The application of an averaging method to intermittently modified and endogenously generated spike activities of neurons in mollusc ganglia

The averaging method was applied for the analysis of the effect of intermittent light as well as for the analysis of the spontaneous spike activities of burster neurons in Helix pomatia and Aplysia depilans ganglia. Owing to such analyses by means of which the unwanted effects of permanently present noise (i.e., irregular frequency modulation of neuron impulse activity) were diminished, the dynamics of the neurons reaction to light and the longer time effects of intermittent illumination on neurons spontancous activity could be observed. The functional characteristics of burster neurons were determined by averaging and the least squares and equalization methods. The results were presented in the table and in two average curves which are asymmetrical with a horizontal asymptote. From these data it was concluded that the dynamics of the spontaneous activity of the two burster neurons in both specia is similar. The possibilities and limitations of the method in physiological analyses are discussed.     

Correlation of <Emphasis Type="Italic">trans</Emphasis>-Lycopene Measurements by the HPLC Method with the Optothermal and Photoacoustic Signals and the Color Readings of Fresh Tomato Homogenates

The trans-lycopene content of fresh tomato homogenates was assessed by means of the laser photoacoustic spectroscopy, the laser optothermal window, micro-Raman spectroscopy, and colorimetry; none of these methods require the extraction from the product matrix prior to the analysis. The wet chemistry method (high-performance liquid chromatography) was used as the absolute quantitative method. Analytical figures of merit for all methods were compared statistically; best linear correlation was achieved for the chromaticity index a* and chroma C*.     

Eiweißkristalloide inOpuntia inermis

Zusammenfassung In den Epidermiszellen der Blätter vonOpuntia inermis wurden neben den X-Körpern und Eiweißspindeln auch echte Eiweißkristalle in Form rhombenförmiger Plättchen gefunden. Diese Kristalle sind vermutlich im Zellsafte lokalisiert.Die spindelhaltigen Exemplare vonOpuntia inermis unterschieden sich auch dadurch von anderen spindelführenden Kakteen, daß sie auch in Schließzellen Eiweißspindeln enthielten. Das Ausbleiben der Eiweißspindeln in den Schließzellen der Kakteen ist demnach keine regelmäßige Erscheinung.Prof. Dr. V.Vouk zum 70. Geburtstag gewidmet.     

Lipid status association with 25-hydroxy vitamin D: Cross sectional study of end stage renal disease patients

BackgroundSome observational studies indicate an association of 25-hydroxy vitamin D (25(OH)D) insufficiency and atherogenic cholesterol concentrations. The aim of this study was to investigate relationship between 25(OH)D concentrations and lipid parameters in end stage renal disease (ESRD) patients, separately for predialysis, hemodialysis and peritoneal dialysis patients.MethodsWe have adjusted 25(OH)D concentrations for seasonal variability with cosinor analysis, and performed all further analysis using these corrected 25(OH)D concentrations. Concentrations of 25(OH)D and the lipid parameters were determined in 214 ESRD patients and 50 control group participants. The analysis included the measurement of 25(OH)D by HPLC, apolipoprotein (Apo) AI, ApoB and Lp(a) by nephelometry, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) by spectrophotometry and manually calculated ApoB/ApoAI and LDL-C/HDL-C ratio.ResultsESRD patients with adjusted 25(OH)D concentrations of 50 nmol/L had significantly higher TC (P = 0.005) and ApoAI (P = 0.049). Significantly higher HDLC (P = 0.011) and ApoAI (P = 0.020) were found in hemodialysis patients with the 25(OH)D concentrations of 50 nmol/L. The other analyzed lipid parameters differed significantly between predialysis, hemodialysis and peritoneal dialysis patients with 25(OH)D concentrations of < 50 nmol/L.ConclusionsOur study indicate the significant relationship between 25(OH)D repletion and optimal concentrations of lipid parameters in ESRD patients. Further research is necessary to explain whether joint evaluation of vitamin D status and lipid abnormalities could improve cardiovascular outcome in ESRD patients.     

Protected areas and prime hoverfly areas: Safe haven for hoverflies or not?

The efficiency of protected areas (PAs) has often been questioned due to global decline of biodiversity. Invertebrates, especially insects, have been historically underrepresented in conservation studies. Our study focuses on hoverflies, an important group of insect pollinators and proven to be good bioindicators. Research was focused in Serbia, one of Europe's hotspots of hoverfly diversity, with a long tradition of hoverfly research, which provided sufficient information for achieving our aims: identifying areas of high hoverfly diversity, evaluating the efficiency of PAs and prime hoverfly areas (PHAs) in the conservation of hoverflies, determining how well they cover the distribution of hoverfly species, especially those of conservation concern, and testing the importance of the size of the area for conservation of hoverfly diversity. We applied weighting of the species to help stress the importance of species of conservation concern. The results indicated that PHAs cover the areas with high hoverfly diversity better than PA networks, especially when it comes to species of conservation concern. Generalized linear model results showed that the area size was a significant predictor of number of species in both PA and PHA. This indicates that area size is key when designating new areas important for conservation, but there are also other factors that need to be taken into account, such as habitat quality or suitability. Studies like this are useful in aiding designation of new areas important for conservation of certain species and in identifying sampling gaps, which could potentially aim future research in that direction.     

A new approach for activation of the kiwifruit cysteine protease for usage in in-vitro testing

Molecular Biology Reports - Actinidin (Act d 1), a highly abundant cysteine protease from kiwifruit, is one of the major contributors to the development of kiwifruit allergy. Many studies have...     

Cytotoxic activities of Hypericum perforatum L. extracts against 2D and 3D cancer cell models

Cytotechnology - Six extracts were obtained from plant species Hypericum perforatum L., collected at Samsun in Turkey. The aim of this study was to examine the mechanisms of the anticancer activity...     

Influence of membrane-cortex linkers on the extrusion of membrane tubes

The cell membrane is an inhomogeneous system composed of phospholipids, sterols, carbohydrates, and proteins that can be directly attached to underlying cytoskeleton. The protein linkers between the membrane and the cytoskeleton are believed to have a profound effect on the mechanical properties of the cell membrane and its ability to reshape. Here, we investigate the role of membrane-cortex linkers on the extrusion of membrane tubes using computer simulations and experiments. In simulations, we find that the force for tube extrusion has a nonlinear dependence on the density of membrane-cortex attachments: at a range of low and intermediate linker densities, the force is not significantly influenced by the presence of the membrane-cortex attachments and resembles that of the bare membrane. For large concentrations of linkers, however, the force substantially increases compared with the bare membrane. In both cases, the linkers provided membrane tubes with increased stability against coalescence. We then pulled tubes from HEK cells using optical tweezers for varying expression levels of the membrane-cortex attachment protein Ezrin. In line with simulations, we observed that overexpression of Ezrin led to an increased extrusion force, while Ezrin depletion had a negligible effect on the force. Our results shed light on the importance of local protein rearrangements for membrane reshaping at nanoscopic scales.