Search results for " Phase"
showing 10 items of 1862 documents
Transcription of the MAT2A gene, coding for methionine adenosyltransferase, is up-regulated by E2F and Sp1 at a chromatin level during proliferation …
2006
Methionine adenosyltransferase (MAT) is an essential enzyme because it catalyzes the formation of S-adenosylmethionine, the main methyl donor. Two MAT-encoding genes (MAT1A, MAT2A) are found in mammals. The latter is expressed in proliferating liver, dedifferentiation and cancer, whereas MAT1A is expressed in adult quiescent hepatocytes. Here, we report studies on the molecular mechanisms controlling the induction of MAT2A in regenerating rat liver and in proliferating hepatocytes. The MAT2A is up-regulated at two discrete moments during liver regeneration, as confirmed by RNApol-ChIP analysis. The first one coincides with hepatocyte priming (i.e. G0-G1 transition), while the second one tak…
Gender differences in escape-avoidance behavior of mice after haloperidol administration.
1993
Gender differences in the disruptive effects of haloperidol on some reinforced behaviors have been observed in different species. However, the inhibitory action of haloperidol on the acquisition and performance of escape-avoidance behavior has only been investigated in male subjects. The present experiment was designed to investigate possible gender differences in the effects of haloperidol on the initial phase of an escape-avoidance learning task. Male and female mice of the OF1 strain were given a single training session in a shuttle-box. Thirty minutes prior to the behavioral test, mice were injected IP with haloperidol (0.25 mg/kg) or physiological saline (10 ml/kg). Latencies of escape…
Determination of globotriaosylceramide in plasma and urine by mass spectrometry
2009
Abstract Background: Fabry disease is an X-chromosomally inherited lysosomal storage disorder leading to accumulation of glycosphingolipids, mainly globotriaosylceramide (ceramide-trihexoside, Gb3). Concentrations of Gb3 in plasma and urine have been used to diagnose Fabry disease and to monitor enzyme replacement therapy with recombinant α-galactosidase. Methods: Gb3 was purified from plasma or urine by combined liquid extraction/protein precipitation and solid-phase extraction, and was detected by flow-injection analysis electrospray mass spectrometry (MS) using multi-reaction-monitoring. Calibration was performed via standard addition using C17-Gb3 as internal standard. The most abundant…
Crystal inclusions in subepithelial fibroblasts of the brood pouch of sea horses (hippocampus kuda)
1968
In the subepithelial connective tissue of the inactive broodpouch of sea horses (Hippocampus kuda), fibroblasts with striking crystal inclusions are described light microscopically and electron microscopically in the tunica adventitia of capillaries. These very electron dense crystals turn out to be hexagonal prisms of heterogeneous structures. Results of the X-ray microanalysis and comparison with other crystalline cell inclusions so far described allow the conclusion that they contain an iron protein stored as crystals. The structure and genesis of these crystals as well as the possible importance of the iron protein for the biology of these animals are discussed.
Determination of microcystins in biological samples by matrix solid-phase dispersion and liquid chromatography–mass spectrometry
2005
A method for the detection and quantification of the microcystins (MCs)-MC-LR, MC-RR and MC-YR-in biological samples by matrix solid-phase dispersion (MSPD) has been developed. The optimum extraction conditions were 500 mg of liver or kidney, C18 bonded silica as dispersant, and a mixture methanol-water (70:30) as eluent. The MCs were determined by liquid chromatography electrospray mass spectrometry (LC/ES/MS). Recoveries of biological extracts at three different spiked levels (1-10 mg kg(-1)) ranged from 40.5 to 87.0% in liver, and from 52.5 to 74.5 in kidney. R.S.D.s were < 15.6% and < 10.6%, respectively. The detection and quantification limits were 0.05 and 0.5 mg kg(-1), for all MCs. …
Burkitt lymphoma with a granulomatous reaction: an M1/Th1‐polarised microenvironment is associated with controlled growth and spontaneous regression
2021
Aims Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that, in some instances, may show a granulomatous reaction associated with a favourable prognosis and occasional spontaneous regression. In the present study, we aimed to define the tumour microenvironment (TME) in four such cases, two of which regressed spontaneously. Methods and results All cases showed aggregates of tumour cells with the typical morphology, molecular cytogenetics and immunophenotype of BL surrounded by a florid epithelioid granulomatous reaction. All four cases were Epstein-Barr virus (EBV)-positive with type I latency. Investigation of the TME showed similar features in all four cases. The analysis revealed a p…
Chronic quercetin feeding decreases plasma concentrations of salicylamide phase II metabolites in pigs following oral administration.
2011
We investigated acute effects and effects after chronic intake of the orally administered flavonol quercetin on pharmacokinetics of salicylamide metabolites (SAM) after oral administration of salicylamide in pigs. Salicylamide (8 mg/kg body weight) was orally administered to seven pigs either without or with quercetin (10 mg/kg body weight). Additionally, salicylamide was administered to five pigs that had received a diet supplemented with the flavonol for 1 week. Daily quercetin intake was 10 mg/kg in these animals. Co-ingestion of quercetin with the drug did not alter area under the concentration-time curve (AUC(0→∞)), time to achieve maximum plasma concentration (t(max)), mean residence …
Effects of typical inducers on olfactory xenobiotic-metabolizing enzyme, transporter, and transcription factor expression in rats.
2010
International audience; Several xenobiotic-metabolizing enzymes (XMEs) have been identified in the olfactory mucosa (OM) of mammals. However, the molecular mechanisms underlying the regulation of these enzymes have been little explored. In particular, information on the expression of the transcriptional factors in this tissue is quite limited. The aim of the present study was to examine the impact of five typical inducers, Aroclor 1254, 3-methylcholanthrene, dexamethasone, phenobarbital, and ethoxyquin, on the activities and mRNA expression of several XMEs in the OM and in the liver of rats. We also evaluated the effects of these treatments on the mRNA expression of transcription factors an…
Determination of benzophenone-3 and its main metabolites in human serum by dispersive liquid–liquid microextraction followed by liquid chromatography…
2013
A new analytical method for the determination of benzophenone-3 (2-hydroxy-4-methoxybenzophenone), and its main metabolites (2,4-dihydroxybenzophenone and 2,2'-dihydroxy-4-methoxybenzophenone) in human serum is presented. The method is based on dispersive liquid-liquid microextraction (DLLME) as preconcentration and clean-up technique, followed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Acidic hydrolysis and protein precipitation with HCl 6 M (1:1) (100 °C, 1 h) were carried out before extraction. The variables involved in the DLLME process were studied. Under the optimized conditions, 70 µL of acetone (disperser solvent) and 30 µL of chloroform (extraction solvent) were …
Early and mid-term effects of obstructive apneas in myocardial injury and inflammation.
2011
Abstract Background Obstructive sleep apnea (OSA) is associated with cardiovascular disorders, but the different comorbidities in OSA patients make it difficult to know their specific effects on the development of cardiovascular injury. The aim of the present study was to investigate whether recurrent obstructive apneas could lead to myocardial injury. Methods Thirty-six male Sprague–Dawley rats (300–350 g) were either acutely (3 h) or sustainably (5 h/day, for 10 days) subjected to obstructive apneas with a pattern of 15 s each, 60 apneas/h. Corresponding control groups were formed for the acute and sustained models. To assess the induction of systemic inflammation, IL1-β was measured in p…