RESUMO
We retrospectively compared preoperative docetaxel, cisplatin, and fluorouracil (DCF) with cisplatin and fluorouracil (CF) in patients with esophageal cancer. The study included patients with advanced thoracic esophageal carcinoma (excluding T4 tumors) receiving preoperative chemotherapy. In the DCF group, five patients received two courses of treatment every 4 weeks, and 33 patients received three courses every 3 weeks. In the CF group, 38 patients received two courses of treatment every 4 weeks. Patients underwent curative surgery 4-5 weeks after completing chemotherapy. Patient demographic characteristics did not differ between the two study groups. The incidence of a grade 3 or 4 hematologic toxicity was significantly higher in the DCF group (33 patients) than in the CF group (five patients; P < 0.001). Curative resection was accomplished in 79% of patients in the DCF group and 66% in the CF group (P = 0.305). There were no in-hospital deaths. The incidence of perioperative complications did not differ between the groups. A grade 2 or 3 histological response was attained in a significantly higher proportion of patients in the DCF group (63%) than in the CF group (5%; P < 0.001). Progression-free survival and overall survival were significantly higher in the DCF group (P = 0.013, hazard ratio 0.473; P = 0.001, hazard ratio 0.344). In conclusion, a grade 3 or 4 hematologic toxicity was common in the DCF group but was managed by supportive therapy. Histological response rate, progression-free survival, and overall survival were significantly higher in the DCF group compared with the CF group.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma/tratamento farmacológico , Neoplasias Esofágicas/tratamento farmacológico , Adenocarcinoma/tratamento farmacológico , Idoso , Carcinoma/mortalidade , Carcinoma/patologia , Cisplatino/administração & dosagem , Intervalo Livre de Doença , Docetaxel , Esquema de Medicação , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Feminino , Fluoruracila/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Período Pré-Operatório , Estudos Retrospectivos , Taxoides/administração & dosagem , Resultado do TratamentoRESUMO
Angioimmunoblastic T-cell lymphoma (AILT) and peripheral T-cell lymphoma, unspecified (PTCL-u) are relatively frequent subtypes of T- or natural killer cell lymphoma. To characterize the structural anomalies of chromosomes associated with these disorders, we here determined chromosome copy number alterations (CNAs) and loss of heterozygosity (LOH) at >55,000 single nucleotide polymorphism loci for clinical specimens of AILT (n=40) or PTCL-u (n=33). Recurrent copy number gain common to both conditions was detected on chromosomes 8, 9 and 19, whereas common LOH was most frequent for a region of chromosome 2. AILT- or PTCL-u-specific CNAs or LOH were also identified at 21 regions, some spanning only a few hundred base pairs. We also identified prognosis-related CNAs or LOH by several approaches, including Cox's proportional hazard analysis. Among the genes that mapped to such loci, a poor prognosis was linked to overexpression of CARMA1 at 7p22 and of MYCBP2 at 13q22, with both genes being localized within regions of frequent copy number gain. For a frequent LOH region at 2q34, we also identified IKAROS family zinc-finger 2 cDNAs encoding truncated proteins. Our data indicate that AILT and PTCL-u consist of heterogeneous subgroups with distinct transforming genetic alterations.
Assuntos
Aberrações Cromossômicas , Perda de Heterozigosidade , Linfoma de Células T Periférico/genética , Linfoma de Células T/genética , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas Adaptadoras de Sinalização CARD/genética , Proteínas de Ligação a DNA/genética , Feminino , Guanilato Ciclase/genética , Humanos , Fator de Transcrição Ikaros/genética , Linfoma de Células T/mortalidade , Linfoma de Células T Periférico/mortalidade , Masculino , Pessoa de Meia-Idade , Neprilisina/análise , Prognóstico , Fatores de Transcrição/genéticaRESUMO
The prolonged survival of patients receiving surgery for esophageal cancer has led to an increased incidence of adenocarcinoma arising in the gastric tube used for reconstruction (gastric tube cancer). In patients with advanced gastric tube cancer, resection of the gastric tube should be considered, but currently available procedures are very invasive. In patients undergoing curative surgery for gastric tube cancer that has developed after reconstruction through the retrosternal route, the gastric tube is usually resected through a median sternotomy, followed by reconstruction with the colon. However, postoperative complications often occur and treatment outcomes remain poor. We developed a new surgical technique for gastric tube resection without performing a sternotomy in patients with gastric tube cancer who had previously undergone reconstruction through the retrosternal route. Our technique was used to treat two patients. Two Kirschner wires were passed subcutaneously through the anterior chest; the chest was lifted to extend the retrosternal space and secure an adequate surgical field. The stomach was separated from the surrounding tissue under videoscopic guidance. Total resection of the gastric tube was done. The retrosternal space was used to lift the jejunum. Roux-en-Y reconstruction was performed. Neither patient had suture line failure or surgical site infection. Their recovery was uneventful. Our surgical technique has several potential advantages including (i) reduced surgical stress; (ii) the ability to use the retrosternal space for reconstruction after gastric tube resection; and (iii) a reduced risk of serious infections such as osteomyelitis in patients with suture line failure. Our findings require confirmation by additional studies.
Assuntos
Gastrectomia/métodos , Neoplasias Gástricas/cirurgia , Parede Torácica/cirurgia , Cirurgia Vídeoassistida , Idoso , Humanos , MasculinoAssuntos
Leucemia Mieloide Aguda/genética , MicroRNAs/genética , Síndromes Mielodisplásicas/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adulto , Idoso , Antígenos CD34/metabolismo , Sequência de Bases , Análise por Conglomerados , Feminino , Expressão Gênica/fisiologia , Humanos , Leucemia Mieloide Aguda/patologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Síndromes Mielodisplásicas/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Homologia de Sequência do Ácido NucleicoRESUMO
BACKGROUND: The development of new surgical instruments and devices has facilitated the performance of esophagojejunostomy after total gastrectomy. However, total prevention of dehiscence of anastomoses remains difficult. We introduced a new procedure for esophagojejunostomy using a circular stapler, requiring sacrifice of only a small part of the jejunum. METHODS: The study group comprised 390 consecutive patients who underwent reconstruction by Roux-en-Y esophagojejunostomy, performed with a circular stapler, sacrificing a small part of the jejunum after total gastrectomy. We assessed anastomotic leakage and anastomotic stenosis after surgery. RESULTS: Only 2 patients (0.5%) had leakage and 4 (1.0%) had anastomotic stenosis after reconstruction. All the patients were cured by conservative therapy. CONCLUSIONS: Esophagojejunostomy performed with a circular stapler after total gastrectomy, with sacrifice of only a small part of the jejunum, is a useful and easy procedure, with a leakage rate of 0.5%.
Assuntos
Anastomose em-Y de Roux/métodos , Esôfago/cirurgia , Grampeamento Cirúrgico/métodos , Deiscência da Ferida Operatória/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Esofagostomia/métodos , Feminino , Gastrectomia , Humanos , Jejunostomia/métodos , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/cirurgiaRESUMO
OBJECTIVES: The purpose of this study was to determine the extent to which baseline clinical and radiographic features were associated with long-term outcomes in patients with temporomandibular joint disorder (TMJD). METHODS: 49 patients with unilateral radiographically proven TMJD were available in this study. Self-reported long-term (mean 96.2 months) outcomes (current joint pain, maximum mouth opening and joint noise) after TMJD treatments were assessed by questionnaire. The impact of multiple initial clinical/radiographic findings (gender, age at first visit, time interval between first visit and questionnaire survey, treatment method, disc displacement, disc morphology, disc mobility, condylar bony change and morphology of the articular eminence) on the long-term outcomes was assessed using stepwise multiple regression and logistic regression analysis. RESULTS: Patient age at the first visit was significantly correlated with current joint pain. Disc mobility and morphology of the articular eminence were significantly correlated with current range of maximal mouth opening. CONCLUSIONS: The results of this study suggest that patients who appeared symptomatic at a younger age or who initially had a fixed disc were the most likely to have recurrent or persisting clinical signs/symptoms of TMJD after 8 years.
Assuntos
Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Adolescente , Adulto , Fatores Etários , Artralgia , Doença Crônica , Dor Facial , Feminino , Humanos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/patologia , Luxações Articulares/terapia , Modelos Logísticos , Imageamento por Ressonância Magnética , Masculino , Côndilo Mandibular/diagnóstico por imagem , Côndilo Mandibular/patologia , Pessoa de Meia-Idade , Análise Multivariada , Valor Preditivo dos Testes , Prognóstico , Radiografia , Amplitude de Movimento Articular , Inquéritos e Questionários , Disco da Articulação Temporomandibular/diagnóstico por imagem , Disco da Articulação Temporomandibular/patologia , Transtornos da Articulação Temporomandibular/patologia , Transtornos da Articulação Temporomandibular/terapiaRESUMO
Gastrointestinal stromal tumours are characteristically positive for KIT (reflective of the c-KIT gene). A case is reported of an apparent rapidly growing gastrointestinal stromal tumour, which arose in the floor of the mouth and metastasized to the left neck without evidence of disease elsewhere.
Assuntos
Tumores do Estroma Gastrointestinal/patologia , Soalho Bucal/patologia , Neoplasias Bucais/patologia , Proteínas Proto-Oncogênicas c-kit/análise , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Tumores do Estroma Gastrointestinal/secundário , Humanos , Neoplasias Musculares/secundário , Músculos do Pescoço/patologiaRESUMO
A benign tumour of osseous and cartilaginous origins, osteochondroma generally develops in osseous tissue and is frequently found near the end of long bones. It is relatively rare in the oral and maxillofacial region but is common in the mandibular condyle and coronoid process in the pediculate form. This is a report on a rare case of osteochondroma in soft tissue near the mandibular angle without pedicle to the bone.
Assuntos
Neoplasias de Cabeça e Pescoço/patologia , Osteocondroma/patologia , Neoplasias de Tecidos Moles/patologia , Adulto , Feminino , HumanosRESUMO
OBJECTIVE: We assess the possibility of methicillin-resistant Staphylococcus aureus (MRSA) transmission via the surfaces of the dental operatory. METHODS: A survey of MRSA contamination on the surfaces of the dental operatory, and an analysis of MRSA transmission via the dental operatory between patients was carried out in the department of special dental care and oral surgery. RESULTS: MRSA was observed on the surfaces of dental operatory including the air-water syringe and reclining chair. Nosocomial infection or colonisation of MRSA occurred in eight out of 140 consecutive patients who had no evidence of MRSA at admission. Antibiograms of 30 antibiotics revealed that the isolates from the eight patients were of the same strain as those from the surface of dental operatory. After treating the patients under a revised infection control (IC) protocol including a single use of barrier covers, MRSA was not detected on the surfaces of the dental operatory, and no nosocomial infection or colonisation occurred during hospitalisation (0/117 patients). CONCLUSIONS: These results suggest that MRSA contaminates the surfaces of the dental operatory, and therefore the dental operatory should be considered a possible reservoir of MRSA.
Assuntos
Infecção Hospitalar/microbiologia , Consultórios Odontológicos , Reservatórios de Doenças/microbiologia , Fômites/microbiologia , Resistência a Meticilina , Infecções Estafilocócicas/transmissão , Equipamentos Odontológicos/microbiologia , Humanos , Controle de Infecções Dentárias , Staphylococcus aureusRESUMO
The purpose of this retrospective study is to assess the relationship between an initial and persisting condition of disk displacement (DD) and the long-term course of radiographically evident degenerative changes of the temporomandibular joint (TMJ). Nineteen patients agreed to a radiographic follow-up examination of 29 joints and were included in this study. The joints were radiographically assessed at the first visit and at least 46 months after the first visit (mean 89.3 months). At the time of the follow-up, all subjects had a good clinical course after a favorable response to the treatments. There were significant relationships between the initial diagnosis of DD and the interval change in the morphology of the articular eminence. The articular eminence became flattened or deformed only in the joints with persistent DD without reduction. And there was a tendency that the condyle became smaller in the joints initially with permanent DD and in the joints which show a progression in the disk-condylar relationship. The results of this study suggested that, in the joints with persisting non-reducing disk displacement, flattening and deformation of the articular eminence and regression of the condylar size were likely to happen even after symptoms and signs of TMJ disorders were resolved or reduced.
Assuntos
Luxações Articulares/diagnóstico por imagem , Osteoartrite/diagnóstico por imagem , Disco da Articulação Temporomandibular/diagnóstico por imagem , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Adolescente , Adulto , Reabsorção Óssea/diagnóstico por imagem , Progressão da Doença , Feminino , Seguimentos , Humanos , Luxações Articulares/terapia , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Côndilo Mandibular/diagnóstico por imagem , Pessoa de Meia-Idade , Placas Oclusais , Radiografia , Estudos Retrospectivos , Osso Temporal/diagnóstico por imagem , Transtornos da Articulação Temporomandibular/terapiaRESUMO
Mutation or epigenetic silencing of mismatch repair genes, such as MLH1 and MSH2, results in microsatellite instability (MSI) in the genome of a subset of colorectal carcinomas (CRCs). However, little is yet known of genes that directly contribute to tumor formation in such cancers. To characterize MSI-dependent changes in gene expression, we have now compared transcriptomes between fresh CRC specimens positive or negative for MSI (n=10 for each) with the use of high-density oligonucleotide microarrays harboring >44,000 probe sets. Correspondence analysis of the expression patterns of isolated MSI-associated genes revealed that the transcriptome of MSI+ CRCs is clearly distinct from that of MSI- CRCs. Such MSI-associated genes included that for AXIN2, an important component of the WNT signaling pathway. AXIN2 was silenced, apparently as a result of extensive methylation of its promoter region, specifically in MSI+ CRC specimens. Forced expression of AXIN2, either by treatment with 5'-azacytidine or by transfection with AXIN2 cDNA, resulted in rapid cell death in an MSI+ CRC cell line. These data indicate that epigenetic silencing of AXIN2 is specifically associated with carcinogenesis in MSI+ CRCs.
Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Proteínas do Citoesqueleto/genética , Epigênese Genética , Inativação Gênica , Repetições de Microssatélites , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteína Axina , Azacitidina/farmacologia , Benzotiazóis , Proteínas de Transporte/metabolismo , Morte Celular , Linhagem Celular Tumoral , Proliferação de Células , Análise por Conglomerados , Ilhas de CpG , Proteínas do Citoesqueleto/metabolismo , Metilação de DNA , Reparo do DNA , DNA Complementar/metabolismo , Diaminas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteína 2 Homóloga a MutS/metabolismo , Proteínas Nucleares/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Compostos Orgânicos/farmacologia , Quinolinas , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Fatores de Tempo , Transfecção , Regulação para CimaRESUMO
OBJECTIVES: The purpose of this study was to analyse the relationship between temporomandibular joint (TMJ)-related pain and morphological change of the TMJ condyle in patients with temporomandibular disorders. METHODS: Data were obtained from 178 joints in 89 patients. The joints were clinically assessed for pain on mandibular function and on lateral palpation of the TMJ. They were also assessed for radiographic evidence of bone change at the articular surface (OAAS) and resorption of the lateral part of the condyle (RLC). RESULTS: A higher prevalence of joint pain on function was observed in joints with OAAS than in those without OAAS (Chi-square test of independence, P < 0.05). Significant relationships were found between palpation pain and OAAS and between palpation pain and RLC (Chi-square test of independence, P < 0.05). In addition, patients with RLC showed a significantly lower pain threshold for external mechanical stimuli than those without RLC (Welch's t-test, P < 0.05). CONCLUSIONS: These results suggest a possible relationship between pain on function and OAAS as well as a relationship between palpation pain and RLC. Pain on lateral palpation may be related to the pathological conditions that induce RLC.
Assuntos
Dor Facial/etiologia , Côndilo Mandibular/patologia , Doenças Mandibulares/complicações , Transtornos da Articulação Temporomandibular/complicações , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Reabsorção Óssea/complicações , Reabsorção Óssea/diagnóstico por imagem , Criança , Feminino , Humanos , Masculino , Côndilo Mandibular/diagnóstico por imagem , Doenças Mandibulares/diagnóstico por imagem , Pessoa de Meia-Idade , Osteoartrite/complicações , Osteoartrite/diagnóstico por imagem , Osteosclerose/complicações , Osteosclerose/diagnóstico por imagem , Limiar da Dor/fisiologia , Palpação , Amplitude de Movimento Articular/fisiologia , Método Simples-Cego , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Tomografia por Raios XRESUMO
In this report, we present CT and MRI findings of a case of a schwannoma that developed in the floor of the oral cavity. A 49-year-old woman visited our hospital with a painless swelling in the oral floor. CT and MRI revealed a well circumscribed oval mass in the sublingual space, which showed cystic degeneration in most of the lesion. In addition, a thickened wall that strongly enhanced after injection of contrast medium and formation of fluid level were observed in the mass. The mass was removed and was histopathologically diagnosed as schwannoma. Only a few cases of schwannoma in the oral floor have been reported. However, when the characteristic findings are observed on CT and MRI, schwannoma should be added to the differential diagnosis.
Assuntos
Soalho Bucal/patologia , Neoplasias Bucais/diagnóstico , Neurilemoma/diagnóstico , Meios de Contraste , Diagnóstico Diferencial , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
The purpose of this study was to test the hypothesis that resorption of postero-superior corner of lateral part of the mandibular condyle (RLC) occurs with the advancement of TMJ internal derangement (ID). One hundred and sixty-seven TMJs in 122 patients were studied. RLC was assessed on plane radiographs of frontal oblique projection. The correlation between the prevalence of RLC and radiological stage of ID was analysed and clinical correlations to the radiological stage of ID and the prevalence of RLC were discussed. The higher prevalence of RLC in joints with advanced ID was statistically significant (Mann-Whitney U-test, P< 0.05). There was no correlation between the prevalence of RLC and neither OA on the articular surface of the condyle nor clinical symptoms/signs. The result of this study suggests that RLC appears to occur in joints with advanced ID as a result of remodelling changes secondary to ID.
Assuntos
Reabsorção Óssea/etiologia , Côndilo Mandibular/fisiopatologia , Transtornos da Articulação Temporomandibular/complicações , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Reabsorção Óssea/diagnóstico por imagem , Progressão da Doença , Dor Facial/fisiopatologia , Feminino , Humanos , Masculino , Côndilo Mandibular/diagnóstico por imagem , Pessoa de Meia-Idade , Osteoartrite/complicações , Osteoartrite/diagnóstico por imagem , Radiografia , Amplitude de Movimento Articular/fisiologia , Estatísticas não Paramétricas , Transtornos da Articulação Temporomandibular/classificaçãoRESUMO
OBJECTIVES: The purpose of this study was to analyse the relationship between horizontal condylar angle, temporomandibular joint (TMJ) disk displacement and resorption of the lateral pole of the mandibular condyle (RLC). METHODS: The study comprised 162 TMJs (81 patients). Disk displacement was assessed and the horizontal angle of the condyle was measured on axial MR images. RLC was assessed on oblique frontal projection plain radiographs. RESULTS: The horizontal angle was increased in joints with disk displacement without reduction (one-factor ANOVA and Scheffe's f-test, P<0.05). The angle was greater in joints with RLC than in the joints without RLC (Student's t-test, P<0.05). CONCLUSIONS: Results suggest that the horizontal condylar angle is increased in joints with disk displacement without reduction. A possible relationship exists between RLC and increased horizontal condylar angle.
Assuntos
Côndilo Mandibular/patologia , Transtornos da Articulação Temporomandibular/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Reabsorção Óssea/patologia , Feminino , Humanos , Luxações Articulares/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Osteoartrite/patologiaRESUMO
OBJECTIVE: To analyse the relationship between horizontal size and morphological changes on the articular surface and the lateral part of the mandibular condyle. METHODS: The study group comprised 139 joints in 88 women aged over 18 years. Horizontal condylar size was measured in the anteroposterior (AP) and mediolateral (ML) dimensions using axial MR images. Bony morphological change on the articular surface (sagittal change) was assessed on the sagittal MR image, and resorption of the lateral part of the condyle (RLC) was assessed on a plane radiograph in the AP projection. RESULTS: There was no significant relationship between horizontal condylar size and sagittal change. However, condyles with RLC were smaller than those without RLC in the ML dimension. CONCLUSIONS: The results of this study suggest a possible relationship between decreased horizontal condylar size and RLC. It is also suggested that sagittal bone changes do not influence the horizontal size of the condyle.
Assuntos
Côndilo Mandibular/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Reabsorção Óssea/diagnóstico por imagem , Reabsorção Óssea/patologia , Cartilagem Articular/diagnóstico por imagem , Cartilagem Articular/patologia , Cefalometria , Exostose/diagnóstico por imagem , Exostose/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Côndilo Mandibular/diagnóstico por imagem , Doenças Mandibulares/diagnóstico por imagem , Doenças Mandibulares/patologia , Pessoa de Meia-Idade , Osteoartrite/diagnóstico por imagem , Osteoartrite/patologia , Radiografia , Estatísticas não Paramétricas , Articulação Temporomandibular/diagnóstico por imagem , Articulação Temporomandibular/patologiaRESUMO
OBJECTIVES: The purpose of this retrospective study was to analyse the relationship between horizontal size of the mandibular condyle and internal derangement (ID) of the temporomandibular joint (TMJ). METHODS: One hundred and thirty-nine joints in 88 women aged over 18 years were included in this study. The horizontal condylar size was measured in the antero-posterior and medio-lateral (ML) dimensions using axial magnetic resonance (MR) images. Radiological findings of ID were also assessed from MR imaging. RESULTS: The condyles in the joints with permanent disk displacement were smaller than those in joints without displacement in both dimensions (Fisher's protected least significant difference, P<0.05). There were statistically significant correlations between horizontal condylar size in the ML dimension and both disk morphology and radiological stage of ID (Spearman's correlation coefficient by rank, P<0.05). CONCLUSIONS: The results of this study suggest a possible relationship between horizontal condylar size and disk displacement. It is also suggested that the condyle becomes smaller in the ML dimension with advancement of ID.
Assuntos
Côndilo Mandibular/patologia , Transtornos da Articulação Temporomandibular/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Cefalometria , Feminino , Humanos , Luxações Articulares/patologia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Osteoartrite/patologia , Amplitude de Movimento Articular , Estudos Retrospectivos , Estatística como Assunto , Estatísticas não Paramétricas , Disco da Articulação Temporomandibular/patologiaRESUMO
The osteoconductive properties of calcium phosphate cements (CPCs) may be improved by the addition of growth factors, such as recombinant human transforming growth factor-beta1 (rhTGF-beta1). Previously we have shown that rhTGF-beta1 was released from cement enriched with rhTGF-beta1 and subsequently stimulated the differentiation of pre-osteoblastic cells from adult rat long bones. It is unknown whether the addition of rhTGF-beta1 changes the material properties of this alpha-tricalcium-phosphate (alpha-TCP)/tetracalcium-phosphate-monoxide (TeCP)/dicalcium-phosphate-dihydrate (DCPD) cement, and what the characteristics of the release of rhTGF-beta1 from this CPC are. Therefore, in the present study we determined the release of rhTGF-beta1 from cement pellets in vitro. The possible intervening effects of the CPC modification for intermixing rhTGF-beta1 on physicochemical properties were studied by assessing the compressive strength and setting time, as well as crystallinity, calcium to phosphorus ratio, porosity and microscopic structure. Most of the previously incorporated rhTGF-beta1 in the cement pellets was released within the first 48 h. For all concentrations of rhTGF-beta1 intermixed (100 ng-2.5 mg/g CPC), approximately 0.5% of the amount of rhTGF-beta1 incorporated initially was released in the first 2 h, increasing to 1.0% after 48 h. The release of rhTGF-beta1 continued hereafter at a rate of about 0.1% up to 1 week, after which no additional release was found. The initial setting time, nor the final setting time was changed in control cement without rhTGF-beta1 (standard CPC) or in cement modified for rhTGF-beta1 (modified CPC) at 20 degrees C and 37 degrees C. Setting times were more than six times decreased at 37 degrees C compared to 20 degrees C. The compressive strength was initially low for both standard CPC and modified CPC, after which it increased between 24 h and 8 weeks. The compressive strength for the modified CPC was significantly higher compared with standard at 1, 2, and 8 weeks after mixing. X-ray diffraction revealed that both standard and modified CPC changed similarly from the original components into crystalline apatite. The calcium to phosphorus ratio as determined by an electron microprobe did not differ at all time points measured for standard CPC and modified CPC. In both standard CPC and modified CPC the separated particles became connected by crystals, forming a structure in which the particles could hardly be recognised in a densifying matrix with some small pores. The present study shows that the calcium phosphate cement is not severely changed by modification for the addition of rhTGF-beta1. The addition of rhTGF-beta1 in CPC enhances the biologic response as shown in our previous study and did not interfere with the aimed physical and chemical properties as shown in this study. We conclude that the addition of rhTGF-beta1 enlarges the potential of the CPC in bone replacement therapy.
Assuntos
Cimentos Ósseos , Fosfatos de Cálcio , Fator de Crescimento Transformador beta/administração & dosagem , Animais , Fenômenos Químicos , Físico-Química , Força Compressiva , Preparações de Ação Retardada , Humanos , Técnicas In Vitro , Teste de Materiais , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Ratos , Proteínas Recombinantes/administração & dosagem , Fator de Crescimento Transformador beta1 , Difração de Raios XRESUMO
Porous calcium phosphate ceramics consisting of hydroxyapatite (HA) and tricalcium phosphate (TCP) with different HA to TCP ratio were implanted intramuscularly in rabbits for six months in order to carry out a comparative study on osteogenic activity of the ceramics. Bone formation was detected only in HT73 (HA to TCP ratio, 7-3) specimens. Other implants, HT28 (2-8) and HT010 (0-10), could not induce bone. After a six-month period of implantation, HT28 and HT010 implants showed obvious degradation of the implants changing their shape and size macro and microscopically. Microscopically, they showed aggregates of fine particles and appearance of multinucleated cells. However, HT73 implants was less degraded and could maintain their original structure macro and microscopically. This study showed that HT73 ceramics can induce bone in rabbit muscle tissue and it is considered that maintenance of porous structure, that is, degradation rate of the materials may be one of the affecting factors in ceramic-induced osteogenesis.