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1.
Clin Chim Acta ; 555: 117827, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38346531

RESUMO

BACKGROUND: Aberrant sialylation is closely associated with the tumorigenesis, progression, and metastasis, and may be of importance for disease diagnosis. However, the analysis of altered expression of sialylated glycans (SGs) in blood is particularly challenging due to the low content and poor ionization efficiency of sialylated glycans in mass spectrometry. METHODS: An analytical strategy based on enrichment of SGs, liquid chromatography-high resolution mass spectrometric detection, and automatic glycan annotation was developed to profile the sialylated N-glycome in serum. The enrichment of sialylated glycans was accomplished using cationic cotton via electrostatic and hydrogen interaction. Using partial least squares-discriminant analysis (PLS-DA), the approach was applied for nontarget screening and profiling of aberrant sialylated N-glycans in hepatocellular carcinoma (HCC). RESULTS: 55 SGs were identified in human serum, and three important SGs (SG35, SG45, and SG46) were screened to have good diagnostic specificity for HCC. Their areas under the receiver operating characteristic (ROC) curve (AUC) were higher than α-fetoprotein (AFP)'s (AUC = 0.85), at 0.88, 0.87, and 0.91, respectively. When three SGs are combined, the diagnostic specificity for HCC may increase to 94 %. The fact that SGs biomarkers are sensitive to AFP-Negative HCC is very noteworthy. CONCLUSIONS: The method significantly advanced the search for sialylated glycan-based cancer biomarkers. In comparison to traditional indicators like AFP and imaging tools, SGs showed a higher diagnostic sensitivity for HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , alfa-Fetoproteínas , Espectrometria de Massa com Cromatografia Líquida , Neoplasias Hepáticas/diagnóstico , Polissacarídeos/análise , Biomarcadores Tumorais
2.
Foods ; 12(4)2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36832787

RESUMO

Stable and sustainable food production is an important guarantee for national security and social stability. The uneven distribution of cultivated land and water resources will threaten national food security. In this study, we adopt the Gini coefficient and water-land matching coefficient for exploring the water-land nexus in the main grain-producing areas of North China Plain (NCP) from 2000 to 2020. The water-land-food nexus considering grain crop production structure is further explored from spatial and temporal multi-scales. The results show the following: (1) The Gini coefficient presents an increasing trend in the NCP, indicating an increasing imbalance in the water-land matching degree among inter-regions. (2) There are significant differences in the WL nexus and WLF nexus among regions, showing a spatial pattern of "worse in the north and better in the south". (3) The cities which belonged to the low WL-low WLF and high WL-low WLF should be considered as key targets when formulating policies. (4) Adjusting the wheat-maize biannual system, optimizing the grain cultivation structure, promoting semi-dryland farming, and developing low water-consuming and high-yielding crop varieties are essential measures for these regions. The research results provide significant reference for the optimal management and sustainable agricultural development of agricultural land and water resources in NCP.

3.
Mol Med ; 29(1): 28, 2023 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-36849907

RESUMO

Vascular aging is an inevitable process with advancing age, which plays a crucial role in the pathogenesis of cardiovascular and microvascular diseases. Diabetic retinopathy (DR) and age-related macular degeneration (AMD), characterized by microvascular dysfunction, are the common causes of irreversible blindness worldwide, however there is still a lack of effective therapeutic strategies for rescuing the visual function. In order to develop novel treatments, it is essential to illuminate the pathological mechanisms underlying the vascular aging during DR and AMD progression. In this review, we have summarized the recent discoveries of the effects of oxidative stress and epigenetics on microvascular degeneration, which could provide potential therapeutic targets for DR and AMD.


Assuntos
Degeneração Macular , Estresse Oxidativo , Humanos , Estresse Oxidativo/genética , Epigênese Genética , Epigenômica , Degeneração Macular/genética
4.
Entropy (Basel) ; 24(5)2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35626605

RESUMO

Learning analysis provides a new opportunity for the development of online education, and has received extensive attention from scholars at home and abroad. How to use data and models to predict learners' academic success or failure and give teaching feedback in a timely manner is a core problem in the field of learning analytics. At present, many scholars use key learning behaviors to improve the prediction effect by exploring the implicit relationship between learning behavior data and grades. At the same time, it is very important to explore the association between categories and prediction effects in learning behavior classification. This paper proposes a self-adaptive feature fusion strategy based on learning behavior classification, aiming to mine the effective E-learning behavior feature space and further improve the performance of the learning performance prediction model. First, a behavior classification model (E-learning Behavior Classification Model, EBC Model) based on interaction objects and learning process is constructed; second, the feature space is preliminarily reduced by entropy weight method and variance filtering method; finally, combined with EBC Model and a self-adaptive feature fusion strategy to build a learning performance predictor. The experiment uses the British Open University Learning Analysis Dataset (OULAD). Through the experimental analysis, an effective feature space is obtained, that is, the basic interactive behavior (BI) and knowledge interaction behavior (KI) of learning behavior category has the strongest correlation with learning performance.And it is proved that the self-adaptive feature fusion strategy proposed in this paper can effectively improve the performance of the learning performance predictor, and the performance index of accuracy(ACC), F1-score(F1) and kappa(K) reach 98.44%, 0.9893, 0.9600. This study constructs E-learning performance predictors and mines the effective feature space from a new perspective, and provides some auxiliary references for online learners and managers.

5.
Artigo em Inglês | MEDLINE | ID: mdl-35463087

RESUMO

Background: Fatigue is a common symptom in adults that may cause physical and psychological problems and reduce quality of life. Aromatherapy could possibly provide relief for those suffering from fatigue. Here, we evaluated the effect of aromatherapy on fatigue in adults. Methods: We searched the PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Chinese Biomedical Literature, SinoMed, Wanfang, and Chinese Scientific Journal Database databases for randomized controlled trials of aromatherapy treatment for fatigue in adults from their inception to June 2021. Two reviewers searched independently, extracted the characteristics of the studies, and assessed the risk of bias using the Cochrane risk-of-bias tool and Stata v. 14.0. Results: Nineteen studies were included in this systematic review. Aromatherapy had a significant effect on fatigue (standardized mean difference -0.64, 95% confidence interval-1.14, -0.15, I2 94.4%, P < 0.001). Subgroup analysis according to aromatic type, substance, frequency, treatment duration, intervention, outcomes measurement, and population type showed that aromatherapy had a significantly greater effect in the intervention group, compared to the control group. Funnel plots and Egger's test indicated no significant publication bias. Conclusion: Our results suggest that aromatherapy ameliorates fatigue in adults who suffer from chronic diseases. A rigorous intervention program and larger randomized controlled trials are needed.

6.
Sci Rep ; 12(1): 453, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35013396

RESUMO

E-learning is achieved by the deep integration of modern education and information technology, and plays an important role in promoting educational equity. With the continuous expansion of user groups and application areas, it has become increasingly important to effectively ensure the quality of e-learning. Currently, one of the methods to ensure the quality of e-learning is to use mutually independent e-learning behaviour data to build a learning performance predictor to achieve real-time supervision and feedback during the learning process. However, this method ignores the inherent correlation between e-learning behaviours. Therefore, we propose the behaviour classification-based e-learning performance (BCEP) prediction framework, which selects the features of e-learning behaviours, uses feature fusion with behaviour data according to the behaviour classification model to obtain the category feature values of each type of behaviour, and finally builds a learning performance predictor based on machine learning. In addition, because existing e-learning behaviour classification methods do not fully consider the process of learning, we also propose an online behaviour classification model based on the e-learning process called the process-behaviour classification (PBC) model. Experimental results with the Open University Learning Analytics Dataset (OULAD) show that the learning performance predictor based on the BCEP prediction framework has a good prediction effect, and the performance of the PBC model in learning performance prediction is better than traditional classification methods. We construct an e-learning performance predictor from a new perspective and provide a new solution for the quantitative evaluation of e-learning classification methods.


Assuntos
Desempenho Acadêmico , Educação a Distância , Estudantes/psicologia , Comportamento , Instrução por Computador , Educação a Distância/normas , Feminino , Humanos , Aprendizagem , Aprendizado de Máquina , Masculino , Estudantes/estatística & dados numéricos , Universidades
7.
Artigo em Inglês | MEDLINE | ID: mdl-34948669

RESUMO

Background: The aim of this study was to assess the relationship between serum 25-hydroxyvitamin D [25(OH)D] and serum intact parathyroid hormone (PTH) in Chinese childbearing women, and to estimate the optimum threshold of 25(OH)D that maximally inhibits the PTH, which is considered to be the optimal status for vitamin D sufficiency. Methods: Serum samples were selected from the biological samples' bank of the Chinese Chronic Diseases and Nutrition Survey (CCDNS) 2015. The serum 25(OH)D concentration was determined by liquid chromatography tandem mass spectrometry and the serum PTH was determined by electronic chemiluminescence. Simple linear and partial correlation analysis, locally weighted regression smooth scatterplot (LOESS), nonlinear least squares estimation (NLS), and segmented regression (SR) were utilized to estimate the relationship of 25(OH)D and PTH, and to determine the threshold of 25(OH)D. Results: A total of 1568 serum samples of 25(OH)D concentration and PTH concentration were analyzed. A significant inverse relationship between 25(OH)D and PTH concentration was observed below 15.25 (14.22-16.28) ng/mL, and PTH decreased slowly with the increase of 25(OH)D above 16.75 (15.43-18.06) ng/mL after adjusting by age, latitude, city type, season, corrected calcium, and phosphorus. A very short plateau of PTH was found at 15.25 ng/mL and 16.75 ng/mL in terms of 25(OH)D according to LOESS, NLS, and SR. Conclusions: The serum 25(OH)D was negatively correlated with the serum PTH. The threshold of VitD sufficiency was found in the range of 14.22-18.06 ng/mL in terms of serum 25(OH)D concentration for Chinese childbearing women aged 18-44 years old.


Assuntos
Hormônio Paratireóideo , Deficiência de Vitamina D , Adolescente , Adulto , China , Feminino , Humanos , Vitamina D , Vitaminas , Adulto Jovem
8.
J Food Sci ; 82(8): 1867-1875, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28696546

RESUMO

Wheat is the most common grain in the temperate region. Modifying its constituent through food processing improves its functionality and nutrient access. In this study, the combined effect of germination and extrusion on physicochemical properties and nutritional qualities of extrudates and tortilla from wheat was evaluated. Results showed that germination significantly increased (P <0.05) the γ-aminobutyric acid content in germinated whole wheat (GW) and extruded germinated whole wheat (EGW) as compared to the control of whole wheat (WW). Germination also significantly increased the protein content, reducing sugar and total soluble sugar content in GW, while extrusion had much increasing impact on reducing sugar content in extruded samples. Specific mechanical energy during extrusion was reduced as feed moisture content increased from 20 to 30%. Higher extruder screw speed (350 rpm) led to better expansion ratio at low moisture content (20%) as compared to low screw speed (200 rpm). Extrusion significantly increased the starch digestibility but decreased the protein digestibility in extrudates. Tortilla made from 100% WW had about the same physical characteristics, namely color and rollability, with tortilla made from 85% WW with 15% GW, 85% WW with 15% extruded whole wheat (EW), and 85% WW with 15% EGW. Tortilla made from 85% WW with 15% GW showed the largest diameter, thinnest thickness and least extensibility. A 15% extruded germinated wheat (350 rpm) addition in 85% WW showed significant increase of γ-aminobutyric acid content in tortilla compared to the control (100% WW).


Assuntos
Pão/análise , Sementes/crescimento & desenvolvimento , Triticum/química , Manipulação de Alimentos , Germinação , Valor Nutritivo , Sementes/química , Amido/química , Triticum/crescimento & desenvolvimento , Ácido gama-Aminobutírico/análise
9.
Wei Sheng Yan Jiu ; 46(1): 62-69, 2017 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-29903154

RESUMO

OBJECTIVE: To investigate the difference of fatty acid content and types between red peanuts and white peanuts. METHODS: After being hydrolyzed, extracted, and methyl-esterificated, fatty acid in the sample were separated with the chromatographic column HP-88( 100 m × 0. 25 mm × 0. 20 µm) and analyzed by gas chromatography-mass spectrometry( GC-MS) method. Meanwhile, t-test and rank sum test will be carried on to analyze the determination results of fatty acid in both red and white peanuts growing in Shenzhen, Qingyuan and other four areas. RESULTS: The standard curves of fatty acid methyl ester hold good linearity( R~2> 0. 9980) in 0. 2- 10 mg / L, with the recovery between 92. 3% and 118. 8% and relative standard deviation( RSD) between 1. 64% and 7. 70%. Those two peanuts contained 21 fatty acids, such as oleic acid, linoleic acid, palmitic acid, stearic acid and behenic acid. The total fat content in peanuts were between 42. 5% and 50. 6%. After statistical analysis, the differences were not statistically significant. CONCLUSION: The method can quickly and sensitively detect fatty acids inpeanuts. Same species and similar content of the fatty acids are in these two peanuts particularly.


Assuntos
Arachis/química , Ácidos Graxos/análise , Cromatografia Gasosa-Espectrometria de Massas , Reprodutibilidade dos Testes
10.
Mol Cancer Res ; 13(1): 41-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25143434

RESUMO

UNLABELLED: P27(Kip1) (CDKN1B) regulates cellular proliferation and senescence, and p27(Kip1) deficiency in cancer is strongly correlated with poor prognosis of multiple cancer types. Understanding the mechanism of p27(Kip1) loss in cancer and the consequences of restoring p27(Kip1) levels is therefore critical for effective management during therapy. Here, SIRT1, a class III histone deacetylase (HDAC), is identified as an important regulator of p27(Kip1) expression. Mechanistically, SIRT1 reduces p27(Kip1) expression by decreasing p27(Kip1) protein stability through the ubiquitin-proteasome pathway. In addition, SIRT1 silencing suppresses non-small cell lung cancer (NSCLC) proliferation and induces senescence in a p27(Kip1)-dependent manner. Furthermore, SIRT1 silencing dramatically suppresses tumor formation and proliferation in two distinct NSCLC xenograft mouse models. Collectively, these data demonstrate that not only SIRT1 is an important regulator of p27(Kip1) but also SIRT inhibition induces senescence and antigrowth potential in lung cancer in vivo. IMPLICATIONS: SIRT1 is a key regulator of p27 protein levels and SIRT1 inhibition is a viable strategy for NSCLC therapy by means of p27 reactivation.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Ciclo Celular/genética , Inibidor de Quinase Dependente de Ciclina p27/biossíntese , Sirtuína 1/biossíntese , Animais , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Senescência Celular/genética , Inibidor de Quinase Dependente de Ciclina p27/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Sirtuína 1/genética
11.
Int J Oncol ; 45(5): 2128-36, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25189993

RESUMO

SIRT1, a class III histone deacetylase, plays a critical role in regulating cancer cell growth, migration and invasion, which makes it a potential target for cancer therapeutics. In this study, we screened derivatives of several groups of natural products and identified a novel SIRT1 inhibitor JQ-101, a synthetic derivative of the polyprenylated acylphloroglucinol (PPAP) natural products, with an IC(50) for SIRT1 of 30 µM in vitro, with 5-fold higher activity for SIRT1 vs. SIRT2. Exposure of tumor cells to JQ-101 significantly enhanced acetylation of p53 and histone H4K16 at known sites of SIRT1 deacetylation, validating SIRT1 as its cellular target. JQ-101 suppressed cancer cell growth and survival by targeting SIRT1, and also exhibited selective cytotoxicity towards a panel of human tumor cell lines, while producing no toxicity in two normal human cell types at comparable concentrations. JQ-101 induced both apoptosis and cell senescence, and suppressed cancer cell invasion in vitro. In summary, we have identified JQ-101 as a new SIRT1 inhibitor which may have potential application in cancer treatment through its ability to induce tumor cell apoptosis and senescence and suppress cancer cell invasion.


Assuntos
Proliferação de Células/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Floroglucinol/administração & dosagem , Sirtuína 1/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Invasividade Neoplásica/patologia , Neoplasias/genética , Neoplasias/patologia , Floroglucinol/análogos & derivados , Sirtuína 1/genética , Sirtuína 2/antagonistas & inibidores , Sirtuína 2/genética
12.
Prostate ; 73(5): 522-30, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23038275

RESUMO

BACKGROUND: Matrix metalloproteinase-2 (MMP2) has been shown to play an important role in cancer cell invasion and the expression of MMP2 is associated with the poor prognosis of prostate cancer; however, the mechanism of MMP2 expression is largely unknown. SIRT1 is a nicotinamide adenine dinucleotide-dependent histone deacetylase (class III HDAC) that has recently been shown to have implications in regulating cancer cell growth and apoptosis. The purpose of this study is to determine the role of SIRT1 in regulating MMP2 expression and tumor invasion in prostate cancer cells. METHODS: The interfering RNAi was used to knockdown SIRT1 from prostate cancer cells. Immunoblots, RT-PCR, zymographic assays, co-immunoprecipitation, analysis and transwell assays were used to examine the effects of SIRT1 silencing on MMP2 expression and activity, on SIRT1 and MMP2 interaction, and on prostate cancer cell invasion. The immuno-histochemical assay was performed to study SIRT1 expression in prostate cancer tissues. RESULTS: We show that SIRT1 associates and deacetylates MMP2 and SIRT1 regulates MMP2 expression by controlling MMP2 protein stability through the proteosomal pathway. Thus, we demonstrated a novel mechanism in that MMP2 expression can be regulated at the posttranslational level by SIRT1. Furthermore, we determined that SIRT1 inhibition reduced prostate cancer cell invasion and SIRT1 is highly expressed in advanced prostate cancer tissues. CONCLUSIONS: SIRT1 is an important regulator of MMP2 expression, activity, and prostate cancer cell invasion. Overexpressed SIRT1 in advanced prostate cancer may play an important role in prostate cancer progression.


Assuntos
Metaloproteinase 2 da Matriz/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Sirtuína 1/metabolismo , Animais , Linhagem Celular Tumoral , Regulação Enzimológica da Expressão Gênica/fisiologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Invasividade Neoplásica/patologia , Invasividade Neoplásica/fisiopatologia , Neoplasias da Próstata/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Estabilidade Proteica , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Ratos , Sirtuína 1/genética , Ubiquitina/metabolismo
13.
J Sci Food Agric ; 93(7): 1543-51, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23238952

RESUMO

BACKGROUND: To understand the reasons for low starch viscosity in rice variety Q11 (Qing-lu-zhan 11), the physiochemical and structural characteristics of flours and starches were investigated and compared with another rice cultivar with similar high amylose but normal viscosity. RESULTS: Our results showed that residual α-amylase activity and proteins were not the major causes of low starch viscosity in Q11 rice. Homogeneous small granule size and lower swelling power of high-amylose Q11 rice starches was one reason for the low swelling volume and thus the low pasting property. Q11 starch paste contained some partially swollen granules, which could increase the fluidity and thus cause the low paste viscosity. The small gelatinization enthalpy might be due to the lower crystallinity in Q11 starches. Moreover, Q11 starches consisted of more amylose with short chains, but also amylopectin with fewer short chains (DP 11-21) and more long chains (DP 22-54), which might be other important factors contributing to the low viscosity of Q11 starches. CONCLUSION: These data can add to our understanding of the relationships between low viscosity and physiochemical properties, and will be helpful in elucidating the underlying mechanism of formation of low starch viscosity, as well as applications for low-viscosity rice starches.


Assuntos
Amilopectina/química , Amilose/química , Oryza/química , Tamanho da Partícula , Sementes/química , Amido/química , Cristalização , Géis , Humanos , Oryza/classificação , Especificidade da Espécie , Termodinâmica , Viscosidade , alfa-Amilases/metabolismo
14.
Wei Sheng Yan Jiu ; 42(6): 907-14, 2013 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-24459900

RESUMO

OBJECTIVE: To screen the biomarkers of the middle-aged type 2 diabetes (T2DM) in urine based on metabolomics. METHODS: First, both the metabolite profiles of morning urine sample in T2DM and control group were obtained by liquid chromatography-mass spectrometry (LC-MS). Second, an automated compound (feature) extraction algorithm was employed for processing background subtracted single MS data. Then principal component analysis (PCA) and t-Test analysis was followed after preprocessing on the extractive data. Third, identifying the potential biomarkers that show significant difference between the two groups by searching the database online and comparing the results of MS/MS experiments to those available in literature and those standards. RESULTS: Three endogenous metabolites, among which tryptophan, kynurenic acid, and shown down-regulation while kynurenine shown up-regulation in T2DM, significantly differentiate between T2DM and control group. CONCLUSION: Tryptophan, kynurenic acid and kynurenine may be considered as the potentail biomarkers related to T2DM.


Assuntos
Biomarcadores/urina , Diabetes Mellitus Tipo 2/urina , Feminino , Humanos , Ácido Cinurênico/urina , Cinurenina/urina , Masculino , Pessoa de Meia-Idade , Triptofano/urina
15.
Food Chem ; 134(4): 2242-8, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23442680

RESUMO

High-amylose cereal starch has a great benefit on human health. Acid modification is very helpful for application of high-amylose starch in food and non-food industries. In this study, the ordered structure of acid-modified high-amylose rice starch was investigated by GPC, HPAEC, (13)C CP/MAS NMR and XRD. Acid preferentially degraded the amylose, then A chain and short B chain of amylopectin. Relative double helix content and crystallinity both initially increased sharply and then progressively with acid hydrolysis. The relative crystallinity of starches obtained from (13)C CP/MAS NMR was higher than that from XRD. The onset gelatinisation temperature decreased, while the peak and conclusion temperatures increased with increasing hydrolysis time. The endothermic value initially increased and then decreased with acid hydrolysis. The swelling power decreased while solubility increased after acid hydrolysis. These results add to our understanding of the effect of acid hydrolysis on the high-amylose rice starch.


Assuntos
Amilose/química , Oryza/química , Ácidos/química , Cristalização , Temperatura Alta , Hidrólise , Estrutura Molecular , Solubilidade
16.
Plant Biotechnol J ; 10(3): 353-62, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22145600

RESUMO

A high-amylose rice with 64.8% amylose content (AC) was developed by transgenic inhibition of two isoforms of starch branching enzyme (SBE), SBEI and SBEIIb, in an indica rice cultivar. The expression of SBEI and SBEIIb was completely inhibited in the transgenic line, whereas the expression of granule-bound starch synthase was normal. Compared with wild-type rice, drastic reductions in both SBEs in the transgenic rice increased apparent AC in flour from 27.2% to 64.8%, resistant starch (RS) content from 0% to 14.6% and total dietary fibre (TDF) from 6.8% to 15.2%. Elevated AC increased the proportion of long unit chains in amylopectin and increased onset gelatinization temperature and resistance to alkaline digestion; however, kernel weight was decreased. A rat feeding trial indicated that consumption of high-amylose rice decreased body weight gain significantly (P < 0.01); increased faecal mass, faecal moisture and short-chain fatty acids; and lowered the faecal pH. An acute oral rice tolerance test revealed that the high-amylose rice had a positive effect on lowering the blood glucose response in diabetic Zucker fatty rats. This novel rice with its high AC, RS and TDF offers potential benefits for its use in foods and in industrial applications.


Assuntos
Amilose/metabolismo , Diabetes Mellitus/dietoterapia , Alimentos Geneticamente Modificados , Oryza/metabolismo , Enzima Ramificadora de 1,4-alfa-Glucana/genética , Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Amilopectina/metabolismo , Amilose/genética , Animais , Glicemia/metabolismo , Dieta , Carboidratos da Dieta/administração & dosagem , Carboidratos da Dieta/uso terapêutico , Fibras na Dieta/metabolismo , Endosperma/genética , Endosperma/metabolismo , Estabilidade Enzimática , Fezes , Feminino , Teste de Tolerância a Glucose/métodos , Concentração de Íons de Hidrogênio , Masculino , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Ratos , Ratos Sprague-Dawley , Ratos Zucker , Sintase do Amido/genética , Sintase do Amido/metabolismo , Redução de Peso
17.
J Agric Food Chem ; 58(22): 11946-54, 2010 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-21033746

RESUMO

C-type starch, which is a combination of both A-type and B-type crystal starch, is usually found in legumes and rhizomes. We have developed a high-amylose transgenic line of rice (TRS) by antisense RNA inhibition of starch branching enzymes. The starch in the endosperm of this TRS was identified as typical C-type crystalline starch, but its fine granular structure and allomorph distribution remained unclear. In this study, we conducted morphological and spectroscopic studies on this TRS starch during acid hydrolysis to determine the distribution of A- and B-type allomorphs. The morphology of starch granules after various durations of acid hydrolysis was compared by optical microscopy, scanning electron microscopy, and transmission electron microscopy. The results showed that amorphous regions were located at the center part of TRS starch subgranules. During acid hydrolysis, starch was degraded from the interior of the subgranule to the outer surface, while the peripheral part of the subgranules and the surrounding band of the starch granule were highly resistant to acid hydrolysis. The spectroscopic changes detected by X-ray powder diffraction, 13C cross-polarization magic-angle spinning NMR, and attenuated total reflectance Fourier transform infrared showed that the A-type allomorph was hydrolyzed more rapidly than the B-type, and that the X-ray diffraction profile gradually changed from a native C-type to a CB-type with increasing hydrolysis time. Our results showed that, in TRS starch, the A-type allomorph was located around the amorphous region, and was surrounded by the B-type allomorph located in the peripheral region of the subgranules and the surrounding band of the starch granule. Thus, the positions of A- and B-type allomorphs in the TRS C-type starch granule differ markedly from those in C-type legume and rhizome starch.


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana/genética , Amilose/análise , Oryza/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/metabolismo , RNA Antissenso/genética , Amido/metabolismo , Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Amilose/metabolismo , Regulação para Baixo , Oryza/química , Oryza/enzimologia , Oryza/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , RNA Antissenso/metabolismo , Amido/química
18.
Int J Biol Sci ; 6(6): 599-612, 2010 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-20941378

RESUMO

SIRT1, an NAD-dependent histone/protein deacetylase, has classically been thought of as a nuclear protein. In this study, we demonstrate that SIRT1 is mainly localized in the nucleus of normal cells, but is predominantly localized in the cytoplasm of the cancer / transformed cells we tested. We found this predominant cytoplasmic localization of SIRT1 is regulated by elevated mitotic activity and PI3K/IGF-1R signaling in cancer cells. We show that aberrant cytoplasmic localization of SIRT1 is due to increased protein stability and is regulated by PI3K/IGF-1R signaling. In addition, we determined that SIRT1 is required for PI3K-mediated cancer cell growth. Our study represents the first identification that aberrant cytoplasm localization is one of the specific alternations to SIRT1 that occur in cancer cells, and PI3K/IGF-1R signaling plays an important role in the regulation of cytoplasmic SIRT1 stability. Our findings suggest that the over-expressed cytoplasmic SIRT1 in cancer cells may greatly contribute to its cancer-specific function by working downstream of the PI3K/IGF-1R signaling pathway.


Assuntos
Citoplasma/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Receptor IGF Tipo 1/metabolismo , Transdução de Sinais/fisiologia , Sirtuína 1/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Imunofluorescência , Humanos , Immunoblotting , Estabilidade Proteica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética , Sirtuína 1/genética
19.
J Agric Food Chem ; 58(12): 7383-8, 2010 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-20499916

RESUMO

High-amylose starch is a source of resistant starch (RS) which has a great benefit on human health. A transgenic rice line (TRS) enriched amylose and RS had been developed by antisense RNA inhibition of starch branching enzymes. In this study, the native starch granules were isolated from TRS grains as well as the wild type, and their crystalline type was carefully investigated before and after acid hydrolysis. In high-amylose TRS rice, the C-type starch, which might result from the combination of both A-type and B-type starch, was observed and subsequently confirmed by multiple physical techniques, including X-ray powder diffraction, solid-state nuclear magnetic resonance, and Fourier transform infrared. Moreover, the change of starch crystalline structure from C- to B-type during acid hydrolysis was also observed in this RS-rich rice. These data could add to our understanding of not only the polymorph structure of cereal starch but also why high-amylose starch is more resistant to digestion.


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana/genética , Oryza/química , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/química , Interferência de RNA , RNA Antissenso/genética , Amido/química , Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Amilose/química , Oryza/enzimologia , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , RNA Antissenso/metabolismo , Amido/isolamento & purificação , Amido/metabolismo , Difração de Raios X
20.
J Agric Food Chem ; 58(2): 1224-32, 2010 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-20030326

RESUMO

A high-amylose transgenic rice line (TRS) modified by antisense RNA inhibition of starch branching enzymes revealed a resistant starch-rich quality. Compound starch granules in whole grains of the regular rice cultivar Teqing (TQ) were readily split during fracturing, whereas the starch granules in TRS were structurally intact and showed large voluminous, non-angular rounded bodies and elongated, filamentous structures tolerant of fracturing. In isolated preparation, TQ starch granules broke up into separate polygonal granules, whereas TRS starch granules kept their intactness. TRS starch granules consisted of packed smaller subgranules, some of which located at the periphery of starch granules were fused to each other with adjacent ones forming a thick band or wall encircling the entire circumference of the granules. TQ starch granules had a high concentration of amylose in the concentric hilum, whereas TRS starch granules showed a relatively even distribution of amylose with intense amylose in both hilum and band.


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana/genética , Amilose/análise , Oryza/química , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/química , RNA Antissenso/genética , Amido/química , Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Oryza/enzimologia , Oryza/genética , Oryza/ultraestrutura , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/ultraestrutura , Amido/metabolismo , Amido/ultraestrutura
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