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1.
S Afr J Surg ; 59(4): 183-190, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34889544

RESUMO

BACKGROUND: Having a mentor during undergraduate surgical training has been shown to positively influence medical students by increasing interest in surgery, improving confidence, and assisting in career planning. This study aimed to evaluate and compare medical student and faculty perceptions of mentorship during undergraduate surgical training and compare results between two teaching institutions in South Africa and Sweden. METHODS: An electronic, online questionnaire was anonymously distributed to medical students and general surgical faculty at the University of Cape Town (UCT), South Africa, and Karolinska Institutet (KI), Stockholm, Sweden. The questionnaire consisted of multiple choice, true or false, and five-point Likert scale questions, exploring perceptions of mentorship and role models, as well as rating the most important mentor characteristics. RESULTS: Approximately one third (34.2%) of students stated they had a mentor during their surgical training, with significant differences found between student cohorts (p < 0.001). The 'registrar' was most commonly reported as the best role model for medical students by faculty from both UCT (50.0%) and KI (69.4%), as well as UCT students (36.6%). Students rated the following mentor qualities significantly higher compared to faculty: student encouragement (p = 0.037), adequate supervision (p = 0.007), setting of fair expectations (p = 0.002), and teaching skills (p = 0.010). CONCLUSION: With significant differences existing in the perceptions of medical students and faculty regarding mentorship and role models during undergraduate surgical training in both South African and Swedish institutions, reconciling and harmonising these differences will be crucial in fostering constructive mentoring relationships.


Assuntos
Mentores , Estudantes de Medicina , Docentes , Humanos , África do Sul , Suécia
3.
Surg Endosc ; 34(9): 3992-3998, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31617091

RESUMO

BACKGROUND: Colon cancer (CC) is the third most commonly diagnosed cancer in the USA. While the overall incidence is declining, it is rising alarmingly in young patients (EOCC). CC in young patients tends to be more aggressive and often diagnosed at more advanced stages and portend poorer prognosis. Our recently published data showed that EOCC is a distinct disease with unique molecular features compared to late-onset CC (LOCC). The Cartilage Oligomeric Matrix Protein (COMP) was shown to be significantly upregulated in EOCC and correlated with poor survival. However, the role of COMP in CC tumorigenesis, especially in young patients, is not well understood. Thus, the aim of this study was to elucidate the role of COMP in CC tumorigenesis by modulating COMP levels in vitro and test how it affects proliferation. Then, patient samples were evaluated by testing the levels of proliferation marker Ki67. In addition, this study investigates whether higher transcriptional mRNA levels of COMP seen in more aggressive early-onset CC correlate with protein levels compared to late-onset CC. METHODS: COMP mRNA levels in fresh frozen colon tumors (young: n = 5; old: n = 5) were assessed by quantitative PCR (qPCR). Additionally, CC cell lines were profiled for COMP expression to choose an in vitro model to study the role of COMP in CC tumorigenesis. HT-29 (low COMP expression) and CaCo-2 (high COMP expression) cells were used for in vitro proliferation studies. Immunohistochemical (IHC) analysis was conducted to assess COMP and Ki67 protein levels in formalin-fixed paraffin-embedded (FFPE) colon tumors. RESULTS: Significantly higher COMP expression levels were observed in fresh frozen EOCC compared to LOCC tumors. This observation confirmed our previously reported results from NanoString gene expression assay using FFPE samples. Cell proliferation was significantly increased in HT-29 and CaCo-2 cells upon treatment with human recombinant COMP protein after 48 and 72 h (P < 0.05). This increase was more profound in HT-29 cells. Staining for COMP and Ki67 revealed high COMP protein levels in EOCC compared to LOCC patients. CONCLUSION: COMP mRNA and protein levels are significantly higher in EOCC patients. Higher COMP levels correlate with increased proliferation suggesting a role in CC tumorigenesis.


Assuntos
Carcinogênese/genética , Proteína de Matriz Oligomérica de Cartilagem/genética , Neoplasias do Colo/genética , Regulação Neoplásica da Expressão Gênica , Adulto , Idoso , Proteína de Matriz Oligomérica de Cartilagem/biossíntese , Linhagem Celular Tumoral , Proliferação de Células , Transformação Celular Neoplásica , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Neoplásico/genética
4.
Diabet Med ; 37(2): 319-325, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31769619

RESUMO

AIMS: A randomized control trial (RCT) of diabetes self-management education (DSME), undertaken by a community-based participatory research (CBPR) partnership between the University of Arkansas for Medical Sciences (UAMS) and the Marshallese community in Arkansas. The RCT examined the effect of hours of intervention exposure, with the hypothesis that increased exposure is one reason the Adapted-Family DSME was found to be more effective than the Standard DSME. METHODS: Some 221 Marshallese with type 2 diabetes were randomized to an Adapted-Family DSME group (in-home setting) (n = 110) or a Standard DMSE group (community setting) (n = 111). The Adapted-Family DSME included 10 h of education that covered the core self-care elements recommended by the American Diabetes Association (ADA) and American Association of Diabetes Educators' (AADE) recommendations. The Standard DSME included 10 h of intervention with all ADA and AADE core elements. RESULTS: The number of hours of intervention exposure in the Adapted-Family DSME arm (mean = 8.0; median = 10.0) was significantly higher than the number of hours of intervention received in the Standard DSME arm (mean = 1.5; median = 0.0). As hypothesized, higher exposure was associated with a significant reduction in HbA1c in a model including only study arm and exposure (P = 0.01), and in a model including study arm, exposure, and all demographic variables (P = 0.046). CONCLUSIONS: This finding is consistent with previous reviews that showed increased exposure to DSME produced improved glycaemic control and ≥ 10 h of DSME produces clinically meaningful reductions in HbA1c .


Assuntos
Pesquisa Participativa Baseada na Comunidade , Assistência à Saúde Culturalmente Competente , Diabetes Mellitus Tipo 2/terapia , Havaiano Nativo ou Outro Ilhéu do Pacífico , Educação de Pacientes como Assunto/métodos , Autogestão/educação , Adulto , Idoso , Idoso de 80 Anos ou mais , Arkansas , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Micronésia/etnologia , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento
5.
J Laryngol Otol ; 133(2): 129-134, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30773143

RESUMO

OBJECTIVE: Total laryngectomy is considered the primary treatment modality for advanced laryngeal carcinoma. This study assessed the quality of life in patients after total laryngectomy, and ascertained whether quality of life is affected by socioeconomic status. METHOD: Forty-seven patients (20 state- and 27 private-sector) who underwent total laryngectomy between 1998 and 2014 responded to the University of Washington Quality of Life Questionnaire, the Voice-Related Quality of Life Questionnaire and the Brief Illness Perception Questionnaire. RESULTS: Significant differences were found in socioeconomic status between state- and private-sector patients (p < 0.001). There was no significant difference in overall quality of life between groups (p = 0.210). State-sector patients scored significantly higher Voice-Related Quality of Life Questionnaire scores (p = 0.043). Perception of illness did not differ significantly between groups. CONCLUSION: Overall quality of life after total laryngectomy appears to be similar in patients from different socioeconomic backgrounds. However, patients from lower socioeconomic circumstances have better voice-related quality of life. The results illustrate the importance of including socioeconomic status when reporting voice outcomes in total laryngectomy patients.


Assuntos
Neoplasias Laríngeas/cirurgia , Laringectomia , Qualidade de Vida , Qualidade da Voz , Idoso , Estudos Transversais , Feminino , Humanos , Neoplasias Laríngeas/psicologia , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Classe Social , Inquéritos e Questionários
6.
World J Surg ; 42(12): 3874-3879, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29947990

RESUMO

AIMS: Post-operative urinary retention (POUR) is a common cause of unplanned admission following day-case surgery and has negative effects on both patient and surgical institution. We aimed to prospectively evaluate potential risk factors for the development of POUR following day-case general surgical procedures. METHODS: Over a 24-week period, consecutive adult patients undergoing elective day-case general surgery at a single institution were prospectively recruited. Data regarding urinary symptoms, comorbidities, drug history, surgery and perioperative anaesthetic drug use were collected. The primary outcome was the incidence of POUR, defined as an impairment of bladder voiding requiring either urethral catheterisation, unplanned overnight admission or both. Potential risk factors for the development of POUR were analysed by logistic regression. RESULTS: A total of 458 patients met the inclusion criteria during the study period, and data were collected on 382 (83%) patients (74.3% male). Sixteen patients (4.2%) experienced POUR. Unadjusted analysis demonstrated three significant risk factors for the development of POUR: age ≥ 56 years (OR 7.77 [2.18-27.78], p = 0.002), laparoscopic surgery (OR 3.37 [1.03-12.10], p = 0.044) and glycopyrrolate administration (OR 5.56 [2.00-15.46], p = 0.001). Male sex and lower urinary tract symptoms were not significant factors. Multivariate analysis combining type of surgery, age and glycopyrrolate use revealed that only age ≥ 56 years (OR 8.14 [2.18-30.32], p = 0.0018) and glycopyrrolate administration (OR 3.48 [1.08-11.24], p = 0.0370) were independently associated with POUR. CONCLUSIONS: Patients aged at least 56 years and/or requiring glycopyrrolate-often administered during laparoscopic procedures-are at increased risk of POUR following ambulatory general surgery.


Assuntos
Procedimentos Cirúrgicos Ambulatórios/efeitos adversos , Laparoscopia/efeitos adversos , Retenção Urinária/epidemiologia , Fatores Etários , Procedimentos Cirúrgicos Eletivos/efeitos adversos , Análise Fatorial , Feminino , Glicopirrolato/administração & dosagem , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Fatores de Risco , Retenção Urinária/etiologia
7.
S Afr J Surg ; 55(2): 2-5, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28876615

RESUMO

The International Association of Student Surgical Societies (IASSS) was founded in 2011 to link up student surgical societies from around the world. These Societies have been formed by students with an aim to promote interest in surgical education and research amongst undergraduate medical students. Their formation has been fostered by the recent realization that adequate surgical care is a neglected component of global public health.1 The insufficient number of trained surgeons is one of the many barriers to meeting global surgical needs, especially in middle- and low-income countries. This barrier is one the IASSS aims to address.2,3 Since its inauguration, the IASSS has been active in creating opportunities for undergraduate medical students across the world to explore the full spectrum of surgery.

8.
S Afr J Surg ; 55(2): 24-30, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28876620

RESUMO

BACKGROUND: Many factors play a role in the decision of a medical student to pursue a career in surgery. With a decline in numbers of applications into surgical programmes seen globally, the aim of this study was to determine the factors that influence medical students in pursuing a career in surgery. METHOD: A descriptive, cross-sectional survey was distributed online to all medical students studying at a tertiary, academic institution. Survey items obtained data on demographics, surgical interest and training, as well as factors affecting a surgical career. RESULTS: A total of 245 medical students responded, of which 56% were female. The majority (69%) stated they were interested in pursuing a career in surgery. Despite 75% of respondents stating South Africa was a good place for surgical training, females reported significantly higher levels of agreement that surgical training would be better overseas when compared to males (p = 0.027). Overall, 20% were undecided on what surgical specialty they would pursue. The largest proportion of respondents (33%) stated that 'Length of training' was the main barrier to pursuing a career in surgery. Thirtythree (13.5%) respondents reported 'Female-unfriendly' as a barrier, of whom all were female. The greatest motivator to pursuing a career in surgery was 'Hands-on work', stated by 36% of respondents. CONCLUSION: Though length of surgical training was deemed the principal barrier, the majority of students indicated they would pursue a career in surgery. Despite continued perceptions that surgery poses a female-unfriendly environment as a career, respondents held South African surgical training in high esteem, and were motivated by a clinically hands-on approach. These factors may play an important role in determining methods of improving numbers of surgical applications worldwide.


Assuntos
Escolha da Profissão , Educação de Pós-Graduação em Medicina , Educação de Graduação em Medicina , Cirurgia Geral/educação , Estudantes de Medicina/psicologia , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , África do Sul , Inquéritos e Questionários , Adulto Jovem
10.
J Phys Condens Matter ; 29(22): 225303, 2017 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-28394256

RESUMO

Electron energy loss spectroscopy (EELS) is a powerful tool for understanding the chemical structure of materials down to the atomic level, but challenges remain in accurately and quantitatively modelling the response. We compare comprehensive theoretical density functional theory (DFT) calculations of 1s core-level EEL K-edge spectra of pure, B-doped and N-doped graphene with and without a core-hole to previously published atomic-resolution experimental electron microscopy data. The ground state approximation is found in this specific system to perform consistently better than the frozen core-hole approximation. The impact of including or excluding a core-hole on the resultant theoretical band structures, densities of states, electron densities and EEL spectra were all thoroughly examined and compared. It is concluded that the frozen core-hole approximation exaggerates the effects of the core-hole in graphene and should be discarded in favour of the ground state approximation. These results are interpreted as an indicator of the overriding need for theorists to embrace many-body effects in the pursuit of accuracy in theoretical spectroscopy instead of a system-tailored approach whose approximations are selected empirically.

11.
Surgeon ; 15(4): 190-195, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26791394

RESUMO

INTRODUCTION: Completion of hand-written consent forms for surgical procedures may suffer from missing or inaccurate information, poor legibility and high variability. We audited the completion of hand-written consent forms and trialled a web-based application to generate modifiable, procedure-specific consent forms. METHODS: The investigation comprised two phases at separate UK hospitals. In phase one, the completion of individual responses in hand-written consent forms for a variety of procedures were prospectively audited. Responses were categorised into three domains (patient details, procedure details and patient sign-off) that were considered "failed" if a contained element was not correct and legible. Phase two was confined to a breast surgical unit where hand-written consent forms were assessed as for phase one and interrogated for missing complications by two independent experts. An electronic consent platform was introduced and electronically-produced consent forms assessed. RESULTS: In phase one, 99 hand-written consent forms were assessed and the domain failure rates were: patient details 10%; procedure details 30%; and patient sign-off 27%. Laparoscopic cholecystectomy was the most common procedure (7/99) but there was significant variability in the documentation of complications: 12 in total, a median of 6 and a range of 2-9. In phase two, 44% (27/61) of hand-written forms were missing essential complications. There were no domain failures amongst 29 electronically-produced consent forms and no variability in the documentation of potential complications. CONCLUSION: Completion of hand-written consent forms suffers from wide variation and is frequently suboptimal. Electronically-produced, procedure-specific consent forms can improve the quality and consistency of consent documentation.


Assuntos
Termos de Consentimento/normas , Consentimento Livre e Esclarecido/normas , Melhoria de Qualidade , Procedimentos Cirúrgicos Operatórios , Termos de Consentimento/estatística & dados numéricos , Humanos , Consentimento Livre e Esclarecido/estatística & dados numéricos , Internet , Auditoria Médica , Informática Médica , Estudos Prospectivos , Garantia da Qualidade dos Cuidados de Saúde , Medicina Estatal , Reino Unido
13.
Eur J Vasc Endovasc Surg ; 51(3): 452-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26684594

RESUMO

OBJECTIVE: Growing confidence in thoracic endovascular aortic repair (TEVAR) for the management of acute type B aortic dissection has resulted in controversies regarding optimum patient selection and the timing of intervention. In this review a clinical vignette to present a practical perspective on the contemporary management of acute type B dissection (ABAD) in a specialist vascular centre with particular focus on areas of debate is used. METHODS: This is a narrative clinical review. RESULTS: Aggressive anti-impulse therapy is the cornerstone of management of all patients with ABAD. However, 20-30% of patients develop complicated ABAD defined by the presence of malperfusion syndromes, acute aortic dilatation, dissection extension, or persistent pain and hypotension. These complicated patients typically require intervention, and non-randomised series suggest TEVAR to be an effective alternative to open repair with a lower morbidity. There is considerable interest and controversy surrounding the use of TEVAR in uncomplicated ABAD patients for whom the intervention-free survival at 6 years is less than 50% for patients managed with anti-impulse therapy. Data regarding this question are sparse, but two randomised trials (ADSORB and INSTEAD) both demonstrated a higher rate of favourable aortic remodelling in patients managed with TEVAR than medical therapy alone. However, it is unclear whether this positive remodelling translates into a reduction in long-term mortality sufficient to balance the early perioperative hazards of endografting. CONCLUSION: Despite increasing adeptness at endovascular stenting, the long-term outcomes of patients with ABAD leave significant room for improvement. In particular, the optimum management of patients with uncomplicated disease is unclear and guidance from trials powered for long-term mortality is awaited. Until then, the principals of management of ABAD remain aggressive medical therapy for all patients, with TEVAR primarily reserved for those who develop complications.


Assuntos
Aneurisma da Aorta Torácica/cirurgia , Gerenciamento Clínico , Procedimentos Endovasculares/métodos , Stents , Humanos , Seleção de Pacientes
15.
Ann Oncol ; 26(9): 1923-1929, 2015 09.
Artigo em Inglês | MEDLINE | ID: mdl-26091808

RESUMO

BACKGROUND: Rigosertib (ON 01910.Na), a first-in-class Ras mimetic and small-molecule inhibitor of multiple signaling pathways including polo-like kinase 1 (PLK1) and phosphoinositide 3-kinase (PI3K), has shown efficacy in preclinical pancreatic cancer models. In this study, rigosertib was assessed in combination with gemcitabine in patients with treatment-naïve metastatic pancreatic adenocarcinoma. MATERIALS AND METHODS: Patients with metastatic pancreatic adenocarcinoma were randomized in a 2:1 fashion to gemcitabine 1000 mg/m(2) weekly for 3 weeks of a 4-week cycle plus rigosertib 1800 mg/m(2) via 2-h continuous IV infusions given twice weekly for 3 weeks of a 4-week cycle (RIG + GEM) versus gemcitabine 1000 mg/m(2) weekly for 3 weeks in a 4-week cycle (GEM). RESULTS: A total of 160 patients were enrolled globally and randomly assigned to RIG + GEM (106 patients) or GEM (54). The most common grade 3 or higher adverse events were neutropenia (8% in the RIG + GEM group versus 6% in the GEM group), hyponatremia (17% versus 4%), and anemia (8% versus 4%). The median overall survival was 6.1 months for RIG + GEM versus 6.4 months for GEM [hazard ratio (HR), 1.24; 95% confidence interval (CI) 0.85-1.81]. The median progression-free survival was 3.4 months for both groups (HR = 0.96; 95% CI 0.68-1.36). The partial response rate was 19% versus 13% for RIG + GEM versus GEM, respectively. Of 64 tumor samples sent for molecular analysis, 47 were adequate for multiplex genetic testing and 41 were positive for mutations. The majority of cases had KRAS gene mutations (40 cases). Other mutations detected included TP53 (13 cases) and PIK3CA (1 case). No correlation between mutational status and efficacy was detected. CONCLUSIONS: The combination of RIG + GEM failed to demonstrate an improvement in survival or response compared with GEM in patients with metastatic pancreatic adenocarcinoma. Rigosertib showed a similar safety profile to that seen in previous trials using the IV formulation.


Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Desoxicitidina/análogos & derivados , Glicina/análogos & derivados , Neoplasias Pancreáticas/tratamento farmacológico , Sulfonas/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/uso terapêutico , Proteínas de Ciclo Celular/antagonistas & inibidores , Classe I de Fosfatidilinositol 3-Quinases , Desoxicitidina/efeitos adversos , Desoxicitidina/uso terapêutico , Intervalo Livre de Doença , Esquema de Medicação , Feminino , Glicina/efeitos adversos , Glicina/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Fosfatidilinositol 3-Quinases/genética , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Sulfonas/efeitos adversos , Proteína Supressora de Tumor p53/genética , Gencitabina , Quinase 1 Polo-Like , Neoplasias Pancreáticas
16.
Drugs Today (Barc) ; 51(4): 223-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26020064

RESUMO

Aberrant proangiogenic pathways have long been implicated in tumorigenesis and metastasis. Antiangiogenic therapies have shown efficacy in the treatment of a variety of solid tumors including lung, breast, colon, glioblastomas, and other solid tumor types. Apatinib, a small-molecule inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2), is an orally bioavailable agent currently being studied in multiple tumor types. Apatinib has shown a survival benefit in gastric cancer in a phase III trial and non-small cell lung cancer in a phase II trial. With a favorable side effect profile and improved outcomes, apatinib has demonstrated a substantial potential to augment therapeutic options in a variety of tumor types.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Neoplasias/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Piridinas/uso terapêutico , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Administração Oral , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/farmacocinética , Ensaios Clínicos como Assunto , Humanos , Neoplasias/irrigação sanguínea , Neoplasias/metabolismo , Neoplasias/patologia , Piridinas/administração & dosagem , Piridinas/efeitos adversos , Piridinas/farmacocinética , Resultado do Tratamento
17.
Faraday Discuss ; 179: 269-89, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25873522

RESUMO

N K-edge near-edge X-ray absorption fine-structure (NEXAFS) spectra of imidazole in concentrated aqueous solutions have been acquired. The NEXAFS spectra of the solution species differ significantly from those of imidazole monomers in the gas phase and in the solid state of imidazole, demonstrating the strong sensitivity of NEXAFS to the local chemical and structural environment. In a concentration range from 0.5 to 8.2 mol L(-1) the NEXAFS spectrum of aqueous imidazole does not change strongly, confirming previous suggestions that imidazole self-associates are already present at concentrations more dilute than the range investigated here. We show that various types of electronic structure calculations (Gaussian, StoBe, CASTEP) provide a consistent and complete interpretation of all features in the gas phase and solid state spectra based on ground state electronic structure. This suggests that such computational modelling of experimental NEXAFS will permit an incisive analysis of the molecular interactions of organic solutes in solutions. It is confirmed that microhydrated clusters with a single imidazole molecule are poor models of imidazole in aqueous solution. Our analysis indicates that models including both a hydrogen-bonded network of hydrate molecules, and imidazole-imidazole interactions, are necessary to explain the electronic structure evident in the NEXAFS spectra.

18.
Br J Surg ; 102(5): 563-72, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25727811

RESUMO

BACKGROUND: Current management of suspected appendicitis is hampered by the overadmission of patients with non-specific abdominal pain and a significant negative exploration rate. The potential benefits of risk stratification by the Appendicitis Inflammatory Response (AIR) score to guide clinical decision-making were assessed. METHODS: During this 50-week prospective observational study at one institution, the AIR score was calculated for all patients admitted with suspected appendicitis. Appendicitis was diagnosed by histological examination, and patients were classified as having non-appendicitis pain if histological findings were negative or surgery was not performed. The diagnostic performance of the AIR score and the potential for risk stratification to reduce admissions, optimize imaging and prevent unnecessary explorations were quantified. RESULTS: A total of 464 patients were included, of whom 210 (63·3 per cent) with non-appendicitis pain were correctly classified as low risk. However, 13 low-risk patients had appendicitis. Low-risk patients accounted for 48·1 per cent of admissions (223 of 464), 57 per cent of negative explorations (48 of 84) and 50·7 per cent of imaging requests (149 of 294). An AIR score of 5 or more (intermediate and high risk) had high sensitivity for all severities of appendicitis (90 per cent) and also for advanced appendicitis (98 per cent). An AIR score of 9 or more (high risk) was very specific (97 per cent) for appendicitis, and the majority of patients with appendicitis in the high-risk group (21 of 30, 70 per cent) had perforation or gangrene. Ultrasound imaging could not exclude appendicitis in low-risk patients (negative likelihood ratio (LR) 1·0) but could rule-in the diagnosis in intermediate-risk patients (positive LR 10·2). CT could exclude appendicitis in low-risk patients (negative LR 0·0) and rule-in appendicitis in the intermediate group (positive LR 10·9). CONCLUSION: Risk stratification of patients with suspected appendicitis by the AIR score could guide decision-making to reduce admissions, optimize utility of diagnostic imaging and prevent negative explorations.


Assuntos
Apendicite/diagnóstico , Dor Abdominal/etiologia , Adulto , Apendicite/cirurgia , Técnicas de Apoio para a Decisão , Feminino , Humanos , Masculino , Exame Físico , Estudos Prospectivos , Medição de Risco/métodos , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X
19.
Phys Med Biol ; 60(7): 2939-53, 2015 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-25789823

RESUMO

Standard commercial diode detectors over-respond within small radiation fields, an effect largely attributable to the relatively high mass-density of silicon. However, Monte Carlo studies can be used to optimise dosimeter designs and have demonstrated that 'mass-density compensation'-for example, introducing a low-density air-gap upstream of a diode's high-density silicon volume-can substantially improve instrument response. In this work we used egs_chamber Monte Carlo simulations to predict the ideal air-gap thickness for a PTW 60017 unshielded diode detector. We then developed a prototype instrument incorporating that air-gap and, for a 6 MV linac, tested it experimentally against EBT3 film. We also tested a further three prototypes with different air-gap thicknesses. Our results demonstrate that for a 10 × 10 cm(2) reference field the DiodeAir, a PTW 60017 diode with a built-in air-gap of 1 mm, has on-axis correction factors near unity. Laterally the DiodeAir performs very well off-axis and reports FWHM and penumbra values consistent with those measured using EBT3. For PDD measurement, the performance of the DiodeAir matches that of the original PTW 60017. The experimental focus of this work was 6 MV but we also simulated the on-axis response of the DiodeAir within 15 MV beams and found that our modification proved robust to this substantial increase in beam energy. However, the original diode 60017 does exhibit low energy scatter dependencies and may over-respond to high linac dose-rates such that applying the mass-density compensation method to an alternative instrument (particularly a diamond detector) could ultimately take us even closer to the small-field ideal.


Assuntos
Dosimetria Fotográfica/métodos , Radiometria/instrumentação , Radiometria/métodos , Algoritmos , Simulação por Computador , Diamante , Desenho de Equipamento , Humanos , Método de Monte Carlo , Aceleradores de Partículas , Silício
20.
Br J Radiol ; 87(1037): 20130681, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24620840

RESUMO

OBJECTIVE: To ascertain the progress being made towards the implementation of stereotactic ablative body radiotherapy (SABR) treatment in the UK, to obtain details of current practice in centres with an active treatment programme and to assess the projected future provision. METHODS: In August 2012, an online questionnaire was sent to all 65 UK radiotherapy institutions. The included questions covered the current number of patients being treated and the intended number of patients for each clinical site; immobilization and motion management methods; CT scanning protocols; target and organ-at-risk delineation; treatment planning; image-guidance and treatment protocols; and quality assurance methods. RESULTS: 48/65 (74%) institutions responded by the end of November 2012, with 15 indicating an active SABR programme. A further four centres indicated that a SABR protocol had been established but was not yet in clinical use. 14 of the 29 remaining responses stated an intention to develop a SABR programme in the next 2 years. CONCLUSION: The survey responses confirm that SABR provision in the UK is increasing and that this should be expected to continue in the next 2 years. A projection of the future uptake would suggest that by the end of 2014, UK SABR provision will be broadly in line with international practice.


Assuntos
Pesquisas sobre Atenção à Saúde , Neoplasias Pulmonares/cirurgia , Garantia da Qualidade dos Cuidados de Saúde , Radiocirurgia/estatística & dados numéricos , Protocolos Clínicos , Humanos , Seleção de Pacientes , Inquéritos e Questionários , Reino Unido
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