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1.
Sci Rep ; 12(1): 12310, 2022 07 19.
Article in English | MEDLINE | ID: mdl-35853977

ABSTRACT

Infants developing necrotizing enterocolitis (NEC) have a different metabolomic profile compared to controls. The potential of specific metabolomics, i.e. amino acids and amino alcohols (AAA), as early diagnostic biomarkers for NEC is largely unexplored. In this multicenter prospective case-control study, longitudinally collected fecal samples from preterm infants (born <30 weeks of gestation) from 1-3 days before diagnosis of severe NEC (Bell's stage IIIA/IIIB), were analyzed by targeted high-performance liquid chromatography (HPLC). Control samples were collected from gestational and postnatal age-matched infants. Thirty-one NEC cases (15 NEC IIIA;16 NEC IIIB) with 1:1 matched controls were included. Preclinical samples of infants with NEC were characterized by five increased essential amino acids-isoleucine, leucine, methionine, phenylalanine and valine. Lysine and ethanolamine ratios were lower prior to NEC, compared to control samples. A multivariate model was rendered based on isoleucine, lysine, ethanolamine, tryptophan and ornithine, modestly discriminating cases from controls (AUC 0.67; p < 0.001). Targeted HPLC pointed to several specific AAA alterations in samples collected 1-3 days before NEC onset, compared to controls. Whether this reflects metabolic alterations and has a role in early biomarker development for NEC, has yet to be elucidated.


Subject(s)
Enterocolitis, Necrotizing , Infant, Newborn, Diseases , Amines , Case-Control Studies , Enterocolitis, Necrotizing/diagnosis , Enterocolitis, Necrotizing/metabolism , Ethanolamines , Humans , Infant , Infant, Newborn , Infant, Premature/metabolism , Isoleucine , Lysine
2.
Ann Cardiol Angeiol (Paris) ; 67(2): 67-73, 2018 Apr.
Article in French | MEDLINE | ID: mdl-28554702

ABSTRACT

Cardiac hydatid cyst is a rare parasitic disease. The purpose of this study was to describe the clinical, pathological features and the outcome of the surgical treatment of cardiac hydatid disease in our unit over a twenty-year period. METHODS: Between May 1994 and May 2014, seventeen cases of cardiac hydatid cysts were operated at our unit. Overall, twelve patients were male (mean age 25±13years). All patients were complaining of dyspnea and 71% presented with chest pain. The diagnosis, based on histological examination, was suspected on echocardiography and computed tomography of chest. RESULTS: Our study revealed five possible locations, which were in decreasing order of frequency: left ventricle, interventricular septum, right ventricle, left atrium and pulmonary artery. The surgical procedure was a controlled puncture and aspiration of the cyst content, with cystectomy (69%), or pericystectomy (31%). The resulting cavity left open in 6 cases (37.5%) or carefully closed in 10 (62.5%). Hospital mortality was 11.8% (n=2). Morbidity was marked by conduction abnormalities (n=2), bleeding and hematoma of the residual cavity that required surgical treatment (n=3). Eleven patients were followed with a mean period of 40.5±19.4 months. At follow-up, neither late deaths nor recurrence have occurred. CONCLUSION: Cardiac hydatid cyst is a serious disease whose treatment is surgical. Cystectomy and pericystectomy remain the two surgical techniques able to offer good chance of cure with acceptable morbidity and mortality.


Subject(s)
Echinococcosis/diagnosis , Echinococcosis/surgery , Echocardiography , Heart Diseases/diagnosis , Heart Diseases/surgery , Tomography, X-Ray Computed , Adolescent , Adult , Chest Pain/parasitology , Child , Diagnosis, Differential , Echocardiography/methods , Female , Heart Diseases/parasitology , Hospitals, University , Humans , Male , Morocco/epidemiology , Retrospective Studies , Tomography, X-Ray Computed/methods , Treatment Outcome
3.
Leukemia ; 31(10): 2020-2028, 2017 10.
Article in English | MEDLINE | ID: mdl-28232670

ABSTRACT

Neomorphic mutations in isocitrate dehydrogenase 1 (IDH1) are frequently found in several human cancer types including acute myeloid leukemia (AML) and lead to the production of high levels of the oncometabolite (R)-2-hydroxyglutarate (R-2HG). Here we report the characterization of BAY1436032, a novel pan-mutant IDH1 inhibitor, both in vitro and in vivo. BAY1436032 specifically inhibits R-2HG production and colony growth, and induces myeloid differentiation of AML cells carrying IDH1R132H, IDH1R132C, IDH1R132G, IDH1R132L and IDH1R132S mutations. In addition, the compound impacts on DNA methylation and attenuates histone hypermethylation. Oral administration of BAY1436032 led to leukemic blast clearance, myeloid differentiation, depletion of leukemic stem cells and prolonged survival in two independent patient-derived xenograft IDH1 mutant AML mouse models. Together, BAY1436032 is highly effective against all major types of IDH1 mutant AML.


Subject(s)
Aniline Compounds/therapeutic use , Antineoplastic Agents/therapeutic use , Benzimidazoles/therapeutic use , Enzyme Inhibitors/therapeutic use , Isocitrate Dehydrogenase/antagonists & inhibitors , Leukemia, Myeloid, Acute/drug therapy , Neoplasm Proteins/antagonists & inhibitors , Aniline Compounds/pharmacology , Animals , Antineoplastic Agents/pharmacology , Benzimidazoles/pharmacology , Cell Line, Tumor , DNA Methylation/drug effects , Enzyme Inhibitors/pharmacology , Glutarates/metabolism , Histone Code/drug effects , Humans , Isocitrate Dehydrogenase/genetics , Leukemia, Myeloid, Acute/enzymology , Leukemia, Myeloid, Acute/genetics , Methylation/drug effects , Mice , Molecular Targeted Therapy , Mutation , Mutation, Missense , Myeloid Cells/drug effects , Myelopoiesis/drug effects , Neoplasm Proteins/genetics , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/enzymology , Point Mutation , Protein Processing, Post-Translational/drug effects , Tumor Stem Cell Assay , Xenograft Model Antitumor Assays
5.
Genome ; 57(3): 145-53, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24884690

ABSTRACT

The wild olive distribution extends from the Mediterranean region to south Asia and Austral Africa. The species is also invasive, particularly in Australia. Here, we investigated the sequence variation at five nuclear single-copy genes in 41 native and invasive accessions of the Mediterranean and African olive subspecies. The nucleotide diversity was assessed and the phylogenetic relationships between alleles were depicted with haplotype networks. A Bayesian clustering method (STRUCTURE) was applied to identify the main gene pools. We found an average of 18.4 alleles per locus. Native Mediterranean and African olives only share one allele, which testifies for ancient admixture on the Red Sea hills. The presence of divergent alleles in the Mediterranean olive, as well as the identification of two main genetic clusters, suggests a complex origin with two highly differentiated gene pools from the eastern and western Mediterranean that recently admixed. In the invasive range, relatively high nucleotide diversity is observed as a consequence of the introduction of alleles from two subspecies. Our data confirm that four invasive individuals are early-generation hybrids. Finally, the utility of single-copy gene sequences in olive population genomic and phylogenetic studies is briefly discussed.


Subject(s)
Genes, Plant , Olea/genetics , Polymorphism, Genetic , Base Sequence , Gene Pool , Haplotypes , Hybridization, Genetic , Molecular Sequence Data , Phylogeography
6.
Ann Bot ; 112(7): 1293-302, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24013386

ABSTRACT

BACKGROUND AND AIMS: The olive (Olea europaea subsp. europaea) was domesticated in the Mediterranean area but its wild relatives are distributed over three continents, from the Mediterranean basin to South Africa and south-western Asia. Recent studies suggested that this crop originated in the Levant while a secondary diversification occurred in most westward areas. A possible contribution of the Saharan subspecies (subsp. laperrinei) has been highlighted, but the data available were too limited to draw definite conclusions. Here, patterns of genetic differentiation in the Mediterranean and Saharan olives are analysed to test for recent admixture between these taxa. METHODS: Nuclear microsatellite and plastid DNA (ptDNA) data were compiled from previous studies and completed for a sample of 470 cultivars, 390 wild Mediterranean trees and 270 Saharan olives. A network was reconstructed for the ptDNA haplotypes, while a Bayesian clustering method was applied to identify the main gene pools in the data set and then simulate and test for early generations of admixture between Mediterranean and Saharan olives. KEY RESULTS: Four lineages of ptDNA haplotypes are recognized: three from the Mediterranean basin and one from the Sahara. Only one haplotype, primarily distributed in the Sahara, is shared between laperrinei and europaea. This haplotype is detected once in 'Dhokar', a cultivar from the Maghreb. Nuclear microsatellites show geographic patterns of genetic differentiation in the Mediterranean olive that reflect the primary origins of cultivars in the Levant, and indicate a high genetic differentiation between europaea and laperrinei. No first-generation hybrid between europaea and laperrinei is detected, but recent, reciprocal admixture between Mediterranean and Saharan subspecies is found in a few accessions, including 'Dhokar'. CONCLUSIONS: This study reports for the first time admixture between Mediterranean and Saharan olives. Although its contribution remains limited, Laperrine's olive has been involved in the diversification of cultivated olives.


Subject(s)
Gene Pool , Geography , Olea/genetics , Africa, Northern , Alleles , Bayes Theorem , Cell Nucleus/genetics , DNA, Chloroplast/genetics , Genetic Variation , Genetics, Population , Haplotypes/genetics , Mediterranean Region , Microsatellite Repeats/genetics , Models, Genetic , Multigene Family/genetics
7.
Proc Biol Sci ; 280(1756): 20122833, 2013 Apr 07.
Article in English | MEDLINE | ID: mdl-23390107

ABSTRACT

The location and timing of domestication of the olive tree, a key crop in Early Mediterranean societies, remain hotly debated. Here, we unravel the history of wild olives (oleasters), and then infer the primary origins of the domesticated olive. Phylogeography and Bayesian molecular dating analyses based on plastid genome profiling of 1263 oleasters and 534 cultivated genotypes reveal three main lineages of pre-Quaternary origin. Regional hotspots of plastid diversity, species distribution modelling and macrofossils support the existence of three long-term refugia; namely the Near East (including Cyprus), the Aegean area and the Strait of Gibraltar. These ancestral wild gene pools have provided the essential foundations for cultivated olive breeding. Comparison of the geographical pattern of plastid diversity between wild and cultivated olives indicates the cradle of first domestication in the northern Levant followed by dispersals across the Mediterranean basin in parallel with the expansion of civilizations and human exchanges in this part of the world.


Subject(s)
Genetic Variation , Olea/physiology , Agriculture , Bayes Theorem , Cyprus , Haplotypes , Mediterranean Region , Middle East , Olea/genetics , Phylogeography , Plastids/genetics
8.
Bioresour Technol ; 127: 242-7, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23131648

ABSTRACT

Clear economic advantages may be obtained from the management of seasonal fruit wastes by codigestion at existing facilities which are working throughout the year with other residues. We have explored the biomethanization of pear residues in a 5L stirred reactor loaded with sludge from the anaerobic digester of a municipal wastewater treatment plant. Different organic loading rates (OLRs) of fruit waste were tested with two delivery procedures: a discontinuous one (fed once a day) and a pseudocontinuous one. For both procedures, as the OLR increases the pH of the digester drops to acidic values and large OLRs may cause the reactor failure. Nevertheless, the pseudocontinuous delivery allows the treatment of more residue, (10.5 versus 6.0 g of volatile solids per litre of reactor and day), maintaining the specific biogas production (0.44 L of biogas per gram of volatile solids), with some improvement in methane concentration (44% vs 39%).


Subject(s)
Biofuels , Bioreactors , Methane/biosynthesis , Pyrus/chemistry , Sewage/microbiology , Waste Products/analysis , Biological Oxygen Demand Analysis , Hydrogen-Ion Concentration , Kinetics , Oxidation-Reduction
9.
Ann Cardiol Angeiol (Paris) ; 61(2): 69-73, 2012 Apr.
Article in French | MEDLINE | ID: mdl-21890105

ABSTRACT

UNLABELLED: The objective of this work was to study the indications, techniques and results of closed heart mitral commissurotomy in patients with rheumatic mitral stenosis in Morocco. METHODS: All patients who had undergone closed heart mitral commissurotomy for rheumatic mitral stenosis, operated between 1999 and 2008 were collected in this study. Mitral stenosis was diagnosed and evaluated using Doppler echocardiography. Patients with commissural calcification, severe mitral regurgitation, and surgical tricuspid or aortic valvular disease were excluded from this study. RESULTS: Six hundred and twenty-five patients have been collected. 62.2% were young with an age between 18 and 35 years and 491 (78.8%) were female. Seventy-nine percent of patients had stage III or IV NYHA and were in sinus regular rhythm. The closed heart mitral commissurotomy was performed for all patients through a left thoracotomy using either digital or dual dilatation. The mitral area was significantly increased postoperatively to 2.11 ± 0.32 with 100% opening of the anterior commissure, while the posterior commissure was opened only for 93.7% of patients. There were nine perioperative deaths (4.9%) and all patients who died had severe mitral stenosis (<0.8 cm(2)) with an elevated systolic pulmonary artery pressure (>60 mmHg). CONCLUSION: The closed heart mitral commissurotomy provides excellent results in young patients with rheumatic mitral stenosis.


Subject(s)
Dilatation/methods , Mitral Valve Stenosis/surgery , Rheumatic Heart Disease/complications , Adolescent , Adult , Aged , Child , Echocardiography, Doppler , Female , Humans , Male , Middle Aged , Mitral Valve Stenosis/microbiology , Retrospective Studies , Young Adult
10.
Ann Cardiol Angeiol (Paris) ; 58(2): 94-8, 2009 Apr.
Article in French | MEDLINE | ID: mdl-19041087

ABSTRACT

OBJECTIVE: This study aims to report clinical particularities, treatment concepts, potential evolution related to cardiac myxoma to the light of our initial experience and reviewed of the literature. METHODS AND RESULTS: Between May 1980 and January 2005: 23 patients were operated in our service for cardiac myxoma. There were 21 left-atrium myxomas and two in right atrium. The mean age was 42.73 years (range 21 to 60 years). The sex-ratio was 2.28 (16 women and seven men). In four cases, the myxomas were chance findings at echocardiography but the 19 symptomatic patients had different symptoms: dyspnea, palpitations, left ventricular failure, positional syncope, systemic embolism, chest pain or right ventricular failure. The diagnostic of myxoma was realized in all cases by echocardiography. The resection of the tumor and a wide part of the inter-atrial septum were performed in all case. The post-operative course was usually uncomplicated: only one patient had double recurrence and died of mediastinitis after the third operation. CONCLUSION: The myxoma is considered to be rare, and remains classical emergency with low operative risk, however the risk of recurrence imposes a long-term follow-up by echocardiography.


Subject(s)
Heart Neoplasms , Myxoma , Adult , Female , Heart Neoplasms/surgery , Humans , Male , Middle Aged , Myxoma/surgery , Young Adult
11.
J Chromatogr A ; 988(1): 33-40, 2003 Feb 21.
Article in English | MEDLINE | ID: mdl-12647819

ABSTRACT

A solid-phase extraction (SPE) method for sample clean-up, followed by reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection is reported for the determination of polycyclic aromatic hydrocarbons (PAHs) in edible oils. The effects of experimental variables, such as washing and elution solvents, sample solvent and drying time have been studied using C18 cartridges. Recoveries and selectivity using other sorbent materials (C8, C2, CH, PH and NH2) were also examined, with C18 being the best one. The recoveries ranged between 50 and 103% depending on the molecular mass of the PAH. The limits of quantitation were lower than 1 ng/g for most PAHs and good precision was achieved. The method was validated using certified reference materials.


Subject(s)
Chromatography, High Pressure Liquid/methods , Oils/chemistry , Polycyclic Compounds/analysis , Reproducibility of Results , Sensitivity and Specificity , Spectrometry, Fluorescence
12.
J Food Prot ; 65(1): 161-6, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11808788

ABSTRACT

An accelerated solvent extraction (ASE) procedure has been optimized for the determination of synthetic acaricides (amitraz, bromopropylate, cymiazole, coumaphos, T-fluvalinate, and flumethrin) and their residues in honey by reversed-phase high-performance liquid chromatography. The effects of experimental variables such as solvent composition, temperature, static extraction time, and solvent flush volume on the ASE efficiency have been studied. The acaricides were extracted by hexane-propanol (1/3, vol/vol) at 95 degrees C and 2.000 psi for 8 min. Recovery values of between 53 and 108% were achieved with the different substances, with coefficients of variation between 2 and 13% and limits of detection from 0.01 to 0.2 microg/g.


Subject(s)
Chromatography, High Pressure Liquid/methods , Honey/analysis , Insecticides/analysis , Pesticide Residues/analysis , Food Contamination , Solvents , Spectrophotometry, Ultraviolet , Temperature , Time Factors
13.
J Agric Food Chem ; 49(12): 5835-42, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11743771

ABSTRACT

A study on the possible degradation of amitraz, bromopropylate, coumaphos, chlordimeform, cymiazole, flumethrin, and tau-fluvalinate during the storage of honey was carried out by HPLC. Except amitraz, the other acaricides are stable in this medium for at least 9 months. Degradation studies of amitraz in honey and beeswax were carried out; the degradation products detected in both matrices were 2,4-dimethylphenylformamide (DMF) and N-(2,4-dimethylphenyl)-N'-methylformamidine (DPMF). The reaction rate constants and the half-lives of the amitraz degradation in honey and wax were calculated. Amitraz was nearly completely degraded within 1 day in beeswax and within 10 days in honey. When amitraz-spiked combs are recycled into new beeswax, DMF was found to be the principal degradation product left in pure wax.


Subject(s)
Honey/analysis , Waxes/chemistry , Animals , Bees , Biodegradation, Environmental , Chromatography, High Pressure Liquid , Half-Life , Insecticides/pharmacokinetics , Kinetics , Time Factors , Toluidines/pharmacokinetics
14.
J Chromatogr A ; 930(1-2): 21-9, 2001 Sep 28.
Article in English | MEDLINE | ID: mdl-11681576

ABSTRACT

A solid-phase extraction (SPE) method followed by a reversed-phase high-performance liquid chromatography (HPLC) procedure is reported for the assay of a wide polarity range acaricide residues in honey. After selection of suitable chromatographic and detection conditions, most steps of the SPE procedure that may affect to the recovery were investigated. Honey sample was buffered at pH 6 and then applied to the preconditioned C18 sorbent. A washing step was performed with 1 ml of a mixture of tetrahydrofuran (THF)-phosphate buffer (10:90, v/v) and finally, the analytes were eluted with 1 ml of THF. The extract was evaporated to dryness, reconstituted in mobile phase and chromatographed on a reversed-phase C18 column with diode array detection. The recoveries of the more polar acaricides were higher than 80% and 60-70% for the more apolar ones. Limits of detection obtained ranged from 1 to 200 ng/g.


Subject(s)
Acari , Chromatography, High Pressure Liquid/methods , Honey/analysis , Pesticide Residues/analysis , Animals , Automation , Reproducibility of Results , Spectrophotometry, Ultraviolet
15.
J Chromatogr B Biomed Sci Appl ; 760(1): 185-90, 2001 Aug 25.
Article in English | MEDLINE | ID: mdl-11522062

ABSTRACT

A matrix solid-phase dispersion (MSPD) procedure for the isolation and HPLC determination of a new antiallergic agent, bilastine, in rat faeces is presented. The effect on recovery of empirical variables such as nature, pH and volume of the washing and elution liquids and nature of the adsorbent has been tested. The best recoveries were attained using an octadecylsilyl sorbent, 10 ml of a 0.1 M NaHCO3-Na2CO3 aqueous buffer of pH 10.0 as washing solvent and 10 ml of methanol as elution solvent. The extracts were evaporated to dryness and reconstituted in mobile phase before their injection into a HPLC system, equipped with a Discovery RP-amide C16 column and a fluorescence detector. The method allows one to reach recoveries of 95.0% within the concentration range 0.05-10 microg/g, with within-day repeatabilities of less than 5% and between-day repeatabilities of less than 9% within this range. This method has been successfully applied to the excretion studies of bilastine in the rat.


Subject(s)
Anti-Allergic Agents/analysis , Benzimidazoles/analysis , Chromatography, High Pressure Liquid/methods , Feces/chemistry , Piperidines/analysis , Animals , Rats , Reference Standards , Reproducibility of Results , Spectrometry, Fluorescence
16.
Talanta ; 52(2): 169-80, 2000 Jun 21.
Article in English | MEDLINE | ID: mdl-18967974

ABSTRACT

Degradation processes of bromopropylate, coumaphos, chlordimeform, cymiazole, flumethrin and fluvalinate in aqueous media have been studied by HPLC. Cymiazole is stable at any tested pH (1-11), while bromopropylate, flumethrin and coumaphos are unstable at basic pH and chlordimeform and fluvalinate in neutral and basic media. The main degradation products have been identified by GC-MS. The reaction rate constants and half-lives were calculated and the effect of co-solvents on the rate and product profile was studied.

17.
J Chromatogr B Biomed Sci Appl ; 729(1-2): 139-45, 1999 Jun 11.
Article in English | MEDLINE | ID: mdl-10410936

ABSTRACT

A selective semi-automated solid-phase extraction (SPE) of the non-steroidal anti-inflammatory drugs diclofenac sodium, indomethacin and phenylbutazone from urine prior to high-performance liquid chromatography was investigated. The drugs were recovered from urine buffered at pH 5.0 using C18 Bond-Elut cartridges as solid sorbent material and mixtures of methanol-aqueous buffer or acetonitrile-aqueous buffer as washing and elution solvents. The extracts were chromatographed on a reversed-phase ODS column using 10 mM acetate buffer (pH 4.0)-acetonitrile (58:42, v/v) as the mobile phase, and the effluent from the column was monitored at 210 nm with ultraviolet detection. Absolute recoveries of the anti-inflammatory drugs within the range 0.02-1.0 microg/ml were about 85% for diclofenac and indomethacin, and 50% for phenylbutazone without any interference from endogenous compounds of the urine. The within-day and between-day repeatabilities were in all cases less than 5% and 10%, respectively. Limits of detection were 0.007 microg/ml for diclofenac sodium and indomethacin and 0.035 microg/ml for phenylbutazone, whereas limits of quantitation were 0.02 microg/ml for diclofenac and indomethacin and 0.1 microg/ml for phenylbutazone.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/urine , Chromatography, High Pressure Liquid/methods , Diclofenac/urine , Indomethacin/urine , Phenylbutazone/urine , Humans , Reproducibility of Results , Sensitivity and Specificity , Spectrophotometry, Ultraviolet
18.
J Chromatogr B Biomed Sci Appl ; 727(1-2): 131-8, 1999 Apr 30.
Article in English | MEDLINE | ID: mdl-10360432

ABSTRACT

A solid-phase extraction (SPE) method for sample clean-up followed by a reversed-phase HPLC procedure for the assay of alinastina (pINN) in biological fluids is reported. The effects of the sample pH, composition of the washing and elution solvents and the nature of the SPE cartridge on recovery were evaluated. The selectivity of SPE was examined using spiked rat urine and plasma samples and the CH and PH cartridges gave rise to the cleanest extracts. The recoveries obtained in spiked rat urine and plasma samples were 91.2+/-2.7 and 99.9+/-2.8%, respectively. The proposed SPE method coupled off-line with a reserved-phase HPLC system with fluorimetric detection was applied to the quantitation of alinastine in real rat urine samples. The analytical method was also applied and validated for the determination of alinastine in dog plasma. The recovery from spiked dog plasma samples using the PH cartridge was around 65%. The within-day and between-day precisions were 7 and 12%, respectively. The detection and quantitation limits in dog plasma were 0.024 and 0.078 microg/ml, respectively.


Subject(s)
Benzimidazoles/pharmacokinetics , Chromatography, High Pressure Liquid/methods , Histamine H1 Antagonists/pharmacokinetics , Piperidines/pharmacokinetics , Animals , Automation , Benzimidazoles/blood , Benzimidazoles/urine , Dogs , Histamine H1 Antagonists/blood , Histamine H1 Antagonists/urine , Piperidines/blood , Piperidines/urine , Rats , Reference Standards , Reproducibility of Results , Sensitivity and Specificity , Spectrometry, Fluorescence
19.
Talanta ; 48(1): 189-99, 1999 Jan.
Article in English | MEDLINE | ID: mdl-18967458

ABSTRACT

Degradation processes of amitraz in aqueous media have been studied by spectrophotometry, HPLC and GC-MS. Amitraz undergoes hydrolysis reactions at any pH, but towards the acidic pH range hydrolysis proceeds at a faster rate. Depending on the pH value, different products of the hydrolysis have been identified. The main degradation products are 2,4-dimethylaniline at very acidic pH values (pH<3), N-(2,4-dimethylphenyl)-N'-methylformamidine and 2,4-dimethylphenylformamide at less acidic media (pH 3-6) and 2,4-dimethylphenylformamide at basic pH. The mechanisms of the different hydrolysis processes have been elucidated.

20.
Talanta ; 49(4): 773-83, 1999 Jul 12.
Article in English | MEDLINE | ID: mdl-18967653

ABSTRACT

A solid-phase extraction (SPE) method for sample clean-up followed by a reversed-phase high-performance liquid chromatography (HPLC) procedure for the assay of five antidepressant drugs (trazodone, doxepin, desipramine, maprotiline and imipramine) is reported. The drugs were recovered from plasma buffered at a suitable pH using C18 Bond-Elut cartridges and mixtures of methanol-aqueous buffer as washing and elution solvents. The recoveries of the drugs using other sorbent materials (C8, C2, cyclohexyl, cyanopropyl and phenyl Bond Elut and copolymer HLB waters cartridges) were also examined. The selectivity of SPE was examined by using spiked plasma samples and the CH cartridge gave rise to the cleanest extracts. Cyclohexyl cartridges were conditioned successively with 2 ml of methanol and 1 ml of acetic acid-sodium acetate buffer (0.1 M, pH 4.0). Plasma sample was buffered at pH 4.0 and then applied to the sorbent. The washing step was performed subsequently with 1.5 ml of acetate buffer (0.1 M, pH 4.0), 100 microl of acetonitrile and 1 ml of methanol-acetate buffer (30:70, v/v). Finally, the analytes were eluted with 0.5 ml of methanol-acetate buffer (70:30, v/v). The extract was evaporated to dryness, reconstituted in mobile phase, and chromatographed on a reversed-phase C18 column with ultraviolet detection at 215 nm. The recoveries of trazodone, doxepin, desipramine, maprotiline and imipramine from spiked plasma samples using the CH cartridge were 58 2, 84 3, 83 3, 83 3 and 82 2%, respectively. The within-day and between-day repeatabilities were lower than 6% and 9%, respectively. The linearity of calibrations for the five antidepressants was between 0.005 and 2 microg/ml. The limits of detection were 1 ng/ml for trazodone, doxepin and desipramine and 2 ng/ml for maprotiline and imipramine.

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