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1.
Zhonghua Gan Zang Bing Za Zhi ; 29(8): 754-758, 2021 Aug 20.
Artigo em Chinês | MEDLINE | ID: mdl-34517456

RESUMO

Objective: To evaluate the short- and medium-term clinical efficacy of TIPS approach combined with AngioJet thrombus aspiration technology treatment in acute portal vein thrombosis. Methods: 63 cases with acute portal vein thrombosis treated in our center from May 2017 to July 2019 were studied retrospectively, including 49 males and 14 females, aged 35-61 (46 ± 5) years. TIPS approach (with/without) combined with Angiojet thrombus aspiration and gastroesophageal varices embolization was performed simultaneously according to the patient's condition. Regular follow-up for 3-33 (22 ± 3) months after surgery was used to observe the curative effect. Results: The technical success rate was 100%. Portal vein and superior mesenteric vein blood flow were returned to normal after the operation. Two cases of biliary tract injury were untreated. Simultaneously, two cases of intrahepatic arteriovenous fistula were treated with superselective arterial embolization. During the follow-up period, 47 cases (74.61%) had complete portal vein recanalization, 13 cases (20.63%) had partial recanalization, 3 cases (4.76%) had complete portal cavernoma, 7 cases (11.11%) had symptomatic hepatic encephalopathy, 1 case had received artificial liver treatment (1.59%), 1 case had peptic ulcer (11.11%), 6 cases (9.52%) had lost to follow-up, and there was no portal hypertension-related bleeding or death. Conclusion: TIPS approach combined with AngioJet thrombus aspiration technology is safe, effective and feasible in the treatment of acute portal vein thrombosis, and the short- and medium-term clinical effects are satisfactory.


Assuntos
Derivação Portossistêmica Transjugular Intra-Hepática , Trombose , Feminino , Humanos , Masculino , Veia Porta/cirurgia , Estudos Retrospectivos , Tecnologia , Resultado do Tratamento
2.
Rev Sci Instrum ; 90(2): 026105, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30831737

RESUMO

In recent years, different traditional interferometers have been the necessary diagnostic of electronic density measurement on fusion devices. Until now, two main problems always influence the density measurement: the mechanical vibration and fringe jump in the calculation. The dispersion interferometer (DI) with a long-wavelength infrared wavelength is a good choice because mechanical vibrations can be canceled and the fringe jump can be inhibited. This paper describes the bench test of phase measurement using a wedge instead of plasma on the DI. The results show good agreement with the theoretical calculations. In the background measurement, this DI without a vibration isolation system has good performance, and the drift of the baseline is less than 2 × 1017 m-2 in 3 s and less than 5 × 1017 m-2 in 400 s. Plasma data will be obtained during the next campaign on EAST (Experimental and Advanced Superconducting Tokamak).

3.
Allergy ; 73(2): 387-394, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28871603

RESUMO

BACKGROUND: The overproduction of IgE plays a critical role in the pathogenesis of allergy; the mechanism is unclear. Histone-acetyltransferase (HAT) activities are required in gene transcription of a large number of molecules in the immune system of the body. OBJECTIVES: This study tests a hypothesis that HAT Tat-interactive protein 60 (Tip60) plays an important role in the initiation of IgE-mediated allergy. METHODS: The effects of Tip60 on regulating IgE expression were assessed with B cells. An intestinal allergy mouse model was developed to assess the role of Tip60 in the induction of IgE-mediated allergic inflammation. RESULTS: High levels of Tip60 were observed in the peripheral B cells of patients with FA. Tat-interactive protein 60 (Tip60) was required in the expression of IgE and IgG1 in B cells by inducing the chromatin remolding at the gene locus, in which histone acetylation, signal transducer and activator of transcription 6 (STAT6), and nuclear factor-κB at the locus of Iε promoter were markedly increased. Blocking Tip60 significantly attenuated the allergic inflammation in the mouse intestinal mucosa. CONCLUSIONS: Tat-interactive protein 60 (Tip60) plays an important role in the induction of IgE in B cells. Blocking Tip60 inhibits the allergic inflammation in the intestine, suggesting Tip60 inhibitor may be a potential anti-allergy drug.


Assuntos
Hipersensibilidade/genética , Hipersensibilidade/imunologia , Enteropatias/genética , Enteropatias/imunologia , Lisina Acetiltransferase 5/genética , Lisina Acetiltransferase 5/imunologia , Adulto , Animais , Modelos Animais de Doenças , Feminino , Histona Acetiltransferases , Humanos , Imunoglobulina E/genética , Imunoglobulina E/imunologia , Intestinos/imunologia , Masculino , Camundongos
4.
Allergy ; 73(1): 106-114, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28718965

RESUMO

BACKGROUND AND AIMS: Mast cell activation interferes with the effects of allergen-specific immunotherapy (SIT). Galectin-1 (Gal-1) is capable of regulating immune cells' functions. This study tests the hypothesis that administration of Gal-1 promotes and prolongs the efficacy of SIT via suppressing mast cell activation. METHODS: An intestinal allergy mouse model was developed. The coadministration of SIT and Gal-1 on suppression of the allergic responses, prevention of mast cell activation, and generation of antigen-specific regulatory T cells (Treg) in the intestine was observed in sensitized mice. RESULTS: The coadministration of Gal-1 and SIT markedly suppressed the allergic responses in the mouse intestine vs the use of either SIT alone or Gal-1 alone. The Gal-1 binds to the IgE/FcɛRI complexes on the surface of mast cells to prevent mast cell activation during SIT. Gal-1 promoted the SIT-generated allergen-specific Tregs in the intestine of sensitized mice. Coadministration of Gal-1 and SIT significantly enhanced the efficacy of immunotherapy in suppressing allergic responses in the intestine, which lasted for at least for 12 months. CONCLUSIONS: Long-term effects of specific immunotherapy on intestinal allergy can be achieved with Gal-1/SIT therapy by inhibiting mast cell activation and facilitating Treg development.


Assuntos
Alérgenos/imunologia , Galectina 1/administração & dosagem , Hipersensibilidade/imunologia , Imunoterapia , Intestinos/imunologia , Citocinas/metabolismo , Dessensibilização Imunológica , Humanos , Hipersensibilidade/metabolismo , Hipersensibilidade/patologia , Imunomodulação/efeitos dos fármacos , Imunoterapia/métodos , Mucosa Intestinal/metabolismo , Intestinos/patologia , Mastócitos/imunologia , Mastócitos/metabolismo , Imunoterapia Sublingual , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Células Th2/imunologia , Células Th2/metabolismo
5.
Clin Exp Allergy ; 47(5): 656-664, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28160341

RESUMO

BACKGROUND: Dendritic cell (DC)-derived immunoglobulin domain molecule (TIM)4 plays a critical role in the initiation of T helper (Th)2 polarization. Vitamin D (VitD) involves the regulation of a number of immune responses. OBJECTIVES: This study tests a hypothesis that VitD regulates TIM4 expression in DCs. METHODS: Peripheral blood samples were collected from patients with allergic rhinitis (AR) and healthy subjects. DCs were isolated from the samples and analyzed for the expression of TIM4. RESULTS: We observed that the levels of calcitriol, the active form of VitD3, in the sera of AR patients were lower than that in healthy subjects. The peripheral DC expressed higher levels of TIM4 and lower levels of VDR. A negative correlation was identified between the data of serum calcitriol and TIM4 in DCs. Exposure DCs to calcitriol in the culture increased the expression of VDR. We also found that VDR bound to the TIM4 promoter locus in DCs to repress the TIM4 gene transcription and expression. CONCLUSIONS AND CLINICAL RELEVANCE: VitD deficiency may contribute to the pathogenesis of AR by increasing the TIM4 expression. The results suggest that to regulate the serum calcitriol levels and the expression of VDR in DCs may be necessary to be taken into account in the treatment of AR.


Assuntos
Calcitriol/farmacologia , Células Dendríticas/imunologia , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Membrana/imunologia , Rinite Alérgica/imunologia , Vitamina D/farmacologia , Adulto , Células Dendríticas/patologia , Feminino , Regulação da Expressão Gênica/imunologia , Humanos , Masculino , Rinite Alérgica/patologia
6.
Allergy ; 72(8): 1184-1192, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27998003

RESUMO

BACKGROUND AND AIMS: Mast cells are the major effector cells in allergic disorders and many other informatory disorders. The mechanism of mast cell stabilization is not fully understood. Cumulative reports indicate that vitamin D (VitD) contributes to the homeostasis in the body. This study tests a hypothesis that VitD is required in the maintenance of the stability of mast cells. METHODS: The stability of mast cell lines, HMC1 cells, RBL-2H3 cells, p815 cells, and mouse bone marrow-derived mast cells (BMMC) was tested in the presence or absence of VitD3. RESULTS: Mast cells activated automatically in a VitD-deficient environment. Exposure to calcitriol in the culture increased the expression of VitD receptor (VDR) in mast cells. VDR formed complexes with Lyn in mast cells to inhibit the binding of Lyn to the ß chain of FcεRI and MyD88, which decreased the phosphorylation of Syk, decreased the levels of MAPK and NF-κB. VDR bound to the promoter of TNF-α to decrease the acetylation of histone H3/H4, RNA polymerase II and OCT1 (a transcription factor of TNF-α) at the promoter locus and repressed the expression of TNF-α in mast cells. CONCLUSIONS: The data demonstrate that VitD is required to maintain the stability of mast cells. The deficiency of VitD results in mast cell activation.


Assuntos
Mastócitos/fisiologia , Vitamina D/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Citocinas/metabolismo , Modelos Animais de Doenças , Hipersensibilidade Alimentar/genética , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Imunoglobulina E/imunologia , Mediadores da Inflamação/metabolismo , Masculino , Mastócitos/efeitos dos fármacos , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas , Ligação Proteica , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Vitamina D/farmacologia , Quinases da Família src/metabolismo
7.
Biofabrication ; 3(3): 034105, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21725153

RESUMO

Engineered scaffolds have been shown to be critical to various tissue engineering applications. This paper presents the development of a novel three-dimensional scaffold made from a mixture of chitosan microspheres (CMs) and poly(L-lactide) by means of the rapid freeze prototyping (RFP) technique. The CMs were used to encapsulate bovine serum albumin (BSA) and improve the scaffold mechanical properties. Experiments to examine the BSA release were carried out; the BSA release could be controlled by adjusting the crosslink degree of the CMs and prolonged after the CMs were embedded into the PLLA scaffolds, while the examination of the mechanical properties of the scaffolds illustrates that they depend on the ratio of CMs to PLLA in the scaffolds as well as the cryogenic temperature used in the RFP fabrication process. The chemical characteristics of the PLLA/chitosan scaffolds were evaluated by Fourier transform infrared (FTIR) spectroscopy. The morphological and pore structure of the scaffolds were also examined by scanning electron microscopy and micro-tomography. The results obtained show that the scaffolds have higher porosity and enhanced pore size distribution compared to those fabricated by the dispensing-based rapid prototyping technique. This study demonstrates that the novel scaffolds have not only enhanced porous structure and mechanical properties but also showed the potential to preserve the bioactivities of the biomolecules and to control the biomolecule distribution and release rate.


Assuntos
Quitosana/química , Poliésteres/química , Engenharia Tecidual , Alicerces Teciduais , Animais , Bovinos , Congelamento , Porosidade , Soroalbumina Bovina/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier
8.
Biofabrication ; 2(4): 045002, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21076186

RESUMO

Axon guidance is a crucial consideration in the design of tissue scaffolds used to promote nerve regeneration. Here we investigate the combined use of laminin (a putative axon adhesion and guidance molecule) and chitosan (a leading candidate base material for the construction of scaffolds) for promoting axon guidance in cultured adult dorsal root ganglion (DRG) neurons. Using a dispensing-based rapid prototyping (DBRP) technique, two-dimensional grid patterns were created by dispensing chitosan or laminin-blended chitosan substrate strands oriented in orthogonal directions. In vitro experiments illustrated DRG neurites on these patterns preferentially grew upon and followed the laminin-blended chitosan pathways. These results suggest that an orientation of neurite growth can be achieved in an artificially patterned substrate by creating selectively biofunctional pathways. The DBRP technique may provide improved strategies for the use of biofunctional pathways in the design of three-dimensional scaffolds for guidance of nerve repair.


Assuntos
Axônios/química , Quitosana/química , Gânglios Espinais/crescimento & desenvolvimento , Laminina/química , Engenharia Tecidual/instrumentação , Alicerces Teciduais/química , Animais , Células Cultivadas , Gânglios Espinais/química , Gânglios Espinais/citologia , Ratos , Ratos Sprague-Dawley
9.
J Biomech Eng ; 132(11): 111001, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21034142

RESUMO

The mechanical properties of tissue engineering scaffolds play a critical role in the success of repairing damaged tissues/organs. Determining the mechanical properties has proven to be a challenging task as these properties are not constant but depend upon time as the scaffold degrades. In this study, the modeling of the time-dependent mechanical properties of a scaffold is performed based on the concept of finite element model updating. This modeling approach contains three steps: (1) development of a finite element model for the effective mechanical properties of the scaffold, (2) parametrizing the finite element model by selecting parameters associated with the scaffold microstructure and/or material properties, which vary with scaffold degradation, and (3) identifying selected parameters as functions of time based on measurements from the tests on the scaffold mechanical properties as they degrade. To validate the developed model, scaffolds were made from the biocompatible polymer polycaprolactone (PCL) mixed with hydroxylapatite (HA) nanoparticles and their mechanical properties were examined in terms of the Young modulus. Based on the bulk degradation exhibited by the PCL/HA scaffold, the molecular weight was selected for model updating. With the identified molecular weight, the finite element model developed was effective for predicting the time-dependent mechanical properties of PCL/HA scaffolds during degradation.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Materiais Biocompatíveis/química , Fenômenos Biomecânicos , Durapatita/química , Módulo de Elasticidade , Análise de Elementos Finitos , Teste de Materiais , Modelos Biológicos , Peso Molecular , Nanopartículas/química , Poliésteres/química , Alicerces Teciduais/química
10.
Folia Microbiol (Praha) ; 55(1): 10-6, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20336498

RESUMO

During the screening program for fungicides, one actinomycete strain ECO 00047 was isolated with the potential activity against fungus. According to the morphology and analysis of the nucleotide sequence of the 16S rRNA gene (1500 bp) this isolate was identified as Streptomyces diastaticus. The active compounds were separated by silica gel column chromatography, Sephadex LH-20 gel filtration and then purified by flash chromatography on C18 (20-45 microm). The chemical structure of the bioactive compounds I and II were elucidated, based on the spectroscopic data of MS, IR, UV, 1H-NMR, 13C-NMR and X-ray single crystal diffraction analysis. Compounds I and II were identical with oligomycins A and C, the macrolide antibiotics which have been known to be produced by Streptomyces diastatochromogenes, S. libani and S. avermitilis. The two compounds exhibited a strong activity against Aspergillus niger, Alternaria alternata, Botrytis cinerea and Phytophthora capsici but no activity toward bacteria. Although the two above antibiotics were known, their isolation has so far not been reported from S. diastaticus.


Assuntos
Oligomicinas/isolamento & purificação , Streptomyces/metabolismo , Alternaria/efeitos dos fármacos , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Aspergillus niger/efeitos dos fármacos , Botrytis/efeitos dos fármacos , Cromatografia Líquida/métodos , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Oligomicinas/química , Oligomicinas/farmacologia , Filogenia , Phytophthora/efeitos dos fármacos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Análise Espectral/métodos , Streptomyces/classificação , Streptomyces/genética , Streptomyces/isolamento & purificação
11.
Biofabrication ; 1(3): 032001, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20811104

RESUMO

Artificial scaffolds play vital roles in tissue engineering as they provide a supportive environment for cell attachment, proliferation and differentiation during tissue formation. Fabrication of tissue scaffolds is thus of fundamental importance for tissue engineering. Of the variety of scaffold fabrication techniques available, rapid prototyping (RP) methods have attracted a great deal of attention in recent years. This method can improve conventional scaffold fabrication by controlling scaffold microstructure, incorporating cells into scaffolds and regulating cell distribution. All of these contribute towards the ultimate goal of tissue engineering: functional tissues or organs. Dispensing is typically used in different RP techniques to implement the layer-by-layer fabrication process. This article reviews RP methods in tissue scaffold fabrication, with emphasis on dispensing-based techniques, and analyzes the effects of different process factors on fabrication performance, including flow rate, pore size and porosity, and mechanical cell damage that can occur in the bio-manufacturing process.


Assuntos
Biotecnologia/instrumentação , Biotecnologia/métodos , Desenho Assistido por Computador , Engenharia Tecidual/instrumentação , Alicerces Teciduais
12.
Biofabrication ; 1(4): 045005, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20811114

RESUMO

Mixtures of alginate and hydroxyapatite (HA) are promising materials for biomedical applications such as the fabrication of tissue scaffolds. In this paper, the flow behavior of alginate/HA mixtures was investigated and determined to be dependent on the concentration of both alginate and HA, and temperature. The relationships were mathematically established and verified with experimental results. As applied to the tissue scaffold fabrication, the flow rate of the biomaterial solution was predicted from the established flow behavior and verified by experiments. On this basis, the moving speed of the needle was determined and used in the tissue scaffold fabrication. The results obtained show that the knowledge of the flow behavior is essential to the fabrication of tissue scaffolds with an interconnected microstructure.


Assuntos
Alginatos/química , Durapatita/química , Reologia/métodos , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Biotecnologia , Simulação por Computador , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Temperatura
13.
J Bone Joint Surg Br ; 90(1): 43-9, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18160498

RESUMO

We have examined the differences in clinical outcome of total knee replacement (TKR) with and without patellar resurfacing in a prospective, randomised study of 181 osteoarthritic knees in 142 patients using the Profix total knee system which has a femoral component with features considered to be anatomical and a domed patellar implant. The procedures were carried out between February 1998 and November 2002. A total of 159 TKRs in 142 patients were available for review at a mean of four years (3 to 7). The patients and the clinical evaluator were blinded in this prospective study. Evaluation was undertaken annually by an independent observer using the knee pain scale and the Knee Society clinical rating system. Specific evaluation of anterior knee pain, stair-climbing and rising from a seated to a standing position was also undertaken. No benefit was shown of TKR with patellar resurfacing over that without resurfacing with respect to any of the measured outcomes. In 22 of 73 knees (30.1%) with and 18 of 86 knees (20.9%) without patellar resurfacing there was some degree of anterior knee pain (p = 0.183). No revisions related to the patellofemoral joint were performed in either group. Only one TKR in each group underwent a re-operation related to the patellofemoral joint. A significant association between knee flexion contracture and anterior knee pain was observed in those knees with patellar resurfacing (p = 0.006).


Assuntos
Artroplastia do Joelho/métodos , Articulação do Joelho/cirurgia , Osteoartrite do Joelho/cirurgia , Patela/cirurgia , Idoso , Idoso de 80 Anos ou mais , Artralgia , Método Duplo-Cego , Feminino , Humanos , Prótese do Joelho , Masculino , Pessoa de Meia-Idade , Medição da Dor , Satisfação do Paciente , Estudos Prospectivos , Desenho de Prótese , Resultado do Tratamento
14.
Brain Res ; 1141: 235-41, 2007 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-17275796

RESUMO

Cerebral blood flow (CBF), a surrogate of neural activity in the identification of brain regions involved in specific functions, has been used in this report to trace the compensatory enhancement of activity in non-traumatized areas of the brain following a focal lesion. We have previously shown activation of CBF in the cortex contralateral to a focal contusion, 24 h after the event. The present report extends the characterization of this trans-hemispheric cortical blood flow activation by studying its time course and regional distribution from 4 days to 4 weeks post-trauma. Adult male Sprague-Dawley rats received a cortical impact through a 6.3 mm craniotomy under halothane anesthesia. CBF was measured with the quantitative autoradiographic (14)C-Iodoantipyrine technique, in conscious animals, 4 days, 2 weeks and 4 weeks post-trauma. CBF was severely decreased at the site of impact where necrosis developed later, and it remained depressed in the surrounding areas throughout the observation period. Trans-hemispheric CBF enhancement was maximal at 4 days and it returned to control levels 28 days post-trauma. This phenomenon was present in all cortical regions symmetrical to the impact zone, but also in auditory, visual, entorhinal and insular cortex. These results suggest that the participation of the contralateral cortex in the recovery from unilateral brain trauma is not limited to the regions homologous to those that received the impact. The time course of CBF changes was found to be consistent with the recovery of motor function in this model.


Assuntos
Lesões Encefálicas/patologia , Lesões Encefálicas/fisiopatologia , Córtex Cerebral/irrigação sanguínea , Circulação Cerebrovascular/fisiologia , Lateralidade Funcional/fisiologia , Análise de Variância , Animais , Anti-Inflamatórios não Esteroides/farmacocinética , Antipirina/análogos & derivados , Antipirina/farmacocinética , Lesões Encefálicas/diagnóstico por imagem , Mapeamento Encefálico , Isótopos de Carbono/farmacocinética , Córtex Cerebral/diagnóstico por imagem , Modelos Animais de Doenças , Radiografia/métodos , Cintilografia , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
15.
Clin Orthop Relat Res ; 448: 73-8, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16826099

RESUMO

UNLABELLED: The CFP stem represents a short collared neck-retaining stem with very proximal metaphyseal anchoring along the calcar combined with up-to-date metallurgy. Despite theoretical advantages, the stability and clinical outcome are unknown. We prospectively measured the migration pattern of this new stem and cup. Twenty-six patients (26 hips) with a mean age of 54 years (range, 40-66 years) underwent THA and were followed for 2 years with radiostereometry, radiographs, and clinical scores. The stem showed some early retroversion (mean, SEM 0.6 degrees, 0.3), but stabilized before 1 year. Subsidence (0.05 mm, 0.06) and varus-valgus tilting (0.03 degrees, 0.01) were low. We observed no bone loss in the calcar region. Factors related to patients, implant design, and implantation did not predict migration patterns. The two-dimensional wear of the ceramic/conventional articulation was 0.09 mm at 2-24 months. The low migration of this short neck preserving stem suggests a favorable long-term outcome but longer followup is needed to substantiate this prediction. This design might become an alternative to standard stems and hip resurfacing. LEVEL OF EVIDENCE: Therapeutic Level IV. See The Guidelines for Authors for a complete description of levels of evidence.


Assuntos
Artroplastia de Quadril/efeitos adversos , Migração de Corpo Estranho/complicações , Articulação do Quadril/fisiopatologia , Prótese de Quadril , Instabilidade Articular/etiologia , Adulto , Artroplastia de Quadril/instrumentação , Feminino , Seguimentos , Migração de Corpo Estranho/fisiopatologia , Articulação do Quadril/cirurgia , Humanos , Instabilidade Articular/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Desenho de Prótese , Falha de Prótese
16.
J Appl Microbiol ; 99(4): 878-84, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16162239

RESUMO

AIMS: To construct a transgenic Bacillus mucilaginosus strain to increase the secretion capability of a wild-type isolate of B. mucilaginosus D4B1 to hydrolyse phytate phosphorus, which can be used as a microbial fertilizer in field application. METHODS AND RESULTS: We constructed a phytase secreting expression vector pSP43 with a mini-Tn5 transposon and a Aspergillus fumigatus phytase expression cassette. The vector pSP43 was successfully transferred into the wild-type B. mucilaginosus using the particle bombardment method, and three transgenic strains with a stable copy of phytase expression cassette integrated into the chromosome of the B. mucilaginosus by Tn5 transposition were selected. The phytase activity of the engineered strains increased 36-46-fold when compared with the wild-type strain of D4B1. CONCLUSIONS: The A. fumigatus phytase gene can be expressed under the direction of p43 promoter in B. mucilaginosus. The expression protein is secreted extracellularly and newly constructed strains showed a high phytase activity. SIGNIFICANCE AND IMPACT OF THE STUDY: A transgenic Bacillus strain by the particle bombardment method was constructed.


Assuntos
6-Fitase/metabolismo , Bacillus/genética , Bacillus/enzimologia , Southern Blotting/métodos , Meios de Cultura , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Eletroforese em Gel de Poliacrilamida/métodos , Expressão Gênica/genética , Engenharia Genética/métodos , Vetores Genéticos , Organismos Geneticamente Modificados/genética , Plasmídeos/genética , Microbiologia do Solo
17.
Proteins ; 53(4): 908-16, 2003 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-14635132

RESUMO

The chitinase gene chi1 of Aeromonas caviae CB101 encodes an 865-amino-acid protein (with signal peptide) composed of four domains named from the N-terminal as an all-beta-sheet domain ChiN, a triosephosphate isomerase (TIM) catalytic domain, a function-unknown A region, and a putative chitin-binding domain (ChBD) composed of two repeated sequences. The N-terminal 563-amino-acid segment of Chi1 (Chi1DeltaADeltaChBD) shares 74% identity with ChiA of Serratia marcescens. By the homology modeling method, the three-dimensional (3D) structure of Chi1DeltaADeltaChBD was constructed. It fit the structure of ChiA very well. To understand fully the function of the C-terminal module of Chi1 (from 564 to 865 amino acids), two different C-terminal truncates, Chi1DeltaChBD and Chi1DeltaADeltaChBD, were constructed, based on polymerase chain reaction (PCR). Comparison studies of the substrate binding, hydrolysis capacity, and specificity among Chi1 and its two truncates showed that the C-terminal putative ChBD contributed to the insoluble substrate-protein binding and hydrolysis; the A region did not have any function in the insoluble substrate-protein binding, but it did have a role in the chitin hydrolysis: Deletion of the A region caused the enzyme to lose 30-40% of its activity toward amorphous colloidal chitin and soluble chitin, and around 50% toward p-nitrophenyl (pNP)-chitobiose pNP-chitotriose, and its activity toward low-molecular-weight chitooligomers (GlcNAc)3-6 also dropped, as shown by analysis of its digestion processes. This is the first clear demonstration that a domain or segment without a function in insoluble substrate-chitinase binding has a role in the digestion of a broad range of chitin substrates, including low-molecular-weight chitin oligomers. The reaction mode of Chi1 is also described and discussed.


Assuntos
Aeromonas/enzimologia , Quitinases/química , Quitinases/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Domínio Catalítico , Quitina/metabolismo , Quitinases/genética , Regulação Enzimológica da Expressão Gênica , Hidrólise , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Oligossacarídeos/metabolismo , Ligação Proteica , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade , Especificidade por Substrato
18.
J Arthroplasty ; 16(7): 893-900, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11607906

RESUMO

The relationship between changes in bone mineral density (BMD) in the proximal tibia and fixation of the tibial component during 2 years postoperatively was investigated in 28 knees. BMD was measured using dual-energy x-ray absorptiometry, and fixation was determined using radiostereometric analysis. BMD decreased at 3 months and returned to baseline level at 24 months, but with large variations on an individual basis. Most of the prosthetic migration occurred within the initial 3 months. The results show that the bone remodeling that occurs during the 2 years after operation has no relation to the migration of the tibial component. The early migration seems to be related more to local activities at the interface rather than to changes in BMD assessed below the interface. The changes in BMD during 2 years reflect the bone remodeling caused by the normalization of alignment after operation and are not related to the implant fixation.


Assuntos
Artroplastia do Joelho , Densidade Óssea , Migração de Corpo Estranho , Tíbia/fisiopatologia , Absorciometria de Fóton , Idoso , Remodelação Óssea , Feminino , Humanos , Modelos Lineares , Masculino , Falha de Prótese , Estatísticas não Paramétricas , Tíbia/cirurgia
19.
J Arthroplasty ; 15(6): 744-53, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11021450

RESUMO

The relationship between the preoperative level of bone mineral density (BMD) in the proximal tibia and the migration of the tibial component 2 years after total knee arthroplasty was investigated in 28 knees with osteoarthrosis (10 men, 18 women; mean age, 71). Sixteen components were inserted uncemented and 12 were cemented. Mean average BMD measured 10 mm below the joint level was 0.81 g/cm2 (range, 0.15-1.33 g/cm2) and was not influenced by gender, age, weight, or preoperative alignment. Local BMD measured in the medial and lateral condyles was influenced by the preoperative alignment. In knees with uncemented fixation, most of the tibial component migration (ie, subsidence and lift-off) occurred within the first months, and thereafter the implants seemed to stabilize. In the uncemented implants, there was a significant relationship between average BMD and migration (regression analysis with curve-fit estimation). The least migration was seen when average BMD was 0.6 to 1.0 g/cm2. Beyond this range, increased subsidence and lift-off was seen. There was no relationship between BMD and the change in maximum migration between 1 and 2 years postoperatively, however. In knees with cemented fixation, subsidence was initially small but continuously increasing. There were no relationships between BMD and subsidence, lift-off, and maximum migration, indicating that bone-cement can compensate for variations in bone quality, at least in the early period after operation.


Assuntos
Artroplastia do Joelho/instrumentação , Densidade Óssea , Tíbia , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Artroplastia do Joelho/métodos , Cimentos Ósseos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/cirurgia , Complicações Pós-Operatórias , Desenho de Prótese , Falha de Prótese
20.
J Orthop Res ; 18(1): 40-7, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10716277

RESUMO

The change in bone mineral density at the proximal tibia during 2 years after total knee arthroplasty was studied in 28 knees (28 patients: 10 men and 18 women; median age: 71 years) with dual energy x-ray absorptiometry. Bone mineral density was measured at the proximal tibia at nine regions of interest below the tibial component within 1 week after the operation (baseline); measurements were repeated at 3, 6, 12, and 24 months. All but one knee was malaligned before the operation, and all but three were corrected to within the normal range of alignment after it. The mean bone mineral density of all nine regions of interest at the proximal tibia temporarily decreased by 13% (p = 0.001) during the initial 3 months, probably due to a general metabolic reaction of the skeleton to the operative trauma combined with the effect of the postoperative immobilization, and then the initial level was regained for as long as 2 years. The overall changes in mean bone mineral density to 2 years were insignificant (p > 0.05); however, a great variation (43.9% decrease to 98.0% increase) was observed on an individual basis. This change over time was significantly associated (R2 = 0.36, p = 0.002) with the level of the baseline bone mineral density, which in turn was partly related (R2 = 0.24, p = 0.009) to the amount of malalignment of the knee before the operation. Knees with high baseline levels (n = 14: 11 with varus and three with valgus alignment) displayed a decrease of 10.0 +/- 14.0% (mean +/- SD, p > 0.05) for as long as 2 years, whereas those with low baseline levels (n = 14: seven with varus and six with valgus alignment and one neutrally aligned) had an increase of 19.1 +/- 38.2% (p = 0.038). In both groups, the mean bone mineral density converged to a level of 0.75-0.95 g/cm2 at 2 years.


Assuntos
Absorciometria de Fóton , Artroplastia do Joelho , Densidade Óssea , Remodelação Óssea , Tíbia/metabolismo , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade
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