bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison between Composition and Density of the Fat-Free Mass of Young Adult Singaporean Chinese and Dutch Caucasians
Authors: Werkman Andrea , Deurenberg-Yap Mabel , Schmidt Gordon , Deurenberg Paul
Published: April 2003

Background: The body composition was measured in 30 female Singapore Chinese and 34 female Dutch Caucasians aged (mean ± SD) 22.7 ± 3.6 years and in 39 male Singapore Chinese and 39 male Dutch Caucasians aged 23.3 ± 3.2 years. Methods: The body fat percentage (BF%) was measured using densitometry and deuterium oxide dilution as well as a chemical four-compartment model, including fat mass, water, mineral, and protein. The chemical composition of the fat-free mass (FFM) and its density were calculated. Results: Mean body mass index (kg/m2) and BF% based on the four-compartment model in the four subgroups were 20.3 ± 1.5 and 29.7 ± 5.3 for the Singapore Chinese females, 22.1 ± 1.2 and 28.9 ± 5.2 for the Dutch females, 21.5 ± 2.5 and 19.4 ± 6.1 for the Singapore males, and 22.2 ± 1.8 and 15.8 ± 4.9 for the Dutch males. The contributions to the FFM of water, protein, and mineral were, respectively, 72.8 ± 1.5, 19.2 ± 1.8, and 7.9 ± 0.8% for the Singaporean females and 74.2 ± 1.4, 18.3 ± 1.5, and 7.6 ± 0.5% for the Dutch females. In males these figures were 73.2 ± 1.7, 19.6 ± 1.7, and 7.3 ± 0.5% for the Singaporeans and 72.9 ± 1.4, 20.5 ± 1.4, and 6.6 ± 0.5% for the Dutch. In females, these figures were for all components significantly different between the ethnic groups; in males the differences were significant for protein and mineral only. The calculated densities (kg/l) of the FFM were 1.1074 ± 0.0057, 1.1012 ± 0.0051, 1.1027 ± 0.0065, and 1.1004 ± 0.0055 for the Chinese females, Caucasian females, Chinese males, and Caucasian males, respectively. Conclusions: Although it cannot be excluded that the differences in density and composition of the FFM are due to methodological differences between the study sites, the findings may have consequences for the validity of single (reference) methods due to violation of normally used assumptions. The findings explain the observed underestimation of BF% from density using Siri’s formula in the Chinese subjects, especially in females. The use of deuterium oxide as a single method to determine the BF% resulted in a smaller bias than densitometry (overall 1.6 ± 2.0% for densitometry, 0.3 ± 1.7% for deuterium dilution), suggesting that the deuterium oxide method may be more suitable as a single method in comparative body composition studies.
Metabolic Transit and in vivo Effects of Melanoidins and Precursor Compounds Deriving from the Maillard Reaction
Authors: Faist Veronika , Erbersdobler Helmut F.
Published: April 2003

Metabolic transit data on food-borne advanced MRPs (Maillard reaction products) termed melanoidins are yet not completely elucidated and it is still an open question whether isolated melanoidin structures undergo metabolic biotransformation and subsequently cause physiological effects in vivo. Advanced MRPs, acting as premelanoidins, and melanoidins are formed under severe heat treatment of foods and are ingested with the habitual diet at considerable amounts. Metabolic transit data are known for Amadori compounds classified as early MRPs, like, e.g., fructose-lysine. For rats and humans, the percentages of ingested free versus protein-bound fructose-lysine excreted in the urine were found within ranges of 60–80% and 3–10%, respectively. Balance studies on free advanced MRPs are still lacking, but protein-bound low-molecular-weight premelanoidins and high-molecular-weight melanoidins have already been investigated in animal experiments using 14C-tracer isotopes. The amount of ingested radioactivity absorbed and excreted in the urine was found at levels ranging from 16 to 30% and from 1 to 5% for premelanoidins and melanoidins, respectively. These different metabolic transit data of premelanoidins and melanoidins can be explained by the following mechanisms involved: (i) intestinal degradation by digestive and microbial enzymes; (ii) absorption of these compounds or their degradates, and (iii) tissue retention. Structure specific in vivo effects have been identified for protein-bound premelanoidins on intestinal microbial activity, xenobiotic biotransformation enzymes and further glycation reactions. The latter are hypothesized to be involved in the aging process and in the course of different diseases. Further investigations are needed to clarify synergistic in vivo effects of dietary ingested melanoidins and endogenously formed glycation products.
Decreased Mitochondrial Oxygen Consumption and Antioxidant Enzyme Activities in Skeletal Muscle of Dystrophic Mice after Low-Intensity Exercise
Authors: Faist V. , König J. , Höger H. , Elmadfa I.
Published: April 2003

To evaluate low-intensity exercise training induced changes of mitochondrial metabolism in dystrophic skeletal muscle, oxygen consumption, reactive oxygen species (ROS) scavengers and antioxidant enzymes were measured in control (C57BL/10) and dystrophic (mdx) mice at 10 (young) and 22 (adult) weeks of age. Dystrophic and control mice were either kept sedentary or daily exercised on a treadmill (480 m/day, exercise training was initiated at 4 and 16 weeks of age for 6 weeks’ duration). Mitochondrial oxygen consumption was significantly lower in skeletal muscle from exercised young compared to sedentary young dystrophics. Whereas oxygen consumption was unchanged in exercised adult dystrophics, exercised adult controls exhibit a significant increase vs. sedentary adult controls. Contents of TBARS and lipofuscin were increased (+48%, +24%), while α-tocopherol concentration tended to decrease (p > 0.05) in exercised vs. sedentary young dystrophics. Compared to sedentary groups, glutathione peroxidase activity was decreased in exercised young dystrophic muscle (–12%), but increased in exercised controls (young controls +60%, adult controls +47%). In conclusion, adaptation to exercise-induced formation of ROS was limited in young dystrophic skeletal muscle but regained in that of adults.
Changes in the Concentration of Carotenoids, Vitamin A, Alpha-Tocopherol and Total Lipids in Human Milk throughout Early Lactation
Authors: Macias Consuelo , Schweigert Florian J.
Published: April 2003

Background: In mammals the composition of milk changes during early lactation showing a rapid decline in fat-soluble vitamins and a continuous increase in total lipids. Changes in the concentrations of carotenoids, vitamin A, α-tocopherol and total lipids in human milk (colostrum, transitory and mature milk) were studied to understand this not well characterised phenomenon. Methods: Colostrum, transitory and mature milk was collected from 21 women and analysed for carotenoids, vitamin A and α-tocopherol by HPLC. Results: Total lipids increased from the lowest levels in colostrum (1.5 ± 1.6 mg/ml) to the highest in transitory milk (3.6 ± 2.5 mg/ml, p < 0.01). Contrary to this, levels of total carotenoids (236.7 ± 121.9 ng/ml), vitamin A (1.02 ± 0.56 µg/ml) and α-tocopherol (11.8 ± 6.3 µg/ml) were highest in colostrum and declined significantly during the first weeks of lactation (63.2 ± 23.3 ng/ml, 0.33 ± 0.14 µg/ml, 2.7 ± 1.1 µg/ml, respectively; p < 0.001). Conclusions: The magnitude of decrease was not the same for all carotenoids and was dependent on the polarity of the carotenoid with the smallest decrease in the polar carotenoids. This might be due to differences in the distribution of carotenoids among plasma lipoproteins and might point to possible selective mechanisms being involved in the transfer of these components in early human milk.
Effects of γ-Irradiated Fats on Plasma Lipid Concentrations and Hepatic Cholesterol Metabolism in Rats
Authors: Kim Eunjung , Jeon Seon-Min , Choi Myung-Sook
Published: April 2003

Currently, there is a growing need for food irradiation that is effective in food preservation and quality improvement. Accordingly, this study was designed to observe the effects of γ-irradiated dietary fat on plasma lipid concentrations and hepatic cholesterol metabolism in rats. Male rats were fed 5-kGy-γ-irradiated beef tallow (γBT), corn oil (γCO), perilla oil (γPO), and nonirradiated fats (BT, CO, and PO) for 6 weeks. The γ-irradiated fat feeding did not affect the plasma lipid concentrations. However, the hepatic cholesterol content was significantly higher in the rats fed γ-CO as compared with the rats fed nonirradiated CO (40.0 vs. 28.2 mg/g liver). The hepatic HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase activities were not significantly different between the controls and the γ-irradiated fat fed groups. However, the hepatic ACAT (acyl-CoA:cholesterol acyltransferase) activity was significantly lower in the γPO group as compared with its control group (138.2 vs. 404.5 pmol min–1 mg–1). Among the nonirradiated groups, the ACAT activities of the CO and PO groups were higher than that of the BT group. The amounts of coprostanone, cholesterol, and total fecal neutral sterol were significantly higher in the γPO group as compared with the other groups. These results indicate that although slight changes in the lipid metabolism were observed as a result of 5-kGy-γ-irradiated fat feeding, they were relative to the fat type and had no harmful consequences.
A Study of Intensified Dietary Support in Underweight Candidates for Lung Transplantation
Authors: Førli Liv , Bjørtuft Øystein , Vatn Morten , Kofstad Johan , Boe Jacob
Published: April 2003

Background: No data is available on dietary intervention in candidates for lung transplantation and on the effect of different strategies for dietary support in this cohort. Aim: We therefore wanted to evaluate the effects of intensified nutritional support compared with simple support on energy intake and nutritional status. Method: Our participants were underweight (n = 42) and normal-weight (control group, n = 29) candidates for lung transplantation. The underweight patients were randomized into two groups. Group A received intensified dietary counselling, ready-made liquid nutritional supplements free of charge and regular follow-ups, while group B received only one session of individual dietary counselling, no supplements and no follow-ups. Results: The mean intervention time was 21 weeks. Groups A and B both increased their energy intake and gained weight. Group A increased their energy intake from a median of 8.7 to 10.1 MJ (p < 0.01 compared with the control group after intervention) and gained a mean of 2.9 kg body weight (95% CI 1.2; 4.7, p = 0.005 compared with the control group), while group B increased from 7.4 to 10.8 MJ (p = 0.005) and gained 2.3 kg (1.2; 3.3, p = 0.002). Only group B increased their fat-free mass. In this group, an increase in O2 saturation and a decrease in PaCO2 were suggested. None of the groups improved its physical performance. Conclusion: In candidates for lung transplantation we were unable to confirm the hypothesis that intensified nutritional support compared with a simple support increased compliance. Both groups achieved the goal for energy intake and gained weight.
Evaluation of Various Rapid Chloride Tests for Assessing Urinary NaCl Excretion
Authors: Brüngel Markus , Kluthe Reinhold , Fürst Peter
Published: April 2003

Background/Aims: The evidence linking NaCl intake to high blood pressure and probably to other diseases has become stronger. Therefore, a population-wide reduction of NaCl intake is generally recommended. Measuring NaCl excretion in urine is the preferred method for estimating dietary NaCl intake. Rapid tests measuring urinary NaCl excretion might be useful for self-monitoring the individual NaCl consumption. Methods: The accuracy of four rapid tests measuring chloride content in urine was assessed. Three tests were originally not designed for urine analysis, but for water and food analysis. Totally 204 urine samples were analysed both with the 4 different rapid tests and with quantitative routine laboratory procedures for chloride and sodium. Results: Chloride and sodium were highly correlated (r = 0.96), indicating chloride determination as a reasonable method to assess sodium and NaCl contents in urine. Accuracy of the rapid tests was acceptable in three cases. The drawback of two tests was their narrow calibration range, so that most urine samples had to be diluted. Use of one test showed problems in interpreting its results because the decolouration of the test pads was difficult to recognize. Conclusion: It is concluded that rapid chloride tests designed for water analysis might be suitable to determine NaCl in urine samples.
Fat-Soluble Vitamin Status Is Not Affected by Diacylglycerol Consumption
Authors: Watanabe Hiroyuki , Onizawa Kouji , Naito Sachio , Taguchi Hiroyuki , Goto Naohiro , Nagao Tomonori , Matsuo Noboru , Tokimitsu Ichiro , Yasukawa Takuji , Tsushima Rikio , Shimasaki Hiroyuki , Itakura Hiroshige
Published: April 2003

Objective: The objective of this study was to examine the effect of dietary diacylglycerol (DAG) on the bioavailability of fat-soluble vitamins in comparison with triacylglycerol (TAG). Methods: We conducted a long-term administration test of DAG and TAG in 27 healthy men aged 27–47 years. After measuring baseline values, subjects were randomized into two groups, one group (n = 15) was given DAG and the other (n = 12) was given TAG. Subjects ingested 20 g of DAG or TAG either in mayonnaise or an emulsion drink of their own choice at meals once a day for 12 weeks. At 4, 8 and 12 weeks, fasting blood samples were drawn and serum levels of vitamin A, E, and D were measured. Results: There were no significant changes in vitamin A levels throughout the study period. Compared to the initial values (using a Student’s t test for paired values), significant differences of vitamin E and D were seen at some points during the experiment. According to a two-way repeated measures analysis of variance, however, DAG and TAG (lipid) and time had no effect on fat-soluble vitamin levels. Conclusions: Our results indicate that DAG does not affect the absorption of the fat-soluble vitamins in diets.
Fat-Soluble Vitamins in the Maternal Diet, Influence of Cod Liver Oil Supplementation and Impact of the Maternal Diet on Human Milk Composition
Authors: Olafsdottir Anna S. , Wagner Karl-Heinz , Thorsdottir Inga , Elmadfa Ibrahim
Published: April 2003

Background/Aims: To investigate lactating mothers’ intake of fat-soluble vitamins in free-living subjects and to what extent cod liver oil supplementation influences the maternal intake in a population with common intake of cod liver oil. The impact of maternal diet on the concentration of fat-soluble vitamins in human milk was studied. Methods: Dietary intake of 77 lactating women was investigated by 24-hour diet recalls and breast-milk samples were taken at the same occasions. Breast milk samples were analyzed for fat-soluble vitamins. Results: The median intakes were 927 µg/day for vitamin A, 5.5 mg/day for vitamin E and 3.3 µg/day for vitamin D. Maternal vitamin A, E and D intakes were higher when the diet was supplemented with cod liver oil. Icelandic breast milk was found to have high contents of vitamin A and E. Only vitamin D was too low in breast milk to meet the recommended intake for infants. Retinylpalmitate in relation to lipids correlated with maternal vitamin A intake (r = 0.23, p < 0.05). The group with cod liver oil supplementation had significantly lower levels of γ-tocopherol in breast milk (p < 0.01), whereas the supplementation did not affect other fat-soluble vitamins. Conclusion: The recommended intake of fat-soluble vitamins for lactating women can more easily be met with a cod liver oil supplementation than diet alone. Only vitamin D in human milk cannot meet the recommended intakes for infants, with normal breastfeeding. There is a relationship between the content of vitamins A and E in human milk and the maternal diet.
The Pathway Enabling External Sounds to Reach and Excite the Fetal Inner Ear
Authors: Sohmer Haim , Perez Ronen , Sichel Jean-Yves , Priner Ronit , Freeman Sharon
Published: April 2003

The human fetus in utero is able to respond to sounds in the amniotic fluid enveloping the fetus after about 20 weeks gestation. The pathway by which sound reaches and activates the fetal inner ear is not entirely known. It has been suggested that in this total fluid environment, the tympanic membrane and the round window membrane become ‘transparent’ to the sound field, enabling the sounds to reach the inner ear directly through the tympanic membrane and the round window membrane. It is also possible that sounds reach the inner ear by means of tympanic membrane – ossicular chain – stapes footplate conduction (as in normal air conduction). There is also evidence that sounds reach the fetal inner ear by bone conduction. Several animal and human models of the fetus in utero were studied here in order to investigate the pathway enabling sounds to reach and activate the fetal inner ear. This included studying the auditory responses to sound stimuli of animals and humans under water. It was clearly shown in all the models that the dominant mechanism was bone conduction, with little if any contribution from the external and middle ears. Based on earlier experiments on the mechanism and pathway of bone conduction, the results of this study lead to the suggestion that the skull bone vibrations induced by the sound field in the amniotic fluid enveloping the fetus probably give rise to a sound field within the fetal cranial cavity (brain and CSF) which reaches the fetal inner ear through fluid communication channels connecting the cranial cavity and the inner ear.
Effect of Preeclampsia in the Mother on the Leucine Metabolism in the Newborn Infant
Authors: Saenz de Pipaón Marcos M. , Wattimena D.J.L. , van Beek R.H.T. , Lotgering F.K. , Sauer P.J.J.
Published: April 2003

The leucine turnover in newborn infants is influenced by factors such as nutritional state and corticosteroid treatment. Little is known about maternal factors influencing the leucine turnover in the newborn. In order to approach the effect of preeclampsia in the mother on neonatal protein turnover, we studied the leucine turnover in preterm infants soon after birth and again after 7 days. Ten infants from preeclamptic mothers (birth weight 1,280 ± 240 g, gestational age 31 ± 2 weeks) and 15 control patients (birth weight 1,320 ± 210 g, gestational age 30 ± 2 weeks) were enrolled. The leucine turnover was measured using a primed constant 5-hour intravenous infusion of [1-13C]leucine within the first 24 h after delivery and again on day 7 of life. The turnover (leucine flux; µmol·kg–1·h–1) was calculated from the enrichment in α-ketoisocaproic acid in plasma. The leucine turnover on day 1 was 300 ± 65 in the preeclampsia group and 358 ± 70 in the controls (ANOVA, p < 0.05). The values on day 7 were 474 ± 73 in the preeclampsia group and 485 ± 80 in the control group (n.s.). To conclude, the leucine turnover on day 1 is lower in infants of preeclamptic mothers as compared with controls. This difference has disappeared on day 7 of life after receiving the same protein and energy intake.
The Role of Temporal Cues in Rhesus Monkey Vocal Recognition: Orienting Asymmetries to Reversed Calls
Authors: Ghazanfar Asif A. , Smith-Rohrberg Duncan , Hauser Marc D.
Published: April 2003

An understanding of the acoustic cues that animals use to categorize their vocalizations has important implications for the way we design neuroethological investigations of auditory function. Compared to other species, we know relatively little about the kinds of acoustic features used by nonhuman primates to recognize and categorize vocalizations. To further our understanding, this study explores the role of temporal features in recognition of conspecific vocalizations by rhesus macaques (Macaca mulatta). Experiments were designed to extend an earlier set of findings showing that adult rhesus macaques selectively turn with the right ear leading when a conspecific vocalization is played 180° behind them, but turn left or not at all when a non-conspecific signal is played. Two call types were used as stimuli: shrill barks (alarm call) and harmonic arches (food call). We found that for normal calls, rhesus macaques turned to the right – supporting earlier findings – but for time- reversed shrill barks and harmonic arches, subjects oriented to the left. These results suggest that for at least a subset of calls, rhesus macaques use temporal cues to recognize conspecific vocal signals. The asymmetry of the behavioral response, and the corresponding asymmetry in the time-amplitude waveform, may have important implications for studies of temporal coding in the primate auditory system.
Potential Cardioprotective Effect of Mibefradil in the Long-Term Treatment of Hypertension
Authors: Waeber Bernard
Published: April 2003

During the last 2 decades, remarkable progress has been made in the treatment of hypertension with the discovery of new drugs lowering blood pressure by various mechanisms, e.g. calcium channel blockers, angiotensin-converting enzyme inhibitors and angiotensin II antagonists. These antihypertensive agents are now widely used as first-line therapy although there is still no definite proof that they have a cardioprotective effect and reduce the mortality rate in patients with coronary heart disease. Mibefradil is a new calcium antagonist with a novel mechanism of action since it is the only drug available so far able to block T channels. This compound might be particularly effective in preventing cardiac morbidity and mortality. It reduces heart rate when lowering blood pressure, has no negative inotropic effect, allows regression of cardiac hypertrophy and is effective in the treatment of angina. Mibefradil produces a sustained blood pressure reduction with a close to optimal trough:peak ratio. A major advantage of this novel compound is its excellent tolerability over the dose range recommended (50–100 mg/day). In particular, leg edema is seen clearly less often during mibefradil treatment than during therapy with dihydropyridines. Mibefradil has therefore an attractive profile in terms of both efficacy and safety and represents a promising first-line option to treat hypertensive patients.
Progression from Hypertension to Heart Failure
Authors: Cleland John G.F.
Published: April 2003

Patients with hypertension are at increased risk of developing heart failure (HF), but the mechanisms by which hypertension leads to HF have not been clarified [although left ventricular hypertrophy (LVH) is clearly a predictor of an increased risk of HF]. Similarly, although antihypertensive therapy has been shown to reduce the risk of HF in hypertensive patients, it is not known how this benefit is produced and, currently, there is no clear evidence that any class of antihypertensive agent is more effective than any other in this respect. On theoretical grounds, beta-blockers would be expected to be ideal agents for the prevention of HF in hypertensive patients. In addition to control of blood pressure and regression of LVH, they have clear benefits on morbidity and mortality after myocardial infarction (MI), which probably plays a major role in the development of HF in hypertensive patients, and on the prognosis of HF itself. A reduction in long-term mortality after MI has been demonstrated only for non-selective beta-blockers. Carvedilol, a non-selective beta-blocker which also has other ancillary properties including alpha-1-receptor blockade and antioxidant effects and a favourable metabolic profile, may be an appropriate choice for the prevention of HF in hypertensive patients. This is reinforced by the salutary benefits of carvedilol for the reduction in the morbidity and mortality of HF itself.
Chronic Use of Continuous Dosing of Long-Term Nitrates Does Not Prevent Cardiac Events in Patients with Severe Acute Myocardial Infarction
Authors: Kanamasa Ken , Hayashi Takahiro , Takenaka Toshihiko , Kimura Akio , Ikeda Akiko , Ishikawa Kinji
Published: April 2003

This study was performed to investigate the effects of the chronic use of continuous, not eccentric, dosing of nitrates on cardiac events in patients with severe acute myocardial infarction. A total of 1,303 patients with healed myocardial infarction were divided into two groups: treatment with nitrates or nontreatment. Primary end points were nonfatal and fatal recurrent myocardial infarction, death from congestive heart failure and sudden death. Among the 725 patients treated with nitrates, 45 patients (6.2%) experienced cardiac events during the observation period, whereas only 17 of the 578 patients treated without nitrates (2.9%) had cardiac events. This difference was statistically significant (p < 0.01; odds ratio 2.18, 95% confidence interval 1.24–3.86). In Killip class II–IV patients, the incidence of cardiac events in patients with nitrates was significantly greater than in patients without nitrates (18.8 vs. 3.5%, p < 0.05). The chronic use of continuous, not eccentric, dosing of nitrates did not prevent cardiac events in patients with severe acute myocardial infarction.
Reduced Heart Rate Variability in Ischemic Heart Disease Is Only Partially Caused by Ischemia
Authors: Wennerblom Bertil , Lurje Leon , Solem Jens , Tygesen Hans , Udén Marita , Vahisalo Rein , Hjalmarson Åke
Published: April 2003

Background: Reduced heart rate variability (HRV) after acute myocardial infarction (AMI) indicates poor prognosis. HRV in patients with uncomplicated coronary artery disease is reduced, and an association with poor prognosis has been suggested. The mechanism of the HRV reduction is not known, but ischemia is a possibility. Aim: To evaluate, in angina patients with no prior AMI, no other disease and drug-free, if complete revascularization and thus important reduction of ischemia by means of PTCA influences HRV. Patients and Methods: Twenty-four-hour Holter recordings were performed at baseline prior to PTCA in 48 patients with angina and in 41 age-matched healthy control subjects. The recording was repeated 1 and 6 months after complete revascularization. In addition, HRV was registered during controlled respiration in the supine and standing positions and during cold pressure test at baseline in all angina patients and controls and in 17 consecutive angina patients 6 months after PTCA. Results: Compared to controls, angina patients had a significantly reduced mean RR interval (p = 0.02), SD (p = 0.003), rMSSD (p = 0.03), pNN50 (p = 0.03), total power (p = 0.003), low- (p = 0.004) and high-frequency peak (p = 0.04), but normal SDNN, SDANN and LF/HF. One and 6 months after PTCA, 42/46 and 32/40 follow-up patients, respectively, were free of angina. Six months after PTCA, there was a significant recovery of vagal modulation seen in the frequency domain during controlled respiration, but only nonsignificant trends in HRV parameters analyzed over 24 h. Conclusion: Patients with uncomplicated angina had reduced HRV, mainly affecting vagal activity, but normal low frequency variability associated with mortality. Complete revascularization caused a partial normalization of vagal modulation indicating that ischemia may be one of but not the only mechanism of the HRV reduction in uncomplicated chronic coronary artery disease.
New Technique for Simultaneous Catheter Mapping of Pulmonary Veins for Catheter Ablation in Focal Atrial Fibrillation
Authors: Kumagai Koichiro , Gondo Naoki , Matsumoto Naomichi , Noguchi Hiroo , Tojo Hideaki , Yasuda Tomoo , Nakashima Hideko , Saku Keijiro
Published: April 2003

Introduction: Most focal atrial fibrillation (AF) can be triggered by premature beats from pulmonary veins (PVs), and ablation of these foci could cure AF. However, it is difficult to locate the trigger points of PVs using only one mapping catheter. The purpose of the present study was to investigate the efficacy of using four mapping catheters in four PVs simultaneously in the ablation of focal AF. Methods and Results: Thirty-two patients with frequent attacks of paroxysmal AF triggered by PV foci were included. After a transseptal procedure, three 2-french microcatheters and one 7-french catheter for ablation were placed into each of the PVs, and mapping of the four PVs was performed simultaneously. Fifty-eight foci were identified; 51 triggers (88%) originated from the PV and 7 (12%) from atrial tissue. The trigger points of AF were found in a single focus in 14 patients, in 2 foci in 12 patients, and in 3–4 foci in 6 patients. During a mean follow-up period of 10 ± 4 months, ablation eliminated AF without drugs in 86, 50 and 33% of the patients with 1, 2 and 3–4 targeted PVs, respectively; 20 patients (63%) were successfully ablated. Age, history of AF, the dimension of the left atrium and the number of focal origins were significant predictors of success. Conclusion: The technique of simultaneous mapping of PVs using quadruple catheters is a feasible and effective method for mapping the trigger points and ablation of focal AF originating from PVs.
Impact of Acute Biventricular Pacing on Left Ventricular Performance and Volumes in Patients with Severe Heart Failure
Authors: Søgaard Peter , Kim Won Yong , Jensen Henrik Kjaerulf , Mortensen Peter , Pedersen Anders Kirstein , Kristensen Bent Østergaard , Egeblad Henrik
Published: April 2003

Objectives: We used tissue velocity imaging (TVI) and three-dimensional echocardiography to evaluate the effect of acute biventricular pacing on left ventricular (LV) performance and volumes in patients with severe heart failure and bundle branch block. Background: Biventricular pacing causes acute hemodynamic improvement in patients with severe heart failure, and QRS duration has been used as a predictor of improved resynchronization. Tissue velocity has the potential of demonstrating the degree of LV resynchronization and three-dimensional echocardiography enables accurate quantitation of LV volumes and function. Methods: TVI and three-dimensional echocardiography were performed during sinus rhythm and biventricular pacing in 25 consecutive patients with severe heart failure. Results: Biventricular pacing significantly improved the extent of contracting myocardium in synchrony by 15.4% and the duration of contraction synchrony by 17% (p < 0.05 for both). Furthermore, end-diastolic and end-systolic volumes decreased by 7 ± 4.5% and 13 ± 6% (p < 0.01) and ejection fraction increased by 22.8 ± 9% (p < 0.01). Baseline duration of QRS and the preejection period as well as the extent of myocardium with asynchronous contraction measured by TVI predicted pacing efficacy. In multivariate analysis, only the extent of myocardium with asynchronous contraction at the LV base predicted biventricular pacing efficacy. Conclusion: Biventricular pacing improves LV systolic performance and reduces LV volumes during short-term treatment. TVI provides important pathophysiological information on the degree of LV resynchronization and may contribute to improved patient selection.
Serum Leptin Levels Increase following Acute Myocardial Infarction
Authors: Meisel Simcha R. , Ellis Martin , Pariente Clara , Pauzner Hanna , Liebowitz Morton , David Daniel , Shimon Ilan
Published: April 2003

Leptin is secreted into the circulation and communicates the peripheral nutritional status to specific hypothalamic centers. Recent studies suggest that leptin may be involved in the acute response to stress, and that its interaction with the hypothalamo-pituitary-adrenal axis and the inflammatory cytokine system may be of clinical importance. Since these systems are activated during acute myocardial infarction (AMI), we studied leptin and cortisol levels during hospitalization in 30 consecutive patients admitted for AMI. The results show that leptin reached its peak on the second day of hospitalization, with a 2-fold increase from its baseline level on admission (p < 0.02). On day 3, leptin levels declined, and were 46%, 9%, and 6% above baseline on days 3, 4 and 5, respectively. The mean cortisol level was elevated on day 1 and decreased toward normal levels thereafter (p < 0.001). The cortisol level did not correlate with leptin concentration throughout the study. These findings suggest that leptin may have a role in the metabolic changes taking place during the first days after an AMI.
Conventional, Digital and Contrast–Enhanced Bitewing Radiographs in the Decision to Restore Approximal Carious Lesions
Authors: Haak Rainer , Wicht Michael J. , Noack Michael J.
Published: April 2003

The purpose of the present investigation was to compare the accuracy of treatment decisions in proximal sites using three intra–oral radiographic systems. Additionally, the impact of an automated non–linear grey–level display was evaluated. Ten observers assessed 84 surfaces on bitewing radiographs for their requirement of restorative treatment using a 6–rank confidence scale. Radiographs were taken with conventional film images (Ultraspeed), a storage phosphor plate (Digora) and a CCD system (Dexis). Additionally, the Dexis software was expanded by a contrast enhancement routine (Dexis+). The restorative treatment threshold was defined as presence of macroscopic cavitation. Regarding the areas below mean ROC curves no significant differences were detected between the groups (p>0.05). Likelihood ratios for positive test results were: 5.29 (Ultraspeed), 8.14 (Digora), 9.67 (Dexis) and 11.37 (Dexis+). The accuracy of restorative treatment decisions based on digital and conventional radiographs is comparable. If a dichotomous treatment decision was requested, the digital systems demonstrated a notable tendency towards higher likelihood of true–positive decisions.
An Intraoral Study of Caries Induced on Enamel in Contact with Fluoride– Releasing Restorative Materials
Authors: Kotsanos N.
Published: April 2003

The aim was to study the effect of three fluoride–releasing restorative materials on sound enamel of approximal teeth under cariogenic conditions intraorally. Bovine enamel slabs were paired with four hemispherical samples from each of three test materials (Ketac Molar, ESPE; Vitremer, F–2000, both from 3M) and one control material (Pertac II, ESPE). Their curved surface touched enamel at a contact point allowing space for plaque accumulation. Pairs were inserted in the buccal flanges of 2 lower dentures for 70 days. Initially and upon dismantling, enamel surface microhardness was measured and the increase in length of indentation in micrometers was recorded at a distance of 0, 0.4, 0.8 and 1.2 mm from the contact point. Respective values were: Pertac II: 16.0±7.5, 27.6±15.4, 38.6±23.3, 47.8±25.2; F–2000: 11.89±9.6, 15.8±14.2, 21.0±15.0, 25.1±15.2; Ketac Molar: 6.6±6.8, 9.4±7.0, 9.5±8.0), 13.4±9.4; Vitremer: 2.7±4.1, 3.5±3.5, 3.6±4.5), 7.4±5.2. Caries protection was Vitremer 82% > Ketac Molar 69% >F–2000 42% in relation to Pertac II (p<0.001). Sections of the slabs examined with polarized light showed typical subsurface lesions only in the Pertac II group, areas of pseudoisotropy in the F–2000 and Ketac Molar groups and no signs of lesion in the Vitremer group.
Is Asthma a Risk Factor for Dental Caries? Findings from a Cohort Study
Authors: Meldrum A.M. , Thomson W.M. , Drummond B.K. , Sears M.R.
Published: April 2003

It has been suggested that asthmatic children may have a higher caries risk, both as a result of their medical condition and the physical and physiological effects of their pharmacotherapy. By examining the association over time between asthma and caries increment, this study tested the hypothesis that childhood asthma is associated with an increased caries increment. In a long–standing New Zealand cohort study, participants’ long–term asthma histories and the 3–year net caries increment between the ages of 15 and 18 years were examined. Of the 781 who were examined at 15 and 18 years, 39 participants were consistently taking anti–asthma medication at the ages of 9, 11, 13 and 15 years (and were labelled in this study as ‘medication–determined asthmatics’), 56 were identified as consistent wheezers at the ages of 9, 11, 13 and 15 years (‘wheeze–determined asthmatics’) and 36 were members of both groups. A smaller group (n = 9) was identified as being very–long–term asthmatics (asthma at 5 years of age and at the ages of 9, 11, 13 and 15 years). Some 206 study members were identified as having no history of asthma, asthma medication or significant wheeze at any time up to and including 18 years. The overall mean net caries increment between the ages of 15 and 18 years was 2.06 surfaces (SD, 3.76). There were no significant differences in caries increment between the 206 asthma–free participants and any of the asthma groups. This study provides little evidence for an asthma–caries causative relationship.
The Pharmacology of Thrombolytic and Fibrinogen-Depleting Agents in the Treatment of Acute Ischaemic Stroke1
Authors: Lowe Gordon
Published: April 2003

In ischaemic stroke, the common pathology of a fibrin-rich thrombus or embolus has led to the concept of acute treatment aimed at preserving the ischaemic penumbra. This is the brain tissue surrounding the area of developing infarction which is threatened but which is still viable, particularly if the clot is either removed, its progression reduced, or if the blood flow from collateral vessels in the surrounding area is increased. The aim of acute antithrombotic or rheological treatment is therefore to reduce the volume of infarction.
Antiplatelet Agents in Stroke Prevention
Authors: Weksler Babette B.
Published: April 2003

Platelets contribute to arterial thrombosis by multiple mechanisms that promote blood clotting, favor vasoconstriction, activate the procoagulant capacity of endothelium, and stimulate inflammation. These activities are augmented by turbulent blood flow. Classic antiplatelet therapy with aspirin to prevent occlusive stroke offers significant clinical benefit (20–25% risk reduction), yet is less effective than in prevention of coronary artery occlusion (up to 50% risk reduction of myocardial infarction in unstable angina). Since aspirin’s antiplatelet effects are limited to blocking a single metabolic pathway – namely inhibition of thromboxane A2 formation –, and aspirin fails to alter platelet adhesion, other antiplatelet agents that target ADP receptors, platelet surface glycoproteins (such as the GPIIb/IIIa complex), or platelet-dependent thrombin generation offer additional clinical benefits by blocking additional separate pathways or the final common pathway of platelet activation. Combinations of antiplatelet agents, such as aspirin/dipyridamole, aspirin/clopidogrel, or aspirin/GPIIb/IIIa inhibitors, have recently been tested for improved efficacy in clinical trials. Soluble recombinant CD39, an ecto-ADPase, protects against stroke in animal models by metabolizing released ADP/ATP to antiplatelet derivatives. In general, combinations of antiplatelet agents promise greater efficacy than single drugs in preventing stroke, since interactions among different antiplatelet mechanisms can be synergistic. However, such combinations may also increase the risk of bleeding, so that precise understanding of risk/benefit ratios that address the possibility of intracranial as well as gastrointestinal bleeding will require careful monitoring in large clinical trials of patients at risk of stroke, with particular attention to the elderly.
Effect of Nicardipine and Magnesiumon Cerebral Infar ction – Brain Surface Perfusion Technique
Authors: Mikami Chiaki , Suzuki Michiyasu , Tsuiki Ko , Ogawa Akira
Published: April 2003

The protective effect of pre- and postischemia treatment of the brain by surface perfusion with nicardipine (Nic) and/or magnesium (Mg) was evaluated in a rat focal cerebral ischemia model. Artificial cerebrospinal fluid was perfused into the subarachnoid space of rats, containing Nic or Nic/Mg prior to vessel occlusion and Nic/Mg after occlusion. Reductions in the total amount of glutamate in the microdialysis perfusate and the volume of infarction tissue stained with 2,3,5-triphenyltetrazolium chloride were significant in all treated groups, even in rats treated after ischemia. An additive effect of Mg was also observed. These results suggest that this method may have clinical applications in patients suffering from ischemic insult.
Economic Evaluation in Stroke Research
Authors: Evers Silvia M.A.A. , Goossens Mariëlle E.J.B. , Ament André J.H.A. , Maarse Johannes A.M.
Published: April 2003

Background and Purpose: Before developing new medical facilities or adapting existing facilities in the field of stroke, it is desirable to assess not only the medical, but also the economic consequences of such facilities. Economic evaluation studies differ from other outcome studies in the way that costs are compared with effects. The purpose of this paper is to give an insight into economic evaluation studies in the field of stroke, so that these studies become easier for neurologists to understand and to apply. Summary of the Article: Crucial aspects in economic evaluation research are addressed successively, such as the techniques used and how the results can be influenced by the perspective of the study. The article also considers the inclusion of costs and consequences in economic evaluation research. At the end of this article, special issues in economic evaluation studies are presented such as discounting, sensitivity analysis, incremental analyses and ratios. Conclusions: Although neurologists have no direct responsibility for allocating scarce resources in the field of stroke, they are confronted with the results of these decisions in their everyday work. Because of this, it might be useful to have clear understanding of economic evaluation studies and their caveats.
Twenty-Four-Hour Blood Pressure Changes in the Course of Lacunar Disease
Authors: Yamamoto Yasumasa , Akiguchi Ichiro , Oiwa Kaiyo , Hayashi Masamichi , Imai Keisuke
Published: April 2003

Background: Changes in blood pressure (BP) over time have not been considered in investigations on the relationship between BP and cerebrovascular disease (CVD). Objective: To investigate BP changes throughout a 24-hour period in lacunar infarct patients with different outcomes. Methods: Twelve control subjects (group 1) and 56 patients with symptomatic lacunar infarcts were studied. The infarct patients were divided into three groups: group 2, 25 patients with a fair outcome without any cerebrovascular attack or progressive dementia (mean follow-up period: 4.4 years); group 3, 14 patients with worsening of clinical dementia rating and silent lesions, which included lacunae and diffuse white matter lesions (4.5 years), and group 4, 17 patients who developed symptomatic infarcts (1.7 years). MRIs and ambulatory BP monitoring were performed for each patient on two separate occasions. No patient was treated with antihypertensive agents during the course of the study. Results: In group 2, the second measurements were significantly higher than the first for 24-hour systolic BP (SBP), daytime SBP, 24-hour diastolic BP (DBP), daytime DBP (p < 0.01, for all) and nighttime DBP (p < 0.05). In group 3, the second measurements were significantly lower than the first for 24-hour SBP, daytime SBP, 24-hour DBP, and daytime DBP (p < 0.01, for all). In group 4, the second measurements were significantly lower than the first for 24-hour SBP and daytime SBP (p < 0.01). The correlation between BP and pulse rate became positive for group 2 in second measurements, but was not positive for groups 3 and 4. Conclusions: BP tended to elevate over time in patients with a fair outcome. In contrast, BP tended to decrease in those who developed dementia and symptomatic infarct. Autonomic functions including sympathetic activity might play a role in changes in BP in lacunar infarct patients during the course of disease.
Treatment of Cerebellar Hematoma in The Netherlands
Authors: Wessels P.H. , ter Berg J.W.M. , Spincemaille G.H. , Dippel D.W.J.
Published: April 2003

A questionnaire was sent to Dutch neurosurgeons and neurologists in order to assess current management strategies for cerebellar hematoma. Seven patients were presented, using as determinants: size of hematoma, coma score, interval to clinical deterioration, hydrocephalus, comorbidity, anticoagulant treatment and age. Neurological management options were: no treatment, monitoring or referral for neurosurgery. Neurosurgical options were: no treatment, monitoring, hematoma evacuation, and/or external ventricular drainage. Ninety-seven of 161 (60%) neurologists, and 58 of 85 neurosurgeons (68%) responded. Only 20 respondents (13%) made use of a local guideline. Overall agreement was perfect in 1 case and moderate to high in the others, but chance-adjusted agreement (kappa) between pairs of neurologists and neurosurgeons who were matched for referral center was not statistically significant except in 1 case, a deeply comatose patient with a 4-cm hematoma. In an alert, slightly ataxic patient with a large (4.5-cm) hematoma, 84 neurologists (88%) decided not to refer the patient. The estimated time for transfer between centers was of no influence on this decision. We conclude that the management of cerebrellar hematoma can be improved upon by encouraging the use of local guidelines, and by promoting early referral to a center with neurosurgical facilities.
Treatment of Acute Cerebral Infarction with Arginine Esterase: A Controlled Study with Heparin
Authors: Kim Jong S. , Yoon Sung S. , Kwon Sun U. , Ha Jeong H. , Suh Eul J. , Chi Hyun S.
Published: April 2003

Background and Purpose: There is no treatment proven to be of definitive benefit for ischemic stroke. Arginine esterase, a natural product from a snake venom, has been shown to reduce the serum fibrinogen level in human beings and may be useful in the treatment of ischemic stroke. In the present study, we compared the therapeutic effect of arginine esterase with that of heparin. Subjects and Methods: We studied 50 consecutive patients with acute ischemic stroke who were admitted to the Asan Medical Center. We randomly administered either arginine esterase 0.005 unit/kg × 2 times/day or heparin (activated partial thromboplastin time 2–3 times of baseline value) intravenously for 7 days. Antiplatelets were administered afterwards in both groups. Blood fibrinogen, fibrinogen degradation product (FDP) and D-dimer levels were measured at 0, 6, 12, 18 h and 1, 2, 3, 7 and 30 days after the onset of stroke. NIH stroke scale was measured daily by 2 neurologists while Barthel index and Rankin scale were assessed at 7 days and 1 month after the onset of stroke by a research nurse. All these investigators were blinded to the therapeutic regimen each patient received. Results: There were no significant differences in the mean age, gender proportion, stroke subtypes and baseline neurological severity between the two groups. One patient in the arginine esterase group died in an acute stage due to massive herniation and 1 in the heparin group underwent surgery for herniation. One (arginine esterase group) died of massive gastrointestinal bleeding due to previously unrecognized stomach cancer. Otherwise, no significant clinical and laboratory side effects were observed in both groups. In the arginine-esterase treated group, D-dimer and FDP levels were significantly (p < 0.05) elevated, and fibrinogen level significantly (p < 0.05) decreased at 2–7 days after the onset of stroke compared to the heparin-treated group. However, there was no significant difference in the neurological improvement reflected by NIH stroke scale, Barthel index and Rankin scale. Conclusion: Arginine esterase seems to be safe and has significant fibrinolytic effects when administered in the patients with acute ischemic stroke. However, in this preliminary study, it was not superior to heparin in terms of the improvement of neurological deficits. Further studies with larger doses and a larger number of subjects are required.