bluuebunny/crossref_metadata_2025 huggingface dataset:
Burning mouth syndrome: a retrospective study investigating spontaneous remission and response to treatments
Authors: Sardella A , Lodi G , Demarosi F , Bez C , Cassano S , Carrassi A
Published: January 2006

Objective:  The aim of this investigation was to evaluate the spontaneous remission rate of burning mouth syndrome (BMS) in a group of subjects suffering from this syndrome.

Subjects and Methods:  The medical records of BMS patients attending the Unit of Oral Medicine (1995–2002) were reviewed. The patients with a follow‐up period of at least 18 months were then contacted over phone and interviewed using a structured ad hoc questionnaire to record their current symptoms and data about their treatment responses to the therapies.

Results:  Forty‐eight women and five men with a mean age of 67.7 years (range 33–82 years) were included in the study (mean duration of BMS 5.5 years, s.d. ±1.9 years, mean follow‐up period of 56 months). As a consequence of different treatments, 26 patients (49.0%) reported no change in oral symptoms, 15 (28.3%) moderate improvement and 10 (18.9%) a worsening of oral complaints. Only two patients (3.7%) reported a complete spontaneous remission of oral symptoms without any treatment.

Conclusions:  In this study, a complete spontaneous remission was observed in 3% of the patients within 5 years after the onset of BMS. A moderate improvement was obtained in <30% of the subjects.
Characterization of a novel DRB1*14 allele (DRB1*1449) in the Han‐Chinese population
Authors: Miao K. R. , Xue M. , Zhou X. Y. , Xu R. , Fei X. M. , Pan Q. Q. , Zhang J. W. , Zhao X. , Fan S. , KuKuruga D. , Xu A. L. , Wang C. Y.
Published: January 2006

We report here a novel human leukocyte antigen (HLA) allele, DRB1*1449, in the Han‐Chinese population. The nature of the new allele was confirmed by the sequencing‐based typing (SBT) method. Genomic DNA and six subclones containing DNA fragment of DRB1 exon 2 were sequenced in both forward and reverse directions. The exon 2 nucleotide sequence of DRB1*1449 is closely related to DRB1*1432 allele based on sequence homology. It has four nucleotide (nt) substitutions at positions 71, 196, 244 and 245 in exon 2, which lead to changes of amino acid sequences. The serological assignment of DRB1*1449 is DR14 based on the serological HLA typing result. This novel allele might be a result of recombination between DRB1*1402 and DRB1*140101 like alleles, which are very common among Chinese population.
Association study of polymorphisms in SOCS family genes with type 1 diabetes mellitus
Authors: Ni R. , Ihara K. , Miyako K. , Takemoto M. , Ishimura M. , Kohno H. , Matsuura N. , Yoshimura A. , Hara T.
Published: January 2006

Suppressors of cytokine signalling (SOCS) proteins play important roles in the negative regulation of cytokine signal. We first searched for polymorphisms in SOCS‐1, SOCS‐3 and SOCS‐5 genes, and examined the association of the polymorphisms with type 1 diabetes (T1D). As a result, we did not find any significant associations between SOCS genes and T1D.
Active Resonators for Noise Absorption
Authors: Yuan Jing
Published: January 2006

Active control is applicable to resonators to improve noise control performance. Many active resonators depend on transfer functions from secondary sources to sensors to generate destructive interference in noise fields. These transfer functions are sensitive to the variance of acoustical parameters in noise fields where the sensors locate. An alternative strategy is to control resonators internally. This approach focuses on the internal dynamics of a resonator and uses an equivalent primary source with unknown strength and impedance to model the external noise field. A robust controller is designed on the basis of the internal dynamics model. It is independent of external parameters and able to minimize resonator reflection for the improved absorption performance. The active resonator is implemented in a set of experiment tests to achieve near perfect absorption performance in a wide frequency range. The closed-loop system is robust with respect to significant variations of acoustical parameters in the external field.
Comparison of Left Anterior Descending Coronary Artery Hemodynamics Before and After Angioplasty
Authors: Ramaswamy S. D. , Vigmostad S. C. , Wahle A. , Lai Y.-G. , Olszewski M. E. , Braddy K. C. , Brennan T. M. H. , Rossen J. D. , Sonka M. , Chandran K. B.
Published: January 2006

Coronary artery disease (CAD) is characterized by the progression of atherosclerosis, a complex pathological process involving the initiation, deposition, development, and breakdown of the plaque. The blood flow mechanics in arteries play a critical role in the targeted locations and progression of atherosclerotic plaque. In coronary arteries with motion during the cardiac contraction and relaxation, the hemodynamic flow field is substantially different from the other arterial sites with predilection of atherosclerosis. In this study, our efforts focused on the effects of arterial motion and local geometry on the hemodynamics of a left anterior descending (LAD) coronary artery before and after clinical intervention to treat the disease. Three-dimensional (3D) arterial segments were reconstructed at 10 phases of the cardiac cycle for both pre- and postintervention based on the fusion of intravascular ultrasound (IVUS) and biplane angiographic images. An arbitrary Lagrangian-Eulerian formulation was used for the computational fluid dynamic analysis. The measured arterial translation was observed to be larger during systole after intervention and more out-of-plane motion was observed before intervention, indicating substantial alterations in the cardiac contraction after angioplasty. The time averaged axial wall shear stress ranged from −0.2to9.5Pa before intervention compared to −0.02to3.53Pa after intervention. Substantial oscillatory shear stress was present in the preintervention flow dynamics compared to that in the postintervention case.
Stresses and Strains in the Medial Meniscus of an ACL Deficient Knee under Anterior Loading: A Finite Element Analysis with Image-Based Experimental Validation
Authors: Yao Jiang , Snibbe Jason , Maloney Michael , Lerner Amy L.
Published: January 2006

The menisci are believed to play a stabilizing role in the ACL-deficient knee, and are known to be at risk for degradation in the chronically unstable knee. Much of our understanding of this behavior is based on ex vivo experiments or clinical studies in which we must infer the function of the menisci from external measures of knee motion. More recently, studies using magnetic resonance (MR) imaging have provided more clear visualization of the motion and deformation of the menisci within the tibio-femoral articulation. In this study, we used such images to generate a finite element model of the medial compartment of an ACL-deficient knee to reproduce the meniscal position under anterior loads of 45, 76, and 107N. Comparisons of the model predictions to boundaries digitized from images acquired in the loaded states demonstrated general agreement, with errors localized to the anterior and posterior regions of the meniscus, areas in which large shear stresses were present. Our model results suggest that further attention is needed to characterize material properties of the peripheral and horn attachments. Although overall translation of the meniscus was predicted well, the changes in curvature and distortion of the meniscus in the posterior region were not captured by the model, suggesting the need for refinement of meniscal tissue properties.
A Theoretical Model of Enlarging Intracranial Fusiform
Aneurysms
Authors: Baek S. , Rajagopal K. R. , Humphrey J. D.
Published: January 2006

The mechanisms by which intracranial aneurysms develop, enlarge, and rupture are unknown, and it remains difficult to collect the longitudinal patient-based information needed to improve our understanding. We submit, therefore, that mathematical models hold promise by allowing us to propose and test competing hypotheses on potential mechanisms of aneurysmal enlargement and to compare predicted outcomes with limited clinical information—in this way, we may begin to narrow the possible mechanisms and thereby focus experimental studies. In this paper, we present a constrained mixture model of evolving thin-walled, fusiform aneurysms and compare multiple competing hypotheses with regard to the production, removal, and alignment of the collagen that provides the structural integrity of the wall. The results show that this type of approach has the capability to infer potential means by which lesions enlarge and whether such changes are likely to produce a stable or unstable process. Such information can better direct the requisite histopathological examinations, particularly on the need to quantify collagen orientations as a function of lesion geometry.
Effects of Major Endoleaks on a Stented Abdominal Aortic Aneurysm
Authors: Li Z. , Kleinstreuer C.
Published: January 2006

Insertion of a stent-graft into an aneurysm, especially abdominal aortic aneurysms (AAAs), is a very attractive surgical intervention; however, it is not without major postoperative complications, such as endoleaks. An endoleak is the transient accumulation of blood in the AAA cavity, which is formed by the stent-graft and AAA walls. Of the four blood pathways, a type I endoleak constitutes the major one. Thus, focusing on both proximal and distal type I endoleaks, i.e., the minute net influx of blood past the attachment points of a stent-graft into the AAA cavity, the transient three-dimensional interactions between luminal blood flow, stent-graft wall, leakage flow, and AAA wall are computationally simulated. For different type I endoleak scenarios and inlet pressure wave forms, the impact of type I endoleaks on cavity pressure, wall stress, and stent-graft migration force is analyzed. The results indicate that both proximal type I-a and distal type I-b endoleaks may cause cavity pressures close to a patient’s systemic pressure; however, with reduced pulsatility. As a result, the AAA-wall stress is elevated up to the level of a nonstented AAA and, hence, such endoleaks render the implant useless in protecting the AAA from possible rupture. Interestingly enough, the net downward force acting on the implant is significantly reduced; thus, in the presence of endoleaks, the risk of stent-graft migration may be mitigated.
Pulsatile Flow and Mass Transport Over an Array of Cylinders: Gas Transfer in a Cardiac-Driven Artificial Lung
Authors: Chan Kit Yan , Fujioka Hideki , Bartlett Robert H. , Hirschl Ronald B. , Grotberg James B.
Published: January 2006

The pulsatile flow and gas transport of a Newtonian passive fluid across an array of cylindrical microfibers are numerically investigated. It is related to an implantable, artificial lung where the blood flow is driven by the right heart. The fibers are modeled as either squared or staggered arrays. The pulsatile flow inputs considered in this study are a steady flow with a sinusoidal perturbation and a cardiac flow. The aims of this study are twofold: identifying favorable array geometry/spacing and system conditions that enhance gas transport; and providing pressure drop data that indicate the degree of flow resistance or the demand on the right heart in driving the flow through the fiber bundle. The results show that pulsatile flow improves the gas transfer to the fluid compared to steady flow. The degree of enhancement is found to be significant when the oscillation frequency is large, when the void fraction of the fiber bundle is decreased, and when the Reynolds number is increased; the use of a cardiac flow input can also improve gas transfer. In terms of array geometry, the staggered array gives both a better gas transfer per fiber (for relatively large void fraction) and a smaller pressure drop (for all cases). For most cases shown, an increase in gas transfer is accompanied by a higher pressure drop required to power the flow through the device.
An Axisymmetric Single-Path Model for Gas Transport in the Conducting Airways
Authors: Madasu Srinath , Borhan Ali , Ultman James S.
Published: January 2006

In conventional one-dimensional single-path models, radially averaged concentration is calculated as a function of time and longitudinal position in the lungs, and coupled convection and diffusion are accounted for with a dispersion coefficient. The axisymmetric single-path model developed in this paper is a two-dimensional model that incorporates convective-diffusion processes in a more fundamental manner by simultaneously solving the Navier-Stokes and continuity equations with the convection-diffusion equation. A single airway path was represented by a series of straight tube segments interconnected by leaky transition regions that provide for flow loss at the airway bifurcations. As a sample application, the model equations were solved by a finite element method to predict the unsteady state dispersion of an inhaled pulse of inert gas along an airway path having dimensions consistent with Weibel’s symmetric airway geometry. Assuming steady, incompressible, and laminar flow, a finite element analysis was used to solve for the axisymmetric pressure, velocity and concentration fields. The dispersion calculated from these numerical solutions exhibited good qualitative agreement with the experimental values, but quantitatively was in error by 20%–30% due to the assumption of axial symmetry and the inability of the model to capture the complex recirculatory flows near bifurcations.
Frictional Response of Bovine Articular Cartilage Under Creep Loading Following Proteoglycan Digestion With Chondroitinase ABC
Authors: Basalo Ines M. , Chen Faye Hui , Hung Clark T. , Ateshian Gerard A.
Published: January 2006

The specific aim of this study was to investigate the effect of chondroitinase ABC treatment on the frictional response of bovine articular cartilage against glass, under creep loading. The hypothesis is that chondroitinase ABC treatment increases the friction coefficient of bovine articular cartilage under creep. Articular cartilage samples (n=12) harvested from two bovine knee joints (1-3months old) were divided into a control group (intact specimens) and a treated group (chondroitinase ABC digestion), and tested in unconfined compression with simultaneous continuous sliding (±4mm at 1mm∕s) under a constant applied stress of 0.5MPa, for 2500s. The time-dependent response of the friction coefficient was measured. With increasing duration of loading, treated samples exhibited a significantly higher friction coefficient than control samples as assessed by the equilibrium value (treated: μeq=0.19±0.02; control: μeq=0.12±0.03; p=0.002), though the coefficient achieved immediately upon loading did not increase significantly (treated: μmin=0.0053±0.0025; control: μmin=0.037±0.0013; p=0.19). Our results demonstrate that removal of the cartilage glycosaminoglycans using chondroitinase ABC significantly increases the overall time-dependent friction coefficient of articular cartilage. These findings strengthen the motivation for developing chondroprotective strategies by increasing cartilage chondroitin sulfate content in osteoarthritic joints.
Cortical Bone Viscoelasticity and Fixation Strength of Press-Fit Femoral Stems: A Finite Element Model
Authors: Shultz T. R. , Blaha J. D. , Gruen T. A. , Norman T. L.
Published: January 2006

Many cementless implant designs rely upon a diaphyseal press-fit in conjunction with a porous coated implant surface to achieve primary or short term fixation, thereby constraining interface micromotion to such a level that bone ingrowth and consequent secondary or long-term fixation, i.e., osseointegration, can occur. Bone viscoelasticity, however, has been found to affect stem primary stability by reducing push-out load. In this investigation, an axisymmetric finite element model of a cylindrical stem and diaphyseal cortical bone section was created in order to parametrically evaluate the effect of bone viscoelasticity on stem push-out while controlling coefficient of friction (μ=0.15, 0.40, and 1.00) and stem-bone diametral interference (δ=0.01, 0.05, 0.10, and 0.50mm). Based on results from a previous study, it was hypothesized that stem-bone interference (i.e., press-fit) would elicit a bone viscoelastic response which would reduce the initial fixation of the stem as measured by push-out load. Results indicate that for all examined combinations of μ and δ, bone viscoelastic behavior reduced the push-out load by a range of 2.6–82.6% due to stress relaxation of the bone. It was found that the push-out load increased with μ for each value of δ, but minimal increases in the push-out load (2.9–4.9%) were observed as δ was increased beyond 0.10mm. Within the range of variables reported for this study, it was concluded that bone viscoelastic behavior, namely stress relaxation, has an asymptotic affect on stem contact pressure, which reduces stem push-out load. It was also found that higher levels of coefficient of friction are beneficial to primary fixation, and that an interference “threshold” exists beyond which no additional gains in push-out load are achieved.
Cortical Bone Viscoelasticity and Fixation Strength of Press-Fit Femoral Stems: An In-Vitro Model
Authors: Norman T. L. , Ackerman E. S. , Smith T. S. , Gruen T. A. , Yates A. J. , Blaha J. D. , Kish V. L.
Published: January 2006

Cementless total hip femoral components rely on press-fit for initial stability and bone healing and remodeling for secondary fixation. However, the determinants of satisfactory press-fit are not well understood. In previous studies, human cortical bone loaded circumferentially to simulate press-fit exhibited viscoelastic, or time dependent, behavior. The effect of bone viscoelastic behavior on the initial stability of press-fit stems is not known. Therefore, in the current study, push-out loads of cylindrical stems press-fit into reamed cadaver diaphyseal femoral specimens were measured immediately after assembly and 24h with stem-bone diametral interference and stem surface treatment as independent variables. It was hypothesized that stem-bone interference would result in a viscoelastic response of bone that would decrease push-out load thereby impairing initial press-fit stability. Results showed that push-out load significantly decreased over a 24h period due to bone viscoelasticity. It was also found that high and low push-out loads occurred at relatively small amounts of stem-bone interference, but a relationship between stem-bone interference and push-out load could not be determined due to variability among specimens. On the basis of this model, it was concluded that press-fit fixation can occur at relatively low levels of diametral interference and that stem-bone interference elicits viscoelastic response that reduces stem stability over time. From a clinical perspective, these results suggest that there could be large variations in initial press-fit fixation among patients.
A Penetration-Based Finite Element Method for Hyperelastic 3D Biphasic Tissues in Contact: Part 1-Derivation of Contact Boundary Conditions
Authors: Ün Kerem , Spilker Robert L.
Published: January 2006

In this study, we extend the penetration method, previously introduced to simulate contact of linear hydrated tissues in an efficient manner with the finite element method, to problems of nonlinear biphasic tissues in contact. This paper presents the derivation of contact boundary conditions for a biphasic tissue with hyperelastic solid phase using experimental kinematics data. Validation of the method for calculating these boundary conditions is demonstrated using a canonical biphasic contact problem. The method is then demonstrated on a shoulder joint model with contacting humerus and glenoid tissues. In both the canonical and shoulder examples, the resulting boundary conditions are found to satisfy the kinetic continuity requirements of biphasic contact. These boundary conditions represent input to a three-dimensional nonlinear biphasic finite element analysis; details of that finite element analysis will be presented in a manuscript to follow.
Evaluation of Filler Materials Used for Uniform Load Distribution at Boundaries During Structural Biomechanical Testing of Whole
Vertebrae
Authors: Kim Do-Gyoon , Dong X. Neil , Cao Ting , Baker Kevin C. , Shaffer Richard R. , Fyhrie David P. , Yeni Yener N.
Published: January 2006

This study was designed to compare the compressive mechanical properties of filler materials, Wood’s metal, dental stone, and polymethylmethacrylate (PMMA), which are widely used for performing structural testing of whole vertebrae. The effect of strain rate and specimen size on the mechanical properties of the filler materials was examined using standardized specimens and mechanical testing. Because Wood’s metal can be reused after remelting, the effect of remelting on the mechanical properties was tested by comparing them before and after remelting. Finite element (FE) models were built to simulate the effect of filler material size and properties on the stiffness of vertebral body construct in compression. Modulus, yield strain, and yield strength were not different between batches (melt-remelt) of Wood’s metal. Strain rate had no effect on the modulus of Wood’s metal, however, Young’s modulus decreased with increasing strain rate in dental stone whereas increased in PMMA. Both Wood’s metal and dental stone were significantly stiffer than PMMA (12.7±1.8GPa, 10.4±3.4GPa, and 2.9±0.4GPa, respectively). PMMA had greater yield strength than Wood’s metal (62.9±8.7MPa and 26.2±2.6MPa). All materials exhibited size-dependent modulus values. The FE results indicated that filler materials, if not accounted for, could cause more than 9% variation in vertebral body stiffness. We conclude that Wood’s metal is a superior moldable bonding material for biomechanical testing of whole bones, especially whole vertebrae, compared to the other candidate materials.
Nonlinear Behavior Analysis of a Rotor Supported on Fluid-Film Bearings
Authors: Shen Guangyan , Xiao Zhonghui , Zhang Wen , Zheng Tiesheng
Published: January 2006

A fast and accurate model to calculate the fluid-film forces of a fluid-film bearing with the Reynolds boundary condition is presented in the paper by using the free boundary theory and the variational method. The model is applied to the nonlinear dynamical behavior analysis of a rigid rotor in the elliptical bearing support. Both balanced and unbalanced rotors are taken into consideration. Numerical simulations show that the balanced rotor undergoes a supercritical Hopf bifurcation as the rotor spin speed increases. The investigation of the unbalanced rotor indicates that the motion can be a synchronous motion, subharmonic motion, quasi-period motion, or chaotic motion at different rotor spin speeds. These nonlinear phenomena are investigated in detail. Poincaré maps, bifurcation diagram and frequency spectra are utilized as diagnostic tools.
Stability Analysis of a Single-Ball Automatic Balancer
Authors: Lu Chung-Jen
Published: January 2006

Under proper working conditions, a ball-type automatic balancer can effectively reduce the imbalance vibrations of an optical disk drive. The proper working conditions can be determined by a stability analysis of the equilibrium states of the nonlinear system formed by the rotating disk, balancer, and suspension system. Several attempts have been made to study the stability of the equilibrium states numerically in some finite regions of the relevant parameter space. This paper in contrast analytically investigates the stability characteristics of the equilibrium states. A theoretical model of an optical disk drive packed with an automatic balancer is constructed first. The governing equations of the theoretical model are derived using Lagrange’s equations and closed-form formulas for the equilibrium positions are presented. Finally, general guidelines on the stability of the equilibrium states are proposed.
Design of Vibration Absorbers for Structures Subject to Multiple-Tonal Excitations
Authors: Wang P. W. , Cheng C. C.
Published: January 2006

The purpose of this paper is to introduce a systematic method of designing a vibration absorber that affects vibration attenuation at multiple frequencies. This vibration absorber is a nonprismatic beam with natural frequencies intentionally designed to coincide with the frequencies of excitation, e.g., the rotating speed of a rotary machine and its harmonic orders. Therefore, it can reduce the vibration response due to rotor eccentric, rotor shaft bending, mechanical looseness, etc. The thickness profile of the nonprismatic beam can be approximated discretely by a large amount of block masses. Each block mass behaves as an elastic structure member, and its thickness can be determined systematically using the impedance technique proposed in this paper. A design is given to demonstrate the methodology, and the result is experimentally validated.
Latex allergy: a follow up study of 1040 healthcare workers
Authors: Larese Filon F , Radman G
Published: January 2006

Background:Natural rubber latex allergy can cause skin and respiratory symptoms The aim of this study was to evaluate the prevalence and incidence of latex related symptoms and sensitisation among a large group of healthcare workers in Trieste hospitals, followed for three years before and after the introduction of powder-free gloves with low latex release.

Methods:In the years 1997–99 the authors evaluated 1040 healthcare workers exposed to latex allergen for latex related symptoms and sensitisation by means of a questionnaire, a medical examination, skin prick tests, and IgE specific antibody assay. The second evaluation was carried out in the years 2000–02, subsequent to the changeover to a powder-free environment.

Results:Glove related symptoms were seen in 21.8% of the nurses (227), mostly consisting of mild dermatitis: 38 (3.6%) complaining of contact urticaria and 24 (2.3%) of asthma and/or rhinitis. These symptoms were significantly related to skin prick tests positive to latex (OR = 9.70; 95% CI 5.5 to 17) and to personal atopy (OR = 2.29; 95% CI 1.6 to 3.2). Follow up was completed in 960 subjects (92.3%): 19 new subjects (2.4%) complained of itching erythema when using gloves, but none was prick positive to latex. Symptoms significantly improved and in most cases disappeared (p<0.0001).

Conclusions:Simple measures such as the avoidance of unnecessary glove use, the use of non-powdered latex gloves by all workers, and use of non-latex gloves by sensitised subjects can stop the progression of latex symptoms and can avoid new cases of sensitisation.
Predictors of early leaving from the cotton spinning mill environment in newly hired workers
Authors: Bakirci N , Kalaca S , Fletcher A M , Pickering C A C , Tumerdem N , Cali S , Oldham L , Francis H , Niven R McL
Published: January 2006

Objective:This longitudinal study aimed to identify the predictors of leaving during the first year of employment from the cotton spinning mill environment in newly hired workers.

Methods:One hundred and ninety eight consecutively appointed new employees were investigated by questionnaire, lung function test, and skin test. They were examined before employment and at the end of the 1st week, and the 1st, 3rd, 6th, and 12th month after starting work and when possible before leaving their job. 572 personal dust sampling and 191 endotoxin measurements were performed to assess the environmental exposure. For the univariate analysis χ2, Studentttests, ANOVA, and Kruskall Wallis tests were used. Cox proportional hazards analysis was used to identify factors associated with leaving the job.

Results:Fifty three per cent of workers left the mill environment during their first working year. Work related lower respiratory tract symptoms reported at the third month were associated with an increase rate of leaving the industry compared to those remaining in the industry (25%v4.8%; p<0.005). Having respiratory symptoms at the first month of work predicted those leaving the industry at some point in the next 11 months. According to the Cox model, increasing age and having work related lower respiratory tract symptoms were found to be predictors for leaving job at the first working year. Atopic status, dust and endotoxin levels, and lung function changes were not consistently predictive of workers who left the industry in the follow up period.

Conclusion:This study demonstrated that work related respiratory symptoms can predict workers likely to leave the cotton mill environment during the first year of employment, but atopy or acute lung function changes do not.
Muscle cell depolarization induces a gain in surface GLUT4 via reduced endocytosis independently of AMPK
Authors: Wijesekara Nadeeja , Tung Amanda , Thong Farah , Klip Amira
Published: January 2006

Contracting skeletal muscle increases glucose uptake to sustain energy demand. This is achieved through a gain in GLUT4 at the membrane, but the traffic mechanisms and regulatory signals involved are unknown. Muscle contraction is elicited by membrane depolarization followed by a rise in cytosolic Ca2+and actomyosin activation, drawing on ATP stores. It is unknown whether one or more of these events triggers the rise in surface GLUT4. Here, we investigate the effect of membrane depolarization on GLUT4 cycling using GLUT4 myc-expressing L6 myotubes devoid of sarcomeres and thus unable to contract. K+-induced membrane depolarization elevated surface GLUT4 myc, and this effect was additive to that of insulin, was not prevented by inhibiting phosphatidylinositol 3-kinase (PI3K) or actin polymerization, and did not involve Akt activation. Instead, depolarization elevated cytosolic Ca2+, and the surface GLUT4 myc elevation was prevented by dantrolene (an inhibitor of Ca2+release from sarcoplasmic reticulum) and by extracellular Ca2+chelation. Ca2+-calmodulin-dependent protein kinase-II (CaMKII) was not phosphorylated after 10 min of K+depolarization, and the CaMK inhibitor KN62 did not prevent the gain in surface GLUT4 myc. Interestingly, although 5′-AMP-activated protein kinase (AMPK) was phosphorylated upon depolarization, lowering AMPKα via siRNA did not alter the surface GLUT4 myc gain. Conversely, the latter response was abolished by the PKC inhibitors bisindolylmaleimide I and calphostin C. Unlike insulin, K+depolarization caused only a small increase in GLUT4 myc exocytosis and a major reduction in its endocytosis. We propose that K+depolarization reduces GLUT4 internalization through signals and mechanisms distinct from those engaged by insulin. Such a pathway(s) is largely independent of PI3K, Akt, AMPK, and CaMKII but may involve PKC.
Intrarenal octreotide treatment prevents sodium retention in liver cirrhotic rats: evidence for direct effects within the thick ascending limb of Henle's loop
Authors: Jonassen Thomas E. N. , Christensen Sten , Marcussen Niels , Petersen Jørgen Søberg
Published: January 2006

We have previously shown that systemic treatment with the somatostatin analog octreotide has marked beneficial effects on renal function in rats with liver cirrhosis induced by common bile duct ligation (CBL; Jonassen TEN, Christensen S, Sørensen AM, Marcussen N, Flyvbjerg A, Andreasen F, and Petersen JS. Hepatology 29: 1387–1395, 1999). In the present study, we tested the hypothesis that octreotide has a direct effect on renal tubular function. Rats (CBL or Sham-CBL) were intrarenally treated with low-dose octreotide in a long-acting release formulation, which had no systemic actions (100 μg/kg body wt as a single dose). Rats receiving low-dose octreotide (sc) were used as controls. The rats were chronically instrumented, and renal function was examined 4 wk after CBL or Sham-CBL. Intrarenal octreotide administration (IROA) prevented sodium retention in CBL rats without changes in renal plasma flow, glomerular filtration rate, or circulating levels of aldosterone and vasopressin. Renal clearance studies revealed that IROA normalized the increased natriuretic efficacy of furosemide found in CBL rats. Furthermore, IROA protected against the development of hypertrophy of the inner stripe of the outer medulla and thereby the increased the volume of thick ascending limb of Henle's loop (TAL) epithelium found in CBL rats. Finally, Western blot analyses of outer medullary homogenates showed increased abundance of the furosemide-sensitive Na-K-2Cl (NKCC2) cotransporter. IROA did not affect the abundance of NCKK2 within the outer medulla. Together with the histological findings, these results indicate that IROA reduces the total number of NKCC2 within the outer medulla. In conclusion, the results indicate a direct intrarenal effect of octreotide on TAL function and morphology in cirrhotic rats.
Chronic hypoxia and the cerebral circulation
Authors: Xu Kui , LaManna Joseph C.
Published: January 2006

Exposure to mild hypoxia elicits a characteristic cerebrovascular response in mammals, including humans. Initially, cerebral blood flow (CBF) increases as much as twofold. The blood flow increase is blunted somewhat by a decreasing arterial Pco2 as a result of the hypoxia-induced hyperventilatory response. After a few days, CBF begins to fall back toward baseline levels as the blood oxygen-carrying capacity is increasing due to increasing hemoglobin concentration and packed red cell volume as a result of erythropoietin upregulation. By the end of 2 wk of hypoxic exposure, brain capillary density has increased with resultant decreased intercapillary distances. The relative time courses of these changes suggest that they are adjusted by different control signals and mechanisms. The CBF response appears linked to the blood oxygen-carrying capacity, whereas the hypoxia-induced brain angiogenesis appears to be in response to tissue hypoxia.
Hypoxic regulation of the fetal cerebral circulation
Authors: Pearce William
Published: January 2006

Fetal cerebrovascular responses to acute hypoxia are fundamentally different from those observed in the adult cerebral circulation. The magnitude of hypoxic vasodilatation in the fetal brain increases with postnatal age although fetal cerebrovascular responses to acute hypoxia can be complicated by age-dependent depressions of blood pressure and ventilation. Acute hypoxia promotes adenosine release, which depresses fetal cerebral oxygen consumption through action of adenosine on neuronal A1 receptors and vasodilatation through activation of A2 receptors on cerebral arteries. The vascular effect of adenosine can account for approximately half the vasodilatation observed in response to hypoxia. Hypoxia-induced release of nitric oxide and opioids can account for much of the adenosine-independent cerebral vasodilatation observed in response to hypoxia in the fetus. Direct effects of hypoxia on cerebral arteries account for the remaining fraction, although the vascular endothelium contributes relatively little to hypoxic vasodilatation in the immature cerebral circulation. In contrast to acute hypoxia, fetal cerebral blood flow tends to normalize during acclimatization to chronic hypoxia even though cardiac output is depressed. However, uncompensated chronic hypoxia in the fetus can produce significant changes in brain structure and function, alteration of respiratory drive and fluid balance, and increased incidence of intracranial hemorrhage and periventricular leukomalacia. At the level of the fetal cerebral arteries, chronic hypoxia increases protein content and depresses norepinephrine release, contractility, and receptor densities associated with contraction but also attenuates endothelial vasodilator capacity and decreases the ability of ATP-sensitive and calcium-sensitive potassium channels to promote vasorelaxation. Overall, fetal cerebrovascular adaptations to chronic hypoxia appear prioritized to conserve energy while preserving basic contractility. Many gaps remain in our understanding of how the effects of acute and chronic hypoxia are mediated in fetal cerebral arteries, but studies of adult cerebral arteries have produced many powerful pharmacological and molecular tools that are simply awaiting application in studies of fetal cerebral artery responses to hypoxia.
Nicotinic and Muscarinic Reduction of Unitary Excitatory Postsynaptic Potentials in Sensory Cortex; Dual Intracellular Recording In Vitro
Authors: Levy Robert B. , Reyes Alex D. , Aoki Chiye
Published: January 2006

We studied the cholinergic modulation of glutamatergic transmission between neighboring layer 5 regular-spiking pyramidal neurons in somatosensory cortical slices from young rats (P10-P26). Brief bath application of 5–10 μM carbachol, a nonspecific cholinergic agonist, decreased the amplitude of evoked unitary excitatory postsynaptic potentials (EPSPs). This effect was blocked by 1 μM atropine, a muscarinic receptor antagonist. Nicotine (10 μM), in contrast to carbachol, reduced EPSPs in nominally magnesium-free solution but not in the presence of 1 mM Mg+2, indicating the involvement of NMDA receptors. Likewise, when the postsynaptic cell was depolarized under voltage clamp to allow NMDA receptor activation in the presence of 1 mM Mg+2, synaptic currents were reduced by nicotine. Nicotinic EPSP reduction was prevented by the NMDA receptor antagonist d-AP5 (50 μM) and by the nicotinic receptor antagonist mecamylamine (10 μM). Both carbachol and nicotine reduced short-term depression of EPSPs evoked by 10 Hz stimulation, indicating that EPSP reduction happens via reduction of presynaptic glutamate release. In the case of nicotine, several possible mechanisms for NMDAR-dependent EPSP reduction are discussed. As a result of NMDA receptor dependence, nicotinic EPSP reduction may serve to reduce the local spread of cortical excitation during heightened sensory activity.
Proteomic profiles of serum inflammatory markers accurately predict atherosclerosis in mice
Authors: Tabibiazar Raymond , Wagner Roger A. , Deng Alicia , Tsao Philip S. , Quertermous Thomas
Published: January 2006

At a population level, inflammatory markers have been shown to predict outcome and response to therapy in patients with atherosclerotic cardiovascular disease. However, current markers are not sufficiently sensitive or specific to provide clinical utility for managing individual patients. We hypothesize that measurement of multiple circulating disease-related inflammatory factors will be more informative, allowing the early identification of vascular wall disease activity. We have investigated whether protein microarray-based abundance measurements of circulating proteins can predict the severity of atherosclerotic disease. Using a longitudinal experimental design with apolipoprotein E-deficient mice and control C57Bl/6J and C3H/HeJ wild-type mice, we measured the time-related serum protein expression of 30 inflammatory markers using a protein microarray. We were able to identify a subset of proteins that classify and predict the severity of atherosclerotic disease with a high level of accuracy. The time-specific vascular expression of these markers was verified by showing that their gene expression in the mouse aorta correlated closely to the temporal pattern of serum protein levels. In conclusion, these data suggest that quantification of multiple disease-related inflammatory proteins can provide a more sensitive and specific methodology for assessing atherosclerotic disease activity in humans, and identify candidate biomarkers for such studies.
Performance Management, Managerial Citizenship and Worker Commitment: A Study of the United States Postal Service with Some Global Implications
Authors: Kick Edward L. , Fraser James C. , Davis Byron L.
Published: January 2006

This exploratory study of the US Postal Service examines worker perceptions of ‘management citizenship’ in a high performance workplace, and assesses the impact of management citizenship on worker commitment. Qualitative data from employee narratives show many workers view performance management practices as unjust and at a disjuncture with perceived organizational and broader societal goals. Especially salient are issues of worker voice, equity and the non-universalistic treatment of employees by managers. Worker perceptions vary across race and gender. Effects of such perceptions on the organizational commitment of workers have been insuf.ciently studied, but regression analyses show that net of other predictors, worker perceptions of management citizenship are consequential to organizational commitment, as are the intersection of their gender and race for black women, and worker views of workplace heterogeneity, colleague citizenship and personal citizenship in the organization. The implications of these .ndings are drawn out generally and globally, with a focus on ameliorative management citizenship strategies.
Managing Co-operation: Trust and Power in Ghanaian Associations
Authors: Lyon Fergus
Published: January 2006

Through a rich empirical study of forms of collective action in Ghana, this paper examines how groups sustain co-operation in the absence of strong legal institutions and mechanisms (such as legal contracts or regulated loan finance) that are often taken for granted in most ‘western’ economies. It presents evidence from case studies of micro-saving groups, palm oil processing groups and transport associations, which indicate that co-operation is based on trust and power, both of which are based on culturally specific norms. Decisions to co-operate are shaped by a combination of conscious calculations, habitual actions and unquestioning compliance or obedience. The way that trust and power are articulated also varies according to local context, and attempts to facilitate and support co-operative activities have to build on the existing co-operative structures that are embedded in the local, culturally specific, social relations.
Organizational Citizenship Behaviour as Performance in Multiple Network Positions
Authors: Lamertz Kai
Published: January 2006

This paper employs structural role theory to theorize why and how the performance of organizational citizenship behaviour (OCB) may be associated with an individual's occupation of social network positions. OCB is modelled as behaviour related to the occupation of position–role combinations in the informal structure of organizations. It is proposed that the performance of OCB occurs in conjunction with informal role enactment at a given network position because such performance is characteristic of position occupancy. A given actor may occupy multiple network positions, which profile the actor's links to the informal organization and place him or her in the position to perform OCB. An empirical study of employees in a telecommunications company showed that cohesiveness, centrality and network bridges predict two different types of OCB that characterize a ‘good colleague’ and a ‘good employee’ role.
Challenges of Teamwork in Production: Demands of Communication
Authors: Minssen Heiner
Published: January 2006

Implementing teamwork in production is an element of a gradual transfer of the company's steering from coordination by hierarchy to a form of coordination which can be characterized as discursive coordination. This generates an increasing density of communication which is the actual challenge — for the team members as well as for the organization as a whole. Workers often unused to communicating at work have to guarantee cooperation and control by self-regulating and so are forced to communicate more than before; superiors who are afraid of losing their influence, status, power and at worst their jobs have to treat workers as experts rather than as recipients of orders. The question is therefore why organizations expose themselves to challenges like these. Regarding the neo-institutionalistic concept of isomorphism it can be argued that the dissemination of teamwork in production is a case of mimetic isomorphism. But a new guideline for rationalization, in this case the implementation of teamwork, must suit the internal situation. Organizations are structurally conservative and react cautiously to the promises offered by new concepts such as teamwork; they cannot reject concepts which are taken for granted in their organizational field, but that does not guarantee realization of the concepts. Obviously, processes of mimetic isomorphism refer to concepts of rationalization rather than to transferred structures.
The Emergence of New Global Institutions: A Discursive Perspective
Authors: Maguire Steve , Hardy Cynthia
Published: January 2006

We examine how a new discourse shapes the emergence of new global regulatory institutions and, specifically, the roles played by actors and the texts they author during the institution-building process, by investigating a case study of the Stockholm Convention on Persistent Organic Pollutants (POPs) and its relationship to the new environmental regulatory discourse of ‘precaution’. We show that new discourses do not neatly supplant legacy discourses but, instead, are made to overlap and interact with them through the authorial agency of actors, as a result of which the meanings of both are changed. It is out of this discursive struggle that new institutions emerge.
An overwhelming sense of injustice? An exploration of child sexual abuse in relation to the concept of justice
Authors: Green Lorraine
Published: January 2006

This article explores the relationship between justice and child sexual abuse, developing a broader theoretical conception of justice than that customarily applied. The traditional legal perception of justice as the attempted prosecution of alleged perpetrators is widened to encompass justice as initial prevention of abuse, the fair treatment of children by the criminal justice and child protection systems, and the subsequent after-care and compensation of abused children and adults. Concepts of justice are therefore examined within a chronological lifecourse trajectory, as well as being extended from traditional notions of due process and desert to include understandings of justice as human rights, ‘fair shares’ and liberation. Particular social constructions of childhood are revealed to be highly significant regarding how justice is perceived and operationalized. Therefore, the interaction between perceptions of justice and responses to child sexual abuse is examined, relative to wider understandings of childhood.
Undoing an activist response: feminism and the Australian government's domestic violence policy
Authors: Phillips Ruth
Published: January 2006

After nine years of socially conservative government in Australia, national domestic violence policy has shifted its focus from a ‘ womencentred’ and gender-based analytic framework to one that favours the family and reflects individualized, relational explanations of this crucial social policy issue. In exploring this issue, first this paper discusses what is meant by feminism in this context, some of the implications arising out of competing ideas amongst feminist activists in Australia and how feminism drove and influenced national policy. Second, through an examination of the current Australian government's efforts and decisions in relation to its only significant policy response to domestic violence, ‘Partnerships Against Domestic Violence’, this paper explores the implications of the socially conservative approach of the Howard Coalition Government and why it appears anti-feminist. Through a brief analysis of a national public education campaign launched in 2004, allocation of recent funding and the government's broad political approach to women's policy practice and implementation, questions are raised about the future of a policy that ignores the relationships between domestic violence and gender relations.