321 research outputs found
Do quantitative and qualitative shear wave elastography have a role in evaluating musculoskeletal soft tissue masses?
Objectives: To determine if quantitative and qualitative shear wave elastography have roles in evaluating musculoskeletal masses. Methods: 105 consecutive patients, prospectively referred for biopsy within a specialist sarcoma centre, underwent B-mode, quantitative (m/s) and qualitative (colour map) shear wave elastography. Reference was histology from subsequent biopsy or excision where possible. Statistical modelling was performed to test elastography data and/or B-mode imaging in predicting malignancy. Results: Of 105 masses, 39 were malignant and 6 had no histology but benign characteristics at 12 months. Radiologist agreement for B-mode and elastography was moderate to excellent Kw 0.52-0.64; PABAKw 0.85-0.90). B-Mode imaging had 78.8% specificity, 76.9% sensitivity for malignancy. Quantitatively, adjusting for age, B-mode and lesion volume there was no statistically significant association between longitudinal velocity and malignancy (OR [95% CI] 0.40[0.10, 1.60], p=0.193), but some evidence that higher transverse velocity was associated with decreased odds of malignancy (0.28[0.06, 1.28], p=0.101). Qualitatively malignant masses tended to be towards the blue spectrum (lower velocities); 39.5% (17/43) of predominantly blue masses were malignant, compared to 14.3% (1/7) of red lesions. Conclusions: Quantitatively and qualitatively there is no statistically significant association between shear wave velocity and malignancy. There is no clear additional role to B-mode imaging currently. Key Points: • Correlation between shear wave velocity and soft tissue malignancy was statistically insignificant• B-mode ultrasound is 76.9 % sensitive and 78.8 % specific• Statistical models show elastography does not significantly add to lesion assessmen
A theoretical model of inflammation- and mechanotransduction- driven asthmatic airway remodelling
Inflammation, airway hyper-responsiveness and airway remodelling are well-established hallmarks of asthma, but their inter-relationships remain elusive. In order to obtain a better understanding of their inter-dependence, we develop a mechanochemical morphoelastic model of the airway wall accounting for local volume changes in airway smooth muscle (ASM) and extracellular matrix in response to transient inflammatory or contractile agonist challenges. We use constrained mixture theory, together with a multiplicative decomposition of growth from the elastic deformation, to model the airway wall as a nonlinear fibre-reinforced elastic cylinder. Local contractile agonist drives ASM cell contraction, generating mechanical stresses in the tissue that drive further release of mitogenic mediators and contractile agonists via underlying mechanotransductive signalling pathways. Our model predictions are consistent with previously described inflammation-induced remodelling within an axisymmetric airway geometry. Additionally, our simulations reveal novel mechanotransductive feedback by which hyper-responsive airways exhibit increased remodelling, for example, via stress-induced release of pro-mitogenic and procontractile cytokines. Simulation results also reveal emergence of a persistent contractile tone observed in asthmatics, via either a pathological mechanotransductive feedback loop, a failure to clear agonists from the tissue, or a combination of both. Furthermore, we identify various parameter combinations that may contribute to the existence of different asthma phenotypes, and we illustrate a combination of factors which may predispose severe asthmatics to fatal bronchospasms
Review: The increasing importance of carbon nanotubes and nanostructured conducting polymers in biosensors
The growing need for analytical devices requiring smaller sample volumes, decreased power consumption and improved performance have been driving forces behind the rapid growth in nanomaterials research. Due to their dimensions, nanostructured materials display unique properties not traditionally observed in bulk materials. Characteristics such as increased surface area along with enhanced electrical/optical properties make them suitable for numerous applications such as nanoelectronics, photovoltaics and chemical/biological sensing. In this review we examine the potential that exists to use nanostructured materials for biosensor devices. By incorporating nanomaterials, it is possible to achieve enhanced sensitivity, improved response time and smaller size. Here we report some of the success that has been achieved in this area. Many nanoparticle and nanofibre geometries are particularly relevant, but in this paper we specifically focus on organic nanostructures, reviewing conducting polymer nanostructures and carbon nanotubes
Bioactive properties of iron-containing carbon monoxide-releasing molecules
Carbon monoxide-releasing molecules (CO-RMs) are compounds capable of delivering controlled amounts of CO within a cellular environment. Ruthenium-based carbonyls [tricarbonyldichloro ruthenium(II) dimer and tricarbonylchloro-(glycinato)ruthenium(II)] and boronacorbonates (sodium boranocarbonate) have been shown to promote vasodilatory, cardioprotective, and anti-inflammatory activities in a variety of experimental models. Here, we extend our previous studies by showing that η-4-(4-bromo-6-methyl-2-pyrone)tricarbonyl iron (0) (CORM-F3), an irontricarbonyl complex that contains a 2-pyrone motif, liberates CO in vitro and exerts pharmacological actions that are typical of CO gas. Specifically, CORM-F3 caused vasorelaxation in isolated aortic rings and inhibited the inflammatory response (e.g., nitrite production) of RAW264.7 macrophages stimulated with endotoxin in a dose-dependent fashion. By
The changing global distribution and prevalence of canine transmissible venereal tumour.
BACKGROUND: The canine transmissible venereal tumour (CTVT) is a contagious cancer that is naturally transmitted between dogs by the allogeneic transfer of living cancer cells during coitus. CTVT first arose several thousand years ago and has been reported in dog populations worldwide; however, its precise distribution patterns and prevalence remain unclear. RESULTS: We analysed historical literature and obtained CTVT prevalence information from 645 veterinarians and animal health workers in 109 countries in order to estimate CTVT's former and current global distribution and prevalence. This analysis confirmed that CTVT is endemic in at least 90 countries worldwide across all inhabited continents. CTVT is estimated to be present at a prevalence of one percent or more in dogs in at least 13 countries in South and Central America as well as in at least 11 countries in Africa and 8 countries in Asia. In the United States and Australia, CTVT was reported to be endemic only in remote indigenous communities. Comparison of current and historical reports of CTVT indicated that its prevalence has declined in Northern Europe, possibly due to changes in dog control laws during the nineteenth and twentieth centuries. Analysis of factors influencing CTVT prevalence showed that presence of free-roaming dogs was associated with increased CTVT prevalence, while dog spaying and neutering were associated with reduced CTVT prevalence. Our analysis indicated no gender bias for CTVT and we found no evidence that animals with CTVT frequently harbour concurrent infectious diseases. Vincristine was widely reported to be the most effective therapy for CTVT. CONCLUSIONS: Our results provide a survey of the current global distribution of CTVT, confirming that CTVT is endemic in at least 90 countries worldwide. Additionally, our analysis highlights factors that continue to modify CTVT's prevalence around the world and implicates free-roaming dogs as a reservoir for the disease. Our analysis also documents the disappearance of the disease from the United Kingdom during the twentieth century, which appears to have been an unintentional result of the introduction of dog control policies.This is the author's accepted manuscript. The final version of this article has been published by BioMed Central: http://www.biomedcentral.com/1746-6148/10/168
BIOACTIVE PROPERTIES OF IRON-CONTAINING CARBON
Carbon monoxide-releasing molecules (CO-RMs) are compounds capable of delivering controlled amounts of CO within a cellular environment. Ruthenium-based carbonyls (CORM-2 and CORM-3) and boronacorbonates (CORM-A1) have been shown to promote vasodilatory, cardioprotective and anti-inflammatory activities in a variety of experimental models. Here we extend our previous studies by showing that CORM-F3, an irontricarbonyl complex which contains a 2-pyrone motif, liberates CO in vitro and exerts pharmacological actions that are typical of CO gas. Specifically, CORM-F3 caused vasorelaxation in isolated aortic rings and inhibited the inflammatory response (eg nitrite production) of RAW264. 7 macrophages stimulated with endotoxin in a dose-dependent fashion. By analyzing the rate of CO release, we found that when the bromide at the 4-position of the 2-pyrone in CORM-F3 is substituted with a chloride group (CORM-F8), the rate of CO release is significantly decreased (4.5 fold) and a further decrease is observed when the 4-and 6-positions are substituted with a methyl group (CORM-F11) or a hydrogen (CORM-F7), respectively. Interestingly, the compounds containing halogens at the 4-position and the methyl at the 6-position of the 2-pyrone ring (CORM-F3 and CORM-F8) were found to be less cytotoxic compared to other CO-RMs when tested in RAW246. 7 macrophages. Thus, iron-based carbonyls mediate pharmacological responses that are achieved through liberation of CO and the nature of the substituents in the organic ligand have a profound effect on both the rate of CO release and cytotoxicity
Relevance of MRI in prediction of malignancy of musculoskeletal system-A prospective evaluation
Retention of basic laparoscopic skills after a structured training program
The purpose of this study was to test the retention of basic laparoscopic skills on a box trainer 1 year after a short training program. For a prior study, eight medical students without prior experience (novices) underwent baseline testing, followed by five weekly training sessions and a final test. During each of seven sessions, they performed five tasks on an inanimate box trainer. Scores were calculated by adding up the time to completion of the task with penalty points, consequently rewarding speed and precision. The sum score was the sum of the five scores. One year later, seven of them underwent retention testing for the current study. The final test results were compared with retention test results as a measure of durability of acquired skills. Novices’ scores did not worsen significantly for four out of five tasks (i.e., placing a pipe cleaner p = 0.46, placing beads p = 0.24, cutting a circle p = 0.31, and knot tying p = 0.13). However, deterioration was observed in the performance on stretching a rubber band (p < 0.05), as well as in the sum score (p < 0.05). Nevertheless, all retention scores remained better than the baseline results. In conclusion, basic laparoscopic skills acquired during a short training program merely sustain over time. However, ongoing practice is advisable, especially to preserve tissue-handling skills, since these may be the first to deteriorate
Grading and characterization of soft tissue tumors on magnetic resonance imaging: the value of an expert second opinion report
Genetic and epigenetic alterations on the short arm of chromosome 11 are involved in a majority of sporadic Wilms' tumours
Wilms' tumour is one of the most common solid tumours of childhood. 11p13 (WT1 locus) and 11p15.5 (WT2 locus) are known to have genetic or epigenetic aberrations in these tumours. In Wilms' tumours, mutation of the Wilms tumour 1 (WT1) gene at the WT1 locus has been reported, and the WT2 locus, comprising the two independent imprinted domains IGF2/H19 and KIP2/LIT1, can undergo maternal deletion or alterations associated with imprinting. Although these alterations have been identified in many studies, it is still not clear how frequently combined genetic and epigenetic alterations of these loci are involved in Wilms' tumours or how these alterations occur. To answer both questions, we performed genetic and epigenetic analyses of these loci, together with an additional gene, CTNNB1, in 35 sporadic Wilms' tumours. Loss of heterozygosity of 11p15.5 and loss of imprinting of IGF2 were the most frequent genetic (29%) and epigenetic (40%) alterations in Wilms' tumours, respectively. In total, 83% of the tumours had at least one alteration at 11p15.5 and/or 11p13. One-third of the tumours had alterations at multiple loci. Our results suggest that chromosome 11p is not only genetically but also epigenetically critical for the majority of Wilms' tumours
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