Tubulin bond energies and microtubule biomechanics determined from nanoindentation in silico

Microtubules, the primary components of the chromosome segregation machinery, are stabilized by longitudinal and lateral non-covalent bonds between the tubulin subunits. However, the thermodynamics of these bonds and the microtubule physico-chemical properties are poorly understood. Here, we explore the biomechanics of microtubule polymers using multiscale computational modeling and nanoindentations in silico of a contiguous microtubule fragment. A close match between the simulated and experimental force-deformation spectra enabled us to correlate the microtubule biomechanics with dynamic structural transitions at the nanoscale. Our mechanical testing revealed that the compressed MT behaves as a system of rigid elements interconnected through a network of lateral and longitudinal elastic bonds. The initial regime of continuous elastic deformation of the microtubule is followed by the transition regime, during which the microtubule lattice undergoes discrete structural changes, which include first the reversible dissociation of lateral bonds followed by irreversible dissociation of the longitudinal bonds. We have determined the free energies of dissociation of the lateral (6.9+/-0.4 kcal/mol) and longitudinal (14.9+/-1.5 kcal/mol) tubulin-tubulin bonds. These values in conjunction with the large flexural rigidity of tubulin protofilaments obtained (18,000-26,000 pN*nm^2), support the idea that the disassembling microtubule is capable of generating a large mechanical force to move chromosomes during cell division. Our computational modeling offers a comprehensive quantitative platform to link molecular tubulin characteristics with the physiological behavior of microtubules. The developed in silico nanoindentation method provides a powerful tool for the exploration of biomechanical properties of other cytoskeletal and multiprotein assemblie

Antibiotic sensitivity analysis of clinical coagulase-negative staphylococci

Background. The increasing role of coagulase-negative staphylococci in the occurrence of staphylococcal infections leads to the need for close attention to them. Special control is required over the sensitivity of bacteria to antibiotics and the spread of methicillin resistance, as a sign of multiple resistance to antibacterial drugs. It is also important to identify the virulence factors of coagulase-negative staphylococci, which determine their behavior in the environment.The aim. To evaluate the sensitivity of strains of coagulase-negative staphylococci to clinically significant antibiotics daptomycin, vancomycin, linezolid and oxacillin and lantibiotic warnerin.Methods. Determination of the minimal inhibitory concentrations of antibacterial compounds for clinical coagulase-negative staphylococci by standard methods of serial dilutions and disc diffusion. Identification of the phenomenon of decreased susceptibility of bacteria to vancomycin by population analysis and concentration gradient. Lipid analysis by thin layer chromatography. Results. High antibacterial activity of vancomycin, daptomycin and linezolid against clinical strains of coagulase-negative staphylococci was shown. The upper limit of the minimum inhibitory concentrations of vancomycin within the sensitive phenotype and the expansion of the ranges of the minimum inhibitory concentrations of daptomycin and warnerin towards an increase in oxacillin-resistant isolates were revealed. The heterogeneous nature of sensitivity to vancomycin of the cultures of the studied strains and the possibility of their rapid enrichment with subpopulations with reduced sensitivity to this antibiotic have been established. The selection of resistance of coagulase-negative staphylococci to vancomycin was accompanied by an increase in the synthesis of lysylphosphatidylglycerol and a decrease in their sensitivity to cationic peptide compounds.Conclusion. The revealed prevalence of the methicillin-resistant phenotype of clinical strains of coagulase-negative staphylococci, along with the presence in the lipid spectrum of the universal factor of resistance to cationic antibacterial compounds, lysylphosphatidylglycerol, entails the need for new methodological solutions for diagnosing infections caused by coagulase-negative staphylococci

The Incidence of Cervical Disease in Women of Different Age Groups in the Republic of Sakha (Yakutia)

The purpose of this study was to investigate the incidence of cervical disease in women of different age groups in the Republic of Sakha (Yakutia). Materials and Methods: The cytological material of the cervix of 7,600 women aged between 18 and 88 years was analyzed in the laboratory of pathomorphology, histology and cytology. The material of the cytological study consisted of smears of cervical mucosa and the cervical canal, stained according to the method of Romanovsky-Giemsa. The study was conducted with subjects grouped according to age: Group 1 (18-29), Group 2 (30-44), Group 3 (45-59), and Group 4 (60-74). Results: According to the results of cytological analysis, inflammatory diseases of the cervix uteri were diagnosed in 4,629/61% cases. Among age groups, the highest rate of inflammatory diseases of the cervix uteri was registered in Group 1 and Group 2. Benign cervical lesions were found in 563/7.4% cases with the highest incidence in Groups 1 and 2. The most frequently diagnosed pathology was squamous cell metaplasia with maximum frequency in Group 2 and Group 1. Cervical intraepithelial neoplasia (or dysplasia) (CIN) was detected in 359/4.7% cases. CIN I, CIN II and CIN III were registered in 220/61.3%, 84/24.5%, and 38/10.6% women, respectively. At the same time, the maximum frequency of dysplasia was noted in Group 1 and Group 2. Thus, results obtained indicate a high incidence of cervical disease in women of reproductive age

ВЛИЯНИЕ РАЗЛИЧНЫХ ТЕХНОЛОГИЙ СОДЕРЖАНИЯ НА ФИЗИЧЕСКОЕ И ФИЗИОЛОГИЧЕСКОЕ РАЗВИТИЕ РЕМОНТНЫХ СВИНОК

The paper find out the regularities of physical and physiological development of the replacement young pigs, bred at different housing technologies. The experiment was conducted in OOO “SVK” Krasnogvardeyskiy district (industrial technology) and “SHP Svobodny trud” (traditional technology) of Novoselytsya districts of Stavropol Territory. In order to conduct the experiment on the basis of analogues, the Company selected bipedal pigs (50% large white (CB) + 50% Landrace (L)) aged one month. Each group had 25 pigs. In order to study the development of reproductive organs at the age of 6 and 8 months, a control slaughter of experimental animals was carried out (3 pigs from each group). The live body weight of 6-month-old pigs in OOO “SVK” averaged 110 kg, while in OOO “SHP “Svobodnyy trud” the animals weight was 67-70 kg. At the age of 8 months, the weight of animals in “SHP “Svobodnyy trud” was 103-110 kg, and in OOO “SVK” - 145-150 kg. At the age of 180 days the animal reproductive organs were at the initial stage of development. Only primary follicles of 0.1-0.3 cm in diameter were observed in ovaries weighing 3.1-3.5 g. The bipedal hybrids grown on the intensive technology were inferior to the pigs with the traditional technology of breeding for the development of reproductive organs. They had a lower uterine weight by 9.1%, ovarian weight by 12.9%, and the length of uterine and ovarian horns by 10.9 and 8.6%, respectively. Repair pigs grown according to the traditional technology had ovaries weighing 9.2 g and had fresh yellow bodies. When growing guinea pigs under industrial technology, the rejection of first-pigs amounted to 63.6%, while in the case of animals grown under traditional technology, this indicator was within 26.6%.Целью работы являлось установление закономерностей физического и физиологического развития ремонтного молодняка свиней, выращиваемых при различных технологиях содержания. Опыт проводился в ООО «СВК» Красногвардейского (промышленная технология) и ООО «СХП “Свободный труд”» (традиционная технология) Новоселицкого районов Ставропольского края. Для проведения опыта по принципу аналогов отобрали двухпородных свинок (50% крупная белая (КБ) +50% ландрас (Л)) в возрасте одного месяца. В каждой группе было по 25 свинок. С целью изучения развития репродуктивных органов в возрасте 6 и 8 месяцев провели контрольный убой подопытных животных (по 3 головы из каждой группы). Живая масса 6-месячных свинок в ООО «СВК» составила в среднем 110 кг, в то время как в ООО «СХП “Свободный труд”» масса животных равнялась 67– 70 кг. В 8-месячном возрасте масса животных в ООО «СХП “Свободный труд”» составила 103–110, а в ООО «СВК» – 145-150 кг. В возрасте 180 дней репродуктивные органы животных находятся на начальной стадии развития. В яичниках массой 3,1–3,5 г наблюдались только первичные фолликулы диаметром 0,1–0,3 см. Двухпородные гибриды, выращенные по интенсивной технологии, уступали свинкам с традиционной технологией выращивания по развитию органов репродукции. Масса матки у них была меньше на 9,1%, масса яичников – на 12,9, а длина рогов матки и яйцеводов меньше соответственно на 10,9 и 8,6%. У ремонтных свинок, выращенных по традиционной технологии, масса яичников составляла 9,2 г и в них имелись свежие желтые тела. При выращивании ремонтных свинок при промышленной технологии выбраковка свиноматок-первоопоросок составила 63,6%, в то время как у животных, выращенных по традиционной технологии, этот показатель был в пределах 26,6%

Дифференциация и субпопуляционный состав VEGFR2+ моноцитов крови и костного мозга при ишемической кардиомиопатии

Aim. To identify disturbances of differentiation and subpopulation composition of VEGFR2+ cells in the blood and bone marrow associated with the features of the cytokine profile in the blood and bone marrow in patients with coronary artery disease (CAD) with and without ischemic cardiomyopathy (ICM).Materials and methods. The study included 74 patients with СAD with and without ICM (30 and 44 people, respectively) and 18 healthy donors. In all patients with СAD, peripheral blood sampling was performed immediately before coronary artery bypass grafting, and bone marrow samples were taken during the surgery via a sternal incision. In the healthy donors, only peripheral blood sampling was performed. In the bone marrow and blood samples, the number of VEGFR2+ cells (CD14+VEGFR2+ cells) and their immunophenotypes CD14++CD16-VEGFR2+, CD14++CD16+VEGFR2+, CD14+CD16++VEGFR2+, and CD14+CD16-VEGFR2+ was determined by flow cytometry. Using enzyme-linked immunosorbent assay, the levels of VЕGF-А, TNFα, M-CSF, and IL-13, as well as the content of MCP-1 (only in the blood) and the M-CSF / IL-13 ratio (only in the bone marrow) were determined.Results. The content of CD14+VEGFR2+ cells in the blood of CAD patients with and without ICM was higher than normal values due to the greater number of CD14++CD16-VEGFR2+, CD14++CD16+VEGFR2+, and CD14+CD16++VEGFR2+. In the bone marrow of the patients with ICM, the content of CD14++CD16-VEGFR2+, CD14+CD16++VEGFR2+, and CD14+CD16-VEGFR2+ was lower than in patients with CAD without ICM, and the number of CD14++CD16+VEGFR2+ cells corresponded to that in the controls. Regardless of the presence of ICM in CAD, a high concentration of TNFα and normal levels of VEGF-A and IL-13 were observed in the blood. In CAD without ICM, an excess of MCP-1 and deficiency of M-CSF were revealed in the blood. In the bone marrow, the levels of VEGF-A, TNFα, M-CSF, and IL-13 were comparable between the groups of patients against the background of a decrease in the M-CSF / IL-13 ratio in the patients with ICM.Conclusion. Unlike CAD without cardiomyopathy, in ICM, no excess of VEGFR2+ cells and MCP-1 in the blood is observed, which hinders active migration of CD14+CD16++VEGFR2+ cells from the myeloid tissue, and a decrease in the M-CSF / IL-13 ratio in the bone marrow disrupts differentiation of other forms of VEGFR2+ cells, preventing vascular repair.Цель: установить нарушения дифференцировки и субпопуляционного состава VEGFR2+ моноцитов в крови и костном мозге во взаимосвязи с особенностями цитокинового профиля крови и костного мозга у больных ишемической болезнью сердца (ИБС), страдающих и не страдающих ишемической кардиомиопатией (ИКМП).Материалы и методы. В исследование вошли 74 больных ИБС, страдающих и не страдающих ИКМП (30 и 44 человека соответственно), и 18 здоровых доноров. У всех больных ИБС забор периферической крови производился непосредственно перед операцией коронарного шунтирования, а костного мозга – из разреза грудины во время операции. У здоровых доноров забирали только периферическую кровь.  В костном мозге и крови методом проточной цитофлуориметрии определяли численность VEGFR2+ моноцитов (CD14+VЕGFR2+ клеток) и их иммунофенотипов CD14++CD16-VEGFR2+, CD14++CD16+VEGFR2+, CD14+CD16++VEGFR2+, CD14+CD16-VEGFR2+, методом иммуноферментного анализа регистрировали концентрацию VЕGF-А, TNFα, M-CSF, IL-13, а также содержание MCP-1 (только в крови) и соотношение M-CSF/IL-13 (только в костном мозге).Результаты. Содержание CD14+VEGFR2+ клеток в крови у больных ИБС без кардиомиопатии и с ИКМП было выше нормы из-за большей численности CD14++CD16-VEGFR2+, CD14++CD16+VEGFR2+ и CD14+CD16++VEGFR2+ форм. В костном мозге у больных ИКМП содержание CD14++CD16-VEGFR2+, CD14+CD16++VEGFR2+ и CD14+CD16-VEGFR2+ форм было ниже, чем у больных ИБС без кардиомиопатии, а количество CD14++CD16+VEGFR2+ клеток соответствовало их числу в группе сравнения. Вне зависимости от наличия ИКМП при ИБС в крови отмечалась высокая концентрация TNFα, нормальный уровень VEGF-А и IL-13; при ИБС без кардиомиопатии – избыток МСР-1 и дефицит M-CSF в крови. В костном мозге концентрация VЕGF-А, TNFα, M-CSF, IL-13 была сопоставимой между группами больных на фоне снижения M-CSF/IL-13 у пациентов с ИКМП.Заключение. В отличие от ИБС без кардиомиопатии при ИКМП не формируется избыток VEGFR2+ моноцитов и МСР-1 в крови, что затрудняет активную миграцию CD14+CD16++VEGFR2+ клеток из миелоидной ткани, а снижение M-CSF/IL-13 в костном мозге нарушает дифференцировку остальных форм VEGFR2+ моноцитов, препятствуя репарации сосудов

Detection of tick-borne pathogens in wild birds and their ticks in Western Siberia and high level of their mismatch

Abstract: The Tomsk region located in the south of Western Siberia is one of the most high-risk areas for tick-borne diseases due to elevated incidence of tick-borne encephalitis and Lyme disease in humans. Wild birds may be considered as one of the reservoirs for tick-borne pathogens and hosts for infected ticks. A high mobility of wild birds leads to unpredictable possibilities for the dissemination of tick-borne pathogens into new geographical regions. The primary goal of this study was to evaluate the prevalence of tick-borne pathogens in wild birds and ticks that feed on them as well as to determine the role of different species of birds in maintaining the tickborne infectious foci. We analysed the samples of 443 wild birds (60 species) and 378 ticks belonging to the genus Ixodes Latraille, 1795 collected from the wild birds, for detecting occurrence of eight tick-borne pathogens, the namely tick-borne encephalitis virus (TBEV), West Nile virus (WNV), and species of Borrelia, Rickettsia, Ehrlichia, Anaplasma, Bartonella and Babesia Starcovici, 1893, using RT-PCR/or PCR and enzyme immunoassay. One or more tick-borne infection markers were detected in 43 species of birds. All markers were detected in samples collected from fieldfare Turdus pilaris Linnaeus, Blyth’s reed warbler Acrocephalus dumetorum Blyth, common redstart Phoenicurus phoenicurus (Linnaeus), and common chaffinch Fringilla coelebs Linnaeus. Although all pathogens have been identified in birds and ticks, we found that in the majority of cases (75.5%), there were mismatches of pathogens in birds and ticks collected from them. Wild birds and their ticks may play an extremely important role in the dissemination of tick-borne pathogens into different geographical regions

European registry on the management of helicobacter pylori infection (HP-EUREG protocol): The first results of Russian centers

Aim: To assess the clinical practice of diagnosis and treatment in patients with Helicobacter pylori infection and to compare this practice with the international guidelines in the European Registry on the management of Helicobacter pylori infection, Hp-EuReg protocol), a multicenter prospective observational study initiated by the European Helicobacter and Microbiota Study Group. Materials and methods: The data of 813 patients infected with H. pylori and entered in the Hp-EuReg register by the Russian centers in 2013-2015 were analyzed. Results: The most common methods for the primary diagnosis of H. pylori infection are histology (40.3%), rapid urease test (35.7%), and serology (17.2%). The duration of H. pylori eradication therapy was 7, 10, and 14 days in 18.0, 49.3, and 25.1%, respectively. To monitor the effectiveness of treatment, the investigators used a histological examination (34%), a urea breath test (27.3%), H. pylori stool antigen (22.8%), and a rapid urease test (16.3%). A serological test was carried out in 2.5% of the cases. No monitoring was done in 13.5% of the patients. The average eradication efficiency was 82.6%. If the therapy was ineffective, 80% of physicians did not intend to prescribe a new cycle of treatment. Conclusion: Significant differences were found between clinical practice and the current guidelines

Глюкокортикоидиндуцированный остеопороз у неврологических больных: мероприятия по профилактике и лечению

Glucocorticoids (GCs) are often prescribed for neurologic patients. Autoimmune diseases of central and peripheral nervous system, neuromuscular disorders are associated with disability and life-threatening complications, and require long-term high-dosage administration of GCs. GC-therapy is a crucial decision to be made by a neurologist in collaboration with a patient, and requires strict observance of clear guidelines on the prevention, diagnosis and treatment of possible complications. One of the most frequent complications of GCs is osteoporosis. According to the Russian and international guidelines, all the patients must undergo preliminary and follow-up laboratory and instrumental examination, as well as administration of calcium and vitamin D during the whole period of GC-therapy. In case of a high fracture risk or if osteoporosis is diagnosed, antiresorptive therapy is indicated.В практике невролога регулярно возникает необходимость в назначении глюкокортикостероидов (ГКС). Аутоиммунная патология центральной и периферической нервной и нервно-мышечной систем часто сопряжена с выраженной инвалидизацией и жизнеугрожающими осложнениями, что определяет необходимость применения ГКС в высоких дозах в течение длительного периода времени. Назначение ГКС – ответственное решение, которое принимается неврологом совместно с пациентом и требует неукоснительного соблюдения четких рекомендаций по профилактике, диагностике и лечению возможных осложнений. Одним из частых осложнений ГКС является глюкокортикоидиндуцированный остеопороз. Согласно отечественным и зарубежным рекомендациям всем пациентам необходимо предварительное и динамическое лабораторное и инструментальное обследование, а также применение препаратов кальция и витамина D на весь период терапии ГКС. В случае высокого риска возникновения перелома или при выявлении остеопороза показана антирезорбтивная терапия. 

Estímulo no crescimento e na hidrólise de ATP em raízes de alface tratadas com humatos de vermicomposto: i - efeito da concentração.

O vermicomposto contém uma concentração elevada de substâncias húmicas e já é bem conhecido o efeito do seu uso sobre as propriedades do solo. No entanto,a ação direta das substâncias húmicas sobre o metabolismo das plantas é menos conhecida. O objetivo deste trabalho foi avaliar o uso de humatos extraídos de vermicomposto de esterco de curral com KOH 0,1 mol L-1 sobre o desenvolvimento e metabolismo de ATP em plântulas de alface. Após a germinação, plântulas de alface foram tratadas com os humatos em concentrações que variaram de 0 a 100 mg L-1 de C, durante quinze dias. Foram avaliados o crescimento da raiz e a atividade das bombas de H+ isoladas da fração microssomal do sistema radicular. Foi observado aumento na matéria fresca e seca do sistema radicular, bem como no número de sítios de mitose, raízes emergidas do eixo principal, na área e no comprimento radiculares, com o uso do humato na concentração de 25 mg L-1 de C. Também foi observado, nessa concentração, aumento significativo na hidrólise de ATP pelas bombas de H+, responsáveis pela geração de energia necessária à absorção de íons e pelo crescimento celular