INTRODUCTION . Urolithiasis is a common urological pathology with a high recurrence rate. Experimental models on rodents are the main tool for studying the pathogenesis of stone formation and the search for therapeutic targets. THE AIM : To develop models of acute oxalate urolithiasis in ICR mice and evaluate the role of uromodulin (UMO) in protecting the kidneys from crystal-induced damage. MATERIALS AND METHODS. The study was performed on 18 male ICR mice (CD 1). Mice were intraperitoneally injected with sodium oxalate in two doses: 2.5 mg/100 g body weight (NaOx L) and 5 mg/100 g body weight (NaOx H). The biochemical parameters of blood, glomerular filtration rate by FITC inulin clearance, colloidal composition of urine, urinary excretion of UMO and ions, morphology of sediment and internal organs were evaluated in the experiment. RESULTS . A high dose of the pathology inducer caused severe acute nephropathy with pronounced azotemia, decreased GFR, accumulation of large CaOx containing nanoparticles, and deep tubulointerstitial damage. A dose of 2.5 mg/100 g of body weight formed a milder, generally compensated lesion with a transient peak of crystalluria. In this group, the dynamics of urinary UMO excretion and colloidal profile most convincingly demonstrated its nephroprotective and anti-crystallogenic role. CONCLUSIONS. The developed two-dose model of acute Ox urolithiasis in mice allows differentiated study of severe crystal-induced kidney damage (5 mg/100 g) and mechanisms of effective crystal clearance with the participation of UMO (2.5 mg/100 g), which creates the basis for molecular genetic studies on transgenic and knockout lines of mice.

Uromodulin, a key glycoprotein in human urine, plays a crucial role in maintaining urinary tract homeostasis by forming supramolecular structures that influence urine’s rheological properties. This study investigates the effect of uromodulin on both macroscopic (viscosity) and microscopic (nanoparticle mobility) characteristics of solutions, using small-angle X-ray scattering (SAXS), nanoparticle tracking analysis (NTA), and viscometry. Our results reveal that uromodulin forms a dynamic polymer network with distinct structural elements: a central filament (2.7 nm), side chains (8.9 nm), and network cells ( 28 nm at 5 g/L). While macroscopic viscosity remains unchanged in dilute solutions (0.004–1 g/L), uromodulin significantly restricts the mobility of nanoparticles (32–150 nm) in a size- and concentration-dependent manner, with effects becoming more pronounced at protein concentrations above 0.05 g/L. These findings highlight uromodulin’s role in modulating local rheology, which may contribute to urine’s colloidal stability and prevention of pathological crystallization. The study bridges structural insights from SAXS with functional assays, offering a mechanistic understanding of uromodulin’s role in urinary physiology.

Several biophysical techniques were used to study the uromodulin isoforms in experimental models of the urine (ionic composition, osmolality, and pH) in the presence of intact uromodulin and its isoforms isolated from patients with urolithiasis. A prototype medical device for screening persons with preclinical urolithiasis was tested. A concept of targeted therapy of urolithiasis by modulating the uromodulin properties was advanced.

Introduction. Experimental model of intraperitoneal injection of sodium oxalate is one of the most promising and practical models of oxalate urolithiasis in rodents.Purpose of the study. To describe the urolithiasis progression in experimental animals with regard to the changes in the ion balance at various stages of pathology formation.Materials and methods. We treated male ICR (CD‑1) outbred laboratory mice with a single injection of sodium oxalate (NaOx) to perform nephrolithiasis modeling. The ionic composition of urine and blood serum in the control and experimental groups was examined by capillary electrophoresis. The presence of oxalate crystals in the urine sediment and histological data can assess the severity of the pathology.Results and conclusions. Increase of the level of Na and Ca ions and decrease of the level of K, NH4, Mg ions was observed in 4 hours and 24 hours after intraperitoneal injection of sodium oxalate, that can be regarded as a depression of tubular reabsorption and secretion.

Transcriptomic analysis conducted by us previously revealed upregulation of genes involved in low-density lipoprotein particle receptor (LDLR) activity pathway in lethal COVID-19. Last data suggested the possible role of extracellular vesicles and exomeres in COVID-19 pathogenesis. The aim of the present study was to retrospectively evaluate parameters of cholesterol metabolism as possible predictors of fatal outcome of COVID-19. Blood from 39 patients with severe COVID-19 (the main cohort) were collected at the time of admission to the intensive care unit (ICU) (T1) and 7 days after admission to the ICU (T2). After 30 days patients were divided into two subgroups according to outcome-21 non-survivors and 18 survivors. 28 patients (13 non-survivors and 15 survivors) with severe COVID-19 were included as the replication cohort. The study demonstrated that plasma low-and high-density lipoprotein cholesterol levels (LDL-C and HDL-C) were decreased and CCL20/MIP3ɑ, IL-10, IL-15, IL-27 concentrations were increased in non-survivors compared to controls in T1. STAB1 gene expression was higher in non-survivors than in survivors (p=0.017) in T2. The conjoint fraction of exomeres and LDL particles measured by dynamic light scattering (DLS) was decreased in non-survivors com-pared to survivors in both the main and replication cohorts. We first showed that change of exomeres fraction may be critical in fatal outcome of COVID-19.### Competing Interest StatementThe authors have declared no competing interest.### Funding StatementThis work was supported by the Genome Research Centre development program “Kurchatov Genome Centre” (agreement No.075-15-2019-1663)### Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The study was conducted in accordance with the World Medical Assembly Decla-ration of Helsinki: Ethical Principles for Medical Research Involving Human Sub-jects. All blood samples were collected with the informed consent of the investigated patients. The study was approved by the Ethics Committee of the Pavlov First State Medical University of St. Petersburg (Russia). Approval Code: 204 Approval Date: 30 October 2020I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesAll relevant data are within the manuscript and its Supporting Information files.

Введение. Изучение роли олигомерных форм уромодулина в развитии уролитиаза является важной фундаментальной и прикладной задачей. Несмотря на разнообразие моделей уролитиаза на лабораторных животных в настоящее время отсутствует информация относительно динамики концентрации и фракционного состава олигомерных форм уромодулина в моче животных на различных этапах развития патологического процесса. Цель - исследование динамики содержания олигомерных форм уромодулина в моче животных на фоне развития гипероксалатного уролитиаза индуцированного экзогенным введением 1% раствора этиленгликоля в качестве безальтернативного источника питья. Методика. Проводили общеклинический и биохимический анализ образцов крови и мочи на различных этапах развития патологического процесса. До начала моделирования патологии и на фоне экзогенного введения этиленгликоля был исследован осадок мочи. Оценка содержания олигомерных форм уромодулина в моче животных проводилась методом анализа треков наночастиц и динамического рассеяния света. Результаты. Показано, что на фоне развития патологии наблюдается уменьшение концентрации олигомерных форм уромодулина в моче, на начальных этапах развития патологии за счёт увеличения фракции крупных частиц (более 200 нм, олигомерная форма 28 МДа). При дальнейшем развитии патологического процесса на завершающем этапе наблюдается радикальное уменьшение концентрации частиц в моче (более чем в 2 раза). Заключение. Полученные данные показали относительно низкую корреляцию между длительностью моделирования патологии и тяжестью проявления уролитиаза (r-Пирсона = 0,49, p-value = 0,0003). Концентрация олигомеров уромодулина в моче животных уменьшается на фоне увеличения количества кристаллов в осадке мочи, что вероятно связанно с включением уромодулина в структуру кристаллов осадка. Studying uromodulin oligomeric forms in urolithiasis development is important fundamental and applied problem. Despite the variety of in vivo models of urolithiasis, there is currently no information about concentration dynamics and fractional composition of uromodulin oligomeric forms in urine for animals at various stages of pathological process developmen. The purpose We investigate dynamics uromodulin oligomeric forms in urine of animals against the background of development hyperoxalate urolithiasis induced by exogenous administration of 1% ethylene glycol solution as a non-alternative source of drinking. Methods. For urine samples at various stages of pathogenesis, general clinical and biochemical analysis were carried out, for urine samples before the start of pathology modeling and against the background of exogenous administration of ethylene glycol, urine sediment was examined. The study of urine sediment and content uromodulin oligomeric forms was carried out on 0th, 7th, 14th, 21st and 28th days of pathology modeling. Evaluation of the content of uromodulin oligomeric forms in urine of animals was carried out by nanoparticles track analysing and dynamic light scattering. Results. It is shown that against the background of the pathology development there is a decrease in the concentration of oligomeric forms of uromodulin in the urine, at the initial stages of pathology development due to an increase in the fraction of large particles (over 200 nm, oligomeric form 28 МDa). With further development of the pathological process at the final stage, there is a radical decrease in the concentration of particles in the urine (more than 2-fold). Conclusion. The obtained data showed a relatively low correlation between the duration of pathology modeling and the severity of urolithiasis manifestation (Pearson's r = 0.49, p-value = 0.0003). Concentration of uromodulin oligomers in animals urine decreases with an increase in the amount of crystals in urine sediment, which is probably associated with inclusion of uromodulin in structure of sediment crystals.

Введение. Уромодулин является основным белком присутствующим в моче в норме, его физиологическая роль очень разнообразна. Оценка его вклада в стабилизацию коллоида мочи в норме и при различных патологических состояниях требует детального исследования олигомерных форм, присутствующих в моче, их структуры и функций. Цель работы - изучение структурных особенностей олигомерных форм белка уромодулина в моче здоровых добровольцев и пациентов с подтверждённым уролитиазом и выявление связи структуры белка и его роли в стабилизации коллоида мочи. Методика. Методом динамического рассеяния света, анализом треков наночастиц и измерением дзета-потенциала изучены биофизические свойства изоформ уромодулина (UM), присутствующего в нативной моче в виде олигомерных форм, из которых можно выделить 2 основные: UM(7) - глобулярная молекула массой 7MDa, характеризуется гидродинамическим радиусом Rh=90-100 нм и отрицательным поверхностным зарядом величиной 25 - 30 мВ; UM(28) - массой 28MDa обладает палочкоподобной структурой с гидродинамическим радиусом Rh=200-300 нм и существенно меньшим по величине поверхностным зарядом 0 - -7 мВ. Результаты. В норме в моче UM(7) является доминантной формой, при этом вклад UM(28) либо отсутствует, либо незначителен. При уролитиазе доля UM(7) радикально уменьшается и вклад UM(28) становится основным. В модельных экспериментах показаны различия этих переходов в моче здоровых лиц и пациентов с уролитиазом в зависимости от величины pH и концентрации одновалентных катионов: натрия, калия и аммония. Заключение. На основании полученных данных существенно расширено представление о саногенетической системе коллоидного гомеостаза мочеобразования и патогенезе кристаллогенеза. Аппроксимация выдвинутой концепции развития патологического кристаллогенеза в клиническую практику расширяют информативность превентивной диагностики уролитиаза. Introduction. Uromodulin is the major protein, which is normally present in urine and plays multiple physiological roles. Evaluation of the uromodulin contribution to stabilization of urinary colloids in normal and various pathological conditions requires a comprehensive study of uromodulin oligomeric forms occurring in urine, their structure and functions. The aim of this work was studying structural features of uromodulin oligomeric forms in the urine of healthy volunteers and patients with confirmed urolithiasis and identifying a relationship between the protein structure and role in stabilization of urinary colloids. Methods. Dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), and measurement of zeta potential were used to study biophysical properties of uromodulin (UM) isoforms. UM is present in native urine as oligomeric forms, including two major ones: i) UM (7), a 7MDa globular molecule characterized by a hydrodynamic radius Rh = 90-100 nm and a negative surface charge of 25-30 mV and ii) UM (28), a rod-like 28MDa molecule with a hydrodynamic radius of Rh=200-300 nm and a significantly lower surface charge of 0 --7 mV. Results. Normally, UM (7) is a dominant form in urine whereas the UM (28) contribution is either non-existent or minor. In urolithiasis, the proportion of UM (7) decreases drastically, and the contribution of UM (28) becomes primary. Model experiments showed differences between these transitions in the urine of healthy individuals and patients with urolithiasis depending on pH values and concentrations of monovalent cations, including sodium, potassium, and ammonium. Conclusion. The study results considerably expanded the concept of the sanogenetic system of colloidal homeostasis in urine formation and the pathogenesis of crystallogenesis. Approximating the proposed concept of pathological crystallogenesis in clinical practice expands the informative value of preventive diagnosis of urolithiasis.

Introduction. Uromodulin is the major protein, which is normally present in urine and plays multiple physiological roles. Evaluation of the uromodulin contribution to stabilization of urinary colloids in normal and various pathological conditions requires a comprehensive study of uromodulin oligomeric forms occurring in urine, their structure and functions. The aim of this work was studying structural features of uromodulin oligomeric forms in the urine of healthy volunteers and patients with confirmed urolithiasis and identifying a relationship between the protein structure and role in stabilization of urinary colloids. Methods. Dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), and measurement of zeta potential were used to study biophysical properties of uromodulin (UM) isoforms. UM is present in native urine as oligomeric forms, including two major ones: i) UM (7), a 7MDa globular molecule characterized by a hydrodynamic radius Rh = 90−100 nm and a negative surface charge of 25−30 mV and ii) UM (28), a rod-like 28MDa molecule with a hydrodynamic radius of Rh=200−300 nm and a significantly lower surface charge of 0 − -7 mV. Results. Normally, UM (7) is a dominant form in urine whereas the UM (28) contribution is either non-existent or minor. In urolithiasis, the proportion of UM (7) decreases drastically, and the contribution of UM (28) becomes primary. Model experiments showed differences between these transitions in the urine of healthy individuals and patients with urolithiasis depending on pH values and concentrations of monovalent cations, including sodium, potassium, and ammonium. Conclusion. The study results considerably expanded the concept of the sanogenetic system of colloidal homeostasis in urine formation and the pathogenesis of crystallogenesis. Approximating the proposed concept of pathological crystallogenesis in clinical practice expands the informative value of preventive diagnosis of urolithiasis.

Despite the introduction of new anti-tuberculosis drugs, the problem of treating tuberculosis patients with a broad drug-resistant pathogen (XDR MBT) remains relevant.Aim of the study. Тo increase the effectiveness of treatment of this category of patients using an autologous composition based on dendritic cells activated by a specific antigen.Research materials and methods. А prospective study conducted in 2016-2019 included 52 patients, 36 (69.2%) men and 16 (30.8%) women, average age 43.2 ± 1.5 years. All patients received antituberculosis therapy in accordance with existing regulatory documents and recommendations. The main group consisted of 25 patients (48.1%) who agreed to immunotherapy with the introduction of an autologous composition with activated specific peptides ESAT-6 and SFP-10 dendritic cells against the background of anti-tuberculosis therapy. Statistical processing of the material carried out using the Statistica 10.0 application software package.Results. In 70.0% of cases (n = 14), there were no adverse reactions to suspension administration in patients of the main group. One patient (7.2%) had a general reaction in the form of tremor, chills after the first injection. In 5 (38.7%) patients on the 8th and 9th administration, a skin reaction was noted at the injection sites in the form of a papule, with a final regression of these changes after 8 weeks. By 18– 24 months of the course, anti-tuberculosis therapy in combination with immunotherapy in the first month of treatment allowed to obtain a positive effect according to clinical, bacteriological and radiological data in 64% of cases. It was not possible to obtain this result during therapy at the previous stages of treatment. In the comparison group, a positive result achieved only in 45.5% of cases.Conclusion. The results of the study suggest a positive effect of complex treatment with the inclusion of immunotherapy with an autologous composition based on dendritic cells in the most severe contingent of patients with pulmonary tuberculosis with broad drug resistance of the pathogen, even with an ineffective course of chemotherapy at the previous stage in 64% of cases.

An urgent task of modern medicine is the search for drugs that can stop or slow down the course of neurodegenerative diseases, in particular Alzheimer's disease. The aim of this work was to determine the effect of fullerenol C-60(OH)(30) on the pathogenesis of Alzheimer's disease in the Drosophila melanogaster model. The effect of fullerenol on the life expectancy, the level of geotaxis, learning and memory, and the levels of neurodegeneration and reactive oxygen species in the animal brain was studied. Based on the results, it can be assumed that fullerenol C-60(OH)(30) is a promising agent for the development of complex therapy for Alzheimer's disease.

The etiology of sarcoidosis is not completely understood. A hypothesis exists about the relationship between sarcoidosis and a complex of pathological autoimmune reactions that occur under the influence of triggering factors. In this study, specific immune complexes in the blood plasma of patients have been determined, which can indirectly reveal the causes of the disease.The study included 33 patients with lung sarcoidosis (I group), compared to 24 healthy donors who served as a control group (II group). The patients underwent standard examination. Their blood plasma was investigated by the dynamic light scattering method with addition of tuberculosis antigens (ESAT-6/SFP-10) and “lung healthy tissue extract”. Statistical analysis was performed using the Statistica 7.0 program. Test results were considered significant at p < 0.05.Аccording to the data obtained, addition of ESAT-6/SFP-10 to patient’s blood plasma almost did not lead to the formation of immune complexes in most samples. Meanwhile, development of such complexes after addition of “lung tissue extract” was revealed in all the patients. The immune complexes were not detected in any donor from control group after stimulation with both kinds of antigens (p < 0.01).The data on distinct formation of immune complexes with the addition of “lung healthy tissue extract” in patients with lung sarcoidosis may be considered an indirect evidence for occurrence of autoimmune reaction under the influence of some pathogenic factors. Absence of de novo immune complex formation after addition of tuberculosis antigens (ESAT-6/SFP-10) makes it unlikely any direct effects of tuberculosis bacteria upon development of sarcoidosis.

The diagnostic of tuberculosis infection, including the use of immunological methods, evolved significant changes. The introduction of new diagnostic tests allowed to improve the diagnosis of latent tuberculosis infection (LTI). However, the positive results of immunological tests in both tuberculosis patients and in those with LTI do not allow to divide these conditions, which requires the development and implementation of new diagnostic approaches.Materials and methods. A prospective study with a survey of two groups of patients was conducted: group I (n=50) - patients with verified pulmonary tuberculosis, MBT (+); group II (n =15) – subjects with LTI and control group – healthy subjects (n=14). The examination complex included clinical, radiological, bacteriological, immunological (Mantoux test with 2 TU, T-SPOT.TB, QFT and Diaskintest) methods. Immune complexes were determined in all patients and healthy individuals by the method of dynamic light scattering after the in vitro addition of specific antigens - peptides ESAT-6 and SFP-10.Results. The obtained data demonstrate the low informativeness of the clinical method in the diagnostic of pulmonary tuberculosis. In the presence of characteristic X-ray changes, bacteriological verification of tuberculosis was obtained only in 46% of cases. The use of various immunological tests allows to obtain positive test results in 84-90% of cases simultaneously with the 100% of the positive results in subjects with LTI. Determination of specific immune complexes by the method of dynamic light scattering allows to determine the activity of tuberculosis infection in 100 % of cases and to identify a high-risk group for the development of active tuberculosis in people with latent tuberculosis infection.Conclusions: the obtained data can be applied not only in the diagnosis of active tuberculosis in the absence of diagnosis verification, but also allow to identify a high-risk group for the development of the disease in people with latent tuberculosis infection.

Early diagnosis of tuberculosis remains essential for the prevention of the disease and control of its incidence. The diagnosis of latent tuberculosis infection (LTBI) has significantly improved over the last years due to the use of new immunological tests, including the Diaskintest.The aim of the study was to assess the potential of immunological assays for diagnosis of latent tuberculosis infection and determination of risk groups for tuberculosis among personnel of different institutions.Materials and methods: in 2015–2018, a prospective group-control study was conducted that included employees of various medical centres (n = 154) and healthy individuals (n = 30). There were no significant age differences between the subjects. All the subjects included in the study shared their medical history, underwent general examination, X-ray examination, and were tested with Diaskintest. Multispiral computed tomography (MSCT) of the chest was performed for every subject with a positive Diaskintest result.Results: the comparison of the number of persons with LTBI in general care hospitals, personnel of a manufacturing firm, and among healthy individuals showed that the risk of being infected with Mycobacterium tuberculosis is very similar in all the groups (from 6.8 to 10.0 %). The highest risk of developing LTBI was found in people who worked in an infectious area for more than 5 years (48.4 %). The analysis of the level of immune complexes (ICs) demonstrated that individuals with LTBI did not have isotypes of IgG3 and IgE immune complexes, which are found in patients with tuberculosis. The identification of particular isotypes indicates a borderline state between LTBI and tuberculosis and requires therapeutic intervention.Conclusions: the use of the Diaskintest makes it possible to distinguish groups of employees of various institutions who are at a higher risk of developing tuberculosis. At the same time, determination of the ICs helps to reveal the borderline condition which requires medical intervention.

In this study, we present a model for visualization of the exosome transfer of p53-GFP protein between cultured mammalian cells. The temporal parameters of the accumulation of fluorescent labeled protein in recipient cells have been analyzed. We employed HEK293 cells transfected with p53∆Y126-GFP plasmid (a GFP clone) as donor of the exosomes, while the original HEK293 cell line was used as a recipient. Our results provide evidence that the transfer of the GFP protein from cell to cell is carried out via exosomes. It has been shown that the accumulation of this protein by the recipient cells in cocultures of these cells takes a prolonged time. The temporal parameters of this transfer differ between the cells within the same population.

In this paper we introduce new approach in formed in heterogeneous biological fluids immune complexes analysis. The approach is based on an analysis of the contribution of immune complexes in dynamic light scattering, recorded by laser correlometer with heterodyne measurement circuit. We demonstrated our approach sensitivity using embryonic calf serum model in addition of monoclonal antibody against hepatocuprein. Proposed approach is capable to detect forming immune complexes by adding antigen at a concentration greater than 150 pg/ml. Using immunoaffinity techniques we confirmed the lawfulness of identified peaks in the histograms of dynamic light scattering as appropriate immune complexes. For these purposes, we selectively removed immune complexes using staphylococcal protein A sepharose immobilized on the particles or increased in size immune complexes due to their further aggregation using antibodies specific for human immunoglobulin. The proposed approach can detect immune complexes in various biological fluids.