[show abstract][hide abstract] ABSTRACT: Food allergen labeling has not yet been implemented in China. Therefore, a gold immunochromatography assay (GICA) was developed using two monoclonal antibodies (mAb) against the peanut allergen Ara h1. The GICA was specific for standard peanut samples with a sensitivity of 10 ng/ml. Peanut protein traces extracted from 124 food products imported and exported by China Customs were easily and rapidly detected by GICA. 68 food samples originally labeled as containing peanuts were positive for Ara h1 and 54 food samples labeled as not containing peanuts were negative for Ara h1, indicating that the labels from the manufacturers were accurate. However, 2 food samples labeled as not containing peanuts tested positive for Ara h1. The present GICA provides a fast, simple, semi-quantitative method for the determination of peanut allergens in foods. This detection system can be used to ensure the safety of food imported and exported by China Customs.
[show abstract][hide abstract] ABSTRACT: Home dust mite derived materials are known to be a major source of problematic inhalant allergens. The aim of this study was to determine the localization of the group 3 allergen, Der f 3, within Dermatophagoides farinae, in order to assess the relative importance of excreted materials and nonexcreted body components as allergen sources. Recombinant Der f 3 (rDer f 3) was expressed in bacteria and purified as an immunogen for production of monoclonal antibodies (mAb) against it. Dermatophagoides farinae mites and their faecal pellets were embedded in paraffin, and serial sections were immunoprobed with mAb clone 3D3 against Der f 3. D. farinae midgut mucosa, gut contents and faecal pellets were strongly immunopositive for Der f 3. Der f 3 immunoreactive products were not detected in any other internal organs of the mite. These results suggest that Der f 3 allergen may be synthesized in and secreted from the digestive tract and excreted from the mite's body in the faecal pellets.
Experimental and Applied Acarology 03/2010; 52(1):63-71. · 1.85 Impact Factor
[show abstract][hide abstract] ABSTRACT: Allergen-specific sublingual immunotherapy is a potential treatment for allergic diseases. Its effective dose and underlying mechanism are still to be explored. Here, we investigated the efficacy and mechanism of sublingually administered Dermatophagoides farinae (Der f) vaccine in a murine asthma model.
BALB/c mice were sensitized intraperitoneally with Der f extract absorbed to alum, followed by sublingual treatment with Der f vaccine for 6 weeks. The mice were subsequently challenged intranasally with Der f extract for 1 week. We analyzed their clinical symptoms, antibody levels, cytokine levels, T-cell proliferation and the regulatory T-cell numbers.
Mice treated with high-dose Der f sublingual vaccine prior to challenge displayed alleviated symptoms such as airway hyperreactivity, lung inflammation and mucus production, as well as less eosinophilic cells in bronchoalveolar lavage fluid. Interestingly, reduced responses of Der-f-specific IgE and increased responses of Der-f-specific IgA and IgG1 were aroused in the high-dose Der f sublingual vaccine group. We also observed that interleukin-4 was reduced and interferon-gamma and interleukin-10 were increased among splenocytes and in bronchoalveolar lavage fluid, which inhibited Der-f-specific T-cell proliferation of the spleen and increased CD4+CD25+Foxp3+regulatory T cells in the spleen. However, mice treated with low-dose Der f sublingual vaccine developed allergic asthma.
Our results illustrate that high-dose Der f sublingual vaccine may play a role in immunologic protection in murine allergic asthma, possibly by inducing regulatory T cells and Th1 reaction.
International Archives of Allergy and Immunology 11/2009; 152(1):41-8. · 2.25 Impact Factor
[show abstract][hide abstract] ABSTRACT: Pancreatic cancer is highly resistant to the currently available chemotherapeutic agents. Less than 5% of patients diagnosed with this disease could survive beyond 5 years. Thus, there is an urgent need for the development of novel, efficacious drugs that can treat pancreatic cancer. Herein we report the identification of artesunate (ART), a derivative of artemisinin, as a potent and selective antitumor agent against human pancreatic cancer cells in vitro and in vivo. ART exhibits selective cytotoxic activity against Panc-1, BxPC-3 and CFPAC-1 pancreatic cancer cells with IC(50) values that are 2.3- to 24-fold less than that of the normal human hepatic cells (HL-7702). The pan caspase inhibitor zVAD-fmk did not inhibit the cytotoxic activity of ART. Electron microscopy of ART-treated cells revealed severe cytoplasmic swelling and vacuolization, swollen and internally disorganized mitochondria, dilation (but not fragmentation) of the nuclei without chromatin condensation, and cell lysis, yielding a morphotype that is typical of oncosis. The ART-treated cells exhibited a loss of mitochondrial membrane potential (DeltaPsim) and ART-induced cell death was inhibited in the presence of the reactive oxygen species (ROS) scavenger N-acetyl-cysteine (NAC). Importantly, ART produced a dose-dependent tumor regression in an in vivo pancreatic cancer xenografts model. The in vivo antitumor activity of ART was similar to that of gemcitabine. Taken together, our study suggests that ART exhibits antitumor activity against human pancreatic cancer via a novel form of oncosis-like cell death, and that ART should be considered a potential therapeutic candidate for treating pancreatic cancer.
Cancer Chemotherapy and Pharmacology 09/2009; 65(5):895-902. · 2.80 Impact Factor
[show abstract][hide abstract] ABSTRACT: In this article we report our experience with the diagnostic screening and management of children with melamine-induced nephrolithiasis.
A total of 1091 children younger than 4 years who had been exposed to melamine-contaminated formula from September 17 to October 12, 2008, were screened for nephrolithiasis at the department of pediatrics at Shenzhen Nanshan Hospital in China. During the clinical examination, each patient's demographic characteristics were recorded together with the details of his or her milk-consumption profile during the contamination scare and any clinical signs of poisoning. Urinary stones were detected by B-ultrasonography, and renal status was examined by a routine urine test panel and a renal function test. When urinary stones were detected, patients were ordered to cease consumption of the suspected formula, and a conservative treatment course was adopted, including infusion of fluids, urinary alkalinization, increased water consumption, and diuresis.
Of the 1091 children screened, 12 (1.1%) were diagnosed with kidney stones. They had been exposed to the contaminated milk from 1 to 24 months. Eleven (91.7%) of these 12 patients had consumed milk with a high level of melamine content (955-2563 ppm); 1 patient (8.3%) had consumed milk with a low-level melamine content (6.2-17.0 ppm). Six patients exhibited dysuria; the remaining 6 patients were asymptomatic. All 12 patients had normal renal function, although 4 had proteinuria, and 1 had hematuria. The kidney stones were resolved within 3 to 5 days of commencing treatment in all 12 cases.
Nephrolithiasis was associated with high melamine-exposure levels. A combination of B-ultrasonography and urinalysis is suitable for screening for pediatric nephrolithiasis caused by melamine poisoning. The condition can be resolved with a conservative treatment approach in patients without serious clinical symptoms who have normal kidney function.
[show abstract][hide abstract] ABSTRACT: To clone the gene of arginine kinase (AK) from Periplaneta americana, produce its recombinant protein and investigate its allergenicity.
The cDNA of AK was cloned using specific primers from the total RNA of P. americana. The cloned gene was inserted into pMD18-T vector and digested by BamHI and HindIII. The cDNA was sequenced and subcloned into pET-28a expression vector. The cloned AK cDNA gene was expressed in Escherichia coli BL21 (DE3) by IPTG induction. The recombinant AK (rAK) was purified by metal (Ni2+) chelating affinity chromatography. Its allergenicity was examined by both Western blotting and enzyme-linked immunosorbent assay (ELISA).
The cloned cDNA ORF sequence (Accession no. EU429466) contained 1068 bp and encoded 365 amino acids. Its sequence homology with the published one (Accession no. AY563004) was 99.9% at nucleotide level. The allergen rAK was highly expressed in E. coli BL21 (DE3) as a soluble protein mainly with the molecular weight of about Mr 45000 under induction of IPTG and purified by 6-His-tag purification system. Both in the non-denaturalization and denaturalization conditions, the recombinant allergen was identified as its affinity to IgE antibodies from the cockroach-allergic patient sera by Western blotting and ELISA.
The recombinant cockroach arginine kinase has been obtained with proper allergenicity.
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases 11/2008; 26(5):356-60.
[show abstract][hide abstract] ABSTRACT: The viral lytic gene BZLF1 triggers replication of the Epstein-Barr virus (EBV), which is commonly found in nasopharyngeal carcinoma (NPC). Here, RT-PCR revealed five new BZLF1 variants in 8 of 12 NPC and 4 of 12 non-NPC nasopharyngeal biopsies from an NPC-endemic area in southern China. The deduced peptide sequence of the dominant BZLF1 variant differed by 11 amino acids from that of the prototypical strain B95.8 (V01555). Anti-ZEBRA antibody levels were higher in NPC than that in non-NPC patients (P < 0.001). These findings demonstrated a dominant BZLF1 variant in southern Chinese EBV-associated NPC and non-NPC patients.
Archives of Virology 09/2008; 153(10):1949-53. · 2.03 Impact Factor
[show abstract][hide abstract] ABSTRACT: To clone, express and identify Der f 3 gene.
Live mites were collected from southern China region, identified as Dermatophagoides farinae, and cultured. The total RNA was extracted. The Der f 3 gene fragment was amplified by RT-PCR and sequenced. The Der f 3 gene fragment encoding a serine protease mature peptide was sub-cloned into the expression vector pET-His. The recombinant pET-Der f 3 plasmid was inserted into E.coli BL21 and induced to express Der f 3 coding protein by IPTG. The recombinant Der f 3 with 6 his-tag was then purified by chelating resin and its allergic activity was identified by Western blotting.
The Der f 3 gene fragment with 840 bases was determined. Its sequence homology with the published one (GenBank No.D63858) was 99.5% at nucleotide level. It was sub-cloned into expressing vector pET-His and the recombinant allergen rDer f 3 was highly expressed in E.coli BL21 (DE3) under induction of IPTG, and purified by 6-His-tag purification system. Using Western blotting method, the allergic activity of the purified recombinant allergen was identified as its affinity to IgE antibodies from the mite-allergic patient sera.
Der f3 gene has been successfully cloned and its prokaryotic expression vector is constructed.
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases 03/2007; 25(1):22-6.
[show abstract][hide abstract] ABSTRACT: Crude extract of Periplaneta americana was prepared by liquid nitrogen grinding. After being purified with DEAE Sephadex A-50 ion exchange chromatography, the protein content of the extract was determined and the extract solution was prepared at gradient concentrations. The crude extract and purified allergen at different concentrations were dotted respectively on nitrocellulose (NC) membrane. Patient serum, bio-IgE, sa-HRP, luminal regents were added to the membrane. The chemiluminescence was displayed by exposing to X-film. The result revealed that the minimum protein content of crude Periplaneta americana extract detected by CLIA is 0.87 microg/ml, with 90% accordance to skin test positive patients, and 100% accordance to those with negative skin test and ELISA detection.
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases 01/2007; 24(6):471-2.