bluuebunny/crossref_metadata_2025 huggingface dataset:
New X-ray powder diffraction data for the series CpMn(CO)3, Cp(CO)2Mn=C=CHPh, [Cp(CO)2Mn]2(μ-C=CHPh), and [Cp(CO)2Mn]2(μ-C4Ph2) complexes (Cp=η5-C5H5)
Authors: Antonova Alla B. , Chudin Oleg S. , Kirik Sergei D.
Published: June 2004

Four manganese carbonyl complexes: CpMn(CO)3 (1) and its phenylvinylidene derivatives Cp(CO)2Mn=C=CHPh (2), [Cp(CO)2Mn]2(μ-C=CHPh) (3), and Cp(CO)2Mn=C=C(Ph)–C(Ph)=C=Mn(CO)2Cp (4) have been studied by X-ray powder diffraction and their unit cell parameters are reported. The monoclinic cell parameters found for complex (1) are a=12.0479(7) Å, b=7.0614(5) Å, c=10.9172(6) Å, β=117.626(2)°, Z=4, space group P2(1)/a (No. 14). The orthorhombic cells parameters for complex (2) are a=10.5240(12) Å, b=33.1105(48) Å, c=7.5007(9) Å, Z=8, space group PCCN (No. 56); for complex (3) are a=15.3545(17) Å, b=15.3966(18) Å, c=8.0033(7) Å, Z=4, space group P21212121 (No. 19). The parameters found for complexes (1–3) are in good agreement with those obtained from single crystal X-ray diffractometry. The single crystal structure of complex (4) has not been studied. The orthorhombic cell parameters for complex (4) found by X-ray powder diffraction method are a=10.0986(9) Å, b=33.2937(27) Å, c=7.4139(5) Å, Z=4, space group P21 (No. 4).
Crystal structure of guaifenesin, 3-(2-methoxyphenoxy)-1,2-propanediol
Authors: Kaduk James A.
Published: June 2004

The crystal structure of the common expectorant guaifenesin, 3-(2-methoxyphenoxy)-1, 2-propanediol (C10H14O4) was solved by applying Monte Carlo simulated annealing techniques to synchrotron powder data, and refined using the Rietveld method. Initial structure solutions yielded an unreasonable conformation, and an unacceptable refinement. Quantum chemical geometry optimizations were used to identify the correct conformation. Guaifenesin crystallizes in the orthorhombic space group P212121 (#19), with a=7.657 05(7), b=25.670 20(24), c=4.979 66(4) Å, V=978.79(2) Å3, and Z=4. Both hydroxyl groups act as hydrogen bond donors and acceptors, resulting in the formation of a two-dimensional network of strong hydrogen bonds in the ac plane. The solid state conformation is ∼4 kcal/mol higher in energy than the minimum-energy conformation of an isolated molecule, but the formation of the hydrogen bonds results in an energy gain of ∼100 kcal/mol. Knowledge of the crystal structure permits quantitative phase analysis of guaifenesin-containing pharmaceuticals (such as Duratuss GP 120-1200) by the Rietveld method.
Micro X-ray fluorescence in materials characterization
Authors: Havrilla George J. , Miller Thomasin
Published: June 2004

Micro X-ray fluorescence (MXRF) offers the analyst a new approach to materials characterization. The range of applications is expanding rapidly. Single point analysis has been demonstrated for nanoliter volumes with detection limits at the 0.5 ng level. MXRF can be used as an element specific detector for capillary electrophoresis. Elemental imaging applications include analysis of sample corrosion and polymers, use as a combinatorial chemistry screening tool, and integration with molecular spectroscopic imaging methods to provide a more comprehensive characterization. Three-dimensional elemental imaging is a reality with the development of a confocal X-ray fluorescence microscope. Stereoview elemental X-ray imaging can provide unique views of materials that flat two-dimensional images cannot achieve. Spectral imaging offers chemical imaging capability, moving MXRF into a higher level of information content. The future is bright for MXRF as a materials characterization tool.
Microdiffraction using two-dimensional detectors
Authors: He Bob Baoping
Published: June 2004

X-ray diffraction analysis on small samples or micro-area of large samples is always a challenge due to weak diffraction and poor statistics, especially when dealing with samples containing large grain size, inhomogeneous phase distribution, and preferred orientation. Two-dimensional X-ray diffraction has many advantages in microdiffraction analysis. A two-dimensional detector can collect a large amount of data both in terms of speed and angular coverage. This paper covers some aspects about instrumentation of two-dimensional X-ray diffraction and its applications in phase identification and stress analysis on small samples and micro-area of large samples.
Measurement volume considerations in X-ray microdiffraction stress analysis
Authors: Noyan I. C. , Kaldor S. K.
Published: June 2004

The Lorenz-polarization (LP) factor, which is used for X-ray intensity calculations from polycrystalline materials, contains a term that describes the fraction of diffracting grains in the irradiated sample volume. We present extensions of this term and a series of experiments that tests its applicability. The implications of the analysis on microbeam diffraction are also discussed.
IL-8 Plasma Concentrations and the Risk of Future Coronary Artery Disease in Apparently Healthy Men and Women
Authors: Boekholdt S. Matthijs , Peters Ron J. G. , Hack C. Erik , Day Nicholas E. , Luben Robert , Bingham Sheila A. , Wareham Nicholas J. , Reitsma Pieter H. , Khaw Kay-Tee
Published: June 2004

Objective—To study the role of IL-8 in predicting future coronary artery disease (CAD) in apparently healthy men and women.

Methods and Results—A nested case-control study was performed in the prospective EPIC-Norfolk population study. We measured baseline IL-8 concentrations among 785 apparently healthy individuals in whom fatal or nonfatal CAD developed during follow-up and 1570 matched controls. Baseline IL-8 concentrations were higher in cases than in matched controls (3.5 pg/mL versus 3.1 pg/mL,P=0.001). The risk of future CAD increased with increasing quartiles of IL-8 (Plinearity <0.0001). Among individuals in the highest IL-8 quartile, the unadjusted odds ratio for future CAD was 1.72 (95% CI, 1.34 to 2.21;P<0.0001). The odds ratio for future CAD was still significant after adjustment for traditional risk factors (OR, 1.58; 95%CI, 1.19 to 2.09;P=0.002) and after additional adjustment for C-reactive protein and white cell count (OR, 1.77; 95% CI, 1.21 to 2.60;P=0.001).

Conclusions—We conclude that among apparently healthy men and women, elevated levels of IL-8 are associated with an increased risk of future CAD. These prospective data support a role for IL-8 in the development of CAD events.
A Novel Efflux–Recapture Process Underlies the Mechanism of High-Density Lipoprotein Cholesteryl Ester-Selective Uptake Mediated by the Low-Density Lipoprotein Receptor–Related Protein
Authors: Vassiliou Gerard , McPherson Ruth
Published: June 2004

Objective—

To determine the mechanism of low-density lipoprotein (LDL) receptor-related protein (LRP)-mediated selective uptake of high-density lipoprotein (HDL)-derived cholesteryl esters (CE).

Methods and Results—

Apolipoprotein E (apoE) and heparin sulfate proteoglycans are required for LRP-mediated selective uptake in adipocytes. Furthermore, 2-deoxyglucose and NaN
3
abolish this process, indicating that cellular energy is required. LRP-mediated selective uptake is also abolished by monensin or when clathrin-mediated internalization is inhibited (using hypotonic, K
+
-free medium or hyperosmolar sucrose), clearly implicating receptor endocytosis. The receptor-associated protein (RAP), an inhibitor of ligand binding to LRP, reduced the transport of CE into an intracellular compartment but not into the plasma membrane. Remarkably, the CE that is ultimately transported by LRP first enters the plasma membrane then undergoes apoE-mediated CE efflux before being recaptured and internalized by LRP.

Conclusion—

According to this “efflux-recapture” model, LRP contributes to selective uptake because it recovers CE that would normally be lost by efflux mediated by apoE.
EGF-Like Domain of Tenascin-C Is Proapoptotic for Cultured Smooth Muscle Cells
Authors: Wallner Kurt , Li Chen , Shah Prediman K. , Wu Kai-Jin , Schwartz Stephen M. , Sharifi Behrooz G.
Published: June 2004

Objective—

Based on our previous observations on the expression of Tenascin-C (Tn-C) in human atherosclerotic plaques and its colocalization with macrophages, we explored whether Tn-C undergoes fragmentation and the potential pathobiological significance of this fragmentation.

Methods and Results—

Using cultured human smooth muscle cells (SMCs), we found that Tn-C upregulates expression of matrix metalloproteinases (MMPs). Western blot analysis revealed that Tn-C substrate is fragmented and most of the cleavage products have fibronectin-like and epidermal growth factor-like (EGF-like) domains of Tn-C. One fragment that contains an EGF-like domain was found in some human atherosclerotic plaques. Cell culture studies revealed that the recombinant EGF-like domain inhibits growth, induces apoptosis of SMCs in a dose-dependent, time-dependent, and caspase-dependent manner, and activates caspase-3 before SMC detachment. Conversely, the caspase inhibitor z-YVAD.cmk, serum, and protease inhibitors blocked cell apoptosis conferred by the EGF-like domain. In addition, these inhibitors blocked EGF-like domain-induced caspase-3 activation. In contrast to this EGF-like domain, intact Tn-C, its fibronectin-like, and its fibrinogen-like domains were inactive.

Conclusions—

Together with our previous observations, our data suggest that Tn-C upregulates MMP expression that cleaves Tn-C into fragments containing the EGF-like domain. This domain has proapoptotic activity for SMCs.
Heat Shock Protein 90 Transfection Reduces Ischemia-Reperfusion–Induced Myocardial Dysfunction via Reciprocal Endothelial NO Synthase Serine 1177 Phosphorylation and Threonine 495 Dephosphorylation
Authors: Kupatt Christian , Dessy Chantal , Hinkel Rabea , Raake Philip , Daneau Géraldine , Bouzin Caroline , Boekstegers Peter , Feron Olivier
Published: June 2004

Objectives—

The interaction of the heat shock protein 90 (Hsp90) with the endothelial NO synthase (eNOS) has been shown to account for a sustained production of NO in vitro. Here, we examined whether overexpression of Hsp90 in a pig model of cardiac infarct could preserve the myocardium from the deleterious effects of ischemia–reperfusion.

Methods and Results—

Percutaneous liposome-based gene transfer was performed by retroinfusion of the anterior interventricular vein before left anterior descending occlusion and reperfusion. We found that recombinant Hsp90 expression in the ischemic region of the heart led to a 33% reduction in infarct size and prevented the increase in postischemic left ventricular end diastolic pressure observed in mock-transfected animals. Regional myocardial function, assessed by subendocardial segment shortening in the infarct region, was increased in Hsp90-transfected animals at baseline and after pacing. All these effects were completely abrogated by administration of the NOS inhibitor
N
G
-nitro-
l
-arginine methyl ester. We further documented in vivo and in cultured endothelial cells that the cardioprotective effects of Hsp90 were associated to its capacity to act as an adaptor for both the kinase Akt and the phosphatase calcineurin, thereby promoting eNOS serine 1177 phosphorylation and threonine 495 dephosphorylation, respectively.

Conclusions—

Hsp90 is a promising target to enhance NO formation in vivo, which may efficiently reduce myocardial reperfusion injury.
Lysophosphatidylcholine Enhances Cytokine Production of Endothelial Cells via Induction of L-Type Amino Acid Transporter 1 and Cell Surface Antigen 4F2
Authors: Takabe Wakako , Kanai Yoshikatsu , Chairoungdua Arthit , Shibata Noriyuki , Toi Sono , Kobayashi Makio , Kodama Tatsuhiko , Noguchi Noriko
Published: June 2004

Objective—

A diverse range of lipid oxidation products detected in oxidized low-density lipoprotein (oxLDL) and atherosclerotic lesions are capable of eliciting biological responses in vascular cells. We performed DNA microarray experiments to explore novel responses of human umbilical vein endothelial cells (HUVECs) to oxLDL and its components.

Methods and Results—

cDNA microarray analysis showed that oxLDL, lysophosphatidylcholine (LysoPC), 4-hydroxy-2-nonenal, and oxysterols altered gene expression specifically, but some genes were commonly induced in HUVECs. Solute carrier family 3 member 2 and family 7 member 5, encoding the heavy chain of the cell surface antigen 4F2 (4F2hc) and the L-type amino acid transporter 1 (LAT1), respectively, were induced by oxLDL and many oxidation products. LAT1 requires 4F2hc to form a heterodimeric functional complex to transport neutral amino acids into the cell. LysoPC increased membrane protein levels of LAT1 confirmed by Western blot analysis and also uptake of L-[
14
C]leucine, which was inhibited by a competitive inhibitor for LAT1. The release of interleukin 6 (IL-6) and IL-8 was increased in LysoPC-treated cells and was attenuated by the LAT1 inhibitor.

Conclusions—

These findings suggest that an increase in uptake of neutral amino acids induced by LysoPC results in enhancement of inflammatory responses of endothelial cells.
Leukocyte-Derived Interleukin 10 Is Required for Protection Against Atherosclerosis in Low-Density Lipoprotein Receptor Knockout Mice
Authors: Potteaux Stéphane , Esposito Bruno , van Oostrom Olivia , Brun Valérie , Ardouin Patrice , Groux Hervé , Tedgui Alain , Mallat Ziad
Published: June 2004

Background—

Atherosclerosis is an immunoinflammatory disease. Here we examined the role of leukocyte-derived interleukin 10 (IL-10) on advanced atherosclerosis development in low-density lipoprotein receptor knockout (LDLr−/−) mice.

Methods and Results—

Bone marrow cells harvested from C57BL/6 IL-10−/− and IL-10+/+ mice were transplanted into irradiated male LDLr−/− mice. Four weeks after transplantation, mice were fed a high-fat cholate-free diet for 14 weeks. Despite no differences in weights, serum total, and HDL-cholesterol levels between the 2 groups, IL-10 deficiency in leukocytes induced a >2-fold increase in lesion development in the thoracic aorta compared with controls. We also found a significant 35% increase in aortic root lesion area of IL-10−/− mice compared with IL-10+/+ mice. Furthermore, IL-10 deficiency led to a marked increase in lymphocyte and macrophage accumulation associated with a significant reduction in collagen accumulation. Finally, transfer of IL-10−/− splenocytes to LDLr−/− mice resulted in a 3-fold increase in lesion size in the aortic sinus compared with mice transplanted with IL-10+/+ splenocytes.

Conclusion—

IL-10 expressed by leukocytes prevents exaggerated advanced atherosclerosis development and plays a critical role in modulation of cellular and collagen plaque composition, at least in part, through a modulation of the systemic immune response.
Endothelial Overexpression of Fas Ligand Decreases Atherosclerosis in Apolipoprotein E–Deficient Mice
Authors: Yang Jiang , Sato Kaori , Aprahamian Tamar , Brown Nathaniel J. , Hutcheson Jack , Bialik Ann , Perlman Harris , Walsh Kenneth
Published: June 2004

Objective—Fas ligand (FasL) can induce apoptosis in cells bearing the Fas receptor. The role of FasL in the vasculature with regard to atherosclerosis is controversial. This study examined the function of endothelial FasL during atherosclerosis.

Methods and Results—Transgenic (Tg) mice that specifically overexpress different levels of FasL on vascular endothelial cells were crossed into the apolipoprotein E–knockout background (ApoE-KO) to generate ApoE-KO/FasL–Tg mice. Although plasma cholesterol and triglyceride levels were not different between ApoE-KO/FasL–Tg mice and ApoE-KO mice after 12 weeks of a high-fat diet, overexpression of the FasL transgene significantly reduced atherosclerotic lesion area in aortae by 49%. The reduction of atherosclerotic lesion area was more pronounced in thoracic and abdominal aortae than in the aortic arch, and a 34% reduction in lesion area was observed in aortic root sections from the ApoE-KO/FasL–Tg group compared with the ApoE-KO group. Immunostaining revealed significant decreases in both macrophage and CD8 T-cell accumulation in lesions of ApoE-KO/FasL–Tg mice. ApoE-KO/FasL–Tg mice that express lower levels of endothelial FasL also displayed reduced lesion size, but this reduction was statistically significant at the aortic arch only.

Conclusions—Overexpression of endothelial FasL is antiinflammatory and inhibits atherosclerosis under hypercholesterolemic conditions.
Cholesterol-Lowering Independent Regression and Stabilization of Atherosclerotic Lesions by Pravastatin and by Antimonocyte Chemoattractant Protein-1 Therapy in Nonhuman Primates
Authors: Kitamoto Shiro , Nakano Kaku , Hirouchi Yasuhiko , Kohjimoto Yoshiro , Kitajima Shunichi , Usui Makoto , Inoue Shujiro , Egashira Kensuke
Published: June 2004

Objective—

Anti-atherosclerotic effects of statins might be mediated partly by pleiotropic cholesterol-lowering independent mechanisms. We used nonhuman primates and examined whether treatment with pravastatin or antimonocyte chemoattractant protein-1 (MCP-1) therapy can induce regression and stabilization of established atherosclerotic lesions through cholesterol-lowering independent mechanisms.

Methods and Results—

Advanced atherosclerosis was induced in the abdominal aorta and the common iliac artery of cynomolgus monkeys by undergoing balloon injury and giving atherogenic diet for 6 months. At 6 months, the diet was changed to normal chow, and the animals were allocated to 4 treatment groups: control vehicle group and other groups treated with pravastatin (1 or 10 mg/kg) or with mutant MCP-1 gene transfection for additional 6 months. Each compound was treated instead of the atherogenic diet, and cholesterol contents in pravastatin-treated groups were adjusted to equalize plasma cholesterol level among groups. Pravastatin reduced neointimal formation in the aorta, but not in the common iliac artery. Pravastatin reduced intimal macrophage area and other markers of plaque destabilization in the common iliac artery. Equivalent inhibitory effects were observed in animals that received mutant MCP-1 gene transfection. No serious side effects were noted by 2 therapeutic modalities.

Conclusion—

This study demonstrated cholesterol-lowering independent regression and stabilization of established atherosclerotic lesions by pravastatin and by anti-MCP-1 therapy in nonhuman primates. An anti-inflammatory mechanism may be involved in the beneficial effects of pravastatin.
Statins Upregulate
PCSK9
, the Gene Encoding the Proprotein Convertase Neural Apoptosis-Regulated Convertase-1 Implicated in Familial Hypercholesterolemia
Authors: Dubuc Geneviève , Chamberland Ann , Wassef Hanny , Davignon Jean , Seidah Nabil G. , Bernier Lise , Prat Annik
Published: June 2004

Objective—

Neural apoptosis-regulated convertase (NARC)-1 is the newest member of the proprotein convertase family implicated in the cleavage of a variety of protein precursors. The NARC-1 gene,
PCSK9
, has been identified recently as the third locus implicated in autosomal dominant hypercholesterolemia (ADH). The 2 other known genes implicated in ADH encode the low-density lipoprotein receptor and apolipoprotein B. As an approach toward the elucidation of the physiological role(s) of NARC-1, we studied its transcriptional regulation.

Methods and Results—

Using quantitative RT-PCR, we assessed NARC-1 regulation under conditions known to regulate genes involved in cholesterol metabolism in HepG2 cells and in human primary hepatocytes. We found that NARC-1 expression was strongly induced by statins in a dose-dependent manner and that this induction was efficiently reversed by mevalonate. NARC-1 mRNA level was increased by cholesterol depletion but insensitive to liver X receptor activation. Human, mouse, and rat
PCSK9
promoters contain 2 typical conserved motifs for cholesterol regulation: a sterol regulatory element (SRE) and an Sp1 site.

Conclusions—

PCSK9
regulation is typical of that of the genes implicated in lipoprotein metabolism. In vivo,
PCSK9
is probably a target of SRE-binding protein (SREBP)-2.
Vasodilator-Stimulated Phosphoprotein Regulates Proliferation and Growth Inhibition by Nitric Oxide in Vascular Smooth Muscle Cells
Authors: Chen Lihua , Daum Günter , Chitaley Kanchan , Coats Scott A. , Bowen-Pope Daniel F. , Eigenthaler Martin , Thumati Naresh R. , Walter Ulrich , Clowes Alexander W.
Published: June 2004

Objective—

Vasodilator-stimulated phosphoprotein (VASP) was identified as a substrate for cGMP-dependent protein kinase (PKG) and cAMP-dependent protein kinase (PKA). It is preferentially phosphorylated at serine239 by PKG, whereas serine157 is a preferred phosphorylation site for PKA. In addition, serine157 is phosphorylated by PKC in response to serum. We have investigated the effects of VASP and VASP phosphorylation at serine157 and serine239 on smooth muscle cell (SMC) proliferation and nitric oxide (NO)-mediated growth inhibition.

Methods and Results—

Aortic SMCs derived from VASP-deficient mice were transduced with retroviral vectors encoding either wild-type VASP or VASP mutants (S157A-VASP and S239A-VASP), in which serine157 and serine239, respectively, were replaced by a nonphosphorylatable amino acid, alanine. Expression of wt-VASP and S239A-VASP significantly increased proliferation, whereas expression of S157A-VASP was inhibitory. Expression of S239A-VASP rendered SMCs less sensitive to growth inhibition by the NO donor, S-nitroso-n-acetylpenicillamine, when compared with cells expressing wt-VASP. Similar effects were observed in cultured rat SMCs in which wt-VASP, S157A-VASP, and S239A-VASP were expressed.

Conclusions—

Our data suggest that VASP phosphorylation at serine157 is required for the growth-stimulatory effect of VASP in SMCs, whereas VASP phosphorylation at serine239 is involved in the growth inhibitory effects of NO on SMCs.
Impact of Amoxicillin Prophylaxis on the Incidence, Nature, and Duration of Bacteremia in Children After Intubation and Dental Procedures
Authors: Lockhart Peter B. , Brennan Michael T. , Kent M. Louise , Norton H. James , Weinrib David A.
Published: June 2004

Background—

Controversy exists about the impact of prophylactic antibiotics on bacteremia after invasive dental procedures. The purpose of this double-blind, randomized, placebo-controlled study was to determine the impact of amoxicillin prophylaxis on the incidence, nature, and duration of bacteremia from nasotracheal intubation and dental procedures in children.

Methods and Results—

Children were randomly assigned before surgery to the American Heart Association (AHA)–recommended dose of amoxicillin or to a placebo. Aerobic and anaerobic blood cultures were drawn at 8 specific time points after intubation, dental restorative and cleaning procedures, and before, during, and after dental extraction(s), to include blood drawings up to 45 minutes after the last extraction. Aerobic and anaerobic blood culture results were used to determine the incidence, nature, and duration of bacteremia from these procedures. For the 100 children enrolled (mean age, 3.5 years), the overall incidence of positive blood cultures, defined as at least 1 positive culture of the 8, was significantly higher in the placebo (84%) than the amoxicillin group (33%) (
P
<0.0001). Bacteremia occurrence rates after intubation and after dental restorations and cleaning were 18% and 20% in the placebo group and 4% and 6% in the amoxicillin group (
P
=0.05 and
P
=0.07, respectively). At 1.5 minutes after the initiation of dental extractions, bacteremia occurred in 76% of the placebo group versus 15% of the amoxicillin group (
P
<0.001). The majority of the 152 positive cultures and of the 29 different bacteria identified were Gram-positive cocci. Bacteremia persisted longer in the placebo group.

Conclusions—

Bacteremia from these procedures occurs more often, from a wider variety of bacterial species, and for a longer duration after dental extractions than previously reported in any age group. Amoxicillin has a significant impact on the incidence, nature, and duration of bacteremia after nasal intubation, dental restorative and cleaning procedures, and dental extractions.
Increased Atrial and Brain Natriuretic Peptides in Adults With Cyanotic Congenital Heart Disease
Authors: Hopkins William E. , Chen Zengyi , Fukagawa Naomi K. , Hall Christian , Knot Harm J. , LeWinter Martin M.
Published: June 2004

Background—

Brain natriuretic peptide (BNP) levels are used in the evaluation of patients with heart disease, yet there is little understanding of the effect of hypoxia on natriuretic peptide secretion. Furthermore, recent data suggest that oxytocin may mediate stretch-induced atrial natriuretic peptide (ANP) secretion.

Methods and Results—

Ten patients with cyanotic congenital heart defects and 10 control subjects were studied. N-terminal proatrial natriuretic peptide and N-terminal probrain natriuretic peptide levels were 4-fold (
P
=0.02) and 12-fold (
P
=0.03) greater in cyanotic patients than in control subjects. Cyanotic patients had reduced body water compared with control subjects, although the difference did not reach statistical significance (
P
=0.22). In a separate group of patients, cardiac myocytes were isolated from the right atrial appendage during CABG. The amount of oxygen in the buffered saline was varied to simulate hypoxia. Isolated hypoxic atrial myocytes had 43% fewer dense surface secretory granules compared with normoxic myocytes (
P
<0.0001). Immunohistochemical staining demonstrated decreased ANP and BNP in hypoxic compared with normoxic right atrial tissue. Isolated myocytes also degranulated when incubated with oxytocin (
P
<0.0001), but there was no difference in oxytocin levels in cyanotic patients compared with control subjects (
P
=0.49).

Conclusions—

ANP and BNP are markedly elevated in adults with cyanotic congenital heart disease despite reduced body water. Our results show that hypoxia is a direct stimulus for ANP and BNP secretion in human cardiac myocytes. These findings may have implications for the interpretation of BNP levels in the assessment of patients with heart and lung disease.
G(−30)A Polymorphism in the Pancreatic Promoter of the Glucokinase Gene Associated With Angiographic Coronary Artery Disease and Type 2 Diabetes Mellitus
Authors: März Winfried , Nauck Markus , Hoffmann Michael M. , Nagel Dietmar , Boehm Bernhard O. , Koenig Wolfgang , Rothenbacher Dietrich , Winkelmann Bernhard R.
Published: June 2004

Background—

Type 2 diabetes mellitus (T2DM) increases the risk of coronary artery disease (CAD). A G(−30)A polymorphism in the β-cell–specific promoter of glucokinase (GK-30PM) has been implicated in reduced pancreatic β-cell function. Its impact on CAD has not been examined.

Methods and Results—

The glucokinase G(−30)A variant was determined in 2567 patients with angiographic CAD and in 731 individuals in whom CAD had been ruled out by angiography. In carriers of the A allele, the adjusted OR of CAD was 1.39 (95% CI, 1.15 to 1.70). Corresponding ORs were 1.27 (95% CI, 1.02 to 1.59) and 1.92 (95% CI, 1.26 to 2.93) in individuals without and with T2DM, respectively. The prevalence of the A allele increased in parallel with the Friesinger coronary score. Patients with T2DM were more frequent among carriers of ≥1 A allele (OR, 1.17; 95% CI, 1.00 to 1.28). This association was stronger if CAD patients only were considered. The A allele was associated with higher glucose (fasting,
P
=0.002; 2 hours after oral glucose,
P
=0.017) and glycohemoglobin (HbA1c;
P
=0.002). Furthermore, presence of 1 A allele was negatively related to β-cell function, estimated by β percent (
P
=0.012) and by the ratios of proinsulin to insulin (
P
=0.025) and proinsulin to C peptide (
P
=0.019).

Conclusions—

The A allele of the pancreatic promoter of glucokinase increases the risk of CAD in individuals with and without T2DM. Furthermore, at least in CAD, it is associated with an augmented prevalence of T2DM.
Aerobic Fitness Is Associated With Cardiomyocyte Contractile Capacity and Endothelial Function in Exercise Training and Detraining
Authors: Kemi Ole Johan , Haram Per Magnus , Wisløff Ulrik , Ellingsen Øyvind
Published: June 2004

Background—

Physical fitness and level of regular exercise are closely related to cardiovascular health. A regimen of regular intensity-controlled treadmill exercise was implemented and withdrawn to identify cellular mechanisms associated with exercise capacity and maximal oxygen uptake (V̇
o
2
max).

Methods and Results—

Time-dependent associations between cardiomyocyte dimensions, contractile capacity, and V̇
o
2
max were assessed in adult rats after high-level intensity-controlled treadmill running for 2, 4, 8, and 13 weeks and detraining for 2 and 4 weeks. With training, cardiomyocyte length, relaxation, shortening, Ca
2+
decay, and estimated cell volume correlated with increased V̇
o
2
max (
r
=0.92, −0.92, 0.88, −0.84, 0.73;
P
<0.01). Multiple regression analysis identified cell length, relaxation, and Ca
2+
decay as the main explanatory variables for V̇
o
2
max (
R
2
=0.87,
P
<0.02). When training stopped, exercise-gained V̇
o
2
max decreased 50% within 2 weeks and stabilized at 5% above sedentary controls after 4 weeks. Cardiomyocyte size regressed in parallel with V̇
o
2
max and remained (9%) above sedentary after 4 weeks, whereas cardiomyocyte shortening, contraction/relaxation- and Ca
2+
-transient time courses, and endothelium-dependent vasorelaxation regressed completely within 2 to 4 weeks of detraining. Cardiomyocyte length, estimated cell volume, width, shortening, and Ca
2+
decay and endothelium-dependent arterial relaxation all correlated with V̇
o
2
max (
r
=0.85, 0.84, 0.75, 0.63, −0.54, −0.37;
P
<0.01). Multiple regression identified cardiomyocyte length and vasorelaxation as the main determinants for regressed V̇
o
2
max during detraining (
R
2
=0.76,
P
=0.02).

Conclusions—

Cardiovascular adaptation to regular exercise is highly dynamic. On detraining, most of the exercise-gained aerobic fitness acquired over 2 to 3 months is lost within 2 to 4 weeks. The close association between cardiomyocyte dimensions, contractile capacity, arterial relaxation, and aerobic fitness suggests cellular mechanisms underlying these changes.
p66
ShcA
Modulates Tissue Response to Hindlimb Ischemia
Authors: Zaccagnini Germana , Martelli Fabio , Fasanaro Pasquale , Magenta Alessandra , Gaetano Carlo , Di Carlo Anna , Biglioli Paolo , Giorgio Marco , Martin-Padura Ines , Pelicci Pier Giuseppe , Capogrossi Maurizio C.
Published: June 2004

Background—

Oxidative stress plays a pivotal role in ischemia and ischemia/reperfusion injury. Because p66
ShcA
-null (p66
ShcA
−/−) mice exhibit both lower levels of intracellular reactive oxygen species and increased resistance to cell death induced by oxidative stress, we investigated whether tissue damage that follows acute ischemia or ischemia/reperfusion was altered in p66
ShcA
−/− mice.

Methods and Results—

Unilateral hindlimb ischemia was induced by femoral artery dissection, and ischemia/reperfusion was induced with an elastic tourniquet. Both procedures caused similar changes in blood perfusion in p66
ShcA
wild-type (p66
ShcA
wt) and p66
ShcA
−/− mice. However, significant differences in tissue damage were found: p66
ShcA
wt mice displayed marked capillary density decrease and muscle fiber necrosis. In contrast, in p66
ShcA
−/− mice, minimal capillary density decrease and myofiber death were present. When apoptosis after ischemia was assayed, significantly lower levels of apoptotic endothelial cells and myofibers were found in p66
ShcA
−/− mice. In agreement with these data, both satellite muscle cells and endothelial cells isolated from p66
ShcA
−/− mice were resistant to apoptosis induced by simulated ischemia in vitro. Lower apoptosis levels after ischemia in p66
ShcA
−/− cells correlated with decreased levels of oxidative stress both in vivo and in vitro.

Conclusions—

p66
ShcA
plays a crucial role in the cell death pathways activated by acute ischemia and ischemia/reperfusion, indicating p66
ShcA
as a potential therapeutic target for prevention and treatment of ischemic tissue damage.
Tissue Factor Binding of Activated Factor VII Triggers Smooth Muscle Cell Proliferation via Extracellular Signal–Regulated Kinase Activation
Authors: Cirillo Plinio , Calì Gaetano , Golino Paolo , Calabrò Paolo , Forte Lavinia , Rosa Salvatore De , Pacileo Mario , Ragni Massimo , Scopacasa Francesco , Nitsch Lucio , Chiariello Massimo
Published: June 2004

Background—

Tissue factor (TF) is the main initiator of coagulation in vivo. Recently, however, a role for TF as a cell receptor involved in signal transduction has been suggested. The aim of the present study was to assess whether activated factor VII (FVIIa) binding to TF could induce smooth muscle cell (SMC) proliferation and to clarify the possible intracellular mechanism(s) responsible for this proliferation.

Methods and Results—

Cell proliferation was induced by FVIIa in a dose-dependent manner, as assessed by [
3
H]thymidine incorporation and direct cell counting, whereas no response was observed with active site–inhibited FVIIa (FVIIai), which is identical to FVIIa but is devoid of enzymatic activity. Similarly, no proliferation was observed when binding of FVIIa to TF was prevented by the monoclonal anti-TF antibody AP-1. Activation of the p44/42 mitogen-activated protein (MAP) kinase (extracellular signal–regulated kinases 1 and 2 [ERK 1/2]) pathway on binding of FVIIa to TF was demonstrated by transient ERK phosphorylation in Western blots and by suppression of proliferation with the specific MEK (MAP kinase/ERK kinase) inhibitor UO126. ERK phosphorylation was not observed with FVIIai or when cells were pretreated with AP-1.

Conclusions—

These data indicate a specific effect by which binding of FVIIa to TF on the surface of SMCs induces proliferation via a coagulation-independent mechanism and possibly indicate a new link between coagulation, inflammation, and atherosclerosis.
Relations of Plasma Matrix Metalloproteinase-9 to Clinical Cardiovascular Risk Factors and Echocardiographic Left Ventricular Measures
Authors: Sundström Johan , Evans Jane C. , Benjamin Emelia J. , Levy Daniel , Larson Martin G. , Sawyer Douglas B. , Siwik Deborah A. , Colucci Wilson S. , Sutherland Patrice , Wilson Peter W.F. , Vasan Ramachandran S.
Published: June 2004

Background—

Plasma levels of matrix metalloproteinase-9 (MMP-9), a key determinant of extracellular matrix degradation, are increased in heart failure and in acute coronary syndromes. We investigated cross-sectional relations of plasma MMP-9 to vascular risk factors and echocardiographic left ventricular (LV) measurements.

Methods and Results—

We studied 699 Framingham Study participants (mean age, 57 years; 58% women), free of heart failure and previous myocardial infarction, who underwent routine echocardiography. We examined sex-specific distributions of LV internal dimensions (LVEDD) and wall thickness (LVWT) and sampled persons with both LVEDD and LVWT below the sex-specific median (referent, n=299), with increased LVEDD (LVEDD ≥90th percentile, n=204) and increased LVWT (LVWT ≥90th percentile, n=221) in a 3:2:2 ratio. Plasma MMP-9 was detectable in 138 persons (20%). In multivariable models, increasing heart rate (OR per SD, 1.41; 95% CI, 1.17 to 1.71) and antihypertensive treatment (OR, 1.63; 95% CI, 1.06 to 2.50) were key clinical correlates of detectable plasma MMP-9. In multivariable-adjusted models, detectable plasma MMP-9 was associated with increased LVEDD (OR, 2.84; 95% CI, 1.13 to 7.11), increased LVWT (OR, 2.54; 95% CI, 1.00 to 6.46), and higher LV mass (
P
=0.06) in men but not in women (OR for increased LVEDD, 1.37; 95% CI, 0.54 to 3.46; for increased LVWT, 0.99; 95% CI, 0.39 to 2.52;
P
=0.59 for LV mass).

Conclusions—

In our community-based sample, detectable plasma MMP-9 levels were associated with increased LV diastolic dimensions and increased wall thickness in men. These observations indicate that plasma MMP-9 level may be a marker for cardiac extracellular matrix degradation, a process involved in LV remodeling.
Circulating Humoral Factors and Endothelial Progenitor Cells in Patients With Differing Coronary Collateral Support
Authors: Lambiase Pier D. , Edwards Richard J. , Anthopoulos Prodromos , Rahman Salman , Meng Y. Gloria , Bucknall Clifford A. , Redwood Simon R. , Pearson Jeremy D. , Marber Michael S.
Published: June 2004

Background—

The mechanisms underlying the variation in collateral formation between patients, even with similar patterns of coronary artery disease, remain unclear. This study investigates whether circulating humoral or cellular factors can provide an insight into this variation.

Methods and Results—

Thirty patients with isolated left anterior descending coronary artery disease underwent percutaneous coronary intervention with collateral flow index (CFI) determined using a pressure wire. Patients with inadequate (CFI <0.25) compared with those with adequate (CFI ≥0.25) collateral support had, or tended to have, lower concentrations of coronary sinus growth factors and plasma exerting a weaker effect on endothelial cell migration and angiogenesis in vitro. However, there was an inverse correlation between serum mitogenicity and CFI (
r
=−0.61,
P
<0.01). No significant differences were detected between the 2 groups in plasma levels of total vascular endothelial growth factor, vascular endothelial growth factor
165
, or placental growth factor. There was a strong positive correlation between numbers of CD34/CD133-positive circulating hemopoietic precursor cells and CFI (
r
=0.75,
P
<0.001). In patients with inadequate, compared with those with adequate, CFI, the numbers of differentiated endothelial progenitor cells (EPCs) appearing in the circulation and in culture were significantly reduced by 75% (
P
<0.05) and 70% (
P
<0.05), respectively.

Conclusions—

In this study, inadequate coronary collateral development is associated with reduced numbers of circulating EPCs and impaired chemotactic and proangiogenic but not mitogenic activity. These findings are consistent with current efforts to enhance collateral formation by augmentation of circulating EPCs.
Obesity Is an Important Determinant of Baseline Serum C-Reactive Protein Concentration in Monozygotic Twins, Independent of Genetic Influences
Authors: Greenfield Jerry R. , Samaras Katherine , Jenkins Arthur B. , Kelly Paul J. , Spector Tim D. , Gallimore J. Ruth , Pepys Mark B. , Campbell Lesley V.
Published: June 2004

Background—

C-reactive protein (CRP) values predict atherothrombotic cardiovascular disease and type 2 diabetes mellitus. Associations between CRP and obesity, predominantly assessed anthropometrically, may partly explain these observations. Previous studies have been unable to control for genetic influences on CRP and obesity. The aim of this study was to examine the relationship between CRP and accurately measured body fat, lipids, apolipoproteins, blood pressure, and environmental and behavioral factors, independent of genetic influences.

Methods and Results—

One hundred ninety-four healthy female twins (age 57.2±7 years) were studied after excluding pairs with CRP values >10 mg/L. Total body fat and central abdominal fat (CAF) were measured by dual-energy x-ray absorptiometry. CRP concentration was strongly related to surrogate and direct measures of body fat (
r
=0.31 to 0.54,
P
<0.001), diastolic blood pressure (
r
=0.20,
P
=0.003), and lipid and apolipoprotein levels (
r
=0.21 to 0.51,
P
<0.008). Light-to-moderate alcohol consumers and nonusers of hormone replacement therapy (HRT) had lower CRP levels than abstainers and HRT users, respectively. In stepwise multiple regression analysis, CAF, triglycerides, apolipoprotein B, and HRT use explained 46% of the variance in circulating CRP. In analyses controlling for genetic influences in monozygotic twins, within-pair differences in CRP were associated with within-pair differences in total body fat (
r
=0.39,
P
<0.001), CAF (
r
=0.34,
P
=0.002), diastolic blood pressure (
r
=0.24,
P
=0.03), apolipoprotein AI (
r
=−0.33,
P
=0.01), HDL cholesterol (
r
=−0.42,
P
=0.001), and triglycerides (
r
=0.35,
P
=0.007).

Conclusions—

CRP was strongly related to total and central abdominal obesity, blood pressure, and lipid levels, independent of genetic influences. These relationships are likely to contribute significantly to prospective associations between CRP and type 2 diabetes and coronary events.
Inhibition of mTOR Signaling With Rapamycin Regresses Established Cardiac Hypertrophy Induced by Pressure Overload
Authors: McMullen Julie R. , Sherwood Megan C. , Tarnavski Oleg , Zhang Li , Dorfman Adam L. , Shioi Tetsuo , Izumo Seigo
Published: June 2004

Background—

Rapamycin is a specific inhibitor of the mammalian target of rapamycin (mTOR). We recently reported that administration of rapamycin before exposure to ascending aortic constriction significantly attenuated the load-induced increase in heart weight by ≈70%.

Methods and Results—

To examine whether rapamycin can regress established cardiac hypertrophy, mice were subjected to pressure overload (ascending aortic constriction) for 1 week, echocardiography was performed to verify an increase in ventricular wall thickness, and mice were given rapamycin (2 mg · kg
−1
· d
−1
) for 1 week. After 1 week of pressure overload (before treatment), 2 distinct groups of animals became apparent: (1) mice with compensated cardiac hypertrophy (normal function) and (2) mice with decompensated hypertrophy (dilated with depressed function). Rapamycin regressed the pressure overload-induced increase in heart weight/body weight (HW/BW) ratio by 68% in mice with compensated hypertrophy and 41% in mice with decompensated hypertrophy. Rapamycin improved left ventricular end-systolic dimensions, fractional shortening, and ejection fraction in mice with decompensated cardiac hypertrophy. Rapamycin also altered the expression of some fetal genes, reversing, in part, changes in α-myosin heavy chain and sarcoplasmic reticulum Ca
2+
ATPase.

Conclusions—

Rapamycin may be a therapeutic tool to regress established cardiac hypertrophy and improve cardiac function.
In Vivo Evidence of Angiogenesis Induced by Transcription Factor Ets-1
Authors: Hashiya Naotaka , Jo Nobuo , Aoki Motokuni , Matsumoto Kunio , Nakamura Toshikazu , Sato Yasufumi , Ogata Nahoko , Ogihara Toshio , Kaneda Yasufumi , Morishita Ryuichi
Published: June 2004

Background—

A transcription factor, ets-1, regulates the transcription of metalloproteinase genes, the activity of which is necessary for matrix degradation and the migration of endothelial cells. However, no study has demonstrated that ets-1 itself has an angiogenic action in vivo. Thus, we examined (1) the effects of overexpression of the ets-1 gene on angiogenesis in a rat hindlimb ischemia model, and (2) how ets-1 induced angiogenesis.

Methods and Results—

In this study, we used the HVJ-liposome method, which is highly effective for transfection, to transfect the human ets-1 gene. At 4 weeks after transfection, the capillary density and blood flow were significantly increased in a hindlimb transfected with the human ets-1 gene compared with control. These data clearly demonstrated that ets-1 has the ability to stimulate angiogenesis in vivo. To elucidate the molecular mechanisms by which ets-1 induced angiogenesis, we focused especially on the expression of hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF), potent angiogenic growth factors, because the promoter regions of both genes contain ets binding sites. Interestingly, overexpression of ets-1 upregulated both tissue HGF and VEGF concentrations in rat hindlimb. More importantly, administration of neutralizing antibody against HGF and VEGF attenuated the increase in blood flow and BrdU-positive cells induced by ets-1. Upregulation of HGF and VEGF by ets-1 was also confirmed by in vitro experiments using human vascular smooth muscle cells.

Conclusions—

The present study demonstrated that ets-1 regulated angiogenesis through the induction of angiogenic growth factors (VEGF and HGF). Overexpression of ets may provide a new therapeutic strategy to treat peripheral arterial disease.
Role of Akt Signaling in Mitochondrial Survival Pathway Triggered by Hypoxic Preconditioning
Authors: Uchiyama Takamichi , Engelman Richard M. , Maulik Nilanjana , Das Dipak K.
Published: June 2004

Background—

The signaling pathways that control ischemia/reperfusion-induced cardiomyocyte apoptosis in heart have not been fully defined. In this study, we investigated whether Akt signaling has a role in the antiapoptotic pathways of preconditioning against hypoxia/reoxygenation (H/R).

Methods and Results—

Primary cultures of adult rat ventricular myocytes (ARVMs) were subjected to preconditioning (PC) by exposing the cells to 10 minutes of hypoxia followed by 30 minutes of reoxygenation. Non-PC and PC myocytes were subjected to 90 minutes of hypoxia followed by 120 minutes of reoxygenation. Hypoxic-PC protected the myocytes from subsequent H/R injury, as evidenced by decreased apoptosis and LDH release and increased cell viability. H/R-induced cytochrome
c
release and activation of caspase-3 and -9 were blocked by PC. This protective effect was inhibited by treating the cells with LY294002 (50 μmol/L), a PI3 kinase inhibitor, for 10 minutes before and during PC. PC also induced phosphorylation of Akt and BAD. Protein levels of Bcl-2 in mitochondria were maintained in PC. ARVMs were infected with either a control adenovirus (Adeno lac-Z), an adenovirus expressing dominant-negative Akt, or an adenovirus expressing constitutively active Akt. Ectopic overexpression of constitutively active Akt protected ARVMs from apoptosis induced by hypoxia/reoxygenation compared with Adeno lac-Z. In contrast, dominant negative Akt overexpression abolished the antiapoptotic effect of PC.

Conclusions—

Our data demonstrated that in adult cardiomyocytes, the antiapoptotic effect of PC against H/R requires Akt signaling leading to phosphorylation of BAD, inhibition of cytochrome
c
release, and prevention of caspase activation.
Recurrent Third-Trimester Fetal Loss and Maternal Mosaicism for Long-QT Syndrome
Authors: Miller Todd E. , Estrella Elicia , Myerburg Robert J. , de Viera Jocelyn Garcia , Moreno Niberto , Rusconi Paolo , Ahearn Mary Ellen , Baumbach Lisa , Kurlansky Paul , Wolff Grace , Bishopric Nanette H.
Published: June 2004

Background—

The importance of germ-line mosaicism in genetic disease is probably underestimated, even though recent studies indicate that it may be involved in 10% to 20% of apparently de novo cases of several dominantly inherited genetic diseases.

Methods and Results—

We describe here a case of repeated germ-line transmission of a severe form of long-QT syndrome (LQTS) from an asymptomatic mother with mosaicism for a mutation in the cardiac sodium channel,
SCN5A
. A male infant was diagnosed with ventricular arrhythmias and cardiac decompensation in utero at 28 weeks and with LQTS after birth, ultimately requiring cardiac transplantation for control of ventricular tachycardia. The mother had no ECG abnormalities, but her only previous pregnancy had ended in stillbirth with evidence of cardiac decompensation at 7 months’ gestation. A third pregnancy also ended in stillbirth at 7 months, again with nonimmune fetal hydrops. The surviving infant was found to have a heterozygous mutation in
SCN5A
(
R1623Q
), previously reported as a de novo mutation causing neonatal ventricular arrhythmia and LQTS. Initial studies of the mother detected no genetic abnormality, but a sensitive restriction enzyme-based assay identified a small (8% to 10%) percentage of cells harboring the mutation in her blood, skin, and buccal mucosa. Cord blood from the third fetus also harbored the mutant allele, suggesting that all 3 cases of late-term fetal distress resulted from germ-line transfer of the LQTS-associated mutation.

Conclusions—

Recurrent late-term fetal loss or sudden infant death can result from unsuspected parental mosaicism for LQTS-associated mutations, with important implications for genetic counseling.