Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Zookeys ; (760): 73-88, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29872364

RESUMO

A new brackish-water species of melitid amphipod, Melita choshigawaensis, from the Choshigawa River, Mie Prefecture, Japan, is named and described. Melita choshigawaensissp. n. is distinguished from the most similar M. shimizui (Uéno, 1940) by having an elongate and weakly arched male uropod 3, and a deep and strongly hooked anterior lobe of the coxa on the female's pereopod 6. Nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) of M. choshigawaensis and M. shimizui support divergence at the species level. A key to the Japanese species of Melita is provided.

2.
Blood ; 131(4): 426-438, 2018 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-29187377

RESUMO

An activating mutation of Fms-like tyrosine kinase 3 (FLT3) is the most frequent genetic alteration associated with poor prognosis in acute myeloid leukemia (AML). Although many FLT3 inhibitors have been clinically developed, no first-generation inhibitors have demonstrated clinical efficacy by monotherapy, due to poor pharmacokinetics or unfavorable safety profiles possibly associated with low selectivity against FLT3 kinase. Recently, a selective FLT3 inhibitor, quizartinib, demonstrated favorable outcomes in clinical studies. However, several resistant mutations emerged during the disease progression. To overcome these problems, we developed a novel FLT3 inhibitor, FF-10101, designed to possess selective and irreversible FLT3 inhibition. The co-crystal structure of FLT3 protein bound to FF-10101 revealed the formation of a covalent bond between FF-10101 and the cysteine residue at 695 of FLT3. The unique binding brought high selectivity and inhibitory activity against FLT3 kinase. FF-10101 showed potent growth inhibitory effects on human AML cell lines harboring FLT3 internal tandem duplication (FLT3-ITD), MOLM-13, MOLM-14, and MV4-11, and all tested types of mutant FLT3-expressing 32D cells including quizartinib-resistant mutations at D835, Y842, and F691 residues in the FLT3 kinase domain. In mouse subcutaneous implantation models, orally administered FF-10101 showed significant growth inhibitory effect on FLT3-ITD-D835Y- and FLT3-ITD-F691L-expressing 32D cells. Furthermore, FF-10101 potently inhibited growth of primary AML cells harboring either FLT3-ITD or FLT3-D835 mutation in vitro and in vivo. These results indicate that FF-10101 is a promising agent for the treatment of patients with AML with FLT3 mutations, including the activation loop mutations clinically identified as quizartinib-resistant mutations.


Assuntos
Amidas/uso terapêutico , Antineoplásicos/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/genética , Amidas/farmacocinética , Amidas/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Camundongos , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacocinética , Pirimidinas/farmacologia , Tirosina Quinase 3 Semelhante a fms/química
3.
Bioorg Med Chem Lett ; 23(16): 4557-61, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23845222

RESUMO

The structure-activity relationship of phenylpyrazole derivative 1 was investigated for the development of novel anti-HIV agents. Initial efforts revealed that the diazenyl group can be replaced by an aminomethylene group. In addition, we synthesized various derivatives by the reductive amination of benzaldehydes with 5-aminopyrazoles and carried out parallel structural optimization on the benzyl group and the pyrazole ring. This optimization led to a six-fold more potent derivative 32j than the lead compound 1, and this derivative has a 3',4'-dichloro-(1,1'-biphenyl)-3-yl group.


Assuntos
Fármacos Anti-HIV/química , Derivados de Benzeno/síntese química , Pirazóis/síntese química , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/farmacologia , Derivados de Benzeno/química , Derivados de Benzeno/farmacologia , HIV/efeitos dos fármacos , Concentração Inibidora 50 , Pirazóis/química , Pirazóis/farmacologia , Relação Estrutura-Atividade
4.
Biol Bull ; 222(1): 1-5, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22426626

RESUMO

The phyllosoma, a larva of spiny and slipper lobsters, has an exceptionally flat body and long appendages. It is known to associate with several species of cnidarian jellyfish, a behavior that is not rare in crustaceans. Indeed, phyllosomas clinging onto jellyfish have been observed both in the laboratory and in the natural environment. Wild phyllosomas have been found to contain jellyfish tissues in their hepatopancreas and feces, suggesting that the larvae utilize jellyfish as a food source; however, how they capture jellyfish and what species of jellyfish they prefer have rarely been investigated. The few previous studies conducted have suggested that phyllosomas have a high specificity for jellyfish (preying on only a few species); in contrast, the results of our study indicate that specificity is low. We show that phyllosomas prey on a variety of jellyfish species including deadly stinging types, on a variety of jellyfish developmental stages, and on various parts of the jellyfish body. When making contact with a jellyfish, phyllosomas first cling onto its exumbrella, feed on its tentacles or oral arms, and then consume the exumbrella. Phyllosomas may be capable of defending themselves against any types of nematocyst sting, and it is likely that they have evolved to utilize venomous jellyfish as a food in the open sea, where food may be scarce.


Assuntos
Cnidários , Palinuridae/fisiologia , Comportamento Predatório/fisiologia , Animais , Preferências Alimentares/fisiologia , Larva/fisiologia , Especificidade da Espécie
5.
J Hepatobiliary Pancreat Surg ; 15(2): 237-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18392723

RESUMO

Carcinomatous meningitis is clinically less common than brain metastasis or spinal cord compression, but has dire consequences for both the quality of life and the overall survival of patients with various kinds of malignancies. It occurs in about 5% of all adult cancer patients, though autopsies may double this number. The primary tumors that frequently cause carcinomatous meningitis include lung cancer, breast cancer, leukemia, lymphoma, and melanoma. Carcinomatous meningitis secondary to primary tumors in the gastrointestinal tract is clinically infrequent. In this report, we describe a 73-year-old man with lower bile duct cancer, who developed carcinomatous meningitis following surgical resection of the primary cancer. To our knowledge, this is the third case of carcinomatous meningitis secondary to cholangiocarcinoma described in the literature so far.


Assuntos
Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos , Colangiocarcinoma/secundário , Neoplasias Meníngeas/secundário , Meningite/etiologia , Idoso , Neoplasias dos Ductos Biliares/cirurgia , Colangiocarcinoma/radioterapia , Colangiocarcinoma/cirurgia , Evolução Fatal , Humanos , Masculino , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/radioterapia
7.
Plant Cell Physiol ; 47(7): 995-1003, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16774928

RESUMO

Histone modifications such as methylation and acetylation in the chromatin surrounding a gene are thought to regulate transcriptional activity. In this study, to determine whether dynamic changes occur in histone modification on the loci of stress-responsive genes in plants, we chose rice submergence-inducible ADH1 and PDC1 genes. When submerged, the rice ADH1 and PDC1 genes were activated in a biphasic manner: the first and second inductions occurred after approximately 2 and 12 h of submergence, respectively. Their expression was transcriptionally induced as shown by increased binding of RNA polymerase II to the ADH1 and PDC1 loci during submergence. The Lys4 residues of the histone H3 proteins (H3-K4s) at both the 5'- and 3'-coding regions of ADH1 and PDC1 were found to change from a di-methylated state to a tri-methylated state at the first induction period. On the other hand, acetylation of H3 increased throughout ADH1 and PDC1 genes at the later induction period. The methylation and acetylation levels recovered to the initial levels during re-aeration. Treatment of seedlings with a histone deacetylase (HDAC) inhibitor, trichostatin A, increased acetylation of histones H3 and association of RNA polymerase II on the ADH1 and PDC1 loci, thereby increasing transcript levels of ADH1 and PDC1. Together, these results showed dynamic and reversible changes of histone H3-K4 methylation and H3 acetylation in stress-responsive genes in a higher plant in response to the appearance or disappearance of an environmental stress.


Assuntos
Genes de Plantas/genética , Histonas/metabolismo , Lisina/metabolismo , Oryza/genética , Acetilação/efeitos dos fármacos , Cromatina/metabolismo , DNA de Plantas/genética , DNA de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Histonas/genética , Ácidos Hidroxâmicos/farmacologia , Lisina/genética , Metilação/efeitos dos fármacos , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , RNA Polimerase II/metabolismo
9.
Mol Genet Genomics ; 274(6): 606-15, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16208489

RESUMO

A new type of transposon, named Anaconda (Anac) has been found in rice (Oryza sativa). In this paper, we demonstrate that Anaconda elements have diversified by acquisition of host cellular genes, amplification of the elements, and substitution and deletion of short segments. We identified four Anaconda elements in studies of rice alternative oxidase (AOX) genes, and subsequently isolated an additional 23 elements based on the identity of their terminal inverted repeats (TIRs). The Anaconda elements have long TIRs (114-458 bp). They also have direct repeats of 9 or 10 bp in their flanking regions that are thought to have been generated upon transposition. These structural features reveal that the Anaconda elements belong to the Mu superfamily. The most prominent feature of the Anaconda elements is the high frequency with which they have acquired host cellular genes. Of the 27 elements found here, 19 appear to have sequences presumably derived from rice genes, for example, the genes for AOX1c (four elements), cytochrome P450 (five elements), L: -asparaginase (five elements), and PCF8 (two elements). Four elements, AnacA1-A4, have both the AOX1c and P450 genes. One element, AnacB14, involves a gene similar to mudrA of maize MuDR. Database analyses revealed that the loci of 26 of the 27 Anaconda elements in the subspecies japonica are the same as those in the subspecies indica. This suggests that these elements were incorporated before the divergence of these two subspecies.


Assuntos
Elementos de DNA Transponíveis/genética , Evolução Molecular , Oryza/genética , Sequência de Aminoácidos , DNA de Plantas/genética , Proteínas Mitocondriais , Dados de Sequência Molecular , Oxirredutases/genética , Proteínas de Plantas , Homologia de Sequência de Aminoácidos , Sequências Repetidas Terminais/genética , Transposases/genética
10.
J Exp Bot ; 55(394): 145-6, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14645394

RESUMO

The rice pyruvate decarboxylase 3 gene (PDC3), which has no introns, was previously postulated to be a pseudogene because no PDC3 mRNA had been detected, even under anaerobic conditions. However, in this study, it was found that rice PDC3 transcripts accumulated in panicles after heading. Within anthers obtained from the panicles, PDC3 was shown to be transcribed in mature pollen by in situ hybridization. These results suggest that the rice PDC3 is a functional gene. Its product may play a role in aerobic alcoholic fermentation in mature pollen.


Assuntos
Íntrons/genética , Oryza/enzimologia , Proteínas de Plantas/genética , Pólen/enzimologia , Piruvato Descarboxilase/genética , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hibridização In Situ , Dados de Sequência Molecular , Oryza/genética , Proteínas de Plantas/metabolismo , Pólen/genética , Piruvato Descarboxilase/metabolismo
11.
Chem Commun (Camb) ; (19): 2482-3, 2003 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-14587742

RESUMO

A palladium-catalyzed stereospecific epoxide-opening reaction of gamma,delta-epoxy-alpha,beta-unsaturated esters with an alkylboronic acid leading to gamma,delta-vicinal diols is described, which proceeds with retention of the configuration, i.e., via two consecutive S(N)2 processes, to afford the corresponding gamma,delta-cyclic boronates in high yields.

12.
Org Biomol Chem ; 1(14): 2604-11, 2003 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-12956084

RESUMO

Treatment of a 1,7-diorgano[60]fullerene with Grignard reagents or organocopper reagents affords a [60]fullerene indenide or a [60]fullerene cyclopentadienide regioselectively in good to excellent yields. These reactions gave an insight into the reaction mechanism of the organocopper penta-addition reaction of [60]fullerene, giving [60]fullerene cyclopentadienide in quantitative yield.

13.
FEBS Lett ; 546(2-3): 369-73, 2003 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-12832071

RESUMO

Post-hypoxic injuries in plants are primarily caused by bursts of reactive oxygen species and acetaldehyde. In agreement with previous studies, we found accumulations of acetaldehyde in rice during re-aeration following submergence. During re-aeration, acetaldehyde-oxidizing aldehyde dehydrogenase (ALDH) activity increased, thereby causing the acetaldehyde content to decrease in rice. Interestingly, re-aerated rice plants showed an intense mitochondrial ALDH2a protein induction, even though ALDH2a mRNA was submergence induced and declined upon re-aeration. This suggests that rice ALDH2a mRNA is accumulated in order to quickly metabolize acetaldehyde that is produced upon re-aeration.


Assuntos
Acetaldeído/metabolismo , Aldeído Desidrogenase/biossíntese , Mitocôndrias/enzimologia , Oryza/metabolismo , Aldeído Desidrogenase/genética , Aldeído Desidrogenase/metabolismo , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Oryza/enzimologia , Oryza/genética , Oxirredução
14.
Org Lett ; 5(10): 1789-91, 2003 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-12735778

RESUMO

[reaction: see text] Highly efficient C2 selective substitution reactions of 2,3-epoxy alcohols with nucleophiles were developed by using NaN(3)-(CH(3)O)(3)B, NaSPh-(CH(3)O)(3)B, or NaCN-(C(2)H(5)O)(3)B system. The reaction proceeds through novel endo-mode epoxide opening of an intramolecular boron chelate, which was suggested from both experimental and quantum mechanic studies.

15.
Gene ; 305(2): 195-204, 2003 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-12609740

RESUMO

Recent studies have suggested that mitochondrial aldehyde dehydrogenase (aldehyde:NAD(P)(+) oxidoreductase, EC 1.2.1.3) (ALDH2) plays essential roles in pollen development in plants. Rice (Oryza sativa L.) ALDH2 is encoded by at least two ALDH2 genes, one of which (ALDH2a) was previously identified. In this study, to understand the roles of ALDH2 in rice, we isolated and characterized a cDNA clone encoding another rice ALDH2 (ALDH2b). An in vitro ALDH assay indicated that ALDH2b possesses an NAD(+)-linked activity for oxidation of acetaldehyde, glycolaldehyde and propionaldehyde. Northern blot and immunoblot analyses revealed that ALDH2b was constitutively present in all the organs examined, whereas ALDH2a was expressed in leaves of dark-grown seedlings and panicles. By RFLP linkage mapping, the ALDH2a and ALDH2b genes were mapped to the long arm of chromosome 2 and the short arm of chromosome 6, respectively. We suggest that the rice ALDH2a and ALDH2b genes are orthologues of maize mitochondrial ALDH genes, rf2b and rf2a, respectively.


Assuntos
Aldeído Desidrogenase/genética , Cromossomos de Plantas/genética , Mitocôndrias/enzimologia , Oryza/genética , Folhas de Planta/genética , Aldeído Desidrogenase/metabolismo , Sequência de Aminoácidos , Northern Blotting , Southern Blotting , Western Blotting , Mapeamento Cromossômico , DNA Complementar/química , DNA Complementar/genética , DNA de Plantas/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Isoenzimas/genética , Isoenzimas/metabolismo , Dados de Sequência Molecular , Família Multigênica/genética , Oryza/enzimologia , Oryza/crescimento & desenvolvimento , Filogenia , Folhas de Planta/enzimologia , Folhas de Planta/crescimento & desenvolvimento , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
16.
J Am Chem Soc ; 125(8): 2341-50, 2003 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-12590564

RESUMO

The cyclopropanation reaction of an alkene with a metal carbenoid has been studied by means of the B3LYP hybrid density functional method. The cyclopropanation of ethylene with a lithium carbenoid or a zinc carbenoid [Simmons-Smith (SS) reagent] goes through two competing pathways, methylene transfer and carbometalation. Both processes are fast for the lithium carbenoid, while, for the zinc carbenoid, only the former is fast enough to be experimentally feasible. The reaction of an SS reagent (ClZnCH(2)Cl) with ethylene and an allyl alcohol in the presence of ZnCl(2) was also studied. The allyl alcohol reaction was modeled with an SS reagent/alkoxide complex (ClCH(2)ZnOCH(2)CH=CH(2)) formed from the SS reagent and allyl alcohol. Two modes of acceleration were found. The first involves the well-accepted mechanism of 1,2-chlorine migration, and the second involves a five-centered bond alternation. The latter was found to be more facile than the former and to operate equally well both with ethylene and with aggregates of SS reagent/alkoxide complexes. Calculations on the SS reaction with 2-cyclohexen-1-ol offer a reasonable model for the hydroxy-directed diastereoselective SS reaction, which has been used for a long time in organic synthesis.

17.
Chirality ; 15(1): 108-9, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12467053

RESUMO

A new synthetic methodology for aldoses and aldonitols was developed in which two stereospecific epoxide-opening reactions with double inversion of the configuration, i.e., the ring-opening reaction of epoxy sulfides with phenylboronic acid and the stereospecific interconversion of trans- and cis-epoxy sulfides, were designed as the key steps. The synthetic potential of the new methodology was exemplified by the highly stereoselective synthesis of two pentose-derived sugars, arabitol and adonitol (ribitol).


Assuntos
Carboidratos/síntese química , Compostos de Epóxi , Carboidratos/química , Indicadores e Reagentes , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Estereoisomerismo
19.
Chem Commun (Camb) ; (17): 1970-1, 2002 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-12271699

RESUMO

A highly regio- and stereoselective alpha-methylation reaction of gamma,delta-epoxy-alpha,beta-unsaturated esters was achieved by using a Me2Zn-CuCN reagent.

20.
Genes Genet Syst ; 77(1): 31-8, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12036102

RESUMO

A novel gene for alternative oxidase (AOX) was isolated from rice (Oryza sativa L.) and characterized. The deduced amino acid sequence of the novel AOX gene contains features that are conserved among other AOXs. This AOX gene was designated AOX1c based on a phylogenetic analysis of the AOX genes. Northern hybridization analyses revealed that AOX1c and AOX1a/AOX1b transcripts accumulated differently in various rice organs and rice seedlings under low temperature conditions. AOX1c mRNA was mainly present in young leaves under constant light, mature leaves and panicles after heading, but it was not detected in young etiolated leaves and young roots of seedlings or young panicles. On the other hand, the mRNAs of the rice AOX1a and AOX1b genes were mainly present in young roots and mature leaves. Under low temperature conditions, the steady-state mRNA levels of the rice AOX1a and AOX1b genes clearly increased with time but the rice AOX1c gene was apparently not responsive to low temperature. The rice AOX gene family and differences in their regulation are discussed.


Assuntos
Oryza/enzimologia , Oxirredutases/genética , Sequência de Aminoácidos , Sequência de Bases , Temperatura Baixa , DNA de Plantas , Escuridão , Proteínas Mitocondriais , Dados de Sequência Molecular , Oryza/genética , Oryza/metabolismo , Oxirredutases/metabolismo , Filogenia , Proteínas de Plantas , RNA Mensageiro/metabolismo , Alinhamento de Sequência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...