bluuebunny/crossref_metadata_2025 huggingface dataset:
Beyond Coalitions of the Willing: Assessing U.S. Multilateralism
Authors: Patrick Stewart
Published: September 2006

Contemporary debates over the appropriate balance of unilateralism and multilateralism in U.S. foreign policy reflect disagreements not simply about the practical effectiveness of these alternative options but also about their legitimacy. Advocates of multilateral and unilateral action alike tend to bundle prudential calculations with normative claims, making assessments about costs and benefits difficult to disentangle from ethical arguments about fairness, justice, morality and obligation. Greater clarity may be possible by classifying U.S. foreign policy into six analytical categories, based on whether the aims pursued are nationalist, internationalist, or cosmopolitan and the strategies adopted to realize them are unilateral or multilateral. Each set of aims has different ethical justifications that generate and help to explain divergent attitudes and judgments about the role of multilateral cooperation in U.S. foreign policy. The article sheds new light on alleged U.S. unilateralism, showing that the U.S. decision to go it alone–or to act with others–can be motivated by the desire to advance the narrow interests of the United States, to advance the interests of all states, or to advance the interests of humanity at large. The article suggests that purely nationalist policies, whether pursued through unilateral or multilateral means, will become increasingly untenable and illegitimate as world politics becomes institutionalized and as humanity becomes integrated, albeit slowly, into a single cosmopolitan community.
Developing Just Monetary Arrangements
Authors: Reddy Sanjay G.
Published: September 2006

International monetary arrangements–the practices and rules governing the creation, distribution, and management of money and credit in the world economy–have received little attention from philosophers concerned with international distributive justice. A convincing account of international distributive justice requires a description of how these arrangements should function. International monetary arrangements currently appear to have consequences that are incompatible with a global egalitarian conception of distributive justice.

There are at least three categories of questions– relating respectively to money supply, exchange rates, and debt–that can be raised in the international context. First, who should have control over key monetary decisions, such as how much, and on what terms, money and credit are being supplied within each monetary zone? Should this control belong to the citizens of a given monetary zone and their representatives alone? How should the benefits arising from the ability to create money be distributed internationally? Second, should the stability of exchange rates be a goal and, if so, how should the responsibility for maintaining stability be apportioned? When adjustment of exchange rates is required, who should bear the burdens associated with such adjustment? Third, what arrangements should govern the accumulation and discharge of debt in the international setting? In what respects should debt contracted by states be governed by different rules than debt contracted by private agents? What forms of conditionality may be imposed by creditors, such as international institutions, governments, or private lenders, as part of a just framework of international borrowing and repayment? These questions exemplify rather than exhaust the dilemmas that arise with regard to international monetary arrangements. Global egalitarians should imagine the alternative forms that such arrangements can take as elements of a realistic utopia.
If Not Combatants, Certainly Not Civilians
Authors: David Steven R.
Published: September 2006

Stein and I see targeted killing in fundamentally different ways. Stein sees the Palestinian terrorists as civilian noncombatants who are not engaged in war or even armed conflict with Israel. As such, there is no legal or moral right to target them. I see targeted killing as an appropriate response to an intolerable threat. Israel has the right and obligation to defend itself against armed Palestinians who seek to kill as many innocent Israeli civilians as possible. So long as the Palestinian Authority is incapable or unwilling to halt terrorist attacks, most interpretations of international law, Israeli law, and just war tradition support Israel's efforts to stop these murderous attacks before they can be carried out.
Race and Ethnicity: Responsible Use from Epidemiological and Public Health Perspectives
Authors: Bhopal Raj
Published: September 2006

Race and ethnicity are closely related, contentious concepts that have been abused and misinterpreted through history, but have a vast potential for good, at least in the health sciences. This article is not intending to elaborate on the conceptual foundations of race and ethnicity; I have addressed that elsewhere and summarized my stance in the glossary reprinted below in the Appendix. The terminology used here follows the glossary. Assuming that the conceptual foundations of my stance are reasonable, the questions addressed here focus on public health and its primary health science, epidemiology, in a European context. The questions are simple ones:

1.

In epidemiology and public health what are we trying to achieve when we use the concepts of race and ethnicity?

2.

What would we lose by rejecting these concepts?

3.

If we do not reject them, how do we put the concepts into operation to help achieve our goals?

4.

What practical actions can result from the application of these concepts in order to improve the health and well-being of populations?
Medical Ethics at Guantanamo Bay and Abu Ghraib: The Problem of Dual Loyalty
Authors: Clark Peter A.
Published: September 2006

Although knowledge of torture and physical and psychological abuse was widespread at both the Guantanamo Bay detention facility and Abu Ghraib prison in Iraq, and known to medical personnel, there was no official report before the January 2004 Army investigation of military health personnel reporting abuse, degradation, or signs of torture. Mounting information from many sources, including Pentagon documents, the International Committee of the Red Cross (ICRC), Amnesty International, Human Rights Watch, etc., indicate that medical personnel failed to maintain medical records, conduct routine medical examinations, provide proper care of disabled and injured detainees, accurately report illnesses and injuries, and falsified medical records and death certificates. Medical personnel and medical information was also used to design and implement psychologically and physically coercive interrogations. The United States military medical system failed to protect detainee's human rights, violated the basic principles of medical ethics and ignored the basic tenets of medical professionalism.
Currents in Contemporary Ethics
Authors: DeCoster Barry
Published: September 2006

The flu has an interesting history with respect to health care rationing in the United States. Consider that just about two years ago, the American public faced a shortage of influenza vaccine. Dire predictions were made about how many people might perish, and rationing protocols were created. However, many of the rationing protocols were ignored. Luckily, that flu season did not result in the horrible fatalities that were predicted. For these reasons, problems of health care rationing around issues of the flu were postponed, rather than resolved.

Over the last year, the public has focused its anxious attention on the possible avian influenza pandemic. Last week I noticed that at least once each day I heard mention in some discussion or another of the threat of this disease becoming easily transmissible from human to human.
A single‐blinded case controlled study on effects of cardiopulmonary circulation on hearing during coronary artery bypass grafting
Authors: Donne A.J. , Waterman P. , Crawford L. , Balaji H.P. , Nigam A.
Published: October 2006

Objectives:  To evaluate the effect of extra‐corporeal (cardiopulmonary) bypass on hearing during coronary artery bypass grafting.

Design:  Prospective (single‐blinded) controlled study.

Setting:  District General Hospital.

Participants:  Fifty‐two patients undergoing coronary artery bypass grafting completed this study. Comparison was made between 14 control patients undergoing off‐pump coronary artery bypass grafting and 38 study patients undergoing on‐pump coronary artery bypass grafting. The age range of patients was 48–81 years, with 50% between 64 and 66 years.

Main outcome measures:  Pure tone audiograms were performed in all patients before and after coronary artery bypass grafting. Data were analysed for any significant difference between pre‐ and post‐operative pure tone audiograms.

Results:  Mann–Whitney U‐test demonstrated no difference between the area generated between mean pre‐ and post‐operative audiograms (P = 0.754). No significant difference between off versus on pump was demonstrated for average differences at 250–500 Hz, 4 kHz, 4–8 kHz and 8 kHz. Wilcoxon matched‐pairs signed‐rank test demonstrated no difference between right and left ears for each individual frequency. Spearman's test to analyse the effect on vessel number or minutes on bypass pump revealed no significant difference at 4–8 kHz (P = 0.550 for number of vessels and P = 0.276 for minutes on pump.)

Conclusion:  In this study, it was not possible to demonstrate any statistically significant deleterious effect of extra‐corporeal (cardiopulmonary) bypass on hearing during coronary artery bypass grafting.
Paraventricular nucleus influence on renal sympathetic activity in vasopressin gene‐deleted rats
Authors: Yang Zhou , Coote J. H.
Published: September 2006

In Wistar rats, an increase in renal sympathetic activity is induced by activation of presympathetic neurones in the paraventricular nucleus (PVN) and reflexly by a mild venous haemorrhage. Both stimuli are dependent on the release of vasopressin and glutamate at spinal synapses. The significance of the supraspinal pathway and the co‐operative interaction of vasopressin with an excitatory amino acid is unclear. The present study examines this in Brattleboro rats, which have a natural vasopressin gene deletion. The responses were compared with Long–Evans rats, from which Brattleboro rats are derived. All rats were anaesthetized with a mixture of urethane (650 mg kg−1i.v.) and chloralose (50 mg kg−1i.v.). Recordings were made of blood pressure, heart rate and renal sympathetic nerve activity (RSNA). Microinjection of d,l‐homocysteic acid (DLH, 0.2 m, 100 nl) at sites restricted to the PVN elicited significant increases in RSNA (P < 0.001) in both strains of rats. These changes were significantly reduced (P < 0.01) in Long–Evans rats by intrathecal application to the spinal cord of either a V1a antagonist or a glutamate antagonist (kynurenic acid), whereas in Brattleboro rats the changes were significantly reduced (P < 0.05) only by kynurenic acid. Removal of 1 ml of venous blood in Long–Evans rats increased RSNA by 28 ± 4% (P < 0.01), which was significantly reduced (P < 0.05) by prior intrathecal application of either the V1a antagonist or by kynurenic acid. The same test in Brattleboro rats caused a significanty greater (P < 0.05) increase (63 ± 14.7%) in RSNA which, in contrast to Long–Evans rats, was unchanged by intrathecal application of the V1a antagonist, being significantly reduced (P < 0.01) only by intrathecal kynurenic acid. Thus, in Brattleboro rats, the lack of vasopressin in the brain sympathetic pathways appears to be compensated, acutely, by glutamate‐releasing pathways. This might indicate that, in normal rats, vasopressin is more important in maintaining longer term adjustments to stressors.
Interstitial matrix proteins determine hyaluronan reflection and fluid retention in rabbit joints: effect of protease
Authors: Sabaratnam S. , Coleman P. J. , Mason R. M. , Levick J. R.
Published: September 2006

Hyaluronan (HA) retention inside the synovial cavity of joints serves diverse protective roles. We tested the hypothesis that HA retention is mediated by the network of extracellular matrix proteins in the synovial lining. Cannulated rabbit knee joints were infused with HA solution with or without pretreatment by chymopapain, a collagen‐sparing protease. Trans‐synovial fluid escape rate was measured and, after a period of trans‐synovial filtration, samples of intra‐articular fluid and subsynovial fluid were analysed for HA to assess its trans‐synovial ultrafiltration. In control joints, HA ultrafiltration was confirmed by postfiltration increases in intra‐articular HA concentration (259 ± 17% of infused concentration) and reduced subsynovial concentration (30 ± 8%; n= 11). The proportion of HA molecules reflected by the synovium was 57–75%. Chymopapain treatment increased the hydraulic permeability of the synovial lining ∼13‐fold, almost abolished the trans‐synovial difference in HA concentration and reduced the HA reflected fraction to 3–7% (n= 6; P < 0.001, ANOVA). Structural studies confirmed that chymopapain treatment depleted the matrix of proteoglycans but preserved its collagen. The findings thus demonstrate that HA ultrafiltration and synovial hydraulic permeability are determined by the network of non‐collagen, extracellular matrix proteins. This may be important clinically, since protease activity is raised in rheumatoid arthritis, as are HA and fluid escape.
Molecular system bioenergetics: regulation of substrate supply in response to heart energy demands
Authors: Saks Valdur , Favier Roland , Guzun Rita , Schlattner Uwe , Wallimann Theo
Published: September 2006

This review re‐evaluates regulatory aspects of substrate supply in heart. In aerobic heart, the preferred substrates are always free fatty acids, and workload‐induced increase in their oxidation is observed at unchanged global levels of ATP, phosphocreatine and AMP. Here, we evaluate the mechanisms of regulation of substrate supply for mitochondrial respiration in muscle cells, and show that a system approach is useful also for revealing mechanisms of feedback signalling within the network of substrate oxidation and particularly for explaining the role of malonyl‐CoA in regulation of fatty acid oxidation in cardiac muscle. This approach shows that a key regulator of fatty acid oxidation is the energy demand. Alterations in malonyl‐CoA would not be the reason for, but rather the consequence of, the increased fatty acid oxidation at elevated workloads, when the level of acetyl‐CoA decreases due to shifts in the kinetics of the Krebs cycle. This would make malonyl‐CoA a feedback regulator that allows acyl‐CoA entry into mitochondrial matrix space only when it is needed. Regulation of malonyl‐CoA levels by AMPK does not seem to work as a master on–off switch, but rather as a modulator of fatty acid import.
Anatomy of a Flaring Proto-Planetary Disk Around a Young Intermediate-Mass Star
Authors: Lagage Pierre-Olivier , Doucet Coralie , Pantin Eric , Habart Emilie , Duchêne Gaspard , Ménard François , Pinte Christophe , Charnoz Sébastien , Pel Jan-Willem
Published: September 2006

Although planets are being discovered around stars more massive than the Sun, information about the proto-planetary disks where such planets have built up is sparse. We have imaged mid-infrared emission from polycyclic aromatic hydrocarbons at the surface of the disk surrounding the young intermediate-mass star HD 97048 and characterized the disk. The disk is in an early stage of evolution, as indicated by its large content of dust and its hydrostatic flared geometry, indicative of the presence of a large amount of gas that is well mixed with dust and gravitationally stable. The disk is a precursor of debris disks found around more-evolved A stars such as β-Pictoris and provides the rare opportunity to witness the conditions prevailing before (or during) planet formation.
Correcting Quantum Errors with Entanglement
Authors: Brun Todd , Devetak Igor , Hsieh Min-Hsiu
Published: September 2006

We show how entanglement shared between encoder and decoder can simplify the theory of quantum error correction. The entanglement-assisted quantum codes we describe do not require the dual-containing constraint necessary for standard quantum error–correcting codes, thus allowing us to “quantize” all of classical linear coding theory. In particular, efficient modern classical codes that attain the Shannon capacity can be made into entanglement-assisted quantum codes attaining the hashing bound (closely related to the quantum capacity). For systems without large amounts of shared entanglement, these codes can also be used as catalytic codes, in which a small amount of initial entanglement enables quantum communication.
Decisions at the end of life: an empirical study on the involvement, legal understanding and ethical views of preregistration house officers
Authors: Schildmann J , Doyal L , Cushing A , Vollmann J
Published: September 2006

Objectives:To collect information on the involvement, legal understanding and ethical views of preregistration house officers (PRHO) regarding end-of-life decision making in clinical practice.

Design:Structured telephone interviews.

Participants:104 PRHO who responded.

Main outcome measures:Information on the frequency and quality of involvement of PRHO in end-of-life decision making, their legal understanding and ethical views on do-not-resuscitate (DNR) order and withdrawal of treatment.

Results:Most PRHO participated in team discussions on the withdrawal of treatment (n = 95, 91.3%) or a DNR order (n = 99, 95.2%). Of them, 46 (44.2%) participants had themselves discussed the DNR order with patients. In all, it was agreed by 84 (80.8%) respondents that it would be unethical to make a DNR order on any patient who is competent without consulting her or him. With one exception, it was indicated by the participants that patients who are competent may refuse tube feeding (n = 103, 99.0%) and 101 (97.1%) participants thought that patients may refuse intravenous nutrition. The withdrawal of artificial ventilation in incompetent patients with serious and permanent brain damage was considered to be morally appropriate by 95 (91.3%) and 97 (93.3%) thought so about the withdrawal of antibiotics. The withdrawal of intravenous hydration was considered by 67 (64.4%) to be morally appropriate in this case.

Conclusions:PRHO are often involved with end-of-life decision making. The results on ethical and legal understanding about the limitations of treatment may be interpreted as a positive outcome of the extensive undergraduate teaching on this subject. Future empirical studies, by a qualitative method, may provide valuable information about the arguments underlying the ethical views of doctors on the limitations of different types of medical treatment.
Ethical issues in screening for hearing impairment in newborns in developing countries
Authors: Olusanya B O , Luxon L M , Wirz S L
Published: September 2006

Screening of newborns for permanent congenital or early-onset hearing impairment has emerged as an essential component of neonatal care in developed countries, following favourable outcomes from early intervention in the critical period for optimal speech and language development. Progress towards a similar programme in developing countries, where most of the world’s children with hearing impairment reside, may be impeded by reservations about the available level of support services and the possible effect of the prevailing healthcare challenges. Ethical justification for the systematic introduction of screening programmes for hearing in newborns based on the limitations in current primary prevention strategies, lack of credible alternative early-detection strategies and the incentives for capacity-building for the requisite support services is examined.
Defining phytochemical phenotypes: size and shape analysis of phenolic compounds in oaks (Fagaceae, Quercus) of the Chihuahuan Desert
Authors: Yarnes Christopher T. , Boecklen William J. , Tuominen Kati , Salminen Juha-Pekka
Published: September 2006

Interspecific variation in phenolic metabolism across plant species has been correlated to numerous ecological factors, yet generalities concerning the ecological role(s) of phenolics remain elusive. Moreover, studies of allometric variation (absolute and relative concentration) in phenolic metabolism are rare despite the importance of each to ecological interactions. In this study, we characterize individual phenolics in a group of 12 oak species from the Chihuahuan Desert and examine interspecific variation in the absolute and relative concentrations of phenolics using size and shape analysis. Size and shape analysis was able to successfully identify those compounds that contribute most to the interspecific allometric variation in phenolics and classify the oak species on the basis of phenolic metabolism. White versus black oak subgenera were found to be most different in their phenolic composition, where the two black oak species contained fewer and less diverse phenolics. Within the 10 white oak species, a predominantly eastern white oak, Quercus muhlenbergii Engelmann, was found to vary significantly from the more widespread white oaks of the Chihuahuan Desert. We also report the occurrence of complex tannins in oaks of North America for the first time, update proposed pathways of ellagitannin biosynthesis in oaks, and discuss the applicability of size and shape analysis to ecological studies of phenolics.
Stand age and sampling year effect on the fungal fruit body community in Pinus pinaster forests in central Spain
Authors: Fernández-Toirán L.M. , Ágreda T. , Olano J.M.
Published: September 2006

The process of fungal community succession in forests is still insufficiently known, especially in Mediterranean ecosystems. To reveal successional patterns, we studied changes in aboveground sporocarp composition in managed Pinus pinaster Ait. forests across a stand age chronosequence from 5 to more than 90 years in Soria province (Central Spain). We evaluated the effect of yearly conditions and stand age on species richness, composition, and trophic groups. All aboveground sporocarps were collected and identified in 21 plots, each measuring 150 m2, placed in a random stand age-stratified survey. Sampling was performed weekly in the autumn during 6 years (1997–2002). The effect of year and stand age on species richness was analysed using repeated measures analysis of variance and change in composition. Changes in community composition were evaluated via canonical correspondence analysis (CCA). The response of different trophic groups was analyzed using ANOVA with age as a fixed factor. Fungal community richness increased with stand age. This increase was related to the rise in humicolous saprotroph and mycorrhizal species. The presence of parasitic and lignicolous fungi was always very low, probably as a result of forest management. Yearly conditions exerted a stronger effect than stand age on aboveground sporocarp community richness and composition.
Fluctuations of γ-aminobutyrate, γ-hydroxybutyrate, and related amino acids in Arabidopsis leaves as a function of the light–dark cycle, leaf age, and N stressEditorial decisions for this paper were made by Robert Ireland, Associate Editor, Canadian Journal of Botany.
Authors: Allan Wendy L. , Shelp Barry J.
Published: September 2006

To gain further insight into the metabolic role of γ-aminobutyrate (GABA), we determined the pool sizes of GABA and its catabolic products, alanine and γ-hydroxybutyrate (GHB), as well as key amino acids (Glu, Gln, Asp, Asn, Pro, Gly, Ser), in Arabidopsis leaves as a function of the light–dark cycle, leaf age (old versus young), and N stress (continuous versus interrupted N supply). Regardless of time of day and leaf age, there was a close relationship among Glu, GABA, and GHB when N was supplied continuously, indicating that GABA and GHB were probably derived exclusively from Glu and GABA, respectively. Ala was also closely linked to GABA in young leaves, but not in old leaves, a result consistent with the existence of multiple sources of Ala. The nature of the responses of GABA and GHB to an interrupted N supply depended on leaf age, and differed from responses exhibited by Glu, Gln, and Asn. Overall fluctuations in primary amino acids under both continuous and interrupted N supply, as well as those associated with photorespiration, aging, and stress, suggest that the old and young leaves chosen for study here function in Arabidopsis as source and sink leaves, respectively.
LOW ELECTRODE EROSION RATE OF NANOCRYSTALLINE CuCr-50 ALLOY IN VACUUM
Authors: ZHANG CHENGYU , YANG ZHIMAO , DING BINGJUN
Published: October 2006

The CuCr-50 alloy with grain size of less than 50 nm was prepared by the mechanical alloy and hot pressing technique. Its microstructure was examined by XRD, SEM and TEM. The electrode erosion rates of nanocrystalline and microcrystalline CuCr-50 were investigated. It is found that the electrode erosion rate of nanocrystalline CuCr-50 is 24.8 μg/C, much lower than that of microcrystalline CuCr-50 . The main cause is that the vacuum arc shows diffusional features on the nanocrystalline electrode, decreasing the heat flux, current density and the dimensions of the droplets emmited from the cathode.
MAGNETIC PROPERTIES OF THE (DyxU1-x)2AlCo3 SYSTEM
Authors: LUPSA ILEANA
Published: October 2006

The magnetic properties of the Dy x U 1-x AlCo 3 system, investigated in the 4–800 K temperature range and fields up to 80 kOe indicated ferrimagnetic order for x≥0.2. The cobalt magnetic moments opposite to dysprosium and the Curie temperatures decrease with decreasing Dy content. The internal magnetic field dependence of the Co moment shows that cobalt moment becomes saturated above 1000 kOe. The high temperature paramagnetic behavior follows a Curie–Weiss type law evidencing effective magnetic moments on Co positions. The paramagnetic properties are analyzed in the spin fluctuations model.
ON SOME SYMPLECTIC ASPECTS OF KNOT FRAMINGS
Authors: BESANA ALBERTO , SPERA MAURO
Published: October 2006

The present article delves into some symplectic features arising in basic knot theory. An interpretation of the writhing number of a knot (with reference to a plane projection thereof) is provided in terms of a phase function analogous to those encountered in geometrical optics, its variation upon switching a crossing being akin to the passage through a caustic, yielding a knot theoretical analogue of Maslov's theory, via classical fluidodynamical helicity. The Maslov cycle is given by knots having exactly one double point, among those having a fixed plane shadow and lying on a semi-cone issued therefrom, which turn out to build up a Lagrangian submanifold of Brylinski's symplectic manifold of (mildly) singular knots. A Morse family (generating function) for this submanifold is determined and can be taken to be the Abelian Chern–Simons action plus a source term (knot insertion) appearing in the Jones–Witten theory. The relevance of the Bohr–Sommerfeld conditions arising in geometric quantization are investigated and a relationship with the Gauss linking number integral formula is also established, together with a novel derivation of the so-called Feynman–Onsager quantization condition. Furthermore, an additional Chern–Simons interpretation of the writhe of a braid is discussed and interpreted symplectically, also making contact with the Goldin–Menikoff–Sharp approach to vortices and anyons. Finally, a geometrical setting for the ground state wave functions arising in the theory of the Fractional Quantum Hall Effect is established.
A NOVEL METHOD FOR MULTISTAGE SCENARIO GENERATION BASED ON CLUSTER ANALYSIS
Authors: JI XIAODONG , ZHAO XIUJUAN , CHAO XIULI
Published: October 2006

Based on cluster analysis, a novel method is introduced in this paper to generate multistage scenarios. A linear programming model is proposed to exclude the arbitrage opportunity by appending a scenario to the generated scenario set. By means of a cited stochastic linear goal programming portfolio model, a case is given to exhibit the virtues of this scenario generation approach.
Both Ca2+-dependent and -independent pathways are involved in rat hepatic stellate cell contraction and intrahepatic hyperresponsiveness to methoxamine
Authors: Laleman Wim , Van Landeghem Lien , Severi Tamara , Elst Ingrid Vander , Zeegers Marcel , Bisschops Raf , Van Pelt Jos , Roskams Tania , Cassiman David , Fevery Johan , Nevens Frederik
Published: September 2006

In chronic liver injury, hepatic stellate cells (HSCs) have been implicated as regulators of sinusoidal vascular tone. We studied the relative role of Ca2+-dependent and Ca2+-independent contraction pathways in rat HSCs and correlated these findings to in situ perfused cirrhotic rat livers. Contraction of primary rat HSCs was studied by a stress-relaxed collagen lattice model. Dose-response curves to the Ca2+ionophore A-23187 and to the calmodulin/myosin light chain kinase inhibitor W-7 served to study Ca2+-dependent pathways. Y-27632, staurosporin, and calyculin (inhibitors of Rho kinase, protein kinase C, and myosin light chain phosphatase, respectively) were used to investigate Ca2+-independent pathways. The actomyosin interaction, the common end target, was inhibited by 2,3-butanedione monoxime. Additionally, the effects of W-7, Y-27632, and staurosporin on intrahepatic vascular resistance were evaluated by in situ perfusion of normal and thioacetamide-treated cirrhotic rat livers stimulated with methoxamine ( n = 25 each). In vitro, HSC contraction was shown to be actomyosin based with a regulating role for both Ca2+-dependent and -independent pathways. Although the former seem important, an important auxiliary role for the latter was illustrated through their involvement in the phenomenon of “Ca2+sensitization.” In vivo, preincubation of cirrhotic livers with Y-27632 (10−4M) and staurosporin (25 nM), more than with W-7 (10−4M), significantly reduced the hyperresponsiveness to methoxamine (10−4M) by −66.8 ± 1.3%, −52.4 ± 2.7%, and −28.7 ± 2.8%, respectively, whereas in normal livers this was significantly less: −43.1 ± 4.2%, −40.2 ± 4.2%, and −3.8 ± 6.3%, respectively. Taken together, these results suggest that HSC contraction is based on both Ca2+-dependent and -independent pathways, which were shown to be upregulated in the perfused cirrhotic liver, with a predominance of Ca2+-independent pathways.
Sex-based differences in myocardial contractile reserve
Authors: Petre Rebecca E. , Quaile Michael P. , Rossman Eric I. , Ratcliffe Sarah J. , Bailey Beth A. , Houser Steven R. , Margulies Kenneth B.
Published: September 2006

Recent studies have identified sex differences in heart function that may affect the risk of developing heart failure. We hypothesized that there are fundamental differences in calcium (Ca) regulation in cardiac myocytes of males and premenopausal females. Isometric force transients ( n = 45) were measured at various stimulation frequencies to define the force frequency responses (FFR) (0.5, 1.0, 1.5, and 2.0 Hz) during either changes in bath Ca ([Ca]o) (1.0, 1.75, 3.5, and 7.0 mM) or length-tension (20, 40, 60, 80, and 100% Lmax) in right ventricle trabeculae from normal male (MT) and premenopausal female (FT) cats. Force-Ca measurements were also obtained in chemically skinned trabeculae. Under basal conditions (0.5 Hz, 1.75 mM Ca, 80% Lmax) both MT and FT achieved similar developed forces (DF) (MT 11 ± 1, FT = 10 ± 1 mN/mm2). At low rates and lengths, there is no sex difference. At higher preloads and rates, there is a separation in DF in MT and FT. At basal [Ca]o both MT and FT exhibited positive FFR (2.0 Hz, 1.75 mM Ca: MT 38 ± 3, FT 21 ± 4 mN/mm2); however, at higher [Ca]o, MT achieved greater DF (2.0 Hz, 7.0 mM Ca: MT 40 ± 3 and FT = 24 ± 4 mN/mm2). We detected no sex difference in myofilament Ca sensitivity at a sarcomere length of 2.1 μm. However, rapid cooling contractures indicated greater sarcoplasmic reticulum (SR) Ca load in MT at higher frequencies. Despite virtually identical contractile performance under basal conditions, significant sex differences emerge under conditions of increased physiological stress. Given the lack of sex differences in myofilament Ca sensitivity, these studies suggest fundamental sex differences in cellular Ca regulation to achieve contractile reserve, with myocardium from males exhibiting higher SR Ca load.
Temperature acclimation modifies sinoatrial pacemaker mechanism of the rainbow trout heart
Authors: Haverinen Jaakko , Vornanen Matti
Published: September 2006

The hypothesis of pacemaker level origin of thermal compensation in heart rate was tested by recording action potentials (AP) in intact sinoatrial tissue and enzymatically isolated pacemaker cells of rainbow trout acclimated at 4°C (cold) and 18°C (warm). With electrophysiological recordings, the primary pacemaker was located at the base of the sinoatrial valve, where a morphologically distinct ring of tissue comprising myocytes and neural elements was found by histological examination. Intrinsic beating rate of this pacemaker was higher in cold-acclimated (46 ± 6 APs/min) than warm-acclimated trout (38 ± 3 APs/min; P < 0.05), and a similar difference was seen in beating rate of isolated pacemaker cells (44 ± 6 vs. 38 ± 6 APs/min; P < 0.05), supporting the hypothesis that thermal acclimation modifies the intrinsic pacemaker mechanism of fish heart. Inhibition of sarcoplasmic reticulum (SR) with 10 μM ryanodine and 1 μM thapsigargin did not affect heart rate in either warm- or cold-acclimated trout at 11°C but reduced heart rate in warm-acclimated trout from 74 ± 2 to 42 ± 6 APs/min ( P < 0.05) at 18°C. At 11°C, a half-maximal blockade of the delayed rectifier K+current ( IKr) with 0.1 μM E-4031 reduced heart rate more in warm-acclimated (from 45 ± 1 to 24 ± 5 APs/min) than cold-acclimated trout (56 ± 3 vs. 48 ± 2 APs/min), whereas IKrdensity was higher and AP duration less in cold-acclimated trout ( P > 0.05). Collectively, these findings suggest that a cold-induced increase in AP discharge frequency is at least partly due to higher density of the IKrin the cold-acclimated trout, whereas contribution of SR Ca2+release to thermal compensation of heart rate is negligible.
The effects of hyperthermia and hypoxia on ventilation during low-intensity steady-state exercise
Authors: Chu Aaron L. , Jay Ollie , White Matthew D.
Published: September 2006

This study assessed whether the elevated sensitivity of ventilation to hypoxia during exercise is accounted for by an elevation of esophageal temperature (Tes). Eleven males volunteered for two exercise sessions on an underwater, head-out cycle ergometer at a steady-state rate of oxygen consumption (V̇o2) of ∼0.87 l/min (SD 0.07). In one exercise session, 31.5°C (SD 1.4) water held Tesat a normothermic level of ∼37.1°C, and in the other exercise session, water at 38.2°C (SD 0.1) maintained a hyperthermic Tesof ∼38.5°C. After a 30-min rest and 20-min warm-up, exercising participants inhaled air for 10 min [Euoxia 1 (E1)], an isocapnic hypoxic gas mixture with 12% O2in N2(H1) for the next 10 min and air again [Euoxia 2 (E2)] for the last 10 min. A significant increase in V̇Eduring all hyperthermia conditions (0.01< P < 0.048) was evident; however, during hyperthermic hypoxia, there was a disproportionate and significant ( P = 0.017) increase in V̇Erelative to normothermic hypoxia. This was the main explanation for a significant esophageal temperature and gas type interaction ( P = 0.012) for V̇E. Significant effects of hyperthermia, isocapnic hypoxia, and their positive interaction remained evident after removing the influence of V̇o2on V̇E. Serum lactate and potassium concentrations, as well as hemoglobin oxygen saturation, were each not significantly different between normothermic and hyperthermic-hypoxic conditions. In conclusion, the elevated sensitivity of exercise ventilation to hypoxia during exertion appears to be modulated by elevations in esophageal temperature, potentially because of a temperature-mediated stimulation of the peripheral chemoreceptors.
Intrinsic and antigen-induced airway hyperresponsiveness are the result of diverse physiological mechanisms
Authors: Wagers Scott S. , Haverkamp Hans C. , Bates Jason H. T. , Norton Ryan J. , Thompson-Figueroa John A. , Sullivan Michael J. , Irvin Charles G.
Published: September 2006

Airway hyperresponsiveness (AHR) is a defining feature of asthma. We have previously shown, in mice sensitized and challenged with antigen, that AHR is attributable to normal airway smooth muscle contraction with exaggerated airway closure. In the present study we sought to determine if the same was true for mice known to have intrinsic AHR, the genetic strain of mice, A/J. We found that A/J mice have AHR characterized by minimal increase in elastance following aerosolized methacholine challenge compared with mice (BALB/c) that have been antigen sensitized and challenged [concentration that evokes 50% change in elastance (PC50): 22.9 ± 5.7 mg/ml for A/J vs. 3.3 ± 0.4 mg/ml for antigen-challenged and -sensitized mice; P < 0.004]. Similar results were found when intravenous methacholine was used (PC30 0.22 ± 0.08 mg/ml for A/J vs. 0.03 ± 0.004 mg/ml for antigen-challenged and -sensitized mice). Computational model analysis revealed that the AHR in A/J mice is dominated by exaggerated airway smooth muscle contraction and that when the route of methacholine administration was changed to intravenous, central airway constriction dominates. Absorption atelectasis was used to provide evidence of the lack of airway closure in A/J mice. Bronchoconstriction during ventilation with 100% oxygen resulted in a mean 9.8% loss of visible lung area in A/J mice compared with 28% in antigen-sensitized and -challenged mice ( P < 0.02). We conclude that the physiology of AHR depends on the mouse model used and the route of bronchial agonist administration.
Detection threshold for inspiratory resistive loads and respiratory-related evoked potentials
Authors: Davenport Paul W. , Chan Pei-Ying Sarah , Zhang Weirong , Chou Yang-Ling
Published: September 2006

The relationship between detection threshold of inspiratory resistive loads and the peaks of the respiratory-related evoked potential (RREP) is unknown. It was hypothesized that the short-latency and long-latency peaks of the RREP would only be elicited by inspiratory loads that exceeded the detection threshold. The detection threshold for inspiratory resistive loads was measured in healthy subjects with inspiratory-interruption or onset load presentations. In a separate protocol, the RREPs were recorded with resistive loads that spanned the detection threshold. The loads were presented in stimulus attend and ignore sessions. Onset and interruption load presentations had the same resistive load detection threshold. The P1, Nf, and N1 peaks of the RREP were observed with loads that exceeded the detection threshold in both attend and ignore conditions. The P300 was present with loads that exceeded the detection threshold only in the attend condition. No RREP components were elicited with subthreshold loads. The P1, Nf, and P300 amplitudes varied with resistive load magnitude. The results support the hypothesis that there is a resistive load threshold for eliciting the RREPs. The amplitude of the RREP peaks vary as a function of load magnitude. The cognitive P300 RREP peak is present only for detectable loads and when the subject attends to the stimulus. The absence of the RREP with loads below the detection threshold and the presence of the RREP elicited by suprathreshold loads are consistent with the gating of these neural measures of respiratory mechanosensory information processing.
The Single Nucleotide Polymorphisms of IKs Potassium Channel Genes and Their Association with Atrial Fibrillation in a Chinese Population
Authors: Zeng Zhiyu , Tan Chen , Teng Siyong , Chen Jianhong , Su Shaoyong , Zhou Xiaoyang , Wang Fangzheng , Zhang Shu , Gu Dongfeng , Makielski Jonathan C. , Pu Jielin
Published: September 2006

Recent studies suggest that genetic mutation of the slow delayed rectifier potassium channel (IKs) may underlie atrial fibrillation (AF). We investigated the association between AF and the single nucleotide polymorphisms (SNPs) of genes KCNQ1, KCNE1 and KCNE4 associated with this channel. Common non-synonymous SNPs in KCNQ1 and KCNE1 known to be frequent in Asian people were selected and direct sequencing of KCNE4 was performed to identify possible SNPs. The AF group consisted of 142 hospitalized patients with AF, the community control group consisted of 120 subjects, and a ward control group consisted of 118 hospitalized patients without AF. Restriction fragment length polymorphism analysis was performed to determine the genotypes. The minor allele frequencies of P448R, R519H, G643S for KCNQ1 and G38S and D85N for KCNE1 in the AF group, the community control group and the ward control group were 9.9, 7.9, 9.3%; 0, 0, –; 4.3, 4.2, 1.7%; 28.4, 31.7, 29.7%; 0.7, 0.4%, –, respectively. There was no significant association between these SNPs and AF phenotype. There were eight SNPs in the whole length of KCNE4 plus 1,000 bases upstream of this gene including the non-synonymous SNP E145D. Logistical regression analysis revealed a difference in the distribution of KCNE4 E145D in the AF and the community control group (minor allele frequency was 34.0 versus 27.1% respectively, OR = 1.66, p = 0.044). We provided the frequencies of non-synonymous SNPs of KCNQ1 and KCNE1 in Chinese population; none of these SNPs was associated with AF. But KCNE4 E145D may be associated with the AF phenotype.
Effects of Enhanced External Counterpulsation on Carotid Circulation in Patients with Coronary Artery Disease
Authors: Levenson Jaime , Simon Alain , Megnien Jean L. , Chironi Gilles , Gariepy Jerome , Pernollet Marie G. , Craiem Damian , Iliou Marie C.
Published: September 2006

Background: Enhanced external counterpulsation (EECP) is a noninvasive method previously shown to improve measures of myocardial ischemia in patients with coronary artery disease. However, the concomitant effects of EECP on large and small arterial properties have been poorly examined. In a randomized controlled study, we investigated whether arterial stiffness and resistance of the carotid circulation are altered by EECP. Methods: Thirty patients with angiographically demonstrated coronary artery disease were randomized into two groups to receive either ‘sham’ or active EECP therapy for 35 1-hour sessions. The β stiffness index was calculated by the ln(Ps/Pd)/DD equation where Ps and Pd = systolic and diastolic blood pressure, and DD = the ratio between carotid pulse and diastolic diameter, measured by ultrasound sequential frames during the cardiac cycle. Carotid vascular resistance was calculated as the ratio between mean arterial pressure and mean common carotid blood flow. Results: No significant between-group differences were seen in clinical characteristics or carotid hemodynamics at baseline. The β stiffness index and carotid vascular resistance were significantly reduced after 35 h of active EECP (p < 0.01), and the decrease was significantly different when compared with controls (p < 0.05 for β stiffness index and p < 0.001 for carotid vascular resistance). These reductions persisted after multiple covariate adjustment. Conclusions: This study suggests that EECP exerts clear arterial effects on large and small vessels of the carotid circulation. The combined effects on arterial stiffness and vascular resistance are of particular interest in cardiovascular disease involving reduction in blood flow, in which techniques that increase regional blood flow may be beneficial.
Comparison between Molecular Epidemiology, Geographical Regions and Drug Resistance in Mycobacterium tuberculosis Strains Isolated from Iranian and Afghan Patients
Authors: Ramazanzadeh Rashid , Farnia Parissa , Amirmozafari Nour , Ghazi Farideh , Ghadertotonchi Zeinab , Kamran Jaber , Mohammadi Frouzan , Mirsaedi Mehdi , Masjedi Mohammadreza
Published: September 2006

The aim of this study was to determine the prevalence of drug-resistant tuberculosis (TB) and its associated risk factors. The susceptibilities of Mycobacterium tuberculosis isolates were tested against four first-line antituberculous drugs and were typed by spoligotyping. Spoligotyping of M. tuberculosis strains resulted in 95 different patterns that were divided into three evolutionary groups (1–3). Eighty-six (90%) of the isolates had unique patterns that were reported for the first time. Interestingly, 9.4% of the strains belonged to the Beijing family. Multidrug resistance (MDR) was seen in group 1 of the evolutionary scenario. All M. tuberculosis isolates belonging to the Beijing family were associated with a resistance pattern. MDR was much higher in bacteria isolated from Afghan TB patients residing in Iran.
Evaluation on Scolicidal Efficacy of Propolis
Authors: Kismet Kemal , Kilicoglu Bulent , Koru Ozgur , Tanyuksel Mehmet , Oruc Mehmet Tahir , Sorkun Kadriye , Salih Bekir , Akkus Mehmet Ali
Published: September 2006

Background: Propolis is a resinous material collected by bees from various plants. It has antimicrobial, antioxidative, immunostimulative, and regenerative properties. We determined the scolicidal effect of propolis in different concentrations and various exposure times. Materials and Methods: Tubes containing Echinococcus granulosus protoscoleces were supplementedwith different concentrations of ethyl alcohol extract of propolis. At the end of the incubation times, viabilityof protoscoleces was assessed by trypan blue exclusion test. We also applied 5 ml of 1 µg/ml propolis intraperitoneally for determination of side effects and mortality rates. Results: We determined that 1 µg/ml concentration of propolis killed all of the protoscoleces at the end of the 3rd minute. In the in vivo part of the study, intraperitoneal application of propolis did not cause any side effects or mortality. Conclusion: We concluded that this natural agent can be used as a potent scolicidal agent after studies which will determine in vivo efficacy and the effects on liver and biliary tree when injected directly into the common bile duct.
Methylene Blue Decreases Ischemia-Reperfusion (I/R)-Induced Spinal Cord Injury: An in vivo Study in an I/R Rabbit Model
Authors: Bardakci H. , Kaplan S. , Karadeniz U. , Ozer C. , Bardakci Y. , Ozogul C. , Birincioglu C.L. , Cobanoglu A.
Published: September 2006

Objectives: To evaluate the effects of intravenous methylene blue (MB) administration on ischemia-reperfusion (I/R) injury of the spinal cord (SC). Methods: 16 rabbits were randomly assigned either to group M (n = 8; receiving MB, intervention group) or group C (n = 8; control group) and underwent a 30-min period of SC ischemia by clamping the abdominal aorta between the left renal artery and the aortic bifurcation. 15 min before clamping, rabbits received either intravenous MB (10 mg/kg; group M) or normal saline (group C). The two groups were compared 24 h postoperatively both histologically and for neurological function, using a Tarlov score. Measurements to determine levels of malondialdehyde (MDA) and glutathione (GSH) in the SC tissue were also performed. Results: Neurological impairment and spinal tissue MDA levels were significantly lower in animals treated with MB (p < 0.001). In contrast, spinal GSH levels were significantly higher in group M (p < 0.001). Histological examination revealed that the integrity of the SC was better preserved in the MB group, whereas cords from the control group exhibited evidence of acute neuronal injury. Conclusions: The prophylactic use of MB reduces neurological injury and improves clinical outcomes in the rabbit SC I/R model. These effects are probably mediated by the drug’s antioxidant properties.