bluuebunny/crossref_metadata_2025 huggingface dataset:
A qualitative exploration of rural feeding and weaning practices, knowledge and attitudes on nutrition
Authors: Kruger R , Gericke GJ
Published: April 2003

Aim:

An exploratory qualitative investigation was done to determine the feeding and weaning practices, knowledge and attitudes towards nutrition of mothers/caregivers of children up to 3 years old attending baby clinics in the Moretele district (South Africa).

Methodology:

Qualitative data collection on six relevant nutrition topics was done using focus group interviews. Trained moderators, using a pre-tested, structured interview schedule, interviewed participants in six age groups. Focus group interviews were taped, transcribed and translated. Content analysis produced systematic data descriptions and ethnography provided descriptive data.

Results:

Breast-feeding was the choice feed and bottle-feeding was only given when breast-feeding was impossible. Solid food was introduced early (at 2–3 months) and a mixed family diet at 7–9 months. Milk feeds were stopped completely from 18–24 months. Weaning diets were compromised due to poor food choices, preparation practices and limited variety. The participant's nutrition knowledge regarding specific foods, their functions and recommended quantities was poor. The women adhered to their cultural beliefs regarding food choices and preparation practices.

Conclusion:

The data analysis revealed that inadequate nutrition knowledge and adherence to cultural practices lead to poor-quality feeding practices. Cultural factors and taboos have a powerful influence on feeding practices and eating patterns. Young mothers often find it impossible to ignore their ill-informed elders or peer group. Nutrition knowledge needs to be changed in a first step towards implementing improved feeding practices. Facilitated group discussions could focus on possible solutions for the identified nutrition-related problems.
Initiation and Synergistic Fibrillization of Tau and Alpha-Synuclein
Authors: Giasson Benoit I. , Forman Mark S. , Higuchi Makoto , Golbe Lawrence I. , Graves Charles L. , Kotzbauer Paul T. , Trojanowski John Q. , Lee Virginia M.-Y.
Published: April 2003

Alpha-synuclein (α-syn) and tau polymerize into amyloid fibrils and form intraneuronal filamentous inclusions characteristic of neurodegenerative diseases. We demonstrate that α-syn induces fibrillization of tau and that coincubation of tau and α-syn synergistically promotes fibrillization of both proteins. The in vivo relevance of these findings is grounded in the co-occurrence of α-syn and tau filamentous amyloid inclusions in humans, in single transgenic mice that express A53T human α-syn in neurons, and in oligodendrocytes of bigenic mice that express wild-type human α-syn plus P301L mutant tau. This suggests that interactions between α-syn and tau can promote their fibrillization and drive the formation of pathological inclusions in human neurodegenerative diseases.
The Glass-to-Glass Transition and Its End Point in a Copolymer Micellar System
Authors: Chen Sow-Hsin , Chen Wei-Ren , Mallamace Francesco
Published: April 2003

We present experimental evidence, obtained from small-angle neutron scattering and photon correlation measurements, indicating the existence of two types of structurally arrested (glassy) states in a copolymer micellar system with a short-range interparticle attractive interaction. Within a certain range of micellar volume fractions, a sharp transition between these two types of glass is observed by varying the temperature. Furthermore, we found an end point of this transition line beyond which the two glasses become identical in their local structure and their long-time dynamics. These findings confirm the recent mode-coupling theory predictions regarding the phase behavior of the structurally arrested states for this type of system.
DAF-16 Target Genes That Control
C. elegans
Life-Span and Metabolism
Authors: Lee Siu Sylvia , Kennedy Scott , Tolonen Andrew C. , Ruvkun Gary
Published: April 2003

Signaling from the DAF-2/insulin receptor to the DAF-16/FOXO transcription factor controls longevity, metabolism, and development in disparate phyla. To identify genes that mediate the conserved biological outputs of
daf-2
/insulin-like signaling, we usedcomparative genomics to identify 17 orthologous genes from
Caenorhabditis
and
Drosophila
, each of which bears a DAF-16 binding site in the promoter region. One-third of these DAF-16 downstream candidate genes were regulatedby
daf-2
/insulin-like signaling in
C. elegans
, and RNA interference inactivation of the candidates showed that many of these genes mediate distinct aspects of
daf-16
function, including longevity, metabolism, anddevelopment.
PROTOFIBRILS, PORES, FIBRILS, AND NEURODEGENERATION: Separating the Responsible Protein Aggregates from The Innocent Bystanders
Authors: Caughey Byron , Lansbury Peter T.
Published: April 2003

▪ Abstract  Many neurodegenerative diseases, including Alzheimer's and Parkinson's and the transmissible spongiform encephalopathies (prion diseases), are characterized at autopsy by neuronal loss and protein aggregates that are typically fibrillar. A convergence of evidence strongly suggests that protein aggregation is neurotoxic and not a product of cell death. However, the identity of the neurotoxic aggregate and the mechanism by which it disables and eventually kills a neuron are unknown. Both biophysical studies aimed at elucidating the precise mechanism of in vitro aggregation and animal modeling studies support the emerging notion that an ordered prefibrillar oligomer, or protofibril, may be responsible for cell death and that the fibrillar form that is typically observed at autopsy may actually be neuroprotective. A subpopulation of protofibrils may function as pathogenic amyloid pores. An analogous mechanism may explain the neurotoxicity of the prion protein; recent data demonstrates that the disease-associated, infectious form of the prion protein differs from the neurotoxic species. This review focuses on recent experimental studies aimed at identification and characterization of the neurotoxic protein aggregates.
Afferent and Efferent Connections of the Dorsocentral Telencephalon in an Electrosensory Teleost, Gymnotus carapo
Authors: Lopes Corrêa Sônia Aparecida , Grant Kirsty , Hoffmann Anette
Published: April 2003

Biotinylated dextran amine was injected unilaterally into dorsal regions of the telencephalon of the weakly electric fish Gymnotus carapo in order to study the afferent and efferent connections of specific dorsal regions with ventral regions of the telencephalon and with other regions of the central nervous system. Efferent pathways from the dorsolateral area of the telencephalon project ipsilaterally to the anterior hypothalamic nucleus, the ventral thalamus and magnocellular tegmental nucleus, whose axons reach the spinal cord. Anterograde labeling showed that the central division of the dorsal telencephalon sends efferent projections through the lateral forebrain bundle towards the ipsilateral lateral and medial preglomerular nucleus, the pretectal nucleus, the optic tectum and the dorsal torus semicircularis, regions that are all involved in the processing of electrosensory and/or multisensory information. In addition, when biotinylated dextran amine was injected into the dorsal torus semicircularis, retrogradely labeled neurons were observed in the dorsocentral area of the telencephalon. The dorsocentral area is also a target of the extra-telencephalic afferents originating from rostral, lateral and medial regions of preglomerular complex. Within the telencephalon, neurons of many ventral subdivisions project ipsilaterally to the dorsocentral area. The dorsocentral, dorsolateral and dorsomedial areas are connected ipsilaterally and reciprocally. The dorsocentral area is reciprocally connected with its contralateral homologue through the anterior commissure.
Did Auditory Sensitivity and Vocalization Evolve Independently in Otophysan Fishes?
Authors: Ladich Friedrich
Published: April 2003

Otophysine fishes have a series of bones, the Weberian ossicles, which acoustically couple the swimbladder to the inner ear. These fishes have evolved a diversity of sound-generating organs and acoustic signals, although some species, such as the goldfish, are not known to be vocal. Utilizing a recently developed auditory brainstem response (ABR)-recording technique, the auditory sensitivities of representatives of seven families from all four otophysine orders were investigated and compared to the spectral content of their vocalizations. All species examined detect tone bursts from 100 Hz to 5 kHz, but ABR-audiograms revealed major differences in auditory sensitivities, especially at higher frequencies (>1 kHz) where thresholds differed by up to 50 dB. These differences showed no apparent correspondence to the ability to produce sounds (vocal versus non-vocal species) or to the spectral content of species-specific sounds. All fishes have maximum sensitivity between 400 Hz and 1,500 Hz, whereas the major portion of the energy of acoustic signals was in the frequency range of 100–400 Hz (swimbladder drumming sounds) and of 1–3 kHz (stridulatory sounds). Species producing stridulatory sounds exhibited better high-frequency hearing sensitivity (pimelodids, doradids), except for callichthyids, which had poorest hearing ability in this range. Furthermore, fishes emitting both low- and high-frequency sounds, such as pimelodid and doradid catfishes, did not possess two corresponding auditory sensitivity maxima. Based on these results it is concluded that selective pressures involved in the evolution of the Weberian apparatus and the design of vocal signals in otophysines were others (primarily predator or prey detection in quiet freshwater habitats) than those serving to optimize acoustical communication.
Modality-Specific Segregation of Input to Ant Mushroom Bodies
Authors: Gronenberg Wulfila
Published: April 2003

The mushroom bodies are central brain neuropils involved in the control of complex behavior. In ants, the mushroom bodies are relatively large compared to those of honey bees, whereas the optic lobes of ants are considerably smaller. The general morphology of ant mushroom bodies is similar to that of honey bees. As in other Hymenoptera, the main input region of the mushroom bodies, the calyx, is subdivided into three compartments: the lip, the collar, and the basal ring. In many ant species this compartmentalization is not obvious and can only be visualized using neuronal tracers. The lip region receives antennal input and is large in all ant species. It appears to be composed of at least two different regions that have not yet been characterized in detail. The collar is large in other Hymenoptera, yet in ant workers it varies in size and is always much smaller than the lip region. The collar receives visual input and is relatively larger in males, which generally are more dependant on vision than are workers. The basal ring receives input from both the optic and antennal lobes. In one ant tribe, the Ponerini, the collar region appears to have changed its position, but based on afferent input it appears to be homologous to the hymenopteran collar. Generally, the composition of the mushroom body calyx correlates with the living conditions of ants, reflecting the great importance of olfaction and the lesser and more variable significance of vision for workers of the observed ant species.
The Ocular Morphology of the Southern Hemisphere Lamprey Geotria australis Gray, with Special Reference to Optical Specialisations and the Characterisation and Phylogeny of Photoreceptor Types
Authors: Collin Shaun P. , Potter Ian C. , Braekevelt Charlie R.
Published: April 2003

This paper describes the ocular morphology of young adults of the southern hemisphere lamprey Geotria australis, the sole representative of the Geotriidae, and makes comparisons with those of holarctic lampreys (Petromyzontidae). As previously reported for the holarctic lamprey Ichthyomyzon unicuspis [Collin and Fritzsch, 1993], the lens of G. australis is non-spherical and possesses a cone-shaped posterior that may be capable of mediating variable focus. The avascular retina of G. australis is well differentiated, containing three retinal ganglion cell populations, three layers of horizontal cells and three photoreceptor types. In contrast to petromyzontids that contain only two photoreceptor types (short and long), G. australis possesses one rod-like (R1) and two cone-like (C1 and C2) photoreceptors. Although the rod-like receptor in G. australis may be homologous with the short receptors of holarctic lampreys, the two cone-like receptors have morphological characteristics that differ markedly from those of the long receptors of their holarctic counterparts. The features which distinguish the two cone-like receptors from those of the long receptor type in holarctic lampreys are the characteristics of the mitochondria and the presence of large amounts of two different types of stored secretory material in the endoplasmic reticulum of the myoid (refractile bodies). The endoplasmic reticulum of each receptor type has a different shape and staining profile and is polymorphic, each showing a continuum of distension. It is proposed that the presence of two cone-like photoreceptors with different characteristics would increase the spectral range of G. australis and thus be of value during the parasitic phase, when this lamprey lives in the surface marine waters. The irideal flap, present in G. australis but not petromyzontids, would assist in reducing intraocular flare during life in surface waters. The results of this study, which are discussed in the context of the proposed evolution of lampreys, emphasise that it is important to take into account the characteristics of the eyes of southern hemisphere lampreys when making generalizations about the eyes of lampreys as a whole.
Short-Term Effects of Fights for Social Dominance and the Establishment of Dominant-Subordinate Relationships on Brain Monoamines and Cortisol in Rainbow Trout
Authors: Øverli Øyvind , Harris Charmaine A. , Winberg Svante
Published: April 2003

We report changes in brain serotonergic, noradrenergic and dopaminergic activity, along with plasma cortisol concentrations, occurring during the initial 24-h period following the establishment of dominant-subordinate relationships in pairs of rainbow trout. Immediately (within 5 min) after the termination of staged fights for social dominance, a large increase in blood plasma cortisol was observed in both fight losers (future subordinate fish) and winners (future dominant fish). In dominant fish, cortisol decreased rapidly (within 3 h) to the level of unstressed controls, while continuing to increase in subordinate fish. At 3 h following fights, the brain serotonergic system was activated in both dominant fish and subordinate fish, at least in some brain regions (telencephalon). This effect was reversed in dominant individuals within 24 h of social interaction, whereas in subordinate fish a substantial activation of the serotonergic system was manifest in all brain regions by 24 h. Similarly, a strong increase in brain catecholaminergic activation was indicated after 24 h of social interaction in subordinate fish, but not in dominant fish. Relationships between plasma cortisol and brain serotonergic and noradrenergic activity in the various experimental groups suggest that these systems influence cortisol secretion under normal conditions and during moderate or short-term stress.
Responses of Single Neurons in the Toad’s Caudal Ventral Striatum to Moving Visual Stimuli and Test of Their Efferent Projection by Extracellular Antidromic Stimulation/Recording Techniques
Authors: Buxbaum-Conradi H. , Ewert J.-P.
Published: April 2003

Previous work in anuran amphibians has shown that activity in the caudal ventral striatum correlates with visuomotor activity: orienting responses toward prey fail to occur after striatal lesions. Thus it has been suggested that the striatum influences visually guided behavior. Therefore, the present study investigates visual response properties from neurons recorded in the striatum. Extracellular recordings of 104 single neurons of the cane toad’s (Bufo marinus) caudal ventral striatum (STR) reveal five different response properties: resting discharge activity uninfluenced by the visual test stimuli (group STR1, 24.0%); resting discharge activity increased by any moving visual object (STR2, 31.7%); preference to moving compact objects (STR3, 15.4%); preference to certain configurational moving objects (STR4a and b, 13.5%), and resting activity reduced by visual stimuli (STR5, 15.4%). The receptive fields of these neurons encompassed the contralateral (46%) or the entire field of vision (54%). Of the neurons recorded in the striatum, 34% responded to electrical stimuli applied in the rostral diencephalon to the ipsilateral lateral forebrain bundle (LFB) which connects the striatum with the optic tectum (e.g. either directly or via pretectum or tegmentum). Various electrically driven STR neurons (40%) have axons that project caudally through the LFB, which was suggested by their antidromic activation in response to electrical stimuli applied to the LFB in the rostral diencephalon. In the present study, the main striatal output is mediated by ‘motion detectors’ (STR2) and ‘compact object perceivers’ (STR3). It is suggested that the caudal ventral striatum is involved in visual attentional processes that allow the translation of perception into action.
Cortical Organization in Insectivora: The Parallel Evolution of the Sensory Periphery and the Brain
Authors: Catania Kenneth C.
Published: April 2003

Insectivores are traditionally described as a primitive group that has not changed much in the course of mammalian evolution. In contrast, recent studies reveal a great diversity of sensorimotor specializations among insectivores adapted to a number of different ecological niches, indicating that there has been significant diversification and change in the course of their evolution. Here the organization of sensory cortex is compared in the African hedgehog (Atelerix albiventris), the masked shrew (Sorex cinereus), the eastern mole (Scalopus aquaticus), and the star-nosed mole (Condylura cristata). Each of these four closely related species lives in a unique ecological niche, exhibits a different repertoire of behaviors, and has a different configuration of peripheral sensory receptors. Corresponding specializations of cortical sensory areas reveal a number of ways in which the cortex has evolved in parallel with changes to the sensory periphery. These specializations include expansion of cortical representations (cortical magnification), the addition or loss of cortical areas in the processing network, and the subdivision of areas into modules (barrels and stripes).
Does Heart Rate Variability Change in Angina Pectoris Patients Treated with Spinal Cord Stimulation?
Authors: Andersen Claus
Published: April 2003

To determine whether spinal cord stimulation has any effect on the autonomic nervous tone of the heart, heart rate variability was used as an indicator of autonomic nervous control of the heart. The components time domain and power spectral analyses of heart rate variability were measured in 21 patients with angina pectoris. Twenty-four-hour Holter recordings were obtained before and after 12 months with spinal cord stimulation. No significant attenuation of time domain or spectral components of heart rate variability analyses were found. Apparently, spinal cord stimulation does not influence the autonomic tone of the heart.
A Prospective Randomized Comparison between Fixed Rate Response Programming and Automatic Rate Response Optimization in Activity-Triggered DDDR Pacemakers
Authors: Schuchert A. , van Langen H. , Michels K. , Meinertz T.
Published: April 2003

Activity rate response programming depends on the physician’s experience and on the limited knowledge of patient’s daily activities. The present investigation compares a new continuous automatic adjustment of the activity rate response called rate response optimization (OPT) with fixed activity rate response programming (FIXED). At hospital discharge 37 patients with Thera DR pacemakers (Medtronic) were randomized either to FIXED (n = 20; 65 ± 12 years, male n = 12) or to OPT (n = 17; 65 ± 12 years, male n = 13). After 1 month’s follow-up occurrence of complaints related to rate-responsive pacing and the percentage of pacing were assessed. Other activity sensor parameters were programmed according to clinical judgement and similarly distributed in the two groups. Activity rate response was 7.1 ± 1.4 (FIXED) and 7.2 ± 1.7 (OPT), activity threshold was medium in 9 (FIXED) and 8 (OPT), and medium/low in 11 (FIXED) and 9 (OPT) patients, respectively. No patient with FIXED had any complaints with respect to activity-triggered rate response. One patient with OPT reported palpitations due to rapid changes in the pacing rate leading to reprogramming of the pacemaker. Atrium and ventricle were paced in 56 ± 31% (FIXED) and in 58 ± 35% (OPT; not significant) and the atrium only in 4 ± 10% (FIXED) and 0% (OPT; not significant), respectively. In the 17 patients programmed to OPT the pacemaker increased activity rate response in 5 and decreased activity rate response in 3 patients. In conclusion, as only 1 (3%) patient had complaints related to the activity rate response and fixed rate response programming according to clinical judgement already resulting in symptom-free DDDR pacing, no differences could be detected between the fixed rate response programming and rate response optimization.
Assessment of the Coronary Artery Disease and Systolic Dysfunction in Hypertensive Patients with the Dobutamine-Atropine Stress Echocardiography: Effect of the Left Ventricular Hypertrophy
Authors: Ho Yi-Lwun , Wu Chau-Chung , Lin Lung-Chun , Huang Chien-Hua , Chen Wen-Jone , Chen Ming-Fong , Liau Chiau-Suong , Lee Yuan-Teh
Published: April 2003

This study was performed to evaluate whether left ventricular hypertrophy (LVH) can influence the diagnostic accuracy of coronary artery disease (CAD) using the dobutamine stress echocardiography (DSE) in hypertensive patients. In addition to the detection of CAD, the relationship between systolic dysfunction and the quantitation wall motion scoring system of DSE was studied also. DSE was performed in 101 patients. There were 45 (45%) patients with a history of acute myocardial infarction. Twenty-eight patients (28%) had electrocardiographic LVH and 59 patients (58%) had echocardiographic LVH. A total of 74 patients (73%) had angiographically documented CAD defined as ≧50% diameter stenosis. For the 56 patients without history of myocardial infarction, the diagnostic sensitivity, specificity, and accuracy in detecting CAD were not influenced by LVH defined by either electrocardiography or echocardiography. For the total patients, the diagnostic sensitivity, specificity, and accuracy in detecting multivessel disease were also not influenced by LVH defined by either method. The resting global wall motion score was correlated well with the left ventricular ejection fraction in patients with and without LVH (r = –0.70, p < 0.001 vs. r = –0.70, p < 0.001). When using the resting wall motion score of 24 as a cutoff value, the diagnostic sensitivity, specificity, and accuracy of systolic dysfunction (defined by left ventricular ejection fraction <40%) were 79, 86 and 85%, respectively. In conclusion, the diagnostic accuracy of CAD using the DSE was not affected by LVH in hypertensive patients. In addition to detection of coronary artery disease, the resting wall motion score of DSE was able to detect systolic dysfunction in patients with and without LVH.
Therapeutic Benefits of Cilazapril in Patients with Syndrome X
Authors: Nalbantgil Istemi , Önder Remzi , Altintig Ahmet , Nalbantgil Sanem , Kiliçcioglu Bülent , Boydak Bahar , Yilmaz Hasan
Published: April 2003

Objectives: Although the pathophysiology of syndrome X (angina pectoris, positive ECG test findings and normal coronary arteriogram) is unclear, it is generally accepted that intracellular metabolic changes resulting from abnormal constriction of prearteriolar vessels due to endothelium-dependent vasodilation abnormalities may play a role in the pathogenesis. We established the effect of long-term treatment with cilazapril, an angiotensin-converting enzyme inhibitor, which prevents the effect of angiotensin II in the tonic control of vascular resistance. Methods: 18 patients (15 women and 3 men, mean age 43.2 ± 4.6 years) with syndrome X were included in this study. A randomized double-blind crossover placebo-controlled trial was done. After a 1-week washout period, patients received either cilazapril 2 × 2.5 mg or placebo for 3 weeks, followed by 3 weeks of the other therapy. At the end of two periods, an exercise ECG test (modified Bruce protocol) was employed. Results: The magnitude of ST segment depression was significantly decreased during treatment with cilazapril compared with placebo. On the other hand, total exercise time and time to 1 mm ST segment depression were significantly prolonged by cilazapril. However, rate pressure products were not significantly different at peak exercise at or at 1 mm of ST segment depression during both therapies. Conclusion: Cilazapril exerted a beneficial therapeutic effect in cases with syndrome X. The possible mechanism of this effect may be a modulation of coronary tone at the microcirculation level.
Downregulation of Endothelin B Receptors in Cardiomyopathic Hamsters
Authors: Wong Wendy H.Y. , Wong Bonita P.H. , Wong Eric F.C. , Huang Min-Huo , Wong Norman L.M.
Published: April 2003

The mechanisms responsible for abnormal fluid retention in congestive heart failure (CHF) are unclear. Studies were conducted to elucidate how endothelin (ET) may contribute to salt and water retention. Cardiomyopathic (CM) hamsters with moderate heart failure were employed for in vivo and in vitro trials. Clearance methods were used to compare the level of renal function in CM hamsters and control animals. Radioligand binding studies were also performed to determine ET receptor distribution in the inner medullary collecting ducts. CM hamsters exhibited an attenuated response to ANF infusion (FENa: 2.7 ± 0.5 vs. 5.9 ± 0.8%, p < 0.01; FEH2O: 1.7 ± 0.3 vs. 3.2 ± 0.4%, p < 0.01; UcGMP: 11.2 ± 2.3 vs. 16.6 ± 2.0 pmol/min, p < 0.05) and a decrease in total ET receptor density (532 ± 77 vs. 959 ± 154 fmol/mg protein, p < 0.005). Particularly ETB receptors were significantly reduced (214 ± 26 vs. 483 ± 88 fmol/mg protein, p < 0.003). Enalapril therapy simultaneously restored the natriuretic and diuretic effects of ANF and ET receptor density in the diseased animals. These studies suggest that the renin-angiotensin-aldosterone system and ET hormonal system act together, via ETB receptor downregulation, to promote the abnormal fluid retention observed in CHF.
Serial Changes in Atrial Natriuretic Peptide and Endothelin-1 Concentrations
Authors: Petersen Claus Leth , Munch Michael , Frandsen Erik , Nielsen Jens Rokkedal , Hesse Birger , Dige-Petersen Harriet
Published: April 2003

Aim: The study was designed to assess temporal changes in atrial natriuretic peptide (ANP) and endothelin-1 (ET) concentrations in patients hospitalized for acute myocardial infarction (AMI) and their relationships to cardiac performance determined by radionuclide ventriculography. Patients and Methods: 20 patients with first AMI were studied. Blood samples were drawn within the first 4–18 h, after 18–24 h, and on days 2, 3 and 6. Plasma concentrations of ANP and ET were measured in blood samples taken simultaneously. Radionuclide ventriculography was performed on the day of discharge to determine left-ventricular ejection fraction (LVEF), left-ventricular end-diastolic volume index, end-systolic volume index and left-ventricular stroke volume index. Results: Median concentrations of ET decreased from 2.15 pmol/l on admission to 1.45 pmol/l at discharge (32%, p < 0.001). Median ANP rose from 29 to 79 pg/ml (172%, p < 0.001). The increment in ANP and the decrease in ET concentrations from admission to discharge was inversely correlated (r = –0.81, p < 0.005). ANP was inversely correlated to LVEF (r = –0.82, p < 0.001) and to the end-systolic volume index at discharge (r = –0.73, p < 0.003). Conclusion: Dynamic and inverse fluctuations in ET and ANP occur within the 1st week of AMI. The magnitude of endocrine activation in the ANP-ET system seems to reflect an impairment in the left-ventricular systolic performance.
Long-Term Effects on Cardiac Output and Peripheral Resistance in Patients Treated with Enalapril after Acute Myocardial Infarction
Authors: Edner Magnus , Caidahl Kenneth , Bonarjee Vernon V.S. , Nilsen Dennis W.T. , Carstensen Steen , Berning Jens , On behalf of the CONSENSUS IIMulti-Echo Study Group J.
Published: April 2003

In the Cooperative New Scandinavian Enalapril Survival Study (CONSENSUS II), in which enalapril treatment was initiated intravenously within 24 h after acute myocardial infarction, there was a neutral effect on 6-month mortality, whereas a beneficial effect on the progression of congestive heart failure was noted. We studied the effect of enalapril on left ventricular systolic function in terms of cardiac output and mean acceleration time measured by pulsed-wave Doppler in the left ventricular outflow tract and peripheral resistance. Early angiotensin-converting enzyme inhibition after acute myocardial infarction did not result in a general improvement of cardiac output. However, a small increase in cardiac output was observed in a subgroup of enalapril-treated patients with ejection fraction ≥45%, probably due to a reduction in peripheral resistance in these patients.
Influence of Thermal Stress on the Incidence of Acute Myocardial Infarction in a Temperate Climate
Authors: Fries Roland , Jung Jens , Özbek Cem , Bay Wolfgang , Schieffer Hermann , Heisel Armin
Published: April 2003

Using a Poisson regression model the relative incidence of acute myocardial infarctions (AMI) prospectively registered in 8 hospitals within a radius of 50 km during a 2-year period was correlated with the outside conditions characterized by a complete thermophysiological model (Klima-Michel Model) defining thermal stress. An increase in the incidence of AMI related to thermal stress could be demonstrated neither by splitting the study period into 12 equally sized ‘felt-temperature’ classes by months of the year nor by single days. This was confirmed by correlation of the AMI rate with the mean felt-temperature level during the preceding 14 days. Thermal stress caused by the atmospheric conditions in a temperate climate may be too weak to influence significantly the incidence of AMI.
Evidence of Apoptosis Induced by Myocardial Ischemia: A Case of Ventricular Septal Rupture following Acute Myocardial Infarction
Authors: Toyoda Yoshiya , Shida Tsutomu , Wakita Noboru , Ozaki Nobuchika , Takahashi Rei , Okada Masayoshi
Published: April 2003

Recent studies have reported that apoptosis may be induced by reperfusion injury following ischemia in cardiomyocytes. We present a case with evidence of apoptosis induced by myocardial ischemia without reperfusion. DNA fragmentation was demonstrated in the nuclei of the myocardial cells surrounding the ventricular septal rupture following acute myocardial infarction without reperfusion in the infarct-related left anterior descending coronary artery. This finding suggests that ischemia without reperfusion may induce apoptosis in myocardial cells.
L-Arginine: Rediscovery in Progress
Authors: Tenenbaum Alexander , Fisman Enrique Z. , Motro Michael
Published: April 2003

Since the recognition that L-arginine (LA) is the natural metabolic donor of nitric oxide, this amino acid has reached the medical spotlight. LA exerts favorable effects in the prevention and treatment of endothelial damage and the restoration of endothelial function in patients with cardiovascular risk factors (hypercholesterolemia, smoking, hypertension, diabetes and advanced age) or with several chronic cardiovascular disorders (coronary, peripheral and cerebral vascular disease, and mild-to-moderate heart failure). LA administration is likely to represent a potentially novel therapeutic strategy during angioplasty, coronary bypass grafting and cardiac transplantation. More conclusive research findings for the rediscovered role of this well-known substance merit close attention.
Serial Holter ST-Segment Monitoring after First Acute Myocardial Infarction
Authors: Mickley Hans , Nielsen Jens R. , Berning Jens , Junker Anders , Møller Mogens
Published: April 2003

Based on serial Holter monitoring performed 7 times within 3 years after a first acute myocardial infarction, we assessed the prevalence, variability and long-term clinical importance of transient myocardial ischemia (TMI) defined as episodes of ambulatory ST-segment depression. In all, 121 consecutive male patients <70 years old were studied. The prevalence of TMI on different Holter recordings varied around 20% ranging between 18 and 27%. Fifty-five of the patients (46%) had TMI on at least 1 of the 7 Holter recordings. Considerable variability was found within and between patients for the presence of TMI. No high-risk group for cardiac death, nonfatal reinfarction or coronary revascularization during up to 10 years of follow-up could be identified by the detection of TMI. From these results we conclude that a routine search for TMI on serial Holter monitoring cannot be recommended in male survivors of an uncomplicated first acute myocardial infarction.
Intracellular Magnesium Predicts Functional Capacity in Patients with Coronary Artery Disease
Authors: Shechter Michael , Paul-Labrador Maura J. , Rude Robert K. , Bairey Merz C. Noel
Published: April 2003

To determine whether increased intracellular levels of magnesium ([Mg]i) are associated with enhanced functional capacity, we performed symptom-limited exercise treadmill testing on 42 stable coronary artery disease (CAD) patients (37 men, 5 women, mean age 68 ± 9 years). [Mg]i was found to be an independent and significant predictor of exercise duration (R = 0.31, p = 0.02) in a multivariate stepwise regression model. Patients with > normal [Mg]i of 1.23 µg/mg protein (n = 13) had a significantly greater mean functional capacity, measured in higher achieved metabolic equivalents (10.6 ± 2.5 vs. 8.9 ± 2.3, p < 0.05) and exercise duration (9.4 ± 2.3 vs. 7.9 ± 2.2 min, p < 0.05) compared to patients with [Mg]i ≤ the normal (n = 29). Thus, functional capacity is greater in stable CAD patients with higher [Mg]i, suggesting that magnesium may play a role in CAD pathophysiology, possibly via ventricular unloading.
Abnormal Myocardial Adrenergic Nerve Function in Orthostatic Hypotension
Authors: Nakamura Motoyuki , Yamazaki Takuya , Hiramori Katsuhiko
Published: April 2003

A 70-year-old man had frequent syncope and faintness when in an upright position. A diagnosis of primary orthostatic hypotension was obtained by a head-up tilt test and various autonomic nerve function tests. No abnormalities were seen on myocardium scintigraphy using 201Tl. However, 123I-metaiodobenzyl-guanidine did not accumulate in the heart. This suggests that globally denervated myocardium may impair a prompt increase in cardiac contractility and fail to maintain cerebral blood flow, thereby contributing to postural hypotension in this disorder.
Heart Rate Variability as a Marker of Myocardial Perfusion
Authors: Schechter David , Sapoznikov Dan , Luria Myron H. , Mendelson Susan , Bocher Moshe , Chisin Roland
Published: April 2003

RR variability (HRV), an independent predictor of death following myocardial infarction, may also be related to other features of coronary artery disease. We evaluated its ability to differentiate among sedentary patients with chest pain ≥45 years of age demonstrating either normal or abnormal myocardial perfusion with rest and exercise thallium-210 tomographic imaging. The major HRV difference between 48 men and 50 women with normal perfusion was a significantly higher high frequency power in women. No significant differences in mean HRV values were found between the 57 men with abnormal perfusion scans and the 48 men with normal perfusion. In both men and women with normal perfusion scans, duration of exercise was significantly related to age. In men with abnormal scans, impaired myocardial perfusion alters the relationship between exercise duration and age, and a group of individuals with diminished HRV and low levels of physical fitness, regardless of age, can be identified. Despite these latter selective findings, we conclude that HRV is not a sensitive indicator to differentiate patients with normal and abnormal myocardial perfusion.
Evidence of Excess Hereditary Predisposition in Women with Angiographically Documented Coronary Artery Disease
Authors: Hofstad Ann Elin , Os Ingrid , Abdelnoor Michael , Platou Eivind S. , Westheim Arne
Published: April 2003

In a hospital-based case-control study including women and men with angiographically documented coronary artery disease (CAD) admitted to a university hospital during a 6-month period, we observed an excessive hereditary predisposition in women. Clustering of risk factors was more pronounced in women than in men. Thus, the results suggest that hereditary factors as well as multiple risk factors are essential when CAD is expressed in women.
Aortic Sinotubular Atherosclerotic Debris Associated with Cerebral Embolic Events Can Be Identifiedby Transthoracic Echocardiography
Authors: Barasch Eddy , Kaushik Vinod , Ahn Chul
Published: April 2003

Objective: To evaluate the association between the presence of aortic sinotubular debris (STAD) identified by transthoracic echocardiography (TTE) and embolic strokes. Background: The presence of atherosclerotic debris in the ascending aorta or aortic arch detected by transesophageal echocardiography or epiaortic echocardiography has been well established to be correlated with embolic stroke or other thromboembolic events. No data are available on the role of TTE in describing aortic pathology in thromboembolic events. Methods: We identified 60 transthoracic echocardiographic studies from 11,275 studies, in which STAD was diagnosed. The charts of these patients (group 1; mean age 67 ± 10 years) were reviewed and compared with those of 57 patients (group 2) without STAD, matched for age, gender and risk factors for advanced atherosclerosis. The results of brain imaging procedures, carotid duplex and coronary angiography were also reviewed. Results: Ischemic stroke was found in 15 of group 1 (25%) and 4 patients of group 2 (7%, odds ratio = 4.4; 95% confidence interval, 1.3–19.4, p = 0.008). The average thickness of STAD was 0.7 ± 0.2 cm in stroke patients and 0.6 ± 0.2 cm in patients without stroke (p = n.s.). STAD was associated with ≤40% carotid artery stenosis. Conclusion: STAD detected by TTE is strongly associated with embolic strokes. Our findings expand the role of TTE in the evaluation of patients with embolic strokes.
Relationship between Depressed Baroreflex Function and Exaggerated Sympathetic Response to Exercise in Patients with Heart Failure
Authors: Rostagno Carlo , Caciolli Sabina , Felici Massimo , Galanti Giorgio , Comeglio Marco , Boddi Maria , Coppo Mirella , Olivo Giuseppe , NeriSerneri Gian Gastone
Published: April 2003

The relationship between impaired baroreflex sensitivity (BS) and the degree of sympathetic activation during exercise in patients with heart failure (HF) has not been studied in detail. For this purpose, we studied BS and measured plasma norepinephrine (NE) at rest, and during and after treadmill exercise in 15 patients and 10 controls. HF patients showed lower BS in comparison to controls (3.51 ± 3.62 vs. 9.74 ± 4.56 ms/mm Hg; p < 0.001), and higher levels of plasma NE at rest (449.3 ± 147.1 vs. 261.1 ± 82.48 pg/ml; p < 0.001) and during exercise (1,542 ± 361.2 vs. 524.6 ± 92.61 pg/ml; p < 0.001). BS was directly related to pVO2 (r = 0.62; p = 0.0008) and inversely related to NE at peak exercise and to the increase in NE during exercise (r = 0.59, p = 0.005, and r = 0.53; p = 0.0058). Thus, during exercise, a marked sympathetic activation exists in patients with moderate HF. The relationship between increased plasma NE during exercise and decreased BS suggests that impaired baroreceptor function may be present in sympathetic activation in HF patients.
Heart Rate Behavior in Children with Atrial Septal Defect
Authors: Massin Martial M. , Derkenne Bénédicte , von Bernuth Götz
Published: April 2003

The aim of this study was to assess heart rate variability, a noninvasive parameter for studying the neurohumoral control of heart rate, in children with atrial septal defect. We examined five time-domain and three frequency-domain indices of heart rate variability determined from 24-hour Holter recordings in 20 children, aged 3–14 years, with secundum atrial septal defect who were about to undergo operation. The measures were compared to normal ranges and to the hemodynamic data of the preoperative cardiac catheterization. Most indices of heart rate variability were moderately depressed in children with atrial septal defect. Our data revealed negative correlations between indices and the mean right atrial pressure and the enddiastolic right ventricular pressure, respectively. The study demonstrates the importance of the right ventricular filling pressures for the autonomic control of the heart in children with atrial septal defect.
Aspirin Sensitivity: The Role for Aspirin Challenge and Desensitization in Postmyocardial Infarction Patients
Authors: Schaefer Oren P. , Gore Joel M.
Published: April 2003

Aspirin is one of the world’s most commonly used medications and its use benefits many diverse conditions. Adverse reactions, however, are relatively common as well. Hypersensitivity to aspirin can be manifested as acute asthma, urticaria and/or angioedema, or a systemic anaphylactoid reaction. We report 3 cases in whom aspirin was indicated for secondary prophylaxis of myocardial infarction but in whom a remote history of an untoward reaction to it prevented its initial use. These patients all underwent further evaluation of their pulmonary and allergic history and all 3 were challenged with aspirin. Two patients were found not to be sensitive and started on aspirin, the other had a classic asthmatic reaction to the drug and was successfully desensitized to aspirin allowing for its use.
Recurrence Risk of Supraventricular Tachycardia in Pediatric Patients
Authors: Riggs Thomas W. , Byrd Julie A. , Weinhouse Elliott
Published: April 2003

We analyzed risk of recurrence of supraventricular tachycardia (SVT) in 70 pediatric patients using both Kaplan-Meier survival analysis and logistic regression of likelihood of recurrence, each with covariates: (1) age at onset of SVT; (2) presence of Wolff-Parkinson-White syndrome (WPW), and (3) gender. Among 38 patients who had onset of SVT <1 year, only 11 had a recurrence, while among 32 older patients, 30 had a recurrence of SVT (p < 0.00001, Fisher’s exact test). The survival analyses, stratified by age at onset <1 versus >1 year, were significantly different (p < 0.0001) as was stratification by presence of WPW (p < 0.01). Logistic regression analysis showed that the only significant predictor of recurrence was age at onset; the additional information provided by presence of WPW and gender did not significantly add to the prediction of recurrence. The odds ratio of recurrence for age at onset >1 versus <1 year was 34.6, with a 95% confidence interval of 6.98–172.
Fibrinolytic Therapy and n-Acetylocysteine in the Treatment of Patients with Acute Myocardial Infarction: Its Influence on Authentic Plasma Hydroperoxide Levels and Polymorphonuclear Neutrophil Oxygen Metabolism
Authors: Sajkowska A. , Wykretowicz A. , Szczepanik A. , Kempa M. , Minczykowski A. , Wysocki H.
Published: April 2003

Recently it has been demonstrated that the administration of n-acetylocysteine (NAC), in combination with streptokinase, significantly diminished oxidative stress in patients with myocardial infarction. The aim of our study was to assess the influence of NAC treatment, as adjunct therapy in an evolving myocardial infarction, on the polymorphonuclear count, superoxide anion and hydrogen peroxide levels and nitric oxide production by PMNs and authentic plasma hydroperoxide (ROOH). Treatment of patients with NAC in addition to reperfusion therapy was accompanied by a significant decrease in the number of circulating polymorphonuclear neutrophils. However, the oxygen metabolism of PMNs was not affected by NAC administration. The concentration of authentic plasma hydroperoxide was significantly reduced by the administration of NAC which suggests diminished oxidative stress during acute myocardial infarction.
Gender Differences in Postinfarction Left Ventricular Remodeling
Authors: Litwin Sheldon E. , Katz Sarah E. , Litwin Christine M. , Morgan James P. , Douglas Pamela S.
Published: April 2003

Objective: Previous studies suggest that gender affects the adaptive responses of the heart to some forms of cardiac overload. It is unknown whether gender influences left ventricular (LV) remodeling after myocardial infarction (MI). Methods: We performed transthoracic echocardiographic-Doppler examinations in age-matched male (n = 17) and female (n = 16) rats before, and 1 and 6 weeks after transmural MI or sham surgery. Results: Following large MI (male = 45 ± 1% LV circumference vs. female = 48 ± 4%, p = NS), both male and female rats developed progressive LV dilatation. Infarctions caused a similar degree of global and regional LV systolic dysfunction in males and females. Male rats had significant increases in the thickness of the noninfarcted posterior wall by 6 weeks after MI. However, posterior wall thickness did not change in the infarcted female rats. Average myocyte diameter in the noninfarcted region of the heart was also greater in male than female MI rats. The combination of increased cavity size with little change in wall thickness resulted in a greater decline in relative wall thickness in the female rats compared to the males. Male rats with MI showed progressively restricted LV diastolic filling as assessed by transmitral Doppler recordings. Female rats had less of an increase in the ratio of early to late transmitral velocities and less of an increase in the E wave deceleration rate after MI. Conclusions: Female rats showed a different pattern of LV remodeling than males with less of an increase in thickness of the noninfarcted portions of the left ventricle than males, but comparable LV cavity enlargement and systolic dysfunction. Despite similar infarct size, females developed less pronounced abnormalities of LV diastolic filling. We hypothesize that the gender-related differences in postinfarction LV remodeling may contribute to the different LV filling patterns, and might ultimately relate to differences in clinical outcome.
Doppler Velocity and Flow through the Aortic Isthmus in Normal Term Neonates
Authors: Ithuralde Alejandro , Riggs Thomas , Hussey Mary E. , Weinhouse Elliott
Published: April 2003

Our hypothesis was that the relationship between the internal aortic diameter and the Doppler flow velocity across the aortic isthmus could be modeled by applying the principle of conservation of mass flow. The aortic diameter decreased at the isthmus by a mean of 18% (t = 11.02, p < 0.0001), while the flow velocity increased by a mean of 44% (t = 10.09, p < 0.0001). The mean peak mass flow rate was 34.5 ml/s preisthmus and 32.9 ml/s at the isthmus with excellent correlation (r = 0.830). We conclude that the increase in Doppler velocity observed in the descending aorta can be explained by the normal narrowing observed at the aortic isthmus and application of the continuity equation for conservation of mass flow.