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1.
New Microbiol ; 43(3)2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32596741

RESUMO

Prosthetic joint infections (PJI) represent the most serious cause of prosthetic joint loosening, with high impact on patient life and health economics. Although not entirely reliable, the cultivation of intraoperative prosthetic tissue or synovial fluid remains the gold standard for determining the cause of PJI. Therefore, molecular methods are increasingly being introduced. The aim of this study was to optimize and assess an alternative molecular approach with the use of bacteriophage K for more rapid and specific detection of staphylococci in sonicate fluid (SF) of PJI. The best results with the method were obtained after 180 min of sample incubation with 104 PFU/mL of bacteriophage K. DNA isolation prior to qPCR analysis was confirmed unnecessary, while chloroform addition to samples after incubation with bacteriophage K improved bacterial detection by 100×. The method had a limit of detection of 6.8 × 102 CFU/mL and was found suitable for the detection of staphylococci in SF of removed prosthetic joints, giving results comparable to standard microbiological methods in just four hours. The optimized method was found fit for the purpose, offering potential advantages over the use of molecular detection methods to detect bacterial DNA.

2.
Growth Factors ; 36(5-6): 263-273, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30764675

RESUMO

Paired cartilage and subchondral bone of subjects with no clinical history of joint disorders were analyzed to determine whether antioxidant enzymes, inflammatory cytokines and growth factors can be linked to a pre-osteoarthritis. Tissue explants were phenotyped according to Osteoarthritis Research Society International grading and micro-computed tomography, and also screened for the expression of several markers using quantitative polymerase chain reaction. The expression of these same genes was measured in SW1353 cells treated with hydrogen peroxide, to gain insight into the pathways involved with oxidative stress responses. Vascular endothelial growth factor A (VEGF-A) was up-regulated in the cartilage samples that showed early cartilage or bone degeneration. Oxidative stress in chondrocytes provoked up-regulation of interleukin-1ß, interleukin-6, aggrecan, and SRY-box containing gene 9. Our results confirm the hitherto evidence of the deteriorating effects of the oxidative stress on cartilage and suggest the link between VEGF-A and pre-osteoarthritis.


Assuntos
Osso e Ossos/metabolismo , Cartilagem/metabolismo , Osteoartrite/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Idoso , Agrecanas/genética , Agrecanas/metabolismo , Osso e Ossos/patologia , Cartilagem/patologia , Linhagem Celular Tumoral , Células Cultivadas , Feminino , Humanos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/genética
3.
New Microbiol ; 40(3): 190-196, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28675248

RESUMO

Staphylococcus spp. accounts for up to two thirds of all microorganisms causing prosthetic joint infections, with Staphylococcus aureus and Staphylococcus epidermidis being the major cause. The present study describes a diagnostic model to detect staphylococci using a specific bacteriophage and bioluminescence detection, exploring the possibility of its use on sonicate fluid of orthopaedic artificial joints. Intracellular adenosine-5'-triphosphate release by bacteriophage mediated lysis of staphylococci was assessed to determine optimal parameters for detection. With the optimized method, a limit of detection of around 103 CFU/mL was obtained after incubation with bacteriophage for 2 h. Importantly, sonicate fluid did not prevent the ability of bacteriophage to infect bacteria and all simulated infected sonicate fluid as well as 6 clinical samples with microbiologically proven staphylococcal infection were detected as positive. The total assay took approximately 4 h. Collectively, the results indicate that the developed method promises a rapid, inexpensive and specific diagnostic detection of staphylococci in sonicate fluid of infected prosthetic joints. In addition, the unlimited pool of different existing bacteriophages, with different specificity for all kind of bacteria gives the opportunity for further investigations, improvements of the current model and implementation in other medical fields for the purpose of the establishment of a rapid diagnosis.


Assuntos
Prótese Articular/microbiologia , Infecções Relacionadas à Prótese/microbiologia , Staphylococcus/isolamento & purificação , Trifosfato de Adenosina/metabolismo , Prótese de Quadril/microbiologia , Humanos , Prótese do Joelho/microbiologia , Medições Luminescentes/métodos , Projetos Piloto , Falha de Prótese , Sonicação , Fagos de Staphylococcus
4.
Hip Int ; 26(3): 237-43, 2016 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-27102552

RESUMO

PURPOSE: The purpose of this study was to compare the results of revision total hip arthroplasty after fracture of primary ceramic components using different type of revision bearing surfaces. METHODS: We analysed the results of 16 patients with a follow-up more than 3 years after first revision. 6 were revised to ceramic-on-ceramic (CoC) bearing, 9 to metal-on-polyethylene (MoP) and 1 to ceramic-on-cross-linked polyethylene (CoXLP) bearing. RESULTS: The mean follow-up was 87 months. Patients with revision to CoC had higher Harris Hip Score (HHS) of 89 points in comparison to the patients with revision to MoP with 84 points. Radiographic examinations revealed visible eccentric polyethylene wear with osteolysis in 3 out of 9 patients revised to MoP. There were no detrimental x-ray changes in patients revised to CoC components. CONCLUSIONS: We consider CoC as the best option at revision operation for ceramic component fracture.


Assuntos
Óxido de Alumínio/efeitos adversos , Artroplastia de Quadril/efeitos adversos , Prótese de Quadril , Fraturas Periprotéticas/cirurgia , Reoperação/métodos , Idoso , Artroplastia de Quadril/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas Periprotéticas/diagnóstico por imagem , Desenho de Prótese , Sistema de Registros , Estudos Retrospectivos , Medição de Risco , Fatores de Tempo , Resultado do Tratamento , Suporte de Carga
5.
Int Orthop ; 39(5): 975-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25326855

RESUMO

PURPOSE: Prosthetic joint infection (PJI) is a devastating complication of total joint arthroplasty. No single laboratory test has perfect sensitivity and specificity; however, culture of periprosthetic tissue is the standard method for PJI diagnosis. Interpretation of positive culture results in PJI diagnostics can be difficult due to the possibility of contamination with microorganisms originating from skin micro flora. Criteria have been established to aid in distinguishing pathogen from contaminant for culture results. A similar criterion has not however been established for polymerase chain reaction (PCR) analysis, which is in part responsible for confusion about the reliability of PCR for PJI diagnostics. The aim of our study was to establish a criterion for interpretation of broad range (BR) PCR results in PJI diagnostics. METHODS: Samples of periprosthetic tissue were retrieved from 100 patients with joint prosthesis failure and analysed with BR-PCR. The results of BR-PCR were evaluated based on the number of samples of periprosthetic tissue with the same bacterial species. RESULTS: The sensitivity (87.5%) of BR-PCR was highest if the same species was present in at least one sample, although this criterion also resulted in the lowest specificity (92.1%). The sensitivity decreased (83.2%), although without a statistically significant difference, if the same species was present in two or more samples but, at the same time, specificity increased (100%), with a statistically significant difference. CONCLUSIONS: For diagnostics of PJI with BR-PCR the criterion of the same bacterial species in at least two specimens of periprosthetic tissue from the same patient should be used for interpretation of positive results.


Assuntos
Prótese Articular/microbiologia , Reação em Cadeia da Polimerase/métodos , Infecções Relacionadas à Prótese/microbiologia , Idoso , Idoso de 80 Anos ou mais , Artroplastia , Artroplastia de Substituição , Infecções Bacterianas/microbiologia , Feminino , Humanos , Período Intraoperatório , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Falha de Prótese , Infecções Relacionadas à Prótese/diagnóstico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
J Orthop Res ; 32(9): 1241-6, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24897980

RESUMO

Aseptic loosening of hip replacements is driven by the macrophage reaction to wear particles. The extent of particle-induced macrophage activation is dependent on the state of macrophage polarization, which is dictated by the local cytokine microenvironment. The aim of the study was to characterize cytokine microenvironment surrounding failed, loose hip replacements with an emphasis on identification of cytokines that regulate macrophage polarization. Using qRT-PCR, the expression of interferon gamma (IFN-γ), interleukin-4 (IL-4), granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-13, and IL-17A was low and similar to the expression in control synovial tissues of patients undergoing primary hip replacement. Using immunostaining, no definite source of IFN-γ or IL-4 could be identified. IL-17A positive cells, identified as mast cells by double staining, were detected but their number was significantly reduced in interface tissues compared to the controls. Significant up-regulation of IL-10, M-CSF, IL-8, CCL2-4, CXCL9-10, CCL22, TRAP, cathepsin K, and down regulation of OPG was seen in the interface tissues, while expression of TNF-α, IL-1ß, and CD206 were similar between the conditions. It is concluded that at the time of the revision surgery the peri-implant macrophage phenotype has both M1 and M2 characteristics and that the phenotype is regulated by other local and systemic factors than traditional macrophage polarizing cytokines.


Assuntos
Artroplastia de Quadril/instrumentação , Polaridade Celular/fisiologia , Citocinas/fisiologia , Prótese de Quadril , Macrófagos/patologia , Falha de Prótese , Idoso , Idoso de 80 Anos ou mais , Microambiente Celular/fisiologia , Feminino , Articulação do Quadril/patologia , Humanos , Macrófagos/fisiologia , Masculino , Pessoa de Meia-Idade , Osteoartrite do Quadril/cirurgia , Reoperação , Estudos Retrospectivos , Membrana Sinovial/patologia
7.
J Mech Behav Biomed Mater ; 34: 243-52, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24608233

RESUMO

BACKGROUND AND PURPOSE: Metal-on-metal (MoM) bearings were introduced as an alternative to conventional metal-on-polyethylene (MoP) bearings to reduce the wear and to increase the survival of hip prostheses. The goal of the present study was to compare tribological properties and to evaluate periprosthetic tissue reaction in two identical groups of prostheses differing only in the type of bearings. PATIENTS AND METHODS: At revision operations 26 MoM and 12 MoP bearing components and perisprosthetic tissue samples were collected. Prosthetic components were used to assess wear damage, linear and volumetric wear and roughness. Periprosthetic tissue samples were used for histological as well as immunohistochemical analysis and isolation and characterization of wear particles. RESULTS: The mean linear wear rate in the MoM group was 2.34 (SD 1.93)µm/year, significantly lower than the value in the MoP group, 11.52 (SD 7.82)µm/year. Significantly lower was also the volumetric wear, 0.19 (SD 0.32)mm(3)/year for MoM compared to 0.98 (SD 0.78)mm(3)/year for MoP. In both groups the main wear mode was abrasive wear. Histological results for MoM group indicate more lymphocyte dominated periprosthetic tissue reaction compared to MoP group. The mean size of polyethylene particles in the MoP group was 0.21 (SD 0.44)µm. In the MoM nanosized CoCrMo particles were identified. The characterization of metal particles was complex and required special attention in terms of instrumentation (field emission scanning electron microscopy in back-scattered mode); otherwise it was difficult to distinguish metal particles from other particles in the tissue. CONCLUSIONS: Despite a significantly lower wear and, consequently, smaller load of periprosthetic tissue with wear particles in the MoM group, the tissue reaction was similar, if not more intense than in the MoP group.


Assuntos
Artroplastia de Quadril , Fêmur/citologia , Prótese de Quadril , Teste de Materiais , Metais , Polietileno , Fêmur/cirurgia , Humanos , Falha de Prótese , Propriedades de Superfície
8.
J Mater Sci Mater Med ; 25(4): 1099-114, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24452270

RESUMO

Samples of the quaternary Ti-20Nb-10Zr-5Ta alloy were immersed in Hanks' simulated physiological solution and in minimum essential medium (MEM) for 25 days. Samples of Ti metal served as controls. During immersion, the concentration of ions dissolved in MEM was measured by inductively coupled plasma mass spectrometry, while at the end of the experiment the composition of the surface layers was analyzed by X-ray photoelectron spectroscopy, and their morphology by scanning electron microscopy equipped for chemical analysis. The surface layer formed during immersion was comprised primarily of TiO2 but contained oxides of alloying elements as well. The degree of oxidation differed for different metal cations; while titanium achieved the highest valency, tantalum remained as the metal or is oxidized to its sub-oxides. Calcium phosphate was formed in both solutions, while formation of organic-related species was observed only in MEM. Dissolution of titanium ions was similar for metal and alloy. Among alloying elements, zirconium dissolved in the largest quantity. The long-term effects of alloy implanted in the recipient's body were investigated in MEM, using two types of human cells-an osteoblast-like cell line and immortalized pulmonary fibroblasts. The in vitro biocompatibility of the quaternary alloy was similar to that of titanium, since no detrimental effects on cell survival, induction of apoptosis, delay of growth, or change in alkaline phosphatase activity were observed on incubation in MEM.


Assuntos
Ligas/química , Materiais Biocompatíveis/química , Nióbio/química , Tantálio/química , Titânio/química , Zircônio/química , Fosfatase Alcalina/metabolismo , Ligas/toxicidade , Apoptose/efeitos dos fármacos , Materiais Biocompatíveis/toxicidade , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Soluções Isotônicas , Teste de Materiais , Nióbio/toxicidade , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/enzimologia , Espectroscopia Fotoeletrônica , Solubilidade , Propriedades de Superfície , Tantálio/toxicidade , Titânio/toxicidade , Zircônio/toxicidade
9.
Acta Orthop ; 85(1): 97-101, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24359029

RESUMO

BACKGROUND AND PURPOSE: Dupuytren's disease (DD) is a benign fibroproliferative process of the palmar aponeurosis showing similarities to wound healing. Communication of cells involved in wound healing is mediated by the composition of gap junction (GJ) proteins. We investigated the expression of 3 GJ proteins, connexins 26, 30, and 43 (Cx26, Cx30, and Cx43) in DD. PATIENTS AND METHODS: Fragments of Dupuytren's tissue from 31 patients (mean age 56 (30-76) years, 24 male) were analyzed immunohistochemically and compared to control tissue for expression of the GJ proteins Cx26, Cx30, and Cx43 and also alfa-smooth muscle actin (α-SMA). RESULTS: 14 of 31 samples could be attributed to the involutional phase (α-SMA positive) whereas 17 samples had to be considered cords in the residual phase (α-SMA negative). Expression of Cx26 and Cx43 was seen in 12 of the 14 samples from the involutional phase, and Cx30 was seen in 7 of these. Only 4 of the 17 samples from the residual phase showed any Cx, and there was none in the controls. INTERPRETATION: The high expression of GJ proteins Cx26, Cx30, and Cx43 in α-SMA positive myofibroblast-rich nodules, which are characteristic of the active involutional phase of DD, suggests that connexins could be a novel treatment target for the treatment of DD.


Assuntos
Conexinas/metabolismo , Contratura de Dupuytren/metabolismo , Actinas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Conexina 26 , Conexina 30 , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
10.
Acta Orthop ; 84(4): 420-5, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23992143

RESUMO

BACKGROUND AND PURPOSE: Dupuytren's disease (DD) is a benign fibroproliferative process that affects the palmar fascia. The pathology of DD shows similarities with wound healing and tumor growth; hypoxia and angiogenesis play important roles in both. We investigated the role of angiogenic proteins in DD. PATIENTS AND METHODS: The expression of vascular endothelial growth factor (VEGF), its receptors vascular endothelial growth factor receptor 1 (VEGFR1) and vascular endothelial growth factor receptor 2 (VEGFR2), hypoxia-inducible factor alfa (HIF-1α), and alfa-smooth muscle actin (α-SMA) were analyzed immunohistochemically in fragments of excised Dupuytren's tissue from 32 patients. We compared these values to values for expression in a control group. RESULTS: 15 of 32 samples could be attributed to the involutional phase (α-SMA positive), whereas 17 samples were considered to be cords at the residual phase (α-SMA negative). In the involutional phase, the HIF-1α and VEGFR2 expression was statistically significantly higher than in the residual phase and in the controls. INTERPRETATION: Both the VEGFR2 receptor and HIF-1α were expressed in α-SMA positive myofibroblast-rich nodules with characteristics of DD in the active involutional phase. Thus, hypoxia and (subsequently) angiogenesis may have a role in the pathophysiology of DD.


Assuntos
Contratura de Dupuytren/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neovascularização Patológica/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade
11.
FEMS Microbiol Lett ; 343(1): 42-8, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23480104

RESUMO

Diagnosis of prosthetic joint infection with culture technique can be problematic since the causative agent(s) are not possible to cultivate in all cases. Molecular methods had been evaluated in many studies but their inclusion in routine diagnostics is still controversial. The purpose of our prospective study was to compare the diagnostic accuracy of broad-range (BR)-PCR and culture technique. Intraoperative samples of periprosthetic tissue were retrieved in 67 patients undergoing revision arthroplasty. Samples were analyzed with culture technique, immunohistochemistry and BR 16S rRNA gene PCR. Bacteria in PCR-positive samples were identified using two different methods: direct sequencing of PCR products and specific TaqMan assays. In 63 cases, full concordance was found between BR-PCR and culture technique. Specific TaqMan assays failed to identify bacteria in four culture- and BR-PCR-positive cases and therefore had a lower sensitivity in comparison with BR-PCR. Molecular methods detected bacteria with the same accuracy as culture; however, identification of bacteria was inferior to culture. Further development of species-recognition techniques is required to improve identification of causative microorganisms.


Assuntos
Bactérias/isolamento & purificação , Infecções Bacterianas/diagnóstico , Técnicas Bacteriológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Osteoartrite/diagnóstico , Infecções Relacionadas à Prótese/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Bactérias/classificação , Bactérias/genética , Infecções Bacterianas/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/microbiologia , Reação em Cadeia da Polimerase/métodos , Estudos Prospectivos , Infecções Relacionadas à Prótese/microbiologia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Sensibilidade e Especificidade
12.
Arch Oral Biol ; 58(7): 788-95, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23411402

RESUMO

OBJECTIVES: Difference in phenotypes of sensory neurons innervating dental pulp or gingivomucosa may be responsible for intense pain sensations in pulpitis in contrast to relatively painless chronic periodontitis. Therefore, we classified these neurons according to their size and two neurochemical characteristics of nociceptors, their TrkA expression and isolectin IB4 binding. DESIGN: In rats (n=6) fluorescent tracers Fluorogold and TrueBlue were simultaneously applied into the standard-sized tooth cavity and nearby gingival sulcus, respectively. After the fluorescence on paraffin trigeminal ganglia (TG) sections was identified and photographed, immunohistochemistry for TrkA expression and IB4 binding was performed on the same sections. RESULTS: The average sizes of TG neurons projecting to the gingivomucosa and dental pulp were 894±441µm(2) and 1012±381µm(2), respectively. The proportions of small-sized gingival and pulpal neurons were 14% and 5%, respectively (p<0.05). The proportions of TrkA-positive neurons among all gingival or pulpal neurons were 76% and 86%, respectively (p<0.05). Among all gingival or pulpal neurons the proportions of IB4-positive neurons were 46% and 3% (p<0.001), respectively, and the majority of them were small-medium sized. CONCLUSIONS: Dental pulp and gingivomucosa are richly innervated by nociceptive TrkA-expressing neurons. However, while great majority of pulpal neurons are larger NGF-dependent A-fibre nociceptors without affinity to bind IB4, almost half of the gingival neurons are smaller IB4 binding C-fibre nociceptors. The difference in phenotype of sensory neurons might partially explain the different sensitivity of both tissues during normal and pathological conditions.


Assuntos
Polpa Dentária/inervação , Gengiva/inervação , Mucosa Bucal/inervação , Nociceptores/metabolismo , Receptor trkA/metabolismo , Gânglio Trigeminal/citologia , Animais , Polpa Dentária/metabolismo , Feminino , Gengiva/metabolismo , Imuno-Histoquímica , Lectinas de Plantas/imunologia , Ratos , Ratos Wistar , Gânglio Trigeminal/metabolismo
13.
Virchows Arch ; 462(3): 315-21, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23358691

RESUMO

Malignant pleural mesothelioma is an incurable cancer strongly associated with asbestos exposure and characterised by poor response to treatment. The inhibitor-of-apoptosis protein family member survivin is involved in apoptosis and proliferation and is expressed in cancer cells only. The aims of the present study were to elucidate whether survivin expression is associated with tumour cell apoptosis and proliferation and to assess the prognostic and predictive value of survivin expression in malignant pleural mesothelioma. Archival pleural mesothelioma tissue samples from 101 patients were immunohistochemically analysed for nuclear expression of survivin, for proliferation with the use of Ki-67 as marker and for apoptosis using active caspase-3 as a marker. Staining results and clinical data were included in a survival analysis. Survivin was highly expressed in tumour cell nuclei in all samples and this correlated positively with both apoptosis and proliferation, but did not have a significant prognostic value. We found significantly higher survivin expression in patients who responded to chemotherapy compared to patients with progressive disease. Survivin expression might contribute to treatment response prediction, but survivin expression in malignant pleural mesothelioma did not have prognostic significance.


Assuntos
Biomarcadores Tumorais/análise , Proteínas Inibidoras de Apoptose/biossíntese , Mesotelioma/metabolismo , Neoplasias Pleurais/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imuno-Histoquímica , Proteínas Inibidoras de Apoptose/análise , Masculino , Mesotelioma/mortalidade , Pessoa de Meia-Idade , Neoplasias Pleurais/mortalidade , Prognóstico , Modelos de Riscos Proporcionais , Survivina
14.
J Mater Sci Mater Med ; 24(3): 555-71, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23250579

RESUMO

The behaviour of CoCrMo alloy has been studied in two simulated physiological solutions-NaCl and Hanks' solutions-each containing the sodium salt of hyaluronic acid. Hyaluronic acid is a component of synovial joint fluid, so the behaviour of orthopaedic alloys in its presence needs to be assessed. Electrochemical methods, X-ray photoelectron spectroscopy and scanning electron microscopy have been used to analyse the composition, thickness and morphology of any layers formed on the alloy. The addition of hyaluronic acid shifts the corrosion potential and increases the value of polarization resistance. The presence of hyaluronic acid in simulated Hanks' physiological solution stimulates the formation of a calcium phosphate layer, opening up the possibility for tailoring the surface properties of CoCrMo alloy. The viability of human osteoblast-like was determined using the Alamar(®) Blue Assay, while the osteogenic activity was evaluated by alkaline phosphatase activity. The presence of hyaluronic acid affects the alkaline phosphatase activity.


Assuntos
Ligas , Fosfatos de Cálcio/química , Ácido Hialurônico/química , Fosfatase Alcalina/metabolismo , Linhagem Celular Tumoral , Cromo/química , Cobalto/química , Técnicas Eletroquímicas , Humanos , Microscopia Eletrônica de Varredura , Molibdênio/química , Espectroscopia Fotoeletrônica
15.
J Cancer Res Clin Oncol ; 137(11): 1641-51, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21861135

RESUMO

PURPOSE: Malignant pleural mesothelioma is an incurable, asbestos-associated cancer. Its incidence is rapidly increasing and survival remains short. Apoptosis deregulation is an important feature of cancer and survivin, a member of the inhibitor-of-apoptosis-protein family encoded by the BIRC5 gene, has been suggested to have a role in the development and progression of several cancers. Genetic variability, in particular single nucleotide polymorphisms in the BIRC5 promoter, may affect the protein's expression levels. The aim of our study was to elucidate the effects of BIRC5 promoter single nucleotide polymorphisms on survivin expression, patient survival and age at diagnosis in malignant pleural mesothelioma. METHODS: Archival mesothelioma samples from 101 Slovenian patients were immunohistochemically analysed for survivin expression. DNA was extracted from tumour samples and genotyped for three BIRC5 promoter single nucleotide polymorphisms (-31G > C, -241C > T and -625G > C). Genotypes were associated with nuclear survivin expression. Nuclear survivin expression, genotypes, haplotypes, histological type, gender and asbestos exposure were included in univariate Cox survival analyses. RESULTS: Survivin expression was detected in both tumour cell nuclei and cytoplasms in all analysed samples. No association between BIRC5 promoter polymorphism genotypes or haplotypes and nuclear survivin expression was found. Polymorphism -241C > T affected patients' age at diagnosis. Survival analysis confirmed that younger age at diagnosis and epitheloid histological type improved survival, but no significant effects of nuclear survivin expression or genotype/haplotype on overall survival were observed. CONCLUSION: Our findings indicate no relationship between BIRC5 genotypes and survivin expression or overall survival in mesothelioma patients. We observed that BIRC5 -241C > T polymorphism had a significant effect on patient age at diagnosis.


Assuntos
Núcleo Celular/metabolismo , Proteínas Inibidoras de Apoptose/genética , Mesotelioma/genética , Neoplasias Pleurais/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Genótipo , Haplótipos , Humanos , Proteínas Inibidoras de Apoptose/metabolismo , Mesotelioma/metabolismo , Mesotelioma/patologia , Neoplasias Pleurais/metabolismo , Neoplasias Pleurais/patologia , Análise de Sobrevida , Survivina
16.
Am J Orthod Dentofacial Orthop ; 139(4): e323-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21457838

RESUMO

INTRODUCTION: Histamine (H(1)) receptor antagonists are widely used drugs for treatment of allergic conditions. Although histamine was shown to be involved in bone remodeling, the aim of this study was to determine the effects of cetirizine, an H(1) receptor antagonist, on bone modeling processes during orthodontic tooth movement. METHODS: We used 3 groups of Wistar rats: control group (n = 16), appliance-only group (n = 16) and cetirizine group (n = 16). Each animal of the last 2 groups was fitted with a superelastic closed-coil spring appliance and treated daily with saline solution or cetirizine. Tooth movement was measured weekly from day 0 to day 42. Gene expression levels for bone turnover markers cathepsin K and osteocalcin were determined by means of real-time polymerase chain reaction. Histologic samples were analyzed by using histomorphometry. RESULTS: Cetirizine decreased the amount of tooth movement from day 28 onward (P <0.01), and it also decreased osteoclast volume density (P <0.001). An increase in alveolar bone volume density was observed in the cetirizine group (P <0.01) compared with the appliance-only group. No statistically significant differences were observed in osteoclast activity, osteoblast volume density, and osteoblast activity between the cetirizine and the appliance-only groups. CONCLUSIONS: Cetirizine influences bone modeling, mainly by inhibiting bone resorption. Therefore, H(1) receptor antagonists could interfere with orthodontic treatment.


Assuntos
Remodelação Óssea/efeitos dos fármacos , Cetirizina/farmacologia , Antagonistas dos Receptores Histamínicos H1/farmacologia , Técnicas de Movimentação Dentária , Processo Alveolar/efeitos dos fármacos , Animais , Densidade Óssea/efeitos dos fármacos , Reabsorção Óssea/patologia , Reabsorção Óssea/prevenção & controle , Catepsina K/análise , Contagem de Células , Masculino , Maxila/efeitos dos fármacos , Maxila/patologia , Fios Ortodônticos , Osteoblastos/efeitos dos fármacos , Osteocalcina/análise , Osteoclastos/efeitos dos fármacos , Ratos , Ratos Wistar , Fatores de Tempo , Técnicas de Movimentação Dentária/instrumentação
17.
J Neurooncol ; 103(3): 459-67, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20953661

RESUMO

Activation of the sonic hedgehog (SHH) signalling pathway, which is involved in the formation of a significant proportion of medulloblastomas, is characterised by up-regulation and nuclear localisation of downstream transcription factor Gli1. Our aim was to analyse Gli1 expression by immunohistochemistry in a large group of medulloblastomas, to assess possible correlations with WNT (wingless) pathway activation and poly(ADP-ribose) polymerase-1 (PARP1) expression, previously shown to be associated with SHH pathway activation in a mouse model of medulloblastoma. We analysed expression and localisation of Gli1, ß-catenin and PARP1 by immunohistochemistry in a series of 65 consecutive medulloblastomas. Gli1 was positive in 40 (61.5%) medulloblastomas, as revealed by either strong (21 cases) or mild (19 cases) nuclear reaction in more than 50% of tumour cells. Nuclear positivity for PARP1 was noted in all 65 cases, ranging from 46% to 100% (mean 80%) but was not correlated with Gli1 positivity. Gli1 was positive in 9 of 11 cases with nuclear localisation of ß-catenin, signifying concurrent activation of SHH and WNT pathways. Overall survival of patients with strong nuclear reaction to Gli1 was better compared with patients with Gli1-negative medulloblastomas. Immunohistochemical detection of Gli1 could be useful in identifying medulloblastomas with SHH pathway activation. As revealed by nuclear reaction to Gli1, the SHH pathway is activated in approximately 60% of medulloblastomas. In some medulloblastomas, both SHH and WNT appear to be activated. PARP1 is highly expressed in medulloblastomas. It might be useful as a target to increase the effectiveness of current treatment modalities.


Assuntos
Neoplasias Cerebelares/metabolismo , Meduloblastoma/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Fatores de Transcrição/metabolismo , Adolescente , Adulto , Neoplasias Cerebelares/mortalidade , Neoplasias Cerebelares/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Estimativa de Kaplan-Meier , Masculino , Meduloblastoma/mortalidade , Meduloblastoma/patologia , Pessoa de Meia-Idade , Poli(ADP-Ribose) Polimerase-1 , Adulto Jovem , Proteína GLI1 em Dedos de Zinco
18.
Radiol Oncol ; 45(1): 31-9, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22933932

RESUMO

BACKGROUND: Mast cell tumors (MCT) are the most common malignant cutaneous tumors in dogs with extremely variable biological behaviour. Different treatment approaches can be used in canine cutaneous MCT, with surgical excision being the treatment of choice. In this study, electrogene therapy (EGT) as a new therapeutic approach to canine MCTs, was established. MATERIALS AND METHODS.: Eight dogs with a total of eleven cutaneous MCTs were treated with intratumoral EGT using DNA plasmid encoding human interleukin-12 (IL-12). The local response to the therapy was evaluated by repeated measurements of tumor size and histological examination of treated tumors. A possible systemic response was assessed by determination of IL-12 and interferon- γ (IFN-γ) in patients' sera. The occurence of side effects was monitored with weekly clinical examinations of treated animals and by performing basic bloodwork, consisting of the complete bloodcount and determination of selected biochemistry parameters. RESULTS: Intratumoral EGT with IL-12 elicits significant reduction of treated tumors' size, ranging from 13% to 83% (median 50%) of the initial tumor volume. Additionally, a change in the histological structure of treated nodules was seen. There was a reduction in number of malignant mast cells and inflammatory cell infiltration of treated tumors. Systemic release of IL-12 in four patients was detected, without any noticeable local or systemic side effects. CONCLUSIONS: These data suggest that intratumoral EGT with plasmid encoding IL-12 may be useful in the treatment of canine MCTs, exerting a local antitumor effect.

19.
Neurosurgery ; 67(4): 1124-32, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20881577

RESUMO

BACKGROUND: Since precise diagnostic criteria for atypical and malignant meningiomas (AMMs) were provided for the first time in the 2000 World Health Organization (WHO) criteria, there is only sparse information about possible prognostic factors in the group of AMMs. OBJECTIVE: To evaluate the prognostic significance of various histological and clinical parameters in AMMs, with an emphasis on location, mitotic count, brain invasion, and Ki67 labeling index. METHODS: We analyzed 86 primary AMMs, 76 of which were atypical and 10 of which were malignant, diagnosed according to the 2000 WHO classification. Multivariate Cox survival analyses were performed. RESULTS: High mitotic count, brain invasion, and the parasagittal-falcine location of the tumor were significantly associated with decreased recurrence-free survival in multivariate analysis. Brain invasion was present in 25 of 37 cases in which brain tissue was identified in the tumor specimens. When brain invasion was not included in the analysis because of the limited number of cases in which it could be assessed, high mitotic count, Ki67 index >4%, the presence of macronucleoli, and parasagittal-falcine location were significant predictors of shorter recurrence-free survival. CONCLUSION: AMMs, as defined by 2000 WHO, are biologically heterogeneous. Recurrence-free survival can be further stratified by location and histological parameters, especially mitotic count, brain invasion, and Ki67 labeling index. Not only brain invasion, but also the presence or absence of brain tissue in surgical specimens should be reported, because the absence of brain invasion, when brain tissue is identified, provides very important positive prognostic information.


Assuntos
Encéfalo/patologia , Neoplasias Meníngeas , Meningioma , Índice Mitótico , Recidiva Local de Neoplasia/mortalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Antígeno Ki-67/metabolismo , Masculino , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/metabolismo , Neoplasias Meníngeas/mortalidade , Meningioma/diagnóstico , Meningioma/metabolismo , Meningioma/mortalidade , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Adulto Jovem
20.
Tumori ; 96(5): 667-73, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21302609

RESUMO

BACKGROUND AND AIM: Malignant mesothelioma is predominantly caused by asbestos exposure, although the association of Simian virus 40 in its pathogenesis is currently still under debate. Simian virus 40, a DNA rhesus monkey virus with oncogenic properties, accidentally contaminated early batches of polio vaccine in the 1960s. In the 1990s, viral sequences and proteins were discovered in several human tumors, which triggered research to find a link between Simian virus 40 and human cancers, especially malignant mesothelioma. The aim of our study was to establish an effective laboratory procedure for Simian virus 40 detection and to investigate the presence of Simian virus 40 DNA and small t antigen in mesothelioma samples from Slovenian patients. METHODS AND STUDY DESIGN: Paraffin-embedded malignant pleural mesothelioma specimens from 103 Slovenian patients were collected and used for total DNA isolation and real-time polymerase chain reaction for Simian virus 40 small t and large T DNA analysis. Special attention was devoted to primer design, good laboratory practice and polymerase chain reaction contamination prevention. Polymerase chain reaction products were sequenced and BLAST aligned. One 5 microm thick paraffin section from each patient's tissue block was stained with hematoxylin and eosin for histological typing and one for immunohistochemical detection of Simian virus 40 small t antigen using a monoclonal antibody against Simian virus 40 (Pab280). SV40-expressing Wi-38 cells were used as positive control in both PCR and immunohistochemistry. RESULTS: In real-time polymerase chain reaction analyses, only 4 samples gave products with primer pairs amplifying small t antigen and were inconsistent and poorly reproducible. BLAST alignment showed no homology with any deposited SV40 sequences. No immunopositive staining for SV40 small t antigen was found in any of the samples. CONCLUSIONS: We found no evidence of SV40 presence in tissue samples from 103 Slovenian patients with malignant pleural mesothelioma. Asbestos exposure remains the main risk factor for malignant pleural mesothelioma in Slovenia.


Assuntos
Antígenos Virais de Tumores/análise , Mesotelioma/epidemiologia , Neoplasias Pleurais/epidemiologia , Vírus 40 dos Símios/isolamento & purificação , DNA Viral/isolamento & purificação , Humanos , Imuno-Histoquímica , Mesotelioma/virologia , Neoplasias Pleurais/virologia , Reação em Cadeia da Polimerase , Vírus 40 dos Símios/genética , Vírus 40 dos Símios/imunologia , Eslovênia/epidemiologia
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