Electrospun magnetic composite poly-3-hydroxybutyrate/magnetite scaffolds for biomedical applications: composition, structure, magnetic properties, and biological performance

Magnetically responsive composite polymer scaffolds have good potential for a variety of biomedical applications. In this work, electrospun composite scaffolds made of polyhydroxybutyrate (PHB) and magnetite (Fe3O4) particles (MPs) were studied before and after degradation in either PBS or a lipase solution. MPs of different sizes with high saturation magnetization were synthesized by the coprecipitation method followed by coating with citric acid (CA). Nanosized MPs were prone to magnetite-maghemite phase transformation during scaffold fabrication, as revealed by Raman spectroscopy; however, for CA-functionalized nanoparticles, the main phase was found to be magnetite, with some traces of maghemite. Submicron MPs were resistant to the magnetite-maghemite phase transformation. MPs did not significantly affect the morphology and diameter of PHB fibers. The scaffolds containing CA-coated MPs lost 0.3 or 0.2% of mass in the lipase solution and PBS, respectively, whereas scaffolds doped with unmodified MPs showed no mass changes after 1 month of incubation in either medium. In all electrospun scaffolds, no alterations of the fiber morphology were observed. Possible mechanisms of the crystalline-lamellar-structure changes in hybrid PHB/Fe3O4 scaffolds during hydrolytic and enzymatic degradation are proposed. It was revealed that particle size and particle surface functionalization affect the mechanical properties of the hybrid scaffolds. The addition of unmodified MPs increased scaffolds' ultimate strength but reduced elongation at break after the biodegradation, whereas simultaneous increases in both parameters were observed for composite scaffolds doped with CA-coated MPs. The highest saturation magnetization-higher than that published in the literature-was registered for composite PHB scaffolds doped with submicron MPs. All PHB scaffolds proved to be biocompatible, and the ones doped with nanosized MPs yielded faster proliferation of rat mesenchymal stem cells. In addition, all electrospun scaffolds were able to support angiogenesis in vivo at 30 days after implantation in Wistar rats

Заболеваемость гриппом в январе-марте 2016 г. в Российской Федерации: эпидемический и пандемический потенциал вируса гриппа A(H1N1)pdm09

The World Health Organization (WHO) searches influenza virus circulation in community and in natural biocenosis, studies virus strains and their properties, develops diagnostic methods and preventive measures since 1940th worldwide because of epidemic actuality and high pandemic potential of the influenza virus. The Federal Influenza Center (including Federal Research Institute of Influenza, Saint-Petersburg, and the Center of Virus Ecology, D.I.Ivanovskiy Virology Institute, Honorary Academician N.F.GamaleyaFederal Research Center of Epidemiology and Microbiology, Federal Research Center for Epidemiology and Microbiology, Moscow) performs similar work in Russia in close cooperation with WHO within the framework of the International Programme of Influenza Monitoring. A(H1N1)pdm09 influenza virus dominated in the Northern Hemisphere in the 2015 – 2016 epidemic season. Morbidity growth was noted from the end of January, 2016, to the beginning of March, 2016. The peak morbidity at the 5th week of the year exceeded the epidemic threshold (132 cases per 10,000 of population) and morbidity in the 2014 – 2015 season significantly and approached to the peak morbidity of the 2009 – 2010 epidemic season. The epidemic growth in Russian Federation was provided by three influenza viruses: A(H1N1)pdm09, В and A (H3N2). A(H1N1)pdm09 virus caused 18% of all acute respiratory diseases and accounted for 84% of circulating influenza viruses.Flu was diagnosed in patients of different age with maximal frequency in 3- to 6-year old children. Peak admission number was registered at 5 and 6 weeks (3,538 and 4,109 cases, respectively); this number exceeded the similar parameter of the 2009 – 2010 season. Patients of 15 to 64 years old were admitted more often including those with acute respiratory infection. Two hundred and thirty nine deaths were registered to the 5th of April, 2016, according to data from the Federal Influenza Center and the Center of Virus Ecology. The diagnosis of A(H1N1)pdm09 flu was confirmed in 97.9% of deaths. Molecular analysis of isolated strains of A(H1N1)pdm09 influenza virus revealed amino acid substitutions in receptor binding site and SA site of hemagglutinin and in genes coding intrinsic proteins PA, NP, M1, and NS1. Influenza virus strains resistive to anti-neuraminidase drugs were encountered in #< 1% in the Northern Hemisphere countries. No strains studied were sensitive to adamantine derivates.Актуальность. С 1947 г. в связи с эпидемической актуальностью и высоким пандемическим потенциалом вируса гриппа типа А по инициативе Всемирной организации здравоохранения (ВОЗ) организована Глобальная система по надзору за гриппом и ответу (Global Influenza Surveillance and Response System – GISRS), которая в настоящее время представлена 6 сотрудничающими центрами по гриппу, 143 национальными центрами по гриппу в 113 странах, а также производителями гриппозных вакцин. Российская Федерация представлена в этой системе двумя национальными центрами – Федеральным центром по гриппу (ФЦГ) ФГБУ «Научно-исследовательский институт гриппа» Минздрава России (Санкт-Петербург) и Центром экологии и эпидемиологии гриппа (ЦЭЭГ) Института вирусологии им. Д.И.Ивановского ФГБУ «Федеральный научно-исследовательский центр эпидемиологии и микробиологии имени почетного академика Н.Ф.Гамалеи» Минздрава России (Москва). Оба центра осуществляют еженедельный надзор за циркуляцией вирусов гриппа в 59 городах Российской Федерации, который предполагает анализ заболеваемости, госпитализации, летальных случаев от гриппа и острой респираторной вирусной инфекции (ОРВИ) в разных возрастных группах, а также проведение диагностики с помощью широкого спектра лабораторных методов. Материалы и методы. В странах Северного полушария в эпидемическом сезоне 2015–2016 гг. в этиологии подъема заболеваемости доминировал вирус гриппа A(H1N1)pdm09. Подъем заболеваемости гриппом в России зарегистрирован с конца января до начала марта 2016 г. Показатель заболеваемости на пике эпидемии (5-я неделя 2016 г.), значительно превысив эпидемический порог (132 случая на 10 тыс. населения) и значение сезона 2014–2015 гг., отмечен на уровне эпидемического сезона 2009–2010 гг. Результаты. Этиологическую структуру эпидемического подъема заболеваемости в РФ определили 3 вируса гриппа – A(H1N1)pdm09, В и A(H3N2) при разном долевом участии. Грипп A(H1N1)pdm09 в структуре ОРВИ составила 18,0 %, в структуре циркулирующих вирусов гриппа – 84,0 %. Заболеваемость зарегистрирована во всех возрастных группах. Бόльшая вовлеченность в эпидемический процесс зафиксирована у детей 3–6 лет. Максимальное число госпитализаций отмечено на 5-й и 6-й неделях 2016 г. – 3 538 и 4 109 случаев соответственно, что превысило показатели сезона 2009–2010 гг. Наибольшее число случаев госпитализации, в т. ч. с тяжелой острой респираторной инфекцией, отмечено в возрастной группе 15–64 лет. По данным ФЦГ и ЦЭЭГ, на 05.04.16 зарегистрировано 239 летальных исходов. В 97,9 % случаев лабораторными исследованиями подтвержден грипп A(H1N1)pdm09. Заключение. По результатам молекулярно-генетического анализа выделенных штаммов вируса гриппа A / H1N1pdm09 показано наличие аминокислотных замен в гемагглютинине (рецептор-связывающем и Sa сайтах) и в генах, кодирующих внутренние белки (PA, NP, M1, NS1). Доля резистентных штаммов к препаратам с антинейраминидазной активностью в странах Северного полушария не превысила 1 %, а к производным адамантана оказались нечувствительными все изученные циркулирующие штаммы

NEW METHOD OF PHARMACOLOGICAL CORRECTION OF POST-HYPOXIC CARDIOPATHY IN NEWBORNS

Early diagnosis and timely correction of pathological changes in the newborns’ heart can be a major factor in reducing the frequency and severity of cardiovascular pathology in older children and adults. Given the important role of secondary carnitine deficiency in developing disadaptant cardiopathies in newborns (especially premature and immature), the study of the efficacy of exogenous levocarnitine (L-carnitine) in neonatal cardiology offers the greatest promise. The study was aimed at evaluating the efficacy of L-carnitine solution in the post-hypoxic syndrome of cardiovascular deconditioning in newborns, including premature infants. After the treatment course, the newborns showed the effective reduction of signs of electrical instability and myocardial ischemia, restoration of heart rate and resetting of systolic and diastolic function of the heart, the size of the heart cavities, a decrease in the diameter and hemodynamic significance of functioning fetal communications, the restoration of the circadian heart rhythm profile, as well as a reduction in the duration of pauses in rhythm and arrhythmias. The study results showed the efficacy and safety of the L-carnitine solution in correcting cardiac disorders in newborns with hypoxic myocardial damage

Features of studying angiogenesis factors in patients with arterial hypertension and associated clinical conditions

The study of angiogenesis factors in patients with cardiovascular disease by determining the plasma concentration of endostatin and vascular growth factor (VEGF). 82 patients with cardiovascular disease (CVD) and 19 healthy volunteers were examined. Revealed that the level of endostatin is reliably higher among patients with high blood pressure (BP) than in relatively healthy persons. Established that the maximum values of VEGF were in patients with arterial hypertension (AH) and acute coronary syndrome (ACS) in history. The VEGF level was reliably lower in patients with hypertension only persons. Maximum values of endostatin were observed in patients who had undergone ACS

Study of the features of microvasculature in patients with arterial hypertension and end-organ damage

Assessing the microvasculature (MV) in patients with arterial hypertension (AH) compared to the relatively healthy volunteers and in patients with different severity level kidney disease, by determining parameters of capillary blood flow using Doppler ultrasonic. 326 people examined, 34 of them were relatively healthy volunteers, 144 patients with hypertension, 148 patients with hypertension and concomitant renal disease. It is revealed that relatively healthy volunteers have normal microvasculature reaction in response to the test with an external action (cold test and reactive hyperemia test), and in patients with arterial hypertension this reaction is disrupted and appears as a slow and inadequate response of the microvasculature to stimuli. The comparison of the microvasculature in persons with normal and reduced GFR obtained that decreased GFR is accompanied by a deterioration in microcirculation both at rest and during functional tests. This can be used as a preclinical marker of kidney damage in hypertensive patients along with the calculated GFR