bluuebunny/crossref_metadata_2025 huggingface dataset:
Polychlorinated Biphenyls and Hexachlorobenzene in Full-Term Neonates
Authors: Lackmann Gerd M.
Published: April 2003

Objective: To determine actual reference values of polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) in full-term neonates. Patients and Methods: Cord blood samples were taken from 200 healthy, full-term neonates in 1998. Blood specimens were immediately centrifuged, and serum was stored in glass tubes at –20°C up to analysis. Six PCB congeners (IUPAC No. 28, 52, 101, 138, 153, and 180) and HCB were determined with capillary gas chromatography with electron capture detection. Study groups were tested on mean differences with Wilcoxon’s test of independent samples. The 95th percentiles by rank were calculated as reference values. Results: One sample was excluded from further evaluation because of unusually high PCB concentrations. Personal data of the remaining 199 newborns showed 106 male and 93 female neonates. Mean gestational age was 40 weeks (range 38–43 weeks), mean birth weight was 3,450 g (2,300–5,060 g). The concentrations of the lower-chlorinated PCB congeners 28, 52, and 101 were below the detection limit with exception of two probes. Reference values (95th percentile by rank) of the higher-chlorinated PCB congeners and HCB were as follows: PCB 138, 0.5 µg/l; PCB 153, 0.5 µg/l; PCB 180, 0.4 µg/l; and HCB, 0.5 µg/l. Conclusions: The results of the present study clearly demonstrate a further decline in the prenatal uptake of PCBs and HCB since 1994–1995. During the past 15 years, a 75% decline in the prenatal burden with PCBs and a 90% reduction in the burden with HCB could be demonstrated.
Prolonged Apneas and Hypoxia Mediated by Nicotine and Endotoxin in Piglets
Authors: Frøen J. Frederik , Akre Harriet , Stray-Pedersen Babill , Saugstad Ola Didrik
Published: April 2003

Objective: Infections and maternal smoking are risk factors for SIDS, and toxins from common bacteria have been proposed as a causative link between infections and SIDS. Nicotine can be transferred in significant amounts postnatally to the infant through environmental tobacco smoke or maternal smoking before nursing. We investigated the acute effects of nicotine and endotoxin on repeated apnea by laryngeal reflex stimulation and the following autoresuscitation. Design: Thirty-four 1-week-old (± 1 day) piglets were sedated and randomized to 1 of 4 pretreatment groups: (1) 1 µg endotoxin i.v./kg; (2) 5 µg nicotine i.v./kg; (3) 1 µg endotoxin i.v./kg and 5 µg nicotine i.v./kg, and (4) placebo. Apnea was induced by insufflation of 0.1 ml of acidified saline (pH 2) in the subglottic space of the trachea three times with intervals of 2 min. Results: Pretreatment with endotoxin caused a significant increase in plasma TNF-α in the endotoxin groups (mean value ± SEM 953 ± 246 and 980 ± 226 pg/ml, respectively) but no significant change in plasma IL-1β. Blood pressure, respiratory rate or SaO2 was not significantly affected before induced apnea. Both pretreatment with nicotine and endotoxin caused prolonged apneas by 35–45%, a complete loss of normal hyperventilation during autoresuscitation, and prolonged hypoxia after apnea. Conclusions: Nicotine and endotoxin interferes with autoresuscitation after apnea. This experimental model on piglets may shed light over important mechanisms involved in the causation of SIDS.
Relative Size of the Hyperstriatum ventrale Is the Best Predictor of Feeding Innovation Rate in Birds
Authors: Timmermans Sarah , Lefebvre Louis , Boire Denis , Basu Paroma
Published: April 2003

Within the avian telencephalon, the dorsal ventricular ridge (DVR) contains higher order and multimodal integration areas. Using multiple regressions on 17 avian taxa, we show that an operational estimate of behavioral flexibility, the frequency of feeding innovation reports in ornithology journals, is most closely predicted by relative size of one of these DVR areas, the hyperstriatum ventrale. Neither phylogeny, juvenile development mode, nor species sampled account for the relationship. Similar results are found when the hyperstriatum ventrale is lumped with a second DVR structure, the neostriatum. In simple correlations, size of the wulst and the striatopallidal complex is associated with feeding innovation rate, but the two structures are eliminated from the multiple regressions. Our results parallel those on primates showing a correlation between innovation rate and neocortex size and support the idea that the mammalian neocortex and the neostriatum-hyperstriatum ventrale complex in birds have similar integrative roles.
Conservation of Absolute Foveal Area in New World Monkeys
Authors: Franco E.C.S. , Finlay B.L. , Silveira L.C.L. , Yamada E.S. , Crowley J.C.
Published: April 2003

The foveal specializations of five New World monkeys, the marmoset, Callithrix jacchus; the golden-handed tamarin, Saguinus midas niger; the squirrel monkey, Saimiri ustius; the capuchin monkey, Cebus apella; and the howler monkey, Alouatta caraya were compared. Although retinal area varies by over a factor of two in these monkeys, the area of the fovea does not covary with retinal area and remains approximately the same absolute size, as measured by the dimensions of the high density region of cones, or the rod-free region. This constancy in foveal size also holds for rhesus monkeys and humans, bringing the variation in retinal area to a factor of five. Alouatta caraya is unusual, distinguished by a very high central cone density and a small rod-free zone. Physiological constraints that might limit foveal area over a wide range of eye sizes are considered.
Sylvian Fissure Asymmetries in Nonhuman Primates Revisited: A Comparative MRI Study
Authors: Hopkins William D. , Pilcher Dawn L. , MacGregor Leslie
Published: April 2003

Magnetic resonance images (MRI) were collected in a sample of 28 apes, 16 Old World monkeys and 8 New World monkeys. The length of the sylvian fissure (SF) and the superior temporal sulcus (STS) was traced in each hemisphere from three regions of the cerebral cortex. These three regions were labeled according to their position on the sagittal plane as lateral, medial and insular. It was hypothesized that the length and asymmetry of these fissures would be dependent on the region of measurement and that a leftward asymmetry in the SF and STS would be more robust in the great ape sample than for the monkeys. The results indicated within the ape sample a population-level leftward asymmetry in the medial and insular regions of the SF. Within the Old and New World monkey samples, the SF was leftward in the medial region at the population level, but not at the insular region. Additionally, the Old World monkeys exhibited a population-level rightward lateral SF and a rightward lateral STS. No other families exhibited population-level asymmetries in the lateral region of the SF or in any region of the STS. These results are consistent with findings reported in apes and, to a lesser extent, monkeys. MRI has excellent potential for comparing neuroanatomy across taxonomic families that will help future investigations.
Visual Fields and Foraging in Procellariiform Seabirds: Sensory Aspects of Dietary Segregation
Authors: Martin Graham R. , Prince Peter A.
Published: April 2003

Retinal visual fields were determined using an ophthalmoscopic reflex technique in two seabird species of the family Procellariidae: white-chinned petrel Procellaria aequinoctialis and antarctic prion Pachyptila desolata. The binocular fields of both species show a similar shape but they differ in size and in the position of the bill within the field. In white-chinned petrels the binocular field extends vertically through approximately 140° and has a maximum width of approximately 40°. The bill is placed approximately central within the field. The binocular field of the prions is approximately half this width and vertical extent, and the bill is placed close to the ventral edge. These differences in binocular field topography can be correlated with the different foraging techniques that these birds employ when seeking a similar diet within the same environment. White-chinned petrels pursue individual items both at the surface and while diving to moderate depths. Antarctic prions feed primarily by filtering items from surface waters. These differences in visual field topography mirror those found in different terrestrial bird species that primarily employ visual or tactile cues in the pursuit of food items. White-chinned petrel eyes and visual fields show features of an amphibious optical design similar to those found in penguins and albatrosses.
Acoustic Nuclei in the Medulla and Midbrain of the Vocalizing Gulf Toadfish (Opsanus beta)
Authors: Bass Andrew H. , Bodnar Deana A. , Marchaterre Margaret A.
Published: April 2003

The organization of the descending and secondary octaval nuclei in the hindbrain of the Gulf toadfish, Opsanus beta, was revealed following the injection of biotin compounds into a physiologically identified auditory region of the torus semicircularis. The results show retrogradely-filled neurons mainly in a dorsomedial division of the descending octaval nucleus, and dorsal and ventral divisions of a secondary octaval nucleus; minor labeling also appeared in dorsolateral and rostromedial intermediate divisions of the descending nucleus. The pattern identified is consistent with that reported in other teleosts, including both vocal and non-vocal species, and clarifies earlier reports of the organization of hindbrain octaval nuclei in toadfish and the closely related midshipman fish.
Comparison of Brain Volumes between Single and Multiple Foundresses in the Paper Wasp Polistes dominulus
Authors: Ehmer Birgit , Reeve H. Kern , Hoy Ron R.
Published: April 2003

Queens of the paper wasp Polistes dominulus have the option to found nests in spring alone or together with other queens. In the latter case a dominance hierarchy is established among the cofoundresses with the dominant wasp getting the major share of the reproductive output of the nest. The different reproductive strategies of an individual wasp will necessitate different behaviors. We measured the volumes of brain structures as a potential indicator of differential use and elaboration of a number of brain structures. We found a significant increase in the volume of the antennal lobe in members of multiple foundress associations in comparison to single foundresses. The volume of the collar, a substructure of the calyx of the mushroom body, was also significantly larger, especially in the dominant queen of a foundress association. No significant differences between dominant or subordinate wasps in regard to volume of the measured brain substructures were found.
Avoiding the ‘Costs’ of Testosterone: Ecological Bases of Hormone-Behavior Interactions
Authors: Wingfield John C. , Lynn Sharon E. , Soma Kiran K.
Published: April 2003

A combination of laboratory and field investigations of birds has shown that expression of behavior such as territorial aggression can occur throughout the year in many species and in different life history stages. Although it is well known that testosterone regulates territorial aggression in males during the breeding season, the correlation of plasma testosterone and aggression appears to be limited to periods of social instability when a male is challenged for his territory by another male, or when mate-guarding a sexually receptive female. How essentially identical aggression is modulated in non-breeding life history stages is not fully resolved, but despite low circulating levels of testosterone outside the breeding season, expression of territorial aggression does appear to be dependent upon aromatization of testosterone and an estrogen receptor-mediated mechanism. There is accumulating evidence that prolonged high levels of circulating testosterone may incur costs that may potentially reduce lifetime fitness. These include interference with paternal care, exposure to predators, increased risk of injury, loss of fat stores and possibly impaired immune system function and oncogenic effects. We propose six hypotheses to explain how these costs of high testosterone levels in blood may be avoided. These hypotheses are testable and may reveal many mechanisms resulting from selection to avoid the costs of testosterone. It should also be noted that the hypotheses are applicable to vertebrates in general, and may also be relevant for other hormones that have a highly specialized suite of actions in one life history stage (such as breeding), but also have a limited action in other life history stages when the full spectrum of effects would be inappropriate.
Dynamic Interactions of Behavior and Amine Neurochemistry in Acquisition and Maintenance of Social Rank in Crayfish
Authors: Huber R. , Panksepp J.B. , Yue Z. , Delago A. , Moore P.
Published: April 2003

This review summarizes a set of experimental approaches with which we explore fighting behavior in crayfish and the importance of aminergic systems in its control. Our results illustrate that agonistic behavior in crustaceans can be characterized within a quantitative framework, that different types of behavioral plasticity in aggressive behavior are in need of physiological explanation, and that pharmacological intervention involving serotonergic systems produces characteristic changes in fighting. Moreover, we attempt to identify changes in neurochemistry during the acquisition of social status. Many of the studies presented here summarize ongoing work. Nonetheless, results to date complement and extend previous detailed physiological, morphological and biochemical studies exploring the roles of amines in aggression.
The Role of Monoaminergic Nuclei during Aggression and Sympathetic Social Signaling
Authors: Korzan Wayne J. , Summers Tangi R. , Ronan Patrick J. , Renner Kenneth J. , Summers Cliff H.
Published: April 2003

A social sign stimulus that is sympathetically induced affects aggressive approaches and influences serotonergic, dopaminergic and noradrenergic activity in the brainstem nuclei of Anolis carolinensis. Darkening of postorbital skin via sympathetic activation of adrenal catecholamines and β2-adrenergic receptors provides a visual signal that forms more rapidly in dominant than subordinate males during social interactions. This signal limits aggressive interactions. Males were painted postorbitally with green or black paint and then exposed to a mirror. Aggressive approaches to the mirror were inhibited in males viewing a reflection with darkened eyespots, and increased in males viewing a reflection without eyespots (hidden). Noradrenergic turnover in the raphe and locus ceruleus were greatest in test subjects that viewed a reflection with eyespots hidden by green paint. Perception of darkened eyespots stimulated greater serotonergic turnover in raphe, locus ceruleus and substantia nigra/ventral tegmental area (SN/VTA). Dopaminergic turnover was higher in the raphe and SN/VTA of Anolis that viewed a reflection with darkened eyespots. However, these animals had lower dopamine turnover in the locus ceruleus than isolated and hidden eyespot groups. Of the possible roles of perikarya on central function and behavior, our results suggest feedback, cross-nuclear regulation, and some independence of function between nuclei and the forebrain terminal fields. Decreased serotonergic activity corresponds with increased aggression only in the raphe, suggesting that the raphe nuclei might be important for this behavioral trait. Increased serotonergic, noradrenergic and dopaminergic activities in SN/VTA in Anolis that view a reflected opponent with dark eyespots suggests that the SN/VTA might be directly involved in recognition of this social sign stimulus and the resulting inhibition of aggression.
Seasonal Changes in Brain GnRH Immunoreactivity and Song-Control Nuclei Volumes in an Opportunistically Breeding Songbird
Authors: MacDougall-Shackleton Scott A. , Deviche Pierre J. , Crain Renee D. , Ball Gregory F. , Hahn Thomas P.
Published: April 2003

White-winged crossbills (Loxia leucoptera) are opportunistic breeders that can nest at almost any time of year if there is sufficient food. Other cardueline finches that have been shown to breed on a strictly seasonal schedule become absolutely refractory to the stimulatory effects of long-day photoperiod, dramatically down-regulate hypothalamic gonadotropin-releasing hormone (GnRH), and reduce the volume of several song-control nuclei in autumn. This study examined whether changes in photoperiod modify the GnRH and song-control systems in white-winged crossbills. Adult male and female crossbills were captured and held on a naturally changing photoperiod. Brains of male and female birds were collected in May, October, and January. GnRH content was assessed by immunocytochemistry and the volumes of Nissl-defined song-control nuclei (HVc, Area X, and the robust nucleus of the archistriatum) were reconstructed. In contrast to other cardueline finches, GnRH immunoreactivity was relatively stable across the year, exhibiting only modest seasonal variation. The song control system, on the other hand, exhibited large seasonal changes as well as sex differences. Thus, crossbills appear to maintain hypothalamic GnRH content year round, perhaps to facilitate a rapid response to favorable breeding conditions, even on short days. However, song control nuclei are dramatically affected by photoperiod. Future work should examine these systems in crossbills breeding on short days to compare photoperiod-dependent and -independent effects on neural plasticity.
Long-Term Potential of Angiotensin Receptor Blockade for Cardiovascular Protection in Hypertension: The VALUE Trial
Authors: Julius Stevo
Published: April 2003

The recent decrease of cardiovascular mortality in the USA is less pronounced than it has been in the preceding three decades. Elsewhere, cardiovascular mortality decreased and in some countries it increased. Cerebrovascular disease and ischemic heart disease were responsible for 21% of deaths recorded by the World Health Organization in 1990 and 1997, of which hypertension was estimated to be directly responsible for half of these deaths. Apart from blood pressure (BP) elevation, essential hypertension is frequently associated with factors that increase the risk of poor cardiovascular outcomes: insulin resistance/dyslipidemia, elevated angiotensin and norepinephrine, a tendency for hypercoagulability, platelet overactivity, tachycardia, vulnerability to arrhythmias, vascular hypertrophy, endothelial dysfunction, and left ventricular hypertrophy. Excess activation of the renin-angiotensin system, independent of BP elevation, contributes to these abnormalities. To achieve better results in the future, focus must be shifted from BP lowering to recognition of specific effects of drugs on these diverse pathophysiologic aspects of hypertension. The Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial, which is evaluating the effect of valsartan (Diovan®) vs. amlodipine, is a milestone in the effort to test whether newer compounds offer a better reduction of the cardiovascular consequences of hypertension, as well as good BP control. The hypothesis is that valsartan by antagonizing the negative effects of angiotensin on smooth muscle cell growth, endothelial function, sympathetic overactivity, and coagulation, may have for the same degree of BP lowering, better protective effects than the leading calcium antagonist amlodipine.
Increased Plasma Group II Phospholipase A2 Concentrations in Patients with Acute Myocardial Infarction: Correlation with Tumor Necrosis Factor-Alpha
Authors: Arakawa Naoshi , Endo Shigeatsu , Nakamura Motoyuki , Saito Seiichi , Inada Katsuya , Ogawa Michio , Hiramori Katsuhiko
Published: April 2003

Aims: Group II phospholipase A2 (PLA2) is thought to play an important role in inflammation and tissue injury. It has been suggested that the inflammatory process is important in the setting and progression of myocardial ischemia or reperfusion. We measured plasma PLA2 as well as inflammatory cytokines in patients in the acute stage of myocardial infarction. Methods and Results: In 48 patients with acute myocardial infarction, blood samples were taken to measure plasma PLA2, tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) 36–48 h after onset. Serial changes in plasma PLA2 were also examined in 15 consecutive patients in this group. Plasma PLA2 levels were significantly higher in complicated patients (Killip’s class ≧ II) than in uncomplicated patients (Killip’s class = I) (35.9 ± 11.9 vs. 5.3 ± 1.1 ng/ml, p < 0.01). Plasma PLA2 concentrations increased gradually over time during the first 3 days and at 36–48 h after onset were correlated with left-ventricular ejection fraction on admission (r = –0.42, p < 0.01), and with plasma TNF-α (r = 0.39, p < 0.01), but not with IL-1β. Conclusion: Plasma PLA2 concentrations rose during the acute stage of myocardial infarction, especially in severe cases mainly with heart failure. TNF-α may be associated with PLA2 activity as a potent stimulator in vivo.
Long-Term Mortality Rates Reflect Progressive Prognostic Benefits of Thrombolysis in Patients with First Acute Myocardial Infarction
Authors: Shapira Itzhak , Pines Amos , Goldbourt Uri , Villa Yael , Drory Yaacov
Published: April 2003

This community nonrandomized study comprised a consecutive cohort of 1,545 (81% males) ≤65-year-old patients who survived a first acute myocardial infarction (AMI). The all-cause 4- to 5-year mortality rate was 9% (80% cardiac). Univariate analysis revealed that older age, female gender, hypertension, diabetes, not undergoing thrombolysis, higher Killip class, preinfarction heart disease, peripheral vascular disease (PVD) and chronic obstructive lung disease (COLD) were significantly associated with increased mortality. Multivariate analyses disclosed the latter five parameters as being independent predictors of mortality. Our results show that patients undergoing thrombolysis enjoyed a progressive prognostic benefit over time. The independent contribution of PVD and COLD to long-term mortality is highlighted, in addition to the contribution of thrombolytic therapy, Killip class, and heart disease prior to infarction as being important predictors of long-term mortality in patients with a first AMI.
Intraventricular Isovolumic Relaxation Flow Patterns Improve the Predicting Power of Doppler Echocardiography for the Left Ventricular Filling Pressure in Patients with Anterior Wall Myocardial Infarction
Authors: Wu Chau-Chung , Lin Lung-Chun , Ho Yi-Lwun , Liau Chiau-Suong , Lee Yuan-Teh
Published: April 2003

Background and Purpose: Previous studies have shown that left ventricular systolic asynchrony affects both the relaxation and filling phases of diastole. The purpose of this study was to delinate how the anterior wall dyssynergy influenced the intraventricular flow redistribution patterns during the isovolumic relaxation (IVR) period, which delineated the changes in diastolic suction performance and, therefore, determined the significant Doppler flow variables for predicting left ventricular filling pressure. Methods: Seventy-three patients with anterior wall myocardial infarction and dyssynergy were enrolled. Those who exhibited the whole IVR intraventricular flow redistributing toward the mitral apparatus, which indicated the reverse physiologic intraventricular pressure gradient in early diastole, were classified as group B, otherwise, as group A. The Doppler echocardiographic variables of mitral inflow were correlated with the left ventricular end-diastolic pressures (LVEDP). Results: With lower ejection fraction rate and more apical dyssynergy, the group B patients had much slower mitral flow propagation. For group A patients, the independent determinants for LVEDP were the ratio of mitral flow propagation rate to peak velocity in early diastole, the early mitral flow deceleration time and the IVR time, all occurring in early diastole. In contrast, the only independent determinant for LVEDP in group B patients was the ratio of mitral peak flow velocity in early diastole to that in late diastole. Conclusions: The intraventricular IVR flow patterns could delineate how the left ventricular systolic dyssynergy influenced the diastolic process, and determine which echocardiographic variables were more useful for predicting LVEDP in patients with anterior wall myocardial infarction.
Prognostic Value of Antibody Titre to Heat-Shock Protein 65 on Cardiovascular Events
Authors: Hoppichler Friedrich , Koch Thorsten , Dzien Alexander , Gschwandtner G. , Lechleitner Monika
Published: April 2003

Accumulating evidence suggests that the immune system is involved in atherogenesis, such as the correlation of the antibody titre to heat shock protein (hsp) with atherosclerotic lesions in the carotid and coronary arteries. Because the prognostic value of the hsp antibody titre for future cardiovascular events has not been evaluated until now, we performed a follow-up study on 195 subjects without a history of established cardiovascular risk factors (e.g. hypercholesterolaemia, diabetes, smoking), recruited for hsp antibody titre determination in 1995. Cardiovascular events were defined as unstable angina with the need for hospitalisation, myocardial infarction, re-vascularisation (PTCA, bypass), stroke and cardiovascular death. Among 79 men with coronary artery disease defined by coronary angiography, hsp antibody titres were signficantly higher in those with future cardiovascular events (467.0 ± 56.3) than in patients without further events (351.0 ± 23.3; p < 0.049). Because anti-hsp-antibody titres might be of prognostic value for coronary artery disease, patients with an increased hsp antibody titre should obtain intensive management of classical risk factors.
Familial Idiopathic Dilatation of the Right Atrium with Complete Atrio-Ventricular Block: A New Syndrome?
Authors: Blondheim David S. , Klein Roberto , Plich Michael , Marmor Alon T.
Published: April 2003

Familial occurrence of idopathic dilatation of the right atrium is extremely rare. This is the first description of a family in which 2 siblings had a syndrome of idiopathic dilatation of the right atrium associated with complete atrio-ventricular block. The family workup did not show other family members to be affected, and the question we raise is whether or not this might be a new syndrome.
Effect of Ascorbic Acid on Endothelial Dysfunction of Epicardial Coronary Arteries in Chronic Smokers Assessed by Cold Pressor Testing
Authors: Schindler Thomas H. , Magosaki Nobuhisa , Jeserich Michael , Olschewski Manfred , Nitzsche Egbert , Holubarsch Christian , Solzbach Ulrich , Just Hanjörg
Published: April 2003

Background: In chronic smokers there is evidence for increased formation of oxygen-derived free radicals within the vessel wall impairing endothelial function. It has been suggested that the inactivation of endothelium-derived nitric oxide by oxygen free radicals contributes to endothelial dysfunction. Hence, we tested the hypothesis that in chronic smokers the antioxidant ascorbic acid could improve abnormal endothelial function of epicardial coronary arteries. Methods and Results: Thirty-one patients (mean age 57 ± 9 years) referred for routine diagnostic catheterization for evaluation of chest pain and without angiographically significant coronary artery stenoses were randomly assigned to one of the study groups to assess vasomotor response of epicardial coronary arteries due to cold pressor testing (CPT) before and after intravenous infusion of 3 g of ascorbic acid or 100 ml × 0.9% saline infusion. In 6 controls (mean age 55 ± 3 years) CPT led to a similar increase in luminal area before and after ascorbic acid administration (26.5 ± 15.0 vs. 28.4 ± 17.7%, p = NS). In 15 chronic smokers (mean age 55 ± 9 years), CPT induced a decrease in the luminal area of –18.5 ± 6.3%. This flow-dependent vasoconstriction was significantly reversed to 7.7 ± 6.2% (p ≤ 0.03) vasodilation after intravenous ascorbic acid administration. In 10 chronic smokers (mean age 57 ± 11 years) saline infusion (placebo) did not have a significant effect on CPT-induced vasoconstriction (–12.7 ± 5.1 vs. –13.1 ± 5.1%, p = NS). The CPT-induced increase in luminal area in chronic smokers after ascorbic acid infusion was significant compared to controls and placebo (each p ≤ 0.05). Our assessment of endothelium-independent responses to nitroglycerin revealed no significant differences between the single study groups (p = NS). Conclusion: In chronic smokers acute intravenous administration of ascorbic acid significantly improves CPT-induced coronary endothelium-dependent dysfunction. According to the current understanding, this effect is due to improved cellular redox imbalance and prevention of nitric oxide inactivation in the endothelium and subendothelial space.
High Cardiac Angiotensin-II-Forming Activity in Infarcted and Non-Infarcted Human Myocardium
Authors: Ihara Makoto , Urata Hidenori , Shirai Kazuyuki , Ideishi Munehito , Hoshino Fumihiro , Suzumiya Junji , Kikuchi Masahiro , Arakawa Kikuo
Published: April 2003

The aims of this study were to compare human cardiac angiotensin-II-forming activity (AIIFA) between the intact area of control autopsy hearts without cardiac disease (n = 10) and the infarcted or non-infarcted area of autopsy hearts with myocardial infarction (MI, n = 7) and to determine responsible angiotensin-II-forming enzymes. Cardiac total and chymase-dependent AIIFAs were significantly higher in the infarcted and non-infarcted myocardium than those in non-MI heart, while angiotensin-converting enzyme-dependent AIIFA increased only in the infarcted myocardium. The density of chymase antibody-positive mast cells in the non-infarcted area of MI heart correlated positively with total or chymase-dependent AIIFA. Augmented AIIFA was also detected in the left atrium of post-MI hearts. Our results indicated that cardiac angiotensin II formation could be activated in the infarcted as well as in non-infarcted myocardium of the post-MI human heart.
Coronary Artery Disease but Not Coronary Calcification Is Associated with Elevated Levels of Cardiolipin, Beta-2-Glycoprotein-I, and Oxidized LDL Antibodies
Authors: Sherer Yaniv , Tenenbaum Alexander , Praprotnik Sonja , Shemesh Joseph , Blank Miri , Fisman Enrique Z. , Harats Dror , George Jacob , Levy Yair , Peter James B. , Motro Michael , Shoenfeld Yehuda
Published: April 2003

Background: Autoimmune factors have been shown to play a role in atherosclerosis. The aim of this study is to correlate 5 autoantibodies (anticardiolipin, anti-CL, β2-glycoprotein-I, β2GPI, phosphatidylcholine, oxidized low-density lipoprotein, oxLDL, endothelial cell) with the presence of coronary heart disease, angiographic findings, and with coronary artery calcification. Methods: The levels of the 5 autoantibodies and a control antifibroblast line of 126 coronary heart disease patients and 20 healthy controls were measured. Fifty-one patients underwent coronary angiography, and 98 patients had coronary artery calcium determination using spiral computerized tomography (dual mode). Results: Levels of 3 autoantibodies (anti-CL, β2GPI, oxLDL) were significantly elevated in coronary heart disease patients compared with controls (p < 0.001,p = 0.001, p < 0.001, respectively). Within the subgroup of patients with significant coronary artery stenosis, anti-CL antibodies were also elevated (p = 0.008). No correlation was found between anti-CL, and anti-β2GPI autoantibody levels and coronary calcium scores as measured by spiral computerized tomography. However, anti-oxLDL antibodies were raised in patients with no calcification detected by spiral computerized tomography, compared with the patients with any coronary calcification (p = 0.046). Conclusion: Anti-CL, β2GPI and oxLDL antibodies are elevated in coronary heart disease patients regardless of coronary calcification.
Severe Intracranial Bleeding Mimicking Acute Inferior Myocardial Infarction with Right Ventricular Involvement
Authors: Jung Frank , Setzer Matthias , Hohnloser Stefan H.
Published: April 2003

Electrocardiographic (ECG) changes and wall motion abnormalities of the left ventricle have been observed in patients with severe intracranial hemorrhage. However, ECG evidence of an acute myocardial infarction in this setting is extremely rare but may have important therapeutic consequences. We report the case of a 45-year-old female who became unconscious with respiratory insufficiency after an endoscopic retrograde cholangiopancreaticoscopy with ECG changes consistent of an inferior myocardial infarction with right ventricular involvement. Immediate coronary angiography revealed normal coronaries; however, left ventricular angiography showed extensive wall motion abnormalities predominantly in the anteroseptal region. Immediate cranial computer tomography demonstrated massive intracranial bleeding. Intracranial hemorrhage can be associated in the initial phase with ECG evidence of an acute myocardial infarction. This has to be taken into consideration in the setting of unexplained loss of consciousness or nonresponsiveness of a patient. A rapid diagnostic evaluation has to be initiated to rule out a myocardial infarction and to diagnose intracranial hemorrhage before the use of thrombolytic or anticoagulant therapy.
Platelet Function and Fibrinolytic Agents: Two Sides of a Coin?
Authors: Callahan Kevin P. , Malinin Alex I. , Gurbel Paul A. , Alexander John H. , Granger Christopher B. , Serebruany Victor L.
Published: April 2003

Fibrinolytic therapy is sthe established treatment for the management of patients with ST elevation acute myocardial infarction (AMI). Present fibrinolytic regimens have a number of shortcomings, including the failure to produce early and sustained reperfusion, as well as failure to prevent reocclusion in at least some patients. Platelets play an important role in coronary thrombosis responsible for AMI. The effect of coronary fibrinolysis on platelets has been extensively debated in the literature with evidence of both platelet activation and inhibition. Among fibrinolytic agents, tissue plasminogen activator (t-PA) is considered to be the mainstay in the treatment of coronary artery disease. The native t-PA molecule has been modified in an attempt to achieve improved lytic characteristics with less risk of bleeding. The result is a group of mutant t-PA variants considered third-generation plasminogen activators. TNK-t-PA is one bioengineered variant of t-PA. Another third-generation plasminogen activator is reteplase (r-PA). Like TNK-t-PA, it is a variant of t-PA that has been developed to establish a more rapid, complete, and stable coronary artery patency, thus promising reduced mortality. Both r-PA and TNK-t-PA are effective when given as bolus therapy. This feature may facilitate more rapid treatment as well as decrease overall costs of treatment. New fibrinolytic regimens include potent antiplatelet agents that may improve sustained reperfusion. This review summarizes the latest and often confusing data on the interaction between fibrinolytic therapy and platelets in certain in vitro, animal and clinical scenarios.
Cardiac Troponins in Suspected Acute Coronary Syndrome
Authors: Fleming Sean M. , Daly Kieran M.
Published: April 2003

We performed a meta-analysis of published trials to determine the predictive value of cardiac troponin I (cTnI) and T (cTnT) levels for adverse events (death and myocardial infarction) in acute coronary syndrome without ST elevation (ACS). The accumulated odds ratio (OR) for adverse events (30 days) in ACS with elevated cTnI (n = 5,759) and cTnT (n = 5,483) was 4.9 (95% confidence interval, CI, 3.9–6.2) and 4.6 (95% CI 3.8–5.5), respectively. Trials that mandated timed serum sampling (6 or more hours after symptom onset) had an improved predictive value for elevated cTnI (n = 2,807, OR 8.8; 95% CI 5.9–13.2) and cTnT (n = 1,990, OR 8.5; 95% CI 5.9–12.5). In conclusion, cTnI and cTnT provide similar information in ACS. The risk of adverse events is 4-fold higher in patients with suspected ACS and elevated serum cTn. For patients with an elevated timed (6-hour) sample the risk is over 8-fold higher.
Plasma Atrial Natriuretic Peptide Levels for Predicting the Outcome of Atrial Fibrillation
Authors: Arad Michael , Shotan Avraham , Weinberger Avraham , Aurbach Ilan , Rabinowitz Babeth
Published: April 2003

The predictive value of plasma atrial natriuretic peptide (ANP) on the cardioversion outcome was evaluated in 46 hospitalized patients with recent-onset atrial fibrillation (AF). Cardioversion was successful in 42 (91%) patients, 7 (15%) of them regained sinus rhythm spontaneously. After 12 months, 14 (33%) cardioverted patients were in chronic AF. There were no differences in plasma ANP levels between groups where cardioversion failed, those who cardioverted but later developed chronic AF or those who remained in sinus rhythm. However, among patients who were on antiarrhythmic therapy, ANP levels obtained after cardioversion were lower in those who later remained in sinus rhythm. We conclude that lower ANP after cardioversion may be associated with increased chances of long-term preservation of sinus rhythm.
Tissue Factor Expression in Coronary Circulation as a Prognostic Factor for Late Restenosis after Coronary Angioplasty
Authors: Mizuno Osamu , Ikeda Uichi , Hojo Yukihiro , Fujikawa Hideyuki , Katsuki Taka-aki , Shimada Kazuyuki
Published: April 2003

We investigated changes in blood coagulation in the coronary circulation after percutaneous transluminal coronary angioplasty (PTCA) and its clinical significance. We examined 43 patients with ischemic heart disease who underwent elective PTCA of isolated stenotic lesions in the left coronary artery. Ten patients underwent PTCA alone, 15 received percutaneous transluminal rotational atherectomy (PTRA) and 18 stent implantation. Blood samples were drawn from the coronary sinus before and immediately after PTCA, as well as 4 and 24 h later. Plasma levels of tissue factor (TF), thrombin-antithrombin III complex (TAT) and prothrombin fragment 1+2 (F 1+2) were measured by enzyme-linked immunosorbent assay. Follow-up coronary angiography was performed 6 months after PTCA. Minimal luminal diameter was assessed by quantitative coronary angiography to evaluate late loss index. TF, TAT and F 1+2 levels in the coronary sinus blood showed significant increases 24 h after PTCA. A significant positive correlation was found between changes in TF levels 24 h after PTCA and late loss index 6 months after the procedure. TF levels in the coronary sinus blood were significantly higher in patients with late restenosis than in those without restenosis. These results suggest that TF expression in the coronary circulation after PTCA is a prognostic factor for late restenosis.
Influence of the Availability of Laser Transmyocardial Revascularisation on Surgical Strategy in Patients with Advanced Coronary Artery Disease
Authors: Prendergast B.D. , Campanella C. , Shaw T.R.D.
Published: April 2003

Objective: To compare the planned and actual revascularisation techniques used in patients undergoing cardiac surgery for refractory angina when excimer transmyocardial laser revascularisation (TMR) is available. Methods: Observational series of 31 patients (mean age 65 years) with severe angina [mean CCS score (SD) 3.8 (0.4)] and three-vessel coronary artery disease judged unsuitable for conventional bypass surgery alone. All patients underwent cardiac surgery: revascularisation techniques were determined by the operative findings. Results: Pre-operative strategy was altered by the intra-operative findings in 13 patients (42%). In 5 (16%), the coronary vessels proved graftable and TMR was unnecessary. Conversely, in 6 patients (19%) an anticipated graft could not be performed and TMR was used as an alternative. In 2 patients (7%), neither strategy was possible. Overall, TMR was performed as a stand-alone procedure in 9 (29%) and combined with CABG in 17 (55%). Operative mortality was low: 0% at 30 days and 6% at 6 months. Mean CCS class (SD) improved post-operatively from 3.8 (0.4) to 1.7 (1.1) (p < 0.01). Conclusions: The pre-operative coronary angiogram is an imperfect predictor of which coronary vessels are suitable for grafting. The availability of laser TMR allows the cardiac surgeon to accept cases which would otherwise be considered inoperable and to respond better to intraoperative findings. The combination of laser TMR and bypass grafts provides good short- and medium-term symptomatic improvement with a low post-operative mortality.
The Doppler Echocardiographic Myocardial Performance Index Predicts Left-Ventricular Dilation and Cardiac Death after Myocardial Infarction
Authors: Møller Jacob E. , Søndergaard Eva , Poulsen Steen H. , Egstrup Kenneth
Published: April 2003

To investigate the value of the Doppler-derived myocardial performance index to predict early left-ventricular (LV) dilation and cardiac death after a first acute myocardial infarction (AMI), Doppler echocardiography was performed within 24 h of hospital admission, on day 5, 1 and 3 months after AMI in 125 consecutive patients. The index measured on day 1 correlated well with the change in end-diastolic volume index observed from day 1 to 3 months following AMI (r = 0.66, p < 0.0001). One-year survival in patients with Doppler index <0.63 was 89%, and 37% in patients with index ≧0.63, (p < 0.0001). Multivariate analysis identified myocardial performance index ≧0.63 (relative risk 5.6, p < 0.0001), E-wave deceleration time <140 ms (relative risk 2.7, p = 0.008) and Killip class ≧II (relative risk 4.0, p = 0.04) to be independent predictors of cardiac death. Therefore, we conclude that the Doppler echocardiographic myocardial performance index is a predictor of LV dilation and cardiac death after a first AMI.
Aspirin and Percutaneous Coronary Angioplasty Are Associated with a Decline in Mortality from Cardiogenic Shock
Authors: Barbash Israel M. , Battler Alexander , Behar Solomon , Boyko Valentina , Gottlieb Shmuel , Hasdai David , Leor Jonathan
Published: April 2003

Background and Methods: Despite the significant progress in the care and outcome of patients with acute myocardial infarction (AMI), the impact of evolving therapies on the incidence and outcome of patients with cardiogenic shock complicating AMI has been questioned. We analyzed trends in the incidence, care and outcome of cardiogenic shock from four national surveys conducted during 1992–1998. Results: Of the 5,351 AMI patients admitted to all coronary care units in Israel, 254 (4.7%) developed cardiogenic shock. The incidence of cardiogenic shock decreased over time (5.8, 5.1, 4.3 and 4.4% for the years 1992, 1994, 1996 and 1998, respectively, p = 0.08). Concomitantly, there was an increase in utilization of coronary angiography, urgent angioplasty and intra-aortic balloon counterpulsation. In addition, there was an increase in hospital use of aspirin, nitrates, ACE inhibitors and β-blockers. Patients with shock were more likely to die within 7 days compared with AMI patients not having shock (65 vs. 4%; p < 0.001). During the study period, the mortality of patients with shock decreased: at 7 days (72% in 1992 to 60% in 1998; p = 0.09), at 30 days (87 to 70%, respectively; p = 0.01) and at 6 months (89 to 77%, respectively; p = 0.02). Both aspirin and angioplasty were independently associated with improved outcome after adjustment for baseline characteristics and study period. Conclusions: Although the mortality rate of cardiogenic shock complicating AMI remains high, the increased utilization of aspirin and angioplasty is associated with improved outcome.
Determinants of Short-Period Heart Rate Variability in the General Population
Authors: Kuch B. , Hense H.W. , Sinnreich R. , Kark J.D. , von Eckardstein A. , Sapoznikov D. , Bolte H.-D.
Published: April 2003

Decreased heart rate variability (HRV) is associated with a worse prognosis in a variety of diseases and disorders. We evaluated the determinants of short-period HRV in a random sample of 149 middle-aged men and 137 women from the general population. Spectral analysis was used to compute low-frequency (LF), high-frequency (HF) and total-frequency power. HRV showed a strong inverse association with age and heart rate in both sexes with a more pronounced effect of heart rate on HRV in women. Age and heart rate-adjusted LF was significantly higher in men and HF higher in women. Significant negative correlations of BMI, triglycerides, insulin and positive correlations of HDL cholesterol with LF and total power occurred only in men. In multivariate analyses, heart rate and age persisted as prominent independent predictors of HRV. In addition, BMI was strongly negatively associated with LF in men but not in women. We conclude that the more pronounced vagal influence in cardiac regulation in middle-aged women and the gender-different influence of heart rate and metabolic factors on HRV may help to explain the lower susceptibility of women for cardiac arrhythmias.
Efficacy and Safety of Imidapril in Patients with Essential Hypertension: A Double-Blind Comparison with Captopril
Authors: Huang Por-Jau , Chien Kou-Liong , Chen Ming-Fong , Lai Ling-Ping , Chiang Fu-Tien
Published: April 2003

In this 12-week, double-blind, parallel-group, comparative trial, 57 adult patients with mild-to-moderate hypertension were randomly allocated to receive imidapril or captopril, initially at a dose of 5 mg once a day and 25 mg twice daily, respectively. After 4 weeks of therapy, the dose of each drug was increased twice if diastolic blood pressure (DBP) remained ≧90 mm Hg. Both treatments effectively lowered DBP in a comparable manner. Mean changes from baseline in DBP at 12 weeks were –9.9 mm Hg for imidapril and –8.8 mm Hg for captopril (p = 0.488). Responder rates in patients receiving active treatment for at least 6 weeks were 53.9% for imidapril and 48% for captopril (p = 0.676). Both treatments were well tolerated. Adverse drug reactions were observed in 20.7% (6/29) of the imidapril group and 46.4% (13/28) of the captopril group (p < 0.05). A cough was the most frequent side effect, reported in 13.8% of the imidapril group and 35.7% of the captopril group. The results indicate that imidapril is as effective as captopril in the treatment of hypertension. Imidapril produces less adverse effects compared with captopril.
Can Pre-Treatment with β-Agonists Reduce Stress Test Time and the Use of Atropine in Dobutamine Stress Testing?
Authors: Desai Milind Y. , De la Peña-Almaguer Erasmo , Mannting Finn
Published: April 2003

Aim: To determine whether the use of inhaled β-agonists decreases the duration of dobutamine stress testing (DAS), reduces the amount of dobutamine infused and decreases the use of atropine. Methods: 34 patients on β-agonists (group A) (mean age 65 ± 8 years) and 32 patients not on β-agonists or β-blockers (group B) (mean age 65 ± 10 years) undergoing DAS with SPECT were enrolled. Results: The time of infusion of dobutamine in group A was 6.41 ± 1.58 min and in group B was 9.77 ± 3.60 min (p < 0.001). The amount of dobutamine infused was 10.64 ± 5 mg in group A and 19.20 ± 8 mg in group B (p < 0.001). In group A, 2 of 34 patients and 18 of 32 patients in group B needed atropine to reach peak HR (p < 0.001). Conclusion: Patients on short acting β-agonists require smaller amounts of dobutamine with a shorter infusion time during DAS, and lesser use of side-effect prone atropine.