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Hypoxia‐ischemia (HI) of the brain not only impairs neurodevelopment but also causes pineal gland dysfunction, which leads to circadian rhythm disruption. However, the underlying mechanism of circadian rhythm disruption associated with HI‐induced pineal dysfunction remains unknown. The zinc finger protein repressor protein with a predicted molecular mass of 58 kDa (RP58) is involved in the development and differentiation of nerve cells. In this study, we established an HI model in neonatal rats to investigate the expression of RP58 and its role in pineal dysfunction and circadian rhythm disruption induced by HI. We demonstrated that RP58 was highly expressed in the pineal gland under normal conditions and significantly downregulated in the pineal gland and primary pinealocytes following HI. Knockdown of RP58 decreased the expression of enzymes in the melatonin (Mel) synthesis pathway (tryptophan hydroxylase 1 [TPH1], acetylserotonin O‐methyltransferase [ASMT], and arylalkylamine N‐acetyltransferase [AANAT]) and clock genes (circadian locomotor output cycles kaput [CLOCK] and brain and muscle ARNT‐like 1 [BMAL1]), and it also reduced the production of Mel, caused pineal cell injury, and disrupted circadian rhythms in vivo and in vitro. Similarly, HI reduced the expression of Mel synthesis enzymes (TPH1, ASMT, and AANAT) and clock genes (CLOCK and BMAL1), and caused pineal injury and circadian rhythm disruption, which were exacerbated by RP58 knockdown. The detrimental effect of RP58 knockdown on pineal dysfunction and circadian rhythm disruption was reversed by the addition of exogenous Mel. Furthermore, exogenous Mel reversed HI‐induced pineal dysfunction and circadian rhythm disruption, as reflected by improvements in Mel production, voluntary activity periods, and activity frequency, as well as a diminished decrease in the expression of Mel synthesis enzymes and clock genes. The present study suggests that RP58 is an endogenous source of protection against pineal dysfunction and circadian rhythm disruption after neonatal HI. [ABSTRACT FROM AUTHOR]

Spatiotemporal reflectance fusion has received considerable attention in recent decades. However, various challenges remain despite varying levels of success, especially regarding the recovery of spatial details with complex land cover changes. Taking the blending of Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS) images as an example, this article presents a locally weighted unmixing-based spatiotemporal image fusion model (LWU-STFM) that focuses on recovering complex land cover changes. The core idea is to redefine the land use class of each pixel featuring land cover change at the prediction date. The spatial unmixing process is enhanced using a proposed geographically spectrum-weighted regression (GSWR), and then, we optimize similar neighboring pixels for the final weighted-based prediction. Experiments are conducted using semisimulated and actual time-series Landsat–MODIS datasets to demonstrate the performance of the proposed LWU-STFM compared with the classic spatial and temporal adaptive reflectance fusion model (STARFM), flexible spatiotemporal data fusion (FSDAF), two enhanced FSDAF models (SFSDAF and FSDAF 2.0), and a virtual image pair-based spatiotemporal fusion model for spatial weighting (VIPSTF-SW). The results reveal that the proposed LWU-STFM outperforms the other five models with the best quantitative accuracy. In terms of the relative dimensionless global error (ERGAS) index, the errors of Landsat-like images generated using LWU-STFM are 2.8%–63.4% lower than those of other models. From visual comparisons, LWU-STFM predictions illustrate encouraging improvements in recovering spatial details of pixels with complex land cover changes in heterogeneous landscapes and, thus, advancing applications of spatiotemporal image fusion for continuous and fine-scale land surface monitoring. [ABSTRACT FROM AUTHOR]

This study explored the differences in emotional memory between adolescents with and without suicidal ideation. Fifty adolescents with depression and suicidal ideation, 36 with depression but no suicidal ideation, and 41 healthy controls rated the emotional valence of positive, neutral, and negative pictures. Then, the recognition of the images was evaluated 72 h later. Adolescents with suicidal ideation reported more negative emotional valence scores for positive and neutral pictures and were significantly less likely to recognize negative pictures than were those without suicidal ideation. The performance of adolescents with suicidal ideation on the negative picture recognition test was closely related to anxiety, depression severity, and intensity of suicidal ideation. The negative bias toward neutral stimuli and cognitive impairment may be important risk factors for adolescents with suicidal ideation. Improving emotional memory via targeted management approaches may help young people with suicidal ideation. [ABSTRACT FROM AUTHOR]

Background: Cognitive impairment is a core feature of schizophrenia that is more serious in patients with early-onset schizophrenia (EOS). However, the neuroimaging basis of cognitive functions, including neurocognition and social cognition, remains unclear in patients with EOS. Methods: Forty-three patients with EOS underwent structural and resting state functional magnetic resonance imaging scans. Brain structure and function were evaluated through the analysis of brain gray matter volume (GMV) and amplitude of low-frequency fluctuations (ALFF). They underwent comprehensive assessments for neurocognition (verbal memory, verbal expression, attention, and executive function) and social cognition (theory of mind and attributional bias). Correlation analyses were conducted to detect the potential link between cognitive function indices and brain imaging parameters. Results: First, neurocognition was linked to brain structure characterized by higher immediate recall scores associated with increased GMV in the left temporal pole, higher verbal fluency scores associated with increased GMV in the left temporal pole: middle temporal gyrus, and higher Stroop-word scores associated with increased GMV in the right middle frontal gyrus. Second, social cognition was related to brain function characterized by lower sense of reality scores associated with increased ALFF in the left precentral gyrus, higher scores of accidental hostility bias associated with increased ALFF in the right middle temporal gyrus, and higher scores of accidental aggression bias associated with increased ALFF in the left precentral gyrus. Conclusion: These findings may add to the existing knowledge about the cognitive function-brain relationship. They may have clinical significance for studying the mechanism of neurocognitive and social cognitive impairment in patients with EOS and providing potential neural targets for their treatment and intervention. [ABSTRACT FROM AUTHOR]

Background: Multiple myeloma (MM) is the most common malignant hematological disease in the people worldwide. Glaucocalyxin A (GLA) is a bioactive ent-kauranoid diterpenoid, that is derived from Rabdosia japonica var. GLA has been demonstrated that it had various pharmacological activities, such as anti-coagulation, anti-bacterial, anti-tumor, anti-inflammation, antioxidant activities. Although GLA has effective anti-tumor properties, its effects on multiple myeloma remain unclear. The aim of this study was to examine the possible anti-cancer effects of GLA and their molecular mechanisms on MM cells in vitro and in vivo. Methods: To evaluate the role of GLA on the proliferation of MM cells in vitro and in vivo, we used MTT method to detect the role of GLA on the proliferation of MM cells. Cell apoptosis and cell cycle assay were evaluated by flow cytometry. Protein expressions in GLA-treated and untreated MM cells were evaluated by western blot analyses. MM xenograft nude mice model was used to investigate the role of GLA on the proliferation of MM cells in vivo. IHC assay was used to examine the role of GLA on the MM xenograft model in vivo. Results: In the present study, we firstly reported the potent anti-myeloma activity of GLA on MM cells. We found that GLA could induce apoptosis in vitro and in vivo. GLA could inhibit the phosphorylation of the signal transducer and activator of transcription 3 (STAT3) and downregulate interleukin IL-6 induced STAT3 phosphorylation in MM. Overexpression of STAT3 could significantly prevent apoptosis induced by GLA; while knockdown of STAT3 enhanced it. Moreover, GLA could inhibit cell proliferation by inducing the cell cycle arrest. GLA reduced the expression of cell cycle-related proteins CCNB1, CCND1, CCND2, and CCND3 and increased the expression of p21 in MM cell lines. In addition, in the MM xenograft nude mice model, GLA exhibited very good anti-myeloma activity. Administration of GLA almost completely inhibited tumor growth within 19 days without physical toxicity. And the IHC results showed GLA significantly inhibited cell proliferation and interfered STAT3 pathway on MM xenograft model tumor tissues. Conclusions: Taken together, our present research indicated that GLA inhibits the MM cell proliferation, induces MM cell apoptosis and cell cycle arrest through blocking the activation of STAT3 pathway. Thus, GLA may be a potential therapeutic candidate for MM patients in the future. [ABSTRACT FROM AUTHOR]

Background: Multiple myeloma (MM) is the most common malignant hematological disease in the people worldwide. Glaucocalyxin A (GLA) is a bioactive ent-kauranoid diterpenoid, that is derived from Rabdosia japonica var. GLA has been demonstrated that it had various pharmacological activities, such as anti-coagulation, anti-bacterial, anti-tumor, anti-inflammation, antioxidant activities. Although GLA has effective anti-tumor properties, its effects on multiple myeloma remain unclear. The aim of this study was to examine the possible anti-cancer effects of GLA and their molecular mechanisms on MM cells in vitro and in vivo. Methods: To evaluate the role of GLA on the proliferation of MM cells in vitro and in vivo, we used MTT method to detect the role of GLA on the proliferation of MM cells. Cell apoptosis and cell cycle assay were evaluated by flow cytometry. Protein expressions in GLA-treated and untreated MM cells were evaluated by western blot analyses. MM xenograft nude mice model was used to investigate the role of GLA on the proliferation of MM cells in vivo. IHC assay was used to examine the role of GLA on the MM xenograft model in vivo. Results: In the present study, we firstly reported the potent anti-myeloma activity of GLA on MM cells. We found that GLA could induce apoptosis in vitro and in vivo. GLA could inhibit the phosphorylation of the signal transducer and activator of transcription 3 (STAT3) and downregulate interleukin IL-6 induced STAT3 phosphorylation in MM. Overexpression of STAT3 could significantly prevent apoptosis induced by GLA; while knockdown of STAT3 enhanced it. Moreover, GLA could inhibit cell proliferation by inducing the cell cycle arrest. GLA reduced the expression of cell cycle-related proteins CCNB1, CCND1, CCND2, and CCND3 and increased the expression of p21 in MM cell lines. In addition, in the MM xenograft nude mice model, GLA exhibited very good anti-myeloma activity. Administration of GLA almost completely inhibited tumor growth within 19 days without physical toxicity. And the IHC results showed GLA significantly inhibited cell proliferation and interfered STAT3 pathway on MM xenograft model tumor tissues. Conclusions: Taken together, our present research indicated that GLA inhibits the MM cell proliferation, induces MM cell apoptosis and cell cycle arrest through blocking the activation of STAT3 pathway. Thus, GLA may be a potential therapeutic candidate for MM patients in the future. [ABSTRACT FROM AUTHOR]

Background: While great attention has been paid to motor and cognitive impairments in children with neonatal Hypoxic-Ischemic Encephalopathy (HIE), sleep related circadian rhythm problems, although commonly present, are often neglected. Subsequently, no early clinical indicators have been reported to correlate with sleep-related circadian dysfunction during development.Methods: In this study, we first analyzed patterns of the amplitude integrated electroencephalogram (aEEG) in a cohort of newborns with various degrees of HIE. Next, during follow-ups, we collected information of sleep and circadian related problems in these patients and performed correlation analysis between aEEG parameters and different sleep/circadian disorders.Results: A total of 101 neonates were included. Our results demonstrated that abnormal aEEG background pattern is significantly correlated with circadian rhythmic (r = 0.289, P = 0.01) and breathing issues during sleep (r = 0.237, P = 0.037). In contrast, the establishment of sleep-wake cycle (SWC) showed no correlation with sleep/circadian problems. Detailed analysis showed that summation of aEEG score, along with low base voltage (r = 0.272, P = 0.017 and r = -0.228, P = 0.048, respectively), correlates with sleep circadian problems. In contrast, background pattern (BP) score highly correlates with sleep breathing problem (r = 0.319, P = 0.004).Conclusion: Abnormal neonatal aEEG pattern is correlated with circadian related sleep problems. Our study thus provides novel insights into predictive values of aEEG in sleep-related circadian problems in children with HIE. [ABSTRACT FROM AUTHOR]

The differentiated components of alginate-derived oligosaccharides (AOS) lead to different activities on plant. Optimizing AOS use efficiency is, therefore, of major importance for the implementation of precision agriculture. Effects of AOS on biophysical characteristics and growth and development of barley (Hordeum vulgare L.) have been investigated. The experiments were conducted by soaking the seeds in AOS solutions with different molecular weights and Mannuronate/Guluronate ratio. The results showed that depending on their components, AOS stimulated the growth of seedlings and roots differently. AOS with low MW (500–3000 Da) and higher M/G ratio (> 1) had better promotion on the plant. The promoting effects on seedlings and roots were not an exact match. Our results suggested that the promotion effects of AOS on seedlings might be caused by the stimulation on photosynthesis and the roots growth were promoted probably due to the enhanced absorption activity. In gene level, we demonstrated that AOS induced the expression of development-related genes including auxin response factor and mitogen-activated protein kinase, thereby promoting the growth. Our research may provide a basis for more targeted and precise use of AOS in agriculture. [ABSTRACT FROM AUTHOR]

Summary: A novel synbiotic multiparticulate microparticle containing alginate oligosaccharide (AOS), chitosan oligosaccharide (COS) and Bifidobacterium longum CICC 6259 was produced in the current study to expand the synbiotic industrial applications. The influences of these treatments on encapsulation yield, size, morphology, protective effect and stability of microcapsules and on mice gut microbiome were studied in vitro and in vivo. In vitro experiments detected no significant difference (P > 0.05) in encapsulation yield with different types of microcapsules. However, the microcapsule diameter of marine oligosaccharide was approximately 60 μm greater, and these microcapsules increased the number of surviving cells by more than 3 log cfu/g after treatment with simulated gastrointestinal juices, compared to basic alginate microcapsules. In vivo, these microcapsules significantly increased the content of Bifidobacterium and Lactobacillus and reduced the content of Enterococcus and Escherichia in mice gut microbiome. Marine oligosaccharide probiotic microcapsules are promising as a novel functional food ingredient. [ABSTRACT FROM AUTHOR]

The present study investigated the effects of Porphyra yezoensis enzyme degradation extract (PYEDE) on the brain injuries and neurodegenerative diseases due to oxidative stress. We used in vitro antioxidant systems to verify the antioxidant potential of PYEDE. The results indicated that the PYEDE alleviated weight loss and organ atrophy, reduced the levels of lipid peroxidation and protein carbonylation and elevated reduced glutathione (GSH) content in the serum and brains of the d -galactose-induced ageing model mice. The PYEDE also renewed the glutathione peroxidase (GSH-Px), superoxide dismutase and total antioxidant capability activities, down-regulated the inducible nitric oxide synthase activity and nitric oxide levels, normalised the hippocampal neurons and modulated multiple neurotransmitter systems by inhibiting the activities of acetylcholinesterase and monoamine oxidase in the up-regulation of acetylcholine, dopamine and noradrenaline levels. Overall, the PYEDE is a promising supplement for the alleviation of oxidative stress and age-associated brain diseases. [ABSTRACT FROM AUTHOR]

The effect of polysaccharidases (agarase and cellulase) on R-phycoerythrin (R-PE) extraction from dry Pyropia yezoensis was investigated and optimized. First, single-factor experiments of agarase dosage, cellulase dosage, temperature, hydrolysis time, and solid/liquid ratio were performed and factors for further optimization were selected based on Pearson's correlation analysis. Next, response surface methodology (RSM) based on a three-level three-factor Box Behnken Design (BBD) was applied to optimize R-PE extraction conditions including agarase dosage, temperature, and solid/liquid ratio. The experimental data were adequately fitted into the second-order polynomial models. Under the optimized extraction conditions, agarase dosage (104 U g−1 biomass), cellulase dosage (100 U g−1 biomass), temperature (29 °C), hydrolysis time (5 h), and solid/liquid ratio (1/26 w/v), the experimental yield of R-PE was 3.33 times greater than the extraction method lacking enzyme treatment, and 1.85 and 2.82 times, respectively, greater than the yields obtained by freeze-thaw and maceration experiments. The optimized enzyme-assisted extraction method enhanced the purity index 1.95-fold. R-PE extraction from dry P. yezoensis using agarase and cellulase is a promising method to utilize some high-value compounds from P. yezoensis. [ABSTRACT FROM AUTHOR]

The present meta-analysis aimed to evaluate the interaction between type 2 diabetes mellitus (T2DM) and the risk of cognitive impairment. The studies that fulfilled certain inclusion criteria were selected from online databases including PubMed, Embase, and the Cochrane Library. Data extraction and quality assessment were conducted, and subgroup analysis was performed according to the study area, population sources, and types of cognitive impairment. Publication bias and sensitivity analysis were evaluated. In total, 30 studies from 25 articles, including 2 case-control studies, 9 cohort studies, and 19 cross-sectional studies, were included. Subgroup analysis showed that despite the presence of hospital-based and multi-center subgroups in the cohort studies, the association between T2DM and cognitive impairment risk was statistically significant in all other subgroups (P < 0.05). Furthermore, the sensitivity and publication bias analysis showed good stability in all enrolled studies. T2DM might be associated with the risk of cognitive impairment. Further studies on early detection and appropriate management of cognitive impairment might be required in T2DM patients of different regions. [ABSTRACT FROM AUTHOR]

Melanocortin 4 receptor: (MC4R) and Myostatin (MSTN) are two important growth trait-related genes in animals. In this study, we showed that two SNPs, MC4R-719A>G and MSTN-519C>T, found in the promoters of the MC4R and MSTN genes, respectively, are both associated with growth traits in Spinibarbus hollandi. Furthermore, we observed that there were significant associations between the expression levels of the MC4R and MSTN genes and these two growth trait-related SNPs. The expression level of MC4R gene in brain was lower in GG genotype fish with extremely high growth performance than that in AA genotype fish with extremely low growth performance. Expression level of the MSTN gene in muscle was lower in TT genotype fish with extremely high growth performance than that in CC and CT genotype fish with lower growth performance. The results indicated that these SNPs located in the promoters of MC4R and MSTN are associated with growth-related traits through modification of gene expression levels. The MSTN and MC4R SNPs may have useful application in effective marker-assisted selection aimed to increase output in S. hollandi. [ABSTRACT FROM AUTHOR]

The mechanistic target of rapamycin complex 1 (mTORC1) controls cell growth and metabolism in response to nutrients, energy levels, and growth factors. It contains the atypical kinase mTOR and the RAPTOR subunit that binds to the Tor signalling sequence (TOS) motif of substrates and regulators. mTORC1 is activated by the small GTPase RHEB (Ras homologue enriched in brain) and inhibited by PRAS40. Here we present the 3.0 ångström cryo-electron microscopy structure of mTORC1 and the 3.4 ångström structure of activated RHEB-mTORC1. RHEB binds to mTOR distally from the kinase active site, yet causes a global conformational change that allosterically realigns active-site residues, accelerating catalysis. Cancer-associated hyperactivating mutations map to structural elements that maintain the inactive state, and we provide biochemical evidence that they mimic RHEB relieving auto-inhibition. We also present crystal structures of RAPTOR-TOS motif complexes that define the determinants of TOS recognition, of an mTOR FKBP12-rapamycin-binding (FRB) domain-substrate complex that establishes a second substrate-recruitment mechanism, and of a truncated mTOR-PRAS40 complex that reveals PRAS40 inhibits both substrate-recruitment sites. These findings help explain how mTORC1 selects its substrates, how its kinase activity is controlled, and how it is activated by cancer-associated mutations. [ABSTRACT FROM AUTHOR]

This study was designed to examine the immunoregulatory effects of alginate-derived oligosaccharides (ADOs) on farm-cultured Pacific white shrimpPenaeus vannameiand its resistance toVibrio harveyi. Total hemocyte count, superoxide dismutase (SOD) activity, bacteriolytic activity, phagocytic rate (PR), the average number of beads ingested per cell (ABPC), and the protective efficacy forP. vannameichallenged withVibrio harveyiwere determined. The study showed that the administration of ADOs at 1.0 g/kg of diet improved SOD activity, bacteriolytic activity, and PR by 25.2, 20.4, and 20.9%, respectively, 30 d after exposure. Total hemocyte count and ABPC showed no significant differences. The 96-h survival of the shrimp reached 46.7% and 90.0% when they were challenged withV. harveyiat concentrations of 1 × 107and 1 × 106cfu/shrimp, which was significantly higher than that in the control group. The results obtained indicate that ADOs can act as an immunoregulant forP. vannamei. Received February 11, 2017; accepted July 29, 2017Published online September 18, 2017 [ABSTRACT FROM PUBLISHER]

A hyaluronate lyase was obtained by cultivating Arthrobacter globiformis strain A152. The enzyme was purified to homogeneity from the supernatant by ammonium sulfate fractionation, Q Sepharose Fast Flow, and Sephadex G-100 chromatography. The purification resulted in a 32.78-fold increase in hyaluronate lyase activity with specific activity of 297.2 U/mg. The molecular weight of the enzyme determined by SDS-PAGE was approximately 73.7 kDa. Using hyaluronic acid (HA) as a substrate, the maximal reaction rate (V) and the Michaelis-Menten constant (K) of hyaluronate lyase were found to be 4.76 μmol/min/ml and 0.11 mg/ml, respectively. The optimum pH and temperature values for hyaluronate lyase activity were pH 6.0 and 42 °C, respectively. This enzyme was stable at pH 4-10, 5-7, and 5-7 at 4, 37, and 42 °C, respectively. Investigation about temperature effects on hyaluronate lyase displayed that it was stable at 30-37 °C and also showed high activity at 37 °C. The enzymatic activity was enhanced by Ca and was strongly inhibited by Cu and SDS. These properties suggested that the hyaluronate lyase in this study could bring promising prospects in medical and industry applications. [ABSTRACT FROM AUTHOR]

Objectives: To noninvasively assess global cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) in young adults with end-stage renal disease (ESRD).Methods: Thirty-six patients and 38 healthy volunteers were included and took part in MR examinations, blood and neuropsychological tests. CBF and OEF were measured by phase-contrast and T2-relaxation-under-spin-tagging MRI techniques, respectively. CMRO2 was computed from CBF, OEF and hematocrit according to Fick's principle. Correlations were performed between MR measurements, blood biochemistry measurements and neuropsychological test scores.Results: Compared with controls, ESRD patients had elevated CBF (72.9 ± 12.5 vs. 63.8 ± 8.5 ml min(-1) 100 g(-1), P < 0.001), elevated OEF (47.2 ± 10.2 vs. 35.8 ± 5.4 %, P < 0.001), but unaffected CMRO2 (199.5 ± 36.4 vs. 193.8 ± 28.6 μmol O2 min(-1) 100 g(-1), P = 0.879). Hematocrit negatively correlated with CBF (r = -0.640, P < 0.001) and OEF (r = -0.701, P < 0.001), but not with CMRO2. Altered neuropsychological test scores of ESRD patients were associated with OEF and CBF, but not with CMRO2. There were weak relationships between eGFR and hematocrit (r = 0.308, P = 0.068) or CBF (r = 0.318, P = 0.059).Conclusion: Our findings suggested that anaemic young adults with ESRD may afford higher CBF and OEF to maintain a normal CMRO2. Despite this compensatory process, however, cognitive function was still impaired and its severity was correlated with their CBF and OEF abnormality.Key Points: • Anaemic young adults with ESRD may afford higher CBF and OEF. • Anaemic young adults with ESRD maintain a normal CMRO 2 . • Cognitive function was still impaired in young ESRD adults. • The severity of cognitive dysfunction correlated with CBF and OEF changes. [ABSTRACT FROM AUTHOR]

Cordyceps is a rare and exotic mushroom that grows out of the head of a mummified caterpillar. Many companies are cultivating Cordyceps to meet the increased demand for its medicinal applications. However, the structures and functions of polysaccharides, one of the pharmaceutical active ingredients in Cordyceps, are difficult to reproduce in vitro. We hypothesized that mimicking the salty environment inside caterpillar bodies might make the cultured fungus synthesize polysaccharides with similar structures and functions to that of wild Cordyceps. By adding either sodium sulfate or sodium chloride into growth media, we observed the salinity-induced anti-angiogenesis activities of the polysaccharides purified from the cultured C. Militaris. To correlate the activities with the polysaccharide structures, we performed the 13C-NMR analysis and observed profound structural changes including different proportions of α and β glycosidic bonds and appearances of uronic acid signals in the polysaccharides purified from the culture after the salts were added. By coupling the techniques of stable 34S-sulfate isotope labeling, aniline- and D5-aniline tagging, and stable isotope facilitated uronic acid-reduction with LC-MS analysis, our data revealed for the first time the existence of covalently linked sulfate and the presence of polygalacuronic acids in the polysaccharides purified from the salt added C. Militaris culture. Our data showed that culturing C. Militaris with added salts changed the biosynthetic scheme and resulted in novel polysaccharide structures and functions. These findings might be insightful in terms of how to make C. Militaris cultures to reach or to exceed the potency of wild Cordyceps in future. [ABSTRACT FROM AUTHOR]

A new kind of extracellular polysaccharide (EPS) from Pseudomonas fluorescens PGM37 was obtained and culture media was optimized using the statistical methods single factor experiments and response surface methodology (RSM) design. As a result, the optimum cultivation conditions initial pH value, medium volume, inoculum size, temperature, and rotation speed were 7.5, 100 mL/250 mL, 5 %, 28 °C, and 180 rpm, respectively. The optimized media: sucrose 36.23 g L, yeast extract 3.32 g L, sodium chloride 1.13 g L, and calcium chloride 0.20 g L. The maximum predicted yield of EPS was 10.1163 g L under these conditions. The validation data was 10.012 g L, which could strongly confirm the correlation between the experimental and theoretical values. Gas Chromatography analysis revealed that the polymer was made up of mannose and glucose in the ratio of 1:1. Infrared spectroscopy showed that the polysaccharide had β-D-pyranoid configuration and contained no other substituent. Graded by different multiples of alcohol after specific degradation by enzyme and then detected by LC-ESI-MS, the EPS structure was β-D-Glc p-(1, 4)-β-D-Man p-(1, 4)-β-D-Glc p-(1, 4)-β-D-Man p. The moisture retention ability of the EPS was found to be superior to glycerol and only a little inferior to hyaluronic acid (HA), which presented potential application value in cosmetics and clinical medicine fields. [ABSTRACT FROM AUTHOR]

ABSTRACT A β-mannanase-producing bacterial strain Bacillus circulans M-21 was isolated from soil. The strain grew well when mannan (konjac gum, guar gum or locust bean gum) was used as sole carbon source. The optimum fermentation conditions were determined as follows: 4 g/L guar gum as carbon source, 20 g/L soybean powder and 5 g/L (NH4)2HPO4 as nitrogen source, initial pH 8.0, and 32C. An extracellular β-mannanase was purified by anion-exchange chromatography on Q-Sepharose Fast Flow. The purified protein exhibited a single band on sodium dodecyl sulphate-polyacrylamide gel electrophoresis with a molecular mass of 33.4 kDa. Kinetic analysis showed that the enzyme exhibited the strongest binding affinity to konjac gum. The β-mannanase activity reached the maximum at 50C and pH 7.0, and was completely suppressed by Hg2+ and Ag+. The β-mannanase degrading products were mainly composed by disaccharide, trisaccharide and tetrasaccharide, which were all neutral hexose polymers. PRACTICAL APPLICATIONS Microbial β-mannanases are applied broadly in industrial processes, such as improving the quality of food and feed, biobleaching of softwood pulps in the paper and pulp industries, and reducing the viscosity of coffee extracts. They are also found application in oil drilling and detergent industry. β-Mannanase is an ideal tool for the preparation of manno-oligosaccharides, which have been proved to be excellent prebiotics stimulating growth of human-beneficial intestinal microflora. Potential applications of manno-oligosaccharides are found in foods, beverages and confectionary, especially in functional food additives. In the current study a β-1,4-mannanase was extracted and purified from Bacillus circulans M-21. The research results showed that this enzyme is suitable for the preparation of glucomanno- and galactomanno-oligosaccharide. [ABSTRACT FROM AUTHOR]

In order to determine the role of alginate-derived oligosaccharides (ADO) in drought stress resistance of tomato ( Lycopersicon esculentum Miller) seedlings, the leaves were exposed to different concentrations of ADO (0.05%, 0.10%, 0.20%, 0.30% and 0.50%) after drought stress was simulated by exposing the roots to 0.6 molL−1 PEG-6000 solution for 6 h. Changes in biomass, electrolyte leakage and malondialdehyde (MDA), free proline, total soluble sugars (TSS) and abscisic acid (ABA), the enzyme activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) were measured to investigate the effects of ADO treatment. The results showed that the treatment with an ADO concentration of 0.20% exhibited the highest performance of drought stress resistance in the tomato seedlings by decreasing the electrolyte leakage and the concentration of MDA, increasing the contents of free proline, TSS and ABA, and increasing the activities of CAT, SOD, POD and PAL after treatment with ADO. It is suggested that changes in electrolyte leakage, MDA, osmotic solutes, ABA, anti-oxidative enzyme and PAL activities were responsible for the increased drought stress resistance in tomato seedlings. To our best knowledge, this is the first report of the effect of ADO treatment on enhancing the drought stress resistance of tomato seedlings. [ABSTRACT FROM AUTHOR]

Four typical coastal sites (rocky shore, sandy shore, mud flat shore, and artificial harbor) at the Yellow Sea were chosen to investigate the spatial and seasonal variations in bacterial communities. This was accomplished by using terminal restriction fragment length polymorphism (T-RFLP) analysis of PCR amplified 16S rDNA fragments. Two kinds of tetrameric restriction enzymes, HhaI and MspI, were used in the experiment to depict the bacterial community diversity in different marine environments. It was found that the community compositions digested by the two enzymes separately were different. However, the results of bacterial community diversity derived from them were similar. The MDA analysis results of T-RFLP profiles coming from HhaI and MspI both exhibited a significant seasonal community shift for bacteria and a relatively low spatial variation among the four locations. With HhaI as the sample, the pair wise T-tests also revealed that variations were minor between each pair of marine environments, with R ranging from 0.198 to 0.349. However, the bacterial community structure in the mud flat site depicted a larger difference than each of the other three sites ( R ranging from 0.282 to 0.349). [ABSTRACT FROM AUTHOR]

The antioxidant activities of three marine oligosaccharides, alginate oligosaccharides (AOs), chitosan oligosaccharides (COs), and fucoidan oligosaccharides (FOs), were investigated in vitro by several antioxidant assays, including hydroxyl radical scavenging, superoxide radical scavenging, erythrocyte hemolysis inhibiting, metal chelating activities, and anti-lipid peroxidation. The results show that these oligosaccharides exhibited different activities in various assays. AOs had the highest scavenging hydroxyl radical activity than FOs and COs at all the tested amounts. COs had the highest scavenging superoxide radical and inhibiting erythrocyte hemolysis activity than AOs and FOs at all the tested amounts. In the assay of chelating Fe2+, COs and FOs indicated good chelation while AOs hardly had any activity. In the assay of anti-lipid peroxidation, only COs had significantly high antioxidant activity. [ABSTRACT FROM AUTHOR]

Carrageenan oligosaccharides were produced from the final products of commercial extractions of gelling carrageenan and thickening carrageenan, which were specifically depolymerized by κ-carrageenase extracted from the marine bacterium Cytophaga MCA-2. The weight-average molecular weights of the two oligosaccharides produced were 681 and 798 Da. The sulfate contents were assayed as 17.2% and 21.8%. Antitumor activities of the oligosaccharides were tested on Sarcoma 180 tumor transplanted in mice. The carrageenan oligosaccharide from the thickening carrageenan product showed much higher tumor inhibition (70.8%) and catalase activity at a dosage of 100 mg kg-1 compared with the control group. The gelling and thickening carrageenan oligosaccarides could also significantly increase the weight of immune organs such as the thymus, which suggests that the antitumor mechanism of the carrageenan oligosaccharides may be initiated via organ-mediated defense reactions. [ABSTRACT FROM AUTHOR]

Alginate lyase, isolated from a marine culture of Vibrio sp. 510, was used to depolymerize alginate. Two alginate-derived oligosaccharides (ADOs) of different molecular weight were sulphated with the formamide-chlorosulphonic acid method. The antitumour activities of the two ADOs and their sulphated substitution derivatives that exhibited no direct cytotoxic effects on tsFT210 cells, were subsequently determined on Kunming mice. The best antitumour performer was Oligosaccharide A (molecular weight 3798 Da, sulphation degree 1.3), which exhibited 70.4 and 66.0% tumour inhibition against solid Sarcoma 180 at doses of 100 and 50 mg kg  - 1 , respectively. For ADOs and their sulphated derivatives, an indirect antitumour effect via modulation of the host-mediated immune defences is postulated. [ABSTRACT FROM AUTHOR]

The influence of alginate-derived oligosaccharide (molecular weight 1445 Da) was tested on the maize seed germination at different concentrations. Assays of α-and β-amylase and protease activities showed the highest response at 0.75‰.Compared with the control, root growth on days 3 and 7 showed increases of 34% and18%, respectively; and shoot growth on day 7 an increase of 46%. In the case of protease activity, treatments with both 0.75‰ and 1.50‰ alginate-derived oligosaccharide gave higher activities than the control. These results indicate that the rate of seed germination was enhanced by increasing the activities of several enzymes beneficial for germination. [ABSTRACT FROM AUTHOR]

Depolymerization of κ-carrageenan was performed using carrageenase isolated from the cell-free medium of a culture of marine Cytophaga sp. MCA-2. The low-molecular-weight carrageenans after ultrafiltration and lyophilization were sulfonated with formamide-chlorosulfonic acid. The anti-tumor activity of the products with different molecular weight was determined by using Sarcoma 180 tumor in mouse. A carrageenan oligosaccharide with a molecular weight of 1726, administered orally at a dose of 100 mg kg−1 mouse markedly inhibited tumor formation. However, the anti-tumor activity of high-sulfonated carrageenan was much less than that of the non-sulfonated or light-sulfonated preparation. The activities of the latter products on superoxide dismutase and catalase were enhanced considerably, which suggests that carrageenan oligosaccharide was effective in promoting the antioxidation ability and eliminating danger from free radicals. The preparations showed special effects on immunological regulation, especially the phagocytosis ratio and phagocytosis index of macrophage, which might be beneficial for the anti-tumor activity. Although no anti-tumor activity of this product was detected in vitro, suggesting that its activity differs between in vitro and in vivo, this 1726 molecular weight product provides a potent clinical use in tumor treatment. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) are the key factors that cause many diseases in the human body. Polysaccharides from seaweed have been shown to have significant antioxidant activity both in vivo and in vitro. The ameliorative effect of Ulva lactuca polysaccharide extract (UPE) on renal injury induced by oxidative stress was analyzed. As shown by hematoxylin–eosin staining results, UPE can significantly improve the kidney injury induced by D-galactose (D-gal). Additionally, the protective mechanism of UPE on the kidney was explored. The results showed that UPE could decrease the levels of serum creatinine (Scr), blood urea nitrogen (BUN), serum cystatin C (Cys-C), lipid peroxidation, protein carbonylation, and DNA oxidative damage (8-OHdG) and improve kidney glutathione content. Moreover, UPE significantly increased the activities of superoxide dismutase and glutathione peroxidase and total antioxidant activity in mice. UPE also decreased the levels of inflammatory cytokines TNF-α and IL-6. Further investigation into the expression of apoptotic protein caspase-3 showed that UPE decreased the expression of apoptotic protein caspase-3. These results indicate that UPE has a potential therapeutic effect on renal injury caused by oxidative stress, providing a new theoretical basis for the treatment of oxidative damage diseases in the future. [ABSTRACT FROM AUTHOR]

The aim of the study was to extract Porphyra haitanensis polysaccharides (PHPs) using the water extraction and alcohol precipitation methods and explore their antioxidant activity and physicochemical properties. The single-factor and Box-Behnken response surface methodologies were used to optimize the extraction of polysaccharides from Porphyra haitanensis. Our results showed that the polysaccharide yield was as high as 20.48% with a raw material to water ratio of 0.04, and extraction time of 3 h at 80 °C. The extraction rate observed was similar to the actual extraction rate, thus proving the reliability of the optimization model. The extracted polysaccharides primarily consisted of galactose, glucose, and fucose in the molar ratio 76.2:2.1:1, respectively. The high performance gel permeation chromatography (HPGPC) results showed that the molecular weight of the PHPs obtained was 6.3 × 105 Da, and the sulfate content was 2.7 mg/mL. Fourier infrared spectroscopy was used to analyze the functional groups and structures of the polysaccharides. The effect of concentration, temperature, and pH on the apparent viscosity of the PHPs solution were studied using rheology experiments, which revealed that PHPs were a "non-Newtonian fluid" with shear-thinning behavior. The viscosity of the PHPs gradually increased with increasing sugar concentration, and decreased with increasing temperature, acidity, and alkalinity. Detection of the antioxidant activity of OH*, DPPH*, and ABTS* revealed that the scavenging activity of ABTS* was higher than that of OH* and DPPH* in the concentration range of 1–5 mg/mL. In the experiments of simulating gastric juice and alpha amylase in vitro, it was found that PHPs can better resist digestion of alpha amylase, and have better resistance than fructooligosaccharide (FOS), so PHPs have potential prebiotic activity. These findings demonstrate the potential of PHPs for use in the food and cosmetic industries. [ABSTRACT FROM AUTHOR]