Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
1.
Small ; 18(19): e2107881, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35417059

RESUMO

In contrast to the 2D organic-inorganic hybrid Ruddlesden-Popper halide perovskites (RPP), a new class of 2D all inorganic RPP (IRPP) has been recently proposed by substituting the organic spacers with an optimal inorganic alternative of cesium cations (Cs+ ). Nevertheless, the synthesis of high-membered 2D IRPPs (n > 1) has been a very challenging task because the Cs+ need to act as both spacers and A-site cations simultaneously. This work presents the successful synthesis of stable phase-pure high-membered 2D IRPPs of Csn+1 Pbn Br3n+1 nanosheets (NSs) with n = 3 and 4 by employing the strategy of using additional strong binding bidentate ligands. The structures of the 2D IRPPs (n = 3 and 4) NSs are confirmed by powder X-ray diffraction and high-resolution aberration-corrected scanning transmission electron microscope measurements. These 2D IRPPs NSs exhibit a strong quantum confinement effect with tunable absorption and emission in the visible light range by varying their n values, attributed to their inherent 2D quantum-well structure. The superior structural and optical stability of the phase-pure high-membered 2D IRPPs make them a promising candidate as photocatalysts in CO2 reduction reactions with outstanding photocatalytic performance and long-term stability.

2.
Nanotechnology ; 31(36): 364001, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32438349

RESUMO

Silicon is expected to be a useful anode material in lithium ion batteries for future energy storage applications, because of its high theoretical charge storage density of Li+ ions. However, volume expansion due to lithiation fractures the Si anode material, leading to poor cycle stability of battery operation. The approaches to overcome the problem include using Si nanowires to relieve the stress induced by volume expansion and coating a protective layer on the Si anode to prevent delamination. In this study, we use in-situ scanning electron microscopy to monitor the morphological changes of 90 nm thick pristine Si nanowires and the Si nanowires coated with amorphous TiO2, respectively, during electrochemical lithiation. The results of in-situ observation show that both kinds of Si nanowires exhibit a larger thickness after 10 h lithiation and suffer fracture after 25 h. It is also found that the TiO2 layer is not strong enough to prevent Si nanowires from fracture. Since the TiO2 layer can not be elastically deformed, this surface shell fractures earlier in the lithiation process than pristine Si nanowires. Transformation of the crystalline Si nanowires to an amorphous phase and lithium composition detected in the nanowires support that the observed fracture indeed results from lithiation.

3.
Mol Carcinog ; 57(2): 147-158, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28949402

RESUMO

The mutation p53N236S (p53S) has been identified as one of the recurrent mutations in human cancers by TCGA database. Our in vitro data revealed the oncogenic gain of function of p53S. To understand the function of p53S in vivo, we generated the p53S knock-in mouse. The p53S/S mice manifested highly invasive lymphomas and metastatic sarcomas with dramatically increased double minute chromosomes. The survival curve, the incidence of tumors and the tumor spectrum of p53S/S mice is very similar to the p53R172H mouse model. The p53S/+ mice showed delayed onset of tumorigenesis and a high metastasis rate (40%) and low loss of heterozygosity rate (2/16). The activation of CDKN2A pathway in p53S/S MEF and tumors, and the accumulation of p19ARF protein in tumor tissues suggested p19ARF might contribute to the accumulation of mutant p53S protein in the tumor and promote tumorigenesis. The high expression of p19ARF correlated with mutant p53 accumulation and tumor progression, suggesting a dual role of p19ARF in tumor promotion or suppression that might depend on the p53 mutation status in tumor cells. The oncogenic gain of function of this recurrent mutation p53S prompts the reconsideration of p53 mutations function that occurs at a low frequency.


Assuntos
Carcinogênese/genética , Cromossomos/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Mutação/genética , Oncogenes/genética , Proteína Supressora de Tumor p53/genética , Animais , Modelos Animais de Doenças , Progressão da Doença , Linfoma/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Sarcoma/genética
4.
Eur Heart J ; 38(19): 1498-1508, 2017 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-28329361

RESUMO

AIMS: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is characterized by fibrofatty infiltration of the myocardium and ventricular arrhythmias that may lead to sudden cardiac death. It has been observed that male patients develop the disease earlier and present with more severe phenotypes as compared to females. Thus, we hypothesized that serum levels of sex hormones may contribute to major arrhythmic cardiovascular events (MACE) in patients with ARVC/D. METHODS AND RESULTS: The serum levels of five sex hormones, sex hormone-binding globulin, high sensitivity troponin T, pro-brain natriuretic peptide, cholesterol, triglycerides, insulin, and glucose were measured in 54 ARVC/D patients (72% male). Twenty-six patients (48%) experienced MACE. Total and free testosterone levels were significantly increased in males with MACE as compared to males with a favourable outcome, whereas estradiol was significantly lower in females with MACE as compared to females with a favourable outcome. Increased testosterone levels remained independently associated with MACE in males after adjusting for age, body mass index, Task Force criteria, ventricular function, and desmosomal mutation status. Furthermore, an induced pluripotent stem cell-derived ARVC/D cardiomyocyte model was used to investigate the effects of sex hormones. In this model, testosterone worsened and estradiol improved ARVC/D-related pathologies such as cardiomyocyte apoptosis and lipogenesis, strongly supporting our clinical findings. CONCLUSIONS: Elevated serum testosterone levels in males and decreased estradiol levels in females are independently associated with MACE in ARVC/D, and directly influence disease pathology. Therefore, determining the levels of sex hormones may be useful for risk stratification and may open a new window for preventive interventions.


Assuntos
Displasia Arritmogênica Ventricular Direita/etiologia , Hormônios Esteroides Gonadais/metabolismo , Caracteres Sexuais , Adulto , Análise de Variância , Displasia Arritmogênica Ventricular Direita/sangue , Biomarcadores/metabolismo , Morte Súbita Cardíaca/etiologia , Desmossomos/genética , Estradiol/metabolismo , Exercício Físico/fisiologia , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/fisiologia , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Miócitos Cardíacos/fisiologia , Prognóstico , Testosterona/metabolismo
5.
Tumour Biol ; 37(8): 10317-27, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26842926

RESUMO

Unlike heterogeneous tumor cells, cancer-associated fibroblasts (CAF) are genetically more stable which serve as a reliable target for tumor immunotherapy. Fibroblast activation protein (FAP) which is restrictively expressed in tumor cells and CAF in vivo and plays a prominent role in tumor initiation, progression, and metastasis can function as a tumor rejection antigen. In the current study, we have constructed artificial FAP(+) stromal cells which mimicked the FAP(+) CAF in vivo. We immunized a breast cancer mouse model with FAP(+) stromal cells to perform immunotherapy against FAP(+) cells in the tumor microenvironment. By forced expression of FAP, we have obtained FAP(+) stromal cells whose phenotype was CD11b(+)/CD34(+)/Sca-1(+)/FSP-1(+)/MHC class I(+). Interestingly, proliferation capacity of the fibroblasts was significantly enhanced by FAP. In the breast cancer-bearing mouse model, vaccination with FAP(+) stromal cells has significantly inhibited the growth of allograft tumor and reduced lung metastasis indeed. Depletion of T cell assays has suggested that both CD4(+) and CD8(+) T cells were involved in the tumor cytotoxic immune response. Furthermore, tumor tissue from FAP-immunized mice revealed that targeting FAP(+) CAF has induced apoptosis and decreased collagen type I and CD31 expression in the tumor microenvironment. These results implicated that immunization with FAP(+) stromal cells led to the disruption of the tumor microenvironment. Our study may provide a novel strategy for immunotherapy of a broad range of cancer.


Assuntos
Neoplasias da Mama/patologia , Fibroblastos/imunologia , Gelatinases/imunologia , Imunoterapia/métodos , Proteínas de Membrana/imunologia , Serina Endopeptidases/imunologia , Microambiente Tumoral/imunologia , Animais , Western Blotting , Neoplasias da Mama/imunologia , Modelos Animais de Doenças , Endopeptidases , Feminino , Imunofluorescência , Imunização , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL
6.
Circ J ; 79(7): 1402-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25971409

RESUMO

Cellular reprogramming of somatic cells to patient-specific induced pluripotent stem cells (iPSCs) enables in-vitro modeling of human cardiac disorders for pathogenic and therapeutic investigations. However, using iPSC-derived cardiomyocytes (iPSC-CMs) to model an adult-onset heart disease remains challenging because of the uncertainty regarding the ability of relatively immature iPSC-CMs to fully recapitulate adult disease phenotypes. Arrhythmogenic right ventricular dysplasia (ARVD) is an inherited cardiomyopathy characterized by pathological fibrofatty infiltration and cardiomyocyte (CM) loss predominantly in the right ventricle (RV), leading to heart failure and lethal arrhythmias. Over 50% of affected individuals have desmosome gene mutations, most commonly inPKP2encoding plakophilin-2. Using Yamanaka's pluripotent factors, we generated iPSC lines from ARVD patients withPKP2mutations. We first developed a method to induce metabolic maturation of iPSC-CMs and showed that induction of adult-like metabolic energetics from an embryonic/glycolytic state is essential to model an adult-onset cardiac disease using patient-specific iPSCs. Furthermore, we showed that coactivation of normal peroxisome proliferator-activated receptor (PPAR)-α and abnormal PPARγ pathways in ARVD iPSC-CMs resulted in exaggerated CM lipogenesis, CM apoptosis, Na(+)channel downregulation and defective intracellular calcium handling, recapitulating the pathological signatures of ARVD. Using this model, we revealed novel pathogenic insights that metabolic derangement in an adult-like metabolic milieu underlies ARVD pathologies, enabling us to propose novel disease-modifying therapeutic strategies.


Assuntos
Displasia Arritmogênica Ventricular Direita/metabolismo , Displasia Arritmogênica Ventricular Direita/patologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Modelos Cardiovasculares , Adulto , Displasia Arritmogênica Ventricular Direita/genética , Diferenciação Celular , Células Cultivadas , Reprogramação Celular , Desmossomos/genética , Humanos , Mutação , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , PPAR alfa/metabolismo , PPAR gama/metabolismo , Placofilinas/genética
7.
Tumour Biol ; 35(3): 1997-2007, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24104501

RESUMO

Generation of cytokine-induced killer (CIK) cells is an emerging approach in adoptive donor lymphocyte infusion for patients with a wide range of tumors. However, our previous in vitro studies have shown that the killing efficacy of CIK cells against lung cancer was lower than other tumor cells, while the underlying mechanisms are not clear. We explored the feasibility to improve CIK cells mediated cytotoxicity against lung cancer. Interleukin (IL)-15 is a pleiotropic cytokine that stimulates cytolytic activity and cytokine secretion of NK cells, which may enhance the cytotoxic activity of CIK cells. In this study, we intended to stimulate the CIK cells by IL-2 in combination with IL-15 in cell expansion to achieve enhanced cytotoxicity against lung cancer cells. The different phenotypes of IL-2 or combination of IL-2 and IL-15 stimulated cytokine-induced killer cells were determined, and the improved cytotoxicity of IL-2 and IL-15 induced CIK cells against lung adenocarcinoma were evaluated both in vitro and in vivo. CIK cells stimulated with both IL-2 and IL-15 has shown greater proliferative potential than CIK cells treated with IL-2 alone. IL-15 induction also has driven the expansion of CD3+CD56+ subset and significantly enhanced cytotoxicity against tumor cells. Further analysis has demonstrated that CIKIL-2&IL-15 injected mice models have shown significant tumor regression and lower expression level of CyclinD1 in tumor tissue. This study has provided preclinical evidences that CIKIL-2&IL-15 with enhanced cytotoxicity may offer alternative treatment option for patients with lung cancer.


Assuntos
Adenocarcinoma/imunologia , Células Matadoras Induzidas por Citocinas/imunologia , Imunoterapia Adotiva/métodos , Interleucina-15/imunologia , Interleucina-2/imunologia , Neoplasias Pulmonares/imunologia , Adenocarcinoma/terapia , Adenocarcinoma de Pulmão , Animais , Apoptose/imunologia , Técnicas de Cultura de Células/métodos , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/terapia , Camundongos , Camundongos Endogâmicos BALB C , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Mol Cell Biochem ; 387(1-2): 135-41, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24178239

RESUMO

Angiotensin II(Ang II)-stimulated cardiomyocytes hypertrophy and apoptosis are associated with nuclear factor-κB (NF-κB) activation. NF-κB, a redox-sensitive transcription factor, contributes a critical role in cell death, but, Ang II-stimulated NF-κB-mediated cardiomyocytes apoptosis remains less understood. Recently, microRNAs (miRNAs) have been shown to be critical regulators in various cardiac remodeling processes; however, NF-κB-mediated miRNA's role in cardiomyocytes apoptosis remains undetermined. The miR-30b has been implicated in diverse cardiac remodeling; but, NF-κB-mediated miR-30b modulation in Ang II-induced cardiomyocytes death is currently unknown. In the present study, neonatal cardiomyocytes were pretreated with SN50, a selective cell permeable peptide inhibitor of NF-κB, or transfected with miR-30b mimetic and inhibitors separately, and then challenged with Ang II. The target gene, Bcl-2, and NF-κB transcriptional activity were analyzed. Our results demonstrated that NF-κB positively regulated miR-30b expression in Ang II-induced cardiomyocytes apoptosis, and Bcl-2 was a direct target for miR-30b. NF-κB further regulated the expression of Bcl-2 in the above setting. Furthermore, Ang II-induced cardiomyocytes apoptosis rescued by inhibiting either NF-κB or miR-30b provided an important role in cardiomyocytes cell death. We evaluated a critical role of NF-κB-mediated miR-30b modulation in Ang II-stimulated cardiomyocytes targeting Bcl-2. Our data may provide a new insight of miR-30b's role in myocardial infarction or ischemia.


Assuntos
Apoptose , MicroRNAs/metabolismo , Miócitos Cardíacos/fisiologia , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Regiões 3' não Traduzidas , Angiotensina II/fisiologia , Animais , Sequência de Bases , Células HEK293 , Humanos , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Interferência de RNA , Ratos , Transcrição Gênica , Ativação Transcricional
9.
Polymers (Basel) ; 16(2)2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38276684

RESUMO

Natural rubber (NR) is extensively utilized in numerous industries, such as aerospace, military, and transportation, because of its exceptional elasticity and all-around mechanical qualities. However, commercial NR made using various techniques typically has distinct mechanical characteristics. For instance, whole field latex rubber (SCR-WF) cured with accelerator 2-Mercaptobenzothiazole exhibits poor mechanical properties. This work attempts to enhance the mechanical property of SCR-WF via the addition of lanthanum stearate (LaSt). The influence of LaSt on strain-induced crystallization (SIC) and the mechanical properties of SCR-WF were investigated. The results of crosslinking density measured by the equilibrium swelling method demonstrate that the presence of LaSt significantly increases the crosslinking density of SCR-WF with lower loading of LaSt. The results of the mechanical properties show that the introduction of LaSt can enhance the tensile strength and fracture toughness of SCR-WF. To reveal the mechanism of LaSt improving the mechanical properties of SCR-WF, synchrotron radiation wide-angle X-ray diffraction (WAXD) experiments were used to investigate the SIC behaviors of SCR-WF. We found that the LaSt leads to higher crystallinity of SIC for the strain higher than 3.5. The tube model indicates the contribution of LaSt in both crosslinking and topological constraints. This work may provide an instruction for developing SCR-WF with superior mechanical properties.

10.
bioRxiv ; 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39314404

RESUMO

Background: Pathological fibrosis is a major finding in cardiovascular diseases and can result in arrhythmia and heart failure. Desmosome gene mutations can lead to arrhythmogenic cardiomyopathy (ACM). Among ACM, pathogenic desmoplakin ( DSP ) variants cause a distinctive cardiomyopathy with excessive cardiac fibrosis that could precede ventricular dysfunction. DSP variants are also linked to other fibrotic diseases. Whether DSP plays any role in pathological fibrosis remain unknown. Methods: Mesenchymal stromal cells (MSCs) are resident fibroblast-like cells that are responsible for fibrogenesis in most organs, including hearts. We first used unbiased genome-wide analyses to generate cardiac fibroblasts-like, induced pluripotent stem cell-derived MSCs from normal donors and ACM patients with DSP mutations. We then studied the fibrogenic responses of cardiac MSCs to transforming growth factor beta-1 (TGF-ß1) using Western/Co-IP, autophagy assay, gene knockdowns/over-expressions, genomic analyses, mouse DSP knockdown models, immunostaining, and qPCR. Results: TGFß1 induced excessive accumulations of vimentin (VIM)/fibrillar collagens, and over-activated fibrotic genes in DSP- mutant MSCs when compared to normal MSCs. In normal MSCs, VIMs bind to wild-type DSP during normal fibrogenesis after TGFß1. DSP- mutant MSCs exhibited a haplo-insufficient phenotype with increased DSP-unbound VIMs that sequestered beclin-1 (BECN1) from activating autophagy and caveolin-1 (CAV1)-mediated endocytosis. Decreased autophagy caused collagen accumulations and diminished CAV1 endocytosis resulted in abnormal CAV1 plaque formation that over-activated fibrotic genes [ COL1A1, COL3A1, and fibronectin ( FN )] via heightened p38 activities after TGFß1. Genome-wide analysis and DSP knockdown in mouse fibroblasts confirmed this novel role of DSP mutations in pathological fibrosis. Overexpression of VIM-binding domains of DSP could suppress pathological fibrosis by increasing collagen autophagic degradation and decreasing fibrotic gene expressions. Conclusions: Our data reveal that DSP deficiency in MSCs/fibroblasts leads to exaggerated fibrogenesis in DSP-cardiomyopathy by decreasing BECN1 availability for autophagy and CAV1-endocytosis. Overexpression of VIM binding domains of DSP could be a new strategy to treat pathological fibrosis.

11.
J Cell Physiol ; 228(7): 1433-42, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23254997

RESUMO

Micro-RNAs (miRNAs) are a class of small non-coding RNAs, recently emerged as a post-transcriptional regulator having a key role in various cardiac pathologies. Among them, cardiac fibrosis that occurs as a result from an imbalance of extracellular matrix proteins turnover and is a highly debilitating process that eventually lead to organ dysfunction. An emerging theme on is that miRNAs participate in feedback loop with transcription factors that regulate their transcription. NF-κB, a key transcription factor regulator controls a series of gene program in various cardiac diseases through positive and negative feedback mechanism. But, NF-κB mediated miRNA regulation in cardiac fibrosis remains obscure. Bioinformatics analysis revealed that miR-26a has targets collagen I and CTGF and possesses putative NF-κB binding element in its promoter region. Here, we show that inhibition of NF-κB in cardiac fibroblast restores miR-26a expression, attenuating collagen I, and CTGF gene expression in the presence of Ang II, conferring a feedback regulatory mechanism in cardiac fibrosis. The target genes for miR-26a were confirmed using 3'-UTR luciferase reporter assays for collagen I and CTGF genes. Using NF-κB reporter assays, we determine that miR-26a overexpression inhibits NF-κB activity. Finally, we show that miR-26a expression is restored along with the attenuation of collagen I and CTGF genes in cardiac specific IkBa triple mutant transgenic mice (preventing NF-κB activation) subjected to 4 weeks transverse aortic banding (TAC), compared to wild type (WT) mice. The data indicate a potential role of miR-26a in cardiac fibrosis and, offer novel therapeutic intervention.


Assuntos
MicroRNAs/genética , MicroRNAs/metabolismo , Miocárdio/metabolismo , Miocárdio/patologia , NF-kappa B/metabolismo , Angiotensina II/farmacologia , Animais , Células Cultivadas , Colágeno Tipo I/genética , Fator de Crescimento do Tecido Conjuntivo/genética , Fibrose , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas I-kappa B/genética , Proteínas I-kappa B/metabolismo , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Modelos Cardiovasculares , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Inibidor de NF-kappaB alfa , NF-kappa B/antagonistas & inibidores , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Remodelação Ventricular/genética , Remodelação Ventricular/fisiologia
12.
Rheumatol Int ; 33(5): 1283-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23129427

RESUMO

Toll-like receptor4 (TLR4) plays an important role in the induction and regulation of the innate or adaptive immune responses. Thus, the genetic variation in TLR4 gene may influence the development of autoimmune diseases such as rheumatoid arthritis (RA). Several studies have investigated the roles of genetic polymorphisms of TLR4 gene in RA, but most of these studies were restricted to two cosegregating functional missense polymorphisms Asp299Gly and Thr399Ile. To determine whether non-missense genetic polymorphisms located in regulatory region of TLR4 are related to RA in a Chinese Han population, four single nucleotide polymorphisms (SNPs) situated on 3' untranslating region (UTR) and 5' UTR were genotyped in 213 RA patients and 247 unrelated ethnically matched controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing techniques. Significant genetic associations were observed with the 3' UTR SNP rs41426344 and rs7873784. The minor allele C and homozygotic variant genotype CC of rs41426344 and minor allele C of rs7873784 were identified to be risk factors for the development of RA in Chinese Han people. Furthermore, by comparing the variation allele frequencies to other populations, prevalent genetic ethnic specificity was observed in all the four SNPs. Our study suggested that the effect of non-missense polymorphisms located in regulatory region would not be neglected in disease association analysis.


Assuntos
Artrite Reumatoide/genética , Povo Asiático , Polimorfismo de Nucleotídeo Único , Receptor 4 Toll-Like/genética , Regiões 3' não Traduzidas , Regiões 5' não Traduzidas , Adulto , Artrite Reumatoide/etnologia , Artrite Reumatoide/imunologia , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , China/epidemiologia , Análise Mutacional de DNA , Feminino , Frequência do Gene , Predisposição Genética para Doença , Haplótipos , Humanos , Desequilíbrio de Ligação , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fenótipo , Reação em Cadeia da Polimerase , Fatores de Risco
13.
Poult Sci ; 102(7): 102462, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37209651

RESUMO

A Campylobacter species was first described as the etiological agent of Spotty Liver Disease (SLD) in 2015 and subsequently named as Campylobacter hepaticus in 2016. The bacterium predominantly affects barn and/or free-range hens at peak lay, is fastidious and difficult to isolate, which has impeded elucidation of its sources, means of persistence and transmission. Ten farms from South-Eastern Australia, of which 7 were free range entities participated in the study. A total of 1,404 specimens from layers and 201 from environmental sources, were examined for the presence of C. hepaticus. In this study, our principal findings included the continuing detection of C. hepaticus infection in a flock following an outbreak, indicating a possible transition of infected hens to asymptomatic carriers, that was also characterized by no further occurrence of SLD in the flock. We also report that the first outbreaks of SLD on newly commissioned free-range farms affected layers ranging from 23 to 74 wk of age, while subsequent outbreaks in replacement flocks on these farms occurred during the more conventional peak lay period (23-32 wk of age). Finally, we report that in the on-farm environment, C. hepaticus DNA was detected in layer feces, inert elements such as stormwater, mud, soil, as well as in fauna such as flies, red mites, Darkling beetles, and rats. While in off-farm locations, the bacterium was detected in feces from a variety of wild birds and a canine.


Assuntos
Infecções por Campylobacter , Campylobacter , Doenças do Cão , Hepatopatias , Doenças das Aves Domésticas , Animais , Feminino , Cães , Ratos , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/veterinária , Infecções por Campylobacter/microbiologia , Galinhas/microbiologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/microbiologia , Hepatopatias/epidemiologia , Hepatopatias/veterinária
14.
Am J Physiol Heart Circ Physiol ; 302(8): H1655-66, 2012 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-22245771

RESUMO

Uncontrolled pulmonary arterial hypertension (PAH) results in right ventricular (RV) hypertrophy (RVH), progressive RV failure, and low cardiac output leading to increased morbidity and mortality (McLaughlin VV, Archer SL, Badesch DB, Barst RJ, Farber HW, Lindner JR, Mathier MA, McGoon MD, Park MH, Rosenson RS, Rubin LJ, Tapson VF, Varga J. J Am Coll Cardiol 53: 1573-1619, 2009). Although the exact figures of its prevalence are difficult to obtain because of the diversity of identifiable causes, it is estimated that the incidence of pulmonary hypertension is seven to nine cases per million persons in the general population and is most prevalent in the age group of 20-40, occurring more commonly in women than in men (ratio: 1.7 to 1; Rubin LJ. N Engl J Med 336: 111-117, 1997). PAH is characterized by dyspnea, chest pain, and syncope. Unfortunately, there is no cure for this disease and medical regimens are limited (Simon MA. Curr Opin Crit Care 16: 237-243, 2010). PAH leads to adverse remodeling that results in RVH, progressive right heart failure, low cardiac output, and ultimately death if left untreated (Humbert M, Morrell NW, Archer SL, Stenmark KR, MacLean MR, Lang IM, Christman BW, Weir EK, Eickelberg O, Voelkel NF, Rabinovitch M. J Am Coll Cardiol 43: 13S-24S, 2004; Humbert M, Sitbon O, Simonneau G. N Engl J Med 351: 1425-1436, 2004. LaRaia AV, Waxman AB. South Med J 100: 393-399, 2007). As there are no direct tools to assess the onset and progression of PAH and RVH, the disease is often detected in later stages marked by full-blown RVH, with the outcome predominantly determined by the level of increased afterload (D'Alonzo GE, Barst RJ, Ayres SM, Bergofsky EH, Brundage BH, Detre KM, Fishman AP, Goldring RM, Groves BM, Kernis JT, et al. Ann Intern Med 115: 343-349, 1991; Sandoval J, Bauerle O, Palomar A, Gomez A, Martinez-Guerra ML, Beltran M, Guerrero ML. Validation of a prognostic equation Circulation 89: 1733-1744, 1994). Various studies have been performed to assess the genetic, biochemical, and morphological components that contribute to PAH. Despite major advances in the understanding of the pathogenesis of PAH, the molecular mechanism(s) by which PAH promotes RVH and cardiac failure still remains elusive. Of all the mechanisms involved in the pathogenesis, inflammation and oxidative stress remain the core of the etiology of PAH that leads to development of RVH (Dorfmüller P, Perros F, Balabanian K, Humbert M. Eur Respir J 22: 358-363, 2003).


Assuntos
Coração/fisiologia , Hipertrofia Ventricular Direita/induzido quimicamente , Hipertrofia Ventricular Direita/prevenção & controle , Monocrotalina , NF-kappa B/genética , Venenos , Animais , Western Blotting , Moléculas de Adesão Celular/biossíntese , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Imunofluorescência , Hipertensão Pulmonar/induzido quimicamente , Hipertensão Pulmonar/fisiopatologia , Hipertrofia Ventricular Direita/genética , Proteínas I-kappa B/fisiologia , Inflamação/patologia , Masculino , Camundongos , Miocárdio/metabolismo , Miocárdio/patologia , Inibidor de NF-kappaB alfa , RNA/biossíntese , RNA/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/fisiologia , Remodelação Ventricular/efeitos dos fármacos
15.
ACS Nano ; 15(3): 4627-4635, 2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33651590

RESUMO

Platinum diselenide (PtSe2) is a group-10 two-dimensional (2D) transition metal dichalcogenide that exhibits the most prominent atomic-layer-dependent electronic behavior of "semiconductor-to-semimetal" transition when going from monolayer to bulk form. This work demonstrates an efficient photoelectrochemical (PEC) conversion for direct solar-to-hydrogen (H2) production based on 2D layered PtSe2/Si heterojunction photocathodes. By systematically controlling the number of atomic layers of wafer-scale 2D PtSe2 films through chemical vapor deposition (CVD), the interfacial band alignments at the 2D layered PtSe2/Si heterojunctions can be appropriately engineered. The 2D PtSe2/p-Si heterojunction photocathode consisting of a PtSe2 thin film with a thickness of 2.2 nm (or 3 atomic layers) exhibits the optimized band alignment and delivers the best PEC performance for hydrogen production with a photocurrent density of -32.4 mA cm-2 at 0 V and an onset potential of 1 mA cm-2 at 0.29 V versus a reversible hydrogen electrode (RHE) after post-treatment. The wafer-scale atomic-layer controlled band engineering of 2D PtSe2 thin-film catalysts integrated with the Si light absorber provides an effective way in the renewable energy application for direct solar-to-hydrogen production.

17.
J Hum Genet ; 55(5): 314-22, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20414255

RESUMO

Northwest China is closely adjacent to Central Asia, an intermediate region of the Eurasian continent. Moreover, the Silk Road through the northwest of China once had a vital role in the east-west intercommunications. Nevertheless, little has been known about the genetic makeup of populations in this region. We collected 503 male samples from 14 ethnic groups in the northwest of China, and surveyed 29 Y-chromosomal biallelic markers and 8 short tandem repeats (STRs) loci to reconstruct the paternal architecture. Our results illustrated obvious genetic difference among these ethnic groups, and in general their genetic background is more similar with Central Asians than with East Asians. The ancestors of present northwestern populations were the admixture of early East Asians peopling northwestward and later Central Asians immigrating eastward. This population mixture was dated to occur within the past 10 000 years. The J2-M172 lineages likely entered China during the eastward migration of Central Asians. The influence from West Eurasia through gene flows on the extant ethnic groups in Northwest China was relatively weak.


Assuntos
Cromossomos Humanos Y/genética , Genética Populacional , Repetições de Microssatélites/genética , Polimorfismo de Nucleotídeo Único , Análise de Variância , Ásia/etnologia , Povo Asiático/genética , China , Análise por Conglomerados , Etnicidade/genética , Frequência do Gene , Variação Genética , Genótipo , Geografia , Haplótipos , Humanos , Masculino , Filogenia
18.
Rheumatol Int ; 30(9): 1249-52, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20306049

RESUMO

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of synovium and subsequent joint destruction. Recently, genetic polymorphisms within the toll-like receptor 4 (TLR4) genes have been reported to be associated with RA. To analyze the association between the genetic polymorphisms within TLR4 gene and the susceptibility to RA in Chinese people, two functional variants, Asp299Gly and Thr399Ile, in the TLR4 gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing techniques from 213 RA patients and 247 ethnically matched controls. None polymorphisms of Asp299Gly and Thr399Ile were detected in all RA cases and controls, which indicates that there is no relevance between these two SNPs and RA in the Chinese Han population. Further studies with extended single nucleotide polymorphisms (SNP) should be performed.


Assuntos
Artrite Reumatoide/genética , Povo Asiático/genética , Polimorfismo Genético/genética , Receptor 4 Toll-Like/genética , Adulto , Estudos de Casos e Controles , China , Feminino , Genes , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Polimorfismo de Nucleotídeo Único , Grupos Populacionais/genética
19.
Infect Genet Evol ; 77: 104094, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31689545

RESUMO

Cyclic GMP-AMP synthase (cGAS) is a cytosolic nucleic acid sensor that can bind to dsDNA. It maintains an autoinhibited state in the absence of cytosolic dsDNA, while when activated, it in turn activates its adaptor protein STING, ultimately triggering a cascade that produces inflammatory cytokines and type I interferons (IFNs). With further research, additional types of nucleic acids have been found to be activators of the cGAS-STING pathway. The cGAS-STING pathway can provide protection or resistance against infections; however, improper or overactivation might cause severe inflammatory pathologies, including autoimmunity. This article systematically reviews the latest research progress on the axis, including categorical pathway triggers, the connection with autoimmune disease and drug therapy progress.


Assuntos
Doenças Autoimunes/metabolismo , Inflamação/metabolismo , Proteínas de Membrana/metabolismo , Nucleotidiltransferases/metabolismo , Animais , Doenças Autoimunes/imunologia , Citocinas/metabolismo , Humanos , Inflamação/imunologia , Interferons/metabolismo , Transdução de Sinais
20.
Indian Pediatr ; 57(2): 138-141, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-32060241

RESUMO

OBJECTIVE: To investigate the prevalence and risk factors of congenital heart disease in Yunnan, China which has diverse ethnic groups. METHODS: This cross-sectional study enrolled 244,023 children from 2010 to 2015. To diagnose CHD, a conventional physical examination was used to screen suspicious cases, which were further confirmed by echocardiography. RESULTS: A total of 1695 children were diagnosed with CHD. The estimated prevalence was 6.94%. Atrial septal defects were the most common cardiac abnormalities. A higher prevalence of CHD was observed with preterm birth, low birth weight, maternal age ≥35 years, and high-altitude regions. The prevalence also showed differences between diverse ethnic groups. CONCLUSIONS: The prevalence of CHD in China may have ethnic differences.


Assuntos
Cardiopatias Congênitas/epidemiologia , Altitude , Povo Asiático/estatística & dados numéricos , Criança , China/epidemiologia , Estudos Transversais , Etnicidade/estatística & dados numéricos , Feminino , Humanos , Masculino , Idade Materna , Prevalência , Fatores de Risco , Estudantes/estatística & dados numéricos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA