93 resultados para compression parallel


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Cement augmentation using PMMA cement is known as an efficient treatment for osteoporotic vertebral compression fractures with a rapid release of pain in most patients and prevention of an ongoing kyphotic deformity of the vertebrae treated. However, after a vertebroplasty there is no chance to restore vertebral height. Using the technique of kyphoplasty a certain restoration of vertebral body height can be achieved. But there is a limitation of recovery due to loss of correction when deflating the kyphoplastic ballon and before injecting the cement. In addition, the instruments used are quite expensive. Lordoplasty is another technique to restore kyphosis by indirect fracture reduction as it is used with an internal fixateur. The fractured and the adjacent vertebrae are instrumented with bone cannulas bipediculary and the adjacent vertebrae are augmentated with cement. After curing of the cement the fractured vertebra is reduced by applying a lordotic moment via the cannulas. While maintaining the pretension the fractured vertebra is reinforced. We performed a prospective trial of 26 patients with a lordoplastic procedure. There was a pain relief of about 87% and a significant decrease in VAS value from 7.3 to 1.9. Due to lordoplasty there was a significant and permanent correction in vertebral and segmental kyphotic angle about 15.2 degrees and 10.0 degrees , respectively and also a significant restoration in anterior and mid vertebral height. Lordoplasty is a minimal invasive technique to restore vertebral body height. An immediate relief of pain is achieved in most patients. The procedure is safe and cost effective.

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Despite changes in patient demographics and short-ened length of hospital stay deep vein thrombosis (DVT) remains a major health care problem which may lead to a variety of other high risk complications. Current treatment guidelines focus on preventive measures. Beside drug therapy, physical measures executed by nursing professionals exist, the outcomes of which are discussed controversially. Based on 25 studies that were found in MEDLINE and the Cochrane library, this systematic literature review identifies the effectiveness of intermittent pneumatic compression (IPC) on thrombosis prophylaxis. In almost all medical settings IPC contributes to a significant reduction of the incidence of DVT. At the same time, IPC has minimal negative side effects and is also cost effective. Correct application of IPC and patient compliance are essential to achieve its effectiveness. An increased awareness within the healthcare team in identifying the risk for and implementing measures against DVT is needed. Guidelines need to be developed in order to improve the effectiveness of thrombosis prophylaxis with the implementation of IPC.

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BACKGROUND: Chronic idiopathic urticaria (CIU) is defined by the almost daily presence of urticaria for at least 6 weeks without an identifiable cause. Symptoms include short-lived wheals, itching, and erythema. CIU impedes significantly a patient's quality of life (QoL). Levocetirizine is an antihistamine from the latest generation approved for CIU. AIM: To investigate the efficacy of levocetirizine, 5 mg, and placebo for the symptoms and signs of CIU, as well as for the QoL and productivity. METHODS: The primary criteria of evaluation were the pruritus severity scores over 1 week of treatment and over 4 weeks. The QoL was assessed via the Dermatology Life Quality Index (DLQI). RESULTS: Baseline pruritus severity scores were comparable in the two treatment groups (2.06+/-0.58). After 1 week, levocetirizine was superior to placebo and demonstrated a considerable efficacy (difference=0.78, P<0.001). This efficacy was maintained over the entire study period (4 weeks, P<0.001). The number and size of wheals were considerably reduced compared with placebo over 1 week and over the total treatment period (P paralleled by an improvement in the QoL (DLQI: 7.3 units in the levocetirizine group and 2.4 units in the placebo group) and a higher productivity at work in the levocetirizine group (3.0 workdays lost per patient per month in the placebo group, 0.3 in the levocetirizine group). No unexpected adverse events occurred. CONCLUSIONS: Levocetirizine, 5 mg once daily, is an effective treatment for CIU, characterized not only by a rapid and sustained response, but also by an important improvement in QoL.

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Colour pattern diversity can be due to random processes or to natural or sexual selection. Consequently, similarities in colour patterns are not always correlated with common ancestry, but may result from convergent evolution under shared selection pressures or drift. Neolamprologus brichardi and Neolamprologus pulcher have been described as two distinct species based on differences in the arrangement of two dark bars on the operculum. Our study uses DNA sequences of the mitochondrial control region to show that relatedness of haplotypes disagrees with species assignment based on head colour pattern. This suggests repeated parallel evolution of particular stripe patterns. The complete lack of shared haplotypes between populations of the same or different phenotypes reflects strong philopatric behaviour, possibly induced by the cooperative breeding mode in which offspring remain in their natal territory and serve as helpers until they disperse to nearby territories or take over a breeding position. Concordant phylogeographic patterns between N. brichardi/N. pulcher populations and other rock-dwelling cichlids suggest that the same colonization routes have been taken by sympatric species and that these routes were affected by lake level fluctuations in the past. (C) 2007 Elsevier Inc. All rights reserved.

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OBJECTIVE: To investigate whether intermittent pneumatic compression (IPC) augments skin blood flow through transient suspension of local vasoregulation, the veno-arteriolar response (VAR), in healthy controls and in patients with peripheral arterial disease (PAD). METHODS: Nineteen healthy limbs and twenty-two limbs with PAD were examined. To assess VAR, skin blood flow (SBF) was measured using laser Doppler fluxmetry in the horizontal and sitting positions and was defined as percentage change with postural alteration [(horizontal SBF--sitting SBF)/horizontal SBF x 100]. On IPC application to the foot, the calf, or both, SBF was measured with laser Doppler fluxmetry, the probe being attached to the pulp of the big toe. RESULTS: Baseline VAR was higher in the controls 63.8 +/- 6.4% than in patients with PAD (31.7 +/- 13.4%, P = .0162). In both groups SBF was significantly higher with IPC than at rest (P < .0001). A higher percentage increase with IPC was demonstrated in the controls (242 +/- 85% to 788 +/- 318%) than in subjects with PAD, for each one of the three different IPC modes investigated (98 +/- 33% to 275 +/- 72%) with IPC was demonstrated. The SBF enhancement with IPC correlated with VAR for all three compression modes (r = 0.58, P = .002 for calf compression, r = 0.65, P < .0001 for foot compression alone, and r = 0.64, P = .0002 for combined foot and calf compression). CONCLUSION: The integrity of the veno-arteriolar response correlates with the level of skin blood flow augmentation generated with intermittent pneumatic compression, indicating that this may be associated with a transient suspension of the autoregulatory vasoconstriction both in healthy controls and in patients with PAD.

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Due to the inherent limitations of DXA, assessment of the biomechanical properties of vertebral bodies relies increasingly on CT-based finite element (FE) models, but these often use simplistic material behaviour and/or single loading cases. In this study, we applied a novel constitutive law for bone elasticity, plasticity and damage to FE models created from coarsened pQCT images of human vertebrae, and compared vertebral stiffness, strength and damage accumulation for axial compression, anterior flexion and a combination of these two cases. FE axial stiffness and strength correlated with experiments and were linearly related to flexion properties. In all loading modes, damage localised preferentially in the trabecular compartment. Damage for the combined loading was higher than cumulated damage produced by individual compression and flexion. In conclusion, this FE method predicts stiffness and strength of vertebral bodies from CT images with clinical resolution and provides insight into damage accumulation in various loading modes.

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To analyze the impact of opacities in the optical pathway and image compression of 32-bit raw data to 8-bit jpg images on quantified optical coherence tomography (OCT) image analysis.

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OBJECTIVE: The effects of mechanical deformation of intact cartilage tissue on chondrocyte biosynthesis in situ have been well documented, but the mechanotransduction pathways that regulate such phenomena have not been elucidated completely. The goal of this study was to examine the effects of tissue deformation on the morphology of a range of intracellular organelles which play a major role in cell biosynthesis and metabolism. DESIGN: Using chemical fixation, high pressure freezing, and electron microscopy, we imaged chondrocytes within mechanically compressed cartilage explants at high magnification and quantitatively and qualitatively assessed changes in organelle volume and shape caused by graded levels of loading. RESULTS: Compression of the tissue caused a concomitant reduction in the volume of the extracellular matrix (ECM), chondrocyte, nucleus, rough endoplasmic reticulum, and mitochondria. Interestingly, however, the Golgi apparatus was able to resist loss of intraorganelle water and retain a portion of its volume relative to the remainder of the cell. These combined results suggest that a balance between intracellular mechanical and osmotic gradients govern the changes in shape and volume of the organelles as the tissue is compressed. CONCLUSIONS: Our results lead to the interpretive hypothesis that organelle volume changes appear to be driven mainly by osmotic interactions while shape changes are mediated by structural factors, such as cytoskeletal interactions that may be linked to extracellular matrix deformations. The observed volume and shape changes of the chondrocyte organelles and the differential behavior between organelles during tissue compression provide evidence for an important mechanotransduction pathway linking translational and post-translational events (e.g., elongation and sulfation of glycosaminoglycans (GAGs) in the Golgi) to cell deformation.