Sicherheit von Nahrungsergänzungsmitteln

Food supplements are foodstuffs. Food which is not safe shall not be placed on the market. Adherence to the laws which aim for the safety of food ensures that food supplements are safe. Unfortunately, there are still gaps in the legislation for food supplements. However, even intrinsically safe foods can bear a risk for the consumer if not used appropriately, for example if food supplements are consumed instead of healthy diets or if food supplements are used as substitutes for indicated drugs.     

Neuromagnetic topography of photoconvulsive response in man.

The neuromagnetic method was applied to the study of photoconvulsive responses. The identification of specific magnetic field distributions over the scalp was achieved by; (a) a stimulation paradigm consisting of series of trains of flicker stimuli randomly presented to the epileptic patient, after eye closure, to get epileptic responses while avoiding seizures; (b) a novel procedure for data analysis, to select consistent responses. These patterns, when sufficiently stable in time and dipolar in shape, were used for source localization in the usual biomagnetic framework of the equivalent current dipole source representation. The results of this approach suggest that different specific cortical areas are repeatedly and randomly activated, involving mainly the frontal, occipital and temporal areas, often with a hemispheric prevalence.     

A novel approach for the averaging of magnetocardiographically recorded heart beats

Performing signal averaging in an efficient and correct way is indispensable since it is a prerequisite for a broad variety of magnetocardiographic (MCG) analysis methods. One of the most common procedures for performing the signal averaging to increase the signal-to-noise ratio (SNR) in magnetocardiography, as well as in electrocardiography (ECG), is done by means of spatial or temporal techniques. In this paper, an improvement of the temporal averaging method is presented. In order to obtain an accurate signal detection, temporal alignment methods and objective classification criteria are developed. The processing technique based on hierarchical clustering is introduced to take into account the non-stationarity of the noise and, to some extent, the biological variability of the signals reaching the optimum SNR. The method implemented is especially designed to run fast and does not require any interaction from the operator. The averaging procedure described in this work is applied to the averaging of MCG data as an example, but with its intrinsic properties it can also be applied to the averaging of ECG recording, averaging of body-surface-potential mapping (BSPM) and averaging of magnetoencephalographic (MEG) or electroencephalographic (EEG) signals.     

Investigation of metabolites for estimating blood deposition time

Trace deposition timing reflects a novel concept in forensic molecular biology involving the use of rhythmic biomarkers for estimating the time within a 24-h day/night cycle a human biological sample was left at the crime scene, which in principle allows verifying a sample donor’s alibi. Previously, we introduced two circadian hormones for trace deposition timing and recently demonstrated that messenger RNA (mRNA) biomarkers significantly improve time prediction accuracy. Here, we investigate the suitability of metabolites measured using a targeted metabolomics approach, for trace deposition timing. Analysis of 171 plasma metabolites collected around the clock at 2-h intervals for 36 h from 12 male participants under controlled laboratory conditions identified 56 metabolites showing statistically significant oscillations, with peak times falling into three day/night time categories: morning/noon, afternoon/evening and night/early morning. Time prediction modelling identified 10 independently contributing metabolite biomarkers, which together achieved prediction accuracies expressed as AUC of 0.81, 0.86 and 0.90 for these three time categories respectively. Combining metabolites with previously established hormone and mRNA biomarkers in time prediction modelling resulted in an improved prediction accuracy reaching AUCs of 0.85, 0.89 and 0.96 respectively. The additional impact of metabolite biomarkers, however, was rather minor as the previously established model with melatonin, cortisol and three mRNA biomarkers achieved AUC values of 0.88, 0.88 and 0.95 for the same three time categories respectively. Nevertheless, the selected metabolites could become practically useful in scenarios where RNA marker information is unavailable such as due to RNA degradation. This is the first metabolomics study investigating circulating metabolites for trace deposition timing, and more work is needed to fully establish their usefulness for this forensic purpose.

     

Duplication of chromosome arms 9q and 11q: evidence for a novel, 14q32 translocation-independent pathogenetic pathway in multiple myeloma

14q32 translocations [t(14q)] represent critical but not universal events in multiple myeloma (MM). Gains of chromosome arms 1q, 9q, and 11q (+1q, +9q, and +11q) have recently been identified as frequent aberrations in this disease, but their pathogenetic significance remains unclear. We studied a series of 108 MM patients using fluorescence in situ hybridization and DNA probes mapping to chromosome bands 1q21, 9q34, 11q25, 13q14, and 14q32. Three subsets of tumors were defined: (1) MM+/+ (detection of +9q and +11q; 43.5% of cases), (2) MM+/- (+9q or +11q; 21.3%), and (3) MM-/- (neither +9q nor +11q; 35.2%). The incidence of t(14q) was significantly different in these subgroups: 23% in MM+/+, 56% in MM+/-, and 89% in MM-/-. Deletion of 13q (13q-) also was significantly less frequent in MM+/+ (23%) than in MM+/- and MM-/- (36% and 63%, respectively). The nonrandom distribution of chromosomal aberrations in the present series of MM tumors points to a novel, 14q32 translocation-independent pathogenetic pathway in plasma cell neoplasms.