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1.
Can Vet J ; 59(9): 988-992, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30197442

RESUMO

This study tested the hypothesis that the presence of prostaglandin E2 in seminal plasma would aid in the transport of phenolsulfonphthalein (PSP) across the uterotubal junction. Five mares in estrus were inseminated during estrus with PSP dissolved in phosphate-buffered saline and during the subsequent estrus with PSP added to a standard insemination dose. Serum and urine samples were obtained at hours 0, 1, 2, and 3 following treatment and examined for the presence of PSP. Phenolsulfonphthalein could not be detected in any of the urine samples collected from mares following either treatment. None of the serum samples collected following intrauterine installation of PSP in PBS contained PSP. Phenolsulfonphthalein was detected in serum samples from 1 mare following insemination with semen containing PSP. Components in seminal plasma such as PGE2 did not facilitate the transport of PSP across the uterotubal junction as had been hypothesized.


Assuntos
Doenças dos Anexos/veterinária , Doenças dos Cavalos/diagnóstico , Fenolsulfonaftaleína/administração & dosagem , Doenças dos Anexos/diagnóstico , Animais , Dinoprostona , Estro , Feminino , Cavalos , Inseminação Artificial/veterinária , Masculino , Oviductos/fisiopatologia , Fenolftaleínas/sangue , Fenolftaleínas/urina , Fenolsulfonaftaleína/análise , Sêmen/química
2.
Drug Test Anal ; 9(6): 916-923, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27649484

RESUMO

Procedures for the extraction-spectrophotometric determination of tris(2-chloroethyl)amine, an alkylating agent known as a drug as well as a chemical warfare agent (nitrogen mustard HN-3), with 7 acid-base indicators of a triphenylmethane lactone type, phthaleins, were developed. Representatives of phthaleins without an oxygen bridge (thymolphthalein, o-cresolphthalein, naphtholphthalein) and with an oxygen bridge (fluorescein, 2',7'-dichlorofluorescein, eosin B and eosin Y) were used. The methods were based on the formation of ion pair complexes. Chloroform was used as a non-polar solvent for an extraction. The conditions to determine were optimized for the optimal pH of the buffer and the concentration of a phthalein as a reagent. The dependence on the reaction time in a water phase and the stoichiometry of extraction products were studied. The detection limits and the limits of the determination of separate procedures and conditional extraction constants were determined. Comparison with the spectrophotometric method of the group determination of alkyl halides and acyl halides using alkaline ethanol-water solution of thymolphthalein, the so-called T-135 agent, was conducted. While studying the selectivity, the possible interference of bis(2-chloroethyl)sulphide and 3 nitrogen mustards in the proposed procedures were verified. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Alquilantes/isolamento & purificação , Substâncias para a Guerra Química/isolamento & purificação , Compostos de Mostarda Nitrogenada/isolamento & purificação , Fenolftaleínas/química , Alquilantes/análise , Tampões (Química) , Substâncias para a Guerra Química/análise , Concentração de Íons de Hidrogênio , Limite de Detecção , Compostos de Mostarda Nitrogenada/análise , Espectrofotometria/métodos , Água/análise
3.
Mar Pollut Bull ; 101(2): 566-74, 2015 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-26522162

RESUMO

Number of heterotrophic bacteria ability to decompose organic phosphorus compounds and the level of phosphatase activity in the sand of two marine beaches (southern coast of the Baltic Sea) differing in the level of anthropopressure were studied. The study showed that the number of bacteria and level phosphatase activity were higher in the sand of the beach subjected to stronger anthropopressure. In both studied beaches bacteria hydrolysing DNA were the most numerous (92.7-302.8 CFU·g(-1) d.w.). The least numerous were phytin (26.0·10(3) CFU·g(-1) d.w.) and phenolphthalein diphosphate (11.1·10(3) CFU·g(-1) d.w.) decomposing bacteria. Number of bacteria able to attack tested organic phosphorus compounds were the most numerous in dry zones (10.77-739.92 CFU·g(-1) d.w.) then wet zones (3.34-218.15 CFU·g(-1) d.w.). In both studied beaches bacteria hydrolysing organic phosphorus compounds and phosphatase activity generally were more numerous in surface sand layer. Seasonal variation in the occurrence of bacteria in both studied beaches was observed.


Assuntos
Bactérias/metabolismo , Praias , Biodegradação Ambiental , Monoéster Fosfórico Hidrolases/metabolismo , Compostos de Fósforo/metabolismo , DNA/metabolismo , Sedimentos Geológicos/microbiologia , Processos Heterotróficos , Fenolftaleínas/metabolismo , Ácido Fítico/metabolismo , Polônia , Estações do Ano , Dióxido de Silício
4.
J Basic Clin Physiol Pharmacol ; 26(2): 141-5, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25046310

RESUMO

BACKGROUND: Investigation of the direct link between l-carnitine (LC), a quaternary ammonium compound that facilitates the passage of unsaturated fatty acids into the mitochondrial matrix, and free calcium (Ca2+) is needed to explain a number of varying results obtained from different in vitro and in vivo studies of LC as a supplement. METHODS: The chemical structure of LC, which contains oxygen ligand atoms, prompted to measure its activity asa Ca2+ chelator. The measurement was carried out spectrophotometri cally by measuring the reduction in the formation of Ca2+-o-cresolphthalein complexone (Ca-CPC) in the presence of different doses of LC (0.075, 0.75, and 7.5 mM) compared to the control (0.0 mM LC). RESULTS: The effect of LC was measured as a free entity in solution and when added to human serum. Our results showed a significant decrease (p < 0.05) in the average absorbance of Ca-CPC in the presence of LC compared to the control. CONCLUSIONS: In conclusion, LC exhibits a significant Ca2+ chelating activity. As Ca2+ is vital in the biochemical and physiological processes of living cells, LC could be affecting the calcium-dependent biological systems by limiting the levels of free Ca2+. Examples include decelerating the blood clotting process, amplifying the effect of anticoagulants, reducing nitric oxide synthase activity, inhibiting


Assuntos
Quelantes de Cálcio/farmacologia , Cálcio/metabolismo , Carnitina/farmacologia , Quelantes de Cálcio/administração & dosagem , Quelantes de Cálcio/química , Carnitina/administração & dosagem , Carnitina/química , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Humanos , Fenolftaleínas/metabolismo
5.
Rinsho Byori ; 62(2): 133-8, 2014 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-24800488

RESUMO

The ionized or free fraction of serum calcium is physiologically important for cellular function, but we most often measure total serum calcium. There are a number of correction formulas that can be used to estimate whether low total serum calcium can be attributed simply to low albumin or serum protein. In Japan, Payne's formula has been widely used to correct calcium concentration. However, there are some problems in the measurement methods of total calcium and serum albumin which were used to establish Payne's formula with respect to specificity, calibration curve and stability. Recently, improved measurement methods of calcium and albumin have been adopted at clinical laboratories. Here we evaluated Payne's formula by comparing it with improved measurement methods of total calcium and serum albumin. For the total calcium measurement, o-CPC (o-cresolphthaleincomplexone), CPZ(chlorophosphonazo) III, and enzymatic methods were used. For the serum albumin measurement, BCG (bromocresol green) and improved BCP(bromocresol purple) methods were used. The results of this comparison study suggest that the calcium correction equation is not affected by changes in total calcium concentration, but the assay used for albumin may affect the calcium correction equation. Using multiple linear regression, the following equations were derived: BCG between CPZ III [corrected Ca(mg/dL) = total Ca-0.76ALB + 3.2], and improved BCP between CPZ III [corrected Ca = total Ca-0.7ALB + 2.6]. These formulas are simplified respectively as [corrected Ca = total Ca + 0.8(4-ALB], and [corrected Ca = total Ca + 0.7 (4-ALB)]. We conclude that Payne's formula is valid with the BCG method, but with the improved BCP method, our formula is more suitable for correcting calcium.


Assuntos
Análise Química do Sangue , Proteínas Sanguíneas/análise , Cálcio/sangue , Albumina Sérica/análise , Análise Química do Sangue/métodos , Humanos , Japão , Fenolftaleínas/análise
6.
Biopharm Drug Dispos ; 35(5): 275-83, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24615849

RESUMO

The interaction between mycophenolate (MPA) and quinolone antibiotics such as ciprofloxacin is considered to reduce the enterohepatic recycling of MPA, which is biotransformed in the intestine from MPA glucuronide (MPAG) conjugate excreted via the biliary system; however, the molecular mechanism underlying this biotransformation of MPA is still unclear. In this study, an in vitro system was established to evaluate ß-glucuronidase-mediated deconjugation and to examine the influence of ciprofloxacin on the enzymatic deconjugation of MPAG and MPA resynthesis. Resynthesis of MPA via deconjugation of MPAG increased in a time-dependent manner from 5 to 60 min in the presence of ß-glucuronidase. Ciprofloxacin and phenolphthalein-ß-d-glucuronide (PhePG), a typical ß-glucuronidase substrate, significantly decreased the production of MPA from MPAG in the ß-glucuronidase-mediated deconjugation system. In addition, enoxacin significantly inhibited the production of MPA from MPAG, while levofloxacin and ofloxacin had no inhibitory effect on MPA synthesis. Pharmacokinetic analysis revealed that ciprofloxacin showed a dose-dependent inhibitory effect on MPA production from MPAG via ß-glucuronidase with a half-maximal inhibitory concentration (IC50 ) value of 30.4 µm. While PhePG inhibited the ß-glucuronidase-mediated production of MPA from MPAG in a competitive manner, ciprofloxacin inhibited MPA synthesis via noncompetitive inhibition. These findings suggest that the reduction in the serum MPA concentration during the co-administration of ciprofloxacin is at least in part due to the decreased enterohepatic circulation of MPA because of noncompetitive inhibition of deconjugation of MPAG by intestinal ß-glucuronidase.


Assuntos
Ciprofloxacino/farmacologia , Glucuronidase/metabolismo , Glucuronídeos/farmacocinética , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/farmacocinética , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Ciprofloxacino/administração & dosagem , Relação Dose-Resposta a Droga , Enoxacino/farmacologia , Circulação Êntero-Hepática/efeitos dos fármacos , Imunossupressores/administração & dosagem , Imunossupressores/farmacocinética , Técnicas In Vitro , Concentração Inibidora 50 , Levofloxacino/farmacologia , Ofloxacino/farmacologia , Fenolftaleínas/farmacologia , Fatores de Tempo
7.
J Am Chem Soc ; 135(25): 9311-4, 2013 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-23745607

RESUMO

Deduced from thermodynamics and the Thomson-Gibbs equation that the surface energy of crystal face is in proportion to the supersaturation of crystal growth units during the crystal growth, we propose that the exposed crystal faces can be simply tuned by controlling the supersaturation, and higher supersaturation will result in the formation of crystallites with higher surface-energy faces. We have successfully applied it for the growth of ionic (NaCl), molecular (TBPe), and metallic (Au, Pd) micro/nanocrystals with high-surface-energy faces. The above proposed strategy can be rationally designed to synthesize micro/nanocrystals with specific crystal faces and functionality toward specific applications.


Assuntos
Ouro/química , Nanopartículas/química , Paládio/química , Fenolftaleínas/química , Cloreto de Sódio/química , Íons/química , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície , Termodinâmica
8.
Talanta ; 107: 61-6, 2013 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-23598193

RESUMO

A new methodology based on fluorescent signal enhancement of o-cresolphthalein (o-CPT) for traces of cadmium determination is proposed. The dye was retained on membrane filters in the presence of a micellar surfactant solution of carbon nanotubes (CNTs). All the experimental variables that influence both the preconcentration procedure and the fluorimetric sensitivity were carefully optimized. The calibration graph using zeroth order regression was linear from 6.5 ng L(-1) to 5.65×10(5) ng L(-1), with a correlation coefficient higher than 0.999. Under optimal conditions, the limits of detection and quantification were of 2 ng L(-1) and 6.5 ng L(-1). respectively. The proposed method showed good sensitivity and selectivity, with good tolerance to foreign ions, and it was applied to the determination of trace amounts of cadmium in leachate from cigarettes' tobacco samples with satisfactory results. The trueness of the recommended procedure was assessed through parallel analysis of the samples with electrothermal atomization atomic absorption spectrometry. This methodology represents an innovative and attractive application of membrane filters that enables metal traces determination by solid surface fluorescence.


Assuntos
Cádmio/análise , Nanotubos de Carbono/química , Nylons/química , Espectrometria de Fluorescência/métodos , Produtos do Tabaco/análise , Poluentes Químicos da Água/análise , Corantes Fluorescentes/química , Limite de Detecção , Membranas Artificiais , Fenolftaleínas/química , Tensoativos/química
9.
J Med Chem ; 56(6): 2406-14, 2013 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-23437772

RESUMO

Colloidal aggregation is the dominant mechanism for artifactual inhibition of soluble proteins, and controls against it are now widely deployed. Conversely, investigating this mechanism for membrane-bound receptors has proven difficult. Here we investigate the activity of four well-characterized aggregators against three G protein-coupled receptors (GPCRs) recognizing peptide and protein ligands. Each of the aggregators was active at micromolar concentrations against the three GPCRs in cell-based assays. This activity could be attenuated by either centrifugation of the inhibitor stock solution or by addition of Tween-80 detergent. In the absence of agonist, the aggregators acted as inverse agonists, consistent with a direct receptor interaction. Meanwhile, several literature GPCR ligands that resemble aggregators themselves formed colloids, by both physical and enzymological tests. These observations suggest that some GPCRs may be artifactually antagonized by colloidal aggregates, an effect that merits the attention of investigators in this field.


Assuntos
Coloides/química , Coloides/farmacologia , Receptores Acoplados a Proteínas-G/metabolismo , Linhagem Celular , Clotrimazol/química , Clotrimazol/farmacologia , Itraconazol/química , Itraconazol/farmacologia , Ligantes , Modelos Moleculares , Fenolftaleínas/química , Fenolftaleínas/farmacologia , Conformação Proteica , Quercetina/química , Quercetina/farmacologia , Receptores Acoplados a Proteínas-G/química , Transdução de Sinais/efeitos dos fármacos
10.
Anal Chim Acta ; 655(1-2): 66-74, 2009 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-19925917

RESUMO

A study of different strategies to prepare phosphorescence-based sensors for gaseous CO(2) determination has been performed. It includes the characterization of different configurations tested, a discussion of the results obtained and possibilities for the future. The optical sensor for gaseous CO(2) is based on changes in the phosphorescence intensity of the platinum octaethylporphyrin (PtOEP) complex trapped both on oxygen-insensitive poly(vinylidene chloride-co-vinyl chloride) (PVCD) membranes and PVCD microparticles, due to the displacement of the alpha-naphtholphthalein acid-base equilibrium with CO(2) concentration. A secondary inner-filter mechanism was tested for the sensor and a full range linearized calibration was obtained by plotting (I(100)-I(0))/(I-I(0)) versus the inverse of the CO(2) concentration, where I(0) and I(100) are the detected luminescence intensities from a membrane exposed to 100% nitrogen and 100% CO(2), respectively, and I at a defined CO(2) concentration. The different configurations tested included the use of membranes containing luminophore and pH-sensitive dye placed on two opposite sides of a transparent support to prevent the observed degradation of the PtOEP complex in the presence of the tetraoctylammonium hydroxide (TOAOH) phase transfer agent, which produced better results regarding stability and sensitivity. The CO(2) gas sensor based on PtOEP homogeneous membranes presented better properties in terms of response time and sensitivity than that based on PtOEP microparticles. With a detection limit of 0.02%, the response time (10-90% maximum signal) is 9 s and the recovery time (90-10%) is 115 s. The lifetime of the membranes for CO(2) sensing preserved in a 94% RH atmosphere and dark conditions is longer than at least 4 months.


Assuntos
Dióxido de Carbono/análise , Corantes Fluorescentes/química , Espectrometria de Fluorescência/métodos , Equilíbrio Ácido-Base , Fenolftaleínas/química , Platina/química , Polivinil/química , Porfirinas/química
11.
Radiology ; 252(3): 754-62, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19717754

RESUMO

PURPOSE: To develop a new glucuronide probe for micro-positron emission topography (PET) that can depict beta-glucuronidase (betaG)-expressing tumors in vivo. MATERIALS AND METHODS: All animal experiments were preapproved by the Institutional Animal Care and Use Committee. A betaG-specific probe was generated by labeling phenolphthalein glucuronide (PTH-G) with iodine 131 ((131)I) or (124)I. To test the specificity of the probe in vitro, (124)I-PTH-G was added to CT26 and betaG-expressing CT26 (CT26/betaG) cells. Mice bearing CT26 and CT26/betaG tumors (n = 6) were injected with (124)I-PTH-G and subjected to micro-PET imaging. A betaG-specific inhibitor D-saccharic acid 1,4-lactone monohydrate was used in vitro and in vivo to ascertain the specificity of the glucuronide probes. Finally, the biodistributions of the probes were determined in selected organs after injection of (131)I-PTH-G to mice bearing CT26 and CT26/betaG tumors (n = 14). Differences in the radioactivity in CT26 and CT26/betaG tumors were analyzed with the Wilcoxon signed rank test. RESULTS: (124)I-PTH-G was selectively converted to (124)I-PTH (phenolphthalein), which accumulated in CT26/betaG cells and tumors in vitro. The micro-PET images demonstrated enhanced activity in CT26/betaG tumors resulting from betaG-mediated conversion and trapping of the radioactive probes. Accumulation of radioactive signals was 3.6-, 3.4-, and 3.3-fold higher in the CT26/betaG tumors than in parental CT26 tumors at 1, 3, and 20 hours, respectively, after injection of the probe (for all the three time points, P < .05). CONCLUSION: Hydrophilic-hydrophobic conversion of (124)I-PTH-G probe can aid in imaging of betaG-expressing tumors in vivo.


Assuntos
Neoplasias do Colo/diagnóstico por imagem , Neoplasias do Colo/enzimologia , Glucuronidase/metabolismo , Animais , Linhagem Celular Tumoral , Feminino , Interações Hidrofóbicas e Hidrofílicas , Radioisótopos do Iodo , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Experimentais , Fenolftaleínas , Tomografia por Emissão de Pósitrons/métodos , Estatísticas não Paramétricas
12.
Artigo em Inglês | MEDLINE | ID: mdl-19734084

RESUMO

This study dealt with the reactions of hexachlorocyclotriphosphazatriene, N(3)P(3)Cl(6) (trimer) (1) with phenolphthalein (2) to give the phenolphthalein bridged compounds 3, 4 and 5. The phenolphthalein bridged cyclotriphosphazatriene derivatives are reported for the first time. The new compounds (3-5) are characterized by elemental analysis, mass spectrometry, UV-vis, FT-IR, (1)H, (31)P NMR and fluorescence spectroscopy. The more bridged phenolphthalein groups show the higher intensity of the absorption bands in the UV-vis spectra. Fluorescence spectrum of compound 3 shows a small band in the lower spectral range, while the spectra of compounds 4 and 5 show more intense and a band in higher spectral range.


Assuntos
Compostos Organofosforados/química , Fenolftaleínas/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier
13.
J Hazard Mater ; 169(1-3): 466-71, 2009 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-19398267

RESUMO

In present study preconcentration followed by solid phase extraction of heavy metal ions, Cu(II), Co(II), Ni(II) and Pb(II) using a multiwalled carbon nanotubes (MWNTs) and complexing reagent o-cresolphthalein complexone were investigated. The effects of parameters, including pH of the solutions, amounts of complexing reagent, eluent type, sample volume, flow rates of solution, and matrix ions, were examined for the optimum recoveries of the analyte ions. The preconcentration factor was 40. Detection limit (3s) obtained for the investigated metals in the optimal conditions were observed in the range of 1.64-5.68 microg l(-1). The validation of the presented method was obtained by the analysis of certified reference material HR 1 (Humber river sediment), the obtained results were agreed with certified values. The optimum experimental conditions that ensure the efficiency of the procedure have been investigated and have been successfully applied to the determination of trace elements in environmental samples with satisfactory results.


Assuntos
Metais Pesados/isolamento & purificação , Extração em Fase Sólida/métodos , Oligoelementos/isolamento & purificação , Adsorção , Monitoramento Ambiental/métodos , Nanotubos de Carbono , Fenolftaleínas/química , Poluentes Químicos da Água/isolamento & purificação
14.
J Colloid Interface Sci ; 323(2): 395-402, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18501373

RESUMO

The premicellar and micelle formation behavior of dye surfactant ion pairs in aqueous solutions monitored by surface tension and spectroscopic measurements has been described. The measurements have been made for three anionic sulfonephthalein dyes and cationic surfactants of different chain lengths, head groups, and counterions. The observations have been attributed to the formation of closely packed dye surfactant ion pairs which is similar to nonionic surfactants in very dilute concentrations of the surfactant. These ion pairs dominate in the monolayer at the air-water interface of the aqueous dye surfactant solutions below the CMC of the pure surfactant. It has been shown that the dye in the ion pair deprotonates on micelle formation by the ion pair surfactants at near CMC but submicellar surfactant concentrations. The results of an equilibrium study at varying pH agree with the model of deprotonated 1:1 dye-surfactant ion pair formation in the near CMC submicellar solutions. At concentrations above the CMC of the cationic surfactant the dye is solubilized in normal micelles and the monolayer at the air-water interface consists of the cationic surfactant alone even in the presence of the dyes.


Assuntos
Corantes/química , Micelas , Tensoativos/química , Água/química , Absorção , Ar , Cátions , Concentração de Íons de Hidrogênio , Íons , Modelos Químicos , Soluções Farmacêuticas/química , Fenolftaleínas/química , Soluções , Propriedades de Superfície
16.
Nat Chem Biol ; 4(3): 197-9, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18223646

RESUMO

Many amyloid inhibitors resemble molecules that form chemical aggregates, which are known to inhibit many proteins. Eight known chemical aggregators inhibited amyloid formation of the yeast and mouse prion proteins Sup35 and recMoPrP in a manner characteristic of colloidal inhibition. Similarly, three known anti-amyloid molecules inhibited beta-lactamase in a detergent-dependent manner, which suggests that they too form colloidal aggregates. The colloids localized to preformed fibers and prevented new fiber formation in electron micrographs. They also blocked infection of yeast cells with Sup35 prions, which suggests that colloidal inhibition may be relevant in more biological milieus.


Assuntos
Acetofenonas/farmacologia , Benzopiranos/farmacologia , Clioquinol/farmacologia , Vermelho Congo/farmacologia , Flavanonas/farmacologia , Fenolftaleínas/farmacologia , Ftalimidas/farmacologia , Príons/antagonistas & inibidores , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Saccharomyces cerevisiae/metabolismo , Acetofenonas/química , Animais , Benzopiranos/química , Clioquinol/química , Vermelho Congo/química , Detergentes/química , Flavanonas/química , Camundongos , Microscopia Eletrônica de Transmissão/métodos , Estrutura Molecular , Peso Molecular , Tamanho da Partícula , Fatores de Terminação de Peptídeos , Fenolftaleínas/química , Ftalimidas/química , Príons/química , Príons/metabolismo , Príons/farmacocinética , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/farmacocinética , Sensibilidade e Especificidade , Relação Estrutura-Atividade , Inibidores de beta-Lactamases , beta-Lactamases/química
17.
J Steroid Biochem Mol Biol ; 107(1-2): 120-6, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17629694

RESUMO

The effects of flavonoids and quinones on NADPH- and NADH-dependent 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) activities were examined in cytosolic fractions from the liver and kidney of mice. Judging from the data for the inhibition of NADPH- and NADH-dependent 20alpha-HSD activities by flavonoids and quinones, enzyme catalyzing renal NADPH-dependent 20alpha-HSD activity was found to be distinct from enzyme(s) catalyzing hepatic NADPH- and NADH-dependent 20alpha-HSD activities. Sulfobromophthalein (SBP) had little ability to inhibit hepatic NADPH-dependent 20alpha-HSD activity and bromophenol blue (BPB) exhibited a weak activation against the enzyme activity, whereas SBP and BPB were potent and moderate inhibitors, respectively, of hepatic NADH-dependent 20alpha-HSD activity. Thus, enzyme catalyzing hepatic NADPH-dependent 20alpha-HSD activity appeared to be distinct from enzyme catalyzing hepatic NADH-dependent 20alpha-HSD activity. The data for the pH profiles of hepatic NADPH- and NADH-dependent 20alpha-HSD activities also led us to the conclusion. Based on these results, we propose the possibility that several distinct enzymes catalyze NADPH- and NADH-dependent 20alpha-HSD activities in cytosolic fractions from the liver and kidney of mice.


Assuntos
20-alfa-Hidroxiesteroide Desidrogenase/metabolismo , Benzoquinonas/farmacologia , Flavonoides/farmacologia , Rim/enzimologia , Fígado/enzimologia , Fenolftaleínas/farmacologia , Animais , Catálise , Citosol/enzimologia , Ativação Enzimática , Técnicas In Vitro , Masculino , Camundongos , NADP/metabolismo , NADP/farmacologia
18.
J Med Chem ; 49(25): 7274-7, 2006 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-17149857

RESUMO

Many screening hits inhibit enzymes with steep dose-response curves, which are considered pathological. Three models might explain these curves: multisite binding, an inhibitor phase transition, or stoichiometric inhibition caused by a high enzyme to Kd ratio. Experiments with promiscuous aggregators, for which steep curves are common, suggest that these curves owe to stoichiometric inhibition, which predicts that IC50 should vary linearly with enzyme concentration. Most steep dose-response curves in screening may be due to this effect.


Assuntos
Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Acetofenonas/química , Benzopiranos/química , Coloides , Vermelho Congo/química , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/química , Modelos Biológicos , Fenolftaleínas/química , Ligação Proteica , Inibidores de beta-Lactamases , beta-Lactamases/química
20.
Acta Anaesthesiol Scand ; 50(6): 685-7, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16987362

RESUMO

BACKGROUND: During complicated technical conditions in epidural or spinal anaesthesia, it may be difficult to safely identify the epidural space. The confirmation or exclusion of the presence of cerebrospinal fluid (CSF) during the procedure of regional anaesthesia is helpful to determine the position of the epidural needle in order to proceed with the anaesthetic block. METHODS: We have examined how CSF and different anaesthetic solutions change the colour of yellowish phenol red absorbed in cotton pads. RESULTS: Sodium chloride and local anaesthetic agents do not change the colour of yellowish phenol red. However, CSF immediately changes the colour from yellow to pink or red. Letting a drop of fluid from the epidural/spinal needle fall on to the cleaning pads filled with phenol red will enable the anaesthesiologist to immediately confirm the presence or absence of CSF. The higher pH of CSF relative to that of sodium chloride and local anaesthetic agents explains the different colour reaction. CONCLUSION: This colour reaction quickly identifies the presence of CSF and thus the intradural space during the procedure of spinal or epidural anaesthesia.


Assuntos
Absorventes Higiênicos , Anestesia Epidural , Raquianestesia , Líquido Cefalorraquidiano/química , Desinfecção , Absorção , Clorexidina , Cor , Corantes , Desinfetantes , Humanos , Concentração de Íons de Hidrogênio , Fenolftaleínas/química , Fenolsulfonaftaleína/química
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