Effect of long-term serum sodium levels on the prognosis of patients on maintenance hemodialysis.

Abnormal serum Na (SNa) levels are common in patients with chronic kidney disease (CKD) which is associated with increased morbidity and mortality. There are relatively few studies on the effect of SNa indicators on the prognosis of patients undergoing maintenance hemodialysis (MHD). We aim to investigate the effect of long-term SNa levels on the survival and prognosis of patients undergoing hemodialysis (HD). Newly entered HD patients in the registration system of Zhejiang Provincial Dialysis Quality Control Center between January 1, 2010 and December 31, 2019 were included and followed up until December 31, 2020. Multiple sodium levels were collected from patients, defining long-term SNa as the mean of multiple SNa, according to which patients were grouped, with the prognostic differences between subgroups compared by Kaplan-Meier modeling and multifactorial Cox regression modeling. Finally, a total of 21,701 patients were included in this study and Cox regression showed that decreased SNa levels (Na < 135 mmol/L, HR = 1.704, 95% CI 1.408-2.063, p < 0.001; 135≦Na≦137.5 mmol/L, HR = 1.127,95% CI 1.016-1.250, p = 0.024) and elevated SNa levels (142.5 < Na≦145mmol/L, HR = 1.198, 95% CI 1.063-1.350, p = 0.003; Na > 145mmol/L, HR = 2.150, 95% CI 1.615-2.863, p < 0.001) were all independent risk factors for all-cause mortality in MHD patients.

Efficacy of Rituximab for Minimal Change Disease and Focal Segmental Glomerulosclerosis with Frequently Relapsing or Steroid-Dependent Nephrotic Syndrome in Adults: A Chinese Multicenter Retrospective Study.

INTRODUCTION: Rituximab has been proven effective and safe in pediatric patients with frequently relapsing or steroid-dependent nephrotic syndrome (FR/SDNS). We aimed to analyze the efficacy and safety of rituximab in adult FR/SDNS patients with minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS). METHODS: A retrospective cohort study at three nephrology centers in China included adult FR/SDNS patients with biopsy-proven MCD or FSGS. Primary outcomes were relapse frequency and first relapse-free survival time. Adverse events were well recorded, and logistic regression analyses were used to investigate the risk factors of relapse. RESULTS: Eighty-one patients (age, 25.0 years; interquartile range, 20.0-40.5; 67% males; 82.7% MCD) received an average rituximab dose of 1,393.8 ± 618.7 mg/2 years during the 2-year follow-up period. The relapse frequency, calculated as the ratio of relapse times to follow-up years, significantly decreased after rituximab treatment (0.04 [0.00, 0.08] vs. 1.71 [1.00, 2.45], p < 0.001). The first relapse-free survival time was 16.7 ± 8.0 months. Fifty-seven patients (70.4%) achieved cessation of corticosteroids and immunosuppressants within 3 months after the first rituximab infusion. Adverse events were mostly mild, and no severe treatment-related adverse events were observed. Low serum albumin level before rituximab and high CD56+CD16+ natural killer cell count after rituximab were independent risk factors of relapse within 2 years after rituximab treatment. CONCLUSION: Rituximab was proven an effective and safe treatment option for adult FR/SDNS patients with MCD or FSGS in maintaining disease remission and minimizing corticosteroid exposure.

The relationship between dietary inflammatory index and osteoporosis among chronic kidney disease population.

Dietary inflammation index (DII) is an epidemiological survey tool to evaluate dietary inflammation potential. Osteoporosis, whose development is deeply affected by inflammation, may be also affected by dietary inflammatory patterns. However, the relationship between DII and osteoporosis is unclear for chronic kidney disease (CKD) population. Our study involved 526 CKD patients from the US National Health and Nutrition Examination Survey (NHANES). DII levels were stratified into four quantile groups. Multivariable regression models were used to examine the association between DII and osteoporosis. Restricted cubic splines and subgroup analysis were additionally adopted. Results showed that the overall prevalence of osteoporosis among CKD patients was 25.3%. After fully adjusted, OR (95% confidence interval) for Q4 group compared with Q3 (reference group) in total and female population were 2.09 (1.05, 4.23) and 2.80 (1.14, 7.08), respectively. Subgroup analysis indicated that these results had no interaction with age, gender, body mass index (BMI), renal function, urinary protein, calcium, phosphorus and total 25-hydroxyvitamin D. DII was negatively correlated with lumbar spine bone mineral density (BMD) in CKD population (P < 0.05). Therefore, in CKD patients, higher DII was associated with higher osteoporosis risk and lower BMD of lumber spine, especially in female. Anti-inflammatory diet patterns may be a protective intervention for some CKD-related osteoporosis.

Study on the correlation between bioelectrical impedance analysis index and protein energy consumption in maintenance dialysis patients.

BACKGROUND: Protein-energy wasting (PEW) has been reported to be pretty common in maintenance dialysis patients. However, the existing PEW diagnostic standard is limited in clinical use due to the complexity of it. Bioelectrical impedance analysis (BIA), as a non-invasive nutritional assessment method, can objectively and quantitatively analyze the changes of body tissue components under different nutritional states. We aim to explore the association between PEW and BIA and establish a reliable diagnostic model of PEW. METHODS: We collected cross-sectional data of 609 maintenance dialysis patients at the First Affiliated Hospital, College of Medicine, Zhejiang University. PEW was diagnosed according to International Society of Renal Nutrition and Metabolism (ISRNM) criteria. Among them, 448 consecutive patients were included in the training set for the establishment of a diagnostic nomogram. 161 consecutive patients were included for internal validation. 52 patients from Zhejiang Hospital were included for external validation of the diagnostic model. Correlation analysis of BIA indexes with other nutritional indicators was performed. Logistic regression was used to examine the association of BIA indexes with PEW. 12 diagnostic models of PEW in maintenance dialysis patients were developed and the performance of them in terms of discrimination and calibration was evaluated using C statistics and Hosmer-Lemeshow-type χ2 statistics. After comparing to existing diagnostic models, and performing both internal and external validation, we finally established a simple but reliable PEW diagnostic model which may have great value of clinical application. RESULTS: A total of 609 individuals from First Affiliated Hospital, College of Medicine, Zhejiang University and 52 individuals from Zhejiang Hospital were included. After full adjustment, age, peritoneal dialysis (compared to hemodialysis), subjective global assessment (SGA, compared to non-SGA) and water ratio were independent risk factors, while triglyceride, urea nitrogen, calcium, ferritin, BCM, VFA and phase angle were independent protective factors of PEW. The model incorporated water ratio, VFA, BCM, phase angle and cholesterol revealed best performance. A nomogram was developed according to the results of model performance. The model achieved high C-indexes of 0.843 in the training set, 0.841 and 0.829 in the internal and external validation sets, respectively, and had a well-fitted calibration curve. The net reclassification improvement (NRI) showed 8%, 13%, 2%, 38%, 36% improvement of diagnostic accuracy of our model compared with "PEW score model", "modified PEW score model", "3-index model", "SGA model" and "BIA decision tree model", respectively. CONCLUSIONS: BIA can be used as an auxiliary tool to evaluate PEW risk and may have certain clinical application value.

Preliminary Structural Characterization of Selenium Nanoparticle Composites Modified by Astragalus Polysaccharide and the Cytotoxicity Mechanism on Liver Cancer Cells.

Astragalus alcohol soluble polysaccharide (AASP) could present superior water solubility and antitumor activity with high concentration. Selenium nanoparticles (SeNPs) have received growing attention in various fields, but their unstable property increases the application difficulties. In the present study, functionalized nano-composites (AASP-SeNPs) were synthesized through SeNPs using AASP (average molecular weight of 2.1 × 103 Da) as a surface modifier, and the preliminary structural characteristics and inhibitory mechanism on liver cancer (HepG2) cells were investigated. Results showed that AASP-SeNPs prepared under a sodium selenite/AASP mass ratio of 1/20 (w/w) were uniformly spherical with a mean grain size of 49.80 nm and exhibited superior dispersivity and stability in water solution. Moreover, the composites could dose-dependently inhibit HepG2 cell proliferation and induce apoptosis through effectively regulating mitochondria-relevant indicators including ΔΨm depletion stimulation, intracellular ROS accumulation, Bax/Bcl-2 ratio improvement, and Cytochrome c liberation promotion. These results provide scientific references for future applications in functional food and drug industries.

Changes in texture, rheology and volatile compounds of golden pomfret sticks inoculated with Shewanella baltica during spoilage.

Shewanella baltica has a high spoilage ability to decompose nutrients in fish. To investigate the role of S. baltica in fish protein and flavour during spoilage, the texture, rheology, protein patterns and volatile compounds of golden pomfret inoculated with S. baltica during 10-day storage were tested. During storage, S. baltica reduced the hardness of fish sticks by 29.73-49.24 %. Compared to the control (G0': 20.27 ± 2.15 kPa), inoculated samples showed lower moduli (G0': 16.71 ± 0.82-17.50 ± 1.80 kPa). Their myosin heavy chains, myosin-binding protein C and actin were decomposed into smaller proteins, which was validated by the lower intensities of molecules with Mw 160-176 kDa. Furthermore, S. baltica generated volatile spoilage markers, including dimethyl sulfide, 2-methyl-butanal and 3-methyl-butanal. This study reveals the mechanism of fish texture and flavour changes induced by S. baltica, and provides insights into controlling bacterial spoilage of seafood.

Integrated metabolomics analysis of Lactobacillus in fermented milk with fish gelatin hydrolysate in different degrees of hydrolysis.

Dual-platform metabolomics combined with multivariate data analysis was used to investigate the effects of adding fish gelatin (FGH) at different degrees of hydrolysis (DH) on the growth and metabolic pathways of different species of Lactobacillus in fermented milk. The results showed that the promotion effect of FGH on Lactobacillus was related to the species of probiotics. The corresponding metabolic pathways also changed, with the promotion of Lactobacillus by FGH mainly regulated through amino acid metabolism, lipid metabolism, and nucleotide metabolism pathways. The excess DH inhibited the growth of L. paracasei by adjusting its metabolic state through reducing nucleotide requirements, allocating protein resources, and adopting a stress response. In conclusion, this study revealed the effectiveness of dual-platform metabolomics in explaining the metabolic mechanisms of probiotics, providing theoretical support and a scientific basis for the development of functional fermented foods.

NMR-based metabolomics reveals the antibacterial effect of electrolysed water combined with citric acid on Aeromonas spp. in barramundi (Lates calcarifer) fillets.

The citric acid (CA) and electrolysed water (EW) are considered effectively in inactivating microorganisms. The objective of this study was to explore the bactericidal mechanism of CA combined with EW on Aeromonas spp. in barramundi (Lates calcarifer) by in vitro metabolomics method. This study determined the survival population of three strains of Aeromonas bacteria (strain 1: Aeromonas salmonicida strain A1 (skin); strain 2: A. veronii strain Til2 (gut), and strain 3: A. hydrophila strain B11 (gill)), which were isolated and identified from putrid barramundi treated alone or in combination with 1 % CA and EW (free available chlorine (FAC) 25 mg/L, pH 3.23, oxidation-reduction potential (ORP) 1015 mV). The bactericidal mechanism was investigated by microbiological analysis, nuclear magnetic resonance (NMR), multivariate data analysis, and fluorescence staining analysis. The results showed that the combined treatment significantly reduced the number of Aeromonas bacteria at 1.64-1.69 log CFU/g and extended the shelf life of barramundi fillets. In addition, the combined treatment had a higher effect on the cell membrane integrity of the bacteria. In total, 36 metabolites were identified in the three strains. The undissociated molecules of CA can enter the cytoplasm, resulting in cell damage and inhibiting metabolic pathways. EW could lead to the reduction of metabolic products caused by oxidative stress and acid stress. Under the synergistic stress of CA and EW, the changes of main metabolite contents in the combined treatment group were significantly reduced. After combined treatment, there were 20, 31, and 31 pathways in which carbohydrate metabolism, amino acid metabolism, and energy metabolism were changed considerably. These findings indicated that the bactericidal mechanism of the bactericidal substance might be explained by the interference of the metabolic pathway, which guided post-treatment sanitisation and extended the applicability of the NMR spectrum to specific spoilage organisms (SSO) analysis in fish.

Associations between short-term exposure of ambient particulate matter and hemodialysis patients death: A nationwide, longitudinal case-control study in China.

BACKGROUND: Long-term exposure to particulate air pollutants can lead to an increase in mortality of hemodialysis patients, but evidence of mortality risk with short-term exposure to ambient particulate matter is lacking. This study aimed to estimate the association of short-term exposure to ambient particulate matter across a wide range of concentrations with hemodialysis patients mortality. METHODS: We performed a time-stratified case-crossover study to estimate the association between short-term exposures to PM2.5 and PM10 and mortality of hemodialysis patients. The study included 18,114 hemodialysis death case from 279 hospitals in 41 cities since 2013. Daily particulate matter exposures were calculated by the inverse distance-weighted model based on each case's dialysis center address. Conditional logistic regression were implemented to quantify exposure-response associations. The sensitivity analysis mainly explored the lag effect of particulate matter. RESULTS: During the study period, there were 18,114 case days and 61,726 control days. Of all case and control days, average PM2.5 and PM10 levels were 43.98 µg/m3 and 70.86 µg/m3, respectively. Each short-term increase of 10 µg/m3 in PM2.5 and PM10 were statistically significantly associated with a relative increase of 1.07 % (95 % confidence interval [CI]: 0.99 % - 1.15 %) and 0.89 % (95 % CI: 0.84 % - 0.94 %) in daily mortality rate of hemodialysis patients, respectively. There was no evidence of a threshold in the exposure-response relationship. The mean of daily exposure on the same day of death and one-day prior (Lag 01 Day) was the most plausible exposure time window. CONCLUSIONS: This study confirms that short-term exposure to particulate matter leads to increased mortality in hemodialysis patients. Policy makers and public health practices have a clear and urgent opportunity to pass air quality control policies that care for hemodialysis populations and incorporate air quality into the daily medical management of hemodialysis patients.

Nanoemulsified clove essential oils-based edible coating controls Pseudomonas spp.-causing spoilage of tilapia (Oreochromis niloticus) fillets: Working mechanism and bacteria metabolic responses.

Fish products suffer Pseudomonas-causing spoilage quickly during refrigeration storage, which could be solved by applying edible coating derived from nanoemulsified clove essential oils and fish gelatin (NCEO-FG). This study aimed to evaluate the effects and mechanism of NCEO-FG in preserving tilapia (Oreochromis niloticus) fillets that were inoculated with Pseudomonas spp. (Pseudomonas sp. strain ABa3, P. psychrophila strain ABe3, and P. fragi strain BBa3). NCEO caused remarkable leakage of proteins (198.5-252.8 µg/L) and nucleic acids (0.30-0.34 of OD260). After being incorporated into FG, NCEO-FG effectively delayed the deterioration of tilapia fillets because it significantly reduced the surviving bacteria populations (0.78 - 1.80 log CFU/g reductions) and inhibited the proteolysis and oxidation during cold storage. Further, the metabolic responses of NCEO-FG coated Pseudomonas spp. were revealed using NMR spectroscopy: the reducing levels of metabolites (e.g., pyruvate, amino acids, and betaine) suggested that the NCEO-FG disturbed energy and amino acid metabolisms of bacteria cells. However, the levels of metabolites (e.g., amino acids and osmoprotectants) were upregulated after 3 h and then back to normal concentration after 24 h, which indicated a defense system was built in bacterial cells to tolerate NCEO-FG. In short, this study confirmed that NCEO-FG could control the Pseudomonas-causing spoilage in fish fillets via elucidating the metabolisms.

LuxS in Lactobacillus plantarum SS-128 Improves the Texture of Refrigerated Litopenaeus vannamei: Mechanism Exploration Using a Proteomics Approach.

This study illustrated the texture changes of Shewanella baltica-inoculated Litopenaeus vannamei during refrigerated storage with the exogenous addition of Lactobacillus plantarum SS-128. The group inoculated with SS-128 had an improved texture compared with that inoculated with the luxS-mutant group (ΔluxS). Proteomics were conducted to analyze the protein alterations in L. vannamei and supernatant, respectively. During storage, many texture-related proteins, including myosin heavy chain and beta-actin, were maintained due to luxS. Some endogenous enzymes related to the energy metabolism and hydrolysis of L. vannamei were downregulated. The luxS-induced interaction with S. baltica showed significant changes in the expression of some critical enzymes and pathways. The ATP-dependent zinc metalloprotease FtsH and protease subunit HslV were downregulated, and the oxidative phosphorylation and glycosaminoglycan degradation pathways in S. baltica were inhibited, resulting in the slow deterioration of L. vannamei. By exploring the mechanism underlying SS-128-led manipulation of the metabolism of spoilage bacteria, we clarified the texture maintenance mechanism of luxS in SS-128, providing theoretical evidence for SS-128 application in food preservation.

Physical activity and somatic symptoms among hemodialysis patients: a multi-center study in Zhejiang, China.

BACKGROUND: Somatic symptoms are commonly reported by patients on maintenance hemodialysis. Based on evidence that exercise can improve psychological state among the general population, we aimed to evaluate the effects of physical activity on somatic symptoms specifically in this clinical population. METHODS: This was a multicenter, cross-sectional study that included patients receiving hemodialysis treatment ≥3 times per week for > 3 months, aged 18 years or older, and who were willing to complete our study questionnaires and wear a pedometer; they were recruited from four hemodialysis centers in Zhejiang, China. Physical activity was quantified using pedometer data, with somatic symptoms quantified using the Symptom Checklist-90 (SCL-90). Hemodialysis information and blood laboratory tests were obtained from patients' medical record. The score on the somatic dimension of the SCL-90 (S1-score) subdivided into tertiles for analysis: ≤1.17 (Q1), 1.17-1.58 (Q2) and ≥ 1.58 (Q3). A multivariate logistic regression analysis was performed to estimate the crude and adjusted odd ratios (ORs) and 95% confidence intervals (CIs) for the S1- somatic score according to the physical activity level during the last week. For this analysis, patients were stratified in a high and low exercise group using a cutoff of 3000 MET-min/week. Model 1 was adjusted for skinfold thickness of the triceps, upper arm circumference, grip strength, 5-m walking time, and 30-s sit-to-stand test. In model 2, we further adjusted for the leukocyte count, high-sensitivity C-reactive protein level, and albumin level. RESULTS: After screening, 320 patients were enrolled into the study group (37.50% male, average age of 58.60 ± 14.2 years and mean average number of steps per day of 3725.92 ± 2663.47). The S1-score (1.51 ± 0.39) was significantly higher for patients than for the normal reference population (P < 0.001). As the S1-score increased, the average number of steps per day decreased, both on dialysis and non-dialysis days. Total physical activity, measured by pedometry, showed the best correlation to S1 scores (r = - 0.813; P < 0.01). The OR of a high S1-score was 1.97 [95% CI, 0.63-4.08] for patients in the low physical activity group. CONCLUSION: Higher S1 (somatic symptom) score was related to low physical activity among patients on maintenance hemodialysis.

Validity and Reliability of the International Physical Activity Questionnaire in Chinese Hemodialysis Patients: A Multicenter Study in China.

BACKGROUND This study aimed to assess the reliability and validity of the International Physical Activity Questionnaire (IPAQ) in Chinese maintenance hemodialysis (MHD) patients. These findings could help increase the validity of future MHD physical activity (PA) studies, both within China and throughout the world. MATERIAL AND METHODS A multicenter prospective cohort study including 320 patients was conducted in Zhejiang, China. Patients' PA was assessed by analyzing answers to the International Physical Activity Questionnaire Chinese version (IPAQ-C) during hemodialysis, and comparing the results with 1 week of pedometer data. RESULTS The IPAQ-C had good internal reliability and test-retest stability (total ICC=0.84, 95%CI 0.76-0.89), and all PA-related variables correlated significantly between the IPAQ-C and pedometer data (r=0.280-0.561). When stratified by sex, there was a significant correlation for total PA (Spearman r=0.468 p<0.01 for women; Spearman r=0.603 p<0.01 for men) and intensity between pedometry and IPAQ-C. After adjustment for several factors, no relationships were observed among women, but significant relationships existed for men (total partial r=0.486 p<0.05, moderate PA partial r=0.358 p<0.05, walking partial r=0.465 p<0.05, vigorous PA not significant). CONCLUSIONS This is the first study to test the reliability and validity of the IPAQ-C in Chinese MHD patients. Overall, we conclude that IPAQ-C is a simple and reliable instrument for measuring PA in Chinese MHD patients, but possible sex and age bias should be considered when interpreting these results.

Comparison of metabolic response between the planktonic and air-dried Escherichia coli to electrolysed water combined with ultrasound by 1H NMR spectroscopy.

The antimicrobial effects of electrolysed water and ultrasound have been well reported; however, little attention was paid to their effects on the metabolite changes of bacteria in different states. In this study, the metabolomic variations of Escherichia coli ATCC 25922 in planktonic and adherent state (air-dried on stainless steel coupons) after the combination treatment of low-concentration acidic electrolysed water (AEW, free available chlorine (FAC): 4 mg/L) and ultrasound were characterised, by conducting multivariate data analysis based on nuclear magnetic resonance (NMR) spectroscopy. Overall, 43 metabolites were identified in two states of E. coli, including a wide range of amino acids, organic acids, nucleotides and their derivatives. The quantification of whole-cell metabolism in planktonic and air-dried cultures was quite different: air-dried E. coli exhibited more resistance to ultrasound and AEW treatments due to initiating a protective response against oxidative and acid stresses, which was not observed in planktonic E. coli, whose levels of all identified metabolites were decreased significantly after the combined treatment. Further pathway analysis revealed that alanine, aspartate and glutamate metabolism, glycolysis, pyruvate metabolism and tricarboxylic acid (TCA) cycle were changed significantly in planktonic culture, but to a less extent in air-dried culture, in which some shifts in glutamate decarboxylase (GAD) system and some shunts like mixed acid fermentation and pentose phosphate pathway were observed for maintaining metabolic balance. These findings suggest that NMR-based metabolomics strategy is promising in identifying different metabolic shifts in different states of bacteria. They also provide some guidance for food equipment sanitisation, especially for organic food processing.

Comparison of the Effects of Indobufen and Warfarin in a Rat Model of Adenine-Induced Chronic Kidney Disease.

BACKGROUND Worldwide, the treatment of patients with chronic kidney disease (CKD) remains a challenge as warfarin treatment can be associated with severe adverse events related to bleeding. Alternative anticoagulants that can be used in CKD remain to be identified. This study aimed to compare the effects of indobufen, a new antiplatelet agent, with warfarin in a rat model of adenine-induced CKD. MATERIAL AND METHODS Forty-eight male Wistar rats were treated with intragastric adenine to create the rat model of CKD and were divided into four groups: an untreated control group (N=12), a group treated with dimethyl sulfoxide (DMSO) (N=12), a group treated with indobufen, (N=12) and a group treated with warfarin (N-12). Treatment was given for 4 weeks and 8 weeks. Kidney histology was performed, and the degree of fibrosis was quantified using Masson trichrome staining. RESULTS In the rat model of adenine-induced CKD, Masson trichrome staining showed that the degree of kidney fibrosis in the indobufen group (26%) was significantly reduced (p<0.05) when compared the DMSO group (58%) and the warfarin group (49%). Kidney fibrosis was associated with upregulation of 6-keto-PGI2/TXB2 in the rat kidney tissue. CONCLUSIONS In a rat model of adenine-induced CKD, preliminary findings showed that indobufen was associated with reduced kidney fibrosis when compared with warfarin.

Effect of high-pressure treatment on taste and metabolite profiles of ducks with two different vinasse-curing processes.

The effect of high-pressure (HP) (0.1, 150 and 300MPa, 15min) on taste profiles of vinasse-cured ducks was investigated; the metabolite profiles were determined using 1H NMR. HP at 150MPa increased the taste intensity of products compared with the controls, while HP at 300MPa did not further improve their taste compared with 150MPa treated samples. The metabonome of vinasse-cured ducks was dominated by 27 metabolites. HP increased amino acids, glucose, alkaloids and organic acids, but decreased inosine monophosphate and its derivatives, compared with the controls. The increments of metabolites in vinasse-dry-cured duck were higher than those in vinasse-wet-cured duck. The change of metabolites could be related to the enzyme activity, the degradations of proteins, sugars and nucleotides, and the permeation from vinasse-curing agents to duck meat. These findings suggest that 150MPa treatment was effective to improve the taste of vinasse-cured duck.

The effect of microwave on the interaction of flavour compounds with G-actin from grass carp (Catenopharyngodon idella).

BACKGROUND: In order to investigate the influence of non-thermal effects of microwaves on the flavour of fish and meat products, the G-actin of grass carp in ice baths was exposed to different microwave powers (0, 100, 300 or 500 W); the surface hydrophobicity, sulfhydryl contents, secondary structures and adsorption capacity of G-actin to ketones were determined. RESULTS: As microwave power increased from 0 to 300 W, the surface hydrophobicity, total and reactive sulfhydryls increased; α-helix, ß-sheet and random coil fractions turned into ß-turn fractions. As microwave power increased from 300 to 500 W, however, hydrophobicity and sulfhydryl contents decreased; ß-turn and random coil fractions turned into α-helix and ß-sheet fractions. The tendencies of adsorbed capacity of ketones were similar to hydrophobicity and sulfhydryl contents. CONCLUSION: The increased adsorbing of ketones could be attributed to the unfolding of secondary structures by revealing new binding sites, including thiol groups and hydrophobic binding sites. The decreased binding capacity was related to the refolding and aggregation of protein. The results suggested that microwave powers had obvious effects on the flavour retention and proteins structures in muscle foods. © 2017 Society of Chemical Industry.

Involvement of xanthine oxidase and paraoxonase 1 in the process of oxidative stress in nonalcoholic fatty liver disease.

Xanthine oxidase (XOD) and paraoxonase 1 (PON1) are important enzymes in redox reactions in vivo, and are predominantly synthesized by the liver. The aim of the present study was to investigate the redox state in nonalcoholic fatty liver disease, and determine the association between the activities of XOD and PON1 and the severity of NAFLD. Sprague­Dawley rats were randomly divided into control, model and α­lipoic acid (high and low dose) groups. The rats in the NAFLD model were induced by feeding a high fat diet for 12 weeks and the in vitro cell model of hepatocyte steatosis was induced by treating L­02 cells with oleic acid for 24 h. The body weight, liver function, lipid and oxidative stress indices, and histological features of the liver were examined in the rats. Compared with the control group, the rats in the NAFLD model group showed impaired liver function, lipid disorders and damage from oxidative stress. The serum activity of XOD increased significantly from the 4th week and was markedly higher, compared with that in the control group, reaching a peak in the 12th week. The activity of PON1 was negatively correlated with that of XOD. Compared with the control cells, the activity of XOD and levels of free­fatty acids were significantly higher, and the activity of PON1 was significantly lower in the NAFLD L­02 cell model. All the above indicators were significantly improved by treatment with the antioxidant, α­lipoic acid. The activities of XOD and PON1 may be promising as markers in a noninvasive approach for detecting the severity of NAFLD clinically. α­lipoic acid had protective effects on the NAFLD rats, and the potential mechanism may be associated with the inhibition of oxidative stress and lipid peroxidation.

Liposomes as delivery systems for carotenoids: comparative studies of loading ability, storage stability and in vitro release.

This study compared the loading ability of various carotenoids into liposomal membrane, lipid peroxidation inhibition capacity, storage stability and in vitro release behavior in simulated gastrointestinal (GI) media. It was found that carotenoids exhibited various incorporating abilities into liposomes ranging from the strongest to the weakest: lutein > ß-carotene > lycopene > canthaxanthin. A similar trend was also observed in their antioxidant activities against lipid peroxidation during preparation. Storage measurements demonstrated that a liposomal membrane can strongly retain ß-carotene and lutein, whereas this effect was not pronounced for lycopene and canthaxanthin. In vitro release experiments showed that lutein and ß-carotene were hardly released in a simulated gastric fluid, while displaying a slow and sustained release in a simulated intestinal fluid. By contrast, lycopene and canthaxanthin underwent fast and considerable release in GI media. Dynamic light scattering indicated that carotenoid incorporation strongly affected the particle stability and dispersion during preparation and GI incubation. The differences in molecular release may be attributed to the different modulating effects of carotenoids. Our results may guide the potential application of liposomes as carriers for the controlled delivery of carotenoids in nutraceutical and functional foods.