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Background. In myotonic dystrophy, a significantly increased potassium release upon exercise was previously described. However, it remained unclear so far whether this is a specific feature of myotonic dystrophies or a consequence of distal muscular weakness in general. Methods. We performed non-ischemic forearm exercise test (NIFET) and measured venous K+ concentration at rest and at three different force levels (20–30%, 50–60%, 70–80%) related to maximal contraction force (MCF) in patients with different myopathies (n = 7), motor neuropathies (n = 8) with distal phenotype and healthy volunteers (n = 12). The specific K+ production was defined as venous K+ increase related to workload. Results. Maximal contraction force, workload and venous K+ increase were lower at all force levels in both myopathy and neuropathy groups compared to the control group. With increasing workload, the control group showed a quasi-linear increase in K+ release, resulting in a nearly constant specific K+ production within the three force levels (p = 0.752, Kruskal-Wallis-Test). In contrast, in myopathies a higher specific K+ production was measured at low force levels (20-30% MCF) in comparison to higher force levels (p = 0.015, Kruskal-Wallis test). In neuropathies, the lowest specific K+ production was obtained at 20–30% MCF. At this force level, the specific K+ production was significantly higher in myopathies compared to neuropathies (Fig. 1; p = 0.005, Mann-Whitney U Test). At 50–60% and 70–80% MCF, the specific K+ values increasingly converged and did not significantly differ between the three groups (Fig. 1; p = 0.09 and p = 0.37, Kruskal-Wallis test). Conclusion. In our study, increased K+ efflux related to workload occurred in patients with myogenic in comparison to neurogenic distal muscular weakness at low force levels. High specific K+ production does not seem to be an exclusive feature of myotonic dystrophies but of myogenic muscular weakness in general. Our results point to a different regulation of K+ balance in neurogenic and myogenic muscular weakness possibly due to a different recruitment behaviour of motor units and the action potential frequency of motor neurons in neurogenic and myogenic processes. Fig. 1.

Atmospheric Pressure Photoionization (APPI) in Mass Spectrometry (MS) has been utilized for a lumber of indigo-related compounds and was found to exhibit an excellent response. All structures were ionizad in negative ion mode yielding almost exclusively deprotonated molecules. Their product ion mass spectra were also recorded and showed characteristic losses mainly of small neutrals such as CO, HBr and CONH2. APPI-MS was applied further to the analysis of indigo dyestuffs of historical importance. HPLC with single ion monitoring (SIM) was employed for the separation and detection of the compounds. A simple HPLC gradient that separated the components in less than 10 min was developed. MS/MS spectra of the colouring components were also recorded and compared to that of the referente substances. The composition of Tyrian purple originating from Murex trunculus (Hexaplex trunculus), was by far the most complex, whereas some of the structures were also detected in Purpura haemastoma (Stramonita haemastoma) and Plicopurpura pansa (Plicopurpura patula subs. pansa). Further, a number of synthetic indigo dyes, produced at different times of the 19thcentury by different manufacturers, were analyzed; similar spectra were obtained suggesting that these were highly pure. Overall, the developed analytical procedure was very efficient offering high sensitivity and selectivity. APPI was proved suitable for ionizing the species under investigation producing clear mass spectra with characteristic fragment ions and may be used successfully in the future for the characterization of similar structures in historical art objects.

Background Training simulators have been used for decades with success; however, a standardized educational strategy for diagnostic EGD is still lacking. Objective Development of a training strategy for diagnostic upper endoscopy. Study design Prospective, randomized trial. Settings A total of 28 medical and surgical residents without endoscopic experience were enrolled. Basic skills evaluations were performed following a structured program involving theoretical lectures and a hands-on course in diagnostic EGD. Subsequently, stratified randomization to clinical plus simulator training (group 1, n=10), clinical training only (group 2, n=9), or simulator training only (group 3, n=9) was performed. Ten sessions of simulator training were conducted for groups 1 and 3 during the 4-month program. Group 2 underwent standard training in endoscopy without supplemental simulator training. The final evaluation was performed on the simulator and by observation of 3 clinical cases. Skills and procedural times were recorded by blinded and unblinded evaluators. Main Outcome Measurements Time to reach the duodenum, pylorus, or esophagus. Results All trainees demonstrated a significant reduction in procedure time during a simple manual skills test ( P P = .006, P = .042 and P = .017) in the simulator independent of the training strategy. Group 1 showed shorter times to intubate the esophagus (61 ± 26 seconds vs 85 ± 30 seconds and 95 ± 36 seconds) and the pylorus (183 ± 65 seconds vs 207 ± 61 seconds and 247 ± 66 seconds) during the clinical evaluation. Blinded assessment of EGD skills showed significantly better results for group 1 compared with group 3. Blinded and unblinded evaluations were not statistically different. Limitations Small sample size. Conclusions Structured simulator training supplementing clinical training in upper endoscopy appears to be superior to clinical training alone. Simulator training alone does not seem to be sufficient to improve endoscopic skills.

Diagnostic and interventional endoscopy has undergone an enormous evolution and refinement in the past 2 decades. Consequently, the requirement of skill sets for endoscopists increased and a need for training and education have become clear. Since the mid-1990s, different training simulators have been developed. This article describes the status of endoscopy training in Europe and the current use of simulators in various European countries. Several working groups have developed and established various simulators and training platforms for nearly all diagnostic and interventional techniques. Therefore, the availability of different training simulators is not unexpected in most European countries.

Mathematical modeling of skin transport is considered a valuable alternative of in-vitro and in-vivo investigations especially considering ethical and economical questions. Mechanistic diffusion models describe skin transport by solving Fick's 2nd law of diffusion in time and space; however models relying entirely on a consistent experimental data set are missing. For a two-dimensional model membrane consisting of a biphasic stratum corneum (SC) and a homogeneous epidermal/dermal compartment (DSL) methods are presented to determine all relevant input parameters. The data were generated for flufenamic acid (M(W) 281.24g/mol; logK(Oct/H2O) 4.8; pK(a) 3.9) and caffeine (M(W) 194.2g/mol; logK(Oct/H2O) -0.083; pK(a) 1.39) using female abdominal skin. K(lip/don) (lipid-donor partition coefficient) was determined in equilibration experiments with human SC lipids. K(cor/lip) (corneocyte-lipid) and K(DSL/lip) (DSL-lipid) were derived from easily available experimental data, i.e. K(SC/don) (SC-donor), K(lip/don) and K(SC/DSL) (SC-DSL) considering realistic volume fractions of the lipid and corneocyte phases. Lipid and DSL diffusion coefficients D(lip) and D(DSL) were calculated based on steady state flux. The corneocyte diffusion coefficient D(cor) is not accessible experimentally and needs to be estimated by simulation. Based on these results time-dependent stratum corneum concentration-depth profiles were simulated and compared to experimental profiles in an accompanying study.

Background. The objective benefit of a training using the compact Erlangen Active Simulator for Interventional Endoscopy-simulator was demonstrated in two prospective educational trials (New York, France). The present study analysed whether endoscopic novices are able to reach a comparable level of endoscopic skills as in the above-described projects. Methods. Twenty-seven endoscopic novices (medical students, first year residents) were enrolled in this prospective, randomised trial. The compact Erlangen Active Simulator for Interventional Endoscopy-simulator with an upper GI-organ package and blood perfusion system was used as a training tool. Basic evaluation of endoscopic skills was performed after a practical and theoretical course in diagnostic upper GI endoscopy followed by a stratified randomisation according to the rating in endoscopic skills into intensive (n = 14) and control group (n = 13). The intensive group was trained 12 times every second week over 7 months in 4 endoscopic disciplines (manual skills, injection therapy, haemoclip, band ligation) by skilled endoscopist (three trainees/simulator). Assessment was performed (single steps/overall) using an analogue scale from 1 to 10 (1 = worst, 10 = optimal performance) by expert tutors. The control group was not trained. Blinded final evaluation of all participants was performed in January 2003. Results. We observed in all techniques applied a significant improvement of endoscopic skills and of the performance time in the intensive group compared to the control group (p < 0.001). The comparison with the previous projects showed that the intensively trained novices achieved comparable levels of performance to the GI fellows in the New York and France Project (at least 80% of the median score in three out of four techniques). Conclusion. Endoscopic novices acquired notable skills in interventional endoscopy in the simulator by an intensive, periodical training using the compactEASIE ® .

Background Transcutaneous direct current stimulation (tDCS) is a known tool for inducing changes in cortical excitability influencing motor as cognitive functions. Previous studies suggest that application of tDCS might be a therapeutic approach for pain disorders as well. Objective The aim of the study was to investigate pain-related changes in cerebral activation pattern and its modulation by direct current stimulation. Methods Thirteen right-handed healthy participants received 20 min of tDCS applied over primary motor cortex (M1) under three different conditions which are anodal-tDCS, cathodal-tDCS, and sham-tDCS in a blinded cross-over design. Afterwards tDCS neural response to electric trigeminal pain stimulation was investigated using a block designed fMRI. Between the three tDCS conditions a time interval of at least 2 months was kept. Results All pain stimulation showed distinct activation pattern in the established brain areas of pain processing. Following anodal tDCS increased activation was detected in different part of the pain processing network including thalamus, basal ganglia, cingulate cortex, dorsolateral prefrontal cortex, and amygdala while cathodal t-DCS showed decreased BOLD response in these pain processing areas. Behavioral data were not changed irrespective of tDCS stimulation mode. Discussion Our study shows polarity-specific modulation of cerebral pain processing, which are in line with previous electrophysiological data. Anodal tDCS leads to an increased activation of the central pain-network compared to cathodal tDCS. Our results contribute to a network-based understanding of the underlying mechanism in tDCS.

During laboratory experiments Artemia were fed 14 days from nauplius to adult stage with a commercially available, enriched and unenriched, inert, dry baby food (‘Nestum’). Growth, survival, and nutrient content of Artemia were determined, and compared with Artemia fed with the unicellular microalgae Chaetoceros sp. Raising Artemia on Nestum resulted in a high survival rate (Nestum: 72%; Nestum enriched 79%) and after 11 days a growth of 4.93 mm with Nestum and 5.02 mm with enriched Nestum, which was similar to Artemia reared on Chaetoceros. The lipid content of Artemia reared on Nestum was significantly higher and the protein content lower than Artemia reared on Chaetoceros. The carbohydrate and ash content were similar. The results show that rearing Artemia with Nestum is a viable and economical alternative to the laborious production of unicellular algae.

In aquaculture, accurate sampling and counting procedures are essential to determine precisely the number of animals in culture, to develop feeding regimes and water exchange rates, and to calculate the survival rates. Volumetric sampling techniques were applied using Artemia for the determination of the precision of larval population density estimates. By a descriptive distribution frequency of Artemia nauplii and adults counted in different sample volumes, we noted the variation decreases significantly with increasing sample volume, although no significant differences were seen in the means of the sample counts in different volumes. For precise direct counting of fish and shrimp larvae, we suggest selecting sample volumes yielding 30 to 80 animals per sample. Using this relatively large number of animals per sample allows using less replicates to achieve the desired standard error.

Although the recycling of excrements in integrated agriculture-aquaculture farming systems offers many advantages, the spread of diseases to man via aquatic organisms multiplying in excreta-laden water needs special attention. There is strong evidence that aquatic organisms may be more important vectors for human diseases than generally realized. However, conclusive epidemiological studies linking the use of excreta in aquaculture with human diseases are lacking.