Search results for "terase"
showing 10 items of 446 documents
Amyloid precursor protein in platelets of patients with Alzheimer disease: effect of acetylcholinesterase inhibitor treatment.
2001
BACKGROUND:Amyloid precursor protein (APP) forms with apparent molecular weights of 130, 110, and 106 kd are present in human platelets. It has been demonstrated that Alzheimer disease (AD) is specifically associated with a decreased APP forms ratio in platelets. OBJECTIVE:To investigate whether acetylcholinesterase (AChE) inhibitor treatment modifies the ratio of platelet APP forms in patients with AD. PATIENTS AND METHODS:From a large sample of patients with probable AD, 30 with mild to moderate AD were selected. Each patient underwent a clinical evaluation including the Mini-Mental State Examination (MMSE) and platelet APP forms analysis at baseline and after 30 days. During this interva…
Synergistic interaction of adenylate cyclase activators and nitric oxide donor SIN-1 on platelet cyclic AMP
1995
Abstract The molecular mechanism of the synergistic platelet inhibition by activators of adenylate cyclase and guanylate cyclase in human platelets was investigated. The adenylate cyclase activators iloprost and prostaglandin E 1 and the guanylate cyclase activator 3-morpholino-synonimine (SIN-1) dose-dependently inhibited thrombin-induced aggregation of washed human platelets. Furthermore, SIN-1 at a concentration inhibiting platelet aggregation by only 10% shifted the IC 50 values of iloprost and prostaglandin E 1 by one order of magnitude to the left, indicating a synergistic action of adenylate cyclase and guanylate cyclase activators. Iloprost and prostaglandin E 1 dose-dependently ele…
Therapeutic properties of haemodialysis and blood exchange transfusion in organophosphate poisoning
1976
Human blood was contaminated with nitrostigmine, dimethoate and demeton-S-methyl sulfoxide. It was then dialysed, concentrations of organophosphates were determined and dialysance values calculated. The influence of blood exchange transfusion on poison elimination as well as on the cholinesterase activity of blood, brain and muscle was studied in rats poisoned with nitrostigmine. Haemodialysis was found to be quite an effective method for eliminating demeton-S-methyl sulfoxide and dimethoate, dialysance values of 52.98 ml/min and 59.07 ml/min being found for demeton-S-methyl sulfoxide and dimethoate respectively. Nitrostigmine could not be removed by haemodialysis. These findings suggest th…
Selective chromo-fluorogenic detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) with a unique probe based on a boron dipyrromethene …
2014
[EN] A novel colorimetric probe (P4) for the selective differential detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) was prepared. Probe P4 contains three reactive sites; i.e. (i) a nucleophilic phenol group able to undergo phosphorylation with nerve gases, (ii) a carbonyl group as a reactive site for cyanide; and (iii) a triisopropylsilyl (TIPS) protecting group that is known to react with fluoride. The reaction of P4 with DCNP in acetonitrile resulted in both the phosphorylation of the phenoxy group and the release of cyanide, which was able to react with the carbonyl group of P4 to produce a colour modulation from pink to orange. In contrast, phosphorylation of P4 with…
Effects of thrombin and of the phospholipase C inhibitor, D609, on the vascularity of the chick chorioallantoic membrane.
2000
Abstract Microvascular corrosion casting was used to assess the effects of thrombin and D609, a phospholipase C inhibitor, on the vascularity of the chick embryo chorioallantoic membrane (CAM). Discs containing vehicle, thrombin or D609 were placed on the CAM of fertilized white Leghorn eggs on Day 9 of gestation and vascularity was assessed on Day 11. Thrombin caused significant increases in the numbers (43%), diameters (5%) and lengths (17%), of both pre- and postcapillaries (first-order vessels by centripetal ordering). Conversely, D609 caused a decrease in the numbers (27%), lengths (12%) and diameters (8%) of first-order vessels. D609 decreased the total vascular volume of first- to th…
Cholinesterase Activity and Hematological Parameters as Biomarkers of Sublethal Molinate Exposure in Anguilla anguilla
2000
Cholinesterase (ChE) activity was measured in plasma, whole blood [using 5,5'-dithiobis(2-nitrobenzoic acid) and 2-PDS as chromophores], brain, and whole eyes of Anguilla anguilla exposed to a sublethal concentration of 11.15 mg/L (one-third of the 96-h LC(50)) of the carbamate herbicide molinate. ChE activity was evaluated after 6, 24, 48, 72, and 96 h of pesticide exposure. Results indicated that ChE activity in eel tissues decreased as time of exposure increased, especially in eel blood. Eels exposed to molinate were transferred to a pesticide-free water for a recovery period of 4 days and ChE activity was also evaluated. Results indicated that ChE activity for those animals with preexpo…
Ester Hydrolases, ATPases and Carboanhydrases
1994
Many biomolecules are esterified with carbonic acid, phosphoric acid or sulphuric acid. The enzymes responsible for the hydrolytic cleavage of the esters are the carboxylester hydrolases, phosphoesterases and sulphatases. In addition to the phosphomonoesterases, we will also consider the phosphodiesterases and nucleases that are specific for cAMP and cGMP, as well as the ATPases that cleave phosphoric acid anhydride bonds. The ion-transporting ATPases will be discussed together with comparative biochemical data on ion channels. The chapter ends with a discussion of carboanhydrases.
Response and Recovery of Brain Acetylcholinesterase Activity in the European Eel,Anguilla anguilla,Exposed to Fenitrothion
1998
European eel (Anguilla anguilla) were exposed to sublethal fenitrothion concentrations in a continuous flow-through system for 4 days. Brain acetylcholinesterase (AChE) activity was evaluated after 2, 8, 12, 24, 32, 48, 56, 72, and 96 h pesticide exposure. Results indicated that AChE activity in eel brains decreased as the concentration of fenitrothion increased. The pesticide induced significant inhibitory effects on the AChE activity ofA. anguilla,ranging from >40% inhibition at a sublethal concentration of 0.02 ppm to >60% inhibition at a sublethal concentration of 0.04 ppm. Eel were exposed to both fenitrothion concentrations for 96 h and then allowed a period of recovery in pesticide-f…
C1-esterase inhibitor in ischemia and reperfusion.
2002
Summary Myocardial injury from ischemia can be aggravated by reperfusion of the jeopardized area. The precise underlying mechanisms have not been clearly defined, but proinflammatory events including complement activation play important roles. Cardioprotection by complement inhibition inter alia C1-esterase-inhibitor (C1-INH) was examined in several experimental models and under clinical conditions with ischemia and reperfusion. C1-INH reduced local anaphylatoxin release revealing the importance of the classical complement pathway. Inhibition of local complement activation was accompanied by improvement of myocardial function and perfusion of the previously ischemic myocardium. Leukocyte en…
Sphingomyelin inhibition of Ciona intestinalis (Tunicata) cytotoxic hemocytes assayed against sheep erythrocytes
1995
Hemocytes from the ascidian, Ciona intestinalis, are capable of lysing erythrocytes in vitro following cell membrane contact. With the aim of examining the mechanism of cytotoxicity, we performed inhibition experiments with lipid components of erythrocyte membranes. Cholesterol is not an inhibitor, whereas, among the phospholipids tested, (sphingomyelin, phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine) sphingomyelin inhibits the hemolytic activity of hemocytes. However, thin layer chromatography showed that sphingomyelinase activity was not contained in the chloroform-methanol extracts from hemocyte debris. The inhibition capacity of the components ceramide and phosphorylc…