Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
BMC Nephrol ; 23(1): 115, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35317735

RESUMO

BACKGROUND: Studies have revealed that patients with chronic kidney disease (CKD) have dietary patterns different from those of the general population. However, no studies have compared the dietary patterns of between patients with early-stages (stages 1-3a) and late-stages (stages 3b-5) of CKD. Our objective was to investigate the associations between dietary patterns in early and late-stage CKD. METHODS: We analyzed 4480 participants with CKD at various stages based on the data recorded between 2007 and 2016 from the database of the American National Health and Nutrition Examination Survey. RESULTS: In total, 3683 and 797 participants had early and late-stage CKD, respectively. Through principal components analysis, the dietary intake dimension was reduced from 63 variables to 3 dietary patterns. We adopted logistic regression for analysis. The three dietary patterns are as follows: (1) saturated fatty acids and mono-unsaturated fatty acids (MUFA); (2) vitamins and minerals; and (3) cholesterols and polyunsaturated fatty acids (PUFA). These 3 patterns explained > 50% of dietary nutrient intake. Results indicated that among participants with dietary patterns 2 (vitamins and minerals) and 3 (cholesterols and PUFA), those with low intakes were more likely to have late-stage CKD. The odds ratios for patterns 2 and 3 were 1.74 (95% CI: 1.21-2.50) and 1.66 (95% CI: 1.13-2.43), respectively. CONCLUSIONS: This study revealed that intakes of vitamins and minerals and cholesterols and PUFA were associated with the stages of CKD.


Assuntos
Gorduras na Dieta , Insuficiência Renal Crônica , Colesterol , Dieta , Feminino , Humanos , Masculino , Minerais , Inquéritos Nutricionais , Insuficiência Renal Crônica/epidemiologia , Vitamina A , Vitaminas
2.
J Appl Biomater Funct Mater ; 19: 22808000211006878, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33909530

RESUMO

Here, we present a bone implant system of phase-oriented titanium dioxide (TiO2) fabricated by the micro-arc oxidation method (MAO) on ß-Ti to facilitate improved osseointegration. This (101) rutile-phase-dominant MAO TiO2 (R-TiO2) is biocompatible due to its high surface roughness, bone-mimetic structure, and preferential crystalline orientation. Furthermore, (101) R-TiO2 possesses active and abundant hydroxyl groups that play a significant role in enhancing hydroxyapatite formation and cell adhesion and promote cell activity leading to osseointegration. The implants had been elicited their favorable cellular behavior in vitro in the previous publications; in addition, they exhibit excellent shear strength and promote bone-implant contact, osteogenesis, and tissue formation in vivo. Hence, it can be concluded that this MAO R-TiO2 bone implant system provides a favorable active surface for efficient osseointegration and is suitable for clinical applications.


Assuntos
Materiais Revestidos Biocompatíveis , Titânio , Osseointegração , Propriedades de Superfície
3.
Plast Reconstr Surg Glob Open ; 7(1): e2045, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30859030

RESUMO

BACKGROUND: Management of facial rejuvenation has evolved over past decades. Facelift with barbed suture is a minimally invasive surgical technique for facial rejuvenation. This study examined the efficacy and associated complications of a new thread-looping procedure called minimal access multiple plane suspension. METHODS: A total of 103 thread lifts were performed between 2014 and 2017. Patient satisfaction and adverse effects were evaluated. RESULTS: In the majority of patients (88/103, 85.4%), the results obtained were considered satisfactory 3 months after the procedure. The incidence of complications was low. Only 5.8% of the patients had slight postoperation asymmetry that was easily corrected. Minor complications experienced by patients included palpable suture knots (12.6%), persistent facial swelling (7.88%), and facial dimpling (2.9%). The causes of procedure-related complications were reviewed and discussed. CONCLUSION: Reinforced by select anchoring points, "minimal access multiple plane suspension" suspends ptotic anatomic tissues, serving as an effective facial rejuvenation procedure with minimal downtime and satisfactory cosmetic results.

4.
Stud Health Technol Inform ; 257: 455-459, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30741239

RESUMO

In this study, a mobile cloud healthcare system was implemented to assist middle- and old-aged people with diabetes preventive healthcare. First of all, a prototype system was developed. It was a system relying on data mining computing technology and big data analytics. Besides, it was constructed under the environment architecture of VMware cloud computing. This mobile cloud healthcare system was developed via mobile devices. Its purpose was to set up a diabetes preventive healthcare service for users, and to further assess the usability of this mobile cloud care system.


Assuntos
Computação em Nuvem , Mineração de Dados , Atenção à Saúde , Diabetes Mellitus , Idoso , Diabetes Mellitus/prevenção & controle , Humanos , Pessoa de Meia-Idade
5.
Sci Rep ; 8(1): 14253, 2018 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-30250121

RESUMO

We developed an osseocompatible ß-type Ti-28Nb-11Ta-8Zr (TNTZ) alloy that displays the excellent elastic modulus, cellular response, corrosion resistance and antibacterial capability demanded for bone-mimetic materials. The TNTZ alloy exhibited an elastic modulus of 49 GPa, which approximates that of human bones and prevent stress shielding effects. A further anodic oxidation and subsequent post-annealing modification formed a crystalline nanoporous TNTZ oxide layer (NPTNTZO(c)) on the alloy surface, potentially promoting interlocking with the extracellular matrix of bone cells and cell proliferation. Osteoblast viability tests also verified that NPTNTZO(c) enhanced cell growth more significantly than that of flat TNTZ. In addition, potentiodynamic polarization tests in Hanks' balanced salt solution (HBSS) revealed that both TNTZ and NPTNTZO(c) exhibited better corrosion resistance than commercial pure titanium. Finally, NPTNTZO(c) reinforced with silver nanoparticles (NPTNTZO


Assuntos
Nióbio/química , Osteoblastos/efeitos dos fármacos , Tantálio/química , Titânio/química , Zircônio/química , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/uso terapêutico , Corrosão , Humanos , Teste de Materiais , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Nióbio/uso terapêutico , Osteoblastos/citologia , Oxirredução/efeitos dos fármacos , Prata/química , Tantálio/uso terapêutico , Titânio/uso terapêutico , Zircônio/uso terapêutico
6.
Sci Rep ; 8(1): 12913, 2018 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-30150652

RESUMO

While biophysical stimuli from polymeric matrices are known to significantly affect the fates of human mesenchymal stem cells (hMSCs), the stimulatory effects of nano-sized silicon-based matrices on hMSCs have not been thoroughly investigated. We previously demonstrated that vertically aligned, single-crystalline silicon nanowires (SiNWs) can control the osteogenicity of hMSCs via controllable spring constants from SiNWs matrix. However, other possible differentiation fates of hMSCs on SiNWs have not been explored. We hypothesize that tunable spring constant from artificial SiNWs matrices can direct different types of hMSC differentiations. The spring constants of tunable SiNW matrices can be consistently controlled by tuning the SiNW length. The results of gene expression and cell stiffness suggest that hMSCs differentiations are sensitive to our distinguishable spring constants from the SiNWs groups, and simultaneously conduct osteogenicity and adipogenicity. These findings suggest that SiNW matrices can regulate the fates of hMSCs when the SiNW characteristics are carefully tuned.


Assuntos
Células-Tronco Mesenquimais/citologia , Nanofios/química , Silício/química , Diferenciação Celular/fisiologia , Humanos , Células-Tronco Mesenquimais/metabolismo , Microscopia Eletrônica de Varredura
7.
Lab Chip ; 15(2): 486-94, 2015 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-25408102

RESUMO

Blood glycated hemoglobin (HbA1c) levels reflecting average glucose concentrations over the past three months are fundamental for the diagnosis, monitoring, and risk assessment of diabetes. It has been hypothesized that aptamers, which are single-stranded DNAs or RNAs that demonstrate high affinity to a large variety of molecules ranging from small drugs, metabolites, or proteins, could be used for the measurement of HbA1c. Aptamers are selected through an in vitro process called systematic evolution of ligands by exponential enrichment (SELEX), and they can be chemically synthesized with high reproducibility at relatively low costs. This study therefore aimed to select HbA1c- and hemoglobin (Hb)-specific single-stranded DNA aptamers using an on-chip SELEX protocol. A microfluidic SELEX chip was developed to continuously and automatically carry out multiple rounds of SELEX to screen specific aptamers for HbA1c and Hb. HbA1c and Hb were first coated onto magnetic beads. Following several rounds of selection and enrichment with a randomized 40-mer DNA library, specific oligonucleotides were selected. The binding specificity and affinity were assessed by competitive and binding assays. Using the developed microfluidic system, the incubation and partitioning times were greatly decreased, and the entire process was shortened dramatically. Both HbA1c- and Hb-specific aptamers selected by the microfluidic system showed high specificity and affinity (dissociation constant, Kd = 7.6 ± 3.0 nM and 7.3 ± 2.2 nM for HbA1c and Hb, respectively). With further refinements in the assay, these aptamers may replace the conventional antibodies for in vitro diagnostics applications in the near future.


Assuntos
Aptâmeros de Nucleotídeos/química , Hemoglobinas Glicadas/análise , Técnicas Analíticas Microfluídicas/instrumentação , Técnica de Seleção de Aptâmeros/métodos , DNA de Cadeia Simples/química , DNA de Cadeia Simples/metabolismo , Hemoglobinas Glicadas/metabolismo , Hemoglobinas/análise , Hemoglobinas/metabolismo , Humanos , Imunoensaio , Cinética , Ligação Proteica , Técnica de Seleção de Aptâmeros/instrumentação
8.
Nanoscale Res Lett ; 9(1): 75, 2014 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-24521308

RESUMO

Quasi-one-dimensional (quasi-1D) ZnO nanowire arrays with hexagonal pattern have been successfully synthesized via the vapor transport process without any metal catalyst. By utilizing polystyrene microsphere self-assembled monolayer, sol-gel-derived ZnO thin films were used as the periodic nucleation sites for the growth of ZnO nanowires. High-quality quasi-1D ZnO nanowires were grown from nucleation sites, and the original hexagonal periodicity is well-preserved. According to the experimental results, the vapor transport solid condensation mechanism was proposed, in which the sol-gel-derived ZnO film acting as a seed layer for nucleation. This simple method provides a favorable way to form quasi-1D ZnO nanostructures applicable to diverse fields such as two-dimensional photonic crystal, nanolaser, sensor arrays, and other optoelectronic devices.

9.
Nanoscale Res Lett ; 9(1): 70, 2014 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-24517113

RESUMO

Vertically aligned ZnO nanowire (NW) arrays have been synthesized on silicon substrates by chemical vapor deposition. The growth of ZnO NWs may be dominated by vapor-solid nucleation mechanism. Morphological, structural, optical, and field emission characteristics can be modified by varying the growth time. For growth time that reaches 120 min, the length and diameter of ZnO NWs are 1.5 µm and 350 nm, respectively, and they also show preferential growth orientation along the c-axis. Room-temperature photoluminescence spectra exhibit a sharp UV emission and broad green emission, and the enhanced UV-to-green emission ratio with increasing growth time might originate from the reduced concentration of surface defects. Furthermore, strong alignment and uniform distribution of ZnO NWs can also effectively enhance the antireflection to reach the average reflectance of 5.7% in the visible region. The field emission measurement indicated that the growth time plays an important role in density- and morphology-controlled ZnO NWs, and thus, ZnO NWs are expected to be used in versatile optoelectronic devices.

10.
Biomaterials ; 33(20): 5013-22, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22513273

RESUMO

Extracellular stimuli imposed on stem cells enable efficient initiation of mechanotransductive signaling to regulate stem cell fates; however, how such physical cues conferred by the stereo-topographical matrix govern the fate of stem cells still remains unknown. The purpose of this study is to delineate the effects of stereotopography and its various relevant physical properties on the fate regulation of human mesenchymal stem cells (hMSCs). Stereo-topographical silicon nanowires (SiNWs) that were precisely controlled with respect to their various dimensions and their growth orientation were used in this study. hMSCs cultured on stereo SiNWs of different lengths in the absence of biochemical osteogenic induction cues displayed a spherical and less-elongated morphology and showed an approximately 10% loss of cell viability compared to those grown on two-dimensional (2-D) flat Si. Moreover, osteogenic gene expression of COL1A1 and Runx2 in hMSCs cultured on the shortest SiNWs was significantly higher than those grown on the longer SiNWs and 2-D flat Si. hMSCs grown on shorter SiNWs also demonstrated higher expression levels for F-actin, phosphorylated focal adhesion kinase (pFAK), vinculin and alpha 2 integrin. Stereo-topographical cues provided by SiNWs are able to regulate osteogenic differentiation of hMSCs via cytoskeleton remodeling and this is correlated with the differential expression of alpha 2/beta 1 integrin heterodimers and the focal adhesion molecules pFAK and vinculin. The findings in this study provide insights in terms of the design of stereo-topographical structures for use in tissue engineering, bone regeneration and relevant medical applications.


Assuntos
Células-Tronco Mesenquimais/citologia , Nanofios , Silício/química , Sequência de Bases , Fenômenos Biomecânicos , Adesão Celular , Divisão Celular , Linhagem da Célula , Primers do DNA , Imunofluorescência , Proteína-Tirosina Quinases de Adesão Focal/genética , Humanos , Integrinas/genética , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/ultraestrutura , Microscopia Eletrônica de Varredura , Reação em Cadeia da Polimerase
11.
Biosens Bioelectron ; 35(1): 50-55, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22410487

RESUMO

The systematic evolution of ligands by exponential enrichment (SELEX) is a screening technique that involves the progressive selection of highly specific ligands via repeated rounds of partition and amplification from a large random pool of nucleic acid sequences. The products of this selection process are called aptamers and are either short single-stranded deoxyribonucleic acid (ssDNA) or ribonucleic acid (RNA) molecules with a high binding affinity to a large variety of target analytes. However, SELEX is a lengthy, labor-intensive, iterative process requiring multiple rounds of extraction and polymerase chain reaction (PCR) amplification. In order to address these problems, this study presents a new integrated microfluidic system consisting of a magnetic bead-based microfluidic SELEX chip and a competitive assay chip to automate the aptamer screening process. More importantly, the selected ssDNA sequences were confirmed to have a high affinity and specificity to the target molecules, using the developed competitive assay chip. With this approach, an aptamer specific to alpha-fetoprotein (AFP), which is a biomarker for liver cancers, has been successfully selected. The screened aptamer was used as a recognition molecule for AFP and has a linear detection range from 12.5 to 800 ng/mL, which was suitable for rapid clinical applications.


Assuntos
Técnicas Analíticas Microfluídicas/métodos , Técnica de Seleção de Aptâmeros/métodos , alfa-Fetoproteínas/análise , Aptâmeros de Nucleotídeos/genética , Sequência de Bases , Ligação Competitiva , Biomarcadores Tumorais/análise , DNA de Cadeia Simples/genética , Desenho de Equipamento , Humanos , Imunoensaio , Neoplasias Hepáticas/química , Técnicas Analíticas Microfluídicas/instrumentação , Técnica de Seleção de Aptâmeros/instrumentação
12.
PLoS One ; 5(12): e15299, 2010 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-21187959

RESUMO

The aim of this study is to understand if human mesenchymal stem cells (hMSCs) and neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) have synergistic protective effect that promotes functional recovery in rats with severe spinal cord injury (SCI). To evaluate the effect of delayed combinatorial therapy of PACAP and hMSCs on spinal cord tissue repair, we used the immortalized hMSCs that retain their potential of neuronal differentiation under the stimulation of neurogenic factors and possess the properties for the production of several growth factors beneficial for neural cell survival. The results indicated that delayed treatment with PACAP and hMSCs at day 7 post SCI increased the remaining neuronal fibers in the injured spinal cord, leading to better locomotor functional recovery in SCI rats when compared to treatment only with PACAP or hMSCs. Western blotting also showed that the levels of antioxidant enzymes, Mn-superoxide dismutase (MnSOD) and peroxiredoxin-1/6 (Prx-1 and Prx-6), were increased at the lesion center 1 week after the delayed treatment with the combinatorial therapy when compared to that observed in the vehicle-treated control. Furthermore, in vitro studies showed that co-culture with hMSCs in the presence of PACAP not only increased a subpopulation of microglia expressing galectin-3, but also enhanced the ability of astrocytes to uptake extracellular glutamate. In summary, our in vivo and in vitro studies reveal that delayed transplantation of hMSCs combined with PACAP provides trophic molecules to promote neuronal cell survival, which also foster beneficial microenvironment for endogenous glia to increase their neuroprotective effect on the repair of injured spinal cord tissue.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/métodos , Células-Tronco Mesenquimais/citologia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Traumatismos da Medula Espinal/terapia , Regeneração da Medula Espinal , Medula Espinal/patologia , Animais , Astrócitos/metabolismo , Sobrevivência Celular , Ácido Glutâmico/metabolismo , Humanos , Microglia/metabolismo , Modelos Biológicos , Ratos , Superóxido Dismutase/metabolismo
13.
Biosens Bioelectron ; 25(7): 1761-6, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20061133

RESUMO

The systematic evolution of ligands by exponential enrichment (SELEX) is an experimental procedure that allows screening of given molecular targets by desired binding affinities from an initial random pool of oligonucleotides and oligomers. The final products of SELEX are usually referred as aptamers, which are recognized as promising molecules for a variety of biomedical applications. However, SELEX is an iterative process requiring multiple rounds of extraction and amplification that demands significant time and labor. Therefore, this study presents a novel, automatic, miniature SELEX platform. As a demonstration, the rapid screening of C-reactive protein (CRP) aptamers was performed. By utilizing microfluidic technologies and magnetic beads conjugated with CRP, aptamers with a high affinity to CRP were extracted from a random single-strand deoxyribonucleic acid (ssDNA) pool. These aptamers were further amplified by an on-chip polymerase chain reaction (PCR) process. After five consecutive extraction and amplification cycles, a specific aptamer with the highest affinity was screened automatically. The screened aptamers were used as a recognition molecule for the detection of CRP. The developed microsystem demonstrated fast screening of CRP aptamers and can be used as a powerful tool to select analyte-specific aptamers for biomedical applications.


Assuntos
Aptâmeros de Nucleotídeos/genética , Técnicas Biossensoriais/instrumentação , Proteína C-Reativa/análise , Proteína C-Reativa/genética , Técnicas Analíticas Microfluídicas/instrumentação , Técnica de Seleção de Aptâmeros/instrumentação , Técnicas Biossensoriais/métodos , Sistemas Computacionais , Desenho de Equipamento , Análise de Falha de Equipamento , Ligantes , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Integração de Sistemas
14.
Biosens Bioelectron ; 24(10): 3091-6, 2009 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-19403298

RESUMO

This study presents a new microfluidic chip integrated with pneumatic micropumps, normally close microvalves and vortex-type micromixers for C-reactive protein (CRP) measurement. CRP is a protein produced during the inflammation process. It has been reported that CRP in serum can be used for risk assessment of cardiovascular diseases. In this study, CRP measurements were performed by using the integrated microfluidic chip incorporated with magnetic beads. The magnetic beads coated with CRP-specific DNA aptamers were used to recognize, purify and enrich the target CRP. The entire process including sample pre-treatment, and the interaction between the target CRP and anti-CRP antibody was automatically performed on a single chip. The chemiluminescence signal was measured using a luminometer to detect the concentration of CRP afterwards. The entire reaction time is less then 25 min, which is only about 20% of the time required when compared to using traditional bench-top machines (150 min). More importantly, the detection limit has been improved from 0.125 to 0.0125 mg/L with only half the amount of reagent consumption. The development of this microfluidic system is promising for fast, accurate, and sensitive detection of CRP.


Assuntos
Proteína C-Reativa/análise , Técnicas Analíticas Microfluídicas/instrumentação , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/genética , Sequência de Bases , Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Análise Química do Sangue/estatística & dados numéricos , Desenho de Equipamento , Humanos , Magnetismo , Técnicas Analíticas Microfluídicas/métodos , Técnicas Analíticas Microfluídicas/estatística & dados numéricos , Estreptavidina
15.
Biomaterials ; 29(34): 4546-53, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18774604

RESUMO

Glial cell line derived neurotrophic factor (GDNF) induces neuronal survival and tissue repair after spinal cord injury (SCI). A continuous GDNF supply is believed to gain greater efficacy in the neural restoration of the injured spinal cord. Accordingly, nanovehicle formulation for their efficient delivery and sustained release in injured spinal cord was examined. We first used fluorescence-labeled bovine serum albumin (FBSA) loaded in biodegradable poly(lactic acid-co-glycolic acid) (PLGA) for intraspinal administration after SCI and for in vitro study. Our results showed that the preservation of PLGA-FBSA was observed in the injured spinal cord at 24h, and PLGA-FBSA nanoparticles were well absorbed by neurons and glia, indicating that PLGA as a considerable nanovehicle for the delivery of neuroprotective polypeptide into injured spinal cord. Furthermore, intraspinal injection of GDNF encapsulated in PLGA (PLGA-GDNF) nanoparticles into the injured spinal cord proximal to the lesion center had no effect on gliosis when compared to that observed in SCI rats receiving PLGA injection. However, local administration of PLGA-GDNF effectively preserved neuronal fibers and led to the hindlimb locomotor recovery in rats with SCI, providing a potential strategy for the use of PLGA-GDNF in the treatment of SCI.


Assuntos
Implantes Absorvíveis , Fator Neurotrófico Derivado de Linhagem de Célula Glial/administração & dosagem , Nanopartículas/administração & dosagem , Traumatismos da Medula Espinal/tratamento farmacológico , Animais , Astrócitos/efeitos dos fármacos , Células Cultivadas , Contusões/tratamento farmacológico , Vias de Administração de Medicamentos , Feminino , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Fator Neurotrófico Derivado de Linhagem de Célula Glial/farmacologia , Glicolatos/administração & dosagem , Glicolatos/química , Ácido Láctico , Locomoção/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Tamanho da Partícula , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Sprague-Dawley
16.
J Biomed Mater Res B Appl Biomater ; 85(1): 220-4, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17854067

RESUMO

Titanium dioxide (TiO2) has been developed and applied extensively in the form of coatings, in particular for its unique properties such as non-toxicity, high photocatalytic activity, and strong self-cleaning ability. These coatings, which can be prepared via various processes, have not yet been proved to be antimicrobial. This research involves an arc ion plating method to produce TiO2 film on medical grade AISI 304 stainless steel. Antimicrobial efficacy of the deposits is expected due to the photocatalysis action of the anatase phase presented in the deposit. The performance of the coating is evaluated by a JIS Z2801:2000 industrial standard. Experimental results show that TiO2 film mainly consisting of anatase structure can be prepared with a high growth rate of 5 microm/h. Antimicrobial activity (R) of the deposited TiO2 film against Staphylococcus aureus and Escherichia coli was 3.0 and 2.5, respectively, far beyond the value designated in JIS standard. This provides an effective antimicrobial surface coating method for medical implements thereby reducing the risk of hospital-acquired infections.


Assuntos
Anti-Infecciosos , Materiais Revestidos Biocompatíveis , Infecção Hospitalar/tratamento farmacológico , Titânio , Animais , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/uso terapêutico , Escherichia coli/efeitos dos fármacos , Humanos , Teste de Materiais , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Titânio/química , Titânio/farmacologia , Titânio/uso terapêutico
17.
J Agric Food Chem ; 54(8): 3101-7, 2006 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-16608237

RESUMO

Three Bo beta fruct cDNAs encoding acid invertases were cloned from shoots of the green bamboo Bambusa oldhamii. On the basis of the amino acid sequences of their products and phylogenetic analyses, Bo beta fruct1 and Bo beta fruct2 were determined to encode cell wall invertases, whereas Bo beta fruct3encodes a vacuolar invertase. The recombinant proteins encoded by Bo beta fruct2 and Bo beta fruct3 were produced in Pichia pastoris and purified to near homogeneity using ammonium sulfate fractionation and immobilized metal affinity chromatography. The pH optima, pI values, and substrate specificities of the isolated enzymes were consistent with those of plant cell wall or vacuolar invertases. The growth-dependent expression of Bo beta fruct1 and Bo beta fruct2 in the base regions of shoots underscores their roles in sucrose unloading and providing substrates for shoot growth. Its high sucrose affinity suggests that the Bo beta fruct2-encoded enzyme is important for maintaining the sucrose gradient between source and sink organs, while the predominant expression of Bo beta fruct3 in regions of active cell differentiation and expansion suggests functions in osmoregulation and cell enlargement.


Assuntos
Bambusa/enzimologia , Clonagem Molecular , Isoenzimas/análise , Isoenzimas/genética , beta-Frutofuranosidase/análise , beta-Frutofuranosidase/genética , Sequência de Aminoácidos , DNA Complementar/genética , Expressão Gênica , Isoenzimas/química , Dados de Sequência Molecular , Filogenia , Pichia/genética , Proteínas Recombinantes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , beta-Frutofuranosidase/química
18.
J Biol Chem ; 281(1): 167-75, 2006 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-16280327

RESUMO

Bcl10 overexpression and nuclear translocation were originally identified in mucosa-associated lymphoid tissue lymphoma with t(1;14)(p32;q32) chromosome translocation. DNA amplification of Bcl10 was also found in other solid tumors. We have recently shown that nuclear translocation of Bcl10 is a specific molecular determinant of Helicobacter pylori-independent mucosa-associated lymphoid tissue lymphoma (Kuo, S.-H., Chen, L. T., Yeh, K.-H., Wu, M. S., Hsu, H. C., Yeh, P. Y., Mao, T. L., Chen, C. L., Doong, S. L., Lin, J. T., and Cheng, A.-L. (2004) J. Clin. Oncol. 22, 3491-3497). However, the molecular mechanism of Bcl10 nuclear translocation remains unknown. In this study, we observed that tumor necrosis factor-alpha (TNFalpha) up-regulates the expression of Bcl10 and induces a fraction of Bcl10 nuclear translocation in human breast carcinoma MCF7 cells. Chromatin immunoprecipitation assays and electrophoretic mobility shift assays indicated that an NF-kappaB-binding site resides in the Bcl10 5 '-untranslated region. This study also demonstrates that Akt1, activated by TNFalpha, phosphorylates Bcl10 at Ser218 and Ser231 and that phosphorylated Bcl10 subsequently complexes with Bcl3 to enter the nucleus. Either inhibition of Akt1 or depletion of Bcl3 blocks Bcl10 nuclear translocation. In summary, these findings characterize a molecular linkage that directs Bcl10 nuclear translocation in response to TNFalpha treatment.


Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/química , Proteína 10 de Linfoma CCL de Células B , Proteína 3 do Linfoma de Células B , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , NF-kappa B/metabolismo , Fosforilação , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina/metabolismo , Fatores de Transcrição , Ativação Transcricional/fisiologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologia
19.
Brain Res ; 1054(2): 152-8, 2005 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-16054598

RESUMO

Neural progenitor cells (NPCs) in developing and adult CNS are capable of giving rise to various neuronal and glial cell populations. Neurogenesis in the adult hippocampus has been found to be inhibited by a proinflammatory cytokine, interleukin-6 (IL-6), suggesting that activated microglia in the inflamed brain may control neurogenesis. Yet, little is known about the effect of microglia-derived factors on the cell fate of embryonic NPCs. In this study, we show that neurons with betaIII-tubulin immunoreactivity in the NPC culture were reduced by the condition media collected from microglia treated with endotoxin lipopolysaccharide (LPS/M-CM). Treatment with pentoxifylline (PTX), an inhibitor for tumor necrosis factor-alpha (TNF-alpha) secretion from LPS-activated microglia, blocked the reduction of betaIII-tubulin+ cells in NPC culture. Furthermore, treatment of NPCs with interleukin-18 (IL-18), a recently discovered proinflammatory cytokine, also decreased the number of betaIII-tubulin+ cells in a dose- and time-dependent manner. Surprisingly, we also observed that the remaining betaIII-tubulin+ cells in the LPS/M-CM-treated culture exhibited more branching neurites. Thus, the activated microglia-derived cytokines, TNF-alpha and IL-18, may either inhibit the neuronal differentiation or induce neuronal cell death in the NPC culture, whereas these cells may also produce factors to improve the neurite branching in the NPC culture.


Assuntos
Interleucina-18/metabolismo , Neurônios/fisiologia , Células-Tronco/fisiologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Animais Recém-Nascidos , Western Blotting/métodos , Contagem de Células/métodos , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Células Cultivadas , Relação Dose-Resposta a Droga , Embrião de Mamíferos , Imuno-Histoquímica/métodos , Lipopolissacarídeos/farmacologia , Microglia/efeitos dos fármacos , Microglia/fisiologia , Neurônios/efeitos dos fármacos , Toxina Pertussis/farmacologia , Ratos , Ratos Sprague-Dawley , Células-Tronco/efeitos dos fármacos , Tubulina (Proteína)/metabolismo
20.
Environ Toxicol Chem ; 23(9): 2259-66, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15379005

RESUMO

Bioaccumulation models are used to describe chemical uptake and clearances by organisms. Averaged input parameter values are traditionally used and yield point estimates of model outputs. Hence, the uncertainty and variability of model predictions are ignored. Probabilistic modeling approaches, such as Monte Carlo simulation and the Bayesian method, have been recommended by the U.S. Environmental Protection Agency to provide a quantitative description of the degree of uncertainty and/or variability in risk estimates in ecological hazards and human health effects. In this study, a Bayesian analysis was conducted to account for the combined uncertainty and variability of model parameters in a crayfish bioaccumulation model. After a 5-d exposure in the LaBranche Wetlands (LA, USA), crayfish were analyzed for polycyclic aromatic hydrocarbon concentrations and lipid fractions. The posterior distribution of model parameters were derived from the joint posterior parameter distributions using a Markov chain Monte Carlo approach and the experimental data. The results were then used to predict the distribution of chrysene concentration versus time in the crayfish to compare the predicted ranges at the different study sites.


Assuntos
Astacoidea/metabolismo , Exposição Ambiental/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Animais , Astacoidea/química , Teorema de Bayes , Lipídeos/análise , Louisiana , Modelos Biológicos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA