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1.
Anal Bioanal Chem ; 411(23): 6067-6080, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31273413

RESUMO

Rapid detection of trace Salmonella is urgently needed to ensure food safety. We present an innovative pretreatment strategy, based on a two-step enrichment culture and immunomagnetic separation, combined with a chemiluminescence microparticle immunoassay to detect at least one proliferative Salmonella cell in 25 mL (25 g) food. The capture performance of immunomagnetic beads (IMBs) of sizes for Salmonella was investigated, and the IMBs of size 2.8 µm showed a high capture efficiency of 60.7% in 25 mL milk and 74.5% in 25 mL chicken culture filtrate, which ensured the successful capture of trace Salmonella after 2.5 h in situ enrichment even from only one Salmonella cell. The separated Salmonella cells, reaching an amount of 103 colony-forming units (CFU) by a secondary enrichment for 3 h, were detected by a horseradish peroxidase chemiluminescence reaction with 4-(1-imidazolyl)phenol as an enhancer, which evidenced a linear response for Salmonella concentrations ranging from 2.3 × 102 to 7.8 × 104 CFU/mL. The entire detection process was completed within 8 h, with a very low detection limit of 1 CFU/25 mL (25 g), which was verified by colony counting, and a small degree of interference of 0.17-1.06%. Trace Salmonella from five different serovars in milk and chicken was successfully detected without false negative or false positive results. Furthermore, this study provides a basis to develop a fully automated instrument based on IMBs that includes all steps from sample preparation to chemiluminescence microparticle immunoassay for high-throughput screening of foodborne pathogens. Graphical abstract.


Assuntos
Contaminação de Alimentos/análise , Medições Luminescentes/métodos , Leite/microbiologia , Aves Domésticas/microbiologia , Salmonella/isolamento & purificação , Animais , Galinhas/microbiologia , Contaminação de Alimentos/economia , Inocuidade dos Alimentos/métodos , Imunoensaio/economia , Imunoensaio/métodos , Separação Imunomagnética/economia , Separação Imunomagnética/métodos , Limite de Detecção , Medições Luminescentes/economia , Infecções por Salmonella/microbiologia , Fatores de Tempo
2.
Pak J Pharm Sci ; 30(3(Special)): 1075-1079, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28671084

RESUMO

To research on the effect of DC-CIK cells on human lymphoma cell line Raji the immunophenotype of DC-CIK cells was analyzed using flow cytometry, and its proliferation inhibition effect was detected using MTT assay. 24 nude mice (4-6 weeks old) were employed and inoculated Raji cells on right axillaries for constructing human Burkitt lymphoma model. MTT results showed that DC-CIK cells had a significant inhibitory effect on Raji cells with obvious dose- and time- dependent effect. Western Blot results confirmed that DC-CIK cells could significantly down regulate the expression of BCL-2 (P<0.05). DC-CIK cells possesses significant anti-tumor effect on human Burkitt lymphoma bearing nude mice, and down regulation of Raji induced BCL-2 cell apoptosis may be one of the inhibitory mechanisms of DC-CIK cells.


Assuntos
Proliferação de Células/fisiologia , Células Matadoras Induzidas por Citocinas/fisiologia , Células Dendríticas/fisiologia , Animais , Linhagem Celular Tumoral , Células Matadoras Induzidas por Citocinas/imunologia , Células Dendríticas/imunologia , Humanos , Imunofenotipagem , Masculino , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese
3.
Biotechnol Appl Biochem ; 64(6): 888-894, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27730684

RESUMO

Micro- and nanoimmunomagnetic beads (MIMBs and NIMBs) used for immunomagnetic separation (IMS) with PCR were studied for the rapid detection of Salmonella. The capture efficiency of the two different IMBs was evaluated by a conventional plate counting method, and the binding pattern was studied using scanning electron microscopy. The specificity of the IMBs was tested with Salmonella, Shigella flexneri, enterohemorrhagic Escherichia coli O157:H7, and Listeria monocytogenes. By comparing the pre-enrichment IMS and the IMS enrichment steps with a 5.5-H enrichment time, this study developed a rapid and sensitive method for the detection of Salmonella in chicken. The method was implemented by IMS enrichment and PCR with MIMBs and NIMBs, with a total analysis time of 8 H. We showed that the method was sensitive based on NIMBs with a detection limit of 10° CFU for Salmonella in 25 g of chicken.


Assuntos
Separação Imunomagnética , Reação em Cadeia da Polimerase , Salmonella/genética , Salmonella/isolamento & purificação , Animais , Galinhas , Separação Imunomagnética/instrumentação
4.
Theranostics ; 4(9): 904-18, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25057315

RESUMO

The controllable self-assembly of amphiphilic mixed polymers grafted gold nanoparitcles (AuNPs) leads to strong interparticle plasmonic coupling, which can be tuned to the near-infrared (NIR) region for enhanced photothermal therapy (PTT). In this study, an improved thiolation method was adopted for ATRP and ROP polymer to obtain amphiphilic brushes of PMEO2MA-SH and PCL-SH. By anchoring PCL-SH and PMEO2MA-SH onto the 14 nm AuNPs, a smart hybrid building block for self-assembly was obtained. Increasing the PCL/PMEO2MA chain ratio from 0.8:1, 2:1 and 3:1 to 7:1, the structure of gold assemblies (GAs) was observed to transfer from vesicle to large compound micelle (LCM). Contributed to the special dense packed structure of gold nanoparticles in LCM, the absorption spectrometry of gold nanoparticles drastically red-shifted from 520 nm to 830 nm, which endowed the GAs remarkable NIR photothermal conversion ability. In addition, gold has high X-ray absorption coefficient which qualifies gold nanomaterial a potential CT contrast agent Herein, we obtain a novel gold assembly structure which can be utilized as potential photothermal therapeutic and CT contrast agents. In vitro and In vivo studies testified the excellent treatment efficacy of optimum GAs as a PTT and CT contrast agent. In vitro degradation test, MTT assay and histology study indicated that GAs was a safe, low toxic reagent with good biodegradability. Therefore, the optimum GAs with strong NIR absorption and high X-ray absorption coefficient could be used as a theranostic agent and the formation of novel gold large compound micelle might offers a new theory foundation for engineering design and synthesis of polymer grafted AuNPs for biomedical applications.


Assuntos
Neoplasias Mamárias Experimentais/terapia , Nanopartículas Metálicas , Fototerapia , Tomografia Computadorizada por Raios X , Animais , Feminino , Ouro/química , Humanos , Células MCF-7 , Neoplasias Mamárias Experimentais/diagnóstico por imagem , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Micelas
6.
Biomed Microdevices ; 14(1): 17-23, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21882073

RESUMO

This paper describes a vacuum-accelerated microfluidic immunoassay (we abbreviate it as VAMI) by sandwiching a filter membrane between a two-layer chip. A direct assay of IgG demonstrated that VAMI could simultaneously achieve higher sensitivity and require less time compared with conventional microfluidic immunoassays. We further applied VAMI to carry out a 3-step competitive assay (including antigen immobilization, competitive reaction and 2(nd) antibody reaction) for detecting the illegal food additive Sudan Red. A total assay time of 15 min with a limit of detection (LOD) of 1 ng ml(-1) is achieved.


Assuntos
Imunoensaio/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Ensaio de Imunoadsorção Enzimática , Filtração , Limite de Detecção , Vácuo
7.
Macromol Rapid Commun ; 31(20): 1805-10, 2010 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-21567597

RESUMO

Monodispersed polystyrene beads incorporated with Fe(3) O(4) nanoparticles are prepared via dispersion polymerization. The resultant magnetic beads present well-defined composite structures, excellent colloidal stability, and strong magnetic response. The formation mechanism for the monodispersed composite beads, incorporated with preformed Fe(3) O(4) nanocrystals, was investigated. The potential applications of the monodispersed magnetic beads in bacteria capturing were demonstrated. After being coated with anti-Salmonella CSA-1 antibody, the magnetic beads show capturing efficiencies of >99.4% in isolating Salmonella sp.

8.
J Reprod Dev ; 52(4): 569-76, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16757879

RESUMO

An enzymatic method of isolating primary follicles in the turkey has been described previously, but no similar work has been done in the hen. In this study, primary follicles from domestic hens (Gallus domesticus) were isolated using an enzymatic method, and the isolated follicular quantity, quality, and development in vitro were assessed. About 400 primary follicles ranging from 60 to 1125 microm in diameter were recovered with trypsin and collagenase from hen ovaries (per ovary). Of these, 76.5% were intact follicles with a complete single layer of granulose cells surrounded by the basement membrane, and their ultrastructures appeared this way in situ. Follicles (351 to 500 microm in diameter) were cultured in vitro, and 46.67% of them survived after 5 days. Ultrastructural examination showed that elongated mitochondria forming a ring were distributed to the periphery of the oocyte, the Golgi was oriented with the maturing face toward the granulosa cell layer, and the oocyte plasma membrane presented a few short microvilli lying on the oocyte surface, which confirmed that the surviving follicles were developmental. These results suggest that a simple, rapid, effective enzymatic method can be used to isolate a great number of intact primary follicles from the hen ovary.


Assuntos
Folículo Ovariano/metabolismo , Folículo Ovariano/patologia , Ovário/ultraestrutura , Animais , Técnicas de Cultura de Células/métodos , Membrana Celular/metabolismo , Galinhas , Feminino , Complexo de Golgi/metabolismo , Células da Granulosa/citologia , Mitocôndrias/metabolismo , Oócitos/metabolismo , Folículo Ovariano/anatomia & histologia , Ovário/metabolismo
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