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1.
Int J Obes (Lond) ; 42(2): 147-155, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28852205

RESUMO

BACKGROUND: Probiotics are commonly used after bariatric surgery; however, uncertainty remains regarding their efficacy. Our aim was to compare the effect of probiotics vs placebo on hepatic, inflammatory and clinical outcomes following laparoscopic sleeve gastrectomy (LSG). METHODS: This randomized, double-blind, placebo-controlled, trial of 6-month treatment with probiotics (Bio-25; Supherb) vs placebo and 6 months of additional follow-up was conducted among 100 morbidly obese nonalcoholic fatty liver disease (NAFLD) patients who underwent LSG surgery. The primary outcome was a reduction in liver fat content, measured by abdominal ultrasound, and secondary outcomes were improvement of fibrosis, measured by shear-wave elastography, metabolic and inflammatory parameters, anthropometrics and quality of life (QOL). Fecal samples were collected and analyzed for microbial composition. RESULTS: One hundred patients (60% women, mean age of 41.9±9.8 years and body mass index of 42.3±4.7 kg m-2) were randomized, 80% attended the 6-month visit and 77% completed the 12-month follow-up. Fat content and NAFLD remission rate were similarly reduced in the probiotics and placebo groups at 6 months postsurgery (-0.9±0.5 vs -0.7±0.4 score; P=0.059 and 52.5 vs 40%; P=0.262, respectively) and at 12 months postsurgery. Fibrosis, liver-enzymes, C-reactive protein (CRP), leptin and cytokeratin-18 levels were significantly reduced and QOL significantly improved within groups (P⩽0.014 for all), but not between groups (P⩾0.173 for all) at 6 and 12 months postsurgery. Within-sample microbiota diversity (alpha-diversity) increased at 6-month postsurgery compared with baseline in both study arms (P⩽0.008) and decreased again at 12 months postsurgery compared with 6 months postsurgery (P⩽0.004) but did not reach baseline values. CONCLUSIONS: Probiotics administration does not improve hepatic, inflammatory and clinical outcomes 6- and 12 months post-LSG.


Assuntos
Fígado/diagnóstico por imagem , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Obesidade Mórbida/cirurgia , Probióticos/administração & dosagem , Adulto , Cirurgia Bariátrica , Método Duplo-Cego , Técnicas de Imagem por Elasticidade , Feminino , Seguimentos , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/fisiopatologia , Período Pós-Operatório , Resultado do Tratamento , Ultrassonografia
2.
J Chromatogr A ; 1722: 464860, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38593521

RESUMO

Thanks to the Cassini-Huygens space mission between 2004 and 2017, a lot was learned about Titan, the biggest satellite of Saturn, and its intriguing atmosphere, surface, and organic chemistry complexity. However, key questions about the potential for the atmosphere and surface chemistry to produce organic molecules of direct interest for prebiotic chemistry and life did not find an answer. Due to Titan potential as a habitable world, NASA selected the Dragonfly space mission to be launched in 2027 to Titan's surface and explore the Shangri-La surface region for minimum 3 years. One of the main goals of this mission will be to understand the past and actual abundant prebiotic chemistry on Titan, especially using the Dragonfly Mass Spectrometer (DraMS). Two recently used sample pre-treatments for Gas Chromatography - Mass Spectrometry (GC-MS mode of DraMS) analyses are planned prior analysis to extract refractory organic molecules of interest for prebiotic chemistry and astrobiology. The dimethylformamide dimethylacetal (DMF-DMA) derivatization reaction offers undoubtedly an opportunity to detect biosignatures by volatilizing refractory biological or prebiotic molecules and conserving the chiral carbons' conformation while an enantiomeric excess indicates a chemical feature induced primarily by life (and may be aided on the primitive systems by light polarization). The goal of this study is to investigate the ageing of DMF-DMA in DraMS (and likely MOMA) capsules prior to in situ analysis on Titan (or Mars). The main results highlighted by our work on DMF-DMA are first its satisfactory stability for space requirements through time (no significant degradation over a year of storage and less than 30 % of lost under thermal stress) to a wide range of temperature (0 °C to 250 °C), or the presence of water and oxidants during the derivatization reaction (between 0 and 10 % of DMF-DMA degradation). Moreover, this reagent derivatized very well amines and carboxylic acids in high or trace amounts (ppt to hundreds of ppm), conserving their molecular conformation during the heat at 145 °C for 3 min (0 to 4% in the enantiomeric form change).


Assuntos
Saturno , Estereoisomerismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Dimetilformamida/química , Exobiologia/métodos , Meio Ambiente Extraterreno/química , Voo Espacial
3.
Talanta ; 257: 124283, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36870123

RESUMO

One of the main objectives of present and future space exploration missions dedicated to astrobiology is the detection of organic molecules of interest for life (e.g. amino and fatty acids). With this aim, a sample preparation and a gas chromatograph (connected to a mass spectrometer) are generally used. To date, tetramethylammonium hydroxide (TMAH) has been the first and only thermochemolysis reagent to be used for in situ sample preparation and chemical analysis of planetary environments. Although TMAH is widely used in terrestrial laboratories, numerous applications also leverage other thermochemolysis reagents that may be more relevant than TMAH to meet both scientific and technical objectives of space instrumentation. The present study compares the performance of tetramethylammonium hydroxide (TMAH), trimethylsulfonium hydroxide (TMSH), and trimethylphenylammonium hydroxide (TMPAH) reagents on molecules of interest to astrobiology. The study focuses on the analyses of 13 carboxylic acids (C7-C30), 17 proteinic amino acids, and the 5 nucleobases. Here we report the derivatization yield without stirring or adding solvents, the detection sensitivity with mass spectrometry, and the nature of the degradation products from the reagents produced during pyrolysis. We conclude that TMSH and TMAH are the best reagents for analyzing carboxylic acids and nucleobases. Amino acids are not relevant targets for a thermochemolysis over 300 °C as they are degraded and showed high limits of detection. As TMAH, and probably TMSH, meet the space instrumentation requirements, this study informs sample treatment approaches prior to GC-MS analysis in in situ space studies. The thermochemolysis reaction using TMAH or TMSH is also recommended for space return missions to extract organics from a macromolecular matrix, derivatize polar or refractory organic targets, and volatilize with the fewest organic degradations.

4.
Anal Chim Acta ; 1266: 341270, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37244655

RESUMO

For gas chromatography - mass spectrometry (GC-MS) analyses performed in situ, pH and salts (e.g., chlorides, sulfates) may enhance or inhibit the detection of targeted molecules of interest for astrobiology (e.g. amino acids, fatty acids, nucleobases). Obviously, salts influence the ionic strength of the solutions, the pH value, and the salting effect. But the presence of salts may also produce complexes or mask ions in the sample (masking effect on hydroxide ion, ammonia, etc.). For future space missions, wet chemistry will be conducted before GC-MS analyses to detect the full organic content of a sample. The defined organic targets for space GC-MS instrument requirements are generally strongly polar or refractory organic compounds, such as amino acids playing a role in the protein production and metabolism regulations for life on Earth, nucleobases essential for DNA and RNA formation and mutation, and fatty acids that composed most of the eukaryote and prokaryote membranes on Earth and resist to environmental stress long enough to still be observed on Mars or ocean worlds in geological well-preserved records. The wet-chemistry chemical treatment consists of reacting an organic reagent with the sample to extract and volatilize polar or refractory organic molecules (i.e. dimethylformamide dimethyl acetal (DMF-DMA) in this study). DMF-DMA derivatizes functional groups with labile H in organics, without modifying their chiral conformation. The influence of pH and salt concentration of extraterrestrial materials on the DMF-DMA derivatization remains understudied. In this research, we studied the influence of different salts and pHs on the derivatization of organic molecules of astrobiological interest with DMF-DMA, such as amino acids, carboxylic acids, and nucleobases. Results show that salts and pH influence the derivatization yield, and that their effect depend on the nature of the organics and the salts studied. Second, monovalent salts lead to a higher or similar organic recovery compared to divalent salts regardless of pH below 8. However, a pH above 8 inhibits the DMF-DMA derivatization influencing the carboxylic acid function to become an anionic group without labile H. Overall, considering the negative effect of the salts on the detection of organic molecules, future space missions may have to consider a desalting step prior to derivatization and GC-MS analyses.


Assuntos
Dimetilformamida , Meio Ambiente Extraterreno , Meio Ambiente Extraterreno/química , Sais , Aminoácidos/análise , Ácidos Carboxílicos , Ácidos Graxos
5.
J Chromatogr A ; 1709: 464388, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37742456

RESUMO

Among future space missions, national aeronautics and space administration (NASA) selected two of them to analyze the diversity in organic content within Martian and Titan soil samples using a gas chromatograph - mass spectrometer (GC-MS) instrument. The Dragonfly space mission is planned to be launched in 2027 to Titan's surface and explore the Shangri-La surface region for years. One of the main goals of this mission is to understand the past and actual abundant prebiotic chemistry on Titan, which is not well characterized yet. The ExoMars space mission is planned to be launched in 2028 to Mars' surface and explore the Oxia Planum and Mawrth Vallis region for years. The main objectives focus on the exploration of the subsurface soil samples, potentially richer in organics, that might be relevant for the search of past life traces on Mars where irradiation does not impact the matrices and organics. One recently used sample pre-treatment for gas chromatography - mass spectrometry analysis is planned on both space missions to detect refractory organic molecules of interest for astrobiology. This pre-treatment is called derivatization and uses a chemical reagent - called dimethylformamide dimethyl acetal (DMF-DMA) - to sublimate organic compounds keeping them safe from thermal degradation and conserving the chirality of the molecules extracted from Titan or Mars' matrices. Indeed, the detection of building blocks of life or enantiomeric excess of some organics (e.g. amino acids) after DMF-DMA pre-treatment and GC-MS analyses would be both bioindicators. The main results highlighted by our work on DMF-DMA and Tenax®TA interaction and efficiency to detect organic compounds at ppb levels in a fast and single preparation are first that Tenax®TA did not show the onset of degradation until after 150 experiments - a 120 h at 300 °C experiment - which greatly exceeds the experimental lifetimes for the DraMS and GC-space in situ investigations. Tenax®TA polymer and DMF-DMA produce many by-products (about 70 and 46, respectively, depending on the activation temperature). Further, the interaction between the two leads to the production of 22 additional by-products from DMF-DMA degradation, but these listed by-products do not prevent the detection of trace-level organic molecules after their efficient derivatization and volatilization by DMF-DMA in the oven ahead the GC-MS trap and column.

6.
Fortschr Neurol Psychiatr ; 79(9): 524-30, 2011 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-21870313

RESUMO

Early onset psychoses (EOP, age of onset between age 14 and 18 years) are known to be associated with a poorer outcome than adult onset psychoses, both in terms of psychotic symptoms and social remission. For adult patients with psychosis, numerous cognitive-behavioral interventions have proven their effectiveness in recent years. This contrasts with a dearth of findings for EOP, even though it can be considered as a variant of adult onset psychosis. Thus, we have developed a cognitive-behavioral therapy intervention that was specifically adapted to the characteristics and needs of young people suffering from psychosis. The concept of the intervention is outlined in the present article. Acceptability and feasibility of the intervention are currently undergoing evaluation in a randomised, controlled pilot study.


Assuntos
Terapia Cognitivo-Comportamental , Transtornos Psicóticos/psicologia , Transtornos Psicóticos/terapia , Adolescente , Idade de Início , Antipsicóticos/uso terapêutico , Feminino , Humanos , Masculino , Prognóstico , Transtornos Psicóticos/tratamento farmacológico , Resultado do Tratamento
7.
J Chromatogr A ; 1644: 462087, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33819678

RESUMO

For analytical purpose, thermal desorption is now used in gas chromatographs developed to analyse the chemical composition of planetary environments. Due to technical constraints, the thermal desorption cannot be as finely controlled as in the laboratory resulting in possible thermal alteration of the adsorbents used. For these reasons, the influence of heat on physical and chemical properties of various adsorbents, either used or that could be used in gas chromatographs for space exploration, is studied. If the adsorbents made of carbon molecular sieves and graphitised carbon black that were tested show a very high thermal stability up to 800°C, the porous polymers tested are highly degraded from a minimum temperature that depends on the nature of the polymer. Poly-2,6-diphenylphenylene oxide is shown to be the more thermally robust as it is degraded at higher temperatures, confirming it is currently the best choice for analysing organic molecules with a space instrument. Finally, the products of degradation of the porous polymers tested were analysed after heating the porous polymers at 400 °C and 800 °C. They were identified and listed as potential contaminants of analyses performed with this type of adsorbent. If the exposure to the higher temperature produces numerous organic compounds, mainly aromatic ones, a few ones are also detected at the lower temperature tested, meaning they should be considered as potential contaminants. Again poly-2,6-diphenylphenylene oxide should be preferred because it releases less organic compounds, the structure of which is completely specific to the adsorbent composition.


Assuntos
Cromatografia Gasosa/métodos , Voo Espacial , Temperatura , Adsorção , Gases/análise , Polímeros/química , Pirólise , Termogravimetria , Fatores de Tempo , Volatilização
8.
J Phys Chem A ; 113(42): 11195-203, 2009 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-19827851

RESUMO

In this work Titan's atmospheric chemistry is simulated using a capacitively coupled plasma radio frequency discharge in a N(2)-CH(4) stationnary flux. Samples of Titan's tholins are produced in gaseous mixtures containing either 2 or 10% methane before the plasma discharge, covering the methane concentration range measured in Titan's atmosphere. We study their solubility and associated morphology, their infrared spectroscopy signature and the mass distribution of the soluble fraction by mass spectrometry. An important result is to highlight that the previous Titan's tholin solubility studies are inappropriate to fully characterize such a heterogeneous organic matter and we develop a new protocol to evaluate quantitatively tholins solubility. We find that tholins contain up to 35% in mass of molecules soluble in methanol, attached to a hardly insoluble fraction. Methanol is then chosen as a discriminating solvent to characterize the differences between soluble and insoluble species constituting the bulk tholins. No significant morphological change of shape or surface feature is derived from scanning electron microscopy after the extraction of the soluble fraction. This observation suggests a solid structure despite an important porosity of the grains. Infrared spectroscopy is recorded for both fractions. The IR spectra of the bulk, soluble, and insoluble tholins fractions are found to be very similar and reveal identical chemical signatures of nitrogen bearing functions and aliphatic groups. This result confirms that the chemical information collected when analyzing only the soluble fraction provides a valuable insight representative of the bulk material. The soluble fraction is ionized with an atmospheric pressure photoionization source and analyzed by a hybrid mass spectrometer. The congested mass spectra with one peak at every mass unit between 50 and 800 u confirm that the soluble fraction contains a complex mixture of organic molecules. The broad distribution, however, exhibits a regular pattern of mass clusters. Tandem collision induced dissociation analysis is performed in the negative ion mode to retrieve structural information. It reveals that (i) the molecules are ended by methyl, amine and cyanide groups, (ii) a 27 u neutral moiety (most probably HCN) is often released in the fragmentation of tholin anions, and (iii) an ubiquitous ionic fragment at m/z 66 is found in all tandem spectra. A tentative structure is proposed for this negative ion.


Assuntos
Atmosfera/química , Meio Ambiente Extraterreno/química , Saturno , Pressão Atmosférica , Espectrometria de Massas , Metano/química , Metanol/química , Microscopia Eletrônica de Varredura , Estrutura Molecular , Nitrogênio/química , Tamanho da Partícula , Porosidade , Solubilidade , Solventes/química , Espectrofotometria Infravermelho
9.
J Chromatogr A ; 1598: 183-195, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31047659

RESUMO

The Sample Analysis at Mars (SAM) instrument is a gas chromatograph-mass spectrometer onboard the NASA Curiosity rover, currently operating on the surface of Mars. Organic compounds are of major importance with regard to questions of habitability and the potential presence of life on Mars, and one of the mission's main objectives is to analyze the organic content of soil and rock samples. In SAM's first chromatographic measurements, however, unexpected chlorine-bearing organic molecules were detected. These molecules have different origins but the presence of perchlorates and chlorates detected at the surface of Mars suggests that reactivity between organic molecules and thermal decomposition products from oxychlorines is one of the major sources of the chlorinated organic molecules. Here we perform a comprehensive and systematic study of the separation of volatile chlorohydrocarbons with the chromatographic columns used in the SAM instrument. Despite the constrained operating conditions of the flight instrument, we demonstrate that SAM's capillary chromatographic columns allow for effective separation and identification of a wide range of chlorine-bearing species. We also show that instrumental limitations prevent the detection of certain molecules, obscuring our ability to make definitive conclusions about the origin of these organic materials.


Assuntos
Monitoramento Ambiental/instrumentação , Meio Ambiente Extraterreno/química , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Hidrocarbonetos Clorados/análise , Marte , Solo/química
10.
Talanta ; 204: 802-811, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357367

RESUMO

Thermochemolysis of seven nucleobases-adenine, thymine, uracil, cytosine, guanine, xanthine, and hypoxanthine-in tetramethylammonium hydroxide (TMAH) was studied individually by pyrolysis gas chromatography mass spectrometry in the frame of the Mars surface exploration. The analyses were performed under conditions relevant to the Sample Analysis at Mars (SAM) instrument of the Mars Curiosity Rover and the Mars Organic Molecule Analyzer (MOMA) instrument of the ExoMars Rover. The thermochemolysis products of each nucleobase were identified and the reaction mechanisms studied. The thermochemolysis temperature was optimized and the limit of detection and quantification of each nucleobase were also investigated. Results indicate that 600°C is the optimal thermochemolysis temperature for all seven nucleobases. The methylated products trimethyl-adenine, 1, 3-dimethyl-thymine, 1, 3-dimethyl-uracil, trimethyl-cytosine, 1, 3, 7-trimethyl-xanthine (caffeine), and dimethyl-hypoxanthine, respectively, are the most stable forms of adenine, thymine, uracil, cytosine, guanine, and xanthine, and hypoxanthine in TMAH solutions. The limits of detection for adenine, thymine, and uracil were 0.075 nmol; the limits of detection for guanine, cytosine, and hypoxanthine were higher, at 0.40, 0.55, and 0.75 nmol, respectively. These experiments allowed to well constrain the analytical capabilities of the thermochemolysis experiments that will be performed on Mars to detect nucleobases.


Assuntos
Purinas/análise , Pirimidinonas/análise , Cromatografia Gasosa-Espectrometria de Massas , Temperatura Alta , Limite de Detecção , Marte , Purinas/química , Pirimidinonas/química , Pirólise , Voo Espacial/instrumentação
11.
Artigo em Russo | MEDLINE | ID: mdl-29927398

RESUMO

AIM: To study the effect of therapy with cytoflavin on cognitive function in patients with metabolic syndrome (MS). MATERIAL AND METHODS: The randomized controlled open study included 156 patients with MS. The mean age was 41.27±5.16 years. The duration of observation was 16 weeks. The main group of patients (n=78) received cytoflavin in the dose of 2 tablets 2 times a day. Patients in the control group (n=78) received basic therapy. All patients underwent neuropsychological testing at baseline, after 2 months and at the end of the study. Cognitive evoked potentials (Р300) were recorded to assess cognitive functions. The levels of plasma glucose and lipid profile were measured. RESULTS: Cytoflavin improved cognitive functions. Two months after treatment, the results of neuropsychological testing and electrophysiological study were better in the main group compared to the control group.


Assuntos
Disfunção Cognitiva , Síndrome Metabólica , Adulto , Cognição , Disfunção Cognitiva/terapia , Potenciais Evocados , Humanos , Síndrome Metabólica/terapia , Pessoa de Meia-Idade , Testes Neuropsicológicos
12.
J Chromatogr A ; 1071(1-2): 255-61, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15865201

RESUMO

Gas chromatography-mass spectrometry (GC-MS) will be used in future space exploration missions, in order to seek organic molecules at the surface of Mars, and especially potential chemical indicators of life. Carboxylic acids are among the most expected organic species at the surface of Mars, and they could be numerous in the analysed samples. For this reason, a chemometric method was applied to support the interpretation of chromatograms of carboxylic acid mixtures. The method is based on AutoCovariance Function (ACVF) in order to extract information on the sample--number and chemical structure of the components--and on separation performance. The procedure was applied to standard samples containing targeted compounds which are among the most expected to be present in the Martian soil: n-alkanoic and benzene dicarboxylic acids. ACVF was computed on the obtained chromatograms and plotted versus retention time: peaks of the ACVF plot can be related to specific molecular structures and are diagnostic for chemical identification of compounds.


Assuntos
Exobiologia , Cromatografia Gasosa-Espectrometria de Massas/métodos , Marte , Solo/análise
13.
J Geophys Res Planets ; 120(3): 495-514, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26690960

RESUMO

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C2 to C4 dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles. KEY POINTS: First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

14.
FEBS Lett ; 258(1): 22-6, 1989 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-2591533

RESUMO

Thioredoxins have been purified from pig heart and potato tuber mitochondria which differ in chromatographic behaviour, enzyme activating capacity, and slightly higher molecular mass (Mr = 12,500) from the major thioredoxin(s) present in mitochondria-free fractions of the same tissue. Both mt-thioredoxins can serve as hydrogen donor for E. coli ribonucleotide reductase but only the plant protein activates spinach chloroplast NADP malate dehydrogenase in vitro. Mitochondrial target enzymes specifically activated by thioredoxin have not as yet been identified.


Assuntos
Proteínas de Bactérias/isolamento & purificação , Mitocôndrias Cardíacas/metabolismo , Mitocôndrias/metabolismo , Plantas Comestíveis/metabolismo , Tiorredoxinas/isolamento & purificação , Animais , Cloroplastos/enzimologia , Eletroforese em Gel de Poliacrilamida , Ativação Enzimática/efeitos dos fármacos , Malato Desidrogenase/metabolismo , NADP/metabolismo , Desnaturação Proteica , Suínos , Tiorredoxinas/farmacologia
15.
Aliment Pharmacol Ther ; 19(10): 1089-98, 2004 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-15142198

RESUMO

BACKGROUND: Existing pharmacokinetic data are insufficient to determine whether a delayed-release formulation of mesalamine (Asacol) results in greater systemic exposure to 5-aminosalicylic acid and its major metabolite N-acetyl-5-aminosalicylic acid than a prodrug (balsalazide). AIM: To determine the pharmacokinetic parameters of 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid from equimolar doses of 5-aminosalicylic acid administered as Asacol and balsalazide. METHODS: Nineteen healthy volunteers completed an open-label, single-dose, randomized, crossover study comparing the pharmacokinetics of 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid from equimolar doses of 5-aminosalicylic acid (800 mg) administered as Asacol (800 mg) and balsalazide (2250 mg). Plasma and urine samples were analysed for 5-aminosalicylic acid, N-acetyl-5-aminosalicylic acid, and balsalazide (urine only) using high-performance liquid chromatography methods with mass spectrometric detection. Pharmacokinetic parameters assessed for 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid included: percentage of dose excreted in urine (A(e)%), area under the plasma concentration-time curve (AUCt(last)); and maximum plasma concentration (C(max)). RESULTS: The geometric mean total (5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid) urinary excretion values (A(e)%) of Asacol and balsalazide were 19.26 and 19.31% (P = 0.98). The geometric mean A(e)% values of 5-aminosalicylic acid for Asacol and balsalazide were 0.39 and 0.37% (P = 0.78); the geometric mean A(e)% values of N-acetyl-5-aminosalicylic acid for Asacol and balsalazide were 18.78 and 18.83% (P = 0.98). The geometric mean 5-aminosalicylic acid AUC(t(last)) values for Asacol and balsalazide were 3295 and 3449 ng h/mL (P = 0.85); the geometric mean N-acetyl-5-aminosalicylic acid AUC(t(last)) values for Asacol and balsalazide were 15 364 and 16 050 ng h/mL (P = 0.69). The geometric mean 5-5-aminosalicylic acid C(max) values for Asacol and balsalazide were 319 and 348 ng/mL (P = 0.80); the geometric mean N-acetyl-5-aminosalicylic acid C(max) values for Asacol and balsalazide 927 and 1009 ng/mL (P = 0.67). CONCLUSIONS: The systemic absorption of 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid from Asacol and balsalazide are comparable based upon plasma pharmacokinetic parameters and urinary excretion values.


Assuntos
Ácidos Aminossalicílicos/farmacocinética , Anti-Inflamatórios não Esteroides/farmacocinética , Antiulcerosos/farmacocinética , Mesalamina/farmacocinética , Administração Oral , Adulto , Ácidos Aminossalicílicos/administração & dosagem , Ácidos Aminossalicílicos/efeitos adversos , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/efeitos adversos , Antiulcerosos/administração & dosagem , Antiulcerosos/efeitos adversos , Estudos Cross-Over , Feminino , Humanos , Masculino , Mesalamina/administração & dosagem , Mesalamina/efeitos adversos , Fenil-Hidrazinas
16.
Menopause ; 5(2): 107-12, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9689205

RESUMO

OBJECTIVE: The relative bioavailability of estradiol from two matrix transdermal delivery systems, Alora (0.05 mg/day when applied for 3-4 days) and Climara (0.05 mg/day when applied for 7 days), was evaluated in this two-period, randomized crossover study. DESIGN: A total of 27 healthy, postmenopausal women completed this study. Each subject received four successive doses of Alora every 84 h (3.5 days) and two doses of Climara every 168 h (7 days) in a randomized sequence without a washout period. Serial serum samples were collected over a 7-day period during the second week of each treatment. Samples were analyzed for estradiol and estrone using a validated radioimmunoassay method. Pharmacokinetic analyses were conducted using baseline-corrected parameters. RESULTS: Fluctuations in serum estradiol levels were 44% higher for Climara, as indicated by the ratio of Cmax/Cmin. Because the Cmin values for the two regimens were similar, the differences in fluctuation reflected the difference in their Cmax values (49.8 pg/ml for Alora, 67.7 pg/ml for Climara.) The estradiol AUC for Climara was 124% (95% CI 115.6-133.7) of the value for Alora. CONCLUSIONS: Serum estradiol concentrations were maintained at a more constant level during twice-weekly application of Alora than during once-weekly application of Climara. Both regimens were generally well tolerated and no serious skin or other adverse effects were reported by the subjects. However, Alora exhibited better skin tolerability as indicated by a lower incidence of moderate skin erythema. In addition, there was less adhesive transfer to skin at the application site with Alora.


Assuntos
Sistemas de Liberação de Medicamentos/normas , Estradiol/farmacocinética , Adesivos/efeitos adversos , Administração Cutânea , Idoso , Disponibilidade Biológica , Estudos Cross-Over , Sistemas de Liberação de Medicamentos/efeitos adversos , Eritema/induzido quimicamente , Estradiol/administração & dosagem , Estradiol/sangue , Estrona/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa/metabolismo
17.
J Clin Pharmacol ; 33(11): 1104-9, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8300893

RESUMO

The steady-state pharmacokinetic interaction between buspirone and alprazolam was evaluated in a parallel study with two groups of 12 male volunteers each. On days 1 to 7, group I subjects received a 1-mg alprazolam tablet every 8 hours (q8h) (TRT 1) and group II subjects received 2 x 5-mg buspirone tablets q8h (TRT 2). On days 8 through 14, all subjects received a combination of 1-mg alprazolam and 2 x 5-mg buspirone tablets q8h (TRT 3). Plasma samples, collected 0 to 8 hours after the morning dose on days 7 and 14, were analyzed for buspirone, alprazolam and their metabolites, 1-PP, and alpha-HO-alprazolam, respectively. Additional samples were collected before the morning dose on days 5 and 6 of each session to monitor the attainment of steady state. Steady-state pharmacokinetic parameters Cmax, Tmax, AUC0-8, and Cmin were calculated. The results indicated that for alprazolam, there was a small (< 10%) increase in Cmax and AUC when coadministered with buspirone. For buspirone, there was a 10% and 29% increase in Cmax and AUC, when coadministered with alprazolam. These values were within the normal variability observed with this class of drugs. Except for a 14% decrease in Cmin for alpha-HO-alprazolam, coadministration of buspirone and alprazolam did not affect the parameters for the metabolites. The results of this study suggest that coadministration of buspirone and alprazolam did not markedly affect the steady-state pharmacokinetics of either drug.


Assuntos
Alprazolam/farmacocinética , Buspirona/farmacocinética , Administração Oral , Adulto , Alprazolam/administração & dosagem , Alprazolam/sangue , Buspirona/administração & dosagem , Buspirona/sangue , Interações Medicamentosas , Humanos , Masculino , Comprimidos
18.
J Neurol ; 239(6): 343-4, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1512611

RESUMO

A family with central nervous system tumors in five individuals in two generations is reported. Of five sisters, two had an isolated meningioma and one an ependymoma. Amongst the four children of those affected there was a son with two cerebral meningiomas and a daughter with a spinal meningioma. Signs typical of von Recklinghausen neurofibromatosis (NF1) or bilateral acoustic neurofibromatosis (NF2) were not present. The pattern is consistent with autosomal dominant inheritance with relatively high penetrance.


Assuntos
Neoplasias do Sistema Nervoso Central/genética , Adolescente , Adulto , Ependimoma/genética , Família , Feminino , Humanos , Masculino , Meningioma/genética , Linhagem
19.
AJNR Am J Neuroradiol ; 4(3): 644-5, 1983.
Artigo em Inglês | MEDLINE | ID: mdl-6410821

RESUMO

This paper reports on the respective diagnostic values of myelography with water-soluble contrast media and diskography in a study of 100 patients examined between 1979 and 1981 and operated on because of cervical disk disease. The results of the study led to a change of the diagnostic procedures formerly applied in radicular syndromes (i.e., diskography, and then perhaps myelography) and in cervical myelopathy (myelography, rarely followed by diskography). Now cervical metrizamide myelography is always performed first. Diskography is only indicated in radicular syndromes to determine the segment causing clinical symptoms when there is a polysegmental space-occupying lesion on the myelogram in combination with a mono- or oligoradicular neurologic symptomatology; or in the case of a normal myelogram with complaints resistant to conservative treatment.


Assuntos
Deslocamento do Disco Intervertebral/diagnóstico por imagem , Mielografia/métodos , Vértebras Cervicais/diagnóstico por imagem , Feminino , Humanos , Masculino , Metrizamida , Síndromes de Compressão Nervosa/diagnóstico por imagem , Osteocondrite/diagnóstico por imagem , Raízes Nervosas Espinhais/diagnóstico por imagem
20.
J Chromatogr A ; 999(1-2): 165-74, 2003 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-12885061

RESUMO

A solid-liquid extraction method able to perform in situ extraction of organic compounds on Mars is proposed. The extraction efficiency of various organic solvents was tested and compared to that of water. The selected key compounds are molecules of exobiological interest: glycine, alanine, serine, glutamic acid, oxalic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid and 1,3,5-benzenetricarboxylic acid. Among the organic solvents, propanol gives the highest yield of extraction for all the targeted compounds except for benzoic acid. A mixture of propanol and ethyl acetate increases significantly the extraction yield of benzoic acid. The extraction time was considerably reduced (140 h to 15 min) by using sonication. The method is discussed for an easy automation with coupling to an in situ GC-MS space instrument.


Assuntos
Exobiologia , Marte , Solo/análise , Cromatografia Gasosa-Espectrometria de Massas
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