Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Medicine (Baltimore) ; 101(43): e31341, 2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36316866

RESUMO

The aim was to illuminate the difference in incidence, mortality, and disability-adjusted life-years (DALYs) of gastric cancer (GC) between the United States of America (US) and China. The multiple management was analyzed with stratification to explore an effective survival improvement strategy. The Global Burden of Disease Study data was analyzed to assess GC morbidity, mortality and DALYs from 1990 to 2019 in the US and China. The age-period-cohort model was established to generate estimation of metrics. Verification was completed and stratified analysis of the multiple management was performed by accessing data of Surveillance, Epidemiology, and End Results database in 1992 to 2019. Continuous downtrends in GC incidence, mortality and DALYs from 1990 to 2019 and persistent uptrends in 1-, 3-year survival from 1992 to 2019 were observed in the US population. In the Chinese population, the overall trends of incidence, mortality and DALYs decreased with a fluctuating manner. The lower overall survival rates were observed in elderly, unmarried patients, distant disease and poor grade, as well as patients lacking of medical treatment (P < .05). In stratified analyses, single local therapy decreased and the other modalities increased over time across different stages. Moreover, combined treatment and single systemic therapy decreased, but single local and conservative therapy increased with age. The study quantified the incidence, GC-specific mortality and DALYs in the US and China and estimated stage profiles, 1- and 3-year survival in the US. The heavy burden on later-onset GC (>70) and potential increase on early-onset GC (<40) needed to be addressed. Combined modalities and single chemotherapy were becoming more widely used over time, however, their uses decreased with age because of poor physical fitness. Our findings provide new insights into management tailoring appropriately to specific subgroups contributes to the increasing survival rate.


Assuntos
Neoplasias Gástricas , Humanos , Idoso , Incidência , Anos de Vida Ajustados por Qualidade de Vida , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/terapia , Morbidade , Doença Crônica
2.
J Biochem ; 168(6): 633-641, 2020 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-32730584

RESUMO

Anti-tumour-analgesic peptide (AGAP), one scorpion toxin purified from Buthus martensii Karsch, was known as its analgesic and anti-tumour activities. Trp38, a conserved aromatic residue of AGAP, might play important roles in its interaction with sodium channels. In this study, a mutant W38F was generated and effects of W38F were examined on hNav1.4, hNav1.5 and hNav1.7 by using whole-cell patch-clamp, which were closely associated to the biotoxicity of skeletal and cardiac muscles and pain signalling. The data showed that W38F decreased the inhibition effects of peak currents of hNav1.7, hNav1.4 and hNav1.5 compared with AGAP, notably, W38F reduced the analgesic activity compared with AGAP. The results suggested that Trp38 be a crucial amino acid involved in the interaction with these three sodium channels. The decreased analgesic activity of W38F might result from its much less inhibition of hNav1.7. These findings provided more information about the relationship between structure and function of AGAP and may facilitate the modification of other scorpion toxins with pharmacological effects.


Assuntos
Analgésicos/farmacologia , Canal de Sódio Disparado por Voltagem NAV1.4/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.7/metabolismo , Dor/tratamento farmacológico , Fragmentos de Peptídeos/farmacologia , Venenos de Escorpião/farmacologia , Triptofano/metabolismo , Animais , Feminino , Humanos , Ativação do Canal Iônico , Masculino , Camundongos , Canal de Sódio Disparado por Voltagem NAV1.4/genética , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Canal de Sódio Disparado por Voltagem NAV1.7/genética , Fragmentos de Peptídeos/genética , Venenos de Escorpião/genética , Triptofano/genética
3.
J Biol Chem ; 292(44): 18270-18280, 2017 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-28924048

RESUMO

Scorpion toxins can kill other animals by inducing paralysis and arrhythmia, which limits the potential applications of these agents in the clinical management of diseases. Antitumor-analgesic peptide (AGAP), purified from Buthus martensii Karsch, has been proved to possess analgesic and antitumor activities. Trp38, a conserved aromatic residue of AGAP, might play an important role in mediating AGAP activities according to the sequence and homology-modeling analyses. Therefore, an AGAP mutant, W38G, was generated, and effects of both AGAP and the mutant W38G were examined by whole-cell patch clamp techniques on the sodium channels hNav1.4 and hNav1.5, which were closely associated with the biotoxicity of skeletal and cardiac muscles, respectively. The data showed that both W38G and AGAP inhibited the peak currents of hNav1.4 and hNav1.5; however, W38G induced a much weaker inhibition of both channels than AGAP. Accordingly, W38G exhibited much less toxic effect on both skeletal and cardiac muscles than AGAP in vivo The analgesic activity of W38G and AGAP were verified in vivo as well, and W38G retained analgesic activity similar to AGAP. Inhibition to both Nav1.7 and Nav1.8 was involved in the analgesic mechanism of AGAP and W38G. These findings indicated that Trp38 was a key amino acid involved in the biotoxicity of AGAP, and the AGAP mutant W38G might be a safer alternative for clinical application because it retains the analgesic efficacy with less toxicity to skeletal and cardiac muscles.


Assuntos
Analgésicos não Narcóticos/efeitos adversos , Antineoplásicos/efeitos adversos , Proteínas de Artrópodes/efeitos adversos , Mutação , Peptídeos/efeitos adversos , Venenos de Escorpião/efeitos adversos , Bloqueadores do Canal de Sódio Disparado por Voltagem/efeitos adversos , Substituição de Aminoácidos , Analgésicos não Narcóticos/administração & dosagem , Analgésicos não Narcóticos/farmacologia , Analgésicos não Narcóticos/uso terapêutico , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/farmacologia , Proteínas de Artrópodes/uso terapêutico , Células CHO , Cricetulus , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Camundongos , Canal de Sódio Disparado por Voltagem NAV1.4/química , Canal de Sódio Disparado por Voltagem NAV1.4/genética , Canal de Sódio Disparado por Voltagem NAV1.4/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.5/química , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Peptídeos/genética , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Distribuição Aleatória , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Venenos de Escorpião/genética , Venenos de Escorpião/farmacologia , Venenos de Escorpião/uso terapêutico , Escorpiões , Testes de Toxicidade Aguda , Testes de Toxicidade Subaguda , Bloqueadores do Canal de Sódio Disparado por Voltagem/administração & dosagem , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacologia , Bloqueadores do Canal de Sódio Disparado por Voltagem/uso terapêutico
4.
Biomacromolecules ; 10(4): 884-91, 2009 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-19281152

RESUMO

A new linear saturated terminal diisocyanate was synthesized from oleic acid via Curtius rearrangement, and its chemical structure was identified by FTIR, (1)H and (13)C NMR, and MS. The feasibility of utilizing this new diisocyanate for the production of polyurethanes (PUs) was demonstrated by reacting it with commercial petroleum-derived polyols and canola oil-derived polyols, respectively. The physical properties of the PUs prepared from fatty acid-derived diisocyanate were compared to those prepared from the same polyols with a similar but petroleum-derived commercially available diisocyanate: 1,6-hexamethylene diisocyanate. It was found that the fatty acid-derived diisocyanate was capable of producing PUs with comparable properties within acceptable tolerances. This work is the first that establishes the production of linear saturated terminal diisocyanate derived from fatty acids and corresponding PUs mostly from lipid feedstock.


Assuntos
Isocianatos/química , Isocianatos/síntese química , Ácidos Oleicos/química , Óleos de Plantas/química , Poliuretanos/química , Poliuretanos/síntese química , Cromatografia Gasosa , Cianatos/química , Cianatos/metabolismo , Isocianatos/farmacologia , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Teste de Materiais , Polímeros/química , Poliuretanos/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Mecânico , Difração de Raios X
5.
Biomacromolecules ; 9(8): 2221-9, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18624453

RESUMO

Sequential interpenetrating polymer networks (IPNs) were prepared using polyurethane produced from a canola oil based polyol with primary terminal functional groups and poly(methyl methacrylate) (PMMA). The properties of the material were studied and compared to the IPNs made from commercial castor oil using dynamic mechanical analysis, differential scanning calorimetry, as well as tensile measurements. The morphology of the IPNs was investigated using scanning electron microscopy and transmission electron microscopy. The chemical diversity of the starting materials allowed the evaluation of the effects of dangling chains and graftings on the properties of the IPNs. The polymerization process of canola oil based IPNs was accelerated because of the utilization of polyol with primary functional groups, which efficiently lessened the effect of dangling chains and yielded a higher degree of phase mixing. The mechanical properties of canola oil based IPNs containing more than 75 wt % PMMA were comparable to the corresponding castor oil based IPNs; both were superior to those of the constituent polymers due to the finely divided rubber and plastic combination structures in these IPNs. However, when PMMA content was less than 65 wt %, canola oil based IPNs exhibited a typical mechanical behavior of rigid plastics, whereas castor oil based IPNs showed a typical mechanical behavior of soft rubber. It is proposed that these new IPN materials with high performance prepared from alternative renewable resources can prove to be valuable substitutes for existing materials in various applications.


Assuntos
Óleos de Plantas/metabolismo , Polímeros/química , Polimetil Metacrilato/química , Poliuretanos/química , Materiais Biocompatíveis/química , Varredura Diferencial de Calorimetria/métodos , Desenho de Equipamento , Teste de Materiais , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Plásticos , Estresse Mecânico , Resistência à Tração , Termodinâmica
6.
Biomacromolecules ; 9(5): 1424-33, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18410139

RESUMO

Sequential interpenetrating polymer networks (IPNs) were prepared using polyurethane (PUR) synthesized from canola oil-based polyol with terminal primary functional groups and poly(methyl methacrylate) (PMMA). The properties of the material were evaluated by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and modulated differential scanning calorimetry (MDSC), as well as tensile properties measurements. The morphology of the IPNs was investigated using scanning electron microscopy (SEM) and MDSC. A five-phase morphology, that is, sol phase, PUR-rich phase, PUR-rich interphase, PMMA-rich interphase, and PMMA-rich phase, was observed for all the IPNs by applying a new quantitative method based on the measurement of the differential of reversing heat capacity versus temperature from MDSC, although not confirmed by SEM, most likely due to resolution restrictions. NCO/OH molar ratios (cross-linking density) and compositional variations of PUR/PMMA both affected the thermal properties and phase behaviors of the IPNs. Higher degrees of mixing occurred for the IPN with higher NCO/OH molar ratio (2.0/1.0) at PUR concentration of 25 wt %, whereas for the IPN with lower NCO/OH molar ratio (1.6/1.0), higher degrees of mixing occurred at PUR concentration of 35 wt %. The mechanical properties of the IPNs were superior to those of the constituent polymers due to the finely divided rubber and plastic combination structures in these IPNs.


Assuntos
Ácidos Graxos Monoinsaturados/química , Polimetil Metacrilato/química , Poliuretanos/química , Varredura Diferencial de Calorimetria , Teste de Materiais , Transição de Fase , Óleo de Brassica napus , Propriedades de Superfície , Resistência à Tração
7.
Biomacromolecules ; 8(11): 3584-9, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17910494

RESUMO

A new generation polyol (generation-II) with significantly higher triol content and higher hydroxyl value was synthesized from canola oil by introducing a mild solvent (ethyl acetate) and a more efficient reductive reagent (zinc) to the previous synthetic procedure (Narine, S. S.; Yue, J.; Kong, X. J. Am. Oil Chem. Soc. 2007, 84, 173-179). Polyurethane (PUR) elastomers were prepared by reacting this type of polyol with aliphatic diisocyanates. The physical and thermal properties of the PUR elastomers were studied using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) and compared to the elastomers made from the old generation polyol (generation-I). The concentration of elastically active network chains (nue) of the polymer networks was calculated based on rubber elasticity theory. Larger nue and narrower distribution of nue was observed in the case of the PURs prepared from the generation-II polyol. The relatively faster relaxation at higher temperature for this type of PUR elastomer, suggests a tighter cross-linked network structure by reducing the dangling chains effect. With the same OH/NCO molar ratio, the PURs prepared from the generation-II polyol showed higher glass transition temperatures (Tg), higher Young's modulus and tensile strength, and longer elongation at break.


Assuntos
Ácidos Graxos Monoinsaturados/química , Poliuretanos/química , Fenômenos Químicos , Físico-Química , Estrutura Molecular , Polímeros/química , Óleo de Brassica napus , Temperatura , Trioleína/química
8.
Biomacromolecules ; 8(7): 2203-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17550287

RESUMO

Polyurethane (PUR) plastic sheets were prepared by reacting polyols synthesized from canola oil with aromatic diphenylmethane diisocyanate. The properties of the material were measured by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) as well as tensile properties measurements. The effect of stoichiometric balance (i.e., OH/NCO molar ratio) on the final properties was evaluated. The concentration of elastically active network chains (EANCs), nue, of the polymer networks was calculated using rubber elasticity theory. The glass transition temperatures (Tg) for the plastic sheets with OH/NCO molar ratios of 1.0/1.0, 1.0/1.1, and 1.0/1.2 were found to be 23, 41, and 43 degrees C, respectively. The kinetic studies of the degradation process of the PUR plastics showed three well-defined steps of degradation. The PUR plastic sheets with OH/NCO molar ratio 1.0/1.1 had the highest nue, lowest number-average molecule weight between cross-links, MC, and excellent mechanical properties, indicating that this is the optimum ratio in the PUR formulations.


Assuntos
Ácidos Graxos Monoinsaturados/química , Polímeros/química , Poliuretanos/química , Cinética , Polímeros/isolamento & purificação , Óleo de Brassica napus , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA