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1.
Ann Biomed Eng ; 52(4): 898-907, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38155316

RESUMO

Glaucoma surgery with implantation of aqueous humor draining microstents may compromise long-term corneal health by disrupting aqueous humor circulation. The effect of stent numbers on this circulation was interrogated to determine the number of stents associated with minimal circulation disruption. An in vitro anterior eye model perfusion system was constructed with multiple exit ports. A 3-D model of the anterior eye was imported into ABAQUS CFD, analyzes were carried out for unsteady laminar flow and solved using Navier-Stokes equations. DT Vision Foundry was used to analyze velocity contour plot images. The field variable results output for the CFD model were fluid wall shear, fluid pressure and fluid velocity. In vitro, "aqueous" fluid flow is high through a single stent and "aqueous" stagnation is greatest in the quadrants 180° away. Increasing stent port numbers, results in an exponential decrease in the stagnant flow locations. High wall shear stress was seen in the single stent model and is markedly reduced after a second and subsequent stents are introduced. We identify two factors potentially contributing to corneal compromise post glaucoma drainage surgery: aqueous humor stagnation, remote to the stent site and higher exit flows imparting increased stent exit shear stress (particularly with a single stent). With 4 stents, there is minimal disruption of anterior chamber circulation (mimicking physiological conditions). Furthermore we propose that aqueous humor circulation disruption via the usual single-exit port approach disrupts aqueous humor circulation with long-term consequences for corneal health.


Assuntos
Humor Aquoso , Glaucoma , Humanos , Humor Aquoso/fisiologia , Pressão Intraocular , Glaucoma/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos , Perfusão
2.
Radiat Oncol ; 16(1): 237, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34911546

RESUMO

BACKGROUND: Magnetic Resonance Image guided Stereotactic body radiotherapy (MRgRT) is an emerging technology that is increasingly used in treatment of visceral cancers, such as pancreatic adenocarcinoma (PDAC). Given the variable response rates and short progression times of PDAC, there is an unmet clinical need for a method to assess early RT response that may allow better prescription personalization. We hypothesize that quantitative image feature analysis (radiomics) of the longitudinal MR scans acquired before and during MRgRT may be used to extract information related to early treatment response. METHODS: Histogram and texture radiomic features (n = 73) were extracted from the Gross Tumor Volume (GTV) in 0.35T MRgRT scans of 26 locally advanced and borderline resectable PDAC patients treated with 50 Gy RT in 5 fractions. Feature ratios between first (F1) and last (F5) fraction scan were correlated with progression free survival (PFS). Feature stability was assessed through region of interest (ROI) perturbation. RESULTS: Linear normalization of image intensity to median kidney value showed improved reproducibility of feature quantification. Histogram skewness change during treatment showed significant association with PFS (p = 0.005, HR = 2.75), offering a potential predictive biomarker of RT response. Stability analyses revealed a wide distribution of feature sensitivities to ROI delineation and was able to identify features that were robust to variability in contouring. CONCLUSIONS: This study presents a proof-of-concept for the use of quantitative image analysis in MRgRT for treatment response prediction and providing an analysis pipeline that can be utilized in future MRgRT radiomic studies.


Assuntos
Adenocarcinoma/radioterapia , Imageamento por Ressonância Magnética/métodos , Neoplasias Pancreáticas/radioterapia , Radioterapia Guiada por Imagem/métodos , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/mortalidade , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/mortalidade , Carga Tumoral
3.
Carbohydr Polym ; 250: 116869, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33049818

RESUMO

Melanoma is the most lethal form of skin cancer, with a worldwide increase in incidence. Despite the increased overall survival of metastatic melanoma patients given recent advances in targeted and immunotherapy, it still has a poor prognosis and available treatment options carry diverse severe side effects. Polysaccharides from seaweed have been shown to exert antitumor activities. Here we show in vitro and in vivo antitumor activities of a sulfated homogalactan (named 3G4S) from Codium isthmocladum seaweed in the B16-F10 murine melanoma cell line. 3G4S did not induce cytotoxicity or proliferation changes; however, it was able to reduce solid tumor growth and metastasis, while not inducing side effects in mice. B16-F10 cells traits related to the metastatic cascade were also impaired by 3G4S, reducing cell invasion, colony-forming capacity and membrane glycoconjugates. Therefore, 3G4S shows promising antitumor activities without the commonly associated drawbacks of cancer treatments and can be further explored.


Assuntos
Galactanos/farmacologia , Química Verde , Melanoma Experimental/prevenção & controle , Alga Marinha/química , Sulfatos/química , Animais , Apoptose , Proliferação de Células , Feminino , Humanos , Masculino , Melanoma Experimental/secundário , Camundongos , Camundongos Endogâmicos C57BL , Células Tumorais Cultivadas
4.
BJS Open ; 4(5): 847-854, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32841538

RESUMO

BACKGROUND: Risk assessment is relevant to predict postoperative outcomes in patients with gastro-oesophageal cancer. This cohort study aimed to assess body composition changes during neoadjuvant chemotherapy and investigate their association with postoperative complications. METHODS: Consecutive patients with gastro-oesophageal cancer undergoing neoadjuvant chemotherapy and surgery with curative intent between 2016 and 2019 were identified from a specific database and included in the study. CT images before and after neoadjuvant chemotherapy were used to assess the skeletal muscle index, sarcopenia, and subcutaneous and visceral fat index. RESULTS: In a cohort of 199 patients, the mean skeletal muscle index decreased during neoadjuvant therapy (from 51·187 to 49·19 cm2 /m2 ; P < 0·001) and the rate of sarcopenia increased (from 42·2 to 54·3 per cent; P < 0·001). A skeletal muscle index decrease greater than 5 per cent was not associated with an increased risk of total postoperative complications (odds ratio 0·91, 95 per cent c.i. 0·52 to 1·59; P = 0·736) or severe complications (odds ratio 0·66, 0·29 to 1·53; P = 0·329). CONCLUSION: Skeletal muscle index decreased during neoadjuvant therapy but was not associated with postoperative complications.


ANTECEDENTES: La evaluación de riesgo es importante para predecir los resultados postoperatorios en pacientes con cáncer gastroesofágico. Este estudio de cohortes tuvo como objetivo evaluar los cambios en la composición corporal durante la quimioterapia neoadyuvante e investigar su asociación con complicaciones postoperatorias. MÉTODOS: Los pacientes consecutivos con cáncer gastroesofágico sometidos a quimioterapia neoadyuvante y cirugía con intención curativa entre 2016 y 2019, identificados a partir de una base de datos específica, se incluyeron en el estudio. Se utilizaron las imágenes de tomografía computarizada, antes y después de la quimioterapia neoadyuvante, para evaluar el índice de masa muscular esquelética, la sarcopenia y el índice de grasa visceral y subcutánea. RESULTADOS: En una cohorte de 199 pacientes, el índice de masa muscular esquelética disminuyó durante el tratamiento neoadyuvante (de 51,87 cm2 /m2 a 49,19 cm2 /m2 , P < 0,001) y las tasas de sarcopenia aumentaron (de 42,2% a 54,2%, P < 0,001). Una disminución del índice de masa muscular esquelética > 5% no se asoció con un mayor riesgo de complicaciones postoperatorias globales (razón de oportunidades, odds ratio: 0,908; ic. del 95%: 0,520-1,587, P = 0,736) ni de complicaciones graves (odds ratio: 0,661; i.c. del 95%: 0,286-1,525, P = 0,329). CONCLUSIÓN: El índice de masa muscular esquelética disminuyó durante el tratamiento neoadyuvante, pero no se asoció con complicaciones postoperatorias.


Assuntos
Neoplasias Esofágicas/tratamento farmacológico , Esofagectomia/efeitos adversos , Músculo Esquelético/efeitos dos fármacos , Terapia Neoadjuvante/efeitos adversos , Complicações Pós-Operatórias/etiologia , Sarcopenia/etiologia , Neoplasias Gástricas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Composição Corporal , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/fisiopatologia , Neoplasias Esofágicas/cirurgia , Junção Esofagogástrica/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Análise de Regressão , Estudos Retrospectivos , Sarcopenia/patologia , Neoplasias Gástricas/patologia , Neoplasias Gástricas/fisiopatologia , Neoplasias Gástricas/cirurgia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Reino Unido
5.
Ann R Coll Surg Engl ; 102(1): e7-e11, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31530171

RESUMO

Ehlers-Danlos syndrome is a hereditary connective tissue disorder that has gastrointestinal manifestations in over 50% of its cases. We present the first case of bariatric surgery in a patient with Ehlers-Danlos syndrome and outline management challenges in the context of the relevant literature. A 56-year-old man with type IV Ehlers-Danlos syndrome and a body mass index of 41.8 kg/m2 was referred to the bariatric centre of the Churchill Hospital, Oxford, for consideration of surgery for morbid obesity. His comorbidity included type 2 diabetes, hypertension, dyslipidaemia and obstructive sleep apnoea. He underwent a laparoscopic Roux-en-Y gastric bypass. His initial recovery was uneventful and he was discharged on the first postoperative day. Six weeks later, he presented with 43.9% excess weight loss and improved glycaemic control. Three months postoperatively, however, he complained of dysphagia, regurgitation and postprandial pain. A barium meal and gastroscopy suggested the presence of a gastric diverticulum. A surgical exploration was planned. Intraoperative gastroscopy demonstrated an asymmetrical gastric pouch dilatation and the pouch was therefore refashioned laparoscopically. Despite the initial symptomatic relief, two months later he experienced retrosternal pain with progressive dysphagia. Since then, multiple endoscopic dilatations of the gastro-oesophageal junction have been performed for recurrence of symptoms. Finally, a laparoscopic hiatus hernia repair and adhesiolysis was performed resulting in complete relief of patient's symptoms. Bariatric management of patients with Ehlers-Danlos syndrome can prove challenging. The bariatric team must implement a careful management plan including a detailed consent process, a tailored surgical intervention and a follow-up focused on potential gastrointestinal manifestations.


Assuntos
Síndrome de Ehlers-Danlos/complicações , Obesidade Mórbida/cirurgia , Transtornos de Deglutição/etiologia , Diabetes Mellitus Tipo 2/complicações , Endoscopia do Sistema Digestório/métodos , Derivação Gástrica/métodos , Hérnia Hiatal/diagnóstico , Hérnia Hiatal/etiologia , Hérnia Hiatal/cirurgia , Herniorrafia/métodos , Humanos , Laparoscopia/métodos , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/complicações , Dor Pós-Operatória/etiologia , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Reoperação
7.
Sci Rep ; 8(1): 7265, 2018 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-29739952

RESUMO

Oxaliplatin-based chemotherapy is used to treat patients with esophageal adenocarcinoma (EAC), but no biomarkers are currently available for patient selection. We performed a prospective, clinical trial to identify potential biomarkers associated with clinical outcomes. Tumor tissue was obtained from 38 patients with resectable EAC before and after 2 cycles of oxaliplatin-fluorouracil chemotherapy. Pre-treatment mRNA expression of 280 DNA repair (DNAR) genes was tested for association with histopathological regression at surgery, disease-free survival (DFS) and overall survival (OS). High expression of 13 DNA damage repair genes was associated with DFS less than one year (P < 0.05); expression of 11 DNAR genes were associated with worse OS (P < 0.05). From clinical associations with outcomes, two genes, ERCC1 and EME1, were identified as candidate biomarkers. In cell lines in vitro, we showed the mechanism of action related to repair of oxaliplatin-induced DNA damage by depletion and knockout of protein binding partners of the candidate biomarkers, XPF and MUS81 respectively. In clinical samples from the clinical trial, pre-treatment XPF protein levels were associated with pathological response, and MUS81 protein was associated with 1-year DFS. XPF and MUS81 merit further validation in prospective clinical trials as biomarkers that may predict clinical response of EAC to oxaliplatin-based chemotherapy.


Assuntos
Adenocarcinoma/genética , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Neoplasias Esofágicas/genética , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Biomarcadores Tumorais/genética , Dano ao DNA/efeitos dos fármacos , Intervalo Livre de Doença , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/patologia , Feminino , Fluoruracila/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Oxaliplatina/administração & dosagem , Biossíntese de Proteínas/efeitos dos fármacos
8.
AJNR Am J Neuroradiol ; 39(2): 208-216, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28982791

RESUMO

Radiomics describes a broad set of computational methods that extract quantitative features from radiographic images. The resulting features can be used to inform imaging diagnosis, prognosis, and therapy response in oncology. However, major challenges remain for methodologic developments to optimize feature extraction and provide rapid information flow in clinical settings. Equally important, to be clinically useful, predictive radiomic properties must be clearly linked to meaningful biologic characteristics and qualitative imaging properties familiar to radiologists. Here we use a cross-disciplinary approach to highlight studies in radiomics. We review brain tumor radiologic studies (eg, imaging interpretation) through computational models (eg, computer vision and machine learning) that provide novel clinical insights. We outline current quantitative image feature extraction and prediction strategies with different levels of available clinical classes for supporting clinical decision-making. We further discuss machine-learning challenges and data opportunities to advance radiomic studies.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Aprendizado de Máquina , Neuroimagem/métodos , Humanos
9.
Mol Imaging Biol ; 20(1): 4-20, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28971346

RESUMO

The 6th annual meeting to address key issues in positron emission tomography (PET)/magnetic resonance imaging (MRI) was held again in Tübingen, Germany, from March 27 to 29, 2017. Over three days of invited plenary lectures, round table discussions and dialogue board deliberations, participants critically assessed the current state of PET/MRI, both clinically and as a research tool, and attempted to chart future directions. The meeting addressed the use of PET/MRI and workflows in oncology, neurosciences, infection, inflammation and chronic pain syndromes, as well as deeper discussions about how best to characterise the tumour microenvironment, optimise the complementary information available from PET and MRI, and how advanced data mining and bioinformatics, as well as information from liquid biomarkers (circulating tumour cells and nucleic acids) and pathology, can be integrated to give a more complete characterisation of disease phenotype. Some issues that have dominated previous meetings, such as the accuracy of MR-based attenuation correction (AC) of the PET scan, were finally put to rest as having been adequately addressed for the majority of clinical situations. Likewise, the ability to standardise PET systems for use in multicentre trials was confirmed, thus removing a perceived barrier to larger clinical imaging trials. The meeting openly questioned whether PET/MRI should, in all cases, be used as a whole-body imaging modality or whether in many circumstances it would best be employed to give an in-depth study of previously identified disease in a single organ or region. The meeting concluded that there is still much work to be done in the integration of data from different fields and in developing a common language for all stakeholders involved. In addition, the participants advocated joint training and education for individuals who engage in routine PET/MRI. It was agreed that PET/MRI can enhance our understanding of normal and disrupted biology, and we are in a position to describe the in vivo nature of disease processes, metabolism, evolution of cancer and the monitoring of response to pharmacological interventions and therapies. As such, PET/MRI is a key to advancing medicine and patient care.


Assuntos
Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Humanos , Biópsia Líquida , Radioterapia Guiada por Imagem , Microambiente Tumoral
10.
Anaesth Intensive Care ; 45(6): 707-713, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29137581

RESUMO

Malignant hyperthermia (MH) is a hypermetabolic disorder of skeletal muscle triggered almost exclusively by potent inhalational agents and suxamethonium. Signs of an MH reaction are non-specific and may be confused with the presentation of other problems such as sepsis and overheating of a patient. A high index of suspicion is needed to be aware of an early presentation of MH. Nine patients are presented who showed abnormal signs with an earlier anaesthetic where the possible diagnosis of an MH reaction was missed. These patients either presented later with an MH reaction, confirmed by DNA analysis and in some cases in vitro contracture testing, or were diagnosed by the identification of a causative mutation confirming MH susceptibility. The MH clinical grading scale is helpful in determining the likelihood that clinical indicators indicate a possible MH reaction. Masseter muscle rigidity is a known sign of MH, confirmed in this report by positive in vitro contracture testing and DNA analysis. Several uncommon muscle disorders have a high association with MH, and postoperative myalgia unrelated to suxamethonium can be a sign which is associated with MH. These reports emphasise the importance of a thorough family history (as the MH status was known by the family in four patients), a high index of suspicion for MH, and documentation of the possibility of MH susceptibility in the anaesthesia record.


Assuntos
Hipertermia Maligna/diagnóstico , Adolescente , Adulto , Criança , DNA/análise , Suscetibilidade a Doenças , Feminino , Humanos , Masculino , Hipertermia Maligna/etiologia , Hipertermia Maligna/genética , Rigidez Muscular
12.
Br J Surg ; 104(4): 408-417, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28093719

RESUMO

BACKGROUND: The ability to predict recurrence and survival after neoadjuvant chemotherapy (NAC) and surgery for oesophageal cancer remains elusive. This study evaluated the role of [18 F]fluorodeoxyglucose (FDG) PET-CT in assessing tumour and nodal response as a prognostic marker. METHODS: This was a single-centre UK cohort study. From 2006 to 2014, patients with oesophageal cancer staged with PET-CT before NAC, and restaged by CT or PET-CT before resection, were included. Pathological tumour response was evaluated using Mandard regression grades. Metabolic tumour and nodal responses (mTR and mNR respectively) were quantified using absolute and threshold reductions. RESULTS: Among 294 included patients, mTR and mNR independently predicted prognosis before surgery. After surgery, mNR (but not mTR), pathological tumour response, resection margin status and pathological node category predicted prognosis. Patients with FDG-avid nodal disease after NAC were at high risk of recurrence/death at 1 and 2 years (43 and 71 per cent respectively; P = 0·030 and P = 0·025 versus patients without avid nodes), and had a worse prognosis than patients with non-avid nodal metastases: hazard ratio 4·19 (95 per cent c.i. 1·87 to 9·40) and 2·11 (1·12 to 3·97) respectively versus patients without nodal metastases. Considering mTR and mNR response separately improved prognostication. CONCLUSION: mNR is a novel prognostic factor, independent of conventional N status. Primary and nodal tumours may respond discordantly and patients with FDG-avid nodes after NAC have a poor prognosis.


Assuntos
Neoplasias Esofágicas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/terapia , Feminino , Fluordesoxiglucose F18 , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante/mortalidade , Recidiva Local de Neoplasia/etiologia , Estadiamento de Neoplasias , Prognóstico , Compostos Radiofarmacêuticos
13.
Anaesth Intensive Care ; 44(6): 762-768, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27832566

RESUMO

The genetic basis of malignant hyperthermia (MH) is not fully characterised and likely involves more than just the currently classified mutations in the gene encoding the skeletal muscle ryanodine receptor (RYR1) and the gene encoding the α1 subunit of the dihydropyridine receptor (CACNA1S). In this paper we sequence other genes involved in calcium trafficking within skeletal muscle in patients with positive in vitro contracture tests, searching for alternative genes associated with MH. We identified four rare variants in four different genes (CACNB1, CASQ1, SERCA1 and CASQ2) encoding proteins involved in calcium handling in skeletal muscle in a cohort of 30 Australian MH susceptible probands in whom prior complete sequencing of RYR1 and CACNA1S had yielded no rare variants. These four variants have very low minor allele frequencies and while it is tempting to speculate that they have a role in MH, they remain at present variants of unknown significance. Nevertheless they provide the basis for a new set of functional studies, which may indeed identify novel players in MH.


Assuntos
Cálcio/metabolismo , Hipertermia Maligna/genética , Músculo Esquelético/metabolismo , Retículo Sarcoplasmático/metabolismo , Transporte Biológico , Canais de Cálcio/genética , Canais de Cálcio Tipo L , Calsequestrina/genética , Humanos , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética
14.
Mol Imaging Biol ; 18(5): 637-50, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27534971

RESUMO

This article provides a collaborative perspective of the discussions and conclusions from the fifth international workshop of combined positron emission tomorgraphy (PET)/magnetic resonance imaging (MRI) that was held in Tübingen, Germany, from February 15 to 19, 2016. Specifically, we summarise the second part of the workshop made up of invited presentations from active researchers in the field of PET/MRI and associated fields augmented by round table discussions and dialogue boards with specific topics. This year, this included practical advice as to possible approaches to moving PET/MRI into clinical routine, the use of PET/MRI in brain receptor imaging, in assessing cardiovascular diseases, cancer, infection, and inflammatory diseases. To address perceived challenges still remaining to innovatively integrate PET and MRI system technologies, a dedicated round table session brought together key representatives from industry and academia who were engaged with either the conceptualisation or early adoption of hybrid PET/MRI systems. Discussions during the workshop highlighted that emerging unique applications of PET/MRI such as the ability to provide multi-parametric quantitative and visual information which will enable not only overall disease detection but also disease characterisation would eventually be regarded as compelling arguments for the adoption of PET/MR. However, as indicated by previous workshops, evidence in favour of this observation is only growing slowly, mainly due to the ongoing inability to pool data cohorts from independent trials as well as different systems and sites. The participants emphasised that moving from status quo to status go entails the need to adopt standardised imaging procedures and the readiness to act together prospectively across multiple PET/MRI sites and vendors.


Assuntos
Imageamento por Ressonância Magnética , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Animais , Doença , Alemanha , Humanos
15.
J Orthop Case Rep ; 6(1): 40-3, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27299124

RESUMO

INTRODUCTION: This is a report of a mechanical failure of an S-ROM revision total knee prosthesis. The prosthesis was used as a revision implant following deep peri-prosthetic infection in a morbidly obese male. The prosthesis failed on both the femoral and tibial sides at the modular metaphyseal stem junctions and required a further revision using the same type of implant after infection was excluded. CASE PRESENTATION: A 57 year old male had previously undergone a left total knee arthroplasty in 1999 for osteoarthritis. He acquired a late deep peri-prosthetic infection with a multi-resistant Staphylococcus epidermidis. The organism was sensitive to vancomycin and rifampicin. A two stage revision was undertaken after clinical signs of infection had resolved and blood parameters had normalized. Intra-operative gram stain was negative for micro-organisms and frozen section of deep tissue was less than five polymorphs per high power field. A cemented S-ROM prosthesis was implanted using a coronal tibial osteotomy and a lateral release for exposure. After three years of the second stage of revision, the patient again presented to the orthopaedic department after reportedly falling on a wet floor six weeks ago. CONCLUSION: Radiographically, there was a broken tibial wire, osteolysis and pedestal formation around both the femoral and distal tibial stem extensions. The prosthesis was bent at the proximal tibial sleeve and stem junction. The prosthesis was considered loose with mechanical failure. At implant removal, it was noted that the femoral and tibial components at the modular metaphyseal sleeve-stem junction were fractured. Surgeons should be cautious in the use of these implants in morbidly obese patients where the stresses generated maybe above the yield stress of the material and the frictional forces that may overcome the modular taper junction's locking mechanism.

16.
Br J Surg ; 102(12): 1488-99, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26458070

RESUMO

BACKGROUND: Following CT, guidelines for staging oesophageal and gastro-oesophageal junction (GOJ) cancer recommend endoscopic ultrasonography (EUS), PET-CT and laparoscopy for T3-T4 GOJ tumours. These recommendations are based on generic utilities, but it is unclear whether the test risk outweighs the potential benefit for some patients. This study sought to quantify investigation risks, benefits and utilities, in order to develop pragmatic, personalized staging recommendations. METHODS: All patients with a histological diagnosis of oesophageal or GOJ cancer staged between May 2006 and July 2013 comprised a development set; those staged from July 2013 to July 2014 formed the prospective validation set. Probability thresholds of altering management were calculated and predictive factors identified. Algorithms and models (decision tree analysis, logistic regression, artificial neural networks) were validated internally and independently. RESULTS: Some 953 patients were staged following CT, by [(18) F]fluorodeoxyglucose PET-CT (918), EUS (798) and laparoscopy (458). Of these patients, 829 comprised the development set (800 PET-CT, 698 EUS, 397 laparoscopy) and 124 the validation set (118 PET-CT, 100 EUS, 61 laparoscopy). EUS utility in the 71.8 per cent of patients with T2-T4a disease on CT was minimal (0.4 per cent), its risk exceeding benefit. EUS was moderately accurate for pT1 N0 disease. A number of factors predicted metastases on PET-CT and laparoscopy, although none could inform an algorithm. PET-CT altered management in 23.0 per cent, and laparoscopy in 7.1 per cent, including those with T2 and distal oesophageal tumours. CONCLUSION: Although EUS provided additional information on T and N category, its risk outweighed potential benefit in patients with T2-T4a disease on CT. Laparoscopy seemed justified for distal oesophageal tumours of T2 or greater.


Assuntos
Teoria da Decisão , Endossonografia/métodos , Neoplasias Esofágicas/diagnóstico , Laparoscopia/métodos , Tomografia Computadorizada Multidetectores/métodos , Estadiamento de Neoplasias/métodos , Tomografia por Emissão de Pósitrons/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Junção Esofagogástrica/diagnóstico por imagem , Feminino , Fluordesoxiglucose F18 , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes
17.
Biomed Mater Eng ; 25(3): 267-78, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26407113

RESUMO

BACKGROUND: The design of femoral component used in total hip arthroplasty is known to influence the incidence of periprosthetic femoral fractures (PFFs) in cementless hip arthroplasty. OBJECTIVE: This study was undertaken to determine if 2 potential changes to an existing ABG II-standard cementless implant - addition of a roughened titanium plasma-sprayed proximal coating (ABG II-plasma) and lack of medial scales (ABG II-NMS) could decrease the risk of PFF in the intraoperative and early postoperative periods. METHODS: Six pairs of human cadaveric femurs were harvested and divided into 2 groups, each receiving either of the altered implants and ABG II-standard (control). Each implant was tested in a biomechanical setup in a single-legged stance orientation. Surface strains were measured in intact femurs, during implant insertion, cyclic loading of the bone with the implant, and loading to failure. Strains with the ABG II-standard and the altered implants were compared. FINDINGS: ABG II-plasma showed better load-bearing capacity, with an average 42% greater failure load than that of ABG II-standard. The cortical hoop, axial and mean strains ABG II-plasma were less than those of ABG II-standard, demonstrating decreased tensile behaviour and better load transfer to the proximal femur. The final residual hoop strains in ABG II-plasma were closer to those of intact bone as compared to the standard stem. No differences in strains were observed between the standard stem and ABG II-NMS. CONCLUSION: The increased load-bearing capacity and decreased proximal surface strains on femurs implanted with ABG II-plasma stem should reduce the risks of intraoperative and early postoperative PFF.


Assuntos
Fraturas do Fêmur/prevenção & controle , Fraturas do Fêmur/fisiopatologia , Prótese de Quadril/efeitos adversos , Fraturas Periprotéticas/prevenção & controle , Fraturas Periprotéticas/fisiopatologia , Titânio/química , Adulto , Idoso , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/instrumentação , Artroplastia de Quadril/métodos , Cadáver , Cimentação , Materiais Revestidos Biocompatíveis/síntese química , Força Compressiva , Módulo de Elasticidade , Análise de Falha de Equipamento , Feminino , Fraturas do Fêmur/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas Periprotéticas/etiologia , Gases em Plasma/química , Desenho de Prótese , Medição de Risco , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração , Resultado do Tratamento
18.
Anaesth Intensive Care ; 43(2): 157-66, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25735680

RESUMO

Defects in the genes coding for the skeletal muscle ryanodine receptor (RYR1) and alpha 1 subunit of the dihydropyridine receptor (CACNA1S) have been identified as causative for malignant hyperthermia (MH). Sixty-two MH susceptible individuals presenting to the same diagnostic centre had copy deoxyribonucleic acid, derived from muscle ribonucleic acid, sequenced to identify variants with the potential to be responsible for the MH phenotype in both RYR1 and CACNA1S. These genetic findings were combined with clinical episode details and in vitro contracture test results to improve our understanding of the Australian MH cohort. Twelve novel variants were identified in RYR1 and six in CACNA1S. Known RYR1 causative mutations were identified in six persons and novel variants in RYR1 and CACNA1S in a further 17 persons. Trends indicated higher mutation identification in those with more definitive clinical episodes and stronger in vitro contracture test responses.


Assuntos
Canais de Cálcio/genética , Hipertermia Maligna/genética , Mutação , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Austrália , Canais de Cálcio Tipo L , Saúde da Família , Predisposição Genética para Doença/genética , Variação Genética/genética , Humanos , Mutação/genética , Análise de Sequência/métodos
19.
BJOG ; 122(2): 183-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25546039

RESUMO

BACKGROUND: Of the 287,000 maternal deaths every year, 99% happen in low- and middle-income countries. The vast majority could be averted with timely access to appropriate emergency obstetric care (EmOC). The proportion of women with complications of pregnancy or childbirth who actually receive treatment is reported as 'Met need for EmOC'. OBJECTIVE: To estimate the global met need for EmOC and to examine the correlation between met need, maternal mortality ratio and other indicators. SEARCH STRATEGY: A systematic review was performed according to the PRISMA guidelines. Searches were made in PubMed, EMBASE and Google Scholar. SELECTION CRITERIA: Studies containing data on met need in EmOC were selected. DATA COLLECTION AND ANALYSIS: Analysis was performed with data extracted from 62 studies representing 51 countries. World Bank data were used for univariate and multiple linear regression. MAIN RESULTS: Global met need for EmOC was 45% (IQR: 28-57%), with significant disparity between low- (21% [12-31%]), middle- (32% [15-56%]), and high-income countries (99% [99-99%]), (P = 0.041). This corresponds to 11.4 million (8.8-14.8) untreated complications yearly and 951 million (645-1174 million) women without access to EmOC. We found an inverse correlation between met need and maternal mortality ratio (r = -0.42, P < 0.001). Met need was significantly correlated with the proportion of births attended by skilled birth attendants (ß = 0.53 [95% CI 0.41-0.65], P < 0.001). AUTHORS' CONCLUSIONS: The results suggest a considerable inadequacy in global met need for EmOC, with vast disparities between countries of different income levels. Met need is a powerful indicator of the response to maternal mortality and strategies to improve EmOC act in synergy with the expansion of skilled birth attendance.


Assuntos
Países Desenvolvidos/estatística & dados numéricos , Países em Desenvolvimento/estatística & dados numéricos , Serviços Médicos de Emergência/provisão & distribuição , Saúde Global , Necessidades e Demandas de Serviços de Saúde , Obstetrícia , Feminino , Humanos , Mortalidade Materna , Gravidez
20.
Dis Esophagus ; 28(6): 567-73, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24835109

RESUMO

Enhanced recovery after surgery (ERAS) pathways aim to accelerate functional return and discharge from hospital. They have proven effective in many forms of surgery, most notably colorectal. However, experience in esophagectomy has been limited. A recent study reported significant reductions in pulmonary complications, mortality, and length of stay following the introduction of an ERAS protocol alone, without the introduction of any clinical changes. We instituted a similar change 16 months ago, introducing a protocol to provide a formal framework, for our existing postoperative care. This retrospective analysis compared outcome following esophagectomy for the 16 months before and 20 months after this change. Data were collected from prospectively maintained secure web-based multidisciplinary databases. Complication severity was classified using the Clavien-Dindo scale. Operative mortality was defined as death within 30 days of surgery, or at any point during the same hospital admission. Lower respiratory tract infection was defined as clinical evidence of infection, with or without radiological signs. Respiratory complications included lower respiratory tract infection, pleural effusion (irrespective of drainage), pulmonary collapse, and pneumothorax. Statistical analysis was performed using SPSS v21. One hundred thirty-two patients underwent esophagectomy (55 protocol group; 77 before). All were performed open. There were no differences between the two groups in terms of age, gender, operation, use of neoadjuvant therapy, cell type, stage, tumor site, or American Society of Anesthesiologists grade. Median length of stay was 14.0 days (protocol) compared with 12.0 before (interquartile range 9-19 and 9.5-15.5, respectively; P = 0.073, Mann-Whitney U-test). Readmission within 30 days of discharge occurred in five (9.26%) and six (8.19%; P = 1.000, Fisher's exact test). There were four in-hospital deaths (3.03%): one (1.82%) and three (3.90%), respectively (P = 0.641). There were no differences in the severity of complications (P = non-significant; Pearson's chi-squared). There were no differences in the type of complications occurring in either group. The protocol was completed successfully by 26 (47.3%). No baseline factors were predictive of this. In contrast to previous studies, we did not demonstrate any improvement in outcome by formalizing our existing pathway using a written protocol. Consequently, improvements in short-term outcome from esophagectomy within ERAS would seem to be primarily due to improvements in components of perioperative care. Consequently, we would recommend that centers introducing new (or reviewing existing) ERAS pathways for esophagectomy focus on optimizing clinical aspects of such standardized pathways.


Assuntos
Assistência ao Convalescente/normas , Procedimentos Clínicos/normas , Esofagectomia/reabilitação , Cuidados Pós-Operatórios/normas , Assistência ao Convalescente/métodos , Assistência ao Convalescente/estatística & dados numéricos , Idoso , Procedimentos Clínicos/estatística & dados numéricos , Esofagectomia/estatística & dados numéricos , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios/métodos , Cuidados Pós-Operatórios/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento
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