bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the mononuclear inflammatory cell infiltrate in the normal breast, benign proliferative breast disease, in situ and infiltrating ductal breast carcinomas: preliminary observations
Authors: Hussein M R , Hassan H I
Published: August 2006

Background:Mammary carcinogenesis is a multistep process entailing the transition from normal breast to benign proliferative breast disease (ductal hyperplasia) to ductal carcinoma in situ to infiltrating ductal carcinoma.

Hypothesis:These transitions are associated with changes in the mononuclear inflammatory cell infiltrate.

Materials and methods:A total of 53 mastectomy specimens of normal breast, benign proliferative breast disease, ductal carcinoma in situ and infiltrating ductal carcinoma were evaluated for mononuclear inflammatory cell infiltrate by using immunohistological methods and monoclonal antibodies including CD20, CD68, CD3 and granzyme B, histiocytes, T cells and cytotoxic T cells.

Results:Transitions from normal breast to the subsequent tissue with lesions (normal skinvbenign proliferative breast diseasevductal carcinoma in situvinfiltrating ductal carcinoma) were associated with significantly (p<0.01) increased mean (SD) density of mononuclear inflammatory cell infiltrate at the parenchyma (3.2 (1.0)v26.4 (7.8)v33.6 (7.9)v39.1 (4.7) for CD20+ B cells; 2.8 (1.0)v81.5 (14.0)v84.0 (14.9)v103.7 (3.9) for CD3; 1.3 (2.0)v3.8 (4.0)v12.7 (23)v22.1 (25.0) for CD68+ macrophages; 2.0 (1.0)v58.3 (5.0)v60.0 (10.0)v74.1 (28.0) for granzyme B+ cytotoxic T cells) and at the stroma (0.7 (1.0)v3.0 (5.0)v13.3 (20)v16.7 (30.0) for CD20+ B cells; 1.0 (2.06)v4.0 (2.5)v16.7 (5.0)v21.7 (15) for CD68+ macrophages; 1.4 (0.6)v4.2 (1.2)v46.6 (16.7)v77.0 (5.0) for CD3+ cells and 0 (0)v0.5 (1.0)v0.7 (1.0)v0.7 (1.0) for granzyme B+ cytotoxic T cells).

Conclusions:The increased mononuclear inflammatory cell infiltrate during mammary carcinogenesis may reflect non-specific or specific immunological processes.
Differential distribution of inflammatory cells in large and small airways in smokers
Authors: Battaglia Salvatore , Mauad Thais , van Schadewijk Annemarie M , Vignola Antonia M , Rabe Klaus F , Bellia Vincenzo , Sterk Peter J , Hiemstra Pieter S
Published: August 2006

Background:Smoking induces structural changes in the airways, and is considered a major factor in the development of airflow obstruction in chronic obstructive pulmonary disease. However, differences in inflammatory cell distribution between large airways (LA) and small airways (SA) have not been systematically explored in smokers.

Hypothesis:The content of cells infiltrating the airway wall differs between LA and SA.

Aims:To compare the content of neutrophils, macrophages, lymphocytes and mast cells infiltrating LA and SA in smokers who underwent surgery for lung cancer.

Methods:Lung tissue from 15 smokers was analysed. Inflammatory cells in the lamina propria were identified by immunohistochemical analysis, quantified by digital image analysis and expressed as number of cells per surface area.

Results:The number of neutrophils infiltrating the lamina propria of SA (median 225.3 cells/mm2) was higher than that in the lamina propria of LA (median 60.2 cells/mm2; p<0.001). Similar results were observed for mast cells: 313.3 and 133.7 cells/mm2in the SA and LA, respectively (p<0.001). In contrast, the number of CD4 cells was higher in LA compared with SA (median 217.8 vs 80.5 cells/mm2; p = 0.042).Conclusions:These findings indicate a non-uniform distribution of neutrophils and mast cells throughout the bronchial tree, and suggest that these cells may be involved in the development of smoking-related peripheral lung injury.
Friend leukaemia integration-1 expression in malignant and benign tumours: a multiple tumour tissue microarray analysis using polyclonal antibody
Authors: Mhawech-Fauceglia Paulette , Herrmann Francois R , Bshara Wiam , Odunsi Kunle , Terracciano Luigi , Sauter Guido , Cheney Richard T , Groth Jeff , Penetrante Remedios , Mhawech-Fauceglia Paulette
Published: August 2006

Background:Friend leukaemia integration-1 (FLI-1) antibody is a useful marker for Ewing’s sarcoma/primitive neuroectodermal tumour (EWS/PNET) and vascular tumours. However, it is also expressed in subsets of lymphoblastic lymphoma, Merkel cell carcinoma (MCC) and desmoplastic small round cell tumour (DSRCT).

Aim:To determine expression of FLI-1 in various benign and malignant neoplasms, by immunohistochemical analysis on 4323 tumours using multiple tumour microarrays, as well as on whole sections.

Results:FLI-1 was expressed in 46/62 EWS/PNETs, 2/3 olfactory neuroblastomas, 7/102 small cell carcinomas of the lung, 10/34 MCCs, 1/14 rhabdomyosarcoma, 19/132 non-Hodgkin’s lymphomas, 2/3 DSRCTs, and in 53/74 benign and malignant vascular tumours. In addition, 27/508 squamous cell carcinomas, 19/837 adenocarcinomas, 10/400 urothelial bladder cancers, 1/40 basal cell carcinomas, 3/29 liposarcomas, 1/40 glioblastoma multiforme and 9/29 medullar carcinomas of the breast expressed FLI-1. The sensitivity and specificity of FLI-1 to distinguish EWS/PNET from all types of malignancies were 74.2% and 96.0%, respectively. Finally, the sensitivity and specificity of FLI-1 to distinguish EWS/PNET from other small round cell tumours (SRCTs) were 74.2% and 91.6%, respectively.

Conclusion:This study was the first to show that FLI-1 can be seen in a variety of solid tumours, some of which had never been explored before. This finding should be kept in mind, especially when using FLI-1 as a marker for finding the primary origin of poorly differentiated metastatic tumour. Finally, despite the expression of FLI-1 in numerous malignancies, it is still considered to be highly sensitive and specific in distinguishing EWS/PNET from other tumour types in general and from other SRCTs in particular.
B cell chronic lymphocytic leukaemia/small lymphocytic lymphoma: role of ZAP70 determination on bone marrow biopsy specimens
Authors: Sabattini Elena , Orduz Rocio , Campidelli Cristina , Zinzani Pier Luigi , Callea Vincenzo , Zupo Simona , Cutrona Giovanna , Morabito Fortunato , Ferrarini Manlio , Pileri Stefano
Published: August 2006

Background:The course of chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) partly depends on the mutational status of the variable region of immunoglobulin heavy chain genes (IgVH), which defines two subgroups of tumours: mutated and unmutated. The expression of zeta-associated protein 70 (ZAP70) is significantly associated with the more aggressive unmutated forms.

Aims:To assess the feasibility of the ZAP70 immunohistochemical test on bone-marrow biopsy (BMB) specimens and to compare the results with those of western blotting (WB) and IgVHmutational status assessed on neoplastic cells from peripheral blood.

Methods:26 patients with CLL/SLL detected on BMB and with known IgVHmutational status were selected. ZAP70 was determined by immunohistochemistry (IHC) comparing three antibodies from different sources (Upstate, Cell Signaling, Santa Cruz, California, USA) and two different methods (APAAP and EnVision+). In 23 cases, ZAP70 WB results were also available.

Results:ZAP70 determination on BMB specimens turned out to be easily feasible with routine procedures with reagents from Upstate and Cell Signaling. The results were concordant with those obtained with WB and mutational status analysis in >80% of the cases with both reagents. Three of four discordant cases were mutated/ZAP70 positive, with two staining weakly for ZAP70 on both WB and IHC.

Conclusions:The study confirms the role of ZAP70 as a possible surrogate of mutational status and emphasises its application in routine diagnostics; it discloses a small subset of discordant cases (mutated/ZAP70 weakly positive) that clinically cluster with the more favourable forms.
Plant 5S rDNA has multiple alternative nucleosome positions
Authors: Fulnecek Jaroslav , Matyasek Roman , Kovarik Ales
Published: August 2006

In plants, 5S ribosomal DNA (5S rDNA) is typically found in hundreds of copies of tandemly arranged units. Nucleotide database searches revealed that the majority of 5S genes (>90%) have repeat lengths that are not simple multiples of a plant nucleosomal unit, ranging in plants from 175–185 bp. To get insight into the chromatin structure, we have determined positions of nucleosomes in the Nicotiana sylvestris and Nicotiana tomentosiformis 5S rDNA units with repeat lengths of about 430 and 645 bp, respectively. Mapping experiments carried out on isolated nucleo somal DNA revealed many (>50) micrococcal nuclease cleavage sites in each class of repeats. Permutation analysis and theoretical computer prediction showed multiple DNA bend sites, mostly located in the nontranscribed spacer region. The distance between bend sites, however, did not correspond to the average spacing of nucleosomes in 5S chromatin (~180 bp). These data indicate that 5S rDNA does not have fixed nucleosomal positioning sites and that units can be wrapped in a number of alternative nucleosome frames. Consequently, accessibility of transcription factors to cognate motifs might vary across the tandem array, potentially influencing gene expression.Key words: Nicotiana, 5S rDNA, heterochromatin, tandem repeats, nucleosomes, DNA curvature.
Fledgling production and population trends in Finnish common eiders (Somateria mollissima mollissima) — evidence for density dependence
Authors: Hario Martti , Rintala Jukka
Published: August 2006

We present a 57-year time series of a common eider, Somateria mollissima mollissima (L., 1758), population from one of the core monitoring areas in the Baltic Sea, the Söderskär bird sanctuary, Gulf of Finland. We applied permutation tests to inspect the relationships between breeding parameters and population density. Of the parameters studied, only fledging rate (during a 34-year period) showed a significant negative relationship with population size, indicating density dependence. Furthermore, the fledging rate responded strongly to the population growth rate and to the rate of recruitment. Clutch size and duckling (downy young entering the water) rate did not show negative density dependence. Thus, losses during brood rearing seem to be the regulatory factor. The population decline at Söderskär is similar to those recorded in many other monitoring sites around the southern coast of Finland. Compared with data from more productive sea districts in northwestern Europe (Dutch Wadden Sea and Scottish North Sea), the Finnish fledging rates do not seem excessively bad. There are indications of viral infections playing an increasingly central role in duckling mortality, whereas adult female mortality has not been affected.
THE ASYMPTOTIC ITERATION METHOD FOR DIRAC AND KLEIN–GORDON EQUATIONS WITH A LINEAR SCALAR POTENTIAL
Authors: BARAKAT T.
Published: August 2006

The asymptotic iteration method is used for Dirac and Klein–Gordon equations with a linear scalar potential to obtain the relativistic eigenenergies. A parameter, ς = 0, 1, is introduced in such a way that one can obtain Klein–Gordon bound states from Dirac bound states. It is shown that this method asymptotically gives accurate results for both Dirac and Klein–Gordon equations.
A SYSTEMATIC STUDY ON NONRELATIVISTIC QUARKONIUM INTERACTION
Authors: IKHDAIR SAMEER M. , SEVER RAMAZAN
Published: August 2006

A recently proposed strictly phenomenological static quark–antiquark potential belonging to the generality V(r) = -Ar-α + κrβ + V0 is tested with heavy quarkonia in the context of the shifted large N-expansion method. This nonrelativistic potential model fits the spin-averaged mass spectra of the [Formula: see text], [Formula: see text] and [Formula: see text] quarkonia within a few MeV and also the five experimentally known leptonic decay widths of the [Formula: see text] and [Formula: see text] vector states. Further, we compute the hyperfine splittings of the bottomonium spectrum as well as the fine and hyperfine splittings of the charmonium spectrum. We give predictions for not yet observed Bc splittings. The model is then used to predict the masses of the remaining quarkonia and the leptonic decay widths of the two pseudoscalar [Formula: see text] states. Our results are compared with other models to gauge the reliability of the predictions and point out differences.
SPIN POLARIZABILITY OF THE NUCLEON IN THE EFFECTIVE FIELD THEORY OF HEAVY BARYON
Authors: VIJAYA KUMAR K. B. , MA YONG-LIANG , WU YUE-LIANG
Published: August 2006

We have constructed a heavy baryon effective field theory with photon as an external field in accordance with the symmetry requirements similar to the heavy quark effective field theory. By treating the heavy baryon and antibaryon equally on the same footing in the effective field theory, we have calculated the spin polarizabilities γi, i = 1,…,4 of the nucleon at third order and at fourth-order of the spin-dependent Compton scattering. At leading order (LO), our results agree with the corresponding results of the heavy baryon chiral perturbation theory, at the next-to-leading order (NLO) the results show a large correction to the ones in the heavy baryon chiral perturbation theory due to baryon–antibaryon coupling terms. The low-energy theorem is satisfied both at LO and at NLO. The contributions arising from the heavy baryon–antibaryon vertex were found to be significant and the results of the polarizabilities obtained from our theory is much closer to the experimental data.
QUANTUM MECHANICS IN NONINERTIAL FRAMES WITH A MULTITEMPORAL QUANTIZATION SCHEME II: NONRELATIVISTIC PARTICLES
Authors: ALBA DAVID
Published: August 2006

The nonrelativistic version of the multitemporal quantization scheme of relativistic particles in a family of noninertial frames (see Ref. 1) is defined. At the classical level the description of a family of nonrigid noninertial frames, containing the standard rigidly linear accelerated and rotating ones, is given in the framework of parametrized Galilei theories. Then the multitemporal quantization, in which the gauge variables, describing the noninertial effects, are not quantized but considered as c-number generalized times, is applied to nonrelativistic particles. It is shown that with a suitable ordering there is unitary evolution in all times and that, after the separation of the center-of-mass, it is still possible to identify the inertial bound states. The few existing results of quantization in rigid noninertial frames are recovered as special cases.
THE DIRAC–HESTENES EQUATION FOR SPHERICAL SYMMETRIC POTENTIALS IN THE SPHERICAL AND CARTESIAN GAUGES
Authors: DA ROCHA ROLDÃO , RODRIGUES WALDYR A.
Published: August 2006

In this paper, using the apparatus of the Clifford bundle formalism, we show how straightforwardly solve in Minkowski space–time the Dirac–Hestenes equation — which is an appropriate representative in the Clifford bundle of differential forms of the usual Dirac equation — by separation of variables for the case of a potential having spherical symmetry in the Cartesian and spherical gauges. We show that, contrary to what is expected at a first sight, the solution of the Dirac–Hestenes equation in both gauges has exactly the same mathematical difficulty.
EFFECTS OF PHASE-BREAKING ON LONG-RANGE CHARGE TRANSFER IN DNA: PARTIALLY-COHERENT-TUNNELING MODEL STUDY
Authors: HAN PING , LI XIN-QI , ZHANG HOUYU , HE GUOZHONG , YAN YIJING
Published: August 2006

The mechanism of hole charge transfer in DNA of various lengths and sequences is investigated based on a partially coherent tunneling theory (Zhang et al., J Chem Phys117:4578, 2002), where the effects of phase-breaking in adenine–thymine and guanine–cytosine base pairs are treated on equal foot. This work aims at providing a self-consistent microscopic interpretation for rate experiments on various DNA systems. We will also clarify the condition under which the simple superexchange-mediated-hopping picture is valid, and make some comments on the further development of present theory.
THEORETICAL STUDY ON HYDROLYSIS MECHANISM OF β-PHOSPHOLACTAMS
Authors: YU LINGJUAN , FENG DACHENG , HE MAOXIA , LI RUI , CAI ZHENGTING
Published: August 2006

The neutral hydrolysis mechanisms of a simple β-phospholactam with and without water-assisted reaction have been studied by using quantum chemical method at HF/6-31G**, MP2/6-31G** and B3LYP/6-31G** levels, respectively. The reaction can proceed by two different mechanisms: concerted and stepwise. There are two pathways in stepwise, i.e. pathway a and b, and the energy barriers of them are close. The energy barriers of water-assisted hydrolysis of β-phospholactam are obviously lower than those of no-water-assisted hydrolysis system. The energy barriers of stepwise mechanism are much lower than those of the concerted pathway in both cases. The solvent effects have been considered by means of a polarizable continuum model. The hydrolysis mechanism of β-phospholactam with that of the β-lactam and β-sultam was compared.
THE PECULIAR ELECTRONIC STRUCTURE OF THE DI-METALLOCENE: THE EVIDENCE FOR THE STABILITY AND THE CHARACTER OF METAL–METAL BOND
Authors: WANG HONGMING , YANG CHUANLU , WAN BOSHUN , HAN KE-LI
Published: August 2006

Quantum chemical density functional theory (DFT) calculations using B3LYP and BP86 functionals have been carried out for the di-metallocene complexes. The equilibrium geometries and the bond characters have been reported. The calculations of Cp 2 Zn 2, Cp 2 Cd 2 and Cp 2 Hg 2 demonstrate that the di-metallocene complexes slightly favor D 5 h conformations for the free molecules, where Cp is C 5 H 5. The predicted Cd-Cd distance of 2.723 Å and Hg-Hg distance of 2.826 Å are indicative of substantial Cd-Cd and Hg-Hg bonds. In this work, we have reported DFT MO energy level diagrams for the di-metallocene complexes. The strong interaction between Cp and Zn atoms is mainly due to the π orbital of the Cp and the s and dz2 orbitals of the Zn atom. The metal–metal bonds were studied in detail. The results indicated that there are two δ, one σ and two π interactions between five d orbitals and one σ interaction between s orbitals of the two metal atoms. The electron configurations are pictured as [Formula: see text], and so the bond order is determined by the molecular orbital theory, which is in agreement with the NBO analysis that shows that each metal atom has one covalent bond (to the other metal atom) and a nearly pure s character of metal–metal bonds. At last, from the behavior of the HOMO and HOMO-LUMO gap, the order of the stability of those di-metallocene complexes is Cp 2 Zn 2 > Cp 2 Cd 2 > Cp 2 Hg 2.
MAGNETIC EXCHANGE IN POLYNUCLEAR TRANSITION METAL SYSTEM: AB INITIO CASPT2 AND DENSITY FUNCTIONAL THEORY STUDY ON TRIANGULAR COPPER(II) COMPLEXES
Authors: WEI HAIYAN , CHEN ZHIDA
Published: August 2006

The magnetic exchange interactions for five representative triangular Copper(II) complexes: antiferromagnetic Cu 3( TiPB )6 (1), [ Cu 3(μ3- OH )( aaat )3( H 2 O )3]2+ (2), [ PPN ]2 [ Cu 3(μ3- O )(μ- pz )3 Cl 3] (3), [ PPN ][ Cu 3(μ3- OH )(μ- pz )3 Cl 3] (4) and ferromagnetic [ Cu 3(2- CH 3 C 6 H 4 CO 2)4{( C 2 H 5)2 NC 2 H 4 O }2 H 2 O ] (5) are investigated by using density functional theory combined with broken-symmetry approach (DFT-BS) and ab initio CASPT2 method. Our calculated results show that DFT-BS has remarkable dependence on the particular chosen XC functionals and is system-dependent, while the calculations at CASPT2 level of theory are able to give the accurate magnetic coupling constants. Qualitatively, the two theoretical methods reproduce consistently the linear correlation between the magnetic coupling constants and the departure of the (μ3- O ) oxygen atom from the { Cu3 } plane in the complexes (3) and (4). Spin population analyses reveal that the DFT-BS method overestimates the spin electronic delocalization from the Cu(II) center to the bridging ligands.
An Engineer Becomes Astronomer
Authors: Mills Bernard
Published: August 2006

The early days of radio astronomy in Australia are revisited. The evolution of ideas and the way they led to various instrumental developments and some of the results of these developments are presented. Besides these personal reminiscences, an indication of the political background that sometimes influenced developments is given and, as a coda, an account of a different approach to relativity through the so-called twin paradox.
X-Ray Properties of Black-Hole Binaries
Authors: Remillard Ronald A. , McClintock Jeffrey E.
Published: August 2006

We review the properties and behavior of 20 X-ray binaries that contain a dynamically-confirmed black hole, 17 of which are transient systems. During the past decade, many of these transient sources were observed daily throughout the course of their typically year-long outburst cycles using the large-area timing detector aboard the Rossi X-Ray Timing Explorer. The evolution of these transient sources is complex. Nevertheless, there are behavior patterns common to all of them as we show in a comprehensive comparison of six selected systems. Central to this comparison are three X-ray states of accretion, which are reviewed and defined quantitatively. We discuss phenomena that arise in strong gravitational fields, including relativistically-broadened Fe lines, high-frequency quasi-periodic oscillations (100–450 Hz), and relativistic radio and X-ray jets. Such phenomena show us how a black hole interacts with its environment, thereby complementing the picture of black holes that gravitational wave detectors will provide. We sketch a scenario for the potential impact of timing/spectral studies of accreting black holes on physics and discuss a current frontier topic, namely, the measurement of black hole spin.
Late Quaternary Extinctions: State of the Debate
Authors: Koch Paul L. , Barnosky Anthony D.
Published: August 2006

Between fifty and ten thousand years ago, most large mammals became extinct everywhere except Africa. Slow-breeding animals also were hard hit, regardless of size. This unusual extinction of large and slow-breeding animals provides some of the strongest support for a human contribution to their extinction and is consistent with various human hunting models, but it is difficult to explain by models relying solely on environmental change. It is an oversimplification, however, to say that a wave of hunting-induced extinctions swept continents immediately after first human contact. Results from recent studies suggest that humans precipitated extinction in many parts of the globe through combined direct (hunting) and perhaps indirect (competition, habitat alteration) impacts, but that the timing and geography of extinction might have been different and the worldwide magnitude less, had not climatic change coincided with human impacts in many places.
Endometrial Carcinoma
Authors: Di Cristofano Antonio , Ellenson Lora Hedrick
Published: August 2006

Endometrial carcinoma, a common malignancy of the female genital tract, is composed of a number of tumor types with different light-microscopic features, molecular genetic alterations, and prognoses. In addition, hormonal influences significantly impact growth regulatory pathways and interact with genetic alterations in the pathogenesis of at least some types of endometrial carcinoma. These factors have complicated the analyses of endometrial carcinoma, but over the past decades, awareness of the different types of endometrial carcinoma, in addition to careful clinicopathological studies, molecular analyses, and animal studies of the biological underpinnings of the different tumor types, has increased. We present the current understanding of endometrial carcinoma, from a molecular vantage point, highlighting what are presently thought to be the fundamental pathways involved in the development and progression of the major types of endometrial carcinoma.
Femoral artery neointimal hyperplasia is reduced after wire injury in Ref-1+/− mice
Authors: Basi David L. , Adhikari Neeta , Mariash Ami , Li Qinglu , Kao Esther , Mullegama Sureni V. , Hall Jennifer L.
Published: August 2006

Redox factor-1 (Ref-1) is a multifunctional protein that regulates redox, DNA repair, and the response to cell stress. We previously demonstrated that Ref-1+/− mice exhibit a significantly reduced Ref-1 mRNA and protein levels within the vasculature, which are associated with increased oxidative stress. The goal of this study was to test the hypothesis that partial loss of Ref-1 altered the cellular response to vascular injury. Fourteen days after femoral artery wire injury, we found that vessel intima-to-media ratio was significantly reduced in Ref-1+/− mice compared with that in wild-type mice ( P < 0.01). Bromodeoxyuridine labeling and transferase-mediated dUTP nick-end labeling staining at 14 days did not differ in the Ref-1+/− mice. In vitro studies found no significant changes in either serum-induced proliferation or baseline apoptosis in Ref-1+/− vascular smooth muscle cells. Exposure to Fas ligand; however, did result in increased susceptibility of Ref-1+/− vascular smooth muscle cells to apoptosis ( P < 0.001). Ref-1+/− mice exhibited an increase in circulating baseline levels of IL-10, IL-1α, and VEGF compared with those in wild-type mice but a marked impairment in these pathways in response to injury. In sum, loss of a single allele of Ref-1 is sufficient to reduce intimal lesion formation and to alter circulating cytokine and growth factor expression.
Ontogeny of chicken ductus arteriosus response to oxygen and vasoconstrictors
Authors: Ågren Pia , Cogolludo Angel L. , Kessels Carolina G. A. , Pérez-Vizcaíno Francisco , De Mey Jo G. R. , Blanco Carlos E. , Villamor Eduardo
Published: August 2006

The present study aimed to characterize the contractile reactivity of the chicken ductus arteriosus (DA) from the last stage of prenatal development and throughout the perinatal period. Isolated DA rings from 15-day, noninternally-pipped 19-day, and externally-pipped 21-day embryos were studied using myograph techniques. On embryonic day 15, the chicken DA did not respond to O2(0 to 21%), norepinephrine (NE), or phenylephrine (Phe) but contracted in response to high-K+solution, the inhibitor of voltage-gated channels 4-aminopyridine, U-46619, and endothelin (ET)-1. These responses increased with advancing incubation age. Contractile responses to O2, NE, and Phe were present in the 19- and 21-day embryo. Oxygen-induced contraction was restricted to the pulmonary side of the DA and was augmented by the nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester and the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one and reduced by the peptidic ETAand ETB-receptor antagonist PD-142,893. Transmural electrical stimulation of nerves, the nonselective cyclooxygenase (COX) inhibitor indomethacin, the COX-1 inhibitor valeryl salicylate, the COX-2 inhibitor nimesulide, the inhibitor of ATP-sensitive K+channels glibenclamide, and the inhibitor of Ca2+-activated K+channels tetraethylammonium did not cause contraction of the DA rings at any age. We conclude that transition to ex ovo life is accompanied by dramatic changes in chicken DA reactivity. At 0.7 incubation, excitation-contraction and pharmacomechanical coupling for several contractile agonists are already present, whereas the constrictor effects of O2and cathecolamines appear later in development and are located in the pulmonary side of the DA.
A high-potassium diet reduces infarct size and improves vascular structure in hypertensive rats
Authors: Dorrance Anne M. , Pollock David M. , Romanko Olga P. , Stepp David W.
Published: August 2006

High-potassium diets can improve vascular function, yet the effects of potassium supplementation on ischemic stroke have not been studied. We hypothesized that dietary potassium supplementation would reduce ischemic cerebral infarct size by reversing cerebral artery hypertrophy. Six-week-old male stroke-prone spontaneously hypertensive rats (SHRSP) were fed diets containing 0.79% potassium (LK) or 2.11% potassium (HK) for 6 wk; Wistar-Kyoto (WKY) rats were fed the LK diet. The HK diet did not reduce blood pressure, as measured by telemetry, in the SHRSP. Cerebral ischemia was induced by middle cerebral artery (MCA) occlusion. The resultant infarct was smaller in the HK-SHRSP than in the LK-SHRSP: 55.1 ± 6.3 vs. 71.4 ± 2.4% of the hemisphere infarcted ( P < 0.05). Infarcts were smaller in WKY rats (33.5 ± 4.8%) than in LK-SHRSP or HK-SHRSP. The vessel wall of MCAs from LK-SHRSP was hypertrophied compared with WKY rats; this was reversed in HK-SHRSP. RT-PCR analysis of the cerebral vessels showed that expression of platelet-derived growth factor receptors-α and -β, epidermal growth factor receptor, and collagen I and III was increased in the vessels from LK-SHRSP compared with WKY rats and reduced in HK-SHRSP. These results suggest that potassium supplementation provides neuroprotection in a model of ischemic stroke independent of blood pressure and possibly through changes in vascular structure.
Inflammatory cells do not decrease the ultimate tensile strength of intact tendons in vivo and in vitro: protective role of mechanical loading
Authors: Marsolais David , Duchesne Élise , Côté Claude H. , Frenette Jérôme
Published: August 2006

Although inflammatory cells and their products are involved in various pathological processes, a possible role in tendon dysfunction has never been convincingly confirmed and extensively investigated. The goal of this study was to determine whether or not an acute inflammatory process deprived of mechanical trauma can induce nonspecific damages to intact collagen fibers. To induce leukocyte accumulation, carrageenan was injected into rat Achilles tendons. We first tested the effect of leukocyte recruitment on the concentrations or activities of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases. Second, we analyzed at the biochemical, histological, and biomechanical levels the impact of leukocyte invasion on tendons. Finally, collagen bundles isolated from rat-tail tendons were exposed in vitro to mechanical stress and/or inflammatory cells to determine if mechanical loading could protect tendons from the leukocyte proteolytic activity. Carrageenan-induced leukocyte accumulation was associated with an increased matrix metalloproteinase activity and a decreased content of tissue inhibitors of matrix metalloproteinases. However, hydroxyproline content and load to failure did not change significantly in these tendons. Interestingly, mechanical stress, when applied in vitro, protected collagen bundles from inflammatory cell-induced deterioration. Together, our results suggest that acute inflammation does not induce damages to intact and mechanically stressed collagen fibers. This protective effect would not rely on increased tissue inhibitors of matrix metalloproteinases content but would rather be conferred to the intrinsic resistance of mechanically loaded collagen fibers to proteolytic degradation.
Pulmonary responses to acute ozone exposure in fasted mice: effect of leptin administration
Authors: Johnston Richard A. , Theman Todd A. , Terry Raya D. , Williams Erin S. , Shore Stephanie A.
Published: August 2006

Leptin is a satiety hormone that also has proinflammatory effects, including augmentation of ozone-induced pulmonary inflammation. The purpose of this study was to determine whether reductions in endogenous levels of leptin can attenuate pulmonary responses to ozone. To reduce serum leptin, we fasted mice overnight before ozone exposure. Fasting caused a marked reduction in serum leptin to approximately one-sixth the levels observed in fed mice, and continuous infusion of leptin via Alzet micro-osmotic pumps restored serum leptin to, but not above, fed levels. Ozone exposure (2 ppm for 3 h) caused a significant, ∼40% increase in pulmonary resistance ( P < 0.01) and increased airway responsiveness in fasted but not in fed mice. The increased effect of ozone on pulmonary mechanics and airway responsiveness in fasted mice was not observed when leptin was restored via continuous infusion. Ozone exposure caused pulmonary inflammation, as evident by increases in bronchoalveolar lavage cells, protein, and soluble tumor necrosis factor receptors. There was no effect of fasting status on ozone-induced changes in the bronchoalveolar lavage inflammatory profile, and leptin treatment did not alter these responses. Our results indicate that fasting augments ozone-induced changes in pulmonary mechanics and airway responsiveness in mice. These effects of fasting are the result of declines in serum leptin. The mechanistic basis for this protective effect of leptin in fasted mice remains to be determined but is not related to effects on ozone-induced inflammation.
Diaphragm and cardiac mitochondrial creatine kinases are impaired in sepsis
Authors: Callahan Leigh A. , Supinski Gerald S.
Published: August 2006

Previous studies indicate that ATP formation by the electron transport chain is impaired in sepsis. However, it is not known whether sepsis affects the mitochondrial ATP transport system. We hypothesized that sepsis inactivates the mitochondrial creatine kinase (MtCK)-high energy phosphate transport system. To examine this issue, we assessed the effects of endotoxin administration on mitochondrial membrane-bound creatine kinase, an important trans-mitochondrial ATP transport system. Diaphragms and hearts were isolated from control ( n = 12) and endotoxin-treated (8 mg·kg−1·day−1; n = 13) rats after pentobarbital anesthesia. We isolated mitochondria using techniques that allow evaluation of the functional coupling of mitochondrial creatine kinase MtCK activity to oxidative phosphorylation. MtCK functional activity was established by 1) determining ATP/creatine-stimulated oxygen consumption and 2) assessing total creatine kinase activity in mitochondria using an enzyme-linked assay. We examined MtCK protein content using Western blots. Endotoxin markedly reduced diaphragm and cardiac MtCK activity, as determined both by ATP/creatine-stimulated oxygen consumption and by the enzyme-linked assay (e.g., ATP/creatine-stimulated mitochondrial respiration was 173.8 ± 7.3, 60.5 ± 9.3, 210.7 ± 18.9, was 67.9 ± 7.3 natoms O·min−1·mg−1in diaphragm control, diaphragm septic, cardiac control, and cardiac septic samples, respectively; P < 0.001 for each tissue comparison). Endotoxin also reduced diaphragm and cardiac MtCK protein levels (e.g., protein levels declined by 39.5% in diaphragm mitochondria and by 44.2% in cardiac mitochondria; P < 0.001 and P = 0.009, respectively, comparing sepsis to control conditions). Our data indicate that endotoxin markedly impairs the MtCK-ATP transporter system; this phenomenon may have significant effects on diaphragm and cardiac function.
Decreased Atherosclerosis in Low-Density Lipoprotein Receptor Knockout Mice Transplanted With
Abcg1
−/−
Bone Marrow
Authors: Ranalletta Mollie , Wang Nan , Han Seongah , Yvan-Charvet Laurent , Welch Carrie , Tall Alan R.
Published: August 2006

Objective—

Recent studies indicate that the ATP-binding cassette transporter ABCG1 can promote cholesterol efflux from macrophages to high-density lipoprotein. This study was designed to assess the in vivo role of macrophage ABCG1 in atherosclerosis.

Methods and Results—

Bone marrow from
Abcg1
−/−
mice was transplanted into irradiated
Ldlr
−/−
recipients, and atherosclerosis was evaluated by aortic root assay after 7 or 11 weeks of feeding on a Western diet. After 7 weeks, there was no difference in lesion area in mice receiving either wild-type or
Abcg1
−/−
bone marrow, whereas after 11 weeks, lesion area was moderately but significantly reduced in
Abcg1
−/−
recipients. ABCG1-deficient peritoneal macrophages showed induction of several liver X receptor target genes, such as
Abca1
and
Srebp1c
, and a dramatic increase in apolipoprotein E (apoE) protein both in cell media and lysates, without parallel change in apoE mRNA.
Abca1
knockdown prevented the increase in apoE secretion but had minimal effects on apoE accumulation in cell lysates of
Abcg1
−/−
macrophages. Plasma apoE levels were markedly increased in recipients of
Abcg1
−/−
bone marrow.

Conclusions—

These studies reveal an inverse relationship between
Abcg1
expression and apoE accumulation and secretion in macrophages. The reduced atherosclerosis in recipients of
Abcg1
-deficient bone marrow may be explained by induction of
Abca1
and an associated increase in macrophage apoE secretion.
S-Glutathiolation of p21ras by Peroxynitrite Mediates Endothelial Insulin Resistance Caused by Oxidized Low-Density Lipoprotein
Authors: Clavreul Nicolas , Bachschmid Markus M. , Hou Xiuyun , Shi Chaomei , Idrizovic Azra , Ido Yasuo , Pimentel David , Cohen Richard A.
Published: August 2006

Objectives—

To understand the mechanism by which oxidants are linked to insulin resistance, bovine aortic endothelial cells were exposed to oxidized low-density lipoproteins (oxLDL) or peroxynitrite.

Methods and Results—

OxLDL transiently increased phosphorylation of Erk and Akt within 5 minutes, but 60 minutes later, resulted in decreased insulin-induced Akt phosphorylation. OxLDL promoted a 2- to 5-fold increase in oxidant generation as measured by dihydrorhodamine or dihydroethidium oxidation that was ascribed to peroxynitrite. Exogenous peroxynitrite (25 to 100 μmol/L) or oxidized glutathione mimicked the effects of oxLDL. OxLDL increased the
S
-glutathiolation of p21ras, and adenoviral transfection with either a mutant p21ras (C118S) lacking the predominant site of
S
-glutathiolation or a dominant-negative mutant restored insulin-induced Akt phosphorylation. The requirement for oxidant-mediated
S
-glutathiolation and activation of p21ras in mediating insulin resistance was further implicated by showing that insulin signaling was restored by Mek inhibitors or by overexpression of glutaredoxin-1. Furthermore, oxLDL increased Erk-dependent phosphorylation of insulin receptor substrate-1 serine-616 that was prevented by inhibiting oxidant generation, Erk activation, or by the p21ras C118S mutant.

Conclusions—

This study provides direct evidence for a novel molecular mechanism by which oxidants can induce insulin resistance via
S
-glutathiolation of p21ras and Erk-dependent inhibition of insulin signaling.
C-Reactive Protein Alters Antioxidant Defenses and Promotes Apoptosis in Endothelial Progenitor Cells
Authors: Fujii Hiroko , Li Shu-Hong , Szmitko Paul E. , Fedak Paul W.M. , Verma Subodh
Published: August 2006

Objective—C-reactive protein (CRP) has been suggested to participate in the development of atherosclerosis, in part, by promoting endothelial dysfunction and impairing endothelial progenitor cell (EPC) survival and differentiation. In the present study, we evaluated the effects of CRP on antioxidative enzymes, reactive oxygen species production, telomerase activity, and apoptosis in human circulating EPCs.

Methods and Results—EPCs, isolated from peripheral venous blood, were cultured in the absence or presence of native pentameric azide and lipopolysaccharide (LPS)-free CRP (0, 5, 15, and 20 μg/mL), N-acetylcysteine (NAC), hydrogen peroxide (H2O2) or monoclonal anti-CRP antibodies. Fluorescence-activated cell sorter (FACS) analysis was used for the measurement of intracellular H2O2and superoxide (O2−) by loading cells with 2′,7′-dichlorodihydrofluorescein diacetate (H2DCF-DA). Apoptosis was evaluated with Annexin V immunostaining and cytosolic cytochrome c expression. Western blot analysis was used for the determination of manganese superoxide dismutase (MnSOD) and glutathione peroxidase expression, and polymerase chain reaction enzyme-linked immunosorbent assay was used to assess telomerase activity. Incubation of EPCs with CRP caused a concentration dependent increase in reactive oxygen species (ROS) production and apoptosis, with an effect quantitatively similar to H2O2. This effect was attenuated during coincubation with NAC or anti-CRP antibodies. Furthermore, CRP altered EPC antioxidative enzyme levels, demonstrating a reduced expression of glutathione peroxidase and a significant increase in MnSOD expression. Transfection of EPCs with MnSOD-RNAi resulted in a reduction in CRP-induced ROS production, apoptosis, and telomerase inactivation.

Conclusions—CRP, at concentrations known to predict cardiovascular events, may serve to impair EPC antioxidant defenses, and promote EPC sensitivity toward oxidant-mediated apoptosis and telomerase inactivation. These data further support a direct role of CRP in the development and/or progression of atherothrombosis.
The Range of Adaptation by Collateral Vessels After Femoral Artery Occlusion
Authors: Eitenmüller Inka , Volger Oscar , Kluge Alexander , Troidl Kerstin , Barancik Miroslav , Cai Wei-Jun , Heil Matthias , Pipp Frederic , Fischer Silvia , Horrevoets Anton J.G. , Schmitz-Rixen Thomas , Schaper Wolfgang
Published: August 2006

Natural adaptation to femoral artery occlusion in animals by collateral artery growth restores only ≈35% of adenosine-recruitable maximal conductance (C
max
) probably because initially elevated fluid shear stress (FSS) quickly normalizes. We tested the hypothesis whether this deficit can be mended by artificially increasing FSS or whether anatomical restraints prevent complete restitution. We chronically increased FSS by draining the collateral flow directly into the venous system by a side-to-side anastomosis between the distal stump of the occluded femoral artery and the accompanying vein. After reclosure of the shunt collateral flow was measured at maximal vasodilatation. C
max
reached 100% already at day 7 and had, after 4 weeks, surpassed (2-fold) the C
max
of the normal vasculature before occlusion. Expression profiling showed upregulation of members of the Rho-pathway (RhoA, cofilin, focal adhesion kinase, vimentin) and the Rho-antagonist Fasudil markedly inhibited arteriogenesis. The activities of Ras and ERK-1,-2 were markedly increased in collateral vessels of the shunt experiment, and infusions of L-NAME and L-NNA strongly inhibited MAPK activity as well as shunt-induced arteriogenesis. Infusions of the peroxinitrite donor Sin-1 inhibited arteriogenesis. The radical scavengers urate, ebselen, SOD, and catalase had no effect. We conclude that increased FSS can overcome the anatomical restrictions of collateral arteries and is potentially able to completely restore maximal collateral conductance. Increased FSS activates the Ras-ERK-, the Rho-, and the NO- (but not the Akt-) pathway enabling collateral artery growth.
Depolymerized Hyaluronan Induces Vascular Endothelial Growth Factor, a Negative Regulator of Developmental Epithelial-to-Mesenchymal Transformation
Authors: Rodgers Laurel S. , Lalani Sofia , Hardy Katharine M. , Xiang Xueyu , Broka Derrick , Antin Parker B. , Camenisch Todd D.
Published: August 2006

Cardiac malformations constitute the most common birth defects, of which heart septal and valve defects are the most frequent forms diagnosed in infancy. These cardiac structures arise from the endocardial cushions through dynamic interactions between cells and the extracellular matrix (cardiac jelly). Targeted deletion of the hyaluronan synthase-2 (
Has2
) gene in mice results in an absence of hyaluronan (HA), cardiac jelly, and endocardial cushions, a loss of vascular integrity, and death at embryonic day 9.5. Despite the requirements for Has2 and its product, HA, in the developing heart, little is known about the normal processing and removal of HA during development. Cell culture studies show that HA obtains new bioactivity after depolymerization into small oligosaccharides. We previously showed reduction in Has2 expression and diminished presence of HA at later stages of heart development as tissue remodeling formed the leaflets of the cardiac valves. Here we show that small oligosaccharide forms of HA (o-HA) act antagonistically to developmental epithelial-to-mesenchymal transformation (EMT), which is required to generate the progenitor cells that populate the endocardial cushions. We further show that o-HA induces vascular endothelial growth factor (VEGF), which acts as a negative regulator of EMT. This is the first report illustrating a functional link between oligosaccharide HA and VEGF. Collectively, our data indicate that following endocardial cell EMT, native HA is likely processed to o-HA, which stimulates VEGF activity to attenuate cardiac developmental EMT.
Inhibition of Nuclear Import of Calcineurin Prevents Myocardial Hypertrophy
Authors: Hallhuber Matthias , Burkard Natalie , Wu Rongxue , Buch Mamta H. , Engelhardt Stefan , Hein Lutz , Neyses Ludwig , Schuh Kai , Ritter Oliver
Published: August 2006

The time that transcription factors remain nuclear is a major determinant for transcriptional activity. It has recently been demonstrated that the phosphatase calcineurin is translocated to the nucleus with the transcription factor nuclear factor of activated T cells (NF-AT). This study identifies a nuclear localization sequence (NLS) and a nuclear export signal (NES) in the sequence of calcineurin. Furthermore we identified the nuclear cargo protein importinβ
1
to be responsible for nuclear translocation of calcineurin. Inhibition of the calcineurin/importin interaction by a competitive peptide (KQECKIKYSERV), which mimicked the calcineurin NLS, prevented nuclear entry of calcineurin. A noninhibitory control peptide did not interfere with the calcineurin/importin binding. Using this approach, we were able to prevent the development of myocardial hypertrophy. In angiotensin II-stimulated cardiomyocytes, [
3
H]-leucine incorporation (159%±9 versus 111%±11;
P
<0.01) and cell size were suppressed significantly by the NLS peptide compared with a control peptide. The NLS peptide inhibited calcineurin/NF-AT transcriptional activity (227%±11 versus 133%±8;
P
<0.01), whereas calcineurin phosphatase activity was unaffected (298%±9 versus 270%±11;
P
=NS). We conclude that calcineurin is not only capable of dephosphorylating NF-AT, thus enabling its nuclear import, but the presence of calcineurin in the nucleus is also important for full NF-AT transcriptional activity.
Stem Cell Factor Deficiency Is Vasculoprotective
Authors: Wang Chao-Hung , Anderson Nicole , Li Shu-Hong , Szmitko Paul E. , Cherng Wen-Jing , Fedak Paul W.M. , Fazel Shafie , Li Ren-Ke , Yau Terrence M. , Weisel Richard D. , Stanford William L. , Verma Subodh
Published: August 2006

Evidence suggests that bone marrow (BM) cells may give rise to a significant proportion of smooth muscle cells (SMCs) that contribute to intimal hyperplasia after vascular injury; however, the molecular pathways involved and the timeline of these events remain poorly characterized. We hypothesized that the stem cell factor (SCF)/c-Kit tyrosine kinase signaling pathway is critical to neointimal formation by BM-derived progenitors. Wire-induced femoral artery injury in mice reconstituted with wild-type BM cells expressing yellow fluorescent protein was performed, which revealed that 66±12% of the SMCs (α-smooth muscle actin-positive [αSMA
+
] cells) in the neointima were from BM. To characterize the role of the SCF/c-Kit pathway, we used c-Kit deficient

W/W
v

and SCF-deficient Steel-Dickie mice. Strikingly, vascular injury in these mice resulted in almost a complete inhibition of neointimal formation, whereas wild-type BM reconstitution of c-Kit mutant mice led to neointimal formation in a similar fashion as wild-type animals, as did chronic administration of SCF in matrix metalloproteinase-9–deficient mice, a model of soluble SCF deficiency. Pharmacological antagonism of the SCF/c-Kit pathway with imatinib mesylate (Gleevec) or ACK2 (c-Kit antibody) also resulted in a marked reduction in intimal hyperplasia. Vascular injury resulted in the local upregulation of SCF expression. c-Kit
+
progenitor cells (PCs) homed to the injured vascular wall and differentiated into αSMA
+
cells. Vascular injury also caused an increase in circulating SCF levels which promoted CD34
+
PC mobilization, a response that was blunted in mutant and imatinib mesylate-treated mice. In vitro, SCF promoted adhesion of BM PCs to fibronectin. Additionally, anti-SCF antibodies inhibited adhesion of BM PCs to activated SMCs and diminished SMC differentiation. These data indicate that SCF/c-Kit signaling plays a pivotal role in the development of neointima by BM-derived PCs and that the inhibition of this pathway may serve as a novel therapeutic target to limit aberrant vascular remodeling.