bluuebunny/crossref_metadata_2025 huggingface dataset:
Architectural acoustics and the heritage of theater architecture in Andalusia (Acustica arquitectonica y patrimonio teatral en Andalucia)
Authors: Leon Angel Luis
Published: November 2003

This thesis reports on the study of the acoustic properties of 18 theaters belonging to the Andalusian historical and architectural heritage. These theaters have undergone recent renovations to modernize and equip them appropriately. Coincident with this work, evaluations and qualification assessments with regard to their acoustic properties have been carried out for the individual theaters and for the group as a whole. Data measurements for this purpose consisted of acoustic measurements in situ, both before the renovation and after the renovation. These results have been compared with computer simulations of sound fields. Variables and parameters considered include the following: reverberation time, rapid speech transition index, back-ground noise, definition, clarity, strength, lateral efficiency, interaural cross-correlation coefficient, volume/seat ratio, volume/audience-area ratio. Based on the measurements and analysis, general conclusions are given in regard to the acoustic performance of theaters whose typology and size are comparable to those that were used in this study (between 800 and 8000 cubic meters). It is noted that these properties are comparable to those of the majority of European theaters. The results and conclusions are presented so that they should be of interest to architectural acoustics practitioners and to architects who are involved in the planning of renovation projects for theaters.

Thesis advisors: Juan J. Sendra and Jaime Navarro Copies of this thesis written in Spanish may be obtained by contacting the author, Angel L. Leon, E.T.S. de Arquitectura de Sevilla, Dpto. de Construcciones Arquitectonicas I, Av. Reina Mercedes, 2, 41012 Sevilla, Spain. E-mail address: leonr@us.es
Changes in F2−F1 as a voicing cue
Authors: Warren Willis J. , Coren Amy E.
Published: November 2003

The interaction between formant transitions and vowel length was measured with respect to syllable final voicing distinctions. A synthesized ad VC token of 360 ms was edited in 5-ms intervals from either side, onset or offset, so that 260 ms were preserved. Ten subjects were asked to make final voicing judgments for the words ‘‘odd’’ and ‘‘ought’’ ([ad] vs [at]) when hearing the 20 edited tokens. Each token was presented five times, randomly, for a total of 1000 judgements. Results showed an overwhelming number of voiced responses when the entire offset was preserved and symmetrical voiceless results with the deletion of offset. A follow-up experiment utilized a similarly synthesized token of 460 ms. The results when adding 100 ms onto the vowel were insignificantly different than the results acquired for formant transitions, suggesting the latter are a more important cue for syllable final voicing distinctions. These findings contradict previous vowel length conclusions [L. J. Raphael, J. Acoust. Soc. Am. 51, 1296–1303 (1972)] and further suggest that in addition to F1 [V. Summers, J. Acoust. Soc. Am. 84, 485–492 (1988)], F2 transitions are also an important cue to final voicing distinctions in low vowel contexts.
Acoustic diffraction by a disk in a viscous medium
Authors: Davis Anthony M. J. , Nagem Raymond J.
Published: November 2003

The diffraction of a time-harmonic acoustic plane wave by a circular disk in a viscous fluid medium is considered by using the linearized equations of viscous fluid flow and the no-slip condition on the rigid disk. Sets of dual integral equations for the fluid velocity and pressure are derived for an arbitrary disk radius and an arbitrary angle of incidence. The dual integral equations are solved by an analytic reduction to sets of linear algebraic equations. In the cases of normal or tangential incidence, numerical results are presented for the fluid velocity in the plane of the disk and the scattered acoustic disturbance in the far field.
Negative Feedback Regulation Ensures the One Receptor-One Olfactory Neuron Rule in Mouse
Authors: Serizawa Shou , Miyamichi Kazunari , Nakatani Hiroko , Suzuki Misao , Saito Michiko , Yoshihara Yoshihiro , Sakano Hitoshi
Published: November 2003

In the mouse olfactory system, each olfactory sensory neuron (OSN) expresses only one odorant receptor (OR) gene in a monoallelic and mutually exclusive manner. Such expression forms the genetic basis for OR-instructed axonal projection of OSNs to the olfactory bulb of the brain during development. Here, we identify an upstream cis-acting DNA region that activates the OR gene cluster in mouse and allows the expression of only one OR gene within the cluster. Deletion of the coding region of the expressed OR gene or a naturally occurring frame-shift mutation allows a second OR gene to be expressed. We propose that stochastic activation of only one OR gene within the cluster and negative feedback regulation by that OR gene product are necessary to ensure the one receptor–one neuron rule.
Regulation of Flowering Time by Histone Acetylation inArabidopsis
Authors: He Yuehui , Michaels Scott D. , Amasino Richard M.
Published: November 2003

TheArabidopsisautonomous floral-promotion pathway promotes flowering independently of the photoperiod and vernalization pathways by repressingFLOWERING LOCUS C(FLC), a MADS-boxtranscription factor that blocks the transition from vegetative to reproductive development. Here, we report thatFLOWERING LOCUS D(FLD), one of sixgenes in the autonomous pathway, encodes a plant homolog of a protein found in histone deacetylase complexes in mammals. Lesions inFLDresult in hyperacetylation of histones inFLCchromatin, up-regulation ofFLCexpression, and extremely delayed flowering. Thus, the autonomous pathway regulates flowering in part by histone deacetylation. However, not all autonomous-pathway mutants exhibitFLChyperacetylation, indicating that multiple means exist by which this pathway repressesFLCexpression.
Mycothiol Is Essential for Growth ofMycobacterium tuberculosisErdman
Authors: Sareen Dipti , Newton Gerald L. , Fahey Robert C. , Buchmeier Nancy A.
Published: November 2003

Mycothiol (MSH) is the major low-molecular-mass thiol in mycobacteria and is associated with the protection ofMycobacterium tuberculosisfrom toxic oxidants and antibiotics. The biosynthesis of MSH is a multistep process, with the enzymatic reaction designated MshC being the ligase step in MSH production. A targeted disruption of the nativemshCgene inM.tuberculosisErdman produced no viable clones possessing either a disruptedmshCgene or reduced levels of MSH. However, when a second copy of themshCgene was incorporated into the chromosome prior to the targeted disruption, multiple clones having the native gene disrupted and the second copy ofmshCintact were obtained. These clones produced normal levels of MSH. These results demonstrate that themshCgene and, more generally, the production of MSH are essential for the growth ofM. tuberculosisErdman under laboratory conditions.
Effect of Acupuncture at Hsien-Ku (St-43) on the Pulse Spectrum and a Discussion of the Evidence for the Frequency Structure of Chinese Medicine
Authors: Wang Wei Kung , Hsu Tse Lin , Chang Hsi Chan , Lin Wang Yuh Yin
Published: November 2003

We investigated the pulse spectrum variation of the human radial artery when Hsien-Ku (St 43), an acupoint on the stomach meridian, was needled and compared the results with the acupuncture effects of two other acupoints, Tsu-San-Li (St-36) and Tai-Shih (K-3), reported previously. For Hsien-Ku, the harmonic proportions were redistributed: the second harmonic (C2) decreased, C3, C5, C6, C7, C8 and C9 increased, C3, C6 and C9 became the relative peaks to their neighboring harmonics and C2, C4 became the relative minimums. The phase angles of the 2nd harmonic (P2) and 5th harmonic (P5) decreased, propagating faster. These effects were similar to that of Tsu-San-Li which is also on the stomach meridian. A totally different pattern was found for Tai-Shih on the kidney meridian. These results strengthen the theory that a meridian can be classified according to its effects on the pulse spectrum, and that all the meridian related effects such as those caused by acupuncture or meridian specific herbs are frequency specific.
Inhibition of Human Smooth Muscle Cell Proliferation by Gamigeonsim-Tang through the transcriptional Regulation of Cell Cycle-Controlling Genes
Authors: Ko Seong-Gyu , Lee Kyung-Sup , Cho Ki-Ho , Kim Young-Suk , Bae Hyung-Sup , Moon Sang-Kwan
Published: November 2003

The effects of Gamigeonsim-tang (GGT) on cellular proliferation and expression of cell cycle-related genes were investigated in human smooth muscle cell HISM. HISM cells were treated with an aqueous extract of GGT. Cellular proliferation was investigated by an immunocytometric analysis of PCNA expression and a flow cytometric analysis of the cell cycle progression. Reduced expression of PCNA and a significant accumulation of G1phase cells were observed following treatment, indicating that GGT inhibits cellular proliferation of human smooth muscle cells. To explore whether GGT affects the transcription of cell cycle-regulating genes, we evaluated mRNA expression of p53, p21Waf1, PCNA, Cyclin D1, Cdc2, Histone H3, c-Myc, and c-Fos using a quantitative RT-PCR analysis. While increased expressions of two negative cell cycle regulators, p53 and p21Waf1were found, reduced expressions of cell cycle stimulators, PCNA, c-Fos, and c-Myc, were identified following treatment. Taken together, our study demonstrates that GGT inhibits cellular proliferation of human smooth muscle cell through the up- and down-regulation of growth-inhibiting and growth-promoting genes, respectively.
Reduction of the Oxidative Injury to the Rabbits with Established Atherosclerosis by Protein Bound Polysaccharide fromCoriolus Vesicolor
Authors: Zhou Mei , Chen Yuan , Quyang Qian , Liu Shang-Xi , Pang Zhan-Jun
Published: November 2003

Recent evidence has emerged that macrophage glutathione (GSH) content and selenium dependent glutathione peroxidase (SeGSHPx) activity are inversely related to cell-mediated oxidation of LDL, and intervention means to enhance the macrophage GSH-SeGSHPx status may contribute to attenuation of the atherosclerotic process. Our previous works showed that protein bound polysaccharide (PSK) injected intraperitoneally could enhance SeGSHPx activity and mRNA content of mouse macrophages. The aim of the present study is to demonstrate whether PSK can reduce the oxidative injury to the established atherosclerotic rabbits. Using the established atherosclerotic rabbit model, we studied the effect of PSK on oxidatively modified LDL (Ox-LDL), lipoperoxide (LPO) cholesterol contents and SeGSHPx activities of plasma and tissues (aorta, heart and liver) in the established atherosclerotic rabbits. As compared with the control group, Ox-LDL, LPO and cholesterol contents were much lover; SeGSHPx activities and SeGSHPx/LPO ratios were much higher in plasma and tissues (aorta, heart and liver); and the lesion area of aortae was reduced in the PSK group. Through the increment of SeGSHPx activity in macrophages and aortae, PSK enhances their antioxidation potentiality and improves the antioxidant/prooxidant imbalance in them, and thus decreases Ox-LDL, LPO and cholesterol contents of plasma and tissues, and regresses lesion area of aortae in the established atherosclerotic rabbits.
Radix Angelica Sinensis Extracts Ameliorate Scopolamine- and Cycloheximide-Induced Amnesia, but not p-Chloroamphetamine-Induced Amnesia in Rats
Authors: Hsieh Ming-Tsuen , Lin Ying-Tsung , Lin Ying-Chih , Wu Chi-Rei
Published: November 2003

The effects if the methanolic extract of Radix Angelica Sinensis (Umbellifera) (abbreviated as RAS extract) and n-hexane fraction of RAS extract ( RAS H fraction) on the various drugs-induced amnesia in rats were studied by using passive avoidance task. RAS extract (1 g/kg) significantly prolonged the shortened step-through latency induced by SCOP and CXM, but not PCA. Furthermore, RAS H fraction (1 g/kg) also significantly prolonged the shortened step-through latency induced by SCOP and CXM but not PCA. RAS extract at any dose alone did not influence the step-through latency in the training trial produced by non-shocked rats, but it plus PCA prolonged the latency compared with PCA alone. However, RAS H fraction (1 g/kg) prolonged the latency in the training trial produced by non-shocked rats, but it plus any induced drugs did not differ from any induced drugs alone. These results suggest that the attenuating effects of RAS extract on the various drugs-induced amnesia were related to the memory processes, n-Hexane fraction of RAS extract might be one of the active fractions of RAS extract in the treatment of amnesia.
Yang-Gan-Wan Protects Mice Against Apoptosis Induced by Anti-Fas Antibody (Jo2)
Authors: Yang Melissa , Chen Kevin , Shih Jean Chen
Published: November 2003

We investigated the protective effect of Yang-Gan-Wan (YGW, Pro-Liver pill), a Chinese herbal remedy, against liver apoptosis (programmed cell death) induced by anti-Fas antibody (Jo2). Mice were pretreated daily with 200 mg/kg YGW for 14 day before treatment with 10 μg/20 kg body weight Jo2. YGW significantly reduced the elevated activity of alanine aminotransferase (ALT) and also reduced the elevated activity of sorbitol dehydrogenase (SDH) produced 4 hrs after treatment with Jo2. YGW also increased the survival of mice treated with Jo2 by about 1 hr in 11 out of 16 mice (69 %). Most of the mice died 9 hrs after Jo2 injection. This study demonstrates that YGW has protective effects against liver apoptosis induced by Jo2.
The Effect of Fasting on the Pulse Spectrum
Authors: Su Yi Chang , Huang Ke Feng , Chang Yu Hsin , Li Tsai Chung , Huang Wei San , Lin Jaung Geng
Published: November 2003

Nutrition is the major source of bioenergy. The present study investigated the physiological response to fasting by analyzing the effect of fasting on the pulse spectrum of the radial artery. Sixteen subjects were allowed to take only mineral water for 24 hours, and the pulse was measured at intervals during fasting and after eating resumed. Data were analyzed using one-way analysis of variance (ANOVA) with Scheffe's test for pairwise comparisons. The results indicate the second harmonic of the radial pulse increased and the sixth harmonic decreased significantly after 24 hours of fasting. The proportions of the second harmonic then decreased significantly and those of the sixth harmonic increased significantly 12 hours after eating resumed. These findings suggest that a rhythm exists in physiological changes and the distribution of bioenergy, which ensures that the overall heart load will remain unchanged during the fasting and re-feeding periods, maintaining a stable overall balance in body function.
Decreased Macrophage Paraoxonase 2 Expression in Patients With Hypercholesterolemia Is the Result of Their Increased Cellular Cholesterol Content: Effect of Atorvastatin Therapy
Authors: Rosenblat Mira , Hayek Tony , Hussein Khetam , Aviram Michael
Published: November 2003

Objective—

To analyze paraoxonase2 (PON2) expression in human monocyte-derived macrophages (HMDM) from patients with hypercholesterolemia in relation to cellular cholesterol and oxidative stress.

Methods and Results—

Ten healthy subjects (controls) and 10 patients with hypercholesterolema who received 20-mg/d atorvastatin participated in the study. The patients’ versus controls’ HMDM demonstrated increased cholesterol content (270%) and oxidative stress (30% to 45%). Atorvastatin therapy reduced these parameters (59% and 25%, respectively). The patients’ versus controls’ macrophage-PON2 mRNA expression and PON2 activity were lower (100% and 40%, respectively), and atorvastatin therapy increased these parameters (76% and 200%, respectively). Untreated patient HMDM incubation with atorvastatin (0 to 10 μmol/L) resulted in a dose-dependent reduction in cellular cholesterol content and in cell-mediated low-density lipoprotein (LDL) oxidation up to 79% and 66%, respectively. In parallel, PON2 mRNA expression and PON2 activity increased dose-dependently up to 3.6- and 2.1-fold, respectively. On incubation of control HMDM with acetylated-LDL or aggregated-LDL, cellular cholesterol content increased (77% and 100%), and macrophage-PON2 activity decreased (49% and 22%), respectively. In contrast, oxidized LDL increased both cellular oxidative stress and PON2 expression.

Conclusions—

HMDM-PON2 expression is reduced in patients with hypercholesterolemia as a result of their increased cellular cholesterol content. Atorvastatin therapy reduced both macrophage oxidative stress and cholesterol content, and upregulated PON2 expression, thus contributing to attenuation of foam cells formation.
Formation and Metabolism of Prebeta-Migrating, Lipid-Poor Apolipoprotein A-I
Authors: Rye Kerry-Anne , Barter Philip J.
Published: November 2003

The preferred extracellular acceptor of cell phospholipids and unesterified cholesterol in the process mediated by the ATP-binding cassette A1 (ABCA1) transporter is a monomolecular, prebeta-migrating, lipid-poor or lipid-free form of apolipoprotein (apo) A-I. This monomolecular form of apoA-I is quite distinct from the prebeta-migrating, discoidal high-density lipoprotein (HDL) that contains two or three molecules of apoA-I per particle and which are present as minor components of the HDL fraction in human plasma. The mechanism of the ABCA1-mediated efflux of phospholipid and cholesterol from cells has been studied extensively. In contrast, much less attention has been given to the origin and subsequent metabolism of the acceptor lipid-free/lipid-poor apoA-I. There is a substantial body of evidence from studies conducted in vitro that a monomolecular, lipid-free/lipid-poor form of apoA-I dissociates from HDL during the remodeling of HDLs by plasma factors such as cholesteryl ester transfer protein, hepatic lipase, and phospholipid transfer protein. The rate at which apoA-I dissociates from HDL is influenced by the phospholipid composition of the particles and by the presence of apoA-II. This review describes current knowledge regarding the formation, metabolism, and regulation of monomolecular, lipid-free/lipid-poor apoA-I in plasma.
Long-Term Inhibition of Rho-Kinase Suppresses Neointimal Formation After Stent Implantation in Porcine Coronary Arteries: Involvement of Multiple Mechanisms
Authors: Matsumoto Yasuharu , Uwatoku Toyokazu , Oi Keiji , Abe Kohtaro , Hattori Tsuyoshi , Morishige Kunio , Eto Yasuhiro , Fukumoto Yoshihiro , Nakamura Kei-ichiro , Shibata Yosaburo , Matsuda Takehisa , Takeshita Akira , Shimokawa Hiroaki
Published: November 2003

Objective—We recently demonstrated that Rho-kinase, an effector of the small GTPase Rho, is substantially involved in the pathogenesis of arteriosclerosis. In this study, we examined whether Rho-kinase is also involved in in-stent restenosis and if so, what mechanism is involved.

Methods and Results—Pigs underwent stent implantation in the left coronary artery with or without administration of fasudil (30 mg/kg per day orally), a specific Rho-kinase inhibitor, starting 2 days before the procedure for a duration of 4 weeks. On day 28, reductions in coronary diameter and neointimal formation associated with macrophage accumulation, collagen deposition, and transforming growth factor (TGF)-β1 expression were noted at the stent site, and all were significantly suppressed by fasudil. On day 7, fasudil significantly increased the frequency of TUNEL-positive apoptotic cells, while it tended to reduce that of bromodeoxyuridine-positive proliferating cells in the neointima. Western blot analysis on day 7 demonstrated that phosphorylations of the ezrin/radixin/moesin family (a marker of Rho-kinase activity in vivo) and protein expression of monocyte chemoattractant protein-1and bcl-2 were upregulated at the stent site and were significantly suppressed by fasudil.

Conclusions—These results indicate that long-term inhibition of Rho-kinase suppresses in-stent neointimal formation by multiple mechanisms, including reduced vascular inflammation, enhanced apoptosis, and decreased collagen deposition.
Effect of Posture on Blood and Intraocular Pressures in Multiple System Atrophy, Pure Autonomic Failure, and Baroreflex Failure
Authors: Singleton Chasidy D. , Robertson David , Byrne Daniel W. , Joos Karen M.
Published: November 2003

Background—

Intraocular pressure (IOP) may be partially under systemic vascular control. This study examined whether a correlation exists between blood and intraocular pressures in patients with autonomic dysfunction.

Methods and Results—

Eleven patients with 3 types of confirmed autonomic dysfunction (multiple system atrophy, pure autonomic failure, and baroreflex failure) were compared with age- and gender-matched controls and had IOP, systolic blood pressure, diastolic blood pressure, heart rates, and calculated mean arterial pressures (MAP) and mean ocular perfusion pressures (MOPP) measured in the supine, sitting, and standing positions. Data were analyzed with a general linear model repeated-measures ANOVA. All pressures for patients showed a dramatic decline (
P
<0.001) from supine to standing (MAP −31±14 mm Hg; IOP −6±3 mm Hg; MOPP −25±14 mm Hg) compared with controls (MAP +4±7 mm Hg; IOP −1±2 mm Hg; MOPP +6±7 mm Hg). There was no significant change in heart rate from supine to standing for patients compared with controls (
P
=0.648). Within both the multiple system atrophy (n=5) and pure autonomic failure (n=4) groups, all initial pressures were similar to control pressures in the supine position, whereas patients with baroreflex failure (n=2) had higher mean pressures than respective controls in the supine position.

Conclusions—

In autonomic dysfunction, a large decrease in MAP correlated with a large decrease in IOP. These data suggest that the autonomic nervous system, perhaps through an influence on systemic blood pressure, has a significant role in IOP regulation.
Stratification of Pediatric Heart Failure on the Basis of Neurohormonal and Cardiac Autonomic Nervous Activities in Patients With Congenital Heart Disease
Authors: Ohuchi Hideo , Takasugi Hisashi , Ohashi Hiroyuki , Okada Yoko , Yamada Osamu , Ono Yasuo , Yagihara Toshikatsu , Echigo Shigeyuki
Published: November 2003

Background—

Stratification of pediatric patients with congenital heart disease (CHD) has been based on their hemodynamics and/or functional capacity. Our purpose was to compare cardiac autonomic nervous activity (CANA) and neurohormonal activities (NHA) with postoperative status in stable CHD patients with biventricular physiology.

Methods and Results—

We divided 379 subjects (297 CHD patients, 28 dilated cardiomyopathy patient, and 54 control subjects) into 4 subgroups according to New York Heart Association (NYHA) class (1.3±0.7) and measured various CANA and NHA indices. Stepwise decreases in baroreflex sensitivity (BRS), heart rate variability (HRV), adrenergic imaging, and vital capacity (VC) were observed in proportion to functional capacity in normal to NYHA II patients (
P
<0.001). However, there were no differences in these indices between NYHA II and III+IV groups, whereas a stepwise proportional increase in NHA indices was observed in these groups (
P
<0.001). Natriuretic peptides differentiated all NYHA classes. BRS, HRV, and VC were greater in the adult patients than in the child patients (
P
<0.05 to 0.01), although the functional class in adult patients was lower. Cardiac surgeries resulted in low BRS and VC, and the VC reduction independently determined a small HRV. Even if functional class and ejection fraction were comparable, CANA and brain natriuretic peptide were lower in CHD patients than in dilated cardiomyopathy patients (
P
<0.05 to 0.001).

Conclusions—

CANA and NHA indices are useful to stratify mild and severe heart failure in stable postoperative CHD patients, respectively. However, careful attention should be paid to age- and surgery-related influences on these indices.
Plasma Homocysteine, Hypertension Incidence, and Blood Pressure Tracking
Authors: Sundström Johan , Sullivan Lisa , D’Agostino Ralph B. , Jacques Paul F. , Selhub Jacob , Rosenberg Irwin H. , Wilson Peter W.F. , Levy Daniel , Vasan Ramachandran S.
Published: November 2003

Plasma homocysteine is cross-sectionally associated with blood pressure in large, community-based studies. It is unknown whether elevated plasma homocysteine predicts hypertension incidence. We investigated the relations of baseline plasma total homocysteine levels to hypertension incidence and blood pressure tracking in 2104 Framingham Heart Study participants (mean age, 57 years; 58% women), who were free of hypertension, myocardial infarction, heart failure, atrial fibrillation, or renal failure at baseline. Baseline mean±SD plasma homocysteine was 10.1±3.7 μmol/L. On follow-up 4 years from baseline, 360 persons (17.1%) had developed hypertension, and 878 persons (41.7%) had progressed to a higher blood pressure stage. In unadjusted analyses, a 1-SD higher log homocysteine value was associated with increased odds of developing hypertension (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.05 to 1.32) and increased odds of blood pressure progression (OR, 1.17; 95% CI, 1.07 to 1.27). The relations of plasma homocysteine to the incidence of hypertension or blood pressure progression were statistically nonsignificant in age- and sex-adjusted logistic regression models (OR, 0.98; 95% CI, 0.87 to 1.11 and OR, 1.05; 95% CI, 0.96 to 1.16, respectively) and in multivariable models adjusted for age, sex, body mass index, diabetes, interim weight change, smoking, serum creatinine, baseline blood pressure, and blood pressure category (OR, 0.92; 95% CI, 0.81 to 1.06 and OR, 1.07; 95% CI, 0.97 to 1.18, respectively). In conclusion, we found no major relation of baseline plasma homocysteine levels to hypertension incidence or longitudinal blood pressure progression in a large, community-based cohort of nonhypertensive individuals after adjustment for age, sex, and other important covariates.
Role of Superoxide in Modulating the Renal Effects of Angiotensin II
Authors: López Bernardo , Salom Miguel García , Arregui Begoña , Valero Fernando , Fenoy Francisco J.
Published: November 2003

Angiotensin II is known to stimulate NADPH oxidase-dependent superoxide (O
2
−
) generation, which may contribute to the acute renal vasoconstrictor and antinatriuretic actions of this peptide. To evaluate this hypothesis, the effects of a superoxide dismutase mimetic (tempol) or a NADPH inhibitor (apocynin) on the angiotensin renal actions were studied. Renal cortical nitric oxide (NO) was measured electrochemically in vivo. Tempol increased sodium excretion and NO levels. Apocynin raised renal blood flow, glomerular filtration rate, sodium excretion, and NO levels. These results indicate the presence of an endogenous NADPH oxidase-dependent O
2
−
generation that may modulate renal function by scavenging NO. Angiotensin II infusion reduced renal blood flow, glomerular filtration, sodium excretion, and NO levels in a dose-dependent manner. The angiotensin receptor antagonist valsartan, tempol, or apocynin blunted the angiotensin effects on renal excretion and NO, suggesting that angiotensin receptors stimulation induces the NADPH oxidase-dependent O
2
−
generation that might reduce NO bioavailability. This idea is supported by the finding that angiotensin increased O
2
−
generation in renal homogenates, and this effect was prevented by valsartan, apocynin, or tempol. These results indicate that some of the acute renal effects of angiotensin II may be enhanced by an increased NADPH oxidase-derived O
2
−
production that reduces renal NO bioavailability.
Effect of Intravenous Angiotensin II Infusion on Responses to Hypothalamic PVN Injection of Bicuculline
Authors: LaGrange Lila P. , Toney Glenn M. , Bishop Vernon S.
Published: November 2003

The hypothalamic paraventricular nucleus (PVN) plays an important role in the sympathoexcitatory response to elevated plasma angiotensin II (Ang II). However, the mechanism by which Ang II influences sympathetic activity is not fully understood. In this study, we tested the hypothesis that GABA(γ-aminobutyric acid)-ergic function in the PVN is reduced by peripheral infusion of Ang II. To accomplish this, rats received either intravenous Ang II (12 ng/kg per minute) or vehicle (D5W) for 7 days, and renal sympathetic nerve activity (SNA), mean arterial pressure (MAP), and heart rate (HR) responses were recorded after unilateral PVN microinjection of the GABA-A receptor antagonist bicuculline methiodide (BMI, 0.1 nmol). Results indicate that in contrast to a significant increase in renal SNA, MAP, and HR observed in vehicle-infused rats (
P
<0.05), BMI injection into the PVN of Ang II–infused animals was without effect on all recorded variables. In a separate groups of animals, ganglionic blockade produced a significantly greater fall in MAP (
P
<0.01) in Ang II–infused rats than in vehicle-infused control rats, indicating that the contribution of SNA to the maintenance of blood pressure was elevated in the Ang II–infused group. Overall, these data indicate that cardiovascular and sympathoexcitatory responses to acute GABA-A receptor antagonism in the PVN are significantly blunted in rats after 7 days of intravenous infusion of Ang II. We conclude that an Ang II–induced reduction in GABAergic inhibition within the PVN may contribute to elevated SNA observed in this study.
Pulsatile Versus Oscillatory Shear Stress Regulates NADPH Oxidase Subunit Expression
Authors: Hwang Juliana , Ing Michael H. , Salazar Adler , Lassègue Bernard , Griendling Kathy , Navab Mohamad , Sevanian Alex , Hsiai Tzung K.
Published: November 2003

Shear stress regulates endothelial nitric oxide and superoxide (O
2
−·
) production, implicating the role of NADPH oxidase activity. It is unknown whether shear stress regulates the sources of reactive species production, consequent low-density lipoprotein (LDL) modification, and initiation of inflammatory events. Bovine aortic endothelial cells (BAECs) in the presence of 50 μg/mL of native LDL were exposed to (1) pulsatile flow with a mean shear stress (τ
ave
) of 25 dyne/cm
2
and (2) oscillating flow at τ
ave
of 0. After 4 hours, aliquots of culture medium were collected for high-performance liquid chromatography analyses of electronegative LDL species, described as LDL
−
and LDL
2−
. In response to oscillatory shear stress, gp91
phox
mRNA expression was upregulated by 2.9±0.3-fold, and its homologue, Nox4, by 3.9±0.9-fold (
P
<0.05, n=4), with a corresponding increase in O
2
−·
production rate. The proportion of LDL
−
and LDL
2−
relative to static conditions increased by 67±17% and 30±7%, respectively, with the concomitant upregulation of monocyte chemoattractant protein-1 expression and increase in monocyte/BAEC binding (
P
<0.05, n=5). In contrast, pulsatile flow downregulated both gp91
phox
and Nox4 mRNA expression (by 1.8±0.2-fold and 3.0±0.12-fold, respectively), with an accompanying reduction in O
2
−·
production, reduction in the extent of LDL modification (51±12% for LDL
−
and 30±7% for LDL
2−
), and monocyte/BAEC binding. The flow-dependent LDL oxidation is determined in part by the NADPH oxidase activity. The formation of modified LDL via O
2
−·
production may also affect the regulation of monocyte chemoattractant protein-1 expression and monocyte/BAEC binding.
Validation of Computed Tomographic Middle Cerebral Artery “Dot” Sign
Authors: Leary Megan C. , Kidwell Chelsea S. , Villablanca J. Pablo , Starkman Sidney , Jahan Reza , Duckwiler Gary R. , Gobin Y. Pierre , Sykes Steven , Gough Kristi J. , Ferguson Katrina , Llanes Jennifer N. , Masamed Rinat , Tremwel Margaret , Ovbiagele Bruce , Vespa Paul M. , Vinuela Fernando , Saver Jeffrey L.
Published: November 2003

Background and Purpose—

The middle cerebral artery (MCA) “dot” sign consists of hyperdensity of an arterial structure, seen as a dot in the sylvian fissure. The MCA dot sign has been proposed to indicate thrombosis of M2 or M3 MCA branches, analogous to the hyperdense middle cerebral artery (HMCA) sign indicating M1 thrombosis. The MCA dot sign has not been validated previously against the gold standard of conventional cerebral angiography.

Methods—

Noncontrast CT scans and immediately subsequent cerebral angiograms from 54 acute stroke patients within 8 hours of symptom onset were analyzed. CT films were inspected for the MCA dot sign and HMCA sign. Vascular findings on CT were compared with findings at angiography.

Results—

Mean patient age was 71 years; median National Institutes of Health Stroke Scale score was 16.5. Mean time from symptom onset to CT was 125 minutes, and that from CT to angiography was 117 minutes. All patients had arterial occlusion at angiography. Of the anterior circulation occlusions, M1 occlusions were noted in 28 patients, isolated M2 in 15, and isolated M3 in 4. One definite MCA dot sign was observed in 16.7% of patients, and an HMCA sign was observed in 13.9%. MCA dot sign performance in predicting the presence of M2 or M3 clot at angiography was as follows: sensitivity 38%, specificity 100%, positive predictive value 100%, negative predictive value 68%, and overall accuracy 73%.

Conclusions—

The MCA dot sign is a highly specific and moderately sensitive indicator of acute thrombus in the M2/M3 MCA branches, as validated by catheter angiography. The MCA dot sign is a useful additional acute stroke CT marker.
Thymosin β4 induces the synthesis of plasminogen activator inhibitor 1 in cultured endothelial cells and increases its extracellular expression
Authors: Al-Nedawi Khalid N. I. , Czyz Malgorzata , Bednarek Radoslaw , Szemraj Janusz , Swiatkowska Maria , Cierniewska-Cieslak Aleksandra , Wyczolkowska Janina , Cierniewski Czeslaw S.
Published: November 2003

Thymosin β4(Tβ4), a 4.9-kDa polypeptide primarily known as a main G-actin–sequestering peptide, is present in high concentrations in various cells and in the circulation. We have found that Tβ4 upregulates the expression of plasminogen activator inhibitor 1 (PAI-1) in endothelial cells measured both at the level of mRNA and protein synthesis. This effect seems to be cell specific and was not observed when other cells such as human fibroblasts, PC3, and U937 were tested. Tβ4 significantly activated the PAI-1 promoter in EA.hy 926 cells transiently transfected either with plasmid p800LUC containing PAI-1 promoter fragment (–800 to +71) or the PAI-1 promoter linked with green fluorescent protein. Tβ4 mediated up-regulation of PAI-1 involved activation of the mitogen-activated protein kinase cascade. Furthermore, Tβ4 enhanced c-Fos/c-Jun DNA-binding activity to the activator protein 1 (AP-1)–like element (–59 to –52). The specificity of this binding activity was demonstrated by competition electrophoretic mobility shift assay and after transfection of EA.hy 926 cells with the mutated PAI-1 promoter. Taken together, these data indicate that, in response to Tβ4 stimulation, AP-1 activity increases to enhance PAI-1 transcription through its unique AP-1–like element at –59 to –52 in the PAI-1 promoter.
Inhibition of restenosis by tissue factor pathway inhibitor: in vivo and in vitro evidence for suppressed monocyte chemoattraction and reduced gelatinolytic activity
Authors: Kopp Christoph W. , Hölzenbein Thomas , Steiner Sabine , Marculescu Rodrig , Bergmeister Helga , Seidinger Daniela , Mosberger Isabella , Kaun Christoph , Cejna Manfred , Horvat Reinhard , Wojta Johann , Maurer Gerald , Binder Bernd R. , Breuss Johannes M. , Ecker Rupert C. , de Martin Rainer , Minar Erich
Published: November 2003

Activation of inflammatory and procoagulant mechanisms is thought to contribute significantly to the initiation of restenosis, a common complication after balloon angioplasty of obstructed arteries. During this process, expression of tissue factor (TF) represents one of the major physiologic triggers of coagulation that results in thrombus formation and the generation of additional signals leading to vascular smooth muscle cell (VSMC) proliferation and migration. In this study, we have investigated the mechanisms by which inhibition of coagulation at an early stage through overexpression of tissue factor pathway inhibitor (TFPI), an endogenous inhibitor of TF, might reduce restenosis. In a rabbit femoral artery model, percutaneous delivery of TFPI using a recombinant adenoviral vector resulted in a significant reduction of the intimamedia ratio 21 days after injury. Investigating several markers of inflammation and coagulation, we found reduced neointimal expression of monocyte chemoattractant protein-1 (MCP-1), lesional monocyte infiltration, and expression of vascular TF, matrix metalloproteinase-2 (MMP-2), and MMP-9. Moreover, overexpression of TFPI suppressed the autocrine release of platelet-derived growth factor BB (PDGF-BB), MCP-1, and MMP-2 in response to factors VIIa and Xa from VSMCs in vitro and inhibited monocyte TF activity. These results suggest that TFPI exerts its action in vivo through not only thrombotic, but also nonthrombotic mechanisms.
A signaling mechanism for growth-related expression of fetal hemoglobin
Authors: Bhanu Natarajan V. , Trice Tiffany A. , Lee Y. Terry , Miller Jeffery L.
Published: November 2003

Increases in fetal hemoglobin have been identified after birth in several clinical settings associated with stressed or malignant erythropoiesis. To better understand the relationship between the expression of this fetal protein and growth, donated human erythroid progenitor cells were cultured in the presence of erythropoietin (EPO) plus the growth-modifying cytokine stem cell factor (SCF), and several growth-related signaling pathways were interrogated. Only the MEK1/2 inhibitor (PD98059) demonstrated significant effects on fetal hemoglobin. In the absence of PD98059, levels of fetal hemoglobin averaged 27.4% ± 7.9% in EPO+SCF compared with 1.26% ± 1.7% in EPO alone (P = .02). A linear dose response in levels of fetal hemoglobin to PD98059 was detected (0.16 μM = 27.13%, 0.8 μM = 19.6%, 4 μM = 12.2%, 20 μM = 1.54%). Western blot analyses revealed that SCF was required for phosphorylation of MEK and p44MAPK in this setting, and quantitative polymerase chain reaction demonstrated a significant increase in γ-globin mRNA. Particular perturbations of growth-related signaling may also function to activate tissue-specific genes normally expressed during fetal development. This concept may be relevant for the development of new treatment rationales for beta hemoglobinopathies.
Syndecan-2 is essential for angiogenic sprouting during zebrafish development
Authors: Chen Eleanor , Hermanson Spencer , Ekker Stephen C.
Published: November 2003

We used a morpholino-based gene-targeting screen to identify a novel protein essential for vascular development using the zebrafish, Danio rerio. We show that syndecan-2, a cell-surface heparan sulfate proteoglycan, is essential for angiogenic sprouting during embryogenesis. The vascular function of syndecan-2 is likely conserved, as zebrafish and mouse syndecan-2 show similar expression patterns around major trunk vessels, and human syndecan-2 can restore angiogenic sprouting in syndecan-2 morphants. In contrast, forced expression of a truncated form of syndecan-2 results in embryos with defects in angiogenesis, indicating that the highly conserved cytoplasmic tail is important for the vascular function of syndecan-2. We further show that vascular endothelial growth factor (VEGF) and syndecan-2 genetically interact in vivo using both gain-of-function and loss-of-function studies in zebrafish. VEGF-mediated ectopic signaling is compromised in syndecan-2 morphants, and ectopic syndecan-2 potentiates ectopic VEGF signaling. Syndecan-2 as a novel angiogenic factor is a potential candidate for use in the development of angiogenesis-based therapies.
Novel heat shock protein Hsp70L1 activates dendritic cells and acts as a Th1 polarizing adjuvant
Authors: Wan Tao , Zhou Xiangyang , Chen Guoyou , An Huazhang , Chen Taoyong , Zhang Weiping , Liu Shuxun , Jiang Yingming , Yang Feng , Wu Yanfeng , Cao Xuetao
Published: November 2003

Heat shock proteins (HSPs) are reported to act as effective adjuvants to elicit anti-tumor and anti-infection immunity. Here, we report that Hsp70-like protein 1 (Hsp70L1), a novel HSP derived from human dendritic cells (DCs), has potent adjuvant effects that polarize responses toward Th1. With a calculated molecular weight of 54.8 kDa, Hsp70L1 is smaller in size than Hsp70 but resembles it both structurally and functionally. Hsp70L1 shares common receptors on DCs with Hsp70 and can interact with DCs, promoting DC maturation and stimulating secretion of the proinflammatory cytokines interleukin 12p70 (IL-12p70), IL-1β, tumor necrosis factor-α (TNF-α), and the chemokines IP-10, macrophage inflammatory protein-1α (MIP-1α), MIP-1β, and normal T cell expressed and secreted (RANTES). The induction of interferon-γ–inducible protein 10 (IP-10) secretion by Hsp70L1 is not shared by Hsp70, and other functional differences include more potent stimulation of DC IL-12p70, CC-chemokine, and CCR7 and CXCR4 expression by Hsp70L1. Immunization of mice with the hybrid peptide Hsp70L1-ovalbumin(OVA)257-264 induces an OVA257-264-specific Th1 response and cytotoxic T lymphocyte (CTL) that results in significant inhibition of E.G7-OVA tumor growth. The ability of Hsp70L1 to activate DCs indicates its potential as a novel adjuvant for use with peptide immunizations; the Hsp70L1 antigen peptide hybrid may serve as a more effective vaccine for the control of cancer and infectious diseases.
An Attenuated Adenovirus, ONYX-015, As Mouthwash Therapy for Premalignant Oral Dysplasia
Authors: Rudin Charles M. , Cohen Ezra E.W. , Papadimitrakopoulou Vassiliki A. , Silverman Sol , Recant Wendy , El-Naggar Adel K. , Stenson Kirsten , Lippman Scott M. , Hong Waun Ki , Vokes Everett E.
Published: November 2003

Purpose: Dysplastic lesions of the oral epithelium are known precursors of oral cancer. A significant proportion of oral dysplastic lesions have functional defects in p53 response pathways. The ONYX-015 adenovirus is selectively cytotoxic to cells carrying defects in p53-dependent signaling pathways. The current study sought to establish the feasibility and activity of ONYX-015 administered topically as a mouthwash to patients with clinically apparent and histologically dysplastic lesions of the oral mucosa.

Patients and Methods: A total of 22 patients (19 assessable patients) were enrolled onto the study. ONYX-015 was administered on three different schedules to consecutive cohorts. Biopsies of the involved mucosa were performed to evaluate histologic response and changes in expression of putative markers of malignant potential, including p53, cyclin D1, and Ki-67. Serology was performed to measure antiadenoviral titers.

Results: Histologic resolution of dysplasia was seen in seven (37%) of 19 patients, and the grade of dysplasia improved in one additional patient. The majority of responses were transient. No toxicity greater than grade 2 (febrile episode in one patient) was observed. Only one of seven patients demonstrated an increase in circulating antiadenoviral antibody titer while on therapy. Although responding and resistant lesions had similar mean p53 staining at baseline, histologic response correlated with a decrease in p53 positivity over time. Significant changes in cyclin D1 or Ki-67 were not observed. Viral replication was confirmed in two of three lesions examined.

Conclusion: This novel approach to cancer prevention is tolerable, feasible, and has demonstrable activity.
Agouti-Related Protein Antagonizes Glucocorticoid Production Induced through Melanocortin 4 Receptor Activation in Bovine Adrenal Cells: A Possible Autocrine Control
Authors: Doghman Mabrouka , Delagrange Philippe , Blondet Antonine , Berthelon Marie-Claude , Durand Philippe , Naville Danielle , Bégeot Martine
Published: November 2003

Agouti-related protein (Agrp), primarily expressed in the hypothalamus, is an endogenous antagonist of αMSH at the level of melanocortin 3 receptor (MC3-R) and MC4-R, but the adrenal gland represents the second major Agrp-expressing tissue. In adrenal fasciculata cells, the glucocorticoid secretion is under the control of ACTH, which binds specifically MC2-R, the only functional melanocortin receptor described in these cells to date. Nevertheless, using cultured bovine fasciculata adrenal cells, we report that Agrp has no antagonistic properties against ACTH at the level of MC2-R. In our studies, (Nle4, d-Phe7)-αMSH (NDP-αMSH) stimulated the production of cortisol in a dose-dependent manner, and these effects were abolished by Agrp or SHU9119, a synthetic antagonist of MC3-R and MC4-R. Using a more specific antagonist (JKC-363) and RT-PCR analysis, we can postulate that the effects of NDP-αMSH were mediated via MC4-R. These results are suggestive that adrenal glucocorticoid production could be regulated through MC4-R that may have some relevance in the physiology of adrenal cells. Moreover, Agrp might exert an autocrine control on adrenal cells because a protein with biological Agrp-like activity is secreted by these cells. This peptide could then modulate locally the functions of some peripheral tissues such as adrenals.
Galanin Receptor Subtype GalR2 Mediates Apoptosis in SH-SY5Y Neuroblastoma Cells
Authors: Berger Alexandra , Lang Roland , Moritz Kerstin , Santic Radmila , Hermann Anton , Sperl Wolfgang , Kofler Barbara
Published: November 2003

Recently we have shown that galanin binding significantly correlates with survival in neuroblastoma patients, indicating a possible modulatory role of galanin receptors in neuroblastic tumor biology. However, the molecular mechanisms beyond this correlation have not been elucidated. Here, the cellular effects on activation of specific galanin receptor subtypes in human SH-SY5Y neuroblastoma cells were analyzed using a tetracycline-controlled expression system. Pharmacological studies confirmed the inducible expression of high affinity binding sites for galanin in SH-SY5Y cells transfected with the galanin receptors GalR1 (SY5Y/GalR1) and GalR2 (SY5Y/GalR2). Microphysiometry revealed that both receptor subtypes were able to mediate an intracellular signal upon galanin application. Interestingly, induction of receptor expression and treatment with 100 nm galanin resulted in a dramatic decrease in cell viability in SY5Y/GalR2 cells (93 ± 3%) compared with a less pronounced effect in SY5Y/GalR1 cells (19 ± 10%). The antiproliferative potency of galanin was 100-fold higher in SY5Y/GalR2 (50% effective concentration, 1.1 nm) than in SY5Y/GalR1 cells (50% effective concentration, 190 nm). Furthermore, activation of receptor expression and exposure to galanin resulted in apparent morphological changes indicative of apoptosis in SY5Y/GalR2 cells only. Induction of cell death by the apoptotic process was confirmed by poly-(ADP-ribose)-polymerase cleavage, caspase-3 activation, and the typical laddering of DNA. This study indicates that a high level of GalR2 expression is able to inhibit cell proliferation and induce apoptosis in neuroblastoma cells and therefore identifies GalR2 as a possible target for pharmacological intervention in neuroblastoma.