Метаболизм и микроструктура стенки тонкой кишки у пациентов с колоректальным раком

RELEVANCE In patients with colorectal cancer (CRC), the normal small intestine, located outside the pathological focus, undergoes changes that may be the cause of digestive dysfunction after radical surgery to remove the tumor.The assessment of metabolic and microstructural changes in the ileum mucosa in patients with colorectal cancer is necessary to correct the algorithms of postoperative therapy and enteral nutrition. Modern means of optical bioimaging are potentially capable of solving this complex diagnostic problem.AIM OF STUDY To study the features of metabolism and morphological structure of the wall of a conditionally normal small intestine in the mucosa in patients with stage 1–3 CRC using macro- FLIM and optical coherence tomography (OCT).MATERIAL AND METHODS The object of the study was the wall of the ileum (66 samples) from the mucosal side of patients with histologically confirmed CRC stages 1–3 with tumor location in the right sections of the colon. Eight samples were obtained from patients with stage 1 CRC, 38 samples were obtained from patients with stage 2 and 20 samples were obtained from patients with stage 3 tumor. The volume of surgical intervention is right-sided hemicolectomy with total mesocolonectomy, CME (D2 lymph node dissection). Fresh tissue samples were examined using fluorescent lifetime macroimaging (macro-FLIM ) and OCT, followed by histological analysis of the material.RESULTS According to a histological study in the small intestine of patients with stage 1 CRC, the mucosa is covered with a normal single-layer prismatic border epithelium. In the intestine samples of patients with stage 2 CRC, mucus hypersecretion with areas of fibrosis and vascular congestion was observed. At the 3rd stage of CRC, the mucous membrane of the small intestine was loose, with local thickenings, areas of fibrosis with severe leukostasis, and foci of atrophy. None of the samples showed histological signs of a malignant tumor.According to OCT data, in the mucous membrane of the small intestine in patients with the 1st and 2nd stages of CRC, the contours of the villi and, partially, the crypts were well visualized. The structure of the villi was smooth, not coarse, and the shape was regular. In patients with stage 3 CRC, the contours of the crypts and villi were indistinct. There were no differences in the OCT picture between histologic preparations in the 1st and 2nd stages of CRC: the structure of the villi of the small intestine was clear, the shape was unchanged. According to FLIM data, statistically significant differences were revealed in the mean fluorescence lifetime values of reduced nicotinamide dinucleotide (phosphate) NAD(P)H (τm) between 2nd and 3rd (p=0.031), 1st and 3rd (p=0.018) by CRC stages. At the 1st stage of CRC τm was 1.61 [1.30; 2.02] ns, at the 2nd stage 1.50 [1.36; 1.73] ns, at the 3rd stage 1.37 [1.22; 1.51] ns. The FLIM results suggest an increase in the role of glycolysis in enterocyte energy metabolism along with progression of the CRC stage.CONCLUSION In patients with cancer of the right colon, lesions of the microstructure of the mucous membrane were revealed in the ileum not affected by the malignancy. At the same time, the severity of microstructural disorders in the wall of the small intestine is associated with the stage of tumor development in the colon. Bioimaging technologies, namely, methods of optical coherence tomography and fluorescence lifetime macroimaging, made it possible to objectively display microstructural and metabolic disorders in the ileum wall. The data of optical colorectal tomography demonstrated differences in the structural picture of the intestinal villi in patients with stages 1–2 and 3 of colorectal cancer. Results of fluorescence lifetime macroimaging of the metabolic cofactor nicotinamide dinucleotide (phosphate) confirmed an increase in the role of glycolysis in the energy metabolism of enterocytes along with an increase in the stage of colorectal cancer. The identified disorders in the state of the small intestine develop in patients with colorectal cancer before surgery and are highly likely to be an important pathogenetic link of malabsorption in the postoperative period. If the hypothesis is confirmed, the developed algorithm for the complex diagnosis of microstructural and metabolic disorders in tissues will expand the possibilities for the rehabilitation of patients with cancer of the right colon.АКТУАЛЬНОСТЬ У пациентов с колоректальным раком (КРР) нормальная тонкая кишка, расположенная вне патологического очага, претерпевает изменения, которые могут быть причиной пищеварительной дисфункции после радикальной операции по удалению опухоли.Оценка метаболических и микроструктурных изменений в слизистой оболочке подвздошной кишки у пациентов с КРР необходима для коррекции алгоритмов послеоперационной терапии, энтерального питания. Современные средства оптического биоимиджинга потенциально способны решить эту сложную диагностическую задачу.ЦЕЛЬ Исследовать особенности метаболизма и морфологической структуры стенки условно нормальной тонкой кишки со стороны слизистой оболочки у пациентов с КРР 1–3-й стадий методами макро-FLIM и оптической когерентной томографии (ОКТ).МАТЕРИАЛ И МЕТОДЫ Объектом исследования являлась стенка подвздошной кишки (66 образцов) со стороны слизистой оболочки у пациентов с гистологически подтвержденным КРР 1–3-й стадий с локализацией опухоли в правых отделах ободочной кишки. 8 образцов получены у пациентов с 1-й стадией КРР, 38 образцов — у пациентов со 2-й стадией и 20 образцов — с 3-й стадией развития опухоли. Объем оперативного вмешательства — правосторонняя гемиколэктомия с тотальной мезо­колонэктомией — CME (лимфодиссекцией Д2). Свежие образцы ткани исследовали методами флуоресцентного время-разрешенного макроимиджинга (макро-FLIM) и ОКТ с последующим гистологическим анализом материала.РЕЗУЛЬТАТЫ По данным гистологического исследования в тонкой кишке пациентов с 1-й стадией КРР слизистая оболочка покрыта нормальным однослойным призматическим каемчатым эпителием. В образцах кишки пациентов со 2-й стадией КРР наблюдалась гиперсекреция слизи с участками фиброза и полнокровием сосудов. При 3-й стадии КРР слизистая оболочка тонкой кишки была рыхлой, с локальными утолщениями, участками фиброза с выраженным лейкостазом и очагами атрофии. Ни в одном из образцов не обнаружены гистологические признаки злокачественной опухоли.По данным ОКТ в слизистой оболочке тонкой кишки у пациентов с 1-й и 2-й стадиями КРР хорошо визуализировались контуры ворсинок и, частично, крипты. Структура ворсинок была гладкой, негрубой, а форма регулярной. У пациентов с 3-й стадией КРР контуры крипт и ворсинок были нечеткими. Различий в картине ОКТ между гистологическими препаратами при 1-й и 2-й стадиях КРР получено не было: структура ворсинок тонкой кишки была четкой, форма неизмененной. По данным FLIM выявлены статистически значимые отличия в показателях среднего времени жизни флуоресценции восстановленного никотинамиддинуклеотида (фосфата) НАД(Ф)Н (τm) между 2-й и 3-й (p=0,031), 1-й и 3-й (p=0,018) стадиями КРР. При 1-й стадии КРР τm составило 1,61 [1,30; 2,02] нс, при 2-й стадии — 1,50 [1,36; 1,73] нс, при 3-й стадии — 1,37 [1,22; 1,51] нс. Результаты FLIM предположительно свидетельствуют об увеличении роли гликолиза в энергетическом метаболизме энтероцитов вместе с увеличением стадии КРР.ЗАКЛЮЧЕНИЕ У пациентов с раком правых отделов ободочной кишки в не затронутой злокачественным поражением подвздошной кишке зафиксированы нарушения микроструктуры слизистой оболочки. При этом выраженность нарушений микроструктуры в стенке тонкой кишки связана со стадией развития опухоли в толстой кишке. Технологии биовизуализации, а именно — методы оптической когерентной томографии и флуоресцентного время-разрешенного макроимиджинга, позволили объективно отобразить нарушения микроструктуры и метаболизма в стенке подвздошной кишки. Данные оптической колоректальной томографии продемонстрировали различия в структурной картине ворсинок кишки у пациентов 1–2-й и 3-й стадий колоректального рака. Результаты флуоресцентного время-разрешенного макроимиджинга метаболического кофактора никотинамиддинуклеотида (фосфата) свидетельствовали об увеличении роли гликолиза в энергетическом метаболизме энтероцитов вместе с ростом стадии колоректального рака. Выявленные нарушения в состоянии тонкой кишки развиваются у пациентов с колоректальным раком до операции и с высокой вероятностью являются важным патогенетическим звеном мальабсорбции в послеоперационном периоде. В случае подтверждения гипотезы, разработанный алгоритм комплексной диагностики нарушений микроструктуры и метаболизма в тканях расширит возможности реабилитации пациентов с раком правых отделов толстой кишки

Absorption de l’eau et son effet sur la durabilité des bétons de sable allégés par ajout de copeaux de bois

L’objectif principal de ce travail est d’étudier l’effet de l’eau sur les bétons de sable léger à base de matériaux et de déchets locaux. Les matériaux utilisés sont un sable de dune et un sable d’oued et les déchets sont des fillers calcaires (déchets de concassage) et des copeaux de bois (déchets de la menuiserie) [1, 2]. En général, on a remarqué que dans le cas de copeaux de bois non traités, plus le taux de bois est élevé, plus l’absorption d’eau est importante, que ce soit par immersion ou par capillarité. En soumettant le matériau à une série de cycles “mouillage – séchage” accélérés, une légère diminution dans la résistance à la compression a été enregistrée. Par ailleurs, le traitement des copeaux de bois avant leur utilisation [3] a considérablement amélioré la résistance vis à vis de ces cycles “mouillage-séchage”. De même, l’absorption d’eau, par immersion et par capillarité, a été considérablement diminuée. Il convient de noter enfin, que ces résultats viennent confirmer la possibilité d’utilisation de ce matériau montrée par les résultats encourageants trouvés dans les travaux précédents, telles que les propriétés mécaniques et thermiques

Effect of marble powder on the properties of self-compacting sand concrete

Self-compacting sand concrete (SCSC) can be regarded as a flowing sand concrete, containing as principal aggregate natural sand, which can be cast without compaction or vibration. Due to the finesses of aggregates in SCSC, it requires a high amount of fine materials than other types of concretes. This paper studies the effect of marble powder content (MP) on the properties of the sand concrete (SCSC) at fresh and hardened states. The properties of the fresh prepared mixes tested are the mini-slump flow, the V-funnel flow time and viscosity. At the hardened state, the parameter which has been determined is the 28-day compressive strength. The obtained test results show that the increase of MP content in SCSC, from 150 kg/m3 to 350 kg/m3, improves the properties at fresh state by decreasing v-funnel flow time (from 5s to 1.5s) and increasing the mini-cone slump (from 28cm to 34cm). With the use of 250 kg/m3 of MP we can reach the highest initial viscosity while retaining good fluidity at high rotational speeds, compared to the MP contents of 150 kg/m3 and 350 kg/m3. In other hand, the 28-days compressive strength decreases with an increase of MP conten

Modeling of dimensional variations of a dune sand concrete reinforced by addition of steel fibers

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Contribution of hybrid fibers on the improvement of sand concrete properties: Barley straws treated with hot water and steel fibers

International audienceThis study is a continuation of previous work undertaken on a sand concrete lightened by barley straws treated with hot water. Indeed, this type of lightweight concrete presented good thermo-physical properties. But on the other hand, its mechanical properties have been slightly reduced. In order to mechanically strengthen the material, it was decided to incorporate steel fibers in the cement matrix. Thus, we have to develop a new lightweight sand concrete based on hybrid fibers: barley straws and steel fibers. The main objective is therefore to improve the mechanical properties of a lightweight sand concrete, without greatly affecting its thermo-physical properties. Since the effect of the barley straws has already been studied in previous works, the present study mainly focuses on the effect of the steel fibers addition. In order to determine the best compromise between the effect of barley straws and that of steel fibers, different percentages of steel fiber (0%; 0.5%; 1%; 1.5% & 2%), as vol. %, have been investigated. The obtained results showed interesting improvements in the physico-mechanical properties of the studied concrete; these findings were confirmed by a microstructural analysis. The optimal proportion of steel fibers that constitutes the best compromise between the studied properties is 1%. In addition, the compressive strength at 90 days has been improved by about 18%, while slight increases in the thermal conductivity and density have been recorded. The thermal diffusivity has been reduced by about 2% and the specific heat has been increased by about 15%. As for the shrinkage, a reduction of about 30% has been noted. It should be noted that, according to the obtained results, the material still retains its qualities of lightweight concrete. Finally, a microstructural study has revealed that the adhesion between the used fibers and the cement matrix is very good. (C) 2019 Elsevier Ltd. All rights reserved

Durability of a lightweight construction material made with dune sand and expanded polystyrene

International audienceThe partial/total substitution of ordinary aggregates by other unused local materials in order to produce new lightweight concretes/mortars is an interesting alternative that can solve technical, economical and environmental problems. On the other hand, the replacement of cement by other binders in the elaboration of concretes and mortars can also provide other properties and benefits more important and more interesting. In this context, previous works have been undertaken and have shown the possibility and the effectiveness of the use of expanded polystyrene aggregates and dune sands on the physicomechanical properties of plaster mortars, especially in term of lightness and thermal insulation. Our current concern is to know: how this composite will behave in certain aggressive environments. Therefore, the main objective of the present work is to study the effect of some chemical environments on the behaviour of a plaster mortar based on dune sands and expanded polystyrene beads. For this study, three different environments have been envisaged: demineralised water (as reference), sulphuric acid solution and magnesium sulphate solution. The obtained results showed that although the surface of the studied samples seems to be degraded, in their interior, the material appears more homogeneous and compact with relatively a good adhesion sand/plaster and EPS/plaster. The presence of the acid or the sulphate in water does not increase the water effect; besides, the acid considerably improves its effect in compression