PubMed · 5271068
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
L P Hendra. 1970. EBA cement. A practical system for all cementation.. https://doi.org/10.1111/j.1365-2591.1970.tb00013.x
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
We established an effective monoepoxide-generating system by combining cytochrome-c (Cyt-c) with a hydrogen peroxide (H2O2)-generating system comprising hypoxanthine (HX), xanthine oxidase (XO) and superoxide dismutase (SOD; HX-XO-SOD-Cyt-c system). Using this and the H2O2-Cyt-c system, we proved that monoepoxide production from linoleic acid was due to hydroxy radical formation by the reaction of Cyt-c with H2O2 and not to the formation of other active oxygen species.
Retinoids stimulate tissue-type plasminogen-activator (t-PA) gene expression in human endothelial cells, and are likely to do so by binding to one or more nuclear retinoid receptors. The present study was initiated to identify the retinoid receptor(s) involved in this process. Expression and regulation of retinoic acid receptors (RARs) and retinoid X receptors (RXRs) were analyzed by Northern-blot analysis of total or poly(A)-rich RNA prepared from cultured human umbilical vein endothelial cells (HUVEC). Prior to any exposure to retinoids, HUVEC express two transcripts for RAR-alpha (3.6 kb and 2.8 kb), and low levels of transcripts for RAR-beta (3.4 kb and 3.2 kb) and RAR-gamma (3.3 kb and 3.1 kb). Two RXR subtypes were identified, RXR-alpha (4.8 kb) and, at a much lower concentration, RXR-beta (2.4 kb); no evidence for the presence of RXR-gamma was found. Furthermore, HUVEC express cellular retinol-binding protein I (CRBP-I) and cellular retinoic-acid-binding protein I (CRABP-I) mRNA. Exposure of HUVEC to 1 microM retinoic acid or the retinobenzoic acid, Ch55, led to the induction of the two RAR-beta mRNAs, RXR-alpha mRNA and CRBP-I mRNA, whereas the expression of the other receptor and CRABP-I transcripts did not change appreciably. Using retinoid analogues that bind preferentially to one of the RAR or RXR subtypes, we found evidence that RAR-alpha is involved in the retinoid-induced t-PA expression in HUVEC. This conclusion was strengthened by experiments in which blocking of RAR-alpha with a specific RAR-alpha antagonist, Ro 41-5253, was demonstrated to suppress the induction of t-PA by retinoids.
A new series of heterocyclic ring-containing benzoic acids was prepared, and the binding affinity and antagonism of its members against all-trans-retinoic acid were evaluated by in vitro assay systems using human promyelocytic leukemia (HL-60) cells. Structure-activity relationships indicated that both an N-substituted pyrrole or pyrazole (1-position) and a hydrophobic region, with these linked by a ring system, were indispensable for effective antagonism. Among the compounds evaluated, optimal antagonism was exhibited by 4-[4,5,7,8,9,10-hexahydro-7,7,10,-10-tetramethyl-1-(3- pyridylmethyl)anthra[1,2-b]pyrrol-3-yl]benzoic acid (31), 4-[4,5,7,8,9,10-hexahydro-7,7,10,10-tetramethyl-1-(3-pyridylmethyl)-5- thiaanthral[1,2-b]pyrrol-3-yl]benzoic acid (40), and 4-[4,5,7,8,9,10-hexahydro-7,7,10,10-tetramethyl-1-(3- pyridylmethyl)anthra[2,1-d]pyrazol-3-yl]benzoic acid (55), all of which possess a 3-pyridylmethyl group at the five-membered ring nitrogen atom.