Impact of Progerbalin LG® on the apple fruit physical attributes

During two consecutive years (2010 and 2011) we evaluated the impact of Progerbalin LG^® (mixture of gibberellins (GA₄₊₇) and N ⁶-benzyladenine) on fruit weight, fruit dimensions, elongation, geometric mean diameter or fruit size, aspect ratio, surface area and fruit volume of five apple cultivars belonging to ‘Red Delicious’ group (‘Hapke’ grafted on M.9 and M.26, ‘Hi Red’, ‘Starking’ and ‘Top Red’ on M.9, and ‘Red Chief Camspur’ on MM.106 rootstock). Trees were sprayed twice with 30, 50 or 100 ml L^?1 i.e. between 80 % of open flowers and the following petal fall (first treatment), and 10 days after first application (second treatment); control trees were not sprayed. Results showed that the lowest dose increased fruit weight in all cultivars, except ‘Top Red’ and ‘Red Chief Camspur’; this dose promoted fruit dimensions, fruit size and elongation in ‘Hapke’ on both rootstocks, and also fruit dimensions, surface area and fruit volume in ‘Hi Red’. Regarding ‘Starking’, different doses of Progerbalin LG^® did not affect other properties evaluated, but season played an important role in these cases. In contrast, the highest dose of this hormone improved all physical attributes in ‘Top Red’ and ‘Red Chief Camspur’, except elongation and/or aspect ratio. In some cases, good values were found in control treatment.     

Frequency of the ΔF508 deletion and G551D,R553X and G542X mutations in Yugoslav CF patients

Summary A study was undertaken to find the frequency of the F508 deletion and those of the G551D, R553X and G524X mutations among the mainly Slavic population of Serbia, Bosnia, Herzegovina, and Montenegro and compare the frequencies determined with those in other European populations. The F508 mutation was found to account for about 70% of CF genes in central Jugoslavia, where its frequency is significantly higher than elsewhere in Southern European populations.     

The Effects of Growth Regulators on Flowering of Chenopodium murale Plants in vitro

In vitro culture of Chenopodium murale L. (ecotype 197) green and herbicide SAN 9789 - treated "white" plants was established and the effects of benzylaminopurine (BAP), indole-3-acetic acid (IAA) and gibberellic acid (GA₃) on growth and flowering were tested. Green plants did not flower on glucose free media, while 17 % of plants flowered on 5 % glucose-containing medium. SAN 9789 (10^–5 M) inhibited growth and flowering. BAP and IAA (0.1 – 5 mg dm^–3) also inhibited growth and flowering of green and "white" plants. GA₃ (10 mg dm^–3) stimulated leaf development in green plants, but had no significant effect on "white" plants, and stimulated flowering of green (41 %) and "white" (33 %) plants.     

Pure MnTBAP selectively scavenges peroxynitrite over superoxide: Comparison of pure and commercial MnTBAP samples to MnTE-2-PyP in two models of oxidative stress injury,an SOD-specific Escherichia coli model and carrageenan-induced pleurisy

MnTBAP is often referred to as an SOD mimic in numerous models of oxidative stress. We have recently reported that pure MnTBAP does not dismute superoxide, but commercial or poorly purified samples are able to perform O₂^·?dismutation with low-to-moderate efficacy via non-innocent Mn-containing impurities. Herein, we show that neither commercial nor pure MnTBAP could substitute for SOD enzyme in a SOD-deficient Escherichia coli model, whereas MnTE-2-PyP-treated SOD-deficient E. coli grew as well as a wild-type strain. This SOD-specific system indicates that MnTBAP does not act as an SOD mimic in vivo. In another model, carrageenan-induced pleurisy in mice, inflammation was evidenced by increased pleural fluid exudate and neutrophil infiltration and activation: these events were blocked by 0.3 mg/kg MnTE-2-PyP and, to a slightly lesser extent, by 10 mg/kg of either MnTBAP. Also, 3-nitrotyrosine formation, an indication of peroxynitrite existence in vivo, was blocked by both compounds; again MnTE-2-PyP was 33-fold more effective. Pleurisy model data indicate that MnTBAP exerts some protective actions in common with MnTE-2-PyP, which are not O₂^·? related and can be fully rationalized if one considers that the common biological role shared by MnTBAP and MnTE-2-PyP is related to their reduction of peroxynitrite and carbonate radical, the latter arising from ONOOCO₂ adduct. The log k_cat (O₂^·?) value for MnTBAP is estimated to be about 3.16, which is ~ 5 and ~ 6 orders of magnitude smaller than the SOD activities of the potent SOD mimic MnTE-2-PyP and Cu,Zn-SOD, respectively. This very low value indicates that MnTBAP is too inefficient at dismuting superoxide to be of any biological impact, which was confirmed in the SOD-deficient E. coli model. The peroxynitrite scavenging ability of MnTBAP, however, is only ~ 2.5 orders of magnitude smaller than that of MnTE-2-PyP and is not significantly affected by the presence of the SOD-active impurities in the commercial MnTBAP sample (log k_red (ONOO^?) = 5.06 for pure and 4.97 for commercial sample). The reduction of carbonate radical is equally fast with MnTBAP and MnTE-2-PyP. The dose of MnTBAP required to yield oxidative stress protection and block nitrotyrosine formation in the pleurisy model is > 1.5 orders of magnitude higher than that of MnTE-2-PyP, which could be related to the lower ability of MnTBAP to scavenge peroxynitrite. The slightly better protection observed with the commercial MnTBAP sample (relative to the pure MnTBAP) could arise from its impurities, which, by scavenging O₂^·?, reduce consequently the overall peroxynitrite and secondary ROS/RNS levels. These observations have profound biological repercussions as they may suggest that the effect of MnTBAP observed in numerous studies may conceivably relate to peroxynitrite scavenging. Moreover, provided that pure MnTBAP is unable to dismute superoxide at any significant extent, but is able to partially scavenge peroxynitrite and carbonate radical, this compound may prove valuable in distinguishing ONOO^?/CO₃^·? from O₂^·? pathways.     

Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92

AIMS: To investigate aggregation and adhesiveness of Lactobacillus acidophilus M92 to porcine ileal epithelial cells in vitro, and the influence of cell surface proteins on autoaggregation and adhesiveness of this strain. METHODS AND RESULTS: Lactobacillus acidophilus M92 exhibits a strong autoaggregating phenotype and manifests a high degree of hydrophobicity determined by microbial adhesion to xylene. Aggregation and hydrophobicity were abolished upon exposure of the cells to pronase and pepsin. Sodium dodecyl sulphate polyacrylamide gel electrophoresis of cell surface proteins revealed the presence of potential surface layer (S-layer) proteins, approximated at 45 kDa, in L. acidophilus M92. The relationship between autoaggregation and adhesiveness to intestinal tissue was investigated by observing the adhesiveness of L. acidophilus M92 to porcine ileal epithelial cells. Removal of the S-layer proteins by extraction with 5 mol l-1 LiCl reduced autoaggregation and in vitro adhesion of this strain. CONCLUSIONS: These results demonstrate that there is relationship between autoaggregation and adhesiveness ability of L. acidophilus M92, mediated by proteinaceous components on the cell surface. SIGNIFICANCE AND IMPACT OF THE STUDY: This investigation has shown that L. acidophilus M92 has the ability to establish in the human gastrointestinal tract, which is an important determinant in the choice of probiotic strains.     

Clinical utility of red cell distribution width in alcoholic and non-alcoholic liver cirrhosis

Red blood cell distribution width (RDW) is a measure of the variation of red blood cell width that is reported as apart of standard complete blood count. Red blood cell distribution width results are often used together with mean corpuscular volume (MCV) results to figure out mixed anemia. The aim of our study was to compare the values of RDW in alcoholic and non-alcoholic liver cirrhosis and to determine if RDW follows the severity of disease according to Child-Pugh score. We retrospectively analyzed 241 patients (176 men and 65 women) with liver cirrhosis and anemia, defined as a hemoglobin value < 130 g/L in men and < 120 g/L in women, which were hospitalized in our Division in a period between 2006 and 2008. Patients were divided in two groups; in first were patients with alcoholic liver cirrhosis, and in second with non-alcoholic cirrhosis. Severity of disease was determined according to Child-Pugh score. Red blood cells distribution width Normal reference range is 11-15%. Alcoholic liver cirrhosis had 204 patients (85%) while non-alcoholic cirrhosis had 37 patients (15%). In group of alcoholic cirrhosis the average RDW was 16.8%. In relation to severity of disease the average RDW for Child-Pugh A was 16.80%, for Child-Pugh B was 16.92%, for Child-Pugh C was 17.10%. In the group of non-alcoholic cirrhosis the average RDW was 16.73% and in relation to severity of disease for Child-Pugh A was 16.25%, for Child-Pugh B 17.01% and for Child-Pugh C was 16.87%. We didn't find statistically significant difference of RDW between alcoholic and non alcoholic cirrhosis (p > 0.05) and we didn't proved any statistically significant increase of RDW in relation to severity of disease in group of alcoholic cirrhosis (p = 0.915) nor in group of patients with non-alcoholic cirrhosis (p = 0.697). Our study showed that RDW had not any clinical value in differentiation of anemia neither in alcoholic and non-alcoholic liver cirrhosis nor in severity of liver disease.     

Identification of the reactive cysteine residues in yeast dipeptidyl peptidase III

Dipeptidyl peptidases III (DPPs III) form a distinct metallopeptidase family characterized by the unique HEXXGH motif. High susceptibility to inactivation by organomercurials suggests the presence of a reactive cysteine residue(s) in, or close to, their active site. Yeast DPP III contains five Cys, none of which is absolutely conserved within the family. In order to identify reactive residue(s), site-directed mutagenesis on yeast His₆-tagged DPP III was employed to substitute specifically all five cysteine residues to serine. The variant enzymes thus obtained were enzymatically active and showed an overall structure not greatly affected by the mutations as judged by circular dichroism. Analysis by native and SDS-PAGE under non-reducing conditions revealed the existence of a monomeric and dimeric form in all DPP III proteins except in the C130S, implying that dimerization of yeast DPP III is mediated by the surface-exposed cysteine 130.     

Electric organ polyamines and their effects on the acetylcholine receptor

1. The electric organ of Torpedo nobiliana contained putrescine (PUT), spermidine (SPD), spermine (SPM), and cadaverine (CAD). Traces of acetylated SPD and SPM were occasionaly seen. 2. Upon fractionation of the tissue by differential centrifugation, the polyamines (PA) were found predominantly in the soluble fraction. The postsynaptic membrane fraction, containing a high concentration of acetylcholine receptor (AChR), was proportionally enriched in SPM. The molar ratio of SPM to AChR was approximately two in these membranes. 3. The effect of exogeneous PA on AChR function was studied by two methods: carbamoylcholine (CCh)-dependent 86Rb+ influx into receptor-rich membrane vesicles and [alpha-125I]bungarotoxin (Bgt) binding to the AChR. 4. SPM inhibited both ion influx and the rate of Bgt binding at concentrations above 1 mM, and therefore it appears to act as a competitive antagonist of the AChR. 5. At submicromolar concentrations, and only after preincubation with the receptor-rich membrane, SPM and PUT increased the ion influx by about 20% over control values. 6. Preincubation with 100 nM SPM did not affect the equilibrium binding of iodinated toxin or the rate of toxin binding, and therefore SPM was not uncovering new receptors. 7. By measuring the initial rate of toxin binding after different periods of preincubation with 1 microM CCh, the rate of the slow phase of receptor desensitization was determined. This rate was not changed by 100 nM SPM. 8. Although these results suggest that at low concentrations SPM is a positive modulator of the AChR, the precise mechanism of action is not determined yet.     

Age-related changes in chromatin of liver cell nuclei of different ploidity

Summary A comparsion of the Feulgen hydrolysis curves and the chromatin compactness of the liver cell nuclei of young and old rats was made. It was found that the rate of DNA depurination and chromatin compactness are higher in the liver cell nuclei of old rats, both in di-and tetraploidal cells. The effect of fixation upon the course of the hydrolysis curves is discussed.This investigation was supported by grant 474/VI Committee of Cell Pathology, Polish Academy of Sciences