29 research outputs found
Effectiveness of joint mobilisation after cast immobilisation for ankle fracture: a protocol for a randomised controlled trial [ACTRN012605000143628]
Background: Passive joint mobilisation is a technique frequently used by physiotherapists to reduce pain, improve joint movement and facilitate a return to activities after injury, but its use after ankle fracture is currently based on limited evidence. The primary aim of this trial is to determine if adding joint mobilisation to a standard exercise programme is effective and cost-effective after cast immobilisation for ankle fracture in adults. Methods/Design: Ninety participants will be recruited from the physiotherapy departments of three teaching hospitals and randomly allocated to treatment or control groups using a concealed procedure. All participants will perform an exercise programme. Participants in the treatment group will also receive joint mobilisation twice a week for four weeks. Blinded follow-up assessments will be conducted four, 12 and 24 weeks after randomisation. The primary outcome measures will be the Lower Extremity Functional Scale and the Assessment of Quality of Life. Secondary outcomes will include measures of impairments, activity limitation and participation. Data on the use of physiotherapy services and participants' out-of-pocket costs will be collected for the cost-effective and cost-utility analyses. To test the effects of treatment, between-group differences will be examined with analysis of covariance using a regression approach. The primary conclusions will be based on the four-week follow-up data. Discussion: This trial incorporates features known to minimise bias. It uses a pragmatic design to reflect clinical practice and maximise generalisability. Results from this trial will contribute to an evidence-based approach for rehabilitation after ankle fracture. © 2006 Lin et al; licensee BioMed Central Ltd
Opening of endothelial cell–cell contacts due to sonoporation
Ultrasound insonification of microbubbles can locally increase vascular permeability to enhance drug delivery. To control and optimize the therapeutic potential, we need to better understand the underlying biological mechanisms of the drug delivery pathways. The aim of this in vitro study was to elucidate the microbubble-endothelial cell interaction using the Brandaris 128 ultra-high-speed camera (up to 25 Mfps) coupled to a custom-built Nikon confocal microscope, to visualize both microbubble oscillation and the cellular response. Sonoporation and opening of cell-cell contacts by single αVβ3-targeted microbubbles (n = 152) was monitored up to 4 min after ultrasound insonification (2 MHz, 100–400 kPa, 10 cycles). Sonoporation occurred when microbubble excursion amplitudes exceeded 0.7 μm. Quantification of the influx of the fluorescent model drug propidium iodide upon sonoporation showed that the size of the created pore increased for larger microbubble excursion amplitudes. Microbubble-mediated opening of cell-cell contacts occurred as a cellular response upon sonoporation and did not correlate with the microbubble excursion amplitude itself. The initial integrity of the cell-cell contacts affected the susceptibly to drug delivery, since cell-cell contacts opened more often when cells were only partially attached to their neighbors (48%) than when fully attached (14%). The drug delivery outcomes were independent of nonlinear microbubble behavior, microbubble location, and cell size. In conclusion, by studying the microbubble–cell interaction at nanosecond and nanometer resolution the relationship between drug delivery pathways and their underlying mechanisms was further unraveled. These novel insights will aid the development of safe and efficient microbubble-mediated drug delivery
High-Resolution Imaging of Intracellular Calcium Fluctuations Caused by Oscillating Microbubbles
Ultrasound insonification of microbubbles can locally enhance drug delivery, but the microbubble–cell interaction remains poorly understood. Because intracellular calcium (Cai 2+) is a key cellular regulator, unraveling the Cai 2+ fluctuations caused by an oscillating microbubble provides crucial insight into the underlying bio-effects. Therefore, we developed an optical imaging system at nanometer and nanosecond resolution that can resolve Cai 2+ fluctuations and microbubble oscillations. Using this system, we clearly distinguished three Cai 2+ uptake profiles upon sonoporation of endothelial cells, which strongly correlated with the microbubble oscillation amplitude, severity of sonoporation and opening of cell–cell contacts. We found a narrow operating range for viable drug delivery without lethal cell damage. Moreover, adjacent cells were affected by a calcium wave propagating at 15 μm/s. With the unique optical system, we unraveled the microbubble oscillation behavior required for drug delivery and Cai 2+ fluctuations, providing new insight into the microbubble–cell interaction to aid clinical translation
Quantification of systematic errors in the electron density and temperature measured with Thomson scattering at W7-X
The electron density and temperature profiles measured with Thomson
scattering at the stellarator Wendelstein 7-X show features which seem to be
unphysical, but so far could not be associated with any source of error
considered in the data processing. A detailed Bayesian analysis reveals that
errors in the spectral calibration cannot explain the features observed in the
profiles. Rather, it seems that small fluctuations in the laser position are
sufficient to affect the profile substantially. The impact of these
fluctuations depends on the laser position itself, which, in turn, provides a
method to find the optimum laser alignment in the future
Real-time photoacoustic assessment of radiofrequency ablation lesion formation in the left atrium
In interventional electrophysiology, catheter-based radiofrequency (RF) ablation procedures restore cardiac heart rhythm by interrupting aberrant conduction paths. Real-time feedback on lesion formation and post-treatment lesion assessment could overcome procedural challenges related to ablation of underlying structures and lesion gaps. This study aims to evaluate real-time visualization of lesion progression and continuity during intra-atrial ablation with photoacoustic (PA) imaging, using clinically deployable technology. A PA-enabled RF ablation catheter was used to ablate and illuminate porcine left atrium, both excised and intact in a passive beating heart ex-vivo, for photoacoustic signal generation. PA signals were received with an intracardiac echography catheter. Using the ratio of PA images acquired with excitation wavelengths of 790 nm and 930 nm, ablation lesions were successfully imaged through c
Comparison of three methods for detection of gametocytes in Melanesian children treated for uncomplicated malaria
Background: Gametocytes are the transmission stages of Plasmodium parasites, the causative agents of malaria. As their density in the human host is typically low, they are often undetected by conventional light microscopy. Furthermore, application of RNA-based molecular detection methods for gametocyte detection remains challenging in remote field settings. In the present study, a detailed comparison of three methods, namely light microscopy, magnetic fractionation and reverse transcriptase polymerase chain reaction for detection of Plasmodium falciparum and Plasmodium vivax gametocytes was conducted.Methods. Peripheral blood samples from 70 children aged 0.5 to five years with uncomplicated malaria who were treated with either artemether-lumefantrine or artemisinin-naphthoquine were collected from two health facilities on the north coast of Papua New Guinea. The samples were taken prior to treatment (day 0) and at pre-specified intervals during follow-up. Gametocytes were measured in each sample by three methods: i) light microscopy (LM), ii) quantitative magnetic fractionation (MF) and, iii) reverse transcriptase PCR (RTPCR). Data were analysed using censored linear regression and Bland and Altman techniques.Results: MF and RTPCR were similarly sensitive and specific, and both were superior to LM. Overall, there were approximately 20% gametocyte-positive samples by LM, whereas gametocyte positivity by MF and RTPCR were both more than two-fold this level. In the subset of samples collected prior to treatment, 29% of children were positive by LM, and 85% were gametocyte positive by MF and RTPCR, respectively.Conclusions: The present study represents the first direct comparison of standard LM, MF and RTPCR for gametocyte detection in field isolates. It provides strong evidence that MF is superior to LM and can be used to detect gametocytaemic patients under field conditions with similar sensitivity and specificity as RTPCR
Combined Confocal Microscope and Brandaris 128 Ultra-High-Speed Camera
Controlling microbubble-mediated drug delivery requires the underlying biological and physical mechanisms to be unraveled. To image both microbubble oscillation upon ultrasound insonification and the resulting cellular response, we developed an optical imaging system that can achieve the necessary nanosecond temporal and nanometer spatial resolutions. We coupled the Brandaris 128 ultra-high-speed camera (up to 25 million frames per second) to a custom-built Nikon A1R+ confocal microscope. The unique capabilities of this combined system are demonstrated with three experiments showing microbubble oscillation leading to either endothelial drug delivery, bacterial biofilm disruption, or structural changes in the microbubble coating. In conclusion, using this state-of-the-art optical imaging system, microbubble-mediated drug delivery can be studied with high temporal resolution to resolve microbubble oscillation and high spatial resolution and detector sensitivity to discern cellular response. Combining these two imaging technologies will substantially advance our knowledge on microbubble behavior and its role in drug delivery
Effectiveness of behavioural graded activity compared with physiotherapy treatment in chronic neck pain: design of a randomised clinical trial [ISRCTN88733332]
BACKGROUND: Chronic neck pain is a common complaint in the Netherlands
with a point prevalence of 14.3%. Patients with chronic neck pain are
often referred to a physiotherapist and, although many treatments are
available, it remains unclear which type of treatment is to be
preferred.The objective of this article is to present the design of a
randomised clinical trial, Ephysion, which examines the clinical and cost
effectiveness of behavioural graded activity compared with a physiotherapy
treatment for patients with chronic non-specific neck pain. METHODS:
Eligible patients with non-specific neck pain persisting longer than 3
months will be randomly allocated to either the behavioural graded
activity programme or to the physiotherapy treatment. The graded activity
programme is based on an operant approach, which uses a time-contingent
method to increase the patient's activity level. This treatment is
compared with physiotherapy treatment using a pain-contingent
method.Primary treatment outcome is the patient's global perceived effect
concerning recovery from the complaint. Global perceived effect on daily
functioning is also explored as primary outcome to establish the impact of
treatment on daily activity. Direct and indirect costs will also be
assessed. Secondary outcomes include the patient's main complaints, pain
intensity, medical consumption, functional status, quality of life, and
psychological variables. Recruitment of patients will take place up to the
end of the year 2004 and follow-up measurement will continue until end
2005
