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1.
New Microbes New Infect ; 46: 100954, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35251667

RESUMO

Mycoplasma pneumoniae, which causes atypical pneumonia, is a well-established pathogen of the respiratory tract. This bacterium is intrinsically susceptible to fluoroquinolones. But recently, drug-resistant forms of this bacterium have been reported. This study aims to determine the prevalence of this bacterium by ELISA and PCR and MIC to ciprofloxacin. The clinical samples (blood and nasopharyngeal swab) were collected from 100 patients, who were referred to selective hospitals in Tehran with respiratory complaints, were enrolled in 2017. Nasopharyngeal swab sample collections were cultured on PPLO broth and PPLO agar. After culturing and DNA extraction, PCR was performed by specific P1 genes primers. Ciprofloxacin's MIC of Mycoplasma pneumonia isolated was determined by the Micro-broth dilution method. The serum of IgG antibody titers was also measured by ELISA Mycoplasma pneumonia. In this study, out of 100 samples, 12 bacteria were isolated on PPLO agar. Using specific primers, 7 samples of Mycoplasma speciesism-specific were positive for the presence of M.pneumoniae and 2 Ciprofloxacin resistant isolates were evaluated. ELISA results show that IgG titer antibody is existent in 19 samples and 5 samples are intermediate as well. IgG antibody titer average in the whole sample is 27/66 U/ml, but it is in Positive samples by P1 PCR is 45/75 U/ml. This study showed that PCR is a sensitive and reliable method for rapid detection of M. pneumoniae bacteria in respiratory infectious samples, but the results of this method are different from the ELISA method. Additionally, it seems that the resistance to ciprofloxacin is relatively common among M. pneumoniae.

2.
Allergol. immunopatol ; 46(2): 155-159, mar.-abr. 2018. tab
Artigo em Inglês | IBECS | ID: ibc-172174

RESUMO

Background: Atopic dermatitis is an inflammatory skin disease in which both genetic and environmental factors interact to determine the susceptibility and severity of the disease. Objective: The aim of this study was to determine the association between atopic dermatitis and IL-10 and TGF-Beta1 gene polymorphisms. Methods: The allele and genotype frequencies of genes encoding for IL-10 and TGF-Beta1 were investigated in 89 patients with atopic dermatitis in comparison with 138 in the control group using the PCR-SSP method. Results: A significant increase was found in the frequency of the TGF-Beta1 codon 10/C allele among patients (p < 0.001, OR = 6.77), whereas a significant decrease was observed in the frequency of the T allele at the same position (p < 0.001, OR = 0.14). The frequency of the TGF-Beta1 codon 25/G allele in the control group was significantly higher than among patients (p < 0.001, OR = 0.08). A significant positive correlation was seen between CC (p < 0.001, OR = 15.10) and CG (p < 0.001) genotypes and AD at codons 10 and 25, respectively. The most frequent haplotypes among patients was TGF-Beta1 CG which was significantly higher than in the control subjects (50% in patients vs. 39.9% in controls, p = 0.042). A significant increase was found in the frequency of TGF-Beta CC (36% in patients vs. 7.6% in controls, p < 0.001) and TC (14% in patients vs. 0% in controls, p < 0.001) haplotypes among patients compared to controls. By contrast, the TGF-Beta1 TG haplotype was significantly lower in patients than controls (0% in patients vs. 52.5% in controls, p < 0.001). There were no significant differences in the frequency of alleles, genotypes and haplotypes of the IL-10 gene. Conclusions: We found a strong association between the polymorphisms of the TGF-Beta1 gene at codon 10 and codon 25 positions and atopic dermatitis (AU)


No disponible


Assuntos
Humanos , Criança , Polimorfismo de Nucleotídeo Único/imunologia , Dermatite Atópica/imunologia , Interleucina-10/imunologia , Fator de Crescimento Transformador beta1/imunologia , Dermatite Atópica/genética , Predisposição Genética para Doença , Índice de Gravidade de Doença , Técnicas de Genotipagem , Haplótipos/imunologia , Irã (Geográfico)/epidemiologia
3.
Allergol Immunopathol (Madr) ; 46(2): 155-159, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29310944

RESUMO

BACKGROUND: Atopic dermatitis is an inflammatory skin disease in which both genetic and environmental factors interact to determine the susceptibility and severity of the disease. OBJECTIVE: The aim of this study was to determine the association between atopic dermatitis and IL-10 and TGF-ß1 gene polymorphisms. METHODS: The allele and genotype frequencies of genes encoding for IL-10 and TGF-ß1 were investigated in 89 patients with atopic dermatitis in comparison with 138 in the control group using the PCR-SSP method. RESULTS: A significant increase was found in the frequency of the TGF-ß1 codon 10/C allele among patients (p<0.001, OR=6.77), whereas a significant decrease was observed in the frequency of the T allele at the same position (p<0.001, OR=0.14). The frequency of the TGF-ß1 codon 25/G allele in the control group was significantly higher than among patients (p<0.001, OR=0.08). A significant positive correlation was seen between CC (p<0.001, OR=15.10) and CG (p<0.001) genotypes and AD at codons 10 and 25, respectively. The most frequent haplotypes among patients was TGF-ß1 CG which was significantly higher than in the control subjects (50% in patients vs. 39.9% in controls, p=0.042). A significant increase was found in the frequency of TGF-ß CC (36% in patients vs. 7.6% in controls, p<0.001) and TC (14% in patients vs. 0% in controls, p<0.001) haplotypes among patients compared to controls. By contrast, the TGF-ß1 TG haplotype was significantly lower in patients than controls (0% in patients vs. 52.5% in controls, p<0.001). There were no significant differences in the frequency of alleles, genotypes and haplotypes of the IL-10 gene. CONCLUSIONS: We found a strong association between the polymorphisms of the TGF-ß1 gene at codon 10 and codon 25 positions and atopic dermatitis.


Assuntos
Dermatite Atópica/genética , Interleucina-10/genética , Fator de Crescimento Transformador beta1/genética , Criança , Pré-Escolar , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Lactente , Irã (Geográfico) , Masculino , Polimorfismo de Nucleotídeo Único
4.
Allergol. immunopatol ; 42(3): 212-215, mayo-jun. 2014. tab
Artigo em Inglês | IBECS | ID: ibc-122680

RESUMO

BACKGROUND: Interleukin-1 (IL-1) seems to have an important role in early reactions towards microbes, while its genetic variability could affect this role in atopic patients who have a distressed immunity towards dermatological infections. METHODS: Eighty-nine patients with atopic dermatitis (AD), who were referred to a main referral paediatric hospital, were enrolled in this study. Single nucleotide polymorphisms (SNP) of the following IL-1 cluster genes were assessed in this group of patients: IL-1α −889, IL-1β −511, IL-1β +3962, IL-1R Pst-I 1970, and IL-1RA Mspa-I 11100. The results were compared with a group of 140 healthy subjects from the same region. RESULTS: Fourteen percent of the controls had TT homozygous genotype in IL-1R at position Pst-I 1970, while only 2% of the patients with AD had this genotype (p = 0.005, OR: 0.14, 95%CI: 0.02-0.64). The CC homozygous genotype was the most common genotype in IL-1α position −889 and IL-1β at position +3962 in both groups of patients with AD and the controls, while the TC heterozygous genotype was the most common genotype in IL-1β at position −511 and IL-1R at position Pst-I 1970, with no significant difference between the two groups. CONCLUSIONS: This study showed a significant negative association in the IL-1R Mspa-I 11100 TT homozygous genotype in the patients with AD


No disponible


Assuntos
Humanos , Dermatite Atópica/imunologia , Interleucina-1/imunologia , Polimorfismo de Nucleotídeo Único/imunologia , Citocinas/análise , Frequência do Gene
5.
Allergol Immunopathol (Madr) ; 42(3): 212-5, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23253688

RESUMO

BACKGROUND: Interleukin-1 (IL-1) seems to have an important role in early reactions towards microbes, while its genetic variability could affect this role in atopic patients who have a distressed immunity towards dermatological infections. METHODS: Eighty-nine patients with atopic dermatitis (AD), who were referred to a main referral paediatric hospital, were enrolled in this study. Single nucleotide polymorphisms (SNP) of the following IL-1 cluster genes were assessed in this group of patients: IL-1α -889, IL-1ß -511, IL-1ß +3962, IL-1R Pst-I 1970, and IL-1RA Mspa-I 11100. The results were compared with a group of 140 healthy subjects from the same region. RESULTS: Fourteen percent of the controls had TT homozygous genotype in IL-1R at position Pst-I 1970, while only 2% of the patients with AD had this genotype (p=0.005, OR: 0.14, 95%CI: 0.02-0.64). The CC homozygous genotype was the most common genotype in IL-1α position -889 and IL-1ß at position +3962 in both groups of patients with AD and the controls, while the TC heterozygous genotype was the most common genotype in IL-1ß at position -511 and IL-1R at position Pst-I 1970, with no significant difference between the two groups. CONCLUSIONS: This study showed a significant negative association in the IL-1R Mspa-I 11100 TT homozygous genotype in the patients with AD.


Assuntos
Dermatite Atópica/genética , Dermatite Atópica/imunologia , Proteína Antagonista do Receptor de Interleucina 1/genética , Interleucina-1alfa/genética , Interleucina-1beta/genética , Criança , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Irã (Geográfico) , Polimorfismo de Nucleotídeo Único
6.
Artigo em Inglês | MEDLINE | ID: mdl-23654074

RESUMO

BACKGROUND: Atopic dermatitis (AD) is a chronic skin disorder of unknown origin that usually manifests for the first time in early infancy. Different types of genetic predisposition and environmental factors seem to be associated with the disease. METHODS: This study was performed to evaluate the frequency of alleles, genotypes, and haplotypes of interleukin (IL) 6 single-nucleotide polymorphisms (SNPs) at positions -174 and nt565 in 89 Iranian children with AD and 139 healthy controls. RESULTS: The G allele was significantly more frequent at position -174 in IL6 in atopic patients than in the healthy controls (P < .001; OR, 2.82). Genotype GG was found at the same position in 71% of the patients; this frequency was significantly higher than the frequency of 30% recorded in the controls (P < .001; OR, 5.60). The GG haplotype of IL6 (-174, nt565) was significantly more frequent in the atopic patients than in the healthy controls (P < .001; OR, 2.99). CONCLUSIONS: A significant increase in the frequency of the G allele and GG genotype at position -174 of IL6 was found in patients with AD, thus suggesting that production of this cytokine is greater in atopic patients.


Assuntos
Dermatite Atópica/genética , Haplótipos , Interleucina-6/genética , Adolescente , Alelos , Estudos de Casos e Controles , Criança , Pré-Escolar , Cromossomos Humanos Par 7 , Dermatite Atópica/imunologia , Dermatite Atópica/patologia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Técnicas de Genotipagem , Humanos , Imunoglobulina E/imunologia , Lactente , Interleucina-6/imunologia , Masculino , Fenótipo , Polimorfismo de Nucleotídeo Único
7.
J. investig. allergol. clin. immunol ; 23(2): 89-93, mar.-abr. 2013. tab
Artigo em Inglês | IBECS | ID: ibc-111784

RESUMO

Antecedentes: La dermatitis atópica (DA) es una alteración crónica de la piel de origen desconocido, que habitualmente comienza en la infancia. Diferentes predisposiciones y factores ambientales se asocian a esta enfermedad. Métodos: Este estudio se realizó en 89 niños iraníes con DA para evaluar la frecuencia de alelos, genotipos y haplotipos de polimorfismos genéticos simples (SNPs) de la IL6 en las posiciones 174 y nt565 en comparación con 139 controles sanos. Resultados: Observamos un incremento significativo del alelo G de la IL6 en la posición –174 en los pacientes con DA comparado con el grupo control (p<0.001, OR=2.82). El genotipo GG de la misma posición se encontró en el 71% de los pacientes frente al 30% en los controles (p<0.001, OR=5.60). También se observa un incremento significativo en el haplotipo GG de la IL6 (-174, nt565) en los pacientes con DA comparados con los controles sanos (p<0.001, OR=2.99). Conclusiones: En conclusión observamos un aumento significativo del alelo Gallele y del genotipo GG en la posición -174 de la IL6 en pacientes con DA, lo que podría sugerir un aumento de la producción de esta citocina en los pacientes con DA (AU)


Background: Atopic dermatitis (AD) is a chronic skin disorder of unknown origin that usually manifests for the first time in early infancy. Different types of genetic predisposition and environmental factors seem to be associated with the disease. Methods: This study was performed to evaluate the frequency of alleles, genotypes, and haplotypes of interleukin (IL) 6 single-nucleotide polymorphisms (SNPs) at positions –174 and nt565 in 89 Iranian children with AD and 139 healthy controls. Results: The G allele was significantly more frequent at position –174 in IL6 in atopic patients than in the healthy controls (P<.001; OR, 2.82). Genotype GG was found at the same position in 71% of the patients; this frequency was significantly higher than the frequency of 30% recorded in the controls (P<.001; OR, 5.60). The GG haplotype of IL6 (–174, nt565) was significantly more frequent in the atopic patients than in the healthy controls (P<.001; OR, 2.99). Conclusions: A significant increase in the frequency of the G allele and GG genotype at position –174 of IL6 was found in patients with AD, thus suggesting that production of this cytokine is greater in atopic patients (AU)


Assuntos
Humanos , Dermatite Atópica/genética , Interleucina-6/análise , Técnicas de Genotipagem/métodos , Alelos , Frequência do Gene , Citocinas/análise , Polimorfismo Genético/genética , Haplótipos/genética , Genótipo
8.
Electrophoresis ; 22(17): 3765-70, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11699916

RESUMO

We demonstrate the use of simple extraction procedures to separate nuclear and cytoplasmic material from cell extracts, which have been scrape-loaded with a 2-O-methyl phosphorothioate antisense oligonucleotide. Separation and quantitation of the fluorescein-labeled antisense and the flourescein isothiocyanate (FITC)-dextran (molecular weight 40000) as an internal standard is done using capillary electrophoresis coupled with laser-induced fluorescence detection (CE-LIF). The bulky FITC-dextran is unable to penetrate the nuclear membrane thereby making it a quantitative indicator of any overlap between the nuclear and cytoplasmic materials during separation of the two phases. Using this procedure, the fluorescein-labeled phosphorothioate oligomer was quantitated at 4.1 x 10(-13) and 3.4x 10(-14) mol antisense/microg-total cellular protein in the nuclear and cytoplasmic extracts respectively following scrape-load delivery of the phosphorothioate to a batch of confluent HeLa cells at a concentration of 0.5 microM (5 x 10(-10) total moles of oligomer). Additionally, gene expression was monitored by measurement of the luciferase reporter protein activity. Scrape-load, spontaneous and liposomal delivery were investigated and compared for subcellular distribution of the oligomer and subsequent gene expression.


Assuntos
Núcleo Celular/ultraestrutura , DNA Antissenso/análise , Fracionamento Celular/métodos , Citoplasma/ultraestrutura , Dextranos , Eletroforese Capilar/métodos , Fluoresceína-5-Isotiocianato/análogos & derivados , Células HeLa , Humanos , Lasers , Espectrometria de Fluorescência/métodos , Tionucleotídeos
9.
Anal Biochem ; 293(1): 1-7, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11373071

RESUMO

Antisense oligonucleotides have shown great promise over the past several years as viable drugs to combat various forms of cancer and viral diseases. However, quantitative detection to monitor cellular association is difficult using conventional methods such as radiolabeling of the oligonucleotide or fluorescence confocal microscopy. In this paper quantitation of intracellular concentration of the morpholino oligonucleotide is investigated using capillary electrophoresis coupled with laser-induced fluorescence detection (CE-LIF). HeLa cells, which produce luciferase as the antisense oligomer enters the cell, were scrape-loaded with varying concentrations of the morpholino antisense. The intracellular antisense concentration measured by CE-LIF was found to correlate with those obtained with the cellular functional assay based on upregulation of luciferase. Intracellular concentrations of the antisense were found to be in the range of 6 to 29 nmol/g total cell protein, depending on the amounts that were scrape-loaded. To our best knowledge, this is the first reported quantitative correlation between delivered antisense concentration in a cell extract and the subsequent antisense upregulation of gene expression.


Assuntos
Eletroforese Capilar/métodos , Células HeLa/metabolismo , Luciferases/genética , Oligonucleotídeos Antissenso/análise , Preparações Farmacêuticas/análise , Membrana Celular/fisiologia , Sistemas de Liberação de Medicamentos , Fluoresceínas , Fluorescência , Corantes Fluorescentes , Expressão Gênica , Humanos , Lasers , Fluidez de Membrana , Microscopia Confocal , Regulação para Cima
10.
Anal Chem ; 73(24): 6057-62, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11791580

RESUMO

Like other chromatographic techniques, retention factor, k, in micellar electrokinetic chromatography (MEKC) is directly related to solute partition coefficient and the chromatographic phase ratio as k = Kphi. Unlike conventional chromatography, however, the phase ratio and partition coefficient can be accurately determined in MEKC for a given micellar pseudostationary phase. This means that retention factor in MEKC can be predicted for solutes with known micelle-water partition coefficients without any prior experimentation. In this paper, the use of this simple relationship for prediction of retention behavior in MEKC is examined. The principle of additivity of functional group contribution to partitioning is used to calculate the micelle-water partition coefficient, Kmw, for SDS micellar pseudophase. The micellar substituent constants for 20 functional groups (training set) were determined. Using these substituent constants, the Kmw and retention factors for a group of 80 neutral solutes (test set) were predicted. The linear plot of predicted versus observed log k had an R2 = 0.97 and a slope equal to 1.01. It is shown that the retention times (thus chromatograms) in MEKC can be predicted from the calculated retention factors after only one initial experiment to measure teo and t(mc) under the experimental conditions.

11.
J Chromatogr A ; 886(1-2): 245-57, 2000 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-10950292

RESUMO

Characterization of retention and selectivity differences between surfactants in micellar electrokinetic chromatography (MEKC) using linear solvation energy relationships (LSERs) has been given a significant amount of attention in the last four years. This report evaluates the validity of using the two LSER models that have been used to fit retention in MEKC in the literature. The results and the fit of the revised model and parameters developed by Abraham and coworkers are compared to the original model developed by Kamlet, Taft, and coworkers. LSERs can generally only be used as a comparative tool to describe the selectivity differences between surfactant systems used in MEKC. With this in mind, it was determined that the results of both models essentially provide the same information about these differences. However, the revised model and parameters have been found to yield a statistically better fit of the MEKC retention data as well as providing more chemically sound LSER coefficients.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , Modelos Químicos
12.
J Chromatogr A ; 888(1-2): 229-40, 2000 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-10949489

RESUMO

Linear solvation energy relationships and free energy of transfer data were used to evaluate the influence of the surfactant counter-ion on selectivity in micellar electrokinetic chromatography. It was determined that selectivity differences are dependent on the valency of the counter-ion but not the type of counter-ion. Monovalent surfactants, sodium dodecyl sulfate (SDS) and lithium dodecyl sulfate, have nearly identical selectivity behavior. The divalent surfactants, magnesium didodecyl sulfate and copper didodecyl sulfate also show very similar behavior. However, when the divalent counter-ion species is compared to SDS under similar conditions, significant differences are observed. Most notably, the utilization of divalent counter-ion species of dodecyl sulfate surfactants causes the micelles to become more hydrophobic and a weaker hydrogen bond donating pseudo-stationary phases. It is believed that the divalent counter-ions reduce the electrostatic repulsion between the surfactant head groups and therefore, increase the chain packing of the monomers in the micelle aggregates. This reduces the degree of hydration of the micellar palisade layer leading to a decreased ability of the micelle to participate in polar/polarizable and hydrogen bonding interactions with solute molecules.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/instrumentação , Tensoativos/química , Sensibilidade e Especificidade , Termodinâmica
13.
J Chromatogr A ; 888(1-2): 251-66, 2000 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-10949491

RESUMO

Nonaqueous capillary electrophoresis (NACE) is a chemical separation technique that has grown in popularity over the past few years. In this report, we focus on the combination of heteroconjugation and deprotonation in the NACE separation of phenols using acetonitrile (ACN) as the buffer solvent. By preparing various dilute buffers consisting of carboxylic acids and tetrabutylammonium hydroxide in ACN, selectivity may be manipulated based on a solute's dissociation constant as well as its ability to form heterogeneous ions with the buffer components. ACN's low viscosity, coupled with its ability to allow for heteroconjugation, often leads to rapid and efficient separations that are not possible in aqueous media. In this report, equations are derived showing the dependence of mobility on various factors, including the pKa of the analyte, the pH and concentration of the buffer, and the analyte-buffer heteroconjugation constant (Kf). The validity of these equations is tested as several nitrophenols are separated at different pH values and concentrations. Using nonlinear regression, the Kf values for the heteroconjugate formation between the nitrophenols and several carboxylate anions are calculated. Also presented in this report are the NACE separations of the 19 chlorophenol congeners and the 11 priority pollutant phenols (used in US Environmental Protection Agency methods 604, 625/1625 and 8270B).


Assuntos
Acetonitrilas/química , Ácidos/isolamento & purificação , Eletroforese Capilar/métodos , Soluções Tampão , Poluentes Ambientais/isolamento & purificação , Prótons
14.
Anal Biochem ; 284(2): 334-41, 2000 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-10964417

RESUMO

The fusion of the human immunodeficiency virus (HIV) with the target cell was assisted by the interaction between the viral envelope glycoprotein HIV-1 gp120 and a chemokine receptor. Studies have shown that the efficiency of the binding depends on the presence of the V3 loop of the gp120 which is known to interact with polyanions, such as phosphorothioate oligodeoxynucleotides (Sd, potential anti-HIV drugs). In this study, capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) was used to systematically evaluate binding between Sd and HIV-1 gp120. A 25-mer fluorescently tagged phosphorothioate oligodeoxynucleotide (GEM) was employed as a probe to study this interaction. The dissociation constant (K(d)) between GEM and gp120 was determined to be 0.98 nM by Scatchard analysis. The competition constants (K(c)) of a set of Sd that compete with GEM for binding to gp120 were also determined. The results showed that the interaction had a strong dependence on the sulfur phosphorothioate backbone. Chain length and the sequence of Sd also affect the ability of binding to gp120. The ability to study the protein-drug binding in the solution with minimal sample consumption makes CE-LIF very attractive for biological studies.


Assuntos
Fármacos Anti-HIV/metabolismo , Eletroforese Capilar/métodos , Proteína gp120 do Envelope de HIV/metabolismo , Sequência de Bases , Ligação Competitiva , Primers do DNA , Estudos de Avaliação como Assunto , HIV-1/metabolismo , Lasers , Ligação Proteica , Espectrometria de Fluorescência
15.
Electrophoresis ; 21(12): 2390-6, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10939450

RESUMO

The selectivity differences between six anionic surfactants in micellar electrokinetic chromatography (MEKC) are presented and the structural influence of the surfactant head-group is investigated. It was determined that the surfactant structure can have a significant impact on retention and selectivity. Linear solvation energy relationships (LSERs) are used to study the role of solute size, polarity/polarizability, and hydrogen bonding characteristics in determining retention and selectivity. While both the solute size and hydrogen bond accepting ability were found to be the most important factors in solute retention, the hydrogen bonding characteristic of the solutes have the largest influence on selectivity differences between surfactants.


Assuntos
Amidas/química , Cromatografia Capilar Eletrocinética Micelar/métodos , Ésteres/química , Tensoativos/química , Transferência de Energia , Taurina/análogos & derivados , Taurina/química
16.
J Chromatogr A ; 875(1-2): 277-93, 2000 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-10839148

RESUMO

This paper reviews the recent advances in enantioseparations by nonaqueous capillary electrophoresis (NACE) and the effect of organic solvents on mobility of enantiomers, separation selectivity and resolution. In general, the enantioseparation systems in NACE are similar to those of aqueous capillary electrophoresis (CE) except pure organic solvents are used. The influence of important parameters such as concentration and type of chiral selectors, apparent pH, ionic strength, temperature, and control of electroosmotic flow is discussed. In addition, the reported applications of NACE separations of racemates are presented.


Assuntos
Eletroforese Capilar/métodos , Estereoisomerismo , Água
17.
J Am Soc Mass Spectrom ; 11(4): 273-82, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10757163

RESUMO

Consecutive enzymatic reactions of analytes which are affinity bound to immobilized metal ion beads with subsequent direct analysis of the products by matrix-assisted laser desorption/ionization mass spectrometry have been used for detecting phosphorylation sites. The usefulness of this method was demonstrated by analyzing two commercially available phosphoproteins, beta-casein and alpha-casein, as well as one phosphopeptide from a kinase reaction mixture. Agarose loaded with either Fe3+ or Ga3+ was used to isolate phosphopeptides from the protein digest. Results from using either metal ion were complementary. Less overall suppression effect was achieved when Ga3+-loaded agarose was used to isolate phosphopeptides. The selectivity for monophosphorylated peptides, however, was better with Fe3+-loaded agarose. This technique is easy to use and has the ability to analyze extremely complicated phosphopeptide mixtures. Moreover, it eliminates the need for prior high-performance liquid chromatography separation or radiolabeling, thus greatly simplifying the sample preparation.


Assuntos
Metais/química , Fosfopeptídeos/análise , Sequência de Aminoácidos , Carboxipeptidases , Caseínas/química , Catepsina A , Cromatografia de Afinidade , Gálio , Hidrólise , Indicadores e Reagentes , Ferro , Dados de Sequência Molecular , Fosfopeptídeos/isolamento & purificação , Fosforilação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Tripsina
18.
Anal Chem ; 72(6): 1228-35, 2000 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10740864

RESUMO

Linear Solvation Energy Relationships (LSERs) are used to explain the congeneric behavior observed when using Micellar Electrokinetic Chromatography (MEKC) to estimate the octanol-water partition coefficient scale of solute hydrophobicity. Such studies provide useful insights about the nature of solute interactions that are responsible for the sources of congeneric relationships between MEKC retention and log Po/w. It was determined that solute dipolarity/polarizability and hydrogen-bonding character play the most important roles in the congeneric behavior observed for many surfactant systems. The individual dipolarity/polarizability and hydrogen-bonding contributions to the free energy of transfer were also investigated.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , Octanóis/química , Água/química , Ligação de Hidrogênio
19.
J Chromatogr A ; 868(2): 277-84, 2000 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-10701677

RESUMO

In order to correlate/predict electrophoretic mobility data in the mixture of water+organic modifier four equations have been presented and examined. The experimental mobilities of five analytes were determined in a water-methanol mixture. These data have been used to assess the accuracy and predictability of the models. Also, some previously published mobility data in water-organic modifier mixtures has been employed for further evaluation of the models. The models produced accurate results and the means of percentage deviations were in the range of 0.66-1.30.


Assuntos
Eletroforese Capilar/métodos , Modelos Químicos , Compostos Orgânicos/química , Água/química
20.
J Chromatogr A ; 859(2): 203-19, 1999 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-10574213

RESUMO

Nonaqueous capillary electrophoresis (NACE) is a relatively new area with several advantages that include enhanced efficiency and improved detection sensitivity. The goal of this study was to investigate the influence of NACE compared to aqueous CE on the separation efficiency of oligosaccharides. The applied voltage and buffer concentration were optimized for the aqueous and nonaqueous buffer media to minimize the band broadening effects of Joule heating and electrophoretic dispersion. At the optimized conditions a 1.5-fold enhancement in efficiency was obtained with the nonaqueous buffer medium.


Assuntos
Eletroforese Capilar/métodos , Soluções Tampão , Formamidas , Indicadores e Reagentes , Oligossacarídeos/isolamento & purificação , Controle de Qualidade , Sensibilidade e Especificidade , Água
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