bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of adrenaline on echocardiographic parameters of left ventricular function in the horse
Authors: Gehlen Heidrun , Marnette Silke , Stadler Peter 
Published: August 2005

AbstractThe purpose of the present study was to investigate the effect of adrenaline on cardiac function parameters. The infusion of adrenaline for induction of stress, its prospective side-effects as well as its effect on left ventricular function were investigated. A clinical examination and echocardiography were performed on 10 healthy horses before and after infusion of adrenaline. During a period of 6 min, infusion of 1 μg adrenaline kg−1min−1led to a significant increase in mean heart rate, from 36.5 to 55 beats min−1. Echocardiography during adrenaline infusion revealed a significant thickening of the interventricular septum (during systole) as well as a significant decrease in left ventricular diameter at the papillary muscle level (during both systole and diastole), and thus an increased contractility. The left ventricular area and the left ventricular volume were significantly decreased during adrenaline infusion, expressing the increased left ventricular contractility (during both systole and diastole). Other echocardiographic parameters of regional left ventricular function changed with only low-grade significance or without any significance at all. During and after infusion of adrenaline, the horses showed sweating, muscle tremor and other symptoms of discomfort. The study revealed that the increases in heart rate and myocardial contractility after infusion of adrenaline were low compared with changes observed during physical performance. Furthermore, severe adverse effects were observed. Taking into account the possible cardiotoxic effects of adrenaline, we do not consider this method appropriate for stress induction, particularly in horses with cardiac disorders.
A Cautionary Tale
Authors: Gorog Diana A , Russell Georgina , Casian Alina , Peters Nicholas S 
Published: August 2005

Abstract

Myotonic dystrophy (MD) is associated with important cardiac abnormalities, and 30% of deaths are attributable to cardiac causes, predominantly arrhythmias. Sodium channel blockers have been used to improve muscle strength and relaxation in MD. Flecainide is a potent selective blocker of the mutant sodium channel in myotonia and inhibits the abnormal noninactivating sodium current in both painful myotonia congenita and painless MD with a resultant improvement in muscle relaxation. We describe the case of a 41-year-old woman with MD who developed ventricular tachycardia (VT) while taking flecainide to improve her muscle strength. Flecainide was discontinued and VT could not subsequently be induced. Although flecainide is an effective antiarrhythmic agent, it may also be proarrhythmic, particularly in patients at risk for VT. We recommend careful cardiac assessment, risk stratification, and consideration of high-risk patients for early screening electrophysiological studies, especially if considering use of a class 1 antiarrhythmic agent.
Primary Lateral Sclerosis
Authors: Singer Mike A , Kojan Suleiman , Barohn Richard J , Herbelin Laura , Nations Sharon P , Trivedi Jaya R , Jackson Carlayne E , Burns Dennis K , Boyer Philip J , Wolfe Gil I 
Published: August 2005

Abstract

Objective:
The objective of this study was to characterize the clinical features and natural history of primary lateral sclerosis (PLS).

Background:
PLS is a motor neuron disorder defined by corticospinal and corticobulbar tract dysfunction without clinically significant lower motor neuron involvement.

Methods:
We collected data from 25 patients with PLS seen in 2 academic neurology departments over a 5-year period.

Results:
The PLS population represented approximately 3% of acquired motor neuron disease cases seen during that period. Twenty-three patients (92%) presented with lower limb weakness, spasticity, or difficulty with ambulation. None presented with upper limb symptoms. Eleven patients (44%) developed bulbar symptoms. All patients had hyperreflexia and increased muscle tone. Muscle weakness was observed in 15 patients (60%) and tended to be mild and asymmetric. Needle electromyography (EMG) was normal or showed only fasciculations in 15 patients (60%); 10 patients had features of mild active denervation, consisting of fibrillation or positive sharp wave potentials, but the extent of these findings did not satisfy World Federation of Neurology electrophysiological criteria for the diagnosis of amyotrophic lateral sclerosis. Fourteen patients (52%) continued independent ambulation. Of the 10 patients with active denervation on EMG, 6 (60%) required a walker, scooter, or wheelchair at a mean follow up of 6.2 years. There were no fatalities over the 5-year period.

Conclusions:
Our experience supports the observation that PLS progresses more slowly than other forms of acquired motor neuron disease, particularly amyotrophic lateral sclerosis. Follow-up data suggest that patients with active denervation changes develop greater disability.
Perindopril Regulates β-Agonist-Induced Cardiac Apoptosis
Authors: Gálvez Anita S , Fiedler Jenny L , Ocaranza María Paz , Jalil Jorge E , Lavandero Sergio , Díaz-Araya Guillermo 
Published: August 2005

Abstract:

Administration of the β-adrenergic agonist isoproterenol results in cardiac apoptosis. The effect of short-term β-adrenergic stimulation by isoproterenol on the activity of plasma, lung, and left ventricular (LV) angiotensin I-converting enzyme (ACE) activity and its association with the development of cardiac apoptosis was investigated. β-Adrenergic stimulation for 24 hours produced an early increase only in the proapoptotic proteins bax and bcl-XS without changes in the levels of the antiapoptotic protein bcl-XL. The ratio between these bcl family proteins was indicative of apoptosis and correlated with an early and significant increase (300%) in DNA laddering. However, after 5 days of the β-adrenergic stimulation, the ratio changed in favor of antiapoptotic proteins and correlated with the absence of DNA fragmentation. In addition, LV and plasma ACE activities increased markedly with isoproterenol over the study period up to 5 days. ACE activity also regulated expression of the antiapoptotic gene bcl
-XL. The administration of perindopril (an ACE inhibitor) prevented the observed increase in bax and bcl-XS levels and attenuated (50% decrease, P < 0.05) the effect of isoproterenol on DNA fragmentation. Thus, early and transient cardiac apoptosis triggered by the β-adrenergic agonist isoproterenol is reversed in the presence of perindopril.
Antihypertensive and Endothelium-Dependent Vasodilator Effects of Alpinia zerumbet, a Medicinal Plant
Authors: de Moura R Soares , Emiliano A F , de Carvalho L C. R. Marins , Souza M A. V , Guedes D C , Tano T , Resende A C 
Published: August 2005

Abstract:

Alpinia zerumbet (K. Schum), a medicinal plant originated from West Asia, is used in the northeast and southeast of Brazil as infusions or decoctions as a diuretic, antihypertensive, and antiulcerogenic. Experiments were undertaken to determine whether a hydroalcoholic extract obtained from leaves of Alpinia zerumbet (AZE) induces vasodilation in the mesenteric vascular bed (MVB), and an antihypertensive effect was also assessed in rats with DOCA-salt hypertension. In MVB precontracted with norepinephrine, AZE induces a long-lasting endothelium-dependent vasodilation that is not reduced by indomethacin. Inhibition of NO synthase by NG-nitro-L-arginine methyl ester (L-NAME) and guanylyl cyclase by 1H-[1,2,3]oxadiazolo [4,4-a]quinoxalin-1-one (ODQ) reduces the vasodilator effect of AZE. In vessels precontracted with norepinephrine, the vasodilator effect of AZE was not changed by 4-aminopyridine, glibenclamide, or by charybdotoxin plus apamin. Concentrations of atropine, pyrilamine, and yohimbine that significantly reduced the vasodilator effect of acetylcholine, histamine, and clonidine, respectively, did not change the vasodilator effect of AZE. HOE 140, which significantly reduced the vasodilator effect of bradykinin, induced a slight but significant reduction on the vasodilator effect of AZE. Chronic oral administration of AZE induced a significant reduction in systolic, mean, and diastolic arterial pressure in rats with DOCA-salt hypertension. Probably the vasodilator effect of AZE is dependent on the activation of the NO-cGMP pathway and independent of activation of ATP-dependent, voltage-dependent, and calcium-dependent K+ channels. Bradykinin receptors may also participate in the vasodilator effect of AZE. Finally, the vasodilator and antihypertensive effects of AZE demonstrated in the present study provide experimental support for the indication of Alpinia zerumbet as an antihypertensive medicinal plant.
Effect of Acetylsalicylic Acid on Nuclear Factor-κB Activation and on Late Preconditioning Against Infarction in the Myocardium
Authors: Jancso Gabor , Cserepes Barbara , Gasz Balázs , Benkő Laszlo , Ferencz Andrea , Borsiczky Balazs , Lantos Janos , Dureja Anjali , Kiss Katalin , Szeberényi Jozsef , Rőth Elizabeth 
Published: August 2005

Abstract:

Nuclear factor-κB (NF-κB) plays an essential role in the intracellular signal transduction of the second window of protection (SWOP). Acetylsalicylic acid (ASA) blocks NF-κB-dependent gene activation in leukocytes and endothelial cells through preventing phosphorylation and subsequent degradation of the inhibitor IκB-α. This study investigated the effect of ASA on the late phase of ischemic preconditioning (PC) against myocardial infarction and on the activation of NF-κB in the preconditioned myocardium. Conscious rabbits were subjected to 4 cycles of 5 minutes of coronary occlusion and 5 minutes of reperfusion together with 3 different doses of ASA (5 mg/kg; 25 mg/kg; 130 mg/kg). After 30 minutes of reperfusion we determined the activation of NF-κB with an electrophoretic mobility shift assay (EMSA). Twenty-four hours later, after 30 minutes of test ischemia, we performed infarct size analysis using triphenyltetrazolium-chloride (TTC) staining. Neither 5 mg/kg (antithrombotic dose) nor 25 mg/kg (analgesic/antipyretic dose) of ASA interfered with the NF-κB activation and the protective effect of late preconditioning against myocardial infarction. In contrast, NF-kB activation and late PC effect were completely abrogated by 130 mg/kg of ASA. Our results suggest that nonselective doses of NSAIDs should be used with caution in patients with atherosclerotic cardiovascular disease because they may deprive the heart of its innate defensive response.
2-Bromoethylamine, a Suicide Inhibitor of Semicarbazide-Sensitive Amine Oxidase, Increases Hydralazine Hypotension in Rats
Authors: Vidrio Horacio , Medina Martha 
Published: August 2005

Abstract:

Previous work has shown that inhibitors of the predominantly vascular enzyme semicarbazide-sensitive amine oxidase (SSAO) potentiate the hypotensive response to hydralazine, itself a SSAO inhibitor, in anesthetized rats. The present study was carried out to determine whether the recently described suicide SSAO inhibitor 2-bromoethylamine shares this effect. Hypotensive responses to hydralazine, 0.1 mg/kg IV, were obtained in chloralose-urethane-anesthetized rats, either unpretreated or receiving bromoethylamine at different doses and pretreatment intervals. Parallel experiments were run with semicarbazide, the prototypical hydrazine SSAO inhibitor. Both inhibitors potentiated hydralazine hypotension, bromoethylamine having a longer latency and a shorter duration of action than semicarbazide. High doses of bromoethylamine did not produce potentiation, a phenomenon attributed to SSAO inactivation by excess substrate and decreased formation by the enzyme of the inhibitor product. Experiments with combined administration of both inhibitors were also carried out. When semicarbazide was administered before bromoethylamine, potentiaton was prevented, apparently by a mechanism similar to the above; when it was given after the amine, potentiation was increased. This was attributed to enzyme inhibition by interaction with 2 different active sites. The charactertistics of hydralazine potentiation by bromoethylamine were considered compatible with the mechanism of SSAO inhibition by the amine.
Dehydroepiandrosterone Sulfate Induces Acute Vasodilation of Porcine Coronary Arteries In Vitro and In Vivo
Authors: Hutchison Stuart J , Browne Amanda E M , Ko Eitetsu , Chou Tony M , Zellner Christian , Komesaroff Paul A , Chatterjee Kanu , Sudhir Krishnankutty 
Published: August 2005

Abstract:Although an inverse relationship between dehydroepiandrosterone sulfate (DHEAS) and coronary artery disease has been demonstrated in men, the vascular effects of DHEAS are not well defined. The vasoactive effects of intracoronary DHEAS and testosterone (0.1 nM to 1 μM) were examined in vivo in 24 pigs. Epicardial cross-sectional area was measured by intravascular ultrasound, and coronary flow velocity by intravascular Doppler velocimetry. We also examined the effects of antagonism of the androgen receptor, nitric oxide synthase, and potassium channels on DHEAS-induced vasodilation in vitro in coronary rings from male and female pig hearts. DHEAS and testosterone induced increases in cross-sectional area, average peak velocity, and coronary blood flow. The maximal increase in coronary blood flow in response to testosterone was 1.26-fold (P= 0.02), and in average peak velocity 1.43-fold (P= 0.05), greater than that to DHEAS, whereas increases in cross-sectional area were similar. Vasodilation to both hormones was rapid, with maximal responses occurring <10 minutes after administration. In vitro, DHEAS and testosterone induced vasodilation in coronary rings, greater with testosterone. At doses of 0.1 and 1 μM, the vasodilator effects of DHEAS and testosterone were inhibited by the androgen receptor antagonist flutamide but not the estrogen receptor antagonist ICI 182,780. At 10 μM, neither DHEAS- nor testosterone-induced vasorelaxation was inhibited by flutamide, ICI 182,780, L-NAME, or deendothelialization, but both were attenuated by pretreatment with glibenclamide. No gender differences were observed in any of the responses examined. In conclusion, DHEAS is an acute coronary artery vasodilator, but less potent than testosterone. Its effect might be mediated via androgen receptors and may involve ATP-sensitive potassium channels.
Effect of cassava fluid on corrosion performance of mild steel
Authors: Jekayinfa S.O. , Waheed M.A. , Adebiyi K.A. , Adebiyi F.T. 
Published: August 2005

PurposeThe cheapest and most rapidly available metal for agro‐processing equipment fabrication in Nigeria is plain carbon steel. However, there are some aggressive ions present in raw agricultural and food products, which may attack the steel components of these processing machinery, resulting in their untimely failure in service. The present study investigates the effect of fluid squeezed from cassava tuber on the corrosion behaviour of mild steel.Design/methodology/approachThe investigation involved periodic weight loss measurements of 0.8 per cent carbon and 0.36 per cent carbon steel rods as they were exposed to cassava fluid. The relationships between loss in weight of the exposed samples and exposure period were determined. Models were developed to relate corrosion rate in each environment with total surface area and exposure period.FindingsThe results show that 0.36 per cent carbon steel was less affected by corrosion than 0.18 per cent carbon steel, with corrosion intensity in both cases, increasing with duration of immersion. Generally, there was low level of corrosion resistance (high corrosion rate) by the two steel materials. The correlation coefficient between the experimental values of corrosion rates and predicted values (using the developed models) was high.Originality/valueIn food and agricultural industries, product quality, health and sanitation issues are the major concerns. The industries cannot tolerate corrosion deposits in the manufactured products. Hence, material selection for machinery fabrication is essential. In line with this, the results of this study indicate that mild steel materials are unsuitable for use in cassava processing without some forms of surface treatment.
The inhibition of aluminium corrosion in potassium hydroxide by “Congo Red” dye, and synergistic action with halide ions
Authors: Oguzie E.E. , Onuoha G.N. , Onuchukwu A.I. 
Published: August 2005

PurposeTo investigate the inhibitive effect of Congo red dye (CR) for aluminium corrosion in strong alkaline solutions and evaluate the synergistic effect of halide ions on the inhibition efficiency.Design/methodology/approachCorrosion rates of aluminium test coupons were determined by gravimetric technique at 30 and 60°C. Inhibition efficiencies of the additives (0.01‐5.0 mM CR and 5.0 mM CR+0.5 mM halides) were evaluated by comparing corrosion rates of the test coupons in 2 M KOH solution in the absence and presence of the additives.FindingsCR inhibited aluminium corrosion in 2 M KOH by physical adsorption of the dye molecules on the corroding metal surface. Maximum efficiency at 30 and 60°C was 31.72 and 19.32 per cent, respectively. Dye adsorption was enhanced in the presence of halides in the order KCl < KBr < KI, with KI increasing efficiency up to 48.63 and 41.70 per cent at 30 and 60°C, respectively.Research limitations/implicationsFurther studies to involve variation of dye and halide concentrations for CR+halide systems to determine the best combination for optimum inhibition synergism.Originality/valueThis paper forms part of an extensive database on the inhibition characteristics of organic dyes for corrosion of different metals in various aggressive environments. This is to serve as a guide to possible applications in metal‐surface anodizing and as additives in surface coatings for service in different environments.
Robot cleans glass roof of Louvre pyramid
Authors: Kochan Anna 
Published: August 2005

PurposeAims to describe the application of robotics to the cleaning of the glass roof of the 21 m high pyramid that stands in front of the Louvre in Paris.Design/methodology/approachPresents the design of the robot, its traction mechanism, cleaning system and operating mode.FindingsFinds that a robot is capable of cleaning a glass roof at a great height and on a steep slope using only suction to adhere to the surface.Originality/valueIntroduces the concept of a robot in commercial use that cleans a steeply sloping glass roof.
Incorporating cannibalization models into demand forecasting
Authors: Ragharan Srinivasan Sundara , Ramakrishnan Sreeram , Grasman Scott E. 
Published: August 2005

PurposeQuantitative measures are not commonly available to identify and measure product cannibalization resulting from the introduction of new products, and existing forecasting methods such as ARIMA do not explicitly account for the phenomenon. This paper aims to present a methodology to build cannibalization effects into forecasting models as measured through product attributes. It follows on from a paper by the same authors in Vol. 23 No. 4Design/methodology/approachThe contribution of product attributes to cannibalization is tested by a series of hypotheses, then integrated into the proposed cannibalization model. Results are compared with predictions from an ARIMA‐based model and actual historical sales data.FindingsThe proposed model improves on the fidelity of ARIMA‐based models, by between 16 and 42 percent.Originality/valueEffective prediction of cannibalization losses will allow marketing planners to make better‐informed decisions with respect to new product introduction.
Building an open archive union catalog for digital archives
Authors: Yu Shien‐Chiang , Chen Hsueh‐hua , Chang Huai‐wen 
Published: August 2005

PurposeIn January 2002, the National Science Council of Taiwan launched a National Digital Archives Program (NDAP) and has proceeded with the implementation of a system related to the open archives initiative (OAI) framework. This paper aims to introduce the protocol and the prototype system of the project.Design/methodology/approachA general review of the project.FindingsThe OAI interoperability framework has received much attention from scholars of library and information sciences. In Europe and North America, many academic organizations and universities have undertaken theoretical studies, system design, and implementation of the OAI framework. In January 2002, the National Science Council of Taiwan launched a NDAP, and the institutional project of the National Taiwan University is one of its institutional projects. Now, the project has proceeded with the implementation of a system related to the OAI framework.Originality/valueProvides information of value to information professionals.
The development of digital libraries in China and the shaping of digital librarians
Authors: Zhou Qian 
Published: August 2005

PurposeAims to focus on the need for appropriately trained librarians of the next‐generation, the “Digital Librarians”, with particular emphasis on China.Design/methodology/approachThe paper first analyzes the definition and features of the digital library, and is followed by an introduction to digital libraries developing in China. Work modes and quality composition of digital librarians are then analyzed and discussed.FindingsDigital libraries emerging in the information age represent an inevitable trend for library development. A digital library contains a vast amount of digital information resources in multiple media. It may provide readers with diversified information services using digital and network technologies. In addition to certain hardware and software availabilities, the evolving digital library requires appropriately trained librarians of the next‐generation, the “Digital Librarians”, which forms the theme of this paper.Originality/valueProvides recommendations and measures on how China can develop further its digital librarians.
On numerical implementation of a coupled rate dependent damage‐plasticity constitutive model for concrete in application to high‐rate dynamics
Authors: Hervé Guillaume , Gatuingt Fabrice , Ibrahimbegović Adnan 
Published: August 2005

PurposeTo provide an efficient and robust constitutive equations for concrete ion application to high rate dynamics.Design/methodology/approachDevelops an explicit‐implicit integration scheme for a concrete model. This robust integration scheme ensures computational efficiency. Comparison between simulations of impact of equivalent aircraft engine projectiles and the tests carried out in Sandia laboratory also demonstrate its efficiency.FindingsShows that modeling transient high rate dynamic behavior of concrete is very important to take into account for design concrete structures in the cases of dynamic loading conditions, such as an impact on the structure.Originality/valueProposes an original integration scheme for a coupled rate dependent damage plasticity model. Also provides a detailed consideration of the numerical stability of this kind of scheme for rate‐dependent damage model.