Antitumor activity of compounds isolated from leaves of Eriobotrya japonica   总被引：3，自引：0，他引：3  

Ito H  Kobayashi E  Li SH  Hatano T  Sugita D  Kubo N  Shimura S  Itoh Y  Tokuda H  Nishino H  Yoshida T 《Journal of agricultural and food chemistry》2002,50(8):2400-2403

In a search for possible antitumor agents from natural sources, megastigmane glycosides and polyphenolic constituents isolated from the leaves of Eriobotrya japonica (Rosaceae) were found to inhibit the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced activation of Epstein-Barr virus early antigen in Raji cells. Roseoside and procyanidin B-2 were among the active compounds found in an in vitro assay; these compounds were further assessed for antitumor activity in vivo in a two-stage carcinogenesis assay on mouse skin. Roseoside significantly delayed carcinogenesis induced by peroxynitrite (initiator) and TPA (promoter), and its potency was comparable to that of a green tea polyphenol, (-)-epigallocatechin 3-O-gallate, in the same assay.  相似文献   

Anaemia, iron deficiency and vitamin A status among school-aged children in rural Kazakhstan     

Hashizume M  Chiba M  Shinohara A  Iwabuchi S  Sasaki S  Shimoda T  Kunii O  Caypil W  Dauletbaev D  Alnazarova A 《Public health nutrition》2005,8(6):564-571

OBJECTIVES: To investigate the prevalence of anaemia and iron deficiency and vitamin A status among school-aged children in rural Kazakhstan and identify factors associated with anaemia in this population. DESIGN: A cross-sectional design. SETTING: School-aged children in rural Kazakhstan. SUBJECTS: Socio-economic and anthropometric information was collected from 159 school-aged children living in the Kzyl-Orda region of Kazakhstan. Blood samples were collected and the concentrations of haemoglobin (Hb), serum iron, serum ferritin (SF), erythrocyte protoporphyrin (EP), serum retinol and beta-carotene, total iron binding capacity (TIBC), transferrin saturation (TS) and other haematological indices were measured. RESULTS: Among the 159 children, the prevalence of anaemia and iron deficiency defined by the multiple criteria model (SF, TS and EP) was 27% and 13%, respectively. Nine per cent had iron-deficiency anaemia and 21% had serum retinol value < 1.05 micromol l(-1). Mean SF and serum iron concentrations and TS were significantly lower in anaemic children than in their non-anaemic peers, while TIBC and EP were significantly higher in children with anaemia. Hb was significantly correlated with serum iron and retinol concentrations. Serum retinol and SF concentrations and mean corpuscular volume were significantly correlated with Hb by multiple regression analysis. CONCLUSIONS: Anaemia among school-aged children in rural Kazakhstan appears to be related to iron indices and vitamin A status.  相似文献   

Identification and semiquantitation of monensin sodium in liver tissue     

E E Martinez  W Shimoda 《Journal of the Association of Official Analytical Chemists》1984,67(4):845-846

A bioautographic technique for the determination of monensin sodium in animal feed has been applied to chicken and beef liver tissues. The reliable limit of sensitivity is 100 ppb, but 10 ppb can be detected. This technique can be used to semiquantitate monensin in tissues by comparing the zones of inhibition of unknown test samples against monensin standards.  相似文献   

Traces of human migrations in Helicobacter pylori populations     

Falush D  Wirth T  Linz B  Pritchard JK  Stephens M  Kidd M  Blaser MJ  Graham DY  Vacher S  Perez-Perez GI  Yamaoka Y  Mégraud F  Otto K  Reichard U  Katzowitsch E  Wang X  Achtman M  Suerbaum S 《Science (New York, N.Y.)》2003,299(5612):1582-1585

Helicobacter pylori, a chronic gastric pathogen of human beings, can be divided into seven populations and subpopulations with distinct geographical distributions. These modern populations derive their gene pools from ancestral populations that arose in Africa, Central Asia, and East Asia. Subsequent spread can be attributed to human migratory fluxes such as the prehistoric colonization of Polynesia and the Americas, the neolithic introduction of farming to Europe, the Bantu expansion within Africa, and the slave trade.  相似文献   

Cartilage acidic protein-1B (LOTUS), an endogenous Nogo receptor antagonist for axon tract formation     

Sato Y  Iketani M  Kurihara Y  Yamaguchi M  Yamashita N  Nakamura F  Arie Y  Kawasaki T  Hirata T  Abe T  Kiyonari H  Strittmatter SM  Goshima Y  Takei K 《Science (New York, N.Y.)》2011,333(6043):769-773

Neural circuitry formation depends on the molecular control of axonal projection during development. By screening with fluorophore-assisted light inactivation in the developing mouse brain, we identified cartilage acidic protein-1B as a key molecule for lateral olfactory tract (LOT) formation and named it LOT usher substance (LOTUS). We further identified Nogo receptor-1 (NgR1) as a LOTUS-binding protein. NgR1 is a receptor of myelin-derived axon growth inhibitors, such as Nogo, which prevent neural regeneration in the adult. LOTUS suppressed Nogo-NgR1 binding and Nogo-induced growth cone collapse. A defasciculated LOT was present in lotus-deficient mice but not in mice lacking both lotus- and ngr1. These findings suggest that endogenous antagonism of NgR1 by LOTUS is crucial for normal LOT formation.  相似文献   

Control mechanism of the circadian clock for timing of cell division in vivo     

Matsuo T  Yamaguchi S  Mitsui S  Emi A  Shimoda F  Okamura H 《Science (New York, N.Y.)》2003,302(5643):255-259

Cell division in many mammalian tissues is associated with specific times of day, but just how the circadian clock controls this timing has not been clear. Here, we show in the regenerating liver (of mice) that the circadian clock controls the expression of cell cycle-related genes that in turn modulate the expression of active Cyclin B1-Cdc2 kinase, a key regulator of mitosis. Among these genes, expression of wee1 was directly regulated by the molecular components of the circadian clockwork. In contrast, the circadian clockwork oscillated independently of the cell cycle in single cells. Thus, the intracellular circadian clockwork can control the cell-division cycle directly and unidirectionally in proliferating cells.  相似文献   

Recovery of antioxidant activity from carnosol quinone: antioxidants obtained from a water-promoted conversion of carnosol quinone     

Masuda T  Kirikihira T  Takeda Y 《Journal of agricultural and food chemistry》2005,53(17):6831-6834

Carnosol is one of the main antioxidants in sage and rosemary. Although carnosol quinone is the antioxidation product of carnosol and has a very weak antioxidant activity, its treatment in water-containing solvent restored its strong antioxidant activity. HPLC analysis of the water-stimulated recovery reaction of the antioxidant activity revealed that the strong activity was due to the reproduced carnosol. The analysis also showed that an almost equal amount of quinone derivatives of rosmanol (rosmanol quinone) was produced in the reaction along with the carnosol. The rosmanol was formed by the addition of 1 equiv of water and the following isomerization from carnosol quinone in the water-containing solvent. The formed rosmanol was also found to be oxidized by the remaining carnosol quinone to produce rosmanol quinone. At the same time, carnosol quinone was reduced to afford carnosol. This redox phenomenon is an important part of the mechanism for the recovery of the antioxidant activity from carnosol quinone under the water-containing conditions.  相似文献   

Determination of gentian violet, its demethylated metabolites, and leucogentian violet in chicken tissue by liquid chromatography with electrochemical detection   总被引：1，自引：0，他引：1  

J E Roybal  R K Munns  J A Hurlbut  W Shimoda 《Journal of the Association of Official Analytical Chemists》1990,73(6):940-946

A method is presented for determination of residues of gentian violet (GV), its demethylated metabolites (pentamethyl and tetramethyl), and leucogentian violet (LGV) in chicken tissue. The analytes are extracted from tissue with acetonitrile/buffer and partitioned into methylene chloride. Polar lipids are removed on an alumina column followed by partitioning into methylene chloride from a citrate buffer. The compounds of interest are isolated on a disposable carboxylic acid cation exchange column and then eluted with 0.02% HCl in methanol. GV, its metabolites, and LGV are determined by liquid chromatography using isocratic elution with a buffered mobile phase from a cyano column and amperometric electrochemical detection at +1.000 V. Average recoveries of GV and LGV from commercially purchased chicken liver fortified with 20 ppb of each compound were 92% [standard deviation (SD) = 7, coefficient of variation (CV) = 7.6%] and 86% (SD = 7, CV = 8.1%), respectively. Average recoveries of GV, LGV, the pentamethyl metabolite, and 1 of the tetramethyl metabolites from control chicken liver (provided by the Center for Veterinary Medicine) fortified with 20 ppb of each compound were 80% (SD = 7, CV = 8.8%), 76% (SD = 3, CV = 3.9%), 83% (SD = 6, CV = 7.2%), and 76% (SD = 8, CV = 10.5%), respectively. Mean results from 10 analyses of residue-incurred chicken liver were 31 ppb GV (SD = 3, CV = 9.7%), 34 ppb pentamethyl metabolite (SD = 3, CV = 8.8%), and 40 ppb tetramethyl metabolite(s) (SD = 2, CV = 5.0%), for an average value of 105 ppb total residues (SD = 6, CV = 5.7%); no LGV was found. Data are also presented to show applicability of the method to muscle tissue.  相似文献   

Multiresidue method for determination of eight neutral beta-lactam penicillins in milk by fluorescence-liquid chromatography     

R K Munns  W Shimoda  J E Roybal  C Vieira 《Journal of the Association of Official Analytical Chemists》1985,68(5):968-971

A method of determining total penicillins begins with an enzymatic hydrolysis of the beta-lactam ring to form their respective penicilloate product. Acetonitrile precipitates much of the casein and protein, which are then separated from the liquid by centrifugation. The lipids are removed from the aqueous fraction with methylene chloride. Mercuric chloride is added, which reacts with the penicilloate to liberate the side chain that has a terminal aldehyde. These penilloaldehyde products are extracted with methylene chloride and are subsequently reacted with dansyl hydrazine. The resulting fluorolabeled side chains are separated by liquid chromatography on a C18 column with acetonitrile-water as mobile phase. The fluorescence is measured by the mercury line at 254 nm excitation wavelength and a 500 nm filter on the emission side. The overall average recoveries from milk spiked at 25, 50, and 100 ppb are benzyl penicillin 79.4%; phenoxymethyl penicillin 59.7%; phenethicillin 75.9%; nafcillin 87.7%; methacillin 47.5%; oxacillin 57.6%; cloxicillin 37.3%; and dicloxicillin 26.4%.  相似文献   

Inhibitory effect of several fluoroquinolones on hepatic microsomal cytochrome P-450 1A activities in dogs     

Regmi NL  Abd El-Aty AM  Kuroha M  Nakamura M  Shimoda M 《Journal of veterinary pharmacology and therapeutics》2005,28(6):553-557

We examined inhibitory effects of ofloxacin (OFX), orbifloxacin (OBFX), ciprofloxacin (CFX), enrofloxacin (EFX) and norfloxacin (NFX) on cytochrome P-450 1A (CYP1A) activities using hepatic microsomes from four beagle dogs. Ethoxyresorufin O-de-ethylation was referred as CYP1A activities. All the fluoroquinolones inhibited the reaction in a noncompetitive manner. The determined inhibitory constants were the followings; 10.1 +/- 3.8 mM for OFX, 6.43 +/- 2.01 mM for OBFX, 0.726 +/- 0.134 mM for CFX, 4.06 +/- 1.19 mM for EFX and 4.75 +/- 1.63 mM for NFX respectively. As these values are >100-fold of plasma concentrations after a clinical single dose of the fluoroquinolones, it is suggested that the inhibitory effect on CYP1A activities is not so high to elicit drug-drug interaction with CYP1A substrates, when these fluoroquinolones are co-administered. Mechanism based inhibition was also examined in this study. Of the five fluoroquinolones examined, OFX, OBFX and CFX had this inhibition manner. As this inhibition is irreversible, inhibitory effects of the three fluoroquinolones may accumulate, when they are repeatedly administered. Therefore, OFX, OBFX and CFX may result in substantial drug-drug interaction with a CYP1A substrate even in clinical states. As EFX is metabolized to CFX in the body, it may also have the same possibility.  相似文献