Chlorophyllase Activity and Chlorophyll Content in Wild and Mutant Plants of Arabidopsis thaliana

The activity of chlorophyllase in wild type (WT) was higher than in ethylene insensitive mutant (eti 5) of Arabidopsis thaliana (L.) Heynh plants during the vegetative period. Chlorophyll content in eti 5 leaves was higher than in WT but the difference decreased by the end of the experimental period.     

Genetic linkage to chromosome 22q12 for a heavy-smoking quantitative trait in two independent samples

We conducted a genomewide linkage screen of a simple heavy-smoking quantitative trait, the maximum number of cigarettes smoked in a 24-h period, using two independent samples: 289 Australian and 155 Finnish nuclear multiplex families, all of which were of European ancestry and were targeted for DNA analysis by use of probands with a heavy-smoking phenotype. We analyzed the trait, using a regression of identity-by-descent allele sharing on the sum and difference of the trait values for relative pairs. Suggestive linkage was detected on chromosome 22 at 27-29 cM in each sample, with a LOD score of 5.98 at 26.96 cM in the combined sample. After additional markers were used to localize the signal, the LOD score was 5.21 at 25.46 cM. To assess the statistical significance of the LOD score in the combined sample, 1,000 simulated genomewide screens were conducted, resulting in an empirical P value of .006 for the LOD score of 5.21. This linkage signal is driven mainly by the microsatellite marker D22S315 (22.59 cM), which had a single-point LOD score of 5.41 in the combined sample and an empirical P value <.001 from 1,000 simulated genomewide screens. This marker is located within an intron of the gene ADRBK2, encoding the beta-adrenergic receptor kinase 2. Fine mapping of this linkage region may reveal variants contributing to heaviness of smoking, which will lead to a better understanding of the genetic mechanisms underlying nicotine dependence.     

Influence of sarmesin on some dopamine-related types of behaviour

Summary The present study was undertaken to investigate the effects of sarmesin, an analogue of [Sar¹] angiotensin II (ANG II) where the tyrosine hydroxyl group in position 4 is methylated, on dopamine (DA)-related paradigms: locomotor and exploratory behaviour as well as apomorphine (3 mg/kg, ip)-induced stereotypy in rats. Sarmesin (0.5 and 1 g, icv) significantly decreased ambulation and rearing movements, and blocked the inhibitory effect of ANG II (0.1 g) on both types of activity. Sarmesin induced biphasic effects on apomorphine-induced stereotypy depending on the dose increase (0.5 and 5 g, icv) and decrease (10 g). Moreover, sarmesin (5 g) blocked the inhibitory effect of ANG II (2 g, icv) on apomorphine stereotypy. Taken together, these results suggest that sarmesin might interact with AT₁ and AT₂ receptor subtypes. The results further confirm the statement for ANG II-DA interaction in brain structures involved in these types of behaviour.     

Cosynthesis of erythromycin A N-oxide by mutants ofSaccharopolyspora erythraea blocked in erythromycin production

The production of erythromycin A (1) and free erythronolide B (2) inSaccharopolyspora erythraea BTCC-2 is accompanied by formation of erythromycin A N-oxide (3) and other minor components, the ratio of yields of1 and3 being 97:3. Erythromycin-blocked mutants of type I (impaired in some unidentified steps prior to lactone synthesis) and type II (accumulating only2) cosynthesized both1 and the accompanying metabolites, but the ratio of1 and3 changed to 70:30. In pure cultures of type I, exogenous2 was converted to1 and minor components in ratios typical of the strain BTCC-2, whereas mutants of type II were effective convertors of1 to3.     

Increase in protein kinase C activity is associated with human fibroblast growth inhibition.

Protein kinase C (PKC) activity and DNA synthesis were measured in human fetal bone marrow fibroblasts following treatment with tumor necrosis factor alpha (TNF alpha) (500 U/ml) or conditioned media containing natural cell proliferation inhibitor (CM-NCPI). Treatment with TNF alpha led to growth stimulation (120 +/- 7% of control in 24 h, 141 +/- 6% in 72 h). At the same time particulate PKC activity diminished, reaching 55 +/- 8% of control in 24 h and remaining at this level at 72 h. CM-NCPI treatment of the cells resulted in a decrease in DNA synthesis (by 39 +/- 6% in 2 h, by 58 +/- 5% in 24 h, and by 78 +/- 8% in 72 h). This was accompanied by a significant rise in particulate PKC activity which increased over 3-fold in 2 h, over 5-fold in 24 h, and up to 11-fold in 72 h. This 11-fold elevation was maintained after 2 week exposure of the fibroblasts to CM-NCPI. The PKC inhibitor neomycin abolished CM-NCPI induced growth inhibition, whereas PKC activator 12-O-tetradecanoylphorbol 13-acetate intensified it. These results suggest that CM-NCPI acts as PKC activator and that negative growth regulation by extracellular agents may involve stimulation of PKC activity.     

Specific features of the structural organization of the mitochondrial genome in RAT liver

Summary The nature of intramolecular heterogeneity of mtDNA in the liver of white rats has been studied. The peculiarities of the melting curve, and the possibility of DNA fractionation of nucleotide compounds with hydroxylapatite (HA) column chromatography has shown the presence of sequences differing in the mean nucleotide content. A section of about 350 pairs in size repeated four times was found in the reassociation of most thermolabile fraction with a mean composition of 28% GC. These sections are well seen on the denaturation map of the recorded molecules formed in the range of temperature transition helix-coil. The distance between the centers of fusible sections (in percentage of total length) is 32.5, 32, 14.0 and 21.5.     

Sensitization to mites in house dust among children suffering bronchial asthma]

The results of studying allergy to domestic dust in 168 patients suffering from bronchial asthma are presented. The diagnosis was made by means of the domestic dust allergen (10000 PNU), fraction E extracted from the whole allergen by Berrens and Young's method, and with lyophilized extract from D. pteronussinus, farinae and Glycyphagus ticks isolated from domestic dust by Voohorst and Spieksma's method. In parallel, IgE was determined in the blood serum of the patients under study by the radio-allergo-sorbent test; IgG was also determined. Microticks proved to be not the only factor determining the activity of domestic dust. Results of diagnosis in vivo and in vitro were found to correlate. The authors believe that the activity of domestic dust allergen formed on account of the reactions of the Maillard's type, in which a significant role was played by the "lysine-sugar) compounds.     

Beneficial properties of lactic acid bacteria naturally present in dairy production

Background

Consumers are increasingly demanding for natural and beneficial foods, in order to improve their health and well-being. Probiotics play an important role in such demand, and dairy foods are commonly used as vehicles for such bacteria, represented predominantly by lactic acid bacteria. Due to consumers demand, food industry is constantly looking for novel bacterial strains, leading to studies that aims the isolation and characterization of their beneficial features. This study aimed to characterize the naturally occurring lactic acid bacteria obtained from a dairy environment, in order to assess their potential use as probiotics.

Results

Preliminary screening and PCR analysis, based on 16S rRNA sequencing, were applied to select and identify 15 LAB strains from the genera Lactobacillus (n?=?11), Pediococcus (n?=?2) and Weissella (n?=?2). All strains showed resistance to low pH and the evaluated bile salt concentrations in vitro. The API ZYM test characterized the enzymatic activity of the strains, and a high β-galactosidase activity was observed in 13 strains. All strains presented resistance to simulated gastric (3?h) and intestinal (4?h) conditions in vitro, the ability to auto- and co-aggregate with indicator microorganisms and a high cell surface hydrophobicity. Most of the strains were positive for map and EFTu beneficial genes. All strains exhibited strong deconjugation of bile salts in vitro and all assimilated lactose.

Conclusions

The phenotypes exhibited in vitro and the presence of beneficial genes revealed the beneficial potential of the studied strains, demanding further analyses in a food matrix and in vivo to allow the development of a functional product, with health-related properties.

     

In vitro and in vivo characterization of a novel,highly potent p53-MDM2 inhibitor

Small molecule inhibitors of the p53-MDM2 protein complex are under intense investigation in clinical trials as anti-cancer agents, including our first generation inhibitor NVP-CGM097. We recently described the rational design of a novel pyrazolopyrrolidinone core as a new lead structure and now we report on the synthesis and optimization of this to provide a highly potent lead compound. This new compound displayed excellent oral efficacy in our preclinical mechanistic in vivo model and marked a significant milestone towards the identification of our second generation clinical candidate NVP-HDM201.