bluuebunny/crossref_metadata_2025 huggingface dataset:
Flow Around a Simplified Car, Part 2: Understanding the Flow
Authors: Krajnović Siniša , Davidson Lars
Published: September 2005

Results of a large eddy simulation (LES) are used to explore the flow around a generic car model. A new, refined picture of this flow is established. Many parts and aspects of this flow are studied and explained. The development of the instantaneous flow and its resulting time-averaged flow are depicted. Large differences are found between the instantaneous and the time-averaged flows. Special attention is given to the flow above the rear slanted surface. The origin, the development, and the interactions of the instantaneous vortices in this part of the flow are presented for the first time. This instantaneous flow is shown to be very unsteady and to contain a large number of different vortices that range in size from those of the size of the body over the intermediate hairpin-like vortices to very small coherent structures. Besides the variety in the length scales, the flow covers a wide spectrum of the time scales from the relatively steady motion of the cone-like trailing vortices on the slanted edges to highly frequent collisions of the hairpin-like vortices in the region of the attachment on the rear slanted surface.
Separation of Condensation Jet Image Using Filter Effect of Wavelets Transform
Authors: Kimura Motoaki , Takei Masahiro , Saito Yoshifuru , Saima Atsushi
Published: September 2005

The present paper describes the application of discrete wavelet transform to the analysis of condensation jets in order to clarify the fluid and heat transfer phenomenon. The condensation jets in the nozzle vicinity are experimentally visualized via the laser light sheet method to obtain condensation particle density images of the jets. The image of the condensation particle density in the jet is decomposed to mean and fluctuation images via wavelet multiresolution. The dominant temperature boundary and the mean component outside the boundary were obtained from wavelet separation images. The boundary was compared to the experimentally obtained temperature distribution.
Detached-Eddy Simulation of the Separated Flow Over a Rounded-Corner Square
Authors: Squires Kyle D. , Forsythe James R. , Spalart Philippe R.
Published: September 2005

Detached-eddy simulation (DES) is used to study the massively separated flow over a rounded-corner square. The configuration is an idealization of the flow around a forebody cross section rotating at high angle of attack. Simulations are performed at sub- and supercritical Reynolds numbers, between which experimental measurements show a reversal of the side force. DES predictions are evaluated using experimental measurements and contrasted with unsteady Reynolds-averaged Navier–Stokes (URANS) results. The computations are also subjected to a moderate grid refinement, a doubling of the spanwise period, an enlargement of the domain in the other directions, and the removal of any explicit turbulence model. The sub- and supercritical flows are computed at Reynolds numbers of 105 and 8×105, respectively, and with the freestream at 10deg angle of attack. Boundary-layer separation characteristics (laminar or turbulent) are established via the initial and boundary conditions of the eddy viscosity. Following boundary layer detachment, a chaotic and three-dimensional wake rapidly develops. For the supercritical flow, the pressure distribution is close to the measured values and both the streamwise and side forces are in adequate agreement with measurements. For the subcritical flow, DES side-force predictions do not follow the experimental measurements far enough to achieve reversal.
DNS of Drag-Reducing Turbulent Channel Flow With Coexisting Newtonian and Non-Newtonian Fluid
Authors: Yu Bo , Kawaguchi Yasuo
Published: September 2005

In the present study, we numerically investigated drag-reducing turbulent channel flows by surfactant additives. Surfactant additives were assumed to be uniformly distributed in the entire flow region by turbulent convection and diffusion, etc., but it was assumed that the shear-induced structure (SIS) (network of rod-like micelles) could form either in the region next to the walls or in the center region of the channel, making the fluid viscoelastic. In other regions surfactant additives were assumed to be incapable of building a network structure, and to exist in the form of molecules or micelles that do not affect the Newtonian properties of the fluid. With these assumptions, we studied the drag-reducing phenomenon with coexisting Newtonian and non-Newtonian fluids. From the study we identified the effectiveness of the network structures at different flow regions, and showed that the phenomenon of drag-reduction (DR) by surfactant additives is not only closely associated with the reduction of Reynolds shear stress but also related to the induced viscoelastic shear stress.
Detached-Eddy Simulation of High-Reynolds-Number Beveled-Trailing-Edge Boundary Layers and Wakes
Authors: Paterson Eric G. , Peltier Leonard J.
Published: September 2005

Flow over three different trailing-edge geometries is studied using incompressible detached-eddy simulation and unsteady Reynolds-averaged Navier Stokes CFD methods. Of interest is the ability of DES, coupled, with localized overset-grid refinement, to resolve the proper physics of separated flows from trailing edges—trailing-edge turbulence and vortex shedding, in particular. The DES model is shown to provide a good qualitative description of the trailing-edge flow. However, the modeled separations are overly energetic due to premature separation related to artificially low turbulence levels from upstream. The transition from RANS to DES is isolated as an issue. The simulated physics of the wake are shown to be in agreement with other LES studies: the model produces the “rib/roller” structures representing the first instability modes, horseshoe vortices are observed, and in regions of high resolution, small scales are formed, as expected. The turbulence statistics are qualitatively similar to benchmark data near the trailing edge and in the near wake, however, quantitative comparisons of urms show an over prediction in magnitude of 50%–100%. Despite this, the results are promising, and future modeling efforts have been motivated and identified.
A Periodically Perturbed Backward-Facing Step Flow by Means of LES, DES and T-RANS: An Example of Flow Separation Control
Authors: Šarić S. , Jakirlić S. , Tropea C.
Published: September 2005

Turbulent flow over a backward-facing step, perturbed periodically by alternative blowing∕suction through a thin slit (0.05H width) situated at the step edge, was studied computationally using (LES) large eddy simulation, (DES) detached eddy simulation, and (T-RANS) transient Reynolds-averaged Navier–Stokes techniques. The flow configuration considered (ReH=UcH∕ν=3700) has been investigated experimentally by Yoshioka et al. (12). The periodic blowing∕suction with zero net mass flux is governed by a sinusoidal law: ve=0.3Ucsin(2πfet), Uc being the centerline velocity in the inlet channel. Perturbation frequencies fe corresponding to the Strouhal numbers St=0.08, 0.19, and 0.30 were investigated (St=feH∕Uc). The experimental observation that the perturbation frequency St=0.19 represents the most effective case, that is the case with the minimum reattachment length, was confirmed by all computational methods. However, the closest agreement with experiment (the reattachment length reduction of 28.3% compared to the unperturbed case) was obtained with LES (24.5%) and DES (35%), whereas the T-RANS computations showed a weaker sensitivity to the perturbation: 5.9% when using the Spalart–Allmaras model and 12.9% using the k-ω SST model.
Detached Eddy Simulation of Turbulent Flow and Heat Transfer in a Ribbed Duct
Authors: Viswanathan Aroon K. , Tafti Danesh K.
Published: September 2005

Detached Eddy Simulation (DES) of a hydrodynamic and thermally developed turbulent flow is presented for a stationary duct with square ribs aligned normal to the main flow direction. The rib height to channel hydraulic diameter (e∕Dh) is 0.1, the rib pitch to rib height (P∕e) is 10 and the calculations have been carried out for a bulk Reynolds number of 20,000. DES calculations are carried out on a 963 grid, a 643 grid, and a 483 grid to study the effect of grid resolution. Based on the agreement with earlier LES computations, the 643 grid is observed to be suitable for the DES computation. DES and RANS calculations carried out on the 643 grid are compared to LES calculations on 963∕1283 grids and experimental measurements. The flow and heat transfer characteristics for the DES cases compare well with the LES results and the experiments. The average friction and the augmentation ratios are consistent with experimental results, predicting values within 10% of the measured quantities, at a cost lower than the LES calculations. RANS fails to capture some key features of the flow.
Comparative LES and Unsteady RANS Computations for a Periodically-Perturbed Separated Flow Over a Backward-Facing Step
Authors: Dejoan A. , Jang Y.-J. , Leschziner M. A.
Published: September 2005

Large eddy simulation and statistical turbulence closures are used to investigate and contrast the ability of both strategies to represent the effects arising from the unsteady perturbation of a separated backward-facing-step flow caused by a slot jet injected periodically at zero net mass-flow rate into the flow at the step edge, at an angle of 45 deg relative to the flow direction. Experimental data show the effects to depend nonlinearly on the perturbation frequency, the strongest response arising at a Strouhal number of 0.2, which is the condition investigated herein. The principal response is a shortening of the separation bubble by almost 30%, a result that is highly pertinent to active flow control. As the injection frequency lies within the low-frequency range of the large scales of the turbulence spectrum, an issue of particular interest that is addressed herein is the ability of the statistical models, operating within a phase-averaged URANS framework, to reproduce the experimental observations and the response derived from the simulation.
Will RANS Survive LES? A View of Perspectives
Authors: Hanjalic K.
Published: September 2005

The paper provides a view of some developments and a perspective on the future role of the Reynolds-averaged Navier-Stokes (RANS) approach in the computation of turbulent flows and heat transfer in competition with large-eddy simulations (LES). It is argued that RANS will further play an important role, especially in industrial and environmental computations, and that the further increase in the computing power will be used more to utilize advanced RANS models to shorten the design and marketing cycle rather than to yield the way to LES. We also discuss some current and future developments in RANS aimed at improving their performance and range of applicability, as well as their potential in hybrid approaches in combination with the LES strategy. Limitations in LES at high Reynolds (Re) and Rayleigh (Ra) number flows and heat transfer are revisited and some hybrid RANS/LES routes are discussed. The potential of very large eddy simulations (VLES) of flows dominated by (pseudo)-deterministic eddy structures, based on transient RANS (T-RANS) and similar approaches, is discussed and illustrated in an example of “ultra-hard” (very high Ra) thermal convection.
Antagonistic Actions of Ecdysone and Insulins Determine Final Size in
Drosophila
Authors: Colombani Julien , Bianchini Laurence , Layalle Sophie , Pondeville Emilie , Dauphin-Villemant Chantal , Antoniewski Christophe , Carré Clément , Noselli Stéphane , Léopold Pierre
Published: September 2005

All animals coordinate growth and maturation to reach their final size and shape. In insects, insulin family molecules control growth and metabolism, whereas pulses of the steroid 20-hydroxyecdysone (20E) initiate major developmental transitions. We show that 20E signaling also negatively controls animal growth rates by impeding general insulin signaling involving localization of the transcription factor dFOXO and transcription of the translation inhibitor
4E-BP
. We also demonstrate that the larval fat body, equivalent to the vertebrate liver, is a key relay element for ecdysone-dependent growth inhibition. Hence, ecdysone counteracts the growth-promoting action of insulins, thus forming a humoral regulatory loop that determines organismal size.
Epidemiology of injuries in English professional rugby union: part 1 match injuries
Authors: Brooks J H M , Fuller C W , Kemp S P T , Reddin D B
Published: September 2005

Objectives:To undertake a detailed, large scale epidemiological study of match injuries sustained by professional rugby union players in order to define their incidence, nature, severity, and causes.

Methods:A two season prospective design was used to study match injuries associated with 546 rugby union players at 12 English Premiership clubs. Team clinicians reported all match injuries on a weekly basis and provided details of the location, diagnosis, severity, and mechanism of each injury. Match exposures for individual players were recorded on a weekly basis. Loss of time from training and match play was used as the definition of an injury.

Results:The overall incidence of injury was 91 injuries/1000 player-hours, and each injury resulted on average in 18 days lost time. Recurrences, which accounted for 18% of injuries, were significantly more severe (27 days) than new injuries (16 days). Thigh haematomas were the most common injury for forwards and backs, but anterior cruciate ligament injuries for forwards and hamstring injuries for backs caused the greatest number of days absence. Contact mechanisms accounted for 72% of injuries, but foul play was only implicated in 6% of injuries. The ruck and maul elements of the game caused most injuries to forwards, and being tackled caused most injuries to backs. The hooker and outside centre were the playing positions at greatest risk of injury.

Conclusions:On average, a club will have 18% of their players unavailable for selection as a consequence of match injuries.
Strength training and detraining effects on muscular strength, anaerobic power, and mobility of inactive older men are intensity dependent
Authors: Fatouros I G , Kambas A , Katrabasas I , Nikolaidis K , Chatzinikolaou A , Leontsini D , Taxildaris K
Published: September 2005

Background:Although strength training (ST) enhances physical function in the elderly, little is known about the effect of training intensity on training and detraining adaptations in musculoskeletal fitness.

Objective:To determine the effect of exercise intensity on strength, anaerobic power, and mobility of older men subjected to a 24 week ST protocol followed by prolonged detraining.

Methods:Fifty two healthy but inactive older men (mean (SD) age 71.2 (4.1) years) were assigned to a control (n  =  14), low intensity training (LIST; n  =  18; 55% 1RM), or high intensity training (HIST; n  =  20; 82% 1RM) group. They carried out a 24 week, whole body (10 exercises, two to three sets/exercise) ST programme followed by a 48 week detraining period. Upper and lower body strength, anaerobic power (Wingate testing), and mobility (timed up and go, walking, climbing stairs) were measured at baseline and immediately after training and during detraining.

Results:Although low intensity training improved (p<0.05) strength (42–66%), anaerobic power (10%), and mobility (5–7%), high intensity training elicited greater (p<0.05) gains (63–91% in strength, 17–25% in anaerobic power, 9–14% in mobility). All training induced gains in the LIST group had been abolished after four to eight months of detraining, whereas in the HIST group strength and mobility gains were maintained throughout detraining. However, anaerobic power had returned to baseline levels after four months of detraining in both groups.

Conclusions:Higher intensity training protocols induce greater gains in strength, anaerobic power, and whole body physical function of older men. Moreover, higher intensity training may maintain the gains for more prolonged periods after training ceases.
TOWARDS SCALEable PROTEIN STRUCTURE COMPARISON AND DATABASE SEARCH
Authors: CHIONH CHERN-HOOI , HUANG ZHIYONG , TAN KIAN-LEE , YAO ZHEN
Published: September 2005

Comparing protein structures in three dimensions is a computationally expensive process that makes a full scan of a protein against a library of known protein structures impractical. To reduce the cost, we can use an approximation of the three dimensional structure that allows protein comparison to be performed quickly to filter away dissimilar proteins. In this paper, we present a new algorithm, called SCALE, for protein structure comparison. In SCALE, a protein is represented as a sequence of secondary structure elements (SSEs) augmented with 3D structural properties such as the distances and angles between the SSEs. As such, the comparison between two proteins is reduced to a sequence alignment problem between their corresponding sequences of SSEs. The 3-D structural properties of the proteins contribute to the similarity score between the two sequences. We have implemented SCALE, and compared its performance against existing schemes. Our performance study shows that SCALE outperforms existing methods in terms of both efficiency and effectiveness (measured in terms of precision and recall). To avoid exhaustive search, an index based on the structural properties is also proposed. The index prunes away a considerable amount of dissimilar proteins given a query protein.
PREDICTION OF CONTACT MAPS USING SUPPORT VECTOR MACHINES
Authors: ZHAO YING , KARYPIS GEORGE
Published: September 2005

Contact map prediction is of great interest for its application in fold recognition and protein 3D structure determination. In this paper we present a contact-map prediction algorithm that employs Support Vector Machines as the machine learning tool and incorporates various features such as sequence profiles and their conservations, correlated mutation analysis based on various amino acid physicochemical properties, and secondary structure. In addition, we evaluated the effectiveness of the different features on contact map prediction for different fold classes. On average, our predictor achieved a prediction accuracy of 0.224 with an improvement over a random predictor of a factor 11.7, which is better than reported studies. Our study showed that predicted secondary structure features play an important roles for the proteins containing beta-structures. Models based on secondary structure features and correlated mutation analysis features produce different sets of predictions. Our study also suggests that models learned separately for different protein fold families may achieve better performance than a unified model.
AN ASSESSMENT OF A METRIC SPACE DATABASE INDEX TO SUPPORT SEQUENCE HOMOLOGY
Authors: MAO RUI , XU WEIJIA , SINGH NEHA , MIRANKER DANIEL P.
Published: September 2005

Hierarchical metric-space clustering methods have been commonly used to organize proteomes into taxonomies. Consequently, it is often anticipated that hierarchical clustering can be leveraged as a basis for scalable database index structures capable of managing the hyper-exponential growth of sequence data. M-tree is one such data structure specialized for the management of large data sets on disk.

We explore the application of M-trees to the storage and retrieval of peptide sequence data. Exploiting a technique first suggested by Myers, we organize the database as records of fixed length substrings. Empirical results are promising. However, metric-space indexes are subject to "the curse of dimensionality" and the ultimate performance of an index is sensitive to the quality of the initial construction of the index. We introduce new hierarchical bulk-load algorithm that alternates between top-down and bottom-up clustering to initialize the index. Using the Yeast Proteomes, the bi-directional bulk load produces a more effective index than the existing M-tree initialization algorithms.
DISTURBANCE ATTENUATION IN CONTROL SYSTEMS
Authors: KNOBLOCH HANS W.
Published: September 2005

The paper deals with standard mathematical models for nonlinear affine control systems with two (vector-valued) inputs u (=control) and w (unknown except for a bound for the sup-norm). Interpretation of this scenario and its wide range of applications (in control and differential game theory): See the introduction. The main result of the paper is the presentation of a dissipation equality which seems to be new and which is the result of a special control strategy (discretized state feedback, see the introduction). Combination with Lyapunov techniques leads to a concrete proposal for stabilizing disturbed control system. The mathematical background — which is worked out in detail — amounts to an explicit integration of the Hamilton-Jacobi partial differential equation via the method of characteristics.
Flagellin/TLR5 responses in epithelia reveal intertwined activation of inflammatory and apoptotic pathways
Authors: Zeng Hui , Wu Huixia , Sloane Valerie , Jones Rheinallt , Yu Yimin , Lin Patricia , Gewirtz Andrew T. , Neish Andrew S.
Published: September 2005

Flagellin, the primary structural component of bacterial flagella, is recognized by Toll-like receptor 5 (TLR5) present on the basolateral surface of intestinal epithelial cells. Utilizing biochemical assays of proinflammatory signaling pathways and mRNA expression profiling, we found that purified flagellin could recapitulate the human epithelial cell proinflammatory responses activated by flagellated pathogenic bacteria. Flagellin-induced proinflammatory activation showed similar kinetics and gene specificity as that induced by the classical endogenous proinflammatory cytokine TNF-α, although both responses were more rapid than that elicited by viable flagellated bacteria. Flagellin, like TNF-α, activated a number of antiapoptotic mediators, and pretreatment of epithelial cells with this bacterial protein could protect cells from subsequent bacterially mediated apoptotic challenge. However, when NF-κB-mediated or phosphatidylinositol 3-kinase/Akt proinflammatory signaling was blocked, flagellin could induce programmed cell death. Consistently, we demonstrate that flagellin and viable flagellate Salmonella induces both the extrinsic and intrinsic caspase activation pathways, with the extrinsic pathway (caspase 8) activated by purified flagellin in a TLR5-dependant fashion. We conclude that interaction of flagellin with epithelial cells induces caspase activation in parallel with proinflammatory responses. Such intertwining of proinflammatory and apoptotic signaling mediated by bacterial products suggests roles for host programmed cell death in the pathogenesis of enteric infections.
Impact of myocardial structure and function postinfarction on diastolic strain measurements: implications for assessment of myocardial viability
Authors: Park Tae-Ho , Nagueh Sherif F. , Khoury Dirar S. , Kopelen Helen A. , Akrivakis Spyridon , Nasser Kamal , Ren Guofeng , Frangogiannis Nikolaos G.
Published: September 2005

We sought to assess the role of regional diastolic function by Doppler echocardiography in predicting myocardial viability. Sixteen dogs underwent left anterior descending coronary artery ( n = 8) or circumflex ( n = 8) occlusion. All animals were imaged at baseline and 1–8 wk postinfarction (post-MI). In 10 dogs, invasive hemodynamic monitoring with a conductance catheter placed in the left ventricle (LV) was performed at the above time points. Dobutamine was infused at 1–8 wk post-MI to determine LV contractile reserve. Histomorphological analysis was performed to determine the presence of viable myocardium and changes in interstitial matrix. Post-MI, diastolic strain rate measurements (in radial and longitudinal planes) decreased significantly in the distribution of the diseased artery ( P < 0.01) and on multiple regression analysis were determined by time constant of LV relaxation, end-diastolic pressure, regional stiffness, and the ratio of cellular infiltration to collagen deposition in the interstitial matrix. Among several indexes, diastolic strain rate during dobutamine infusion readily identified segments with >20% transmural infarction and related best to the extent of interstitial fibrosis ( r = −0.86, P < 0.01). In an animal model of healing canine infarcts, diastolic strain rate by Doppler echocardiography appears to be a promising novel index of myocardial viability.
Xanthine oxidase inhibitors improve energetics and function after infarction in failing mouse hearts
Authors: Naumova Anna V. , Chacko Vadappuram P. , Ouwerkerk Ronald , Stull Linda , Marbán Eduardo , Weiss Robert G.
Published: September 2005

After myocardial infarction, ventricular geometry and function, as well as energy metabolism, change markedly. In nonischemic heart failure, inhibition of xanthine oxidase (XO) improves mechanoenergetic coupling by improving contractile performance relative to a reduced energetic demand. However, the metabolic and contractile effects of XO inhibitors (XOIs) have not been characterized in failing hearts after infarction. After undergoing permanent coronary ligation, mice received a XOI (allopurinol or oxypurinol) or matching placebo in the daily drinking water. Four weeks later, 1H MRI and 31P magnetic resonance spectroscopy (MRS) were used to quantify in vivo functional and metabolic changes in postinfarction remodeled mouse myocardium and the effects of XOIs on that process. End-systolic (ESV) and end-diastolic volumes (EDV) were increased by more than sixfold after infarction, left ventricle (LV) mass doubled ( P < 0.005), and the LV ejection fraction (EF) decreased (14 ± 9%) compared with control hearts (59 ± 8%, P < 0.005) at 1 mo. The myocardial phosphocreatine (PCr)-to-ATP ratio (PCr/ATP) was also significantly decreased in infarct remodeled hearts (1.4 ± 0.6) compared with control animals (2.1 ± 0.5, P < 0.02), in agreement with prior studies in larger animals. The XOIs allopurinol and oxypurinol did not change LV mass but limited the increase in ESV and EDV of infarct hearts by 50%, increased EF (23 ± 9%, P = 0.01), and normalized cardiac PCr/ATP (2.0 ± 0.5, P < 0.04). We conclude that XOIs improve ventricular function after infarction and normalize high-energy phosphate ratio in heart failure. Thus XOI therapy offers a new and potentially complementary approach to limit the adverse contractile and metabolic consequences after infarction.
State-dependent effects of light-dark cycle on somatosensory and visual cortex EEG in rats
Authors: Yasuda Tadanobu , Yasuda Kyo , Brown Richard A. , Krueger James M.
Published: September 2005

Somatosensory (SSctx) and visual cortex (Vctx) EEG were evaluated in rats under a 12:12-h light-dark (LD) cycle and under constant light (LL) or constant dark (DD) in each sleep or wake state. Under LD conditions during light period, relative Vctx EEG slow-wave activity (SWA) was higher than that of the SSctx, whereas during dark period, relative Vctx EEG SWA was lower than in the SSctx. These effects were state specific, occurring only during non-rapid eye movement sleep (NREMS). Under LL conditions, the duration of REMS and NREMS during the period that would have been dark if the LD cycle had continued (subjective dark period) was greater than under LD conditions. DD conditions had little effect on the duration of NREMS and REMS. SSctx and Vctx EEG SWA were suppressed by LL during the subjective dark period; however, the degree of Vctx SWA suppression was smaller than that of the SSctx. DD conditions during the subjective light period enhanced SSctx SWA, whereas Vctx SWA was suppressed. Under LL conditions during the subjective dark period, Vctx EEG power was higher than that of the SSctx across a broad frequency range during NREMS, REMS, and wakefulness. During DD, SSctx EEG power during NREMS was higher than that of the Vctx in the delta wave band, whereas SSctx power during REMS and wakefulness was higher than that of the Vctx in frequencies higher than 8 Hz. We concluded that the SSctx and Vctx EEGs are differentially affected by light during subsequent sleep. Results provide support for the notion that regional sleep intensity is dependent on prior regional afferent input.
Exercise training improves lung gas exchange and attenuates acute hypoxic pulmonary hypertension but does not prevent pulmonary hypertension of prolonged hypoxia
Authors: Favret Fabrice , Henderson Kyle K. , Allen Julie , Richalet Jean-Paul , Gonzalez Norberto C.
Published: September 2005

Our laboratory has previously shown an attenuation of hypoxic pulmonary hypertension by exercise training (ET) (Henderson KK, Clancy RL, and Gonzalez NC. J Appl Physiol 90: 2057–2062, 2001), although the mechanism was not determined. The present study examined the effect of ET on the pulmonary arterial pressure (Pap) response of rats to short- and long-term hypoxia. After 3 wk of treadmill training, male rats were divided into two groups: one (HT) was placed in hypobaric hypoxia (380 Torr); the second remained in normoxia (NT). Both groups continued to train in normoxia for 10 days, after which they were studied at rest and during hypoxic and normoxic exercise. Sedentary normoxic (NS) and hypoxic (HS) littermates were exposed to the same environments as their trained counterparts. Resting and exercise hypoxic arterial Po2 were higher in NT and HT than in NS and HS, respectively, although alveolar ventilation of trained rats was not higher. Lower alveolar-arterial Po2 difference and higher effective lung diffusing capacity for O2 in NT vs. NS and in HT vs. HS suggest ET improved efficacy of gas exchange. Pap and Pap/cardiac output were lower in NT than NS in hypoxia, indicating that ET attenuates the initial vasoconstriction of hypoxia. However, ET had no effect on chronic hypoxic pulmonary hypertension: Pap and Pap/cardiac output in hypoxia were similar in HS vs HT. However, right ventricular weight was lower in HT than in HS, although Pap was not different. Because ET attenuates the initial pulmonary vasoconstriction of hypoxia, development of pulmonary hypertension may be delayed in HT rats, and the time during which right ventricular afterload is elevated may be shorter in this group. ET effects may improve the response to acute hypoxia by increasing efficacy of gas exchange and lowering right ventricular work.
Immunogenetics of Severe Respiratory Infections: Models for the Development of New Therapeutic Strategies
Authors: Bocchino Marialuisa , Marruchella Almerico , Saltini Cesare
Published: September 2005

Innate and adaptive immunity plays a critical role in the defence of the lung and other mucosal surfaces exposed to micro-organisms. Anti-microbial peptides and proteins, cytokines and chemokines are important immune weapons as they build up the protective front for the respiratory tract. The notion that susceptibility to infectious diseases may be inherited is widely accepted and, as it is the failure to activate adaptive immunity that may allow infection to become established and progress toward invasion and dissemination, the recognition of specific gene defects affecting the ability of the immune system to overcome invading pathogens may shed light upon those mechanisms of immune regulation that are playing the most critical roles. The aim of the present review is to discuss some of the advances in infection immunogenetics that may lead to identify new strategies in the development of new anti-infectious and anti-inflammatory drugs.
Insomnia Subtypes and Their Relationships to Daytime Sleepiness in Patients with Obstructive Sleep Apnea
Authors: Chung Ka Fai
Published: September 2005

Background: Insomnia and obstructive sleep apnea syndrome (OSA) are the two most common sleep disorders. Studies showed that insomnia complaints were prevalent in OSA. Relatively little is known about the causes of insomnia in OSA and whether etiological factors differ for insomnia subtypes. We hypothesized that sleep onset problem was mainly due to hyperarousal and sleep maintenance difficulty was primarily related to sleep-disordered breathing. Objectives: To determine the prevalence of insomnia subtypes in OSA, compare subjects with sleep onset insomnia, sleep maintenance insomnia and no insomnia symptom, and study the relationship of insomnia subtypes to daytime sleepiness. Methods: We analyzed intake questionnaires and polysomnography and Multiple Sleep Latency Test results of 157 OSA patients. Results: Forty-two percent of the sample had at least one problematic insomnia symptom. The prevalence of sleep onset insomnia, sleep maintenance insomnia and insomnia with early awakening was 6, 26 and 19%, respectively. Patients with sleep onset insomnia had significantly lower apnea-hypopnea (AHI) and arousal indices. There were significant inverse relationships between sleep onset insomnia and measures of daytime sleepiness. On the contrary, subjects with repeated wakening had more severe subjective sleepiness. Results were similar in patients with AHI ≧5 or ≧15. Conclusions: Insomnia symptoms were common in OSA patients. Insomnia subtypes related differently to measures of daytime sleepiness. Our findings suggest that OSA patients with sleep onset insomnia may be in a state of hyperarousal. It is clinically relevant to examine insomnia subtypes, which may influence the treatment decision in sleep-disordered breathing.
Prevalence of Chronic Obstructive Pulmonary Disease according to BTS, ERS, GOLD and ATS Criteria in Relation to Doctor’s Diagnosis, Symptoms, Age, Gender, and Smoking Habits
Authors: Lindberg Anne , Jonsson Ann-Christin , Rönmark Eva , Lundgren Rune , Larsson Lars-Gunnar , Lundbäck Bo
Published: September 2005

Background: Guidelines and standards for diagnosis and management of chronic obstructive pulmonary disease (COPD) have been presented by different national and international societies, but the spirometric criteria for COPD differ between guidelines. Objectives: To estimate prevalence of COPD using the guidelines of the British Thoracic Society (BTS), the European Respiratory Society (ERS), the Global Initiative for Chronic Obstructive Lung Disease (GOLD), and the American Thoracic Society (ATS). Further, to evaluate reported airway symptoms, contacts with health care providers, and physician diagnosis of COPD in relation to the respective criteria, and gender differences. Method: In 1992 a postal questionnaire was sent to a random sample of adults aged 20–69 years, 4,851 (85%) out of 5,681 subjects responded. In 1994–1995 a random sample of the responders, 970 subjects, were invited to a structured interview and a lung function test; 666 (69%) participated. Results: The prevalence of COPD was 7.6, 14.0, 14.1, 12.2 and 34.1% according to BTS, ERS, GOLD, clinical ATS (with symptoms or physician diagnosis), and spirometric ATS criteria, respectively. Prevalent COPD was related to age, smoking habits and family history of obstructive airway disease but not to gender. Physician diagnosis of chronic bronchitis or emphysema was only reported by 16.3, 12.2, 11.0, 23.4 and 8.2% of subjects fulfilling the respective criteria, though a majority reported airway symptoms. Conclusion: The main determinants for prevalent COPD were age, smoking habits and spirometric criteria of COPD. Though a majority reported airway symptoms and contact with health care providers due to respiratory complaints, only a minority was diagnosed as having COPD, indicating a large underdiagnosis.
Cell Profiles of Bronchoalveolar Lavage Fluid as Prognosticators of Idiopathic Pulmonary Fibrosis/Usual Interstitial Pneumonia among Japanese Patients
Authors: Tabuena Rollin P. , Nagai Sonoko , Tsutsumi Takeo , Handa Tomohiro , Minoru Takeuchi , Mikuniya Takeshi , Shigematsu Michio , Hamada Kunio , Izumi Takateru , Mishima Michiaki
Published: September 2005

Background: The role of bronchoalveolar lavage fluid (BALF) cell profiles in predicting the clinical outcome of idiopathic pulmonary fibrosis (IPF)/usual interstitial pneumonia (UIP) is still under discussion. Objective: To determine whether BALF cell profiles affect the survival of patients with UIP diagnosed by surgical lung biopsy/autopsy at the early stage of IPF. Methods: This hospital-based retrospective cohort study used 81 Japanese patients with histologically proven IPF/UIP who underwent BAL examination. The BALF samples were obtained from non-current smokers: NCS (n = 41) and current smokers: CS (n = 40). The Kaplan-Meier and Cox’s proportional hazard methods were used to estimate the survival and evaluate the risk ratio for death in the two groups. To detect the multicollinearity, a stepwise regression was employed. Results: A slight increase in the absolute numbers of BALF neutrophils tended to relate to a decrease in the relative risk for death in NCS patients and CS patients in the univariate analysis. In stepwise regression, the increase in percent vital capacity and the increase in the BALF CD4/CD8 ratio in NCS was detected as a favorable predictor, while increased BALF cells affected the results due to chronic smoking in CS. Conclusions: Based on the study bias of the biopsy-proven IPF/UIP patients at stable stages, an independent variable indicating a favorable outcome was an increased BALF CD4/CD8 ratio in NCS patients, while it was difficult to identify definite prognosticators in CS patients.
The Association of Adenocarcinoma and Hemosputum in Pulmonary Malignancies
Authors: Yamauchi Setsuko , Kudoh Shinzoh , Kimura Tatsuo , Yoshimura Naruo , Mukohara Toru , Hirata Kazuto , Yoshikawa Junichi
Published: September 2005

Background: Hemosputum was considered one of the popular symptoms of patients with centrally located carcinoma of the lung, especially squamous cell or small cell type. Recent studies reported a relative increase in adenocarcinoma compared with squamous cell carcinoma, especially in developed countries. Objectives: The main purpose of this study was to determine the trend of histological type associated with the occurrence of hemosputum in patients with pulmonary malignancy. Methods: Retrospectively, the data from 1,050 patients with pulmonary malignancy who underwent bronchoendoscopic examination at our institution between May 1993 and May 2000 were analyzed. Results: One hundred and forty-nine out of 1,050 patients had hemosputum. There were 66 patients with adenocarcinoma, 55 with squamous cell carcinoma, 15 with small cell carcinoma, 5 with large cell carcinoma, 3 with other cell type carcinoma and 5 with metastatic carcinoma. On bronchoendoscopic examination, abnormal findings in the segmental or more proximal bronchi were found in 82 patients, including 36 with squamous cell carcinoma, 31 with adenocarcinoma, 12 with small cell carcinoma, 2 with large cell carcinoma and 1 with metastatic carcinoma. On the other hand, 67 patients were diagnosed with pulmonary malignancy in the subsegmental or more distal area, including 35 with adenocarcinoma, 19 with squamous cell carcinoma, 3 with small cell carcinoma, 3 with large cell carcinoma, 3 with other cell type carcinoma and 4 with metastatic carcinoma. Conclusions: The most frequent histological type of malignancy with hemosputum was adenocarcinoma. The number of abnormalities in the peripheral region with hemosputum showed a progressive increase. The number of adenocarcinoma with hemosputum was increased in both central and peripheral regions.
Cardiopulmonary Exercise Testing in Fabry Disease
Authors: Bierer Gregory , Kamangar Nader , Balfe David , Wilcox William R. , Mosenifar Zab
Published: September 2005

Background: Fabry disease is a rare X-linked disorder that results from a deficiency in a lysosomal enzyme known as α-galactosidase A, with accumulation of globotriaosylceramide (Gl3). Early manifestations include angiokeratomas, acroparesthesias, and hypohidrosis and may progress to renal failure, cardiac dysfunction, and stroke. Patients exhibit decreased exercise tolerance and often complain of fatigue. Objective: Our study evaluates the cardiopulmonary characteristics in a cohort of Fabry disease patients at rest and during exercise. Methods: Thirty-nine patients with a diagnosis of Fabry disease underwent a health screening history and physical examination, an electrocardiogram, an echocardiogram, pulmonary function testing (spirometry), and a non-invasive cardiopulmonary exercise test. A control group was selected for comparison. Results: Eighteen of the 39 Fabry patients (46%) exhibited a significant decrease in diastolic blood pressure (DBP) during exercise. The average decrease in DBP was 10 mm Hg. The maximum drop in DBP was 44 mm Hg. The drop in DBP was evident in 9 of the 24 female patients (38%). None of the control patients had a significant drop in DBP during exercise. Conclusions: Our finding of a significant decrease in DBP in patients with Fabry disease may explain deficits in exercise tolerance. It is notable that this abnormality is manifested in female patients, even though they are typically not as severely affected as males.
The Effect of Red Cell Transfusion on Nitric Oxide Diffusing Capacity
Authors: van der Lee I. , Zanen P. , Biesma D.H. , van den Bosch J.M.M.
Published: September 2005

Background: The diffusion capacity of the lung for nitric oxide (DLNO) is supposed to reflect the properties of the alveolocapillary membrane better than the diffusion capacity of the lung for carbon monoxide (DLCO), due to a much stronger binding of NO to haemoglobin (Hb). Objectives: The aim of this study was to investigate the effect of Hb concentration on the DLNO. Methods: The DLNO and DLCO (single-breath method) were measured in 10 anaemic patients before and shortly after red cell transfusion. Results: The mean increase in Hb concentration was 2.6 g/dl. Whereas DLCO increased as predicted by the reference equations, the DLNO did not change: mean DLCO rose from 13.6 to 16.5 ml/min/mm Hg (increase of 122%), mean DLCO corrected for Hb rose from 18.8 to 19.3 ml/min/mm Hg (103%) and mean DLNO rose from 75.6 to 77.8 ml/min/mm Hg (103%). Conclusion: The DLNO is not influenced by Hb concentration.
Quantitative Assessment and Repeatability of Chlorine in Exhaled Breath Condensate
Authors: Davidsson A. , Naidu Sjöswärd K. , Lundman L. , Schmekel B.
Published: September 2005

Background: Airway condition is presumably reflected in epithelial lining fluid (ELF). Exhaled breath condensate (EBC) has been used as a surrogate marker of the composition of ELF. Objectives: This study aimed at assessing the technical repeatability of chlorine measurements in EBC and comparing two separate condensators (Ecoscreen® and R Tube™) regarding recovery and repeatability. Furthermore, the association between condensate recoveries and variations in the airway status were scrutinized. Methods: EBC was collected using two condensators from 10 healthy volunteers. In addition, 13 asthmatic patients produced EBC with or without an added resistance of 5 cm H2O (Res5), applied to the outflow tract of Ecoscreen. All tests were done in random order. Chlorine levels (analyzed by a coulometric technique) in EBC served as a tool for investigation. Results: Chlorine was measurable in all samples. The coefficient of repeatability of chlorine measurements was <10%. Chlorine levels were higher in EBC obtained from R Tube (p < 0.001), and differences in recoveries and variability in chlorine levels were presumably related to technical differences in the condensators and not to the repeatability of chlorine measurements per se. Air-flow-dependent chlorine levels were obtained from healthy volunteers. Application of Res5, recruiting additional alveoli, resulted in increased recovery of the EBC volume, but not of chlorine, from those that had the most pronounced airway obstruction (p = 0.05). Conclusion: We conclude that by employing a sensitive analysis technique, chlorine is repeatedly measurable in EBC. We suggest that the bulk of chlorine in EBC originates from large airways and not from the alveolar area. Both condensators were comparable regarding repeatability but differed regarding chlorine recovery.
An Unusual Endobronchial Foreign Body: A Gauze That Migrated from the Mediastinum
Authors: Öztuna Funda , Bülbül Yılmaz , Özlü Tevfik
Published: September 2005

The authors report a 48-year-old white male with lung cancer who was admitted to their clinic with a 1-year history of cough and shortness of breath. The patient was hospitalized because of progression of his complaints over 1 month. On the 3rd day of hospitalization, he expectorated a piece of gauze. The authors performed a fiber-optic bronchoscopy and saw pieces of gauze originating from granulation tissue located in the angle of the lower trachea and left main bronchi. A detailed anamnesis revealed that a mediastinoscopy had been performed 3 years ago for lung cancer staging: the gauze had migrated from the mediastinum to the endobrochial space.
Chylothorax following Innominate Vein Thrombosis: A Rare Complication of Transvenous Pacemaker Implantation
Authors: Thomas Rajesh , Christopher D.J. , Roy Anil , Rose Anand , Chandy Sunil Thomas , Cherian Rekha Aley , Rima Jeeva
Published: September 2005

A case of chylothorax following innominate vein thrombosis, which developed as a late complication of transvenous pacemaker implantation, is discussed. A 78-year-old man presented with a refractory left-sided pleural effusion, which turned out to be chylothorax. He had undergone a transvenous pacemaker implantation 6 years earlier for sick sinus syndrome. The aetiological workup showed occlusion of the innominate vein as the cause for the chylothorax. The chylothorax resolved following pleurodesis with talc slurry, and the innominate vein was recanalized by angioplasty. To our knowledge this is the first report of a case of this nature.
Reduced Lung Uptake of Iodine-123 Metaiodobenzylguanidine in Patients with Myeloperoxidase Antineutrophil Cytoplasmic Antibodies-Positive Vasculitis
Authors: Yoshiike Fumiaki , Koizumi Tomonobu , Urushihata Kazuhisa , Hanaoka Masayuki , Kubo Keishi
Published: September 2005

Background: Iodine-123 metaiodobenzylguanidine (123I-MIBG) lung uptake in the early phase has been proposed as a potential marker of endothelial function because MIBG behaves qualitatively similarly to norepinephrine in pulmonary circulation. Objectives: The purpose of the present study was to examine the lung uptake of 123I-MIBG in patients diagnosed with myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA)-associated vasculitis without clinical or radiological abnormalities of the thorax. Methods: Six patients with MPO-ANCA-associated vasculitis were enrolled. They had severe renal damage (mean creatinine: 5.1 mg/dl, mean blood urea nitrogen: 54.6 mg/dl), but no respiratory symptoms clinically or radiographic findings on chest computed tomography. The total lung to upper mediastinum ratio of 123I-MIBG uptake (L/M) 15 min after the injection was measured. The result was compared with those for 6 patients with renal damage due to other diseases (mean creatinine: 6.2 mg/dl, blood urea nitrogen: 51.7 mg/dl) and for 8 healthy subjects. Results: The mean value of L/M in patients with MPO-ANCA-positive vasculitis was 1.21 ± 0.04, which was significantly less than that of other groups (1.41 ± 0.06 for patients with renal failure and 1.45 ± 0.03 for normal volunteers). There were no significant differences in MIBG accumulation in the heart among the groups. Conclusions: The reduction in kinetic behavior of MIBG in the lung reflects the presence of pulmonary endothelial impairment in patients with MPO-ANCA-associated vasculitis, even though there are no clinical manifestations in the lungs.