[Polyphenolic compounds analysis and antioxidant activity in fruits of Prunus spinosa L.] / Not available.

INTRODUCTION: Prunus spinosa L. (blackthorn, sloe) is a com- mon species in the wild flora of Europe. Marmalade, syrup, and alcoholic beverages have been prepared from fruits. In folk medicine they'are used due to the astringent effect. However there are few studies on these indigenous fruits. According to the literature they contain tannins, anthocyanins, sugars, vitamin C etc. METHODS: Our objective is to determine the antioxidant activity as related to their phenolic composition. For this purpose we prepared extracts using methanol, methanol-water (1: 1) and water. The antioxidant activity was determined by DPPH method and by photochemiluminescens (PCL) method. The total polyphenols, total anthocyanins and flavonoids were determined by colorimetric methods. Individual polyphenols were identified by a RP-HPLC-UVIVIS method. RESULTS: The antioxidant activity decreased in the extracts as follows: methanol > methanol-water > water (IC50= 1.33 mg/ml for DPPH; 11.94 µmol AAEIml for PCL > IC50 = 1.87 mg/ml for DPPH; 10.35 µmol AAElml for PCL > IC50 = 15.29 mg/ml for DPPH, 1.89 µmol AAElml for PCL) which is cor- related with the total polyphenol content (369 mg/100g > 244 mg1100g > 101 mg1100g) and total anthocyanin content (37.11 mg/100 g > 16.33 mg/100g > 7.76 mg/100g). The fla- vonoid content is similar in the three extracts (between 35.82 - 37.32 mg1100 g). The HPLC analysis shows high chloro- genic and neochlorogenic acid levels, followed by glycosides of quercetin. CONCLUSIONS: Our results demonstrated that blackthorn fruits are a rich source of phenolic compounds, with anti- oxidant activity, which are best extracted with methanol or methanol-water.

Dexamethasone decreases membrane fluidity of leukemia cells.

Lipid fluidity in the plasma membrane of leukemia cells was determined by measuring steady-state fluorescence polarization (P) of 1,6-diphenyl-1,3,5-hexatriene. In vitro dexamethasone treatment induced a dose-, time- and temperature-dependent and reversible increase in P values of primary leukemia cells and glucocorticoid-sensitive leukemia cell lines having specific glucocorticoid receptors. Membrane fluidity of glucocorticoid-resistant subclones with impaired specific dexamethasone binding capacity was not influenced by the drug. The results of this study suggest that dexamethasone modulates leukemia cell membrane fluidity via a classical glucocorticoid receptor dependent pathway.

3D reconstruction based on hard tissue microtome cross-section pictures in dentistry.

The aim of this study was to examine the accuracy of the computerized 3D surface analyzing and volume measuring method in dentistry. Two different types of test objects were used in the first part of the measurements. Each sample of the two groups was cross-sectioned using a hard tissue microtome. The sections were photographed on both sides and were projected on a graphical tablet and analyzed using a computer program. The measured and calculated parameters were compared. In the second part, 200 microm thick horizontal sections were prepared from 11 human incisor roots using the hard tissue microtome. This way, five sections were prepared from the apical 2 mm of each root. The effects of section thickness and number were modeled by decreasing the inclusion rate of the obtained number of sections from 10 to 2 and its influence on the calculated results was determined. This method was suitable for the approximation and analysis of 3D parameters. The results indicated that using 200-300 microm section thickness, the measured values were approximately 8-21% lower than the real parameters.

Changes of calcium compartmentalization of skeletal muscle under ionic and drug influence.

Compartmentalization of calcium was studied in frog semitendinosus using 45Ca radioisotope under exchange diffusion condition. Computer based deconvolution was employed to determine the "volume" and the apparent binding constant of the resolved six components. Assuming kinetically parallel and independent compartments nickel treatment slows down the calcium movement through the sarcoplasmic reticulum membrane and for the calcium ions causes competition of the membrane of transverse tubuli and of the sarcoplasmic reticulum. Veratrine treatment caused different effect in the presence and in the absence of sodium ions, demonstrating the essential role of Na+ in equilibrium with Ca2+ exchange processes/ATPases in the Ca2+ uptake and release by sarcoplasmic reticulum. Effect of caffeine and Dantrolene basically opposite on the compartment corresponds to the sarcoplasmic reticulum and similar on the transverse tubuli in term of speed of exchange diffusion.