Search results for "PHOSPHATE"
showing 10 items of 1874 documents
Elimination of Ehrlich tumours by ATP-induced growth inhibition, glutathione depletion and X-rays
1995
ATP-induced tumour growth inhibition is accompanied by a selective decrease in the content of the tripeptide glutathione (GSH) within the cancer cells in vivo. Depletion of cellular GSH sensitizes tumours to chemotherapy and radiation, but the usefulness of this depletion depends on whether the levels of GSH can be reduced in the tumour relative to normal tissues. We report here that administration of ATP in combination with diethylmaleate and X-rays leads to complete regression of 95% of Ehrlich ascites tumours in mice. This shows that an aggressive tumour can be eliminated by using a therapy based on modulation of GSH levels in cancer cells.
Regulation of phospholipase D activity in synaptosomes permeabilized with Staphylococcus aureus alpha-toxin.
1998
In order to investigate the regulation of presynaptic phospholipase D (PLD) activity by calcium and G proteins, we established a permeabilization procedure for rat cortical synaptosomes using Staphylococcus aureus alpha-toxin (30-100 microg/ml). In permeabilized synaptosomes, PLD activity was significantly stimulated when the concentration of free calcium was increased from 0.1 microM to 1 microM. This activation was inhibited in the presence of KN-62 (1 microM), an inhibitor of calcium/calmodulin-dependent kinase II (CaMKII), but not by the protein kinase C inhibitor, Ro 31-8220 (1-10 microM). Synaptosomal PLD activity was also stimulated in the presence of 1 microM GTPgammaS. When Rho pro…
Effect of Thyroid Hormones on Urea Biosynthesis and Related Processes in Rat Liver*
1988
The results of the few studies on the effect of the thyroid status on nitrogen metabolism have been inconclusive and/or contradictory. In an attempt to elucidate this important relationship, we have studied the effect of experimental hypo- and hyperthyroidism on urea biosynthesis and related processes. We have found that the capacity of the liver to synthesize urea was increased in hypothyroid rats, as were the activities of the urea cycle enzymes; there were also changes in the activities of some related enzymes and in the levels of intermediates and amino acids. Isolated hepatocytes from these rats showed an increased capacity for urea synthesis. In hyperthyroid rats the picture was more …
Dynamics of complement activation in aHUS and how to monitor eculizumab therapy.
2014
Atypical hemolytic-uremic syndrome (aHUS) is associated with genetic complement abnormalities/anti–complement factor H antibodies, which paved the way to treatment with eculizumab. We studied 44 aHUS patients and their relatives to (1) test new assays of complement activation, (2) verify whether such abnormality occurs also in unaffected mutation carriers, and (3) search for a tool for eculizumab titration. An abnormal circulating complement profile (low C3, high C5a, or SC5b-9) was found in 47% to 64% of patients, irrespective of disease phase. Acute aHUS serum, but not serum from remission, caused wider C3 and C5b-9 deposits than control serum on unstimulated human microvascular endotheli…
In situ hybridization of dihydroxyacetone phosphate acyltransferase, the regulating enzyme involved in plasmalogen biosynthesis
2005
International audience; In situ hybridization can be carried out using different methods. The experimenter has to choose various parameters: the type of tissue fixation, the time of incubation, and the duration of the exposure time. All these parameters are determinant for the sensitivity and the resolution of this technique. This publication of technical aspects described different experiments performed for in situ hybridization on liver tissue. We may conclude on the parameters to optimize each step of the hybridization procedure. Moreover, this technique could be transposed to the brain and applied to little structures with a light expression of DHAP-AT.
Transdermal iontophoresis of dexamethasone sodium phosphate in vitro and in vivo: effect of experimental parameters and skin type on drug stability a…
2010
The aim of this study was to investigate the cathodal iontophoresis of dexamethasone sodium phosphate (DEX-P) in vitro and in vivo and to determine the feasibility of delivering therapeutic amounts of the drug for the treatment of chemotherapy-induced emesis. Stability studies, performed to investigate the susceptibility of the phosphate ester linkage to hydrolysis, confirmed that conversion of DEX-P to dexamethasone (DEX) upon exposure to samples of human, porcine and rat dermis for 7 h was limited (82.2+/-0.4%, 72.5+/-4.8% and 78.6+/-6.0% remained intact) and did not point to any major inter-species differences. Iontophoretic transport of DEX-P across dermatomed porcine skin (0.75 mm thic…
Photo-induced chemiluminometric determination of Karbutilate in a continuous-flow Multicommutation assembly
2006
The present paper deals with the chemiluminescent determination of the herbicide Karbutilate on the basis of its previous photodegradation by using a low-pressure Hg lamp as UV source in a continuous-flow multicommutation assembly (a solenoid valves set). The pesticide solution was segmented by a solenoid valve and sequentially alternated with segments of the 0.001 mol l(-1) of NaOH solution, the suitable media for the formation of photo-fragments; then it passes through the photo-reactor and was lead to the flow-cell after being divided in small segments which were sequentially alternated with the oxidizing system; 2 x 10(-5) mol l(-1) of potassium permanganate in 0.2% pyrophosphoric acid.…
Formation of mono- and diglucuronides and other glycosides of benzo(a)pyrene-3,6-quinol by V79 cell-expressed human phenol UDP-glucuronosyltransferas…
1995
Glucuronidation of quinols of polycyclic aromatic hydrocarbons (PAHs) represents an important detoxication pathway preventing toxic quinone/quinol redox cycles. Therefore, mono- and diglucuronide formation of benzo(a)pyrene-3,6-quinol was investigated and compared to that of structurally related 3,6-dihydroxychrysene and simple phenols (1-naphthol and 4-methylumbelliferone) using V79 cell-expressed human UGT1.6 (= P1) and human UGT1.7 (= P4). Properties of human UGT1.6 were compared to those of the rat ortholog. Cofactors related to UDP-glucuronic acid such as UDP-galacturonic acid and UDP-glucose were also studied. It was found that rat and human UGT1.6 and human UGT1.7 catalyse monoglucur…
A multicentre trial to evaluate the efficacy and tolerability of alpha-glycerylphosphorylcholine versus cytosine diphosphocholine in patients with va…
1991
An open clinical trial was carried out to compare the efficacy and the tolerability of 1 g/day α-glycerylphosphorylcholine (α-GPC) with 1 g/day cytosine diphosphocholine (CDP) both given intramuscularly for 90 days in 120 patients with mild to moderate vascular dementia. The clinical evaluation, carried out at the start as well as halfway through (45 days) and at the end of treatment (90 days), was expressed by psychometric tests (modified Parkside behaviour rating scale, Sandoz clinical assessment geriatric scale, word fluency test, Hamilton's rating scale of depression, narration subtest of Wechsler memory scale). Both treatments produced a definite symptomatic improvement and showed a v…
Xanthine oxidase is involved in exercise-induced oxidative stress in chronic obstructive pulmonary disease
1999
In the present study, we hypothesized that exhaustive exercise in patients with chronic obstructive pulmonary disease (COPD) results in glutathione oxidation and lipid peroxidation and that xanthine oxidase (XO) contributes to free radical generation during exercise. COPD patients performed incremental cycle ergometry until exhaustion with (n = 8) or without (n = 8) prior treatment with allopurinol, an XO inhibitor. Reduced (GSH) and oxidized glutathione (GSSG) and lipid peroxides [malondialdehyde (MDA)] were measured in arterial blood. In nontreated COPD patients, maximal exercise (approximately 75 W) resulted in a significant increase in the GSSG-to-GSH ratio (4. 6 +/- 0.9% at rest vs. 9.…