bluuebunny/crossref_metadata_2025 huggingface dataset:
Oestrogen Receptors and Selective Oestrogen Receptor Modulators: Molecular and Cellular Pharmacology
Authors: Nilsson Stefan , Koehler Konrad F.
Published: January 2005

Abstract: The early termination of the two arms of the Women's Health Initiative Trials has led to an increased interest and demand for selective oestrogen receptor modulators because of their potential to retain the benefits of hormone replacement therapy (oestrogen plus a gestagen) and at the same time avoid most of its severe adverse events. Selective oestrogen receptor modulators are a class of oestrogen receptor binding, small organic molecules that take advantage of the plasticity of the oestrogen receptors (α and β, respectively), modulating the surface conformation of the oestrogen receptors upon binding in the respective ligand binding cavity. By doing so they affect the binding of various co‐factors to the surface of the oestrogen receptors that, at least in part, explains why selective oestrogen receptor modulators may mimic the activity of oestrogen in some tissues where so desired, while opposing its activity in tissues where oestrogen‐like activity is undesirable. Although selective oestrogen receptor modulators have many properties in common they also display unique activities including oestrogen receptor surface modulation and regulation of target gene expression. Selective oestrogen receptor modulators therefore offer the opportunity to develop pharmaceuticals with very distinct pharmacology and mechanism of action. Furthermore, these modulators offer the advantage of decreased risk for the development of breast and endometrial cancer and circumvent the need for combination with a gestagen. Most selective oestrogen receptor modulators in development bind with roughly equal affinity to both oestrogen receptor α and β (balanced) and our view is that it is unlikely that a balanced selective oestrogen receptor modulator will inherit all desired effects of oestrogen (e.g. 17β‐oestradiol) and at the same time be devoid of all undesired effects. We therefore propose that the development of oestrogen receptor‐subtype (α and β, respectively) selective pharmaceuticals for specific applications (designer drugs) would better provide the benefits of hormone replacement therapy without its associated risks.
In vitro Assessment of Renal Toxicity and Inflammatory Events of Two Protein Phosphatase Inhibitors Cantharidin and Nor‐Cantharidin*
Authors: Massicot France , Dutertre‐Catella Hélène , Pham‐Huy Chuong , Liu Xu‐Hui , Duc Huynh Thien , Warnet Jean‐Michel
Published: January 2005

Abstract: In China, cantharidin has been reported to be active against various human cancers, but with severe side effects such as nephrotoxicity. In order to reduce this toxicity, its demethylated analogue nor‐cantharidin has been synthesized and used in cancer therapy, but with only few data regarding safety assessment. The aim of this study was to compare the in vitro effects of cantharidin and nor‐cantharidin on renal toxicity and on inflammatory events associated with tumoural process where protein phosphatases could be involved (energy status, prostanoid production, glutathione and nitrite contents) on RAW 264.7 and LLC‐PK1 cells. In macrophages, both cantharidin and nor‐cantharidin decreased cell viability, in a concentration‐ and time‐dependent manner. However, IC50 was lower with cantharidin than with nor‐cantharidin. These two drugs significantly decreased the ATP level after 24 hr incubation. However, ATP decreased much more with cantharidin (up to 4 times) than with nor‐cantharidin. When control macrophages were activated with lipopolysaccharide+interferon‐γ for 24 hr a significant increase in nitrite content and in prostanoids were observed. Addition of either drug decreased nitrite generation and prostanoids, however these decreases were greater with cantharidin than with nor‐cantharidin. In LLC‐PK1 cells, incubated with either cantharidin or nor‐cantharidin, our results show significant differences between the two drugs, similar to those observed in peritoneal macrophages, except for GSH content with opposite variations in both cells. We provide a better understanding of the various mechanisms of cantharidin side effects, allowing an easier comparison with nor‐cantharidin which could be an attractive therapeutic potential in cancer chemotherapy in western countries.
In vitro Activity of Phenothiazine Derivatives in Enterococcus faecalis and Enterococcus faecium
Authors: Hendricks Oliver , Molnar Annamaria , Butterworth Trine Sørensen , Butaye Patrick , Kolmos Hans Jørn , Christensen Jørn Bolstad , Kristiansen Jette E.
Published: January 2005

Abstract: The antimicrobial activity of the phenothiazine derivatives thioridazine and prochlorperazine have been evaluated with 11 Enterococcus faecalis strains and 9 Enterococcus faecium strains, originating from human infections and animal faecal flora. We found that all E. faecalis and E. faecium strains, regardless of their susceptibility to commonly used antibiotics, were inhibited by thioridazine at a concentration of 16–32 μg/ml and by prochlorperazine at a concentration of 32–64 μg/ ml. Combinations of the antibiotics vancomycin or ampicillin and thioridazine and prochlorperazine at subinhibitory concentrations, could render vancomycin‐ or ampicillin‐resistant bacteria sensitive to each of the antibiotics. Verapamil and reserpine, inhibitors of P‐glycoprotein‐mediated multidrug resistance, did not reduce resistance. Our results outline modification of resistance in enterococci induced by phenothiazine derivatives unrelated to P‐glycoprotein‐mediated multidrug resistance.
Evaluation of Chondroitin Sulfate Bioactivity in Hippocampal Neurones and the Astrocyte Cell Line U373: Influence of Position of Sulfate Groups and Charge Density
Authors: Rapp Alfred , Brandl Nina , Volpi Nicola , Huettinger Manfred
Published: January 2005

Abstract: Chondroitin sulfates are linear polysaccharides of alternating glucuronic acid and N‐acetylgalactosamine, sulfated in varying positions. They form the extracellular framework providing the information for the structural establishment of tissues in multicellular organisms. Growth cones of neurones modulate their outgrowth according to signals received from proteoglycans. The exact molecular structures behind these functions are not fully understood, but structural details of the carbohydrate backbone are crucial. In this report we have employed quantitative cytometry on hippocampal neurite outgrowth in the presence of chondroitin sulfate added in solution to determine the influence of the position and density of the sulfate groups of the N‐acetyl‐D‐galactosamine‐residues of chondroitin sulfates. It is of profound interest whether externally added chondroitin sulfates can compete with core protein bound chondroitin sulfate to modulate the effects of tissue‐synthesized matrix. In series of microscopic images 3 parameters of neuritic outgrowth activity, neurite length, number of neurites and fasciculation (thickness of neurites) are analyzed at concentrations occurring in intact tissues. Fasciculation increased and number of neurites decreased with high di‐sulfation. No significant differences on process length reduction were found between the isotypes. Specificity of effects found is emphasized, as no influence on cell proliferation with U373 human astrocyte cell line is detectable, while neurones clearly are inhibited. The IC30 and IC50 values of chondroitin sulfates isoforms are presented for neurones. The data indicate that the soluble fragments from chondroitin sulfate are actively modulating cell development. Besides dosage, sulfation density and position are relevant for effects of chondroitin sulfate in neuronal regenerative activity.
All‐trans Retinoic Acid Induction of Sulfotransferases
Authors: Maiti Smarajit , Chen Xinrong , Chen Guangping
Published: January 2005

Abstract: All‐trans retinoic acid is the bioactive form of vitamin A (retinol). Retinoids have been used clinically as therapeutic agents against a number of cancers. Retinoids have been reported to induce the phase I drug metabolizing enzymes, cytochrome P‐450s. In contrast, effects of retinoids on sulfotransferases have not been as well studied. The present investigation evaluates the role of retinoic acid on the expression of aryl sulfotransferase IV and hydroxysteroid sulfotransferase a in male and female Sprague‐Dawley rat liver and intestine. Cultured human hepatic carcinoma cells (Hep G2) and intestinal carcinoma cells (Caco‐2) were also used to study retinoic acid's effect on simple phenol sulfating sulfotransferase, dehydroepiandrosterone sulfotransferase and oestrogen sulfotransferase. Enzyme assay and Western blot were used to determine sulfotransferase protein expression. Retinoic acid induced aryl sulfotransferase IV in liver of female rats and sulfotransferase a in liver of male rats. Intestinal rat aryl sulfotransferase IV and sulfotransferase a in male rats and intestinal aryl sulfotransferase IV in female rats were also induced after retinoic acid treatment. In Hep G2 and Caco‐2 cells, retinoic acid differentially induced the three human sulfotransferase isoforms. In general, intestinal sulfotransferases were found to be more responsive than hepatic sulfotransferases to retinoic acid treatment. mRNA expressions were investigated using reverse transcription polymerase chain reaction with gene specific primers. Reverse transcription polymerase chain reaction results are in good agreement with enzyme activity and Western blot results. This suggests that retinoic acid induction of sulfotransferases is at the transcriptional level.
Effect of Sodium Azulene Sulfonate on Capsaicin‐Induced Pharyngitis in Rats
Authors: Sakai Hiroyasu , Misawa Miwa
Published: January 2005

Abstract: Sodium azulene sulfonate is a water‐soluble derivative of azulene which is an antiinflammatory component of chamomile of the family of Asteraceae. Sodium azulene sulfonate is clinically used as a therapeutic agent in the treatment of pharyngitis as well as other inflammatory diseases such as tonsillitis, stomatitis and conjunctivitis. There has been no documentation on the effect of sodium azulene sulfonate on pharyngitis in laboratory models, probably because of no availability of such models. We recently established a pharyngitis model using capsaicin application on pharyngeal mucosa in rats. The present study investigated the antipharyngitis activity of sodium azulene sulfonate comparing with those of ruthenium red (vanilloid receptor antagonist, 8.5 and 85 mg/ml), ascorbic acid (antioxidative compound, 100 μg/ml), povidone iodine (gargle as disinfectant, oxidative compound, 5 and 20 mg/ml) and diclofenac sodium (cyclooxygenase inhibitor, 0.1 and 1 mg/ml). As an antipharyngeal effect, the capsaicin‐induced plasma exudation in the pharyngeal mucosa of the rat was evaluated. The capsaicin‐induced plasma exudation in the pharyngeal mucosa was inhibited by sodium azulene sulfonate (100 and 200 μg/ml) as well as ruthenium red and ascorbic acid, but not by povidone iodine and dicrofenac sodium; povidone iodine rather promoted the plasma exudation. In conclusion, the antipharyngitis effect of sodium azulene sulfonate was demonstrated for the first time in a laboratory model. Although the mechanism by which sodium azulene sulfonate inhibited the capsaicin‐induced pharyngitis is not yet unraveled, antioxidative effect, but not inhibitory effect on cyclooxygenase pathway, might be involved.
Population Pharmacokinetics of Caffeine and its Metabolites Theobromine, Paraxanthine and Theophylline after Inhalation in Combination with Diacetylmorphine
Authors: Zandvliet Anthe S. , Huitema Alwin D. R. , De Jonge Milly E. , Den Hoed Rob , Sparidans Rolf W. , Hendriks Vincent M. , Van Den Brink Wim , Van Ree Jan M. , Beijnen Jos H.
Published: January 2005

Abstract: The stimulant effect of caffeine, as an additive in diacetylmorphine preparations for study purposes, may interfere with the pharmacodynamic effects of diacetylmorphine. In order to obtain insight into the pharmacology of caffeine after inhalation in heroin users, the pharmacokinetics of caffeine and its dimethylxanthine metabolites were studied. The objectives were to establish the population pharmacokinetics under these exceptional circumstances and to compare the results to published data regarding intravenous and oral administration in healthy volunteers. Diacetylmorphine preparations containing 100 mg of caffeine were used by 10 persons by inhalation. Plasma concentrations of caffeine, theobromine, paraxanthine and theophylline were measured by high performance liquid chromatography. Non‐linear mixed effects modelling was used to estimate population pharmacokinetic parameters. The model was evaluated by the jack‐knife procedure. Caffeine was rapidly and effectively absorbed after inhalation. Population pharmacokinetics of caffeine and its dimethylxanthine metabolites could adequately and simultaneously be described by a linear multi‐compartment model. The volume of distribution for the central compartment was estimated to be 45.7 l and the apparent elimination rate constant of caffeine at 8 hr after inhalation was 0.150 hr−1 for a typical individual. The bioavailability was approximately 60%. The presented model adequately describes the population pharmacokinetics of caffeine and its dimethylxanthine metabolites after inhalation of the caffeine sublimate of a 100 mg tablet. Validation proved the stability of the model. Pharmacokinetics of caffeine after inhalation and intravenous administration are to a large extent similar. The bioavailability of inhaled caffeine is approximately 60% in experienced smokers.
Effect of Underfill Entrapment on the Reliability of Flip-Chip Solder Joint
Authors: Chan Y. C. , Alam M. O. , Hung K. C. , Lu H. , Bailey C.
Published: January 2005

The application of underfill materials to fill up the room between the chip and substrate is known to substantially improve the thermal fatigue life of flip chip solder joints. Nowadays, no-flow underfill materials are gaining much interest over traditional underfill as the application and curing of this type of underfill can be undertaken before and during the reflow process and thus aiding high volume throughput. However, there is always a potential chance of entrapping no-flow underfill in the solder joints. This work, attempts to find out the extent of underfill entrapment in the solder joints and its reliability effect on the flip chip packages. Some unavoidable underfill entrapments at the edges of the joint between solder bumps and substrate pads are found for certain solder joints whatever bonding conditions are applied. It is interesting to report for the first time that partial underfill entrapment at the edges of the solder joint seems to have no adverse effect on the fatigue lifetime of the samples since most of the first solder joint failure in the no-flow flip chip samples during thermal cycling are not at the site of solder interconnection with underfill entrapment. Our modeling results show good agreement with the experiment that shows underfill entrapment can actually increase the fatigue lifetime of the no-flow flip chip package.
Thermal Performance of Next Generation of Modulated Pump Lasers in Telco Equipment
Authors: Refai-Ahmed Gamal , Trottier Stephanie
Published: January 2005

The present investigation numerically modeled the thermal behavior of the laser diode using the parabolic transient conduction equation. In addition, the current study compared the thermal performance of the continuous wave pump lasers versus the modulated wave pump lasers. This comparison revealed that the temperature of the modulated wave pump laser can approach the temperature of the continuous wave pump laser with the same average power dissipation when the frequency approaches infinity. Finally, the resulting thermal behavior was correlated and expressed in an empirical form, which physically described the thermal performance of the modulating pump laser.
Thermal Model of a Thinned-Die Cooling System
Authors: Boiadjieva N. , Koev P.
Published: January 2005

For through-silicon optical probing of microprocessors, the heat generated by devices with power over 100W must be dissipated 1. To accommodate optical probing, a seemingly elaborate cooling system that controls the microprocessor temperature from 60 to 100°C for device power up to 150 W was designed 2. The system parameters to achieve the desired thermal debug environment were cooling air temperature and air flow. A mathematical model was developed to determine both device temperature and input power. The 3D heat equation that governs the temperature distribution was simplified to a case of a 1D rod with one end at the device center and the other at the cooling air intake. Thus the cooling system was reduced to an analytical expression. From experimental data, we computed all coefficients in the model, then ran extensive tests to verify—the accuracy was better than 10% over the entire temperature and power ranges.
Highlights from the European Thermal Project PROFIT
Authors: Lasance Clemens J. M.
Published: January 2005

On January 1, 2000, the European project PROFIT commenced as a follow up to the successfully finished EC-funded projects DELPHI, SEED, and THERMINIC. PROFIT finished in March 2003. The project aimed at creating methods and tools to enable a sufficiently accurate measurement and prediction of temperature gradients in time and space required for a more accurate and timely assessment of cost, performance, safety, and reliability of electronic products in all stages of the product realization process. The PROFIT partners produced 55 deliverables and 83 conference and journal papers. The paper discusses some highlights of the project and indicates shortly their potential for small-scale applications.
A New Role of CFD Simulation in Thermal Design of Compact Electronic Equipment: Application of the Build-up Approach to Thermal Analysis of a Benchmark Model
Authors: Nakayama Wataru , Matsuki Ryuichi , Hacho Yukari , Yajima Kiyoko
Published: January 2005

Computational Fluid Dynamics (CFD) codes have proved their high potential as a tool of thermal design of electronic equipment. However, as the product development cycle is shortened, the CFD-based thermal design needs a new format that allows the packaging designer fast and versatile searches for better design options. The most serious factor that slows the CFD-based design is geometric complexity created by packing various components in a tight space of the system box. In a proposed methodology coined “Build-up Approach (BUA),” CFD simulations are conducted on a set of hardware models to gain insight into the effects of component placement on the junction temperature. Two algorithms are introduced before and after CFD simulations: one defines the geometric parameters through singular value decomposition (SVD) of components placement patterns and the other identifies important geometric parameters by means of the Taguchi method. A case study was conducted on a simple hardware model (benchmark model) that embodies essential features of portable electronic equipment. The results proved the effectiveness of these algorithms in measuring the relative importance of geometric parameters and weeding out unimportant geometric details.
Evaluation of Thermal Enhancements to Flip-Chip-Plastic Ball Grid Array Packages
Authors: Ramakrishna K. , Lee T.-Y. Tom
Published: January 2005

Enhancements to thermal performance of FC-PBGA packages due to underfill thermal conductivity, controlled collapse chip connection (C4) pitch, package to printed wiring board (PWB) interconnection through thermal balls, a heat spreader on the backside of the die, and an overmolded die with and without a heat spreader have been studied by solving a conjugate heat transfer problem. These enhancements have been investigated under natural and forced convection conditions for freestream velocities up to 2 m/s. The following ranges of parameters have been covered in this study: substrate size: 25–35 mm, die size: 6.19×7.81 mm (48 mm2 area) and 9.13×12.95 mm (118 mm2 area), underfill thermal conductivity: 0.6–3.0 W/(m K), C4 pitch: 250 μm and below, no thermal balls to 9×9 array of thermal balls on 1.27 mm square pitch, and with copper heat spreader on the back of a bare and an overmolded die. Based on our previous work, predictions in this study are expected to be within ±10% of measured data. The conclusions of the study are: (i) Thermal conductivity of the underfill in the range 0.6 to 10 W/(m K) has negligible effect on thermal performance of FC-PBGA packages investigated here. (ii) Thermal resistances decrease 12–15% as C4 pitch decreases below 250 μm. This enhancement is smaller with increase in die area. (iii) Thermal balls connected to the PTHs in the PWB decrease thermal resistance of the package by 10–15% with 9×9 array of thermal balls and PTHs compared to no thermal balls. The effect of die size on this enhancement is more noticeable on junction to board thermal resistance, Ψjb, than the other two package thermal metrics. (iv) Heat spreader on the back of the die decreases junction-to-ambient thermal resistance, Θja, by 6% in natural convection and by 25% in forced convection. (v) An overmolded die with a heat spreader provides better a thermal enhancement than a heat spreader on a bare die for freestream velocities up to about 1 m/s. Beyond 1 m/s, a heat spreader on bare die has better thermal performance.
Design of Cooling Systems for Electronic Equipment Using Both Experimental and Numerical Inputs
Authors: Icoz Tunc , Jaluria Yogesh
Published: January 2005

This paper presents a methodology for the design and optimization of cooling systems for electronic equipment. In this approach, inputs from both experimentation and numerical modeling are to be used concurrently to obtain an acceptable or optimal design. The experimental conditions considered are driven by the numerical simulation and vice versa. Thus, the two approaches are employed in conjunction, rather than separately, as is the case in traditional design methods. Numerical simulation is used to consider different geometries, materials, and dimensions, whereas experiments are used for obtaining results for different flow rates and heat inputs, as these can often be varied more easily in experiments than in simulations. Also, transitional and turbulent flows are more accurately and more conveniently investigated experimentally. Thus, by using both approaches concurrently, the entire design domain is covered, leading to a rapid, convergent, and realistic design process. Two simple configurations of electronic cooling systems are used to demonstrate this approach.
Development of Compact Models for Electronics Cooling: Using the Multigrid Operator to Generate Reduced-Order Description of Devices
Authors: Sathyamurthy Prabhu , Nagulapally Manoj , Nair Rajesh
Published: January 2005

The need for compact models for ICs is a well-recognized problem in electronics cooling simulations of systems containing multiple PCBs and many devices per board. The disparate length scales inherent in the problem and the necessity of resolving these size scales render the computational problem intractable. Many resistance-capacitance (RC) network compact models have been proposed in the literature. We present a methodology to automatically construct both the topology and characteristics of the reduced-order or compact models of devices [primarily Integrated Circuit (IC) packages] for use in system-level simulations using the multigrid operator. The multigrid technique has been extensively used over the past 20 years to accelerate the solution of linear systems. In addition to automatically generating both the RC network topology and its values, the procedure is general enough to be applicable for complex IC device types (such as multichip modules), stack-up dies, distributed sources on the die, DC-DC converters, and devices such as hard disk drives.
h adiabatic and umax′
Authors: Moffat Robert J.
Published: January 2005

In all electronics cooling situations, and many other practical situations, the surface temperature may vary rapidly in the streamwise direction. In these cases, defining the heat transfer coefficient using the adiabatic temperature of the surface instead of the mixed mean temperature of the coolant results in significant benefits. The resulting coefficient, called hadiabatic, is well behaved, being a function only of the geometry and flow characteristics. Calling attention to Tadiabatic, as opposed to Tmean, helps designers identify the root cause of overheating problems and more quickly reach good solutions. The theoretical and practical bases for hadiabatic are presented. Examples of its use in electronics cooling are described to show the operational advantages this approach offers. Turbulence strongly affects heat transfer. A simple, turbulence-based correlation is presented that yields an estimate of the heat transfer coefficient good enough for preliminary design estimates and often as accurate as can be relied on from CFD calculations using present codes.
Cluster of High-Powered Racks Within a Raised-Floor Computer Data Center: Effect of Perforated Tile Flow Distribution on Rack Inlet Air Temperatures
Authors: Schmidt Roger , Cruz Ethan
Published: January 2005

This paper focuses on the effect on rack inlet air temperatures as a result of maldistribution of airflows exiting the perforated tiles located adjacent to the fronts of the racks. The flow distribution exiting the perforated tiles was generated from a computational fluid dynamics (CFD) tool called Tileflow (trademark of Innovative Research, Inc.). Both raised floor heights and perforated tile-free areas were varied in order to explore the effect on rack inlet temperatures. The flow distribution exiting the perforated tiles was used as boundary conditions to the above-floor CFD model. A CFD model was generated for the room with electronic equipment installed on a raised floor. Forty racks of data processing (DP) equipment were arranged in rows in a data center cooled by chilled air exhausting from perforated floor tiles. The chilled air was provided by four A/C units placed inside a room 12.1 m wide×13.4 m long. Because the arrangement of the racks in the data center was symmetric, only half of the data center was modeled. The numerical modeling for the area above the raised floor was performed using a commercially available finite control volume computer code called Flotherm (trademark of Flomerics, Inc.). The flow was modeled using the k-e turbulence model. Results are displayed to provide some guidance on the design and layout of a data center.
Mixed Convection of Impinging Air Cooling Over Heat Sink in Telecom System Application
Authors: Bhopte Siddharth , Alshuqairi Musa S. , Agonafer Dereje , Refai-Ahmed Gamal
Published: January 2005

The current numerical investigation will examine the effect of an impinging mixed convection air jet on the heat transfer rate of a parallel flat plate heat sink. A three-dimensional numerical model was developed to evaluate the effects of the nozzle diameter d, nozzle-to-target vertical placement H/d, Rayleigh number, and the jet Reynolds number on the heat transfer rates from a discrete heat source. Simulations were performed for a Prandtl number of 0.7 and for Reynolds numbers ranging from 100 to 5000. The governing equations were solved in the dimensionless form using a commercial finite-volume package. Average Nusselt numbers were obtained, at H/d=3 and two jet diameters, for the bare heat source, for the heat source with a base heat sink, and for the heat source with the finned heat sink. The heat transfer rates from the bare heat source surface have been compared with the ones obtained with the heat sink in order to determine the overall performance of the heat sink in an impingement configuration.
Abrupt and Gradual Extinction Among Late Permian Land Vertebrates in the Karoo Basin, South Africa
Authors: Ward Peter D. , Botha Jennifer , Buick Roger , De Kock Michiel O. , Erwin Douglas H. , Garrison Geoffrey H. , Kirschvink Joseph L. , Smith Roger
Published: January 2005

The Karoo basin of South Africa exposes a succession of Upper Permian to Lower Triassic terrestrial strata containing abundant terrestrial vertebrate fossils. Paleomagnetic/magnetostratigraphic and carbon-isotope data allow sections to be correlated across the basin. With this stratigraphy, the vertebrate fossil data show a gradual extinction in the Upper Permian punctuated by an enhanced extinction pulse at the Permian-Triassic boundary interval, particularly among the dicynodont therapsids, coinciding with negative carbon-isotope anomalies.
Differential PsaA-, PspA-, PspC-, and PdB-Specific Immune Responses in a Mouse Model of Pneumococcal Carriage
Authors: Palaniappan Ravichandran , Singh Shailesh , Singh Udai P. , Sakthivel Senthil Kumar K. , Ades Edwin W. , Briles David E. , Hollingshead Susan K. , Paton James C. , Sampson Jacquelyn S. , Lillard James W.
Published: January 2005

Larger numbers of pneumococci were detected in the nasal tract compared to the lung, cervical lymph nodes, and spleen 1, 2, 4, 7, 14, and 21 days after nasal challenge withStreptococcus pneumoniaestrain EF3030. In this mouse model of pneumococcal carriage, peripheralS. pneumoniaepneumococcal surface adhesin A (PsaA)-specific humoral responses (immunoglobulin G2a [IgG2a] ≫ IgG1 = IgG2b > IgG3) were significantly higher than pneumococcal surface protein A (PspA)-specific, genetic toxoid derivative of pneumolysin (PdB)-specific, or pneumococcal surface protein C (PspC)-specific serum antibody levels. However, PspA-specific mucosal IgA antibody levels were significantly higher than those against PsaA, PdB, and PspC. In general, both PsaA- and PspA-specific lung-, cervical lymph node-, nasal tract-, and spleen-derived CD4+T-cell cytokine (interleukin-4, interleukin-6, granulocyte-macrophage colony-stimulating factor, gamma interferon, and tumor necrosis factor alpha) and proliferative responses were higher than those for either PspC or PdB. Taken together, these findings suggest that PsaA- and PspA-specific mucosal responses as well as systemic humoral and T helper cell cytokine responses are predominantly yet differentially induced during pneumococcal carriage.
Effect of Capsulation of Opportunistic Pathogenic Bacteria on Binding of the Pattern Recognition Molecules Mannan-Binding Lectin, L-Ficolin, and H-Ficolin
Authors: Krarup Anders , Sørensen Uffe B. Skov , Matsushita Misao , Jensenius Jens C. , Thiel Steffen
Published: January 2005

Mannan-binding lectin (MBL), L-ficolin, and H-ficolin are pattern recognition molecules of the innate immune system. We investigated their ability to bind to different serotypes and noncapsulated variants of two gram-positive bacterial species,
Streptococcus pneumoniae
and
Staphylococcus aureus
. MBL did not bind to capsulated
S. aureus
or capsulated
S. pneumoniae
but did bind to a noncapsulated
S. aureus
variant (Wood). L-ficolin bound to some capsulated
S. aureus
serotypes (serotypes 1, 8, 9, 11, and 12) and capsulated
S. pneumoniae
serotypes (11A, 11D, and 11F) but not to noncapsulated strains. H-ficolin did not bind to any of the
S. pneumoniae
and
S. aureus
serotypes included in this study but did bind to one strain of
Aerococcus viridans
. The concentrations of the three proteins in 97 plasma samples were estimated. The median concentrations were 0.8 μg per ml for MBL, 3.3 μg per ml for L-ficolin, and 18.4 μg per ml for H-ficolin.
A549 Lung Epithelial Cells Grown as Three-Dimensional Aggregates: Alternative Tissue Culture Model forPseudomonas aeruginosaPathogenesis
Authors: Carterson A. J. , Höner zu Bentrup K. , Ott C. M. , Clarke M. S. , Pierson D. L. , Vanderburg C. R. , Buchanan K. L. , Nickerson C. A. , Schurr M. J.
Published: January 2005

A three-dimensional (3-D) lung aggregate model was developed from A549 human lung epithelial cells by using a rotating-wall vessel bioreactor to study the interactions betweenPseudomonas aeruginosaand lung epithelial cells. The suitability of the 3-D aggregates as an infection model was examined by immunohistochemistry, adherence and invasion assays, scanning electron microscopy, and cytokine and mucoglycoprotein production. Immunohistochemical characterization of the 3-D A549 aggregates showed increased expression of epithelial cell-specific markers and decreased expression of cancer-specific markers compared to their monolayer counterparts. Immunohistochemistry of junctional markers on A549 3-D cells revealed that these cells formed tight junctions and polarity, in contrast to the cells grown as monolayers. Additionally, the 3-D aggregates stained positively for the production of mucoglycoprotein while the monolayers showed no indication of staining. Moreover, mucin-specific antibodies to MUC1 and MUC5A bound with greater affinity to 3-D aggregates than to the monolayers.P. aeruginosaattached to and penetrated A549 monolayers significantly more than the same cells grown as 3-D aggregates. Scanning electron microscopy of A549 cells grown as monolayers and 3-D aggregates infected withP. aeruginosashowed that monolayers detached from the surface of the culture plate postinfection, in contrast to the 3-D aggregates, which remained attached to the microcarrier beads. In response to infection, proinflammatory cytokine levels were elevated for the 3-D A549 aggregates compared to monolayer controls. These findings suggest that A549 lung cells grown as 3-D aggregates may represent a more physiologically relevant model to examine the interactions betweenP. aeruginosaand the lung epithelium during infection.
Fusobacterium nucleatum
Increases Collagenase 3 Production and Migration of Epithelial Cells
Authors: Uitto Veli-Jukka , Baillie Daniel , Wu Qiang , Gendron Renee , Grenier Daniel , Putnins Edward E. , Kanervo Arja , Firth James D.
Published: January 2005

Fusobacterium nucleatum
is closely associated with human periodontal diseases and may also be a causative agent in other infections, such as pericarditis, septic arthritis, and abscesses of tonsils and liver. Initiation and outcome of infective diseases depend critically on the host cell signaling system altered by the microbe. Production of proteinases by infected cells is an important factor in pericellular tissue destruction and cell migration. We studied binding of
F. nucleatum
to human epithelial cells (HaCaT keratinocyte line) and subsequent cell signaling related to collagenase 3 expression, cell motility, and cell survival, using a scratch wound cell culture model.
F. nucleatum
increased levels of 12 protein kinases involved in cell migration, proliferation, and cell survival signaling, as assessed by the Kinetworks immunoblotting system. Epithelial cells of the artificial wound margins were clearly preferential targets of
F. nucleatum
. The bacterium colocalized with lysosomal structures and stimulated migration of these cells. Of the 13 anaerobic oral bacterial species,
F. nucleatum
and
Fusobacterium necrophorum
were among the best inducers of collagenase 3 mRNA levels, a powerful matrix metalloproteinase. Production of collagenase 3 was detected in fusobacterium-infected cells and cell culture medium by immunocytochemistry, immunoblotting, and zymography. The proteinase production involved activation of p38 mitogen-activated protein kinase in the infected cells. The study suggests that
F. nucleatum
may be involved in the pathogenesis of periodontal diseases (and other infections) by activating multiple cell signaling systems that lead to stimulation of collagenase 3 expression and increased migration and survival of the infected epithelial cells.
DistinctLeishmania braziliensisIsolates Induce Different Paces of Chemokine Expression Patterns
Authors: Teixeira Maria Jania , Fernandes Juliana Dumet , Teixeira Clarissa Romero , Andrade Bruno Bezerril , Pompeu Margarida Lima , Santana da Silva João , Brodskyn Cláudia Ida , Barral-Netto Manoel , Barral Aldina
Published: January 2005

Inflammatory events duringLeishmania braziliensisinfection in mice were investigated. Large lesions were directly correlated with the inflammatory reaction but not with parasite burden. DifferentL. braziliensisstrains induce different paces of chemokine expression patterns, leading to diverse cell recruitment and differential inflammatory responses.
Genetic Control of
Bordetella pertussis
Infection: Identification of Susceptibility Loci Using Recombinant Congenic Strains of Mice
Authors: Banus H. A. , van Kranen H. J. , Mooi F. R. , Hoebee B. , Nagelkerke N. J. , Demant P. , Kimman T. G.
Published: January 2005

Susceptibility to and severity of
Bordetella pertussis
infection in infants and children vary widely. The spectrum of clinical symptoms ranges from subclinical infection to mild disease, severe whooping cough, and death. The aims of this study were to examine genetic susceptibilities of mice to
B. pertussis
and to identify genetic loci in the mouse genome that are involved in susceptibility to
B. pertussis
infection. For this purpose we screened two sets of recombinant congenic strains (RCS) of mice, HcB and CcS, for differences in the numbers of bacteria in the lung 7 days after inoculation. For both CcS and in HcB mice, a wide range in numbers of bacteria in the lung was found, suggesting that the course of infection is under multigenic control. From both RCS sets of mice, we selected one strain to identify possible susceptibility loci in F
2
hybrid mice. The degree of lung colonization 7 days postinoculation in these F
2
mice was evaluated in relation to genetic markers by linkage analysis. We found three novel loci that are involved in the control of
B. pertussis
infection. One locus, designated
B. pertussis susceptibility locus 1
(
Bps-1
), was identified on chromosome 12. The presence of the C57BL/10 genome on this locus instead of the C3H genome significantly decreased the number of
B. pertussis
bacteria in the lung.
Bps-1
has a dominant-positive effect on the clearance of
B. pertussis
from the lung. The function of most genes in this region is unknown. Two other loci,
Bps-2
and
Bps-3
, showed genetic interaction and are located on chromosomes 5 and 11. We aim to identify the gene(s) in these regions which modify susceptibility to
B. pertussis
.
Role of Sulfated Glycans in Adherence of the Microsporidian
Encephalitozoon intestinalis
to Host Cells In Vitro
Authors: Hayman J. Russell , Southern Timothy R. , Nash Theodore E.
Published: January 2005

Microsporidia are obligate intracellular opportunistic protists that infect a wide variety of animals, including humans, via environmentally resistant spores. Infection requires that spores be in close proximity to host cells so that the hollow polar tube can pierce the cell membrane and inject the spore contents into the cell cytoplasm. Like other eukaryotic microbes, microsporidia may use specific mechanisms for adherence in order to achieve target cell proximity and increase the likelihood of successful infection. Our data show that
Encephalitozoon intestinalis
exploits sulfated glycans such as the cell surface glycosaminoglycans (GAGs) in selection of and attachment to host cells. When exogenous sulfated glycans are used as inhibitors in spore adherence assays,
E. intestinalis
spore adherence is reduced by as much as 88%. However, there is no inhibition when nonsulfated glycans are used, suggesting that
E. intestinalis
spores utilize sulfated host cell glycans in adherence. These studies were confirmed by exposure of host cells to xylopyranoside, which limits host cell surface GAGs, and sodium chlorate, which decreases surface sulfation. Spore adherence studies with CHO mutant cell lines that are deficient in either surface GAGs or surface heparan sulfate also confirmed the necessity of sulfated glycans. Furthermore, when spore adherence is inhibited, host cell infection is reduced, indicating a direct association between spore adherence and infectivity. These data show that
E. intestinalis
specifically adheres to target cells by way of sulfated host cell surface GAGs and that this mechanism serves to enhance infectivity.
Deletion of theSSK1Response Regulator Gene inCandida albicansContributes to Enhanced Killing by Human Polymorphonuclear Neutrophils
Authors: Du Chen , Calderone Richard , Richert John , Li Dongmei
Published: January 2005

The isolation and partial functional characterization of the two-component response regulatorSSK1gene ofCandida albicanswas previously reported. Compared to wild-type (CAF2-1) and gene-reconstituted (SSK23) strains, thessk1null strain (SSK21) was avirulent in a murine model of hematogenously disseminated candidiasis and less able to adhere to human esophageal cells. More recent data indicate that SSK21 is sensitive to 4 to 8 mM H2O2in vitro than CAF2-1 and SSK23. Furthermore, microarray studies indicate that the regulation of two classes of genes, those encoding cell wall functions and stress adaptation, are altered in thessk1mutant. In the present study, the susceptibility of strains CAF2-1, SSK21, and SSK23 to killing by human polymorphonuclear neutrophils (PMNs) was assessed. Results are also described for a newly constructedssk1mutant (SSK24) in which theURA3gene is integrated into its native locus. Our results indicate that killing of SSK21 and SSK24 was significantly greater than that of CAF2-1 and SSK23 (P< 0.01). In order to determine why Ssk1p at least partially protects the organism against the killing activity of human PMNs, we compared the signal transduction activity and the inflammatory response gene profiles of PMNs infected with either the wild type or thessk1mutant. Phosphorylation of the mitogen-activated protein kinases p42/44 and p38 from neutrophils infected with either CAF2-1 (wild type) or SSK21 (ssk1/ssk1) was similar, while expression and phosphorylation of the JNK mitogen-activated protein kinase was not observed following infection with either strain. On the other hand, we observed an upregulation of seven inflammatory response genes in PMNs infected with the SSK21 mutant only, while an increase in interleukin-10 expression was measured in PMNs infected with either strain. Downregulation of interleukin-2 was observed in PMNs infected with either strain. Verification of the transcriptional profiling was obtained by reverse transcription-PCR for three of the genes that were upregulated in neutrophils infected with thessk1mutant. Also, the sensitivity of strain SSK21 to human defensin-1, one of the nonoxidative, antimicrobial peptides of PMNs, was greater than that of CAF2-1, demonstrating that nonoxidative killing in PMNs may contribute to the increased susceptibility of thessk1mutant. Our results indicate that the Ssk1p response regulator protein may provide at least partial adaptive functions for the survival ofC. albicansfollowing its encounter with human neutrophils.
Large-Scale Screen Highlights the Importance of Capsule for Virulence in the Zoonotic PathogenStreptococcus iniae
Authors: Miller Jesse D. , Neely Melody N.
Published: January 2005

Zoonotic pathogens have the unique ability to cross the species barrier, causing disease in both humans and specific animal hosts.Streptococcus iniaeis a zoonotic pathogen of both fish and humans, and the clinical presentations ofS. iniaeinfections in fish and humans are very similar to those caused by various human-specific streptococcal pathogens. Virulence mechanisms required for infection by this pathogen of either host have yet to be determined. Using the previously reported zebrafish infectious disease model, we performed a large-scale screening to determine genes required for systemic infection. Screening 1,128 signature-tagged transposon mutants through the zebrafish model allowed identification of 41 potential mutants that were unable to survive within the host environment. Greater than 50% of the mutants that could be identified through homology searches were highly homologous to genes found in other human-specific streptococcal pathogens, while 32% were found to have no homology to any sequences found in the databases, suggesting as yet unknown gram-positive bacterial virulence factors. A large percentage of the insertions were found to be located in several putative capsule synthesis genes, an important virulence component for other systemic pathogens. Density gradient assays demonstrated that several of these putative capsule mutants have dissimilar buoyant densities, suggesting different levels of capsule synthesis. Putative capsule mutants were also less resistant to phagocytosis in whole-blood assays than wild-typeS. iniae. Our initial large-scale characterization ofS. iniaevirulence highlights the importance of the capsule for successful infection.
Inverse Associations of Human Leukocyte Antigen and Malaria Parasite Types in Two West African Populations
Authors: Young Karen , Frodsham Angela , Doumbo Ogobara K. , Gupta Sunetra , Dolo Amagana , Hu Jiang Ting , Robson Kathryn J. H. , Crisanti Andrea , Hill Adrian V. S. , Gilbert Sarah C.
Published: January 2005

Differences in allelic associations between populations continue to cause difficulties in the mapping and identification of susceptibility genes for complex polygenic diseases. Although well recognized, the basis of such interpopulation differences is poorly understood. We present an example of an inverse allelic association of an immune response genotype to an infectious disease in two neighboring West African populations. In this case, both the key environmental contributor, i.e., the malaria parasite, and a major biological mechanism are well defined. We show that this surprising result fits well with the predictions of a mathematical model describing the population genetics and dynamics of this interaction.
Management of ankle sprains: a randomised controlled trial of the treatment of inversion injuries using an elastic support bandage or an Aircast ankle brace
Authors: Boyce S H , Quigley M A , Campbell S
Published: January 2005

Background:Lateral ligament ankle sprains are the single most common sports injury.

Objective:To determine the functional outcome of the ankle joint after a moderate or severe inversion injury, comparing standard treatment with an elastic support bandage against an Aircast ankle brace.

Design:Prospective, randomised controlled trial.

Setting:Two accident and emergency departments.

Method:Fifty patients presenting consecutively were randomised into two equal groups: one group was treated with an elastic support bandage and the other with an Aircast ankle brace. All patients were given a standardised advice sheet referring to rest, ice, compression, and elevation. Patients were reviewed after 48–72 hours, 10 days, and one month.

Primary outcome measure:Ankle joint function assessed at 10 days and one month using the modified Karlsson scoring method (maximum score 90).

Secondary outcome measure:The difference in ankle girth (swelling) and pain score at 10 days.

Results:Seventeen patients in the elastic support bandage group (six defaulted, two excluded) and 18 patients in the Aircast ankle brace group (six defaulted, one excluded) completed the study. There were no significant differences between the two groups at presentation in terms of age (mean 35.3 and 32.6 years respectively), sex, dominant leg, left or right ankle injured, previous injury, time to presentation (median three and four hours respectively), difference in ankle girth (mean 14.5 and 14.3 mm respectively), and pain scores (mean 6.2 and 5.8 respectively). The Karlsson score was significantly higher in the Aircast ankle cast group than in the elastic bandage group at 10 days (mean 50v35, p  =  0.028, 95% confidence interval (CI) 1.7 to 27.7) and one month (mean 68v55, p  =  0.029, 95% CI 1.4 to 24.8) (Student’sttest). There was no difference between the groups in the secondary outcome measures (swelling, p  =  0.09; pain, p  =  0.07). When hierarchical multiple regression analysis was used to correct for possible baseline confounding factors, the Aircast ankle brace group was significantly associated with higher Karlsson scores at 10 days (p  =  0.009) and one month (p  =  0.024).

Conclusion:The use of an Aircast ankle brace for the treatment of lateral ligament ankle sprains produces a significant improvement in ankle joint function at both 10 days and one month compared with standard management with an elastic support bandage.