High-density electron anions in a nanoporous single crystal: [Ca24Al28O64]4+(4e-)   总被引：1，自引：0，他引：1  

Matsuishi S  Toda Y  Miyakawa M  Hayashi K  Kamiya T  Hirano M  Tanaka I  Hosono H 《Science (New York, N.Y.)》2003,301(5633):626-629

We removed approximately 100% of clathrated oxygen ions from the crystallographic cages in a single crystal of 12CaO.7Al2O3, leading to the formation of high-density (approximately 2 x 10(21) cm-3) electrons highly localized in the cages. The resulting electron forms a structure that we interpret as an F+ center and migrates throughout the crystal by hopping to a neighboring cage with conductivity approximately 100 siemens per centimeter, demonstrating that the encaged electron behaves as an anion. The electron anions couple antiferromagnetically with each other, forming a diamagnetic pair or singlet bipolaron. The resulting [Ca24Al28O64]4+(4e-) may be regarded as a thermally and chemically stable single crystalline "electride."  相似文献   

Early origin and recent expansion of Plasmodium falciparum     

Joy DA  Feng X  Mu J  Furuya T  Chotivanich K  Krettli AU  Ho M  Wang A  White NJ  Suh E  Beerli P  Su XZ 《Science (New York, N.Y.)》2003,300(5617):318-321

The emergence of virulent Plasmodium falciparum in Africa within the past 6000 years as a result of a cascade of changes in human behavior and mosquito transmission has recently been hypothesized. Here, we provide genetic evidence for a sudden increase in the African malaria parasite population about 10,000 years ago, followed by migration to other regions on the basis of variation in 100 worldwide mitochondrial DNA sequences. However, both the world and some regional populations appear to be older (50,000 to 100,000 years old), suggesting an earlier wave of migration out of Africa, perhaps during the Pleistocene migration of human beings.  相似文献   

MET amplification leads to gefitinib resistance in lung cancer by activating ERBB3 signaling     

Engelman JA  Zejnullahu K  Mitsudomi T  Song Y  Hyland C  Park JO  Lindeman N  Gale CM  Zhao X  Christensen J  Kosaka T  Holmes AJ  Rogers AM  Cappuzzo F  Mok T  Lee C  Johnson BE  Cantley LC  Jänne PA 《Science (New York, N.Y.)》2007,316(5827):1039-1043

The epidermal growth factor receptor (EGFR) kinase inhibitors gefitinib and erlotinib are effective treatments for lung cancers with EGFR activating mutations, but these tumors invariably develop drug resistance. Here, we describe a gefitinib-sensitive lung cancer cell line that developed resistance to gefitinib as a result of focal amplification of the MET proto-oncogene. inhibition of MET signaling in these cells restored their sensitivity to gefitinib. MET amplification was detected in 4 of 18 (22%) lung cancer specimens that had developed resistance to gefitinib or erlotinib. We find that amplification of MET causes gefitinib resistance by driving ERBB3 (HER3)-dependent activation of PI3K, a pathway thought to be specific to EGFR/ERBB family receptors. Thus, we propose that MET amplification may promote drug resistance in other ERBB-driven cancers as well.  相似文献   

Food-drug interaction between ferulic acid and nateglinide involving the fluorescein/H+ cotransport system   总被引：2，自引：0，他引：2  

Itagaki S  Kobayashi Y  Otsuka Y  Kubo S  Kobayashi M  Hirano T  Iseki K 《Journal of agricultural and food chemistry》2005,53(7):2499-2502

In clinical, patients usually take many kinds of drugs at the same time. Thus, drug-drug interactions involving transporters can often directly affect the therapeutic safety and efficacy of many drugs. However, there have been few studies on food-drug interactions involving transporters. Dietary polyphenols have been widely assumed to be beneficial to human health. Polyphenols are commercially prepared and used as functional foods. We report here for the first time that ferulic acid, which is widely used as a functional food, affects the transport of clinical agents. It is important to be aware of the potential of food-drug interactions and to act in order to prevent undesirable and harmful clinical consequences.  相似文献   

Reduced immunogenicity of beta-lactoglobulin by conjugation with carboxymethyl dextran differing in molecular weight   总被引：2，自引：0，他引：2  

Kobayashi K  Hirano A  Ohta A  Yoshida T  Takahashi K  Hattori M 《Journal of agricultural and food chemistry》2001,49(2):823-831

To reduce the immunogenicity of beta-lactoglobulin (beta-LG), two beta-LG-carboxymethyl dextran (CMD) conjugates (Conj. 40 and Conj. 162) were prepared by using water-soluble carbodiimide (EDC). The molar ratios of beta-LG to CMD in Conj. 40 and Conj. 162 were 8:1 and 7:1, respectively. Each conjugate maintained approximately 50% of the retinol binding activity of beta-LG. Structural analyses by intrinsic fluorescence, CD spectra, and ELISA with monoclonal antibodies indicated that the surface of beta-LG in each conjugate was covered by CMD without great disruption of native conformation. By conjugation with CMD, the antibody response to beta-LG was reduced in BALB/c, C3H/He, and C57BL/6 mice, which was eminent in Conj. 162. The results of B cell epitope scanning using overlapping synthesized peptides showed that the linear epitope profiles of the conjugates were similar to those of beta-LG, whereas the antibody response to each epitope was reduced, which was eminent in Conj. 162. It was concluded that conjugation with CMD of higher molecular weight is effective in reducing the immunogenicity of beta-LG and that masking of epitopes by CMD is responsible for the reduced immunogenicity.  相似文献   

Effects of phosphate supply and elevated CO2 on root acid phosphatase activity in Pinus densiflora seedlings     

Mariko Norisada  Tetsuya Motoshige  Katsumi Kojima  Takeshi Tange 《植物养料与土壤学杂志》2006,169(2):274-279

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Extended glucuronidation is another major path of cyanidin 3-O-beta-D-glucopyranoside metabolism in rats     

Ichiyanagi T  Shida Y  Rahman MM  Hatano Y  Konishi T 《Journal of agricultural and food chemistry》2005,53(18):7312-7319

We previously determined that five rather hydrophobic metabolites appeared in blood plasma after oral administration of cyanidin 3-O-beta-D-glucopyranoside, but a group of hydrophilic metabolites still remained unidentified. In the present study, 12 hydrophilic metabolites found were collected from urine and plasma samples by high-performance liquid chromatography (HPLC) and then analyzed by tandem MS spectrometry. From the MS spectra, four metabolites out of 12 were assigned as glucuronides of cyanidin 3-O-beta-D-glucopyranoside and six out of 12 were glucuronides of the primary metabolites of cyanidin 3-O-beta-D-glucopyranoside (O-methyl cyanidin 3-O-beta-D-glucopyranoside). Extended glucuronides of cyanidin 3-O-beta-D-glucopyranoside and O-methyl cyanidin 3-O-beta-D-glucopyranoside showed their maximum plasma concentrations at 15 and 60 min (or 30 min) after oral administration, respectively. Their maximum plasma concentrations ranged from 15 to 70 nM. From the profile of urinary-excreted anthocyanins after intravenous administration, it was deduced that extended glucuronides of cyanidin 3-O-beta-D-glucopyranoside and O-methyl cyanidin 3-O-beta-D-glucopyranoside were mainly produced in the liver rather than by intestinal flora. The area under the plasma concentration curve was 0.25 micromol min/L for extended glucuronides of cyanidin 3-O-beta-D-glucopyranoside and 0.14 micromol min/L for O-methyl cyanidin 3-O-beta-D-glucopyranoside, respectively, when evaluated as cyanidin 3-O-beta-D-glucopyranoside equivalent, indicating that extended glucuronidation is a critical pathway in cyanidin 3-O-beta-D-glucopyranoside metabolism in rats.  相似文献   

A survey of feline respiratory infections     

N Hirano  R Sato  Y Matsuda 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1986,48(2):423-427

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Pathogenicity of Mycoplasma synoviae in chicken tracheal organ cultures   总被引：1，自引：0，他引：1  

H Hirano  E Hayatsu  K Kume  Y Kawakubo  S Nakagawa  Y Nishiyama  M Yoshioka 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1978,40(2):147-156

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Serum creatine kinase activities in dogs with dirofilariasis.     

H Kitagawa  M Kano  Y Sasaki  Y Hirano 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(4):569-575

Total serum creatine kinase (CK) and its isozyme activities were determined in dogs with dirofilariasis. Before heartworm removal, total CK and isozyme activities in dogs of the mild group were not different from those in dogs of the heartworm-free group. BB activity was higher in dogs of the hemoptysis group. Dogs of the ascites group displayed a mild increase in MM activity. In dogs of the caval syndrome (CS) group, total CK and MM activities were highest among the heartworm-free and heartworm-infected dogs, and MM isozyme accounted for most (75%) of total CK activity. MB and BB activities were also higher. However, there were no significant differences in CK activities between the surviving and non-surviving cases. In dogs with pulmonary heartworm disease (mild and ascites groups), MM activity correlated significantly with the number of heartworms (r = 0.45), hematocrit value (Ht, r = -0.40), serum alanine aminotransferase (ALT, r = 0.42) and lactate dehydrogenase (LDH, r = 0.46) activities, mean pulmonary arterial pressure (r = 0.64) and total pulmonary resistance (r = 0.50). In dogs with CS, MM activity did not correlate with any parameter, but BB activity correlated with the number of heartworms at the right atrium (r = 0.61), Ht (r = -0.53), ALT (r = 0.80), LDH (r = 0.73) and serum urea nitrogen (r = 0.47). At 1 week after heartworm removal, BB and MM activity decreased in dogs of the hemoptysis and ascites groups, respectively. In dogs of the CS group, total CK and MM isozyme activities decreased markedly (P less than 0.01) regardless of their prognosis.  相似文献