Sandwich ELISA (sandwich + elisa)

Distribution by Scientific Domains


Selected Abstracts


Sensitive Monoclonal Antibody-based Sandwich ELISA for the Detection of Porcine Skeletal Muscle in Meat and Feed Products

JOURNAL OF FOOD SCIENCE, Issue 1 2006
Lihua Liu
ABSTRACT: A monoclonal antibody-based sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the sensitive detection of porcine skeletal muscle in raw and heat-processed meat and feed products. Heat treatment of meat samples up to 132 °C for 2 h did not affect the assay performance. The assay uses a pair of monoclonal antibodies (MAbs 8F10 and 5H9) specific to skeletal muscle troponin I (TnI). MAb 8F10, reacting to mammalian TnI, is the capture antibody and the biotin-conjugated MAb 5H9, specific to porcine TnI, the detection antibody. The sandwich ELISA is able to detect 0.05% (w/w) of laboratory-adulterated pork in chicken, 0.1% (w/w) pork in beef mixtures, 0.05% (w/w) pork meal in soy-based feed, and 1% commercial meat and bone meal (MBM), containing an unknown amount of pork, in soy-based feed. This new assay provides a rapid and reliable means to detect the contamination of meat and feed products with trace amounts of porcine muscle tissue to ensure product quality and safety. [source]


Alleviating peanut allergy using genetic engineering: the silencing of the immunodominant allergen Ara h 2 leads to its significant reduction and a decrease in peanut allergenicity

PLANT BIOTECHNOLOGY JOURNAL, Issue 2 2008
Hortense W. Dodo
Summary Peanut allergy is one of the most life-threatening food allergies and one of the serious challenges facing the peanut and food industries. Current proposed solutions focus primarily on ways to alter the immune system of patients allergic to peanut. However, with the advent of genetic engineering novel strategies can be proposed to solve the problem of peanut allergy from the source. The objectives of this study were to eliminate the immunodominant Ara h 2 protein from transgenic peanut using RNA interference (RNAi), and to evaluate the allergenicity of resulting transgenic peanut seeds. A 265-bp-long PCR product was generated from the coding region of Ara h 2 genomic DNA, and cloned as inverted repeats in pHANNIBAL, an RNAi-inducing plant transformation vector. The Ara h 2-specific RNAi transformation cassette was subcloned into a binary pART27 vector to construct plasmid pDK28. Transgenic peanuts were produced by infecting peanut hypocotyl explants with Agrobacterium tumefaciens EHA 105 harbouring the pDK28 construct. A total of 59 kanamycin-resistant peanut plants were regenerated with phenotype and growth rates comparable to wild type. PCR and Southern analyses revealed that 44% of plants stably integrated the transgene. Sandwich ELISA performed using Ara h 2-mAbs revealed a significant (P < 0.05) reduction in Ara h 2 content in several transgenic seeds. Western immunobloting performed with Ara h 2-mAb corroborated the results obtained with ELISA and showed absence of the Ara h 2 protein from crude extracts of several transgenic seeds of the T0 plants. The allergenicity of transgenic peanut seeds expressed as IgE binding capacity was evaluated by ELISA using sera of patients allergic to peanut. The data showed a significant decrease in the IgE binding capacity of selected transgenic seeds compared to wild type, hence, demonstrating the feasibility of alleviating peanut allergy using the RNAi technology. [source]


Effect of risperidone on plasma catecholamine metabolites and brain-derived neurotrophic factor in patients with bipolar disorders

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2006
Reiji Yoshimura
Abstract A combination treatment with a mood stabilizer and an antipsychotic drug is often used in as many as 90% of subjects with acute mania. Recently, augmentation therapy with atypical antipsychotics has been investigated in both the acute and long-term treatment of bipolar disorder with or without psychosis. In the present study, the authors investigated the efficacy of risperidone treatment for both acute manic and depressive episodes in bipolar disorder. Eighteen patients (M/F: 8/10, age: 34,±,15,yr) who met the DSM-IV criteria for bipolar I disorder (12 cases of manic episodes, 6 cases of depressive episodes) with risperidone treatment were evaluated regarding their clinical improvement using the Young Mania rating Scale (YMRS) and the Hamilton rating Scale for Depression (Ham-D). Plasma concentrations of HVA and MHPG were analyzed by HPLC-ECD and plasma brain-derived neurotrophic factor (BDNF) levels were detected by sandwich ELISA. The mean scores of the YMRS were 22, 18, 12, 8, and 5 at time points before and 1, 2, 3, and 4 weeks after the risperidone administration, respectively. The mean scores of the Ham-D were 24, 25, 21, 21, and 19 at time points before and 1, 2, 3, and 4 weeks after the risperidone administration, respectively. The plasma levels of HVA and 3-methoxy-4-hydroxyphenylglycol (MHPG) were observed to have decreased 4 weeks after risperidone administration in manic patients. The levels did not change in depressive patients. The plasma levels of BDNF were decreased in depressive patients compared with manic patients or healthy controls. However, the administration of risperidone did not alter plasma BDNF levels. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Detection of ciguatoxin in fish tissue using sandwich ELISA and neuroblastoma cell bioassay

JOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 4 2008
Cara Empey Campora
Abstract The applicability of a new enzyme-linked immunoassay (ELISA) for detecting ciguatoxin (CTX) in fish tissue was evaluated by testing three fish species commonly implicated in ciguatera fish poisoning in Hawaii. A total of 164 individual almaco jack (Seriola rivoliana) and greater amberjack (S. dumerili) and a total of 175 individuals of the blue-spotted grouper (Cephalopholis argus) were caught at various locations in the Hawaiian Islands. Muscle tissue from each individual was assessed for the presence of CTX using two methods: a semi-quantitative ELISA that was recently developed for detecting picogram levels of CTX in fish extract and a neuroblastoma (NB) cell assay commonly used to screen for marine toxins in fish. Results of the tests were highly correlated, with the ELISA indicating the presence of CTX in 9.4% of all fish samples, and the NB assay indicating toxicity in 6.8% of the fish samples. We conclude that the ELISA produces reliable and accurate results that are consistent with those provided by the accepted NB assay and that the ELISA has potential for future applications in screening fish populations for CTX. J. Clin. Lab. Anal. 22:246,253, 2008. © 2008 Wiley-Liss, Inc. [source]


Longitudinal evaluation of GCF IFN-, levels and periodontal status in HIV+ patients

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2003
T. Alpagot
Abstract Background/Aim: Loss of periodontal support and related tooth loss is a common finding among HIV+ patients. The etiology of this destruction may be an increase in the levels of pro-inflammatory cytokines and subsequent increase in periodontal disease activity. The purpose of this study was to investigate the associations between gingival crevicular fluid interferon gamma (GCF IFN- ,) and clinical measures of periodontal disease in HIV+ individuals. We monitored GCF IFN- , and periodontal status of selected sites in 33 HIV+ subjects over a 6-month period. Method: Clinical measurements including gingival index, plaque index, bleeding on probing, probing depth, attachment loss (AL), and GCF samples were taken from four lower incisors and the upper right posterior sextant of each patient at baseline and 6-month visits by means of sterile paper strips. GCF levels of IFN- , were determined by sandwich ELISA assays. A progressing site was defined as a site that had 2 mm or more AL during the 6-month study period. Results: Twenty-five of the 264 examination sites showed 2 mm or more clinical AL during the 6-month study period. Significantly higher GCF levels of IFN- , were found at progressing sites than in nonprogressing sites (p<0.001). GCF levels of IFN- , were highly correlated with clinical measurements taken at baseline and 6-month visits (0.001[source]


Inhibitors of advanced glycation end-products prevent loss of enteric neuronal nitric oxide synthase in diabetic rats

NEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2008
P. V. S. Jeyabal
Abstract, Gastrointestinal dysfunction is common in diabetes, and several studies indicate that loss of neuronal nitrergic inhibition may play an important role in its pathogenesis. However, the mechanisms responsible for this effect remain largely unknown. We have previously shown that advanced glycation end-products (AGEs) formed by non-enzymatic glycation dependent processes, can inhibit the expression of intestinal neuronal nitric oxide synthase (nNOS) in vitro acting via their receptor, receptor for AGEs. We now hypothesized that this effect may also be important in experimental diabetes in vivo. We aimed to evaluate the role of AGEs on duodenal nNOS expression and the effects of aminoguanidine (a drug that prevents AGE formation) and ALT-711 (AGE cross-link breaker) in experimental diabetes. Streptozotocin induced diabetic rats were randomized to no treatment, treatment with aminoguanidine (1 g L,1 daily through drinking water) at the induction of diabetes, or treatment with ALT-711 (3 mg kg,1 intraperitoneally), beginning at week 6. A fourth group was used as healthy controls. We performed real time polymerase chain reaction, Western blotting and immunohistochemistry to detect nNOS expression. AGE levels were analysed using sandwich ELISA. Diabetes enhanced accumulation of AGEs in serum, an effect that was prevented by treatment with aminoguanidine and ALT-711. Further, diabetic rats showed a significant reduction in duodenal nNOS expression by mRNA, protein and immunocytochemistry, an effect that was prevented by aminoguanidine. ALT-711 had similar effects on nNOS protein and immunohistochemistry (but not on mRNA levels). The generation of AGEs in diabetes results in loss of intestinal nNOS expression and may be responsible for enteric dysfunction in this condition. This study suggests that treatment directed against AGEs may be useful for the treatment of gastrointestinal complications of diabetes. [source]


JNK is constitutively active in mantle cell lymphoma: cell cycle deregulation and polyploidy by JNK inhibitor SP600125,

THE JOURNAL OF PATHOLOGY, Issue 1 2009
Miao Wang
Abstract Mantle cell lymphoma (MCL) is characterized by genetic instability and a poor prognosis. Many blastoid variants are (hypo)tetraploid and have an even worse prognosis. We investigated the role of signalling by mitogen-activated protein kinases (MAPKs) in MCL. As compared to normal tonsil B cells, MCL cells showed higher activation of the JNK MAPK in both an MAPK array and a sandwich ELISA assay. Immunohistochemistry showed overexpression of phospho (p)-JNK (Thr183/Tyr185) in 30 of 37 MCL cases. Inhibition of p-JNK with SP600125 resulted in growth arrest in all four MCL cell lines (Jeko-1, HBL-2, UPN-1, Granta-519), which could be partly reversed by the addition of CD40L and IL-4. Furthermore, SP600125 led to G2/M phase arrest on day 1 and a striking increase in endoreduplication on day 2 and day 3, which was confirmed by karyotype analysis. G2/M arrest was associated with down-regulation of EGR1 and p21 protein expression. SP600125-induced polyploidy could be blocked by the BCL-2 inhibitor YC137. These data suggest that constitutive JNK activity is necessary to promote proliferation and maintain diploidy in MCL. JNK inhibition leads to cell cycle deregulation and endoreduplication, mimicking the tetraploid state seen in a subset of MCL cases. Thus, our data also provide an experimental model to study polyploid MCL cells. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source]


Novel ELISA system for detection of N-ERC/mesothelin in the sera of mesothelioma patients

CANCER SCIENCE, Issue 9 2006
Kazu Shiomi
We have developed a novel enzyme-linked immunosorbent assay (ELISA) system for the detection of N-ERC/mesothelin in the serum of mesothelioma patients and have begun to examine its clinical usefulness. N-ERC/mesothelin is a 31-kDa protein that forms the N-terminal fragment of the full-length 71-kDa ERC/mesothelin protein, and is physiologically secreted into the blood of mesothelioma patients where it can be detected using our sandwich ELISA containing two antibodies (rabbit polyclonal anti-ERC/mesothelin antibody-282 and mouse monoclonal antibody 7E7). Our ELISA system has thus far detected much higher serum levels of N-ERC/mesothelin in mesothelioma patients than in healthy controls or patients with other lung or pleural diseases. In conclusion, N-ERC/mesothelin is a promising candidate tumor marker for mesothelioma. (Cancer Sci 2006; 97: 928,932) [source]