ELISA immunoassay

  • 文章类型: Journal Article
    口腔鳞状细胞癌(OSCC)约占口腔恶性肿瘤的90%,5年死亡率接近50%。所有口腔癌的一致部分(70%)在晚期被诊断,因为可用的筛查技术是无效的。因此,迫切需要改进它们。诊断金标准是具有组织学和免疫组织化学评估的组织活检。这种方法存在一些局限性。活检是侵入性的,组织病理学评估是半定量的,并且不能可靠地确定目标的绝对丰度。此外,组织是高度加工的,可能导致自然状态的信息丢失。在用细胞刷收集的组织/细胞碎片上寻找经典和新的临床生物标志物是一种非常有希望的早期检测和诊断OSCC的技术。由于其无创采样和易于收集的方法。
    在这里,我们通过应用创新的高灵敏度ELISA技术,分析了从15例已经诊断出OSCC的患者口腔中收集的细胞刷活检样本,为了验证这种方法是否可以为检测提供有用的信息,诊断,OSCC的预后。为此,我们选择了六种生物标志物,已经在临床实践中用于诊断OSCC(EGFR,Ki67,p53)或根据最近的科学和临床数据进行选择,这些数据表明它们在正在发生转化的细胞中的存在或过表达,以及它们在免疫刺激点阻断疗法中可能作为分子靶标的作用(PD-L1,HLA-E,B7-H6).
    所选择的肿瘤生物标志物在肿瘤核心中高表达,而从同一患者收集的健康组织几乎为阴性。这些差异具有高度统计学意义,并且与使用黄金标准测试获得的差异一致,清楚地表明所提出的方法,即通过定制ELISA技术分析生物标志物,非常可靠。
    这些初步数据表明,这种非侵入性快速表型鉴定技术可用作口腔病变表型鉴定的筛查工具,并通过对病变特征的精确指示来支持临床实践,还着眼于新的抗肿瘤治疗方法的应用,比如免疫疗法,针对OSCC患者。
    Oral squamous cell carcinoma (OSCC) accounts for approximately 90% of oral malignancies and has a 5-year mortality rate close to 50%. A consistent part (70%) of all oral cancers is diagnosed at an advanced stage since available screening techniques are ineffective. Therefore, it would be urgent to improve them. The diagnostic gold standard is tissue biopsy with histological and immunohistochemical assessment. This method presents some limitations. Biopsy is invasive and the histopathological evaluation is semi-quantitative, and the absolute abundance of the target cannot be reliably determined. In addition, tissue is highly processed and may lead to loss of information of the natural state. The search for classical and new clinical biomarkers on fragments of tissue/cells collected with a cytobrush is a highly hopeful technique for early detection and diagnosis of OSCC, because of its non-invasive sampling and easy collection method.
    Here we analyzed cytobrush biopsies samples collected from the oral cavity of 15 patients with already diagnosed OSCC by applying an innovative high-sensitivity ELISA technique, in order to verify if this approach may provide useful information for detection, diagnosis, and prognosis of OSCC. To this end, we selected six biomarkers, already used in clinical practice for the diagnosis of OSCC (EGFR, Ki67, p53) or selected based on recent scientific and clinical data which indicate their presence or over-expression in cells undergoing transformation and their role as possible molecular targets in immunecheckpoints blockade therapies (PD-L1, HLA-E, B7-H6).
    The selected tumor biomarkers were highly expressed in the tumor core, while were virtually negative in healthy tissue collected from the same patients. These differences were highly statistically significant and consistent with those obtained using the gold standard test clearly indicating that the proposed approach, i.e. analysis of biomarkers by a custom ELISA technique, is strongly reliable.
    These preliminary data suggest that this non-invasive rapid phenotyping technique could be useful as a screening tool for phenotyping oral lesions and support clinical practice by precise indications on the characteristics of the lesion, also with a view to the application of new anti-tumor treatments, such as immunotherapy, aimed at OSCC patients.
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  • 文章类型: Journal Article
    Numerous unknown factors influence anthrax epidemiology in multi-host systems, especially at wildlife/livestock/human interfaces. Serology tests for anti-anthrax antibodies in carnivores are useful tools in identifying the presence or absence of Bacillus anthracis in a range. These were employed to ascertain whether the disease pattern followed the recognized high- and low-risk anthrax zonation in Zimbabwe and also to establish whether anthrax was absent from Hwange National Park in which there have been no reported outbreaks. African lions (Panthera leo) (n = 114) drawn from free-range protected areas and captive game parks located in recognized high- and low-risk zones across Zimbabwe were tested for antibodies to anthrax PA antigen using the ELISA immunoassay. A random selection of 27 lion sera samples comprising 17 seropositive and 10 seronegative sera was further tested in the species-independent toxin neutralization assay (TNA) in order to validate the former as a surveillance tool for anthrax in African lions. Using the ELISA-PA immunoassay, 21.9% (25/114) of the lions tested positive for antibodies to anthrax. Seropositivity was recorded in all study areas, and there was no significant difference (p = .852) in seropositivity between lions in high- and low-risk anthrax zones. Also, there was no significant difference (McNemar\'s chi-square test = 0.9, p = .343) in the proportion of lions testing positive to anti-PA anthrax antibodies on ELISA-PA immunoassay compared with the TNA, with fair agreement between the two tests [kappa (K) statistic = 0.30; 0.08 < K<0.613]. Results of this study indicate that anthrax could be more widespread than 42 currently realized in Zimbabwe, and present in recognized high- and low-risk zones, including 43 where it has not been reported in over 20 years such as Hwange National Park. This is also the 44 first report documenting the presence of anthrax lethal toxin-neutralizing antibodies in naturally 45 infected carnivores, further confirming exposure to B. anthracis. The research results point to a 46 need for revisiting the currently recognized anthrax risk zones in Zimbabwe. This should be based 47 on improved surveillance of the disease in both wild and domestic animals for better understanding and control of the disease.
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  • 文章类型: Journal Article
    Nowadays, the ideal biomarker for colorectal cancer (CRC) has not been found. Two-dimensional electrophoresis (2-DE) and mass spectrometry (MS) are suitable techniques for searching new biomarkers. In this chapter, we describe methodology for biomarker discovery based on a proteomic approach. In addition, special attention is given to the sample preparation, including protein extraction, fractionation, and cleanup, as we consider this a critical step. Comparing the proteomic profile of tumor and mucosa, we identified the nucleoside diphosphate kinase A (NDKA) protein as a candidate biomarker for CRC. Finally, we validated NDKA with an ELISA kit using serum samples from individuals of a screening cohort. Our results suggest that serum NDKA is a potential biomarker for screening of CRC and premalignant advanced adenomas (AA).
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  • 文章类型: Journal Article
    Carbamazepine (CBZ), an antiepileptic drug, is one of the most commonly detected pharmaceutical drugs in aquatic ecosystems, and is used as a marker of urban pollution. Since CBZ is designed to exert a biological effect, when it reaches aquatic environment high probability exist for toxic effects on non-target organisms. The present study evaluated the acute toxicity of environmentally relevant concentrations of CBZ (0.00, 0.03, 0.30, 3.00, 9.00μg/L) in the edible clams Venerupis decussata (a native species) and Venerupis philippinarum (an invasive species) collected from the Ria de Aveiro. The effects on both species were assessed through the use of a battery of biomarkers mainly related with health status and oxidative stress. Furthermore, in this work an alternative and promising tool, the direct competitive immunoassay ELISA, for the direct CBZ quantification in clam\'s tissues, was applied. The results of the present work showed that CBZ in clam\'s tissues increased with the exposure concentration and V. decussata gave slightly higher values than V. philippinarum. Although the clams accumulated lower levels of CBZ than the concentration of exposure, these concentrations were enough to impair the health status and induce oxidative stress. However, a different response to CBZ was observed in the two species. While in V. philippinarum the lipid peroxidation levels increased at the highest CBZ concentration (9.00μg/L), in V. decussata a significant decrease was seen. Moreover, glutathionse S-transferase activity was stimulated in V. decussata and decreased in V. philippinarum. Nevertheless, an induction of glutathione reductase, superoxide dismutase and cytochrome P450 3A4 activities was found in both species as a result of the exposure. The results indicate that, probably, V. philippinarum have a less efficient antioxidant system than V. decussata, and are therefore less capable to neutralize oxidative stress and consequently more sensitive to CBZ. The risk quotient determined for the Ria de Aveiro was higher than 1 indicating that a ecotoxicological risk is suspected. Furthermore, bioaccumulation of CBZ in clams should be taken into consideration since this chemical might be transferred along the food chain and affect non-target organisms.
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