Influences of Flavonoids on Erythrocyte Membrane and Metabolic Implication Through Anionic Exchange Modulation

The antioxidative activity of some natural flavonoids was analyzed against the stable free radical 2,2-diphenyl-1-picryhydrazyl. The results indicate that the scavenging power of the tested flavonols is higher than that of the synthetic antioxidants butylated hydroxyanisole and butylated hydroxytoluene; instead, the flavanones show little activity, as indicated by efficient concentration (EC₅₀) values. Flavonoid autoxidation and interaction with Fe²⁺ and hydrogen peroxide were tested using erythrocyte membranes as a model. The results show that some compounds, like hesperetin, evidence a pro-oxidant activity higher than the ascorbic acid/iron reference system. The compounds with strong oxidative capability do not only influence cellular redox balance but also activate caspase-3, producing lactate dehydrogenase release and enhancing anionic exchange at the level of band 3 protein.     

Tracking the origin of the invading Caulerpa (Caulerpales, Chlorophyta) with Geographic Profiling, a criminological technique for a killer alga

The application of the Geographic Profiling technique (with the “Rossmo formula”) proved to be effective in assessing the spreading origin of invading species of Caulerpa in the Mediterranean. Geoprofiling is a technique more frequently used in criminology. We applied this method to an algal invasion for the first time. The method was calibrated with the distribution data of Caulerpa taxifolia, whose spreading in the Mediterranean Sea started from the aquarium of Monaco. This is the first time that Geographic Profiling is calibrated on a data set of sites of presence of a biological invader, of which the spreading origin is known. The application on Caulerpa racemosa var. cylindracea showed that the probable spreading center of the alga should be located in Western Sicily for the Mediterranean and in the southern part of Tenerife for the Canary Islands (Las Galletas, a fishing village). The spreading centers correspond to areas with ports, indicating that the spreading of this alga should be related to (fishing) boats. This result confirmed the opinion of other authors. The parameters used in the Rossmo Formula, obtained through calibration with the known origin of C. taxifolia invasion for identifying the origin of the spread of C. racemosa var. cylindracea may be extended to other algae with similar propagation mode and similar habitat requirements.     

Evaluation of corneal structures in myopic eyes more than twenty‐two years after photorefractive keratectomy

The aim of this study is to evaluate corneal epithelial thickness (CET), corneal densitometry (CD) in 84 myopic eyes (57 patients) more than 22 years after photorefractive keratectomy, using anterior segment‐optical coherence tomography (AS‐OCT) and Scheimpflug imaging system. The CET was significantly higher in all operated eyes than in unoperated eyes in central sector. A statistically significant increase in CD in corneal anterior layer of central sector was shown in groups of operated eyes with greater ablation depth respect to unoperated eyes. While there was no significant difference in CD between the operated eyes groups with lower ablation depth and unoperated eyes. A significant trend toward higher values in anterior CD with deeper ablations in central sector was found. These noninvasive imaging techniques allow to better understand the corneal remodeling process after photoablation and to monitor the patients over time.     

Linkage analysis of Fanconi anaemia in Italy and mapping of the complementation group A gene

Fanconi anaemia (FA) is an autosomal recessive disease characterised by genetic heterogeneity, with at least five complementation groups (FA-A to FA-E). The FAC gene has been cloned and localised to 9q22.3. The most frequent defective gene, FAA, was recently mapped to chromosome 16q24.3, in a region of 10 cM between D16S498 and the telomere. Eleven FA-A and 16 unclassified Italian families were analysed by microsatellite markers. To define the localisation of the FAA locus further, microsatellites were analysed at 16q24. All the families were consistent with linkage, the highest lod score being observed with D16S1320. Evidence for common haplotypes was obtained in two genetic isolates from the Brenta basin and the Naples region. Autozygosity mapping and haplotype analysis suggest that the FAA locus is distal to D16S305. Received: 29 July 1996     

Uncovering the spatial pattern of invasion of the honeybee pest small hive beetle,Aethina tumida,in Italy

The fast tracking of invasion spatial patterns of alien species is crucial for the implementation of preventive and management strategies of those species. Recently, a honeybee pest, the small hive beetle Aethina tumida (hereafter SHB), has been reported in Italy, where it colonized more than 50 apiaries in an area of about 300 km². SHB is a nest parasite and scavenger of honeybee colonies native of Sub-Saharian Africa. Likely being helped by the globalization of apiculture, SHB underwent several invasions in the last twenty years, causing locally relevant economic impact. While many features of its biology have been addressed, an important knowledge gap concerns the spatial invasion dynamics in invaded areas. In this paper we coupled two spatial analysis techniques (geographic profiling and a density-based spatial clustering algorithm) to uncover the possible invasion pattern of SHB in Italy. We identified the port town of Gioia Tauro as the most likely point from which SHB may have spread and suggested the possible successive axes of diffusion. These putative diffusion paths suggest that the SHB spread in south Italy might have been due to a mix of natural dispersal between close apiaries and longer distance movement through faster, likely human-mediated, communication routes.     

Synthesis and biological evaluation of 1,7,8,8a-tetrahydro-3H-oxazolo[3,4-a]pyrazin-6(5H)-ones as antitumoral agents

A series of 1,7,8,8a-tetrahydro-3H-oxazolo[3,4-a]pyrazin-6(5H)-ones has been synthesized by an intramolecular, palladium(II) catalyzed, aminooxygenation of alkenyl ureas, readily available from glycine allylamides as starting materials. Biological tests showed that the obtained compounds are endowed with an interesting antitumoral activity against two human thyroid cancer cell lines, namely FTC-133 and 8305C, by promoting the apoptotic pathway and DNA fragmentation.     

Synthesis and conformational analysis of cyclo-TRI[l-valyl-d-hexahydromandelyl]

The synthesis of the cyclo-hexadepsipeptide [l-valyl-d-hexahydromandelyl]₃ is described. Examination of this macrocyclic compound by 220-MHz nuclear magnetic resonance spectroscopy shows that symmetrical conformations are stabilized in strongly polar solvents (trifluoroacetic acid, acetonitrile), whereas asymmetric conformations are preferred in nonpolar or slightly polar media such as carbon tetrachloride, chloroform, cyclohexane, and benzene.From analysis of the temperature dependence of the chemical shift and of the coupling constants, together with conformational energy calculations, a model is proposed for the preferred conformation of this molecule in nonpolar solvents.     

Effect of salinity on cable bacteria species composition and diversity

Cable bacteria (CB) are Desulfobulbaceae that couple sulphide oxidation to oxygen reduction over centimetre distances by mediating electric currents. Recently, it was suggested that the CB clade is composed of two genera, Ca. Electronema and Ca. Electrothrix, with distinct freshwater and marine habitats respectively. However, only a few studies have reported CB from freshwater sediment, making this distinction uncertain. Here, we report novel data to show that salinity is a controlling factor for the diversity and the species composition within CB populations. CB sampled from a freshwater site (salinity 0.3) grouped into Ca. Electronema and could not grow under brackish conditions (salinity 21), whereas CB from a brackish site (salinity 21) grouped into Ca. Electrothrix and decreased by 93% in activity under freshwater conditions. On a regional scale (Baltic Sea), salinity significantly influenced species richness and composition. However, other environmental factors, such as temperature and quantity and quality of organic matter were also important to explain the observed variation. A global survey of 16S rRNA gene amplicon sequencing revealed that the two genera did not co-occur likely because of competitive exclusion and identified a possible third genus.     

Unravelling HP1 functions: post-transcriptional regulation of stem cell fate

Chromosoma - Heterochromatin protein 1 (HP1) is a non-histone chromosomal protein first identified in Drosophila as a major component of constitutive heterochromatin, required for stable epigenetic...