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1.
Osteoarthritis Cartilage ; 17(8): 1106-14, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19303468

RESUMO

OBJECTIVE: Osteoarthritis (OA) is clinically characterized by degeneration of the joints and has been traditionally considered a primary disorder of articular cartilage, with secondary changes in the subchondral bone. The increased bone mass and generalized changes in bone quality observed in osteoarthritic patients suggest that OA may be a primary systemic bone disorder with secondary articular cartilage damage. The iliac crest is a skeletal site distant from the affected joint, with a minimal load-bearing function. To provide evidence that OA is a systemic disorder, we searched for differentially expressed genes in the iliac crest bone of patients suffering from hip OA. MATERIAL AND METHODS: Gene expression levels between bone samples collected at surgery from the iliac crest of patients undergoing total hip arthroplasty for primary OA and younger donors, who were undergoing spinal arthrodesis, were investigated by means of oligonucleotide microarrays. To verify data detected by microarrays technology, Real Time Reverse Transcription-Polymerase Chain Reaction (RT-PCR) assays were performed with specimens from osteoarthritic patients and donors, as well as from elderly donors who were undergoing arthroplasty for subcapital femoral neck fracture. RESULTS: The microarray analysis surveyed 8327 genes and identified 83 whose expression levels differed at least 1.5-fold in the OA group (P<0.005). Comparisons between Real Time RT-PCR data from OA and the two donor groups indicated differential expression of genes involved in bone cell functions in the group of OA patients. The genes identified, including CCL2, FOS, PRSS11, DVL2, AKT1, CA2, BMP6, OMD, MMP2, TGFBR3, FLT1, BMP1 and TNFRS11B, have known roles in osteoblast or osteoclast activities. CONCLUSIONS: The data from this study identify a set of genes, closely related to bone cell functions, in which differential regulation in osteoarthritic bone distant from the diseased subchondral bone might underlie the etiopathogenesis of OA as a generalized bone disease.


Assuntos
Cartilagem Articular/patologia , Ílio/patologia , Osteoartrite do Quadril/patologia , Proteoglicanas/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Feminino , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Quadril/genética , Valores de Referência , Reação em Cadeia da Polimerase Via Transcriptase Reversa
2.
J Biomed Mater Res A ; 81(2): 334-46, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17120220

RESUMO

Oxidation of Ti6Al4V at 500 degrees C for 1 h in air results in the formation of an outer ceramic layer that improves osteoblast behavior and decreases Ti and Al ion release. In this work, alumina blasted Ti6Al4V alloy has been thermally treated and its in vitro biocompatibility has been assessed. Roughness of the blasted alloy was not found significantly altered after heat treatment while chemical surface analysis indicated an increase in stable TiO(2) and Al(2)O(3) oxides. Cell attachment, spreading, cytoskeleton organization as well as cell proliferation, viability, and procollagen I peptide secretion of human primary osteoblasts, impaired on alumina blasted Ti6Al4V, were found to be greatly enhanced on the thermally oxidized blasted alloy. Other informative markers of the osteoblastic phenotype such as alkaline phosphatase, osteocalcin, osteoprotegerin, and mineralized nodule formation were evaluated and indicated that osteoblasts responded at the same extent on untreated and thermally treated blasted alloys. Taken together, our in vitro results indicate that thermal oxidation of alumina blasted Ti6Al4V may favor successful osseointegration by promoting early interactions of osteoblastic cells and the modified surface alloy.


Assuntos
Materiais Biocompatíveis/química , Osteoblastos/citologia , Titânio/química , Actinas/metabolismo , Fosfatase Alcalina/metabolismo , Ligas/química , Adesão Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Temperatura Alta , Humanos , Técnicas In Vitro , Teste de Materiais , Microscopia Eletrônica de Varredura , Osteoblastos/metabolismo , Osteocalcina/metabolismo , Osteoprotegerina/metabolismo , Oxirredução , Fragmentos de Peptídeos/metabolismo , Pró-Colágeno/metabolismo , Ligante RANK/metabolismo , Análise Espectral , Propriedades de Superfície , Raios X
3.
An Sist Sanit Navar ; 30(3): 353-62, 2007.
Artigo em Espanhol | MEDLINE | ID: mdl-18227892

RESUMO

BACKGROUND: Lung cancer is one of the main health problems in the developed world. Our aims were to determine the symptomatic time prior to a specific diagnosis, the clinical and histological characteristics of the cases of lung cancer diagnosed in a department of internal medicine, and to analyze the survival factors. MATERIAL AND METHODS: We studied retrospectively all patients diagnosed with lung cancer in the internal medicine department in the period between January 2001 and September 2006 reviewing clinical records. We specifically recorded age, gender, smoking habit, time and type of symptomatic presentation, radiological manifestations, methods of histological diagnosis, tumour staging, and performance status measured by ECOG classification. We also evaluated the factors associated with the survival time. RESULTS: In this period 124 patients were diagnosed with lung cancer [mean age 68 +/-12 years, male 105 (85%), female 18 (15%), smokers 85%]. The mean symptomatic time before hospitalization was 74.5 +/-7 days. On hospitalization, respiratory symptoms were present in 40 (32%) patients. Tumour staging was carried out in 120 (97%) patients. In 96 (77%) patients non-small lung cancer was diagnosed, 62 (64%) in stage IV. In 28 (23%) patients small lung cancer was diagnosed, 22 (79%) in extended stage. Median time to diagnosis as an in-patient was 7 days. One hundred and thirteen (91%) patients died with a median survival time of 3 months. Factors associated with longer survival were the performance status and tumour stage. CONCLUSIONS: In this community, lung cancer is diagnosed late and in advanced stages, with a high mortality rate. A better performance status and lower tumour stages appear to be associated with longer survival.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Broncoscopia , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Interpretação Estatística de Dados , Feminino , Humanos , Estimativa de Kaplan-Meier , Pulmão/patologia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Radiografia Torácica , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Fumar/efeitos adversos , Análise de Sobrevida , Fatores de Tempo , Tomografia Computadorizada por Raios X
4.
J Orthop Res ; 24(1): 46-54, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16419968

RESUMO

The purpose of the current study was to evaluate the effects of alumina particles on secretion of several cytokines involved in bone resorption in cocultures of macrophages and osteoblasts. To distinguish the contribution of each individual cell type, we have established a heterologous in vitro system that makes use of mouse J774 cells and primary cultured human osteoblasts. J744 cells decreased the production of TNF-alpha when they were cocultured with osteoblasts. Treatment of J744 cells with alumina particles increased TNF-alpha secretion, but the induction was lower when cells were cocultured with osteoblasts. Secretion of IL-6 by J744 cells was very low, and increased in the presence of osteoblasts. Alumina particles were only able to stimulate the release of IL-6 by J744 cells when cells were cocultured with osteoblasts. On the other hand, incubation of osteoblasts with alumina particles enhanced the release of IL-6 and GM-CSF. Coculturing osteoblasts with J744 cells induced them to release IL-6 and GM-CSF, and treatment with alumina further increased the secretion of both mediators by osteoblasts. According to these in vitro results, it seems rather plausible that alumina particles are able to initiate an inflammatory response in vivo.


Assuntos
Óxido de Alumínio/farmacologia , Citocinas/metabolismo , Macrófagos/fisiologia , Osteoblastos/fisiologia , Idoso , Animais , Materiais Biocompatíveis/farmacologia , Técnicas de Cocultura , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Interleucina-6/metabolismo , Macrófagos/efeitos dos fármacos , Camundongos , Pessoa de Meia-Idade , Osteoblastos/efeitos dos fármacos , Tamanho da Partícula , Fator de Necrose Tumoral alfa/metabolismo
5.
J Biomed Mater Res A ; 77(3): 608-17, 2006 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-16506177

RESUMO

We have evaluated the in-vitro biocompatibility of Ti6Al4V alloy coated by plasma spraying with an identical alloy. These surfaces are widely used in cementless prosthetic components, although osteoblasts behavior on this treated alloy has not been evaluated to date. Cross sectional examination revealed a thick and rough coating of identical composition without sign of delamination. Within the coating, small discontinuities and nonconnected pores were observed. Osteoblast response was evaluated by assessing cell adhesion, proliferation, and differentiation of primary cultures of human osteoblastic cells. Compared to the polished alloy, osteoblast adhesion measured as cell attachment and actin network reorganization was delayed on the plasma-sprayed surface. Cell proliferation and viability were also impaired on the rough surface. Several informative markers of osteoblastic differentiation such as procollagen I peptide, alkaline phosphatase, osteocalcin, osteoprotegerin, and mineralized nodule formation were evaluated and indicated that the plasma-sprayed alloy favored a more differentiated phenotype than polished alloy. Taken together, our in vitro results indicate that successful osseointegration of plasma spraying of Ti6Al4V with an identical alloy is mediated by modulation of osteoblastic differentiation and mineralization.


Assuntos
Materiais Revestidos Biocompatíveis , Teste de Materiais , Osteoblastos , Titânio , Idoso , Ligas , Células Cultivadas , Humanos
6.
J Biomed Mater Res A ; 77(2): 220-9, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16392123

RESUMO

Thermal oxidation treatments of Ti6Al4V, at 500 and 700 degrees C, for 1 h result in the formation of an outer "ceramic" layer of rutile, which enhances osteoblast response. In the present study, we have measured in vitro Ti and Al ion release from Ti64 alloy in the as-received state and after thermal oxidation treatments at 500 or 700 degrees C, to culture medium under standard cell-culture conditions. Concentrations of both Ti and Al released from both thermal oxidation treatments were lower than from polished alloy. Al was released from the treated or untreated surfaces in substantially lower extent than Ti. Titanium and aluminium ions affected primary human osteoblast proliferation, metabolic activity, and differentiation in a dose-dependent manner. Treatments with individual Ti or Al metal ions in similar concentration ranges than released from the surfaces did not alter osteoblast response, which also remained unaffected after treatments with combinations of Ti plus Al applied in the proportional relations than detected in ion-release experiments. We then selected higher concentrations of Ti that impaired osteoblast proliferation and differentiation, while the proportional lower concentrations of Al did not alter osteoblast behavior. In spite of its inert character, it was found that Al significantly enhanced the deleterious effect of Ti on osteoblast differentiation. Therefore, thermal oxidation treatments of Ti6Al4V alloy may improve the biocompatibility of the alloy by reducing both Ti and Al release, and thus attenuating ion-mediated interference with osteoblast differentiation.


Assuntos
Alumínio/metabolismo , Osteoblastos/metabolismo , Titânio/metabolismo , Idoso , Ligas , Alumínio/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Biomarcadores/metabolismo , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Humanos , Íons/química , Íons/metabolismo , Teste de Materiais , Osteoblastos/citologia , Soluções/química , Titânio/química
7.
An Med Interna ; 23(1): 34-6, 2006 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-16542121

RESUMO

A tumor of germinal cells should be considered in the differential diagnosis of a retroperitoneal mass in a young patient. Although, this kind of tumors are relatively uncommon, inducing less than 1% of all the tumors in the masculine sex, very often they may present as a retroperitoneal mass clinically characterized by a lumbar pain that sometimes may simulate a renal colic. Occassionally, physical examination of the testis may reveal a mass. Moreover, even in advanced stages the prognosis of germ cell tumor is favorable, and there are a series of tumor markers very helpful for the diagnosis and follow up of the tumor. We report a patient with a retroperitoneal mass presenting clinically as a renal colic.


Assuntos
Neoplasias Retroperitoneais/diagnóstico , Seminoma/diagnóstico , Neoplasias Testiculares/diagnóstico , Adulto , Humanos , Masculino , Neoplasias Retroperitoneais/secundário , Seminoma/secundário , Neoplasias Testiculares/patologia
8.
J Biomed Mater Res A ; 73(1): 97-107, 2005 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-15704115

RESUMO

We have recently reported that thermal oxidation treatments of Ti6Al4V at 500 degrees and 700 degrees C for 1 h result in the formation of an outer "ceramic" layer of rutile that do not decrease the high in vitro corrosion resistance of the alloy. In the present work, surface roughness was measured and found marginally increased as a consequence of oxidation of the alloy at 700 degrees C, but not at 500 degrees C. We have evaluated the biocompatibility of the oxidized surfaces, by assessing cell adhesion, proliferation, and differentiation of primary cultures of human osteoblastic cells. Compared with polished alloy, both thermal treatments increased osteoblast adhesion measured as cell attachment, beta1 integrin and FAK-Y397 expression, as well as cytoskeletal reorganization. Compared with treatment at 500 degrees C, thermal oxidation at 700 degrees C enhanced cell adhesion. Treatment at 700 degrees C transiently impaired cell proliferation and viability, which were not altered in alloys oxidized at 500 degrees C. Several markers of osteoblastic differentiation such as procollagen I peptide, alkaline phosphatase, osteocalcin, and mineralized nodule formation were found either unaffected or differentially increased by alloys treated either at 500 degrees or 700 degrees C. In addition, thermal oxidation at 700 degrees C also increased osteoprotegerin secretion. Taken together, our results indicate that thermal oxidation treatments at 500 degrees or 700 degrees C for 1 h improve the in vitro biocompatibility of Ti6Al4V.


Assuntos
Osteoblastos/efeitos dos fármacos , Titânio/química , Titânio/farmacologia , Actinas/metabolismo , Idoso , Ligas , Osso e Ossos/citologia , Calcificação Fisiológica/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Humanos , Cadeias beta de Integrinas/metabolismo , Osteoblastos/citologia , Osteoblastos/metabolismo , Oxirredução , Proteínas Tirosina Quinases/metabolismo , Temperatura
9.
Bone ; 24(3): 203-9, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10071912

RESUMO

Age-related bone loss may be a consequence of a lack of osteoblastic formation and/or function. In vitro, the osteoblastic response to 1,25(OH)2D3, an important regulator of osteoblastic function, appears to depend on the stage of osteoblastic maturation. In this study, we examined the response to 1,25(OH)2D3 of C-terminal type I procollagen (PICP), alkaline phosphatase (ALP), and osteocalcin (OC) secretion in primary cultures of osteoblastic cells from human trabecular bone (hOB). Forty-four bone samples were obtained from subjects undergoing knee arthroplastia, 20 aged 50-70 (64 +/- 5), and 24 >70 (73 +/- 2) years. Another 33 bone samples were obtained from subjects undergoing hip arthroplastia, 21 were aged 50-70 (64 +/- 4) and 12 >70 (75 +/- 5) years. Pooling knee and hip hOB cell cultures, we found that PICP secretion decreased after 1,25(OH)2D3 in hOB cells from the older group (>70 years). Treatment with 1,25(OH)2D3 increased ALP secretion in these cells only in the younger group (50-70 years), whereas it increased OC secretion in hOB cells in both age groups. By pooling hOB cell cultures from both age groups we found that knee hOB cells increased OC secretion, and decreased PICP secretion, after 1,25(OH)2D3. This metabolite also increased OC secretion in hip hOB cells. Considering the influence of donor age at the same skeletal site, 1,25(OH)2D3 was found to stimulate ALP secretion only in knee hOB cells in the younger group. In contrast, this metabolite decreased ALP secretion in hip hOB cells in the older group. PICP secretion decreased after 1,25(OH)2D3 only in hOB cells in the older group, at both skeletal sites. In age-matched cultures, OC secretion was lower in hip hOB cells compared with those from the knee in the older group, but was similar in these cell cultures from both skeletal sites in the younger group. OC secretion after 1,25(OH)2D3 stimulation did not show age differences in knee hOB cells, but was lower in hip hOB in the older group. In summary, our results demonstrate that the response of various osteoblastic markers to 1,25(OH)2D3 in primary cultures of hOB cells depends on the donor age and skeletal site of origin.


Assuntos
Envelhecimento/fisiologia , Desenvolvimento Ósseo/efeitos dos fármacos , Calcitriol/farmacologia , Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Osteoblastos/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Fosfatase Alcalina/metabolismo , Desenvolvimento Ósseo/fisiologia , Células Cultivadas , Feminino , Fêmur/metabolismo , Fêmur/fisiologia , Articulação do Quadril/citologia , Articulação do Quadril/metabolismo , Humanos , Articulação do Joelho/citologia , Articulação do Joelho/metabolismo , Masculino , Pessoa de Meia-Idade , Osteoblastos/metabolismo , Osteocalcina/metabolismo , Fragmentos de Peptídeos/metabolismo , Pró-Colágeno/metabolismo , Tíbia/metabolismo , Tíbia/fisiologia
10.
Biomaterials ; 19(1-3): 183-7, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9678866

RESUMO

In this study, we have analyzed the direct effect of ultrahigh molecular weight polyethylene (polyethylene) on the osteoblastic cell growth in primary cultures. The cells were cultured from human bone samples obtained during reconstructive joint surgery. When cell cultures reached confluence (4-6 weeks) they were separated into three subcultures. One subculture was without particle addition (plain culture). In the other two subcultures, polyethylene or alumina was added. Two different sizes of particles were used, <80 and <160 microm. The subcultures were incubated until confluence. Proliferation of each subculture was measured by cell counts after 3, 6, 9 and 13 days, and the area under the curve (AUC) was calculated. Polyethylene particles of <160 microm induced a decrease in growth, whereas alumina of the same size did not. Polyethylene and alumina particles of <80 microm induced an inhibition in the osteoblastic cell growth; <80 microm polyethylene induced a higher inhibition than alumina of the same particle size. In conclusion, we have observed a direct effect of polyethylene on osteoblastic cell growth. This study shows that polyethylene may decrease the growth rate of human osteoblastic cells in primary cultures. Smaller particles produce a more marked reduction.


Assuntos
Materiais Biocompatíveis/farmacologia , Osteoblastos/efeitos dos fármacos , Polietilenos/farmacologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Osteoblastos/citologia , Tamanho da Partícula
11.
Biomaterials ; 22(8): 755-62, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11246943

RESUMO

The influence of two different sizes of polyethylene particles (< 30 and 20-200 microm) on osteoblastic function has been studied in primary human bone cell cultures. Cells were obtained from trabecular bone fragments of patients undergoing knee reconstructive surgery. On reaching confluency, cells were subcultured in three flasks: < 30 microm polyethylene particles were added to the first flask, 20-200 microm particles to the second flask and none to the third flask, which was the control. The resulting subcultures were incubated until confluence. Osteoblastic function was evaluated by assaying the secretion of osteocalcin, alkaline phosphatase, and C-terminal type I procollagen (PICP), with or without 1.25(OH)2D3 stimulation in the cell-conditioned medium. Adding < 30 microm polyethylene particles to these osteoblastic cell cultures increased the levels of osteocalcin secreted after 1,25(OH)2D3 stimulation. Treating stimulated or basal osteoblastic cultures with either polyethylene particle size did not affect alkaline phosphatase secretion. However, the addition of <30 microm polyethylene particles decreased PICP levels in the basal and stimulated cultures. A parallel series of osteoblastic cultures was treated with < 30 microm polyethylene particles and stimulated or not with 1,25(OH)2D3 to determine the effect on osteocalcin mRNA expression using RT-PCR amplification. Polyethylene particle-treated cultures had higher osteocalcin mRNA expression regardless of whether they had been stimulated with 1,25(OH)2D3 or not. We conclude that particle size affects the influence of polyethylene on osteoblastic function markers. Particles with a diameter of less than 30 microm increase osteocalcin expression and secretion.


Assuntos
Materiais Biocompatíveis/toxicidade , Osteoblastos/efeitos dos fármacos , Osteoblastos/fisiologia , Polietileno/toxicidade , Fosfatase Alcalina/metabolismo , Materiais Biocompatíveis/química , Calcitriol/farmacologia , Células Cultivadas , Meios de Cultivo Condicionados , Reação a Corpo Estranho/etiologia , Expressão Gênica/efeitos dos fármacos , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Osteoblastos/citologia , Osteocalcina/genética , Osteocalcina/metabolismo , Tamanho da Partícula , Fragmentos de Peptídeos/metabolismo , Polietileno/química , Pró-Colágeno/metabolismo , Falha de Prótese , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
12.
Biomaterials ; 23(3): 901-8, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11771709

RESUMO

The effect of two biomaterials, polyethylene and alpha-alumina, on interleukin-6 (IL-6) secretion and expression has been studied in human osteoblasts in primary culture. Human osteoblastic cells were derived from fresh trabecular bone explants removed during total knee arthroplasty. On reaching confluence, cells were subcultured in 6 well plates; the resulting subcultures were incubated until confluence and polyethylene or alpha-alumina particles were added to some while the rest were left as controls. The IL-6 mRNA levels were assessed by reverse transcription (RT) followed by polymerase chain reaction (PCR). IL-6 secretion was measured in the conditioned medium. The IL-6 expression was higher in the presence of both biomaterials. Maximum expression occurred in response to a dose of 50 mg particles well with both biomaterials and was greater after polyethylene particle addition than after alpha-alumina particle addition at this dose. The maximum IL-6 secretion elicited by alpha-alumina was produced at 10 mg particles well while maximum response with polyethylene required 50 mg well. At a dose of 10 mg/well, alpha-alumina particles induced more secretion than 10 mg of polyethylene particles. Nevertheless, at a dose of 50 mg/well maximum secretion was produced with polyethylene particles. In conclusion and in our experimental conditions, polyethylene as well as alpha-alumina increased both the expression and the secretion of IL-6 in human osteoblastic cells in primary culture and stimulation from polyethylene appears stronger than that from alpha-alumina at the same dose.


Assuntos
Óxido de Alumínio/farmacologia , Materiais Biocompatíveis/farmacologia , Interleucina-6/genética , Osteoblastos/imunologia , Polietileno/farmacologia , Artroplastia do Joelho , Células Cultivadas , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-6/metabolismo , Cinética , Osteoblastos/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos
13.
Biomaterials ; 24(1): 19-26, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12417174

RESUMO

In this work, the influence of thermal oxidation treatments of Ti6Al4V at 500 degrees C and 700 degrees C for 1 h on the in vitro corrosion behaviour and osteoblast response is studied. The potential of these treatments, aimed to improve the wear surface performance as biomaterial, relies in the formation of an outer "ceramic" layer of rutile. The corrosion behaviour was evaluated in simulated human fluids by electrochemical impedance spectroscopy and anodic polarisation tests. The effect of these thermal oxidation treatments on osteoblastic behaviour was studied in primary cultures of human osteoblastic cells. Results show that thermal oxidation treatments do not decrease the high in vitro corrosion resistance of the Ti6Al4V alloy. Osteoblast adhesion studies indicate that thermal oxidation treatments do not impair the material biocompatibility. Moreover, the thermal oxidation at 700 degrees C enhances the in vitro osteoblastic cell attachment compared to the thermal oxidation at 500 degrees C.


Assuntos
Materiais Biocompatíveis/química , Titânio/química , Ligas/química , Adesão Celular , Células Cultivadas , Corrosão , Temperatura Alta , Humanos , Técnicas In Vitro , Teste de Materiais , Microscopia Eletrônica de Varredura , Osteoblastos/citologia , Oxirredução , Próteses e Implantes , Propriedades de Superfície , Difração de Raios X
14.
J Orthop Res ; 14(4): 663-7, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8764878

RESUMO

Experiments were performed on 120 rabbits to compare the probability of infection after bone surgery without an implant, with polymethylmethacrylate, and with autografts. Staphylococcus aureus phage type 94/96, isolated from a human osteomyelitis, was instilled into the intramedullar cavity after reaming of the femoral canal and before insertion of the implant. The different 50% infective doses were determined for each of the groups for comparative purposes. The bacterial concentrations required to produce infection in femora without an implant were two times less than those necessary in femora implanted with polymethylmethacrylate. The bone graft required bacterial concentrations nine times less than those necessary to infect femora containing polymethylmethacrylate and four times less than those required to infect femora without an implant. The results presented here confirm that the susceptibility to infection in orthopaedic surgery is not only material dependent but also bacteria dependent.


Assuntos
Osso e Ossos/microbiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus , Infecção dos Ferimentos , Animais , Técnicas Bacteriológicas , Transplante Ósseo , Humanos , Masculino , Ácidos Polimetacrílicos , Próteses e Implantes , Coelhos , Transplante Autólogo , Cicatrização/fisiologia
15.
J Orthop Res ; 16(6): 650-3, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9877387

RESUMO

To investigate the effect of 25-OH-vitamin D supplements (calcidiol) on fracture healing in the elderly, an experimental model with 15 18-month-old female Wistar rats was designed. An experimental fracture in the middle third of both femora of each rat was made. Then the rats were randomly assigned to two groups: one group was subcutaneously treated with 25-OH-vitamin D during all healing processes, and the other group (the control group) was not. After 5 weeks of healing, the animals were killed and both femora were extracted. Blood samples were collected before fracture and at death to determine the levels of 25-OH-vitamin D. All bones that were extracted were subjected to a torsion test to assess healing; a significantly greater maximum shear force before failure was supported in the treated group (p < 0.01). Moreover, a positive correlation (p < 0.01; r=0.55) was found between blood levels of 25-OH-vitamin D at death and the mechanical strength of the callus. Thus, the administration of 25-OH-vitamin D after the experimental fracture significantly improved the mechanical strength of the fractured bone. If similar results are found in the human, then treatment with 25-OH-vitamin D after the occurrence of a fracture would be a good way to improve fracture healing in the elderly.


Assuntos
Calcifediol/farmacologia , Consolidação da Fratura/efeitos dos fármacos , Envelhecimento/fisiologia , Animais , Fenômenos Biomecânicos , Calcifediol/sangue , Feminino , Ratos , Ratos Wistar
16.
J Bone Joint Surg Am ; 74(8): 1119-29, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1400540

RESUMO

Between 1971 and 1979, 680 low-friction arthroplasties of the hip were performed in 598 patients. The average duration of follow-up was twelve years and eight months. Sixty-one acetabular cups had loosening as seen on roentgenograms eighteen years postoperatively, resulting in a total cumulative probability of loosening of 19 per cent, according to survivorship analysis. In twenty-nine cups, the loosening appeared within ten years after the operation (early loosening) and in thirty-two, more than ten years after the operation (late loosening). Early loosening was associated with deficient structure of the bone of the acetabulum, a previous congenital dislocation of the hip, acetabular fracture, or acetabular protrusion in all instances (p < 0.01). Late loosening was associated with the depth of acetabular wear. Of the thirty-two cups that had more than two millimeters of wear, eighteen (56 per cent) had loosening on the roentgenograms (p < 0.001). In hips that had early loosening, migration was the most frequent finding, and its rate of progression was higher than in hips that had late loosening (p < 0.001). In late loosening, a complete bone-cement radiolucency of more than two millimeters was the most frequent finding. Clinical failure was seen in twenty-two (76 per cent) of the twenty-nine cups that loosened early and in nine (28 per cent) of the thirty-two cups that loosened late. The probability of extensive resorption of bone necessitates close observation of patients who have early loosening, while a reasonable period of observation is possible for those who have late loosening.


Assuntos
Acetábulo/patologia , Prótese de Quadril/efeitos adversos , Acetábulo/lesões , Adulto , Idoso , Reabsorção Óssea/etiologia , Feminino , Seguimentos , Luxação Congênita de Quadril/complicações , Fraturas do Quadril/complicações , Articulação do Quadril/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Falha de Prótese , Radiografia , Fatores de Tempo
17.
J Bone Joint Surg Am ; 79(9): 1373-80, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9314400

RESUMO

We analyzed the progression of radiolucent lines around the acetabular cup after 452 Charnley low-friction arthroplasties that had been performed in 392 patients between 1971 and 1976. The average duration of follow-up was twenty years (range, eleven to twenty-five years) for the 442 hips (382 patients) that had the original component in place at ten years. The demarcation of the bone-cement interface was classified according to the system of Hodgkinson et al. We sought to determine if there was a relationship between the progression of the radiolucent line and the age, gender, and weight of the patient; the level of activity; the preoperative diagnosis; or the amount of wear of the acetabular cup. The demarcation increased over time in 138 (31 per cent) of the 452 hips. Radiographs made at the time of the latest follow-up showed migration of eleven (5 per cent) of the 233 acetabular cups with no demarcation on the initial postoperative radiograph, eighteen (11 per cent) of the 167 cups with type-1 demarcation, twelve (35 per cent) of the thirty-four cups with type-2 demarcation, and thirteen of the eighteen cups with type-3 demarcation. Preoperative acetabular protrusion, inflammatory arthritis, and severe acetabular dysplasia as well as a previous operation were associated with the extent of the radiolucent line on the most recent radiograph (p < or = 0.05 for all). A high level of activity and more than two millimeters of wear of the acetabular cup also were related to the progression of the radiolucent line (p = 0.0004 and p < 0.0001, respectively). Kaplan-Meier survivorship analysis demonstrated that the greater the demarcation on the initial postoperative radiograph, the greater the risk of migration (p < 0.0001, Mantel-Cox test). Our data suggest that, after a Charnley low-friction arthroplasty, any cemented cup, even one with the least amount of demarcation (types 0 and 1), can migrate. As the type of the initial postoperative demarcation increases, so does the risk of migration of the cup, particularly when there is loss of the acetabular bone stock.


Assuntos
Acetábulo/diagnóstico por imagem , Prótese de Quadril , Falha de Prótese , Adolescente , Adulto , Idoso , Cimentação , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Reoperação , Análise de Sobrevida
18.
Spine (Phila Pa 1976) ; 18(7): 918-22, 1993 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-8316894

RESUMO

To assess the existence of disturbances in proprioception in adolescent idiopathic scoliosis and an hypothetical relationship with generalized joint laxity, a blind comparative study of short-latency somatosensory evoked potentials by posterior tibial nerve stimulation was designed. One hundred twenty-one subjects were included: fifty-two were diagnosed as having adolescent idiopathic scoliosis, thirty-two met criteria for generalized joint laxity, twenty-one had curvatures with Cobb angles less than 10, and twenty-eight were matched control subjects; twelve subjects were initially seen with both adolescent idiopathic scoliosis and generalized joint laxity. We failed to find alterations in somatosensory evoked potentials in patients with adolescent idiopathic scoliosis that could suggest proprioceptive disturbances as a causative factor; however, in a subgroup of thoracolumbar curvatures we were able to demonstrate a functional alteration in somatosensory evoked potentials that could represent a neurologic basis for some curves considered as idiopathic thus far; generalized joint laxity seems to be implicated in this situation.


Assuntos
Potenciais Somatossensoriais Evocados/fisiologia , Instabilidade Articular/complicações , Propriocepção/fisiologia , Escoliose/complicações , Adolescente , Feminino , Humanos , Instabilidade Articular/etiologia , Instabilidade Articular/fisiopatologia , Masculino , Escoliose/etiologia , Escoliose/fisiopatologia , Nervo Tibial/fisiologia
19.
J Bone Joint Surg Br ; 76(5): 717-20, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8083257

RESUMO

We implanted cylinders of cobalt-chrome or titanium, with smooth or porous surfaces, into rabbit bones which had been inoculated with suspensions of Staphylococcus aureus in various doses. The bacterial concentration required to produce infection of porous-coated titanium implants was 2.5 times smaller than that necessary to infect implants with polished surfaces. Porous-coated cobalt-chromium implants required bacterial concentrations that were 40 times smaller than those needed to infect implants with polished surfaces, and 15 times smaller than those required to infect porous-coated titanium implants. The other advantages and disadvantages of the various implants, such as improved osseointegration, larger ion-release surfaces, surface wear and relative stiffness, must be weighed against the higher infection rates in the porous-coated implants, and particularly in the cobalt-chromium implants.


Assuntos
Ligas de Cromo , Prótese de Quadril/efeitos adversos , Próteses e Implantes , Infecções Relacionadas à Prótese/microbiologia , Infecções Estafilocócicas/microbiologia , Titânio , Animais , Método Duplo-Cego , Contaminação de Equipamentos , Reações Falso-Negativas , Reações Falso-Positivas , Masculino , Modelos Biológicos , Desenho de Prótese , Infecções Relacionadas à Prótese/epidemiologia , Coelhos , Distribuição Aleatória , Reprodutibilidade dos Testes , Infecções Estafilocócicas/epidemiologia , Propriedades de Superfície
20.
J Bone Joint Surg Br ; 82(6): 856-63, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10990311

RESUMO

We performed a prospective, randomised study on 110 patients more than 50 years old with fractures of the distal radius to compare the outcome of conservative treatment with that using remodellable bone cement (Norian skeletal repair system, SRS) and immobilisation in a cast for two weeks. Patients treated with SRS had less pain and earlier restoration of movement and grip strength. The results at one year were satisfactory in 81.54% of the SRS patients and 55.55% of the control group. The rates of malunion were 18.2% and 41.8%, respectively. There was a significant relationship between the functional and radiological results. Soft-tissue extrusion was present initially in 69.1% of the SRS patients; most deposits disappeared progressively, but persisted in 32.73% at one year. We conclude that the injection of a remodellable bone cement into the trabecular defect of fractures of the distal radius provides a better clinical and radiological result than conventional treatment.


Assuntos
Cimentos Ósseos/uso terapêutico , Fosfatos de Cálcio/uso terapêutico , Fratura de Colles/terapia , Osseointegração , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Moldes Cirúrgicos , Fratura de Colles/complicações , Fratura de Colles/diagnóstico por imagem , Fratura de Colles/fisiopatologia , Terapia Combinada , Feminino , Força da Mão , Humanos , Injeções , Masculino , Manipulação Ortopédica , Pessoa de Meia-Idade , Dor/etiologia , Estudos Prospectivos , Radiografia , Amplitude de Movimento Articular , Tração , Resultado do Tratamento
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