Study of the functional product’s protein compounds digestion features

The aim of the study was to investigate the transformation of meat product’s proteins from pig hearts and aortas during enzymatic hydrolysis in an in vitro model of the gastrointestinal tract. The model consisted of three phases simulating digestion processes: “oral cavity” phase (a-amylase, pH 7.0; 2 min), “stomach” phase (pork pepsin, pH 3.0; 120 min), “intestine” phase (pork pancreatin, pH 7.0; 130 min). The product was sequentially subjected to hydrolysis, at the end of each phase, samples were taken to determine the protein concentration (biuret method) and visualize the protein fractions (one-dimensional electrophoresis). A significant increase in protein concentration at the “stomach” phase was revealed by 3.2 times, and the absolute content by 4.6 times. At the “intestine” phase, a decrease in the number of peptide complexes with copper ions by 1.8 times, the absolute protein content by 8.5% was re‑ vealed. The noted tendency was confirmed by electrophoretic studies — at the stage, simulating digestion in the stomach, the prod‑ ucts of meat product’s proteins hydrolysis were visualized; at the “intestine” phase, a low expression of protein fractions in the range of more than 10 kDa is shown. The maximum hydrolysis of protein compounds at the “stomach” phase to poly- and oligopeptides was confirmed, continuing at the “intestine” stage with the accumulation of free amino acids. This methodology makes it possible to visualize the products of hydrolysis of proteins in a meat product at all stages of the model and to monitor changes in protein concentration in the system

Evolution of in vitro digestibility techniques: a systematic review

The inability to reproduce certain digestive processes in vivo, high research costs and ethical aspects have led to the development of a large number of in vitro digestion models. These models allow us to take into account various factors of modeling complex multistage physiological processes occurring in the gastrointestinal tract, which makes them promising and widely used. A significant part of in vitro methods includes assessment by enzymatic digestion and are based on the calculation of nitrogen remaining after digestion in relation to the initial total nitrogen (according to the Dumas, Kjeldahl method, spectrophotometric or chromatographic method). There are also a number of titrometric methods (pH‑stat), which are mainly used to assess the digestibility of feed, most successfully for aquatic animals due to the simplicity of their digestive tract. Methods for assessing the digestibility of food products by enzymatic digestion have undergone various stages of evolution (since 1947) and have been widely modified by including various enzymes (pepsin, trypsin, pancreatin, erepsin, etc.) in model systems, indices for various products have been determined on their basis (pepsin-digest-residue (PDR) index, 1956; pepsin pancreatin digest (PPD) index, 1964; pepsin digest dialysate (PDD), 1989). As a result, a single protocol was formed to study the digestibility of food — INFOGEST (2014–2019), which includes three stages of digestion (oral, gastric and intestinal). It allows researchers to accurately reproduce the conditions of the human gastrointestinal tract and is widely used by scientists around the world

ОПТИЧЕСКАЯ СИСТЕМА НА ОСНОВЕ ЛАЗЕРНОГО СВЕТОДИОДА ДЛЯ КОНТРОЛЯ ДИНАМИКИ КРОВОТОКА И ФУНКЦИОНАЛЬНОГО СОСТОЯНИЯ МЫЩЦ В БИОЛОГИЧЕСКИХ ТКАНЯХ

The blood flow in the skin of the temporal region and the functional state of the muscles were investigated using the speckle-optical method. It is shown that the speckle-optical method can be used to objectify the skin blood flow and to evaluate vascular reactivity during breath-holding and hyperventilation. Obtained objective data of the tonic state of the anterior tibial muscle of healthy people can be used as indicators of the norm in the clinic for comparison with the results of examinations of patients with diseases of the motor sphere and the pathology of the neuromuscular apparatus, as well as in sports medicine.С использованием спекл-оптического метода исследованы кровоток в кожных покровах височной области и функциональное состояние мышц. Показано, что спекл-оптический метод может применяться для объективизации кожного кровотока и оценки сосудистой реактивности при задержке дыхания и гипервентиляции. Полученные объективные данные тонического состояния передней большеберцовой мышцы здоровых людей могут быть использованы в клинике в качестве показателей нормы при сравнения с результатами обследования пациентов с заболеваниями двигательной сферы и патологией нервно-мышечного аппарата, а также в спортивной медицине

Оценка функционального состояния кожной микрогемодинамики методами допплеровской флоуметрии и спекл-метрии

The characteristics of blood microcirculation in human tissues have been investigated by recording and analyzing a dynamic speckle pattern. Methodical approaches have been proposed for evaluating the obtained data in order to verify speckle measurements using the widely used Doppler flowmetry technique.Исследованы характеристики микроциркуляции крови в тканях человека посредством регистрации и анализа динамической спекл-картины. Предложены методические подходы для оценки полученных данных с целью верификации спекл-измерений с помощью широко используемой методики допплеровской флоуметрии

Применение метода тонкослойной хроматографии для анализа антиоксидантной активности

Plants are a rich source of effective non-toxic biologically active substances. Various physicochemical methods of analysis are used for evaluation of plant antioxidant activity. Composition of ethanol extracts of red, yellow and white onion husks, dried rosemary, basil, and chaga were studied by high performance thin layer chromatography (HPTLC) method. The antioxidant activity of the obtained fractions on a chromatographic plate was assessed by subsequent DPPH screening. The extracts red and yellow onion husk and rosemary demonstrated the highest antioxidant activity, variability of the qualitative composition and similarity of antioxidant profiles, while extract of white onion husks did not contain any antioxidant classes. Intensive spots with Rf of 0.13-0.97 were observed along the whole chromatogram track corresponding to red onion husks. It was also found that all tested extract, excepting white onion husk and chaga, contained spots with varying degrees of intensity in the Rf range of 0.96-0.98, which corresponded quercetin Rf value.Для исследования антиоксидантной активности растительного сырья, которое является богатым источником эффективных нетоксичных биологически активных веществ, используются различные физикохимические методы анализа. В данной работе был применен метод высокоэффективной тонкослойной хроматографии (ВЭТСХ) для разделения биологически активных веществ, входящих в этанольные экстракты шелухи красного, желтого и белого лука, сушенных розмарина, базилика и чаги. Антиоксидантную активность полученных фракций на хроматографической пластине оценивали последующим DPPH-скринингом. Наибольшими показателями антиоксидантной активности и вариабельностью качественного состава характеризовались экстракты шелухи красного и желтого лука, а также розмарина, причем для этих образцов была отмечена схожесть антиоксидантных профилей. В экстракте белого лука не было обнаружено каких-либо классов антиоксидантов. Для шелухи красного лука было отменено наличие значительно выраженных пятен по всему треку, значения Rf которых расположены в диапазоне 0,13-0,97. Доказано, что все экстракты, кроме шелухи белого лука и чаги, в разной степени интенсивности имеют пятна с коэффициентом замедления в диапазоне 0,96-0,98, что соответствует полученному значению Rf кверцетина

МЕТАБОЛИЧЕСКИЕ И КЛИНИКО-РАДИОЛОГИЧЕСКИЕ ИЗМЕНЕНИЯ У ПАЦИЕНТОВ С СИМПТОМАТИЧЕСКОЙ ЭПИЛЕПСИЕЙ ПРИ РАЗОРВАВШИХСЯ АНЕВРИЗМАХ СОСУДОВ ГОЛОВНОГО МОЗГА

The results of the study of metabolic and clinical-radiological changes in patients of two groups with and without symptomatic epilepsy on the background of hemorrhages from ruptured arterial aneurysms are shown. The findings suggest that there is the development of hypoxic nature of violations with the activation of prooxidant reactions in both groups, however, in patients with symptomatic epilepsy was found a significant decrease in antioxidant activity of enzymatic and non-enzymatic cell protection systems with increasing the production of the proinflammatory cytokine TNF-alpha in contrast to the group of patients without epilepsy.Приведены результаты исследования метаболических и клинико-радиологических изменений у пациентов двух групп с симптоматической эпилепсией или без эпиприступов при кровоизлияниях из разорвавшихся артериальных аневризм. Полученные данные свидетельствуют о развитии нарушений гипоксического характера с активацией прооксидантных реакций в обеих группах, однако у пациентов с симптоматической эпилепсией установлено значительное снижение антиоксидантной активности ферментативных и неферментативных систем защиты клеток при повышении продукции провоспалительного цитокина ФНО-альфа в отличие от группы пациентов без эписиндрома

СПЕКЛ-ОПТИЧЕСКАЯ ХАРАКТЕРИСТИКА МИКРОГЕМОДИНАМИКИ КОЖНЫХ ПОКРОВОВ ВИСОЧНОЙ ОБЛАСТИ У ПАЦИЕНТОВ С АРТЕРИАЛЬНЫМИ АНЕВРИЗМАМИ

The possibility of application of the speckle-optical method for the objectivization of cutaneous blood flow and evaluation of vascular reactivity with respiratory arrest and hyperventilation is shown. 21 patients with arterial aneurysms (AA) of the brain were examined. Recording of blood flow was carried out on skin of the temporal region on both sides. Violation of vascular reactivity during respiratory tests in the form of development of paradoxical reactions or reduction of adequate responses to HF and HB on the side with AA has been established. The most informative are the power of the spectrum and the mean frequency of the spectrum.Показана возможность применения спекл-оптического метода для объективизации кожного кровотока и оценки сосудистой реактивности при задержке дыхания (ЗД) и гипервентиляции (ГВ). Обследован 21 пациент с артериальными аневризмами (АА) головного мозга. Запись кровотока проводили в кожных покровах височной области с обеих сторон. Установлено нарушение сосудистой реактивности при проведении дыхательных проб в виде развития парадоксальных реакций или снижения адекватных реакций на ЗД и ГВ на стороне с АА. Наиболее информативными являются мощность спектра и средняя частота спектра

Selective BRAFV600E Inhibitor PLX4720, Requires TRAIL Assistance to Overcome Oncogenic PIK3CA Resistance

Documented sensitivity of melanoma cells to PLX4720, a selective BRAFV600E inhibitor, is based on the presence of mutant BRAFV600E alone, while wt-BRAF or mutated KRAS result in cell proliferation. In colon cancer appearance of oncogenic alterations is complex , since BRAF, like KRAS mutations, tend to co-exist with those in PIK3CA and mutated PI3K has been shown to interfere with the successful application of MEK inhibitors. When PLX4720 was used to treat colon tumours, results were not encouraging and herein we attempt to understand the cause of this recorded resistance and discover rational therapeutic combinations to resensitize oncogene driven tumours to apoptosis. Treatment of two genetically different BRAFV600E mutant colon cancer cell lines with PLX4720 conferred complete resistance to cell death. Even though p-MAPK/ ERK kinase (MEK) suppression was achieved, TRAIL, an apoptosis inducing agent, was used synergistically in order to achieve cell death by apoptosis in RKOBRAFV600E/PIK3CAH1047 cells. In contrast, for the same level of apoptosis in HT29BRAFV600E/PIK3CAP449T cells, TRAIL was combined with 17-AAG, an Hsp90 inhibitor. For cells where PLX4720 was completely ineffective, 17-AAG was alternatively used to target mutant BRAFV600E. TRAIL dependence on the constitutive activation of BRAFV600E is emphasised through the overexpression of BRAFV600E in the permissive genetic background of colon adenocarcinoma Caco-2 cells. Pharmacological suppression of the PI3K pathway further enhances the synergistic effect between TRAIL and PLX4720 in RKO cells, indicating the presence of PIK3CAMT as the inhibitory factor. Another rational combination includes 17-AAG synergism with TRAIL in a BRAFV600E mutant dependent manner to commit cells to apoptosis, through DR5 and the amplification of the apoptotic pathway. We have successfully utilised combinations of two chemically unrelated BRAFV600E inhibitors in combination with TRAIL in a BRAFV600E mutated background and provided insight for new anti-cancer strategies where the activated PI3KCA mutation oncogene should be suppressed

Structure of Metaphase Chromosomes: A Role for Effects of Macromolecular Crowding

In metaphase chromosomes, chromatin is compacted to a concentration of several hundred mg/ml by mechanisms which remain elusive. Effects mediated by the ionic environment are considered most frequently because mono- and di-valent cations cause polynucleosome chains to form compact ∼30-nm diameter fibres in vitro, but this conformation is not detected in chromosomes in situ. A further unconsidered factor is predicted to influence the compaction of chromosomes, namely the forces which arise from crowding by macromolecules in the surrounding cytoplasm whose measured concentration is 100–200 mg/ml. To mimic these conditions, chromosomes were released from mitotic CHO cells in solutions containing an inert volume-occupying macromolecule (8 kDa polyethylene glycol, 10.5 kDa dextran, or 70 kDa Ficoll) in 100 µM K-Hepes buffer, with contaminating cations at only low micromolar concentrations. Optical and electron microscopy showed that these chromosomes conserved their characteristic structure and compaction, and their volume varied inversely with the concentration of a crowding macromolecule. They showed a canonical nucleosomal structure and contained the characteristic proteins topoisomerase IIα and the condensin subunit SMC2. These observations, together with evidence that the cytoplasm is crowded in vivo, suggest that macromolecular crowding effects should be considered a significant and perhaps major factor in compacting chromosomes. This model may explain why ∼30-nm fibres characteristic of cation-mediated compaction are not seen in chromosomes in situ. Considering that crowding by cytoplasmic macromolecules maintains the compaction of bacterial chromosomes and has been proposed to form the liquid crystalline chromosomes of dinoflagellates, a crowded environment may be an essential characteristic of all genomes