81 research outputs found
Determination of the degree of substitution of cellulose esters via ATR‐FTIR spectroscopy
Cellulose derivatives are promising bio-based polymeric materials with possible applications ranging from thickening agents and stabilizers to optical films. The precise determination of their degree of substitution (DS) is crucial, as the DS substantially influences the material properties of such cellulose derivatives. Herein, the applicability of attenuated total reflection-Fourier transform infrared for DS determination of cellulose esters was investigated. Sixteen cellulose acetates with DS ranging from 0.41 to 2.99 were synthesized and three acetyl group-specific vibrational signals were evaluated quantitatively in reference to the cellulose anhydroglucose unit vibration ν(C-O). A non-linear correlation for the absorbance intensity with the DS was observed and the data was fitted based on a newly developed model with correlation coefficients R between 0.958 and 0.998, depending on the evaluated signal. This DS determination method is simple and efficient, since it does not need any prederivatization or extensive sample preparation and can furthermore be applied to non-soluble samples. In order to widen the scope, eight cellulose butyrates, six cellulose laurates and six cellulose benzoates with different DS were synthesized and the DS determination method could be analogously applied to these cellulose esters, but a separate calibration for the different esters was found to be necessary
DYNAMICS OF SURFACE EXPRESSION OF TRIGGER RECEPTOR, EXPRESSED BY MYELOID CELLS-1 (TREM-1) ON VARIOUS SUBPOPULATIONS OF MONOCYTES IN EARLY POSTOPERATIVE PERIOD OF DIRECT REVASCULARIZATION OF MYOCARDIUM
We studied surface expression of trigger receptor, expressed by myeloid cells-1 (TREM-1) on various subpopulations of monocytes before direct revascularization of myocardium with artificial blood flow and in early postoperative period. We registered that various expression of TREM-1 on the surface corresponds to subpopulations of monocytes, and the highest level is observed on CD14hiCD16+ monocytes. By the 1st day of postoperative period elevation of surface expression of TREM-1 occurs on all subpopulations of monocytes, testifying to enlargement of their proinflammatory potential
Biochemical changes of synovial fluid in patients with osteoporosis of knee joint of various etiology
The aim of this study was to perform comparative analysis of biochemical composition of synovial fluid in patients with osteoarthrosis of various etiology. Studies were conducted on samples of synovial fluid of patients which were divided into two groups. Thefirstgroup consisted of 16 patients with patellofemoral arthrosis of the 2nd stage, the second group included 54 patients with bilateral gonarthrosis. The samples of synovial fluid of 11 cadavers of suddenly dead people of both sexes (4 men and 7 women) of 23-79 years who didn't have articular pathology registered by an expert were considered as a norm. Conducted study testifies significant imbalance of prooxidant and antioxidant processes in the synovial fluid and development of oxidative stress the intensity of which depends on the severity of the pathological process but is regardless to its etiology
Mesoporous Silicon Microparticles Enhance MHC Class I Cross-Antigen Presentation by Human Dendritic Cells
The mesoporous silicon microparticles (MSMPs) are excellent vehicles for releasing molecules inside the cell. The aim of this work was to use MSMPs to deliver viral specific MHC class I restricted epitopes into human antigen presenting cells (monocyte derived dendritic cells, MDDCs) to facilitate their capture, processing, and presentation to CD8+ (cytotoxic) T lymphocytes. We show for the first time that MSMPs vehiculation of antigenic peptides enhances their MHC class I presentation by human MDDCs to CD8 T lymphocytes
Случай необычного инородного тела пищевода
Abstract Relevance. Esophageal foreign body may be safely removed with rigid esophagoscopy. However, endoscopic methods are not always successful, and this may require a surgery. Aim of study We report a case of an unusual esophageal foreign body.Materials and methods A 34-year-old male patient P. with a foreign body in the esophagus. Endoscopic, radiological, and laboratory diagnostic methods were performed to confirm a foreign body in the esophagus.Results A rare clinical observation of a 34-year-old male patient P. with a foreign body in the esophagus is presented (package with psychoactive substances). After an unsuccessful attempt to remove a foreign body using esophagoscopy, thoracotomy was performed and a foreign body was mechanically brought down into the stomach without opening the lumen of the esophagus. In the postoperative period, the condition was serious, the patient had been in coma for 10 days. There was hectic fever on day 7. On day 9, the left thoracotomy was performed, the revision showed no damage to the esophagus. Urine analysis for psychoactive substances was performed and detected tetrahydrocannabinol acid and aminochlorobenzophenone, a derivative of 1,4-benzodiazepine. On day 9, after repeated surgery, the patient confirmed the fact of swallowing a package of psychoactive substances, being conscious. On day 14 after the second operation, the patient was transferred to the regional narcological hospital.Conclusion In patients with a foreign body in the esophagus in difficult clinical situations, it is necessary to collect anamnesis carefully, apply endoscopic, radiological and laboratory diagnostic methods, including urinalysis for psychoactive substances.Актуальность Инородные тела пищевода (ИТП) могут быть безопасно удалены при ригидной эзофагоскопии, но эндоскопические методы не всегда успешны, что требует проведения оперативного вмешательства.Цель Представить случай необычного ИТП.Материал и методы Пациент Т. 34 лет с ИТП. Для диагностики ИТП выполнены эндоскопические, рентгенологические и лабораторные методы диагностики.Результаты Представлено редкое клиническое наблюдение пациента Т. 34 лет с ИТП (пакет с психоактивными веществами). После безуспешной попытки извлечения инородного тела с помощью эзофагоскопии проведена торакотомия, механическое низведение инородного тела в желудок без вскрытия просвета пищевода. В послеоперационном периоде состояние тяжелое, сознание на уровне комы в течение 10 суток, гектическая лихорадка на 7-е сутки. На 9-е сутки реторакотомия слева, при ревизии повреждений пищевода нет. Проведен анализ мочи на психоактивные вещества (ПАВ), выявлены тетрагидроканнабиноловая кислота, аминохлорбензофенон — производное 1,4-бензодиазепина. На 9-е сутки после повторной операции больной в сознании, подтвердил факт проглатывания пакета с ПАВ. На 14-е сутки после повторной операции больной переведен в областную наркологическую больницу.Заключение У больных с инородным телом пищевода в сложных клинических ситуациях необходимо тщательно собирать анамнез, применять эндоскопические, рентгенологические и лабораторные методы диагностики, в том числе анализ мочи на психоактивные вещества
IMPACT OF BONE MARROW-DERIVED MULTIPOTENT MESENCHYMAL STROMAL CELLS ON SPEED OF POLYCAPROLACTONE AND POLYHYDROXYALKANOATE SCAFFOLDS BIODEGRADATION
The impact of bone marrow-derived multipotent mesenchymal stromal cells of a bone brain (MSCs BB) on the speed of polycaprolactone and polyhydroxyalkanoate scaffolds biodegradation was studied. The presence of cells on the scaffolds surface was found to catalyze their resorption. 2 months after MSCs-covered scaffolds had. been subcutaneously implanted in rats they degraded completely while scaffolds, which had no MSCs cover, had partially resorbed by that time. The obtained results make necessary further studying of MSCs impact mechanisms on biopolymers resorption speed
ИССЛЕДОВАНИЕ ГОЛОВНОГО МОЗГА У ПАЦИЕНТА С САХАРНЫМ ДИАБЕТОМ 1-го ТИПА С ИСПОЛЬЗОВАНИЕМ МЕТОДИК МАГНИТНО-РЕЗОНАНСНОЙ ТОМОГРАФИИ
Type 1 diabetes mellitus (T1DM) is now widely distributed worldwide and in theRussian Federation, it is an important medical and social problem in connection with the development of serious, disabling complications. Some of these complications could make changes in the brain which are accompanied by cognitive impairments that decrease quality of life and worsening disease compensation. The diagnosis of these disorders to date, possible by using modern methods of magnetic resonance imaging, which describe not only the morphological changes of the brain, but also the metabolism of nervous tissue. The study of the brain, namely structural and metabolic manifestations of diabetes, is one of the priority problem of modern medical science.The aim of the study was to evaluate dynamics in the different techniques of magnetic resonance imaging in the diagnosis of brain changes in patients with T1DM.Research methods included physical examination, in accordance with the diagnostic algorithm of patients with T1DM, a neurologist consultation, an assessment of cognitive function, analysis of brain changes using standard magnetic resonance imaging and spectroscopy. Statistical processing was performed using software package R-system. This publication presents a clinical case of a patient with T1DM and severe cognitive impairments are associated with changes in the brain, diagnosed using standard magnetic resonance imaging and spectroscopy. The study shows the positive role of correction of carbohydrate metabolism in improving cognitive function in a patient with T1DM.In addition, the process analysis revealed the absence of dynamic changes in the brain of a patient with T1DM according to standard magnetic resonance imaging. This required the use of additional techniques – magnetic resonance spectroscopy, which revealed changes of metabolism in the thalamus N-acetyl aspartate, choline and creatinine.Сахарный диабет (СД) 1-го типа (СД-1) в настоящее время широко распространен как во всем мире, так и в Российской Федерации, и является важной медико-социальной проблемой в связи с развитием серьезных инвалидизирующих осложнений. К таким осложнениям относятся изменения головного мозга, которые сопровождаются когнитивными нарушениями, значительно снижающими качество жизни и ухудшающими компенсацию заболевания. Диагностика и выявление этих нарушений на сегодняшний день возможны с помощью современных методик магнитно-резонансной томографии (МРТ), которые описывают не только морфологические изменения головного мозга, но и метаболизм нервной ткани. Исследование структурных и метаболических изменений головного мозга на фоне СД является одной из приоритетных задач современной медицинской науки.Цель исследования – оценить изменения головного мозга с помощью различных методик магнитно-резонансной томографии у пациента с СД-1 и когнитивной дисфункцией.Материал и методы. Проведены общеклиническое обследование в соответствии с алгоритмом диагностики больных СД-1, консультация невролога, оценка когнитивной функции, анализ изменений головного мозга с помощью стандартной МРТ и спектроскопии.В данной публикации представлен клинический случай пациента с СД-1 и выраженными когнитивными нарушениями, а также с изменениями головного мозга, диагностированными с помощью стандартной МРТ и спектроскопии.Результаты. Выявлены нарушение углеводного обмена и наличие когнитивной дисфункции у пациента с СД-1. Кроме того, в процессе анализа обнаружены неспецифические изменения головного мозга у пациента с СД-1 по данным стандартной МРТ. Это потребовало использования дополнительной методики – магнитно-резонансной спектроскопии, с помощью которой удалось выявить изменения метаболизма в таламусе N-ацетиласпартата, холина и креатина
ISOLATION OF GLICOPROTEID FROM THE FIXED RABIES VIRUS, STRAIN «MOSCOW 3253», AND CONSTRUCTING OF DOT-IMMUNOASSAY DIAGNOSTICUM ON ITS BASIS
Described here are the results of glicoproteid isolation from the fixed rabies virus, strain «Moscow 3253», using non-ionic detergent with subsequent chromatographic purification. The obtained antigen was demonstrated to be applicable as immunoreagent for construction of diagnosticum, by means of conjugation with colloid gold nanoparticles. The diagnosticum is meant for detection of specific antibodies in immune sera of horsesproducers, and in the preparation of anti-rabies immunoglobulin, in dot-immunoassay
Влияние различных вариантов модификации поверхности биодеградируемых пленочных матриксов на адгезию и жизнеспособность мультипотентных мезенхимальных стромальных клеток
Designing a hybrid vascular graft using biocompatible and biodegradable polymers is one of the ways to fill the market with vascular grafts of a small diameter necessary for coronary artery bypass surgery. Good adhesive properties of cultivated cells and low cytotoxicity of biopolymers can improve biocompatibility of polymer-based vascular grafts. The impact of protein modification of membranous polyhydroxyalkanoate and polycaprolactone scaffolds surface on their adhesive properties and cytotoxicity to multipotent mesenchimal stromal cells was evaluated. We used the following compositions of membranous scaffolds: № 1 polyhydroxybutyrate valerate ММ 2 307 kDa with polycaprolactone ММ 80 000 kDa, № 2 had the same composition but was made using a magnetic stirrer, №3 polyhydroxybutyrate ММ 541 kDa with polycaprolactone ММ 80 000 kDa and № 4 polycaprolactone ММ 80 000 kDa only. Premodification of scaffolds surfaces with 75, 50 and 25% fetal calf serum was found to significantly reduce cytotoxicity of scaffold № 4 and improve the adhesive properties of scaffolds № 1, 2 and 3. Premodification with fibronectin (10 µg/ml) mostly improved the adhesive properties of scaffolds № 1—4.Создание гибридного сосудистого графта на основе биосовместимых и биодеградируемых полимеров — один из возможных способов решить проблему отсутствия на рынке сосудистых протезов малого диаметра, необходимых для аортокоронарного шунтирования. Хорошие адгезивные свойства относительно культивируемых клеток и низкая цитотоксичность биополимеров способны улучшить биосовместимость сосудистых графтов на их основе. Исследовано влияние белковой модификации поверхности пленочных матриксов из полиоксиалканоатов и поликапролактона на их адгезивные свойства и цитотоксичность относительно мультипотентных мезенхимальных стромальных клеток. В работе использовались пленочные матриксы (ПМ) следующего состава: ПМ № 1 — полигидроксибутират/валерат с молекулярной массой (ММ) 2 307 кДа с поликапролактоном ММ 80 000 кДа, ПМ № 2 — состав идентичен ПМ № 1, но изготовление матрикса выполнено с помощью магнитной мешалки, ПМ № 3 — полигидроксибутират ММ 541 кДа с поликапролактоном ММ 80 000 кДа и ПМ № 4 — чистый поликапролактон ММ 80 000 кДа. Выявлено, что предварительная модификация поверхностей матриксов 75, 50, 25%-м растворами эмбриональной телячьей сыворотки позволила достоверно снизить цитотоксичность ПМ № 4 и улучшить адгезивные свойства ПМ № 1, 2, 4. Предварительная обработка фибронектином в концентрации 10 мкг/мл в наибольшей степени повлияла на улучшение адгезивных свойств ПМ № 1—4
CB2 Cannabinoid Receptors Contribute to Bacterial Invasion and Mortality in Polymicrobial Sepsis
BACKGROUND:Sepsis is a major healthcare problem and current estimates suggest that the incidence of sepsis is approximately 750,000 annually. Sepsis is caused by an inability of the immune system to eliminate invading pathogens. It was recently proposed that endogenous mediators produced during sepsis can contribute to the immune dysfunction that is observed in sepsis. Endocannabinoids that are produced excessively in sepsis are potential factors leading to immune dysfunction, because they suppress immune cell function by binding to G-protein-coupled CB(2) receptors on immune cells. Here we examined the role of CB(2) receptors in regulating the host's response to sepsis. METHODS AND FINDINGS:The role of CB(2) receptors was studied by subjecting CB(2) receptor wild-type and knockout mice to bacterial sepsis induced by cecal ligation and puncture. We report that CB(2) receptor inactivation by knockout decreases sepsis-induced mortality, and bacterial translocation into the bloodstream of septic animals. Furthermore, CB(2) receptor inactivation decreases kidney and muscle injury, suppresses splenic nuclear factor (NF)-kappaB activation, and diminishes the production of IL-10, IL-6 and MIP-2. Finally, CB(2) receptor deficiency prevents apoptosis in lymphoid organs and augments the number of CD11b(+) and CD19(+) cells during CLP. CONCLUSIONS:Taken together, our results establish for the first time that CB(2) receptors are important contributors to septic immune dysfunction and mortality, indicating that CB(2) receptors may be therapeutically targeted for the benefit of patients suffering from sepsis
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