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1.
Pharmacol Res ; 206: 107275, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38908615

RESUMO

Triptolide (TP) is the principal bioactive compound of Tripterygium wilfordii with significant anti-tumor, anti-inflammatory and immunosuppressive activities. However, its severe hepatotoxicity greatly limits its clinical use. The underlying mechanism of TP-induced liver damage is still poorly understood. Here, we estimate the role of the gut microbiota in TP hepatotoxicity and investigate the bile acid metabolism mechanisms involved. The results of the antibiotic cocktail (ABX) and fecal microbiota transplantation (FMT) experiment demonstrate the involvement of intestinal flora in TP hepatotoxicity. Moreover, TP treatment significantly perturbed gut microbial composition and reduced the relative abundances of Lactobacillus rhamnosus GG (LGG). Supplementation with LGG reversed TP-induced hepatotoxicity by increasing bile salt hydrolase (BSH) activity and reducing the increased conjugated bile acids (BA). LGG supplementation upregulates hepatic FXR expression and inhibits NLRP3 inflammasome activation in TP-treated mice. In summary, this study found that gut microbiota is involved in TP hepatotoxicity. LGG supplementation protects mice against TP-induced liver damage. The underlying mechanism was associated with the gut microbiota-BA-FXR axis. Therefore, LGG holds the potential to prevent and treat TP hepatotoxicity in the clinic.


Assuntos
Ácidos e Sais Biliares , Doença Hepática Induzida por Substâncias e Drogas , Diterpenos , Compostos de Epóxi , Microbioma Gastrointestinal , Lacticaseibacillus rhamnosus , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR , Fenantrenos , Receptores Citoplasmáticos e Nucleares , Animais , Diterpenos/farmacologia , Fenantrenos/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Microbioma Gastrointestinal/efeitos dos fármacos , Compostos de Epóxi/farmacologia , Ácidos e Sais Biliares/metabolismo , Masculino , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Probióticos/uso terapêutico , Probióticos/farmacologia , Transplante de Microbiota Fecal , Inflamassomos/metabolismo , Transdução de Sinais/efeitos dos fármacos
2.
Anal Bioanal Chem ; 416(13): 3127-3137, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38580890

RESUMO

Monoclonal antibodies (mAbs) represent the largest class of therapeutic protein drug products. mAb glycosylation produces a heterogeneous, analytically challenging distribution of glycoforms that typically should be adequately characterized because glycosylation-based product quality attributes (PQAs) can impact product quality, immunogenicity, and efficacy. In this study, two products were compared using a panel of analytical methods. Two high-resolution mass spectrometry (HRMS) workflows were used to analyze N-glycans, while nuclear magnetic resonance (NMR) was used to generate monosaccharide fingerprints. These state-of-the-art techniques were compared to conventional analysis using hydrophilic interaction chromatography (HILIC) coupled with fluorescence detection (FLD). The advantages and disadvantages of each method are discussed along with a comparison of the identified glycan distributions. The results demonstrated agreement across all methods for major glycoforms, demonstrating how confidence in glycan characterization is increased by combining orthogonal analytical methodologies. The full panel of methods used represents a diverse toolbox that can be selected from based on the needs for a specific product or analysis.


Assuntos
Anticorpos Monoclonais , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Polissacarídeos , Glicosilação , Anticorpos Monoclonais/química , Polissacarídeos/análise , Polissacarídeos/química , Espectrometria de Massas/métodos , Espectroscopia de Ressonância Magnética/métodos , Cromatografia Líquida/métodos
3.
Eur J Nutr ; 63(3): 763-775, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38160221

RESUMO

PURPOSE: We conducted a network meta-analysis which aims to evaluate the comparative efficacy of different supplementation dosages of vitamin D on cardiometabolic and bone-metabolic indicators as well as insulin resistance in children and adolescents with overweight/obesity. METHODS: Eligible studies published before December 10, 2022 were retrieved from PubMed, EMBASE, Cochrane Library, and Web of Science. Mean difference and 95% confidence interval (CI) were used to express pooled estimates. Network meta-analysis of multiple doses, including low (< 1000 IU/day, LDS), medium (1000-2000 IU/day, MDS), high (2000-4000 IU/day, HDS), and extremely high (> 4000 IU/day, EHDS) dosage strategy, was conducted using STATA/MP 14.0. RESULTS: Our network meta-analysis of 15 RCTs suggested that, compared with placebo and LDS, EHDS was increased 25-(OH)-D, with a pooled MD of 8.65 (95% CI 4.72-12.58) and 7.66 (95% CI 0.91-14.41), respectively. Meanwhile, EHDS also decreased ho meostasis model assessment-insulin resistance (HOMA-IR) (MD: - 0.74; 95% CI: - 1.45 to - 0.04) and C-reactive protein (CRP) (MD: - 18.99; 95% CI - 21.60 to - 16.38), and EHDS was also better than LDS (MD: - 18.47; 95% CI - 20.66 to - 16.28) and MDS (MD: - 19.69; 95% CI - 22.17 to - 17.21) in decreasing CRP. Ranking probability suggested that EHDS ranked best for increasing 25-(OH)-D, and decreasing HOMA-IR and CRP, with a probability of 86.1%, 83.1%, and 76.6%, respectively. CONCLUSIONS: The results of our network meta-analysis suggest that EHDS may be the best strategy for vitamin D supplementation to reduce inflammatory responses as well as improve insulin resistance in children and adolescents with overweight/obesity. PROSPERO REGISTRATION NUMBER: CRD42023387775.


Assuntos
Resistência à Insulina , Criança , Humanos , Adolescente , Resistência à Insulina/fisiologia , Sobrepeso/tratamento farmacológico , Metanálise em Rede , Vitamina D , Obesidade/tratamento farmacológico , Suplementos Nutricionais , Proteína C-Reativa
4.
Pharm Res ; 40(6): 1399-1410, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36513905

RESUMO

PURPOSE: Glycan composition can impact a biotherapeutic's safety and efficacy. For example, changes in the relative abundance of different glycan attributes like afucosylation, galactosylation or high-mannose content can change the properties or functions of a monoclonal antibody (mAb). While established methods can effectively characterize major glycan species in biotherapeutic drug products, there is still a need for more sensitive and specific methods that can effectively monitor low abundance species which may impact mAb function. METHODS: Glycans released from two mAbs, adalimumab and trastuzumab, were derivatized with Rapifluor-MS™. Glycans were separated using HILIC and detected using either fluorescence (FLD) or mass spectrometry (MS). A parallel reaction monitoring (PRM) workflow was used for the MS analysis. RESULTS AND CONCLUSION: FLD analysis identified 18 and 19 glycan peaks in adalimumab and trastuzumab, respectively. Glycan identities were determined using MS-analysis and a high number of FLD peaks containing co-eluting glycan species were observed. PRM analysis quantified 38 and 39 glycan species in adalimumab and trastuzumab, respectively, and the increase in glycans that could be identified was due to superior sensitivity and selectivity compared to FLD. Notably, many low abundance glycans identified by PRM included species that were not reported in other studies. PRM also offered several additional advantages; unique structural features could be identified using the collected MS/MS spectra and de-coupling MS acquisition and data processing simplified the transfer of methods between instruments. The results established PRM as a precise, informative tool for glycan analysis and quantitation.


Assuntos
Anticorpos Monoclonais , Espectrometria de Massas em Tandem , Cromatografia Líquida/métodos , Adalimumab , Anticorpos Monoclonais/química , Trastuzumab , Polissacarídeos/química
5.
AIDS Res Ther ; 20(1): 45, 2023 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-37452359

RESUMO

BACKGROUND: This study conducted a survey of men who have sex with men (MSM) in Maanshan City of Anhui Province to assess the risk behaviors related to human immunodeficiency virus (HIV) infection. METHODS: A cross-sectional survey was conducted from June 2016 to June 2019. The MSM were recruited by a peer-driven sampling method. A face-to-face interview with anonymous questionnaire was used for data collection. The information collected by the survey was summarized and epidemiology described the basic characteristics of MSM, and then the related factors were statistically analyzed. RESULTS: A total of 934 MSM were recruited with a average age was 30.5 (SD = 8.90) years old, including 816 (87.4%) HIV negative participants and 118 (12.6%) HIV positive ones. This study showed that freelancer (OR = 4.02, 95% CI: 1.96-8.23), scope of sexual partners distribution (OR = 1.78, 95% CI: 1.36-2.33), number of male sexual partners (OR = 2.11, 95% CI: 1.47-3.02), role of anal sex with men was receptive (OR = 2.54, 95% CI: 1.25-5.13) and versatile (OR = 2.34, 95% CI: 1.31-4.19) and non-steady sex partners (OR = 2.14, 95% CI: 1.56-2.93) were risk factors for HIV infection, while monthly income (OR = 0.68, 95% CI: 0.57-0.82), education level (OR = 0.79, 95% CI: 0.66-0.95), frequency of condom use (OR = 0.53, 95% CI: 0.35-0.81) and number of oral sex partners (OR = 0.35, 95% CI: 0.24-0.51) in the past 6 months were protective factors for HIV infection. CONCLUSION: Risk behaviors were common in MSM, and urgent need for targeted and comprehensive interventions to reduce risky sexual behaviour and to prevent HIV infection in MSM.


Assuntos
Infecções por HIV , Minorias Sexuais e de Gênero , Masculino , Humanos , Adulto , Criança , Estudos Transversais , Infecções por HIV/prevenção & controle , Homossexualidade Masculina , Comportamento Sexual , Fatores de Risco , China/epidemiologia
6.
BMC Public Health ; 23(1): 1916, 2023 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-37794404

RESUMO

BACKGROUND: Many studies have reported the association between ambient temperature and mortality from cardiovascular disease (CVD). However, the health effects of humidity are still unclear, much less the combined effects of temperature and humidity. In this study, we used humidex to quantify the effect of temperature and humidity combined on CVD mortality. METHODS: Daily meteorological, air pollution, and CVD mortality data were collected in four cities in southwest China. We used a distributed lag non-linear model (DLNM) in the first stage to assess the exposure-response association between humidex and city-specific CVD mortality. A multivariate meta-analysis was conducted in the second stage to pool these effects at the overall level. To evaluate the mortality burden of high and low humidex, we determined the attributable fraction (AF). According to the abovementioned processes, stratified analyses were conducted based on various demographic factors. RESULTS: Humidex and the CVD exposure-response curve showed an inverted "J" shape, the minimum mortality humidex (MMH) was 31.7 (77th percentile), and the cumulative relative risk (CRR) was 2.27 (95% confidence interval [CI], 1.76-2.91). At extremely high and low humidex, CRRs were 1.19 (95% CI, 0.98-1.44) and 2.52 (95% CI, 1.88-3.38), respectively. The burden of CVD mortality attributed to non-optimal humidex was 21.59% (95% empirical CI [eCI], 18.12-24.59%), most of which was due to low humidex, with an AF of 20.16% (95% eCI, 16.72-23.23%). CONCLUSIONS: Low humidex could significantly increase the risk of CVD mortality, and vulnerability to humidex differed across populations with different demographic characteristics. The elderly (> 64 years old), unmarried people, and those with a limited level of education (1-9 years) were especially susceptible to low humidex. Therefore, humidex is appropriate as a predictor in a CVD early-warning system.


Assuntos
Poluição do Ar , Doenças Cardiovasculares , Humanos , Idoso , Pessoa de Meia-Idade , Cidades/epidemiologia , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Temperatura , Umidade , China/epidemiologia
7.
Thorac Cardiovasc Surg ; 70(1): 2-9, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33851407

RESUMO

BACKGROUND: Surgical correction of an anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) has been associated with excellent survival during recent years. The purpose of this study was to evaluate the effectiveness of reimplantation of the coronary artery and to investigate the recovery of postoperative cardiac and mitral valve (MV) function. METHODS: From 2005 to 2015, 80 patients who had ALCAPA received surgical correction. Among them, 49 were infants. The median patient age was 7.8 months. Operative strategies included reimplantation of the coronary artery in 71 patients, the Takeuchi procedure in another 7 patients, and coronary artery ligation in the remaining 2 patients. RESULTS: There were 11 hospital deaths and 2 late deaths. Six patients required intraoperative or postoperative mechanical circulatory support. A significant improvement in the ejection fraction (EF) and shortening fraction (SF) was present in all surviving patients at discharge, at a 3-month follow-up and at a 1-year follow-up. MV function improved gradually after surgical repair with no late secondary intervention. CONCLUSIONS: The repair of ALCAPA can be accomplished by establishment of a dual-coronary system, which offers an acceptable mortality rate and will rarely require a second surgery. Left ventricular (LV) recovery is a progressive process, especially for infants with impaired LV function. Concomitant MV annuloplasty is safe and reliable and can be performed as necessary in patients with moderate or severe mitral valve regurgitation.


Assuntos
Síndrome de Bland-White-Garland , Anomalias dos Vasos Coronários , Insuficiência da Valva Mitral , Síndrome de Bland-White-Garland/complicações , Síndrome de Bland-White-Garland/cirurgia , Criança , Anomalias dos Vasos Coronários/complicações , Humanos , Lactente , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/cirurgia , Artéria Pulmonar/anormalidades , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
8.
Anal Chem ; 92(11): 7547-7555, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32374158

RESUMO

A recently developed synchronous precursor selection (SPS) mass spectrometry to the third (MS3) protocol enables more accurate multiplexed quantification of proteins/peptides using tandem mass tags (TMT) through comparison of reporter ion intensities at the MS3 level. However, challenges still exist for TMT-based simultaneous quantification and identification of intact glycopeptides due to inefficient peptide backbone fragmentation when using collision-induced dissociation (CID). To overcome this limitation, here we report an improved SPS/ETD workflow for TMT-based intact glycopeptide quantification and identification. The SPS/ETD approach was implemented on an Orbitrap Tribrid mass spectrometer and begins with selection of a parent ion in the MS scan, followed by tandem mass spectrometry (MS2) fragmentation by CID in the ion trap. Following MS2 fragmentation, SPS enables simultaneous isolation of the top 10 MS2 fragment ions for further higher energy collisional dissociation (HCD) fragmentation with the resulting MS3 fragments detected in an Orbitrap analyzer. Here, in addition to the standard SPS workflow, an electron-transfer dissociation (ETD) MS2 was performed and analyzed in the ion trap. The resultant ETD and CID spectra were used for the identification of the intact glycopeptides, while the quantitative comparison of site-specific glycans was achieved utilizing TMT reporter ions from HCD MS3 spectra. For intact glycopeptides, through systematic optimization and evaluation using a glycoprotein interference model, the SPS/ETD approach was demonstrated to offer improved accuracy, precision, and sensitivity compared to traditional data-dependent MS2 quantification, while maintaining the glycopeptide identification capability. Finally, this workflow was applied for the site-specific quantitative comparison of the glycoforms for two therapeutic enzymes (Cerezyme and VPRIV) and their different lots. The results demonstrate that this workflow is suitable for TMT-based intact glycopeptide characterization of glycoproteins.


Assuntos
Glicopeptídeos/análise , Transporte de Elétrons , Glucosilceramidase/metabolismo , Glicopeptídeos/metabolismo , Humanos , Espectrometria de Massas , Espectrometria de Massas em Tandem
9.
Cytokine ; 129: 155046, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32114297

RESUMO

Necroptosis is a recently identified programmed cell death, which is initiated by receptor-interacting serine/threonine-protein kinase 1 (RIP1), RIP3 and mixed-lineage kinase domain-like protein (MLKL). It has been reported that necroptosis induced by tumor necrosis factor (TNF) was inhibited by the inhibitor of phosphatidylinositol-3-kinase (PI3K) and its substrate protein AKT, indicating that PI3K-AKT signaling pathway was involved in mediating TNF-induced necroptosis, whereas it is unclear how PI3K initiates necroptosis. In this study, we found that TNF-induced necroptosis was inhibited by chemical inhibition or genetic deletion of PI3K. Moreover, knockdown of p110α, the catalytic subunit of PI3K, significantly suppressed the phosphorylation of PI3K substrate protein AKT, and TNF-induced necroptosis was blocked by AKT inhibitors. Furthermore, we found that p110α knockdown also suppressed the phosphorylation and oligomerization of RIP1, RIP3 and MLKL in response to TNF stimulation. In addition to the critical role in mediating TNF-induced necrosome formation, p110α was also essential for the spontaneous phosphorylation of RIP1 and RIP3. Finally, we found that p110α bound to RIP3, but not RIP1, to form protein complex in the process of TNF-induced necroptosis, and mediated TNF-induced necroptosis in the absence of RIP1. Our results demonstrate that PI3K is essential for TNF-induced necroptosis, which may act as the partner of RIP3 to initiate the activation of RIP1-RIP3-MLKL signal pathway and the subsequent necroptosis.


Assuntos
Necroptose/fisiologia , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Quinases/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Transdução de Sinais/fisiologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Linhagem Celular Tumoral , Células HEK293 , Humanos , Camundongos , Necroptose/efeitos dos fármacos , Necrose/metabolismo , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos
10.
Curr Microbiol ; 75(10): 1362-1371, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29922971

RESUMO

ß-Galactosidase is an essential enzyme for the metabolism of lactose in human beings and has an important role in the treatment of lactose intolerance (LI). ß-Galactosidase expressed by intestinal microflora, such as lactic acid bacteria (LAB), also alleviates LI. A promising approach to LI management is to exploit a food-grade LAB delivery system that can inhabit the human intestine and overproduce ß-galactosidase. In this study, we constructed a food-grade ß-galactosidase surface display delivery system and then integrated into the chromosome of Lactococcus lactis (L. lactis) NZ9000 using recombination. Western blot and immunofluorescence analyses confirmed that ß-galactosidase was expressed on the cell surface of recombinant L. lactis stain NZ-SDL. The whole-cell biocatalyst exhibits Vmax and Km values of 121.38 ± 7.17 UONPG/g and 65.36 ± 5.54 mM, based on ONPG hydrolysis. The optimum temperature for enzyme activity is 37 °C and the optimum pH is 5.0. Activity of the whole-cell biocatalyst is promoted by Mg2+, Ca2+, and K+, but inhibited by Zn2+, Fe2+, and Fe3+. The system has a thermal stability similar to purified ß-galactosidase but better pH stability, and is also more stable in artificial intestinal juice. Oral administration and intraperitoneal injections of NZ-SDL in mice cause no detectable health effects. In conclusion, we have successfully constructed a food-grade gene expression system in L. lactis that displays ß-galactosidase on the cell surface. This system exhibits good enzyme activity and stability in vitro, and is safe in vivo. It is therefore a promising candidate for use in LI management.


Assuntos
Membrana Celular/metabolismo , Expressão Gênica , Lactococcus lactis/genética , Lactococcus lactis/metabolismo , beta-Galactosidase/genética , beta-Galactosidase/metabolismo , Animais , Biocatálise , Clonagem Molecular , Ativação Enzimática , Feminino , Imunofluorescência , Engenharia Genética , Vetores Genéticos/genética , Hidrólise , Camundongos , Transporte Proteico
11.
Opt Express ; 25(2): 560-572, 2017 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-28157946

RESUMO

A self-mixing birefringent dual-frequency laser Doppler velocimeter (SBD-LDV) for high-resolution velocity measurements is presented in this paper. The velocity information of the object can be accurately extracted from the self-mixing Doppler frequency shift of the birefringent light-carried microwave signal. We generate a virtual stable light-carried microwave by using a birefringent dual-frequency He-Ne laser which further simplifies the structure of the light source. Moreover, the optical configuration based on the laser self-mixing interference brings benefits of compact optical setup, self-alignment, and direction discriminability. Experimentally, we extracted the Doppler beat frequency signal by the low-frequency (millihertz) phase lock-in amplifier, measured the beat frequency precisely in time-domain with a low sampling rate and calculated the magnitude of velocity. Compared with the previous self-mixing LDV, the average velocity resolution of SBD-LDV is improved to 0.030 mm/s for a target with longitudinal velocity, benefiting from the high stability of light-carried microwave. It is of great meaning and necessity because it helps to provide an available velocimeter with high stability and an extremely compact configuration, making a potential contribution to the velocimetry in practical engineering application.

12.
Tumour Biol ; 37(3): 3257-64, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26438059

RESUMO

Diagnosis of malignant pleural effusion (MPE) remains a major clinical challenge. The aim of this study was to evaluate the diagnostic value of combined detection of receptor-binding cancer antigen expressed on SiSo cells (RCAS1) and carcinoembryonic antigen (CEA) in patients with MPE and benign pleural effusion (BPE). The serum and pleural fluid samples were collected from 53 patients diagnosed with MPE and 49 patients with BPE. Enzyme-linked immunosorbent assay was used to detect the concentration of RCAS1 in serum and pleural effusion. The clinical data and laboratory information, including CEA levels, were gathered from these cases. The concentration of RCAS1 in MPE was significantly higher than that of BPE (P < 0.001). There was no significant difference between the two serum groups. The diagnostic sensitivity and specificity of pleural fluid RCAS1 were 67.92 and 81.63 %, respectively, at the optimized cutoff value of 7.326 U/mL; meanwhile, the sensitivity and specificity of pleural fluid CEA were 83.02 and 91.84 % at the cutoff value of 3.93 ng/mL. The specificity could be elevated to 98.50 % in serial detection, while the sensitivity may be improved to 94.55 % in parallel detection. Serum RCAS1 concentration was only detected in 53 serum samples out of the 102 samples, indicating that serum RCAS1 may not be a better option in differential diagnosis of malignancies compared with serum CEA, of which the diagnostic sensitivity and specificity were 64.15 and 83.67 % at the cutoff value of 3.90 ng/mL. No significant differences were found in pleural fluid RCAS1 concentration in MPE patients with different ages, gender, and pathological types of lung cancers. The detection of RCAS1 concentration in pleural fluid is informative for the diagnosis of MPE. Joint detection of RCAS1 and CEA can improve the diagnostic sensitivity and specificity. However, the diagnostic value of RCAS1 is not higher than that of CEA.


Assuntos
Antígenos de Neoplasias/análise , Antígeno Carcinoembrionário/análise , Derrame Pleural Maligno/diagnóstico , Derrame Pleural/diagnóstico , Adulto , Idoso , Antígenos de Neoplasias/sangue , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/sangue , Antígeno Carcinoembrionário/sangue , Diagnóstico Diferencial , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pleural/sangue , Derrame Pleural/metabolismo , Derrame Pleural Maligno/sangue , Derrame Pleural Maligno/metabolismo , Curva ROC , Solubilidade
13.
Phys Rev Lett ; 116(2): 026802, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26824558

RESUMO

Precise spatial control of the spin propagation channels is of fundamental and practical importance in future graphene-based spintronic devices. Here we use first-principles calculations to show that when narrow zigzag graphene nanoribbons are connected to form junctions or superlattices, properly placed square-shaped carbon tetragons not only serve as effective bundles of the two incoming spin edge channels, but also act as definitive topological spin switches for the two outgoing channels. The nanoribbon segments are largely drawn from different acene molecules. We further show that such spin switches can lift the degeneracy between the two spin propagation channels, which enables tunability of different magnetic states upon charge doping. Preliminary experimental supports for the realization of such tetragons connecting nanoribbon segments are also presented.

14.
J Cardiovasc Pharmacol ; 68(6): 425-432, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27575008

RESUMO

BACKGROUND: The renewal capacity of neonate human cardiomyocytes provides an opportunity to manipulate endogenous cardiogenic mechanisms for supplementing the loss of cardiomyocytes caused by myocardial infarction or other cardiac diseases. GSK-3ß inhibitors have been recently shown to promote cardiomyocyte proliferation in rats and mice, thus may be ideal candidates for inducing human cardiomyocyte proliferation. METHODS: Human cardiomyocytes were isolated from right atrial specimens obtained during routine surgery for ventricle septal defect and cultured with either GSK-3ß inhibitor (CHIR-99021) or ß-catenin inhibitor (IWR-1). Immunocytochemistry was performed to visualize 5-ethynyl-2'-deoxyuridine (EdU)-positive or Ki67-positive cardiomyocytes, indicative of proliferative cardiomyocytes. RESULTS: GSK-3ß inhibitor significantly increased ß-catenin accumulation in cell nucleus, whereas ß-catenin inhibitor significantly reduced ß-catenin accumulation in cell plasma. In parallel, GSK-3ß inhibitor increased EdU-positive and Ki67-positive cardiomyocytes, whereas ß-catenin inhibitor decreased EdU-positive and Ki67-positive cardiomyocytes. CONCLUSIONS: These results indicate that GSK-3ß inhibitor can promote human atrial cardiomyocyte proliferation. Although it remains to be determined whether the observations in atrial myocytes could be directly applicable to ventricular myocytes, the current findings imply that Wnt/ß-catenin pathway may be a valuable pathway for manipulating endogenous human heart regeneration.


Assuntos
Proliferação de Células/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Miócitos Cardíacos/efeitos dos fármacos , Piridinas/farmacologia , Pirimidinas/farmacologia , Regulação para Cima/efeitos dos fármacos , beta Catenina/biossíntese , Proliferação de Células/fisiologia , Células Cultivadas , Feminino , Glicogênio Sintase Quinase 3 beta/metabolismo , Átrios do Coração/citologia , Átrios do Coração/efeitos dos fármacos , Átrios do Coração/metabolismo , Humanos , Lactente , Recém-Nascido , Masculino , Miócitos Cardíacos/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Regulação para Cima/fisiologia
15.
Anal Bioanal Chem ; 408(7): 1963-73, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26804737

RESUMO

The ionic detergent sodium deoxycholate (SDC) is compatible with in-solution tryptic digestion and LC-MS/MS-based shotgun proteomics by virtue of being easy to separate from the peptide products via precipitation in acidic buffers. However, it remains unclear whether unique human peptides co-precipitate with SDC during acid treatment of complex biological samples. In this study, we demonstrate for the first time that a large quantity of unique peptides in human blood plasma can be co-precipitated with SDC using an optimized sample preparation method prior to shotgun proteomic analysis. We show that the plasma peptides co-precipitated with SDC can be successfully recovered using a sequential re-solubilization and precipitation procedure, and that this approach is particularly efficient at the extraction of long peptides. Recovery of peptides from the SDC pellet dramatically increased overall proteome coverage (>60 %), thereby improving the identification of low-abundance proteins and enhancing the identification of protein components of membrane-bound organelles. In addition, when we analyzed the physiochemical properties of the co-precipitated peptides, we observed that SDC-based sample preparation improved the identification of mildly hydrophilic/hydrophobic proteins that would otherwise be lost upon discarding the pellet. These data demonstrate that the optimized SDC protocol is superior to sodium dodecyl sulfate (SDS)/urea treatment for identifying plasma biomarkers by shotgun proteomics.


Assuntos
Proteínas Sanguíneas/química , Precipitação Química , Ácido Desoxicólico/química , Detergentes/química , Peptídeos/análise , Proteômica/métodos , Humanos , Proteoma/química , Dodecilsulfato de Sódio/química , Espectrometria de Massas em Tandem/métodos , Tripsina/química
16.
Appl Opt ; 55(16): 4423-9, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-27411198

RESUMO

A birefringent dual-frequency laser with a half-intracavity has been used to develop a laser Doppler velocimeter (LDV). The developed LDV utilizes a new signal-processing method based on a lock-in amplifier to achieve high-resolution velocity measurements and the discrimination of positive and negative velocities. Theoretical analysis and simulation results are presented. The velocity measurement experiments by using a high-precision linear stage are performed to verify the performance of the LDV. Compared with the previous dual-frequency LDVs, the average velocity resolution of the developed LDV is improved from 0.31 mm/s to 0.028 mm/s for a target without the rotational velocity. The measurement results show that our new technique can offer a powerful instrument for metrology sciences.

17.
BMC Public Health ; 16: 97, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26831139

RESUMO

BACKGROUND: Unsafe injection practices significantly increase the risk of human immunodeficiency virus (HIV) infection among injection drug users (IDUs). Little is known about how demographic characteristics of IDUs are linked to HIV-related risk behaviors in the central regions of China. METHODS: A cross-sectional survey was conducted at Mandatory Detoxification Centers (MDCs) and the community in Maanshan, China. RESULTS: Of the 916 IDUs, 96.4 % reported a history of heroin use during the past year, 93.4 % had HIV/AIDS knowledge, 16.8 % reported receptive syringe sharing and 12.2 % reported inconsistent condom use in commercial sex in the past year. Unsafe injection practice was associated with increased odds of minority ethnicity, lower level of education, and no peer education in the past year. Unsafe sex practice was associated with increased odds of being single, 18-30 years of age, non-local residence, and history of methamphetamine use in the past year. CONCLUSIONS: Integrated interventions to promote safe injection and protected commercial sex practices targeting IDUs must also consider individual and socio-environmental factors.


Assuntos
Síndrome da Imunodeficiência Adquirida/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Uso Comum de Agulhas e Seringas/estatística & dados numéricos , Assunção de Riscos , Abuso de Substâncias por Via Intravenosa/epidemiologia , Síndrome da Imunodeficiência Adquirida/epidemiologia , China/epidemiologia , Estudos Transversais , Usuários de Drogas , Feminino , Infecções por HIV/epidemiologia , Humanos , Masculino , Trabalho Sexual , Abuso de Substâncias por Via Intravenosa/psicologia , Sexo sem Proteção/estatística & dados numéricos
18.
BMC Microbiol ; 15: 6, 2015 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-25648185

RESUMO

BACKGROUND: Haemophilus influenzae is one of the main pathogens that cause community-acquired respiratory infections in children. Our previous study showed that H. influenzae is the second most common pathogen causing pneumonia and accounts for 30-50% of bacterial meningitis among Chinese children. H. influenzae carriage in children and its resistance to commonly used antimicrobials varies widely both geographically and over time. RESULTS: Surveys of the nasopharyngeal carriage of H. influenzae in children younger than 5 years of age with acute respiratory tract infection (ARI) were conducted in Beijing Children's Hospital, China in 2000, 2002, 2010, and 2012. The overall annual carriage rates of H. influenzae among children younger than 5 years of age with ARI were 35.5%, 20.6%, 14.4%, and 18.7%, and the percentages of H. influenzae isolates producing ß-lactamase were 4%, 13%, 27.1%, and 31%, respectively. The percentages of susceptibility to ampicillin progressively decreased from 96% (2000) to 87% (2002) to 63% (2010) to 61% (2012). All of the ampicillin-resistant isolates were found to be beta-lactamase producers. The susceptibility to tetracycline increased from 54% (2000) to 60% (2002) to 91.5% (2010) to 94.5% (2012). No statistically significant differences were observed in the susceptibility to cefaclor, cefuroxime, sulfamethoxazole, and chloramphenicol. Amoxicillin/clavulanic acid and ceftriaxone were the most effective antimicrobials for the isolates of H. influenzae across the 10-year period. CONCLUSIONS: This report on the H. influenzae carriage rates in children and the susceptibility of these bacteria to commonly used antibiotics showed that H. influenzae carriage decreased from 2000 to 2012. Additionally, the percentage of ß-lactamase-producing isolates increased while their susceptibility to ampicillin progressively decreased during this time. These results indicate that the appropriate empirical antimicrobial therapy should be changed for pediatric patients in China.


Assuntos
Antibacterianos/farmacologia , Portador Sadio/epidemiologia , Infecções por Haemophilus/epidemiologia , Haemophilus influenzae/efeitos dos fármacos , Haemophilus influenzae/isolamento & purificação , Nasofaringe/microbiologia , Pequim/epidemiologia , Portador Sadio/microbiologia , Pré-Escolar , Feminino , Infecções por Haemophilus/microbiologia , Humanos , Lactente , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Prevalência , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Inquéritos e Questionários
19.
Biomed Chromatogr ; 29(7): 1027-34, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25425064

RESUMO

Bulleyaconitine A (BLA) from Aconitum bulleyanum plants is usually used as anti-inflammatory drug in some Asian countries. It has a variety of bioactivities, and at the same time some toxicities. Since the bioactivities and toxicities of BLA are closely related to its metabolism, the metabolites and the metabolic pathways of BLA in rat liver microsomes were investigated by HPLC-MS(n). In this research, the 12 metabolites of BLA were identified according to the results of HPLC-MS(n) data and the relevant literature. The results showed that there are multiple metabolites of BLA in rat liver microsomes, including demethylation, deacetylation, dehydrogenation deacetylation and hydroxylation. The major metabolic pathways of BLA in rat liver microsomes were clarified by HPLC-MS combined with specific inhibitors of CYP450 isoforms. As a result, CYP3A and 2C were found to be the principal CYP isoforms contributing to the metabolism of BLA. Moreover, CYP2D6 and 2E1 are also more important CYP isoforms for the metabolism of BLA. While CYP1A2 only affected the formation rate of M11, its effect on the metabolism of BLA is very small.


Assuntos
Aconitina/análogos & derivados , Cromatografia Líquida/métodos , Microssomos Hepáticos/metabolismo , Espectrometria de Massas em Tandem/métodos , Aconitina/análise , Aconitina/química , Aconitina/metabolismo , Animais , Sistema Enzimático do Citocromo P-450 , Masculino , Redes e Vias Metabólicas , Ratos , Ratos Sprague-Dawley
20.
Hepatology ; 58(6): 2012-22, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23787902

RESUMO

UNLABELLED: Human dachshund homolog 1 (DACH1) is a major component of the Retinal Determination Gene Network (RDGN) and functions as a tumor suppressor. However, the regulation of DACH1 expression and its function in hepatocellular carcinoma (HCC) remain unclear. In this study, epigenetic changes of DACH1 were analyzed in HCC cell lines and primary cancers. We found that promoter region hypermethylation was correlated with loss or reduction of DACH1 expression, and restoration of DACH1 expression was induced by 5-aza-2'-deoxycytidine (5-AZA) in HCC cell lines. Promoter region methylation was found in 42% of primary HCC. Reduced expression of DACH1 was associated with poor differentiation of HCC nodules and higher serum aspartate aminotransferase/alanine aminotransferase ratio. DACH1 suppressed cellular growth by reactivating transforming growth factor beta (TGF-ß) signaling. Ectopic expression of DACH1 enhanced chemosensitivity to 5-fluorouracil (5-FU) by inducing p21 expression in HCC cells. CONCLUSION: DACH1 is frequently methylated in HCC and DACH1 expression is regulated by promoter hypermethylation. Down-regulation of DACH1 is a novel mechanism for gaining resistance to the antiproliferative signaling of TGF-ß1 and 5-FU resistance.


Assuntos
Carcinoma Hepatocelular/fisiopatologia , Proteínas do Olho/genética , Neoplasias Hepáticas/fisiopatologia , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Adolescente , Adulto , Idoso , Azacitidina/farmacologia , Carcinoma Hepatocelular/genética , Metilação de DNA , Feminino , Fluoruracila/farmacologia , Inativação Gênica , Humanos , Neoplasias Hepáticas/genética , Masculino , Pessoa de Meia-Idade , Transdução de Sinais , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo
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