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1.
Plant J ; 112(6): 1447-1461, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36345647

RESUMO

Structural chromosome variations (SCVs) are large-scale genomic variations that can be detected by fluorescence in situ hybridization (FISH). SCVs have played important roles in the genome evolution of wheat (Triticum aestivum L.), but little is known about their genetic effects. In this study, a total of 543 wheat accessions from the Chinese wheat mini-core collection and the Shanxi Province wheat collection were used for chromosome analysis using oligonucleotide probe multiplex FISH. A total of 139 SCVs including translocations, pericentric inversions, presence/absence variations (PAVs), and copy number variations (CNVs) in heterochromatin were identified at 230 loci. The distribution frequency of SCVs varied between ecological regions and between landraces and modern cultivars. Structural analysis using SCVs as markers clearly divided the landraces and modern cultivars into different groups. There are very clear instances illustrating alien introgression and wide application of foreign germplasms improved the chromosome diversity of Chinese modern wheat cultivars. A genome-wide association study (GWAS) identified 29 SCVs associated with 12 phenotypic traits, and five (RT4AS•4AL-1DS/1DL•1DS-4AL, Mg2A-3, Mr3B-10, Mr7B-13, and Mr4A-7) of them were further validated using a doubled haploid population and advanced sib-lines, implying the potential value of these SCVs. Importantly, the number of favored SCVs that were associated with agronomic trait improvement was significantly higher in modern cultivars compared to landraces, indicating positive selection in wheat breeding. This study demonstrates the significant effects of SCVs during wheat breeding and provides an efficient method of mining favored SCVs in wheat and other crops.


Assuntos
Estudo de Associação Genômica Ampla , Triticum , Triticum/genética , Estudo de Associação Genômica Ampla/métodos , Melhoramento Vegetal , Hibridização in Situ Fluorescente , Variações do Número de Cópias de DNA , Cromossomos de Plantas/genética
2.
Ann Bot ; 131(1): 185-198, 2023 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-35451455

RESUMO

BACKGROUND AND AIMS: Dasypyrum villosum (2n = 2x = 14) harbours potentially beneficial genes for hexaploid and tetraploid wheat improvement. Highly diversified chromosome variation exists among and within accessions due to its open-pollination nature. The wheat-D. villosum T6VS·6AL translocation was widely used in breeding mainly because gene Pm21 in the 6VS segment conferred high and lasting powdery mildew resistance. However, the widespread use of this translocation may narrow the genetic base of wheat. A better solution is to utilize diversified D. villosum accessions as the genetic source for wheat breeding. Analysis of cytological and genetic polymorphisms among D. villosum accessions also provides genetic evolution information on the species. Using cytogenetic and molecular tools we analysed genetic polymorphisms among D. villosum accessions and developed consensus karyotypes to assist the introgression of beneficial genes from D. villosum into wheat. METHODS: A multiplex probe of repeats for FISH, GISH and molecular markers were used to detect chromosome polymorphisms among D. villosum accessions. Polymorphic signal block types, chromosome heterogeneity and heterozygosity, and chromosome polymorphic information content were used in genetic diversity analysis. KEY RESULTS: Consensus karyotypes of D. villosum were developed, and the homoeologous statuses of individual D. villosum chromosomes relative to wheat were determined. Tandem repeat probes of pSc119.2, (GAA)10 and the AFA family produced high-resolution signals and not only showed different signal patterns in D. villosum chromosomes but also revealed the varied distribution of tandem repeats among chromosomes and accessions. A total of 106 polymorphic chromosomes were identified from 13 D. villosum accessions and high levels of chromosomal heterozygosity and heterogeneity were observed. A subset of 56 polymorphic chromosomes was transferred into durum wheat through wide crosses, and seven polymorphic chromosomes are described in two newly developed durum-D. villosum amphidiploids. CONCLUSIONS: Consensus karyotypes of D. villosum and oligonucleotide FISH facilitated identification of polymorphic signal blocks and a high level of chromosomal heterozygosity and heterogeneity among D. villosum accessions, seen in newly developed amphiploids. The abundant genetic diversity of D. villosum and range of alleles, exploitable through interploid crosses, backcrosses and recombination (chromosome engineering), allow introduction of biotic and abiotic stress resistances into wheat, translating into increasing yield, end-use quality and crop sustainability.


Assuntos
Melhoramento Vegetal , Triticum , Triticum/genética , Cromossomos de Plantas , Poaceae/genética , Fenótipo
3.
Chemosphere ; 350: 141089, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38163465

RESUMO

The European honey bee, Apis mellifera, serves as the principle managed pollinator species globally. In recent decades, honey bee populations have been facing serious health threats from combined biotic and abiotic stressors, including diseases, limited nutrition, and agrochemical exposure. Understanding the molecular mechanisms underlying xenobiotic adaptation of A. mellifera is critical, considering its extensive exposure to phytochemicals and agrochemicals present in the environment. In this study, we conducted a comprehensive structural and functional characterization of AmGSTD1, a delta class glutathione S-transferase (GST), to unravel its roles in agrochemical detoxification and antioxidative stress responses. We determined the 3-dimensional (3D) structure of a honey bee GST using protein crystallography for the first time, providing new insights into its molecular structure. Our investigations revealed that AmGSTD1 metabolizes model substrates, including 1-chloro-2,4-dinitrobenzene (CDNB), p-nitrophenyl acetate (PNA), phenylethyl isothiocyanate (PEITC), propyl isothiocyanate (PITC), and the oxidation byproduct 4-hydroxynonenal (HNE). Moreover, we discovered that AmGSTD1 exhibits binding affinity with the fluorophore 8-Anilinonaphthalene-1-sulfonic acid (ANS), which can be inhibited with various herbicides, fungicides, insecticides, and their metabolites. These findings highlight the potential contribution of AmGSTD1 in safeguarding honey bee health against various agrochemicals, while also mitigating oxidative stress resulting from exposure to these substances.


Assuntos
Fungicidas Industriais , Inseticidas , Abelhas , Animais , Agroquímicos/toxicidade , Glutationa Transferase/metabolismo , Inseticidas/metabolismo , Estrutura Molecular
4.
Nano Lett ; 12(9): 4738-41, 2012 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-22889473

RESUMO

The bioanode is the defining feature of microbial fuel cell (MFC) technology and often limits its performance. In the current work, we report the engineering of a novel hierarchically porous architecture as an efficient bioanode, consisting of biocompatible chitosan and vacuum-stripped graphene (CHI/VSG). With the hierarchical pores and unique VSG, an optimized bioanode delivered a remarkable maximum power density of 1530 mW m(-2) in a mediator-less MFC, 78 times higher than a carbon cloth anode.


Assuntos
Fontes de Energia Bioelétrica/microbiologia , Quitosana/química , Eletrodos , Grafite/química , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Desenho de Equipamento , Análise de Falha de Equipamento , Tamanho da Partícula , Porosidade , Vácuo
5.
Front Oncol ; 13: 1230164, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37519791

RESUMO

Hepatitis B virus (HBV) is identified as a major risk factor for hepatocellular carcinoma (HCC), resulting in so-called hepatitis B virus-related hepatocellular carcinoma (HBV-related HCC). Hepatectomy for HCC is acknowledged as an efficient treatment strategy, especially for early HCC. Furthermore, patients with advanced HCC can still obtain survival benefits through surgical treatment combined with neoadjuvant therapy, adjuvant therapy, transcatheter arterial chemoembolization, and radiofrequency ablation. Therefore, preoperative and postoperative predictors of HBV-related HCC have crucial indicative functions for the follow-up treatment of patients with feasible hepatectomy. This review covers a variety of research results on preoperative and postoperative predictors of hepatectomy for HBV-related HCC over the past decade and in previous landmark studies. The relevant contents of Hepatitis C virus-related HCC, non-HBV non-HCV HCC, and the artificial intelligence application in this field are briefly addressed in the extended content. Through the integration of this review, a large number of preoperative and postoperative factors can predict the prognosis of HBV-related HCC, while most of the predictors have no standardized thresholds. According to the characteristics, detection methods, and application of predictors, the predictors can be divided into the following categories: 1. serological and hematological predictors, 2. genetic, pathological predictors, 3. imaging predictors, 4. other predictors, 5. analysis models and indexes. Similar results appear in HCV-related HCC, non-HBV non-HCV HCC. Predictions based on AI and big biological data are actively being applied. A reasonable prediction model should be established based on the economic, health, and other levels in specific countries and regions.

6.
Eur J Gastroenterol Hepatol ; 33(1): 76-82, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32049678

RESUMO

BACKGROUND: Hepatitis B surface antigen (HBsAg) is a detectable index after hepatitis B virus (HBV) infection, which is a risk factor of hepatocellular carcinoma (HCC). However, few studies have focused on the expression of HBsAg in HCC patients' liver tissues. This study aimed to explore the potential utility of using HBsAg protein expression in normal liver tissues as a prognostic factor for HCC patients who underwent liver resection. STUDY DESIGN: The study enrolled 100 HCC patients with seropositivity for HBsAg. The liver tissues were collected, and tissue microarrays were constructed. The expression of HBsAg in liver tissues were measured by immunohistochemistry (IHC). Relevant clinical data and follow-up records were collected for analysis. RESULTS: HBsAg expressions was detected in 29 patients (positive group) and was unable to be detected in the remaining 71 patients (negative group). The patients in the positive group had higher HBV DNA levels (P < 0.05) than the patients in the negative group. The overall survival (OS) rate of the positive group was worse than the OS rate of the negative group (P = 0.013). The OS rates after resection at 1 and 2 years in negative group were 90.1% and 85.7%, respectively, while the value in the positive group were 79.3% and 65.5%, respectively. Multivariate analysis showed that HBsAg expression in liver tissues, ascites and alpha-fetoprotein levels were independent factors influencing OS. Similarly, after propensity score matching (PSM), the OS was worse in the positive group than in the negative group, and HBsAg expression could also serve as a predictor for OS (P = 0.039). The OS rates after resection and PSM at 1 and 2 years were 93.2% and 85.9% in the negative group, while the value in the positive group were 79.3% and 65.5%. CONCLUSION: As determined according to grouping based on immunohistochemistry staining results for HBsAg, this study indicated that HBsAg expression in liver tissues could predict the OS of HBV-related HCC patients after liver resection.


Assuntos
Carcinoma Hepatocelular , Hepatite B Crônica , Hepatite B , Neoplasias Hepáticas , Carcinoma Hepatocelular/cirurgia , Hepatite B/complicações , Hepatite B/diagnóstico , Antígenos de Superfície da Hepatite B , Vírus da Hepatite B/genética , Humanos , Neoplasias Hepáticas/cirurgia , Prognóstico
7.
Sci Rep ; 7(1): 5717, 2017 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-28720762

RESUMO

Cerenkov luminescence imaging (CLI) has been an evolutional and alternative approach of nuclear imaging in basic research. This study aimed to measure the 131I thyroid uptake of mouse using CLI for assessment of thyroid function. Quantification of 131I thyroid uptake of mice in euthyroid, hypothyroid and hyperthyroid status was performed by CLI and γ-scintigraphy at 24 hours after injection of 131I. The 131I thyroid uptake was calculated using the equation: (thyroid counts - background counts)/(counts of injected dose of 131I) × 100%. Serum T4 concentration was determined to evaluate the thyroid function. The radioactivity of 131I was linearly correlated with the CL signals in both in vitro and in vivo measurements. CLI showed a significant decrease and increase of 131I thyroid uptake in the mice in hypo- and hyperfunctioning status, respectively, and highly correlated with that measured by γ-scintigraphy. However, the percent thyroid uptake measured by CLI were one-fifth of those measured by γ-scintigraphy due to insufficient tissue penetration of CL. These results indicate that CLI, in addition to nuclear imaging, is able to image and evaluate the 131I thyroid uptake function in mice in preclinical and research settings.


Assuntos
Radioisótopos do Iodo , Medições Luminescentes/métodos , Glândula Tireoide/diagnóstico por imagem , Animais , Hipertireoidismo/induzido quimicamente , Hipertireoidismo/diagnóstico por imagem , Hipertireoidismo/metabolismo , Hipotireoidismo/induzido quimicamente , Hipotireoidismo/diagnóstico por imagem , Hipotireoidismo/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Cintilografia/métodos , Glândula Tireoide/metabolismo
8.
J Immunol Methods ; 435: 7-16, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27142477

RESUMO

Antibody fragments, such as the single-chain variable fragment (scFv), have much potential in research and diagnostics because of their antigen-binding ability similar to a full-sized antibody and their ease of production in microorganisms. Some applications of antibody fragments require immobilization on a surface, and we have established a simple immobilization method that is based on the biotin-streptavidin interaction and does not require a separate purification step. We genetically fused two biotinylation tags-the biotin carboxyl carrier protein (BCCP) or the AviTag minimal sequence-to six different scFvs (scFv13R4, scFvD10, scFv26-10, scFv3, scFv5, and scFv12) for site-specific biotinylation in vivo by endogenous biotin ligases produced by Escherichia coli. The biotinylated scFvs were immobilized onto streptavidin-coated plates directly from cell lysates, and immobilization was detected through enzyme-linked immunosorbent assays. All scFvs fusions were successfully immobilized, and scFvs biotinylated via the BCCP tag tended to immobilize better than those biotinylated via the AviTag, even when biotinylation efficiency was improved with the biotin ligase BirA. The ability of immobilized scFvs to bind antigens was confirmed using scFv13R4 and scFvD10 with their respective targets ß-galactosidase and bacteriophage lambda head protein D (gpD). The immobilized scFv13R4 bound to ß-galactosidase at the same level for both biotinylation tags when the surface was saturated with the scFv, and immobilized scFvs retained their functionality for at least 100days after immobilization. The simplicity and robustness of our method make it a promising approach for future applications that require antibody fragment immobilization.


Assuntos
Anticorpos Imobilizados , Ensaio de Imunoadsorção Enzimática/métodos , Anticorpos de Cadeia Única , Acetil-CoA Carboxilase/química , Acetil-CoA Carboxilase/metabolismo , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Anticorpos Imobilizados/metabolismo , Antígenos/imunologia , Biotina/química , Biotinilação , Carbono-Nitrogênio Ligases/genética , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Ácido Graxo Sintase Tipo II/química , Ácido Graxo Sintase Tipo II/metabolismo , Proteínas Repressoras/genética , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/imunologia , Estreptavidina/química
9.
ChemSusChem ; 9(2): 172-6, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26732134

RESUMO

Conventional techniques for the synthesis of oriented polyaniline (PANI) nanostructures are often complex or time consuming. Through an innovative reduced graphene oxide (rGO) modified FTO and a low-potential electropolymerization strategy, the rapid and template-free growth of a highly ordered PANI nanorod array on the FTO substrate is realized. The highly ordered nanostructure of the PANI array leads to a high electrocatalytic activity and chemical stability. The importance of the polymerization potential and rGO surface modification to achieve this nanostructure is revealed. Compared to platinum, the PANI nanorod array exhibits an enhanced performance and stability as counter electrodes in dye-sensitized solar cells, with a 17.6 % enhancement in power conversion efficiency.


Assuntos
Compostos de Anilina/química , Corantes/química , Fontes de Energia Elétrica , Nanotubos/química , Óxidos/química , Energia Solar , Condutividade Elétrica , Eletroquímica , Eletrodos , Polimerização
10.
Biosens Bioelectron ; 77: 942-9, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26528809

RESUMO

We present a new approach to directly grow uniform and highly-ordered TiO2 nanosheets array (NSA) on a low-cost flexible carbon cloth substrate while simultaneously fulfill precise TiO2 nanostructure tailoring and crystal phase control. The unique vertically-erected TiO2 NSA/carbon cloth with hierarchical structures was directly explored as electrode for enzyme immobilization and biosensing applications without suffering any influences of insulating binders usually used to fix nanomaterials on conductive substrates during sensor fabrications. Efficient direct electron transfer was successfully achieved for glucose oxidase (GOx) immobilized on the TiO2 NSA/carbon cloth, which produces a stable, mediator-free glucose sensor with good selectivity, high-sensitivity (52 µA mM(-1)cm(-2)), low response time (<5s) and low detection limit (23.4 µM, S/N=3). The mechanism of the superior direct electrochemical properties and sensing performance was investigated in detail, and discussed from the aspects of material nanostructure and crystalline form of TiO2 NSA, and an intimate contact between TiO2 and carbon cloth resulted from direct crystallization and growth of TiO2 nanosheets on the substrate.


Assuntos
Técnicas Biossensoriais/instrumentação , Condutometria/instrumentação , Glucose Oxidase/química , Glucose/análise , Nanopartículas Metálicas/química , Titânio/química , Carbono/química , Cristalização/métodos , Enzimas Imobilizadas/química , Desenho de Equipamento , Análise de Falha de Equipamento , Membranas Artificiais , Ligação Proteica , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
11.
Sci Rep ; 6: 20142, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26832603

RESUMO

Covalent bonding of graphene oxide quantum dots (GOQDs) onto amino modified polyvinylidene fluoride (PVDF) membrane has generated a new type of nano-carbon functionalized membrane with significantly enhanced antibacterial and antibiofouling properties. A continuous filtration test using E. coli containing feedwater shows that the relative flux drop over GOQDs modified PVDF is 23%, which is significantly lower than those over pristine PVDF (86%) and GO-sheet modified PVDF (62%) after 10 h of filtration. The presence of GOQD coating layer effectively inactivates E. coli and S. aureus cells, and prevents the biofilm formation on the membrane surface, producing excellent antimicrobial activity and potentially antibiofouling capability, more superior than those of previously reported two-dimensional GO sheets and one-dimensional CNTs modified membranes. The distinctive antimicrobial and antibiofouling performances could be attributed to the unique structure and uniform dispersion of GOQDs, enabling the exposure of a larger fraction of active edges and facilitating the formation of oxidation stress. Furthermore, GOQDs modified membrane possesses satisfying long-term stability and durability due to the strong covalent interaction between PVDF and GOQDs. This study opens up a new synthetic avenue in the fabrication of efficient surface-functionalized polymer membranes for potential waste water treatment and biomolecules separation.


Assuntos
Antibacterianos/farmacologia , Incrustação Biológica , Escherichia coli/efeitos dos fármacos , Grafite/farmacologia , Membranas Artificiais , Polivinil/química , Pontos Quânticos/química , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/ultraestrutura , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Polietilenoglicóis/química , Pontos Quânticos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Zhonghua Nan Ke Xue ; 11(6): 413-8, 2005 Jun.
Artigo em Zh | MEDLINE | ID: mdl-15999482

RESUMO

OBJECTIVE: To study angiogenesis and regulatory factors in the proliferated prostatic tissues of Sprague Dawley (SD) rats with BPH induced by testosterone. METHODS: Sixteen castrated SD rats, aged 8 weeks and weighing 200 approximately 250 g, were equally randomized into a model group and a control group, and the BPH model was established by subcutaneous injection of testosterone. Immunohistochemistry and MIAS (micro-image analysis system) were used to test the manifestations of MVD (microvessel density), VEGF (vascular endothelium growth factor), flk-1, endostatin, MMP-2 (matrix metalloproteinase-2) and TIMP-2 (tissue inhibitor of metalloproteinase-2) in the prostatic tissues of both the model and the control groups. Multiple linear regression with the stepwise method was adopted to analyze the data. RESULTS: The manifestations of MVD, VEGF, flk-1, MMP-2, MMP-2/TIMP-2 and VEGF/endostatin in the model group were higher, while that of endostatin was lower than in the control group (P < 0.01), and the manifestation of TIMP-2 showed no statistical difference between the two groups. The regression analysis indicated that MVD was positively correlated to VEGF, VEGF/endostatin and MMP-2/TIMP-2 (r = 0.974, 0.986, 0.982, P < 0.05) and negatively correlated to endostatin (r = - 0.975, P < 0.05) . CONCLUSION: Testosterone could induce BPH in SD rats by increasing MVD and promoting the multiplication of vascular endothelial cells after regradation of basement membrane.


Assuntos
Neovascularização Patológica/induzido quimicamente , Próstata/irrigação sanguínea , Hiperplasia Prostática/induzido quimicamente , Testosterona , Animais , Modelos Animais de Doenças , Endostatinas/biossíntese , Masculino , Metaloproteinase 2 da Matriz/biossíntese , Neovascularização Patológica/metabolismo , Próstata/metabolismo , Hiperplasia Prostática/metabolismo , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Inibidor Tecidual de Metaloproteinase-2/biossíntese , Fator A de Crescimento do Endotélio Vascular/biossíntese , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/biossíntese
13.
Zhonghua Nan Ke Xue ; 8(2): 112-4, 2002.
Artigo em Zh | MEDLINE | ID: mdl-12479023

RESUMO

OBJECTIVES: To present experience on the diagnosis and treatment of urethral condyloma acuminatum (CA) in male patients. METHODS: Twenty-one cases of urethral CA were studied. The lesion of urethral meatus and intraurethal were resected by electrofulguration or operation and Urethroscopy, respectively. All patients were received intraurethral instillation and local therapy of 5% 5-fluorouracil solution. RESULTS: The patients had been followed up for three to twelve months. Cure rate was 76.2%, recurrence rate was 23.89%. CONCLUSIONS: Transurethral endoscopy is a reliable diagnosis and treatment method. Intraurethral instillation and local therapy of 5% 5-fluorouracil solution may prevent the recurrence of CA.


Assuntos
Condiloma Acuminado/diagnóstico , Fluoruracila/uso terapêutico , Doenças Uretrais/diagnóstico , Condiloma Acuminado/tratamento farmacológico , Seguimentos , Humanos , Instilação de Medicamentos , Masculino , Resultado do Tratamento , Doenças Uretrais/tratamento farmacológico
14.
J Mater Chem B ; 2(17): 2478-2482, 2014 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32261417

RESUMO

A three dimensional chitosan/vacuum-stripped graphene/polypyrrole interface with a hierarchical porous structure was fabricated as a free-standing and flexible electrochemical sensing electrode for dopamine detection, which exhibits unprecedented good selectivity, high sensitivity (632.1 µA mM-1 cm-2), wide linear response range (0.1-200 µM), low detection limit (19.4 nM, S/N = 3) and good sensing performance in human serum samples, outperforming the previously reported 2D and 3D graphene and/or the PPy modified electrode, and exhibiting comparable performance with the Au modified electrode.

15.
Adv Mater ; 25(47): 6900-4, 2013 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-24114931

RESUMO

Conducting AFM reveals a continuous conduction network of a TiO2 -graphene composite in DSSC due to a more intimate contact between the smaller sized TiO2 -graphene composite nanosheets,which reduces the internal resistance at TiO2 /TiO2 and TiO2 /FTO interfaces and ultimately leads to a faster and more efficient electron transport in the photoanode.


Assuntos
Corantes/química , Grafite/química , Energia Solar , Titânio/química , Fontes de Energia Elétrica , Eletrodos , Transporte de Elétrons , Microscopia de Força Atômica , Nanoestruturas/química , Tamanho da Partícula
16.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 20(2): 433-7, 2012 Apr.
Artigo em Zh | MEDLINE | ID: mdl-22541114

RESUMO

The aim of this study was to investigate if transfusion of mesenchymal stem cells (MSC) could exhibit beneficial effects on rheumatoid arthritis. Human bone marrow MSC were intraperitoneally injected into Wistar rats with collagen-induced arthritis at a dose of 10(7) on the next day (preventive group) or 2 weeks (treatment group) after collagen II induction, once a week for 2 weeks (preventive group) or 4 weeks (treatment group). The control group was given normal saline (NS) at corresponding time. The symptom scorings were documented weekly from the second week of the induction. On week 6, the hind joints of the rats were pathologically examined and the activation status of splenocytes was analyzed by flow cytometry. The results showed that all the rats developed arthritis and subsequent joint abnormality. On the sixth week, symptom scores of the rats that received MSC preventive (9.5 ± 0.5) or therapeutic (9.4 ± 0.6) infusions had no significant difference between each other, but were significantly greater than those of the NS controls (7.6 ± 0.6, P < 0.05). Consistently, pathological examination on the involved knees showed that the synovitis and arthritis scorings of MSC treated rats were greatly elevated compared with NS controls. Furthermore, the ratios of CD86(+) cells in the spleens of MSC prevention, MSC treatment and NS control groups were (4.16 ± 1.48), (4.06 ± 1.97) and (4.15 ± 2.04) respectively, while those of CD11b/c(+)CD86(+) cells were (1.04 ± 0.68), (0.95 ± 0.56) and (0.98 ± 0.44), all of which were significantly higher than those of healthy controls [(0.97 ± 0.18) and (0.30 ± 0.17), P < 0.05 for both parameters]. It is concluded that MSC infusion has little beneficial effects on collagen-induced arthritis in rats, conversely, MSC therapy aggravated the damage of the involved joints, its underlying mechanisms need to be further investigated.


Assuntos
Artrite Experimental/terapia , Transplante de Células-Tronco Mesenquimais , Animais , Artrite Experimental/patologia , Artrite Experimental/prevenção & controle , Células da Medula Óssea , Células Cultivadas , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Ratos , Ratos Wistar , Transplante Heterólogo , Resultado do Tratamento
17.
Nanoscale ; 3(12): 4977-83, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22012408

RESUMO

TiO(2)-InVO(4) nanostructured films were coated onto glass substrates and systematically investigated for their bactericidal activities using Escherichia coli (E. coli) as the model bacterium under ambient light illumination. The uniform TiO(2)-InVO(4) nanostructured films were prepared using titanium isopropoxide (TTIP) as the precursor via a simple sol-gel approach. Polyethylenimine (PEI) was used as a surfactant to ensure uniform dispersion of InVO(4) and a sacrificial pore-inducing agent, generating nanostructured films. Compared to unmodified TiO(2) film, the current TiO(2)-InVO(4) films exhibited enhanced bactericidal activities under ambient light illumination. Bacterial cell "photo-fixation" was demonstrated to be crucial in enhancing the bactericidal activity. A bacterial-nanostructured surface interaction mechanism was proposed for the current ambient-light activated nanostructured film.


Assuntos
Antibacterianos/química , Escherichia coli/crescimento & desenvolvimento , Luz , Membranas Artificiais , Nanoestruturas/química , Titânio/química , Escherichia coli/ultraestrutura , Nanoestruturas/ultraestrutura
18.
Nanoscale ; 3(11): 4613-6, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22006266

RESUMO

We present a one-step solvothermal approach to prepare uniform graphene-TiO(2) nanocomposites with delicately controlled TiO(2) nanostructures, including ultra-small 2 nm nanoparticles, 12 nm nanoparticles and nanorods. Using three composites as photoanode materials, the effect of nanostructure of graphene-composited TiO(2) on the performance of dye-sensitized solar cells was investigated, and results showed that the ultra-small 2 nm TiO(2)-graphene composite based photoanode exhibited the highest power conversion efficiency of 7.25%.


Assuntos
Corantes/química , Fontes de Energia Elétrica , Grafite/química , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Nanotecnologia/instrumentação , Energia Solar , Titânio/química , Desenho de Equipamento , Análise de Falha de Equipamento , Temperatura Alta , Tamanho da Partícula , Solventes/química
19.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 17(4): 986-9, 2009 Aug.
Artigo em Zh | MEDLINE | ID: mdl-19698244

RESUMO

This study was purposed to investigate the angiogenesis-promoting activities of human mesenchymal stem cells (hMSCs) modified by hepatocyte growth factor (HGF) and the underlying mechanisms. The hMSCs were transfected by recombinant adenoviral vector carrying human HGF gene and seeded onto the chicken chorioallantoic membrane. Three days later, the number of blood vessels was counted and their angiogenic response was compared with those of hMSCs of same generation, recombinant basic fibroblast growth factor (bFGF) and alpha-MEM as control. The expression levels of bFGF, VEGF, angiopoietin-1 and angiopoietin-2 were evaluated by RT-PCR assay. The results showed that gene-modified hMSCs exhibited greatest activity to promote angiogenesis while the angiogenic response was nearly same between groups treated by hMSCs and bFGF, all of which were significantly higher than that observed in control (p < 0.01). RT-PCR analysis revealed that hMSCs constitutively expressed multiple angiogenesis-associated growth factors and their levels seemed up-regulated by HGF gene transfer. It is concluded that HGF gene-modified hMSCs show a potent angiogenesis-promoting function and may be useful in the treatment of ischemic disorders.


Assuntos
Fator de Crescimento de Hepatócito/genética , Células-Tronco Mesenquimais , Neovascularização Fisiológica/genética , Animais , Células Cultivadas , Embrião de Galinha , Galinhas , Humanos , Transfecção
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