Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Ethnopharmacol ; 235: 183-189, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-30763698

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Copaiba oleoresin has been used in folk medicine in the treatment of bronchitis, syphilis, skin diseases and ulcers due to its anti-inflammatory and antiseptic activities, but there is no information about major compounds oral absorption to support the traditional use. AIM OF STUDY: Considering the potential of copalic (CA) and kaurenoic acid (KA) - major biological activity (in vitro) diterpenes found in the oleoresin, this study aimed to evaluate the intestinal permeability of CA and KA using Caco-2 cells model as predictive test for oral drug absorption. MATERIALS AND METHODS: Chemical stability at pH 1.2 and 7.4 and plasma stability were evaluated to mimic physiological conditions of the gastrointestinal tract. The intestinal permeability of CA and KA was evaluated in Caco-2 cells in the presence and absence of the P-glycoprotein inhibitor verapamil. RESULTS: CA and KA were rapidly degraded at pH 1.2 (0.2 M Clark-Lubs buffer). At pH 7.4 (0.1 M phosphate buffer), CA was stable for up to 24 h and KA for up to 6 h. In human plasma, CA and KA can be considered stable for 24 h and 12 h at 37 °C, respectively. Caco-2 cells were considered viable when incubated with CA or KA in the range of 3.9-250 µM for 24 h. CA and KA exhibited moderate apparent permeability (Papp) of 4.67 (±0.08) × 10-6 cm/s and 4.66 (±0.04) × 10-6 cm/s, respectively. Simultaneous incubation with verapamil showed that P-glycoprotein does not play a relevant role on CA and KA oral absorption, with Papp of 4.48 (±0.26) × 10-6 cm/s and 5.37 (±0.72) × 10-6 cm/s observed for CA and KA, respectively. CONCLUSION: The oral absorption of both CA and KA is driven by mainly passive permeability, is not limited by p-glycoprotein, but enteric-coated dosage forms should be used to avoid chemical instability in the gastric pH.


Assuntos
Diterpenos/farmacocinética , Fabaceae/química , Preparações de Plantas/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Células CACO-2 , Diterpenos/isolamento & purificação , Estabilidade de Medicamentos , Humanos , Concentração de Íons de Hidrogênio , Absorção Intestinal , Permeabilidade , Fatores de Tempo , Verapamil/farmacologia
2.
Int J Biol Macromol ; 108: 291-299, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29191425

RESUMO

The present study describes the one-step purification and biochemical characterization of an endo-1,4-ß-xylanase from Aspergillus tamarii Kita. Extracellular xylanase was purified to homogeneity 7.43-fold through CM-cellulose. Enzyme molecular weight and pI were estimated to be 19.5kDa and 8.5, respectively. The highest activity of the xylanase was obtained at 60°C and it was active over a broad pH range (4.0-9.0), with maximal activity at pH 5.5. The enzyme was thermostable at 50°C, retaining more than 70% of its initial activity for 480min. The K0.5 and Vmax values on beechwood xylan were 8.13mg/mL and 1,330.20µmol/min/mg of protein, respectively. The ions Ba2+ and Ni2+, and the compounds ß-mercaptoethanol and DTT enhanced xylanase activity, while the heavy metals (Co2+, Cu2+, Hg+, Pb2+ and Zn2+) strongly inhibited the enzyme, at 5mM. Enzymatic hydrolysis of xylooligosaccharides monitored in real-time by mass spectrometer showed that the shortest xylooligosaccharide more efficiently hydrolyzed by A. tamarii Kita xylanase corresponded to xylopentaose. In agreement, HPLC analyzes did not detect xylopentaose among the hydrolysis products of xylan. Therefore, this novel GH11 endo-xylanase displays a series of physicochemical properties favorable to its application in the food, feed, pharmaceutical and paper industries.


Assuntos
Aspergillus/enzimologia , Xilosidases/química , Cromatografia , Cromatografia Líquida de Alta Pressão , Ativação Enzimática , Estabilidade Enzimática , Glucuronatos , Hidrólise , Cinética , Espectrometria de Massas , Modelos Moleculares , Peso Molecular , Oligossacarídeos , Conformação Proteica , Proteínas Recombinantes , Especificidade por Substrato , Xilosidases/isolamento & purificação
3.
Chem Soc Rev ; 47(5): 1574-1591, 2018 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-29114668

RESUMO

All living organisms emit, detect, and respond to chemical stimuli, thus creating an almost limitless number of interactions by means of chemical signals. Technological and intellectual advances in the last two decades have enabled chemical signals analyses at several molecular levels, including gene expression, molecular diversity, and receptor affinity. These advances have also deepened our understanding of nature to encompass interactions at multiple organism levels across different taxa. This tutorial review describes the most recent analytical developments in 'omics' technologies (i.e., genomics, transcriptomics, proteomics, and metabolomics) and provide recent examples of its application in studies of chemical signals. We highlight how studies have integrated an enormous amount of information generated from different omics disciplines into one publicly available platform. In addition, we stress the importance of considering different signal modalities and an evolutionary perspective to establish a comprehensive understanding of chemical communication.


Assuntos
Genômica , Metabolômica , Proteômica , Ecologia , Transcriptoma
4.
J Reconstr Microsurg ; 33(4): 298-304, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28201829

RESUMO

Background Autologous breast reconstruction has been noted in the literature to provide superior aesthetic outcomes and patient satisfaction. Additionally, free perforator flap tissue transfer has the potential for lower abdominal donor site morbidity. However, it has been noted that the percentage of women who are undergoing autologous breast reconstruction in the United States is decreasing. Factors related to the technical difficulty, prolonged operative times, and decreasing reimbursement have been implicated as the causes. Methods A retrospective review of electronic medical records over a 5-year period was performed with evaluation of 77 autologous breast reconstructions at a single institution. Patient demographics, comorbidities, number of surgeons involved, operative times, length of stay, and postoperative complications were measured. Wilcoxon rank-sum, Pearson's chi-squared, and proportional odds likelihood ratio tests were performed to compare continuous, categorical, and ordinal outcomes, respectively. Propensity score weighting was used to adjust for presurgical covariates and laterality. Results Operative time and length of stay were both significantly lower in the two- versus the single-microsurgeon groups in the unadjusted setting. When covariates and laterality were adjusted for, operative times still remained significantly shorter in the two-microsurgeon group; there were no differences in complications. Conclusion Based on our findings, we propose that the two-microsurgeon approach can be utilized in more time-consuming microsurgical cases, such as autologous breast reconstruction, to safely decrease operative times and potentially alleviate surgeon fatigue, reduce operative costs, and thus increase overall surgeon productivity.


Assuntos
Neoplasias da Mama/cirurgia , Retalhos de Tecido Biológico/irrigação sanguínea , Mamoplastia/métodos , Mastectomia/métodos , Microcirurgia , Retalho Perfurante/irrigação sanguínea , Complicações Pós-Operatórias/cirurgia , Estética , Feminino , Humanos , Microcirurgia/métodos , Pessoa de Meia-Idade , Duração da Cirurgia , Satisfação do Paciente/estatística & dados numéricos , Reto do Abdome/transplante , Estudos Retrospectivos , Transplante Autólogo , Resultado do Tratamento
5.
Comp Biochem Physiol B ; 78(1): 195-8, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6744824

RESUMO

Trout liver cytosol has proteins that bind bile salts and 8-anilino-1-naphthalene sulphonate and that co-elute from Sephadex G-75. The binding of 8-anilino-1-naphthalene sulphonate is decreased by 90% in the presence of 33 microM lithocholate, implying the proteins are the same. Bile salt-binding protein is present in liver, but was not detected in gills, kidney, muscle or intestine. Bile salt-binding protein, partially-purified by Sephadex G-75 chromatography, was resolved into 2 fractions by cholate-affinity chromatography. Fatty acids do not appear to be bound by bile salt-binding protein. No fatty acid-binding protein was detected in trout liver cytosol.


Assuntos
Proteínas de Transporte/isolamento & purificação , Hidroxiesteroide Desidrogenases , Rim/metabolismo , Fígado/metabolismo , Glicoproteínas de Membrana , Músculos/metabolismo , Animais , Proteínas de Transporte/metabolismo , Cromatografia de Afinidade , Cromatografia em Gel , Citosol/metabolismo , Ácido Litocólico/metabolismo , Masculino , Ácidos Palmíticos/metabolismo , Ratos , Ratos Endogâmicos , Especificidade da Espécie , Truta
6.
Artigo em Inglês | MEDLINE | ID: mdl-6132776

RESUMO

1. Gills, kidney, intestinal caeca and liver of trout have glutathione S-transferase activity with 1-chloro-2,4-dinitrobenzene (200 500 nmol/min/mg protein), and reduced glutathione (0.5 2.0 mmol/kg tissue). 2. Only kidney and intestinal caeca have substantial gamma-glutamyl transpeptidase activity with gamma-glutamyl-rho-nitroanilide (2-9 nmol/min/mg protein). 3. Renal gamma-glutamyl transpeptidase is membrane-bound and has similar kinetic properties to its mammalian counterparts. 4. The data are consistent with the presence of a mercapturic acid pathway in trout.


Assuntos
Aciltransferases/metabolismo , Glutationa Transferase/metabolismo , Salmonidae/metabolismo , Truta/metabolismo , Animais , Ceco/enzimologia , Brânquias/enzimologia , Rim/enzimologia , Cinética , Fígado/enzimologia , Distribuição Tecidual , Transglutaminases
8.
Biochim Biophys Acta ; 575(3): 358-64, 1979 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-518893

RESUMO

Intestinal preparations from rainbow trout fed a diet rich in wax esters incorporated [1(-14)C]hexadecanoic acid and [1(-14)C]hexadecanol into triacylglycerols at the same rate. The ratio of the number of H atoms from C1 of hexadecanol to the number of molecules of hexadecanol incorporated into triacylglycerols was 1.6 : 3.0. [U-14C]Glucose was incorporated much faster into the glycerol moiety of triacylglycerols than was [U-14C]aspartic acid. We conclude that the oxidation of absorbed fatty alcohol to fatty acid and its subsequent incorporation into triacylglycerols is closely linked with the reductive formation of triacylglycerol-glycerol from glucose. The ability of trout intestines to metabolise fatty alcohol to triacylglycerols was the same in fish fed wax esters as in those fed triacylglycerols.


Assuntos
Mucosa Intestinal/metabolismo , Salmonidae/metabolismo , Triglicerídeos/biossíntese , Truta/metabolismo , Ceras , Animais , Dieta , Ésteres , Plâncton
10.
Cell Tissue Res ; 200(3): 475-86, 1979 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-487412

RESUMO

Rainbow trout were killed 4 and 18 h after being fed wax ester-rich marine zooplankton and the absorptive epithelium of the pyloric caeca examined by electron microscopy. Numerous osmiophilic drops were seen in the lamina propria underlying the epithelium of fish killed at both times, but these drops were only abundant within columnar epithelial cells of fish killed 4 h after feeding. Pinocytotic profiles were not common at the luminal plasma membranes, nor were osmiophilic droplets seen in the terminal web area between the luminal plasma membrane and the extensive smooth endoplasmic reticulum. Numerous osmiophilic droplets, 30--100 nm in diameter, were present in the cisternae of the smooth endoplasmic reticulum with up to five separate droplets per individual cisterna. Columnar epithelial cells also contained up to 100 large osmiophilic drops ("conglomerates") which tended to be concentrated in the supranuclear (Golgi) regions. The conglomerates were 250--1200 nm in diameter and were themselves made up of smaller droplets 30--400 nm in diameter. Conglomerates were present both within intracellular membranes and free in the cytoplasm. Osmiophilic droplets in the intercellular spaces and lamina propria were similar in size to individual droplets within conglomerates. We conclude that triacylglycerols are elaborated in the smooth endoplasmic reticulum, transferred to and processed in the Golgi region and finally discharged serosally as chylomicron-like particles of not greater than 400 nm diameter.


Assuntos
Absorção Intestinal , Metabolismo dos Lipídeos , Plâncton , Piloro/metabolismo , Zooplâncton , Animais , Retículo Endoplasmático/ultraestrutura , Mucosa Intestinal/metabolismo , Intestinos/ultraestrutura , Microvilosidades/ultraestrutura , Piloro/ultraestrutura , Truta , Ceras
11.
Biochem J ; 169(2): 437-40, 1978 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-629767

RESUMO

A simple model of zonal gel filtration is analysed numerically to establish semiquantitatively how the capacity of a protein-ligand complex to survive gel filtration intact depends on several experimental variables and on the kinetic characteristics of the complex. The design of gel-filtration experiments aimed at detecting and partially purifying binding proteins is discussed.


Assuntos
Cromatografia em Gel , Ligantes/análise , Proteínas/análise , Cinética , Modelos Químicos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...