Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Am J Hum Genet ; 104(4): 767-773, 2019 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-30929741

RESUMO

The diagnostic gap for rare neurodegenerative diseases is still considerable, despite continuous advances in gene identification. Many novel Mendelian genes have only been identified in a few families worldwide. Here we report the identification of an autosomal-dominant gene for hereditary spastic paraplegia (HSP) in 10 families that are of diverse geographic origin and whose affected members all carry unique truncating changes in a circumscript region of UBAP1 (ubiquitin-associated protein 1). HSP is a neurodegenerative disease characterized by progressive lower-limb spasticity and weakness, as well as frequent bladder dysfunction. At least 40% of affected persons are currently undiagnosed after exome sequencing. We identified pathological truncating variants in UBAP1 in affected persons from Iran, USA, Germany, Canada, Spain, and Bulgarian Roma. The genetic support ranges from linkage in the largest family (LOD = 8.3) to three confirmed de novo mutations. We show that mRNA in the fibroblasts of affected individuals escapes nonsense-mediated decay and thus leads to the expression of truncated proteins; in addition, concentrations of the full-length protein are reduced in comparison to those in controls. This suggests either a dominant-negative effect or haploinsufficiency. UBAP1 links endosomal trafficking to the ubiquitination machinery pathways that have been previously implicated in HSPs, and UBAP1 provides a bridge toward a more unified pathophysiology.


Assuntos
Proteínas de Transporte/genética , Mutação , Paraplegia Espástica Hereditária/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Bases de Dados Factuais , Modelos Animais de Doenças , Endossomos/metabolismo , Saúde da Família , Feminino , Fibroblastos/metabolismo , Genes Dominantes , Ligação Genética , Predisposição Genética para Doença , Genômica , Células HEK293 , Haploinsuficiência , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Isoformas de Proteínas , Adulto Jovem , Peixe-Zebra
2.
Angew Chem Int Ed Engl ; 61(20): e202200872, 2022 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-35191168

RESUMO

Exploring high-efficiency and stable halide perovskite-based photocatalysts for the selective reduction of CO2 to methane is a challenge because of the intrinsic photo- and chemical instability of halide perovskites. In this study, halide perovskites (Cs3 Bi2 Br9 and Cs2 AgBiBr6 ) were grown in situ in mesoporous TiO2 frameworks for an efficient CO2 reduction. Benchmarked CH4 production rates of 32.9 and 24.2 µmol g-1 h-1 with selectivities of 88.7 % and 84.2 %, were achieved, respectively, which are better than most reported halide perovskite photocatalysts. Focused ion-beam sliced-imaging techniques were used to directly image the hyperdispersed perovskite nanodots confined in mesopores with tunable sizes ranging from 3.8 to 9.9 nm. In situ X-ray photoelectronic spectroscopy and Kelvin probe force microscopy showed that the built-in electric field between the perovskite nanodots and mesoporous titania channels efficiently promoted photo-induced charge transfer. Density functional theory calculations indicate that the high methane selectivity was attributed to the Bi-adsorption-mediated hydrogenation of *CO to *HCO that dominates CO desorption.

3.
Am J Hum Genet ; 102(3): 505-514, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29499166

RESUMO

Although mutations in more than 90 genes are known to cause CMT, the underlying genetic cause of CMT remains unknown in more than 50% of affected individuals. The discovery of additional genes that harbor CMT2-causing mutations increasingly depends on sharing sequence data on a global level. In this way-by combining data from seven countries on four continents-we were able to define mutations in ATP1A1, which encodes the alpha1 subunit of the Na+,K+-ATPase, as a cause of autosomal-dominant CMT2. Seven missense changes were identified that segregated within individual pedigrees: c.143T>G (p.Leu48Arg), c.1775T>C (p.Ile592Thr), c.1789G>A (p.Ala597Thr), c.1801_1802delinsTT (p.Asp601Phe), c.1798C>G (p.Pro600Ala), c.1798C>A (p.Pro600Thr), and c.2432A>C (p.Asp811Ala). Immunostaining peripheral nerve axons localized ATP1A1 to the axolemma of myelinated sensory and motor axons and to Schmidt-Lanterman incisures of myelin sheaths. Two-electrode voltage clamp measurements on Xenopus oocytes demonstrated significant reduction in Na+ current activity in some, but not all, ouabain-insensitive ATP1A1 mutants, suggesting a loss-of-function defect of the Na+,K+ pump. Five mutants fall into a remarkably narrow motif within the helical linker region that couples the nucleotide-binding and phosphorylation domains. These findings identify a CMT pathway and a potential target for therapy development in degenerative diseases of peripheral nerve axons.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Genes Dominantes , Mutação/genética , ATPase Trocadora de Sódio-Potássio/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Criança , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , ATPase Trocadora de Sódio-Potássio/química , Adulto Jovem
4.
Anal Chem ; 93(26): 9036-9040, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34161075

RESUMO

Circulating tumor cells (CTCs) play a pivotal role in the early diagnosis of pheochromocytoma (PCC). Herein, we fabricated a new dual-targeting nanoprobe for coinstantaneous identification of rare PCC-CTCs from peripheral blood via targeting the norepinephrine transporter (NET) and somatostatin receptor SSTR2 overexpressed on the surface of PCC cells. Meta-iodobenzylguanidine (MIBG) functionalized magnetic Fe3O4 and octreotide (DOTA) decorated signal amplification Ag@SiO2 nanosphere were used to capture and detect PCC-CTCs by binding to NET and SSTR2. The proposed dual-targeting sensor achieved good reproducibility and high sensitivity for the monitoring of PC12 in the concentration range from 5 to 5 × 104 cells mL-1, with detection limits of 2 cell/mL. This strategy opens a new approach for simple, sensitive, and rapid determination of PCC biomarkers, which shows great potential in early diagnosis, prognosis, and therapeutic evaluation of PCC.


Assuntos
Neoplasias das Glândulas Suprarrenais , Células Neoplásicas Circulantes , Feocromocitoma , Diagnóstico Precoce , Humanos , Feocromocitoma/diagnóstico , Reprodutibilidade dos Testes , Dióxido de Silício
5.
Genet Med ; 22(12): 2114-2119, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32741968

RESUMO

PURPOSE: Inherited axonopathies (IA) are rare, clinically and genetically heterogeneous diseases that lead to length-dependent degeneration of the long axons in central (hereditary spastic paraplegia [HSP]) and peripheral (Charcot-Marie-Tooth type 2 [CMT2]) nervous systems. Mendelian high-penetrance alleles in over 100 different genes have been shown to cause IA; however, about 50% of IA cases do not receive a genetic diagnosis. A more comprehensive spectrum of causative genes and alleles is warranted, including causative and risk alleles, as well as oligogenic multilocus inheritance. METHODS: Through international collaboration, IA exome studies are beginning to be sufficiently powered to perform a pilot rare variant burden analysis. After extensive quality control, our cohort contained 343 CMT cases, 515 HSP cases, and 935 non-neurological controls. We assessed the cumulative mutational burden across disease genes, explored the evidence for multilocus inheritance, and performed an exome-wide rare variant burden analysis. RESULTS: We replicated the previously described mutational burden in a much larger cohort of CMT cases, and observed the same effect in HSP cases. We identified a preliminary risk allele for CMT in the EXOC4 gene (p value= 6.9 × 10-6, odds ratio [OR] = 2.1) and explored the possibility of multilocus inheritance in IA. CONCLUSION: Our results support the continuing emergence of complex inheritance mechanisms in historically Mendelian disorders.


Assuntos
Doença de Charcot-Marie-Tooth , Paraplegia Espástica Hereditária , Alelos , Doença de Charcot-Marie-Tooth/diagnóstico , Doença de Charcot-Marie-Tooth/genética , Humanos , Mutação , Paraplegia Espástica Hereditária/diagnóstico , Paraplegia Espástica Hereditária/genética , Sequenciamento do Exoma
6.
Ann Neurol ; 85(3): 316-330, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30706531

RESUMO

OBJECTIVE: Genetic modifiers in rare disease have long been suspected to contribute to the considerable variance in disease expression, including Charcot-Marie-Tooth disease type 1A (CMT1A). To address this question, the Inherited Neuropathy Consortium collected a large standardized sample of such rare CMT1A patients over a period of 8 years. CMT1A is caused in most patients by a uniformly sized 1.5 Mb duplication event involving the gene PMP22. METHODS: We genotyped DNA samples from 971 CMT1A patients on Illumina BeadChips. Genome-wide analysis was performed in a subset of 330 of these patients, who expressed the extremes of a hallmark symptom: mild and severe foot dorsiflexion strength impairment. SIPA1L2 (signal-induced proliferation-associated 1 like 2), the top identified candidate modifier gene, was expressed in the peripheral nerve, and our functional studies identified and confirmed interacting proteins using coimmunoprecipitation analysis, mass spectrometry, and immunocytochemistry. Chromatin immunoprecipitation and in vitro siRNA experiments were used to analyze gene regulation. RESULTS: We identified significant association of 4 single nucleotide polymorphisms (rs10910527, rs7536385, rs4649265, rs1547740) in SIPA1L2 with foot dorsiflexion strength (p < 1 × 10-7 ). Coimmunoprecipitation and mass spectroscopy studies identified ß-actin and MYH9 as SIPA1L2 binding partners. Furthermore, we show that SIPA1L2 is part of a myelination-associated coexpressed network regulated by the master transcription factor SOX10. Importantly, in vitro knockdown of SIPA1L2 in Schwannoma cells led to a significant reduction of PMP22 expression, hinting at a potential strategy for drug development. INTERPRETATION: SIPA1L2 is a potential genetic modifier of CMT1A phenotypic expressions and offers a new pathway to therapeutic interventions. ANN NEUROL 2019;85:316-330.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Pé/fisiopatologia , Proteínas Ativadoras de GTPase/genética , Genes Modificadores/genética , Debilidade Muscular/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Linhagem Celular Tumoral , Doença de Charcot-Marie-Tooth/fisiopatologia , Criança , Pré-Escolar , Feminino , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Redes Reguladoras de Genes , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Debilidade Muscular/fisiopatologia , Proteínas da Mielina/genética , Neurilemoma/genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Ratos , Índice de Gravidade de Doença , Adulto Jovem
7.
Am J Hum Genet ; 99(3): 607-623, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27588448

RESUMO

Axonal polyneuropathies are a frequent cause of progressive disability in the elderly. Common etiologies comprise diabetes mellitus, paraproteinaemia, and inflammatory disorders, but often the underlying causes remain elusive. Late-onset axonal Charcot-Marie-Tooth neuropathy (CMT2) is an autosomal-dominantly inherited condition that manifests in the second half of life and is genetically largely unexplained. We assumed age-dependent penetrance of mutations in a so far unknown gene causing late-onset CMT2. We screened 51 index case subjects with late-onset CMT2 for mutations by whole-exome (WES) and Sanger sequencing and subsequently queried WES repositories for further case subjects carrying mutations in the identified candidate gene. We studied nerve pathology and tissue levels and function of the abnormal protein in order to explore consequences of the mutations. Altogether, we observed heterozygous rare loss-of-function and missense mutations in MME encoding the metalloprotease neprilysin in 19 index case subjects diagnosed with axonal polyneuropathies or neurodegenerative conditions involving the peripheral nervous system. MME mutations segregated in an autosomal-dominant fashion with age-related incomplete penetrance and some affected individuals were isolated case subjects. We also found that MME mutations resulted in strongly decreased tissue availability of neprilysin and impaired enzymatic activity. Although neprilysin is known to degrade ß-amyloid, we observed no increased amyloid deposition or increased incidence of dementia in individuals with MME mutations. Detection of MME mutations is expected to increase the diagnostic yield in late-onset polyneuropathies, and it will be tempting to explore whether substances that can elevate neprilysin activity could be a rational option for treatment.


Assuntos
Axônios/patologia , Genes Dominantes/genética , Mutação/genética , Neprilisina/genética , Polineuropatias/genética , Polineuropatias/patologia , Tecido Adiposo/metabolismo , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/genética , Alelos , Peptídeos beta-Amiloides/metabolismo , Animais , Doença de Charcot-Marie-Tooth/complicações , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/patologia , Análise Mutacional de DNA , Bases de Dados Genéticas , Demência/complicações , Demência/genética , Exoma/genética , Heterozigoto , Humanos , Camundongos , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/genética , Neprilisina/análise , Neprilisina/sangue , Neprilisina/deficiência , Penetrância , Polineuropatias/complicações , Pele/metabolismo , Nervo Sural
8.
Crit Rev Food Sci Nutr ; 58(9): 1565-1593, 2018 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-28118034

RESUMO

Conventional methods for determining fat content and fatty acids (FAs) composition are generally based on the solvent extraction and gas chromatography techniques, respectively, which are time consuming, laborious, destructive to samples and require use of hazard solvents. These disadvantages make them impossible for large-scale detection or being applied to the production line of meat factories. In this context, the great necessity of developing rapid and nondestructive techniques for fat and FAs analyses has been highlighted. Measurement techniques based on near-infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance and hyperspectral imaging have provided interesting and promising results for fat and FAs prediction in varieties of foods. Thus, the goal of this article is to give an overview of the current research progress in application of the four important techniques for fat and FAs analyses of muscle foods, which consist of pork, beef, lamb, chicken meat, fish and fish oil. The measurement techniques are described in terms of their working principles, features, and application advantages. Research advances for these techniques for specific food are summarized in detail and the factors influencing their modeling results are discussed. Perspectives on the current situation, future trends and challenges associated with the measurement techniques are also discussed.


Assuntos
Gorduras na Dieta/análise , Ácidos Graxos/análise , Análise de Alimentos , Carne/análise , Animais , Bovinos , Peixes , Espectroscopia de Ressonância Magnética , Músculo Esquelético/química , Aves Domésticas , Alimentos Marinhos/análise , Ovinos , Espectroscopia de Luz Próxima ao Infravermelho , Análise Espectral Raman , Suínos
9.
Brain ; 140(6): 1561-1578, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28459997

RESUMO

Despite extensive efforts, half of patients with rare movement disorders such as hereditary spastic paraplegias and cerebellar ataxias remain genetically unexplained, implicating novel genes and unrecognized mutations in known genes. Non-coding DNA variants are suspected to account for a substantial part of undiscovered causes of rare diseases. Here we identified mutations located deep in introns of POLR3A to be a frequent cause of hereditary spastic paraplegia and cerebellar ataxia. First, whole-exome sequencing findings in a recessive spastic ataxia family turned our attention to intronic variants in POLR3A, a gene previously associated with hypomyelinating leukodystrophy type 7. Next, we screened a cohort of hereditary spastic paraplegia and cerebellar ataxia cases (n = 618) for mutations in POLR3A and identified compound heterozygous POLR3A mutations in ∼3.1% of index cases. Interestingly, >80% of POLR3A mutation carriers presented the same deep-intronic mutation (c.1909+22G>A), which activates a cryptic splice site in a tissue and stage of development-specific manner and leads to a novel distinct and uniform phenotype. The phenotype is characterized by adolescent-onset progressive spastic ataxia with frequent occurrence of tremor, involvement of the central sensory tracts and dental problems (hypodontia, early onset of severe and aggressive periodontal disease). Instead of the typical hypomyelination magnetic resonance imaging pattern associated with classical POLR3A mutations, cases carrying c.1909+22G>A demonstrated hyperintensities along the superior cerebellar peduncles. These hyperintensities may represent the structural correlate to the cerebellar symptoms observed in these patients. The associated c.1909+22G>A variant was significantly enriched in 1139 cases with spastic ataxia-related phenotypes as compared to unrelated neurological and non-neurological phenotypes and healthy controls (P = 1.3 × 10-4). In this study we demonstrate that (i) autosomal-recessive mutations in POLR3A are a frequent cause of hereditary spastic ataxias, accounting for about 3% of hitherto genetically unclassified autosomal recessive and sporadic cases; and (ii) hypomyelination is frequently absent in POLR3A-related syndromes, especially when intronic mutations are present, and thus can no longer be considered as the unifying feature of POLR3A disease. Furthermore, our results demonstrate that substantial progress in revealing the causes of Mendelian diseases can be made by exploring the non-coding sequences of the human genome.


Assuntos
Deficiência Intelectual/genética , Espasticidade Muscular/genética , Atrofia Óptica/genética , RNA Polimerase III/genética , Paraplegia Espástica Hereditária/genética , Ataxias Espinocerebelares/genética , Idoso , Técnicas de Cultura de Células , Éxons/genética , Feminino , Estudos de Associação Genética , Humanos , Células-Tronco Pluripotentes Induzidas , Deficiência Intelectual/diagnóstico por imagem , Deficiência Intelectual/fisiopatologia , Íntrons/genética , Masculino , Pessoa de Meia-Idade , Espasticidade Muscular/diagnóstico por imagem , Espasticidade Muscular/fisiopatologia , Mutação , Atrofia Óptica/diagnóstico por imagem , Atrofia Óptica/fisiopatologia , Linhagem , Fenótipo , Paraplegia Espástica Hereditária/diagnóstico por imagem , Paraplegia Espástica Hereditária/fisiopatologia , Ataxias Espinocerebelares/diagnóstico por imagem , Ataxias Espinocerebelares/fisiopatologia
11.
Brain ; 139(Pt 6): 1649-56, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27009151

RESUMO

We performed whole exome sequencing on a patient with Charcot-Marie-Tooth disease type 1 and identified a de novo mutation in PMP2, the gene that encodes the myelin P2 protein. This mutation (p.Ile52Thr) was passed from the proband to his one affected son, and segregates with clinical and electrophysiological evidence of demyelinating neuropathy. We then screened a cohort of 136 European probands with uncharacterized genetic cause of Charcot-Marie-Tooth disease and identified another family with Charcot-Marie-Tooth disease type 1 that has a mutation affecting an adjacent amino acid (p.Thr51Pro), which segregates with disease. Our genetic and clinical findings in these kindred demonstrate that dominant PMP2 mutations cause Charcot-Marie-Tooth disease type 1.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Proteína P2 de Mielina/genética , Adolescente , Exoma/genética , Feminino , Predisposição Genética para Doença/genética , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Condução Nervosa/genética , Linhagem , Adulto Jovem
12.
Molecules ; 22(12)2017 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-29168753

RESUMO

Using ilmenite as a raw material, iron was converted into Fe3O4 magnetic fluid, which further was combined with titanium filtrate by a solvothermal method. Finally Fe3O4/TiO2 nanocomposites with the uniform size of 100-200 nm were prepared. This approach uses rich, inexpensive ilmenite as a titanium and iron source, which effectively reduces the production cost. The crystal structure, chemical properties and morphologies of the products were characterized by SEM, TEM, XRD, FTIR, BET, UV-Vis, XPS and VSM. The novel photocatalyst composed of face-centered cubic Fe3O4 and body-centered tetragonal anatase-TiO2 exhibits a spherical shape with porous structures, superparamagnetic behavior and strong absorption in the visible light range. Using the degradation reaction of Rhodamine B (RhB) to evaluate the photocatalytic performance, the results suggest that Fe3O4/TiO2 nanocomposites exhibit excellent photocatalytic activities and stability under visible light and solar light. Moreover, the magnetic titania nanocomposites displayed good magnetic response and were recoverable over several cycles. Based on the trapping experiments, the main active species in the photocatalytic reaction were confirmed and the possible photocatalytic mechanism of RhB with magnetic titania was proposed. The enhanced photocatalytic activity and stability, combined with excellent magnetic recoverability, make the prepared nanocomposite a potential candidate in wastewater purification.


Assuntos
Ferro/química , Magnetismo , Nanocompostos/química , Titânio/química , Catálise , Concentração de Íons de Hidrogênio , Nanocompostos/ultraestrutura , Processos Fotoquímicos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
13.
Brain ; 138(Pt 8): 2191-205, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26026163

RESUMO

Hereditary spastic paraplegias are heterogeneous neurological disorders characterized by a pyramidal syndrome with symptoms predominantly affecting the lower limbs. Some limited pyramidal involvement also occurs in patients with an autosomal recessive neurocutaneous syndrome due to ALDH18A1 mutations. ALDH18A1 encodes delta-1-pyrroline-5-carboxylate synthase (P5CS), an enzyme that catalyses the first and common step of proline and ornithine biosynthesis from glutamate. Through exome sequencing and candidate gene screening, we report two families with autosomal recessive transmission of ALDH18A1 mutations, and predominant complex hereditary spastic paraplegia with marked cognitive impairment, without any cutaneous abnormality. More interestingly, we also identified monoallelic ALDH18A1 mutations segregating in three independent families with autosomal dominant pure or complex hereditary spastic paraplegia, as well as in two sporadic patients. Low levels of plasma ornithine, citrulline, arginine and proline in four individuals from two families suggested P5CS deficiency. Glutamine loading tests in two fibroblast cultures from two related affected subjects confirmed a metabolic block at the level of P5CS in vivo. Besides expanding the clinical spectrum of ALDH18A1-related pathology, we describe mutations segregating in an autosomal dominant pattern. The latter are associated with a potential trait biomarker; we therefore suggest including amino acid chromatography in the clinico-genetic work-up of hereditary spastic paraplegia, particularly in dominant cases, as the associated phenotype is not distinct from other causative genes.


Assuntos
Aldeído Desidrogenase/genética , Mutação/genética , Ornitina/genética , Ornitina/metabolismo , Paraplegia Espástica Hereditária/genética , Adolescente , Adulto , Arginina/metabolismo , Feminino , Ácido Glutâmico/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Paraplegia Espástica Hereditária/metabolismo , Adulto Jovem
14.
J Org Chem ; 80(5): 2724-32, 2015 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-25642974

RESUMO

Surface-modified titanium dioxides by highly dispersed NiO particles have an extended absorption in the visible light region and a reduced hole-electron pair recombination than unmodified TiO2. They have now been successfully applied as highly active heterogeneous photocatalysts in the visible light mediated direct cyclization of tertiary anilines with maleimides to give tetrahydroquinoline products in moderate to high yields at ambient temperature. In contrast with unmodified titanium dioxide catalysts that are conventionally used in a stoichiometric amount in combination with UVA light, only a catalytic amount (1 mol %) of the surface-modified TiO2 catalyst is needed along with visible light to efficiently catalyze the reaction. Compared with transition-metal complexes such as Ru(bpy)3Cl2 or Ir(ppy)2(dtbbpy)PF6, advantages of these surface-modified titanium dioxides as photocatalyst include high catalytic activity, low cost, ease of recovering, and being able to be used for at least nine times without significant decay of catalytic activity.


Assuntos
Compostos de Anilina/síntese química , Maleimidas/síntese química , Níquel/química , Titânio/química , Compostos de Anilina/química , Catálise , Ciclização , Luz , Maleimidas/química , Fotoquímica
15.
J Immunol ; 191(10): 4969-78, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24123677

RESUMO

Iguratimod, a novel disease-modifying antirheumatic drug, which is now used in clinics in China and Japan, has been confirmed as a highly efficacious and safe drug for rheumatoid arthritis therapy. The antiarthritic mechanism of iguratimod, especially compared with that of the classical disease-modifying antirheumatic drugs, has not been elucidated. In this study, we conducted a comparative analysis of the antiarthritic effects of iguratimod and two reference drugs, methotrexate and leflunomide. We found that iguratimod dose dependently and potently inhibited arthritic inflammation of the synovium in collagen-induced arthritis and predominantly targeted IL-17 signaling. Consistent with its effects in vivo, iguratimod significantly suppressed the expression of various proinflammatory factors triggered by IL-17 in the cultured fibroblast-like synoviocytes. The inhibition of IL-17 signaling by iguratimod was further linked to a decrease in the mRNA stability of related genes and a reduction in phosphorylation of MAPKs. Iguratimod mainly targets Act1 to disrupt the interaction between Act1 and TRAF5 and IKKi in the IL-17 pathway of synoviocytes. Together, our results suggest that iguratimod yields a strong improvement in arthritis via its unique suppression of IL-17 signaling in fibroblast-like synoviocytes. This feature of iguratimod is different from those of methotrexate and leflunomide. This study may be helpful for further understanding the unique antiarthritic mechanism of iguratimod in patients with rheumatoid arthritis.


Assuntos
Antirreumáticos/farmacologia , Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Cromonas/farmacologia , Interleucina-17/metabolismo , Sulfonamidas/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Antirreumáticos/uso terapêutico , Artrite Experimental/metabolismo , Artrite Reumatoide/induzido quimicamente , Artrite Reumatoide/metabolismo , Cromonas/uso terapêutico , Colágeno , Quinase I-kappa B/metabolismo , Inflamação/tratamento farmacológico , Inflamação/imunologia , Interleucina-17/antagonistas & inibidores , Isoxazóis/farmacologia , Leflunomida , Masculino , Metotrexato/farmacologia , Camundongos , Camundongos Endogâmicos DBA , Fosforilação/efeitos dos fármacos , Transdução de Sinais , Sulfonamidas/uso terapêutico , Membrana Sinovial/efeitos dos fármacos , Membrana Sinovial/imunologia , Fator 5 Associado a Receptor de TNF/metabolismo
16.
Anticancer Drugs ; 25(2): 204-11, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24135499

RESUMO

In this study, we investigated the antitumor activity of axitinib, a selective inhibitor of vascular endothelial growth factor receptor tyrosine kinases, against melanoma cells. Axitinib dose-dependently inhibited the proliferation and induced the apoptosis of B16F1 cells in vitro. In a mouse model of melanoma xenograft, axitinib significantly suppressed tumor growth and induced apoptosis of cells in tumor tissues at a dose of 25 mg/kg. In addition, axitinib suppressed the lung metastasis of melanoma cells and prolonged the life span of tumor-bearing mice. Axitinib also enhanced the proportion of CD8⁺ T cells and reduced the proportion of myeloid-derived suppressor cells in CD45.2⁺ cells, whereas the proportions of CD4⁺ T cells and Treg cells were not affected. The mRNA expressions of inducible nitric oxide synthases-2 and arginase-1, which were associated with the function of myeloid-derived suppressor cells in tumor tissues, were inhibited by axitinib. Moreover, axitinib suppressed the expressions of proinflammatory cytokines such as IL-6, TNF-α, and IFN-γ. Altogether, our results showed the unique antitumor mechanism of axitinib and provided useful information for its clinical application.


Assuntos
Antineoplásicos/farmacologia , Imidazóis/farmacologia , Indazóis/farmacologia , Melanoma Experimental/tratamento farmacológico , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/fisiologia , Animais , Apoptose/efeitos dos fármacos , Axitinibe , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Neoplasias Pulmonares/prevenção & controle , Neoplasias Pulmonares/secundário , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Patológica/prevenção & controle , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
17.
J Org Chem ; 79(16): 7572-82, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25057755

RESUMO

A new photoinduced three-component reaction between a cyanoarene, an alkene and an N-protected pyrrole has been developed. This reaction extended the scope of the photo-NOCAS reaction by introducing pyrrole as a neutral carbon-centered nucleophile. The cyanoarenes used include tetracyanobenzene (TCB), 2,3,5,6-tetrafluoro-1,4-dicyanobenzene (TFDCB) and 1,4-dicyanobenzene (DCB). N-Methyl, N-phenyl and N-Boc pyrroles are suitable nucleophiles in the reaction. Taking advantage of the strong electron acceptor ability of the singlet excited TCB, a wide range of alkenes, including the highly electron deficient 4-fluoro-, 4-chloro-, 2,3,4,5,6-pentafluorostyrenes and N-methylmaleimide take part in this reaction, leading to the simultaneous 1,2-diarylation of the alkene and the regioselective 2-alkylation of the pyrrole ring via sequential formation of two new C-C bonds between the three reactants.

18.
J Food Prot ; 87(9): 100335, 2024 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-39074611

RESUMO

The potential of Raman hyperspectral imaging with a 785 nm excitation line laser was examined for the detection of aflatoxin contamination in corn kernels. Nine-hundred kernels were artificially inoculated in the laboratory, with 300 kernels each inoculated with AF13 (aflatoxigenic) fungus, AF36 (nonaflatoxigenic) fungus, and sterile distilled water (control). One-hundred kernels from each treatment were subsequently incubated for 3, 5, and 8 days. The mean spectra of single kernels were extracted from the endosperm side and the embryo area of the germ side, and local Raman peaks were identified based upon the calculated reference spectra of aflatoxin-negative and -positive categories separately. The principal component analysis-linear discriminant analysis models were established using different types of variable inputs including original full spectra, preprocessed full spectra, and identified local peaks over kernel endosperm-side, germ-side, and both sides. The results of the established discriminant models showed that the germ-side spectra performed better than the endosperm-side spectra. Based upon the 20 ppb-threshold, the best mean prediction accuracy of 82.6% was achieved for the aflatoxin-negative category using the original spectra in the combined form of both kernel sides, and the best mean prediction accuracy of 86.7% was obtained for the -positive category using the preprocessed germ-side spectra. Based upon the 100 ppb-threshold, the best mean prediction accuracies of 85.0% and 89.6% were achieved for the aflatoxin-negative and -positive categories separately, using the same type of variable inputs for the 20 ppb-threshold. In terms of overall prediction accuracy, the models established upon the original spectra in the combined form of both kernel sides achieved the best predictive performance, regardless of the threshold. The mean overall prediction accuracies of 81.8% and 84.5% were achieved with the 20 ppb- and 100 ppb-thresholds, respectively.

19.
Toxicol Appl Pharmacol ; 267(2): 167-73, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23276654

RESUMO

In the present study, we aimed to investigate the immunosuppressive activity of vaticaffinol, a resveratrol tetramer isolated from Vatica mangachapoi, on T lymphocytes both in vitro and in vivo, and further explored its potential molecular mechanism. Resveratrol had a wide spectrum of healthy beneficial effects with multiple targets. Interestingly, its tetramer, vaticaffinol, exerted more intensive immunosuppressive activity than resveratrol. Vaticaffinol significantly inhibited T cells proliferation activated by concanavalin A (Con A) or anti-CD3 plus anti-CD28 in a dose- and time-dependent manner. It also induced Con A-activated T cells undergoing apoptosis through mitochondrial pathway. Moreover, this compound prevented cells from entering S phase and G2/M phase during T cells activation. In addition, vaticaffinol inhibited ERK and AKT signaling pathways in Con A-activated T cells. Furthermore, vaticaffinol significantly ameliorated ear swelling in a mouse model of picryl chloride-induced ear contact dermatitis in vivo. In most of the aforementioned experiments, however, resveratrol had only slight effects on the inhibition of T lymphocytes compared with vaticaffinol. Taken together, our findings suggest that vaticaffinol exerts more preferable immunosuppressive activity than its precursor resveratrol both in vitro and in vivo by affecting multiple targets against activated T cells.


Assuntos
Imunossupressores/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Estilbenos/química , Estilbenos/farmacologia , Linfócitos T/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Dermatite de Contato/tratamento farmacológico , Feminino , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Resveratrol
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA