Effect of Maillard induced glycation on protein hydrolysis by lysine/arginine and non-lysine/arginine specific proteases

Enzymatic protein hydrolysis is sensitive to modifications of protein structure, e.g. Maillard reaction. In early stages of the reaction glycation takes place, modifying the protein primary structure. In later stages protein aggregation occurs. The specific effect of glycation on protein hydrolysis was studied using α-lactalbumin glycated with D-glucose at 50 °C (0–10 h). This resulted in proteins with different degrees of glycation (DG = 0–63%) without changes in secondary, tertiary and quaternary structure. These glycated proteins were hydrolyzed by lysine/arginine specific proteases (bovine and porcine trypsin) or by non-lysine/arginine specific proteases (Bacillus licheniformis protease (BLP), α-chymotrypsin and subtilisin A). For bovine and porcine trypsin, the maximal degree of hydrolysis decreased linearly with 65% from untreated to maximal glycated protein (DG = 63%). This means trypsin cannot hydrolyze glycated cleavage sites. BLP and subtilisin A hydrolyses were independent of glycation, while α-chymotrypsin cannot hydrolyze cleavage sites with glycated binding sites. This means for non-lysine/arginine specific proteases, the effect of glycation depends on the enzyme sensitivity towards modifications on binding sites. Since not all cleavage sites are efficiently used by the enzymes, the extent of the effects depends on the enzyme selectivity towards cleavage sites (for trypsin) or cleavage sites near glycation sites (for α-chymotrypsin). Combining the results of all proteases, an equation was derived describing the effect of modification of protein primary structure on the extent of hydrolysis based on the enzyme specificity, selectivity and binding site sensitivity

Самосборка низкоразмерных систем Al, Ni, Ti и Si в условиях околоравновесной конденсации

Дисертація присвячена вивченню закономірностей структуро- утворення тривимірних мікро- та наносистем Al, Ni, Ti та Si за умов близькорівноважної стаціонарної конденсації. Вивчена залежність механізмів структуроутворення конденсату від основних параметрів технологічного процесу: часу конденсації, тиску робочого газу та потужності розряду. Проаналізовані фізичні процеси, що відбуваються під час роботи накопичувальних систем плазма-конденсат. Для цих систем розроблено математичну модель самоорганізації критично малих стаціонарних пересичень, яка вивчена за допомогою фазової площини. Досліджено вплив на кінетику формування мікро- та наносистем Al, Ni, Ti та Si взаємозв’язаних ефекту Гіббса-Томсона та польової селективності. Розроблені та апробовані за допомогою побудови фазових траєкторій математичні моделі, які описують процес самозбірки низькорозмірних систем. Встановлено, що за близько-рівноважних умов можна реалізувати різні структурно-морфологічні форми конденсатів. При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/24862Диссертация посвящена изучению закономерностей структуро- образования микро- и наносистем Al, Ni, Ti и Si в условиях критически малых пересыщений. Изучены процессы формирования конденсатов под влиянием структурной и полевой селективностей, степень проявления которых зависит от таких основных технологических параметров, как время конденсации, давление рабочего газа и мощность разряда. Проанализированы конструкции существующих распылитель- ных систем, разработана и создана накопительная система плазма- конденсат (НСПК) на базе планарного магнетрона и совмещенного с ним полого катода. Проанализированы происходящие в НСПК физические процессы и разработана математическая модель, описы- вающая изменение во времени таких нелинейно взаимозависимых технологических параметров, как пересыщение и температура ростовой поверхности. Методом фазовой плоскости установлена возможность самоорганизации критически малых стационарных пресыщений. С помощью математического моделирования показано, что при повышении давления рабочего газа происходит усреднение энергии распыленных атомов, что является необходимым условием повышения стационарности технологического процесса. Изучен механизм формирования фракталов Ni при осаждении предельно слабых паровых потоков на нагретые до относительно высоких температур (620 К) подложки. Показано, что снижение пересыщения паров Ni до критического значения может предельно локализировать области закрепления атомов и является основой для формирования на ростовой поверхности вискеров. Впервые показано, что диссипативная самоорганизация предельно малых стационарных пересыщений в накопительных системах плазма-конденсат приводит к консервативной самоорганизации низкоразмерных систем в виде тех или иных структурно-морфологических состояний поверхности конденсата. Изучены механизмы самосборки пористых пленок Al, трехмерных систем Ti в виде слабо связанных друг с другом ограненных или округлых кристаллов. Показано, что основой такой самосборки конденсатов является предельная минимизация свободной энергии конденсата. При этом селективная самосборка развитой поверхности металлов при проявлении полевой селективности является следствием выравнивания химических потенциалов в различных точках ростовой поверхности до уровня, при котором локальные скорости наращивания конденсатов не зависят от координат поверхности и не изменяются во времени. Изучены механизмы структурообразования конденсатов Si и разработана математическая модель, описывающая самоорганизацию островков одинаковых размеров и формы. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/24862The aim of dissertation is the study of regularities of Al, Ni, Ti and Si micro- and nanosystems formation under the conditions of critically small supersaturations. It have been studied the processes of condensates forming at influence of structural and field selectivity, they are depend on main technological parameters of condensation process such as time of condensation, pressure of working gas and power discharge. Physical processes in the accumulative ion-plasma system have been analyzed. For this systems was created mathematical model of selforganization extremely low steady-state supersaturation and studied by method of phase plane. The influence of interdependent effects of Gibbs-Thomson and field selectivities on forming kinetic of micro- and nanosystems of Al, Ni, Ti and Si was investigated. It was created and tested due to plotting of phase trajectories mathematical models, which reply for the self-assembly process of low dimensional systems. It was established that different structuralmorphological forms of condensates could be obtain at near equilibrium conditions. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2486

Digestibility of resistant starch type 3 is affected by crystal type, molecular weight and molecular weight distribution

Resistant starch type 3 (RS-3) holds great potential as a prebiotic by supporting gut microbiota following intestinal digestion. However the factors influencing the digestibility of RS-3 are largely unknown. This research aims to reveal how crystal type and molecular weight (distribution) of RS-3 influence its resistance. Narrow and polydisperse α-glucans of degree of polymerization (DP) 14–76, either obtained by enzymatic synthesis or debranching amylopectins from different sources, were crystallized in 12 different A- or B-type crystals and in vitro digested. Crystal type had the largest influence on resistance to digestion (A >>> B), followed by molecular weight (Mw) (high DP >> low DP) and Mw distribution (narrow disperse > polydisperse). B-type crystals escaping digestion changed in Mw and Mw distribution compared to that in the original B-type crystals, whereas A-type crystals were unchanged. This indicates that pancreatic α-amylase binds and acts differently to A- or B-type RS-3 crystals.</p

Arginine-enriched oral nutritional supplementation in the treatment of pressure ulcers: A literature review

Abstract Purpose Pressure ulcers are a common, potentially mortal complication to disease, care and treatment for patients of all ages with mobility impairments. In addition, pressure ulcers not always heal straightforward because of multiple intrinsic factors e.g. undernutrition and extrinsic factors e.g. inadequate nutrition that may influence the healing process. The aim of this descriptive review is to investigate the treatment effect of arginine-enriched oral nutritional supplementation in pressure ulcers. Results The included studies, seven RCTs and four CTs, were published between January 2001 and October 2015, and conducted in different settings: hospital, long-term care/care homes and home care. The duration of follow-up of the studies varied from 2 weeks to complete healing and the sample size varied from 16 to 245 patients aged from 37 to 92 years and with pressure ulcer stages II, III or IV. The wound-specific oral nutritional supplementation contained 3–9 g of arginine. The main outcome measures were complete healing, time needed for complete wound closure, reduction in wound surface area, nursing time, and the number of dressings used. Ten out of eleven studies showed a beneficial effect of the arginine-enriched oral nutritional supplementation on the healing of pressure ulcers. Conclusions This review shows that there is substantial evidence supporting the positive effect of nutritional supplementation with additional protein, arginine and micronutrients to promote pressure ulcer healing. Currently, there is only one large study (N = 200) with level 1 evidence. It may be postulated that at least one extra comparable level 1 study is needed to draw firm conclusions on the importance of key nutrients in complete pressure ulcer healing

The impact of the level and distribution of methyl-esters of pectins on TLR2-1 dependent anti-inflammatory responses

Pectins have anti-inflammatory effects via Toll-like receptor (TLR) inhibition in a degree of methyl-esterification-(DM)-dependent manner. However, pectins also vary in distribution of methyl-esters over the galactumnic-acid (GalA) backbone (Degree of Blockiness - DB) and impact of this on anti-inflammatory capacity is unknown. Pectins mainly inhibit TLR2-1 but magnitude depends on both DM and DB. Low DM pectins (DM18/19) with both low (DB86) and high DB (DB94) strongly inhibit TLR2-1. However, pectins with intermediate DM (DM43/ DM49) and high DB (DB60), but not with low DB (DB33), inhibit TLR2-1 as strongly as low DM. High DM pectins (DM84/88) with DB71 and DB91 do not inhibit TLR2-1 strongly. Pectin-binding to TLR2 was confirmed by capture-ELISA. In human macrophages, low DM and intermediate DM pectins with high DB inhibited TLR2-1 induced IL-6 secretion. Both high number and blockwise distribution of non-esterified GalA in pectins are responsible for the anti-inflammatory effects via inhibition of TLR2-1

Self-report versus care provider registration of healthcare utilization: impact on cost and cost-utility

OBJECTIVES: This study aims to compare the impact of two different sources of resource use, self-report versus care provider registrations, on cost and cost utility. METHODS: Data were gathered for a cost-effectiveness study performed alongside a 2-year randomized controlled trial evaluating the effect of an INTERdisciplinary COMmunity-based management program (INTERCOM) for patients with chronic obstructive pulmonary disease (COPD). The program was offered by physiotherapists, dieticians and respiratory nurses. During the 2-year period, patients reported all resource use in a cost booklet. In addition, data on hospital admissions and outpatient visits, visits to the physiotherapist, dietician or respiratory nurse, diet nutrition, and outpatient medication were obtained from administrative records. The cost per quality-adjusted life-year (QALY) was calculated in two ways, using data from the cost booklet or registrations. RESULTS: In total, 175 patients were included in the study. Agreement between self-report and registrations was almost perfect for hospitalizations (rho = 0.93) and physiotherapist visits (rho = 0.86), but above 0.55, moderate, for all other types of care. The total cost difference between the registrations and the cost booklet was 464 euros with the highest difference for hospitalizations 386 euro. Based on the cost booklet the cost difference between the treatment group and usual care was 2,444 euros (95 percent confidence interval [CI], -819 to 5,950), which resulted in a cost-utility of 29,100 euro/QALY. For the registrations, the results were 2,498 euros (95 percent CI, -88 to 6,084) and 29,390 euro/QALY, respectively. CONCLUSIONS: This study showed that the use of self-reported data or data from registrations effected within-group costs, but not between-group costs or the cost utility

Distinct fermentation of human milk oligosaccharides 3-FL and LNT2 and GOS/inulin by infant gut microbiota and impact on adhesion of Lactobacillus plantarum WCFS1 to gut epithelial cells

Human milk oligosaccharides (hMOs) are unique bioactive components in human milk. 3-Fucosyllactose (3-FL) is an abundantly present hMO that can be produced in sufficient amounts to allow application in infant formula. Lacto-N-triaose II (LNT2) can be obtained by acid hydrolysis of lacto-N-neotetraose (LNnT). Both 3-FL and LNT2 have been shown to have health benefits, but their impact on infant microbiota composition and microbial metabolic products such as short-chain fatty acids (SCFAs) is unknown. To gain more insight in fermentability, we performed in vitro fermentation studies of 3-FL and LNT2 using pooled fecal microbiota from 12-week-old infants. The commonly investigated galacto-oligosaccharides (GOS)/inulin (9 : 1) served as control. Compared to GOS/inulin, we observed a delayed utilization of 3-FL, which was utilized at 60.3% after 36 h of fermentation, and induced the gradual production of acetic acid and lactic acid. 3-FL specifically enriched bacteria of Bacteroides and Enterococcus genus. LNT2 was fermented much faster. After 14 h of fermentation, 90.1% was already utilized, and production of acetic acid, succinic acid, lactic acid and butyric acid was observed. LNT2 specifically increased the abundance of Collinsella, as well as Bifidobacterium. The GOS present in the GOS/inulin mixture was completely fermented after 14 h, while for inulin, only low DP was rapidly utilized after 14 h. To determine whether the fermentation might lead to enhanced colonization of commensal bacteria to gut epithelial cells, we investigated adhesion of the commensal Lactobacillus plantarum WCFS1 to Caco-2 cells. The fermentation digesta of LNT2 collected after 14 h, 24 h, and 36 h, and GOS/inulin after 24 h of fermentation significantly increased the adhesion of L. plantarum WCFS1 to Caco-2 cells, while 3-FL had no such effect. Our findings illustrate that fermentation of hMOs is very structure-dependent and different from the commonly applied GOS/inulin, which might lead to differential potencies to stimulate adhesion of commensal cells to gut epithelium and consequent microbial colonization. This knowledge might contribute to the design of tailored infant formulas containing specific hMO molecules to meet the need of infants during the transition from breastfeeding to formula

Type of intrinsic resistant starch type 3 determines in vitro fermentation by pooled adult faecal inoculum

Resistant starch (RS) results in relatively high health-beneficial butyrate levels upon fermentation by gut microbiota. We studied how physico-chemical characteristics of RS-3 influenced butyrate production during fermentation. Six highly resistant RS-3 substrates (intrinsic RS-3, 80-95 % RS) differing in chain length (DPn 16-76), Mw distribution (PI) and crystal type (A/B) were fermented in vitro by pooled adult faecal inoculum. All intrinsic RS-3 substrates were fermented to relatively high butyrate levels (acetate/butyrate ≤ 2.5), and especially fermentation of A-type RS-3 prepared from polydisperse α-1,4 glucans resulted in the highest relative butyrate amount produced (acetate/butyrate: 1). Analysis of the microbiota composition after fermentation revealed that intrinsic RS-3 stimulated primarily Lachnospiraceae, Bifidobacterium and Ruminococcus, but the relative abundances of these taxa differed slightly depending on the RS-3 physico-chemical characteristics. Especially intrinsic RS-3 of narrow disperse Mw distribution stimulated relatively more Ruminococcus. Selected RS fractions (polydisperse Mw distribution) obtained after pre-digestion were fermented to acetate and butyrate (ratio ≤ 1.8) and stimulated Lachnospiraceae and Bifidobacterium. This study indicates that especially the α-1,4 glucan Mw distribution dependent microstructure of RS-3 influences butyrate production and microbiota composition during RS-3 fermentation.</p

Aerobic and strength exercises for youngsters aged 12 to 15: what do parents think?

BACKGROUND: Although strength exercises evidently have both physiological and psychological health benefits across all ages, they are erroneously considered to adversely affect health status in youngsters. The aim of this study was to examine parental attitudes towards their child's physical activity in general, as well as aerobic and strength exercises in particular. METHODS: In total, 314 parents from an online panel representative of the Dutch population completed an online survey about their own physical activity and that of their child (12-15 years old). The study also explored reasons for non-participation, and attitudes about the parents' own and their child's physical activity level. RESULTS: Parents consistently reported a positive attitude towards aerobic exercises, but a less positive attitude regarding strength exercises. Parents were more likely to indicate that their child was not allowed to participate in strength exercises (29.6 %) than aerobic exercises (4.0 %). They thought that strength exercises could interfere with optimal physical development. CONCLUSIONS: This study consistently shows that parents have a positive attitude towards aerobic exercises, but a less positive attitude regarding strength exercises. We suggest testing interventions to increase parental understanding of the advantages of and possibilities for (e.g., facilities) strength training on their child's health