilitated an efficient electron transfer reaction between FMN- and persulfate, owing to their suitable spectral compatibility and photoactivity. The resulting oxidizing free radicals and excited triplet state of FMN- served as initiating active species for the multiple-photocrosslinking reactions. The combination of FMN- and potassium persulfate (KPS) exhibited exceptional photoinitiation efficiency for various biomaterials, including silk fibroin, gelatin, poly(ethylene glycol) diacrylate, and carboxymethyl cellulose modified with amino acids. Furthermore, the cytocompatibility of the FMN-/KPS photoinitiator was demonstrated by the survival rates of 3T3-LI fibroblasts encapsulated in it, which exceeded 95 % when compared to a commercial initiator. STATEMENT OF SIGNIFICANCE: By introducing persulfate, the photoinitiation efficiency of flavin mononucleotide was significantly improved. The application scenarios of flavin mononucleotide and persulfate combinations were also greatly extended, including radical photopolymerization, dityrosine, diphenylalanine, and ditryptophan coupling crosslinking. Among them, the coupling crosslinking of amino acids (di-phenylalanine, and di-tryptophan) modified carboxymethyl cellulose, to our knowledge, was first reported. The excellent cytocompatibility of cell encapsulation further proved that the combinations of flavin mononucleotide and persulfate have great potential in tissue engineering.

Insight into the enhancing mechanism of exogenous electron mediators on biological denitrification in microbial electrolytic cell.

Sustained nitrate accumulation in surface water ecosystem was continuously grabbing public attention. Autotrophic denitrification by electron supplement has been applied to overcome the requirement of carbon source, thus the new problem that how to improve the efficiency of extracellular electrons transfer to denitrifiers comes to us. The addition of exogenous electron mediators has been considered as an important strategy to promote extracellular electrons transfer in reductive metabolism. To date, knowledge is lacking about the promoting effects and pathways in nitrate removal by electron mediators. Here, we fully investigated the performance of nitrogen removal as well as quantified the characteristics of biofilms with six electron mediators (riboflavin, flavin mononucleotide, AQS, AQDS, biochar and Nano-Fe3O4) treating in microbial electrolytic cell system. The six electron mediators promoted nitrate removal rate by 76.03-90.43 % with electron supplement. The growth and activity of cathodic biofilm, conductive nanowires generation and electrochemically active substance synthesis of extracellular polymeric substances were facilitated by electron mediator addition. Electrochemical analysis revealed that conductivity and redox capacity of cathodic biofilm was increased for accelerating electron transfer. Moreover, they upregulated the abundance of denitrifying communities and denitrifying genes accordingly. Their denitrification efficiency varied due to their promotion ability in the above different strategies and conductive characteristics, and the efficiency could be concluded as: Nano-Fe3O4 > riboflavin > flavin mononucleotide > AQS ≈ AQDS > biochar. This study revealed how addition of electron mediators promoted denitrification with electron supplement, and compared their promoting efficiency in several main aspects.

Roseoflavin, a Natural Riboflavin Analogue, Possesses In Vitro and In Vivo Antiplasmodial Activity.

The ability of the human malaria parasite Plasmodium falciparum to access and utilize vital nutrients is critical to its growth and proliferation. Molecules that interfere with these processes could potentially serve as antimalarials. We found that two riboflavin analogues, roseoflavin and 8-aminoriboflavin, inhibit malaria parasite proliferation by targeting riboflavin metabolism and/or the utilization of the riboflavin metabolites flavin mononucleotide and flavin adenine dinucleotide. An additional eight riboflavin analogues were evaluated, but none were found to be more potent than roseoflavin, nor was their activity on target. Focusing on roseoflavin, we tested its antimalarial activity in vivo against Plasmodium vinckei vinckei in mice. We found that roseoflavin decreased the parasitemia by 46-fold following a 4 day suppression test and, on average, increased the survival of mice by 4 to 5 days. Our data are consistent with riboflavin metabolism and/or the utilization of riboflavin-derived cofactors being viable drug targets for the development of new antimalarials and that roseoflavin could serve as a potential starting point.

Engineering Antisense Oligonucleotides as Antibacterial Agents That Target FMN Riboswitches and Inhibit the Growth of Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli.

In the past several decades, antibiotic drug resistance has emerged as a significant challenge in modern medicine due to the rise of many bacterial pathogenic strains resistant to all known antibiotics. At the same time, riboswitches have emerged as novel targets for antibacterial drug discovery. Here for the first time, we describe the design and applications of antisense oligonucleotides as antibacterial agents that target a riboswitch. The antisense oligonucleotides are covalently coupled with two different cell-penetrating peptides, penetrating Gram-positive and Gram-negative bacterial cells. We specifically target Flavin MonoNucleotide (FMN) riboswitches in Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli that control both synthesis and import of FMN precursors. We have established an average antibiotic dosage by antisense oligonucleotides that inhibit 80% of bacterial growth at 700 nM (4.5 µg/mL). Furthermore, the antisense oligonucleotides do not exhibit toxicity in human cell lines at this concentration. The results demonstrate that riboswitches are suitable targets in antisense technology for antibacterial drug development.

Stabilization of flavin mononucleotide by capturing its "tail" with porous organic polymers for long-term photocatalytic degradation of micropollutants.

Flavin mononucleotide (FMN) produces photo-induced reactive oxygen species (ROS), making it a bio-based and sustainable photosensitizer for micropollutant degradation. However, the rapid self-degradation of FMN under light poses challenges in practical applications. We propose for the first time to use porous organic polymer (POP) structures as particles and in situ grown on nanofibrous membranes to capture the ribityl side chain ("tail") of FMN by electrostatic-driven guest-host interaction. By restraining the free bending mode of FMN in POP, its self-degradation is highly inhibited, showing a prolonged half-life (102.7 and 79.7 times to that in solution and in ß-cyclodextrin, respectively) without any impact on the ROS production even after 16 h of UVA irradiation. As a proof-of-concept, the photocatalytic degradation efficiency of FMN-POP complexes can be achieved at 58-93% against micropollutants under UVA. The stabilization of FMN by the "tail" capture in the POP allows its photocatalytic degradation function to be continuously online.

Photoactivities of Two Vitamin B Derivatives and Their Applications in the Perpetration of Photoinduced Antibacterial Nanofibrous Membranes.

Photoactivities and photoinduced antibacterial functions of two vitamin B2 (VB2) derivatives, riboflavin (RF) and flavin mononucleotide (FMN), were investigated by computational modeling and various experimental evaluations. Under photoirradiation, the ground state of both VB2 derivatives could be excited to generate different reactive oxygen species (ROS) by undergoing different reaction paths. The formed ROS could nonselectively inactivate microorganisms. However, both RF and FMN exhibited negligible photoinduced antimicrobial activity in phosphate-buffered saline (PBS) solutions even at high concentrations. The study revealed that the affinity of both RF and FMN to microorganisms in different application media plays a key role due to the very short lifetime of the generated ROS. The speculation was proven by the preparation of a poly(vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibrous membrane blended with RF or FMN, which could enhance the contact of the agents with microorganisms. The fabricated nanofibrous membranes containing both VB2 derivatives (VBNFMs) showed great photoinduced antibacterial activity against Gram-negative Escherichia coli (E. coli) (99.999% bacterial reduction) and Gram-positive Listeria innocua (L. innocua) (99% bacterial reduction) under 20 min of ultra-violet A irradiation. The photoinduced antimicrobial performances of RF/PVA-co-PE and FMN/PVA-co-PE nanofibrous membranes were comparable. Interestingly, the durability of the photoinduced antibacterial functions of the prepared VBNFMs was questionable, due to the photodegradation of VB2 in nanomaterials.

Cytotoxicity of Nucleotide-Stabilized Graphene Dispersions on Osteosarcoma and Healthy Cells: On the Way to Safe Theranostics Agents.

An appealing strategy that overcomes the hydrophobicity of pristine graphene and favors its interaction with biological media is colloidal stabilization in aqueous medium with the support of a biomolecule, such as flavin mononucleotide (FMN), as exfoliating/dispersing agent. However, to establish FMN-stabilized graphene (PG-FMN) as suitable for use in biomedicine, its biocompatibility must be proved by a complete assessment of cytotoxicity at the cellular level. Furthermore, if PG-FMN is to be proposed as a theranostic agent, such a study should include both healthy and tumoral cells and its outcome should reveal the nanomaterial as selectively toxic to the latter. Here, we provide an in-depth comparative in vitro analysis of the response of Saos-2 human sarcoma osteoblasts (model tumor cells) and MC3T3-E1 murine preosteoblasts (undifferentiated healthy cells) upon incubation with different concentrations (10-50 µg mL-1) of PG-FMN dispersions constituted by flakes with different average lateral size (90 and 270 nm). Specifically, the impact of PG-FMN on the viability and cell proliferation, reactive oxygen species (ROS) production, and the cellular incorporation process, cell-cycle progression, and apoptosis has been evaluated. PG-FMN was found to be toxic to both types of cells by increasing ROS production and triggering cell-cycle arrest. The present results constitute a cautionary tale on the need to establish the effect of a nanomaterial not only on tumor cells but also on healthy ones before proposing it as anticancer agent.

Evaluation of the Protective Effect of Ademetionine, Cytoflavin, and Dihydroquercetetine on Blood Enzymes Activity in Rats Treated with High Doses of Sodium Valproate.

We evaluated the protective effect of ademetionine, cytoflavin, and dihydroquercetin on activity of serum enzymes in rats treated with high doses of sodium valproate for 28 days. Ademetionine and cytoflavin produced the greatest protective effect, the effect of dihydroquercetin was less pronounced. In rats treated with ademetionine, AST activity decreased as soon as on day 7 and remained at this level until the end of the experiment; ALT, alkaline phosphatase, and γ-glutamyl transferase activities decreased on days 21 and 28 of the study. Cytoflavin produced similar effects, the effect of dihydroquercetin was observed on days 21 and 28 for AST, ALT, alkaline phosphatase and on day 28 for γ-glutamyl transferase. These results substantiate the use of hepatoprotective drugs in case of long-term treatment with anticonvulsants in patients with epilepsy.

[Cytoflavin effect on locomotor and psychoemotional status in physiological and pathological aging.]

Currently, the actual problem is the correction of motor, cognitive and psychoemotional disorders in physiological aging, as well as in various pathological processes that accompany aging and accelerate it. In this regard, it became necessary to search for drugs that can restore age-related disorders of the brain. The aim of the study was to evaluate the possibility of Cytoflavin as a pharmacological corrector of age-dependent disorders of the functions of the cerebral cortex during physiological and pathological, accelerated aging. The mouse sensorimotor cortex of the brain was the material for study. The transgenic male mice with HER2/neu overexpression at the age of 2 and 10 months were used as an experimental model, male wild-type FBV/N mice at the age of 2 and 18 months served as a control. We studied locomotor activity, orientational research behavior and the psychoemotional status of animals using the «open field¼ test and the Suok test. It was found that in old FBV/N mice, after the cytoflavin treatment, recovery of locomotor functions and orientational-research behavior is observed. Under conditions of HER2/neu overexpression after the Cytoflavin treatment, an improvement in motor functions occurs. It was also shown that the studied drug has an anxiolytic effect on both wild-type FBV/N mice and transgenic HER2/neu mice during aging. Thus, the positive effect of Cytoflavin on the dynamics of the behavior of experimental mice during physiological and pathological accelerated aging allow to suggest that in the late stages of ontogenesis, Cytoflavin restores the cerebral cortex functions and prevents neurodegeneration.

[The efficacy of metabolic treatment in the early recovery period of patients with ischemic stroke]. / Éffektivnost' metabolicheskoi korrektsii v rannem vosstanovitel'nom periode u patsientov s ishemicheskim insul'tom.

AIM: To evaluate the efficacy of including cytoflavin in rehabilitation measures in the early recovery period of patients with ischemic stroke. MATERIAL AND METHODS: Results of rehabilitation measures of 100 patients (50 women and 50 men, aged 18 to 85 years) in the early recovery period of ischemic stroke were analyzed. Psychological testing included NIHSS, MMSE, Rankin scale, Rivermead mobility index, exercise tolerance test. Depending on the rehabilitation scheme, patients were divided into the main group (n=50), who received a verticalization course and cytoflavin (intravenously, drip 20.0 ml in 250.0 ml 5% glucose for 14 days). The control group (n=50) included patients who received standard treatment. RESULTS AND CONCLUSION: Inclusion of cytoflavin in the rehabilitation scheme for patients with ischemic stroke increased the effectiveness of treatment, which was manifested by a decrease in the severity of neurological disorders assessed with NIHSS by 17.6% in the main group versus 10.8% in the control group (p<0.05) and recovery of cognitive functions assessed with MMSE by 5.8% versus 1.6%, respectively (p<0.05). In addition, there was a positive dynamics in the restoration of blood pressure (by 37.1% in the main group versus 30.6% in the control group (p<0.05)).

FMN-dependent oligomerization of putative lactate oxidase from Pediococcus acidilactici.

Lactate oxidases belong to a group of FMN-dependent enzymes and they catalyze a conversion of lactate to pyruvate with a release of hydrogen peroxide. Hydrogen peroxide is also utilized as a read out in biosensors to quantitate lactate levels in biological samples. Aerococcus viridans lactate oxidase is the best characterized lactate oxidase and our knowledge of lactate oxidases relies largely to studies conducted with that particular enzyme. Pediococcus acidilactici lactate oxidase is also commercially available for e.g. lactate measurements, but this enzyme has not been characterized in detail before. Here we report structural characterization of the recombinant enzyme and its co-factor dependent oligomerization. The crystal structures revealed two distinct conformations in the loop closing the active site, consistent with previous biochemical studies implicating the role of loop in catalysis. Despite the structural conservation of active site residues, we were not able to detect either oxidase or monooxygenase activity when L-lactate was used as a substrate. Pediococcus acidilactici lactate oxidase is therefore an example of a misannotation of an FMN-dependent enzyme, which catalyzes likely a so far unknown oxidation reaction.

[Substantiation of the drug «Cytoflavin¼ application and cognitive-behavioral therapy in complex treatment of deforming coxarthrosis in elderly patients.]

The article presents the results of a study of the effectiveness of the addition of a standard course of conservative therapy to 104 patients of the older age group with coxarthrosis deforming the drug «Cytoflavin¼ and cognitive-behavioral therapy courses. It was found that such scheme increases the effectiveness of therapeutic interventions, which manifests itself as the improvement of the mental and physical components of quality of life by reducing pain and increasing the functionality of some of the affected hip. At the heart of positive clinical effect is a decrease in processes of inflammation and reduction of tension of regulatory processes in the organism.

[Effects of cytoflavin on neuronal apoptotic processes in the murine cerebral cortex on a model of physiologicaland pathological aging]. / Vliianie tsitoflavina na protsessy apoptoza neironov kory golovnogo mozga u myshei na modeli fiziologicheskogo i patologicheskogo stareniia.

Involutional changes in the cerebral cortex substantially affect the activity of the cortex itself and the function of target organs. This necessitates pharmacological correction of age-related diseases, primarily a high level of cell death. OBJECTIVE: To investigate the role of cytoflavin in mechanisms for the apoptotic regulation of cerebral cortical cells during physiological and pathological aging (in the presence of HER-2/neu overexpression). MATERIAL AND METHODS: HER-2/neu transgenic mice were used; wild-type FVB/N mice served as controls. The levels of apoptosis (TUNEL) and the expression of its associated proteins (p53, CD95, Mcl-1, p-AKT, and p-ERK) (Western blotting) were estimated in the sensorimotor cortex. RESULTS: Activation of fundamental AKT and ERK survival pathways promotes a low level of cell death in young FVB/N mice; the extrinsic receptor mechanism of apoptosis is observed to be initiated by aging. The high p-AKT levels in the cortical cells provide suppressed cell death in transgenic mice regardless of their age. After cytoflavin administration, the old wild-type mice show a lower level of apoptosis in the cortical neurons apparently due to the increased expression of the anti-apoptotic protein Mcl-1, while the old transgenic mice exhibited suppression of the AKT and ERK survival pathways and, accordingly, activation of the extrinsic receptor and p53-dependent apoptosis pathways. CONCLUSION: Thus, cytoflavin exerts a pronounced neuroprotective effect during physiological and accelerated aging, while its effect on the level of neuronal apoptosis is ambiguous and depends on the genetic line of animals. So, this is a moderate stimulation of apoptosis when its level is low in HER-2/neu mice with a high level of carcinogenesis, as well as a decrease in the high level of apoptosis in old wild-type animals, which prevents neurodegeneration.

[The intraoperative prophylaxis of local ischemical brain damage in neurosurgical patients with cerebral aneurysm]. / Intraoperatsionnaia profilaktika lokal'nogo ishemicheskogo povrezhdeniia golovnogo mozga u neirokhirurgicheskikh patsientov s tserebral'noi anevrizmoi.

AIM: To study the effectiveness of intraoperative administration of Cytoflavine for the prevention of ischemic brain injury during cerebral aneurysm (CA) clipping with temporary occlusion of the leading artery under general anesthesia. MATERIAL AND METHODS: The prospective cohort single-center study included 40 patients with CA ( the main group - 27 patients with intraoperative administration of cytoflavine; the comparison group -13 patients without use of cytoflavine), who underwent aneurism clipping with temporary occlusion of the afferent artery. We assesed the intraoperative state of the brain, the time of awakening and extubation of patients after surgery, neurological deficit and local ischemic changes in the area of surgery according to the CT of the brain in the early postoperative period, resuscitation bed-day and the relationship of these indicators with the duration of temporary occlusion of the afferent artery in the selected groups of patients. RESULTS: In intergroup comparison, patients of the main group treated with intraoperative cytoflavin showed a reduction in the time of awakening (p=0.013) and the time of extubation (p=0.01) both with temporary occlusion of the afferent artery and in patients without temporary occlusion (p<0.05). The duration of resuscitation bed-day decreased in the main group of patients receiving intraoperatively cytoflavine (p=0.01), as well as in patients in the comparison group without temporary occlusion (p<0.05). CONCLUSION: Temporary occlusion of the afferent artery with short intervals of vessel occlusion in combination with intraoperative intravenous administration of cytoflavine expands the tolerability to artery occlusion in patients operated in the 'cold' period, reduces the possibility of neurological deficit, reduces the recovery period and resuscitation bed-day after surgical clipping CA.

Potentiality of microemulsion systems in treatment of ophthalmic disorders: Keratoconus and dry eye syndrome - In vivo study.

Microemulsions are widely studied as potential ocular drug delivery vehicles. In the present study we show the versatility of possible use microemulsions as ocular delivery vehicle. The ME is loaded with a hydrophilic drug, riboflavin phosphate (RFP) and a lipophilic, docosahexaenoic acid in triglyceride form (TG-DHA), each separately. These drugs treat keratoconus and dry eye syndrome, respectively. The advantage of using ME loaded with RFP is in overcoming eye epithelium debridement during collagen cross-linking therapy for treatment of keratoconus. ME loaded with lipophilic TG-DHA provides convenient dosage in liquid aqueous form of administration of highly lipophilic TG-DHA, which is known as a protective molecule in dry eye syndrome. The capability of RFP-loaded MEs was demonstrated in terms of improvement of biomechanical strength of the rabbit cornea, as a result of successful penetration of RFP through the intact epithelium. TG-DHA-loaded microemulsion applied topically onto an eye with induced dry eye syndrome showed the significant relief of the dry eye condition.

[Investigation of markers for myocardial remodeling during experimental hypobaric hypoxia in the correction with cytoflavin]. / Issledovanie markerov remodelirovaniia miokarda pri éksperimental'noi gipobaricheskoi gipoksii na fone korrektsii preparatom tsitoflavin.

The limited possibilities of determining myocardial morphological changes in the clinic make it necessary to investigate the effects of intermittent hypobaric hypoxia in an experiment setting. OBJECTIVE: To reveal the peculiarities of changes in the markers of myocardial remodeling in experimental hypobaric hypoxia. MATERIAL AND METHODS: The investigation was conducted on 26 mature male Wistar rats weighing 220-310 g, which were divided into 3 groups: 1) 6 intact animals; 2) 10 rats that were exposed to 30-day simulated hypobaric hypoxia without correction; 3) 10 rats that were given once-daily intraperitoneal injections of cytoflavin solution at a rate of 0.5 ml/100 g of body weight for 30 days before immersion in a hypobaric chamber. RESULTS: The early stages of myocardial remodeling in hypobaric hypoxia were found to be characterized by structural re-systematization of the components of the normal ventricular wall, which was manifested by cardiomyocyte hypertrophy and ischemia; circulatory disorders; fibroblast proliferation that dramatically enhances the extracellular expression of protein matrix, which can lead to the formation of fibrous tissue and irreversible myocardial dysfunction. Elevated matrix metalloproteinase levels are evidence for collagen degradation and cardiac remodeling. In the authors' opinion, the cyto- and angioprotective effects of cytoflavin in rats treated with the latter used in combination therapy are associated with the composition of the drug, the active components of which have mutually potentiating effects, are inducers of the major metabolic pathways in the cells and are also activators of key energy-generating processes. CONCLUSION: Identification of the molecular mechanisms of myocardial remodeling is of great practical importance. This enables remodeling markers to be considered as a potential therapeutic target in the treatment of hypoxia-induced myocardial injury.

[Prevention of cognitive dysfunction in elderly cancer patients operated on the pelvic organs in conditions of multimodal anesthesia]. / Profilaktika kognitivnoi disfunktsii u pozhilykh onkologicheskikh bol'nykh, operirovannykh na organakh malogo taza v usloviiakh mul'timodal'noi anestezii.

The aim of the study was to evaluate the impact of various variants of multimodal anesthesia on the cognitive functions of elderly patients after surgical interventions on pelvic organs, the development of preventive measures for POCD. MATERIAL AND METHODS: A study was conducted in 76 elderly patients aged 62 to 84 years with an increased risk of developing POCD. Of these, 46 women and 30 men. Patients were divided into two groups, depending on the type of anesthesia. The 1st group consisted of 37 patients who had low-flow anesthesia with sevoflurane combined with epidural analgesia. 2nd - 39 patients who had anticipated multimodal analgesia on the basis of systemic administration of lidocaine, sulphate magnesia, verapamil. In each group, patients are divided into subgroups - the main (O) and control (K). In the main subgroups anesthetics were supplemented with 20 ml. Cytoflavin, administered 20-25 minutes before the end of surgery and on the 1-3 days of the perioperative period. Cognitive functions were assessed by standardized scales: Mini Mental State Examination (MMSE), Montreal Cognitive Evaluation Scale (MoCA), Frontal Assessment Batteries (FAB). The level of anxiety and depression was determined by the hospital scale of anxiety and depression (HADS). RESULTS: At oncological patients of advanced age in 52.5% of cases there is a moderate degree of cognitive impairment. In the perioperative period, in the study groups, when using different variants of multimodal anesthesia, there is an equivalent transient decrease in cognitive functions by 12.5 and 12.8%. The use of cytoflavin can reduce the manifestation of POCD from 1-day perioperative period, improve the cognitive status of patients. CONCLUSION: In cancer patients of advanced age, cognitive impairment is observed, aggravated after surgical treatment, regardless of the variant of multimodal anesthesia. Protection by Cytoflavin allows to restore the cognitive functions of elderly cancer patients, reduce the manifestations of POCD.

Structure-Activity Relationship of Flavin Analogues That Target the Flavin Mononucleotide Riboswitch.

The flavin mononucleotide (FMN) riboswitch is an emerging target for the development of novel RNA-targeting antibiotics. We previously discovered an FMN derivative, 5FDQD, that protects mice against diarrhea-causing Clostridium difficile bacteria. Here, we present the structure-based drug design strategy that led to the discovery of this fluoro-phenyl derivative with antibacterial properties. This approach involved the following stages: (1) structural analysis of all available free and bound FMN riboswitch structures; (2) design, synthesis, and purification of derivatives; (3) in vitro testing for productive binding using two chemical probing methods; (4) in vitro transcription termination assays; and (5) resolution of the crystal structures of the FMN riboswitch in complex with the most mature candidates. In the process, we delineated principles for productive binding to this riboswitch, thereby demonstrating the effectiveness of a coordinated structure-guided approach to designing drugs against RNA.

[An influence of cytoflavin on oxidative stress and activity of Na/K-ATPase of erythrocytes after brain trauma]. / Vliianie tsitoflavina na okislitel'nyi stress i aktivnost' Na/K-ATFazy éritrotsitov posle cherepno-mozgovoi travmy.

AIM: To study the efficacy of cytoflavin in correction of oxidative stress and the activity of Na/K-ATPase in posttraumatic craniocerebral trauma (CCT) in rats. MATERIAL AND METHODS: The study was performed on white non-linear female rats with a modeled CCT. An effect of cytoflavin on free radical oxidation and plasma antioxidant system, processes of plasma lipid peroxidation and antioxidant properties of red blood cells and erythrocyte Na/KATPases activity was studied on 1, 3, 7- and 12th day after CCT. RESULTS AND CONCLUSION: CCT identified the growth of free-radical processes in blood plasma and an increase in lipid peroxidation in plasma and red blood cells as well as a reduction in the activity of catalase and Na/K-ATPase. Introduction of cytoflavin reduced oxidative stress from the 3rd day and normalized free radical oxidation and lipid peroxidation in plasma and red blood cells to the 7th day of the study against the background of the high total antioxidant capacity of blood and erythrocyte catalase activity. The effect of cytoflavin led to an increase in the activity of Na/K-ATPase on the 3rd-7th day of the study compared with the reduced activity of the enzyme in the control. Recovery of pro- and antioxidant balance under the action of cytoflavin associated with increased activity of Na/K-ATPase aimed at optimizing and reducing the homeostatic mechanisms of secondary damage in the post traumatic period.

[Intraoperative cerebroprotection in total intravenous anesthesia in children of school age]. / Intraoperatsionnaia tserebroprotektsiia pri total'noi vnutrivennoi anestezii u detei shkol'nogo vozrasta.

AIM: To improve the quality of anesthesia in school-age children by using intraoperative metabolic-mediated cerebroprotection to reduce the incidence of cognitive impairment after total intravenous anesthesia based on propofol. MATERIAL AND METHODS: A randomized, prospective, longitudinal clinical study was conducted, involving 60 school-age children operated under total intravenous anesthesia on the basis of propofol. Children were randomized into two equal groups. Patients of the 1st group did not receive intraoperative metabolic-mediated cerebroprotection, patients of the 2nd group were treated with cytoflavin. For Z-assessment of changes in cognitive potential, neuropsychological testing of 30 children of the same age who were not subjected to surgical intervention was performed. RESULTS AND CONCLUSION: On the 1st day of the postoperative period, 13.79% of patients of the 1st group had postoperative cognitive dysfunction (POCD), on the 7th day, POCD was observed in 26.67% of children. In the 2nd group, POCD was detected in 6.67% and 3.33% of patients on the 1st and 7th day, respectively (p=0,009). The results confirm the efficacy of cytoflavin in intraoperative prevention of POCD in school-age children.