To identify genetic mutations a rather time-consuming and expensive method of polymerase chain reaction (PCR) is widely used. The aim of the present work was to evaluate the possibility of using the two schemes of the method of allele-specific isothermal loop amplification (LAMP) to detect the TCG/TTG (S450L) mutation in the rpoB gene of Mycobacterium tuberculosis. 48 clinical isolates of M. tuberculosis and 11 samples of sputum were used, randomized and obtained in the microbiological laboratory of the city of Novosibirsk from incident patients. It is shown that the use of an analysis scheme using the allele-specific primer FIP compared to F3 has the best resolution: the difference between the amplification time of the mutation and the wild type allele was 22 ± 2,4 versus 13 ± 4,1 minutes (p = 0,0011). When using 100 DNA genomic equivalents a true positive signal (amplification of the rpoB gene with a mutation using the corresponding allele-specific primer) was detected after 29,4 ± 3,4 minutes. A positive signal was visualized after adding SYBR Green I to the reaction, both when illuminated with daylight and when using a UV transilluminator. Using the developed method the DNA sample of 20 RIFR isolates from M. tuberculosis was analyzed containing the Ser450Leu mutation in the rpoB gene, 10 RIFR isolates containing other mutations in the rpoB gene and 18 RIFs isolates without any mutations; the presence of mutations in the samples was determined using classical Sanger sequencing. The sensitivity and specificity of LAMP for detecting a Ser450Leu mutation in the rpoB gene was 100%. This approach allows the use of crude lysates of mycobacteria as DNA, which reduces the total analysis time to 1,5 hour.
VIEWS 4976
Essential hypertension (EH) is one of the most common modifiable risk factors for cardiovascular diseases and death. The aim of this study was to investigate a correlation between the levels of some cytokines (interleukins, adhesion molecules, tumor necrosis and growth factors, etc.) in the peripheral blood of patients with stage II EH and the rate of complications (myocardial infarction, acute cerebrovascular events, and transient ischemic attacks) occurring in a 5-year follow-up period. Twenty-eight cytokines were measured using ELISA, including IL1β, IL1α, IL1ra, IL18, IL18BP, IL37, IL6, sIL6r, LIF, sLIFr, IGF-1, IGFBP-1, TNFα, sTNF-RI, sVCAM-1, IL17, IL2, IL4, IL10, TGF-β1, IL8, CX3CL1, CXCL10, INFγ, M-CSF, IL34, VEGF-A, and erythropoietin, and a few vasoactive peptides, including NО, iNOS, eNOS, ADMA, SDMA, Nt-proСNP, and Nt-proBNP, in the peripheral blood samples of 200 patients with stage II EH who had been suffering from this condition for 10 to 14 years and were receiving comparable therapies to bring their blood pressure down. The patients were followed up for 5 years to keep track of complications. The retrospective analysis revealed that the group of patients who developed complications during the 5-year follow-up period exhibited a decline in the levels of IL1ra (р < 0.001) and IL10 (р < 0.001) and a rise in IL1β (р < 0.001), TNFα (р < 0.001) and M-CSF (р < 0.001) in comparison with the group of those who did not develop any complications. The multivariate Cox regression analysis was applied to the following parameters: IL1β > 18.8 pg/ml; IL1ra < 511 pg/ml; IL6 > 23.8 pg/ml; IL10 < 26.3 pg/ml; 389 pg/ml < M-CSF < 453 pg/ml; ADMA > 0.86 μmol/L; total cholesterol > 4.9 mmol/L; LDL> 3.0 mmol/L; HDL in men < 1.0 mmol/L; HDL in women < 1.2 mmol/L. The analysis revealed that M-CSF in the range from 389 to 453 pg/ml (р < 0.001) and LDL above 3.0 mmol/L (р < 0.01) correlated with an increase in the risk for end-organ damage in stage II EH. Changes in the cytokine levels can be regarded as a predictor of myocardial and cerebral damage in patients with stage II EH. Measurement of peripheral blood M-CSF can be included into the classic risk assessment schemes for the cardiovascular complications in the studied cohort of patients.
VIEWS 4801
Ebola virus disease (EVD) is one of the deadliest viral infections affecting humans and nonhuman primates. Of 6 known representatives of the Ebolavirus genus responsible for the disease, 3 can infect humans, causing acute highly contagious fever characterized by up to 90% fatality. These include Bundibugyo ebolavirus (BDBV), Zaire ebolavirus (ZEBOV) and Sudan ebolavirus (SUDV). The majority of the reported EVD cases are caused by ZEBOV. Vaccine development against the virus started in 1976, immediately after the causative agent of the infection was identified. So far, 4 vaccines have been approved. All of them are based on the protective epitope of the ZEBOV glycoprotein GP. Because SUDV and BDBV can also cause outbreaks and epidemics, it is vital to design a vaccine capable of conferring protection against all known ebolaviruses posing a threat to the human population. This article presents systematized data on the structure, immunogenicity and protective properties of ebolavirus glycoprotein GP, looks closely at the immunodominant epitopes of ZEBOV, SUDV and BDBV glycoprotein GP required to elicit a protective immune response, and offers a rational perspective on the development of a universal vaccine against EVD that relies on the use of vectors expressing two variants of GP represented by ZEBOV and SUDV.
VIEWS 5041
Type I hypersensitivity is mediated by the production of IgE antibodies in response to normally harmless substances. Debate still continues about the mechanisms underlying allergic reactions. Reduced barrier tissue function can be one of the risk factors for allergies. The aim of the present work was to compare the humoral immune response to Epstein-Barr virus in patients allergic to the A. alternata fungus or D. farinae house dust mites and healthy donors. It is known that up to 90% of the world population are infected with EBV. This infection occurs at early age when a child develops allergy. The antibodies were analyzed using immuno-PCR and the recombinant EBV protein rEBNA. We were able to demonstrate that infection occurs at early age in both allergic patients and healthy donors. The proportion of EBP-seropositive individuals was comparable between the groups (75% and 74%). The proportion of patients with high IgG1 titers among patients with allergies was lower (7%) than in healthy donors (18%), suggesting a lower viral load. In patients with allergies (but not in healthy donors) IgG1 titers declined as children grew older (р = 0.037). Besides, IgA1 titers were increased in patients with allergies in comparison with healthy donors, but differed between patients allergic to A. alternata and house dust mites. In allergic individuals, production of IgM against EBV was triggered earlier than in healthy donors. We conclude that IgM production and the IgA1-mediated humoral response occur earlier in patients with allergies, causing a decline in IgG1 titers over time.
VIEWS 4851
Injuries to the heart are uncommon in peacetime, yet they result in life-threatening conditions, which makes timely diagnostics a crucial factor in saving patients' lives. In this connection, it is important to define the main signs of heart injuries. This study aimed to analyze the basic clinical symptoms associated with various wounds to the heart. We have retrospectively analyzed such symptoms registered in 86 patients with varying chest injuries that affect the heart. All patients were treated in the emergency surgery unit of the Engels Town Hospital from 1991 to 2017. 41 (47.6%) patient had stab wounds, and there were 45 (52.3%) cases of gunshot wounds. 23 (26.7%) patients had chest injuries affecting heart exclusively, while for 63 (73.2%) the consequences were wounds to other organs. We found that the clinical picture depends on the kind of injury to the heart: stab and slash wounds translate into more pronounced symptoms, while gunshot wounds do not produce such an effect. Accepting patients, practitioners should take this fact into account. The misdiagnosis rate for stab and slash heart wounds is 9.7%, that for gunshot wounds — 17.7%, the latter being the result of vagueness of the clinical picture. The clinical signs are most pronounced in the cases of stab and slash wounds to the heart.
VIEWS 4660
Selection of antibodies using phage display involves the preliminary cloning of the repertoire of sequences encoding antigen-binding domains into phagemid, which is considered the bottleneck of the method, limiting the resulting diversity of libraries and leading to the loss of poorly represented variants before the start of the selection procedure. Selection in cell-free conditions using a ribosomal display is devoid from this drawback, however is highly sensitive to PCR artifacts and the RNase contamination. The aim of the study was to test the efficiency of a combination of both methods, including pre-selection in a cell-free system to enrich the source library, followed by cloning and final selection using phage display. This approach may eliminate the shortcomings of each method and increase the efficiency of selection. For selection, alpaca VHH antibody sequences suitable for building an immune library were used due to the lack of VL domains. Analysis of immune libraries from the genes of the VH3, VHH3 and VH4 families showed that the VHH antibodies share in the VH3 and VH4 gene groups is insignificant, and selection from the combined library is less effective than from the VHH3 family of sequences. We found that the combination of ribosomal and phage displays leads to a higher enrichment of high-affinity fragments and avoids the loss of the original diversity during cloning. The combined method allowed us to obtain a greater number of different high-affinity sequences, and all the tested VHH fragments were able to specifically recognize the target, including the total protein extracts of cell cultures.
VIEWS 5047
The diagnosis and treatment of patients with angiographically normal or near normal coronary arteries remains a clinically relevant problem. The aim of this study was to assess diastolic function in patients with chest pain and normal/near normal coronary arteries (NECA) using ECG-gated SPECT/CT. The study recruited 49 patients presenting with chest pain, a positive cardiac stress test and normal coronary arteries, as demonstrated by coronary angiography. All patients were ordered a myocardial SPECT/CT scan, which was performed according to a two-day protocol. After the scan, the patients were divided into 3 groups. Group 1 consisted of 17 patients with microvascular angina. Group 2 was composed of 22 patients with borderline-high blood pressure or stage I hypertensive heart disease associated with secondary microvascular dysfunction. Ten seemingly healthy individuals constituted the control group. According to coronary angiography, the controls had no cardiovascular pathologies accompanied by coronary artery disorders or impaired myocardial perfusion (SPECT). The majority of patients from groups 1 and 2 were found to have impaired diastolic function. The impairments were more pronounced in group 2 tended to exacerbate with stress. The most sensitive parameter of diastolic function, MFR/3, was outside the reference range in almost all patients in groups 1 and 2. MFR/3 characterizes the mean filling rate of the left ventricle in the first third of diastole. The control group showed no symptoms of diastolic dysfunction. Thus, the patients with chest pain, a positive stress test and NECA had signs of left ventricular diastolic dysfunction exacerbated with stress. Such patients are at risk for heart failure with preserved ejection fraction.
VIEWS 4482