Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Heliyon ; 10(3): e25155, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38322856

RESUMEN

With the advent of the digital economy, enterprises have been engaging in brand management activities through cross-border e-commerce platforms to secure brand identification (BI) and capture market share. However, scant attention has been given to the impact of perceived brand globalness (PBG) and perceived brand localness (PBL) on brand identification in cross-border e-commerce platforms. This study delves into the underlying mechanisms governing the formation of brand identification in the context of cross-border e-commerce platforms. In this end, we employed the AMOS26.0 software to conduct structural equation analysis on a corpus of 300 survey questionnaires. The results show that: (1) PBG and PBL can exert a positive influence on BI through customer perceived value; (2) acculturation (AC) assumes a positive moderating role in the influence of PBG and PBL on emotional value (EV) and functional value (FV) respectively, (3) and that platform reputation (PR) plays a constructive moderating role in the impact of PBG on FV.

2.
J Appl Stat ; 50(11-12): 2547-2560, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37529566

RESUMEN

Since February 2020, COVID-19 has spread rapidly to more than 200 countries in the world. During the pandemic, local governments in China have implemented different interventions to efficiently control the spread of the epidemic. Characterizing transmission of COVID-19 under some typical interventions is essential to help countries develop appropriate interventions. Based on the pre-symptomatic transmission patterns of COVID-19, we established a novel compartmental model: Susceptible-Infectious-Confirmed-Removed (SICR) model, which allowed the effective reproduction number to change over time, thus the effects of policies could be reasonably estimated. Using the epidemic data of Wuhan, Wenzhou, and Shenzhen, we migrated the corresponding estimated policy modes to South Korea, Italy, and the United States and simulated the potential outcomes for these countries when they adopted similar policy strategies to China. We found that the mild interventions implemented in Shenzhen were effective in controlling the epidemic in the early stage, while more stringent policies which were implemented in Wuhan and Wenzhou were necessary if the epidemic became severe and needed to be controlled in a short time.

4.
Sensors (Basel) ; 23(13)2023 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-37447864

RESUMEN

With the development of smart agriculture, deep learning is playing an increasingly important role in crop disease recognition. The existing crop disease recognition models are mainly based on convolutional neural networks (CNN). Although traditional CNN models have excellent performance in modeling local relationships, it is difficult to extract global features. This study combines the advantages of CNN in extracting local disease information and vision transformer in obtaining global receptive fields to design a hybrid model called MSCVT. The model incorporates the multiscale self-attention module, which combines multiscale convolution and self-attention mechanisms and enables the fusion of local and global features at both the shallow and deep levels of the model. In addition, the model uses the inverted residual block to replace normal convolution to maintain a low number of parameters. To verify the validity and adaptability of MSCVT in the crop disease dataset, experiments were conducted in the PlantVillage dataset and the Apple Leaf Pathology dataset, and obtained results with recognition accuracies of 99.86% and 97.50%, respectively. In comparison with other CNN models, the proposed model achieved advanced performance in both cases. The experimental results show that MSCVT can obtain high recognition accuracy in crop disease recognition and shows excellent adaptability in multidisease recognition and small-scale disease recognition.


Asunto(s)
Agricultura , Fabaceae , Suministros de Energía Eléctrica , Redes Neurales de la Computación , Orientación Espacial
5.
J Insect Sci ; 23(2)2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-37052365

RESUMEN

Endosymbionts live symbiotically with insect hosts and play important roles in the evolution, growth, development, reproduction, and environmental fitness of hosts. Weevils are one of the most abundant insect groups that can be infected by various endosymbionts, such as Sodalis, Nardonella, and Wolbachia. The sweet potato weevil, Cylas formicarius (Coleoptera: Brentidae), is a notorious pest in sweet potato (Ipomoea batatas L.) cultivation. Currently, little is known about the presence of endosymbionts in C. formicarius. Herein, we assessed the endosymbiont load of a single geographic population of C. formicarius. The results showed that Nardonella and Rickettsia could infect C. formicarius at different rates, which also varied according to the developmental stages of C. formicarius. The relative titer of Nardonella was significantly related to C. formicarius developmental stages. The Nardonella-infecting sweet potato weevils were most closely related to the Nardonella in Sphenophorus levis (Coleoptera, Curculionidae). The Rickettsia be identified in bellii group. These results preliminarily revealed the endosymbionts in C. formicarius and helped to explore the diversity of endosymbionts in weevils and uncover the physiological roles of endosymbionts in weevils.


Asunto(s)
Escarabajos , Ipomoea batatas , Gorgojos , Animales , Reproducción
6.
J Agric Food Chem ; 71(3): 1713-1726, 2023 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-36634352

RESUMEN

The widespread use of titanium dioxide nanoparticles (TiO2 NPs) in the food industry has brought about human safety risks related to nanotoxicity. In this study, food-related TiO2 NPs (anatase, 40 nm) were given to rats by oral gavage for 90 days at doses of 10, 100, and 1000 mg/kg bw. An additional two satellite groups underwent the same protocol for 45 days and for 90 days followed by a 28 day recovery. TiO2 NPs tended to agglomerate together in H2O, AGJ, and AIJ. No systemic toxicity was observed after 90 day agglomerated TiO2 NP exposure with no Ti distribution in major tissues/organs. Furthermore, TiO2 NP consumption for 90 days had no impact on microbiota diversity; the community structure of the gut microbiota is shifted to some extent at the genus level. Collectively, the NOAEL of agglomerated TiO2 NPs for 90 days of oral administration was 1000 mg/kg bw, the highest dose tested in male and female rats.


Asunto(s)
Microbioma Gastrointestinal , Nanopartículas del Metal , Nanopartículas , Humanos , Ratas , Masculino , Femenino , Animales , Titanio/toxicidad , Titanio/química , Distribución Tisular , Nanopartículas/toxicidad , Administración Oral , Nanopartículas del Metal/toxicidad , Nanopartículas del Metal/química
7.
Biometrics ; 79(3): 2525-2536, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-36517992

RESUMEN

Estimation of age-dependent transmissibility of COVID-19 patients is critical for effective policymaking. Although the transmissibility of symptomatic cases has been extensively studied, asymptomatic infection is understudied due to limited data. Using a dataset with reliably distinguished symptomatic and asymptomatic statuses of COVID-19 cases, we propose an ordinary differential equation model that considers age-dependent transmissibility in transmission dynamics. Under a Bayesian framework, multi-source information is synthesized in our model for identifying transmissibility. A shrinkage prior among age groups is also adopted to improve the estimation behavior of transmissibility from age-structured data. The added values of accounting for age-dependent transmissibility are further evaluated through simulation studies. In real-data analysis, we compare our approach with two basic models using the deviance information criterion (DIC) and its extension. We find that the proposed model is more flexible for our epidemic data. Our results also suggest that the transmissibility of asymptomatic infections is significantly lower (on average, 76.45% with a credible interval (27.38%, 88.65%)) than that of symptomatic cases. In both symptomatic and asymptomatic patients, the transmissibility mainly increases with age. Patients older than 30 years are more likely to develop symptoms with higher transmissibility. We also find that the transmission burden of asymptomatic cases is lower than that of symptomatic patients.


Asunto(s)
COVID-19 , Epidemias , Humanos , SARS-CoV-2 , Teorema de Bayes , Infecciones Asintomáticas/epidemiología
8.
Nanoscale ; 14(44): 16394-16414, 2022 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-36317508

RESUMEN

Self-trapped excitons (STEs) have attracted tremendous attention due to their intriguing properties and potential optoelectronic applications. STEs are formed from the lattice distortion induced by the strong electron (exciton)-phonon coupling in soft semiconductors upon photoexcitation, which features in broadband photoluminescence (PL) emission spectra with a large Stokes shift. Recently, significant progress has been achieved in this field but many remain challenges that need to be solved, including the understanding of the underlying physical mechanism, tuning of the performance, and device applications. Along these lines, for the first time, systematic experimental characterizations and advanced theoretical calculations are presented in this review to shed light on the physical mechanism. The possibility of tuning the STEs through multiple degrees of freedom is also presented, along with an overview of the STE-based emerged applications and future research perspectives.

9.
Epidemiol Infect ; 150: e171, 2022 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-36263615

RESUMEN

Coronavirus disease 2019 (COVID-19) asymptomatic cases are hard to identify, impeding transmissibility estimation. The value of COVID-19 transmissibility is worth further elucidation for key assumptions in further modelling studies. Through a population-based surveillance network, we collected data on 1342 confirmed cases with a 90-days follow-up for all asymptomatic cases. An age-stratified compartmental model containing contact information was built to estimate the transmissibility of symptomatic and asymptomatic COVID-19 cases. The difference in transmissibility of a symptomatic and asymptomatic case depended on age and was most distinct for the middle-age groups. The asymptomatic cases had a 66.7% lower transmissibility rate than symptomatic cases, and 74.1% (95% CI 65.9-80.7) of all asymptomatic cases were missed in detection. The average proportion of asymptomatic cases was 28.2% (95% CI 23.0-34.6). Simulation demonstrated that the burden of asymptomatic transmission increased as the epidemic continued and could potentially dominate total transmission. The transmissibility of asymptomatic COVID-19 cases is high and asymptomatic COVID-19 cases play a significant role in outbreaks.


Asunto(s)
COVID-19 , Epidemias , Humanos , Persona de Mediana Edad , Simulación por Computador , COVID-19/epidemiología , COVID-19/transmisión , Brotes de Enfermedades , SARS-CoV-2 , Infecciones Asintomáticas
10.
Molecules ; 27(19)2022 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-36234885

RESUMEN

Five new furofurans lignans, Brasesquilignan A-E (1-5), were isolated from the aqueous ethanol extract of Selaginella braunii Baker. Their structures were elucidated by extensive analysis of NMR and HRESIMS data. Their absolute configurations were determined by CD spectra, enzymatic hydrolysis, and GCMS analysis. Furthermore, all compounds were evaluated for anti-proliferative activities against various human cancer cellsin vitro. Compounds 2 and 3 exhibited weak inhibitorypotency against five human cancer cells.


Asunto(s)
Lignanos , Selaginellaceae , Etanol , Humanos , Lignanos/química , Lignanos/farmacología , Estructura Molecular , Extractos Vegetales/química , Extractos Vegetales/farmacología , Selaginellaceae/química
11.
Planta Med ; 87(6): 489-497, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33757146

RESUMEN

Four new chlorinated cyclopentene derivatives, rhytidhyesters A - D (1:  - 4: ), were isolated from Rhytidhysteron sp. BZM-9, an endophytic fungus from Leptospermum brachyandrum. The planar structures of compounds 1:  - 4: were mainly elucidated by 1D, 2D NMR, and HRESIMS data. Their absolute configurations were established by X-ray crystallographic analysis, quantum chemical 13C NMR, and electronic circular dichroism calculations. Compounds 1: and 2: are a pair of epimers. Moreover, all the isolated compounds were evaluated for cytotoxic activities against 3 human colon cancer cell lines (SW620, HT29, SW480) and antimicrobial activity against Staphylococcus aureus. All compounds exhibited weak to moderate antiproliferative activities with IC50 values ranging from 15.4 to 37.7 µM but were inactive against S. aureus.


Asunto(s)
Antineoplásicos , Ascomicetos , Antineoplásicos/farmacología , Ciclopentanos/farmacología , Estructura Molecular , Staphylococcus aureus
12.
Ecotoxicol Environ Saf ; 211: 111897, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33493719

RESUMEN

Chronic cadmium (Cd) toxicity is a significant health concern, and the mechanism of long-term low-dose Cd exposure on bone has not been fully elucidated yet. This study aimed to assess the association between long-term environmental Cd exposure and bone remodeling in women who aged over 50. A total of 278 non-smoking subjects from Cd-polluted group (n = 191) and non-Cd polluted group (n = 87) were investigated. Bone mineral density (BMD), the levels of three bone turnover markers (BTMs), including total procollagen type 1 amino-terminal propeptide (P1NP), collagen type 1 cross-linked C-telopeptide (ß-CTX), bone-specific alkaline phosphatase (BALP), together with serum soluble receptor activator of nuclear factor-κB ligand (sRANKL) and osteoprotegerin (OPG) were determined. Early markers of renal dysfunction were measured as well. Urinary Cd concentrations ranged from 0.41 to 87.31 µg/g creatinine, with a median of 4.91 µg/g creatinine. Age, BMD, T-score, and prevalence of osteoporosis showed no statistical differences among the quartiles of urinary Cd concentrations, while serum levels of P1NP, ß-CTX, and OPG were higher in the upper quartiles. Multivariate linear regression models indicated significantly positive associations of urinary Cd concentration with serum levels of P1NP, ß-CTX, BALP, sRANKL, and OPG. A ridge regression analysis with T-score and the three BTMs, sRANKL, and OPG, adjusted for age and body mass index (BMI), indicated that except for age and Cd exposure, ß-CTX was a predictor of T-score. These findings demonstrated that Cd may directly accelerate bone remodeling. Serum ß-CTX might be an appropriate biochemical marker for evaluating and monitoring Cd-related bone loss. Capsule: Cadmium (Cd) may directly accelerate bone remodeling and serum ß-CTX is a valuable biochemical marker for evaluating Cd-related bone loss.


Asunto(s)
Remodelación Ósea , Cadmio/sangre , Exposición a Riesgos Ambientales/estadística & datos numéricos , Contaminantes Ambientales/sangre , Adulto , Anciano , Fosfatasa Alcalina , Biomarcadores/sangre , Índice de Masa Corporal , Densidad Ósea , Huesos , Colágeno Tipo I , Femenino , Humanos , Persona de Mediana Edad , Osteoporosis/sangre , Osteoprotegerina , Péptidos , Ligando RANK/sangre
13.
Biomed Res Int ; 2020: 7187946, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32695819

RESUMEN

Herbal tea with antioxidant ingredients has gained increasing attention in the field of functional foods due to their amelioration potential in aging-related diseases. Wanglaoji herbal tea (WHT) is a kind of traditional beverage made from herbal materials. This study was performed to investigate its antioxidant activity and identify its protective effect on a H2O2-induced cell damage model. In this study, we identified six kinds of phenolic acids with antioxidant activity in WHT, among which rosmarinic acid had the highest content and the highest contribution ratio to the antioxidant activity of WHT. Moreover, compared with the H2O2-induced damage group, the WHT treatment group can significantly increase the viability of cells and decrease the ratio of senescence-associated ß-galactosidase-positive cells, intracellular malondialdehyde levels, and the percentage of G1 phase. Furthermore, enrichment analysis of differentially expressed genes revealed that heme oxygenase1 (HMOX1) was a key gene for protective effect of WHT on oxidative stress-induced cell damage. Thus, WHT exerted protective effects not only by scavenging reactive oxygen species but also by inducing the expression of cytoprotective genes by activating the HMOX1 pathway, which showed that WHT had a potential of promoting health by reducing oxidative stress-induced cell damage.


Asunto(s)
Antioxidantes/farmacología , Citoprotección/efectos de los fármacos , Hemo-Oxigenasa 1/metabolismo , Peróxido de Hidrógeno/toxicidad , Estrés Oxidativo/efectos de los fármacos , Tés de Hierbas , Compuestos de Bifenilo/química , Ciclo Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Citoprotección/genética , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Hidroxibenzoatos/análisis , Estrés Oxidativo/genética , Picratos/química , Sustancias Protectoras/farmacología , Transcriptoma/genética
14.
Wei Sheng Yan Jiu ; 48(6): 907-912, 2019 Nov.
Artículo en Chino | MEDLINE | ID: mdl-31875814

RESUMEN

OBJECTIVE: To investigate the prevalence and change of growth retardation, weight loss and malnutrition among children and adolescents aged 6-17 years in Guangdong Province in 2002-2012. METHODS: A total of 7264 children and adolescents(3804 boys and 3460 girls) aged 6-17 years were selected in thirteen monitoring points of Guangdong for nutritional survey in 2002, and a total of 2319 children and adolescents(1158 boys and 1161 girls) aged 6-17 years were selected in nine counties/districts of Guangdong for nutritional survey during 2009-2012 through multistage random cluster sampling. The body height and weight of all the children and adolescents were measured. RESULTS: The prevalence of growth retardation, weight loss and malnutrition decreased from 10. 0% to 1. 6%, 18. 1% to 8. 0%, and 24. 7% to 9. 3%among children and adolescents in Guangdong from 2002 to 2009-2012. The result of2009-2012 survey indicated the average prevalence of growth retardation were higher in boys(1. 9%) than in girls(1. 1%), and the average prevalence of weight loss and malnutrition was higher in girls(10. 4% and 11. 3%) than in boys(6. 0% and 7. 7%). And the average prevalence of growth retardation, weight loss and malnutrition were all higher in those living in rural area(2. 5%, 12. 4% and 14. 5%) than in city area(0. 8%, 4. 4% and 5. 1%). CONCLUSION: Compared with 2002, the prevalence of growth retardation, weight loss and malnutrition in children and adolescents aged 6-17 in Guangdong Province all decreased significantly. The prevalence was still high in girls and those living in rural, and children aged 6-17, thus more attention should be paid to them.


Asunto(s)
Desnutrición , Encuestas Nutricionales , Adolescente , Peso Corporal , Niño , China , Femenino , Humanos , Masculino , Estado Nutricional , Prevalencia
15.
Environ Pollut ; 249: 620-628, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30933759

RESUMEN

Chronic cadmium (Cd) toxicity is a significant health concern, and the mechanism of long-term low-dose Cd exposure on bone has not been fully elucidated till date. This study aimed to assess the association between rat mesenchymal stem cells (MSCs) and long-term Cd exposure through 38-week intake of CdCl2 at 1 and 2 mg/kg body weight (bw). Increased gene expression of receptor activator of NF-κB ligand (RANKL) and decreased gene expression of osteoprotegerin (OPG) were observed. Fold change of RANKL gene expression (fold change = 1.97) and OPG gene expression (fold change = 1.72) showed statistically significant differences at dose 2 mg/kg bw. Decreased expression of key genes was observed during the early osteogenic differentiation of MSCs. The gene expression of Osterix in 1 mg/kg bw group was decreased by 3.70-fold, and the gene expressions of Osterix, Osteopontin, collagen type I alpha 2 chain (COL1a2) and runt-related transcription factor 2 (RUNX2) in 2 mg/kg bw group were decreased by 1.79, 1.67, 1.45 and 1.35-folds, respectively. Exposure to CdCl2 induced an increase in the renal Cd load, but only an adaptive response was observed, including increased expression of autophagy-related proteins LC3B and Beclin-1, autophagy receptor p62, and heme oxygenase 1 (HO-1), which is an inducible isoform that releases in response to stress. There were no significant changes in the urinary low molecular weight proteins including N-acetyl-b-D-glucosaminidase (NAG), ß2-microglobulin and albumin (U-Alb). Urinary calcium (Ca) excretion showed no increase, and no obvious renal histological changes. Taken together, these results indicated that the chronic CdCl2 exposure directly act on MSCs through RANKL/OPG pathway and downregulate the key genes involved in osteogenic differentiation of MSCs. The toxic effect of Cd on bone may occur in parallel to nephrotoxicity.


Asunto(s)
Cloruro de Cadmio/toxicidad , Cadmio/toxicidad , Células Madre Mesenquimatosas/efectos de los fármacos , Osteogénesis/genética , Osteoprotegerina/metabolismo , Ligando RANK/metabolismo , Animales , Huesos/metabolismo , Proteínas Portadoras/metabolismo , Diferenciación Celular , Colágeno Tipo I/biosíntesis , Subunidad alfa 1 del Factor de Unión al Sitio Principal/biosíntesis , Regulación hacia Abajo , Femenino , Expresión Génica , Humanos , Osteogénesis/efectos de los fármacos , Osteopontina/biosíntesis , Ratas , Ratas Sprague-Dawley , Factores de Transcripción/biosíntesis
16.
Food Funct ; 9(12): 6495-6507, 2018 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-30467564

RESUMEN

Our team has previously demonstrated that Ganoderma lucidum polysaccharides F31 have hypoglycemic effects on diabetic mice. This study provides insight into the system-level hypoglycemic mechanisms of F31 by the integrative analysis of transcriptomics and proteomics data. To explore the omics perspective for the mechanisms of action, the protein and gene expression in the liver from the normal control (NC), diabetic db/db control mice (DC) and F31-treated db/db mice (F31) were analyzed by iTRAQ and RNA-Seq. The differential expression proteins (DEPs) and differential expression genes (DEGs) were analyzed based on their gene ontology (GO) annotations and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and the expression of DEGs and DEPs was verified by quantitative polymerase chain reaction (qPCR) and western blotting (WB). We identified sixty-five DEGs and sixty-two DEPs in the F31-treated group as compared with the DC. Integrated analysis of the RNA-Seq data and proteomics data indicated that the two DEGs/DEPs-Gck [glucokinase (GCK)] and Cyp4a12a [cytochrome P450, family 4, subfamily a, polypeptide 12a (CYP4A12A)]-showed the same trend in mRNA and protein expression levels in the comparison of F31-VS-DC. KEGG analysis revealed that the peroxisome proliferator-activated receptors (PPARs) signaling pathway was enriched in both of the comparisons of NC-VS-DC and F31-VS-DC at the protein expression level. In the analysis of the gene and protein expression of candidate proteins targeting diabetes, we found that three genes [Gck, glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK)] and three proteins [GCK, glucose transporter type 2 (GLUT2), pyruvate kinase (PYK) ] in the glycolysis and gluconeogenesis pathways, proteins of the Janus-activated kinase 2 (JAK2) in the insulin pathway, and two genes [Cyp4a12a and stearoyl-CoA desaturase 2 (SCD2)] in the lipid metabolism were expressed significantly differently in the F31-treated group as compared with the DC group, which played important roles in the hypoglycemic activity of F31. Cluster analysis demonstrated that microRNAs probably participated in the regulation of the genes involved the glucose metabolism. These results provide theoretical evidence for F31 as a potential functional food ingredient for the prevention and treatment of type 2 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/genética , Hipoglucemiantes/administración & dosificación , Extractos Vegetales/administración & dosificación , Polisacáridos/administración & dosificación , Reishi/química , Animales , Glucemia/metabolismo , Familia 4 del Citocromo P450/genética , Familia 4 del Citocromo P450/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animales de Enfermedad , Glucoquinasa/genética , Glucoquinasa/metabolismo , Humanos , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Receptores Activados del Proliferador del Peroxisoma/genética , Receptores Activados del Proliferador del Peroxisoma/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteómica , Estearoil-CoA Desaturasa/genética , Estearoil-CoA Desaturasa/metabolismo
17.
J Bone Miner Res ; 32(10): 1990-2000, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28407309

RESUMEN

This study aimed to assess the association between osteoporosis and long-term environmental Cd exposure through diet in southern China. A total of 1116 subjects from a Cd-polluted area and a non-Cd-polluted area were investigated. All subjects met the criteria of having been living in the investigated area for more than 15 years and lived on a subsistence diet of rice and vegetables grown in that area. Besides bone mineral density, the levels of urinary markers of early renal impairment, such as urinary N-acetyl-ß-D-glucosaminidase (NAG), α1 -microglobulin, ß2 -microglobulin, and urinary albumin, were also determined. Urinary Cd concentrations of all studied subjects ranged from 0.21 to 87.31 µg/g creatinine, with a median of 3.97 µg/g creatinine. Multivariate linear regression models indicated a significant negative association of urinary Cd concentrations with bone mineral density. In logistic regression models, both categorical and continuous urinary Cd concentrations were positively associated with osteoporosis. Subjects in the second, third, and fourth quartiles of urinary Cd concentration had greater odds of osteoporosis compared with subjects in the first quartile (odds ratio [OR] = 3.07, 95% confidence interval [CI], 1.77 to 5.33; OR = 4.63, 95% CI, 2.68 to 7.98; OR = 9.15, 95% CI, 5.26 to 15.94, respectively). Additional adjustment for levels of urinary markers did not attenuate the associations. No evidence existed of an interaction between urinary Cd concentration and renal function using levels of urinary markers, and estimated glomerular filtration rate (eGFR). In all subjects, the benchmark dose and benchmark dose lower bound were 1.14 (0.61) and 2.73 (1.83) µg/g creatinine, with benchmark response set at 5% and 10%, respectively. The benchmark dose of urinary Cd was lower in women than in men. This study demonstrated an inverse association between the body burden of Cd and osteoporosis. The toxic effect of Cd on bone may occur in parallel to nephrotoxicity. © 2017 American Society for Bone and Mineral Research.


Asunto(s)
Benchmarking , Cadmio/efectos adversos , Exposición a Riesgos Ambientales/análisis , Osteoporosis/etiología , Cadmio/orina , China/epidemiología , Demografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Osteoporosis/epidemiología , Osteoporosis/orina , Prevalencia , Análisis de Regresión , Estadísticas no Paramétricas
18.
J Ethnopharmacol ; 196: 47-57, 2017 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-27902927

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Ganoderma lucidum (Lin Zhi) has been used to treat diabetes in Chinese folk for centuries. Our laboratory previously demonstrated that Ganoderma lucidum polysaccharides (GLPs) had hypoglycemic effects in diabetic mice. Our aim was to identify the main bioactives in GLPs and corresponding mechanism of action. MATERIALS AND METHODS: Four polysaccharide-enriched fraction were isolated from GLPs and the antidiabetic activities were evaluated by type 2 diabetic mice. Fasting serum glucose (FSG), fasting serum insulin (FSI) and epididymal fat/BW ratio were measured at the end of the experiment. In liver, the mRNA levels of hepatic glucose regulatory enzymes were determined by quantitative polymerase chain reaction (qPCR) and the protein levels of phospho-AMP-activated protein kinase (p-AMPK)/AMPK were determined by western blotting test. In epididymal fat tissue, the mRNA and protein levels GLUT4, resistin, fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC1) were determined by qPCR and immuno-histochemistry. The structure of polysaccharide F31 was obtained from GPC, FTIR NMR and GC-MS spectroscopy, RESULTS: F31 significantly decreased FSG (P<0.05), FSI and epididymal fat/BW ratio (P<0.01). In liver, F31 decreased the mRNA levels of hepatic glucose regulatory enzymes, and up-regulated the ratio of phospho-AMP-activated protein kinase (p-AMPK)/AMPK. In epididymal fat tissue, F31 increased the mRNA levels of GLUT4 but decreased fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC1) and resistin. Immuno-histochemistry results revealed F31 increased the protein levels of GLUT4 and decreased resistin. CONCLUSION: Data suggested that the main bioactives in GLPs was F31, which was determined to be a ß-heteropolysaccharide with the weight-average molecular weight of 15.9kDa. The possible action mechanism of F31 may be associated with down-regulation of the hepatic glucose regulated enzyme mRNA levels via AMPK activation, improvement of insulin resistance and decrease of epididymal fat/BW ratio. These results strongly suggest that F31 has antidiabetic potential.


Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Polisacáridos Fúngicos , Ganoderma , Hipoglucemiantes , Proteínas Quinasas Activadas por AMP/metabolismo , Acetil-CoA Carboxilasa/genética , Acetil-CoA Carboxilasa/metabolismo , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Animales , Glucemia/análisis , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/metabolismo , Regulación hacia Abajo , Ayuno/sangre , Acido Graso Sintasa Tipo I/genética , Acido Graso Sintasa Tipo I/metabolismo , Cuerpos Fructíferos de los Hongos , Polisacáridos Fúngicos/farmacología , Polisacáridos Fúngicos/uso terapéutico , Transportador de Glucosa de Tipo 4/genética , Transportador de Glucosa de Tipo 4/metabolismo , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Insulina/sangre , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones Endogámicos C57BL , ARN Mensajero/metabolismo
19.
Int J Environ Res Public Health ; 12(10): 11988-2001, 2015 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-26404328

RESUMEN

OBJECTIVES: The aim of this study was to systematically evaluate the relationship between urinary excretion of cadmium (U-Cd) and biomarkers of renal dysfunction. METHODS: One hundred eighty five non-smoking female farmers (aged from 44 to 71 years) were recruited from two rural areas with different cadmium levels of exposure in southern China. Morning spot urine samples were collected for detecting U-Cd, urinary creatinine (U-cre), ß2-microglobulin (ß2-MG), α1-microglobulin (α1-MG), metallothionein (MT), retinol binding protein (RBP), albumin (AB), N-acetyl-ß-D-glucosaminidase (NAG), alkaline phosphatase (ALP), γ-glutamyl transpeptidase (GGT) and kidney injury molecule-1 (KIM-1). Spearman's rank correlation was carried out to assess pairwise bivariate associations between continuous variables. Three different models of multiple linear regression (the cre-corrected, un-corrected and cre-adjusted model) were used to model the dose-response relationships between U-Cd and nine urine markers. RESULTS: Spearman's rank correlation showed that NAG, ALP, RBP, ß2-MG and MT were significantly associated with U-Cd for both cre-corrected and observed data. Generally, NAG correlated best with U-Cd among the nine biomarkers studied, followed by ALP and MT. In the un-corrected model and cre-adjusted model, the regression coefficients and R² of nine biomarkers were larger than the corresponding values in the cre-corrected model, indicating that the use of observed data was better for investigating the relationship between biomarkers and U-Cd than cre-corrected data. CONCLUSIONS: Our results suggest that NAG, MT and ALP in urine were better biomarkers for long-term environmental cadmium exposure assessment among the nine biomarkers studied. Further, data without normalization with creatinine show better relationships between cadmium exposure and renal dysfunction.


Asunto(s)
Cadmio/orina , Riñón/metabolismo , Acetilglucosaminidasa/orina , Adulto , Anciano , Albuminuria , alfa-Globulinas/orina , Biomarcadores/orina , China , Creatinina/orina , Estudios Transversales , Femenino , Receptor Celular 1 del Virus de la Hepatitis A , Humanos , Glicoproteínas de Membrana/orina , Metalotioneína/orina , Persona de Mediana Edad , Receptores Virales , Proteínas Celulares de Unión al Retinol/orina , Población Rural , Microglobulina beta-2/orina , gamma-Glutamiltransferasa/orina
20.
Food Funct ; 6(11): 3567-75, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26311233

RESUMEN

Our laboratory has previously demonstrated that Grifola frondosa polysaccharides (GFPs) showed hypoglycemic effects. This study aimed to investigate which polysaccharide-enriched fractions of GFPs were the main active constituents, and to disclose their hypoglycemic mechanism. F2 and F3 were obtained from GFPs and their hypoglycemic effects were investigated. Fasting serum glucose (FSG) levels, fasting serum insulin (FSI) levels and a homeostasis model assessment of insulin resistance (HOMA-IR) were measured, and the hepatic mRNA levels of insulin receptor (IR), insulin receptor substrate-1 (IRS-1), protein tyrosine phosphatase-1B (PTP1B), phosphatidylinositol 3-kinase (PI3K) and Akt/protein kinase B (PKB) were determined by a quantitative polymerase chain reaction (qPCR). The activity of IR and IRS-1 were determined by an enzyme-linked immunosorbent assay (ELISA), and their phospho-protein levels were analyzed with western blotting. F2 and F3 significantly decreased the levels of FSG, FSI and HOMA-IR compared with a diabetic control group (P < 0.05). F2 and F3 increased the activity and mRNA levels of IR, and the latter also increased the mRNA levels of IRS-1. As for the protein levels of phospho-IR and IRS-1, both F2 and F3 increased the protein levels of IR (Try 1361), but decreased IRS-1 (Ser307). In the PI3K/Akt pathway, F3 increased the mRNA levels of PI3K and Akt, however, F2 inhibited PTP1B expression. F2 and F3 are presumed to cause an improvement in insulin resistance, triggered by the reactivation of IR and IRS-1.


Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Grifola/química , Hipoglucemiantes/farmacología , Resistencia a la Insulina/fisiología , Polisacáridos/farmacología , Animales , Glucemia/análisis , Diabetes Mellitus Experimental/sangre , Ensayo de Inmunoadsorción Enzimática , Ayuno/sangre , Homeostasis , Insulina/sangre , Proteínas Sustrato del Receptor de Insulina/metabolismo , Hígado/enzimología , Masculino , Fosfatidilinositol 3-Quinasas/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 1/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Receptor de Insulina/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA