Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Qual Life Res ; 33(3): 745-752, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38064016

RESUMO

OBJECTIVE: This study aimed to translate and culturally adapt the standardized outcomes in nephrology-hemodialysis fatigue (SONG-HD fatigue) scale and to assess the psychometric properties of the Chinese version of the SONG-HD fatigue (C-SONG-HD fatigue) scale. METHODS: Forward and back translations were used to translate the SONG-HD fatigue scale into Chinese. We used the C-SONG-HD fatigue scale to survey Chinese patients undergoing hemodialysis (HD) in China. We examined the distribution of responses and floor and ceiling effects. Cronbach's alpha and McDonald's omega coefficient, intraclass coefficients, and Spearman correlations were used to assess internal consistency reliability, test-retest reliability, and convergent validity, respectively. Responsiveness was also evaluated. RESULTS: In total, 489 participants across southeast China, northwest China, and central China completed the study. The C-SONG-HD fatigue scale had good internal consistency (Cronbach's alpha coefficient 0.861, omega coefficient 0.916), test-retest reliability (intraclass correlation coefficient 0.695), and convergent validity (Spearman correlation 0.691). The analysis of all first-time HD patients did not show notable responsiveness, and only patients with temporary vascular access had good responsiveness with an effect size (ES) of 0.54, a standardized response mean (SRM) of 0.85, and a standard error of measurement (SEM) of 0.77. CONCLUSION: The Chinese version of the SONG-HD fatigue scale showed satisfactory reliability and validity in patients undergoing hemodialysis (HD) in China. It could be used as a tool to measure the fatigue of Chinese HD patients.


Assuntos
Nefrologia , Humanos , Reprodutibilidade dos Testes , Qualidade de Vida/psicologia , Inquéritos e Questionários , Diálise Renal , Fadiga/terapia , China , Psicometria , Traduções
2.
Gene ; 698: 150-156, 2019 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-30851423

RESUMO

OBJECTIVE: Investigating the expression of the lnc RNAs screened above between normal and insulin resistant 3T3-L1 adipocytes. Addressing the mechanism underlying the regulation of inflammation response by lnc TINCR. METHODS: 3T3-L1 preadipocytes were induced to differentiate into mature adipocytes. Oil red O staining was used to find the fat droplets in mature adipocytes. Mature adipocytes were randomized to normal control group and Tri-DAP (NOD1 ligand) group. After the establishment of insulin resistance model, we used deep RNA sequencing(RNA-Seq) to identify lncRNAs that are regulated during NODI activation in mouse adipocytes. Real-time PCR was used to analyze the expression of lnc TINCR, proinflammatory IL-6, TNF-α, Cxcl1 and RIPK2 in the presence or absence of Tri-DAP(10 µg/ml). We employed siRNA against lnc TINCR to confirm its effects in inflammatory response. RESULTS: Deep RNA sequencing identified 81 lncRNAs and 167 coding genes that were significantly up-related while 78 lncRNAs and 82 coding genes that were significantly down-related greater than twofold during NOD1 activation in adipocytes. We discovered that lnc TINCR, termed lnc TINCR(Tri-DAP-inducible non-protein coding RNA) is greatly upregulated in Tri-DAP activated adipocytes. Moreover knockdown of lnc TINCR dampens the proinflammatory response (P < 0.05; in adipocytes). CONCLUSIONS: lnc TINCR is a positive regulator of inflammation-induced insulin resistance presumably via activation of NOD1 signaling pathways.


Assuntos
Inflamação/genética , Proteína Adaptadora de Sinalização NOD1/genética , RNA Longo não Codificante/genética , Células 3T3-L1 , Adipócitos/metabolismo , Animais , Diferenciação Celular , Insulina/metabolismo , Resistência à Insulina/genética , Camundongos , Proteína Adaptadora de Sinalização NOD1/metabolismo , Fosforilação , RNA Longo não Codificante/metabolismo , RNA Mensageiro , Análise de Sequência de RNA/métodos , Transdução de Sinais
3.
Talanta ; 185: 42-52, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29759222

RESUMO

N-Methoxycarbonyl chitosan was prepared by selectively modifying the amino group at the 2-position of chitosan with methyl chloroformate, which was further functionalized with p-methylbenzylamine to produce chitosan (p-methylbenzylurea). Then, the hydroxyl groups at the 3- and 6-positions of the glucose skeleton were modified with various phenyl isocyanates, affording a series of chitosan 3,6-bis(arylcarbamate)-2-(p-methylbenzylurea)s, which were characterized and proposed as chiral selectors for enantiomer separation. Nineteen racemates, most of which are drugs or intermediates for drugs, were selected as the model analytes to evaluate the enantioseparation performance. The structure-performance relationship of the chiral selectors was investigated in detail. It was found that the methyl-substituted chiral selectors possessed more preferable enantioseparation performance compared with the chloro-substituted ones, and the chiral selectors containing a methyl substituent at the 4-position of the benzene ring showed the best chiral recognition and separation ability with 17 racemates being recognized and 13 racemates being baseline separated. The prepared chiral separation materials derived from these chiral selectors exhibited favorable solvent tolerance towards ethyl acetate, acetone, chloroform and a low proportion of tetrahydrofuran in normal phase. To sum up, this work provided a useful reference for the design and preparation of high-performance chiral separation materials for efficient enantiomer separation.


Assuntos
Quitosana/análogos & derivados , Quitosana/química , Ureia/análogos & derivados , Ureia/química , Quitosana/isolamento & purificação , Estrutura Molecular , Estereoisomerismo , Ureia/isolamento & purificação
4.
J Chromatogr A ; 1532: 112-123, 2018 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-29246422

RESUMO

Chitosan bis(phenylcarbamate)-(N-cyclohexylformamide)s and chitosan bis(phenylcarbamate)-(N-hexanamide)s were synthesized as chiral selectors for enantiomeric separation. Since two types of substituents with different structures were, respectively, introduced onto the 2-position and the 3-/6-positions of the glucose skeleton in the chitosans through a "heterogeneous" modification pathway, the enantioseparation performances of the chiral selectors could be improved. Influence of the type and position of the substituents on chiral recognition and enantioseparation abilities was studied in detail, and the structural dependence on enantioseparation performance was particularly demonstrated. It was found that methyl- and chloro-substituted chitosan bis(phenylcarbamate)-(N-hexanamide)s possessed comparable enantioseparation performances, whereas chloro-substituted chitosan bis(phenylcarbamate)-(N-cyclohexylformamide)s exhibited much more powerful chiral recognition and enantioseparation abilities than the methyl-substituted ones. Among all the prepared chiral selectors, those with the combination of the cyclohexyl group at the 2-position of the glucose skeleton in the chitosan derivatives and the chlorophenyl group at the 3-/6-positions seemed to be more preferable for enantiomeric separation. As a result, the chitosan bis(3,4-dichlorophenylcarbamate)-(N-cyclohexylformamide) possessed the best enantioseparation performance. The solvent tolerability of the prepared chiral selectors was also investigated in the present study. Compared with the classical coated-type chiral separation materials derived from cellulose/amylose derivatives, the N-cyclohexylcarbonyl and N-hexanoyl chitosans based chiral stationary phases were observed to possess more favorable solvent tolerability, thus possibly widening their applications for various practical enantioseparations.


Assuntos
Quitosana/química , Hexanos/química , Cromatografia Líquida de Alta Pressão , Espectroscopia de Prótons por Ressonância Magnética , Solventes , Estereoisomerismo
5.
Anal Chim Acta ; 985: 183-193, 2017 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-28864189

RESUMO

In this study, two series of chitosan 3,6-bis(arylcarbamate)-2-(isobutylurea)s and corresponding coated-type chiral stationary phases (CSPs) were prepared from two kinds of chitosans with different molecular weights. Most of the prepared CSPs demonstrated better enantioseparation performance than the homemade CSP of cellulose tris(3,5-dimethylphenylcarbamate). The CSPs of chitosan 3,6-bis(4-methylphenylcarbamate)-2-(isobutylurea) with higher molecular weight and chitosan 3,6-bis(3-chloro-4-methylphenylcarbamate)-2-(isobutylurea) with lower molecular weight possessed outstanding chiral recognition abilities which were at least as good as that of the commercialized CSP of Chiralcel OD-H towards the tested chiral analytes. Except for the two CSPs derived from chitosan 3,6-bis(4-methylphenylcarbamate)-2-(isobutylurea)s, the CSPs (the first class) with the chiral selectors of lower molecular weight provided better enantioseparations than the ones (the second class) with the chiral selectors of higher molecular weight. On the other hand, the chiral selectors of the first class CSPs showed higher swelling capacities in organic solvents than the ones of the second class. All prepared CSPs could be analyzed with a wider range of mobile phases, in which some "unusual organic solvents" such as ethyl acetate, chloroform and THF etc. could be used as additives. According to separation performance and tolerance against organic solvents, we concluded that the chitosan derivatives with branched-chain alkyl urea at 2-C of glucosamine residue were preferable to be used as chiral selectors for enantiomeric separation.

6.
Carbohydr Polym ; 168: 301-309, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28457453

RESUMO

The goal of present study was to investigate the structural dependence of chitosan derivatives on enantioseparation and mobile phase tolerance of the corresponding chiral packing materials for liquid chromatography. Hence, a series of chitosan bis(arylcarbamate)-(n-pentyl amide)s and the related chiral stationary phases (CSPs) were prepared from chitosans with different molecular weights. Because of the H-bond formed via CH3-π interaction, the CSP bearing methyl substituent exhibited high tolerance than the ones bearing dichloro substituents. The CSP derived from the chitosan bis(3,5-dichlorophenylcarbamate)-(n-pentyl amide) with a higher molecular weight possessed high tolerance to mobile phases, whereas the enantioseparation capability of this CSP was not as good as that of the one prepared from the chitosan derivative with a lower molecular weight. Therefore, enantioseparation capability and mobile phase tolerance have to be counterbalanced in designing chiral selectors for the CSPs derived from chitosan bis(arylcarbamate)-(amide)s.

7.
Carbohydr Polym ; 156: 481-489, 2017 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-27842849

RESUMO

Enantioseparation plays an important role for many fields and for pharmaceutical industry in particular. Chiral stationary phase (CSP) is the core of chiral liquid chromatography that effectively implements enantioseparation. In order to develop coated type CSPs with excellent enantioseparation capability and high tolerance against mobile phases, in this work, a series of chitosan bis(3,5-dimethylphenylcarbamate)-(alkyl urea)s were synthesized, which were coated on 3-aminopropyl silica gel to afford new CSPs. Owing to strong hydrogen bonds formed among the synthesized derivatives, the supra-structure of the derivatives should be highly ordered. Hence, these CSPs could provide excellent separation capability and could tolerate common organic solvents that are usually prohibited for coated type CSPs of cellulose and amylose derivatives. Therefore the newly prepared CSPs exhibited promising prospects for enantioseparation of chiral compounds.

8.
J Chromatogr A ; 1476: 53-62, 2016 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-27863711

RESUMO

In order to comprehensively understand the influence of coordination of the substituent at 2-position with those at 3- and 6-positions on the properties of chitosan derivatives, a series of chitosan 3,6-bis(arylcarbamate)-2-(amide)s (CACAs) and the related chiral stationary phases (CSPs) were prepared and reported in the present study. Specifically, chitosan was N-acylated with carboxylic acid anhydrides, and then further derivatized with various aryl isocyanates to afford CACAs, from which a class of coated-type CSPs were prepared. When the substituent introduced on the acyl group at 2-position and those on the phenyl group of the carbamates at 3- and 6-positions were fittingly combined, these prepared CACAs based CSPs would exhibit powerful chiral recognition ability, further resulting in a class of promising chiral separation materials with excellent enantioseparation performance. Meanwhile, these newly developed materials with suitable molecular weight also bear a high tolerability towards organic solvents, even including pure tetrahydrofuran, thus broadening their application in enantiomeric separation.


Assuntos
Quitosana/análogos & derivados , Cromatografia Líquida de Alta Pressão , Acilação , Quitosana/química , Furanos/química , Isocianatos/química , Solventes , Estereoisomerismo
9.
Molecules ; 21(11)2016 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-27845761

RESUMO

The goal of the present work was to study the influence of the swelling of chitosan derivatives on the enantioseparation and the separation performance recovery of chiral stationary phases (CSPs) based on these derivatives. Therefore, six chitosan bis(phenylcarbamate)-(n-octyl urea)s were synthesized, which were coated on macroporous 3-aminopropyl silica gel affording new CSPs. Most of the CSPs demonstrated strong enantioseparation capability for the tested chiral compounds. The swelling capacity of the chitosan bis(phenylcarbamate)-(n-octyl urea)s in ethyl acetate, acetone and tetrahydrofuran (THF) was evaluated. Among the chitosan derivatives, the chitosan bis(3,5-dichlorophenylcarbamate)-(n-octyl urea) polymer showed the highest swelling capacity in ethyl acetate and THF. The polymer-based CSPs could be utilized with pure ethyl acetate and a normal phase containing 70% THF, but was damaged by pure THF. On the other hand, the separation performance of the damaged CSP could be recovered after it was allowed to stand for a period of time. The observations are important for the development and application of polysaccharide derivative-based CSPs.


Assuntos
Quitosana/síntese química , Fenilcarbamatos/química , Ureia/química , Quitosana/química , Cromatografia Líquida de Alta Pressão/métodos , Estrutura Molecular , Estereoisomerismo
10.
J Chromatogr A ; 1440: 112-122, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26931425

RESUMO

A series of chitosan bis(methylphenylcarbamate)-(isobutyrylamide) derivatives were synthesized by carbamylating chitosan isobutyrylamide with different methylphenyl isocyanates. Then the prepared chitosan derivatives were coated onto 3-aminopropyl silica particles, resulting in a series of new chiral stationary phases (CSPs) for high-performance liquid chromatography. It was observed that the chiral recognition abilities of these coated-type CSPs depended very much on the substituents on the phenyl moieties of the chitosan derivatives, the eluent composition, as well as the structure of racemates. As a typical example, the eluent tolerance of the prepared CSP with the best enantioseparation ability was investigated in detail, and the results revealed that the CSP exhibited extraordinary solvent tolerance and could still work without significant loss in enantioseparation capability after being flushed with chloroform (100%), ethyl acetate (100%) and even THF/n-hexane (70/30, v/v), while the traditional coated-type CSPs based on the cellulose and amylose derivatives, such as cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC) and amylose tris(3,5-dimethylphenylcarbamate) (ADMPC), might be dissolved or highly swollen in these eluents. Therefore, the application of the resultant CSPs could address the problem of the dissolution and high swelling of traditional coated-type CSPs in some unusual eluents, broadening the possibility of eluent choice. In addition, a comparison of the prepared CSPs with the well known CDMPC- and ADMPC- based CSPs concerning the chiral recognition ability was also made. Separation performances achieved on the as-prepared CSPs in different eluents were found to be even superior to CDMPC- and ADMPC-based CSPs for the tested chiral compounds. In summary, we could safely draw the conclusion that the CSPs derived from chitosan isobutyrylamide derivatives were capable of excellent chiral recognition ability, and meanwhile possessed satisfactory eluent tolerance in a wider range of solvents.


Assuntos
Amilose/análogos & derivados , Quitosana/química , Cromatografia Líquida de Alta Pressão/métodos , Fenilcarbamatos/química , Polímeros/química , Amilose/química , Isocianatos/química , Polímeros/síntese química , Polímeros/normas , Dióxido de Silício , Solventes , Estereoisomerismo
11.
Asian Pac J Trop Med ; 7(3): 231-6, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24507646

RESUMO

OBJECTIVE: To establish rabbit model of restenosis after carotid endarterectomy surgery, and to study tissue inflammatory cytokines (TNF-α, IL-6) involved in restenosis. METHODS: A total of 32 rabbits were randomly divided into two groups: model group and control group. The right common carotid artery in rabbits was damaged by carotid endar terectomy in model group. The tissues were harvested at different time points respectively, the pathological changes of the vascular wall after operation were observed at different time points. The changes of expression of tissue vascular wall inflammatory cytokines (TNF-α, IL-6) at different time points after the surgery was observed by RT-PCR, and the changes of serum inflammatory cytokines (TNF-α, IL -6) were detected by ELISA. RESULTS: The new intima appeared after 7 days of the injury and reached the peak on 28 d which is uneven and significantly thicker than the control group (P<0.01). The tissue inflammatory cytokines (TNF-α, IL-6) were significantly increased after the rabbit common carotid artery injury, which was significant difference compared with normal control group (P<0.05). CONCLUSIONS: The tissue inflammatory factors significantly increase after the rabbit carotid artery injury, which suggests the mutual concurrent effects of inflammatory cytokines can result in the proliferation of vascular restenosis.


Assuntos
Artéria Carótida Primitiva/metabolismo , Artéria Carótida Primitiva/cirurgia , Estenose das Carótidas/metabolismo , Endarterectomia das Carótidas/métodos , Interleucina-6/biossíntese , Fator de Necrose Tumoral alfa/metabolismo , Animais , Artéria Carótida Primitiva/química , Interleucina-6/genética , Interleucina-6/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Coelhos , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/genética
12.
J Agric Food Chem ; 61(51): 12604-11, 2013 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-24313881

RESUMO

This study examined the changes of tocopherols (Toc), tocotrienols (T3), γ-oryzanol (GO), and γ-aminobutyric acid (GABA) contents in germinated brown rice (GBR) of pigmented and nonpigmented cultivars under different germination conditions. Results showed that the Toc and T3 contents in GBR were significantly different between treatments in both rice cultivars. The pigmented GBR possessed higher total vitamin E, total Toc, total T3, and GO contents than the nonpigmented GBR; however, its level of GABA was lower. The order of the three highest vitamin E homologues in pigmented and nonpigmented GBR was γ-T3 > γ-Toc > α-Toc and α-Toc > γ-T3 > α-T3, respectively; ß-Toc, ß-T3, δ-Toc, and δ-T3 were present in only small amounts (≤1.0 mg/kg) in GBR of both cultivars. Although both cultivars showed an increase in GABA contents with increasing germination time, the GABA content in nonpigmented GBR was higher.


Assuntos
Oryza/química , Fenilpropionatos/análise , Sementes/crescimento & desenvolvimento , Tocoferóis/análise , Tocotrienóis/análise , Ácido gama-Aminobutírico/análise , Germinação , Oryza/classificação , Oryza/crescimento & desenvolvimento , Sementes/química , Sementes/classificação
13.
J Agric Food Chem ; 59(20): 11150-9, 2011 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-21942383

RESUMO

The eight vitamin E isomers [α-, ß-, γ-, and δ-tocopherols (T) and α-, ß-, γ-, and δ-tocotrienols (T3)] and γ-oryzanol are known to possess diverse biological activities. This study examined the contents of these compounds and their distribution in 16 commercial rice varieties in Taiwan. Results showed that the order of vitamin E, total T, total T3, and γ-oryzanol contents was rice bran > brown rice > rice husk > polished rice. γ-T3 was the highest vitamin E isomer present in all rice samples, while ß-T, ß-T3, δ-T, and δ-T3 were present in trace amounts. The Japonica varieties contained a higher total T, total T3, and γ-oryzanol than the Indica varieties. They also have a higher level of α-T and α-T3 but a lower level of γ-T and γ-T3 than the Indica varieties. However, no obvious difference in total T, total T3, and γ-oryzanol content was noted between black- and red-colored rice varieties.


Assuntos
Oryza/química , Fenilpropionatos/análise , Sementes/química , Tocoferóis/análise , Tocotrienóis/análise , Especificidade da Espécie , Taiwan
14.
J Chromatogr A ; 1218(29): 4709-13, 2011 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-21676402

RESUMO

An improved normal phase high performance liquid chromatographic (NP-HPLC) method was developed for simultaneous quantification of eight vitamin E isomers (α-, ß-, γ- and δ-tocopherols and α-, ß-, γ- and δ-tocotrienols) and γ-oryzanol in rice. A complete separation of all compounds was achieved within 25 min using an Inertsil CN-3, SIL-100A 5 µM (4.6 mm × 250 mm) column and an isocratic elution system of hexane/isopropanol/ethylacetate/acetic acid (97.6:0.8:0.8:0.8, v/v/v/v) at a flow rate varying from 0.7 to 1.5 mL min(-1). A linear correlation coefficient (r(2)>0.99) and high reproducibility were obtained at concentrations ranging 0.05-10 µg mL(-1) for vitamin E isomers and 0.5-500 µg mL(-1) for γ-oryzanol. This method proved to be rapid, accurate and reproducible.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Oryza/química , Fenilpropionatos/análise , Tocoferóis/análise , Tocotrienóis/análise , Modelos Lineares , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Magn Reson Chem ; 47(5): 423-7, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19224544

RESUMO

Two types of chiral analytes, the urea and amide derivatives of alpha-phenylethylamine, were prepared. The effect of inter-molecular hydrogen-bonding interaction on self-discrimination of the enantiomers of analytes has been investigated using high-resolution (1)H NMR. It was found that the urea derivatives with double-hydrogen-bonding interaction exhibit not only the stronger hydrogen-bonding interaction but also better self-recognition abilities than the amide derivatives (except for one bearing two NO(2) groups). The present results suggest that double-hydrogen-bonding interaction promotes the self-discrimination ability of the chiral compounds.


Assuntos
Fenetilaminas/química , Amidas/química , Espectroscopia de Ressonância Magnética , Nitratos/química , Prótons , Estereoisomerismo , Ureia/química
17.
Nan Fang Yi Ke Da Xue Xue Bao ; 28(12): 2139-41, 2008 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-19114340

RESUMO

OBJECTIVE: To investigate the role of Ca(2+)/calmodulin-dependent calcineurin (CaN) signaling pathway in neuropeptide Y (NPY)-induced cardiomyocyte hypertrophy in rat. METHODS: Cardiomyocytes of neonatal Wistar rats were cultured in the presence of 10 and 100 nmol/L NPY, and cyclosporine A (CsA) was applied to inhibit the activity of CaN. The protein synthesis rate, c-jun mRNA expression, CaN protein expression, CaN activity and intracellular Ca(2+) concentration in the cardiomyocytes were assessed. RESULTS: Compared with the control group, (3)H-Leu incorporation and expression of c-jun mRNA in the cardiomyocytes treated with 100 nmol/L NPY increased significantly (P<0.05, P<0.001), and the effect of NPY was blocked by CsA. The activity of CaN (P<0.05), CaN expression (P<0.05), and Ca(2+) concentration in the cytoplasm (P<0.001) and nuclei (P<0.001) of the cells with 100 nmol/L NPY treatment also significantly increased compared with those in the control cells. CONCLUSION: NPY can induce cardiomyocyte hypertrophy in rats, in which process Ca(2+)/calmodulin-dependent CaN signaling pathway plays an important role.


Assuntos
Calcineurina/metabolismo , Miócitos Cardíacos/patologia , Neuropeptídeo Y/farmacologia , Transdução de Sinais , Animais , Animais Recém-Nascidos , Células Cultivadas , Hipertrofia , Miócitos Cardíacos/metabolismo , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar
18.
Chirality ; 20(7): 846-55, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18381735

RESUMO

Four dendrimers were synthesized on aminopropyl-modified silica gel using methyl acrylate and ethylene diamine as building blocks by divergent method. Four generations of chiral stationary phases (CSPs) were prepared by coupling of L-2-(p-toluenesulfonamido)-3-phenylpropionyl chloride to corresponding dendrimers. The derivatives prepared on silica gel were characterized by FT-IR, (1)H NMR, and elemental analysis. The selector loadings of these four generations of CSPs generally showed a decrease tendency with the increase of generation numbers of dendrimers. The enantioseparation properties of these CSPs were preliminarily investigated by high-performance liquid chromatography. The CSP derived from the three-generation dendrimer exhibited the best enantioseparation capability. Effects of the mobile phase composition and molecular structures of racemic mixtures on enantioseparation were further studied.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Dendrímeros/síntese química , Fenilalanina/química , Dendrímeros/química , Etilenodiaminas/química , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Sílica Gel , Dióxido de Silício , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo , Sulfonamidas/química
19.
Chirality ; 19(2): 129-40, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17117402

RESUMO

Two new chiral polymers of different molecular weights were synthesized by the copolymerization of (1R,2R)-(+)-1,2-diphenylethylenediamine, phenyl diisocyanate and terephthaloyl chloride. The polymers were immobilized on aminated silica gel to afford two chiral stationary phases. The polymers and the corresponding chiral stationary phases were characterized by Fourier transform-IR, elemental analysis, 1H and 13C NMR. The surface coverages of chiral structural units on the chiral stationary phases were estimated as 0.27 and 0.39 mmol/g, respectively. The enantioseparation ability of these chiral stationary phases was evaluated with a variety of chiral compounds by high-performance liquid chromatography. The effects of the organic additives, the composition of mobile phases, and the injection amount of sample on enantioseparation were investigated. A comparison of enantioseparation ability between these two chiral stationary phases was made. It was believed that the chain length of polymeric chiral selector significantly affected the enantioseparation ability of corresponding chiral stationary phase.


Assuntos
Etilenodiaminas/química , Isocianatos/química , Ácidos Ftálicos/química , Polímeros/síntese química , Cromatografia Líquida de Alta Pressão , Polímeros/análise , Estereoisomerismo
20.
Zhonghua Yi Xue Za Zhi ; 83(6): 515-7, 2003 Mar 25.
Artigo em Chinês | MEDLINE | ID: mdl-12887769

RESUMO

OBJECTIVE: To study the effect of neuropeptide Y (NPY) on the expression of heat shock protein 70 (HSP70) in vascular smooth muscle cells (VSMCs) of renal arteries. METHODS: The renal veins of SD rats were isolated and broken into pieces. The VSMCs were cultured and then divided into 3 groups, neuropeptide Y (NPY), NPY + losartan, and serum-free DMEM were added into the culture respectively. Automated MTT colorimetric microassay and quantitative immunocytochemistry were used to detect the expression of heat shock protein (HSP70) in the proliferating VSMCs. RESULTS: The fluorescence intensity of labeled HPS70 in the NPY group was 1,825.10 +/- 115.55, significantly stronger than that in the control group (1595.83 +/- 186.54, P < 0.05) and the fluorescence intensity of labeled HPS70 in the NPY + losartan group (1 658.54 +/- 183.78) was not significantly different from that in the control group (P > 0.05). The MTT-OD in NPY group was 0.2626 +/- 0.0025, significantly higher than that in the control group (0.2239 +/- 0.0010, P < 0.01). and the MTT-OD in NPY + losartan group was 0.2440 +/- 0.0013, significantly lower than that in the control group (P < 0.05). CONCLUSION: NPY stimulates the proliferation of renal VSMC, promotes the expression of HPS70, and may cause hypertension. Losartan reduces the NPY stimulation over VSMC proliferation and relevant expression of intracellular HSP70.


Assuntos
Proteínas de Choque Térmico HSP70/biossíntese , Losartan/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Neuropeptídeo Y/farmacologia , Artéria Renal/efeitos dos fármacos , Animais , Divisão Celular/efeitos dos fármacos , Masculino , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Neuropeptídeo Y/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Artéria Renal/citologia , Artéria Renal/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA