bluuebunny/crossref_metadata_2025_split huggingface dataset:
T cell exosomes induce cholesterol accumulation in human monocytes via phosphatidylserine receptor
Authors: Zakharova Liudmila , Svetlova Maria , Fomina Alla F. 
Published: February 2007

AbstractActivated T lymphocytes release vesicles, termed exosomes, enriched in cholesterol and exposing phosphatidylserine (PS) at their outer membrane leaflet. Although CD4+ activated T lymphocytes infiltrate an atherosclerotic plaque, the effects of T cell exosomes on the atheroma‐associated cells are not known. We report here that exosomes isolated from the supernatants of activated human CD4+ T cells enhance cholesterol accumulation in cultured human monocytes and THP‐1 cells. Lipid droplets found in the cytosol of exosome‐treated monocytes contained both cholesterol ester and free cholesterol. Anti‐phosphatidylserine receptor antibodies recognized surface protein on the monocyte plasma membrane and prevented exosome‐induced cholesterol accumulation, indicating that exosome internalization is mediated via endogenous phosphatidylserine receptor. The production of proinflammatory cytokine TNF‐α enhanced in parallel with monocyte cholesterol accumulation. Our data strongly indicate that exosomes released by activated T cells may represent a powerful, previously unknown, atherogenic factor. J. Cell. Physiol. 212: 174–181, 2007. © 2007 Wiley‐Liss, Inc.
Actinobacillus actinomycetemcomitans lipopolysaccharide regulates matrix metalloproteinase, tissue inhibitors of matrix metalloproteinase, and plasminogen activator production by human gingival fibroblasts: A potential role in connective tissue destruction
Authors: Bodet Charles , Andrian Elisoa , Tanabe Shin‐ichi , Grenier Daniel 
Published: February 2007

AbstractFibroblasts, a major constituent of gingival connective tissue, can produce immunoregulatory cytokines and proteolytic enzymes that may contribute to tissue destruction. In this study, we evaluated the production of matrix metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs), and plasminogen activators by gingival fibroblasts stimulated with lipopolysaccharides (LPS) produced by periodontopathogens, including Actinobacillus actinomycetemcomitans. In addition, changes in the expression and phosphorylation state of fibroblast intracellular signaling proteins induced by A. actinomycetemcomitans LPS were characterized using antibody microarrays. We showed that A. actinomycetemcomitans LPS induced the production of a 50 kDa plasminogen activator, MMP‐2 and, to a lesser extent, MMP‐3 by fibroblasts. The stimulation of fibroblasts with A. actinomycetemcomitans LPS also resulted in the overproduction of TIMP‐1, but had no effect on the production of TIMP‐2. Comparable responses were also obtained with Porphyromonas gingivalis and Fusobacterium nucleatum subsp. nucleatum LPS. The results of the microarray analyses showed that A. actinomycetemcomitans LPS induced changes in the phosphorylation state and expression of gingival fibroblast intracellular signaling proteins. More specifically, they suggested that A. actinomycetemcomitans LPS may induce both Jun N‐terminus protein‐serine kinases (JNK) and mitogen‐activated protein‐serine kinase p38 alpha (p38α MAPK) pathway activation, leading to increased activator protein‐1 (AP‐1) and nuclear factor kappa‐B (NFκB) activities, which in turn can stimulate MMP‐2, MMP‐3, TIMP‐1, and urokinase‐type plasminogen activator (uPA) expression. This may contribute to periodontal connective tissue destruction. J. Cell. Physiol. 212: 189–194, 2007. © 2007 Wiley‐Liss, Inc.
Oscillating fluid flow activation of gap junction hemichannels induces atp release from MLO‐Y4 osteocytes
Authors: Genetos Damian C. , Kephart Curtis J. , Zhang Yue , Yellowley Clare E. , Donahue Henry J. 
Published: February 2007

AbstractMechanical loads are required for optimal bone mass. One mechanism whereby mechanical loads are transduced into localized cellular signals is strain‐induced fluid flow through lacunae and canaliculi of bone. Gap junctions (GJs) between osteocytes and osteoblasts provides a mechanism whereby flow‐induced signals are detected by osteocytes and transduced to osteoblasts. We have demonstrated the importance of GJ and gap junctional intercellular communication (GJIC) in intracellular calcium and prostaglandin E2 (PGE2) increases in response to flow. Unapposed connexons, or hemichannels, are themselves functional and may constitute a novel mechanotransduction mechanism. Using MC3T3‐E1 osteoblasts and MLO‐Y4 osteocytes, we examined the time course and mechanism of hemichannel activation in response to fluid flow, the composition of the hemichannels, and the role of hemichannels in flow‐induced ATP release. We demonstrate that fluid flow activates hemichannels in MLO‐Y4, but not MC3T3‐E1, through a mechanism involving protein kinase C, which induces ATP and PGE2 release.. J. Cell. Physiol. 212: 207–214, 2007. © 2007 Wiley‐Liss, Inc.
Tripartite Ramsey numbers for paths
Authors: Gyárfás András , Ruszinkó Miklós , Sárközy Gábor N. , Szemerédi Endre 
Published: February 2007

AbstractIn this article, we study the tripartite Ramsey numbers of paths. We show that in any two‐coloring of the edges of the complete tripartite graph K(n, n, n) there is a monochromatic path of length (1 − o(1))2n. Since R(P2n+1,P2n+1)=3n, this means that the length of the longest monochromatic path is about the same when two‐colorings of K3n and K(n, n, n) are considered. © 2007 Wiley Periodicals, Inc. J Graph Theory 55: 164–174, 2007
Non‐invasive probing of pharmaceutical capsules using transmission Raman spectroscopy
Authors: Matousek P. , Parker A. W. 
Published: February 2007

AbstractWe demonstrate how transmission Raman geometry can be effectively used for non‐invasive probing of the content of pharmaceutical capsules. This approach is particularly beneficial in situations where the conventional Raman backscattering method is hampered or fails because of excessive surface Raman or fluorescence signals emanating from the capsule shell material, which pollute the much weaker subsurface Raman signals with undesired noise. It is demonstrated that such interfering signals can be effectively suppressed by the transmission geometry. The ability to avoid surface fluorescence and Raman signals in conjunction with the superior, bulk‐probing properties of the transmission Raman geometry provides an analytical technique ideally suited for fast on‐line process control monitoring applications in pharmaceutical industry where rapid, chemically specific bulk analysis is required. Copyright © 2007 John Wiley & Sons, Ltd.
Single‐molecule detection of thionine on aggregated gold nanoparticles by surface enhanced Raman scattering
Authors: Ruan Chuanmin , Wang Wei , Gu Baohua 
Published: February 2007

AbstractWe report observations of single‐molecule detection of thionine and its dynamic interactions on aggregated gold nanoparticle clusters using surface enhanced Raman scattering (SERS). Spectral intensities were found to be independent of the size of Au nanoparticles studied (from 17 to 80 nm) at thionine concentration below 10−12 M or at single‐molecule concentration levels. Raman line separations and, in particular, spectral fluctuations and blinking were also observed, suggesting temporal changes in single molecular motion and/or arrangements of thionine on Au nanoparticle surfaces. In contrast, by using dispersed Au nanoparticles, only ensemble SERS spectra could be observed at relatively high concentrations (> 10−8 M thionine), and spectral intensities varied with the size of Au nanoparticles. Copyright © 2007 John Wiley & Sons, Ltd.
Laser Micro Sintering – a Versatile Instrument for the Generation of Microparts
Authors: Regenfuß Peter , Ebert Robby , Exner Horst 
Published: February 2007

AbstractMiniaturization is one of the main imperatives in high‐tech development and therefore a persistent challenge for mechanical engineering. Recently a freeform technique – Laser Micro Sintering – has been developed by which micro parts with an overall resolution of 30 μm can be produced from powder materials. The technique is a generative freeform fabrication method based on selective laser sintering; it can produce hollows and undercuts and does not afford shape‐specific tools. Functional micro bodies can be generated from metals and ceramics.
Femtosecond time‐resolved spectroscopy on biological photoreceptor chromophores
Authors: Schmitt M. , Dietzek B. , Hermann G. , Popp J. 
Published: February 2007

AbstractThis paper reviews our results on femtosecond time‐resolved spectroscopy (transient absorption, transient‐grating and fluorescence spectroscopy) to study the photophysics and photochemistry of the two very important biological photoreceptor chromophores phycocyanobilin (PCB) and protochlorophyllide a (PChla). The compound PCB serves as a model chromophore for the photoreceptor phytochrome. By means of transient‐grating spectroscopy where the excitation wavelength was varied ove
r the spectral region of the S0→ S1‐absorption the ultrafast processes were studied upon excitation with varying excess energy delivered to the system. On the basis of the results obtained, both the rate of the photoreaction in PCB and the rate of the decay of different excited‐state species via different decay channels depend on the excitation wavelength. Furthermore, transient absorption experiments illuminating the excited‐state dynamics of PChla, a porphyrin‐like compound and, as substrate of
the NADPH/protochlorophyllide oxidoreductase (POR), a precursor of the chlorophyll biosynthesis are presented. In addition to pump‐energy‐dependent measurements performed with PChla dissolved in methanol, the excited‐state dynamics of PChla was interrogated in different solvents that were chosen to mimic different environmental conditions. In addition to the femtosecond time‐resolved absorption experiments the picosecond time‐resolved fluorescence of the system was studied. The transient absorption and tim
e‐resolved fluorescence data allow suggesting a detailed model for the excited‐state relaxation of PChla describing the excited‐state processes in terms of a branching of the initially excited state population into a reactive and nonreactive path. Thus, the excited‐state potential energy surface exhibits two distinct S1 and Sx minima separated from the Franck–Condon region along two most likely orthogonal reaction coordinates. Finally, the model derived is related to models suggested to acco
unt for the reduction of PChla to chlorophyllide a within the natural enzymatic environment of POR.
Gender‐related neuronal and smooth muscle damage of guinea pig isolated urinary bladder from anoxia‐glucopenia and reperfusion injury and its relationship to glycogen content
Authors: Pessina Federica , Valeri Aurora , Dragoni Stefania , Valoti Massimo , Sgaragli Giampietro 
Published: February 2007

AbstractAimsTo investigate the effects of anoxia and glucopenia (A‐G) on both male and female guinea pig urinary bladder.MethodsIn whole bladders superfused with oxygenated Krebs' solution, intrinsic nerves underwent electrical field stimulation (EFS) and smooth muscle stimulated with carbachol, ATP, and high potassium. The effect of 1, 2, or 3 hr A‐G on the contractile response and the ensuing recovery in Krebs' solution, was monitored. Glycogen content in male and female urinary bladders was also measured.ResultsUnder different stimuli male urinary bladder proved to contract more efficiently than female organ. After 1 hr A‐G the EFS response of male urinary bladder was virtually abolished and returned to 60% of control response in the recovery phase; in female bladder the EFS responses fully recovered during the reperfusion phase. Full recovery of the response to carbachol, ATP, and high potassium stimulations was observed in both genders. A‐G had to be extended to 2 hr to cause smooth muscle impairment (higher in male than in female) and a neuronal impairment in female urinary bladders. When 2‐deoxyglucose (2‐DG), an inhibitor of glycolysis, was added during 1 hr A‐G, both neuronal and smooth muscle damages were significantly enhanced in male, as well as, though to a lesser extent, in female bladder. A significantly higher glycogen content was observed in female as compared to male bladders, which was inversely related with the duration of exposure to A‐G.ConclusionsThe higher resistance of female urinary bladder to A‐G/reperfusion, can be partly ascribed to the higher glycogen content. Neurourol. Urodynam. 26:416–423, 2007. © 2007 Wiley‐Liss, Inc.
A remark on model reduction for singular systems
Authors: Liu Chao , Zhang Qingling , Duan Xiaodong 
Published: February 2007

AbstractThis note comments on the results of the following two papers, ‘model reduction problem for singular systemsviacovariance approximation’ (Optim. Contr. Appl. Meth.2004;25:263–278) and ‘A remark on model reduction for singular systemsviacovariance approximation’ (Optim. Contr. Appl. Meth.2006;27:293–298), which all studied the model reduction for singular systems. In this note the model reduction for singular systems is investigated based on particle swarm optimization and the error criterionviacovariance approximation. The reduced model for singular systems obtained in this note is stable and impulse controllable. Furthermore, compared with the above two papers, the reduced‐order system approximates the original system better. Finally, an example is provided to show the effectiveness and improvement of the proposed algorithm. Copyright © 2007 John Wiley & Sons, Ltd.
Transient and dynamic control of a variable speed wind turbine with synchronous generator
Authors: Jauch Clemens 
Published: February 2007

AbstractIn this article, a controller for dynamic and transient control of a variable speed wind turbine with a full‐scale converter‐connected high‐speed synchronous generator is presented. First, the phenomenon of drive train oscillations in wind turbines with full‐scale converter‐connected generators is discussed. Based on this discussion, a controller is presented that dampens these oscillations without impacting on the power that the wind turbine injects into the grid. Since wind turbines are increasingly demanded to take over power system stabilizing and control tasks, the presented wind turbine design is further enhanced to support the grid in transient grid events. A controller is designed that allows the wind turbine to ride through transient grid faults. Since such faults often cause power system oscillations, another controller is added that enables the turbine to participate in the damping of such oscillations. It is concluded that the controllers presented keep the wind turbine stable under any operating conditions, and that they are capable of adding substantial damping to the power system. Copyright © 2007 John Wiley & Sons, Ltd.
Housing for the aging population
Authors: Demirkan Halime 
Published: February 2007

Abstract
Based on the concept of ‘aging in place,’ design of houses in the past years are explored. Design features in the built environment become barriers for aging people with functional limitations. Initially, houses were designed according to the required needs of the user with the physical limitations. Later, adaptable house design was introduced that allows the house to meet the specific needs of the user, while maintaining the appearance of the house until more obvious accessibility features are needed. Today, ‘design for all’ is recognised as a tool for ensuring physical accessibility for aging people. The holistic perspective embedded in the universal design theory should be systematically and consistently developed during the design process.
Influence of thyroid hormones on maturation of rat cerebellar astrocytes
Authors: Manzano Jimena , Bernal Juan , Morte Beatriz 
Published: February 2007

AbstractThyroid hormone influences brain maturation through interaction with nuclear receptors and regulation of gene expression. Their role on astrocyte maturation remains unclear. We have analyzed the role of thyroid hormone in rat cerebellar astrocyte maturation by comparing the sequential patterns of intermediate filament expression in normal and hypothyroid animals. During normal development astroglial cells sequentially express nestin, vimentin, and glial fibrillary acidic protein. Differentiated astrocytes appeared in the superior medullary vellum by postnatal day 2 and reached the white mater and internal granular layer by postnatal day 4. Intermediate filament marker expression was transiently lost from postnatal days 6 to 8 in anterior lobes, without an increased apoptosis. Vimentin expression was replaced by glial fibrillary acidic protein between postnatal days 10 and 32. The differentiated astrocytes were evenly distributed throughout the cerebellar slices, including the internal granular layer. Differences between normal and hypothyroid rats were observed starting from postnatal day 4, with lack of differentiated astrocytes in the internal granular layer. The transient decrease of astrocyte markers immunoreactivity in the anterior lobe did not take place in hypothyroid rats. The vimentin–glial fibrillary acidic protein transition was delayed and most differentiated astrocytes remained confined to the white matter. The results indicate that thyroid hormone deficiency induces a delay and a partial arrest of astrocyte differentiation. Astrocytes express thyroid hormone receptor α and β subtypes suggesting that astrocytes are direct target cells of thyroid hormones.
Reduction of erythroid progenitors in protein–energy malnutrition
Authors: Borelli Primavera , Blatt Solange , Pereira Juliana , Beutler de Maurino Beatriz , Tsujita Maristela , Cristina de Souza Ana , Guilherme Xavier José , Ambrósio Fock Ricardo 
Published: February 2007

Protein–energy malnutrition is a syndrome in which anaemia together with multivitamin and mineral deficiency may be present. The pathophysiological mechanisms involved have not, however, yet been completely elucidated. The aim of the present study was to evaluate the pathophysiological processes that occur in this anaemia in animals that were submitted to protein–energy malnutrition, in particular with respect to Fe concentration and the proliferative activity of haemopoietic cells. For this, histological, histochemical, cell culture and immunophenotyping techniques were used. Two-month-old male Swiss mice were submitted to protein–energy malnutrition with a low-protein diet (20 g/kg) compared with control diet (400 g/kg). When the experimental group had attained a 20 % loss of their original body weight, the animals from both groups received, intravenously, 20 IU erythropoietin every other day for 14 d. Malnourished animals showed a decrease in red blood cells, Hb concentration and reticulocytopenia, as well as severe bone marrow and splenic atrophy. The results for serum Fe, total Fe-binding capacity, transferrin and erythropoietin in malnourished animals were no different from those of the control animals. Fe reserves in the spleen, liver and bone marrow were found to be greater in the malnourished animals. The mixed colony-forming unit assays revealed a smaller production of granulocyte–macrophage colony-forming units, erythroid burst-forming units, erythroid colony-forming units and CD45, CD117, CD119 and CD71 expression in the bone marrow and spleen cells of malnourished animals. These findings suggest that, in this protein–energy malnutrition model, anaemia is not caused by Fe deficiency or erythropoietin deficiency, but is a result of ineffective erythropoiesis.
Effects of plant extracts on antioxidant status and oxidant-induced stress in Caco-2 cells
Authors: Aherne S. Aisling , Kerry Joseph P. , O'Brien Nora M. 
Published: February 2007

Experimental evidence suggests that most herbs and spices possess a wide range of biological and pharmacological activities that may protect tissues against O2-induced damage. The objectives of the present study were: first, to determine the effects of plant extracts on the viability, membrane integrity, antioxidant status and DNA integrity of Caco-2 cells and second, to investigate the cytoprotective and genoprotective effects of these plant extracts against oxidative stress in Caco-2 cells. The plant extracts examined were rosemary (Rosmarinus officinalisL.), oregano (Origanum vulgareL.), sage (Salvia officinalisL.) and echinacea (Echinacea purpureaL.). Cell membrane integrity was assessed by the lactate dehydrogenase release assay. Viability was determined by the neutral red uptake assay (NRUA) and the concentration of compound that resulted in 50 % cell death (IC50) was calculated. Antioxidant status of the cells was assessed by measuring GSH content, catalase activity and superoxide dismutase activity. To examine their cytoprotective and genoprotective effects, Caco-2 cells were pre-treated with each plant extract for 24 h followed by exposure to H2O2. DNA damage was assessed by the comet assay and cell injury was determined by the NRUA. Rosemary was the most toxic (IC50123 μg/ml) and echinacea the least toxic (IC501421 μg/ml). Sage was the only plant extract to affect the antioxidant status of the cells by increasing GSH content. Sage, oregano and rosemary protected against H2O2-induced DNA damage (olive tail moment and percentage tail DNA), whereas protection against H2O2-induced cytotoxicity was afforded by sage only.
Breast milk sodium concentration, sodium intake and weight loss in breast-feeding newborn infants
Authors: Manganaro Rosa , Marseglia Lucia , Mamì Carmelo , Palmara Antonella , Paolata Antonina , Loddo Saverio , Gargano Romana , Mondello Maurizio , Gemelli Marina 
Published: February 2007

Elevated breast milk (BM) Na concentration is regarded as responsible for elevated Na intake. To verify the clinical significance of milk Na concentration, we studied the relationship between BM Na+concentration and infants' daily Na+intake, infants' daily BM intake (DBMI) and percentage weight loss (%WL) in healthy newborn infants. All mothers who gave birth to a single healthy infant, between February and March 2004 at the Obstetric Clinic of University of Messina (Italy), were invited to participate if they were willing to attempt to breastfeed exclusively. BM Na+concentration, DBMI, Na+intake and %WL were determined on the third day after delivery. Statistical analysis was performed by Spearman's correlation test, classification and regression trees and the generalised linear model. Of the 270 eligible mothers, 208 participated in the study. The results showed that on the third day postpartum BM Na+concentration was 23·05 (sd1·10) mmol/l, mean DBMI was 202 (sd68·9) g/d, and mean Na+intake was 4·36 (sd0·22) mmol/d and 1·36 (sd0·07) mmol/kg per d. BM Na+concentration was inversely related to infant DBMI, and Na+intake was directly related to infant DBMI and not to BM Na+concentration. %WL was significantly correlated only to DBMI. In conclusion, the present data demonstrate, for the first time, that when lactogenesis is suboptimal, BM Na+concentration is higher, but infants' Na+intake is lower. Finally, the present data probably suggest that for the clinical assessment of breast-feeding, evaluation of milk intake remains the best method.