bluuebunny/crossref_metadata_2025 huggingface dataset:
Variation in timing of bud-burst ofUlmus minorclones from different geographical origins
Authors: Ghelardini Luisa , Falusi Mauro , Santini Alberto
Published: September 2006

The vegetative bud-burst phenology of field elm (Ulmus minor Mill.) clones originating from a large geographical range within the species natural area was studied at three European sites over a 5-year period in ex situ collections constituted for the conservation of elm genetic resources. At all the sites and in all the years of study, the date of bud burst and the required thermal time to bud burst were directly related to latitude and altitude of origin of the clones. Nevertheless, the differences among origins were reduced with increasing the chilling duration, suggesting that the clones from more northern latitudes and higher altitudes required longer chilling for dormancy release. Analyses of variance performed on selected groups of clones from different latitudinal origins showed that the order of bud burst was stable among years and that the thermal time requirements decreased in all the groups with increasing chilling, with significant differences among groups; southern clones satisfied their chilling requirements after a shorter chilling duration.
Genetic diversity of poplar leaf rust populations in the north-central United States
Authors: Chen W , Harrington T C
Published: September 2006

Uredinia of poplar leaf rust, Melampsora medusae Thüm f.sp. deltoides, appeared in late July 1998, June 1999, and August 2000 in a cottonwood (Populus deltoides Bartr.) stand in Ames, Iowa. Seedlings of the alternate host (eastern larch, Larix laricina (Du Roi) K. Koch) set out at the site in spring 2000 formed aecia 3 months before uredinia appeared. Using three PCR-based microsatellite markers, the aecial population was genetically diverse and in Hardy–Weinberg equilibrium, typical of a population that had gone through sexual reproduction. Uredinia populations in 1998–2000 had lower levels of gene diversities (from 0.58 to 0.71) and were not in Hardy–Weinberg equilibrium. Of nine populations in Minnesota, Iowa, and Missouri during the early stage of the 1999 epidemic, the two populations with the highest gene diversity, the highest level of heterozygosity, and the greatest number of unique genotypes were within the natural geographic range of larch. However, the southernmost population in Missouri was also in Hardy–Weinberg equilibrium. Epidemics started sooner in Iowa than in Minnesota, which contradicts the hypothesis that epidemics begin in northern regions where the alternate hosts naturally overlap. Epidemics appeared to commence independently in the various locations, perhaps focused around areas where ornamental larch is in proximity to P. deltoides.
QTL analysis of growth and wood chemical content traits in an interspecific backcross family of white poplar (Populus tomentosa×P. bolleana) ×P. tomentosa
Authors: Zhang Deqiang , Zhang Zhiyi , Yang Kai
Published: September 2006

The genetic control of tree growth and wood chemical content traits was studied using interspecific backcross progeny between clone TB01 (Populus tomentosa × Populus bolleana) and clone LM50 (P. tomentosa). In total, 247 and 146 amplified fragment length polymorphism (AFLP) markers from genetic maps previously constructed for backcross parents LM50 and TB01 were used for the analyses of quantitative trait loci (QTL). These markers were distributed among 19 linkage groups and covered 3265 and 1992 cM in the backcross parents, respectively. A total of 32 putative QTLs, associated with five growth and chemical content traits, sylleptic branch number, sylleptic branch angle, stem volume, wood cellulose content, and wood lignin content, were detected. These QTLs were dispersed among 16 linkage groups in parent LM50 and 10 groups in parent TB01. The phenotypic variance explained by each QTL ranged from 7.0% to 14.6%. QTLs controlling sylleptic branch number and stem volume were colocalized in two linkage groups, TLG6 and TLG8, respectively. The favorable alleles were mostly from P. tomentosa, which is phenotypically superior to P. bolleana for sylleptic branch angle, stem volume, and wood chemical content traits. The favorable alleles for sylleptic branch number were from P.bolleana. These AFLP markers that were associated with the QTLs have potential use in P. tomentosa breeding programs.
Hydrogeological influences on forest community type along forest–peatland complexes in coastal British Columbia
Authors: Emili Lisa A , Price Jonathan S , Fitzgerald Daniel F
Published: September 2006

The prospect of harvesting forest–peatland systems in the coastal western hemlock forest region of British Columbia has created the need for an understanding of the interrelationship between topography, groundwater flow, and site productivity. Detailed topographic mapping including the use of ground-penetrating radar coupled with point measurements of specific yield, bulk density, saturated hydraulic conductivity, and groundwater level were used to determine the characteristics of groundwater flow along forest–peatland complexes. A topographic index was then used to characterize the spatial distribution of groundwater flow and site conditions (as represented by water table depth and organic horizon thickness) influencing forest community type. Forest community type mean index decreased from open peatland to upland forest. Areas with high slope indices had thicker organic horizons (0.7–1.8 m), water tables closer to the surface (0–0.2 m), and higher soil moisture contents (46–92%). These conditions affect successional dynamics and favour the invasion of hydrophytic species such as Sphagnum mosses. Areas with low slope index values were associated with shallower organic horizons (<0.4 m), deeper water table (0.3 to >1.6 m), and drier soil moisture (35–76%), favouring more prolific timber growth.
STUDY OF ELECTROMAGNETIC FIELD SIMULATION USING TWO KINDS OF FINITE ELEMENT METHODS
Authors: LIU NIAN , XIE CHI , BO LI , JIANG KE-XUN
Published: September 2006

The simulation comparison research of two types of high-order triangular finite element methods for the numerical simulation of two-dimensional nonlinear electromagnetic fields is presented in this paper. The comparative study has been done in many ways, such as the accuracy of computation, the computation time and computer storage requirement. The comparative results obtained in this paper are very useful to calculation methods used in electromagnetic fields in modern physics fields.
MAGNETIC FIELD RESPONSES OF HARMONIC SUSCEPTIBILITIES OF HIGH TC SUPERCONDUCTOR YBCO
Authors: OZOGUL OZER
Published: September 2006

The temperature dependence of the harmonic susceptibilities has been measured on a melt textured YBCO for different amplitudes of the AC magnetic field with combination of a DC magnetic field. The model calculations have been performed on the basis of a model which incorporates the effects of the collective creep concept in a critical-state equation. The temperature dependencies of the activation energy and the critical current density chosen as U = [U0(1 - (T/Tc)4)/μ)][(Jc/J)μ - 1] and Jc = J0[(1 + (T/Tc)2)]-1/2[(1 - (T/Tc)2)]5/2 respectively have been used to explain the DC bias field and temperature dependencies of the harmonic susceptibilities. The predictions of the model for fundamental and higher harmonic susceptibilities were consistent with the experimental data.
EFFECT OF PARTICLE SIZE ON THE PROPERTIES OF Mg–Mn FERRITES
Authors: SINGH M.
Published: September 2006

Processing of ferrites has gained tremendous importance in recent times in order to meet high performance demands on ferrites in keeping with the fast emerging technologies. The main focus of research in the 21st century is towards the formation of smaller magnetic particles. In normal ceramic methods we cannot control particle size and porosity, whereas in precursor methods we can control both. In the present study we have synthesized Mg 0.9 Mn 0.1 Fe 2 O 4 ferrites by the normal ceramic method and the citrate precursor method. By the citrate method we have simultaneously reduced the particle size and sintering temperature as compared to the normal ceramic method. By the citrate method, direct current (DC) resistivity is increased by two orders of magnitude, and electrical as well as magnetic losses are reduced as compared to the normal ceramic method. The initial permeability is reduced in both citrate method as compared to the normal ceramic methods. However, with sintering temperature the initial permeability increases. The dielectric constant is reduced by the citrate method as compared to normal ceramic methods. These observations are explained on the basis of various mechanisms and models.
SOFT X-RAY ABSORPTION SPECTROSCOPY OF THE MgB2 BORON K EDGE IN AN MgB2/Mg COMPOSITE
Authors: FISCHER D. A. , MOODENBAUGH A. R. , LI QIANG , GU G. D. , ZHU YIMEI , DAVENPORT J. W. , WELCH D. O. , SU HAIBIN
Published: September 2006

Soft X-ray absorption spectroscopy (XAS), using fluorescence yield, was used to study the boron K near edge in MgB 2 superconductor. The sample consists of MgB 2 crystallites randomly oriented in a magnesium matrix. Abrasion of the sample surface in vacuum provides a surface relatively free of boron-containing impurities. The intrinsic boron K near edge spectrum of the sample at a temperature of 295 K is identified. This spectrum is then compared in detail with a spectrum calculated using the full potential linearized augmented plane wave method. Features predicted by the theory appear near the expected energies, with qualitative agreement regarding shape and intensity.
HAMILTONIAN FORMALISM AND SPACE–TIME SYMMETRIES IN GENERIC DSR MODELS
Authors: MIGNEMI S.
Published: September 2006

We study the structure of the classical phase space of generic models of deformed special relativity, which gives rise to a definition of velocity consistent with the deformed Lorentz symmetry. In this way we can also determine the laws of transformation of space–time coordinates.
NON-SELF-SIMILARITY IN COSMOLOGICAL SCALING LAWS
Authors: DEL POPOLO A.
Published: September 2006

Some years ago, the resolved temperature profile of X-ray clusters, observed by ASCA, led us to conclude that there is a break (bent) in the M–T relation. The quoted bent was interpreted in different ways: in some papers it was connected to the effect of the formation redshift,20 or to cooling processes29 and heating.5 In the present paper, we re-derive the mass-temperature relation and its time evolution for clusters of galaxies in different cosmologies by means of a model based on the merging-halo formalism of Lacey and Cole (Mon. Not. R. Astron. Soc.262, 627 (1993)) modified to take account of angular momentum acquisition by protostructures, of an external pressure term in the virial theorem, and a non-zero cosmological constant. In contrast to previous results, we show that the non-similarity in the M–T relation can be naturally explained in the quoted model that takes into account the amount of the angular momentum of a proto-structure. This result is in disagreement with the widely accepted idea that the above non-similarity is due to non-gravitating processes such as those of heating/cooling. The main result of the present paper is that the self-similarity of the M–T relation is broken at the low mas end (T ≤ 3 keV ), and that the evolution of the M–T relation, for a given M vir , is more modest both in flat and open universes in comparison to previous estimate found in literature, even more modest than that found by Voit (Astrophys. J.543, 113 (2000)). Moreover, the time evolution is more rapid in models with L = 0 than in models in which the angular momentum acquisition by protostructures is taken into account (L ≠ 0).
RADIATION OF THE INNER HORIZON OF THE REISSNER–NORDSTRÖM BLACK HOLE
Authors: PELTOLA ARI , MÄKELÄ JARMO
Published: September 2006

Despite over thirty years of research in black hole thermodynamics, our understanding of the possible role played by the inner horizons of Reissner–Nordström and Kerr–Newman black holes in black hole thermodynamics is still somewhat incomplete. There are derivations which imply that the temperature of the inner horizon is negative and it is not quite clear what this means. Motivated by this problem, we perform a detailed analysis of the radiation emitted by the inner horizon of the Reissner–Nordström black hole. As a result, we find that in a maximally extended Reissner–Nordström space–time virtual particle–antiparticle pairs are created at the inner horizon of the Reissner–Nordström black hole such that real particles with positive energy and temperature are emitted towards the singularity from the inner horizon and, as a consequence, antiparticles with negative energy are radiated away from the singularity through the inner horizon. We show that these antiparticles will be emitted from the white hole horizon in the maximally extended Reissner–Nordström space–time, at least when the hole is near extremality. The energy spectrum of the antiparticles leads to a positive temperature for the white hole horizon. In other words, our analysis predicts that in addition to the radition effects of black hole horizons, the white hole horizon also radiates. The black hole radiation is caused by the quantum effects at the outer horizon, whereas the white hole radiation is caused by the quantum effects at the inner horizon of the Reissner–Nordström black hole.
A TRACKER SOLUTION FOR A HOLOGRAPHIC DARK ENERGY MODEL
Authors: LI HUI , GUO ZONG-KUAN , ZHANG YUAN-ZHONG
Published: September 2006

We investigate a kind of holographic dark energy model with a future event horizon being IR cutoff and the equation of state -1. In this model, the constraint on the equation of state automatically specifies an interaction between matter and dark energy. With this interaction included, an accelerating expansion is obtained as well as the transition from deceleration to acceleration. It is found that there exists a stable tracker solution for the numerical parameter d > 1, and d smaller than one will not lead to a physical solution. This model provides another possible phenomenological framework to alleviate the cosmological coincidence problem in the context of holographic dark energy. Some properties of the evolution which are relevant to cosmological parameters are also discussed.
QUASINORMAL MODES FOR ARBITRARY SPINS IN THE SCHWARZSCHILD BACKGROUND
Authors: KHRIPLOVICH I. B. , Yu. RUBAN G.
Published: September 2006

The leading term of the asymptotic of quasinormal modes in the Schwarzschild background, ωn = -in/2, is obtained in two straightforward, analytical ways for arbitrary spins. One of these approaches requires almost no calculations. As simply we demonstrate that for any odd integer spin, described by the Teukolsky equation, the first correction to the leading term vanishes. Then, this correction for half-integer spins is obtained in a slightly more intricate way. Finally, we derive analytically the general expression for the first correction for all spins, described by the Teukolsky equation.
QUASINORMAL FREQUENCIES OF THE RARITA–SCHWINGER FIELD IN REISSNER–NORDSTRÖM-ANTI-DE SITTER SPACE–TIME
Authors: ZHANG YUN , JING JILIANG
Published: September 2006

We investigate the quasinormal modes (QNMs) of Rarita–Schwinger field perturbations of a Reissner–Nordström black hole in an asymptotically anti-de Sitter space–time. We find that both the real and imaginary parts of the fundamental quasinormal frequencies of the large black hole are the linear functions of the Hawking temperature. The slope of the lines increases as the charge increases, but the imaginary parts decrease as the charge increases. We show that the quasinormal frequencies become evenly spaced for high overtone number n and the spacings are related to the charge and mass of the black hole. We also find that the real parts of the QNMs increase and the imaginary parts decrease as the angular quantum number increases.
ROLE OF ADDITIVE GAUSSIAN NOISE IN SUPPRESSING CHAOS BY WEAK HARMONIC EXCITATIONS
Authors: CHACÓN R. , MARTÍNEZ P. J.
Published: September 2006

The effect of additive Gaussian noise on the chaos-suppression scenario of a broad and important family of dissipative nonautonomous systems subjected to chaos-suppressing excitations is investigated by means of Melnikov's method. The analysis indicates that the optimal suppressory initial phase differences between the chaos-inducing and chaos suppressing forcing terms remain the same as in the purely deterministic case, while the ranges of suppressory initial phase differences and amplitudes narrow as noise strenght is increased from zero. Computer simulations of a two-well Duffing oscillator confirm the theoretical predictions.
Phosphatonins and the Regulation of Phosphate Homeostasis
Authors: Berndt Theresa , Kumar Rajiv
Published: September 2006

Inorganic phosphate (Pi) is required for energy metabolism, nucleic acid synthesis, bone mineralization, and cell signaling. The activity of cell-surface sodium-phosphate (Na+-Pi) cotransporters mediates the uptake of Pi from the extracellular environment. Na+-Pi cotransporters and organ-specific Pi absorptive processes are regulated by peptide and sterol hormones, such as parathyroid hormone (PTH) and 1α,25-dihydroxyvitamin D (1α,25(OH)2D3), which interact in a coordinated fashion to regulate Pi homeostasis. Recently, several phosphaturic peptides such as fibroblast growth factor-23 (FGF-23), secreted frizzled related protein-4 (sFRP-4), matrix extracellular phosphoglycoprotein, and fibroblast growth factor-7 have been demonstrated to play a pathogenic role in several hypophosphatemic disorders. By inhibiting Na+-Pi transporters in renal epithelial cells, these proteins increase renal Pi excretion, resulting in hypophosphatemia. FGF-23 and sFRP-4 inhibit 25-hydroxyvitamin D 1α-hydroxylase activity, reducing 1α,25(OH)2D3 synthesis and thus intestinal Pi absorption. This review examines the role of these factors in Pi homeostasis in health and disease.
Contribution of nitric oxide to cutaneous microvascular dilation in individuals with type 2 diabetes mellitus
Authors: Sokolnicki Lynn A. , Roberts Shelly K. , Wilkins Bradley W. , Basu Ananda , Charkoudian Nisha
Published: September 2006

Microvascular pathophysiology associated with type 2 diabetes mellitus (T2DM) contributes to several aspects of the morbidity associated with the disease. We quantified the contribution of nitric oxide (NO) to the cutaneous vasodilator response to nonpainful local warming in subjects with T2DM (average duration of diabetes mellitus 7 ± 1 yr) and in age-matched control subjects. We measured skin blood flow in conjunction with intradermal microdialysis of NG-nitro-l-arginine methyl ester (l-NAME; NO synthase inhibitor) or vehicle during 35 min of local warming to 42°C. Microdialysis of sodium nitroprusside (SNP) was used for assessment of maximum cutaneous vascular conductance (CVC). Resting CVC was higher in T2DM subjects at vehicle sites (T2DM: 19 ± 2 vs. control: 11 ± 3%maxCVC; P < 0.05); this difference was abolished by l-NAME (T2DM: 10 ± 1 vs. control: 8 ± 1%maxCVC; P > 0.05). The relative contribution of NO to the vasodilator response to local warming was not different between groups (T2DM: 46 ± 4 vs. control: 44 ± 6%maxCVC; P > 0.05). However, absolute CVC during local warming was ∼25% lower in T2DM subjects (T2DM: 1.79 ± 0.15 AU/mmHg; controls: 2.42 ± 0.20 AU/mmHg; P < 0.01), and absolute CVC during SNP was ∼20% lower (T2DM: 1.91 ± 0.12 vs. control: 2.38 ± 0.13 AU/mmHg; P < 0.01). We conclude that the relative contribution of NO to vasodilation during local warming is similar between subjects with T2DM and control subjects, although T2DM was associated with a lower absolute maximum vasodilation.
Novel in vitro system for functional assessment of oxytocin action
Authors: Devost Dominic , Zingg Hans H.
Published: September 2006

One of the classical biological actions mediated by the posterior pituitary hormone oxytocin (OT) is contraction of the uterus at parturition. Moreover, premature activation of the OT system is thought to contribute to preterm labor, a major clinical problem in obstetrical practice. However, the molecular mechanisms linking activation of the OT receptor (OTR) to myometrial contractions are not fully understood. Here, we describe an in vitro system that should serve as a useful tool to study this question at a cellular level. The system consists of a collagen lattice contraction assay and two different human myometrial cell lines: a cell clone from a telomerase-immortalized human myometrial cell population (hTERT-C3) as well as a cell line derived from a primary culture of human myometrial cells (M11). Using this approach, we observed that 1 nM OT promoted an almost maximal effect on cell contraction in both cell lines tested. Furthermore, this dose-dependent, OT-induced contraction was antagonized by the specific OTR antagonist d(CH2)5[Tyr(Me)2,Thr4,Tyr-NH29]OVT as well as the clinically used antagonist atosiban. This cell line-based contraction assay enables the application of molecular tools aimed at suppressing or overexpressing specific genes. It is also amenable to high-throughput testing approaches. Therefore, this system represents a powerful and improved experimental model that should facilitate the study of the molecular signal transduction pathways involved in the uterotonic actions of OT.
TRPV4 as a flow sensor in flow-dependent K+ secretion from the cortical collecting duct
Authors: Taniguchi Junichi , Tsuruoka Shuichi , Mizuno Atsuko , Sato Jun-ichi , Fujimura Akio , Suzuki Makoto
Published: September 2006

The transient receptor vanilloid-4 (TRPV4) is a mechanosensitive, swell-activated cation channel that is abundant in the renal distal tubules. Immunolocalization studies, however, present conflicting data as to whether TRPV4 is expressed along the apical and/or basolateral membranes. To disclose the role of TRPV4 in flow-dependent K+ secretion in distal tubules in vivo, urinary K+ excretion and net transports of K+ and Na+ in the cortical collecting duct (CCD) were measured with an in vitro microperfusion technique in TRPV4 +/+ and TRPV4 −/− mice. Both net K+ secretion and Na+ reabsorption were flow dependently increased in the CCDs isolated from TRPV4 +/+mice, which were significantly enhanced by a luminal application of 50 μM 4α-phorbol-12,13-didecanoate (4αPDD), an agonist of TRPV4. No flow dependence of net K+ and Na+ transports or effects of 4αPDD on CCDs were observed in TRPV4 −/− mice. A basolateral application of 4αPDD had little effect on these ion transports in the TRPV4 +/+ CCDs, while the luminal application did. Urinary K+ excretion was significantly smaller in TRPV4 −/− than in TRPV4 +/+ mice when urine production was stimulated by a venous application of furosemide. These observations suggested an essential role of the TRPV4 channels in the luminal or basolateral membrane as flow sensors in the mechanism underlying the flow-dependent K+ secretion in mouse CCDs.
Ex-oxalate magnesium oxide, a strain-free nanopowder studied with diffraction line profile analysis
Authors: Audebrand Nathalie , Bourgel Christine , Louër Daniel
Published: September 2006

An analysis of the microstructure of nanocrystalline magnesium oxide produced by thermal decomposition of magnesium oxalate, in the temperature range 500 °C–1200 °C, is described. The study is based on diffraction line broadening analysis carried out with the integral breadth (Langford) and Fourier methods, combined with the pattern decomposition technique. Additionally, the whole pattern matching method is also applied. No marked line broadening anisotropy is observed in the patterns. It is shown that the nanopowders are characterized by minimal strain and that crystallites have an average spherical shape. Volume-weighted and area-weighted apparent sizes are in the ranges 98–480 Å and 72–282 Å, respectively, within the temperature range considered. The results obtained from line broadening analysis are compared to those observed with scanning electron microscopy and surface area measurements. A satisfactory agreement is found between sizes derived from the different techniques.
A simple method of monitoring the size, location, and inhomogeneity of the incident X-ray beam in a powder diffractometer
Authors: Kishima Noriaki , Matsuzaki Takuya
Published: September 2006

A simple method is described that uses a KCl powder sample and a digital camera to monitor the size, location, and inhomogeneity of the incident X-ray beam in a powder diffractometer. The method has been used successfully to detect problems in the sample holder and the divergence slit of a powder diffractometer used in our laboratory.
Efficacy and Safety of ab interno Excimer Laser Trabeculotomy in Primary Open-Angle Glaucoma: Two Years of Follow-Up
Authors: Babighian Silvia , Rapizzi Emilio , Galan Alessandro
Published: September 2006

Ab interno trabeculotomy was performed using the recently developed XeCl excimer laser in 21 eyes of 21 patients with primary open-angle glaucoma refractory to medical therapy. The patients were followed at the Eye Department of S. Antonio Hospital in Padova, for an average of 25.3 ± 1.3 months. Intraocular pressure (IOP), visual acuity and ocular complications were evaluated. The laser procedure was quick and relatively easy, with minimal manipulation of tissues; complications were clinically insignificant. At the last follow-up, a marked IOP-lowering effect compared to baseline was observed (from 24.8 ± 2.0 to 16.9 ± 2.1 mm Hg; –31.8%, p < 0.0001). Nineteen patients (90.5%) had an IOP lowering of 20% or more; however, 8 of these eyes (38.1%) required additional IOP-lowering medical therapy. The procedure failed in 2 cases (9.5%) despite additional therapy. In conclusion ab interno excimer laser trabeculotomy seems effective to decrease IOP, serves to reduce the number of antiglaucoma medications and is relatively safe, proving to be a promising therapeutic option in glaucoma surgery.
Corneal Curvature after Penetrating Keratoplasty before and after Suture Removal: A Comparison between Keratoconus and Fuchs’ Dystrophy
Authors: Seitz Berthold , Langenbucher Achim , Szentmary Nora , Naumann Gottfried O.H.
Published: September 2006

Purpose: To assess the differences concerning corneal curvature and visual acuity after penetrating keratoplasty (PKP) comparing keratoconus (KC) and Fuchs’ dystrophy (FUCHS). Methods: Inclusion criteria for this prospective, comparative, interventional study were: (1) one surgeon, (2) central round nonmechanical excimer laser PKP without previous surgery, (3) FUCHS (n = 35) or KC (n = 52), (4) standardized graft size (7.5–8.0 mm) and technique, 16-bite double running cross-stitch suture. In 69% of FUCHS, a triple procedure was performed. The main outcome measures were: keratometric astigmatism, surface regularity index, surface asymmetry index, keratometric central corneal power and best-corrected visual acuity before (1.2 ± 0.4 years) and after suture removal (1.8 ± 0.6 years). Results: Astigmatism did not differ significantly between KC and FUCHS (p > 0.1) before (3.3 dpt vs. 3.5 dpt median) and after suture removal (2.5 dpt vs. 3.0 dpt). Surface regularity index and surface asymmetry index were significantly higher in FUCHS than in KC (p < 0.001) at both time stages. Central power was significantly greater in KC than in FUCHS (p < 0.001) with sutures in place. Due to a significant steepening in FUCHS and flattening in KC, this difference was no longer present after suture removal. Visual acuity in KC exceeded that in FUCHS before (0.68 vs. 0.60) and even more after suture removal (0.86 vs. 0.60; p < 0.001). Conclusions: In KC, keratometric astigmatism is not higher than in FUCHS after PKP. After suture removal, graft topography in KC and FUCHS may be expected to regularize and the excessive corneal flattening in FUCHS to normalize in the mid-term.
Effect of High Glucose Concentration on Corneal Collagen Biosynthesis
Authors: Robert L. , Menasche M. , Robert A.M. , Renard G.
Published: September 2006

The effect of high glucose concentration (3 g/l) on bovine corneal total protein and collagen biosynthesis was studied, using 3H-proline incorporation in explant cultures with protein and collagen determinations. The high glucose concentration increased the incorporation of 3H-proline in total corneal proteins as well as in collagens. The specific radioactivity of stromal collagens was strongly increased in these conditions. Mannitol was used to control the osmotic effect of the high glucose concentration, both at 1 and 3 g/l concentrations. Mannitol did not increase the incorporation of 3H-proline in total proteins or collagens, but on the contrary decreased it. The high glucose concentration decreased the excretion of neosynthesized proteins and collagens in the culture medium, but did not affect the total protein or collagen content of the corneas. The strong increase in the specific radioactivity of corneal collagens in the presence of 3 g/l glucose suggests an increased turnover of collagens in diabetic corneas. The increased biosynthesis of collagens together with their decreased elimination in the extracellular compartment can create the conditions for the formation and accumulation of advanced glycation endproducts by the Maillard reaction. This can induce and stimulate the liquefaction of the vitreous body leading to sight-threatening disorders such as diabetic retinopathy, retinal detachment, glaucoma, cataract formation and age-related macular degeneration.
Pain Relief after Pterygium Surgery with Viscous Lidocaine
Authors: Öksüz H. , Tamer C.
Published: September 2006

Purpose:The aim of the current study is to investigate the efficacy of lidocaine 2% gel for the control of pain experienced after pterygium surgery. Methods: We conducted a prospective, randomized clinical trial on 45 eyes of 45 patients who underwent pterygium surgery. The patients were randomized into 2 groups. Group 1 was provided with topical 2% lidocaine gel and group 2 with artificial tear gel. The primary outcome of interest was the pain experienced at the 4th, 7th and 10th postoperative hours. Corneal reepithelization was evaluated by slitlamp biomicroscopy. Pain was determined using a 10-point linear visual analogue scale. No systemic analgesic or topical nonsteroidal anti-inflammatory drop was administered. Results: The groups had similar demographic data. The mean pain scores of the study and the control groups according to the visual analogue scale were: 4.13 ± 1.86 and 6.50 ± 1.47 (p = 0.001) at the 4th postoperative hour, 4.00 ± 1.16 and 4.00 ± 1.16 (p = 0.001) at the 7th , and 2.39 ± 0.89 and 3.63 ± 1.00 (p = 0.001) at the 10th postoperative hour, respectively. The mean area of the corneal epithelial defect in the lidocaine gel group was 4.78 ± 1.04 mm2 and 4.68 ± 0.89 in the artificial tear gel group (p = 0.42). The mean corneal reepithelization time was 37.56 ± 10.42 h in the lidocaine gel group and 34.36 ± 10.00 h in the artificial tear gel group (p = 0.26). There were no side effects related to the drugs observed in either of the 2 treatment groups. Conclusion: We conclude that topical lidocaine gel is an effective and safe anesthetic agent for the control of pain experienced shortly after pterygium surgery.
Pharmacokinetic and Toxicity Investigations of a New Intraocular Lens with a Dexamethasone Drug Delivery System: A Pilot Study
Authors: Siqueira Rubens C. , Ribeiro Filho Elias , Fialho Sílvia L. , Lucena Levy R. , Maia Filho Alfredo , Haddad Antônio , Jorge Rodrigo , Scott Ingrid U. , da Silva Cunha Armando
Published: September 2006

Aim: To investigate the short-term safety and pharmacokinetic behavior of a new intraocular lens containing a dexamethasone drug delivery system (IOL-DDS) in rabbit eyes. Methods: A modified polymethylmethacrylate IOL containing a biodegradable dexamethasone DDS was implanted into the posterior chamber of the right eyes of 9 New Zealand white rabbits. Serial slitlamp and indirect ophthalmoscopic examinations (including grading of intraocular inflammation) were performed. After 3, 6 and 9 days, the rabbits were euthanized and the globes were removed for histological examination and for determination of dexamethasone levels in the aqueous humor and in the vitreous. Analysis of dexamethasone concentrations was performed by ELISA. Results: Therapeutic concentrations of dexamethasone were detectable in the aqueous and vitreous of the study eyes throughout the 9-day period in all tested animals. The mean aqueous dexamethasone concentration (ng/ml, ±SD) was 1,015.42 (±43.05), 970.11 (±32.47) and 757.58 (±30.19) and the mean vitreous concentration (ng/ml, ±SD) was 399.82 (±38.05), 287.38 (±34.47) and 268.15 (±32.00) at 3, 6 and 9 days after the surgical procedure, respectively. No corneal or retinal histological changes were observed during the study period. Conclusion: The IOL-DDS is effective in delivering therapeutic concentrations of dexamethasone to the aqueous and vitreous, without acute damage to the cornea and retina. Further controlled studies in the same animal model are under way to determine the potential value of this lens in the prevention and treatment of inflammation following cataract surgery.
Elevated Plasma Brain Natriuretic Peptide Level in Cardiac Sarcoidosis Patients with Preserved Ejection Fraction
Authors: Date Taro , Shinozaki Toshihide , Yamakawa Midori , Taniguchi Ikuo , Suda Akira , Hara Hiromichi , Yamane Teiichi , Komukai Kimiaki , Sugimoto Ken-ichi , Mochizuki Seibu
Published: September 2006

We sought to examine whether the plasma brain natriuretic peptide (BNP) levels are elevated in the cardiac sarcoidosis patients even with a preserved ejection fraction. The data from the patients with either pulmonary sarcoidosis without any evidence of cardiac involvement (n = 13) or cardiac sarcoidosis (n = 8) with a preserved ejection fraction (>55%) on echocardiography were analyzed. The median plasma BNP levels were significantly higher in the patients with cardiac sarcoidosis than in those with pulmonary sarcoidosis (101.5 ± 65.1 vs. 15.6 ± 10.5 pg/ml, p < 0.001), although there was no significant difference in left ventricular ejection fraction between the two populations. The plasma BNP level is thus considered to be a useful non-invasive biomarker for identifying a possible cardiac involvement in the sarcoidosis patients with a preserved ejection fraction.
Activated mTOR and PKR Kinases in Lymphocytes Correlate with Memory and Cognitive Decline in Alzheimer’s Disease
Authors: Paccalin Marc , Pain-Barc Stéphanie , Pluchon Claudette , Paul Chloé , Besson Marie-Noelle , Carret-Rebillat Anne-Sophie , Rioux-Bilan Agnès , Gil Roger , Hugon Jacques
Published: September 2006

Background: The control of translation, involving the kinases mTOR (mammalian target of rapamycin) and PKR (double-stranded RNA-dependent protein kinase), modulates cell survival and death and is altered in the brains of patients with Alzheimer’s disease (AD). In AD increased susceptibility of lymphocytes to apoptosis has been reported. Methods: We investigated the level of the kinases mTOR and PKR and the eukaryotic initiation factor 2α (eIF2α) in lymphocytes of patients with AD in comparison with controls. In AD patients we also looked for a correlation between activated proteins and cognitive and memory tests. Results: We report significant alterations of the levels of these kinases and eIF2α in lymphocytes of AD patients that were also significantly correlated with cognitive and memory test scores. Conclusion: These results suggest that the levels of mTOR, PKR and eIF2α in lymphocytes could follow the cognitive decline in AD.
Cognitive-Impairment-Free Life Expectancy for Canadian Seniors
Authors: Dubois Marie-France , Hébert Réjean
Published: September 2006

Background/Aims: While cognitive impairment (CI) and dementia are among the most common morbid conditions in later life, life expectancies free from CI or dementia have been the object of much less investigation than life expectancy based on measures of physical functioning. Methods: We estimated sex-specific CI-free life expectancy in Canada for people aged 65 and older using data from a nationwide, multicenter Canadian study on the epidemiology of dementia. Results: The absolute number of years with CI remains virtually constant with increasing age. Whatever the current age, senior men can expect to live 2.5–3 years of their remaining life with some form of CI and about 1.5 years of those with dementia. For women, these figures rise to 3–4 years with CI, of which 2–2.5 years are spent with dementia. Conclusion: Surviving to an older age does not result in a longer average absolute period of CI. This period is associated with a significant reduction in quality of life, the use of home and institutional services, as well as psychological and physical distress for formal and informal caregivers. Results are compared to findings reported in other countries.
Transfection of Human Hepatocyte Growth Factor Gene Ameliorates Secondary Lymphedema via Promotion of Lymphangiogenesis
Authors: Saito Yukihiro , Nakagami Hironori , Morishita Ryuichi , Takami Yoichi , Kikuchi Yasushi , Hayashi Hiroki , Nishikawa Tomoyuki , Tamai Katsuto , Azuma Nobuyoshi , Sasajima Tadahiro , Kaneda Yasufumi
Published: September 2006

Background—

Lymphedema is a disorder of the lymphatic vascular system characterized by impaired lymphatic return and swelling of the extremities. Treatment for this disabling condition remains limited and largely ineffective. The goal of the present study was to investigate the therapeutic efficacy of hepatocyte growth factor (HGF) in animal models of lymphedema.

Methods and Results—

Immunofluorescent analysis demonstrated that canine primary lymphatic endothelial cells (cLECs) were positive for lymphatic-specific markers (vascular endothelial growth factor receptor-3, LYVE-1, podoplanin, and Prox1) and the HGF receptor c-Met. Treating cLECs with human recombinant HGF resulted in a dose-dependent increase in cell growth and migration and increased activity of extracellular signal-regulated kinase and Akt. In human LECs, c-Met also was expressed, and treatment with HGF increased cell growth and migration in a dose-dependent manner. Transfection of human HGF plasmid DNA in cLECs also increased the c-
fos
promoter activity. Furthermore, weekly HGF gene transfer in a rat tail lymphedema model by disruption of lymphatic vessels resulted in a decrease in lymphedema thickness. Although expression of the endothelial cell marker PECAM-1 was increased in both HGF- and vascular endothelial growth factor 165–injected groups, expression of LEC markers (LYVE-1 and Prox1) was increased only in the HGF-injected group.

Conclusions—

These data demonstrate that expression of HGF via plasmid transfer improves lymphedema via promotion of lymphangiogenesis. Further studies to determine the clinical utility of this approach would be of benefit to patients with lymphedema.
How Sudden Is Sudden Cardiac Death?
Authors: Müller Dirk , Agrawal Rahul , Arntz Hans-Richard
Published: September 2006

Background—

Out-of-hospital sudden cardiac death (SCD) is a frequent cause of death. Survival rates remain low despite increasing efforts in medical care. Better understanding of the circumstances of SCD could be helpful in developing preventive measures and facilitating proper reactions to such a pending event.

Methods and Results—

Information on cases of out-of-hospital SCD was collected in the Berlin, Germany, emergency medical system via a questionnaire. Bystander interviews were performed by the emergency physician on scene immediately after declaration of death or return of circulation. Of 5831 rescue missions, 406 involved patients with presumed cardiac arrest. Sixty-six percent had a known cardiac disease. In 72%, the arrest occurred at home, and in 67%, it occurred in the presence of an eyewitness. Information on symptoms immediately preceding the arrest was available in 80% (n=323) of all 406 patients and in 274 of those with witnessed arrest. Symptoms were identical in the 2 groups. Typical angina was present for a median of 120 minutes in 25% of the 274 patients with witnessed arrest and in 33% with a symptom duration of less than 1 hour.

Conclusions—

SCD occurs most often at home in the presence of relatives and after a longer period of typical warning symptoms. Although the much-hailed use of public access defibrillation is supported by several studies, the present results raise the question of whether educational measures and targeted educational programs tailored for patients at risk and their relatives should have a higher priority.
Cardiac S100A1 Protein Levels Determine Contractile Performance and Propensity Toward Heart Failure After Myocardial Infarction
Authors: Most Patrick , Seifert Hanna , Gao Erhe , Funakoshi Hajime , Völkers Mirko , Heierhorst Jörg , Remppis Andrew , Pleger Sven T. , DeGeorge Brent R. , Eckhart Andrea D. , Feldman Arthur M. , Koch Walter J.
Published: September 2006

Background—

Diminished cardiac S100A1 protein levels are characteristic of ischemic and dilated human cardiomyopathy. Because S100A1 has recently been identified as a Ca
2+
-dependent inotropic factor in the heart, this study sought to explore the pathophysiological relevance of S100A1 levels in development and progression of postischemic heart failure (HF).

Methods and Results—

S100A1-transgenic (STG) and S100A1-knockout (SKO) mice were subjected to myocardial infarction (MI) by surgical left anterior descending coronary artery ligation, and survival, cardiac function, and remodeling were compared with nontransgenic littermate control (NLC) and wild-type (WT) animals up to 4 weeks. Although MI size was similar in all groups, infarcted S100A1-deficient hearts (SKO-MI) responded with acute contractile decompensation and accelerated transition to HF, rapid onset of cardiac remodeling with augmented apoptosis, and excessive mortality. NLC/WT-MI mice, displaying a progressive decrease in cardiac S100A1 expression, showed a later onset of cardiac remodeling and progression to HF. Infarcted S100A1-overexpressing hearts (STG-MI), however, showed preserved global contractile performance, abrogated apoptosis, and prevention from cardiac hypertrophy and HF with superior survival compared with NLC/WT-MI and SKO-MI. Both Gq-protein–dependent signaling and protein kinase C activation resulted in decreased cardiac S100A1 mRNA and protein levels, whereas Gs-protein–related signaling exerted opposite effects on cardiac S100A1 abundance. Mechanistically, sarcoplasmic reticulum Ca
2+
cycling and β-adrenergic signaling were severely impaired in SKO-MI myocardium but preserved in STG-MI.

Conclusions—

Our novel proof-of-concept study provides evidence that downregulation of S100A1 protein critically contributes to contractile dysfunction of the diseased heart, which is potentially responsible for driving the progressive downhill clinical course of patients with HF.
Identification of the Oxidized Low-Density Lipoprotein Scavenger Receptor CD36 in Plasma
Authors: Handberg Aase , Levin Klaus , Højlund Kurt , Beck-Nielsen Henning
Published: September 2006

Background—

Macrophage CD36 scavenges oxidized low-density lipoprotein, leading to foam cell formation, and appears to be a key proatherogenic molecule. Increased expression of CD36 has been attributed to hyperglycemia and to defective macrophage insulin signaling in insulin resistance. Premature atherosclerosis is the major cause of morbidity and mortality in type 2 diabetes. Here, we report the identification of a soluble form of CD36 (sCD36) in plasma and hypothesize that sCD36 would be elevated in patients with type 2 diabetes and insulin resistance.

Methods and Results—

sCD36 in plasma was demonstrated by immunopurification and Western blotting. We established ELISA assays to determine sCD36 in plasma and measured sCD36 in obese type 2 diabetic patients, obese nondiabetic relatives, and obese and lean control subjects. sCD36 was markedly elevated in type 2 diabetic patients compared with both lean (5-fold) and obese (2- to 3-fold) control subjects. There was a strong, inverse correlation between sCD36 and insulin-stimulated glucose disposal and a direct correlation with fasting plasma glucose, fasting insulin, and body mass index.

Conclusions—

Our study demonstrates sCD36 in plasma for the first time. sCD36 is highly related to risk factors of accelerated atherosclerosis in type 2 diabetes such as insulin resistance and glycemic control, and we propose that sCD36 might represent a marker of the metabolic syndrome and a potential surrogate marker of atherosclerosis.
Transcriptional Genomics Associates FOX Transcription Factors With Human Heart Failure
Authors: Hannenhalli Sridhar , Putt Mary E. , Gilmore Joan M. , Wang Junwen , Parmacek Michael S. , Epstein Jonathan A. , Morrisey Edward E. , Margulies Kenneth B. , Cappola Thomas P.
Published: September 2006

Background—

Specific transcription factors (TFs) modulate cardiac gene expression in murine models of heart failure, but their relevance in human subjects remains untested. We developed and applied a computational approach called transcriptional genomics to test the hypothesis that a discrete set of cardiac TFs is associated with human heart failure.

Methods and Results—

RNA isolates from failing (n=196) and nonfailing (n=16) human hearts were hybridized with Affymetrix HU133A arrays, and differentially expressed heart failure genes were determined. TF binding sites overrepresented in the −5-kb promoter sequences of these heart failure genes were then determined with the use of public genome sequence databases. Binding sites for TFs identified in murine heart failure models (MEF2, NKX, NF-AT, and GATA) were significantly overrepresented in promoters of human heart failure genes (
P
<0.002; false discovery rate 2% to 4%). In addition, binding sites for FOX TFs showed substantial overrepresentation in both advanced human and early murine heart failure (
P
<0.002 and false discovery rate <4% for each). A role for FOX TFs was supported further by expression of FOXC1, C2, P1, P4, and O1A in failing human cardiac myocytes at levels similar to established hypertrophic TFs and by abundant FOXP1 protein in failing human cardiac myocyte nuclei.

Conclusions—

Our results provide the first evidence that specific TFs identified in murine models (MEF2, NKX, NFAT, and GATA) are associated with human heart failure. Moreover, these data implicate specific members of the FOX family of TFs (FOXC1, C2, P1, P4, and O1A) not previously suggested in heart failure pathogenesis. These findings provide a crucial link between animal models and human disease and suggest a specific role for FOX signaling in modulating the hypertrophic response of the heart to stress in humans.