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1.
Food Chem ; 455: 139920, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38850994

RESUMO

This work presents a hydrothermal method followed by a sonochemical treatment for synthesizing tantalum decorated on iron selenide (Ta/FeSe2) integrated with nitrogen-doped graphene (NGR) as a susceptible electrode material for detecting trolox (TRX) in berries samples. The surface morphology, structural characterizations, and electrochemical performances of the synthesized Ta/FeSe2/NGR composite were analyzed via spectrophotometric and voltammetry techniques. The GCE modified with Ta/FeSe2/NGR demonstrated an impressive linear range of 0.1 to 580.3 µM for TRX detection. Additionally, it achieved a remarkable limit of detection (LOD) of 0.059 µM, and it shows a high sensitivity of 2.266 µA µÐœ-1 cm-2. Here, we used density functional theory (DFT) to investigate the structures of TRX and TRX quinone and the locations of energy levels and electron transfer sites. The developed sensor exhibits significant selectivity, satisfactory cyclic and storage stability, and notable reproducibility. Moreover, the practicality of TRX was assessed in different types of berries, yielding satisfactory recoveries.

2.
Vaccines (Basel) ; 11(11)2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-38005998

RESUMO

To simultaneously express and improve expression levels of multiple viral proteins of a porcine reproductive and respiratory syndrome virus (PRRSV), polycistronic baculovirus surface display vectors were constructed and characterized. We engineered polycistronic baculovirus surface display vectors, namely, pBacDual Display EGFP(BacDD)-2GP2-2GP4 and pBacDD-4GP5N34A/N51A (mtGP5), which simultaneously express and display the ectodomain of His-tagged GP2-gp64TM-CTD, His-tagged GP4-gp64TM-CTD, and His-tagged mtGP5-gp64TM-CTD fusion proteins of PRRSV on cell membrane of Sf-9 cells. Specific pathogen-free (SPF) pigs were administered intramuscularly in 2 doses at 21 and 35 days of age with genetic recombinant baculoviruses-infected cells. Our results revealed a high level of ELISA-specific antibodies, neutralizing antibodies, IL-4, and IFN-γ in SPF pigs immunized with the developed PRRSV subunit vaccine. To further assess the co-expression efficiency of different gene combinations, pBacDD-GP2-GP3-2GP4 and pBacDD-2mtGP5-2M constructs were designed for the co-expression of the ectodomain of His-tagged GP2-gp64TM-CTD, His-tagged GP3-gp64TM-CTD, and His-tagged GP4-gp64TM-CTD proteins as well as the ectodomain of His-tagged mtGP5-gp64TM-CTD and His-tagged M-gp64TM-CTD fusion proteins of PRRSV. To develop an ELISA assay for detecting antibodies against PRRSV proteins, the sequences encoding the ectodomain of the GP2, GP3, GP4, mtGP5, and M of PRRSV were amplified and subcloned into the pET32a vector and expressed in E. coli. In this work, the optimum conditions for expressing PRRSV proteins were evaluated, and the results suggested that 4 × 105 of Sf-9 cells supplemented with 7% fetal bovine serum and infected with the recombinant baculoviruses at an MOI of 20 for three days showed a higher expression levels of the protein. Taken together, the polycistronic baculovirus surface display system is a useful tool to increase expression levels of viral proteins and to simultaneously express multiple viral proteins of PRRSV for the preparation of subunit vaccines.

3.
Vet Microbiol ; 264: 109277, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826648

RESUMO

Avian reoviruses (ARVs) are important pathogens that cause considerable economic losses in poultry farming. To date, host factors that control stabilization of ARV proteins remain largely unknown. In this work we determined that the eukaryotic chaperonin T-complex protein-1 (TCP-1) ring complex (TRiC) is essential for avian reovirus (ARV) replication by stabilizing outer-capsid protein σC, inner core protein σA, and the non-structural protein σNS of ARV. TriC serves as a chaperone of viral proteins and prevent their degradation via the ubiquitin-proteasome pathway. Furthermore, reciprocal co-immunoprecipitation assays confirmed the association of viral proteins (σA, σC, and σNS) with TRiC. Immunofluorescence staining indicated that the TRiC chaperonins (CCT2 and CCT5) are colocalized with viral proteins σC, σA, and σNS of ARV. In this study, inhibition of TRiC chaperonins (CCT2 and CCT5) by the inhibitor HSF1A or shRNAs significantly reduced expression levels of the σC, σA, and σNS proteins of ARV as well as virus yield, suggesting that the TRiC complex functions in stabilization of viral proteins and virus replication. This study provides novel insights into TRiC chaperonin governing virus replication via stabilization of outer-capsid protein σC, inner core protein σA, and the non-structural protein σNS of ARV.


Assuntos
Chaperonina com TCP-1 , Orthoreovirus Aviário , Proteínas Virais , Replicação Viral , Animais , Proteínas do Capsídeo/metabolismo , Chaperonina com TCP-1/metabolismo , Orthoreovirus Aviário/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ubiquitina/metabolismo , Proteínas do Core Viral/metabolismo , Proteínas Virais/metabolismo , Proteínas Virais Reguladoras e Acessórias/metabolismo , Replicação Viral/genética
4.
Food Chem ; 375: 131844, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34952385

RESUMO

This study describes an immunomagnetic nanoparticle (IMNP)-based lateral flow assay (LFA) for detecting the major peanut allergen Ara h 1. We developed a clearly specific method in identifying peanut from ten other seeds and nuts, and a good visual limit of detection (vLOD) of 0.01 µg/mL Ara h 1 in PBS. PBS that contains 1 M NaCl and 2% Tween 20 was determined to be the optimal extraction buffer for isolating Ara h 1 from cookie, milk and chocolate with vLOD values of 0.5 µg/g, 0.5 µg/mL, and 1 µg/g, respectively. Forty two processed foods were simultaneously analyzed using this method and an AOAC-approved ELISA kit. The specificity and sensitivity of this assay were thus determined to be 100 and 95%, respectively. This new IMNP-based LFA has potential as a rapid tool for screening processed foods for Ara h 1 residues.


Assuntos
Nanopartículas de Magnetita , Hipersensibilidade a Amendoim , Albuminas 2S de Plantas , Alérgenos , Antígenos de Plantas , Arachis , Ensaio de Imunoadsorção Enzimática , Glicoproteínas , Humanos , Imunoensaio , Proteínas de Plantas
5.
Electron. j. biotechnol ; 47: 89-99, sept. 2020. ilus, tab, graf
Artigo em Inglês | LILACS | ID: biblio-1253101

RESUMO

BACKGROUND: Koelreuteria henryi Dummer is an indigenous plant in Taiwan. The species has been used in traditional folk medicine for the promotion of liver functions and for treating malaria and urethritis. The present study investigated the antioxidant activity of the flower extract of Koelreuteria henryi Dummer. The extraction conditions were optimized by the contents of total phenolic acids and total flavonoids, and antioxidant activity assays. Moreover, an in vitro study for investigating antioxidant activity of K. henryi flower extract was demonstrated by hydrogen peroxide (H2O2)-induced apoptosis. RESULTS: K. henryi flower extracted for 150 min showed high contents of total phenolic acids and total flavonoids. In an in vitro model, L929 cells were pretreated with K. henryi flower extract, and then treated with H2O2 to induce oxidative damage. Results demonstrated that H2O2-induced apoptosis was inhibited by the treatment of 200 µg/ml K. henryi flower extract through the mitochondria-mediated pathway and mitogen-activated protein kinase (MAPK) pathway. The caspase 8/9 activity and expression of p-p38 and pERK were repressed by K. henryi flower extract. In addition, the prevention of H2O2-induced apoptosis by K. henryi flower extract activated the nuclear factor-erythroid 2-related factor (Nrf2) stress response pathway to transcript heme oxygenase 1 (HO-1). Also, K. henryi flower extract prevented H2O2-induced apoptosis through HO-1 production, as evident by the use of HO-1 inhibitor. CONCLUSIONS: The present study demonstrated that K. henryi flower extract could inhibit the H2O2-induced apoptosis in L929 cells through the activation of the Nrf2/HO-1 pathway.


Assuntos
Extratos Vegetais/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Sapindaceae/química , Antioxidantes/farmacologia , Flavonoides/análise , Western Blotting , Apoptose , Flores/química , Heme Oxigenase-1 , Fator 2 Relacionado a NF-E2 , Caspase 8 , Peróxido de Hidrogênio
6.
Electron. j. biotechnol ; 45: 38-45, May 15, 2020. ilus, graf, tab
Artigo em Inglês | LILACS | ID: biblio-1177420

RESUMO

BACKGROUND: Taraxacum species (commonly known as dandelion) used as herbal medicine have been reported to exhibit an antiproliferative effect on hepatoma cells and antitumor activity in non-small-cell lung cancer cells. Although several investigations have demonstrated the safety of Taraxacum officinale, the safety of tissue-cultured plants of T. formosanum has not been assessed so far. Therefore, the present study examines the safety of the water extract of the entire plant of tissue cultured T. formosanum based on acute and subacute toxicity tests in rats, as well as the Ames tests. RESULTS: No death or toxicity symptoms were observed in the acute and subacute tests. The results of the acute test revealed that the LD50 (50% of lethal dose) value of the T. formosanum water extract for rats exceeded 5 g/kg bw. No abnormal changes in the body weight, weekly food consumption, organ weight, or hematological, biochemical, and morphological parameters were observed in the subacute toxicity test. Thus, the no observed adverse effect level (NOAEL) of T. formosanum water extract was estimated to be higher than 2.0 g/kg. Finally, the results of the Ames test revealed that T. formosanum water extract was not genotoxic at any tested concentration to any of five Salmonella strains. CONCLUSIONS: The water extract of tissue-cultured T. formosanum was non-toxic to rats in acute and subacute tests and exhibited no genotoxicity to five Salmonella strains.


Assuntos
Animais , Ratos , Extratos Vegetais/toxicidade , Taraxacum/toxicidade , Técnicas de Cultura de Tecidos/métodos , Segurança , Flavonoides/análise , Cromatografia Líquida de Alta Pressão , Urinálise , Ratos Sprague-Dawley , Fenol/análise , Testes de Toxicidade Aguda , Medicina Herbária , Taraxacum/química , Soro , Proliferação de Células/efeitos dos fármacos , Testes de Toxicidade Subaguda , Testes de Mutagenicidade
7.
Food Chem ; 271: 505-515, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30236709

RESUMO

Ara h2 is a major peanut allergen that induces rashes, vomiting, diarrhea, and anaphylactic shock. Since peanut is a major source in producing edible oils globally, Ara h2 residues can be present in various edible oils. In this work, an immunomagnetic nanoparticle-based lateral flow assay for identifying Ara h2 in edible oils is developed. This assay exhibits high sensitivity with a visual detection limit of 0.1 mg/kg Ara h2 in oil, and favorable specificity in differentiating peanut from seeds and nuts. The calculated CV values of intra- and inter-assay were 6.73-10.21% and 4.75-8.57%, respectively, indicating high reproducibility. In an analysis of 26 oil products, Ara h2 was detected in two peanut oils as 0.122 ±â€¯0.026 mg/kg and 0.247 ±â€¯0.027 mg/kg. The entire method takes 5 h, including a 3.5-h sample preparation. Hence, this method has the potential to be an effective way to screen edible oils for Ara h2.


Assuntos
Alérgenos/análise , Arachis/imunologia , Hipersensibilidade a Amendoim/imunologia , Óleos de Plantas/análise , Albuminas 2S de Plantas , Alérgenos/química , Alérgenos/imunologia , Antígenos de Plantas , Glicoproteínas , Proteínas de Membrana , Nanopartículas , Óleos , Proteínas de Plantas , Reprodutibilidade dos Testes
8.
Protein Expr Purif ; 130: 35-43, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27350535

RESUMO

In recent years, the number of people around the world who suffer from fruit allergies has increased. Mango can induce anaphylaxis, and two major mango allergens have been identified - Man i 1 and Man i 2. Apart from their molecular weights and pI values, no other information about them is known. This work identifies the DNA and amino acid sequences of Man i 1 and constructs an expression system for recombinant Man i 1 (rMan i 1). Firstly, 3' and 5' RACE assays were used to identify the cDNA fragment of Man i 1. Subsequently, the full length of Man i 1 cDNA was inserted into a pET-21a(+) vector, and the inserted plasmid was transformed to Escherichia coli BL21 (DE3) to express rMan i 1. The conditions for the expression of rMan i 1, including IPTG concentration, induction temperature, and induction time, were optimized. The highest amount of soluble rMan i 1 was obtained after induction with 0.1 mM IPTG at 16 °C for 20 h. The His-tagged rMan i 1 was purified using Ni-NTA agarose and its identity was verified using an anti-histidine antibody and the serum of a mango-allergic person. Additionally, rMan i 1 was identified as glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and shared 86.2% identity in amino acid sequence of GAPDH from wheat. Finally, an E. coli expression system of rMan i 1 was established, with the potential to be used in immunotherapy against mango allergy or the development of assays for detecting the residues of mango allergens.


Assuntos
Alérgenos , Clonagem Molecular , Escherichia coli/metabolismo , Expressão Gênica , Mangifera/genética , Proteínas de Plantas , Alérgenos/biossíntese , Alérgenos/química , Alérgenos/genética , Alérgenos/isolamento & purificação , Escherichia coli/genética , Mangifera/metabolismo , Proteínas de Plantas/biossíntese , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação
9.
Food Chem ; 192: 934-42, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26304432

RESUMO

In this work, a barcode-style lateral flow immunoassay is developed using two cut-off values (10 and 50 mg kg(-1) gliadin) to provide a semi-quantification for identifying "gluten-free" and "very low gluten" foods, based on the international Codex Alimentarius Standard. This developed assay exhibits favorable specificity in differentiating wheat from seven commonly used grains, with only a slight cross-reaction with barely. The intra-assay and inter-assay CV values of this assay were 1.5-1.7% and 2.5-4.5%, respectively, revealing high reproducibility. In the analysis of 48 food samples, the results of this assay closely agreed with those obtained using AOAC-approved ELISA or strip kits, as the Cohen's kappa coefficients for both comparisons exceeded 0.8. Thus, this developed assay can be used to quickly estimate the gliadin content in foods in order to protect people with wheat allergy or celiac disease from the accidental ingestion of gliadin.


Assuntos
Doença Celíaca/imunologia , Hipersensibilidade Alimentar/imunologia , Gliadina/química , Imunoensaio/métodos , Triticum/imunologia , Glutens/análise
10.
J Environ Radioact ; 146: 80-7, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25957049

RESUMO

The ubiquitous nature of microbes has made them the pioneers in radionuclides adsorption and transport. In this study, the radiation resistance and nuclide biosorption capacity of microbes isolated from the Lanyu low-level radioactive waste (LLRW) repository in Taiwan was assessed, the evaluation of the possibility of using the isolated strain as biosorbents for (60)Co and Co (II) from contaminated aqueous solution and the potential impact on radionuclides release. The microbial content of solidified waste and broken fragments of containers at the Lanyu LLRW repository reached 10(5) CFU/g. Two yeast strains, Candida guilliermondii (CT1) and Rhodotorula calyptogenae (RT1) were isolated. The radiation dose necessary to reduce the microbial count by one log cycle of CT1 and RT1 was 2.1 and 0.8 kGy, respectively. Both CT1 and RT1 can grow under a radiation field with dose rate of 6.8 Gy/h, about 100 times higher than that on the surface of the LLRW container in Lanyu repository. CT1 and RT1 had the maximum (60)Co biosorption efficiency of 99.7 ± 0.1% and 98.3 ± 0.2%, respectively in (60)Co aqueous solution (700 Bq/mL), and the (60)Co could stably retained for more than 30 days in CT 1. Nearly all of the Co was absorbed and reached equilibrium within 1 h by CT1 and RT1 in the 10 µg/g Co (II) aqueous solution. Biosorption efficiency test showed almost all of the Co (II) was adsorbed by CT1 in 20 µg/g Co (II) aqueous solution, the efficiency of biosorption by RT1 in 10 µg/g of Co (II) was lower. The maximum Co (II) sorption capacity of CT1 and RT1 was 5324.0 ± 349.0 µg/g (dry wt) and 3737.6 ± 86.5 µg/g (dry wt), respectively, in the 20 µg/g Co (II) aqueous solution. Experimental results show that microbial activity was high in the Lanyu LLRW repository in Taiwan. Two isolated yeast strains, CT1 and RT1 have high potential for use as biosorbents for (60)Co and Co (II) from contaminated aqueous solution, on the other hand, but may have the impact on radionuclides release from LLRW repository.


Assuntos
Candida/efeitos da radiação , Radioisótopos de Cobalto/química , Poluentes Radioativos/química , Rhodotorula/efeitos da radiação , Adsorção , Candida/química , Candida/crescimento & desenvolvimento , Monitoramento de Radiação , Resíduos Radioativos , Rhodotorula/química , Rhodotorula/crescimento & desenvolvimento , Taiwan
11.
Anal Chim Acta ; 787: 246-53, 2013 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-23830446

RESUMO

Gliadin from wheat is a common food allergen that can induce baker's asthma, wheat-dependent exercise-induced anaphylaxis, atopic dermatitis, and celiac disease. This gliadin assay focuses on rapidly screen and check for gluten contamination in raw materials and in the gluten-free food production process, not only for wheat-sensitive patients but also for the industries producing gluten-free foodstuffs. The developed assay incorporates the use of anti-gliadin antibody-conjugated immunomagnetic beads (IMBs) to capture the gliadin in samples and fluorescent dyes-loaded immunoliposomal nanovesicles (IMLNs) to produce and enhance the detection signal. Hence, a sandwich complex is formed as "IMBs-gliadin-IMLNs". Experimental results indicate that this detection platform exhibits good sensitivity for gliadin with a detection limit as low as 0.6 µg mL(-1) of gliadin; as the polyclonal antibody showed slight cross-reactions with barley and rye. Excellent recovery rates were found ranging from 83.5 to 102.6% as testing the spiked samples. Moreover, the CV (%) of intra- and inter-assay of this developed assay are 4.8-10.6% and 3.5-9.9%, respectively. Based on a parallel analysis of twenty food samples, the results of this developed assay provide a good consistency with those of an AOAC-approved ELISA kit without any false-negative results. The proposed assay method is thus a highly promising alternative method for detecting the contamination of gliadin in the food industry.


Assuntos
Contaminação de Alimentos/análise , Gliadina/análise , Glutens/análise , Separação Imunomagnética/métodos , Limite de Detecção , Lipossomos/química , Animais , Galinhas , Dieta Livre de Glúten/normas , Ensaio de Imunoadsorção Enzimática/métodos , Imunofluorescência/métodos
12.
PLoS One ; 8(5): e62482, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23658730

RESUMO

Curcumin, a natural compound and ingredient in curry, has antiinflammatory, antioxidant, and anticarcinogenic properties. Previously, we reported that curcumin abrogated influenza virus infectivity by inhibiting hemagglutination (HA) activity. This study demonstrates a novel mechanism by which curcumin inhibits the infectivity of enveloped viruses. In all analyzed enveloped viruses, including the influenza virus, curcumin inhibited plaque formation. In contrast, the nonenveloped enterovirus 71 remained unaffected by curcumin treatment. We evaluated the effects of curcumin on the membrane structure using fluorescent dye (sulforhodamine B; SRB)-containing liposomes that mimic the viral envelope. Curcumin treatment induced the leakage of SRB from these liposomes and the addition of the influenza virus reduced the leakage, indicating that curcumin disrupts the integrity of the membranes of viral envelopes and of liposomes. When testing liposomes of various diameters, we detected higher levels of SRB leakage from the smaller-sized liposomes than from the larger liposomes. Interestingly, the curcumin concentration required to reduce plaque formation was lower for the influenza virus (approximately 100 nm in diameter) than for the pseudorabies virus (approximately 180 nm) and the vaccinia virus (roughly 335 × 200 × 200 nm). These data provide insights on the molecular antiviral mechanisms of curcumin and its potential use as an antiviral agent for enveloped viruses.


Assuntos
Antivirais/farmacologia , Curcumina/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Doença de Newcastle/efeitos dos fármacos , Animais , Antivirais/química , Embrião de Galinha , Chlorocebus aethiops , Curcumina/química , Vírus da Dengue/efeitos dos fármacos , Cães , Vírus da Encefalite Japonesa (Espécie)/efeitos dos fármacos , Enterovirus Humano A/efeitos dos fármacos , Lipossomos/química , Células Madin Darby de Rim Canino , Transfecção , Células Vero , Ensaio de Placa Viral , Internalização do Vírus/efeitos dos fármacos
13.
Int J Pharm ; 441(1-2): 381-8, 2013 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-23220078

RESUMO

The aim of this work is to establish an optimal process for generating liposomal berberine and assessing its anticancer ability against human hepatic carcinoma in a murine xenograft model. Of various forms of liposomal berberine with different lipid compositions, preparation by various methods, the one that contained 5 mol% polyethenyl glycol (PEG) that was produced by a thin-film hydration/extrusion method exhibited the highest encapsulation efficiency (E.E.) of berberine (14%). Additionally, in vitro studies reveal that this batch of liposomal berberine inhibited the growth of HepG2 cells 2.5 times as effectively as berberine solution since the half maximal inhibitory concentration (IC(50)) of berberine solution was 4.23 µg berberine/mL while that of liposomal berberine was only 1.67 µg berberine/mL, and this inhibition effect was based on the induction of apoptosis through the caspase/mitochondria-dependent pathway. Additionally, the results of in vivo studies indicate that the liposome effectively reduced the rate of elimination of berberine in both plasma and tissues, and liposomal berberine effectively reduced the size and weight of tumors as compared with the untreated tumor control group. Therefore, this work demonstrates that liposome is a good carrier for berberine to inhibit the tumor growth in HepG2 tumor-bearing mice.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Berberina/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Apoptose/efeitos dos fármacos , Berberina/administração & dosagem , Carcinoma Hepatocelular/patologia , Caspases/metabolismo , Excipientes/química , Células Hep G2 , Humanos , Concentração Inibidora 50 , Lipossomos , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos Nus , Mitocôndrias/metabolismo , Polietilenoglicóis/química , Ensaios Antitumorais Modelo de Xenoenxerto
14.
J Agric Food Chem ; 60(26): 6483-92, 2012 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-22694361

RESUMO

This work develops a label-free gliadin immunosensor that is based on changes in the frequency of a quartz crystal microbalance (QCM) chip. A higher sensitivity was obtained by applying 25 nm gold nanoparticles (AuNPs) to the surface of a bare QCM electrode. Subsequently, chicken anti-gliadin antibodies (IgY) were immobilized directly on the AuNP-modified surface by cross-linking amine groups in IgY with glutaraldehyde. Experimental results revealed that the change in frequency exhibited when 2 ppm gliadin was bound to the AuNP-modified electrode was 35 Hz (48%) greater than that of the bare gold electrode. The linear dynamic range in 60% ethanol was from 1 × 10(1) to 2 × 10(5) ppb gliadin, and the calculated limit of detection (LOD) was 8 ppb. The entire detection process was completed in 40 min and was highly repeatable. Additionally, the AuNP-modified QCM system generated results in the detection of gliadin in 10 commercial food products that were consistent with those obtained using an AOAC-approved gliadin kit. In conclusion, the QCM platform provides a potential alternative means of ensuring that people with wheat allergies and celiac patients have access to gliadin-free food.


Assuntos
Análise de Alimentos/métodos , Gliadina/análise , Ouro , Nanopartículas Metálicas , Técnicas de Microbalança de Cristal de Quartzo/métodos , Técnicas Biossensoriais , Eletrodos
15.
J Biomed Mater Res A ; 94(4): 1133-40, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20694980

RESUMO

Bamboo charcoal beads (BCBs) were formed by coprecipitating bamboo charcoal particles with chitosan in alkaline solution. The amount of chitosan in the BCBs and their surface properties were measured. When 13-52 mg BCBs were exposed to RAW 264.7 macrophages, the amount of nitric oxide released and the cell viability were close to those of the blank. The amount of cytokine IL-6 secreted by macrophages did not depend on the dose of BCBs but macrophages secreted more TNF-alpha in response to higher doses of BCBs. However, the cytokine levels were relatively low, suggesting the favorable biocompatibility of BCBs. In adsorption experiments, BCBs adsorbed and released bovine serum albumin at particular concentrations, whereas BCBs adsorbed L-phenylalanine without a sign of release. This difference is attributed to the hydrophilicity and the pore size of the BCBs. Finally, the potential of BCBs as biocompatible adsorbents in blood detoxification is considered.


Assuntos
Bambusa/química , Remoção de Componentes Sanguíneos/métodos , Carvão Vegetal/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Teste de Materiais/métodos , Microesferas , Adsorção/efeitos dos fármacos , Animais , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Inativação Metabólica , Interleucina-6/metabolismo , Macrófagos/citologia , Camundongos , Microscopia Eletrônica de Varredura , Óxido Nítrico/metabolismo , Fenilalanina/metabolismo , Coelhos , Soroalbumina Bovina/metabolismo , Propriedades de Superfície/efeitos dos fármacos , Termogravimetria , Fator de Necrose Tumoral alfa/metabolismo
16.
Peptides ; 31(10): 1811-20, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20600422

RESUMO

We have designed and synthesized a series of cationic α-helical AMPs with improved antibacterial activity and selectivity against a broad spectrum of G(+) and G(-) bacteria. In the current study, we intended to gain further insight into the mechanisms of action between AMPs and cellular membranes using model liposomes of various phospholipid compositions. Circular dichroism measurements showed that AMPs adopted amphipathic α-helical conformation in the presence of negatively charged vesicles (DOPC/DOPG=1:3), while they were largely unstructured when incubated with neutral vesicles (DOPC). The interaction of AMPs with phospholipid vesicles were further analyzed by calcein leakage experiments. AMPs exhibited weak dye-leakage activity for DOPC (neutral) vesicles, while they effectively induced calcein leakage when interacted with DOPC/DOPG-entrapped vesicles. These results indicated that our newly designed cationic AMPs did show preferences for bacteria-mimicking anionic membranes. All of them exert their cytolytic activity by folding into an amphipathic helix upon selectively binding and insertion into the target membrane, leading to breakdown of the membrane structure, thus causing leakage of cell contents, resulting finally in cell death. Elucidating the mechanism of the membranolytic activity of AMPs may facilitate the development of more effective antimicrobial agents.


Assuntos
Antibacterianos , Peptídeos Catiônicos Antimicrobianos , Bactérias/efeitos dos fármacos , Lipossomos/metabolismo , Fosfolipídeos/metabolismo , Sequência de Aminoácidos , Antibacterianos/síntese química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/síntese química , Peptídeos Catiônicos Antimicrobianos/metabolismo , Peptídeos Catiônicos Antimicrobianos/farmacologia , Fluoresceínas/metabolismo , Corantes Fluorescentes/metabolismo , Hemólise/efeitos dos fármacos , Humanos , Lipossomos/química , Dados de Sequência Molecular , Fosfolipídeos/química
17.
J Hazard Mater ; 176(1-3): 280-7, 2010 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-19959285

RESUMO

This study investigates the feasibility of using gamma irradiation for photodegradation of a common residual fungicide, pentachloronitrobenzene (PCNB), in ginseng, and for microbial decontamination. American ginseng, Panax quinquefolius, was subjected to gamma irradiation. PCNB residues were analyzed by gas chromatography with electron capture detection and mass spectrometry. Eighty percent of PCNB (100 ppm) in a methanol aqueous solution was degraded by 5 kGy irradiation, and the primary degradation product was pentachloroaniline. Furthermore, contaminated PCNB (3.7 ppm) in ginseng were reduced to 0.2 ppm after 20 kGy irradiation. The IC(50) for treatment of Sclerotium rolfsii with 20 kGy irradiated PCNB was about 2.7 times higher than that for treatment with unirradiated PCNB. The survival rate of mouse fibroblast L929 cells treated with 20 kGy irradiated PCNB was about 12.9% higher than that of L929 cells treated with unirradiated PCNB. Additionally, after 20 kGy irradiation, less than 5% reduction of contents of ginsenoside Rb1 and Re were observed, and amounts of ginsenosides Rc, Rd, and Rg1 were not reduced significantly. The minimal gamma dose for microbial decontamination was 10 kGy. Therefore, gamma irradiation can be used for both PCNB photodegradation and microbial decontamination of ginseng without obvious loses of ginsenoside contents.


Assuntos
Bactérias/efeitos da radiação , Raios gama , Nitrobenzenos/efeitos da radiação , Panax/efeitos da radiação , Fotólise , Compostos de Anilina/análise , Animais , Linhagem Celular , Estudos de Viabilidade , Fibroblastos/efeitos dos fármacos , Fungicidas Industriais/efeitos da radiação , Espectrometria de Massas , Camundongos , Panax/química , Panax/microbiologia
18.
J Nanosci Nanotechnol ; 9(7): 4108-15, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19916416

RESUMO

The objective of this study is to investigate the nano-fabrication method for ginseng extract powders (GEPs) and detect the differences in physical and chemical properties, and cytotoxicity of GEPs before and after fabrication. White ginseng was used as the raw material to produce the GEPs (Sample A). After grinding, the GEPs passed a 40-mesh sieve (particle size < 105 microm) and was named as Sample B. The residue (particle size > 105 microm) was named as Sample C. Samples A and B were used for nanofabrication though the use of a high-energy ball mill. Sample B was ground for 3 hr (Sample D) and 1 hr (Sample E), while Sample A was ground for 3 hr (Sample F) and 1 hr (Sample G). Nanoparticles of GEPs with ranges of 300 nm approximately 1 microm and 500 nm approximately 3 microm were produced. The heavy metal content (As, Cd, Co, Cu, Fe, Hg, Mn, Ni, Pb, Se and W) of Samples A-G were all under the maximum residue limit. Sample C contained a higher amount of yellow crystal material and had the highest ginsenoside contents and antioxidant capacity. There were enrichments of ginsenosides (approximately 1.3 fold) and antioxidant capacities (approximately 1.6 fold) in Sample C compared to Sample A. Moreover, after nano-fabrication, the antioxidant capacity was not changed significantly. However, the cellular growth enhancement ability was increased significantly. Samples F and G had the higher cellular growth enhancement ability and improved the cellular growth of L929 cells about 1.3 times as compared to Sample A. In future studies, Sample C will be used for nanofabrication in order to enhance the curative efficiency of ginseng.


Assuntos
Composição de Medicamentos/métodos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Nanotecnologia/métodos , Panax/química , Extratos Vegetais/química , Teste de Materiais , Tamanho da Partícula , Pós
19.
Biomol Eng ; 24(5): 459-61, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17804291

RESUMO

Hydroxyapatite (HAp) is the major inorganic component in natural bones. Because HAp has the advantages of excellent biocompatibility, free of cell toxicity, and forming strong bonding to bone osteoinductively, it has been widely studied and prepared in many forms for orthopedic and dental applications. In the recent years, silicon based bio-chip was extensively studied. To improve the biocompatibility and search for novel application of bio-chip are not only an important aim but also a challenge. In the previous literatures, it's reported that HAp is relatively difficult to be coated onto a Si(1 0 0) substrate. In this study, we successfully manufactured crystalline HAp on to Si(1 0 0) using simplified supersaturated solution and investigated the structural characteristics through the measurements of XRD, FTIR, FE-SEM, and XPS. The photo-luminescent properties of the coatings were also studied.


Assuntos
Biomimética , Materiais Revestidos Biocompatíveis/química , Durapatita/química , Silício/química , Luminescência , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Fotoquímica , Espectrofotometria , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Difração de Raios X , Raios X
20.
Compr Rev Food Sci Food Saf ; 6(2): 47-58, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33412748

RESUMO

Attention to peanut allergy has been rising rapidly for the last 5 y, because it accounts for the majority of severe food-related anaphylaxis, it tends to appear early in life, and it usually is not resolved. Low milligram amounts of peanut allergens can induce severe allergic reactions in highly sensitized individuals, and no cure is available for peanut allergy. This review presents updated information on peanut allergy, peanut allergens (Ara h1 to h8), and available methods for detecting peanuts in foods. These methods are based on the detection of either peanut proteins or a specific DNA fragment of peanut allergens. A summary of published methods for detecting peanut in foods is given with a comparison of assay formats, target analyte, and assay sensitivity. Moreover, a summary of the current availability of commercial peanut allergen kits is presented with information about assay format, target analyte, sensitivity, testing time, company/kit name, and AOAC validation.

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