bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary Clinical Experience with the First Dual Chamber Pacemaker Defibrillator
Authors: LAVERGNE THOMAS , DAUBERT JEAN‐CLAUDE , CHAUVIN MICHEL , DOLLA ERIC , KACET SALEM , LEENHARDT ANTOINE , MABO PHILIPPE , RITTER PHILIPPE , SADOUL NICOLAS , SAOUDI NADIR , HENRY CHRISTINE , NITZSCHE RÉMI , RIPART ALAIN , MURGATROYD FRANCIS
Published: June 2006

The lack of specificity of VT detection is a significant shortcoming of current ICDs. In a French multicenter study, 18 patients underwent implantation of the Defender 9001 (ELA Medical), an ICD utilizing dual chamber pacing and arrhythmia detection. Over a mean follow‐up period of 7.1 ± 4.5 months, 176 tachycardia episodes recorded in the device memory were analyzed, and physician diagnosis was compared with that by the device. All 122 VT/VF episodes were correctly diagnosed, as were 51 of 53 supraventricular tachyarrhythmias. Two episodes of AF with rapid regular ventricular rates were treated as VT, and a third episode, treated as VT, could not be diagnosed with certainty. A dual chamber pacemaker defibrillator offers improved diagnostic specificity without loss of sensitivity, in addition to the hemodynamic benefit of dual chamber pacing. (PACE 1997;20
Circadian Modulation of Ventricular Tachycardia Cycle Length Variability in ICD Patients with Dilated Cardiomyopathy
Authors: MANOLIS ATHANASIOS G. , KATSIVAS APOSTOLOS , LAZARIS EUSTATHIOS , KOUTSOGEOGIS DIMITRIOS , LOUVROS NIKOLAOS
Published: June 2006

VT is usually characterized by stability of the RR intervals after a few cycles from the onset. The aim of this study was to evaluate the VT cycle length (VTCL) variability in patients with dilated cardiomyopathy (DCM), in whom a third‐generation ICD was previously implanted. Eighty‐three episodes of VT were analyzed in 10 patients (8 male, 2 female, 65 ± 6 years) with DCM, and NYHA Class II (7 patients) or III (3 patients). As an index of VTCL variability, the coefficient of variance of the last 15 consecutive RR intervals (CVRR) of the detected and stored VT by the device was considered. The mean value of the RR intervals and the mean value of CVRR of the VT episodes recorded during day versus night time were compared. Fifty‐five VT episodes were recorded during the day and 28 episodes during the night time. The mean RR intervals of VT episodes during day time was 335 ± 29 ms and during the night time was 350 ± 22 ms (P = NS). The mean CVRR of VT episodes during day time and night time were 2.83 ± 0.52 and 3.36 ± 0.48, respectively (P = 0.017). In conclusion, a circadian modulation of VTCL variability exists in patients with DCM. The VTCL variability is less during day time compared to night time. A possible explanation is a circadian alteration of sympathovagal balance modifying the electrophysiological properties of the arrhythmogenic substrate.
Dysfunction of Implantable Defibrillators Caused by Slot Machines
Authors: MADRID ANTONIO , SÁNCHEZ ANDRÉS , BOSCH ENRIQUE , FERNÁNDEZ ELÍSEO , SERRANO CONCEPCIÓN MORO
Published: June 2006

The electrogram storage is a feature offered by the last generation of defibrillators, which enables the physician to establish whether the sensed episode and the electrical therapy delivered by the device was appropriate. The incidence of electromagnetic interferences may be higher than initially suspected with the latest generation of defibrillators. Such interference was documented in 4 out of 100 patients over a 24‐month period. The electrical interference occurred in all four of them, while they were playing with slot machines. In the RR interval history, irregular QRS sensing of variable frequency was documented in some episodes. The intervals were irregular and nonphysiological, satisfying the rate cut‐off criteria in an intermittent and nonsustained way. There maybe high risk of electromagnetic interference between slot machines and defibrillators. Our experience calls for a warning to all defibrillator patients and, perhaps some regulatory intervention.
A Multicenter, Randomized Trial Comparing an Active Can Implantable Defibrillator with a Passive Can System
Authors: HAFFAJEE CHARLES , MARTIN DAVID , BHANDARI ANIL , BARDY GUST H. , DeSOUZA CYNTHIA , KUEHLKAMP VICTOR , CHURCH TIMOTHY ,   for the JEWEL ACTIVE CAN INVESTIGATORS
Published: June 2006

Replacing one defibrillation electrode lead by the defibrillator can may simplify implantation of the ICD. In this multicenter study, 304 patients were randomized to receive either the biphasic active can (AC) (model 7219C system, Medtronic, Inc.) or the passive can (PC) (model 7219D system). The AC and PC systems were compared with respect to their ability to meet the implant defibrillation criterion and to defibrillate VF, and to DFTs, implant time, patient adverse events, and survival rates. A higher percentage fulfilled the implant defibrillation criterion on the first configuration with the AC (86.3% vs 75.9% for PC; P = 0.023), and the first shock success for terminating induced VF was 94% for AC compared to 89% for PC (P = 0.026). DFTs were significantly lower (10.9 vs 12.7 J; P = 0.031), and implant time was significantly shorter for the AC patients (99.2 vs 112.0 min; P = 0.002). The two groups showed no significant differences in 3‐month adverse event rates, 3‐month survival, and hospital stay.
Action Potential Remodeling in the Human Right Atrium with Chronic Lone Atrial Fibrillation
Authors: OSAKA TOSHIYUKI , ATSUSHIITOH  , KODAMA ITSUO
Published: June 2006

It has been shown in animal experiments that recurrent induction of atrial fibrillation (AF) or long‐lasting atrial pacing causes a shortening of the atrial effective refractory period (ERP) and action potential duration (APD) and a loss of their physiological adaptation to rate. Much remains to be clarified as to the electrical remodeling in human patients with chronic AF. We recorded monophasic action potentials (MAPs) from the right atrium at pacing cycle lengths (CLs) of 300, 333, 400, 500, 600, and 750 ms after external cardioversion in 13 patients with chronic lone AF. Their configuration was compared with those obtained from 13 control patients. APDs at 50% and 90% repolarization (APD50, APD90) at the shortest CL (300 ms) in control and AF patients were 131 ± 14, 211 ± 19ms and 136 ± 12, 210 ± 22 ms, respectively (mean ± SD). APDs in control patients increased linearly with increases of CL, reaching maximal values of 174 ± 30 ms (APD50) and 277 ± 38 ms (APD90) at a CL of 750 ms. In AF patients, the steady‐state CL‐APD relation was shifted downward and flattened at CLs > 500ms; APD50 and APD90 at a CL of 750 ms were 158 ± 19 ms, 232 ± 28 ms, respectively. APD90s at CLs of 600 and 750 ms were significantly shorter in AF than in control patients. No statistically significant difference was obtained in APD50 between the two groups at any CL tested. MAP configuration in AF patients was characterized by an acceleration of the late repolarization. The difference between APD90 and APD50 (APD90–50) in control patients was increased with increases of CL, reaching a plateau at a CL of 600 ms. This CL dependent slowing of the late repolarization of MAPs was abolished in AF patients. The atrial ERP, measured at CLs of 400 and 600 ms, showed changes parallel to those of APD90. ERP at a CL of 600 ms in AF patients (224 ± 13 ms) was significantly shorter than that in control patients (247 ± 25 ms). We conclude that chronic lone AF leads to electrical remodeling in the human atrium, which causes a loss of rate response of the late repolarization of action potential, leading to a shortening of APD and ERP at slower heart rates.
Long‐Term Superiority of Steroid Elution in Atrial Active Fixation Platinum Leads
Authors: WIEGAND UWE K.H. , POTRATZ JÜRGEN , BONNEMEIER HENDRIK , BODE FRANK , PANIK RITA , HAASE HENNING , PETERS WERNER , KATUS HUGO A.
Published: June 2006

Steroid elution reduces the acute increase in stimulation threshold particularly in active fixation leads. The aim of this study was to investigate the long‐term efficacy of steroid elution in atrial screw‐in leads compared to conventional lead design. Two different bipolar active fixation platinum lead designs were implanted. Leads were similar except for the presence (group S, n = 66) or absence (group N, n = 68) of steroid elution. Patients received dual chamber pacemakers with the following atrial leads in consecutive order: Medtronic 4058 M (group N, n = 30), Medtronic 4068 (group S, n = 40), Vitatron IMS 13 (identical to 4058 M, group N, n = 38), and Vitatron IMX 13 (identical to 4068, group S, n = 26). The. mean follow‐up period was 40.7 ± 16.1 months (range 10 to 84 months). Stimulation thresholds, pacing impedances, P wave potentials, and sensing threshold were assessed for both groups immediately, 10 days, 6 weeks, and 3 months after implantation followed by 6‐months intervals. Energy thresholds, chron‐axie‐rheobase products, and energy consumption of atrial pacing were calculated. Chronic values were deduced from the most recent measurement performed in an individual patient. Within the first 10 days after implantation, atrial voltage threshold at pulse duration of 0.4 ms increased from 0,91 ± 0.42 to 2.06 ± 0.45 V in group N (P < 0.001). Less increase was observed in group S (0.83 ± 0.39 to 1.08 ± 0,53 V, P = 0.003). Atrial voltage thresholds remained markedly lower in steroid‐eluting leads during whole follow‐up (1.12 ± 0.49 V in group S vs 1.58 ± 0.71 V in group N, P < 0.001). Chronic energy consumption was markedly reduced in group S (4.0 ± 2.7 μJ) compared to group N (9.8 ± 7.5 μJ, P < 0.001). An atrial voltage threshold below 1.25 V at 0.4 ms was achieved in 92.3% of patients of group S allowing programming of an output of 2.5 V. Such low outputs were feasible in only 49.3% of patients in group N (P < 0.001). Chronic P wave amplitudes did not differ significantly between groups (3.27 ± 1.81 mV in group N vs 3.24 ± 1.18 mV in group S, P = 0.91). Steroid elution diminishes the increase of stimulation thresholds of non‐steroid atrial active fixation platinum leads resulting in a long‐term reduction of energy consumption. Thus, use of steroids can be recommended for general use in atrial active fixation lead designs.
Adenosine Induced Monomorphic Ventricular Tachycardia
Authors: MISRA DEEPIKA , VAN TOSH ANDREW , SCHWEITZER PAUL
Published: June 2006

Polymorphic ventricular tachycardia has been reported following the administration of adenosine for the treatment of SVT. We present a case of monomorphic ventricular tachycardia in a 75‐year‐old man following the intravenous administration of adenosine for stress testing.
Assessment of Fetal Rhythm in Complete Congenital Heart Block by Magnetocardiography
Authors: WAKAI RONALD T. , LEUTHOLD ARTHUR C. , CRIPE LINDA , MARTIN CHESTER B.
Published: June 2006

We report high precision assessment of fetal rhythm in utero in a case of isolated congenital complete heart block using fetal magnetocardiography. The recordings reveal a remarkably strong tendency for the atria and ventricles to synchronize, which is manifested by the continual presence of ventriculophasic sinus arrhythmia and frequent episodes of accrochage and isorhythmic AV dissociation.
Ventriculoatrial Cross‐Talk Dependent Pacemaker Syndrome
Authors: BÕHM ÁDÁM , PINTÉR ARNOLD , DÉKÁNY MIKLÓS , FRÉDA ISTVÁN
Published: June 2006

A patient with dilated cardiomyopathy and ODD pacemaker experienced paroxysmal returns of her symptoms, IEGM revealed VA cross‐talk resulting in functional undersensing of the following P wave that occurred during the PVARP and initiating a pacemaker syndrome with the pacemaker as a bystander.
Witnessed and unwitnessed falls among the elderly with dementia in Japanese nursing homes†
Authors: KOBAYASHI Nami , SUGAI Yuuichi
Published: June 2006

Aim:  The purpose of this research was to describe the incidence of witnessed and unwitnessed falls among the elderly with dementia and to examine the differences between them.

Methods:  We analyzed 276 reports from nine nursing homes in Japan. Descriptive statistics were used to investigate the situations when a fall occurred or when an incident was found. Fisher’s exact test was used to calculate the P‐value to examine the association between witnessed or unwitnessed falls and the variables set in each component of our model. After identifying the variables possibly associated with witnessed and unwitnessed falls, we examined the compounded effects among these variables and classified them into two groups: witnessed and unwitnessed falls. Then, we scrutinized the distribution of the observational data among the variables.

Results:  Fourteen percent of the falls were witnessed. Four variables, the careworker/nurse as the reporter, Clinical Dementia Rating, depression in the elderly, and the time of the fall/discovery of the fall, were identified as variables that were different between the witnessed and unwitnessed falls. When compared to nurses, careworkers witnessed more falls specifically during the day. Falls were rarely witnessed among the subjects with mild dementia, although they were found after the incident throughout the day. The number of severely impaired fallers that were either witnessed or found were equal during every hour of the day.

Conclusion:  The cognitive level of the elderly and the work shift of the care professionals potentially influenced the large number of unwitnessed falls. Nursing home administrators should consider these elements in fall prevention, especially for the elderly with dementia.
PHYSICS OF HEAVY ION COLLISIONS
Authors: PŁANETA R.
Published: June 2006

This review article covers a variety of phenomena observed in heavy ion collisions in full range of available collisions energies. The main reaction channels characteristic of each energy domain are discussed in conjuction with existing nuclear reaction models. Methods used to extract characteristic features of hot nuclear objects are shown. Relations between properties of microscopic nuclear objects and infinite nuclear matter are presented. At the end of this review the transition between hadronic phase and the strongly interacting quark-gluon plasma is discussed.
AVERAGE PROPERTY OF FRAGMENTATION REACTION AND MOMENTUM DISSIPATION INDUCED BY HALO-NUCLEI IN HEAVY ION COLLISIONS
Authors: LIU JIAN-YE , GUO WEN-JUN , REN ZHONG-ZHOU , ZUO WEI , LEE XI-GUO , XING YONG-ZHONG
Published: June 2006

We study systematically the average property of fragmentation reaction and momentum dissipation induced by halo-nuclei in intermediate energy heavy ion collisions for different colliding systems and different beam energies within the isospin dependent quantum molecular dynamics model (IQMD). This study is based on the extended halo-nucleus density distributions, which indicates the average property of loosely inner halo nucleus structure, because the interaction potential and in-medium nucleon-nucleon cross section in IQMD model depend on the density distribution. In order to study the average properties of fragmentation reaction and momentum dissipation induced by halo-nuclei we also compare the results for the halo-nuclear colliding systems with those for corresponding stable colliding systems with same mass under the same incident channel condition. We find that the effect of extended halo density distribution on the fragment multiplicity and nuclear stopping (momentum dissipation) are important for the different beam energies and different colliding systems. For example the extended halo density distributions increase the fragment multiplicity but decrease the nuclear stopping for all of incident channel conditions in this paper.
Influence of lead smelter emissions on the distribution of metals in marine sediments from Chaleur Bay, eastern Canada
Authors: Parsons Michael B. , Cranston Ray E.
Published: June 2006

Metal concentrations in surficial marine sediments collected from many parts of Chaleur Bay are significantly higher than background levels. The bay receives metals from various sources including a Pb smelter, an Hg-cell chlor-alkali plant, and numerous mined and unmined base-metal deposits. This study examines the sources, fluxes, and dispersal patterns of metals released to the bay, and the processes that control the transport and fate of these elements in the marine environment. Bottom sediments collected from 124 sites show the following ranges in metal(oid) concentrations (mg/kg): As, 2.8–74; Cd, 0.02–69; Cu, 3.4–200; Hg, <0.01–2.4; Pb, 0.3–2000; and Zn, 22–3200. Dispersion of smelter effluents and atmospheric emissions by wind and/or nearshore currents has resulted in an area of elevated As, Cd, Cu, Hg, Pb, and Zn concentrations in surficial sediments within
c.
10–20 km of the smelter. The concentrations of most metals decrease sharply with increasing distance from the smelter; however, Pb concentrations exceed background levels in surface sediments throughout the bay. Lead isotope ratios suggest that the surface enrichment of Pb throughout the bay is mainly derived from smelter emissions and historical leaded gasoline combustion.
Smelter dust in humus around Rouyn-Noranda, Québec
Authors: Knight R. D. , Henderson P. J.
Published: June 2006

Microbeam analyses can be used to determine the morphology, texture, size and abundance of smelter dust trapped in humus. The geographic distribution of dust correlates with the geographic distribution of the geochemical signature of anthropogenic input to humus. Results of the study indicate that the observed dust may be classified into two morphotypes and five classes on the basis of differences in morphology, texture, size and chemistry. Dust observed at sizes larger than the maximum allowable emission size of modern electostatic precipitators suggests that part of the dust accumulation is historical. Most of the observed particles represent a resistant slag component whereas labile dust, often observed in emissions, is rarely present. A mass balance calculated for Fe indicates that smelter dust contributes a small fraction of the Fe in the humus compared to values determined by geochemical methods. Although emission of smelter-derived dust is probably the primary mechanism for delivery of metal to humus, the preserved particles are not the current primary residence site of metal in the humus. This suggests that, soon after deposition, weathering processes have released metals and other elements from the dust to the humus.
Metal emissions from a Cu smelter, Rouyn-Noranda, Québec: characterization of particles sampled in air and snow
Authors: Zdanowicz Christian M. , Banic Catharine M. , Paktunc Dogan A. , Kliza-Petelle Deborah A.
Published: June 2006

Particles were sampled in air and snow near a Cu smelter in Rouyn-Noranda, Québec, as part of a study of airborne metal emissions. An analytical scanning electron microscope (SEM) was used to measure the size and elemental composition of >38 000 individual particles. Metal-bearing (Me-) particles account for
c.
58% of all particles in the smelter plume, but only
c.
15% in ambient air or snow. The dominant Me-particle type in snow is Fe–S–Cu but Zn–S, Fe–S, and Cu–S are also common. Pb is dominant in air-filtered particles, even those collected far (>60 km) from the smelter. Me-particles in snow are compositionally more variable and complex than in the smelter plume or ambient air, suggesting that Me-particles settling from the plume in snow are chemically transformed in the process, possibly by heterogeneous reaction(s) with other aerosols (e.g. salt particles) and/or gases (e.g. SO
2
). The size distribution of Me-particles in the smelter plume is broader than in snow or ambient air, owing to a larger proportion of sub-micrometre particles in the plume and/or the loss of fine water-soluble Me-particles in snow meltwater. However, the size distribution of different Me-particle groupings (e.g. As-bearing compared to Cd-bearing particles) is not significantly different within the size range measured.
A geoscientific perspective on airborne smelter emissions of metals in the environment: an overview
Authors: Savard Martine M. , Bonham-Carter Graeme F. , Banic Catharine M.
Published: June 2006

Historically, smelters have been a major source of metals and SO
2
released to the environment in Canada. The study of emissions in the environment around smelters is therefore a priority in evaluating policies in relation to sustainable development. This Special Issue is devoted to papers on various projects supported under three Canadian programmes on metals in the environment. Scientific questions addressed by these programmes include understanding how emitted metals impact the surface environment in different settings, estimating the smelter outputs of metals, distinguishing smelter-derived releases from geogenic contributions, and understanding the fate of current emissions of metals and metalloids and their accumulation during the twentieth century. The approach of the scientific team involved characterizing the spatio-temporal distribution of smelter-emitted metals in the plume and in various surficial media around selected Canadian smelters.

This overview paper summarizes some of the findings discussed in the Special Issue, specifically that: (1) smelter-emitted metal-bearing solids have characteristics that allow their quantification and permit the evaluation of their contribution to the metal load of natural media; (2) delineation of smelter ‘footprints’ can be approached by mathematical estimation or by measurement of multi-element or isotope ratios; and (3) investigation of archival geological systems provides time series that reflect the point-source inputs.
Dendrogeochemical distinction between geogenic and anthropogenic emissions of metals and gases near a copper smelter
Authors: Savard Martine M. , Bégin C. , Parent M. , Marion J. , Smirnoff A.
Published: June 2006

For countries where metal resources represent an important economic sector, one of the main challenges of environmental research is to distinguish between natural and anthropogenic accumulations of potentially toxic metals in mining districts. The present work aims to evaluate a new environmental monitoring tool combining dendrochronology with natural (Ca, Ca/Mn, δ
13
C) and anthropogenic (Cd, Pb,
206
Pb/
207
Pb,
208
Pb/
206
Pb) geochemical tracers in tree rings in such a region. We compare spruce trees sampled at a control site near Hudson Bay, with those sampled near the Horne smelter active since 1928 in Rouyn-Noranda.

The first effect of smelter emissions is detected by the tree-ring carbon isotope records. The δ
13
C values obtained on trees near the smelter show major changes immediately after 1928. This is due to the presence of atmospheric SO
2
which generates a rapid response of the foliar system. The Ca/Mn ratios in tree-ring pairs of 1936–1937 and younger suggest a SO
2
-related soil acidification. The concentrations in Cd and Pb show a major increase starting in 1944 which coincides with a decrease of the
206
Pb/
207
Pb ratios. The smelter activities likely generated this increase and the apparent delay of 14 years may have been generated mainly by the residence time of metals in airborne particulates, the buffering effect of the soils and, to a lesser extent, perhaps by mobility of heavy metals in tree stems. The
206
Pb/
207
Pb and
208
Pb/
206
Pb ratios indicate that the growth rings contain at least three types of Pb: natural, derived from the mineral soil horizons; industrial, from coal burning urban pollution; and mining, typical of the volcanogenic massive sulphides treated at the Horne smelter. This new combination of natural and anthropogenic tracers allows recognition of the succession of atmospheric and pedogeochemical changes related to industrial activities in the Rouyn-Noranda mining area.
Multilocus Sequence Typing of Bacteria
Authors: Maiden Martin C.J.
Published: June 2006

Multilocus sequence typing (MLST) was proposed in 1998 as a portable, universal, and definitive method for characterizing bacteria, using the human pathogen Neisseria meningitidis as an example. In addition to providing a standardized approach to data collection, by examining the nucleotide sequences of multiple loci encoding housekeeping genes, or fragments of them, MLST data are made freely available over the Internet to ensure that a uniform nomenclature is readily available to all those interested in categorizing bacteria. At the time of writing, over thirty MLST schemes have been published and made available on the Internet, mostly for pathogenic bacteria, although there are schemes for pathogenic fungi and some nonpathogenic bacteria. MLST data have been employed in epidemiological investigations of various scales and in studies of the population biology, pathogenicity, and evolution of bacteria. The increasing speed and reduced cost of nucleotide sequence determination, together with improved web-based databases and analysis tools, present the prospect of increasingly wide application of MLST.
Progress and Challenges in Bipolar Lead‐Acid Battery Development
Authors: Bullock Kathryn R.
Published: June 2006

Bipolar lead‐acid batteries have higher power densities than any other aqueous battery system. Predicted specific powers based on models and prototypes range from 800 kW/kg for 100 ms discharge times to 1.6 kW/kg for 10 s. A 48 V automotive bipolar battery could have

2
 
1
/
2

times the cold cranking rate of a monopolar 12 V design in the same size. Problems which have precluded the development of commercial bipolar designs include the instability of substrate materials and enhanced side reactions. Design approaches include pseudo‐bipolar configurations, as well as true bipolar designs in planar and tubular configurations. Substrate materials used include lead and lead alloys, carbons, conductive ceramics, and tin‐oxide‐coated glass fibers. These approaches are reviewed and evaluated.
International Trade in Semiconductors: Challenges and Opportunities
Authors: Krist William K.
Published: June 2006

Abstract not Available.
Efficacy of myonuclear addition may explain differential myofiber growth among resistance-trained young and older men and women
Authors: Petrella John K. , Kim Jeong-su , Cross James M. , Kosek David J. , Bamman Marcas M.
Published: June 2006

Skeletal muscle stem (satellite) cells supporting growth/regeneration are thought to be activated and incorporated into growing myofibers by both endocrine and locally expressed autocrine/paracrine growth factors, the latter being load sensitive. We recently found that myofiber hypertrophy with resistance training is superior in young men (YM) vs. young women and older adults (Kosek DJ, Kim JS, Petrella JK, Cross JM, and Bamman MM. J Appl Physiol 101: 531–544, 2006). We hypothesized that the advanced myofiber hypertrophy in YM is facilitated by myonuclear addition in response to a milieu promoting stem cell activation. Twenty-six young (27.0 ± 1 yr, 50% women) and 26 older (63.7 ± 1 yr, 50% women) adults completed 16 wk of knee extensor resistance training. Vastus lateralis biopsies were obtained at baseline, 24 h after one bout, and after 16 wk. Muscle stem cells were identified immunohistochemically with anti-neural cell adhesion molecule (NCAM+). Muscle transcript levels of IGF-I and mechanogrowth factor (MGF) were determined by RT-PCR. Serum IGF-I, IGF-binding protein (IGFBP)-3, IGFBP-1, total and free testosterone, sex hormone-binding globulin (SHBG), and androstenedione were assessed by radioimmunoassay. Myofiber hypertrophy was twofold greater in YM vs. others, and only YM increased NCAM+ cells per 100 myofibers (49%) and myonuclei per fiber (19%) ( P < 0.05). IGF-IEa mRNA was higher in young and increased acutely (29%) with summation by 16 wk (96%) ( P < 0.05). MGF mRNA increased only in young after one bout (81%) and by 16 wk (85%) ( P < 0.001). Circulating IGF-I was twofold higher in young, whereas IGFBP-1 was lowest in YM ( P < 0.05). Among men, free testosterone was 59% higher in YM ( P < 0.01). Myonuclear addition was most effectively accomplished in YM, which likely drove the superior growth.
State-Dependent Gating of Sensory Inputs by Zona Incerta
Authors: Trageser Jason C. , Burke Kathryn A. , Masri Radi , Li Ying , Sellers Larisa , Keller Asaf
Published: June 2006

We have previously shown that the GABAergic nucleus zona incerta (ZI) suppresses vibrissae-evoked responses in the posterior medial (POm) thalamus of the rodent somatosensory system. We proposed that this inhibitory incerto-thalamic pathway regulates POm responses during different behavioral states. Here we tested the hypothesis that the cholinergic reticular activating system, implicated in regulating states of arousal, modulates ZI activity. We show that stimulation of brain stem cholinergic nuclei (laterodorsal tegmental and pedunculopontine tegmental) results in suppression of spontaneous firing of ZI neurons. Iontophoretic application of the cholinergic agonist carbachol to ZI neurons suppresses both their spontaneous firing and their vibrissae-evoked responses. We also found that carbachol application to an in vitro slice preparation suppresses spontaneous firing of neurons in the ventral sector of ZI (ZIv). Finally, we demonstrate that the majority of ZIv neurons contain parvalbumin and project to POm. Based on these results, we present the state-dependent gating hypothesis, which states that differing behavioral states—regulated by the brain stem cholinergic system—modulate ZI activity, thereby regulating the response properties of higher-order nuclei such as POm.
Variable Kainate Receptor Distributions of Oriens Interneurons
Authors: Yang Ellen J. , Harris Alexander Z. , Pettit Diana L.
Published: June 2006

Interneuron kainate receptor (KAR) activation regulates normal network activity and modulates cell excitability. As a result, determining the subcellular distribution of KARs in a cell-specific manner is a necessary step toward understanding their role in network function. We have functionally mapped synaptic and extrasynaptic dendritic KARs on hippocampal oriens interneurons using local photolysis of caged glutamate. We find that the majority of trilaminar and oriens lacunosum-moleculare (O-LM) cells have uniform and continuous current densities along the lengths of their dendrites. However, there is a subpopulation of interneurons that have no KAR currents or currents exclusively at “hot spots” on the soma and dendrites. Finally, bistratified cells have KAR currents on all dendrites except those extending into the stratum radiatum. Thus KARs are functionally distributed in a cell-specific and cell-independent manner that may reflect the physiologically distinct roles they play in the hippocampal network.
Psychosocial Mediators of a Nurse Intervention to Increase Skin Self-examination in Patients at High Risk for Melanoma
Authors: Hay Jennifer L. , Oliveria Susan A. , Dusza Stephen W. , Phelan Deborah L. , Ostroff Jamie S. , Halpern Allan C.
Published: June 2006

This prospective study examines psychosocial mediators of an efficacious skin self-examination (SSE) intervention that includes provision of a whole-body digital photography book depicting the entire skin surface. Individuals (n = 100) with established risk factors for melanoma were recruited from the Memorial Sloan-Kettering Cancer Center Pigmented Lesion Clinic during their initial dermatologist visit and were randomized to receive a photobook immediately (n = 49) or 4 months after intervention delivery (n = 51). Potential mediators included self-efficacy and response efficacy drawn from Social Cognitive Theory, melanoma worry, and SSE anxiety drawn from Self-Regulation Theory, and skin cancer knowledge, and skin awareness. Only self-efficacy was a significant mediator, accounting for 8% of the total effect of photobook enhancement on SSE adherence at 4 months. (Cancer Epidemiol Biomarkers Prev 2006;15(6):1212–6)
Meat Mutagens and Risk of Distal Colon Adenoma in a Cohort of U.S. Men
Authors: Wu Kana , Giovannucci Edward , Byrne Celia , Platz Elizabeth A. , Fuchs Charles , Willett Walter C. , Sinha Rashmi
Published: June 2006

Cooking meats at high temperatures and for long duration produces heterocyclic amines and other mutagens. These meat-derived mutagenic compounds have been hypothesized to increase risk of colorectal neoplasia, but prospective data are unavailable. We examined the association between intakes of the heterocyclic amines 2-amino-3,8-dimethylimidazo[4,5,-f]quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,4,8-trimethylimidazo[4,5,-f]quinoxaline (DiMeIQx), and meat-derived mutagenicity (MDM) and risk of distal colon adenoma using a cooking method questionnaire administered in 1996 in the Health Professionals Follow-up Study cohort. Between 1996 and 2002, 581 distal colon adenoma cases were identified. Higher intake of MDM was marginally associated with increased risk of distal adenoma [fourth versus lowest quintile: odds ratio (OR), 1.39; 95% confidence interval (95% CI), 1.05-1.84; highest versus lowest quintile: OR, 1.29; 95% CI, 0.97-1.72; Ptrend = 0.08]. Adjusting for total red meat or processed meat intake did not explain those associations. Our data also suggested a positive association between higher MeIQx (highest versus lowest quintile: OR, 1.28; 95% CI, 0.95-1.71; Ptrend = 0.22) and risk of adenoma, but this association was attenuated after adjusting for processed meat intake. DiMeIQx and PhIP did not seem to be associated with risk of adenoma. In conclusion, higher consumption of mutagens from meats cooked at higher temperature and longer duration may be associated with higher risk of distal colon adenoma independent of overall meat intake. Because mutagens other than heterocyclic amines also contribute to MDM, our results suggest that mutagens other than heterocyclic amines in cooked meats may also play a role in increasing the risk of distal adenoma. (Cancer Epidemiol Biomarkers Prev 2006;15(6):1120–5)
Dietary Factors of One-Carbon Metabolism in Relation to Non-Hodgkin Lymphoma and Multiple Myeloma in a Cohort of Male Smokers
Authors: Lim Unhee , Weinstein Stephanie , Albanes Demetrius , Pietinen Pirjo , Teerenhovi Lasse , Taylor Philip R. , Virtamo Jarmo , Stolzenberg-Solomon Rachael
Published: June 2006

Reported associations between genetic polymorphisms in folate-metabolizing enzymes and lymphoid malignancies suggest etiologic involvement of one-carbon metabolism and its related dietary exposures. We examined dietary factors of one-carbon metabolism in relation to non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) among 27,111 healthy male smokers who completed baseline dietary questionnaires in the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study cohort. During a follow-up of up to 16.4 years (1985-2001), 195 NHL and 32 MM cases were ascertained. Cox proportional hazard models were used to estimate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (95% CI). There was no significant association between dietary folate and NHL (HR comparing fourth to first quartile, 1.03; 95% CI, 0.68-1.55). Dietary vitamin B12 was inversely associated with NHL (HR, 0.61; 95% CI, 0.37-1.00; Ptrend = 0.06). The inverse association of vitamin B12 was evident for diffuse subtype but did not reach statistical significance. There were no significant associations of dietary vitamin B6 or B2, methionine, or alcohol with NHL. None of the dietary or supplemental one-carbon nutrients were associated with MM, although the power of these analyses was limited. Our results suggest that high intake of vitamin B12 among heavy smokers may be protective against NHL but warrant further studies, including among nonsmokers. (Cancer Epidemiol Biomarkers Prev 2006;15(6):1109–14)
Variants in the Prostate-Specific Antigen (PSA) Gene and Prostate Cancer Risk, Survival, and Circulating PSA
Authors: Severi Gianluca , Hayes Vanessa M. , Neufing Petra , Padilla Emma J.D. , Tilley Wayne D. , Eggleton Sarah A. , Morris Howard A. , English Dallas R. , Southey Melissa C. , Hopper John L. , Sutherland Robert L. , Boyle Peter , Giles Graham G.
Published: June 2006

An A to G substitution, rs925013, in the promoter of the prostate-specific antigen gene (PSA) was recently found to be associated with promoter activity and circulating PSA levels. The objective of this study was to test the associations between rs925013 and another A to G substitution, rs266882, in the PSA gene with prostate cancer risk using a population-based case-control study of 821 prostate cancer cases and 734 controls carried out in Perth and Melbourne, Australia. The study focused on young (i.e., <70 years) and aggressive cases (i.e., well-differentiated tumors were excluded). Cases in the Melbourne arm of the study (N = 638) were followed up prospectively for an average period of 8.2 years and deaths from prostate cancer ascertained through record linkage to study the possible association between genetic variants and disease-specific survival. PSA-circulating levels were measured in controls to test the association with the genetic variants using a cross-sectional design. Linear regression of log PSA levels, unconditional logistic regression, Cox regression, and haplotype analyses were undertaken. For rs925013, the G allele was associated with an increased risk of prostate cancer [odds ratio, 1.4; 95% confidence interval (95% CI), 1.1-1.7; P = 0.001], and the hazard ratio for survival for cases homozygous for the G allele compared with cases homozygous for the A allele was increased but not statistically significant (hazard ratio, 2.3; 95% CI, 1-5.6; P = 0.06). For rs266882, there was no association with overall prostate cancer risk and survival (all P > 0.1). Men homozygous or heterozygous for the G/G (rs925013/rs266882) haplotype were at higher risk of prostate cancer than men homozygous for the A/A haplotype (odds ratio, 1.3; 95% CI, 1.1-1.7; P = 0.009). Adjusted geometric means of circulating PSA levels in controls were similar in men with zero, one, and two copies of the G allele in rs266882 (1.2, 1.1, and 1.3 ng/mL, respectively; all P ≥ 0.2) and rs925013 (1.1, 1.2, and 1.5 ng/mL, respectively; all P > 0.1). For rs925013, our study provides good evidence of association with prostate cancer risk, marginal evidence of association with survival, and little evidence of detectable association with circulating PSA levels in controls. We found no evidence of an independent association between rs266882 and any of the outcomes. The genotypes and haplotypes studied might be associated with the PSA gene function or be in linkage disequilibrium with other unmeasured and functional variants in the PSA or other genes. (Cancer Epidemiol Biomarkers Prev 2006;15(6):1142-7)
Toward a Further Elucidation: Role of Vertebral Artery Hypoplasia in Acute Ischemic Stroke
Authors: Chuang Yu-Ming , Huang Yuarn-Chung , Hu Han-Haw , Yang Ching-Yih
Published: June 2006

Background and Purpose: Congenital vertebral artery (VA) hypoplasia is an uncommon embryonic variation of posterior circulation. The frequency of this congenital variation was reported to be 2–6% from autopsy and angiograms. The aim of our study was to elucidate the role of VA hypoplasia in acute ischemic stroke. Method: We examined 191 acute ischemic stroke patients (age 55.8 ± 14.0 years). TOAST subtypes were determined. A cervical magnetic resonance angiogram was performed in every patient. A duplex study of bilateral VA with flow velocities and vessel diameter recording in the intertransverse (V2) segment was performed within 72 h after onset of ischemic stroke. The net VA flow volume was measured in each subject. Result: The overall incidence of a unilateral congenital hypoplastic VA was 11.51%, which was statistically higher especially in cases of brainstem/cerebellar infarction. Of these, subjects with VA hypoplasia had an etiological preponderance of the ‘large-artery atherosclerosis’ subtype and a topographic preponderance of ipsilateral posterior circulation infarction. Conclusions: Based on our results, VA hypoplasia seemed a contributing factor of acute ischemic stroke, especially in posterior circulation territories.
Cell Proliferation Inhibition in Remitting Multiple Sclerosis CSF
Authors: Westall Fred C. , Seil Fredrick J.
Published: June 2006

Sixty percent of the CSF samples from 21 multiple sclerosis (MS) patients in remission inhibited cellular proliferation of a variety of neuronal and glial cell lines. No inhibition was observed with CSF from relapsing or progressive MS patients (0/19). Two of 82 samples from stationary MS patients were positive. No inhibition was found in MS sera. The CSF samples had no effect on myelination of mouse organotypic cerebellar cultures. Like MS cellular proliferation and subsequent lesion formation, the ‘deactivation’ of the lesion also is an active defined process, rather than just the cessation of the immunological events. Furthermore, approximately 20% of samples from Huntington’s, Alzheimer’s and Parkinson’s disease patients were also positive. However, no inhibition was seen in CSF from amyotrophic lateral sclerosis patients or controls.
Uncertainty and ‘technological horizon’ in qualitative interviews about HIV treatment
Authors: Davis Mark , Frankis Jamie , Flowers Paul
Published: June 2006

Highly Active Anti-Retroviral Treatment (HAART) has reduced death and morbidity among people with HIV. However, HAART is not always effective, can produce serious side-effects and implies uncertainty for patients. To address HAART-related uncertainty, 20 qualitative interviews were conducted with gay men with HIV in Glasgow and London. The interviewees were purposively selected to reflect diversity in terms of year of diagnosis, experiences of illness and treatment-related side-effects. The interviews were analysed using the constant comparison method to derive themes. Among those using HAART, analysis identified themes of ‘good health’, ‘illness’ and ‘loss of confidence’. Uncertainty was managed through a discourse of ‘technological horizon’ that combined the ongoing innovations of HAART and biographical time. These themes are discussed in terms of the implications for HIV care. In particular, technological horizon provides a basis for the management of uncertainty in the prescribing relationship between patient and clinician
Activation-independent platelet adhesion and aggregation under elevated shear stress
Authors: Ruggeri Zaverio M. , Orje Jennifer N. , Habermann Rolf , Federici Augusto B. , Reininger Armin J.
Published: June 2006

Platelet aggregation, which contributes to bleeding arrest and also to thrombovascular disorders, is thought to initiate after signaling-induced activation. We found that this paradigm does not apply under blood flow conditions comparable to those existing in stenotic coronary arteries. Platelets interacting with immobilized von Willebrand factor (VWF) aggregate independently of activation when soluble VWF is present and the shear rate exceeds 10 000 s–1 (shear stress = 400 dyn/cm2). Above this threshold, active A1 domains become exposed in soluble VWF multimers and can bind to glycoprotein Ibα, promoting additional platelet recruitment. Aggregates thus formed are unstable until the shear rate approaches 20 000 s–1 (shear stress = 800 dyn/cm.2). Above this threshold, adherent platelets at the interface of surface-immobilized and membrane-bound VWF are stretched into elongated structures and become the core of aggregates that can persist on the surface for minutes. When isolated dimeric A1 domain is present instead of native VWF multimers, activation-independent platelet aggregation occurs without requiring shear stress above a threshold level, but aggregates never become firmly attached to the surface and progressively disaggregate as shear rate exceeds 6000 s–1. Platelet and VWF modulation by hydrodynamic force is a mechanism for activation-independent aggregation that may support thrombotic arterial occlusion.
DOCK2 regulates chemokine-triggered lateral lymphocyte motility but not transendothelial migration
Authors: Shulman Ziv , Pasvolsky Ronit , Woolf Eilon , Grabovsky Valentin , Feigelson Sara W. , Erez Noam , Fukui Yoshinori , Alon Ronen
Published: June 2006

Rac GTPases are key regulators of leukocyte motility. In lymphocytes, chemokine-mediated Rac activation depends on the CDM adaptor DOCK2. The present studies addressed the role of DOCK2 in chemokine-triggered lymphocyte adhesion and motility. Rapid chemokine-triggered activation of both LFA-1 and VLA-4 integrins took place normally in DOCK2–/– T lymphocytes under various shear flow conditions. Consequently, DOCK2–/– T cells arrested normally on TNFα-activated endothelial cells in response to integrin stimulatory chemokine signals, and their resistance to detachment was similar to that of wild-type (wt) T lymphocytes. Nevertheless, DOCK2–/– T lymphocytes exhibited reduced microvillar collapse and lamellipodium extension in response to chemokine signals, ruling out a role for these events in integrin-mediated adhesion strengthening. Strikingly, arrested DOCK2–/– lymphocytes transmigrated through a CCL21-presenting endothelial barrier with similar efficiency and rate as wt lymphocytes but, unlike wt lymphocytes, could not locomote away from the transmigration site of the basal endothelial side. DOCK2–/– lymphocytes also failed to laterally migrate over multiple integrin ligands coimmobilized with chemokines. This is a first indication that T lymphocytes use 2 different chemokine-triggered actin remodeling programs: the first, DOCK2 dependent, to locomote laterally along apical and basal endothelial surfaces; the second, DOCK2 independent, to cross through a chemokine-bearing endothelial barrier.
Induction of PNAd and N-acetylglucosamine 6-O-sulfotransferases 1 and 2 in mouse collagen-induced arthritis
Authors: Yang Jiwei , Rosen Steven D , Bendele Philip , Hemmerich Stefan
Published: June 2006

Background

Leukocyte recruitment across blood vessels is fundamental to immune surveillance and inflammation. Lymphocyte homing to peripheral lymph nodes is mediated by the adhesion molecule, L-selectin, which binds to sulfated carbohydrate ligands on high endothelial venules (HEV). These glycoprotein ligands are collectively known as peripheral node addressin (PNAd), as defined by the function-blocking monoclonal antibody known as MECA-79. The sulfation of these ligands depends on the action of two HEV-expressed N-acetylglucosamine 6-O-sulfotransferases: GlcNAc6ST-2 and to a lesser degree GlcNAc6ST-1. Induction of PNAd has also been shown to occur in a number of human inflammatory diseases including rheumatoid arthritis (RA).

Results

In order to identify an animal model suitable for investigating the role of PNAd in chronic inflammation, we examined the expression of PNAd as well as GlcNAc6ST-1 and -2 in collagen-induced arthritis in mice. Here we show that PNAd is expressed in the vasculature of arthritic synovium in mice immunized with collagen but not in the normal synovium of control animals. This de novo expression of PNAd correlates strongly with induction of transcripts for both GlcNAc6ST-1 and GlcNAc6ST-2, as well as the expression of GlcNAc6ST-2 protein.

Conclusion

Our results demonstrate that PNAd and the sulfotransferases GlcNAc6ST-1 and 2 are induced in mouse collagen-induced arthritis and suggest that PNAd antagonists or inhibitors of the enzymes may have therapeutic benefit in this widely-used mouse model of RA.