Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
1.
Dalton Trans ; 49(25): 8652-8660, 2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32555848

RESUMO

In this work, multiferroic bismuth ferrite (BFO) was functionalized with meso-tetraphenylporphine-4,4',4'',4'''-tetracarboxylic acid (TCPP). This new hybrid organic-inorganic material shows an enhanced photocatalytic activity for the degradation of organic dyes as it combines the properties of BFO which is an efficient visible light photocatalyst with peculiar porphyrin absorption in visible light. The anchoring of TCPP to the OH-terminations of the BFO surface through its carboxylic tethering groups was demonstrated using X-ray photoelectron spectroscopy and FT-IR spectroscopy. The photocatalytic activity of the material was also demonstrated through the photocatalytic degradation of Methylene Blue (MB) and Rhodamine-B (Rhd-B) in water under simulated solar light illumination. The TCPP molecules anchored to BFO slightly decrease (∼0.06 eV) the bandgap energy of the system and act as new catalytic centres, thus improving its photocatalytic activity. A photodegradation mechanism was also proposed. This new material is reusable and stable, as it maintains an unmodified photo-activity after several MB discoloration runs.

2.
Skeletal Radiol ; 49(6): 869-881, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31897519

RESUMO

OBJECTIVE: To predict accurately whether a soft tissue mass was benign or malignant and to characterize its type using ultrasound, shear wave elastography and MRI. We hypothesized that with the addition of shear wave elastography, it would be possible to determine a threshold velocity value to classify a lesion as benign or malignant. MATERIALS AND METHODS: A total of 151 consecutive, consenting adult patients were prospectively recruited to this study in a tertiary referral musculoskeletal oncology centre. All lesions were assessed with ultrasound, including B mode, Doppler and shear wave elastography measurements. One hundred thirty-eight patients also underwent MRI of the lesion. A histological diagnosis was obtained for all lesions. RESULTS: Malignant lesions were larger than benign lesions and had a greater Doppler activity. There was no useful threshold shear wave velocity to differentiate between benign and malignant lesions. Longitudinal and transverse shear wave velocities were strongly positively correlated with each other. An inverse correlation was shown with lesion size and depth, regardless of whether it was benign or malignant. A logistic regression model combining the ultrasound and MRI characteristics did not confidently classify a lesion as benign or malignant and was inferior to expert opinion. CONCLUSION: The strongest predictors of malignancy are large lesion size and high vascularity. The combination of all ultrasound characteristics (including shear wave elastography) and MRI features does not confidently classify a lesion as benign or malignant, and histological diagnosis remains the gold standard.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Imageamento por Ressonância Magnética/métodos , Neoplasias de Tecidos Moles/diagnóstico por imagem , Ultrassonografia/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias de Tecidos Moles/patologia
3.
Bone Joint J ; 100-B(12): 1647-1654, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30499326

RESUMO

AIMS: The purpose of this study was to identify prognostic indicators of outcome at presentation to the orthopaedic surgeon, in patients with metastatic prostate cancer. Our aim was to use this information in a pragmatic, clinic-based approach so that surgical decision making could be optimized to benefit the patient in their remaining lifetime. PATIENTS AND METHODS: A cohort analysis was undertaken of all patients with metastatic disease of the prostate who presented to a regional orthopaedic centre in the United Kingdom between 2003 and 2016. Biochemical data were collected in addition to disease and demographic data. These included: prostate-specific antigen (PSA) at orthopaedic presentation; haemoglobin (Hb); platelets (plt); alkaline phosphatase (ALP); albumin (Alb); and corrected calcium (CaC). Statistical analysis included Kaplan-Meier survival analysis, and a Cox proportional hazards model was fitted to the data. RESULTS: From the departmental database, 137 episodes were identified in 136 patients with a median age at presentation of 72 years (interquartile range (IQR) 66 to 78). Most patients had stage IV disease (n = 98, 72%), and most did not undergo surgical intervention. At one-year follow-up, 50% of patients had died. Biomarkers found to be independently associated with poor survival were: low Hb, low Alb, relatively low PSA (< 30 mmol/l), and a raised ALP. Patients who needed surgical intervention had a poorer survival rate than patients who were managed nonoperatively. CONCLUSION: The study findings are important for orthopaedic clinical practice in the management of patients with metastatic prostate cancer. The interpretation of routine blood tests can help to predict survival in patients who present with orthopaedic manifestations of prostate cancer. A lower PSA is not necessarily a good prognostic sign. We believe that simple blood testing should be carried out routinely when assessing a patient, guiding potential surgical management and palliative care in the future.


Assuntos
Neoplasias Ósseas/secundário , Estadiamento de Neoplasias , Cuidados Paliativos/métodos , Neoplasias da Próstata/patologia , Idoso , Neoplasias Ósseas/mortalidade , Neoplasias Ósseas/cirurgia , Terapia Combinada , Seguimentos , Humanos , Masculino , Neoplasias da Próstata/mortalidade , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Fatores de Tempo , Reino Unido/epidemiologia
4.
Bone Joint J ; 100-B(8): 1100-1105, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30062934

RESUMO

Aims: The aim of this study was to validate the Mirels score in predicting pathological fractures in metastatic disease of the lower limb. Patients and Methods: A total of 62 patients with confirmed metastatic disease met the inclusion criteria. Of the 62 patients, 32 were female and 30 were male. The mean age of patients was 65 years (35 to 89). The primary malignancy originated from the breast in 27 (44%) patients, prostate in 15 (24%) patients, kidney in seven (11%), and lung in four (6%) of patients. One patient (2%) had metastatic carcinoma from the lacrimal gland, two patients (3%) had multiple myeloma, one patient (2%) had lymphoma of bone, and five patients (8%) had metastatic carcinoma of unknown primary. Plain radiographs at the time of initial presentation were scored using Mirels system by the four authors. The radiographic components of the score (anatomical site, size, and radiographic appearance) were scored two weeks apart. Inter- and intraobserver reliability were calculated with Fleiss' kappa test. Bland-Altman plots were created to compare the variances of the individual components of the score and the total Mirels score. Results: Kappa values for the interobserver variability of the components of the Mirels score were k = 0.554 (95% CI 0.483 to 0.626) for site, k = 0.342 (95% CI 0.285 to 0.400) for size, k = 0.443 (95% CI 0.387 to 0.499) for radiographic appearance, and k = 0.294 (95% CI 0.258 to 0.331)for the total score. Kappa values for the intra-observer reliability were k = 0.608 (95% CI 0.506 to 0.710) for site, k = 0.579 (95% CI 0.487 to 0.670) for size, k = 0.614 (95% CI 0.522 to 0.703) for radiographic appearance, and k = 0.323 (95% CI 0.266 to 0.379) for total score. Conclusion: Our study showed fair to moderate agreement between authors when using the Mirels score, and moderate to substantial agreement when authors rescored radiographs. The Mirels score is subjective and lacks reproducibility in predicting the risk of pathological fracture. Cite this article: Bone Joint J 2018;100-B:1100-5.


Assuntos
Neoplasias Ósseas/secundário , Fraturas Espontâneas/prevenção & controle , Índice de Gravidade de Doença , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Ossos da Perna , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Medição de Risco/métodos
5.
Bone Joint J ; 100-B(1): 101-108, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29305458

RESUMO

AIMS: Dislocation rates are reportedly lower in patients requiring proximal femoral hemiarthroplasty than for patients undergoing hip arthroplasty for neoplasia. Without acetabular replacement, pain due to acetabular wear necessitating revision surgery has been described. We aimed to determine whether wear of the native acetabulum following hemiarthroplasty necessitates revision surgery with secondary replacement of the acetabulum after proximal femoral replacement (PFR) for tumour reconstruction. PATIENTS AND METHODS: We reviewed 100 consecutive PFRs performed between January 2003 and January 2013 without acetabular resurfacing. The procedure was undertaken in 74 patients with metastases, for a primary bone tumour in 20 and for myeloma in six. There were 48 male and 52 female patients, with a mean age of 61.4 years (19 to 85) and median follow-up of two years (interquartile range (IQR) 0.5 to 3.7 years). In total, 52 patients presented with a pathological fracture and six presented with failed fixation of a previously instrumented pathological fracture. RESULTS: All patients underwent reconstruction with either a unipolar (n = 64) or bipolar (n = 36) articulation. There were no dislocations and no acetabular resurfacings. Articular wear was graded using the criteria of Baker et al from 0 to 3, where by 0 is normal; grade 1 represents a narrowing of articular cartilage and no bone erosion; grade 2 represents acetabular bone erosion and early migration; and grade 3 represents protrusio acetabuli. Of the 49 patients with radiological follow-up greater than one year, six demonstrated grade 1 acetabular wear and two demonstrated grade 2 acetabular wear. The remainder demonstrated no radiographic evidence of wear. Median medial migration was 0.3 mm (IQR -0.2 to 0.7) and superior migration was 0.3 mm (IQR -0.2 to 0.6). No relationship between unipolar versus bipolar articulations and wear was evident. CONCLUSION: Hemiarthroplasty PFRs for tumour reconstruction eliminate joint instability and, in the short to medium term, do not lead to native acetabular wear necessitating later acetabular resurfacing. Cite this article: Bone Joint J 2018;100B:101-8.


Assuntos
Acetábulo/cirurgia , Artroplastia de Quadril/métodos , Neoplasias Femorais/cirurgia , Hemiartroplastia/métodos , Prótese de Quadril , Acetábulo/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Quadril/efeitos adversos , Feminino , Neoplasias Femorais/secundário , Seguimentos , Hemiartroplastia/efeitos adversos , Luxação do Quadril/etiologia , Humanos , Salvamento de Membro/métodos , Masculino , Pessoa de Meia-Idade , Falha de Prótese , Radiografia , Reoperação/métodos , Reoperação/estatística & dados numéricos , Adulto Jovem
6.
Toxicology ; 393: 83-89, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29127034

RESUMO

Over the past 30 years, there have been significant advancements in the field of nanomaterials. The possibility to use them in applications such as cancer treatment is extremely promising; however, the toxicity of many nanomaterials as well as the high costs associated with their use is still a concern. This paper aims to study the connection between nanomaterial toxicity and cost. This synergy may be interpreted as a different version of the classic "Prisoner's Dilemma" game, which in this case attempts to explain the possible outcomes of cooperation versus conflict between science advocating for the use of high-risk, possibly toxic materials due to their high returns, and society that might be dubious about the use of high-risk materials. In an effort to create diverse evaluation methodologies, this work uses a forecast horizon to evaluate the current status and expected future of the nanomaterials market. The historical progress of each market, toxicity information, and possible returns stemming from their use is taken into account to analyze the predictions. Our results suggest various trends for the associated costs and nanotoxicity of the studied materials.


Assuntos
Nanoestruturas/economia , Nanoestruturas/toxicidade , Tecnologia Biomédica , Análise Custo-Benefício , Humanos , Expectativa de Vida , Modelos Teóricos , Dilema do Prisioneiro , Medição de Risco
7.
Bone Joint Res ; 6(4): 224-230, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28438971

RESUMO

OBJECTIVES: In this cross sectional study, the impact and the efficacy of a surveillance programme for sarcomas of the extremities was analysed. METHODS: All patients who had treatment with curative intent for a high-grade sarcoma and were diagnosed before 2014 were included and followed for a minimum of two years. RESULTS: Of the 909 patients who had a review appointment in 2014, 131 were under review for a high-grade sarcoma of the extremities following treatment with curative intent. Of these patients, three patients died of disease, two patients died of other causes, 12 are alive, with disease, and 114 have no evidence of disease. The surveillance programme accounts for 14% of all review appointments.Four of five patients (80%) who developed local recurrence identified the recurrence themselves. Chest radiographs are adequate in identifying metastatic disease and 11 (73%) of metastases were diagnosed during a routine follow up visit. However, the chance of cure is small and only two patients were referred for a metastatectomy. Of these only one survived for more than two years.The mean time for developing metastatic disease and local recurrence was 2.0 and 3.9 years respectively. Once identified, the mean time to death was 2.1 years for patients with metastatic disease. CONCLUSIONS: Surveillance of sarcoma patients makes up a substantial amount of the workload of a sarcoma unit. The chance of cure following identification of local recurrence or metastatic disease, however, is small. Alternative methods of surveillance that allow better evaluation of the patient's needs are recommended.Cite this article: P. Cool, G. Cribb. The impact and efficacy of surveillance in patients with sarcoma of the extremities. Bone Joint Res 2017;6:224-230. DOI: 10.1302/2046-3758.64.BJR-2016-0253.R1.

8.
Biochim Biophys Acta Gen Subj ; 1861(6): 1478-1485, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27578596

RESUMO

BACKGROUND: Nanotechnology has been in the limelight since its emergence and its products affect everyday lives. Nanomaterials are characterized by features such as size and shape, thus rendering their possible number essentially unlimited, which in turn makes them difficult to study and categorize regarding possible dangers. This work suggests that grouping could allow studying them with limited testing efforts without endangering safety. METHODS: Initially, the materials are identified and grouped according to their applications in health/medicine, as well as on their environmentally-friendly potential. The materials are then categorized using various toxicity classification methods to identify those with highest risks and group them with others that demonstrate similar behavior. RESULTS: The materials studied show promising uses in diagnostics, drug delivery, biosensors, water purification, oil spill cleaning, emission control and other fields. The toxicity risk assessment shows that the majority pose little to moderate risk, however there are certain materials that can be extremely hazardous or even cause death under specific circumstances. A risk mitigation plan was also developed. CONCLUSIONS: Nanomaterials applications, including drug delivery, cancer treatment, waste treatment, solar energy generation etc. can be very beneficiary, but at the same time, these materials can be extremely harmful or even cause death, thus making the need to prioritize research on high risk materials crucial. A clear regulatory framework that addresses both benefits and risks and communicates that information effectively should play an important part in European and worldwide efforts. GENERAL SIGNIFICANCE: The risk analysis validated the impression that there is limited research on nanomaterial toxicity risks, which calls for a more organized approach. The framework outlined in this work can be utilized by researchers as well as government bodies, in order to form regulatory policies and adopt a universally accepted labeling system. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editor: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.


Assuntos
Nanomedicina/classificação , Nanoestruturas/classificação , Terminologia como Assunto , Animais , Humanos , Nanomedicina/métodos , Nanoestruturas/toxicidade , Segurança do Paciente , Medição de Risco , Fatores de Risco , Testes de Toxicidade
9.
Bone Joint J ; 98-B(11): 1542-1547, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27803232

RESUMO

AIMS: The purpose of this study was to determine if clinical and radiological surveillance of cartilage tumours with low biological activity is appropriate. PATIENTS AND METHODS: A total of 98 patients with an intramedullary cartilage neoplasm in a long bone met our inclusion criteria and were included in the study. These patients had undergone a total of 384 scans. Patients with radiological follow-up of more than three years (46 patients) were divided into two groups: an active group (11 patients) and a latent group (35 patients). RESULTS: Active lesions had a total growth in all three planes that was > 6 mm, whilst latent lesions had < 6 mm of growth. Most latent lesions were heavily calcified: active lesions were calcified less than 50% (p = 0.025). CONCLUSION: Clinico-radiological surveillance can identify growing cartilage lesions: MRI is the surveillance modality of choice. A CT scan is recommended, in addition, at presentation to assess the amount of calcification within the lesion. A first follow-up MRI is suggested one year from diagnosis. If the total growth in the cartilage lesion is > 6 mm, surgical treatment should be considered. Otherwise, a second surveillance scan can be performed at three years to determine further management. Cite this article: Bone Joint J 2016;98-B:1542-7.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Condroma/diagnóstico por imagem , Conduta Expectante/métodos , Adolescente , Adulto , Idoso , Neoplasias Ósseas/patologia , Calcinose/diagnóstico por imagem , Condroma/patologia , Estudos Transversais , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vigilância da População/métodos , Cintilografia , Tomografia Computadorizada por Raios X , Adulto Jovem
10.
Eur J Surg Oncol ; 42(4): 574-80, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26831007

RESUMO

Myxoid liposarcomas (MLS) are a subgroup of soft-tissue sarcomas which have a propensity for extra-pulmonary metastases. Conventional radiological staging of soft-tissue sarcomas consists of chest radiographs (CXR) and thoracic computed tomography (CT) for possible chest metastases, supplemented by magnetic resonance imaging (MRI) for local disease. The optimal radiological modality to detect extra-pulmonary metastases for systemic staging has not been proven. We reviewed the efficacy of Whole-Body MRI (WBMRI) for this purpose. 33 WBMRI and simultaneous CT scans were performed in 28 patients suffering from MLS between 2007 and 2015. 38 metastases were identified in seven patients via WBMRI. Osseous lesions predominated (spine, pelvis, chest-wall and long bones), followed by soft-tissue and abdominal lesions. Of the 29 soft-tissue or osseous metastases that were within the field-of-view of the simultaneous CT scans, five soft-tissue and zero osseous metastases were identified using CT. Metastatic disease was detected in three patients solely using WBMRI, which directly influenced their management. WBMRI is a useful adjunct in the detection of extra-pulmonary metastatic disease, which directly alters patient management. WBMRI has demonstrated an ability to identify more sites of metastatic disease compared to CT. WBMRI should be used in two situations. Firstly, at diagnosis where ablative treatment will be required e.g. amputation, when the diagnosis of occult metastasis would change treatment planning. Secondly, at diagnosis of relapse to confirm if it is a solitary site of relapse prior to consideration of metastectomy.


Assuntos
Neoplasias Ósseas/secundário , Lipossarcoma Mixoide/diagnóstico , Imageamento por Ressonância Magnética/métodos , Neoplasias de Tecidos Moles/patologia , Imagem Corporal Total/métodos , Neoplasias Ósseas/diagnóstico , Diagnóstico Diferencial , Feminino , Humanos , Lipossarcoma Mixoide/secundário , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Reprodutibilidade dos Testes
11.
Bone Joint J ; 97-B(12): 1593-603, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26637671

RESUMO

Plots are an elegant and effective way to represent data. At their best they encourage the reader and promote comprehension. A graphical representation can give a far more intuitive feel to the pattern of results in the study than a list of numerical data, or the result of a statistical calculation. The temptation to exaggerate differences or relationships between variables by using broken axes, overlaid axes, or inconsistent scaling between plots should be avoided. A plot should be self-explanatory and not complicated. It should make good use of the available space. The axes should be scaled appropriately and labelled with an appropriate dimension. Plots are recognised statistical methods of presenting data and usually require specialised statistical software to create them. The statistical analysis and methods to generate the plots are as important as the methodology of the study itself. The software, including dates and version numbers, as well as statistical tests should be appropriately referenced. Following some of the guidance provided in this article will enhance a manuscript.


Assuntos
Ortopedia , Publicações Periódicas como Assunto , Software , Interpretação Estatística de Dados , Humanos
12.
Bone Joint J ; 97-B(9): 1284-90, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26330598

RESUMO

Patients who have limb amputation for musculoskeletal tumours are a rare group of cancer survivors. This was a prospective cross-sectional survey of patients from five specialist centres for sarcoma surgery in England. Physical function, pain and quality of life (QOL) outcomes were collected after lower extremity amputation for bone or soft-tissue tumours to evaluate the survivorship experience and inform service provision. Of 250 patients, 105 (42%) responded between September 2012 and June 2013. From these, completed questionnaires were received from 100 patients with a mean age of 53.6 years (19 to 91). In total 60 (62%) were male and 37 (38%) were female (three not specified). The diagnosis was primary bone sarcoma in 63 and soft-tissue tumour in 37. A total of 20 tumours were located in the hip or pelvis, 31 above the knee, 32 between the knee and ankle and 17 in the ankle or foot. In total 22 had hemipelvectomy, nine hip disarticulation, 35 transfemoral amputation, one knee disarticulation, 30 transtibial amputation, two toe amputations and one rotationplasty. The Toronto Extremity Salvage Score (TESS) differed by amputation level, with poorer scores at higher levels (p < 0.001). Many reported significant pain. In addition, TESS was negatively associated with increasing age, and pain interference scores. QOL for Cancer Survivors was significantly correlated with TESS (p < 0.001). This relationship appeared driven by pain interference scores. This unprecedented national survey confirms amputation level is linked to physical function, but not QOL or pain measures. Pain and physical function significantly impact on QOL. These results are helpful in managing the expectations of patients about treatment and addressing their complex needs.


Assuntos
Amputação Cirúrgica/reabilitação , Neoplasias Ósseas/cirurgia , Extremidade Inferior/cirurgia , Qualidade de Vida , Neoplasias de Tecidos Moles/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Amputação Cirúrgica/efeitos adversos , Amputados/psicologia , Amputados/reabilitação , Membros Artificiais , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor/métodos , Dor Pós-Operatória/etiologia , Psicometria , Recuperação de Função Fisiológica , Adulto Jovem
13.
Ultramicroscopy ; 148: 10-19, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25199748

RESUMO

Electron tomography is currently a versatile tool to investigate the connection between the structure and properties of nanomaterials. However, a quantitative interpretation of electron tomography results is still far from straightforward. Especially accurate quantification of pore-space is hampered by artifacts introduced in all steps of the processing chain, i.e., acquisition, reconstruction, segmentation and quantification. Furthermore, most common approaches require subjective manual user input. In this paper, the PORES algorithm "POre REconstruction and Segmentation" is introduced; it is a tailor-made, integral approach, for the reconstruction, segmentation, and quantification of porous nanomaterials. The PORES processing chain starts by calculating a reconstruction with a nanoporous-specific reconstruction algorithm: the Simultaneous Update of Pore Pixels by iterative REconstruction and Simple Segmentation algorithm (SUPPRESS). It classifies the interior region to the pores during reconstruction, while reconstructing the remaining region by reducing the error with respect to the acquired electron microscopy data. The SUPPRESS reconstruction can be directly plugged into the remaining processing chain of the PORES algorithm, resulting in accurate individual pore quantification and full sample pore statistics. The proposed approach was extensively validated on both simulated and experimental data, indicating its ability to generate accurate statistics of nanoporous materials.

14.
Eur J Radiol ; 83(11): 2051-7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25183557

RESUMO

Stress induced injuries affecting the physeal plate or cortical bone in children and adolescents, especially young athletes, have been well described. However, there are no reports in the current English language literature of stress injury affecting the incompletely ossified epiphyseal cartilage. We present four cases of stress related change to the proximal tibial epiphysis (PTE) along with their respective magnetic resonance imaging (MRI) appearances ranging from subtle oedema signal to a pseudo-tumour like appearance within the epiphyseal cartilage. The site and pattern of intra-epiphyseal injury is determined by the type of tissue that is affected, the maturity of the skeleton and the type of forces that are transmitted through the tissue. We demonstrate how an awareness of the morphological spectrum of MRI appearances in intra-epiphyseal stress injury and the ability to identify concomitant signs of stress in other nearby structures can help reduce misdiagnosis, avoid invasive diagnostic procedures like bone biopsy and reassure patients and their families.


Assuntos
Traumatismos em Atletas/patologia , Epífises/patologia , Fixação Interna de Fraturas/métodos , Lâmina de Crescimento/patologia , Imageamento por Ressonância Magnética , Fraturas da Tíbia/patologia , Adolescente , Criança , Epífises/lesões , Lâmina de Crescimento/irrigação sanguínea , Humanos , Imageamento por Ressonância Magnética/métodos , Fraturas Salter-Harris , Fraturas da Tíbia/cirurgia , Resultado do Tratamento
15.
Mater Sci Eng C Mater Biol Appl ; 33(8): 5071-8, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24094226

RESUMO

Layered double hydroxides (LDH) containing (Mg and Al) or (Zn and Fe) were prepared by coprecipitation at constant pH, using NaOH and urea as precipitation agents. The most pure LDH phase in the Zn/Fe system was obtained with urea and in Mg/Al system when using NaOH. The incorporation of phenyl-alanine (Phe) anions in the interlayer of the LDH was performed by direct coprecipitation, ionic exchange and structure reconstruction of the mixed oxide obtained by the calcination of the coprecipitated product at 400°C. The reconstruction method and the direct coprecipitation in a medium containing Phe in the initial mixture were less successful in terms of high yields of organic-mineral composite than the ionic exchange method. A spectacular change in sample morphology and yield in exchanged solid was noticed for the Zn3Fe sample obtained by ionic exchange for 6h with Phe solution. A delivery test in PBS of pH=7.4 showed the release of the Phe in several steps up to 25 h indicating different host-guest interactions between the Phe and the LDH matrix. This behavior makes the preparation useful to obtain late delivery drugs, by the incorporation of the anion inside the LDH layer.


Assuntos
Alumínio/química , Hidróxidos/química , Ferro/química , Magnésio/química , Zinco/química , Ânions/química , Cloretos/química , Compostos Férricos/química , Concentração de Íons de Hidrogênio , Nitratos/química , Fenilalanina/química , Hidróxido de Sódio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Ureia/química , Compostos de Zinco/química
16.
Bone Joint J ; 95-B(3): 384-90, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23450025

RESUMO

Pigmented villonodular synovitis (PVNS) is a rare benign disease of the synovium of joints and tendon sheaths, which may be locally aggressive. We present 18 patients with diffuse-type PVNS of the foot and ankle followed for a mean of 5.1 years (2 to 11.8). There were seven men and 11 women, with a mean age of 42 years (18 to 73). A total of 13 patients underwent open or arthroscopic synovectomy, without post-operative radiotherapy. One had surgery at the referring unit before presentation with residual tibiotalar PVNS. The four patients who were managed non-operatively remain symptomatically controlled and under clinical and radiological surveillance. At final follow-up the mean Musculoskeletal Tumour Society score was 93.8% (95% confidence interval (CI) 85 to 100), the mean Toronto Extremity Salvage Score was 92 (95% CI 82 to 100) and the mean American Academy of Orthopaedic Surgeons foot and ankle score was 89 (95% CI 79 to 100). The lesion in the patient with residual PVNS resolved radiologically without further intervention six years after surgery. Targeted synovectomy without adjuvant radiotherapy can result in excellent outcomes, without recurrence. Asymptomatic patients can be successfully managed non-operatively. This is the first series to report clinical outcome scores for patients with diffuse-type PVNS of the foot and ankle.


Assuntos
Articulação do Tornozelo , Articulações do Pé , Tumores de Células Gigantes , Sinovite Pigmentada Vilonodular , Adolescente , Adulto , Idoso , Articulação do Tornozelo/patologia , Articulação do Tornozelo/cirurgia , Feminino , Seguimentos , Articulações do Pé/patologia , Articulações do Pé/cirurgia , Tumores de Células Gigantes/diagnóstico , Tumores de Células Gigantes/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estudos Prospectivos , Sinovectomia , Membrana Sinovial/patologia , Sinovite Pigmentada Vilonodular/diagnóstico , Sinovite Pigmentada Vilonodular/terapia , Resultado do Tratamento , Adulto Jovem
18.
J Nanosci Nanotechnol ; 10(12): 8227-33, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21121320

RESUMO

In this study we report the synthesis of a series of composite nanostructures comprising LDH and TiO2 phases. The materials characterization showed that the LDH crystallites are encapsulated inside the TiO2 matrix after the anatase seeds are deposited on MgxAl-LDHs. The structure in which LDH phase is embedded into anatase matrix is unique bringing important advantages to the photocatalytic performances of the nanocomposites. The photocatalytic activity of the prepared nanocomposites was tested on the degradation of the methylene blue (MB) in aqueous solution. The photocatalytic activities of the nanocomposites were compared with commercial TiO2 nanoparticles Degussa P25. The nanocomposites exhibited superior photocatalytic activity in basic environment because the negatively charged surface of TiO2 nanoparticles at high pH attracts the positively charged methylene blue species.


Assuntos
Hidróxido de Alumínio/química , Corantes/química , Hidróxido de Magnésio/química , Nanocompostos/química , Titânio/química , Adsorção , Concentração de Íons de Hidrogênio , Azul de Metileno/química , Microscopia Eletrônica de Transmissão , Processos Fotoquímicos , Análise Espectral Raman , Difração de Raios X
19.
Foot Ankle Surg ; 15(1): 28-32, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19218062

RESUMO

A 36-year-old man presented with a long history of pain in his left ankle. Imaging and biopsy confirmed this to be a giant cell tumour of bone. This was treated with curettage of the lesion and stabilisation with an Ilizarov frame. After a prolonged course of rehabilitation he has excellent function and has returned to hill walking and there is no evidence of recurrence of the giant cell tumour.


Assuntos
Neoplasias Ósseas/cirurgia , Curetagem , Tumor de Células Gigantes do Osso/cirurgia , Técnica de Ilizarov , Tíbia , Adulto , Humanos , Masculino
20.
Langmuir ; 25(2): 939-43, 2009 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-19177649

RESUMO

The porous structure of nanostructured silicas MCM-41 and SBA-15 has been characterized using N2 adsorption at 77 K, before and after n-nonane preadsorption, together with immersion calorimetry into liquids of different molecular dimensions. Selective blocking of the microporosity with n-nonane proves experimentally that MCM-41 is exclusively mesoporous while SBA-15 exhibits both micro- and mesopores. Additionally, N2 adsorption experiments on the preadsorbed samples show that the microporosity on SBA-15 is located in intrawall positions, the micropore volume accounting for only approximately 7-8 % of the total pore volume. Calorimetric measurements into n-hexane (0.43 nm), 2-methylpentane (0.49 nm), and 2,2-dimethylbutane (0.56 nm) estimate the size of these micropores to be < or = 0.56 nm.


Assuntos
Dióxido de Silício/química , Adsorção , Alcanos/química , Calorimetria , Nanoestruturas/química , Nitrogênio/química , Porosidade , Dióxido de Silício/síntese química , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...