Investigation of the inhibitory activity of extracts, fractions and secondary metabolites of <i>Silene</i> spp. (<i>Caryophyllaceae</i>) and <i>Serratula cupuliformis</i> (<i>Asteraceae</i>) on the replication of SARS-CoV-2 coronavirus

Aim. In vitro analysis of the inhibitory activity of extracts, fractions and secondary metabolites of plants of the genus Silene [Caryophylaceae] and Serratula cupuliformis [Asteraceae) on the replication of SARS-CoV-2.

Material and Methods. Silene spp. and Serratula cupuliformis of the Siberian Botanical Garden of National Research Tomsk State University were used. Ethanol extracts and butanol fractions of Silene spp. were prepared. The flavonoid shaftoside and the ecdysteroid 20-hydroxyecdysone from Lychnis chalcedonica were isolated. Analysis of BAS was carried out by the HPLC method. In vitro analysis of the inhibitory activity of extracts on SARS-CoV-2 replication was performed in Vero cell culture by direct inactivation [neutralization) of virions. Comparison samples were dry ethanol extracts of chaga [Inonotus obliquus, Basidiomycota), spices of cloves [Syzygium aromaticum, Myrtaceae) and root of licorice [Glycyrrhiza glabra L., Fabaceae).

Results. The inhibitory activity of ethanol extracts and butanol fractions of Silene spp., as well as individual compounds [shaftozide and 20-E) was revealed in the range of 50% effective concentrations [EC50) when dissolved in water from 339.85±83.92 pg/ml to 1.59±0.39 pg/ml and when dissolved in DMSO from 119.34±26.34 pg/ml to 2.22±0.57 pg/ml, respectively. The butanol fraction of Serratula cupuliformis was active with EC50=21.74±4.80 and 27.42±6.05 pg/mL. These results for some samples of Silene spp. and Serratula cupuliformis are comparable to the EC50 values of the comparators.

Conclusion. The results obtained suggest the presence of biologically active substances in the herbal preparations studied that act destructively on virions of SARS-CoV-2 and affect one of the main stages of its "life" cycle - on the attachment to receptors of sensitive cells.

[Transplantation of the Bowman's layer in combined treatment of recurrent pterygium]

Pterygium is among the most frequent indications for extraocular ophthalmic surgery. The main method of pterygium treatment - its excision - is often combined with transplantation, non-transplantation, medication and other methods. However, the frequency of pterygium recurrence can exceed 35%, and the cosmetic and refraction outcomes satisfy neither the patient, nor the surgeon.

PURPOSE

The study analyses the technical capability and feasibility for transplantation of the Bowman's layer in the treatment of recurrent pterygium.

MATERIAL AND METHODS

The transplantation of the Bowmen's layer was performed according to the developed technique on 7 eyes with recurrent pterygium (7 patients aged 34 to 63 years). The combined surgery technique consisted of pterygium resection, laser ablation, autoconjunctival plasty, exposure to a cytostatic drug, non-suture transplantation of the Bowman's layer. Maximum length of the follow-up was 36 months. Analysis involved data from refractometry, visometry (without correction and with spectacle correction), and optical coherence tomography of the retina.

RESULTS

There were no complications in any of the studied cases. The cornea and the transplant retained transparency throughout the entire follow-up duration. 36 months after surgery mean spectacle-corrected visual acuity amounted to 0.86±0.2, topographic astigmatism - 1.48±1.4 diopters. Recurrence of pterygium was not observed. All patients were satisfied with the cosmetic outcomes of the treatment.

CONCLUSION

Non-suture transplantation of the Bowmen's layer recovers normal anatomy, physiology and transparency of the cornea after repeat surgical intervention for pterygium. No pterygium recurrences were observed throughout the entire follow-up after treatment with the proposed combined technique.

Right ventricular dysfunction during chemotherapy in patients with breast cancer

Aim. To assess the right ventricle (RV) during chemotherapy (CT) in patients with breast cancer (BC).

Material and methods. The study included 40 women aged 35-72 years with BC who underwent anthracycline chemotherapy. The main group (n=40) included women with BC, examined at the first contact, 37 of whom were reexamined after 6 months. Control group (n=25) included women without BC.

Results. In the main group, the median transverse dimension and anterior wall thickness of the RV were significantly greater than in the control group (p<0,001). Early diastolic transtricuspid flow velocity (Et) after 6 months was lower than in the control group (p=0,003). The ratio of Et to late (At) diastolic transtricuspid flow (Et/At) in BC patients significantly decreased during the follow-up period (p<0,05) when compared with the control group and baseline values. Higher values of Tei index were noted in the main group compared to the control one (p<0,05). Using logistic regression for the Tei index, the model included radiation therapy, the total anthracycline dose, and negative affectivity score as follows: F(3,17)=12,548, p<0,001, R2=0,729. For the Et/At ratio, additional radiation therapy and heart rate were significant factors as follows: F(2,16)=12,548, p=0,005, R2=0,526.

Conclusion. Against the background of CT, deterioration of RV systolic (increase in Tei index and RV volume) and diastolic (decrease in Et and Et/At ratio) function was noted.

Right ventricular diastolic dysfunction in breast cancer patients undergoing chemotherapy

Funding Acknowledgements

Type of funding sources: None.

Right ventricular (RV) diastolic dysfunction has been recognized as an independent predictor of adverse events and mortality in a wide range of diseases (1,2). Experimental and clinical data indicate that pathophysiological factors induce the development of RV diastolic dysfunction first, and only later - systolic dysfunction (3). The aim of the study was to assess the right ventricle diastolic function in patients with breast cancer undergoing chemotherapy.

Material and methods

The study included 40 women receiving anthracycline-based chemotherapy for cancer, and 25 age-matched and comorbidity-matched women without cancer as a control group. RV systolic (s"t, Tei-index, and TAPSE) and diastolic (Et, At, Et/At, e"t, a"t, e"t/a"t) function parameters at baseline and after treatment were compared and evaluated.

Results

In cancer patients during anthracycline-based chemotherapy, no signs of cardiotoxicity were detected according to the indicators of the left ventricular ejection fraction and global longitudinal strain. Progressive decline in RV diastolic function was noted in patients receiving anticancer therapy. Et was 53.0 (46.0; 62.0) sm/sec in control, 50.0 (41.0; 53.0) sm/sec in cancer group before treatment, and  45.0 (41.0; 51.0) sm/sec after one-year treatment (p = 0.017 for trend). Et/At was 1.4 (1.28; 1.6), 1.34 (1.23; 1.58), and 1.12 (0.81; 1.35), respectively (p = 0.002 for trend). RV systolic function was without changes during treatment. TAPSE was 2.5 (2.2; 2.8) sm in control, 2.3 (2.2; 2.5) sm in cancer group before treatment, and  2.3 (2.0; 2.4) sm after one-year treatment (p = 0.091 for trend). 

Conclusion

Patients undergoing chemotherapy experience a decline in right ventricular filling rates despite not showing clear signs of anthracycline-associated cardiotoxicity. More research is needed to indicate the clinical and prognostic significance of such changes.

[Experimental study of the effect of corneal hydration and its biomechanical properties on the results of photorefractive keratectomy]

Water content in the cornea may affect the outcome of its excimer laser ablation, especially in presbyopic patients with myopic refraction. This hypothesis can be tested by scanning the cornea in the terahertz (THz) range to determine its hydration level.

PURPOSE

To study the effect of hydration of the cornea determined by non-contact THz scanning and its biomechanical parameters on the results of photorefractive keratectomy (PRK) in an experiment.

MATERIAL AND METHODS

PRK was performed using the Nidek EC-5000 QUEST excimer laser on 8 rabbit eyes. Corneal hydration was evaluated by determining the reflection coefficient (RC) in the THz electromagnetic radiation range before PRK, after 3-5 days, and after 1, 2, 3, and 4 months. Clinical examination included autorefractometry, assessment of corneal thickness and other anatomical and optical parameters of the anterior eye segment (Galilei G6, Ziemer Ophthalmic Systems AG 6.0.2, Switzerland), measurement of corneal hysteresis (CH) and corneal resistance factor (CRF) using the Ocular Response Analyzer (ORA; Reichert, USA), as well as tear production (Schirmer test).

RESULTS

The initial water content in the cornea has a significant effect on the thickness of the removed layer, i.e. on the PRK effect, with correlation coefficient of R_s= -0.976 (p<0.01). The correlation between CH and the ablation depth is less pronounced (R_s=0.643), and CRF had no correlation with it (R_s= -0.089). Biomechanical indicators of the cornea depend on its hydration: changes in CH and CRF after excimer laser ablation qualitatively coincide with changes in RC, the correlation coefficient between RC and the initial value of CH is R= -0.619 (moderate negative correlation).

CONCLUSION

THz scanning is an effective non-contact technology for monitoring corneal hydration level. The mismatch of the hypoeffect of keratorefractive excimer laser intervention planned for patients with presbyopia with the actual outcome can be caused by individual decrease in the initial water content in the cornea.

[Myocardial infarction in a patient with a single ventricle of the heart]

A clinical case of myocardial infarction in a patient with single ventricle heart defect is described.

Prototype of a DNA Vaccine against Marburg Virus

The preparation and study of the biological properties of the pVAKS-GPVM DNA immunogen containing a gene encoding Marburgvirus glycoprotein are described. The specificity of blood serum antibodies of guinea pigs immunized with DNA immunogen was analyzed by ELISA. Inactivated viral preparation, recombinant glycoprotein (GP) obtained in the prokaryotic system and virus-like particles based on the recombinant vesicular stomatitis virus exhibiting Marburgvirus GP were used as the antigens. The neutralizing activity of antibodies of immunized animals was tested in vitro using a pseudovirus system. It was demonstrated that the developed immunogen administered to guinea pigs induced the production of specific antibodies that neutralize virus-like particles and Marburgvirus in cultured Vero cells.

N-terminal propeptide of type III procollagen for predicting diastolic dysfunction in patients with myocardial infarction and preserved ejection fraction

Aim. To study changes in the level of fibrotic scarring marker — the N-terminal propeptide type III procollagen (PIIINP) and structural and functional parameters with the assessment of diastolic function in patients a year after ST segment elevation myocardial infarction (STEMI) and preserved left ventricle (LV) contractility.

Material and methods. At first, the study included 120 (100%) STEMI patients. Next, patients with an LV ejection fraction (EF) ≥50% were selected. The final analysis included 86 STEMI patients. Upon hospitalization, the patients underwent routine diagnostic tests, coronary angiography with stenting of culprit artery. Echocardiography and determination of venous blood PIIINP and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels was on the 1st (time point 1) and 12th day (time point 2) of disease and after a year (time point 3). To compare the obtained values of fibrotic scarring markers, a control group was formed, including 20 (100%) healthy volunteers, identical in age and sex with the studied sample.

Results. On the first day of MI, 25 (29,1%) patients with signs of diastolic dysfunction (DD) were identified among those with preserved LVEF. After 1 year, the number of such patients increased by 10% (n=9). Initially increased (relative to the control group) concentration of PIIINP on the first day (311,2 [220,1; 376,3] ng/ml) decreased by the 12th day (223,3 [195,3; 312,1] ng/ml) and returned to the initial values a year after the MI (312,6 [228,0; 383,8] ng/ml). The NT-proBNP concentration during the hospitalization period did not exceed the reference values and did not differ between 1 and 2 time points (p=0,127). One year later, the NT-proBNP concentration significantly exceeded the values of the previous determinations and amounted to 124,4 pg/ml (p=0,043). According to the ROC analysis, with a PIIINP ≥387,8 ng/ml on the first day, the risk of DD increases (p=0,050, sensitivity, 84,62%, specificity, 55,56%) within a year after STEMI with preserved LVEF.

Conclusion. The threshold of PIIINP (≥387,8 ng/ml) was established for the first day of MI, at which the risk of DD increases one year after the index event. An increase in NT-proBNP concentration one year after STEMI indicates the progression of heart failure.

 

Optimization of a Comprehensive Prehabilitation Program for Patients with Stable Coronary Artery Disease Undergoing Elective Coronary Artery Bypass Grafting

Aim. To evaluate the effectiveness of a comprehensive prehabilitation program including the optimization of drug therapy for patients undergoing elective coronary artery bypass grafting (CABG).

Material and methods. 56 male patients with stable angina referred to elective on-pump CABG were enrolled in a study. All patients were screened for eligibility according to the inclusion/exclusion criteria and then randomized into two groups. Group 1 patients (n=28) underwent preoperative management (prehabilitation) for 14 days, including patient education and physical rehabilitation. Trimetazidine in a dose of 80 mg per day was added to the standard drug therapy. Group 2 patients (n=28) underwent similar preoperative management, but with the standard drug therapy without trimetazidine. In addition to the routine methods of preoperative management, all patients underwent the 6-minute walk test (6MWT) to assess exercise tolerance and speckle tracking echocardiography to measure left ventricular (LV) longitudinal deformation. Serum troponin T was measured in all patients. The measurements were performed at admission and after the surgery.

Results. Patients did not differ in the main clinical and demographic data, as well as the main preoperative speckle tracking echocardiography findings. The intraoperative parameters were comparable in both groups. The rate of early postoperative complications was 61% (n=17) in Group 1 and 64% (n=18) in Group 2 (p>0.05). LV ejection fraction significantly decreased postoperatively in both groups (p<0.01) as well as LV longitudinal deformation as compared to the baseline. Patients receiving the standard therapy without trimetazidine reported a significant decrease in the longitudinal strain after CABG compared with the baseline (p=0.01). There were no statistically significant differences in most preoperative and postoperative indicators of longitudinal deformation among patients treated with trimetazidine. Postoperative values of GLPS-LAX and GLPS-Avg were significantly higher in the trimetazidine group than those in the control group (p=0.04). Group 1 patients reported longer distance covered in 6MWT than Group 2 patients while assessing exercise tolerance: 370.0 [260.0;415.0] vs 242.0 [202.0;350.0] m, respectively (p=0.0059).

Conclusion. The addition of trimetazidine in a dose of 80 mg daily in the prehabilitation program for patients undergoing elective CABG demonstrated better postoperative indicators of LV longitudinal deformation and an increase in exercise tolerance. Obtained findings allowed considering this approach to the preoperative management as an additional method of cardiac protection and optimization of the functional status of patients.

[Dynamics of Parameters of Transmitral Blood Flow and Markers of Myocardial Fibrosis in Patients with Myocardial Infarction]

Aim      To study possible correlations between echocardiography (EchoCG) indexes and markers of myocardial fibrosis, procollagen I C-terminal propeptide (PICP) and procollagen III N-terminal propeptide (PIIINP) during one year following ST-segment elevation myocardial infarction (STEMI).Material and methods  120 patients with STEMI were evaluated. EchoCG was used to assess dimensions and volumes of heart chambers, left ventricular (LV) systolic function, mean pulmonary arterial pressure (mPAP), and indexes of LV diastolic function (Em, early diastolic lateral mitral annular velocity; e', peak early diastolic septal mitral annular velocity; E / e', ratio of peak early diastolic transmitral inflow velocity and mitral annular velocity  -, Е / А, ratio of peak early and late transmitral inflow velocities; DT, deceleration time of LV early diastolic filling). EchoCG indexes and serum concentrations of PICP and PIIINP were determined at 1 (point 1) and 12 (point 2) days of disease and one year after STEMI (point 3). The sample was divided into two groups: group 1 (n=86; 71.7 %) included patients with a LV ejection fraction (EF) ≥50 % and group 2 (n=34; 28.3 %) consisted of patients with LV EF ≤49 %.Results At one year, the number of patients with signs of diastolic dysfunction increased by 10% in group 1 whereas myocardial systolic dysfunction worsened in both groups. LV EF decreased in 15 (17.4%) patients of group 1 and in 4 (11.8%) patients of group 2. Concentrations of PIIINP were correlated with Em, E / e', mPAP, PICP, e', and LV EF.Conclusion      Direct correlations between PIIINP concentrations and Em, E / e', and mPAP were found in the group with LV EF ≥50 %. In the group with LV EF &lt;50 %, correlations were observed between PICP concentrations, LV EF, and e'. Also, in this group, the increase in PIIINP was statistically more significant. These results indicate continuing formation of myocardial fibrosis in a year following MI, which may underlie progression of chronic heart failure.

Synthesis and biological evaluation of 6-nitro-1,2,4-triazoloazines containing polyphenol fragments possessing antioxidant and antiviral activity

Stable σ-adducts of azolo[5,1-c]triazines and azolo[1,5-a]pyrimidines with different polyphenols were synthesized and their antioxidant and antiviral activity were investigated. Their affinity to viral hemagglutinin was assessed using molecular modelling. The phloroglucinol-modified azolo-azines possessed the highest virus-inhibiting activity. According to the results of the study of antioxidant properties of compounds, the most promising ones exhibiting highest antioxidant capacity were adducts containing in their structure pyrogallol and catechol residues and 6-nitro-triazolotriazin-7-ol scaffold. No correlation between antioxidant and virus-inhibiting activity of compounds studied was detected. The most active compounds demonstrated the ability to prevent binding of viral hemagglutinin with cellular receptor as shown in hemagglutination inhibition assay. Our results demonstrate that polyphenol-modified azolo-azines are prospective for further optimization as potential antivirals and that their action is directed against viral hemagglutinin.

First Experience of Sutureless Redo on Mitral Valve Using Valve-in-Valve Technique: Two-Stage Implantation on a Large Animal

Sutureless implantation of the mitral valve bioprosthesis using the valve-in-valve method was performed on a large animal (sheep). According to the results of a two-stage implantation (primary implantation of a xenopericardial 26-mm framed bioprosthesis and reimplantation of the developed 23-mm bioprosthesis), minor changes in quantitative indicators were revealed: an increase in the transprosthetic gradient by 1.3 mm Hg and a decrease in the area of the mitral orifice by 21.6%. Considerable reduction in the intervention time by 18 min was achieved (by 40% in comparison with the primary prosthesis). The absence of adverse events in the animal and complications in the post-operative period, as well as physiological hemodynamic indicators indicate the safety of the developed medical device.

Synthesis and Metabolism of Nitric Oxide (NO) in Chicken Embryos and in the Blood of Adult Chicken

In chicken embryos, nitric oxide (NO) is accumulated in the pool of NO donors: S-nitrosothiols, nitrosyl-iron complexes, high-molecular-weight nitro-compounds. Oxidation of NO to nitrate occurs with different intensity in the embryos of different chicken breeds. In some embryos, NO donors accumulate almost without oxidation. Stable concentration of NO donors and nitrate in the blood of adult chicken is a result of dynamic equilibrium between NO synthesis and elimination (oxidation, consumption by other tissues, and excretion). As NO oxidation occurs mainly not in the blood, but in other tissues, decomposition of NO donors and NO oxidation are determined the properties of these tissues, in particular, the presence of physiological targets of NO, rather than spontaneous processes. Hence, evaluation of the intensity of NO metabolism is important for prediction of the efficiency of preparations containing NO donors and stimulators of its synthesis.

[Possibilities for the diagnosis of inflammatory reaction in ischemic stroke]

AIM

To study diagnostic possibilities for determining the content of nitrite and N-nitroso compounds (NO₂^-+RNNO) in blood plasma and cerebrospinal fluid (CSF) in patients with acute ischemic stroke (IS).

MATERIAL AND METHODS

Twenty-four patients with IS were examined. The content of NO oxidation products was determined in venous blood and CSF by using an enzyme sensor based on the unique property of nitrite (NO₂^-), N-nitroso compounds (RNNO), S-nitrosothiols and dinitrosyl iron complexes to inhibit the enzyme catalase in the presence of halide ions. The study was conducted on the 1st day of IS.

RESULTS AND CONCLUSION

CSF in patients with IS contained nitrite and N-nitroso compounds (NO₂^-+RNNO) in concentrations ranging from 0.4 to 2.0 µm. The relationship between the size of IS and the concentration of NO₂^-+RNNO in CSF was shown. It was 1.01±0.13 µm in patients with medium IS and 0.71±0.07 µm in patients with small IS (U-criterion 16.5; p<0.05). There was no correlation between the severity of neurological deficit at the time of hospitalization and discharge from the hospital and the content of NO₂^-+RNNO in CSF (r=0.134; p>0.5; r=0.155; p>0.5, respectively). Plasma NO₂^-+RNNO levels were not associated with the presence and size of IS though they were elevated in patients with inflammatory complications. In conclusion, NO₂^-+RNNO can be considered as a marker of inflammation in patients with IS. Their presence in CSF reflects the extent of brain damage, but not the presence of concomitant inflammatory diseases.

New antiradical capacity assay with the use potentiometric method

For the first time, the dependence of a redox potential change during a reaction of peroxyl radical generation and their interaction with antioxidants was studied. A regular change of a potential is due to oxidation of an antioxidant by initiating peroxyl radicals accompanied by an electron transfer. An original direct method for determining induction periods, inhibition coefficients and an antiradical capacity using the potentiometric method is proposed. Using the proposed approach the induction periods and the inhibition coefficients of various OH, NH, SH containing antioxidants were determined. The antiradical capacity of a herbal extract was studied. A high degree of correlation with a DPPH assay was obtained. RSD results obtained using the proposed approach do not exceed 7%.

[Clinical Case of Severe Heart Failure Treatment, Produced due to the Development of Arrhythmogenic Cardiomyopathy in a Patient With Permanent Junctional Reciprocating Tachycardia (Coumels Tachycardia) With Additional Left Lateral Accessory Pathway]

Thirty two years old man had history of atrioventricular re-entry tachycardia (AVRT) with concealed left-lateral accessory pathway (AP), 3-5episodes per year, 30-40 minutes duration without hemodynamic compromise. Two years ago patient underwent ablation of concealed left lateral AP. After that tachycardia became malignant (high-frequent 150 beats-min, incessant (lasting up to 18 h/day), resistant to AAD, and led to development of tachycardia-induced cardiomyopathy (EF was 16%, and 2 episodes of pulmonary oedema). During redo EPS we verified AVRT with conduction via decremental retrograde left lateral AP which corresponded to the criteria of permanent junctional reciprocating tachycardia (PJRT). Ablation effectively ceased the arrhythmia. After 18 months of follow up there are no symptoms of heart failure and recurrence of arrhythmia.

CONCLUSIONS

We present a case of effective treatment of severe heart failure in a patient with arhythtmogenic cardiomyopathy due to malignant course of incessant tachycardia AVRT with retrograde decremental conduction via left lateral AP. Ablation of AP eliminated of arrhythmia. After 18 months of follow up patient had signs of left ventricle reverse remodeling and had not heart failure symptoms.

REVIEW OF EPIDEMIOLOGIC SITUATION ON HEMORRHAGIC FEVER WITH RENAL SYNDROME (HERS) IN RUSSIAN FEDERATION IN 1990 - 2015

AIM

Analyze HFRS morbidity in Russian Federation during the last 25 years (1990 - 2015).

MATERIALS AND METHODS

Official statistics of Federal Service for Surveillance on Consumers' Rights Protection and Human Weillbeing (CPS), including Federal Centre of Hygiene and Epidemiology, were used for the analysis, as well as materials from regional departments of CPS and centers of hygiene and epidemiology. Epidemiologic analysis was the main method. Statistical treatment of the results obtained was carried out using gener- ally accepted methods of variation statistics with elements of system analysis. Results; For the studied period (1990 - 2015) 194 116 cases of HFRS were registered. Morbidity was registered in 8 federal districts of the Russian Federation in 58 subjects. The most intense epidemiologic situation was noted in Privolzhsky Federal District, that accounted for 86.4% of total HFRS morbidity during the -studied period. Analysis of morbidity was carried out in every federal district, most epidemically unfavorable territories are shown.

CONCLUSION

The data presented on HFRS morbidity reflect -unfavorable situation for this disease in Russian Federation. Measures to prevent the emergence of diseases to reduce the general level of morbidity in Russian Federation are presented.

Potentiometric study of antioxidant activity: development and prospects

The increasing interest in the study of the antioxidant activity of different objects is caused by an unbalance between the formation of reactive oxygen species (ROS) and the performance of the antioxidant system in humans under certain conditions, which leads to oxidative stress and pathological states of the organism. This article presents a brief critical review of the methods that are used to measure integrated antioxidant activity (AOA). It is shown that the most promising methods for measuring AOA are electrochemical ones, particularly potentiometry, as it best fits the nature of the processes causing oxidative stress. The article gives the theoretical rational for requirements that an oxidizer of antioxidants (AO) should meet. The work presents the thermodynamic grounds for the use of an earlier proposed mediator system, kinetics of chemical reactions between AO and the mediator system. In order to confirm reliability and accuracy of the results, numerous correlation studies were conducted, aiming to compare the data obtained with the use the proposed method and independent analytical methods. The article presents the results of the potentiometric study of AOA for a variety of objects, including individual antioxidant → nutritional supplements → food → blood and blood fractions.

[Receptor tyrosine kinase KIT may regulate expression of genes involved in spontaneous regression of neuroblastoma]

Hallmark of neuroblastoma is an ability of this malignant tumor to undergo spontaneous regression or differentiation into benign tumor during any stage of the disease, but it is little known about mechanisms of these phenomena. We studied effect of receptor tyrosine kinase receptor KIT on expression of genes, which may be involved in tumor spontaneous regression. Downregulation of KIT expression by RNA interference in SH-SY5Y cells causes suppression of neurotrophin receptor NGFR expression that may promote the loss of sensibility of cells to nerve growth factors, also it causes upregulation of TrkA receptor expression which can stimulate cell differentiation or apoptosis in NGF dependent manner. Furthermore there is an upregulation of genes which stimulate malignant cell detection by immune system, such as genes of major histocompatibility complex HLA class I HLA-B and HLA-C, and interferon-γ receptors IFNGR1 and IFNGR2 genes. Thus KIT can mediate neuroblastoma cell sensibility to neurotrophins and immune system components--two factors directly contributing to spontaneous regression of neuroblastoma.

Effect of Green Light on Nitric Oxide Metabolism in Chick Embryos. A Possible Physiological Role

The exposure to green light, which serves as a well-known activating factor for myogenesis during incubation of chicken eggs, contributes to intensification of embryonic metabolism of NO. A metabolic product, nitrate, is mainly accumulated in the muscles. These data suggest that light induces a NO-dependent activation of the factor, which intensifies muscle tissue development.

[Elastogenesis-Related Gene Polymorphisms and the Risk of Pelvic Organ Prolapse Development]

Pelvic organ prolapse (POP) represents a urologic and gynecological disease, the development of which is governed both by environmental and genetic factors. We describe the results of our association study of polymorphic variants of genes involved in the assembly of elastic fibrils, namely, the lysyl oxidase protein 1 (LOXL1) and fibulin-3 (FBLN3) genes. We revealed an association of the rs2304719-T allele and rs2165241 (C)-rs2304719(T)-rs893821(T) haplotype of the LOXL1 gene with an increased risk of POP development, as well as a weak association with the disease of the rs3791660-C allele and the rs3791679(T)- rs1367228(A)-rs3791660(C)-rs2033316(A) haplotype of the FBLN3 gene.

[OPTIMIZATION OF EARLY DIAGNOSIS OF ACUTE KIDNEY INJURY IN NEWBORNS IN CRITICAL CONDITION]

Current diagnosis of acute kidney injury (AKI) is one of the most pressing problems in the newborn in critical condition.

OBJECTIVE

To determine the diagnostic value of indicators of renal blood flow as a marker of acute kidney injury in critically ill newborns.

MATERIALS AND METHODS

The study included 40 infants in critical condition. A clinical assessment of severity of the condition during admission was carried out with Neonatal Multiple Organ Dysfunction Score (NEOMOD) and Neonatal Therapeutic Intervention Scoring System (NTISS). All patients underwent evaluation of clinical and instrumental parameters, including ultrasound of the renal vessels, renal vascular resistance index and speed performance.

CONCLUSIONS

1) biochemical markers used in routine clinical practice were not sufficiently informative for the diagnosis of AKI. 2) For a more accurate assessment of the risk of AKI using serum creatinine, GFR calculation and evaluation on a scale RIFLE it is should be focused on performance standards, appropriate for gestational age and birth weight. 3) Evaluation of blood flow at a particular index in the resistance of the main renal arteries had the greatest predictive value and had a relatively high sensitivity and specificity for the diagnosis of AKI.

Specific role of nitric oxide (NO) in avian embryonic myogenesis

NO plays a specific role in avian embryogenesis stimulating the development of muscle tissue. The main consumer of NO synthesized at the initial stage of avian embryogenesis is presumably a factor stimulating myogenesis.

Possible mechanism of generation of nitrite and non-thiolate nitroso compounds in blood plasma during inflammatory processes

Generation of nitrite (NO2¯) and non-thiolate nitroso compounds in human blood during leukocyte activation mainly occurred due to destruction of NO donors in the plasma, but not due to intensification of NO synthesis. We proposed a mechanism of production of nitrite and non-thiolate nitroso compounds in the blood during inflammation.

[Critical conditions as a logical and appropriate series of events in iron methabolism disorders (the summary of experimental studies)]

It is revealed that in all models of critical conditions will activate the free-radical oxidation, decreasing the total antioxidant activity, the concentration of transferrin decreases in the serum of the blood, increase of the concentration of ferritin, the theological properties of the blood are violated and the signs of endothelial dysfunction are identified. Pre-entered deferoxamine in the dose of 80 mg/kg reduced the intensity of free-radical oxidation processes, restoring the antioxidant potential, concentration of the transferrin, and a lower level of ferritin, contributed to the normalization of blood theological properties and a reduction of the extent endothelium destruction as a result of the reduction Fe2+ concentration in blood serum.

TrkC signaling is activated in adenoid cystic carcinoma and requires NT-3 to stimulate invasive behavior

Treatment options for adenoid cystic carcinoma (ACC) of the salivary gland, a slowly growing tumor with propensity for neuroinvasion and late recurrence, are limited to surgery and radiotherapy. Based on expression analysis performed on clinical specimens of salivary cancers, we identified in ACC expression of the neurotrophin-3 receptor TrkC/NTRK3, neural crest marker SOX10, and other neurologic genes. Here, we characterize TrkC as a novel ACC marker, which was highly expressed in 17 out of 18 ACC primary-tumor specimens, but not in mucoepidermoid salivary carcinomas or head and neck squamous cell carcinoma. Expression of the TrkC ligand NT-3 and Tyr-phosphorylation of TrkC detected in our study suggested the existence of an autocrine signaling loop in ACC with potential therapeutic significance. NT-3 stimulation of U2OS cells with ectopic TrkC expression triggered TrkC phosphorylation and resulted in Ras, Erk 1/2 and Akt activation, as well as VEGFR1 phosphorylation. Without NT-3, TrkC remained unphosphorylated, stimulated accumulation of phospho-p53 and had opposite effects on p-Akt and p-Erk 1/2. NT-3 promoted motility, migration, invasion, soft-agar colony growth and cytoskeleton restructuring in TrkC-expressing U2OS cells. Immunohistochemical analysis demonstrated that TrkC-positive ACC specimens also show high expression of Bcl2, a Trk target regulated via Erk 1/2, in agreement with activation of the TrkC pathway in real tumors. In normal salivary gland tissue, both TrkC and Bcl2 were expressed in myoepithelial cells, suggesting a principal role for this cell lineage in the ACC origin and progression. Sub-micromolar concentrations of a novel potent Trk inhibitor AZD7451 completely blocked TrkC activation and associated tumorigenic behaviors. Pre-clinical studies on ACC tumors engrafted in mice showed efficacy and low toxicity of AZD7451, validating our in vitro data and stimulating more research into its clinical application. In summary, we describe in ACC a previously unrecognized pro-survival neurotrophin signaling pathway and link it with cancer progression.

[The early diagnostic of somatic inflammatory diseases in patients with acute ischemic stroke]

We examined 29 patients with acute ischemic stroke. Measurement of plasma nitrite and N-nitroso-compounds (NO₂- +RNNO) to test for the presence of acute inflammatory process allows to timely and definitely determine its onset before the development of clinical symptoms and to operatively control the treatment, the latter being particularly important due to the restricted communication ability of neurologic patients.

[The content of nitrite and N-nitroso compounds of plasma as a diagnostic test of nonspecific inflammation]

The authors' enzymatic sensor was applied to identify the content of nitrite and nitroso compounds of blood plasma in normal condition and under various inflammatory diseases. It is established that in normal conditions blood plasma contains nitrite, N-nitroso compounds (RNNO) and S-nitroso compounds (RSNO) in concentrations less than 100 nm. The plasma pool of nitroso compounds includes basically thiolferous nitrosate ferrum complex in concentration 3-20 microm. The concentration of nitrite in plasma is from 10 to 150 microm. The concentration (nitrite+RNNO) increases dramatically under inflammatory diseases. This indicator was 0.3-1.0 microm in examined patients with acute and chronic pancreatitis, cholecystitis, ENT diseases of inflammatory character and ARD. In the case of acute appendicitis the indicator reached 10 micro. In case of successful treatment the content (nitrite+RNNO) decreased to the concentration lower than 100 nm. The content of other nitrite and N-nitroso compounds had no reliable variations. Because of this, largely implemented evaluation of intensity of nitric oxide production by the aggregate indicator of nitrites content (NO(x)) in blood seems ambiguous. The reason is that in normal conditions nitrite is presented in trace amount and considerable quantity of nitrate can enter the organism in an exogenous way. Besides that the content of nitrite can depend on kidneys filterability. At the same time, based on the obtained data, the content (nitrite+RNNO) in plasma in concentrations higher than 150 nm are definitely to be considered as pathology.

[Pandemic influenza 2009 in Russia. Characteristics of the isolation and biological properties of viruses]

Research Institute of Influenza, Ministry of Health and Social Development of Russia, Saint Petersburg The characteristics of the isolation of pandemic influenza A(H1N1)v viruses were studied on chick embryos (CE) and MDCK cell culture. The materials (nasal swabs and autopsies) were collected in different regions Russia in the period from 20 July to 30 December 2009. The paper gives the data of the antigenic analysis of isolates, their capacity to multiply in different species-specific and tissue cell cultures. The viruses isolated on CE were shown to have higher hemagglutination titers and to be more stable. Isolation from the autopsies was effective only on CE. All the test cell lines other than MDCK were insensitive to the isolated pandemic influenza strains. The antigenic analysis showed no significant antigenic drift of the viruses isolated during the first wave of the pandemic in the Russian Federation.

[Functional state of rat brain mitochondria at hypoglycemia convulsive syndrome and different ways of its arresting]

Respiratory and phosphorylation functions of rat brain mitochondria was studied under conditions insulin shock and after its treatment with glucose or glutamate (in combination with inhalation of hypercapnic gas mixture--air enriched with 7% CO2). Certain differences in the effects of the applied agents were found. Phosphorylation ability of mitochondria did not reach the normal level even one day after both ways of convulsive state treatment. Some respiratory parameters suggest that unfavorable changes in the respiratory chain functioning mainly occur at the respiratory chain complex I.

Characterization of glycoprotein E C-end of West Nile virus and evaluation of its interaction force with alphaVbeta3 integrin as putative cellular receptor

Recombinant polypeptide containing the 260-466 amino acid sequence of West Nile virus (WNV) strain LEIV-Vlg99-27889-human glycoprotein E (gpE, E(260-466)) was constructed. Immunochemical similarity between the E(260-466) and gpE of WNV was proven by enzyme immunoassay (EIA), immunoblot, competitive EIA, hemagglutination inhibition, and neutralization tests using polyclonal and monoclonal antibodies against the viral gpE and recombinant E(260-466). Polypeptide E(260-466) induced formation of virus neutralizing and cross-reactive antibodies that were interactive with various epitopes of this recombinant protein. It is shown by evaluation of the interaction of E(260-466) with one of the proposed cell receptors of WNV that average E(260-466)-alphaVbeta3 integrin-specific interaction force measured using atomic force spectroscopy was 80 and 140 pN for single and double interactions, correspondingly. Taken together with previously described interaction between laminin-binding protein (LBP) and WNV gpE domain II, it is proposed that WNV gpE can interact specifically with two cellular proteins (LBP and alphaVbeta3 integrin) during virus entry.

[Etiological characteristics of the influenza epidemics of 2006-2009 in the Russian Federation (according to the data of the Research Institute of Influenza, North-Western Branch, Russian Academy of Medical Sciences)]

The basic trends in the evolution of influenza A and B in the Russian Federation during the epidemic seasons of 2006-2009 were studied on the basis of an antigenic analysis of 1774 Influenza isolated at the Research Institute of Influenza (RII), North-Western Branch, Russian Academy of Medical Sciences, and sent from resting bases (the regional centers of the Russian Inspectorate for the Protection of Consumer Rights and Human Welfare, which collaborate with the RII). Although the trends in the substitution of representative strains generally coincide with the world patterns, the authors revealed some specific features of the antigenic drift of influenza viruses in the Russian Federation and regional varieties. Data on some biological properties and those of the antigenic analysis of the first pandemic influenza A(H1NI)v strains isolated at the RII from Saint Petersburg patients in July-August 2009 are also given in the paper.

Loss of PL6 protein expression in renal clear cell carcinomas and other VHL-deficient tumours

Mutations in the von Hippel-Lindau tumour suppressor gene (VHL) cause the VHL hereditary cancer syndrome and occur in most sporadic clear cell renal cell cancers (CC-RCCs). The mechanisms by which VHL loss of function promotes tumour development in the kidney are not fully elucidated. Here, we analyse expression of PL6, one of the potential tumour suppressor genes from the critical 3p21.3 region involved in multiple common cancers. We classify PL6 as a Golgi-resident protein based on its perinuclear co-localization with GPP130 in all cells and tissues analysed. We show that PL6 RNA and protein expression is completely or partially lost in all analysed CC-RCCs and other VHL-deficient tumours studied, including the early precancerous lesions in VHL disease. The restoration of VHL function in vitro in the VHL-deficient CC-RCC cell lines was found to reinstate PL6 expression, thus establishing a direct link between VHL and PL6. Insensitivity of PL6 to hypoxia suggested that PL6 is regulated by VHL via a HIF-1-independent pathway. We ruled out mutations and promoter methylation as possible causes of PL6 down-regulation in CC-RCC. We hypothesize that loss of a putative PL6 secretory function due to VHL deficiency is an early and important event that may promote tumour initiation and growth.

Autoimmunity, spontaneous tumourigenesis, and IL-15 insufficiency in mice with a targeted disruption of the tumour suppressor gene Fus1

The Fus1 gene resides in the critical 3p21.3 human chromosomal region deleted in lung and breast cancers. Recently, the tumour suppressor properties of Fus1 were confirmed experimentally by intra-tumoural administration of Fus1 that suppressed experimental lung metastasis in mice. We generated Fus1-deficient mice that were viable, fertile, and demonstrated a complex immunological phenotype. Animals with a disrupted Fus1 gene developed signs of autoimmune disease, such as vasculitis, glomerulonephritis, anaemia, circulating autoantibodies, and showed an increased frequency of spontaneous vascular tumours. Preliminary analysis of immune cell populations revealed a consistent defect in NK cell maturation in Fus1 null mice that correlated with changes in the expression of IL-15. Injection of IL-15 into Fus1 knockout mice completely rescued the NK cell maturation defect. Based on these results, we propose the hypothesis that Fus1 deficiency affects NK cell maturation through the reduction of IL-15 production but does not directly alter their developmental capacity. Since acquired immunity was not affected in Fus1-deficient animals, we suggest a relationship between the Fus1 protein and the regulation of innate immunity via IL-15 production. The increased frequency of spontaneous cancers and the development of an autoimmune syndrome in Fus1 null mice imply that these mice could serve as a model for studying molecular mechanisms of anti-tumour immunity and autoimmunity.