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1.
Front Psychol ; 12: 580446, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34447325

RESUMO

This study examined the relationships between perfectionism, self-esteem, and the will to win and the effects of gender and the level of achievement on these variables. A total of 318 adolescents in the age group of 12-19 years (M = 16.10 ± 1.01) completed the self-esteem questionnaire, the will-to-win questionnaire, and the perfectionism inventory. Interstate level (ISL) athletes obtained higher scores than interdistrict level (IDL) athletes on the following variables: self-esteem, the will to win, and four of the eight dimensions of perfectionism (i.e., concern over mistakes, the need for approval, organization, and planfulness). Further, male athletes obtained higher self-esteem and perfectionism (i.e., the need for approval and rumination) scores than female athletes. Self-esteem, the will to win, and the dimensions of perfectionism were positively and significantly interrelated. However, one dimension, namely, perceived parental pressure, was unrelated to any factor except striving for excellence. Further, the will to win, concern over mistakes, high standard for others, and planfulness were unrelated to striving for excellence. The results of the discriminant analysis revealed that there was no significant difference between ISL and IDL athletes (variance explained = 9.480%). Finally, using path analysis showed that Model 3 (perfectionism self-esteem will-to-win) has provided good model fit such as Bentler's comparative fit index (CFI) (0.987), Tucker-Lewis index (TLI) (0.876), normed fit index (NFI) (0.973), and the root mean square error of approximation (RMSEA) (0.097).

2.
PLoS One ; 14(8): e0218158, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31369586

RESUMO

Physical education professionals aim to develop quality programmes for physical education. This study aimed to develop and validate a scale using professionals' perceptions of Quality Physical Education QPE in Asia using twenty-four items regarding QPE quality issues. The items covered status and roles, development of educational elements and supportive features in physical education. A sample of N = 799 sport and physical education professionals from eleven Asian cities participated in this questionnaire survey. Twenty-four items relating to QPE were examined via exploratory factor analysis (EFA) using maximum likelihood extraction and direct oblimin rotation methods. Nevertheless, only 20 items were extracted following the EFA examination. Items 1, 9, 14 and 18 were excluded because of low factor loadings. The remaining items were clustered into four subscales: Development and Supportive Elements for Quality Physical Education in Schools (DSFQPE; α = .918), Core Values of Quality Physical Education (CVPE; α = .908), Curriculum Arrangement of Physical Activities (CAPA; α = .884) and Provision and Norms in Physical Education (PNPE; α = .865). The Cronbach's alpha coefficient (α = .875) indicated excellent internal consistency for the overall measure. Furthermore, the 4 retained factors from the EFA were assessed via robust confirmatory factor analysis (CFA). The 4-factor model demonstrated a good fit with the data (CMIN/DF = 3.450, CFI = .928, TLI = .916, PCFI = .801, RMSEA = .078). The study identified a 4-factor structure with internal consistency and acceptable interfactor correlations. The structure seemed to be applicable, including the twenty items identified as useful and necessary tools for the framework of analysis in the investigation of diverse settings for the study of quality physical education.


Assuntos
Educação Profissionalizante/normas , Educação Física e Treinamento/métodos , Professores Escolares/psicologia , Instituições Acadêmicas/normas , Análise Fatorial , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Inquéritos e Questionários
3.
Rev. bras. ciênc. esporte ; 40(4): 361-369, Oct.-Dec. 2018. tab
Artigo em Inglês | LILACS | ID: biblio-977509

RESUMO

Abstract An unsteady plan for curriculum development and supportive issues in physical education (PE) has created confusion among professionals. The purpose of this research is to investigate the factors perceived as important in the development of quality physical education (QPE) by professionals in Latin American (LA) countries. A questionnaire consisting of 24 items based on QPE was responded by 468 professionals collected from 6 LA cities. An exploratory factor analysis (EFA) of the 24 items using ML extraction and direct oblimin rotation were applied, and the retained 17 items were clustered in a three factor solution referred to as, Development and Supportive Elements for QPE in School (DSFQPE) (α = .935), Core Value of QPEtabl (CVPE) (α = .890), and Curriculum Arrangement of Physical Activities (CAPA) (α = .850). The retained items indicated excellent properties and the basic framework as perceived by professionals from PE in LA countries as important in the investigation of QPE.


Resumo Um plano instável para o desenvolvimento de currículos e questões de apoio na educação física (PE) criou confusão entre os profissionais. O objetivo desta pesquisa é investigar os fatores percebidos como importantes no desenvolvimento da educação física de qualidade (QPE) por profissionais de países da América Latina (AL). Um questionário composto por 24 itens com base no QPE foi respondido por 468 profissionais coletados em 6 cidades da América Latina. Uma análise fatorial exploratória dos 24 itens usando extração ML e rotação obliminar direta foram aplicados, e os 17 itens retidos foram agrupados em uma solução de três fatores denominada Elementos de Desenvolvimento e Suporte para QPE na Escola (DSFQPE) (α = 0,935), Valor essencial do QPE (CVPE) (α = 0,890) e Arranjo Curricular das Atividades Físicas (CAPA) (α = 0,850). Os itens retidos indicaram propriedades excelentes e o referencial básico percebido pelos profissionais de EF em países da América Latina como importante na investigação do PEQ.


Resumen Un plan inestable para el desarrollo curricular y aspectos de apoyo para la educación física (EF) han creado confusión entre los profesionales. El propósito de esta investigación es investigar los factores percibidos como importantes en el desarrollo de la educación física de calidad (EFC) por profesionales en países de América Latina (AL). Un cuestionario que consta de 24 ítems basados en EFC fue respondido por 468 profesionales recolectados en 6 ciudades de LA. Se aplicó un Análisis factorial exploratorio de los 24 ítems que utilizan extracción ML y rotación oblicua directa, y los 17 ítems retenidos se agruparon en una solución de tres factores denominada Elementos de desarrollo y de apoyo para EFC en la escuela (EDAEFC) (α = 0,935); Valor principal de EFC (CVPE) (α = 0,890) y Arreglo del plan de actividades físicas (CAPA) (α = 0,850). Los ítems retenidos indicaron excelentes propiedades y el marco básico es percibido por los profesionales de EF en los países de AL como importante en la investigación de EFC.

4.
J Pediatr ; 191: 110-116, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28987751

RESUMO

OBJECTIVE: Childhood obesity may be related to school environment, but previous studies often focused on food environment only. This study aimed to examine the relationship between school physical activity environment and childhood obesity. STUDY DESIGN: This is a cross-sectional study with multilevel data collected on school physical activity environment using teacher questionnaires, students' growth, and obesity status from electronic health records, and neighborhood socioeconomic status from census data. RESULTS: This study included 208 280 students (6-18 years of age) from 438 schools (45% of Hong Kong). Prevalence of obesity was 5.0%. After controlling for socioeconomic status and intraschool correlation, robust Poisson regression revealed a reduced obesity risk associated with higher teachers' perceived physical activity benefits (risk ratio 0.96, 95% CI 0.94-0.99, P = .02), physical activity teaching experience (0.93, 0.91-0.96, P < .001), school campus size (0.93, 0.87-0.99, P = .02), physical activity ethos (0.91, 0.88-0.94, P < .001), number of physical activity programs (0.93, 0.90-0.96, P < .001), and physical activity facilities (0.87, 0.84-0.90, P < .001). Students in schools with at least 3 physical activity-friendly environmental factors (11.7%) had a much lower risk of obesity (0.68, 0.62-0.75, P < .001) than those without (23.7%). CONCLUSIONS: A physical activity-friendly school environment is associated with lower risk of obesity. School physical activity environment should be considered in future epidemiologic and intervention studies.


Assuntos
Planejamento Ambiental/estatística & dados numéricos , Exercício Físico , Obesidade Infantil/etiologia , Instituições Acadêmicas/estatística & dados numéricos , Adolescente , Criança , Estudos Transversais , Feminino , Hong Kong/epidemiologia , Humanos , Masculino , Obesidade Infantil/epidemiologia , Obesidade Infantil/prevenção & controle , Fatores de Proteção , Análise de Regressão , Características de Residência , Fatores de Risco , Classe Social
5.
Pediatrics ; 140(4)2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28951440

RESUMO

OBJECTIVES: To assess the effectiveness of a positive youth development (PYD)-based sports mentorship program on the physical and mental well-being of adolescents recruited in a community setting. METHODS: This is a randomized controlled trial in which we recruited students from 12 secondary schools in Hong Kong, China. Participants were randomly assigned in a 1:1 ratio to an intervention or a control arm after stratification for school from October 2013 to June 2014. Participants were not blinded to allocation because of the nature of the intervention. Students in the intervention arm received an after-school, PYD-based sports mentorship for 18 weeks. Each weekly session lasted 90 minutes. Students in the control arm received exclusive access to a health education Web site. RESULTS: Six hundred and sixty-four students (mean age 12.3 years [SD 0.76]; 386 girls [58.1%]) completed baseline and postintervention assessments. The intervention improved students' mental well-being (Cohen's d, 0.25; 95% confidence interval [CI], 0.10 to 0.40; P = .001), self-efficacy (Cohen's d, 0.22; 95% CI, 0.07 to 0.37; P = .01), resilience (Cohen's d, 0.19; 95% CI, 0.03 to 0.34; P = .02), physical fitness (flexibility [Cohen's d, 0.28; 95% CI, 0.13 to 0.43; P = .02], lower limb muscle strength [Cohen's d, 0.18; 95% CI, 0.03 to 0.33; P = .03], and dynamic balance [Cohen's d, 0.21; 95% CI, 0.06 to 0.37; P = .01]), and physical activity levels (Cohen's d, 0.39; 95% CI, 0.24 to 0.55; P < .0001). The intervention did not significantly improve physical well-being (Cohen's d, -0.01; 95% CI, -0.17 to 0.14; P = .86), BMI z scores (Cohen's d, -0.03; 95% CI, -0.18 to 0.12; P = .69), body fat proportion (Cohen's d, -0.15; 95% CI, -0.31 to 0.00; P = .051), and social connectedness (Cohen's d, -0.03; 95% CI, -0.18 to 0.12; P = .72). CONCLUSIONS: A PYD-based sports mentorship intervention improved healthy adolescents' mental well-being, psychological assets, physical fitness, and physical activity levels.


Assuntos
Desenvolvimento do Adolescente , Saúde do Adolescente , Promoção da Saúde/métodos , Saúde Mental , Tutoria/métodos , Aptidão Física , Esportes , Adolescente , Feminino , Humanos , Masculino , Avaliação de Resultados em Cuidados de Saúde , Esportes/fisiologia , Esportes/psicologia
6.
J Endocrinol ; 194(2): 373-92, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17641286

RESUMO

Two prolactin receptors (PRLRs) encoded by two different genes were identified in the fugu and zebrafish genomes but not in the genomes of other vertebrates. Subsequently, two cDNA sequences corresponding to two PRLRs were identified in black seabream and Nile tilapia. Phylogenetic analysis of PRLR sequences in various vertebrates indicated that the coexistence of two PRLRs in a single species is a unique phenomenon in teleosts. Both PRLRs in teleosts (the classical one named as PRLR1, the newly identified one as PRLR2) resemble the long-form mammalian PRLRs. However, despite their overall structural similarities, the two PRLR subtypes in fish share very low amino acid similarities (about 30%), mainly due to differences in the intracellular domain. In particular, the Box 2 region and some intracellular tyrosine residues are missing in PRLR2. Tissue distribution study by real-time PCR in black seabream (sb) revealed that both receptors (sbPRLR1 and sbPRLR2) are widely expressed in different tissues. In gill, the expression level of sbPRLR2 is much higher than that of sbPRLR1. In the intestine, the expression of sbPRLR1 is higher than that of sbPRLR2. The expression levels of both receptors are relatively low in most other tissues, with sbPRLR1 generally higher than sbPRLR2. The sbPRLR1 and sbPRLR2 were functionally expressed in cultured human embryonic kidney 293 cells. Both receptors can activate the beta-casein and c-fos promoters; however, only sbPRLR1 but not sbPRLR2 can activate the Spi promoter upon receptor stimulation in a ligand-specific manner. These results indicate that both receptors share some common functions but are distinctly different from each other in mobilizing post-receptor events. When challenged with different steroid hormones, the two PRLRs exhibited very different gene expression patterns in the seabream kidney. The sbPRLR1 expression was up-regulated by estradiol and cortisol, whereas testosterone had no significant effect. For sbPRLR2, its expression was down-regulated by estradiol and testosterone, while cortisol exerted no significant effect. The 5'-flanking regions of the sbPRLR1 and sbPRLR2 genes were cloned and the promoter activities were studied in transfected GAKS cells in the absence or presence of different steroid hormones. The results of the promoter studies were in general agreement with the in vivo hormonal regulation of gene expression results. The sbPRLR1 gene promoter activity was activated by estradiol and cortisol, but not by testosterone. In contrast, the sbPRLR2 gene promoter activity was inhibited by estradiol, cortisol, and testosterone.


Assuntos
Hormônios/farmacologia , Rim/metabolismo , RNA Mensageiro/análise , Receptores da Prolactina/genética , Dourada/metabolismo , Transdução de Sinais/fisiologia , Região 5'-Flanqueadora , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Estradiol/genética , Estradiol/farmacologia , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Hidrocortisona/genética , Hidrocortisona/farmacologia , Rim/efeitos dos fármacos , Masculino , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Receptores da Prolactina/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Takifugu , Testosterona/genética , Testosterona/farmacologia , Tilápia , Transfecção/métodos , Peixe-Zebra
7.
Vaccine ; 25(3): 490-9, 2007 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-16949181

RESUMO

The Plasmodium falciparum merozoite surface protein 1 (MSP1), MSP1-42 and MSP1-19 are protective malaria vaccines. MSP1-42 is cleaved to form MSP1-33 and MSP1-19. The role of MSP1-33 in immunity is unclear. We investigated the antibody responses to MSP1-33; and to MSP1-33Trunc, in which major conserved sequences were excised. While anti-MSP1-33 antibodies were subdominant in the anti-MSP1-42 responses, immunizations with MSP1-33 or MSP1-33Trunc induced high levels of antibodies reactive with MSP1-42 or whole merozoites. Anti-MSP1-33 and anti-MSP1-33Tunc antibodies crossreacted with both allelic forms of MSP1-42. Anti-MSP1-33 sera were ineffective in inhibiting parasite growth in vitro; but they significantly enhanced the activities of sub-optimal concentrations of the inhibitory anti-MSP1-42 sera. Thus, immunization strategies with MSP1-based vaccines may benefit from co-induction of anti-MSP1-33 responses to enhance efficacy and potency.


Assuntos
Vacinas Antimaláricas/imunologia , Proteína 1 de Superfície de Merozoito/imunologia , Fragmentos de Peptídeos/imunologia , Plasmodium falciparum/imunologia , Alelos , Animais , Anticorpos Antiprotozoários/análise , Anticorpos Antiprotozoários/biossíntese , Ensaio de Imunoadsorção Enzimática , Técnica Indireta de Fluorescência para Anticorpo , Coelhos , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/imunologia
8.
J Biochem Mol Biol ; 39(2): 150-7, 2006 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-16584629

RESUMO

Native grass carp (Ctenopharygodon idellus) growth hormone, has 5 cysteine amino acid residues, forms two disulphide bridges in its mature form. Recombinant grass carp growth hormone, when over-expressed in E. coli, forms inclusion bodies. In vitro oxidative renaturation of guanidine-hydrochloride dissolved recombinant grass carp growth hormone was achieved by sequential dilution and stepwise dialysis at pH 8.5. The redox potential of the refolding cocktail was maintained by glutathione disulphide/glutathione couple. The oxidative refolded protein is heterogeneous, and contains multimers, oligomers and monomers. The presence of non-disulphide-bond-forming cysteine in recombinant grass carp growth hormone enhances intermolecular disulphide bond formation and also nonnative intramolecular disulphide bond formation during protein folding. The non-disulphide-bond-forming cysteine was converted to serine by PCR-mediated site-directed mutagenesis. The resulting 4-cysteine grass carp growth hormone has improved in vitro oxidative refolding properties when studied by gel filtration and reverse phase chromatography. The refolded 4-cysteine form has less hydrophobic aggregate and has only one monomeric isoform. Both refolded 4-cysteine and 5-cysteine forms are active in radioreceptor binding assay.


Assuntos
Carpas/metabolismo , Hormônio do Crescimento/genética , Hormônio do Crescimento/metabolismo , Serina/química , Substituição de Aminoácidos , Animais , Cisteína/química , Cisteína/genética , Cisteína/metabolismo , Perfilação da Expressão Gênica , Hormônio do Crescimento/efeitos dos fármacos , Guanidina/farmacologia , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Mutagênese Sítio-Dirigida , Oxirredução , Dobramento de Proteína , Renaturação Proteica/efeitos dos fármacos , Proteínas Recombinantes/efeitos dos fármacos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Serina/genética , Serina/metabolismo , Fatores de Tempo
9.
Comp Biochem Physiol B Biochem Mol Biol ; 143(1): 107-15, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16352451

RESUMO

Mouse anti-grass carp growth hormone (gcGH) monoclonal antibody (MAb) secretors were produced by PEG-mediated fusion of NS-1 myeloma cells and splenic B-lymphocytes of gcGH hyper-immunized mice. Positive secretors were screened by direct ELISA and cloned by limiting dilution. Three positive secretors, 21D3, 22G5 and 23B3, were obtained in a single fusion trial. Anti-gcGH MAbs were produced by growing hybridomas in the peritoneal cavity of pristane-primed mouse. The three MAbs were isotyped to be IgG2a, IgG2b and IgM, respectively. IgG MAbs were purified from ascitic fluid by Hitrap protein G column and IgM MAb was purified by gel filtration chromatography. The purified MAbs were highly specific and had moderate binding affinity. The MAbs were successfully used for the purification of native gcGH from mature grass carp pituitary extract by one-step immunoaffinity chromatography, for the quantification of gcGH by competitive sandwich ELISA, and for the probing of somatotropes in grass carp pituitary by immunohistochemistry.


Assuntos
Anticorpos Monoclonais , Carpas/imunologia , Hormônio do Crescimento/imunologia , Animais , Especificidade de Anticorpos , Líquido Ascítico , Linfócitos B/metabolismo , Fusão Celular , Cromatografia de Afinidade , Cromatografia em Gel , Ensaio de Imunoadsorção Enzimática , Feminino , Hibridomas , Imunização , Imunoglobulina G/isolamento & purificação , Imunoglobulina M/isolamento & purificação , Camundongos , Camundongos Endogâmicos BALB C , Mieloma Múltiplo/metabolismo , Hipófise/imunologia , Hipófise/metabolismo , Baço/metabolismo
10.
Biochem Biophys Res Commun ; 338(3): 1654-60, 2005 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-16263078

RESUMO

Infection of SARS-associated coronavirus (SARS-CoV) induced a strong anti-nucleocapsid (anti-N) antibody response. However, the pathophysiological significance of the anti-N antibodies in SARS pathogenesis is largely unknown. To profile the anti-N antibodies, a phage-displayed scFv library was prepared from mice immunized with heat-inactivated SARS-CoV-infected Vero E6 cell lysate. Specific anti-N scFvs were isolated by panning against a recombinant nucleocapsid protein and reactivity was confirmed with phage-ELISA. Sequence analysis indicated that two of the isolated anti-N scFv clones were identical and displayed a high homology with an scFv specific for interleukin 11 (IL-11), an anti-inflammatory cytokine derived from bone marrow stroma cells. In a neutralization assay, IL-11-induced STAT 3 phosphorylation in rat intestinal epithelial IEC-18 cells was completely suppressed by the anti-N scFv clone L9N01.


Assuntos
Anticorpos Antivirais/imunologia , Interleucina-11/imunologia , Proteínas do Nucleocapsídeo/imunologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , Animais , Sequência de Bases , Linhagem Celular , Chlorocebus aethiops , Reações Cruzadas/imunologia , Camundongos , Dados de Sequência Molecular , Proteínas do Nucleocapsídeo/química , Ratos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/química , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico
11.
Int J Food Sci Nutr ; 56(5): 359-66, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16236597

RESUMO

Determination of fat percentage of aortic intimal area stained by Sudan III is useful as an index of atherosclerosis in the rabbit animal model. However, the determination of sudanophilic area of the thoracic aorta is two-dimensional and does not measure the third dimension of depth. The objective of the present study was to quantify and characterize aortic lipids using the gas-liquid chromatographic (GLC) technique and to determine whether elevated measurements of total cholesterol and cholesteryl esters was correlated with increased measurements of sudanophilic area staining of the thoracic aorta in rabbits given either a normal chow or a 1% cholesterol diet. The GLC results showed that there was a mean accumulation of 10.9 mg of cholesterol per gram of aortic tissue in the rabbits given a cholesterol diet (mean sudanophilic area of 23.8%). In contrast, rabbits on a normal chow diet had only a deposition of 0.58 mg of cholesterol per gram of the aortic tissue diet (mean sudanophilic area of 1.4%). The present study suggests that quantification of the aortic lipids can be performed by using GLC techniques and that it could be used as an alternative to the measurement of sudanophilic area when assessing the severity of atherosclerosis.


Assuntos
Aorta/química , Aterosclerose/etiologia , Colesterol/análise , Animais , Aterosclerose/diagnóstico , Colesterol/sangue , Ésteres do Colesterol/análise , Colesterol na Dieta/administração & dosagem , Cromatografia , Ácidos Graxos não Esterificados/análise , Feminino , Masculino , Modelos Animais , Coelhos , Coloração e Rotulagem , Triglicerídeos/análise , Triglicerídeos/sangue
12.
Eur J Pharm Biopharm ; 59(3): 549-55, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15760736

RESUMO

The present study was to investigate oral absorption of the two similar flavonoid glycosides, isoquercitrin (IQ, quercetin-3-O-glucoside) and hyperoside (HP, quercetin-3-O-galactoside) in rats. Two groups of male SD rats received an oral dose of either IQ (4.5 mg/kg) or HP (6.0 mg/kg). Blood samples were collected via jugular vein at time intervals after drug administration and the plasma concentrations of the studied compounds were analyzed by HPLC. The stability of IQ and HP in the GI tract was also measured by incubation with various GI contents from rats. The results showed that unchanged IQ was barely detectable whereas the glucuronidated quercetin (the aglycone of IQ) was found to be the major form in plasma after oral administration of IQ. In contrast, HP could not be detected in plasma neither as unchanged form nor its aglycone or conjugated aglycone form. Additional in vitro stability studies demonstrated that HP is more stable than IQ in the GI tract. This suggests that IQ could be hydrolyzed easier than HP to its aglycone in GI tract before being absorbed. In conclusion, IQ, as a flavonoid glucoside, could be rapidly absorbed and transformed into glucuronidated quercetin and such absorption might be related to the hydrolysis of the type of sugar moieties attached to its aglycone molecule.


Assuntos
Flavonoides/sangue , Glicosídeos/química , Absorção Intestinal/fisiologia , Quercetina/análogos & derivados , Quercetina/química , Animais , Flavonoides/química , Flavonoides/farmacocinética , Glicosídeos/sangue , Glicosídeos/farmacocinética , Hidrólise , Absorção Intestinal/efeitos dos fármacos , Masculino , Estrutura Molecular , Quercetina/sangue , Quercetina/farmacocinética , Ratos , Ratos Sprague-Dawley
13.
J Clin Pharmacol ; 45(1): 106-12, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15601812

RESUMO

The pharmacokinetics of an active herbal substance may be different when administered in an extract form as compared to that when administered as a pure compound. This study investigated the pharmacokinetics of 4 active compounds of hawthorn fruits--namely, (-)-epicatechin, chlorogenic acid, hyperoside, and isoquercitrin--following administration of an extract formulation (as hawthorn phenolic extract, which contained the active compounds) or equivalent doses of individual pure compound in male Sprague-Dawley rats (n = 5 per group). The hawthorn phenolic extract or pure compounds were administered both orally and intravenously. Following administration, multiple plasma samples were obtained, and the plasma concentrations were determined by high-performance liquid chromatography. After the intravenous injection of hawthorn phenolic extract, higher plasma drug concentration, larger area under the plasma concentration-time curve from 0 to infinity, longer terminal elimination half-life, smaller apparent volume of distribution, lower total body clearance, and higher urinary excretion of each compound were obtained when compared to that after the pure compound. Following the oral administration of either hawthorn phenolic extract or pure compound, only epicatechin was absorbed, and their pharmacokinetics were generally not significantly different between these 2 formulations. The differences in the pharmacokinetics of the 2 formulations following intravenous but not oral administration may be attributable to the existence of other co-occurring components in the hawthorn phonolic extract (which may be present in the body after intravenous but not oral administration). The results showed that an herbal extract formulation, when administered intravenously, could potentially alter the pharmacokinetics of its active ingredients.


Assuntos
Crataegus , Fenóis/farmacocinética , Extratos Vegetais/farmacocinética , Administração Oral , Animais , Frutas , Injeções Intravenosas , Masculino , Fenóis/sangue , Fenóis/farmacologia , Extratos Vegetais/sangue , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley
14.
Endocrinology ; 145(10): 4615-28, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15231712

RESUMO

GH feedback on its own secretion at the pituitary level has been previously reported, but the mechanisms involved have not been elucidated. Here we examined the autocrine/paracrine effects of GH on GH synthesis using grass carp pituitary cells as a cell model. GH receptors were identified in carp somatotrophs, and their activation by exogenous GH increased steady-state GH mRNA levels and GH production. Removal of endogenous GH by immunoneutralization using GH antiserum inhibited basal as well as stimulated GH mRNA expression induced by GH-releasing factors in fish, including GnRH, apomorphine, and pituitary adenylate cyclase-activating polypeptide-38. Cytosolic mature GH mRNA levels were elevated by GH treatment and reduced by GH antiserum, whereas nuclear GH primary transcripts were almost undetectable after GH immunoneutralization. Inhibition of Janus kinase-2 (JAK2), phosphoinositide 3-kinase, and MAPK also abolished GH-induced steady-state GH mRNA expression. GH immunoneutralization in pituitary cells pretreated with actinomycin D induced a marked decrease in the half-life of GH mRNA, indicating that the clearance of GH transcripts could be enhanced by removing endogenous GH. These results provide evidence that GH can serve as a novel intrapituitary autocrine/paracrine factor maintaining GH gene expression in somatotrophs, and this action is mediated by JAK2/MAPK and JAK2/phosphoinositide 3-kinase cascades coupled to GH receptors.


Assuntos
Comunicação Autócrina/fisiologia , Carpas/fisiologia , Hormônio do Crescimento/metabolismo , Homeostase/fisiologia , Comunicação Parácrina/fisiologia , Hipófise/metabolismo , Animais , Expressão Gênica , Hormônio do Crescimento/genética , Hormônio do Crescimento/imunologia , Hormônio do Crescimento/farmacologia , Soros Imunes/farmacologia , Hipófise/citologia , Adeno-Hipófise/citologia , Adeno-Hipófise/metabolismo , RNA Mensageiro/metabolismo , Dourada , Transdução de Sinais , Suínos
15.
Infect Immun ; 70(6): 2772-9, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12010962

RESUMO

The 42-kDa carboxyl-terminal processing fragment of Plasmodium falciparum merozoite surface protein 1 (MSP-1(42)) is an anti-erythrocytic stage malaria vaccine candidate. In this study, MSP-1(42) was expressed by using the Bombyx mori nuclear polyhedrosis virus-silkworm expression system, and the antigenicity and immmunogenicity of the recombinant protein, Bmp42, were evaluated. The average yield of Bmp42, as determined by a sandwich enzyme-linked immunosorbent assay (ELISA), was 379 microg/ml of infected silkworm hemolymph, which was >100-fold higher than the level attainable in cell culture medium. N-terminal amino acid sequencing revealed that Bmp42 was correctly processed in silkworm cells. Data from immunoblotting, as well as from the inhibition ELISA, suggested that the conformational B-cell epitopes of MSP-1(42) were recreated in Bmp42. Immunization of rabbits with Bmp42 in complete Freund's adjuvant generated high-titer antibody responses against the immunogen. Specificity analyses of the anti-Bmp42 antibodies using several recombinant MSP-1(19) proteins expressing variant and conserved B-cell epitopes suggested that the anti-Bmp42 antibodies recognized primarily conserved epitopes on MSP-1(19). Furthermore, the anti-Bmp42 antibodies were highly effective in inhibiting the in vitro growth of parasites carrying homologous or heterologous MSP-1(42). Our results demonstrated that the baculovirus-silkworm expression system could be employed to express biologically and immunologically active recombinant MSP-1(42) at elevated levels; thus, it is an attractive alternative for producing a protective MSP-1(42) vaccine for human use.


Assuntos
Expressão Gênica , Vetores Genéticos , Proteína 1 de Superfície de Merozoito/genética , Nucleopoliedrovírus , Plasmodium falciparum/genética , Processamento de Proteína Pós-Traducional , Animais , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Bombyx , Linhagem Celular , Larva , Proteína 1 de Superfície de Merozoito/imunologia , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Plasmodium falciparum/imunologia , Coelhos , Análise de Sequência de Proteína , Vacinas Sintéticas/imunologia
16.
J Nutr ; 132(1): 5-10, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11773500

RESUMO

The present study examined the hypolipidemic activity of hawthorn fruit. New Zealand white rabbits were fed one of three diets, a reference diet with no cholesterol added (NC), a high cholesterol diet (1 g/100 g, HC) and a HC diet supplemented with 2 g/100 g hawthorn fruit powder (HC-H). After 12 wk, serum total cholesterol (TC) and triacylglycerols (TG) were 23.4 and 22.2% lower, respectively, in the hawthorn fruit group compared with the HC rabbits (P < 0.05). Hawthorn supplementation led to 50.6% less cholesterol accumulation in aorta (P < 0.05) and 23-95% greater excretion of neutral and acidic sterols (P < 0.05). Supplementation of hawthorn fruit did not affect the activities of hepatic 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMG-CoA-R) or cholesterol 7alpha-hydroxylase (CH) but it suppressed the activity of intestinal acyl CoA:cholesterol acyltransferase (ACAT, P < 0.05). The results suggest that the mechanism by which hawthorn fruit decreases serum cholesterol involves, at least in part, the inhibition of cholesterol absorption mediated by down-regulation of intestinal ACAT activity.


Assuntos
Colesterol na Dieta/administração & dosagem , Colesterol/sangue , Frutas , Hipercolesterolemia/dietoterapia , Hipolipemiantes/uso terapêutico , Rosaceae , Animais , Aorta/metabolismo , Aorta/patologia , Encéfalo/metabolismo , Colesterol 7-alfa-Hidroxilase/metabolismo , Regulação para Baixo , Fezes/química , Feminino , Hidroximetilglutaril-CoA Redutases/metabolismo , Intestinos/enzimologia , Rim/metabolismo , Fígado/enzimologia , Fígado/metabolismo , Masculino , Miocárdio/metabolismo , Coelhos , Esterol O-Aciltransferase/antagonistas & inibidores , Esterol O-Aciltransferase/metabolismo , Esteróis/análise , Triglicerídeos/sangue
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