Effect of polysaccharide concentration on heat-induced Tremella fuciformis polysaccharide-soy protein isolation gels: Gel properties and interactions.

The formation of a single soybean protein isolate (SPI) gel is limited by the processing conditions, and has the disadvantages of poor gel property, and it is usually necessary to add other biomacromolecules to improve its property. In this study, we investigated the effects of polysaccharide concentration on gel properties and interaction mechanisms of Tremella fuciformis polysaccharide (TFP)-SPI complexes. It was found that (1) the rheological properties, texture properties, water-holding properties, and thermal stability of TFP-SPI composite gels were improved with the addition of TFP (0.25-2.0 %, w/v) in a concentration-dependent manner; (2) hydrogen bond, the electrostatic interaction, hydrophobic interaction, and disulfide bond in the gel system increased with the increase of TFP concentration; (3) the electrostatic and hydrophobic interactions played an important role in the formation of the TFP-SPI composite gel while hydrogen bond formation was the least contributor to the binary composite gel network. Overall, TFP is not only a critical health food but also a promising structural component for improving the gel properties of SPI.

Structural and property changes of starch derivatives under microwave field: A review.

Native starches are commonly modified for desired properties because of their limited applications. Among various modifications, microwave irradiation has been gaining strong interests and becoming a focal area to transform starch during the last few years. Such interests reside in microwave irradiation's high heating rates, lesser extent of loss in nutritional qualities, and so on when compared with other approaches. This review summaries the effects of microwave field on the structural (e.g. morphology characteristic, lamellae structure, crystallinity, and molecular structure) and physicochemical properties (e.g. pasting properties and gelatinization) of naturally existing starch derivatives. Different microwave-assisted chemical derivatizations can directly or indirectly affect starch structure from the macroscopic to the microscopic level, thereby resulting in various functionalities. Moreover, conventional starch modification processes can be optimized by applying microwave irradiation to obtain modified starch with high degree of substitution and low viscosity. The future research will help to better understand the structural changes of microwave-assisted starch chemical derivatization and thereby creating a wide range of functionalities.

Preparation, multi-scale structures, and functionalities of acetylated starch: An updated review.

Acetylated starch has been widely used as food additives. However, there was limited information available regarding the impact of acetylation on starch structure and functionalities, as well as the advanced acetylation technologies. This review aimed to summarize current methods for starch acetylation and discuss the structure and functionalities of acetylated starch. Innovative techniques, such as milling, microwave, pulsed electric fields, ultrasonic, and extrusion, could be employed for environmental-friendly synthesis of acetylated starch. Acetylation led to the degradation of starch structures and weakening of the interactions between starch molecules, resulting in the disorganization of starch multi-scale ordered structure. The introduction of acetyl groups retarded the self-reassembly behavior of starch, leading to increased solubility, clarity, and softness of starch-based hydrogels. Moreover, the acetyl groups improved water/oil absorption capacity, emulsifiability, film-forming properties, and colonic fermentability of starch, while reduced the susceptibility of starch molecules to enzymes. Importantly, starch functionalities were largely influenced by the decoration of acetyl groups on starch molecules, while the impact of multi-scale ordered structures on starch physicochemical properties was relatively minor. These findings will aid in the design of structured acetylated starch with desirable functionalities.

Understanding the multi-scale structure and physicochemical properties of millet starch with varied amylose content.

The multi-scale structure and physicochemical properties of starch from five indigenous millet varieties were investigated and their correlations were revealed. Results showed that apparent amylose content (AAC) ranged from 12.3% to 27.4%, and as the amylose increasing, the ordered degree of starch double-helical, ordered molecular structure and crystalline structures displayed a declined trend. All millet starches showed polygonal, spherical or irregular shapes varied with size, but XIN-3 starch granules (highest AAC) presented higher granule rigidity, compactness and bulk intensity. Specifically, the ordered molecular structure (e.g., higher double-helix content, short-range ordered degree and relative crystallinity) of millet starch with low amylose limited the swelling degree of starch granules and in turn decreased the characteristic viscosity. However, rapidly digestible starch (RDS) was significantly negatively correlated with AAC and ordered molecular structure. The information obtained in this study would be significant in the rational utilization of these millet starches in food industry fields.

Placenta autophagy is closely associated with preeclampsia.

The pathogenesis of preeclampsia (PE) is complex and placental internal homeostasis is regulated by cellular autophagy. However, there are fewer studies related to the role of placental autophagy in the pathogenesis of PE. The GSE75010 and GSE10588 datasets were downloaded from the gene expression omnibus (GEO) database. In the GSE75010 (test cohort), 103 differentially expressed genes (DEGs) were screened using "Limma" package, and 281 PE characteristic genes were screened by weighted gene coexpression network analysis (WGCNA). Combined with the autophagy gene set, a total of 5 autophagy-related hub genes were obtained. Three biomarkers (HK2, PLOD2, and TREM1) were then further screened by random forest(RF) model and least absolute shrinkage and selection operator(LASSO) algorithm as diagnostic of PE. In the unsupervised consensus clustering analysis, HK2, PLOD2, and TREM1 may be synergistically involved in hypoxia-induced autophagy and hypoxia-inducible factor 1(HIF-1) signaling pathway to induce PE. In addition, we constructed and evaluated a nomogram model for PE diagnosis using these three key diagnostic biomarkers, and the results showed that the model had significantly excellent predictive power (AUC values of GSE75010 and GSE10588 datasets were 0.869 and 0.876, respectively). In terms of immune infiltration, a higher proportion of T cells CD8, and a lower proportion of Macrophages M2 were found in PE placentas compared to normal tissue, and high expression of HK2, PLOD2, and TREM1 were accompanied by low levels of Macrophages M2 infiltration. HK2, PLOD2, and TREM1 may be associated with the development of pre-eclampsia, and their mechanisms of action in preeclampsia need to be further investigated.

Dietary compounds slow starch enzymatic digestion: A review.

Dietary compounds significantly affected starch enzymatic digestion. However, effects of dietary compounds on starch digestion and their underlying mechanisms have been not systematically discussed yet. This review summarized the effects of dietary compounds including cell walls, proteins, lipids, non-starchy polysaccharides, and polyphenols on starch enzymatic digestion. Cell walls, proteins, and non-starchy polysaccharides restricted starch disruption during hydrothermal treatment and the retained ordered structures limited enzymatic binding. Moreover, they encapsulated starch granules and formed physical barriers for enzyme accessibility. Proteins, non-starchy polysaccharides along with lipids and polyphenols interacted with starch and formed ordered assemblies. Furthermore, non-starchy polysaccharides and polyphenols showed robust abilities to reduce activities of α-amylase and α-glucosidase. Accordingly, it can be concluded that dietary compounds lowered starch digestion mainly by three modes: (i) prevented ordered structures from disruption and formed ordered assemblies chaperoned with these dietary compounds; (ii) formed physical barriers and prevented enzymes from accessing/binding to starch; (iii) reduced enzymes activities. Dietary compounds showed great potentials in lowering starch enzymatic digestion, thereby modulating postprandial glucose response to food and preventing or treating type II diabetes disease.

Testing the Linearity Assumption for Starch Structure-Property Relationships in Rices.

Many properties of starch-containing foods are significantly statistically correlated with various structural parameters. The significance of a correlation is judged by the p-value, and this evaluation is based on the assumption of linear relationships between structural parameters and properties. We here examined the linearity assumption to see if it can be used to predict properties at conditions that are not close to those under which they were measured. For this we used both common domesticated rices (DRs) and Australian wild rices (AWRs), the latter having significantly different structural parameters and properties compared to DRs. The results showed that (1) the properties were controlled by more than just the amylopectin or amylose chain-length distributions or amylose content, other structural features also being important, (2) the linear model can predict the enthalpy ΔHg of both AWRs and DRs from the structural parameters to some extent but is often not accurate; it can predict the ΔHg of indica rices with acceptable accuracy from the chain length distribution and the amount of longer amylose chains (degree of polymerization > 500), and (3) the linear model can predict the stickiness of both AWRs and DRs to acceptable accuracy in terms of the amount of longer amylose chains. Thus, the commonly used linearity assumption for structure-property correlations needs to be regarded circumspectly if also used for quantitative prediction.

Starch Molecular Structural Features and Volatile Compounds Affecting the Sensory Properties of Polished Australian Wild Rice.

Cooked high-amylose rices, such as Australian wild rice (AWR) varieties, have slower digestion rates, which is nutritionally advantageous, but may have inferior eating qualities. Here, a comparison is made between sensory and starch molecular fine structure properties, and volatile compounds, of polished AWR varieties and some commercial rices (CRs). Starch structural parameters for amylopectin (Ap) and amylose (Am) were obtained using fluorophore-assisted capillary electrophoresis and size-exclusion chromatography. Volatile compounds were putatively using headspace solid-phase microextraction with gas chromatography-mass spectrometry. Sensory properties were evaluated by a trained panel. AWR had a disintegration texture similar to that of Doongara rice, while AWR had a resinous, plastic aroma different from those of commercial rice varieties. Disintegration texture was affected by the amounts of Ap short chains, resinous aroma by 2-heptenal, nonadecane, 2h-pyran, tetrahydro-2-(12-pentadecynyloxy)-, and estra-1,3,5(10)-trien-17ß-ol, and plastic aroma by 2-myristynoyl pantetheine, cis-7-hexadecenoic acid, and estra-1,3,5(10)-trien-17ß-ol. These findings suggest that sensory properties and starch structures of AWR varieties support their potential for commercialization.

Starch structure-property relations in Australian wild rices compared to domesticated rices.

There are many genetic differences between Australian wild rices (AWRs) and domesticated rices (DRs), causing differences in starch molecular structure and starch-related functional properties; these are examined here for polished AWRs and polished DRs. Starch structural parameters for amylopectin and amylose were obtained using size-exclusion chromatography, with and without enzymatic debranching. Thermal properties of starch, in-vitro digestibility and texture of three AWRs were measured and compared to those of typical DRs. The results showed that AWR starches had (a) higher amylose content than most DRs, resulting in a higher gelatinization temperature, (b) fewer amylopectin short chains, causing a higher gelatinization enthalpy, and (c) more amylose shorter chains and more amylopectin longer chains, both causing a slower in-vitro digestion rate. The textural characteristics of AWRs are not significantly different from those of DRs. These findings suggest that AWRs are a potential source of nutritionally-desirable but palatable slowly-digestible starch.

Thymosin ß4 alleviates renal fibrosis and tubular cell apoptosis through TGF-ß pathway inhibition in UUO rat models.

BACKGROUND: Thymosin ß4 (Tß4) is closely associated with the cytoskeleton, inflammation, wound healing, angiogenesis, apoptosis, and myocardial regeneration, but the effects of Tß4 treatment on chronic renal tubular interstitial fibrosis (CRTIF) are poorly known. This study aimed to examine the effects of Tß4 on the renal apoptosis and the expression of transforming growth factor (TGF-ß), E-cadherin, and α-smooth muscle actin (α-SMA) in CRTIF rat models. METHODS: Male SD rats were randomized into four groups (sham group, unilateral ureteral obstruction (UUO) group, UUO + low-dose Tß4 group, and UUO + high-dose Tß4 group). The pathological changes of kidney tissue and its function were assessed two weeks after UUO. In renal interstitial tissue,TGF-ß, E-cadherin and α-SMA expression was detected by western blot. In tubular epithelial cells, E-cadherin and α-SMA expression was detected using Real-time qPCR and western blot. Cell apoptosis of rat renal interstitial tissue and tubular epithelial cells was evaluated by immunofluorescence and western blot. RESULTS: Two weeks after UUO, no differences in blood urea nitrogen and creatinine were observed between the four groups (P > 0.05). Compared to the UUO group, Tß4 treatment decreased the 24-h proteinuria (P < 0.001) and reduced the area of pathological change (P < 0.01); this effect was more apparent in the UUO + high-dose Tß4 group. Compared to the UUO group, a significant decrease in TGF-ß and α-SMA protein expression was observed in the high-dose Tß4 group. The level of E-cadherin protein was lower in the UUO group than the Tß4 groups, and high-dose Tß4 treatment further increased E-cadherin expression and improved cell apoptosis in the renal interstitial tissue. Analysis of in vitro tubular epithelial cells showed that α-SMA mRNA and protein expression decreased, while E-cadherin mRNA and protein expression increased by Tß4 treatment. Similarly, these changes were more significant in the UUO + high-dose Tß4 group. Tß4 treatment improved the apoptosis of In vitro tubular epithelial cells compared with pure TGF-ß stimulation, and equally, the decrease of apoptosis was more apparent in the TGF-ß + high-dose Tß4 group. CONCLUSIONS: Tß4 treatment might alleviate the renal fibrosis and apoptosis of tubular epithelial cells through TGF-ß pathway inhibition in UUO rats with CRTIF.

Influence of microwave vacuum drying on glass transition temperature, gelatinization temperature, physical and chemical qualities of lotus seeds.

This study investigated the effects of microwave power density on effective moisture diffusion coefficient (Deff), glass transition temperature (Tg), gelatinization temperature (TP), physical and chemical qualities of lotus seeds during microwave vacuum drying. Deff increased by 42% and 127% at 15W/g and 20W/g, respectively, when compared with 10W/g. TP was negatively correlated with the relaxation times of T21 and T22, while Tg was negatively correlated with the relative areas A22. The rates of change of color were observed to be divided roughly into two periods, consisting of a rapid change caused by enzymatic browning and a slow change caused by non-enzymatic browning. An equation is provided to illustrate the relationship of k1 and k2 of Peleg's model depending on power density during rehydration kinetics. The samples at 20W/g exhibited the higher content of amino acid (540.19mg/100gd.b.) while lower starch (17.53g/100gd.b.).

Structural characterization of a novel neutral polysaccharide from Lentinus giganteus and its antitumor activity through inducing apoptosis.

A novel neutral polysaccharide (LGPS-1), with a molecular weight of 1.547×10(5)Da, was isolated from Lentinus giganteus by precipitation and purification. The monosaccharides included d-mannose (Man), d-glucose (Glc) and d-galactose (Gal) with a molar ratio of 3.0:4.1:7.1. The backbone of LGPS-1 was composed of 1,6-Galp and 1,3,6-Manp whereas the branches were composed of 1,6-Glcp and 1-Glcp. The anticancer efficacy of LGPS-1 was assessed using HepG2 hepatocellular carcinoma cells. The results showed that LGPS-1 inhibited the proliferation of HepG2 cells and also induced the activation of caspase-3, and cleavage of PARP-1. Western blot analysis revealed that LGSP-1 significantly induced a loss of mitochondrial membrane potential (Δym), increased the ratio of Bax/Bcl-2, promoted the release of cytochrome c into cytoplasm as well as inhibited the phosphorylation of Akt in HepG2 cells. These findings suggest that LGPS-1 induced apoptosis in HepG2 cells through intrinsic mitochondrial apoptosis and PI3K/Akt signaling pathways.

Role of Wnt3a expressed by dendritic cells in the activation of canonical Wnt signaling and generation of memory T cells during primary immune responses.

The presence of memory T cells (TMs) hinders transplant survival. Dendritic cells (DCs) induce the generation of TMs during primary immune responses. However, the specific mechanisms are unclear. In this study, we constructed a Wnt3a-expressing adenovirus and used small interfering RNA (siRNA) targeting Wnt3a to investigate the influence of Wnt3a expression in DCs on the generation of TMs during primary immune responses. Our results demonstrated that the Wnt3a expression levels in DCs influenced the generation of TMs after 5days in co-culture with naïve T cells through activation of the Wnt canonical pathway. Interleukin-7 secretion levels in supernatants of DC/TNs co-cultures showed a similar pattern of Wnt3a expression levels in DCs. These findings provide a better understanding of TMs generation mechanisms that might be useful to improve transplant outcomes.

Effects of different drying methods on the product quality and volatile compounds of whole shiitake mushrooms.

Various drying methods play important roles in the preservation of foods. However, how the different drying methods affect the quality of some foods is not clear. This paper evaluates the effects of hot air, vacuum, microwave, and microwave vacuum drying techniques on important qualities and volatile compounds of whole shiitake (Lentinus edodes) mushrooms. These four drying methods resulted in a significantly (p<0.05) increase in the content of total free amino acids and the relative content of sulfur compounds of dried products. Microwave vacuum drying helped to maintain larger amounts of taste-active amino acids, and improved nutrient retention and color attributes. Furthermore, the uniform honeycomb network created by microwave vacuum drying along with a less collapsed structure of dried samples can be used to explain the observed high rehydration ratio. Therefore, microwave vacuum drying should be a potential method for obtaining high-quality dried mushrooms.

Extraction optimization, structure and antioxidant activities of Fortunella margarita Swingle polysaccharides.

The objective of this study was to maximize the yield of polysaccharides extracted from Fortunella margarita Swingle (FMPS) and investigate the relationship between the structure and antioxidant activities. The optimal conditions for ultrasonic-assisted extraction (UAE) of FMPS were ultrasonic power 171W, extraction temperature 50°C, water volume to raw material weight (W/M) ratio 32 ml/g and extraction time 87 min. Under these conditions, the yield of FMPS was 4.15±0.11% (w/w), which was increased by 129.28% compared to hot water extraction. FMPS3, the main fraction of FMPS, was isolated by DEAE Sepharose CL-6B column chromatography. According to size-exclusion chromatography, multi-angle laser light-scattering and refractive index (SEC-MALLS-RI), the molecular weight (Mw), polydispersity index (Mw/Mn) and root-mean-square turning radius (Rg) of FMPS3 were 4.58×10(5) (±2.02%) Da, 1.08 (±1.23%), 28.13 (±1.73%) nm, respectively. FMPS3, linked mainly by ß-glycosidic bonds, consisted of galactose, galacturonic acid, glucose, mannose and rhamnose as shown by HPLC, FT-IR, 1H NMR and 13C NMR. Furthermore, FMPS3 displayed strong scavenging ability against hydroxyl, superoxide and DPPH radicals. The activity was affected by the monosaccharide composition, molecular weight and proportion of ß-glycosidic bonds and was a result of a combination of multiple structural factors. FMPS3 is potentially a novel natural antioxidant agent.

Urine interleukin-18 in prediction of acute kidney injury: a systemic review and meta-analysis.

BACKGROUND: Interleukin-18 (IL-18) mediates ischemic acute tubular necrosis; it has been proved as a rapid, reliable, and affordable test marker for the early detection of acute kidney injury (AKI), but its predictive accuracy varies greatly. METHODS: MEDLINE and EMBASE, Cochrane Library, Ovid, and Springerlink (from inception to November 15, 2013) were searched for relevant studies (in English) investigating diagnostic accuracy of urine IL-18 to predict AKI in various clinical settings. The text index was increasing or increased urine IL-18 level and the main outcome was the development of AKI, which was primarily based on serum creatinine level [using risk, injury, failure, loss and end-stage renal disease (RIFLE), acute kidney injury network, or modified pediatric RIFLE criteria in pediatric patients]. Pooled estimates of diagnostic odds ratio (OR), sensitivity and specificity were calculated. Summary receiver operating characteristic curves were used to calculate the measures of accuracy and Q point value (Q*). Remarkable heterogeneity was explored further by subgroup analysis based on the different clinical settings. RESULTS: We analyzed data from 11 studies of 3 countries covering 2,796 patients. These studies were marked by limitations of threshold and non-threshold effect heterogeneity. Across all settings, the diagnostic OR for urine IL-18 level to predict AKI was 5.11 [95% confidence interval (CI) 3.22-8.12], with sensitivity and specificity respectively at 0.51 and 0.79. The area under the ROC curve of urine IL-18 level to predict AKI was 0.77 (95% CI 0.71-0.83). Subgroup analysis showed that urine IL-18 level in pediatric patients (<18 years) and early AKI predictive time (<12 h) were more effective in predicting AKI, with diagnostic ORs of 7.51 (2.99-18.88), 8.18 (2.19-30.51), respectively. CONCLUSION: Urine IL-18 holds promise as a biomarker in the prediction of AKI but has only moderate diagnostic value.

Vascular network modeling reveals significant differences in vascular morphology in growth-restricted placentas.

AIM: To construct and examine models of the vascular networks using the technique of vascular corrosion casting in placentas collected from normal pregnancies and from pregnancies complicated by fetal growth restriction (FGR). METHODS: Twenty placentas were collected from normal term pregnancies (Group NP) and an equal number from pregnancies with idiopathic term FGR (Group FGR) and placental vascular network models constructed by perfusing an acrylic-based solution separately into the umbilical vein and arteries. Placental blood volumes and blood vessel characteristics (number of branches, diameter, and morphology) were then examined and compared. RESULTS: In placentas from Group NP, the veins branched five to seven times with a peripheral artery-to-vein ratio ranging from 1:2 to 1:3. In placentas from Group FGR, the veins branched only four to five times with an artery-to-vein ratio of 1:1 to 2:1 and increased evidence of nodularity and pitting of the vessel walls. The two groups showed significant differences in placental blood volume and in the mean diameters of umbilical veins and arteries. In Group FGR, significant positive correlations could be found between birth weight and placental volume, venous diameters, and select arterial diameters. CONCLUSION: Vascular network models can be constructed from term placentas. Such modeling may provide novel insights and improve our understanding of the placental vascular system in both health and disease.

[Correlation between oligohydramnios and abnormal expressions of TXA2, PGI2 and TXA2R in the umbilical arterial blood and placenta].

OBJECTIVE: To investigate the roles of thromboxane A(2) (TXA(2)) and prostaglandin I(2) (PGI(2)) in development of oligohydramnios. METHODS: The concentration of TXB(2) and 6-keto-PGF1 in umbilical cord blood collected from 30 normal parturients (control) and 30 parturients with oligohydramnios was detected by radioimmunoassay to calculate the TXA(2)/PGI(2) ratio. Immunohistochemistry was performed to detect the contents of TXA(2)R in vascular endothelial cell in the placental villi. RESULTS: Compared with the control group, the concentration of umbilical cord blood TXB(2) in oligohydramnios group was significantly increased (P<0.01), but the elevation of 6-keto-PGF(2) concentration was not statistically significant (P>0.05). The oligohydramnios group showed significantly higher positivity rates of TXB2 and 6-keto-PGF1 in than the control group (P<0.01), and the positivity rate of TXA(2)R in the vascular endothelial cells in the placental villi was also significantly higher in the oligohydramnios group (22/30, 77.3% vs 11/30, 36.7%, P<0.05). Most of the TXA(2)R-positive cases in the oligohydramnios group showed strong positivities of TXA(2)R. CONCLUSION: Abnormal elevation of TXA(2) concentration in the umbilical cord blood and the TXA(2)/PGI(2) imbalance are responsible for the development of oligohydramnios.