Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
Oxid Med Cell Longev ; 2021: 9615429, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34413929

RESUMO

Keap1-Nrf2-ARE and heat shock proteins (Hsps) are important endogenous protection mechanisms initiated by heat stress to play a double protective role for cell adaptation and survival. H9C2 cells and 80 300-day-old specific pathogen-free chickens were randomly divided into the control and tea polyphenol groups and used to establish a heat stress model in vitro and in vivo. This task was conducted to explore the protection and mechanism of tea polyphenols in relieving thermal injury. A supplement with 10 µg/mL tea polyphenols could effectively relieve the heat damage of H9C2 cells at 42°C. Accordingly, weaker granular degeneration, vacuolar degeneration, and nucleus deep staining were shown. A strong antioxidant capacity was manifested in the upregulation of the total antioxidant capacity (T-AOC) (at 5 h, P < 0.05), Hemeoxygenase-1 mRNA (at 2 h, P < 0.01), superoxide dismutase (SOD) (at 2, 3, and 5 h, P < 0.05), and Nrf2 (at 0 and 5 h, P < 0.01). A high expression of Hsps was reflected in CRYAB at 3 h; Hsp27 at 0, 2, and 3 h (P < 0.01); and Hsp70 at 3 and 5 h (P < 0.01). The supplement with 0.2 g/L tea polyphenols in the drinking water also had a good effect in alleviating the heat stress damage of the myocardial cells of hens at 38°C. Accordingly, light pathological lesions and downregulation of the myocardial injury-related indicators (LDH, CK, CK-MB, and TNF-α) were shown. The mechanism was related to the upregulation of T-AOC (at 0 h, P < 0.05), GSH-PX (at 0.5 d, P < 0.01), SOD (at 0.5 d), and Nrf2 (at 0 d with P < 0.01 and 2 d with P < 0.05) and the induced expression of CRYAB (at 0.5 and 2 d), Hsp27 (at 0, 0.5, and 5 d), and Hsp70 (at 0 and 0.5 d). In conclusion, the tea polyphenols enhanced the antioxidant capacity and induced Hsps to relieve heat stress injury.


Assuntos
Antioxidantes/farmacologia , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Miócitos Cardíacos/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Polifenóis/farmacologia , Chá/química , Animais , Proteínas de Choque Térmico/genética , Camundongos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo
2.
Sci Rep ; 11(1): 17298, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34453080

RESUMO

We investigated the effects of low and high doses of ß-conglycinin and the ameliorative effects of sodium butyrate (based on high-dose ß-conglycinin) on the growth performance, serum immunity, distal intestinal histopathology, and gene, protein expression related to intestinal health in hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂). The results revealed that the instantaneous growth rate (IGR) of grouper significantly increased, decreased, and increased in the low-dose ß-conglycinin (bL), high-level ß-conglycinin (bH) and high-level ß-conglycinin plus sodium butyrate (bH-NaB), respectively. The feed coefficient ratio (FCR) was significantly increased in the bH and bH-NaB, serum levels of IFN-γ, IL-1ß, and TNF-α were upregulated in the bH. The intestinal diameter/fold height ratio was significantly increased in the bH. Furthermore, there were increases in nitric oxide (NO), total nitric oxide synthase (total NOS), and peroxynitrite anion (ONOO-) in the bH, and decreases in total NOS and ONOO- in the bH-NaB. In the distal intestine, IL-1ß and TGF-ß1 mRNA levels were downregulated and upregulated, respective in the bL. The mRNA levels of TNF-α and IL-6 were upregulated in the bH, and downregulated in the bH-NaB, respectively. Occludin, claudin3 and ZO-3 mRNA levels were upregulated in the bL, downregulated in the bH and then upregulated in the bH-NaB. No significant differences were observed in the mRNA levels of IFN-γ and jam4. And the p-PI3K p85Tyr458/total PI3K p85 value was significantly increased in the bH and then decreased in the bH-NaB, and the total Akt value was significantly increased in the bH. These indicate ß-conglycinin has a regulatory effect on serum immunity and affect distal intestinal development by modulating distal intestinal injury-related parameters. Within the distal intestinal tract, low- and high-dose ß-conglycinin differentially affect immune responses and tight junctions in the distal intestine, which eventually manifests as a reduction in growth performance. Supplementing feed with sodium butyrate might represent an effective approach for enhancing serum immunity, and protects the intestines from damage caused by high-dose ß-conglycinin.


Assuntos
Antígenos de Plantas/química , Ácido Butírico/química , Suplementos Nutricionais/análise , Globulinas/química , Proteínas de Armazenamento de Sementes/química , Proteínas de Soja/química , Ração Animal , Animais , Antígenos de Plantas/metabolismo , Bass , Ácido Butírico/metabolismo , Claudina-3/genética , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica , Globulinas/metabolismo , Humanos , Imunidade Inata , Interleucina-6/genética , Intestinos , RNA Mensageiro , Proteínas de Armazenamento de Sementes/metabolismo , Transdução de Sinais , Proteínas de Soja/metabolismo , Fator de Necrose Tumoral alfa/genética , Proteínas da Zônula de Oclusão/genética
3.
Res Vet Sci ; 133: 124-130, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32977120

RESUMO

In order to explore the function of vitamin C (VC) and VC-Na in the relief of heat stress injury in chicken cardiomyocytes, 150 30-day-old specific-pathogen-free chickens were randomly divided into a control group (fed normal drinking water), a VC group (50 µg/mL VC in drinking water), and a VC-Na group (50 µg/mL VC-Na in drinking water). After 7 days of adaptation feeding, the chickens were subjected to heat stress at 40 ± 2 °C and 60%-70% humidity for 0, 1, 3, 5, and 10 h, respectively, and the sera and heart tissues of the chickens were collected immediately at the corresponding heat stress time points. The effects of VC and VC-Na supplementation on the relief of chicken myocardial cell injury following heat stress was studied by detecting the levels of LDH, CK, CK-MB, and total antioxidant capacity (T-AOC) in the sera, and through histopathological analysis and the expression of CRYAB, Hsp27, and Hsp70 in the myocardial cells. The results showed that supplementing with 50 µg/mL VC or VC-Na significantly reduced the levels of LDH, and CK-MB in serum as well as heat-stress-induced granular and vacuolar degeneration, myocardial fiber breakage, and cell necrosis, indicating effective resistance to heat-stress damage. Additionally, the levels of T-AOC in serum were increased in the VC and VC-Na groups, suggesting enhancing of antioxidant capacity. Furthermore, the expression of CRYAB were induced at 0, 3, 5, and 10 h (P < 0.01) in both VC and VC-Na group, and that of Hsp70 were induced at 0 h (P < 0.05) in VC group and at 0, 3, 5, 10 h (P < 0.01) in VC-Na group. Thus, supplementing chicken diets with VC or VC-Na presented heat-stress damage resistance by enhancing antioxidant capacity and inducing expression of CRYAB and Hsp70.


Assuntos
Ácido Ascórbico/uso terapêutico , Galinhas , Transtornos de Estresse por Calor/veterinária , Proteínas de Choque Térmico/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Doenças das Aves Domésticas/prevenção & controle , Vitaminas/uso terapêutico , Animais , Antioxidantes/metabolismo , Galinhas/metabolismo , Suplementos Nutricionais , Proteínas de Choque Térmico HSP70/metabolismo , Transtornos de Estresse por Calor/prevenção & controle , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Oxirredução , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/metabolismo
4.
Front Immunol ; 11: 615980, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33537033

RESUMO

Soy glycinin (11S) is involved in immune regulation. As an additive, sodium butyrate (SB) can relieve inflammation caused by 11S. To further delve into the mechanisms. A diet containing 50% fishmeal was the control group (FM group), and the experimental groups consisted of the FM group baseline plus 2% glycinin (GL group), 8% glycinin (GH group), and 8% glycinin + 0.13% sodium butyrate (GH-SB group). The specific growth ratio (SGR), feed utilization, and density of distal intestinal (DI) type II mucous cells were increased in the GL group. In the serum, IFN-γ was significantly upregulated in the GL group, and IgG and IL-1ß were upregulated in the GH group. IgG, IL-1ß, and TNF-α in the GH-SB group were significantly downregulated compared to those in the GH group. The mRNA levels of mTOR C1, mTOR C2, and Deptor were upregulated in the GL, GH, and GH-SB groups in the DI compared with those in the FM group, while the mRNA levels of mTOR C1 and Deptor in the GH group were higher than those in the GL and GH-SB groups. 4E-BP1, RICTOR, PRR5, MHC II, and CD4 were upregulated in the GH group. TSC1, mLST8, and NFY mRNA levels in the GL and GH-SB groups were upregulated compared with those in the FM and GH groups. Western blotting showed P-PI3KSer294/T-PI3K, P-AktSer473/T-Akt, and P-mTORSer2448/T-mTOR were upregulated in the GH group. Collectively, our results demonstrate that low-dose 11S could improve serum immune by secreting IFN-γ. The overexpression of IgG and IL-1ß is the reason that high-dose 11S reduces serum immune function, and supplementing SB can suppress this overexpression. Low-dose 11S can block the relationship between PI3K and mTOR C2. It can also inhibit the expression of 4E-BP1 through mTOR C1. High-dose 11S upregulates 4E-BP2 through mTOR C1, aggravating intestinal inflammation. SB could relieve inflammation by blocking PI3K/mTOR C2 and inhibiting 4E-BP2. Generally speaking, the hybrid grouper obtained different serum and DI immune responses under different doses of 11S, and these responses were ultimately manifested in growth performance. SB can effectively enhance serum immunity and relieve intestinal inflammation caused by high dose 11S.


Assuntos
Ácido Butírico/farmacologia , Globulinas/toxicidade , Imunidade Inata/efeitos dos fármacos , Inflamação/imunologia , Alimentos Marinhos , Proteínas de Soja/toxicidade , Ração Animal , Animais , Bass/imunologia , Proteínas de Peixes/metabolismo , Globulinas/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Intestinos/imunologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Proteínas de Soja/imunologia , Serina-Treonina Quinases TOR/metabolismo
5.
Oxid Med Cell Longev ; 2018: 7014126, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30425783

RESUMO

Heat stress negatively affects poultry production and animal health. In response, animals invoke a heat stress response by inducing heat shock proteins (HSPs). Scientists are actively seeking natural products that can enhance the heat shock response. The present study aimed at assessing the effects of a purified rosemary extract comprising antioxidant compounds on the heat shock response and HSP expression profile in broiler chickens. The response of broilers to HS in the presence of purified rosemary extract was assessed using an in vivo myocardial cell model. Pathological lesions of heart tissue were examined microscopically. The levels and activities of enzymes associated with heart damage and oxidative damage were detected. Immunohistochemical staining was performed for HSPs in myocardial cells. The results showed that lactate dehydrogenase (LDH), creatine kinase (CK), and myocardial CK (CKMB) levels were reduced by the purified rosemary extract before and during heat stress. Heat stress alone increased CK and CKMB levels. The levels of oxidative damage-associated enzymes were compared between the rosemary + heat stress and heat stress-alone groups. The results indicated that in terms of these enzymes, the purified rosemary extract induced a more antioxidative state. Pathological examinations showed that heat stress caused myocardial fiber fracture, karyopyknosis, and degeneration. The addition of purified rosemary extract ameliorated these lesions to some degree, preserving more of the basic structure. Heat stress decreased the cellular levels of crystallin alpha B (CRYAB) and HSP70. The addition of the purified rosemary extract significantly increased the levels of CRYAB and HSP70 during heat stress (p < 0.0001). Immunohistochemistry showed that after rosemary treatment, CRYAB and HSP70 showed more intense staining compared with the no heat stress control group. In the rosemary + heat group, after 10 hours of heat stress, the staining intensity of these two proteins remained higher than in the heat stress group. Thus, purified rosemary extract could induce high levels of HSP70 and CRYAB in chicken hearts before and during heat stress. Purified rosemary extract could be used to alleviate heat stress in broiler chickens.


Assuntos
Galinhas/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Resposta ao Choque Térmico/efeitos dos fármacos , Extratos Vegetais/farmacologia , Rosmarinus/química , Cadeia B de alfa-Cristalina/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Emulsões/química , Miocárdio/enzimologia , Miocárdio/patologia , Nanopartículas/química , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação
6.
Fish Shellfish Immunol ; 81: 318-328, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30030116

RESUMO

Cottonseed protein concentrate (CPC) has similar amino acid composition compared with fish meal, and has the characteristics of low gossypol and low toxicity. The present study was conducted to investigate the growth performance, antioxidant capacity and different intestinal segments immune responses of hybrid grouper to replacement dietary fish meal ofCPC. Six iso-nitrogenous (50% crude protein) and iso-lipidic (10% crude lipid) diets were formulated: a reference diet (FM) containing 60% fishmeal and five experimental diets (12%, 24%, 36%, 48 and 60%) in which fishmeal protein was substituted at different levels by CPC to feed fish (initial body weight: 11 ±â€¯0.23 g) for 8 weeks. Thena challenge test with injection of Vibrio parahaemolyticus was conducted for 7 days until the fish stabilized. The results showed that specific growth rate (SGR) was the highest with 24% replacement level and feed conversion ratio (FCR)was significantly increased when the replacement level reached 48% (P < 0.05). The content of malonaldehyde (MDA) in the serum was significantly increased when the replacement level reached 36% (P < 0.05). The plica height in the proximal, mid and distal intestine were significantly decreased with the replacement level up to 48% (P < 0.05). Hepatic fat deposition wasaggravatedwhen the replacement level reached 36% (P < 0.05). The expression of IL-6, TNF-α, and IL-1ß mRNAs were significantly up-regulated (P < 0.05). The hepcidin mRNA expression was significantly down-regulated (P < 0.05). In proximal intestine (PI) and mid intestine (MI), IFN-γ mRNA expression was significantly up-regulated (P < 0.05). These results suggested that the CPC decreased hybrid grouper growth performance and inflammation function, and different inflammation function responses in PI,MI, and distal intestine (DI) were mediated partly by the TLR-2/MyD88 signaling pathway. According to the analysis of specific growth rate, the dietary optimum replacement level and maximum replacement level were estimated to be 17% and 34%, respectively.


Assuntos
Óleo de Sementes de Algodão , Proteínas de Peixes/imunologia , Intestinos/efeitos dos fármacos , Fator 88 de Diferenciação Mieloide/imunologia , Perciformes/imunologia , Preparações de Plantas/administração & dosagem , Proteínas de Plantas/administração & dosagem , Receptor 2 Toll-Like/imunologia , Ração Animal , Animais , Citocinas/genética , Feminino , Intestinos/imunologia , Malondialdeído/sangue , Perciformes/sangue , Transdução de Sinais/efeitos dos fármacos
7.
Saudi J Gastroenterol ; 23(5): 275-280, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28937021

RESUMO

Background\Aim: Quadruple daily administration of proton-pump inhibitor (PPI) therapy achieves potent acid inhibition, and combined with amoxicillin, with its pharmacodynamic and pharmacokinetic characteristics, may be efficient for Helicobacter pylori eradication. We compared the efficacy of two optimized high-dose dual therapies with a bismuth-containing quadruple regimen for treating H. pylori infection. Rabeprazole dosages for H. pylori eradication were also evaluated. PATIENTS AND METHODS: Treatment-naive and H. pylori-positive subjects were recruited and randomly apportioned to three treatment groups: Group A (n = 87), rabeprazole 10 mg plus amoxicillin 750 mg (4 times/day for 14 days); Group B (n = 87), rabeprazole 20 mg plus amoxicillin 750 mg (4 times/day for 14 days); and Group C (n = 89), bismuth-containing quadruple regimen consisting of rabeprazole 20 mg, bismuth 220 mg, amoxicillin 1000 mg, and clarithromycin 500 mg (2 times/day for 14 days). Four weeks after treatment discontinuation, patients were examined for H. pylori infection by 13C-urea breath test. The rates of adverse effects, compliance, and eradication were evaluated. RESULTS: Eradication rates in groups A, B, and C were 78.1, 81.6, and 84.3%, respectively, based on intention-to-treat analysis, or 79.1, 83.5, and 86.2%, according to per-protocol analysis. Rates of adverse events and compliance of the three groups were similar. CONCLUSION: For treating H. pylori infection, optimized high-dose amoxicillin-PPI dual therapies failed to achieve high cure rates in China and held no advantage over a bismuth-containing quadruple regimen.


Assuntos
Amoxicilina/farmacocinética , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/efeitos dos fármacos , Inibidores da Bomba de Prótons/farmacocinética , Rabeprazol/farmacocinética , Adulto , Amoxicilina/administração & dosagem , Amoxicilina/farmacologia , Antibacterianos/administração & dosagem , Bismuto/administração & dosagem , Testes Respiratórios/métodos , China/epidemiologia , Claritromicina/administração & dosagem , Esquema de Medicação , Quimioterapia Combinada/métodos , Feminino , Gastrite/diagnóstico , Gastrite/tratamento farmacológico , Gastrite/microbiologia , Infecções por Helicobacter/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/diagnóstico , Úlcera Péptica/tratamento farmacológico , Úlcera Péptica/microbiologia , Inibidores da Bomba de Prótons/administração & dosagem , Inibidores da Bomba de Prótons/farmacologia , Rabeprazol/administração & dosagem , Rabeprazol/farmacologia , Resultado do Tratamento
8.
J Ginseng Res ; 41(2): 209-214, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28413326

RESUMO

BACKGROUND: Both ginsenoside Re and B-complex vitamins are widely used as nutritional supplements. They are often taken together so as to fully utilize their antifatigue and refreshing effects, respectively. Whether actually a drug-nutrient interaction exists between ginsenoside Re and B-complex vitamins is still unknown. The objective of this study was to simultaneously investigate the effect of B-complex vitamins on the antifatigue activity and bioavailability of ginsenoside Re after their oral administration. The study results will provide valuable theoretical guidance for the combined utilization of ginseng and B-complex vitamins. METHODS: Ginsenoside Re with or without B-complex vitamins was orally administered to mice to evaluate its antifatigue effects and to rats to evaluate its bioavailability. The antifatigue activity was evaluated by the weight-loaded swimming test and biochemical parameters, including hepatic glycogen, plasma urea nitrogen, and blood lactic acid. The concentration of ginsenoside Re in plasma was determined by liquid chromatography-tandem mass spectrometry. RESULTS: No antifatigue effect of ginsenoside Re was noted when ginsenoside Re in combination with B-complex vitamins was orally administered to mice. B-complex vitamins caused to a reduction in the bioavailability of ginsenoside Re with the area under the concentration-time curve from zero to infinity markedly decreasing from 11,830.85 ± 2,366.47 h·ng/mL to 890.55 ± 372.94 h·ng/mL. CONCLUSION: The results suggested that there were pharmacokinetic and pharmacodynamic drug-nutrient interactions between ginsenoside Re and B-complex vitamins. B-complex vitamins can significantly weaken the antifatigue effect and decrease the bioavailability of ginsenoside Re when simultaneously administered orally.

9.
J Dermatol ; 44(5): 573-581, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27943400

RESUMO

In the previous work, we have indicated that HMGB1, a pro-inflammatory cytokine, is closely associated with the pathogenesis of psoriasis. To further clarify the role of HMGB1 in the pathogenesis of psoriasis, we investigated the direct function of HMGB1 application and HMGB1 blockade in imiquimod (IMQ)-induced psoriatic mouse model in this study. Mice were treated with imiquimod (IMQ) to induce psoriasis-like inflammation, and consecutively injected with recombinant HMGB1 or phosphate-buffered saline (PBS) i.d. Abundant cytoplasmic expression of HMGB1 was observed in lesional skin from IMQ-treated skin. The injection of HMGB1 into the IMQ-treated skin further aggravated the psoriasis-like disease, enhanced the infiltration of CD3+ T cells, myeloperoxidase+ neutrophils and CD11c+ dendritic cells, increased the number of γδ T cells, and upregulated the mRNA expression of interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (IFN)-γ and IL-17 compared with the PBS injection. Finally, by using anti-HMGB1 monoclonal antibody or HMGB1 inhibitor glycyrrhizin, we indicated that HMGB1 blockade reduced the number of γδ T cells, suppressed the mRNA expression of IL-6, TNF-α, IFN-γ and IL-17, and moderated clinical and histological evolvement in the IMQ-treated skin. Our data suggest that HMGB1 may act as a pro-inflammatory cytokine, and contribute to the development of IMQ-induced psoriasis-like inflammation. HMGB1 blockade may represent a new direction in the suppression of psoriasis.


Assuntos
Anti-Inflamatórios/uso terapêutico , Ácido Glicirrízico/uso terapêutico , Proteína HMGB1/metabolismo , Psoríase/imunologia , Aminoquinolinas , Animais , Anti-Inflamatórios/farmacologia , Citocinas/metabolismo , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Ácido Glicirrízico/farmacologia , Imiquimode , Fitoterapia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Psoríase/tratamento farmacológico , Psoríase/metabolismo
10.
Analyst ; 141(4): 1301-6, 2016 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-26814697

RESUMO

It is well-known that proximity-dependent probes containing an analyte recognization site and a signal formation domain could be assembled specifically into a sandwich-like structure (probe-analyte-probe) via introducing an analyte. In this work, using the design for zirconium ion (Zr(4+)) detection as the model, we develop a novel and reliable proximity-dependent DNA-scaffolded silver nanocluster (DNA/AgNC) probe for Zr(4+) detection via target-induced emitter proximity. The proposed strategy undergoes the two following processes: target-mediated emitter pair proximity as target recognition implement and the synthesis of DNA/AgNCs with fluorescence as a signal reporter. Upon combination of the rationally designed probe with Zr(4+), the intact templates were obtained according to the -PO3(2-)-Zr(4+)-PO3(2-)- pattern. The resultant structure with an emitter pair serves as a potent template to achieve highly fluorescent DNA/AgNCs. To verify the universality of the proposed proximity-dependent DNA/AgNC probe, we extend the application of the proximity-dependent probe to DNA and adenosine triphosphate (ATP) detection by virtue of a specific DNA complementary sequence and ATP aptamer as a recognition unit, respectively. The produced fluorescence enhancement of the DNA/AgNCs in response to the analyte concentration allows a quantitative evaluation of the target, including Zr(4+), DNA, and ATP with detection limits of ∼3.00 µM, ∼9.83 nM, and ∼0.81 mM, respectively. The proposed probe possesses good performance with simple operation, cost-effectiveness, good selectivity, and without separation procedures.


Assuntos
Técnicas Biossensoriais/métodos , DNA/química , Luz , Nanoestruturas/química , Prata/química , Trifosfato de Adenosina/análise , Trifosfato de Adenosina/química , Aptâmeros de Nucleotídeos/metabolismo , Técnicas Biossensoriais/instrumentação , DNA/análise , Zircônio/análise , Zircônio/química
11.
Biosens Bioelectron ; 77: 995-1000, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26547010

RESUMO

Developing direct and convenient methods for microRNAs (miRNAs) analysis is of great significance in understanding biological functions of miRNAs, and early diagnosis of cancers. We have developed a rapid, enzyme-free method for miRNA detection based on nanoparticle-assisted signal amplification coupling fluorescent metal nanoclusters as signal output. The proposed method involves two processes: target miRNA-mediated nanoparticle capture, which consists of magnetic microparticle (MMP) probe and CuO nanoparticle (NP) probe, and nanoparticle-mediated amplification for signal generation, which consists of fluorescent DNA-Cu/Ag nanocluster (NC) and 3-mercaptopropionic acid (MPA). In the presence of target miRNA, MMP probe and NP probe sandwich-capture the target miRNA via their respective complementary sequence. The resultant sandwich complex (MMP probe-miRNA-CuO NP probe) is separated using a magnetic field and further dissolved by acidolysis to turn CuO NP into a great amount of copper (II) ions (Cu(2+)). Cu(2+) could disrupt the interactions between thiol moiety of MPA and the fluorescent Cu/Ag NCs by preferentially reacting with MPA to form a disulfide compound as intermediate. By this way, the fluorescence emission of the DNA-Cu/Ag NCs in the presence of MPA increases upon the increasing concentration of Cu(2+), which is directly proportional to the amount of target miRNA. The proposed method allows quantitative detection of a liver-specific miR-221-5p in the range of 5 pM to 1000 pM with a detection limit of ~0.73 pM, and shows a good ability to discriminate single-base difference. Moreover, the detection assay can be applied to detect miRNA in cancerous cell lysates in excellent agreement with that from a commercial miRNA detection kit.


Assuntos
Cobre/química , DNA/química , DNA/genética , Nanopartículas de Magnetita/química , MicroRNAs/genética , Análise de Sequência de RNA/instrumentação , Sequência de Bases , Enzimas , Desenho de Equipamento , Análise de Falha de Equipamento , Nanopartículas de Magnetita/ultraestrutura , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , MicroRNAs/química , Dados de Sequência Molecular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Fluorescência/instrumentação
12.
Artigo em Inglês | MEDLINE | ID: mdl-23786975

RESUMO

Coffee is the most heavily consumed beverage in the world after water, for which quality is a key consideration in commercial trade. Therefore, caffeine content which has a significant effect on the final quality of the coffee products requires to be determined fast and reliably by new analytical techniques. The main purpose of this work was to establish a powerful and practical analytical method based on near infrared spectroscopy (NIRS) and chemometrics for quantitative determination of caffeine content in roasted Arabica coffees. Ground coffee samples within a wide range of roasted levels were analyzed by NIR, meanwhile, in which the caffeine contents were quantitative determined by the most commonly used HPLC-UV method as the reference values. Then calibration models based on chemometric analyses of the NIR spectral data and reference concentrations of coffee samples were developed. Partial least squares (PLS) regression was used to construct the models. Furthermore, diverse spectra pretreatment and variable selection techniques were applied in order to obtain robust and reliable reduced-spectrum regression models. Comparing the respective quality of the different models constructed, the application of second derivative pretreatment and stability competitive adaptive reweighted sampling (SCARS) variable selection provided a notably improved regression model, with root mean square error of cross validation (RMSECV) of 0.375 mg/g and correlation coefficient (R) of 0.918 at PLS factor of 7. An independent test set was used to assess the model, with the root mean square error of prediction (RMSEP) of 0.378 mg/g, mean relative error of 1.976% and mean relative standard deviation (RSD) of 1.707%. Thus, the results provided by the high-quality calibration model revealed the feasibility of NIR spectroscopy for at-line application to predict the caffeine content of unknown roasted coffee samples, thanks to the short analysis time of a few seconds and non-destructive advantages of NIRS.


Assuntos
Cafeína/análise , Café/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Calibragem , Análise dos Mínimos Quadrados , Espectroscopia de Luz Próxima ao Infravermelho/economia , Fatores de Tempo
13.
Physiol Meas ; 28(5): 481-8, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17470982

RESUMO

Ventricular arrhythmias are commonly observed in patients with acute coronary occlusion and ischemia. The purpose of the present study is to determine ischemic electrophysiological effects and their role in ischemia-induced arrhythmia. Optical mapping of the membrane potential with voltage-sensitive dyes was used in the study. The mapping was performed with di-4-ANEPPS in Langendorff-perfused rabbit hearts. The excitation-contraction decoupler 2,3-butanedione monoxime was used to suppress motion artifacts caused by contraction of the heart. The acute global ischemia was developed by a rapid reduction of the flow rate. The experiments revealed that ischemic tissues were characterized by an obvious reduction in action potential duration and action potential upstroke, slower conduction velocity (CV) and the property of post-repolarization refractoriness. Moreover, the magnitude of CV reduced both in control and ischemia when the pacing cycle length was short. CV reduction was even early in ischemia, resulting in a broader curve during ischemia. Moreover, the dominant frequency of ventricular tachycardia/ventricular fibrillation (VT/VF) in ischemia was less than that in control, implying a decreasing tendency of VT/VF frequency for low excitability. Therefore, combined with our previous simulation study, the dynamic changes of CV and longer refractory period were suggested to play an important role in the ischemia-related arrhythmia. Low excitability in ischemic tissue was the fundamental mechanism in it.


Assuntos
Arritmias Cardíacas/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Animais , Técnicas Eletrofisiológicas Cardíacas , Ventrículos do Coração/fisiopatologia , Técnicas In Vitro , Coelhos
14.
Int J Syst Evol Microbiol ; 57(Pt 2): 250-254, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17267959

RESUMO

Two novel strains, SL014B61A(T) and SL014B11A, were isolated from an oil-polluted saline soil from Gudao in the coastal Shengli Oilfield, eastern China. Cells of strains SL014B61A(T) and SL014B11A were motile, Gram-negative and rod-shaped. Growth occurred at NaCl concentrations of between 0 and 15 % and at temperatures of between 10 and 45 degrees C. Strain SL014B61A(T) had Q9 as the major respiratory quinone and C16 : 0 (21.2 %), C18 : 1omega9c (20.3 %), C16 : 1omega7c (7.3 %) and C16 : 1omega9c (6.4 %) as predominant fatty acids. The G+C content of the DNA was 57.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SL014B61A(T) belonged to the genus Marinobacter in the class Gammaproteobacteria. Strain SL014B61A(T) showed the highest 16S rRNA gene sequence similarity with Marinobacter bryozoorum (97.9 %) and showed 97.8 % sequence similarity to Marinobacter lipolyticus. DNA-DNA relatedness to the reference strains Marinobacter bryozoorum and Marinobacter lipolyticus was 35.5 % and 33.8 %, respectively. On the basis of these data, it is proposed that strains SL014B61A(T) and SL014B11A represent a novel species, Marinobacter gudaonensis sp. nov. The type strain is strain SL014B61A(T) (=DSM 18066(T)=LMG 23509(T)=CGMCC 1.6294(T)).


Assuntos
Marinobacter/classificação , Marinobacter/isolamento & purificação , Petróleo , Microbiologia do Solo , Poluentes do Solo/análise , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Poluição Ambiental , Ácidos Graxos/análise , Ácidos Graxos/química , Genes de RNAr , Marinobacter/citologia , Marinobacter/fisiologia , Dados de Sequência Molecular , Movimento , Hibridização de Ácido Nucleico , Filogenia , Quinonas/análise , Quinonas/química , RNA Bacteriano/genética , RNA Ribossômico 16S/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA