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1.
ACS Appl Mater Interfaces ; 16(12): 15143-15155, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38481099

RESUMO

Realizing controllable input of botanical pesticides is conducive to improving pesticide utilization, reducing pesticide residues, and avoiding environmental pollution but is extremely challenging. Herein, we constructed a smart pesticide-controlled release platform (namely, SCRP) for enhanced treatment of tobacco black shank based on encapsulating honokiol (HON) with mesoporous hollow structured silica nanospheres covered with pectin and chitosan oligosaccharide (COS). The SCRP has a loading capacity of 12.64% for HON and could effectively protect HON from photolysis. Owing to the pH- and pectinase-sensitive property of the pectin, the SCRP could smartly release HON in response to a low pH or a rich pectinase environment in the black shank-affected area. Consequently, the SCRP effectively inhibits the infection of P. nicotianae on tobacco with a controlled rate for tobacco black shank of up to 87.50%, which is mainly due to the SCRP's capability in accumulating ROS, changing cell membrane permeability, and affecting energy metabolism. In addition, SCRP is biocompatible, and the COS layer enables SCRP to show a significant growth-promoting effect on tobacco. These results indicate that the development of a stimuli-responsive controlled pesticide release system for plant disease control is of great potential and value for practical agriculture production.


Assuntos
Praguicidas , Praguicidas/farmacologia , Preparações de Ação Retardada/farmacologia , Preparações de Ação Retardada/química , Poligalacturonase , Agricultura , Pectinas
2.
Artigo em Inglês | MEDLINE | ID: mdl-38335084

RESUMO

Multiview clustering (MVC) has gained significant attention as it enables the partitioning of samples into their respective categories through unsupervised learning. However, there are a few issues as follows: 1) many existing deep clustering methods use the same latent features to achieve the conflict objectives, namely, reconstruction and view consistency. The reconstruction objective aims to preserve view-specific features for each individual view, while the view-consistency objective strives to obtain common features across all views; 2) some deep embedded clustering (DEC) approaches adopt view-wise fusion to obtain consensus feature representation. However, these approaches overlook the correlation between samples, making it challenging to derive discriminative consensus representations; and 3) many methods use contrastive learning (CL) to align the view's representations; however, they do not take into account cluster information during the construction of sample pairs, which can lead to the presence of false negative pairs. To address these issues, we propose a novel multiview representation learning network, called anchor-sharing and clusterwise CL (CwCL) network for multiview representation learning. Specifically, we separate view-specific learning and view-common learning into different network branches, which addresses the conflict between reconstruction and consistency. Second, we design an anchor-sharing feature aggregation (ASFA) module, which learns the sharing anchors from different batch data samples, establishes the bipartite relationship between anchors and samples, and further leverages it to improve the samples' representations. This module enhances the discriminative power of the common representation from different samples. Third, we design CwCL module, which incorporates the learned transition probability into CL, allowing us to focus on minimizing the similarity between representations from negative pairs with a low transition probability. It alleviates the conflict in previous sample-level contrastive alignment. Experimental results demonstrate that our method outperforms the state-of-the-art performance.

3.
Int J Radiat Biol ; 99(10): 1607-1618, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36947642

RESUMO

PURPOSE: Intestinal injuries caused by ionizing radiation (IR) are a major complication of radiotherapy. Ferrostatin-1 (Fer-1) exerts antioxidant and anti-inflammatory effects. We investigated the influence of Fer-1 on IR-induced intestinal damage and explored the possible mechanisms. MATERIALS AND METHODS: IEC-6 cells were administrated with Fer-1 for 30 min and subsequently subjected to 9.0 Gy-irradiation. Flow cytometry, qPCR, and WB were used to detect changes. For in vivo experiments, Fer-1 was given intraperitoneally to mice at 1 h before and 24 h after 9.0 Gy total body irradiation (TBI) respectively. Three days after TBI, the small intestines were isolated for analysis. The diversity and composition of the gut microbiota were analyzed by 16S rRNA gene sequencing. RESULTS: In vitro, Fer-1 protected IEC-6 cells from IR injury by reducing the production of ROS and inhibiting both ferroptosis and apoptosis. In vivo, Fer-1 enhanced the survival rates of mice subjected to lethal doses of IR and restored intestinal structure and physiological function. Further investigation showed that Fer-1 protected IEC-6 cells and mice by inhibiting the p53-mediated apoptosis signaling pathway and restoring the gut-microbe balance. CONCLUSION: This study confirms that Fer-1 protects intestinal injuries through suppressing apoptosis and ferroptosis.


Assuntos
Ferroptose , Animais , Camundongos , RNA Ribossômico 16S , Apoptose/efeitos da radiação , Radiação Ionizante
4.
Animal Model Exp Med ; 5(6): 565-574, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36376997

RESUMO

BACKGROUND: Gastrointestinal (GI) injury is one of the most common side effects of radiotherapy. However, there is no ideal therapy method except for symptomatic treatment in the clinic. Xuebijing (XBJ) is a traditional Chinese medicine, used to treat sepsis by injection. In this study, the protective effects of XBJ on radiation-induced intestinal injury (RIII) and its mechanism were explored. METHODS: The effect of XBJ on survival of irradiated C57BL/6 mice was monitored. Histological changes including the number of crypts and the length of villi were evaluated by H&E. The expression of Lgr5+ intestinal stem cells (ISCs), Ki67+ cells, villin and lysozymes were examined by immunohistochemistry. The expression of cytokines in the intestinal crypt was detected by RT-PCR. DNA damage and apoptosis rates in the small intestine were also evaluated by immunofluorescence. RESULTS: In the present study, XBJ improved the survival rate of the mice after 8.0 and 9.0 Gy total body irradiation (TBI). XBJ attenuated structural damage of the small intestine, maintained regenerative ability and promoted proliferation and differentiation of crypt cells, decreased apoptosis rate and reduced DNA damage in the intestine. Elevation of IL-6 and TNF-α was limited, but IL-1, TNF-𝛽 and IL-10 levels were increased in XBJ-treated group after irradiation. The expression of Bax and p53 were decreased after XBJ treatment. CONCLUSIONS: Taken together, XBJ provides a protective effect on RIII by inhibiting inflammation and blocking p53-related apoptosis pathway.


Assuntos
Medicamentos de Ervas Chinesas , Proteína Supressora de Tumor p53 , Camundongos , Animais , Proteína Supressora de Tumor p53/metabolismo , Camundongos Endogâmicos C57BL , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Citocinas/metabolismo
5.
J Cell Mol Med ; 25(21): 10306-10312, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34595829

RESUMO

Ionizing radiation (IR)-induced intestinal damage is the major and common injury of patients receiving radiotherapy. Urolithin A (UroA) is a metabolite of the intestinal flora of ellagitannin, a compound found in fruits and nuts such as pomegranates, strawberries and walnuts. UroA shows the immunomodulatory and anti-inflammatory capacity in various metabolic diseases. To evaluate the radioprotective effects, UroA(0.4, 2 and 10 mg/kg) were intraperitoneally injected to C57BL/6 male mice 48, 24, 1 h prior to and 24 h after 9.0Gy TBI. The results showed that UroA markedly upregulated the survival of irradiated mice, especially at concentration of 2 mg/kg. UroA improved the intestine morphology architecture and the regeneration ability of enterocytes in irradiated mice. Then, UroA significantly decreased the apoptosis of enterocytes induced by radiation. Additionally, 16S rRNA sequencing analysis showed the effect of UroA is associated with the recovery of the IR-induced intestinal microbacteria profile changes in mice. Therefore, our results determinated UroA could be developed as a potential candidate for radiomitigators in radiotherapy and accidental nuclear exposure. And the beneficial functions of UroA might be associated with the inhibition of p53-mediated apoptosis and remodelling of the gut microbes.


Assuntos
Cumarínicos/farmacologia , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/efeitos da radiação , Radiação Ionizante , Protetores contra Radiação/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Cumarínicos/metabolismo , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos da radiação , Trato Gastrointestinal/patologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Mucosa Intestinal/efeitos da radiação , Camundongos , Doses de Radiação
6.
Mater Sci Eng C Mater Biol Appl ; 129: 112369, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34579888

RESUMO

Metal-organic frameworks (MOFs) are useful as drug delivery carriers with high loading capacity and excellent biocompatibility. We fabricated a new drug carrier based on MIL-101(Cr) environmentally and loaded it with 47.2 wt% WR-1065 (active metabolite of amifostine). Moreover, the permeability and stability of these nanoparticles increased after PEGylation by the N-hydroxysuccinimide active ester protocol. Then, a "green" continuous-flow system equipped with an ultrasound applicator was newly designed to prepare the nanoparticles under the effect of acoustic cavitation. Response surface methodology (RSM) was used to optimize the large-scale process conditions with Box-Behnken design to obtain high space-time yield (5785 kg m-3 day-1). These less toxic MOFs nanoparticles increased cell viability by scavenging the accumulated reactive oxygen species and resisting DNA damage after irradiation. They are capable of mitigating radiation injury, achieving a 30-d survival rate of 90% in mice after lethal total body irradiation (8.0 Gy). This countermeasure significantly improved the peripheral blood cell count, hematopoietic stem and progenitor cells frequency, and clonogenic function of hematopoietic progenitor cells. It probably prevents irradiation-induced hematopoietic damage through the p53-dependent apoptotic pathway. Therefore, ultrasound-assisted continuous-flow synthesis is a sustainable method to produce MOFs on a large scale for radioprotection.


Assuntos
Estruturas Metalorgânicas , Nanopartículas , Animais , Camundongos , Polietilenoglicóis
7.
Int J Radiat Biol ; 97(11): 1563-1568, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34402381

RESUMO

PURPOSE: This study assesses changes of circulating leukocyte subpopulations and the expression of checkpoint receptors in T cells in patients undergoing radiochemotherapy. MATERIALS AND METHODS: Fifty-seven patients with either esophageal cancer or cervical cancer who received radiochemotherapy were recruited into this study. Serial blood collection was carried out before and during treatments. Leukocyte subpopulations and the level of PD-1 and CTLA-4 in T cells were determined by flow cytometry. The plasma concentrations of 34 human cytokines, chemokines, and growth factors were quantified. RESULTS: Significant decreases of lymphocyte count and percentage of T cells and B cells were observed during radiochemotherapy. Percentages of PD-1hi and CTLA-4hi populations in T cells increased after treatments. Proportion of activated T cells showed no significant difference. No significant changes in the plasma concentrations of the 34 humoral mediators except mild decreases of six cytokines. CONCLUSION: Elevated expression of PD-1 and CTLA-4 in T cells in patients receiving radiochemotherapy, which suggests that exhaustion-like T-cell dysfunction develops during cancer cytotoxic treatments.


Assuntos
Linfócitos T , Antígeno CTLA-4 , Quimiorradioterapia , Citocinas , Humanos , Contagem de Linfócitos , Receptor de Morte Celular Programada 1
8.
AAPS PharmSciTech ; 22(5): 168, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34080070

RESUMO

Formulation development of KO-947-K mesylate injectable drug products was described. Solution formulations were initially attempted, and key parameters such as drug concentration, buffer, pH, complexing agent, and tonicity modifying agent were carefully evaluated in the lab setting, mainly focusing on solubility and chemical stability. A lead solution formulation was advanced to a scaleup campaign. An unexpected stability issue was encountered, and the root cause was attributed to the heterogeneous liquid freezing process of the formulated solution at -20°C, which had not been captured in the lab setting. A lyophilized product was then designed to overcome the issue and supplied to the phase I clinical trial.


Assuntos
Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Desenvolvimento de Medicamentos/métodos , Inibidores Enzimáticos/síntese química , Estabilidade de Medicamentos , Inibidores Enzimáticos/administração & dosagem , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Liofilização , Congelamento , Injeções , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/síntese química , Solubilidade
9.
Life Sci ; 261: 118463, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32950576

RESUMO

AIMS: Ionizing radiation (IR) induces injuries to the hematopoietic and intestinal systems, which are the leading cause of death. Baicalein, a plant-derived flavonoid, shows anti-oxidative stress, anti-apoptosis, anti-inflammation effects in many diseases. In this study, we evaluated the effects and mechanism of baicalein on IR induced intestinal and hematopoietic injuries. MAIN METHODS: Mice were divided into three groups: Control, IR and IR + Baicalein. All of mice were intraperitoneally administered with 100 mg/kg baicalein or normal saline for 1 h before IR, and then a day post-IR. The changes in intestinal structure, function and molecular expression were observed by pathological experiments and western blot. 16S rRNA gene sequencing was performed to analyze gut microbiota and further predicted metabolic pathways through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Hematopoietic function was evaluated by peripheral blood cells count and by flow cytometry analysis of hematopoietic cells composition. KEY FINDINGS: Baicalein improved intestinal structure and the ability of proliferation and regeneration after mice exposed to IR, in which the rebalance of gut microbial composition played an important role. KEGG results showed that p53-related apoptotic pathways played important roles in the composition changes of gut microbiota. Then we observed that baicalein inhibited the activation of p53 and p53 mediated mitochondrial apoptosis and death receptor apoptosis in the intestine. In addition, IR induced injuries to hematopoietic system also could be ameliorated by baicalein. SIGNIFICANCE: These results provide new insights into the mechanism of baicalein and support the potential of baicalein as a radioprotective medicine.


Assuntos
Flavanonas/uso terapêutico , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos da radiação , Lesões Experimentais por Radiação/tratamento farmacológico , Protetores contra Radiação/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Intestinos/efeitos dos fármacos , Intestinos/patologia , Intestinos/efeitos da radiação , Masculino , Camundongos Endogâmicos C57BL , Lesões Experimentais por Radiação/microbiologia , Lesões Experimentais por Radiação/patologia , Radiação Ionizante
10.
Oxid Med Cell Longev ; 2020: 8308616, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32774687

RESUMO

Sitagliptin, an inhibitor of the dipeptidyl peptidase IV (DPP4), has been implicated in the regulation of type 2 diabetes. However, the role and mechanism of sitagliptin administration in total body irradiation (TBI)- induced hematopoietic cells injury are unclear. In this study, we demonstrated that sitagliptin had therapeutic effects on hematopoietic damage, which protected mice from 7.5 Gy TBI-induced death, increased the numbers and colony formation ability of hematopoietic cells. These therapeutic effects might be attributed to the inhibition of NOX4-mediated oxidative stress in hematopoietic cells, and the alleviation of inflammation was also helpful. Therefore, sitagliptin has potential as an effective radiotherapeutic agent for ameliorating TBI-induced hematopoietic injury.


Assuntos
Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Neoplasias Hematológicas/tratamento farmacológico , Fosfato de Sitagliptina/uso terapêutico , Irradiação Corporal Total/métodos , Animais , Inibidores da Dipeptidil Peptidase IV/farmacologia , Neoplasias Hematológicas/mortalidade , Masculino , Camundongos , Fosfato de Sitagliptina/farmacologia , Análise de Sobrevida
11.
Epilepsy Res ; 127: 276-283, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27689807

RESUMO

OBJECTIVE: Numerous microRNAs (miRNAs) are differentially expressed in specific diseases, suggesting possible use as diagnostic or prognostic biomarkers. The purpose of this study is to investigate the expression levels of miR-129-2-3p and miR-935 in cortical brain tissue and plasma samples from controls and refractory temporal lobe epilepsy (TLE) patients to evaluate the utility of these measures as diagnostic biomarkers. METHODS: The study was divided into three phases. First, cortical brain tissue samples from nine refractory TLE patients and eight controls were screened for differential miRNA expression using the Affymetrix miRNA 4.0 microarray. Second, real-time quantitative PCR (qRT-PCR) was used to verify the microarray results in brain tissue samples from 13 refractory TLE patients and 13 healthy controls (including those studied by microarray analysis). Third, we tested the expression levels of selected miRNAs in plasma samples from 25 refractory TLE patients and 25 healthy volunteers by qRT-PCR. The capacity of miR-129-2-3p and miR-935 expression to distinguish refractory TLE from health controls was tested by receiver operator characteristics (ROC) curve analysis. RESULTS: (1) High-resolution miRNA arrays indicated that miR-129-2-3p and miR-935 were significantly upregulated in the cortical brain tissues of TLE patients compared to controls. (2) qRT-PCR confirmed upregulated miR-129-2-3p expression in the brain tissue(P<0.0001) and plasma samples(P=0.0008) of refractory TLE patients. (3) The expression of miR-935 in epilepsy patients was higher than control group, however, there are no significant statistical differences between them whether in plasma samples(P=0.644) or in tissue samples(P=0.258). (4) ROC analysis of miRNA-129-2-3p showed that the area under the curve (AUC) was 0.929 (95% CI: 0.833-1.000; p=0.000) for brain tissue and 0.778 (95% CI: 0.640-0.915; p=0.001) for plasma. CONCLUSION: Expression of miRNA-129-2-3p was upregulated in cortical brain tissue and plasma samples from patients with refractory TLE, but miR-935 not. Plasma miRNA-129-2-3p has great potential as a non-invasive biomarker for early detection and clinical evaluation of refractory TLE.


Assuntos
Córtex Cerebral/metabolismo , Epilepsia Resistente a Medicamentos/metabolismo , Epilepsia do Lobo Temporal/metabolismo , MicroRNAs/metabolismo , Adulto , Idoso , Área Sob a Curva , Biomarcadores/sangue , Estudos de Casos e Controles , Córtex Cerebral/patologia , Córtex Cerebral/cirurgia , Epilepsia Resistente a Medicamentos/patologia , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsia do Lobo Temporal/patologia , Epilepsia do Lobo Temporal/cirurgia , Feminino , Humanos , Masculino , Análise em Microsséries , Pessoa de Meia-Idade , Curva ROC , Reação em Cadeia da Polimerase em Tempo Real , Regulação para Cima
12.
BMC Med Inform Decis Mak ; 16(1): 124, 2016 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-27658851

RESUMO

BACKGROUND: Trauma is the leading cause of death between the ages of 1 to 44 in the United States. Blood loss is the primary cause of these deaths. The discrimination of states through which patients transition would be helpful in understanding the disease process, and in identification of critical states and appropriate interventions. Even though these states are strongly associated with patients' blood composition data, there has not been a way to directly identify them. Statistical tools such as hidden Markov models can be used to infer the discrete latent states from the blood composition data. METHODS: We applied a hidden Markov model to time-series multivariate patient measurements from the UCSF/ San Francisco General Hospital and Trauma Center. Ten blood factor related measurements were used to identify the model: factors II, V, VII, VIII, IX, X, antithrombin III, protein C, prothrombin time and partial thromboplastin time. Missing data in the time-series dataset was considered in the hidden Markov model. The number of states was determined by minimizing the Bayesian information criterion across different numbers of states. RESULTS: After preprocessing, 1090 patients with a total number of 2176 time point measurements were included in the analysis. The hidden Markov model identified 6 disease states and 3 stages. We analyzed their relationships to the blood composition data and the coagulation cascade. The states are very indicative of the disease progression status of patients. CONCLUSIONS: Six disease states and 3 stages associated with Coagulopathy in trauma were identified in our study. The hidden Markov model can be useful in identifying latent states by using patients' time-series multivariate data. The information obtained from the states and stages can be useful in the clinical setting.

13.
Exp Cell Res ; 339(2): 252-60, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26407906

RESUMO

miRNA-125 family, which is a highly conserved miRNA family throughout evolution, is consist of miRNA-125a-3p, miRNA-125a-5p, miRNA-125b-1 and miRNA-125b-2.The aberrant expression of miR-125 familyis tightly related to tumorigenesis and tumor development. The downstream targets of miRNA-125 include transcription factors like STAT3, cytokines like IL-6 and TGF-ß, tumor suppressing protein p53, pro-apoptotic protein Bak1 and RNA binding protein HuR et al. Through regulating these downstream targets miR-125 family is involved in regulating tumorigenesis and tumor development. Nowadays, miR-125b have already became a putative and valuable biomarker for cancer diagnosis, treatment and prognosis. In this review, we mainly summarize the dual function of miRNA-125 family in suppression and promotion of cancer cells and further elaborate its regulatory mechanisms from four facets, proliferation, apoptosis, invasion or metastasis and immune response.


Assuntos
MicroRNAs/metabolismo , Neoplasias/genética , Neoplasias/patologia , Animais , Apoptose , Proliferação de Células , Humanos , MicroRNAs/classificação , MicroRNAs/genética
14.
Mol Biosyst ; 11(4): 980-93, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25627823

RESUMO

Post-traumatic stress disorder (PTSD) is a psychological disorder affecting individuals that have experienced life-changing traumatic events. The symptoms of PTSD experienced by these subjects-including acute anxiety, flashbacks, and hyper-arousal-disrupt their normal functioning. Although PTSD is still categorized as a psychological disorder, recent years have witnessed a multi-directional research effort attempting to understand the biomolecular origins of the disorder. This review begins by providing a brief overview of the known biological underpinnings of the disorder resulting from studies using structural and functional neuroimaging, endocrinology, and genetic and epigenetic assays. Next, we discuss the systems biology approach, which is often used to gain mechanistic insights from the wealth of available high-throughput experimental data. Finally, we provide an overview of the current computational tools used to decipher the heterogeneous types of molecular data collected in the study of PTSD.


Assuntos
Transtornos de Estresse Pós-Traumáticos , Biologia de Sistemas , Animais , Pesquisa Biomédica , Humanos , Camundongos , Transtornos de Estresse Pós-Traumáticos/genética , Transtornos de Estresse Pós-Traumáticos/metabolismo , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Estados Unidos
15.
J Zhejiang Univ Sci B ; 13(2): 118-25, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22302425

RESUMO

To detect gatifloxacin (GAT) residue in swine urine, an electrochemical immunoassay was established. An indirect competitive immunoassay was developed, in which the coating antigen is immobilized in an enzyme-linked immunosorbent assay (ELISA) plate and GAT residue from the sample competes with the limited binding sites in added anti-GAT antibody. Horseradish peroxidase (HRP) conjugated to goat anti-rabbit IgG was used as the enzymatic label. A carbon fiber working electrode was constructed and current signals were detected by using hydrogen peroxide as a substrate and hydroquinone as an electrochemical mediator. The electrochemical immunoassay was evaluated by analysis of GAT in buffer or swine urine and an average value of half inhibition concentration (IC(50)) of 8.9 ng/ml was obtained. Excellent specificity of the antibody was achieved with little cross-reaction with lomefloxacin (3.0%), ciprofloxacin (3.0%), and ofloxacin (1.9%) among commonly used (fluoro)quinolones. In conclusion, the immunoassay system developed in this research can be used as a rapid, powerful and on-site analytical tool to detect GAT residue in foods and food products.


Assuntos
Anti-Infecciosos/urina , Fluoroquinolonas/urina , Imunoensaio/métodos , Suínos/urina , Urinálise/veterinária , Animais , Eletroquímica , Gatifloxacina , Concentração Inibidora 50 , Urinálise/métodos
16.
Food Chem ; 134(4): 2526-31, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23442720

RESUMO

In this research, magnetic beads-based enzyme immunoassays were investigated for rapid analysis of chloramphenicol (CAP) in milk. To improve sensitivity of CAP determination, two kinds of immunomagnetic separation methods were designed and compared. Magnetic polystyrene microspheres were conjugated with anti-CAP antibody (Method I) or goat-anti-mouse IgG (Method II). The whole determination could be finished in 1.25 h. Both methods showed high sensitivity to CAP in buffer, and obtained an IC(50) value of 0.05 ng mL(-1) for Method I and 0.4 ng mL(-1) for Method II. The methods showed high specificity, only showing a little cross-reaction towards CAP succinate. The two methods were applied to detect CAP in milk. The recovery rates were 80-106% and the coefficients of variation (CVs) were 4.7-15%. The immunomagnetic assay showed promising potential in rapid screening field for CAP analysis. Between the two methods, Method I is more sensitive, and Method II is more suitable for producing a general assay by changing a primary antibody for another analyte.


Assuntos
Cloranfenicol/análise , Cloranfenicol/isolamento & purificação , Contaminação de Alimentos/análise , Técnicas Imunoenzimáticas/métodos , Separação Imunomagnética/métodos , Leite/química , Animais , Antibacterianos , Bovinos
17.
Artigo em Inglês | MEDLINE | ID: mdl-21598142

RESUMO

Ronidazole was used as the starting material to prepare an immunogen and coating antigen. An anti-nitroimidazole monoclonal antibody was produced and an indirect competitive ELISA was established to detect nitroimidazole compounds in food products. The IC(50) values were determined to be 0.20 ng/ml for metronidazole, 4.0 ng/ml for tinidazole, 0.17 ng/ml for dimetridazole and 0.24 ng/ml for ornidazole. Considering that nitroimidazoles were commonly used as veterinary drugs, nitroimidazole residues in food products of animal origin were detected by the method. The coefficient of variation for nitroimidazoles determination in contaminated chicken, chicken liver and shrimp were all <14% and the recovery rate was in the range 74.0-90.6%. The results proved that the developed method was successful in detecting nitroimidazoles in food products.


Assuntos
Antiprotozoários/análise , Resíduos de Drogas/análise , Inspeção de Alimentos/métodos , Nitroimidazóis/análise , Animais , Carcinógenos/análise , Galinhas , Ensaio de Imunoadsorção Enzimática , Mel/análise , Fígado/química , Carne/análise , Penaeidae/química , Reprodutibilidade dos Testes , Frutos do Mar/análise , Drogas Veterinárias/análise
18.
Talanta ; 83(3): 732-7, 2011 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-21147313

RESUMO

Trenbolone (TRE) is a steroid used by veterinarians on livestock to increase appetite and body weight. The use of TRE has been restricted because of its harmful side effect for consumers. To effectively control TRE residue in food and food product, a rapid and convenient immunoassay was developed by preparing an anti-TRE monoclonal antibody. The immunogen and coating antigen were prepared by coupling TRE hapten with carrier proteins via 1-ethyl-3-(dimethylaminopropyl)carbodiimide hydrochloride (EDC) method. The optimized method gave an average IC(50) value of 0.323 ng mL(-1) towards TRE and an average detection limit (LOD) of 0.06 ng mL(-1), which is much lower than the maximum residue levels (2.0 ng g(-1)) accepted by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The specificity of the antibody was evaluated by measuring cross-reactivity of six structurally related compounds, including 19-nortestosterone (9.7%), testosterone (0.13%), methyltestosterone (<0.01%), methandrostenolone (<0.01%), (+)-dehydroisoandrosterone (<0.001%) and ß-estradiol (<0.001%). The recovery rates of the test in detection of TRE-fortified animal tissue, urine and animal feed samples were in the range of 81.3-89.4%, while the intra- and inter-assay coefficients of variation were less than 12.0%.


Assuntos
Ração Animal/análise , Anticorpos Monoclonais/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Acetato de Trembolona/análise , Urinálise/métodos , Animais , Especificidade de Anticorpos , Artefatos , Camundongos , Acetato de Trembolona/imunologia , Acetato de Trembolona/urina , Vacinas Sintéticas/imunologia
19.
Analyst ; 135(10): 2566-72, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20689866

RESUMO

Sudan dyes are banned to be used in food additives because of the carcinogenicity of their metabolites. A rapid and sensitive indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed to detect the residues of Sudan dyes. Novel immunogen and coating antigen were synthesized via glutaraldehyde linking. The hapten-bovine serum albumin (BSA) was applied as immunogen and the hapten-ovalbumin (OVA) was served as coating antigen. The monoclonal antibody obtained showed high sensitivity to Sudan I with an IC(50) value of 1.7 µg L(-1) in buffer and was suitable to detect the residues of Sudan red in food products. The specificity of the assay was studied by measuring cross-reactivity of the antibody with the structurally related compounds of Sudan II (<1%), Sudan IV (<1%) and para red (120%). Chilli jam and chilli oil samples spiked with Sudan dyes were analyzed by the method. The detection limit (LOD) of the ELISA method applied in chilli jam and chilli oil was 9.0 µg L(-1) and 19.6 µg L(-1), respectively. The recovery rates of Sudan-I in chilli oil and chilli jam were in the range of 80%-110% with coefficients of variation <25%. The intra-assay variation and inter-assay variation in buffer were both <9%.


Assuntos
Anticorpos Monoclonais/imunologia , Compostos Azo/análise , Ensaio de Imunoadsorção Enzimática/métodos , Aditivos Alimentares/análise , Animais , Compostos Azo/imunologia , Bovinos , Haptenos/imunologia , Ovalbumina/química , Ovalbumina/imunologia , Soroalbumina Bovina/química , Soroalbumina Bovina/imunologia
20.
Opt Express ; 15(13): 8486-91, 2007 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-19547181

RESUMO

We report the measured group delay dispersion (GDD) of new crystals Yb:Gd(2)SiO,(5)(Yb:GSO), Yb:GdYSiO(5) (Yb:GYSO) and Yb:LuYSiO(5) (Yb:LYSO) over wavelengths from 1000nm to 1200nm, with a white-light interferometer. Those GDD data should be useful for the dispersion compensation for femtosecond pulse generation in the lasers with these new crystals as the gain media.

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