Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
Curr Oncol ; 31(2): 849-861, 2024 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-38392057

RESUMO

Fluorescence-guided oncology promises to improve both the detection and treatment of malignancy. We sought to investigate the temporal distribution of indocyanine green (ICG), an exogenous fluorophore in human colorectal cancer. This analysis aims to enhance our understanding of ICG's effectiveness in current tumour detection and inform potential future diagnostic and therapeutic enhancements. METHODS: Fifty consenting patients undergoing treatment for suspected/confirmed colorectal neoplasia provided near infrared (NIR) video and imagery of transanally recorded and ex vivo resected rectal lesions following intravenous ICG administration (0.25 mg/kg), with a subgroup providing tissue samples for microscopic (including near infrared) analysis. Computer vision techniques detailed macroscopic 'early' (<15 min post ICG administration) and 'late' (>2 h) tissue fluorescence appearances from surgical imagery with digital NIR scanning (Licor, Lincoln, NE, USA) and from microscopic analysis (Nikon, Tokyo, Japan) undertaken by a consultant pathologist detailing tissue-level fluorescence distribution over the same time. RESULTS: Significant intra-tumoural fluorescence heterogeneity was seen 'early' in malignant versus benign lesions. In all 'early' samples, fluorescence was predominantly within the tissue stroma, with uptake within plasma cells, blood vessels and lymphatics, but not within malignant or healthy glands. At 'late' stage observation, fluorescence was visualised non-uniformly within the intracellular cytoplasm of malignant tissue but not retained in benign glands. Fluorescence also accumulated within any present peritumoural inflammatory tissue. CONCLUSION: This study demonstrates the time course diffusion patterns of ICG through both benign and malignant tumours in vivo in human patients at both macroscopic and microscopic levels, demonstrating important cellular drivers and features of geolocalisation and how they differ longitudinally after exposure to ICG.


Assuntos
Neoplasias Colorretais , Verde de Indocianina , Humanos , Distribuição Tecidual , Neoplasias Colorretais/cirurgia
2.
Surg Open Sci ; 12: 48-54, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36936453

RESUMO

Introduction: Fluorescence guided surgery for the identification of colorectal liver metastases (CRLM) can be better with low specificity and antecedent dosing impracticalities limiting indocyanine green (ICG) usefulness currently. We investigated the application of artificial intelligence methods (AIM) to demonstrate and characterise CLRMs based on dynamic signalling immediately following intraoperative ICG administration. Methods: Twenty-five patients with liver surface lesions (24 CRLM and 1 benign cyst) undergoing open/laparoscopic/robotic procedures were studied. ICG (0.05 mg/kg) was administered with near-infrared recording of fluorescence perfusion. User-selected region-of-interest (ROI) perfusion profiles were generated, milestones relating to ICG inflow/outflow extracted and used to train a machine learning (ML) classifier. 2D heatmaps were constructed in a subset using AIM to depict whole screen imaging based on dynamic tissue-ICG interaction. Fluorescence appearances were also assessed microscopically (using H&E and fresh-frozen preparations) to provide tissue-level explainability of such methods. Results: The ML algorithm correctly classified 97.2 % of CRLM ROIs (n = 132) and all benign lesion ROIs (n = 6) within 90-s of ICG administration following initial mathematical curve analysis identifying ICG inflow/outflow differentials between healthy liver and CRLMs. Time-fluorescence plots extracted for each pixel in 10 lesions enabled creation of 2D characterising heatmaps using flow parameters and through unsupervised ML. Microscopy confirmed statistically less CLRM fluorescence vs adjacent liver (mean ± std deviation signal/area 2.46 ± 9.56 vs 507.43 ± 160.82 respectively p < 0.001) with H&E diminishing ICG signal (n = 4). Conclusion: ML accurately identifies CRLMs from surrounding liver tissue enabling representative 2D mapping of such lesions from their fluorescence perfusion patterns using AIM. This may assist in reducing positive margin rates at metastatectomy and in identifying unexpected/occult malignancies.

3.
J Nephrol ; 35(3): 851-857, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34152561

RESUMO

OBJECTIVE: Kidney stone disease seems to be associated with an increased risk of incident cardiovascular outcomes; the aim of this study is to identify differences in 24-h urine excretory profiles and stone composition among stone formers with and without cardiovascular disease (CVD). METHODS: Data from patients attending the Department of Renal Medicine's metabolic stone clinic from 1995 to 2012 were reviewed. The sample was divided according to the presence or absence of CVD (myocardial infarction, angina, coronary revascularization, or surgery for calcified heart valves). Univariable and multivariable regression models, adjusted for age, sex, BMI, hypertension, diabetes, eGFR, plasma bicarbonate and potential renal acid load of foods were used to investigate differences across groups. RESULTS: 1826 patients had available data for 24-h urine analysis. Among these, 108 (5.9%) had a history of CVD. Those with CVD were older, have higher prevalence of hypertension and diabetes and lower eGFR. Univariable analysis showed that patients with CVD had significantly lower 24-h urinary excretions for citrate (2.4 vs 2.6 mmol/24 h, p = 0.04), magnesium (3.9 vs 4.2 mmol/24 h, p = 0.03) and urinary pH (6.1 vs 6.2, p = 0.02). After adjustment for confounders, differences in urinary citrate and magnesium excretions remained significant. No differences in the probability of stone formation or stone compositions were found. CONCLUSIONS: Stone formers with CVD have lower renal alkali excretion, possibly suggesting higher acid retention in stone formers with cardiovascular comorbidities. Randomized clinical trials including medications and a controlled diet design are needed to confirm the results presented here.


Assuntos
Diabetes Mellitus , Cardiopatias , Hipertensão , Cálculos Renais , Cálcio/metabolismo , Citratos , Ácido Cítrico , Humanos , Cálculos Renais/epidemiologia , Cálculos Renais/metabolismo , Magnésio , Metaboloma
4.
Urolithiasis ; 49(5): 387-397, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34086105

RESUMO

The aim of the LITHOSCREEN project was to construct a comprehensive screening program and database for recording and assessing the various risk factors for stone-formation in patients with urolithiasis. It is intended for use in Stone Clinics and is now being made available free of charge to researchers in the field who wish to maintain a comprehensive record of their patients' medical histories, demographic backgrounds, lifestyle activities, metabolic abnormalities, biochemical risk of forming stones of various types, diet histories, stone analysis and long-term treatment records. From the recorded data for each patient, the program automatically calculates numerous functions important in the understanding of the clinical and chemical risk factors for stone-formation, including the renal handling of the ions involved, various metabolic functions, the biochemical risk of forming kidney stones (PSF), the Tiselius Indices of the supersaturation of urine with respect to calcium oxalate and calcium phosphate, the projected effects of changing the composition of each patient's urinary composition on the risk of stone recurrence, and a program for analysing the diet of patients. It automatically produces one-page Summaries of each patient's biochemical and dietary records with abnormal values highlighted according to a "traffic-light" colour-coding system and generates charts designed to improve patient compliance with treatment in the form of colour-coded "Target Diagrams" showing (a) the patient's 24-h urine composition, (b) the patient's biochemical risk of forming stones of different types and (c) the composition of the patient's diet. The Summary pages and "Target Diagrams" are suitable for inclusion in the patient's Case Notes. LITHOSCREEN also produces charts projecting the effect of changing the composition of urine on the patient's biochemical risk of forming further stones. These graphs provide clues as to which urinary risk factors to target to reduce the patient's risk of stone recurrence.


Assuntos
Cálculos Renais , Oxalato de Cálcio , Bases de Dados Factuais , Humanos , Rim , Cálculos Renais/diagnóstico , Cálculos Renais/terapia , Programas de Rastreamento , Fatores de Risco , Urolitíase/diagnóstico , Urolitíase/terapia
5.
ACS Biomater Sci Eng ; 6(4): 2415-2426, 2020 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33455309

RESUMO

As a potential osteotomy tool, laser ablation is expected to provide rapid machining of bone, while generating minimal thermal damage (carbonization) and physical attributes within the machined region conducive to healing. As these characteristics vary with laser parameters and modes of laser operation, the clinical trials and in vivo studies render it difficult to explore these aspects for optimization of the laser machining parameters. In light of this, the current work explores various thermal and microstructural aspects of laser-ablated cortical bone in ex vivo study to understand the fundamentals of laser-bone interaction using computational modeling. The study employs the Yb-fiber Nd:YAG laser (λ = 1064 nm) in the continuous wave mode to machine the femur section of bovine bone by a three-dimensional machining approach. The examination involved thermal analysis using differential scanning calorimetry and thermogravimetry, phase analysis using X-ray diffractometry, qualitative analysis using X-ray photoelectron spectroscopy, and microstructural and semiquantitative analysis using scanning electron microscopy equipped with energy-dispersive spectrometry. The mechanism of efficient bone ablation using the Nd:YAG laser was evaluated using the computational thermokinetics outcome. The use of high laser fluence (10.61 J/mm2) was observed to be efficient to reduce the residual amorphous carbon in the heat-affected zone while achieving removal of the desired volume of the bone material at a rapid rate. Minimal thermal effects were predicted through computational simulation and were validated with the experimental outcome. In addition, this work reveals the in situ formation of a scaffold-like structure in the laser-machined region which can be conducive during healing.


Assuntos
Terapia a Laser , Lasers de Estado Sólido , Animais , Osso e Ossos/diagnóstico por imagem , Bovinos , Osso Cortical/diagnóstico por imagem , Osteotomia
6.
Sci Rep ; 7(1): 3233, 2017 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-28607391

RESUMO

Dielectric multilayer structures with a grating profile on the top-most layer adds an additional degree of freedom to the phase matching conditions for Bloch surface wave excitation. The conditions for Bloch surface wave coupling can be achieved by rotating both polar and azimuthal angles. The generation of Bloch surface waves as a function of azimuthal angle has similar characteristics to conventional grating coupled Bloch surface waves. However, azimuthally generated Bloch surface waves have enhanced angular sensitivity compared to conventional polar angle coupled modes, which makes them appropriate for detecting tiny variations in surface refractive index due to the addition of nano-particles such as protein molecules.

7.
Am J Sports Med ; 44(4): 1024-30, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26823452

RESUMO

BACKGROUND: Femoroacetabular impingement (FAI) has been increasingly recognized as a cause of hip pain in athletes at all levels of competition, specifically ice hockey players. PURPOSE/HYPOTHESIS: The purpose of this study was to define the prevalence of cam and pincer radiographic deformity in elite ice hockey players. The hypothesis was that elite hockey players will have a higher prevalence of radiographic hip abnormalities compared with the general population. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Anteroposterior and frog-leg lateral radiographs on 137 elite ice hockey players were prospectively obtained during the 2014-2015 preseason entrance examinations. Study participants included National Hockey League roster players as well as the respective farm team members. Demographic data were collected, including age, position, shooting side, and any history of hip pain or hip surgery. Patients with a history of hip surgery were excluded from the analysis. A single sports medicine fellowship-trained orthopaedic surgeon used standard radiographic measurements to assess for the radiographic presence of cam or pincer deformity. Radiographs with an alpha angle ≥55° on a frog-leg lateral view were defined as cam-positive. Each participant underwent a preseason physical examination with an assessment of hip range of motion and impingement testing. RESULTS: A total of 130 elite ice hockey players were included in the analysis; 180 (69.4%) hips met radiographic criteria for cam-type deformity. The prevalence in right and left hips was 89 (69.5%) and 91 (70.0%), respectively; 70 (60.8%) players demonstrated bilateral involvement. Hips with cam deformity had a mean alpha angle of 67.7° ± 8.3° on the right and 68.9° ± 9.0° on the left. Of the patients with alpha angles ≥55°, 5.6% (5/89) had a positive anterior impingement test of the right hip, while 11% (10/91) had positive anterior impingement test of the left. Players with radiologic cam deformity had a statistically significant deficit in external rotation of the right hip, as well as in both internal and external rotation of the left hip, compared with those with normal alpha angles. When assessing for crossover sign, 64 of 107 (59.8%) had a positive radiographic finding. Forty-one players (38.3%) had evidence of a crossover sign of the right hip and 42 (39.3%) of the left. When comparing position players, goalies had the highest prevalence of cam-type deformity (93.8%) and the least acetabular coverage. CONCLUSION: The study data suggest that elite ice hockey players have a significantly higher prevalence of radiographic cam deformity in comparison to what has been reported for the general population.


Assuntos
Atletas , Impacto Femoroacetabular/diagnóstico por imagem , Articulação do Quadril/diagnóstico por imagem , Hóquei , Adulto , Estudos Transversais , Humanos , Masculino , Prevalência , Adulto Jovem
8.
Eur J Radiol ; 85(1): 15-24, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26724644

RESUMO

Magnetic Resonance Imaging is modality of choice for the non-invasive evaluation of meniscal tears. Accurate and uniform documentation of meniscal pathology is necessary for optimal multi-disciplinary communication, to guide treatment options and for validation of patient outcomes studies. The increasingly used ISAKOS arthroscopic meniscus tear classification system has been shown to provide sufficient interobserver reliability among the surgeons. However, the terminology is not in common use in the radiology world. In this article, the authors discuss the MR imaging appearances of meniscal tears based on ISAKOS classification on 2D and multiplanar 3D isotropic spin echo imaging techniques and illustrate the correlations of various meniscal pathologies with relevant arthroscopic images.


Assuntos
Imageamento Tridimensional , Traumatismos do Joelho/patologia , Imageamento por Ressonância Magnética , Meniscos Tibiais/patologia , Adulto , Artroscopia/métodos , Humanos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Reprodutibilidade dos Testes , Ruptura/patologia , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Terminologia como Assunto , Lesões do Menisco Tibial
9.
Radiol Technol ; 87(1): 21-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26377265

RESUMO

BACKGROUND: Femoroacetabular impingement (FAI) is commonly seen in young or middle-aged patients. Early detection and correction of FAI-related bony deformities or pelvic realignment are essential to prevent the development or progression of hip osteoarthritis. DISCUSSION: Computed tomography (CT) and magnetic resonance (MR) imaging are the reference standards for the evaluation of bony anatomy and treatable internal derangement findings of the hip, respectively. Surgeons prefer CT imaging for preoperative bone delineation because of its 3-D isotropic capabilities and excellent multiplanar reconstructions. Three-Tesla (3T) MR scans enable high-resolution 3-D MR reconstructions for bone depiction similar to 3-D CT reconstructions and have the potential to eliminate the need for duplicate (CT and MR) scanning. CONCLUSION: This technical report illustrates the feasibility of such an approach and compares bone rendering obtained using isotropic data from 3-D MR with 3-D CT in the same patient.


Assuntos
Impacto Femoroacetabular/patologia , Impacto Femoroacetabular/cirurgia , Imageamento por Ressonância Magnética/métodos , Procedimentos de Cirurgia Plástica/métodos , Cuidados Pré-Operatórios/métodos , Cirurgia Assistida por Computador/métodos , Estudos de Viabilidade , Humanos , Imageamento Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Osteotomia/métodos , Tomografia Computadorizada por Raios X/métodos
10.
Int. braz. j. urol ; 40(4): 507-512, Jul-Aug/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-723958

RESUMO

Introduction The aim was to confirm that PSF (probability of stone formation) changed appropriately following medical therapy on recurrent stone formers. Materials and Methods Data were collected on 26 Brazilian stone-formers. A baseline 24-hour urine collection was performed prior to treatment. Details of the medical treatment initiated for stone-disease were recorded. A PSF calculation was performed on the 24 hour urine sample using the 7 urinary parameters required: voided volume, oxalate, calcium, urate, pH, citrate and magnesium. A repeat 24-hour urine sample was performed for PSF calculation after treatment. Comparison was made between the PSF scores before and during treatment. Results At baseline, 20 of the 26 patients (77%) had a high PSF score (> 0.5). Of the 26 patients, 17 (65%) showed an overall reduction in their PSF profiles with a medical treatment regimen. Eleven patients (42%) changed from a high risk (PSF > 0.5) to a low risk (PSF < 0.5) and 6 patients reduced their risk score but did not change risk category. Six (23%) patients remained in a high risk category (> 0.5) during both assessments. Conclusions The PSF score reduced following medical treatment in the majority of patients in this cohort. .


Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco/métodos , Urolitíase/terapia , Urolitíase/urina , Estudos de Coortes , Fosfatos de Cálcio/urina , Citratos/urina , Magnésio/urina , Oxalatos/urina , Probabilidade , Valores de Referência , Reprodutibilidade dos Testes , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Ácido Úrico/urina , Urolitíase/etiologia , Urolitíase/patologia
11.
Knee Surg Sports Traumatol Arthrosc ; 22(10): 2522-30, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24817164

RESUMO

PURPOSE: Both autologous chondrocyte implantation (ACI) and tibial tubercle transfer (TTT) have been used to treat chondral defects in the patellofemoral joint resulting in clinical improvement. Our study investigates the magnetic resonance imaging (MRI) appearance of the matrix-induced autologous chondrocyte implantation (MACI) graft at 5-year follow-up to determine if it provides a durable treatment option in patients with an average age of 42 (standard deviation 11.6). METHODS: Twenty-three patients were available for follow-up. Nine patients required realignment of the extensor mechanism with lateral release and TTT. The MRI magnetic resonance observation of cartilage repair tissue (MOCART) scoring system was used to assess the graft status. Clinical outcomes were assessed at these time periods. RESULTS: The mean weighted MOCART composite score improved from 2.87 at 3 months to 3.39 at 5 years, indicating an intact appearance in most grafts. Graft height measured >50% of the adjacent native cartilage in 82% of patients. Clinical improvement assessed by the Knee Injury and Osteoarthritis Outcome Score, SF-36 (PCS) and the 6-minute walk test was demonstrated between pre-operative scores and final 5-year follow-up. 91% of patients would undergo MACI again. Correlation between MOCART and clinical scores were low in MACI to the patellofemoral joint. No significant difference was found in outcome between those that required realignment surgery compared with those that did not. CONCLUSION: Patellofemoral MACI provides a durable graft on MRI assessment at 5 years with resultant clinical improvement. Further work is needed to determine which defect locations may benefit most from this procedure. LEVEL OF EVIDENCE: IV.


Assuntos
Condrócitos/transplante , Articulação Patelofemoral/lesões , Adolescente , Adulto , Cartilagem Articular/cirurgia , Feminino , Seguimentos , Humanos , Traumatismos do Joelho/cirurgia , Articulação do Joelho/cirurgia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos , Fatores de Tempo , Transplante Autólogo , Adulto Jovem
12.
Med Oncol ; 31(6): 967, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24777549

RESUMO

Management of advanced non-small cell lung cancer patients is dependent on the histologic diagnosis for both testing and treatment. This study was designed to determine the ability of fine needle aspiration and core biopsies to correctly determine histologic diagnosis in non-small cell lung cancer. Our institutional cardiothoracic surgery database was reviewed for cases of non-small cell lung cancer treated with lobectomy after a preoperative biopsy by CT guidance or bronchoscopy over a 10-year period from 2002 to 2011. The histologic diagnosis of the final lobectomy specimen was compared to the histologic diagnosis from the preoperative biopsy, and the concordance rate was calculated. 119 biopsy specimens from 117 patients were reviewed. Eighty of the 119 biopsies had the same histologic diagnosis as the lobectomy specimen, yielding an overall concordance rate of 67.2 %. Patients with poorly differentiated tumors were at the highest risk of an incorrect histologic diagnosis on preoperative biopsy. Reliance on fine needle aspiration and core biopsies to determine histologic diagnosis in non-small cell lung cancer may put some patients at risk for suboptimal treatment.


Assuntos
Biópsia por Agulha Fina/métodos , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Broncoscopia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Feminino , Humanos , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
13.
Knee Surg Sports Traumatol Arthrosc ; 22(2): 357-62, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23471528

RESUMO

PURPOSE: To evaluate whether femoral tunnel preparation using a mono-fluted reamer rather than an acorn reamer would result in less tibial tunnel deformation when using a transtibial technique for anterior cruciate ligament reconstruction. METHODS: Tibial and femoral tunnel preparation was performed in four matched pairs of cadaveric knees. The tibial tunnel was drilled using a standard acorn reamer. The femoral tunnel was prepared using a transtibial technique with a mono-fluted reamer, and then, the same femoral tunnel was re-reamed using an acorn reamer. The anterior-posterior (AP) and medial-lateral (ML) dimensions of the tibial tunnel were recorded after each reamer. We then compared the measurements following the use of each reamer using a paired two-sample t test. RESULTS: There was a significantly larger degree of tibial tunnel deformation following femoral tunnel preparation with the acorn reamer when compared with the mono-fluted reamer. The initial tibial tunnel measured 10.5 and 10.1 mm in the AP and ML dimensions, respectively. The resultant AP diameter of the tibial tunnel after femoral reaming was 16.7 mm (p < 0.001) for the acorn reamer compared with 11.6 mm (p < 0.001) for the mono-fluted reamer. The ML diameters were 11.3 mm (p = 0.003) versus 10.2 mm (p = 0.07) for the acorn and mono-fluted reamer, respectively. CONCLUSION: The use of a mono-fluted reamer for femoral tunnel preparation results in less tibial tunnel deformation during transtibial reaming.


Assuntos
Reconstrução do Ligamento Cruzado Anterior/instrumentação , Ligamento Cruzado Anterior/cirurgia , Fêmur/cirurgia , Articulação do Joelho/cirurgia , Tíbia/cirurgia , Adulto , Reconstrução do Ligamento Cruzado Anterior/métodos , Humanos , Masculino , Pessoa de Meia-Idade
14.
J Air Waste Manag Assoc ; 63(8): 984-96, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24010380

RESUMO

UNLABELLED: In total, 24 polycyclic aromatic hydrocarbons (PAHs) in both gas and particle phases and 35 nitro-PAHs in particle phase were analyzed in the exhaust from heavy-duty diesel vehicles equipped with after-treatment for particulate matter (PM) and NO(x) control. The test vehicles were carried out using a chassis dynamometer under highway cruise, transient Urban Dynamometer Driving Schedule (UDDS), and idle operation. The after-treatment efficiently abated more than 90% of the total PAHs. Indeed, the particle-bound PAHs were reduced by > 99%, and the gaseous PAHs were removed at various extents depending on the type of after-treatment and the test cycles. The PAHs in gas phase dominated the total PAH (gas + particle phases) emissions for all the test vehicles and for all cycles; that is, 99% of the two-ring and 98% of the three-ring and 97% of the four-ring and 95% of the carcinogenic PAHs were in the gas-phase after a diesel particle filter (DPF) and not bound to the very small amount of particulate matter left after a DPF. Consequently, an evaluation of the toxicity of DPF exhaust must include this volatile fraction and cannot be based on the particle fraction only. The selective catalytic reduction (SCR) did not appear to promote nitration of the PAHs in general, although there might be some selective nitration of phenanthrene. Importantly the after-treatment reduced the equivalent B[a]P (B[a]Peq) emissions by > 95%, suggesting a substantial health benefit. IMPLICATIONS: This study demonstrated that after-treatments, including diesel particulate filters (DPF), diesel oxidation catalysts (DOC), and selective catalytic reduction (SCR), significantly reduce the emissions of PAHs from heavy-duty diesel engines. The gas-phase PAHs dominate the total PAH (gas + particle phases) emissions from heavy-duty diesel vehicles retrofitted with various DPFs and not bound to the very small amount of particulate matter left after a DPF. Consequently, an evaluation of the toxicity of DPF exhaust must also include this volatile fraction and cannot be based on the particle fraction only.


Assuntos
Poluição do Ar/prevenção & controle , Hidrocarbonetos Policíclicos Aromáticos/análise , Emissões de Veículos/análise , Poluentes Atmosféricos/análise , Catálise , Filtração
15.
Arthroscopy ; 29(10): 1604-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23993054

RESUMO

PURPOSE: The purpose of this study was to compare the load to fracture of distal clavicles with no tunnels, one tunnel, or 2 tunnels and to evaluate the effect of inserting tenodesis screws in the tunnels on load to fracture of the distal clavicle. METHODS: Fifty right sawbone clavicles were obtained and divided into 5 groups (n = 10): group 1, normal clavicle; group 2, one tunnel, no tenodesis screw; group 3, 2 tunnels, no tenodesis screws; group 4, one tunnel with tenodesis screw; and group 5, 2 tunnels with 2 tenodesis screws. Tunnels were created using a 5-mm-diameter reamer, and 5.5 × 10 mm polyethyl ethyl ketone tenodesis screws were used. A 4-point bending load was applied to the distal clavicles. Load to failure was noted for each specimen. RESULTS: Load to failure in clavicles without tunnels was significantly higher (1,157.18 ± 147.10 N) than in all other groups (P < .0005). No statistical differences were noted between groups 2, 3, 4, and 5. Load to failure was not statistically different in clavicles with one versus 2 tunnels. In addition, the use of tenodesis screws in the tunnels did not affect the load required to fracture. CONCLUSIONS: The use of tunnels in the clavicle for coracoclavicular (CC) ligament reconstruction significantly reduces the load required to fracture the distal clavicle. The addition of tenodesis screws does not appear to significantly increase the strength of the clavicle in this construct. CLINICAL RELEVANCE: CC ligament reconstruction techniques commonly use tunnels in the distal clavicle, which may render the clavicle more susceptible to fracture. This study helps quantify the effect of these tunnels on the strength of the distal clavicle.


Assuntos
Parafusos Ósseos/efeitos adversos , Clavícula/lesões , Fraturas Ósseas/etiologia , Ligamentos Articulares/cirurgia , Osteotomia/efeitos adversos , Procedimentos de Cirurgia Plástica/efeitos adversos , Escápula/cirurgia , Tenodese/métodos , Clavícula/cirurgia , Humanos , Osteotomia/métodos , Procedimentos de Cirurgia Plástica/instrumentação , Procedimentos de Cirurgia Plástica/métodos , Tenodese/instrumentação
16.
Int J Shoulder Surg ; 7(1): 14-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23858290

RESUMO

PURPOSE: The purpose of this study was to quantify the width of bone beyond the peak of the anterior glenoid rim and to determine if this anatomic region of the glenoid significantly affects measurement of the anteroposterior glenoid diameter. MATERIALS AND METHODS: 19 cadaveric scapulae were examined and the width of bone beyond the peak of the anterior glenoid rim was measured. The percent width of this region relative to the anteroposterior diameter of the glenoid was evaluated. Male and female specimens were compared. Measurements of the anteroposterior diameter of the glenoid, both including and excluding this region, were compared. RESULTS: The mean width of bone beyond the peak of the anterior glenoid rim was 3.2 ± 0.7 mm, corresponding to 10.5% of the anteroposterior glenoid diameter. This anatomic region is of similar relative size in males and females (11% vs 10% of the glenoid diameter). Measurement of the anteroposterior diameter of the glenoid is significantly different depending on whether this region is included or not (P = 0.0064). CONCLUSIONS: There exists a portion of the anterior glenoid that is beyond the peak of the anterior rim, and is not part of the concave articular surface. The width of this anatomic area comprises a significant percent of the anteroposterior glenoid diameter, and should be understood when quantifying and describing anterior glenoid bone loss in cases of glenohumeral instability. CLINICAL RELEVANCE: Understanding of anterior glenoid anatomy is important in the evaluation of glenohumeral instability. The portion of glenoid bone beyond the anterior rim peak is likely important for its soft tissue attachments, but its contribution to bony stability may be misunderstood.

17.
Arthroscopy ; 28(7): 1030-5, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22738752

RESUMO

In patients with anterior glenohumeral instability, the most commonly observed osseous defect involves the anterior portion of the inferior glenoid. The amount of glenoid bone loss guides surgical treatment, with progressively larger defects not being amenable to arthroscopic soft-tissue procedures. Currently, there is no universally accepted method of quantifying glenoid bone loss. Two-dimensional area-based methods and 1-dimensional methods of measuring bone loss have both been described but cannot be used interchangeably. The surface area of a glenoid bony defect is a more comprehensive descriptor of its magnitude than the 1-dimensional width of the defect. Calculating surface area can be challenging. We describe a method of quantifying glenoid bone loss using a glenoid arc angle that corresponds to the surface area of the defect. The arc angle is easily measured by use of commonly used imaging software tools and is independent of the size of the glenoid or defect orientation. This method may prove valuable in preoperative planning for patients with anterior glenohumeral instability.


Assuntos
Cavidade Glenoide/patologia , Instabilidade Articular/patologia , Articulação do Ombro/patologia , Fatores Etários , Cavidade Glenoide/diagnóstico por imagem , Humanos , Instabilidade Articular/diagnóstico por imagem , Imageamento por Ressonância Magnética , Articulação do Ombro/diagnóstico por imagem , Tomografia Computadorizada por Raios X
18.
Clin Orthop Relat Res ; 470(3): 853-60, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21997781

RESUMO

BACKGROUND: Biomechanical studies suggest reducing the effective graft length during transtibial posterior cruciate ligament (PCL) reconstruction by augmenting the distal tibial fixation with a proximal screw near the tibial tunnel aperture could increase graft stiffness and provide a more stable reconstruction. However, it remains unknown to what extent this mechanical theory influences in vivo graft performance over time. SURGICAL TECHNIQUE: We developed a technique to augment tibial distal fixation with a proximal screw near the tibial tunnel aperture to shorten the effective graft length and increase graft stiffness. PATIENTS AND METHODS: We retrospectively reviewed all 10 patients who had isolated PCL reconstructions with combined distal and proximal tibial fixation from 2003 to 2007. Mean age of the patients was 36.5 years. We measured ROM and obtained Tegner, International Knee Documentation Committee (IKDC), and Lysholm scores. Anteroposterior stability was evaluated with a KT-2000 arthrometer. Minimum followup was 1 year (mean, 2.5 years; range, 1-4.8 years). RESULTS: Mean Tegner scores before injury and at last followup were 7.3 and 6.5, respectively. Mean postoperative IKDC score was 87 versus a preoperative IKDC score of 43. Mean Lysholm score was 89 at last followup. All patients achieved full terminal extension. No patient had greater than a 5-mm difference in anterior or posterior displacement from the contralateral knee as measured by a KT-2000 arthrometer postoperatively (0.93 ± 0.79 mm). CONCLUSIONS: In this small series, augmentation of tibial distal fixation with a proximal screw near the tibial tunnel aperture during reconstruction of the isolated PCL rupture restored function, motion, and stability. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.


Assuntos
Traumatismos do Joelho/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Ligamento Cruzado Posterior/cirurgia , Adulto , Idoso , Fenômenos Biomecânicos , Parafusos Ósseos , Feminino , Humanos , Traumatismos do Joelho/fisiopatologia , Traumatismos do Joelho/reabilitação , Articulação do Joelho/fisiopatologia , Masculino , Pessoa de Meia-Idade , Ligamento Cruzado Posterior/lesões , Estudos Retrospectivos , Ruptura
19.
Am J Sports Med ; 39(11): 2415-20, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21900626

RESUMO

BACKGROUND: While few comparative studies exist, it has been suggested that open distal clavicle excisions (DCEs) provide inferior results when compared with the all-arthroscopic technique. PURPOSE: The purpose of this study was to compare the intermediate-term (5-year follow-up) results of patients undergoing arthroscopic versus open DCE for the treatment of recalcitrant acromioclavicular joint pain. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: All patients who underwent an arthroscopic or open DCE between January 1999 and September 2006 were reviewed. Forty-eight patients (49 shoulders; 32 arthroscopic, 17 open) following DCE without significant glenohumeral pathologic changes were included. The mean follow-up for group I (open) and group II (arthroscopic) was 5.3 years and 4.2 years, respectively. The American Shoulder and Elbow Surgeons (ASES) score, visual analog scale (VAS) pain score, surgical time, and minimum radiographic acromioclavicular joint distance were calculated. Each patient completed a questionnaire assessing their scar satisfaction, percentage of normal shoulder function, and willingness to have the surgery again. Risk factors for poor outcomes were analyzed. RESULTS: Arthroscopic patients had significantly less pain (P = .035) by VAS (0.61 ± 1.02) compared with open (1.59 ± 2.15) at final follow-up. There was no significant difference between group I and group II with regard to ASES (87.5 ± 17.6 vs 94.6 ± 8.6), percentage of normal shoulder function (89.7% ± 12.5 vs 92.9% ± 8.6), average operative time (53.1 minutes vs 48 minutes), or radiographic resection distance (12.8 ± 2.1 mm vs 9.5 ± 2.9 mm). In the open group, patients with 16 of 17 shoulders were satisfied with their scar and 100% would do it again. In the arthroscopic group, patients with 31 of 32 shoulders (97%) were both satisfied and would have the surgery again. CONCLUSION: Open and arthroscopic DCE are both effective surgeries to treat recalcitrant acromioclavicular joint pain. At intermediate-term follow-up, they provide similarly good to excellent results with regard to patient satisfaction and shoulder function. Although both are effective treatments, less residual pain was found using the arthroscopic technique.


Assuntos
Artroscopia , Clavícula/cirurgia , Articulação Acromioclavicular/cirurgia , Adulto , Idoso , Cicatriz/psicologia , Clavícula/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Satisfação do Paciente , Radiografia , Estudos Retrospectivos , Ombro/fisiologia , Ombro/cirurgia , Dor de Ombro/fisiopatologia , Dor de Ombro/cirurgia , Inquéritos e Questionários , Resultado do Tratamento
20.
Am J Sports Med ; 39(4): 753-63, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21257846

RESUMO

BACKGROUND: The availability remains limited of midterm clinical and radiologic results into matrix-induced autologous chondrocyte implantation (MACI). Outcomes are required to validate the efficacy of MACI as a suitable surgical treatment option for articular cartilage defects in the knee. HYPOTHESIS: A significant improvement in clinical and magnetic resonance imaging-based (MRI-based) outcomes after MACI will exist throughout the postoperative timeline to 5 years after surgery. Furthermore, patient demographics, cartilage defect parameters, and injury/surgery history will be associated with patient and graft outcome, whereas a significant correlation will exist between clinical and MRI-based outcomes at 5 years after surgery. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A prospective evaluation was undertaken to assess clinical and MRI-based outcomes to 5 years in 41 patients (53 grafts) after MACI to the knee. After MACI surgery and a 12-week structured rehabilitation program, patients underwent clinical assessments (Knee injury and Osteoarthritis Outcome Score, SF-36, 6-minute walk test, knee range of motion) and MRI assessments at 3, 12, and 24 months, as well as 5 years after surgery. The MRI evaluation assessed 8 previously defined pertinent parameters of graft repair, as well as a combined MRI composite score. RESULTS: A significant improvement (P < .05) was demonstrated for all Knee injury and Osteoarthritis Outcome Score and SF-36 subscales over the postoperative timeline, as well as the 6-minute walk test and active knee extension. A significant improvement (P < .0001) was observed for the MRI composite score, as well as several individual graft scoring parameters. At 5 years after surgery, 67% of MACI grafts demonstrated complete infill, whereas 89% demonstrated good to excellent filling of the chondral defect. Patient demographics, cartilage defect parameters, and injury/surgery history demonstrated no significant pertinent correlations with clinical or MRI-based outcomes at 5 years, and no significant correlations existed between clinical and MRI-based outcome measures. At 5 years after surgery, 98% of patients were satisfied with the ability of MACI surgery to relieve knee pain; 86%, with improvement in their ability to perform normal daily tasks; and 73%, with their ability to participate in sport 5 years after MACI. CONCLUSION: These results suggest that MACI provides a suitable midterm treatment option for articular cartilage defects in the knee. Long-term follow-up is essential to confirm whether the repair tissue has the durability required to maintain long-term patient quality of life.


Assuntos
Cartilagem Articular/cirurgia , Condrócitos/transplante , Traumatismos do Joelho/cirurgia , Adolescente , Adulto , Idoso , Cartilagem Articular/lesões , Cartilagem Articular/patologia , Criança , Feminino , Seguimentos , Humanos , Traumatismos do Joelho/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Transplante Autólogo , Resultado do Tratamento , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA