89 research outputs found

    Towards accurate and precise T1 and extracellular volume mapping in the myocardium: a guide to current pitfalls and their solutions

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    Mapping of the longitudinal relaxation time (T1) and extracellular volume (ECV) offers a means of identifying pathological changes in myocardial tissue, including diffuse changes that may be invisible to existing T1-weighted methods. This technique has recently shown strong clinical utility for pathologies such as Anderson- Fabry disease and amyloidosis and has generated clinical interest as a possible means of detecting small changes in diffuse fibrosis; however, scatter in T1 and ECV estimates offers challenges for detecting these changes, and bias limits comparisons between sites and vendors. There are several technical and physiological pitfalls that influence the accuracy (bias) and precision (repeatability) of T1 and ECV mapping methods. The goal of this review is to describe the most significant of these, and detail current solutions, in order to aid scientists and clinicians to maximise the utility of T1 mapping in their clinical or research setting. A detailed summary of technical and physiological factors, issues relating to contrast agents, and specific disease-related issues is provided, along with some considerations on the future directions of the field. Towards accurate and precise T1 and extracellular volume mapping in the myocardium: a guide to current pitfalls and their solutions. Available from: https://www.researchgate.net/publication/317548806_Towards_accurate_and_precise_T1_and_extracellular_volume_mapping_in_the_myocardium_a_guide_to_current_pitfalls_and_their_solutions [accessed Jun 13, 2017]

    Non-irradiation-derived reactive oxygen species (ROS) and cancer: therapeutic implications

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    Owing to their chemical reactivity, radicals have cytocidal properties. Destruction of cells by irradiation-induced radical formation is one of the most frequent interventions in cancer therapy. An alternative to irradiation-induced radical formation is in principle drug-induced formation of radicals, and the formation of toxic metabolites by enzyme catalysed reactions. Although these developments are currently still in their infancy, they nevertheless deserve consideration. There are now numerous examples known of conventional anti-cancer drugs that may at least in part exert cytotoxicity by induction of radical formation. Some drugs, such as arsenic trioxide and 2-methoxy-estradiol, were shown to induce programmed cell death due to radical formation. Enzyme-catalysed radical formation has the advantage that cytotoxic products are produced continuously over an extended period of time in the vicinity of tumour cells. Up to now the enzymatic formation of toxic metabolites has nearly exclusively been investigated using bovine serum amine oxidase (BSAO), and spermine as substrate. The metabolites of this reaction, hydrogen peroxide and aldehydes are cytotoxic. The combination of BSAO and spermine is not only able to prevent tumour cell growth, but prevents also tumour growth, particularly well if the enzyme has been conjugated with a biocompatible gel. Since the tumour cells release substrates of BSAO, the administration of spermine is not required. Combination with cytotoxic drugs, and elevation of temperature improves the cytocidal effect of spermine metabolites. The fact that multidrug resistant cells are more sensitive to spermine metabolites than their wild type counterparts makes this new approach especially attractive, since the development of multidrug resistance is one of the major problems of conventional cancer therapy

    Population-based study of the impact of small bowel obstruction due to adhesions on short- and medium-term mortality

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    Abstract Background Small bowel obstruction due to adhesions (aSBO) is a common indication for admission to a surgical unit. Despite the prevalence of this condition, the short- and medium-term survival of this patient population has not been well described. The purpose of this study was to measure the short- and medium-term survival of patients admitted to hospital with aSBO. Methods Linked administrative data were used to identify patients admitted to hospital in Ontario, Canada, for aSBO between 2005 and 2011. Patients were divided into two groups: those aged less than 65 years (younger group) and those aged 65 years and older (older group). Thirty-day, 90-day and 1-year mortality rates were estimated. One-year mortality was compared with that in the general population, adjusting for age and sex. The timing of deaths in relation to admission was assessed, as well as the proportion of patients discharged before experiencing short-term mortality. Results There were 22 197 patients admitted to hospital for aSBO for the first time in the study interval. Mean age was 64·5 years and 52·2 per cent of the patients were women. Overall, the 30-day, 90-day and 1-year mortality rates for the cohort were 5·7 (95 per cent c.i. 5·4 to 6·0), 8·7 (8·3 to 9·0) and 13·9 (13·4 to 14·3) per cent respectively. For both groups, the 1-year risk of death was significantly greater than that of the age-matched general population. The majority of deaths (62·5 per cent) occurred within 90 days of admission, with 36·4 per cent occurring after discharge from the aSBO admission. Conclusion Patients admitted with aSBO have a high short-term mortality rate. Increased monitoring of patients in the early period after admission is advisable. </jats:sec

    Early operative management in patients with adhesive small bowel obstruction: population-based cost analysis

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    Abstract Background Adhesive small bowel obstruction (aSBO) is a potentially recurrent disease. Although non-operative management is often successful, it is associated with greater risk of recurrence than operative intervention, and may have greater downstream morbidity and costs. This study aimed to compare the current standard of care, trial of non-operative management (TNOM), and early operative management (EOM) for aSBO. Methods Patients admitted to hospital between 2005 and 2014 in Ontario, Canada, with their first episode of aSBO were identified and propensity-matched on their likelihood to receive EOM for a cost–utility analysis using population-based administrative data. Patients were followed for 5 years to determine survival, recurrences, adverse events and inpatient costs to the healthcare system. Utility scores were attributed to aSBO-related events. Cost–utility was presented as the incremental cost-effectiveness ratio (ICER), expressed as Canadian dollars per quality-adjusted life-year (QALY). Results Some 25 150 patients were admitted for aSBO and 3174 (12·6 per cent) were managed by EOM. Patients managed by TNOM were more likely to experience recurrence of aSBO (20·9 per cent versus 13·2 per cent for EOM; P &amp;lt; 0·001). The lower recurrence rate associated with EOM contributed to an overall net effectiveness in terms of QALYs. The mean accumulated costs for patients managed with EOM exceeded those of TNOM (17951versus17 951 versus 11 594 (€12 288 versus €7936) respectively; P &amp;lt; 0·001), but the ICER for EOM versus TNOM was $29 881 (€20 454) per QALY, suggesting cost-effectiveness. Conclusion This retrospective study, based on administrative data, documented that EOM may be a cost-effective approach for patients with aSBO in terms of QALYs. Future guidelines on the management of aSBO may also consider the long-term outcomes and costs. </jats:sec
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