Changes in serum lipoproteins in humans following the infusion of a fat emulsion containing medium- and long-chain triglycerides

Abstract. A fat emulsion containing equal parts of medium-chain triglycerides (MCT) and long-chain triglycerides (LCT) and emulsified with egg phospholipids (Lipofundin MCT 10%®) was compared with LCT emulsions (Intralipid 10%®, egg phospholipids; Lipofundin S 10%®, soya phospholipids) in six volunteers, using 4-h periods of infusion and doses of 0·15 g kg^-1 body h^-1. At the end of infusion very low density lipoprotein (VLDL) triglyceride concentrations were highest with Intralipid, marginally less with Lipofundin MCT and lowest with Lipofundin S. With Lipofundin MCT infusion the proportions of free mediumchain fatty acids in serum reached 30%. In VLDL the ratios triglycerides/apolipoprotein B and triglycerides/phospholipids rose most after Lipofundin MCT and least after Lipofundin S. With Lipofundin MCT and Intralipid, surface components in low density lipoproteins (LDL) are lessened in relation to the internal components; this does not occur with Lipofundin S. High density lipoprotein (HDL) subfractions are influenced in identical directions by all fat emulsions with exception of a single increase of phospholipids in (HDL₃) after Lipofundin MCT.     

Value of Heart Rate Variability to Predict Ventricular Arrhythmias in Recipients of Prophylactic Defibrillators with Idiopathic Dilated Cardiomyopathy

GRIMM, W., et al. : Value of Heart Rate Variability to Predict Ventricular Arrhythmias in Recipients of Prophylactic Defibrillators with Idiopathic Dilated Cardiomyopathy. This study investigated the relation between heart rate variability (HRV) measured as standard deviation of normal to normal RR intervals (SDNN) on baseline 24-hour ambulatory electrocardiogram (ECG) and subsequent appropriate implantable cardioverter defibrillator (ICD) interventions in 70 patients with idiopathic dilated cardiomyopathy (IDC) in whom ICDs were implanted prophylactically in the presence of a low left ventricular ejection fraction (LVEF). During   43 ± 26   months of follow-up, 26 of 70 (37%) study patients with IDC received one or more appropriate ICD interventions for sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) documented by electrograms stored in the ICD. Mean SDNN at ICD implant was   94 ± 33 ms   . No difference was found between patients with   (90 ± 25 ms)   versus without   (96 ± 37 ms)   appropriate ICD interventions for VT or VF during follow-up. Multivariate Cox regression analysis of baseline clinical characteristics including age, gender, LVEF, NYHA functional class, nonsustained VT on Holter, history of syncope, left bundle branch block, baseline medication and HRV revealed LVEF as the only significant predictor of arrhythmia. These findings do not support the use of HRV measured as SDNN on 24-hour ambulatory ECG to select patients with IDC for prophylactic ICD therapy. (PACE 2003; 26[Pt. II]:411–415)     

The Six-Minute Walk—An Adequate Exercise Test for Pacemaker Patients?

LANGENFELD, H., ET AL.: The Six-Minute Walk—An Adequate Exercise Test for Pacemaker Patients? In many pacemaker patients bicycle and treadmill ergometry are not practicable. As an alternative, we performed a 6-minute walk on a 20-m corridor in 97 pacemaker patients, who were asked to walk as far as possible determining their speed by themselves. Results were compared with those of bicycle ergometry in 42 of these patients and with treadmill exercise of a group of 92 other pacemaker patients. In the 6-minute walk, performance and maximal heart rate were slightly lower (49 ± 18 W; 96 ± 23 beats/min) than in bicycle (57 ± 16 W; 110 ± 26 beats/min) and treadmill ergometry (50 ± 37 W; 102 ± 35 beats/min). A good correlation was found between walking and bicycling (r = 0.74) and in subgroups of patients with different pacemaker indications. All patients preferred the walk to bicycle ergometry considering it to be more related to daily physical activity. In conclusion, a 6-minute walk is a simple and physiological exercise test for nearly all pacemaker patients with good correlation to other types of exercise. It seems to be preferable to other tests because of its better acceptance and practicability.     

Cognitive brain function in non-demented patients with low-grade and high-grade carotid artery stenosis

Abstract. Atherosclerotic stenosis of the carotid arteries decreases cerebral flow volume and perfusion, and may result in brain dysfunction. We studied the relationship between the degree of carotid artery stenosis and cognitive brain function in non-demented patients. Cognitive brain function was assessed in 76 patients with carotid artery stenosis (38 patients with low-grade stenosis of 50% or less, and 38 patients with high-grade stenosis of 75% or more) by recording of cognitive P300 auditory evoked potentials and trail-making test. Results were compared to 70 age-matched healthy subjects. The P300 peak latency was prolonged in patients with high-grade carotid artery stenosis as compared to patients with low-grade stenosis (403 vs. 371 ms, P < 0·01, vertex; 400 vs. 370 ms, P < 0·01, frontal; means). Analysis of variance revealed that the degree of carotid artery stenosis is an independent predictor of prolonged P300 peak latency ( P = 0·0001). P300 amplitude (12 vs. 15 μ V, vertex; 13 vs. 15 μ V, frontal, NS) and trailmaking test (60 vs. 54 s; NS) tended to be worse in the high-grade stenosis group. There was no difference in cognitive brain function between patients with low-grade stenosis and age-matched healthy subjects. Confirmed on sensitive cognitive P300 measurements, we conclude that (a) cognitive brain function is impaired in non-demented patients with high-grade carotid artery stenosis but unaffected in low-grade stenosis; and (b) cognitive brain dysfunction is directly related to the degree of carotid artery stenosis.     

Arrhythmia Risk Prediction in Idiopathic Dilated Cardiomyopathy Based on Heart Rate Variability and Baroreflex Sensitivity

This study examined the relation between heart rate variability (HRV) and baroreflex sensitivity (BRS) and subsequent major arrhythmic events (MAE), defined as sustained VT, VF or sudden death, in 263 patients with idiopathic dilated cardiomyopathy (IDC) in sinus rhythm. The predefined measure of HRV was the standard deviation of all normal-to-normal RR intervals (SDNN) on baseline 24-hour ambulatory ECG. BRS was determined by the phenylephrine method. Over 52 ± 21 months of follow-up, MAE occurred in 38 patients (14%). SDNN at baseline 24-hour ambulatory ECG (106 ± 46 vs 109 ± 45, ns) and BRS (7.9 ± 5.5 vs 7.7 ± 5.3 ms/mmHg, ns) were both similar in patients with versus without MAE during follow-up. In contrast, left ventricular ejection fraction was significantly lower in patients with versus without MAE (24%± 7% vs 31%± 10%, P < 0.019. Conclusions: Neither HRV nor BRS predicted MAE in patients with IDC.     

Follow-up of Gambian children recruited to a pilot safety and immunogenicity study of the malaria vaccine SPf66

A pilot safety and immunogenicity trial of the malaria vaccine SPf66 was undertaken in The Gambia in 1993. One hundred and fifty infants aged 6–11 months were immunized with either 0.5 mg or 1.0 mg of SPf66 produced either in Colombia or in the USA or with a control vaccine. Children who received SPf66 experienced more clinical attacks of malaria than did children in the control group during the first period of surveillance and the difference in incidence between children who had received high dose Colombian vaccine and the control children was statistically significant at the 5% level. During the 1995 malaria transmission season, 127 children from the original cohort of 150 were observed. During 18 weeks of intensive surveillance, the incidence of clinical malaria was again higher among children who had received SPf66 than among children who had received inactivated polio vaccine (6.23 vs 4.89 clinical attacks per 1000 days at risk), the effect being most marked among children who were in the high dose groups, but differences between groups were now no longer statistically significant .     

Survival in Duchenne muscular dystrophy

Objective:

To determine the survival in a population of German patients with Duchenne muscular dystrophy.

Patients and methods:

Information about 94 patients born between 1970 and 1980 was obtained by telephone interviews and questionnaires. In addition to age of death or actual age during the investigation, data concerning clinical course and medical interventions were collected.

Results:

67 patients with molecularly confirmed diagnoses had a median survival of 24.0 years. Patients without molecular confirmation (clinical diagnosis only) had a chance of 67 % to reach that age. Grouping of our patient cohort according to the year of death (before and after 2000), ventilation was recognized as main intervention affecting survival with ventilated reaching a median survival of 27.0 years. For those without ventilation it was 19.0 years.

Conclusion and clinical relevance:

our study provides survival data for a cohort of DMD patients in Germany stratified by year of death. Median survival was 24.0 years in patients confirmed by molecular testing. Ventilated patients had a median survival of 27 years. We consider this piece of information helpful in the medical care of DMD patients.Key words: duchenne muscular dystrophy, survival, ventilation     

Magnetic Resonance Imaging and Signal-Averaged Electrocardiography in Patients with Repetitive Monomorphic Ventricular Tachycardia and Otherwise Normal Electrocardiogram

Early or localized forms of arrhythmogenic right ventricular dysplasia (ARVD) have been proposed as the arrhythmogenic substrate of repetitive monomorphic ventricular tachycardia (RMVT) originating in the right ventricular outflow tract in patients without any underlying cardiac abnormality on clinical examination and echocardiography. To further examine this hypothesis, magnetic resonance imaging (MRI) and signal-averaged electrocardiography (SAECG) were performed on 23 patients with RMVT and normal 12-lead standard ECG of conducted sinus beats. MRI was performed using ECG-gated turbo spin-echo images of the heart in order to detect signs of early or localized forms of ARVD, such as localized wall thickness reductions, signal intensity increase indicating adipose tissue infiltrates, and regional bulgings or aneurysms. MRI was normal in 22 (96%) of 23 study patients. In the remaining patient (4%), MRI demonstrated signal intensity increase in the intraventricular septum but not in the right ventricular outflow tract. Time-domain analysis of the SAECG was normal in 21 (91 %) of 23 patients and revealed ventricular late potentials in 2 study patients (9%). Frequency-domain analysis of the SAECG was normal in 22 (96%) of 23 patients and revealed ventricular late potentials in one study patient (4 %). We conclude that normal MRI findings of the heart and absence of ventricular late potentials in the SAECC in most patients with RMVT and otherwise normal ECG do not support the hypothesis that early or localized forms of ARVD create the arrhythmogenic substrate in the majority of these patients.     

Neuropeptide Y: identification of the binding site

Based on the hypothetical 3D structure of neuropeptide Y (NPY), NPY 1-4-Aca-25-36, a 17 amino acid analogue, has been synthesized replacing the sequence NPY 5-24 by ε-aminocaproic acid (Aca). This low-molecular weight deletion analogue showed nearly comparable receptor affinity to NPY. In order to elucidate the structural requirements for receptor recognition each amino acid of 1-4-Aca-25-36 was exchanged by its D-enantiomer, glycine and L-alanine. In addition distinct amino acids were replaced by closely related residues. Multiple peptide synthesis was applied using Fmoc-strategy and BOP activation. Binding assay was performed on rabbit kidney membrane preparations. The results of structure affinity studies suggest that the C-terminal tetrapeptide NPY 33-36 is essential for receptor recognition.