The influence of Flutter (R) VRP1 components on mucus transport of patients with bronchiectasis

Background: The Flutter (R) VRP1 combines high frequency oscillation and positive expiratory pressure (PEP). Objective: To separately evaluate the effect of the Flutter (R) VRP1 components (high frequency oscillation and PEP) on mucus transportability in patients with bronchiectasis. Methods: Eighteen patients with bronchiectasis received sessions with the Flutter (R) VRP1 or PEP for 30 min daily in a randomized, crossover study. The treatment duration was four weeks with one of the therapies, one week of a ""wash-out"" period and followed by four more weeks with the other treatment. Weekly secretion samples were collected and evaluated for mucociliary relative transport velocity (RTV), displacement in a simulated cough machine (SCM) and contact angle measurement (CAM). For the proposed comparisons, a linear regression model was used with mixed effects with a significance level of 5%. Results: The Flutter (R) VRP1 treatment resulted in greater displacement in SCM and lower CAM when comparing results from the first (9.6 +/- 3.4 cm and 29.4 +/- 5.7 degrees, respectively) and fourth weeks of treatment (12.44 +/- 10.5 cm and 23.28 +/- 6.2, respectively; p < 0.05). There was no significant difference in the RTV between the treatment weeks for either the Flutter (R) VRP1 or PEP. Conclusion: The use of the Flutter (R) VRP1 for four weeks is capable of altering the respiratory secretion transport properties, and this alteration is related to the high frequency oscillation component. (C) 2011 Elsevier Ltd. All rights reserved.

Histology of the regenerate and docking site in bone transport

Bone transport is based on the principle of distraction osteogenesis described by Ilizarov and is a consecrated method for the treatment of segmental bone defects. One of its most problematic and, paradoxically, least studied aspects is the consolidation of the docking site. We studied histologically the ossification of the docking site and regenerate to determine any difference between them. Nine adult sheep were submitted to correction of a 1-cm tibial diaphyseal defect using a system of plate-fixed bone transport, with latency period of 1 week and 0.2 mm distraction of the transported segment four times a day. The sheep were divided into three groups of three animals each, according to the observation period of 3, 6 or 12 weeks between the fixation of the transported fragment and the euthanasia. The docking site and the regenerate were studied histologically on sections stained with Masson trichrome. The main mode of docking site ossification was the endochondral one and although intramembranous ossification was also observed simultaneously, it was limited to rare and small foci. In contrast, intramembranous ossification played the major role in the regenerate, with bone formation evolving from the base segment to the target segment. The experimental bone transport model proposed in the present study permits us to conclude that there is a clear difference between the ossification of the docking site and of the regenerate.

Pharmacotherapy of the ion transport defect in cystic fibrosis

1. More than 1300 different mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) cause cystic fibrosis (CF), a disease characterized by deficient epithelial Cl- secretion and enhanced Na+ absorption. The clinical course of the disease is determined by the progressive lung disease. Thus, novel approaches in pharmacotherapy are based primarily on correction of the ion transport defect in the airways. 2. The current therapeutic strategies try to counteract the deficiency in Cl- secretion and the enhanced Na+ absorption. A number of compounds have been identified, such as genistein and xanthine derivatives, which directly activate mutant CFTR. Other compounds may activate alternative Ca2+-activated Cl- channels or basolateral K+ channels, which supply the driving force for Cl- secretion. Apart from that, Na+ channel blockers, such as phenamil and benzamil, are being explored, which counteract the hyperabsorption of NaCl in CF airways. 3. Clinical trials are under way using purinergic compounds such as the P2Y(2) receptor agonist INS365. Activation of P2Y(2) receptors has been found to both activate Cl- secretion and inhibit Na+ absorption. 4. The ultimate goal is to recover Cl- channel activity of mutant CFTR by either enhancing synthesis and expression of the protein or by activating silent CFTR Cl- channels. Strategies combining these drugs with compounds facilitating Cl- secretion and inhibiting Na+ absorption in vivo may have the best chance to counteract the ion transport defect in cystic fibrosis.

Solution techniques for transport problems involving steep concentration gradients: application to noncatalytic fluid solid reactions

Some efficient solution techniques for solving models of noncatalytic gas-solid and fluid-solid reactions are presented. These models include those with non-constant diffusivities for which the formulation reduces to that of a convection-diffusion problem. A singular perturbation problem results for such models in the presence of a large Thiele modulus, for which the classical numerical methods can present difficulties. For the convection-diffusion like case, the time-dependent partial differential equations are transformed by a semi-discrete Petrov-Galerkin finite element method into a system of ordinary differential equations of the initial-value type that can be readily solved. In the presence of a constant diffusivity, in slab geometry the convection-like terms are absent, and the combination of a fitted mesh finite difference method with a predictor-corrector method is used to solve the problem. Both the methods are found to converge, and general reaction rate forms can be treated. These methods are simple and highly efficient for arbitrary particle geometry and parameters, including a large Thiele modulus. (C) 2001 Elsevier Science Ltd. All rights reserved.

Influence of seaward boundary condition on contaminant transport in unconfined coastal aquifers

Contaminant transport in coastal aquifers is complicated partly due to the conditions at the seaward boundary including seawater intrusion and tidal variations of sea level. Their inclusion in modelling this system will be computationally expensive. Therefore, it will be instructive to investigate the consequence of simplifying the seaward boundary condition by neglecting the seawater density and tidal variations in numerical predictions of contaminant transport in this zone. This paper presents a comparison of numerical predictions for a simplified seaward boundary condition with experimental results for a corresponding realistic one including a saltwater interface and tidal variations. Different densities for contaminants are considered. The comparison suggests that the neglect of the seawater intrusion and tidal variations does not affect noticeably the overall migration rate of the plume before it reaches the saltwater interface. However, numerical prediction shows that a more dense contaminant travels further seaward and part of the solute mass exits under the sea if the seawater density is not included. This is not consistent with the experimental result, which shows that the contaminant travels upwards to the shoreline along the saltwater interface. Neglect of seawater density, therefore, will result in an underestimation of the exit rate of solute mass around the coastline and fictitious migration paths under the seabed. For a less dense contaminant, neglect of seawater density has little effect on numerical prediction of migration paths. (C) 2001 Elsevier Science B.V. All rights reserved.

Cloning and gastrointestinal expression of rat hephaestin: relationship to other iron transport proteins

The membrane-bound ceruloplasmin homolog hephaestin plays a critical role in intestinal iron absorption. The aims of this study were to clone the rat hephaestin gene and to examine its expression in the gastrointestinal tract in relation to other genes encoding iron transport proteins. The rat hephaestin gene was isolated from intestinal mRNA and was found to encode a protein 96% identical to mouse hephaestin. Analysis by ribonuclease protection assay and Western blotting showed that hephaestin was expressed at high levels throughout the small intestine and colon. Immunofluorescence localized the hephaestin protein to the mature villus enterocytes with little or no expression in the crypts. Variations in iron status had a small but nonsignificant effect on hephaestin expression in the duodenum. The high sequence conservation between rat and mouse hephaestin is consistent with this protein playing a central role in intestinal iron absorption, although its precise function remains to be determined.

Influence of nano-structure on electrolytic properties in CeO2 based system

Doped ceria (CeO2) compounds are fluorite type oxides that show oxygen ionic conductivity higher than yttria stabilized zirconia, in oxidizing atmosphere. In order to improve the conductivity, the effective index was suggested to maximize the oxygen ionic conductivity in doped CeO2 based oxides. In addition, the true microstructure of doped CeO2 was observed at atomic scale for conclusion of conduction mechanism. Doped CeO2 had small domains (10-50 nm) with ordered structure in a grain. It is found that the electrolytic properties strongly depended on the nano-structural feature at atomic scale in doped CeO2 electrolyte.

The effect of soft tissue deloading tape on thoracic spine pressure pain thresholds in asymptomatic subjects

The application of tape to deload soft tissue is used in the management of thoracic spine pain. A reported clinical feature of this treatment is reduced tenderness of the spine during postero-anterior mobilizations. A randomized, single blind, placebo controlled, repeated measures design study was employed to investigate the effects of deloading tape on pressure pain threshold measurements at the level of the T7 spinous process in an asymptomatic group of 24 subjects. Pressure pain thresholds were assessed prior to and following the application of deloading tape, placebo sham tape and no-tape control conditions. All subjects received all three conditions in a randomized order on three separate days. Differences between the pre- and post-measurements were used as indicators of change in a subject's pressure pain threshold. No significant change in pressure pain threshold measurements was found between conditions. In summary, this study demonstrated that deloading tape applied to the level of the T7 spinous process did not significantly change pressure pain threshold measurements in asymptomatic subjects, raising the possibility that any pain relieving effect may well be conditional upon pain being present. (C) 2002 Elsevier Science Ltd. All rights reserved.

Numerical modelling of contaminant transport in coastal aquifers

This paper employs a two-dimensional variable density flow and transport model to investigate the transport of a dense contaminant plume in an unconfined coastal aquifer. Experimental results are also presented to show the contaminant plume in a freshwater-seawater flow system. Both the numerical and experimental results suggest that the neglect of the seawater interface does not noticeably affect the horizontal migration rate of the plume before it reaches the interface. However, the contaminant will travel further seaward and part of the solute mass will exit under the sea if the higher seawater density is not included. If the seawater density is included, the contaminant will travel upwards towards the beach along the freshwater-saltwater interface as shown experimentally. Neglect of seawater density, therefore, will result in an underestimate of solute mass rate exiting around the coastline. (C) 2002 IMACS. Published by Elsevier Science B.V. All rights reserved.

Synaptic vesicle transport and synaptic membrane transporter sites in excitatory amino acid nerve terminals in Alzheimer disease

The apparent L-[H-3]glutamate uptake rate (v') was measured in synaptic vesicles isolated from cerebral cortex synaptosomes prepared from autopsied Alzheimer and non-Alzheimer dementia cases, and age-matched controls. The initial synaptosome preparations exhibited similar densities of D-[H-3]aspartate membrane binding sites (B-MAX values) in the three groups. In control brain the temporal cortex D-[H-3]aspartate B-MAX was 132% of that in motor cortex, parallel with the L- [H-3]glutamate v' values (temporal = 139% of motor; NS). Unlike D- [H-3]aspartate B-MAX values, L- [H-3]glutamate v' values were markedly and selectively lower in Alzheimer brain preparations than in controls, particularly in temporal cortex. The difference could not be attributed to differential effects of autopsy interval or age at death. Non-Alzheimer dementia cases resembled controls. The selective loss of vesicular glutamate transport is consistent with a dysfunction in the recycling of transmitter glutamate.

Abnormal extracellular matrix protein transport associated with increased apoptosis of vascular smooth muscle cells in Marfan syndrome and bicuspid aortic valve thoracic aortic aneurysm

Background - Marfan syndrome (MS) is a genetic disorder caused by a mutation in the fibrillin gene FBN1. Bicuspid aortic valve (BAV) is a congenital heart malformation of unknown cause. Both conditions are associated with ascending aortic aneurysm and premature death. This study examined the relationship among the secretion of extracellular matrix proteins fibrillin, fibronectin, tenascin, and vascular smooth muscle cell (VSMC) apoptosis. The role of matrix metalloproteinase (MMP)- 2 in VSMC apoptosis was studied in MS aneurysm. Methods and Results - Aneurysm tissue was obtained from patients undergoing surgery ( MS: 4 M, 1 F, age 27 - 45 years; BAV: 3 M, 2 F, age 28 - 65 years). Normal aorta from subjects with nonaneurysm disease was also collected ( 4 M, 1 F, age 23 - 93 years). MS and BAV aneurysm histology showed areas of cystic medial necrosis (CMN) without inflammatory infiltrate. Immunohistochemical study of cultured MS and BAV VSMC showed intracellular accumulation and reduction of extracellular distribution of fibrillin, fibronectin, and tenascin. Western blot showed no increase in expression of fibrillin, fibronectin, or tenascin in MS or BAV VSMC and increased expression of MMP-2 in MS VSMCs. There was 4-fold increase in loss of cultured VSMC incubated in serum-free medium for 24 hours in both MS ( 27 +/- 8%) and BAV ( 32 +/- 14%) compared with control ( 7 +/- 5%). Conclusions - In MS and BAV there is alteration in both the amount and quality of secreted proteins and an increased degree of VSMC apoptosis. Up-regulation of MMP-2 might play a role in VSMC apoptosis in MS VSMC. The findings suggest the presence of a fundamental cellular abnormality in BAV thoracic aorta, possibly of genetic origin.

Electrolytic properties and nanostructural features in the La2O3-CeO2 system

Doped ceria (CeO2) compounds are fluorite-type oxides which show oxide ionic conductivity higher than yttria-stabilized zirconia in oxidizing atmosphere. As a consequence of this, considerable interest has been shown in applications of these materials for low or intermediate temperature operation of solid-oxide fuel cells (SOFCs). In this study, the effective index was suggested to maximize the ionic conductivity in La2O3-CeO2 based oxides. The index considers the fluorite structure, and combines the expected oxygen vacancy level with the ionic radius mismatch between host and dopant cations. Using this approach, the ionic conductivity of this system has been optimized and tested under operating conditions of SOFCs. LaxCe1-xO2-delta (x = 0.125, 0.15, 0.175, and 0.20), (LaxSr1-x)(0.175)Ce0.825O2-delta (x = 0.1, 0.2, and 0.4), and (La1-xSr0.2Bax)(0.175)Ce0.825O2-delta (x 5 0.03, 0.05, and 0.07) were prepared and characterized as the specimens with low, intermediate, and high index, respectively. The ionic conductivity was increased with increasing suggested index. The transmission electron microscopy analysis suggested that partial substitution of alkaline earth elements in place of La into Ce site contributes to a decrease of microdomain size and an improvement of conductivity. (La0.75Sr0.2Ba0.05)(0.175)Ce0.825O1.891 with high index and small microdomains exhibited the highest conductivity, wide ionic domain, and good performance in SOFCs. (C) 2003 The Electrochemical Society.

Recombinant expression of Munc18c in a baculovirus system and interaction with syntaxin4

Two protein families that are critical for vesicle transport are the Syntaxin and Munc18/Sec1. families of proteins. These two molecules form a high affinity complex and play an essential role in vesicle docking and fusion. Munc18c was expressed as an N-terminally His-tagged fusion protein from recombinant baculovirus in Sf9 insect cells. His-tagged Munc18c was purified to homogeneity using both cobalt-chelating affinity chromatography and gel filtration chromatography. With this simple two-step protocol, 3.5 mg of purified Munc18c was obtained from a 1 L culture. Further, the N-terminal His-tag could be removed by thrombin cleavage while the tagged protein was bound to metal affinity resin. Recombinant Munc18c produced in this way is functional, in that it forms a stable complex with the SNARE interacting partner, syntaxin4. Thus we have developed a method for producing and purifying large amounts of functional Munc18c-both tagged and detagged-from a baculovirus expression system. We have also developed a method to purify the Munc18c:syntaxin4 complex. These methods will be employed for future functional and structural studies. Crown copyright (C) 2003 Published by Elsevier Inc. All rights reserved.

Mobi-system: assistente pessoal de viagem

Este trabalho sugere uma solução de integração de dados em tempo real no contexto dos transportes públicos. Com o aumento das alternativas oferecidas aos utilizadores dos transportes públicos é importante que estes conheçam todas as alternativas com base em informação em tempo real para que realizem a escolha que melhor se enquadre às suas necessidades. Por outro lado, os operadores de transportes públicos deverão ser capazes de disponibilizar toda a informação pretendida com o mínimo de esforço ou de alterações ao sistema que têm implementado. Neste trabalho serão utilizadas ferramentas que permitem fornecer uma visão homogénea das várias fontes de dados heterogéneas, sendo essa homogeneidade o ponto de integração de todas as fontes de dados com as aplicações cliente.