Search results for "Protein"
showing 10 items of 21431 documents
Mechanisms of arachidonic acid induced glial swelling
2000
Accumulation of arachidonic acid (AA) in the brain during ischaemia may contribute to development of brain oedema. In this study we investigated the effect of selected drugs on AA-induced cytotoxic brain oedema in C6 glioma cells. Suspended C6 glioma cells were preincubated with drugs and AA (0.1 mM) was added. When no drug was administered cell volume increased immediately after the addition of AA with a maximum cell swelling of 13.1+/-1.9% at 15 min (mean +/- S.E. M.). Preincubation of cells with BW 755C, a dual inhibitor of cyclo- and lipoxygenases, showed no reduction in cell swelling from AA, whereas superoxide dismutase, amiloride and the protein kinase inhibitor H-9370 led to a signi…
Anti-inflammatory activity of 5-O-demethylnobiletin, a polymethoxyflavone isolated from Sideritis tragoriganum.
2006
We have studied the effect of 5- O-demethylnobiletin ( 1) on both the inflammation of mouse ears induced by repeated application of 12- O-tetradecanoylphorbol 13-acetate (TPA) and the acute mouse paw oedemas induced by carrageenan and phospholipase A (2) (PLA (2)), and determined its activity on 5-lipoxygenase (5-LOX) and elastase release/activity. Compound 1 reduced the oedema formation, cell infiltration, and tissue damage in the inflammation induced by TPA in mouse ears, along with the acute oedema induced by carrageenan in mouse paws and the acute PLA (2)-induced oedema in mouse paws. The flavone inhibited leukotriene B (4) formation in rat neutrophils and elastase release in human neut…
The Efflux Pump MexXY/OprM Contributes to the Tolerance and Acquired Resistance of Pseudomonas aeruginosa to Colistin
2020
The intrinsic resistance of Pseudomonas aeruginosa to polymyxins in part relies on the addition of 4-amino-4-deoxy-l-arabinose (Ara4N) molecules to the lipid A of lipopolysaccharide (LPS), through induction of operon arnBCADTEF-ugd (arn) expression. As demonstrated previously, at least three two-component regulatory systems (PmrAB, ParRS, and CprRS) are able to upregulate this operon when bacteria are exposed to colistin. In the present study, gene deletion experiments with the bioluminescent strain PAO1::lux showed that ParRS is a key element in the tolerance of P. aeruginosa to this last-resort antibiotic (i.e., resistance to early drug killing). Other loci of the ParR regulon, such as th…
In Vivo Studies on the Anti-Inflammatory Activity of Pachymic and Dehydrotumulosic Acids
2000
Pachymic and dehydrotumulosic acids were studied in different models of acute and chronic inflammation. They proved to be active in most of the methods applied. None of them were active against arachidonic acid-induced ear edema. Dehydrotumulosic acid significantly diminished the mouse ear edema induced by ethyl phenylpropiolate, while pachymic acid was ineffective. When the putative corticoid-like mechanism of both compounds was explored, pachymic acid activity was partially abolished by the glucocorticoid receptor antagonist progesterone, but dehydrotumulosic acid activity was not affected. In vivo experiments demonstrated the inhibition by both principles of the phospholipase A2 (PLA2)-i…
Repurposing of the ALK inhibitor crizotinib for acute leukemia and multiple myeloma cells
2021
Crizotinib was a first generation of ALK tyrosine kinase inhibitor approved for the treatment of ALK-positive non-small-cell lung carcinoma (NSCLC) patients. COMPARE and cluster analyses of transcriptomic data of the NCI cell line panel indicated that genes with different cellular functions regulated the sensitivity or resistance of cancer cells to crizotinib. Transcription factor binding motif analyses in gene promoters divulged two transcription factors possibly regulating the expression of these genes, i.e., RXRA and GATA1, which are important for leukemia and erythroid development, respectively. COMPARE analyses also implied that cell lines of various cancer types displayed varying degr…
Targeting a Targeted Drug: An Approach Toward Hypoxia-Activatable Tyrosine Kinase Inhibitor Prodrugs
2016
Tyrosine kinase inhibitors (TKIs), which have revolutionized cancer therapy over the past 15 years, are limited in their clinical application due to serious side effects. Therefore, we converted two approved TKIs (sunitinib and erlotinib) into 2-nitroimidazole-based hypoxia-activatable prodrugs. Kinetics studies showed very different stabilities over 24 h; however, fast reductive activation via E. coli nitroreductase could be confirmed for both panels. The anticancer activity and signaling inhibition of the compounds against various human cancer cell lines were evaluated in cell culture. These data, together with molecular docking simulations, revealed distinct differences in the impact of …
Demonstration of P29, an oestrogen receptor-associated tumor marker, in human term placenta.
1991
A Mr29,000 serine phosphoprotein (P29) related to oestradiol receptor was studied in human term placenta with the use of a specific monoclonal antibody (D5). D5 was used with two different methods, immunohistochemistry and immunoradiometry. For immunohistochemistry, an indirect immunoperoxidase method was chosen to detect P29 in methacarn-fixed, wax-embedded sections. P29 was mostly confined to the syncytiotrophoblast surrounding placental villi, staining being positive in both cytoplasm and nuclei. The stroma of villi was negative. Content of P29 was uniformly high in crude placental cytosol, as measured by immunoradiometry assays. Specificity of D5 against P29 in placenta was tested by an…
Immunonegative Staining: Epitope Localization on Macromolecules
1996
Relevant literature relating to immunonegative staining is reviewed and integrated with current research of the author and others. The immunonegative staining procedure has been utilized for the study of epitope localization on immune complexes formed from keyhole limpet hemocyanin type 2 (KLH2) di- and multidecamers, and the 20S and 26S proteasome from Xenopus laevis. The IgG linkage pattern of molecules in small immune complexes is considered to provide the most reliable indication of epitope location. For both KLH2 and the 20S proteasome, using domain-specific monoclonal antibodies and a 32-kDa (p32) subunit-specific polyclonal antibody, respectively, it is shown that epitopes (KLH2, sub…
Activation of a murine autoreactive B cell by immunization with human recombinant autoantigen La/SS-B: Characterization of the autoepitope
1995
Immunization of Balb/c mice with a homogeneously purified recombinant human La/SS-B protein resulted in activation of an autoreactive B cell secreting a novel monoclonal anti-La antibody termed La4B6. La4B6 reacted with La protein from a variety of sources including human, bovine, rat and mouse. ATP blocked the binding of La4B6 to recombinant La protein. The human epitope was identified as consisting of the amino acid sequence SKGRRFKGKGKGN, which includes the proposed ATP-binding site of the La protein. In the human and bovine La protein, the epitope exists as a continuous amino acid sequence. In rat and mouse the epitope was found to consist of the amino acid sequence SKG interrupted by a…
Domains of the E1 Protein of Human Papillomavirus Type 33 Involved in Binding to the E2 Protein
1996
Papillomavirus E1 and E2 proteins are essential for the initiation of viral DNA replication. We have now analyzed the interaction of E1 and E2 of human papillomavirus type 33, which is associated with cervical carcinoma. When synthesized in insect cells using the baculovirus expression system, the E1 and E2 proteins interacted efficiently at 4 degree. A monoclonal antibody recognizing E1 amino acids 584--600 inhibited the binding of E2 and vice versa, indicating that these amino acids are involved in E2 binding. To confirm this result, a mutational analysis of E1 was performed. The E2 binding activity of E1 deletion and point mutant proteins was assayed using glutathione S-transferase E1 fu…