Search results for "Bioassay"
showing 10 items of 161 documents
Estrogenic activity of zearalenone, α-zearalenol and β-zearalenol assessed using the E-Screen assay in MCF-7 cells
2017
Mycotoxins, including zearalenone (ZEA), can occur worldwide in cereals. They can enter the food chain and cause several health disorders. ZEA and its derivatives (α-zearalenol, α-ZOL and β-zearalenol, β-ZOL) have structural analogy to estrogen, thus they can bind to estrogen receptors (ERs). In order to characterize the estrogenic activity of ZEA, α-ZOL and β-ZOL, the proliferation of ER-positive human breast cancer cells (MCF-7) exposed to these mycotoxins was measured. After exposure at levels ranging from 6.25 to 25 µM, cell proliferation was evaluated by using the E-Screen bioassay. In accordance with previous studies, our results show the estrogenic activity of ZEA, α-ZOL and β-ZOL in…
Evaluating ancient Egyptian prescriptions today: Anti-inflammatory activity of Ziziphus spina-christi.
2015
Abstract Background Ziziphus spina-christi (L.) Desf. (Christ's Thorn Jujube) is a wild tree today found in Jordan, Israel, Egypt, and some parts of Africa, which was already in use as a medicinal plant in Ancient Egypt. In ancient Egyptian prescriptions, it was used in remedies against swellings, pain, and heat, and thus should have anti-inflammatory effects. Nowadays, Z. spina-christi, is used in Egypt (by Bedouins, and Nubians), the Arabian Peninsula, Jordan, Iraq, and Morocco against a wide range of illnesses, most of them associated with inflammation. Pharmacological research undertaken to date suggests that it possesses anti-inflammatory, hypoglycemic, hypotensive and anti-microbial e…
The synthesis of metallocene-labelled drugs for biological assays
1990
Several drugs (amphetamine, desipramine, nortriptyline, phenobarbital) have been labelled with metallocenic fragments in order to develop a new immunoassay method. The metallocenic fragments are cymantrenic or benchrotrenic derivatives: the linkage between the organic and organometallic moieties has been achieved by reactions between amino and acidic functional groups. All the products (metallohaptens), purified by different chromatography techniques, have been fully characterized by IR and 1H NMR spectroscopy and their mass spectra.
Two New Alternatives to the Conventional Arm-in-Cage Test for Assessing Topical Repellents
2021
Abstract European guidelines for testing attractant and repellent efficacy (i.e., Product type 19 [PT19]) have been in revision since 2017. A key topic of discussion is the current approach to evaluating topical repellents. The European Chemical Agency has stated field testing should be avoided because of mosquito-borne disease risks. However, the most common laboratory method, the arm-in-cage (AIC) test, may limit the reliable extrapolation of lab results to field conditions. This study’s main goal was to assess alternative laboratory methods for evaluating topical mosquito repellents that use mosquito landing rates more representative of those in the field. The study took place at three E…
Effects ofBacillus thuringiensisCry1Ab and Cry3Aa endotoxins on predatory Coleoptera tested through artificial diet-incorporation bioassays
2009
AbstractTraditional approaches to studying the effects of genetically modified (GM) crops on beneficial insects involve either field assays, comparing insect population levels between control and GM crops or tritrophic bioassays with contaminated insects – usually larvae or eggs of Lepidoptera – as preys. Here, we report the results of a bioassay using an artificial diet, suitable for predatory Coleoptera, to supplyBacillus thuringiensis(Bt) solubilized Cry1Ab and Cry3Aa as well as trypsin-activated Cry1Ab toAtheta coriariaandCryptolaemus montrouzieriadults and young larvae ofAdalia bipunctata. Water, solubilization buffer and trypsin-treated solubilization buffer were used as controls. In …
Single-Nucleotide Polymorphism Array-Based Karyotyping of Acute Promyelocytic Leukemia
2014
Acute promyelocytic leukemia (APL) is characterized by the t(15;17)(q22;q21), but additional chromosomal abnormalities (ACA) and other rearrangements can contribute in the development of the whole leukemic phenotype. We hypothesized that some ACA not detected by conventional techniques may be informative of the onset of APL. We performed the high-resolution SNP array (SNP-A) 6.0 (Affymetrix) in 48 patients diagnosed with APL on matched diagnosis and remission sample. Forty-six abnormalities were found as an acquired event in 23 patients (48%): 22 duplications, 23 deletions and 1 Copy-Neutral Loss of Heterozygocity (CN-LOH), being a duplication of 8(q24) (23%) and a deletion of 7(q33-qter) (…
Analytical performance and clinical utility of a bioassay for thyroid-stimulating immunoglobulins.
2013
Abstract The analytical performance and the clinical utility of a thyrotropin receptor (TSHR)–stimulating immunoglobulin (TSI) bioassay were compared with those of a TSHR-binding inhibitory immunoglobulin (TBII) assay. Limits of detection (LoD) and quantitation (LoQ), assay cutoff, and the half-maximal effective concentration (EC50) were measured. Dilution analysis was performed in sera of hyperthyroid patients with Graves disease (GD) during antithyroid treatment (ATD). Titer was defined as the first dilution step at which measurement of TSI or TBII fell below the assay cutoff. The LoD, LoQ, cutoff, and EC50 of the bioassay were 251-, 298-, 814-, and 827-fold lower than for the TBII assay.…
Assessment of oxidative damage to proteins and DNA in urine of newborn infants by a validated UPLC-MS/MS approach
2014
The assessment of oxidative stress is highly relevant in clinical Perinatology as it is associated to adverse outcomes in newborn infants. This study summarizes results from the validation of an Ultra Performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS) method for the simultaneous quantification of the urinary concentrations of a set of endogenous biomarkers, capable to provide a valid snapshot of the oxidative stress status applicable in human clinical trials, especially in the field of Perinatology. The set of analytes included are phenylalanine (Phe), para-tyrosine (p-Tyr), ortho-tyrosine (o-Tyr), meta-tyrosine (m-Tyr), 3-NO2-tyrosine (3NO(2)-Tyr), 3-Cl-tyrosine (3Cl-T…
Possible Fungistatic Implications of Betulin Presence in Betulaceae Plants and their Hymenochaetaceae Parasitic Fungi
2010
Betulin and its derivatives (especially betulinic acid) are known to possess very interesting prospects for their application in medicine, cosmetics and as bioactive agents in pharmaceutical industry. Usually betulin is obtained by extraction from the outer layer of a birch bark. In this work we describe a simple method of betulin isolation from bark of various species of Betulaceae trees and parasitic Hymenochaetaceae fungi associated with these trees. The composition of the extracts was studied by GC-MS, whereas the structures of the isolated compounds were confirmed by FTIR and 1H NMR. Additionally, the significant fungistatic activity of betulin towards some fi lamentous fungi was deter…
Methods used to evaluate the peroxyl (ROO·) radical scavenging capacities of four common antioxidants
2012
Different methods that are used to measure peroxyl radical (ROO) scavenging capacity were used in model systems containing four common antioxidant compounds: ascorbic acid, cysteine, gallic acid and Trolox, a water-soluble vitamin E analogue. Five tests were performed, with differences in the method of peroxyl radical generation (lipoxygenase, azo-compound thermal degradation and spontaneous oxidation from a natural source of fatty acids) and in the addition of probes such as linoleic acid, crocin, fluorescein and electron paramagnetic resonance (EPR) by spin-trapping with a-phenyl-N-tert-butylnitrone. Significant differences were found in antioxidant reactivity, evaluated by dose–effect se…