Die Vegetationsregionen der Rila-Planina

Ohne Zusammenfassung     

Ground beetle assemblages and distribution of functional traits in olive orchards and vineyards depend on the agricultural management practice

BioControl - Biodiversity in the Mediterranean is undergoing a decline resulting in reduced ecosystem service provisions. Here we analysed the functional diversity of ground beetles in...     

The comparative kinetic analysis of Acetocell and Lignoboost® lignin pyrolysis: the estimation of the distributed reactivity models

The non-isothermal pyrolysis kinetics of Acetocell (the organosolv) and Lignoboost? (kraft) lignins, in an inert atmosphere, have been studied by thermogravimetric analysis. Using isoconversional analysis, it was concluded that the apparent activation energy for all lignins strongly depends on conversion, showing that the pyrolysis of lignins is not a single chemical process. It was identified that the pyrolysis process of Acetocell and Lignoboost? lignin takes place over three reaction steps, which was confirmed by appearance of the corresponding isokinetic relationships (IKR). It was found that major pyrolysis stage of both lignins is characterized by stilbene pyrolysis reactions, which were subsequently followed by decomposition reactions of products derived from the stilbene pyrolytic process. It was concluded that non-isothermal pyrolysis of Acetocell and Lignoboost? lignins can be best described by n-th (n>1) reaction order kinetics, using the Weibull mixture model (as distributed reactivity model) with alternating shape parameters.     

The role of the von Willebrand factor in renal diseases and haemodialysis patients

During a period of twenty years, the von Willebrand factor (VWf) biological activity was evaluated in 805 patients with vein thrombosis, diabetes mellitus, chronic renal failure and ischemic heart disease. The examined patients were 168 with vein thrombosis, 129 with diabetes mellitus, 412 with chronic renal failure (CRF), and 96 with ischemic heart disease. The biological activity was also determined in 104 haemodialysis patients using four different haemodialytic membranes: 30 on cuprophan membrane, 30 on polymethylmetacrylate membrane (PMMA), 24 on hemophane and 20 patients on polysulphone (PS) membrane. In 42 patients with arterio-venous fistula prone to thrombosis, the biological activity of the von Willebrand Factor was 178% in comparison to 106% in the control group. The biological activity of VWF was increased in patients with vein thrombosis (p < 0.02), in patients with diabetes mellitus (p < 0.01), CRF (p < 0.05), and in patients with ischemic heart disease (p < 0.01). The highest biological activity was found in patients on PMMA (p < 0.001), then cuprophan (p < 0.05) and hemophane membrane (p < 0.01), while the lowest increase of its concentration was noticed in patients on PS without statistical significance. In arteriovenous fistula prone to thrombosis patients biological activity of the von Willebrand Factor was significantly increased (p < 0.01). Our investigations show the importance of VWF as a marker of endothelial disfunction, a possible predictor of A-V fistula thrombosis, and a possible marker of haemodialysis membranes biocompatibility.     

Health-related quality of life in the patients on maintenance hemodialysis: the analysis of demographic and clinical factors

Health-related quality of life (HRQoL) among hemodialysis (HD) patients recently became a nephrologist's focus of interest. HRQoL is an important predictor of outcome in HD patients and need to be regularly assessed. The aim of the present study was to compare the HRQoL of chronic HD patients with general population and to analyze influencing sociodemographic and clinical factors. We included 255 prevalent HD patients from four dialysis centers. HRQoL was measured with The Medical Outcomes Study Short Form 36 Health Survey Questionnaire (SF-36). This data were compared with control group (N = 132) from the general Croatian population. Comparisons of SF-36 scale scores of HD patients regarding demographic and clinical factors (age, gender, education level, dialysis vintage and diabetes) were also performed and analyzed with a multivariate regression analysis. HRQoL in prevalent HD patients was relatively low (mean Physical Component Summary, PCS = 33.7, mean Mental Component Summary, MCS = 43.0) and was lower compared to the control group from the general population in all HRQoL domains, PCS and MCS scores. Almost 53% of the HD patients had the critical score PCS < 43 + MCS < 51 as the predictor of death and hospitalization. Better HRQoL was revealed in the patients < 65 years old, males, patients with higher educational level and in the patients on maintenance HD less than one year. Age was the only statistically significant predictor of PCS and MCS. Developments of HD technology, treatment of comorbidities, continuous patients' education, social and psychological support and use of other renal replacement modalities, especially kidney transplantation, may improve the HRQoL in these patients.     

Synthesis, alpha 1-adrenoceptor antagonist activity, and SAR study of novel arylpiperazine derivatives of phenytoin

In the search for new antiarrhythmic agents, some active 2-methoxyphenylpiperazine derivatives of phenytoin were obtained as a chemical modification of compound AZ-99 (3-ethyl-1-[2-hydroxy-3-(4-phenylpiperazin-1-yl)-propyl]-2,4-dioxo-5,5-diphenylimidazolidine). These compounds possessed structural properties similar to those of alpha(1)-adrenoceptor antagonists. In the present study, the affinities of the 2-methoxyphenylpiperazine derivatives (1a-3a) for alpha(1)- and alpha(2)-adrenoceptors were evaluated using radioligand ([(3)H]prazosin, [(3)H]clonidine) binding assays. In the next step, a new series of phenylpiperazine derivatives of phenytoin (4a-16a) containing 2-methoxyphenyl-, 2-ethoxyphenyl-, 2-pyridyl- or 2-furoylpiperazine moiety, as well as, various ester or alkyl substituents at 3-position of hydantoin ring were synthesized. The newly synthesized compounds were tested for their affinity to alpha(1)- and alpha(2)-adrenoceptors. They have shown affinities for alpha(1)-adrenoceptors at nanomolar to submicromolar range. Some compounds were moderately selective ligands of alpha(1)-adrenoceptors. Selected compounds (3a-5a, 7a, 13a, 14a) were also evaluated for their alpha(1)-adrenoceptor antagonistic properties in functional bioassays. A SAR study indicated that the most active compounds contain 2-alkoxyphenylpiperazine moieties and methyl or 2-methylpropionate substituent at 3-N position in hydantoin. The exchange of 2-alkoxyphenyl moiety into 2-furoyl or 2-pyridyl group significantly decreased affinities for alpha(1)-adrenoceptors. Molecular modelling results obtained using conformational analysis CONFLEX and PM5 method for geometry optimization, allowed for comparison of the spatial properties of tested compounds with pharmacophore model created by Barbaro et al. for the ideal alpha(1)-adrenoceptor antagonist.     

Evolution of the clinical presentation and outcomes after radical prostatectomy for patients with clinically localized prostate cancer--changing trends over a ten year period

We demonstrate the evolution of the clinical presentation and outcomes for patients with clinically localized prostate cancer (PC) treated with radical retropubic prostatectomy (RRP) at our department, emphasizing epidemiologic significance of changes during the 10-year period. We assessed the annual trends for changes in patients age, preoperative prostate specific antigen (PSA), preoperative versus postoperative stages and Gleason grades, organ confined status and surgical margin status. A total of 488 RRPs were performed from January 1996 to December 2005 with the annual frequency increased from 8 to 129 (1512.5%). Mean patient age increased from 61.5 to 66.12 years in 2005, with the percentage of men aged more than 70 years increased from 12.5 to 26.5%, respectively. The detection of PC based solely on pathological PSA levels (as indication for prostate biopsy) rose impressively from 25.5 to 70% and the rates of postoperative organ-confined disease also increased significantly from 25 to 74.7%. Mean preoperative PSA decreased from 16.7 to 9.89 ng/mL. On the contrary, there was an increase in percentage of patients with preoperative PSA values ranging from 4 to 10 ng/mL (from 20 to 65.4%). Positive surgical margin rate decreased from 49.4 to 25% and percent of patients receiving neoadjuvant therapy decreased from 78.5 to 5.4%. Proportion of patients who were undergraded decreased from 75.1 to 31.7%. The rates of understaging have remained relatively stable over the years. During the study period, PC was increasingly detected by prostate biopsy on the basis of a pathological PSA level only and shifted significantly to more organ-confined stages with more favourable outcomes for pathological variables due to a more accurate assessment of clinical stage prior to surgery, reduced use of neoadjuvant therapy and improved surgical technique. Our data also argue strongly that routine PSA testing should be expanded and not restricted.     

The expression of interleukin-1 alpha, TNF and VEGF in corneal cells of patients with bullous keratopathy

Bullous keratopathy (BK) is a chronic corneal edema with or without subepithelial bullae as a result of a loss of the endothelial cells. 15 patients with BK after cataract surgery with intraocular lens implantation, due to Fuchs dystrophy (n = 3) or corneal endothelial trauma (n = 12) were included in the study. All patients were treated by amniotic membrane transplantation (AMT). Corneal epithelial cells in patients suffering from BK secreted 3.91 +/- 3.09 pg/mL of IL-1 alpha, 4446 +/- 16.8 pg/mL of TNF and 81.43 +/- 37.81 pg/mL of VEGF-I. Levels of all 3 investigated cytokines were significantly higher as compared to controls (p < 0.005). Amniotic membranes that were used to treat investigated patients contained 638.98 +/- 613.98 pg/mL of IL-1ra, 0.026 +/- 0.009 pg/mL of sTNF and 81.39 +/- 21.01 pg/mL of VEGF-R. Beneficial clinical effect of the AMT in treating BK could be explained by its natural production of pro-inflammatory cytokine antagonists such as IL-ra, sTNF antagonist and VEGF-R.     

The cross-road between the mechanisms of protein folding and aggregation; study of human stefin B and its H75W mutant

The role of the aromatic residue at site 75 to protein stability, the mechanism of folding and the mechanism of amyloid-fibril formation were investigated for the human stefin B variant (bearing Y at site 31) and its point mutation H75W. With an aim to reveal the conformation at the cross-road between folding and aggregation, first, the kinetics of folding and oligomer formation by human stefin B(Y31) variant were studied. It was found to fold in three kinetic phases at pH 4.8 and 10% TFE; the pH and solvent conditions that transform the protein into amyloid fibrils at longer times. The same pH leads to the formation of native-like intermediate (known from previous studies of this variant), meaning that the process of folding and amyloid-fibril formation share the same structural intermediate, which is in this case native-like and dimeric. At pH 5.8 and 7.0 stefin B folded to the native state in four kinetic phases over two intermediates. In distinction, the mutant H75W did not fold to completion, ending in intermediate states at all pH values studied: 4.8, 5.8 and 7.0. At pH 4.8 and 5.8, the mutant folded in one kinetic phase to the intermediate of the “molten globule” type, which leads to the conclusion that its mechanism of folding differs from the one of the parent stefin B at the same pH. At pH 7.0 the mutant H75W folded in three kinetic phases to a native-like intermediate, analogous to folding of stefin B at pH 4.8.