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1.
Diabet Med ; 35(8): 1078-1086, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29706032

RESUMO

AIM: To examine the quality of care delivered by a structured primary care-led programme for people with Type 2 diabetes mellitus in 1999-2016. METHODS: The Midland Diabetes Structured Care Programme provides structured primary care-led management. Trends over time in care processes were examined (using a chi-squared trend test and age- and gender-adjusted logistic regression). Screening and annual review attendance were reviewed. A composite of eight National Institute for Health and Care Excellence-recommended processes was used as a quality indicator. Participants who were referred to diabetes nurse specialists were compared with those not referred (Student's t-test, Pearson's chi-squared test, Wilcoxon-Mann-Whitney test). Proportions achieving outcome targets [HbA1c ≤58 mmol/mol (7.5%), blood pressure ≤140/80 mmHg, cholesterol <5.0 mmol/l] were calculated. RESULTS: Data were available for people with diabetes aged ≥18 years: 1998/1999 (n=336); 2003 (n=843); 2008 (n=988); and 2016 (n=1029). Recording of some processes improved significantly over time (HbA1c , cholesterol, blood pressure, creatinine), and in 2016 exceeded 97%. Foot assessment and annual review attendance declined. In 2016, only 29% of participants had all eight National Institute for Health and Care Excellence processes recorded. A higher proportion of people with diabetes who were referred to a diabetes nurse specialist had poor glycaemic control compared with those not referred. The proportions meeting blood pressure and lipid targets increased over time. CONCLUSIONS: Structured primary care led to improvements in the quality of care over time. Poorer recording of some processes, a decline in annual review attendance, and participants remaining at high risk suggest limits to what structured care alone can achieve. Engagement in continuous quality improvement to target other factors, including attendance and self-management, may deliver further improvements.


Assuntos
Redes Comunitárias/normas , Diabetes Mellitus/terapia , Atenção Primária à Saúde/normas , Avaliação de Programas e Projetos de Saúde/tendências , Qualidade da Assistência à Saúde/tendências , Adulto , Idoso , Índice de Massa Corporal , Redes Comunitárias/organização & administração , Redes Comunitárias/tendências , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Irlanda/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/epidemiologia , Obesidade/terapia , Atenção Primária à Saúde/organização & administração , Atenção Primária à Saúde/tendências , Avaliação de Programas e Projetos de Saúde/métodos , Avaliação de Programas e Projetos de Saúde/normas , Qualidade da Assistência à Saúde/organização & administração , Qualidade da Assistência à Saúde/normas
2.
Ir Med J ; 110(6): 583, 2017 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-28952673

RESUMO

Burns and scalds are preventable injuries in children that typically occur in the home. This study aimed to examine the role of hot beverage scalds in paediatric burn admissions in order to identify key target audiences for future safety strategies. Using the Hospital Inpatient Enquiry System (HIPE) a retrospective study of paediatric burn admissions in 2014 examined demographics, cause and severity of injury and location of occurrence. There were 233 paediatric discharges (age 0-18 yrs.) with a principal diagnosis of burn injury; 57% of these occurred in children under three years and 95% of these occurred in the home. Scalds caused 74% of burn injuries; hot beverages accounted for least 33% of these of which 77% were partial thickness and 73% were upper body burns. Effective hot beverage scald prevention strategies, targeted towards caregivers in the home, are required.


Assuntos
Bebidas/efeitos adversos , Queimaduras/epidemiologia , Queimaduras/etiologia , Temperatura Alta/efeitos adversos , Adolescente , Bebidas/estatística & dados numéricos , Queimaduras/patologia , Queimaduras/prevenção & controle , Criança , Pré-Escolar , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Recém-Nascido , Escala de Gravidade do Ferimento , Irlanda/epidemiologia , Estudos Retrospectivos
3.
Angiogenesis ; 18(1): 69-81, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25298070

RESUMO

Targeted ultrasound contrast imaging has the potential to become a reliable molecular imaging tool. A better understanding of the quantitative aspects of molecular ultrasound technology could facilitate the translation of this technique to the clinic for the purposes of assessing vascular pathology and detecting individual response to treatment. The objective of this study was to evaluate whether targeted ultrasound contrast-enhanced imaging can provide a quantitative measure of endogenous biomarkers. Endoglin, an endothelial biomarker involved in the processes of development, vascular homeostasis, and altered in diseases, including hereditary hemorrhagic telangiectasia type 1 and tumor angiogenesis, was the selected target. We used a parallel plate perfusion chamber in which endoglin-targeted (MBE), rat isotype IgG2 control and untargeted microbubbles were perfused across endoglin wild-type (Eng+/+), heterozygous (Eng+/-) and null (Eng-/-) embryonic mouse endothelial cells and their adhesion quantified. Microbubble binding was also assessed in late-gestation, isolated living transgenic Eng+/- and Eng+/+ embryos. Nonlinear contrast-specific ultrasound imaging performed at 21 MHz was used to collect contrast mean power ratios for all bubble types. Statistically significant differences in microbubble binding were found across genotypes for both in vitro (p<0.05) and embryonic studies (p<0.001); MBE binding was approximately twofold higher in Eng+/+ cells and embryos compared with their Eng+/- counterparts. These results suggest that molecular ultrasound is capable of reliably differentiating between molecular genotypes and relating receptor densities to quantifiable molecular ultrasound levels.


Assuntos
Embrião de Mamíferos/diagnóstico por imagem , Células Endoteliais/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Animais , Western Blotting , Adesão Celular/fisiologia , Endoglina , Células Endoteliais/diagnóstico por imagem , Genótipo , Linfócitos Nulos , Camundongos , Camundongos Knockout , Microbolhas , Imagem Molecular , Ratos , Ultrassonografia
4.
J Radiol Prot ; 34(2): 469-84, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24894330

RESUMO

In the UK, as elsewhere, there is potential to improve how radiological challenges are addressed through improvement in, or development of, a strong radiation protection (RP) safety culture. In preliminary work in the UK, two areas have been identified as having a strong influence on UK society: the healthcare and nuclear industry sectors. Each has specific challenges, but with many overlapping common factors. Other sectors will benefit from further consideration.In order to make meaningful comparisons between these two principal sectors, this paper is primarily concerned with cultural aspects of RP in the working environment and occupational exposures rather than patient doses.The healthcare sector delivers a large collective dose to patients each year, particularly for diagnostic purposes, which continues to increase. Although patient dose is not the focus, it must be recognised that collective patient dose is inevitably linked to collective occupational exposure, especially in interventional procedures.The nuclear industry faces major challenges as work moves from operations to decommissioning on many sites. This involves restarting work in the plants responsible for the much higher radiation doses of the 1960/70s, but also performing tasks that are considerably more difficult and hazardous than those original performed in these plants.Factors which influence RP safety culture in the workplace are examined, and proposals are considered for a series of actions that may lead to an improvement in RP culture with an associated reduction in dose in many work areas. These actions include methods to improve knowledge and awareness of radiation safety, plus ways to influence management and colleagues in the workplace. The exchange of knowledge about safety culture between the nuclear industry and medical areas may act to develop RP culture in both sectors, and have a wider impact in other sectors where exposures to ionising radiations can occur.


Assuntos
Setor de Assistência à Saúde/organização & administração , Promoção da Saúde/organização & administração , Centrais Nucleares , Cultura Organizacional , Guias de Prática Clínica como Assunto , Proteção Radiológica/normas , Gestão da Segurança/organização & administração , Brasil , França , Fidelidade a Diretrizes , Reino Unido
5.
Osteoporos Int ; 24(2): 633-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22581294

RESUMO

SUMMARY: This study showed that regional bone blood flow and (18)F-fluoride bone plasma clearance measured by positron emission tomography are three times lower at the hip than the lumbar spine. INTRODUCTION: Measurements of effective bone plasma flow (K (1)), bone plasma clearance (K ( i )) and standardised uptake values (SUV) using (18)F-fluoride positron emission tomography ((18)F-PET) provide a useful means of studying regional bone metabolism at different sites in the skeleton. This study compares the regional (18)F-fluoride kinetics and SUV at the hip and lumbar spine (LS). METHODS: Twelve healthy postmenopausal women with no history of metabolic bone disease apart from two with untreated osteoporosis were recruited. Each subject underwent 60-min dynamic (18)F-PET scans at the LS and proximal femur two weeks apart. K (1), K ( i ) and SUV were measured at the LS (mean of L(1)-L(4)), femoral neck (FN), total hip (TH) and femoral shaft (FS). Differences between sites were assessed using the nonparametric Kruskal-Wallis test with a Bonferroni correction for multiple comparisons. RESULTS: Values of K (1), K ( i ) and SUV at the FN, TH and FS were three times lower than at the LS (p = 0.003). Amongst the proximal femur sites, K ( i ) and SUV were lower at the FS compared with the FN and TH, and SUV was lower at the TH compared with the FN (all p < 0.05). The volume of distribution was lower at the TH and FS compared with the LS (p < 0.05). CONCLUSION: The lower values of K (1), K ( i ) and SUV at the hip suggest that lower bone blood flow in the proximal femur is an important factor explaining the principal reason for the differences in bone fluoride kinetics between the LS and hip sites.


Assuntos
Articulação do Quadril/metabolismo , Vértebras Lombares/metabolismo , Absorciometria de Fóton , Densidade Óssea/fisiologia , Feminino , Colo do Fêmur/irrigação sanguínea , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/metabolismo , Colo do Fêmur/fisiologia , Fluordesoxiglucose F18 , Articulação do Quadril/irrigação sanguínea , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/fisiologia , Humanos , Vértebras Lombares/irrigação sanguínea , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiologia , Pessoa de Meia-Idade , Projetos Piloto , Tomografia por Emissão de Pósitrons/métodos , Pós-Menopausa/fisiologia , Compostos Radiofarmacêuticos , Fluxo Sanguíneo Regional
6.
Allergy ; 68(8): 1050-6, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23888905

RESUMO

BACKGROUND: Metabolomic profiling of exhaled breath condensate offers opportunities for the development of noninvasive diagnostics in asthma. We aimed to determine and validate discriminatory metabolomic profiles in adult asthma and to explore profiles in clinically relevant disease phenotypes. METHODS: Nuclear magnetic resonance spectroscopy was used to analyse breath condensate samples from 82 subjects with asthma and 35 healthy volunteers. Multivariate modelling was performed on a 'training set' (70% of the total sample) in order to produce a discriminatory model classifying asthmatics from healthy controls, and the model tested in the remaining subjects. Secondary analyses were performed to determine the models for the identification of asthmatic subgroups based on sputum eosinophilia, neutrophilia, asthma control and inhaled corticosteroid use. RESULTS: A classification model consisting of five discriminating spectral regions was derived using data from the training set with an area under the receiver operating curve (AUROC) of 0.84. In the test set (the remaining 30% of subjects), the AUROC was 0.91, thus providing external validation for the model. The success of the technique for classifying asthma phenotypes was variable, with AUROC for: sputum eosinophilia (3% cut-off) 0.69; neutrophilia (65% cut-off) 0.88; asthma control (cut-off Asthma Control Questionnaire score of 1) 0.63; and inhaled corticosteroid use 0.89. CONCLUSION: Nuclear magnetic resonance spectroscopy of breath condensate successfully differentiates asthmatics from healthy subjects. With identification of the discriminatory compounds, this technique has the potential to provide novel diagnostics and identify novel pathophysiological mechanisms, biomarkers and therapeutic targets.


Assuntos
Asma/diagnóstico , Asma/metabolismo , Testes Respiratórios/métodos , Metabolômica/métodos , Ressonância Magnética Nuclear Biomolecular/métodos , Adulto , Idoso , Asma/fisiopatologia , Estudos de Coortes , Feminino , Humanos , Imunofenotipagem , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fenótipo , Reprodutibilidade dos Testes
7.
Osteoporos Int ; 23(8): 2107-16, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21983795

RESUMO

UNLABELLED: The aim of this study was to examine the effects of bisphosphonate discontinuation on bone metabolism at the spine and hip measured using (18) F-fluoride PET. Bone metabolism at the spine remained stable following discontinuation of alendronate and risedronate at 1 year but increased in the hip in the alendronate group only. INTRODUCTION: Bisphosphonates such as alendronate (ALN) or risedronate (RIS) have persistent effects on spine BMD following discontinuation. METHODS: Positron emission tomography (PET) was used to examine regional bone metabolism in 20 postmenopausal women treated with ALN (n = 11) or RIS (n = 9) for a minimum of 3 years at screening (range 3-9 years, mean 5 years for both groups). Subjects underwent a dynamic scan of the lumbar spine and a static scan of both hips at baseline and 6 and 12 months following treatment discontinuation. (18) F-fluoride plasma clearance (K(i)) at the spine was calculated using a three-compartment model. Standardised uptake values (SUV) were calculated for the spine, total hip, femoral neck and femoral shaft. Measurements of BMD and biochemical markers of bone turnover were also performed. RESULTS: With the exception of a significant decrease in spine BMD in the ALN group, BMD remained stable. Bone turnover markers increased significantly from baseline by 12 months for both study groups. Measurements of K(i) and SUV at the spine and femoral neck did not change significantly in either group. SUV at the femoral shaft and total hip increased significantly but in the ALN group only, increasing by 33.8% (p = 0.028) and 24.0% (p = 0.013), respectively. CONCLUSIONS: Bone metabolism at the spine remained suppressed following treatment discontinuation. A significant increase in SUV at the femoral shaft and total hip after 12 months was observed but for the ALN group only. This study was small, and further clinical studies are required to fully evaluate the persistence of BP treatment.


Assuntos
Fêmur , Quadril/diagnóstico por imagem , Vértebras Lombares , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/metabolismo , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Alendronato/administração & dosagem , Biomarcadores/metabolismo , Densidade Óssea/efeitos dos fármacos , Densidade Óssea/fisiologia , Conservadores da Densidade Óssea/administração & dosagem , Remodelação Óssea/efeitos dos fármacos , Remodelação Óssea/fisiologia , Ácido Etidrônico/administração & dosagem , Ácido Etidrônico/análogos & derivados , Feminino , Fêmur/diagnóstico por imagem , Fêmur/metabolismo , Fluordesoxiglucose F18/sangue , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/metabolismo , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/tratamento farmacológico , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/sangue , Ácido Risedrônico , Resultado do Tratamento
8.
Med Phys ; 39(10): 6474-83, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23039682

RESUMO

PURPOSE: Although there have been various proposed methods for positron emission tomography (PET) motion correction, there is not sufficient evidence to answer which method is better in practice. This investigation aims to characterize the behavior of the two main motion-correction approaches in terms of convergence and image properties. METHODS: For the first method, reconstruct-transform-average (RTA), reconstructions of each gate are transformed to a reference gate and averaged. In the second method, motion-compensated image reconstruction (MCIR), motion information is incorporated within the reconstruction. Both techniques studied were based on the ordered subsets expectation maximization algorithm. Motion information was obtained from a dynamic MR acquisition performed on a human volunteer and concurrent PET data were simulated from the dynamic MR data. The two approaches were assessed statistically using multiple realizations to accurately define the noise properties of the reconstructed images. RESULTS: MCIR successfully recovers the true values of all regions, whereas RTA has high bias due to the limited count-statistics and interpolation errors during the transformation step. In addition, RTA noise is very small and stabilized, whereas in MCIR noise becomes progressively greater with the number of iterations and therefore MCIR outperforms RTA in terms of MSE only if noise is treated. For example, MCIR with postfiltering results in MSE up to 42% lower than RTA. CONCLUSIONS: This study indicates that MCIR may provide superior performance overall to RTA if noise is minimized. However, in applications where quantification is not the main objective RTA can be a practical and simple method to correct for motion.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Movimento , Tomografia por Emissão de Pósitrons/métodos , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/fisiopatologia
9.
Med Phys ; 49(5): 3298-3313, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35271742

RESUMO

PURPOSE: A novel phantom-imaging platform, a set of software tools, for automated and high-precision imaging of the American College of Radiology (ACR) positron emission tomography (PET) phantom for PET/magnetic resonance (PET/MR) and PET/computed tomography (PET/CT) systems is proposed. METHODS: The key feature of this platform is the vector graphics design that facilitates the automated measurement of the knife-edge response function and hence image resolution, using composite volume of interest templates in a 0.5 mm resolution grid applied to all inserts of the phantom. Furthermore, the proposed platform enables the generation of an accurate µ $\mu$ -map for PET/MR systems with a robust alignment based on two-stage image registration using specifically designed PET templates. The proposed platform is based on the open-source NiftyPET software package used to generate multiple list-mode data bootstrap realizations and image reconstructions to determine the precision of the two-stage registration and any image-derived statistics. For all the analyses, iterative image reconstruction was employed with and without modeled shift-invariant point spread function and with varying iterations of the ordered subsets expectation maximization (OSEM) algorithm. The impact of the activity outside the field of view (FOV) was assessed using two acquisitions of 30 min each, with and without the activity outside the FOV. RESULTS: The utility of the platform has been demonstrated by providing a standard and an advanced phantom analysis including the estimation of spatial resolution using all cylindrical inserts. In the imaging planes close to the edge of the axial FOV, we observed deterioration in the quantitative accuracy, reduced resolution (FWHM increased by 1-2 mm), reduced contrast, and background uniformity due to the activity outside the FOV. Although it slows convergence, the PSF reconstruction had a positive impact on resolution and contrast recovery, but the degree of improvement depended on the regions. The uncertainty analysis based on bootstrap resampling of raw PET data indicated high precision of the two-stage registration. CONCLUSIONS: We demonstrated that phantom imaging using the proposed methodology with the metric of spatial resolution and multiple bootstrap realizations may be helpful in more accurate evaluation of PET systems as well as in facilitating fine tuning for optimal imaging parameters in PET/MR and PET/CT clinical research studies.


Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Algoritmos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Imagens de Fantasmas , Tomografia por Emissão de Pósitrons/métodos , Software
10.
Ann Oncol ; 22(3): 739-745, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20813876

RESUMO

BACKGROUND: Multicentre trials are required to determine how [fluorine-18]-2-fluoro-2-deoxy-D-glucose-positron emission tomography imaging can guide cancer treatment. Consistency in quality control (QC), scan acquisition and reporting is mandatory for high-quality results, which are comparable across sites. METHODS: A national positron emission tomography (PET) clinical trials network (CTN) has been set up with a 'core laboratory' to coordinate QC and interpret scans. The CTN is involved in trials in Hodgkin's lymphoma [Randomised Phase III trial to determine the role of FDG-PET Imaging in Clinical Stages IA/IIA Hodgkin's Disease (RAPID) and Randomised Phase III trial to assess response adapted therapy using FDG-PET imaging in patients with newly diagnosed, advanced Hodgkin lymphoma (RATHL)] and diffuse large B-cell lymphoma [Blinded evaluation of prognostic value of FDG-PET after 2 cycles of chemotherapy in diffuse large B-cell Non-Hodgkins Lymphoma, a sub-study of the R-CHOP-21 vs R-CHOP-14 trial (R-CHOP PET substudy)]. Approval to join requires scanner validation and agreement to follow a standard QC protocol. Scans are transferred to the core laboratory and reported centrally according to predetermined criteria. RESULTS: The qualification procedure was carried out on 15 scanners. All scanners were able to demonstrate the necessary quantitative accuracy, and following modification of image reconstruction where necessary, scanners demonstrated comparable recovery coefficients (RCs) indicating similar performance. The average RC (±1 standard deviation) was 0.56 ± 0.095 for the 13-mm sphere. Reports from 444 of 473 (94%) patients in RAPID and 67 of 73 (92%) patients in RATHL were available for randomisation of therapy. CONCLUSIONS: The CTN has enabled consistent quality assured PET results to be obtained from multiple centres in time for clinical decision making. The results of trials will be significantly strengthened by this system.


Assuntos
Fluordesoxiglucose F18 , Doença de Hodgkin/diagnóstico por imagem , Estudos Multicêntricos como Assunto , Tomografia por Emissão de Pósitrons/normas , Compostos Radiofarmacêuticos , Ensaios Clínicos Controlados Aleatórios como Assunto , Humanos , Controle de Qualidade , Projetos de Pesquisa , Reino Unido
11.
Scand J Rheumatol ; 40(4): 269-78, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21469939

RESUMO

OBJECTIVE: Fibrin deposition is integral to the pathogenesis of collagen-induced arthritis (CIA), an experimental model of rheumatoid arthritis (RA). Membrane-associated fibrinogen-like protein 2 (mFGL2), a novel inducible prothrombinase, generates fibrin by an alternate pathway and has been reported to be involved in the pathogenesis of a number of immune-mediated diseases. We hypothesized that expression of mFGL2 in inflamed synovium contributes to the fibrin deposition and subsequent inflammation in arthritis. METHODS: DBA/1 mice were immunized with 100 µg bovine collagen type II (CII) emulsified in complete Freund's adjuvant (CFA) followed by lipopolysaccharide (LPS) injection. Expression of mFGL2 prothrombinase in association with fibrin deposition was examined in mice with CIA and CD200-treated mice following induction of CIA. To directly assess the contribution of mFGL2, fgl2(-/-) mice were injected with antibody to CII (anti-CII). RESULTS: Levels of fgl2 mRNA transcripts and mFGL2 protein were markedly up-regulated in joints of mice that developed CIA. Fibrin deposition was prominent within the synovial lining and articular joint space associated with expression of mFGL2. Inhibition of CIA by the immunosuppressant CD200 was associated with decreased expression of fgl2 mRNA and mFGL2 protein and absence of fibrin deposition. Following injection of anti-CII, all fgl2(+/+) mice developed severe arthritis with clinical and histological manifestations characteristic of RA, whereas fgl2(-/-) mice failed to develop any clinical manifestation or histological evidence of arthritis. CONCLUSIONS: This study demonstrates that the prothrombinase activity of mFGL2 contributes to the pathogenesis of experimental arthritis. These studies may have therapeutic implications for patients with RA.


Assuntos
Artrite Experimental/etiologia , Artrite Experimental/fisiopatologia , Fibrinogênio/fisiologia , Tromboplastina/fisiologia , Animais , Antígenos CD/farmacologia , Modelos Animais de Doenças , Fibrina/metabolismo , Fibrinogênio/genética , Imunossupressores/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Transdução de Sinais/fisiologia , Membrana Sinovial/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologia
12.
Ir Med J ; 104(6): 185-7, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22111397

RESUMO

A retrospective study of all acute ischaemic stroke patients admitted to Midland Regional Hospital Mullingar (MRHM) between January 2004 and September 2009 was undertaken in order to assess the median time from hospital admission to CT brain scan (n = 496). The median time to CT scan ranged from 19-24 hours between 2004-7. In 2008, coinciding with setting up a new Acute Stroke Service (ACSS), the median time to CT scan dropped to 15 hours (n = 130, p =0.03) and decreased further to 3 hours in 2009 (n = 125, p = 0.003). The proportion scanned within 1 hour of admission increased from 7 patients (4.6%) over 2004-7, to 28 patients (21.5%) in 2008 (p = 0) and 44 patients (35%) in 2009 (p = 0.018). This clinically and statistically significant reduction occurred following reorganisation of existing resources on a budget neutral basis at MRHM and was facilitated by the enthusiastic support of a range of disciplines bridging the community and acute hospital interface. Measurement of admission to CT brain scan time is one of several audit parameters which can assess hospitals responsiveness to acute stroke.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Admissão do Paciente/estatística & dados numéricos , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo
13.
Phys Med Biol ; 66(4): 045001, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33296884

RESUMO

X-ray mammography is the gold standard technique in breast cancer screening programmes. One of the main challenges that mammography is still facing is scattered radiation, which degrades the quality of the image and complicates the diagnosis process. Anti-scatter grids, the main standard physical scattering reduction technique, have some unresolved challenges as they increase the dose delivered to the patient, do not remove all the scattered radiation and increase the cost of the equipment. Alternative scattering reduction methods based on post-processing algorithms, have lately been under investigation. This study is concerned with the use of image post-processing to reduce the scatter contribution in the image, by convolving the primary plus scatter image with kernels obtained from simplified Monte Carlo (MC) simulations. The proposed semi-empirical approach uses up to five thickness-dependant symmetric kernels to accurately estimate the scatter contribution of different areas of the image. Single breast thickness-dependant kernels can over-estimate the scatter signal up to 60%, while kernels adapting to local variations have to be modified for each specific case adding high computational costs. The proposed method reduces the uncertainty to a 4%-10% range for a 35-70 mm breast thickness range, making it a very efficient, case-independent scatter modelling technique. To test the robustness of the method, the scattered corrected image has been successfully compared against full MC simulations for a range of breast thicknesses. In addition, clinical images of the 010A CIRS phantom were acquired with a mammography system with and without the presence of the anti-scatter grid. The grid-less images were post-processed and their quality was compared against the grid images, by evaluating the contrast-to-noise ratio and variance ratio using several test objects, which simulate calcifications and tumour masses. The results obtained show that the method reduces the scatter to similar levels than the anti-scatter grids.


Assuntos
Mamografia/métodos , Modelos Teóricos , Espalhamento de Radiação , Algoritmos , Mama/citologia , Mama/diagnóstico por imagem , Feminino , Humanos , Método de Monte Carlo , Imagens de Fantasmas
14.
J Exp Med ; 172(6): 1843-52, 1990 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-1979590

RESUMO

Endothelium-derived nitric oxide (NO) causes vasodilatation by activating soluble guanylate cyclase, and glomerular mesangial cells respond to NO with elevations of intracellular guanosine 3',5'-cyclic monophosphate (cGMP). We explored whether mesangial cells can be stimulated to produce NO and whether NO modulates mesangial cell function in an autocrine or paracrine fashion. Tumor necrosis factor alpha (TNF-alpha) raised mesangial cell cGMP levels in a time- and concentration-dependent manner (threshold dose 1 ng/ml, IC50 13.8 ng/ml, maximal response 100 ng/ml). TNF-alpha-induced increases in mesangial cGMP content were evident at 8 h and maximal at 18-24 h. The TNF-alpha-induced stimulation of mesangial cell cGMP production was abrogated by actinomycin D or cycloheximide suggesting dependence on new RNA or protein synthesis. Hemoglobin and methylene blue, both known to inhibit NO action, dramatically reduced TNF-alpha-induced mesangial cell cGMP production. Superoxide dismutase, known to potentiate NO action, augmented the TNF-alpha-induced effect. Ng-monomethyl-L-arginine (L-NMMA) decreased cGMP levels in TNF-alpha-treated, but not vehicle-treated mesangial cells in a concentration-dependent manner (IC50 53 microM). L-arginine had no effect on cGMP levels in control or TNF-alpha-treated mesangial cells but reversed L-NMMA-induced inhibition. Interleukin 1 beta and lipopolysaccharide (LPS), but not interferon gamma, also increased mesangial cell cGMP content. Transforming growth factor beta 1 blunted the mesangial cell response to TNF-alpha. TNF-alpha-induced L-arginine-dependent increases in cGMP were also evident in bovine renal artery vascular smooth muscle cells, COS-1 cells, and 1502 human fibroblasts. These findings suggest that TNF-alpha induces expression in mesangial cell of an enzyme(s) involved in the formation of L-arginine-derived NO. Moreover, the data indicate that NO acts in an autocrine and paracrine fashion to activate mesangial cell soluble guanylate cyclase. Cytokine-induced formation of NO in mesangial and vascular smooth muscle cells may be implicated in the pathogenesis of septic shock.


Assuntos
Arginina/metabolismo , Mesângio Glomerular/metabolismo , Guanilato Ciclase/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Animais , Arginina/análogos & derivados , Arginina/farmacologia , Bovinos , Células Cultivadas , GMP Cíclico/metabolismo , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Ativação Enzimática , Mesângio Glomerular/efeitos dos fármacos , Mesângio Glomerular/enzimologia , Humanos , Interferon gama/farmacologia , Interleucina-1/farmacologia , Cinética , Nitratos/metabolismo , Nitritos/metabolismo , Proteínas Recombinantes/farmacologia , ômega-N-Metilarginina
15.
EJNMMI Phys ; 7(1): 24, 2020 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-32372135

RESUMO

BACKGROUND: Despite the advent of clinical PET-MR imaging for routine use in 2011 and the development of several methods to address the problem of attenuation correction, some challenges remain. We have identified and investigated several issues that might affect the reliability and accuracy of current attenuation correction methods when these are implemented for clinical and research studies of the brain. These are (1) the accuracy of converting CT Hounsfield units, obtained from an independently acquired CT scan, to 511 keV linear attenuation coefficients; (2) the effect of padding used in the MR head coil; (3) the presence of close-packed hair; (4) the effect of headphones. For each of these, we have examined the effect on reconstructed PET images and evaluated practical mitigating measures. RESULTS: Our major findings were (1) for both Siemens and GE PET-MR systems, CT data from either a Siemens or a GE PET-CT scanner may be used, provided the conversion to 511 keV µ-map is performed by the PET-MR vendor's own method, as implemented on their PET-CT scanner; (2) the effect of the head coil pads is minimal; (3) the effect of dense hair in the field of view is marked (> 10% error in reconstructed PET images); and (4) using headphones and not including them in the attenuation map causes significant errors in reconstructed PET images, but the risk of scanning without them may be acceptable following sound level measurements. CONCLUSIONS: It is important that the limitations of attenuation correction in PET-MR are considered when designing research and clinical PET-MR protocols in order to enable accurate quantification of brain PET scans. Whilst the effect of pads is not significant, dense hair, the use of headphones and the use of an independently acquired CT-scan can all lead to non-negligible effects on PET quantification. Although seemingly trivial, these effects add complications to setting up protocols for clinical and research PET-MR studies that do not occur with PET-CT. In the absence of more sophisticated PET-MR brain attenuation correction, the effect of all of the issues above can be minimised if the pragmatic approaches presented in this work are followed.

16.
EJNMMI Phys ; 7(1): 47, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32666231

RESUMO

An amendment to this paper has been published and can be accessed via the original article.

17.
Br Dent J ; 226(1): 62-66, 2019 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-30631179

RESUMO

Introduction: Oral surgery services are progressively moving out of traditional hospital departments and into primary care. This necessitates accurate methods of triaging referrals, so patients of varying complexity are managed in the most suitable environment. The latest NHS commissioning proposal identifies 'level 1' procedures as simple extractions which do not require referral. We developed a model for quantifying how accurately these simple extractions can be predicted from information in standard referral letters. Methods: Experienced clinicians (N = 10) were independently asked to predict whether extractions (N = 25) were likely to be simple-forceps or surgical procedures, from information provided in specially developed standardised referral letters. One oral surgeon had previously completed all extractions. The triaging clinicians were asked to comment on reasons for each decision and state their level of confidence in their predictions. Results: Only 67% (range 52­76%) of extractions were correctly predicted as either simple or surgical with a significant propensity to underestimate the complexity of surgical extractions rather than overestimating simple procedures (p <0.05). High levels of confidence reported by the clinicians in their decisions correlated with more accurate predictions (p <0.05). Conclusions: This is the first attempt to develop a model for clinical decision-making in oral surgery triage services. Our findings suggest there is significant scope for improvement and highlight areas for development.


Assuntos
Tomada de Decisão Clínica , Triagem , Humanos , Atenção Primária à Saúde , Encaminhamento e Consulta
18.
Br J Pharmacol ; 153(7): 1420-31, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18278064

RESUMO

BACKGROUND AND PURPOSE: The factors that influence the cellular levels of endothelin-1 (ET-1) include transcription, mRNA localization, stability and translation, post-translational maturation of preproET-1 and degradation of ET-1. We investigated the regulation of ET-1 mRNA abundance by extracellular ET-1 in porcine aortic endothelial cells (PAECs). EXPERIMENTAL APPROACH: Passsage one cultures of PAECs were incubated in starving medium in the presence or absence of ET-1 and antagonists or pharmacological inhibitors. PreproET-1 mRNA, endothelin-1 promoter activity, Erk and p38 MAPK activation were determined. KEY RESULTS: Exogenous ET-1 reduced cellular ET-1 mRNA content: a reduction of 10 000-fold was observed after 4 h. ET-1 simultaneously reduced the stability of ET-1 mRNA and increased the loading of RNA Polymerase II at the endothelin-1 promoter. In the absence of exogenous ET-1, the ETB-selective antagonist, BQ788, increased ET-1 mRNA. An ETA-selective antagonist had no effect. ET-1 mRNA returned to control levels within 24 h. Whereas activation of p38 MAPK induced by ET-1 peaked at 30 min and returned to control levels within 90 min, Erk1/2 remained active after 4 h of stimulation. Inhibition of p38 MAPK prevented the ET-1-induced decrease in ET-1 mRNA. In contrast, Erk1/2 inhibition increased ET-1 mRNA. Similarly, inhibition of receptor internalization increased ET-1 mRNA in the presence or absence of exogenous ET-1. CONCLUSIONS AND IMPLICATIONS: These results suggest that extracellular ET-1 regulates the abundance of ET-1 mRNA in PAECs, in an ETB receptor-dependent manner, by modulating both mRNA stability and transcription via mechanisms involving receptor endocytosis and both ERK and p38 MAPK pathways.


Assuntos
Endotelina-1/metabolismo , Endotélio Vascular/metabolismo , RNA Mensageiro/metabolismo , Receptor de Endotelina B/metabolismo , Animais , Aorta/metabolismo , Endocitose/fisiologia , Células Endoteliais/metabolismo , Endotelina-1/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , RNA Polimerase II/metabolismo , Estabilidade de RNA/fisiologia , Suínos , Fatores de Tempo , Transcrição Gênica/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
19.
Ir J Med Sci ; 187(2): 275-280, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28717986

RESUMO

BACKGROUND: In the setting of a national audit of acute stroke services, we examined the delivery of thrombolytic therapy for ischaemic stroke and whether current practice was achieving safe outcomes and consistent delivery for patients. METHOD: Data obtained from the recent national stroke audit was compared against previous Irish audit, the most recent SSNAP UK stroke audit and the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST) study. RESULTS: Thrombolysis was provided in 27 acute hospitals throughout Ireland during the period assessed with 82% (22/27) providing 24/7 access, the remaining sites using redirect policies. Decision to thrombolyse was made by stroke trained consultants in 63% (17/27) of units, with general physicians and emergency medicine consultants covering the other units. Thrombolysis rate for non-haemorrhagic stroke was 11% (n = 80/742, CI 95% ±2.23) versus a 1% rate in the 2008 audit. Sites receiving patients through a redirect policy had the highest thrombolysis rate, an average of 24%. Nearly 30% of cases were thrombolysed on the weekend. Eighty-three percent of cases were managed in a stroke unit at some time during admission versus 54% of the national total cases. Thirty-seven percent of patients were ≥80 years old. The mortality rate was 11.3% versus the national mortality rate for non-thrombolysed ischaemic strokes of 10% (p > 0.5), and this is comparable to the SITS-MOST 2007 study 3-month mortality rate of 11.3% (p > 0.5). CONCLUSION: Stroke thrombolysis is being effectively and safely provided in acute stroke services in Ireland despite regular involvement of non-specialist staff. There is still potential to improve thrombolysis rate.


Assuntos
Fibrinolíticos/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica/métodos , Idoso , Feminino , Fibrinolíticos/farmacologia , Humanos , Irlanda , Masculino , Acidente Vascular Cerebral/patologia
20.
J Clin Invest ; 88(3): 1054-7, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1885767

RESUMO

Hypoxia in vivo is associated with constriction of the distal vasculature in the lung. Uniquely situated at the interface between blood and the vessel wall proper, the vascular endothelium may release vasoactive mediators in the setting of hypoxia. Endothelin-1 is a potent vasoconstrictor released by endothelial cells that could function as a paracrine regulator of vascular tone. We found that physiologic low oxygen tension (PO2 = 30 Torr) increased endothelin secretion from cultured human endothelial cells four to eightfold above the secretion rate at ambient oxygen tension. This increase in secretion was accompanied by a corresponding increase in the transcriptional rate of the preproendothelin gene resulting in increased steady-state mRNA levels of preproendothelin. In contrast, the transcription of a number of other growth-factor-encoding genes, including transforming growth factor-beta, was unaffected by hypoxia. Endothelin transcript production increased within 1 h of hypoxia and persisted for at least 48 h. In addition, the stimulatory effects of low oxygen tension on endothelin mRNA levels were reversible upon reexposure to 21% oxygen environments. These findings suggest a role for endothelin in the control of regional blood flow in the vasculature in response to changes in oxygen tension.


Assuntos
Hipóxia Celular , Endotelinas/genética , Endotélio Vascular/metabolismo , Expressão Gênica , Células Cultivadas , Endotelina-1 , Endotelinas/metabolismo , Humanos , Oxigênio/análise , Fator de Crescimento Derivado de Plaquetas/genética , Precursores de Proteínas/genética , RNA Mensageiro/análise , Transcrição Gênica
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