bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns of Vertebrate Neurogenesis and the Paths of Vertebrate Evolution
Authors: Finlay Barbara L. , Hersman Michael N. , Darlington Richard B.
Published: April 2003

Any substantial change in brain size requires a change in the number of neurons and their supporting elements in the brain, which in turn requires an alteration in either the rate, or the duration of neurogenesis. The schedule of neurogenesis is surprisingly stable in mammalian brains, and increases in the duration of neurogenesis have predictable outcomes: late-generated structures become disproportionately large. The olfactory bulb and associated limbic structures may deviate in some species from this general brain enlargement: in the rhesus monkey, reduction of limbic system size appears to be produced by an advance in the onset of terminal neurogenesis in limbic system structures. Not only neurogenesis but also many other features of neural maturation such as process extension and retraction, follow the same schedule with the same predictability. Although the underlying order of event onset remains the same for all of the mammals we have yet studied, changes in overall rate of neural maturation distinguish related subclasses, such as marsupial and placental mammals, and changes in duration of neurodevelopment distinguish species within subclasses. A substantial part of the regularity of event sequence in neurogenesis can be related directly to the two dimensions of the neuraxis in a recently proposed prosomeric segmentation of the forebrain [Rubenstein et al., Science, 266: 578, 1994]. Both the spatial and temporal organization of development have been highly conserved in mammalian brain evolution, showing strong constraint on the types of brain adaptations possible. The neural mechanisms for integrative behaviors may become localized to those locations that have enough plasticity in neuron number to support them.
Sensory Development and Its Relation to Habitat Change in Three Species of Sciaenids
Authors: Poling K.R. , Fuiman L.A.
Published: April 2003

Visual and mechanosensory development of three sciaenid species was investigated to examine possible correlations between sensory morphology and patterns of habitat use. Although the three species have different migration patterns as early larvae, few differences in sensory morphology occurred between species until late in the larval period. Atlantic croaker, Micropogonias undulatus, were distinguished by enhancements of visual morphology (large eyes, abundant photoreceptors, and best summation of the three species). Croaker arrive inshore later in the larval period and, after settlement, appear to use deeper water habitats than do the other two species. Spotted seatrout, Cynoscion nebulosus, had the fewest enhancements of visual morphology but had more free neuromasts than the other two species late in the larval period. After settlement, seatrout are primarily associated with seagrass habitats. Red drum, Sciaenops ocellatus, did not have pronounced specialization of one sensory system, as did the other two species. For part of the larval period, neuromast numbers were higher in red drum than in the other two species. Later, enhancements of visual morphology did occur, but only eye and lens size were the same as those of Atlantic croaker. Red drum larvae appear to use a wider variety of habitats than do the other two species. In none of the species examined did sensory changes correlate with offshore to inshore movements, and only initial rod formation occurred prior to settlement. Distinct sensory changes did not occur concurrent with habitat changes, probably due to constructional and phylogenetic constraints. Rather, sensory differences are related to the environmental conditions in the predominant inshore habitat occupied by each species after settlement, when morphological limitations are less severe.
Sexual Dimorphisms in Avian and Reptilian Courtship: Two Systems that Do Not Play by Mammalian Rules
Authors: Wade Juli
Published: April 2003

Sexual dimorphisms in the central nervous system exist in numerous vertebrate species, and in many cases these structural differences between males and females parallel differences in the display of reproductive behaviors. Often both the behavioral and anatomical differences are controlled by exposure to gonadal steroid hormones, either during ontogeny or in adulthood. This article reviews some of the evidence supporting the hypothesis that in mammals, testosterone or its metabolites regulate the structure and function of neural and muscle systems involved in the control of masculine sexual behaviors. It then describes data suggesting that the mechanisms regulating sexually dimorphic courtship systems in zebra finches and green anole lizards are not completely parallel to the mammalian systems. Finally, some directions for future study are suggested, with the hope that they will stimulate thought about the nature of comparisons made across vertebrate models when investigators are attempting to determine both which morphological sex differences are important to the control of the reproductive behaviors, and which mechanisms regulating both structure and function are widely employed or are unique.
A Comparative Volumetric Analysis of the Prefrontal Cortex in Human and Baboon MRI
Authors: McBride Thomas , Arnold Steven E. , Gur Ruben C.
Published: April 2003

The proportion of prefrontal cortex in humans was compared to the proportion of prefrontal cortex in baboons (Papio anubis). Prefrontal cortex, dorsal prefrontal, orbital prefrontal cortex and total brain volumes were determined from magnetic resonance images of 20 healthy adult human females and 5 adult female baboons. Results showed that the proportion of prefrontal cortex volume relative to total brain volume in humans was significantly larger in humans than in baboons. The percentage of prefrontal cortex relative to total brain volume was 12.51 for humans and 10.68 for baboons. Similarly, the proportion of both dorsal and orbital prefrontal cortex volumes is larger in human brains. Relative to total brain volume, the percentages of dorsal and orbital prefrontal cortex was 8.22% and 4.29% respectively in humans and 7.21% and 3.47% in baboons. A regression analysis showed that the human prefrontal cortex was larger than would be predicted for a baboon of equal total brain volume. These results suggest that increased prefrontal lobe volume could underlie some of the differences between human and hominoid primates. On the other hand, the small magnitude of the difference might underlie similarities between the species and should encourage a search for other structures that are disproportionately larger in humans.
Responses of Movement-Sensitive Visual Interneurons to Prey-Like Stimuli in the Praying Mantis Sphodromantis lineola (Burmeister)
Authors: Gonka Mark D. , Laurie Timothy J. , Prete Frederick R.
Published: April 2003

Previous behavioral work using both mechanical and computer-generated visual stimuli has demonstrated that mantids use a computational algorithm to recognize prey similar to that used by some amphibian predators: A stimulus elicits prey capture behavior if it falls within a perceptual envelope defined by five fundamental stimulus parameters: (1) overall size, (2) length of the leading edge, (3) contrast to the background, (4) location in the visual field, and (5) apparent speed. In this study, we recorded simultaneously from both cervical nerve cords of monocular Sphodromantis lineola while they viewed the same visual stimuli successfully used in the behavioral studies. Extracellular recordings showed three consistently proportioned amplitude classes of movement-elicited spikes in each cord and these were repeatedly and reliably identifiable across mantids. Overall, the movement-elicited activity in both cords was dominated by very large spikes suggesting the existence of several large, descending movement-sensitive interneurons projecting both ipsilaterally and contralaterally from the optic lobes. However, only the largest contralateral spikes occurred preferentially to prey-like stimuli, mirrored the behavioral response curves generated by S. lineola to the same visual stimuli, and displayed activity peaks that were correlated with the times at which the mantid emitted predatory strikes.
Succinic Dehydrogenase Histochemistry Reveals the Location of the Putative Primary Visual and Auditory Areas within the Dorsal Ventricular Ridge of Sphenodon punctatus
Authors: Reiner Anton , Northcutt R. Glenn
Published: April 2003

In turtles, crocodilians, lizards and snakes, the dorsal ventricular ridge (DVR) is a nuclear cell mass that contains distinct visual and auditory thalamorecipient cell groups. In the tuatara (Sphenodon punctatus), the DVR is not organized into diverse cell groups but instead possesses a trilaminar cytoarchitecture resembling that characteristic of the telencephalic cortex in reptiles. To determine if visual and auditory fields might also be present in the DVR of Sphenodon punctatus, we used succinic dehydrogenase (SDH) histochemistry, which has been shown to delineate the visual and auditory fields of the DVR in turtles, crocodilians and lizards. We also used acetylcholinesterase (AChE) histochemistry to determine the boundary between the DVR and the basal ganglia in Sphenodon. We found an SDH-rich region in the neuropil ventral to the cell plate of the rostrolateral DVR and a slightly less intense SDH-rich zone in the neuropil deep to the cell plate of the ventromedial DVR. These SDH-rich zones appear to be located at the apical dendrites of the neurons of the adjacent cell plate. These SDH-rich zones were clearly located within the DVR and were distinct from the AChE-rich striatal part of the basal ganglia, which occupied the ventrolateral wall of the telencephalon. Based on findings in other reptiles, it seems likely that the SDH-rich zone in rostrolateral DVR represents the zone of termination of nucleus rotundus visual input to the DVR, whereas the zone in ventromedial DVR represents the zone of termination of nucleus reuniens auditory input. Because a trilaminar DVR such as that in Sphenodon might be the primitive DVR condition for reptiles, our results suggest that the cytoarchitecture of the DVR and the synaptic organization of its thalamic sensory input in the common ancestor of living reptiles might have been much like of the dorsal cortex.
Ganglion Cells Density and Retinal Resolution in the Sea Otter, Enhydra lutris
Authors: Mass Alla M. , Ya. Supin Alexander
Published: April 2003

The topographic distribution, density, and size of ganglion cells were studied in retinal wholemounts of the sea otter, Enhydra lutris. The cell distribution showed a well defined horizontal streak of higher cell density, and within this streak, a narrow area of the highest cell density. The peak cell density in this area ranged from 4050 to 4400 cells/mm2, with a mean of 4225 cells/mm2. The ganglion cell size ranged from 7 μm to 47 μm, but the majority of cells were 7 to 30 μm. Cell size distribution revealed three size groups: 7–16, 17–28, and 29–47 μm. The highest-density area contained mainly small (7–16 μm) cells. The cell-density data predict a retinal resolution around 7’ in water. Retinal organization in the sea otter exhibits more properties common with terrestrial rather than aquatic mammals, both in terms of ganglion cell characteristics and in terms of their topographic distribution.
Regional Variation in Receptive Field Properties of Tectal Neurons in Pigeons
Authors: Gu Yong , Wang Yuan , Wang Shu-Rong
Published: April 2003

The present study provides the first electrophysiological evidence for dorsoventral variation in the receptive field properties of tectal cells in pigeons. According to their receptive field organization, visual response properties and laminar locations, 95 tectal neurons recorded in the present study could be categorized into two groups: (1) Fifty-five DL-neurons were recorded in the dorsal, dorso-lateral, lateral and ventro-lateral tectum and characterized by an excitatory receptive field surrounded by an inhibitory receptive field. Most of them almost equally responded to white and black objects, but did not respond to switch-on and -off of a light spot. (2) Forty VC-neurons were recorded in the ventral tectum and characterized by an excitatory receptive field alone. Their responses to switch-on of a light spot and to a white object were significantly stronger than those to light-off and to a black object, respectively. DL-neurons preferred higher velocity, whereas VC-neurons preferred lower velocity. The recording sites of 53 of 95 cells (56%) examined were marked with pontamine sky blue, showing that DL-neurons were located in tectal layers I–IV, predominantly in layer II, whereas VC-neurons were mainly concentrated in sublayer IIc. The receptive fields of VC-neurons were located within the rostroventral visual field possibly corresponding to the red field of the pigeon retina, suggesting that they might be associated with visual food-foraging behaviors.
Exploitation of an Ancient Escape Circuit by an Avian Predator: Prey Sensitivity to Model Predator Display in the Field
Authors: Jabłoński P.G. , Strausfeld N.J.
Published: April 2003

Certain insectivorous birds, such as the painted redstart (Myioborus pictus), undertake flush pursuit – a characteristic display that elicits an escape reaction by an insect, which the bird then chases in the air and eats. This account describes experiments showing that flush pursuit uses visual displays, which are likely to exploit an ancient neural circuit in dipteran insects, the visual systems of which are well documented as detecting looming stimuli and triggering an escape responses. Using models that decompose components of the redstart display, specific elements of the display were analyzed for their contribution in triggering visually induced escape behavior by dipterous insects. Elements tested were pivoting body movements, patterning on the spread tail and wings, and visual contrast of model redstarts against pale and dark backgrounds. We show that contrasting patterns within the plumage are crucial to foraging success, as is contrast of the bird against a background. Visual motion also significantly contributes to the successful flushing. In contrast, unpatterned models and patterned models that do not contrast with the background are less successful in eliciting escape responses of flies. Natural visual stimuli provided by Myioborus pictus are similar to those known to trigger looming and time-to-collision neurons in the escape circuits of flies and other insects, such as orthopterans. We propose that the tuning properties of these neural pathways might have contributed to the evolution of foraging displays in flush-pursuing birds.
Dual Chamber Pacing in Hypertrophic Cardiomyopathy: Influence of Atrioventricular Delay on Left Ventricular Outflow Tract Obstruction
Authors: Losi Maria-Angela , Betocchi Sandro , Briguori Carlo , Piscione Federico , Manganelli Fiore , Ciampi Quirino , Stabile Giuseppe , Chiariello Massimo
Published: April 2003

The impact of the duration of atrioventricular (AV) delay on obstruction in hypertrophic cardiomyopathy was evaluated in 12 patients by cardiac catheterization, and in 8 of them also by Doppler echocardiography. The AV delay was programmed in random order at 125, 100 and 75 ms in the invasive study and at 120, 100 and 80 ms after pacemaker implantation. The arterial pressure did not changed throughout the studies, whereas the gradient decreased significantly by reducing the AV delay value; the greater gradient reduction was obtained, in both studies, with the AV delay set between 75 or 80 and 100 ms. QRS duration increased significantly by reducing the AV delay during both studies. The widest QRS was not associated with the smallest gradient in all patients. Changes in gradients were similar during the invasive and noninvasive protocols.
Morphological Characterization of Ventricular Septal Defect with Posterior Deviation of the Outlet Septum
Authors: Cheng Ching-Feng , Wang Jou-Kou , Wu Mei-Hwan
Published: April 2003

Ventricular septal defect (VSD) with posterior deviation of the outlet septum is frequently associated with left ventricular outflow obstruction and aortic arch anomalies. In this study, 17 patients with large VSD and posterior deviation of the outlet septum were evaluated. The VSD was further classified into ‘high’ and ‘low’ types according to the extension of the VSD; the high-type VSD (8 patients) extended mainly to the outlet or infundibular portion and the low-type VSD (9 patients) extended mainly to the trabecular or inlet portion. Related morphological features, such as outlet septum hypoplasia, muscle bundle between aortic-mitral valve junction, pulmonary artery overriding and aortic arch anomalies, were found more frequently in patients with high-type VSD, while tricuspid valve straddling and outlet septum hypertrophy were found more often in patients with low-type VSD. This classification for VSD with posterior deviation of the outlet septum helps to predict the morphological features of left ventricular outflow tract and aortic arch anomalies.
Differences in Transmitral Flow Velocity Pattern during Increase in Preload in Patients with Abnormal Left Ventricular Relaxation
Authors: Yamada Hirotsugu , Oki Takashi , Tabata Tomotsugu , Manabe Kazuyo , Fukuda Kazuyo , Abe Miho , Iuchi Arata , Ito Susumu
Published: April 2003

Changes in transmitral flow (TMF) and pulmonary venous flow (PVF) velocities during increases in preload were compared in patients with a higher peak atrial systolic velocity than peak early diastolic velocity (A/E > 1) for the TMF velocity to determine differences in hemodynamic response. Fifteen patients with dilated hearts, 22 with hypertrophied hearts and 15 control patients were studied. TMF and PVF velocities were recorded by transesophageal pulsed Doppler echocardiography before and during application of lower body positive pressure. The value for peak early diastolic velocity increased, while the isovolumic relaxation time decreased with increases in preload in all groups. The value for peak atrial systolic velocity decreased in the dilated-heart group, but increased in the hypertrophied-heart and control groups. The peak second systolic and early diastolic PVF velocities increased in the dilated- and hypertrophied-heart groups, but did not change in the control group. The peak atrial systolic PVF velocity and the difference in duration of the atrial systolic PVF and TMF velocities increased in the dilated- and hypertrophied-heart groups, and its changing rate was highest in the group with dilated hearts. These results suggest that both peak early diastolic and atrial systolic TMF velocities increase during increases in preload through the Frank-Starling mechanism in hypertrophied hearts. Furthermore, the left ventricular functional reserve was lower in the dilated-heart group. Thus, TMF and PVF velocities respond differently during increases in preload, depending on the underlying heart disease.
A Prospective Echocardiographic Study of the Effects of Balloon Mitral Commissurotomy on Pre-Existing Mitral Regurgitation in Patients with Mitral Stenosis
Authors: Rittoo Dylmitr , Sutherland George R. , Shaw Thomas R.D.
Published: April 2003

Mitral regurgitation which is more than mild in severity is usually regarded as a relative contraindication to balloon mitral commissurotomy (BMC) because it is commonly believed that it may be worsened by the procedure. The aim of this study was to investigate the effects of BMC on pre-existing mitral regurgitation. Transthoracic and biplane transoesophageal echocardiography (TTE, TEE) combined with colour flow mapping (CFM) were performed prospectively on 50 consecutive patients immediately before and within 24 h after Inoue BMC. Before BMC, mitral regurgitation (MR) was diagnosed by TEE and left ventriculography in 36 and 13 patients respectively. Angiographic MR was mild in all 13 cases. The precise origins of MR jets were carefully sought by scanning in multiple TTE and TEE views. The maximal area of colour flow MR jets detected by TEE was measured by planimetry. After BMC mean mitral valve area increased from 1.0 ± 0.3 to 1.7 ± 0.8 cm2, p < 0.0001, mean left atrial pressure and volume decreased from 23.7 ± 5.6 mm Hg to 21.6 ± 7.5 ml, p = 0.039, and from 105 ± 56 to 90 ± 46 ml, p = 0.002, respectively. MR jets as assessed by TEE CFM disappeared in 12 patients, in all of whom MR had been undetected by angiography. MR jets remained within 20% of their original sizes in 16 (44%) patients and more than doubled in only 3 patients. However, the latter had only mild angiographic MR after BMC. BMC created new MR jets, distinct from pre-existing ones, in 27 (75%) patients. Their aetiologies were commissural splitting in 24, leaflet tears in 2 and chordal rupture in 1 case. New MR jets were co-existent with old jets in 17 (47%) cases and in 10 (28%) cases old jets were replaced by new jets. The severity of angiographic MR was unchanged in 21 (58%) of the 36 patients; new jets, all originating from one or both commissures, were found in 13 (65%) patients on TEE. Angiographic MR increased by 1 grade in 11 (33%) patients; new jets were detected in 9 patients, 8 from the commissures and 1 due to chordal rupture; in only 1 of the 11 patients did the increase in MR appear to be due to a worsening of a pre-existing jet. Angiographic MR increased by 2 grades in 3 (8%) patients; new jets appeared in all 3, arising from the commissures in 2 and from a leaflet tear in 1 case. One patient with a leaflet tear sustained an increase of 3 grades in angiographic MR. The final degree of angiographic MR was nil in 13, mild in 15, moderate in 6 and severe in 2 patients. Leaflet tears were responsible for both cases of severe MR. BMC does not appear to affect pre-existing mitral regurgitation adversely in almost all patients. It may abolish trivial jets but in most cases it creates new jets alongside the old ones. Leaflet tears are responsible for severe mitral regurgitation after BMC and this is independent of pre-existing regurgitant jets.
Coxsackievirus Genome in Myocardium of Patients with Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy
Authors: Grumbach Isabella M. , Heim Albert , Vonhof Stefan , Stille-Siegener Michael , Mall Gerhard , Gonska Bernd D. , Kreuzer Heinrich , Andreas Stefan , Figulla Hans R.
Published: April 2003

Enteroviruses are known as major infectious agents for inflammatory heart diseases such as myocarditis and dilated cardiomyopathy (DCM). Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC) is characterized by replacement of right ventricular myocardium by fatty and fibrous tissue. In about 65% of patients inflammatory infiltrates suggest an inflammatory or infectious etiopathogenesis. To test this hypothesis, we investigated endomyocardial biopsies of patients with ARVC, with myocarditis or DCM, and from patients with non-inflammatory cardiac disorders for the presence of enteroviral genome. Enteroviral RNA with homology to coxsackieviruses type B was detected in 3 of 8 patients with ARVC (37.5%), in 7 of 23 patients with myocarditis or DCM (30.4%), but in none of 5 patient with non-infectious myocardial diseases (p < 0.05 compared to ARVC patients). These results support earlier suggestions that coxsackievirus infection of the myocardium is possibly related to the pathogenesis of ARVC.
Disrupted Mobile Aortic Plaques Are a Major Risk Factor for Systemic Embolism in the Elderly
Authors: Tenenbaum Alexander , Fisman Enrique Z. , Schneiderman Jacob , Stroh Chaim I. , Shemesh Joseph , Schwammenthal Ehud , Vered Zvi , Motro Michael
Published: April 2003

Protruding aortic plaques – especially those with mobile properties – on transesophageal echocardiography (TEE) are a potential source of stroke and systemic embolism in the elderly. Whether the various morphologies of atheromas with mobile components represent potential differences in the risk for embolic events has not been thoroughly elucidated. The goal of the present study was to determine the association between embolic events and the various types of mobile lesions in the thoracic aorta. Our population consisted of 569 consecutive patients (age 18–83 years) referred for TEE over 27 months; 108 (19%) of them were referred to evaluate recent embolism (cerebral in 97 and peripheral or both in 11; group I) and the remaining 461 were admitted for reasons unrelated to embolism (group II). In group I, 35 patients (32%) exhibited protruding plaques; those were fixed in 10 (9%) and with a mobile component in 25 (23%). In group II, plaques were found in only 13 patients (3%); fixed in 9 (2%) and mobile in 4 (1%). Twenty-four patients with mobile lesions in group I were > 50 years old, and 21 of them (88%) were > 60 years old. While the presence of fixed plaques was associated with a moderate increase in the risk for systemic embolism (adjusted odds ratio 4.1; 95% confidence interval 1.3–56.4), mobile lesions were linked to a striking augmentation of this risk (odds ratio 30.1; 95% confidence interval 7.8–132.6). The majority of mobile lesions (76%) in group I represented disrupted atheromas with charateristic ulcerations or echolucency within the plaque suggestive of intraatheroma hemorrhage, whereas these TEE features were not observed in 89% of the mobile lesions in group II (p = 0.0003). We conclude that among the various types of mobile aortic lesions, the disrupted protruding plaques are a major risk factor for stroke and embolic events in the elderly.
Accuracy of Exercise-Induced Left Axis QRS Deviation as a Specific Marker of Left Anterior Descending Coronary Artery Disease
Authors: Shiran Avinoam , Halon David A. , Merdler Amnon , Makhoul Nabeel , Khader Nader , Ben-David Joseph , Lewis Basil S.
Published: April 2003

In this prospective study, we examined the diagnostic accuracy of exercise-induced left QRS axis deviation as a marker of LAD coronary artery stenosis. The mean frontal QRS axis of 66 consecutive patients with chest pain and exercise-induced ST segment depression referred for diagnostic coronary angiography was analyzed and related to the angiographic findings. An exercise-induced leftward QRS axis deviation was found in 9/40 patients with and 0/26 patients without obstructive (≥70%) LAD disease (sensitivity 23%, specificity 100%, p = 0.025). In 7 of the 9 patients with left axis deviation, the lesion was proximal to and in 2 in the region of the first septal perforator. Inclusion of patients with 0° exercise-induced QRS axis deviation provided a more sensitive but less specific marker of LAD disease [sensitivity 53% (21/40), specificity 81% (21/26), p = 0.015]. The findings were similar in patients with single and with multivessel coronary artery disease. Grouping all patients in the present prospective and two previous retrospective studies (n = 165), the sensitivity was 29% and specificity 100% (p < 0.0001). Exercise-induced left QRS axis deviation was a highly specific marker of LAD coronary artery stenosis.
Depressed Plasma Platelet- Activating Factor Acetylhydrolasein Pat ients Presenting with Acute Myocardial Infarction
Authors: Serebruany Victor L. , Gurbel Paul A. , Murugesan Selva R. , Lowry David R. , Sturm Ekkehard , Svetlov Stanislav I.
Published: April 2003

Cell membrane phospholipids, including platelet-activating factor (PAF), participate in the pathogenesis of acute myocardial infarction (AMI). The plasma level of PAF acetylhydrolase (AH) was determined in 18 patients at presentation with AMI before thrombolysis, and the administration of adjunctive therapy, and compared with 13 healthy controls. Plasma levels of PAF-AH were significantly lower in the AMI patients (23.15 ± 1.75 nmol/min/ml) than in the controls (30.43 ± 2.13 nmol/min/ml; p = 0.027). Considering normal plasma levels of PAF and lyso-PAF, and lack of evidence that anti-PAF antibodies are really beneficial in myocardial ischemia-reperfusion, it is reasonable to speculate that an inability of systemic PAF to ‘turn on’ PAF-AH enzymatic activity could contribute substantially to the observed events. Decreased PAF-AH activity in AMI patients may represent not a consequence, but rather, a risk factor for the development of acute coronary syndromes.
Progression of Cardiac Involvement in Patients with Myotonic Dystrophy, Becker’s Muscular Dystrophy and Mitochondrial Myopathy during a 2-Year Follow-Up
Authors: Stöllberger Claudia , Finsterer Josef , Keller Hans , Mamoli Bruno , Slany Jörg
Published: April 2003

The aim of this prospective noninvasive follow-up study was (1) to assess the progression of cardiac involvement (CI) in patients with myotonic dystrophy (MD), Becker’s muscular dystrophy (BMD) and mitochondrial myopathy (MMP), (2) to find out if CI and neurologic impairment are related and (3) to determine how often cardiac investigations should be performed. Clinical, electrocardiographic, echocardiographic and 24-hour ambulatory electrocardiographic examinations were performed at yearly intervals. CI was assessed qualitatively by the presence of pathologic examinations and quantitatively by the number of pathologic examinations. Qualitatively, CI was present at baseline in 36 of the 38 cases (18–68 years) and the number of cases did not change. Quantitatively, CI progressed after 1 (2) year in 50% (50%) of patients with MD (n = 16), 0% (43%) of patients with BMD (n = 7) and 27% (27%) of patients with MMP (n = 15). CI and neurologic impairment were not related (p = 0.54). Cardiac investigations should be repeated at yearly intervals irrespective of whether there is neurologic deterioration or not.
Sexual Activity after First Acute Myocardial Infarction in Middle-Aged Men: Demographic, Psychological and Medical Predictors
Authors: Drory Yaacov , Kravetz Shlomo , Florian Victor , Weingarten Michael
Published: April 2003

The study examined important diverse sociodemographic, medical and psychological variables as potential predictors of sexual activity frequency/satisfaction in male patients following a first acute myocardial infarction (AMI). The sample comprised 276 Israeli male patients, age range 30–65 years, with a documented first AMI who were admitted to any of eight medical centers in Israel. All patients were sexually active prior to AMI. Data were elicited from interviews and medical charts on two occasions: before discharge and 3–6 months after AMI. The research variables explained a greater extent of the variance in sexual activity frequency than in satisfaction 3–6 months after AMI (32 and 23%, respectively). Sexual activity frequency/satisfaction prior to AMI were the major contributors to frequency/satisfaction after AMI. Of the other variables, age and education were the major contributors to sexual activity frequency; of these two variables, age was the sole contributor to sexual satisfaction. Medical and psychological variables (diabetes and depression) were minor contributors.
Outflow Acceleration Assessed by Continuous-Wave Doppler Echocardiography in Left Ventricular Hypertrophy: An Analysis of 103 Consecutive Cases
Authors: Faber L. , Heemann A. , Sürig M. , Michalowski Z. , Gleichmann U. , Klempt H.W.
Published: April 2003

The effect of provocation on left ventricular (LV) outflow was studied by continuous-wave Doppler echocardiography in 103 nonselected, consecutively enrolled patients with LV hypertrophy (LVH), either due to pressure overload (97 patients) or hypertrophic cardiomyopathy (HCM, 6 patients). In 34 patients with LVH, outflow acceleration (gradients ranging from 18 to 122 mm Hg) was induced or accentuated by the Valsalva maneuver after 1.6 mg nitroglycerine sublingually independent of LVH etiology. Factors associated with LV outflow acceleration were female sex, small body surface area and LV cavity size, increased relative wall thickness, LV contractility, and resting LV outflow velocity, mitral anulus calcifications and systolic anterior movement of the mitral valve. It is concluded that dynamic, intracavity LV gradients are a nonspecific flow abnormality that merit consideration because they can be frequently found in LVH patients.
Specificity of Cardiac Troponin I and Creatine Kinase-MB Isoenzyme in Asymptomatic Long-Term Hemodialysis Patients and Effect of Hemodialysis on These Cardiac Markers
Authors: Tun Aung , Khan IjazA. , Win MoeT. , Hussain Akhtar , Hla TinA. , Wattanasuwan Narrapol , Vasavada BalenduC. , Sacchi TerrenceJ.
Published: April 2003

Objectives: The objectives of this study were: (1) to evaluate the specificity of cardiac troponin I and creatine kinase-MB isoenzyme in ambulatory asymptomatic chronic renal failure patients on long-term hemodialysis, and (2) to evaluate the effect of hemodialysis on the serum levels of cardiac troponin I and creatine kinase-MB isoenzyme. Methods: One hundred and forty-four consecutive ambulatory asymptomatic chronic renal failure patients on hemodialysis for a minimum of 1 year were evaluated clinically. Serum cardiac troponin I and creatine kinase-MB isoenzyme levels were measured with specific monoclonal antibodies before and after dialysis using ACCESS Troponin I and ACCESS CK-MB assays. Results: The specificity of serum cardiac troponin I was 83% with a cutoff level of 0.03 ng/ml, which is an expected level for healthy population, but it rose to 100% with a cutoff level of 0.15 ng/ml, which is a reference level for patients with acute myocardial infarction. Twenty-four (17%) patients had borderline elevation in cardiac troponin I (>0.03 to <0.15 ng/ml). A history of angina pectoris was more common in the borderline-elevated cardiac troponin I subgroup. In 28% of the patients, serum creatine kinase-MB isoenzyme levels were increased with a specificity of 72% at a cutoff level of 4 ng/ml, which is the upper limit of normal, but the specificity rose to 98% by increasing the cutoff level value to 10 ng/ml. There were no statistically significant differences in serum levels of cardiac troponin I and creatine kinase-MB isoenzyme before and after dialysis. Conclusions: Cardiac troponin I is highly specific in ambulatory asymptomatic chronic renal failure patients on long-term hemodialysis; borderline elevations in cardiac troponin I may represent microinjury to the myocardium. A serum level of creatine kinase-MB isoenzyme >2.5 times of the normal upper limit may be highly specific in this patient population. Hemodialysis per se does not significantly change the serum levels of cardiac troponin I and creatine kinase-MB isoenzyme.
Nonischemic End-Systolic Performance
Authors: Meyer Theo E. , Perlini Stefano , Foëx Pierre
Published: April 2003

Nonischemic end-systolic performance decreases during ischemia. These changes in performance are likely to be dependent on the size and site of the ischemic zone, as well as the prevailing loading conditions. This study was designed to examine the effect of regional and generalized changes in inotropy on nonischemic end-systolic performance, independent of the ischemic zone size. Twenty dogs were instrumented with sonomicrometers and micromanometer pressure gauges. End-systolic pressure-thickness relationship data were obained during vena-caval balloon inflation. Measurements were obtained before and 90 s after left circumflex (LC) artery occlusion. Then, simultaneous with the occlusion of the LC artery, isoproterenol (0.04 μg/ml) was infused into the left anterior descending artery. After recovery, the same protocol was repeated before and after propranolol (0.5 mg/kg). In a separate set of animals, the same measurements were made following 2.5 and 5 μg/kg/min dobutamine. The effect of ischemia on the nonischemic end-systolic pressure-thickness relationship was expressed as the extent to which the relationship is shifted to the left. Infusion of intracoronary isoproterenol into the perfusion bed of the nonischemic zone produced a significant increase in the slope of the end-systolic pressure-thickness relationship. During ischemia, however, the extent of leftward shift of this relationship was less than that following β-blockade. Intravenous dobutamine resulted in a dose-dependent increase in the slope of the nonischemic end-systolic pressure thickness relationship, but the extent of leftward displacement of the relationship in response to regional ischemia was less than that following the control occlusion. The nonischemic segment is coupled with the nonfunctioning ischemic zone in such a way that it is required of the nonischemic segment to operate at decreased end-systolic thickness for any end-systolic pressure, the extent of which is to be determined, in part, by the size of the ischemic zone and the contractile state of the nonischemic myocardium. The lower the contractile state prior to coronary occlusion the greater extent of leftward shift of the pressure-thickness relationship.
Dispersion of QT Interval following Ventricular Premature Beats and Mortality after Myocardial Infarction
Authors: Dabrowski Andrzej , Kramarz Elżbieta , Piotrowicz Ryszard
Published: April 2003

In a group of 193 postinfarction patients with ventricular premature beats on a resting 12-lead ECG, the dispersion of QT and JT intervals was calculated as a difference between maximum and minimum QT and JT intervals in ventricular premature beats. During a follow-up of 38 ± 17 months, death from all causes was noted in 56 patients. Univariate predictors of mortality included QT dispersion ≥100 ms, JT dispersion ≥100 ms, left ventricular ejection fraction <40%, complete bundle branch block, ‘R-on-T’ index of ventricular premature beats <1 and age of patients >60 years. At multivariate Cox proportional hazards survival analysis, only QT dispersion ≥100 ms, left ventricular ejection fraction <40% and complete bundle branch block had an independent relation to postinfarction mortality. The final model selected increased QT dispersion as the prognostic factor which was the most strongly related to mortality (χ2 = 23.60, p = 0.0000).
Circulating Levels of Carboxyterminal Propeptide of Type I Procollagen and Left Ventricular Remodeling after Myocardial Infarction
Authors: Takino Toshitake , Nakamura Motoyuki , Hiramori Katsuhiko
Published: April 2003

Alteration in myocardial collagen metabolism is an important factor in the progression of ventricular remodeling after myocardial infarction (MI). This study examined sequential changes in circulating levels of carboxyterminal propeptide of type I procollagen (PICP) as a collagen synthesis marker in order to assess the value of PICP for predicting the progression of left ventricular remodeling after MI. The study group comprised 20 patients with first MI undergoing reperfusion therapy. Peripheral blood samples were obtained on admission and serially up to 4 weeks after admission. Circulating levels of PICP and B-type natriuretic peptide (BNP), a tentative biochemical marker for the severity of MI, were measured by direct radioimmunoassay. Left ventricular end-diastolic volume index (EDVI) in acute and chronic phases were determined by left ventriculography, and changes (Δ) in EDVI were used as an index of left ventricular remodeling. Plasma PICP levels in the non-dilation group (< median ΔEDVI) showed no significant change. However, in the dilation group (> median ΔEDVI) PICP started to increase significantly 3 days after admission, peaking on day 14 (from 74 ± 6 to 104 ± 19 ng/ml, p < 0.05). ΔEDVI was significantly correlated with plasma PICP at 2 and 3 weeks, and with plasma BNP at 1, 2 and 3 weeks. Plasma PICP 2 weeks after MI was the only independent predictor of ΔEDVI (p < 0.001). These results suggest that an increase in plasma PICP levels 2 weeks after admission is a useful biochemical predictor of the progression of ventricular remodeling after MI.
Correlations between Indices of Heart Rate Variability in Healthy Children and Children with Congenital Heart Disease
Authors: Massin Martial M. , Derkenne Bénédicte , von Bernuth Götz
Published: April 2003

Heart rate variability, as determined from 24-hour Holter recordings, represents a noninvasive parameter for studying the autonomic control of the heart. It decreases with certain disease states characterized by autonomic dysfunction such as congestive heart failure. No study in healthy or cardiac children has been performed to determine the correlations between and within time and frequency domain indices of heart rate variability. We examined five time domain (SDNN, SDNNi, SDANNi, rMSSD and pNN50) and five frequency domain measures (ULF, VLF, LF, HF and balance LF/HF) in 200 healthy children and 200 children with congenital heart disease, aged 3 days to 14 years. All measures were significantly correlated with each other. However, the strength of correlation varied greatly. Our data show that variables strongly dependent on vagal tone (rMSSD, pNN50 and HF) were highly correlated (r value > 0.90), as well as SDNN and SDANNi. We conclude that certain time and frequency domain indices correlate so strongly with each other that they can act as surrogates for each other.
A Quick Simple Method of Determining Platelet Aggregability following Glycoprotein IIb/IIIa Receptor Inhibitor Administration
Authors: Poullis Michael
Published: April 2003

Platelet aggregation assessment after therapeutic administration of a GP IIb/IIIa inhibitor has been difficult in routine practice due to the inherent nature of platelet preparation and aggregometry. Platelet microaggregation was performed via the utilisation of a Coulter counter. Citrate and heparin were evaluated as the anticoagulants, and ADP and adrenaline were evaluated as the stimulants. Aprotinin was also assessed. ReoPro was utilised in all assays as the GP IIb/IIIa inhibitor. Platelet microaggregation using the described methodology provides a quick, simple, reliable, and clinically valid method of assessing the percentage platelet inhibition due to the presence of a GP IIb/IIIa inhibitor.
Improved One-Year Survival afterAcute Myocardial Infarction in Iceland between 1986 and 1996
Authors: Kristjansson Jon M. , Andersen Karl
Published: April 2003

During the last decade the treatment of patients with acute myocardial infarction (AMI) has changed dramatically. In order to evaluate the overall impact of these changes on mortality and morbidity, we collected data on all patients hospitalized for AMI in Reykjavik, Iceland, during the calendar years of 1986 and 1996. Demographical characteristics of AMI patients did not change significantly between study periods. One-year mortality decreased from 26.3 to 19.7% (p < 0.05). Patients discharged with aspirin or β-antagonists as well as those who received thrombolytic therapy had decreased 1-year mortality both years. Patients discharged with diuretics, digoxin or antiarrhythmics had increased 1-year mortality. We conclude that the 25% reduction in 1-year mortality is partially due to changes in therapy.
Symptoms of Chest Pain and Dyspnea and Factors Associated with Chest Pain after Coronary Artery Bypass Grafting
Authors: Herlitz Johan , Brandrup-Wognsen Gunnar , Haglid Maria , Karlson Björn W. , Karlsson Thomas , Sjöland Helén , Caidahl Kenneth
Published: April 2003

Patients in western Sweden who underwent CABG from 1988 to 1991 received prior to coronary angiography and 2 and 5 years after CABG a questionnaire, in which they were asked about symptoms of chest pain and dyspnea. In all, 1,226 patients answered the inquiry prior to CABG, 1,531 patients 2 years and 1,359 patients 5 years after surgery. Both in terms of chest pain and dyspnea there was a marked improvement 2 and 5 years after CABG as compared with prior to surgery. However, between 2 and 5 years after surgery there was a minor deterioration, both regarding chest pain and dyspnea. The most statistically significant preoperative predictors for the occurrence of chest pain more than twice a week 5 years after surgery were concomitant valvular heart disease and obesity.
Surgery of the Complete Atrioventricular Canal: Relationship between Age at Operation, Mitral Regurgitation, Size of the Ventricular Septum Defect, Additional Malformations and Early Postoperative Outcome
Authors: Schaffer R. , Berdat P. , Stolle B. , Pfammatter J.P. , Stocker F. , Carrel T.
Published: April 2003

The perioperative risk after repair of the complete atrioventricular canal is reported to be low provided there is a balanced relationship of both ventricles, and elevated pulmonary vascular resistance has been demonstrated to be reversible. However, some pre- and perioperative conditions may adversely affect early postoperative outcome. A consecutive series of 42 patients (mean age 8.5 months, 34/42, 81%, with trisomy 21) operated between 1994 and 1998 was analyzed prospectively for pre- and perioperative risk factors. Echocardiography alone was performed in 35 patients whereas cardiac catheterization was performed in 7 patients aged more than 18 months to confirm operability. Additional malformations were found in 20 patients. Early mortality was 2.3% (1/42), and postoperatively a low cardiac output was observed in 25 patients (59%); NO inhalation was used in 12 patients. Only the size of the ventricular septal defect (> than the diameter of the aortic annulus) could be identified as a predictor of adverse postoperative outcome in multivariate analysis. The presence of associated intracardiac malformations showed a trend to increased perioperative risk in multivariate analysis. Early results after repair of the complete atrioventricular canal are excellent. Survival, postoperative morbidity and normalization of pulmonary artery pressure can be related to the size of the ventricular septal defect. Continuous monitoring of the pulmonary artery pressure (with consequent NO application when indicated) is probably responsible for the low perioperative risk encountered in this series, despite the high incidence of postoperative pulmonary artery hypertension.
Löffler’s Endomyocarditis in the Idiopathic Hypereosinophilic Syndrome
Authors: Corssmit E.P.M. , Trip M.D. , Durrer J.D.
Published: April 2003

The idiopathic hypereosinophilic syndrome (HES) is a leukoproliferative disorder characterized by sustained eosinophilia (> 1.5 × 109/l) and (multi-)organ dysfunction caused by infiltration of eosinophils. Especially the heart is frequently affected. In this report, we describe 2 patients with HES and Löffler’s endomyocarditis. Prednisone is the drug of choice for treatment. Both our patients responded very well to prednisone and came into remission. If prednisone fails, there are other therapeutic options like myelosuppressive drugs (hydroxyurea and vincristine) or interferon-α. We review the literature with regard to clinical presentation, diagnosis and treatment.
The Fractal Dimension of Atrial Fibrillation: A New Method to Predict Left Atrial Dimension from the Surface Electrocardiogram
Authors: Peters Robert M.
Published: April 2003

Background: Previous studies have shown inconsistent relationships between left atrial size and various characteristics of atrial fibrillation seen on the surface electrocardiogram. The purpose of this study was to determine if the fractal dimension of atrial fibrillation derived from the ECG would be useful in predicting left atrial size. Methods: The fractal dimension (D) was calculated using resting 12-lead ECGs from 53 patients (age 48–90) in chronic atrial fibrillation (greater than one year duration). D is the slope of the log/log plot of total length of a strip of atrial fibrillation against progressively decreasing lengths of measurement, plus one. Left atrial size was determined by standard M-mode echocardiography. Results: When D was large (greater than 1.14), all patients had a left atrial size of 4.6 cm or greater. When D was small (less than 1.09), all patients had a left atrial size of 4.6 cm or smaller. Values of D between 1.09 and 1.14 showed no relationship to atrial size. Larger values of D were associated with a higher degree of irregularity, roughness, and complexity in the surface ECG rhythm strips. Conclusions: In patients with chronic atrial fibrillation, the fractal dimension D derived from the surface ECG may be useful in predicting left atrial size.