69 research outputs found

    Effects of Backpacks on Ground Reaction Forces in Children of Different Ages When Walking, Running, and Jumping

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    Backpacks for transporting school loads are heavily utilized by children, and their mechanical advantages have been allowing children to transport heavy loads. These heavy loads may increase ground reaction forces (GRFs), which can have a negative effect on joints and bone health. The aim of this study was to investigate the effect of backpacks on the GRFs generated by children during walking, running, and jumping. Twenty-one children from the fifth (G-5, n = 9) and ninth (G-9, n = 12) grades walked, ran, and jumped over a force plate. When walking, the G-5 had GRF increments in the first (17.3%; p 0.05), unlike the G-5 (p = 0.001). When running, total stance time increased 15% (p < 0.001) and 8.5% (p < 0.001) proportionally to the relative load carried, in the G-5 and G-9, respectively. Peak GRF did not increase in any group when running or landing from a jump over an obstacle. It was found that GRF was affected by the backpack load when walking and running. However, when landing from a jump with the backpack, schoolchildren smoothed the landing by prolonging the reception time and thus avoiding GRF peak magnitudes.info:eu-repo/semantics/publishedVersio

    Upregulation of intrarenal angiotensinogen in diabetes

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    Universidade Federal de SĆ£o Paulo, Dept Med, Div Nephrol, BR-04023040 SĆ£o Paulo, BrazilUniversidade Federal de SĆ£o Paulo, Dept Med, Div Nephrol, BR-04023040 SĆ£o Paulo, BrazilWeb of Scienc

    Efficacy of a broad host range lytic bacteriophage against E. coli adhered to urothelium

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    Persistent urinary tract infections (UTI) are often caused by E. coli adhered to urothelium. This type of cells is generally recognized as very tolerant to antibiotics which renders difficult the treatment of chronic UTI. This work investigates the use of lytic bacteriophages as alternative antimicrobial agents, particularly the interaction of phages with E. coli adhered to urothelium and specifically determines their efficiency against this type of cells. The bacterial adhesion to urothelium was performed varying the bacterial cell concentrations and the period and conditions (static, shaken) of adhesion. Three collection bacteriophages (T1, T4 and phiX174 like phages) were tested against clinical E. coli isolates and only one was selected for further infection experiments. Based on the lytic spectrum against clinical isolates and its ability to infect the highest number of antibiotic resistant strains, the T1-like bacteriophage was selected. This bacteriophage caused nearly a 45 % reduction of the bacterial population after 2 h of treatment. This study provides evidence that bacteriophages are effective in controlling suspended and adhered cells and therefore can be a viable alternative to antibiotics to control urothelium adhered bacteria

    Cardiac magnetic resonance imaging in stable ischaemic heart disease

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    Cardiac magnetic resonance imaging (CMR) is a new robust versatile non-invasive imaging technique that can detect global and regional myocardial dysfunction, presence of myocardial ischaemia and myocardial scar tissue in one imaging session without radiation, with superb spatial and temporal resolution, inherited three-dimensional data collection and with relatively safe contrast material. The reproducibility of CMR is high which makes it possible to use this technique for serial assessment to evaluate the effect of revascularisation therapy in patients with ischaemic heart disease

    Comparison of (semi-)automatic and manually adjusted measurements of left ventricular function in dual source computed tomography using three different software tools

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    To assess the accuracy of (semi-)automatic measurements of left ventricular (LV) functional parameters in cardiac dual-source computed tomography (DSCT) compared to manually adjusted measurements in three different workstations. Forty patients, who underwent cardiac DSCT, were included (31 men, mean age 58Ā Ā±Ā 14Ā years). Multiphase reconstructions were made with ten series at every 10% of the RR-interval. LV function analysis was performed on three different, commercially available workstations. On all three workstations, end-systolic volume (ESV), end-diastolic volume (EDV), LV ejection fraction (LVEF) and myocardial mass (MM) were calculated as automatically as possible. With the same DSCT datasets, LV functional parameters were also calculated with as many manual adjustments as needed for accurate assessment for all three software tools. For both semi-automatic as well as manual methods, time needed for evaluation was recorded. Paired t-tests were employed to calculate differences in LV functional parameters. Repeated measurements were performed to determine intra-observer and inter-observer variability. (Semi-)automatic measurements revealed a good correlation with manually adjusted measurements for Vitrea (LVEF rĀ =Ā 0.93, EDV rĀ =Ā 0.94, ESV rĀ =Ā 0.98 and MM rĀ =Ā 0.94) and Aquarius (LVEF rĀ =Ā 0.96, EDV rĀ =Ā 0.94, ESV rĀ =Ā 0.98 and MM rĀ =Ā 0.96). Also, good correlation was obtained for Circulation, except for LVEF (LVEF rĀ =Ā 0.45, EDV rĀ =Ā 0.93, ESV rĀ =Ā 0.92 and MM rĀ =Ā 0.86). However, statistically significant differences were found between (semi-)automatically and manually adjusted measurements for LVEF (PĀ <Ā 0.05) and ESV (PĀ <Ā 0.001) in Vitrea, all LV functional parameters in Circulation (PĀ <Ā 0.001) and EDV, ESV and MM (<0.001) in Aquarius Workstation. (Semi-)automatic measurement of LV functional parameters is feasible, but significant differences were found for at least two different functional parameters in all three workstations. Therefore, expert manual correction is recommended at all times

    Image quality assessment of the right ventricle with three different delayed enhancement sequences in patients suspected of ARVC/D

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    Histopathologic findings in arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) are replacement of the normal myocardium with fatty and fibrous elements with preferential involvement of the right ventricle. The right ventricular fibrosis can be visualised by post-gadolinium delayed enhancement inversion recovery imaging (DE imaging). We compared the image quality of three different gradient echo MRI sequences for short axis DE imaging of the right ventricle (RV). We retrospectively analysed MRI scans performed between February 2005 and December 2008 in 97 patients (mean age: 41.2Ā years, 67% men) suspected of ARVC/D. For DE imaging either a 2D Phase Sensitive (PSIR), a 2D (2D) or a 3D (3D) inversion recovery sequence was used in respectively 38, 32 and 27 MRI-examinations. The RV, divided in 10 segments, was assessed for image quality by two radiologists in random sequence. A consensus reading was performed if results differed between the two readings. Image quality was good in 24% of all segments in the 3D group, 66% in the 2D group and 79% in the PSIR group. Poor image quality was observed in 51% (3D), 10% (2D), and 2% (PSIR) of all segments. Exams were considered suitable for clinical use in 7% of exams in the 3D group, 75% of exams in the 2D group and 90% of exams of the PSIR group. Breathing-artifacts occurred in 22% (3D), 59% (2D) and 53% (PSIR). Motion-artifacts occurred in 56% (3D), 28% (2D) and 29% (PSIR). Post-gadolinium imaging using the PSIR sequence results in better and more consistent image quality of the RV compared to the 2D and 3D sequences

    Heart valve disease: investigation by cardiovascular magnetic resonance

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    Cardiovascular magnetic resonance (CMR) has become a valuable investigative tool in many areas of cardiac medicine. Its value in heart valve disease is less well appreciated however, particularly as echocardiography is a powerful and widely available technique in valve disease. This review highlights the added value that CMR can bring in valve disease, complementing echocardiography in many areas, but it has also become the first-line investigation in some, such as pulmonary valve disease and assessing the right ventricle. CMR has many advantages, including the ability to image in any plane, which allows full visualisation of valves and their inflow/outflow tracts, direct measurement of valve area (particularly for stenotic valves), and characterisation of the associated great vessel anatomy (e.g. the aortic root and arch in aortic valve disease). A particular strength is the ability to quantify flow, which allows accurate measurement of regurgitation, cardiac shunt volumes/ratios and differential flow volumes (e.g. left and right pulmonary arteries). Quantification of ventricular volumes and mass is vital for determining the impact of valve disease on the heart, and CMR is the 'Gold standard' for this. Limitations of the technique include partial volume effects due to image slice thickness, and a low ability to identify small, highly mobile objects (such as vegetations) due to the need to acquire images over several cardiac cycles. The review examines the advantages and disadvantages of each imaging aspect in detail, and considers how CMR can be used optimally for each valve lesion
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