Search results for "Assay"
showing 10 items of 2241 documents
Genomics and Proteomics Analyses Revealed Novel Candidate Pesticidal Proteins in a Lepidopteran-Toxic Bacillus thuringiensis Strain
2020
Discovery and identification of novel insecticidal proteins in Bacillus thuringiensis (Bt) strains are of crucial importance for efficient biological control of pests and better management of insect resistance. In this study, the Bt strain KhF, toxic for Plodia interpunctella and Grapholita molesta larvae, underwent genomics and proteomics analyses to achieve a better understanding of the bases of its pathogenicity. The whole-genome sequencing results revealed that the KhF strain contained nine coding sequences with homologies to Bt insecticidal genes. The lepidopteran toxic mixture of spores and crystals of this Bt strain was subjected to liquid chromatography and tandem mass spectrometry …
Acute toxicity of some chlorinated phenolic compounds toSelenastrum capricornutum and phytoplankton
1985
Acute toxicity of several chlorinated phenolic compounds detected in waste waters of bleached pulp was determined forSelenastrum capricornutum and indigenous phytoplankton using bioassays. Five of the phenolic compounds were chlorocatechols, four were chloroguaiacols and one was chlorosyringol. The response ofSelenastrum capricornutum to chemicals was measured by cell counting and phytoplankton14C-uptake. Chlorinated catechols inhibited the growth ofSelenastrum cultures in lower concentrations than chlorinated guaiacols. The increasing number of chlorine substituents on the phenolic ring increased the toxicity of both chlorinated catechols and guaiacols. The EC50-values (0-96 hr) of the com…
Comparative toxicant sensitivity of sexual and asexual reproduction in the rotiferBrachionus calyciflorus
1995
Cyclically parthenogenetic zooplankters like rotifers are important tools for assessing toxicity in aquatic environments. Sexual reproduction is an essential component of rotifer life cycles, but current toxicity tests utilize only asexual reproduction. The authors compared the effects of four toxicants on asexual and sexual reproduction of the rotifer Brachionus calyciflorus. Toxicants had a differential effect on sexual and asexual reproduction, with sexual reproduction consistently the most sensitive. Concentrations of 0.2 {mu}g/ml PCP (sodium pentachlorophenate) had no effect on the asexual reproductive rate, but significantly reduced sexual reproduction. Likewise, chlorpyrifos concentr…
20-Hydroxyecdysone-induced differentiation and apoptosis in the Drosophila cell line, l(2)mbn
2001
20-Hydroxyecdysone has an inhibitory effect on the proliferation of l(2)mbn cells, causes vacuolization and fragmentation of cells, and promotes a strong phagocytotic activity. From several lines of evidence, it can be concluded that 20-hydroxyecdysone induces apoptosis. Long-term video observations following the fate of individual cells, scanning and transmission electron microscopy reveal the typical characteristics of apoptosis: sequestration of small cellular protuberances or larger parts of the cell with nuclear fragments (apoptotic bodies), chromatin condensation, condensation and vesiculation of cytoplasm, whereas the mitochondria retain their normal appearance. The induction of apop…
Functional incorporation of green fluorescent protein into hepatitis B virus envelope particles
2004
AbstractThe envelope of hepatitis B virus (HBV), containing the L, M, and S proteins, is essential for virus entry and maturation. For direct visualization of HBV, we determined whether envelope assembly could accommodate the green fluorescent protein (GFP). While the C-terminal addition of GFP to S trans-dominant negatively inhibited empty envelope particle secretion, the N-terminal GFP fusion to S (GFP.S) was co-integrated into the envelope, giving rise to fluorescent particles. Microscopy and topogenesis analyses demonstrated that the proper intracellular distribution and folding of GFP.S, required for particle export were rescued by interprotein interactions with wild-type S. Thereby, a…
Anti-rat liver microsomal and cytosolic antibodies in hepatitis C virus infection.
1994
In order to assess the frequency of autoimmunity markers in hepatitis C virus infection, 229 RIBA 2 HCV positive individuals were tested by ELISA and Immunoblot assay using as antigen rat liver microsomal and cytosolic proteins. Twenty-one out of 229 individuals (9%) showed anti-rat liver microsome antibodies by ELISA, but the titre was low (1:100 to 1:1,600). In Immunoblot, only 5 of these 21 ELISA positive sera recognized also rat liver microsomal proteins (MW between 30 to 64 kDa). Antibodies against rat liver cytosolic proteins were found by ELISA in 14 out of 229 individuals (6%). Three of them showed a reactivity in Immunoblot to 42 kDa or 55 kDA proteins. In conclusion, HCV infection…
Hepatitis C virus antibody secretion in vitro by peripheral blood lymphocytes.
1992
A recombinant polypeptide corresponding to a virus-specific cDNA clone (c100-3) serves as the antigen for a hepatitis C virus (HCV) antibody assay. Previous investigations have shown an 80% prevalence of HCV antibodies in sera of patients suffering from post-transfusional chronic hepatitis non-A, non-B, but positive results were also obtained for 30 to 70% of sera from patients with chronic hepatitis B or autoimmune hepatitis. In this study we show that HCV antibodies are secreted by peripheral blood lymphocytes (PBL) in vitro. PBL from 12/35 patients with chronic non-A, non-B hepatitis and 1/6 patients with chronic active hepatitis B spontaneously secreted HCV antibodies in cell culture su…
Recent Advances in Derivation of Functional Hepatocytes from Placental Stem Cells
2013
Abstract: End-stage liver diseases are one of the leading causes of death in the world. Often orthotopic liver transplantation represents the final therapeutic choice. The limits of this approach are the scarcity of donor livers available, and the many side effects related to the administration of immune suppressants to the patients. Cellular therapy for liver diseases is increasingly being viewed as a promising strategy to provide hepatocytes to replenish the parenchymal cells of the organ. This technique suffers of some important limitations, such as the difficulty in isolating sufficient cell numbers (e.g. when adult or foetal hepatocytes are used for transplantation), the limited viabil…
Mutant p53 gain of function can be at the root of dedifferentiation of human osteosarcoma MG63 cells into 3AB-OS cancer stem cells
2014
Osteosarcoma is a highly metastatic tumor affecting adolescents, for which there is no second-line chemotherapy. As suggested for most tumors, its capability to overgrow is probably driven by cancer stem cells (CSCs), and finding new targets to kill CSCs may be critical for improving patient survival. TP53 is the most frequently mutated tumor suppressor gene in cancers and mutant p53 protein (mutp53) can acquire gain of function (GOF) strongly contributing to malignancy. Studies thus far have not shown p53-GOF in osteosarcoma. Here, we investigated TP53 gene status/role in 3AB-OS cells-a highly aggressive CSC line previously selected from human osteosarcoma MG63 cells-to evaluate its involv…
Immunohistochemical localization of polysialic acid in tissue sections: differential binding to polynucleotides and DNA of a murine IgG and a human I…
1990
For immunolocalization of alpha(2-8)-linked polysialic acid, which forms part of the neural cell adhesion molecule (N-CAM), two monoclonal antibodies, MAb735 and IgMNOV, were employed. Both antibodies have previously been shown to bind the extremely low immunogenic capsular polysaccharide of group B meningococci, which also consists of alpha(2-8) polysialic acid, but not to other, even closely related forms of polysialic acid. Despite the identical polysaccharide specificity of these two MAb, we observed marked differences of the staining pattern in tissue sections. We showed that these differences in immunostaining were due to the crossreactivity of IgMNOV with polynucleotides and DNA. MA…