An ELISA Platform for the Quantitative Analysis of SARS-CoV-2 RBD-neutralizing Antibodies As an Alternative to Monitoring of the Virus-Neutralizing Activity.

Monitoring of the level of the virus-neutralizing activity of serum immunoglobulins ensures that one can reliably assess the effectiveness of any protection against the SARS-CoV-2 infection. For SARS-CoV-2, the RBD-ACE2 neutralizing activity of sera is almost equivalent to the virus-neutralizing activity of their antibodies and can be used to assess the level of SARS-CoV-2 neutralizing antibodies. We are proposing an ELISA platform for performing a quantitative analysis of SARS-CoV-2 RBD-neutralizing antibodies, as an alternative to the monitoring of the virus-neutralizing activity using pseudovirus or "live" virus assays. The advantage of the developed platform is that it can be adapted to newly emerging virus variants in a very short time (1-2 weeks) and, thereby, provide quantitative data on the activity of SARS-CoV-2 RBD-neutralizing antibodies. The developed platform can be used to (1) study herd immunity to SARS-CoV-2, (2) monitor the effectiveness of the vaccination drive (revaccination) in a population, and (3) select potential donors of immune plasma. The protective properties of the humoral immune response in hospitalized patients and outpatients, as well as after prophylaxis with the two most popular SARS-CoV-2 vaccines in Russia, were studied in detail using this platform. The highest RBD-neutralizing activity was observed in the group of hospitalized patients. The protective effect in the group of individuals vaccinated with Gam-COVID-Vac vaccine was 25% higher than that in outpatients and almost four times higher than that in individuals vaccinated with the CoviVac vaccine.

The value of indicators characterizing the state of the cardiovascular system in assessing the hospital prognosis of COVID-19 patients.

Background     Heart damage is one of complications of the novel coronavirus infection. Searching for available predictors for in-hospital death and survival that determine the tactic of managing patients with COVID-19, is a challenge of the present time.Aim      To determine the role echocardiographic (EchoCG) parameters in evaluation of the in-hospital prognosis for patients with the novel coronavirus infection, COVID-19.Material and methods  The study included 158 patients admitted for COVID-19. EchoCG was performed for all patients. The role of left ventricular (LV) ejection fraction (EF) was analyzed in various age groups. EchoCG data were compared with the clinical picture, including the severity of respiratory failure (RF), blood oxygen saturation (SрО2), data of computed tomography (CT) of the lungs, and blood concentration of troponin. Comorbidity was analyzed, and the highest significance of individual pathologies was determined.Results LV EF ≤40 % determined the worst prognosis of patients with COVID-19 (p<0.0001), including the age group older than 70 years (р=0.013). LV EF did not correlate with the degree of lung tissue damage determined by CT upon admission (р=0.54) and over time (р=0.23). The indexes that determined an adverse in-hospital prognosis to a considerable degree were pericardial effusion (p<0.0001) and pulmonary hypertension (p<0.0001). RV end-diastolic dimension and LV end-diastolic volume did not determine the in-hospital mortality and survival. Blood serum concentration of troponin I higher than 165.13 µg/l was an important predictor for in-hospital death with a high degree of significance (р<0.0001). Th degree of RF considerably influenced the in-hospital mortality (р<0.0001). RF severity was associated with LV EF (р=0.024). The SpO2 value determined an adverse immediate prognosis with a high degree of significance (р=0.0009). This parameter weakly correlated with LV EF (r=0.26; p=0.0009). Patients who required artificial ventilation (AV) constituted a group with the worst survival rate (р<0.0001). LV EF was associated with a need for AV with a high degree of significance (р=0.0006). Comorbidities, such as chronic kidney disease, postinfarction cardiosclerosis and oncologic diseases, to the greatest extent determined the risk of fatal outcome.Conclusion      EchoCG can be recommended for patients with COVID-19 at the hospital stage to determine the tactics of management and for the in-hospital prognosis.

COVID-19 in Russia: Clinical and Immunological Features of the First-Wave Patients.

The coronavirus disease outbreak in 2019 (COVID-19) has now achieved the level of a global pandemic and affected more than 100 million people on all five continents and caused over 2 million deaths. Russia is, needless to say, among the countries affected by SARS-CoV-2, and its health authorities have mobilized significant efforts and resources to fight the disease. The paper presents the result of a functional analysis of 155 patients in the Moscow Region who were examined at the Central Clinical Hospital of the Russian Academy of Sciences during the first wave of the pandemic (February-July, 2020). The inclusion criteria were a positive PCR test and typical, computed tomographic findings of viral pneumonia in the form of ground-glass opacities. A clinical correlation analysis was performed in four groups of patients: (1) those who were not on mechanical ventilation, (2) those who were on mechanical ventilation, and (3) those who subsequently recovered or (4) died. The correlation analysis also considered confounding comorbidities (diabetes, metabolic syndrome, hypertension, etc.). The immunological status of the patients was examined (levels of immunoglobulins of the M, A, G classes and their subclasses, as well as the total immunoglobulin level) using an original SARS-CoV-2 antibody ELISA kit. The ELISA kit was developed using linear S-protein RBD-SD1 and NTD fragments, as well as the N-protein, as antigens. These antigens were produced in the prokaryotic E. coli system. Recombinant RBD produced in the eukaryotic CHO system (RBD CHO) was used as an antigen representing conformational RBD epitopes. The immunoglobulin A level was found to be the earliest serological criterion for the development of a SARS-CoV-2 infection and it yielded the best sensitivity and diagnostic significance of ELISA compared to that of class M immunoglobulin. We demonstrated that the seroconversion rate of "early" N-protein-specific IgM and IgA antibodies is comparable to that of antibodies specific to RBD conformational epitopes. At the same time, seroconversion of SARS-CoV-2 N-protein-specific class G immunoglobulins was significantly faster compared to that of other specific antibodies. Our findings suggest that the strong immunogenicity of the RBD fragment is for the most part associated with its conformational epitopes, while the linear RBD and NTD epitopes have the least immunogenicity. An analysis of the occurrence rate of SARS-CoV-2-specific immunoglobulins of different classes revealed that RBD- and N-specific antibodies should be evaluated in parallel to improve the sensitivity of ELISA. An analysis of the immunoglobulin subclass distribution in sera of seropositive patients revealed uniform induction of N-protein-specific IgG subclasses G1-G4 and IgA subclasses A1-A2 in groups of patients with varying severity of COVID-19. In the case of the S-protein, G1, G3, and A1 were the main subclasses of antibodies involved in the immune response.

[Expert Council Resolution. Practical Aspects of the Diagnosis and Correction of Potassium and Magnesium Deficiency States].

The article analyzes properties of potassium and magnesium, which may exert vasodilatory, anti-inflammatory, anti-ischemic, antiaggregant, and antiarrhythmic effects. These are extremely important microelements and potentially beneficial therapeutic agents for treatment of cardiovascular diseases.

Case of thrombosis of the portal vein and its branches in a patient seropositive for Borrelia antigens.

Borreliosis after sucking ticks is an acute problem in the world. People do not go to doctors after that often, which leads to the development of various complications. Thrombosis of veins of various localization can be one of them. Thrombosis of the portal vein represents a significant problem too with high morbidity and mortality. The risk factors for splanchnic vein thrombosis include infections, but its relationship with borreliosis has not been studied. А 34-year-old man with chronic helicobacter-associated gastritis and gallstones was hospitalized due to development during the last 11 days of epigastric pain and fever to 38.7 °C after a picnic at the forest without a registered tick bite. The blood leukocytes were increased to 11.2*109/l, lymphocytes 70%, C-reactive protein 34.6 mg/l, procalcitonin 0.195 ng/ml. The multispiral computed tomography of the abdominal cavity revealed thrombosis of portal, lienalis and superior mesenteric veins. D-dimer was 1.98 mcg/ml, antithrombin III 75%. JACK2V617F, oncological, rheumatic, thrombophilia markers, blood and urine cultures were negative. A high concentration of anti-Borrelia burgdorferi IgM 62.2 U/ml and its increasing to 190 U/ml in dynamics was revealed at the immunofluorescence assay. Anti-Borrelia IgM to OspA, p31 and OspC, p25 were detected at the immunoblotting assay. Anticoagulation, doxycycline, detoxification therapy reduced pain and normalized temperature and inflammation markers. Vein thrombosis was not detected at the control tomography after 2 weeks. Despite that the combination of thrombosis and borreliosis is rare, it is necessary to screen for Borrelia antigens in patients with splanchnic vein thrombosis and fever.

[The role of dynamic perfusion scyntiography of myocardium at rest and during exercise in the assessment of the clinical course of chronic cardiac failure and angina of effort in patients with stable forms of coronary heart disease].

The ever-growing morbidity, disablement, and mortality from coronary heart disease, chronic cardiac failure dictate the necessity of the search for new methods to verify, and evaluate prognosis of the clinical course of these diseases. Currently, myocardial perfusion scintiography is most widely used for the purpose.

[Mental disorders in young serviceman with cardiological emergencies].

Investigated 82 young servicemen with cardiological emergencies (acute cardiac syndrome, hypertension events, rhythm pace disturbance). Divided three periods of mental disorders: acute, subacute and long-term effects. Found that in 95.1% of patients after emergencies developed state of mental maladaptation of varying degree. In further 47.1% of cases of mental disorders place in the form of psychogenic and somatogenically caused disorders of prenosological level. Among clinically executed forms predominated depressive disorder spectrum (nozogennye reaction and state). In the remote period prevailed somatoform dysfunction and manifestations of personality pathology. Shows the clinical and psychopathological features of these disorders and their effects on military service.

[Renal protection in the patients with idiopathic hypertensia: the possibilities of the combined blockade of the reninangiotensinaldosterone system].

Reninangiotensinaldosterone system is a key link in regulation of blood pressure and causes the target organ damage in hypertensive patients. For many years is not lost interest in the pharmacological blockade of RAAS in order to achieve target levels of BP and prevent damage target organs, particularly kidneys. Most recently recommended for clinical application of direct rennin inhibitor--aliskiren, a number of researcher have proven expressed nephroprotective effect. However, at present there is no unequivocal answer to the question whether there are advantages in combined RAAS blockade in hypertensive patients with use of aliskiren and angiotensinconverting enzyme inhibitor or angiotensin receptor blocker.

[Status of mental health of men called up for military service].

Authors analyzed psychic sick rate of selectees for the last 12 years according to data studying of Saint Petersburg military registration and enlistment offices obtained in 1996-2008. It has been established that it is connected with social stress phenomena in consequence of global changes occurring in society. Neurotic and personal disturbances dynamic is similar to neuropsychic instability level dynamic, revealed in selectees by specialists of occupational psychological selection of military registration and enlistment offices.

[A famous figure of military medicine (Zamyatin A.I.--the first chairman of science-technical committee of military-sanitary government of RKKA)].

For the first time was presented life history of Alexander Zamyatin (1873-1931)--a famous military physician, one of leaders of sanitarium service of the Red Army for the period of 1920-s.

[Mental disorders at hypertensive illness at military men of young age (analysis of a condition of a problem)].

The review of the modern literature on the mental disorders arising at hypertensive illness at military men of young age is spent. The basic clinical forms of the mental pathology arising at different stages of hypertensive illness are investigated. Neuroendocrinological, neuromediatorical, neurophysiological, immunological and behavioural mechanisms of infringements of anxiety, depressive disorders and an arterial hypertensia at persons of young age are shown, them reciprocal mutual relations, influence on a current and the forecast of main illness.

[Endothelial dysfunction on initial stages of arterial hypertension among men of young age and it's connection with vascular risk factors].

Frequency of display endothelial dysfunction, arising on the initial stages of development arterial hypertension is investigated, depending on vascular risk factors. The main group was made by 86 men with arterial hypertension I-II stage, group of the control--practically healthy 50 men. Vasomotor endothelial function defined on a degree of vasodilatation a humeral artery in reply to reactive hyperemia. Damage signs of endothelial monolayer estimated by quantity of free circulating endothelial blue blood cells. It is established, that the simultaneous combination of functional or structural vascular infringements among persons with normal blood pressure was registered in 3 times less often in comparison to patients with an arterial hypertension (p<0,01). At the main group at a simultaneous combination inadequate vasodilatation and endotheliaemia occurrence risk factors in 1,5 times is higher, than at their isolated display (p>0,05).

[Swine flu: epidemiology, diagnostics, treatment, and prophylaxis].

Virus of piggy grippe is a virus of type A, which has greatly changed in it's antigenic structure. As a result, has appeared a new variant of germ (syb-type), in relation to which vaccines, used for period 2008-2009, are unsuccessful. Virus represents a real risk for life and health of millions of people. Experts of World Health Organization are sure, that eruption can lead to a global expansion of virus. To the group of high risk refer: children younger then 5 years old, full-growns of 50 years old and older, children and teen-agers (from 6 months to 18 years), treated for a long time by aspirin, gravidas, full-growns with several chronic diseases, persons in nursing homes, hospices, requiring a long-termed hipurgia, compulsory-duty servicemen. Latent period is from 1 to 7 days (2-3 days on the average). Accountancy of clinical data: acute beginning, hyperpyretic fever, predominance of damages of upper respiratory tracts. The article presents a detailed characteristic of therapeutic and prophylactic measures in the Army and NAVY.

[Main directions of growth of specialized medical aid in the Armed Forces].

Systemic and process approaches permit to present a specialized medical aid (SMA) as opened, complicated, hierarchical, self-organizing system. The main tendencies of development of SMA in military and civil health care are differentiation and integration of medical specialties, standardization of types of SMA, multilevelness of SMA, development of microsurgical, endovideosurgical techniques.

[Adrenergic innervation of the myocardium in patients with cardiac syndrome X]. / Issledovanie adrenergicheskoi innervatsii miokarda u bol'nykh kardial'nym sindromom X.

11 syndrome X patients and 8 healthy controls were investigated by myocardial scintigraphy (SPECT) with 123-I-MIBG. Regional defects in cardiac 123-I-MIBG uptake were found in 90% syndrome X patients. Total cardiac 123-I-MIBG uptake appeared significantly higher in syndrome X patients. Perfusion defects on stress 99m-Tc-MIBI scintigraphy were found in 10 syndrome X patients who had also abnormal 123-I-MIBG scintigrams. It is suggested that impairment of efferent cardiac adrenergic nerve fiber function in syndrome X patients may contribute to pathophysiologic and clinical features of syndrome X.

[Effect of anti-arrhythmia preparations on thrombocytic and vascular hemostasis]. / Vliianie nekotorykh antiaritmicheskikh preparatov na trombotsitarnyi i sosudistyi gemostaz.

Platelet aggregation, prostacyclin and thromboxane were studied in 35 individuals: 20 coronary patients with angina of effort and 15 high-risk patients before and after treatment with lidocaine and pyromecaine. Oral administration of lidocaine and pyromecaine pills considerably depresses platelet aggregation and even causes platelet disaggregation. However, lidocaine disaggregating effect is greater than that of pyromecaine. Both agents affect vascular hemostasis by reducing thrombaxane and raising prostacyclin levels. Hence, the anti-aggregant effect of anti-arrhythmic proocaines may be attributed to changes in vascular hemostasis. The results obtained are expanding the range of indications for the use of these drugs.

[Nonspecific immunity factors and elimination of circulating immune complexes in patients with myocardial infarct in the 1st phase of rehabilitation]. / Nespetsificheskie faktory immuniteta i éliminatsiia tsirkuliruiushchikh immunnykh kompleksov u bol'nykh infarktom miokarda v pervoi faze reabilitatsii.

A considerable increment of humoral immunity parameters was demonstrated during the 3d-5th week after the onset of myocardial infarction (MI). The levels of IgG and IgE were increased, and those of circulating immune complexes (CIC), decreased significantly in patients with their first diagnosed infarction, as compared to those with repeated MI. Patients with repeated MI showed significantly reduced blood C3c, C4 and the phagocyte index in the presence of high blood levels of CIC and C-reactive protein, as compared to patients with primary infarction. The results are indicative of a considerable activation of the complement and the phagocytic system and CIC elimination in patients with their first MI diagnosis, and the absence of such a stimulation in repeated MI cases.