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1.
Biomed Chromatogr ; 33(2): e4388, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30238481

RESUMO

In this study, we developed a method for the determination of Penicillium griseofulvum-oriented pyripyropene A (PPPA), a selective inhibitor of acyl-coenzyme A:cholesterol acyltransferase 2, in mouse and human plasma and validated it using liquid chromatography-tandem mass spectrometry. Pyripyropene A (PPPA) and an internal standard, carbamazepine, were separated using a Xterra MS C18 column with a mixture of acetonitrile and 0.1% formic acid as the mobile phase. The ion transitions monitored in positive-ion mode [M + H]+ of multiple-reaction monitoring (MRM) were m/z 148.0 from m/z 584.0 for PPPA and m/z 194.0 from m/z 237.0 for the internal standard. The detector response was specific and linear for PPPA at concentrations within the range from 1 to 5,000 ng/mL. The intra-/inter-day precision and accuracy of the method was acceptable by the criteria for assay validation. The matrix effects of PPPA ranged from 97.6 to 104.2% and from 93.3 to 105.3% in post-preparative mouse and human plasma samples, respectively. PPPA was also stable under various processing and/or handling conditions. Finally, PPPA concentrations in the mouse plasma samples could be measured after intravenous, intraperitoneal, or oral administration of PPPA, suggesting that the assay is useful for pharmacokinetic studies on mice and applicable to human studies.


Assuntos
Cromatografia Líquida/métodos , Penicillium/química , Piridinas/sangue , Piridinas/farmacocinética , Sesquiterpenos/sangue , Sesquiterpenos/farmacocinética , Espectrometria de Massas em Tandem/métodos , Animais , Estabilidade de Medicamentos , Modelos Lineares , Masculino , Camundongos , Camundongos Endogâmicos ICR , Piridinas/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Sesquiterpenos/química , Esterol O-Aciltransferase/antagonistas & inibidores
2.
Micromachines (Basel) ; 8(10)2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-30400478

RESUMO

We present an electromagnetic linear vibration energy harvester with an array of rectangular permanent magnets as a springless proof mass. Instead of supporting the magnet assembly with spring element, ferrofluid has been used as a lubricating material. When external vibration is applied laterally to the harvester, magnet assembly slides back and forth on the channel with reduced friction and wear due to ferrofluid, which significantly improves the long-term reliability of the device. Electric power is generated across an array of copper windings formed at the bottom of the aluminum housing. A proof-of-concept harvester has been fabricated and tested with a vibration exciter at various input frequencies and accelerations. For the device where 5 µL of ferrofluid was used for lubrication, maximum output power of 493 µW has been generated, which was 4.37% higher than that without ferrofluid. Long-term reliability improvement due to ferrofluid lubrication has also been verified. For the device with ferrofluid, 1.02% decrease of output power has been observed, in contrast to 59.73% decrease of output power without ferrofluid after 93,600 cycles.

3.
Food Chem Toxicol ; 96: 244-53, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27523289

RESUMO

In this study, the hepatic expression of cytochrome P450 (CYP) enzymes, including CYP1A1/2, 2B1, 2C11, 2E1, 3A1/2, and 4A, was investigated in 5-week-old (insulinresistant state) and 11-week-old (diabetic) Zucker diabetic fatty (ZDF) rats. Serum glucose and glycated hemoglobin levels were increased in 11-week-old ZDF rats, but not in 5-weekold ZDF rats. Hyperinsulinemia was observed in both age groups. The microsomal protein, total CYP, CYP reductase, CYP1A1/2, and CYP3A1 levels did not differ between 5- and 11-week-old ZDF rats and their respective control rats, while CYP4A was up-regulated in both groups. Hepatic levels of cytochrome b5, CYP2B1, CYP2C11, CYP2E1, and CYP3A2 were decreased in 5-week-old ZDF rats, but not in 11-week-old ZDF rats. Similarly, pentoxyresorufin O-depentylase, testosterone 2α- and 16α-hydroxylase, chlorzoxazone 6- hydroxylase, and midazolam 1'- and 4-hydroxylase activities were decreased only in 5-weekold ZDF rats. Based on these results, the 5-week-old ZDF rats exhibited down-regulation of the major CYP enzymes. These results suggest that hepatic expression of CYP enzymes may be dysregulated during development in ZDF rats. With the exception of CYP2B1 and CYP4A, the hepatic levels and activities of CYP were comparable between 11-week-old ZDF and control rats, suggesting that xenobiotic metabolism is normally regulated in the early diabetic state.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Microssomos Hepáticos/enzimologia , Fatores Etários , Animais , Immunoblotting , Masculino , Ratos , Ratos Zucker
4.
Int J Syst Evol Microbiol ; 61(Pt 4): 938-41, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20495024

RESUMO

A Gram-negative, aerobic, non-motile, yellow-pigmented, rod-shaped bacterium (strain JS-08(T)) isolated from seawater was subjected to a polyphasic taxonomic study. 16S rRNA gene sequence analysis indicated that strain JS-08(T) belongs to the genus Myroides, a member of the phylum Bacteroidetes. Its closest phylogenetic relative was Myroides odoratimimus JCM 7460(T), with which it shared 97.0 % 16S RNA gene sequence similarity. Strain JS-08(T) contained menaquinone-6 (MK-6) as the predominant menaquinone, and the dominant fatty acids were iso-C(15 : 0), iso-C(17 : 0) 3-OH and a summed feature consisting of iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c. The DNA G+C content of strain JS-08(T) was 34.2 mol%. Based on phenotypic, genotypic and phylogenetic evidence, it is suggested that strain JS-08(T) represents a novel species of the genus Myroides, for which the name Myroides marinus sp. nov. is proposed. The type strain is JS-08(T) ( = KCTC 23023(T)  = JCM 16529(T)).


Assuntos
Flavobacteriaceae/classificação , Flavobacteriaceae/isolamento & purificação , Água do Mar/microbiologia , Aerobiose , Técnicas de Tipagem Bacteriana , Composição de Bases , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Flavobacteriaceae/genética , Flavobacteriaceae/fisiologia , Locomoção , Dados de Sequência Molecular , Filogenia , Pigmentos Biológicos/metabolismo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análise
5.
Int J Syst Evol Microbiol ; 61(Pt 11): 2654-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21148671

RESUMO

A Gram-reaction-negative, yellow-pigmented, gliding, rod-shaped, aerobic bacterium (RA5-111(T)) was isolated from foreshore soil. The taxonomic status of the novel isolate was determined using a polyphasic approach. On the basis of 16S rRNA gene sequence similarities, strain RA5-111(T) could be assigned to the genus Gramella, with sequence similarities of 97.7, 97.3 and 96.2 % to the type strains of Gramella echinicola, Gramella portivictoriae and Gramella marina, respectively. Chemotaxonomic and phenotypic characteristics also supported the affiliation of strain RA5-111(T) with the genus Gramella. The genomic DNA G+C content was 39.1 mol%. The isolate contained MK-6 as the predominant menaquinone, iso-C(15 : 0), iso-C(17 : 0) 3-OH and a summed feature (iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c) as major fatty acids, and phosphatidylethanolamine and unknown phospholipids as the polar lipids. DNA-DNA relatedness, phenotypic, genotypic and chemotaxonomic data clearly indicate that the isolate represents a novel species of the genus Gramella, for which the name Gramella gaetbulicola sp. nov. is proposed. The type strain is RA5-111(T) ( = KCTC 23022(T) = JCM 16528(T) = NBRC 106272(T)).


Assuntos
Flavobacteriaceae/classificação , Flavobacteriaceae/isolamento & purificação , Microbiologia do Solo , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/metabolismo , Flavobacteriaceae/genética , Flavobacteriaceae/metabolismo , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética
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