Superoxidedismutase-mimetic copper(II) complexes containing saccharinate and 4-aminopyridine/4-cyanopyridine

Two copper(II) complexes, [Cu(sac)₂(4-cypy)₂(H₂O)], 1 and [Cu(sac)₂(4-Ampy)₂(H₂O)], 2 (4-cypy: 4-cyanopyridine; 4-Ampy: 4-aminopyridine) were prepared. Physicochemical properties of the complexes were studied by spectroscopic (solution UV–vis, diffuse reflectance and IR) techniques. Structural X-ray diffraction data could be obtained only for [Cu(sac)₂(4-cypy)₂(H₂O)] that it crystallized in the tetragonal space group P4cc with a=b=15.313(1), c=13.240(1) Å, and Z=4 molecules per unit cell. The complex was cited on a crystallographic C₂-axis with the Cu(II) ion in a square–pyramidal environment, coordinated at the pyramid basis to the nitrogen atom of two saccharine anions [d(Cu–N)=2.011(3) Å] and the pyridine N-atom of two 4-cyanopyridine ligands [d(Cu–N)=2.038(4) Å]. The coordination was completed by a water molecule at the pyramid apex [d(Cu–Ow)=2.189(5) Å]. Elemental and spectroscopic analyses revealed an O-saccharinate coordination mode for complex 2 and a square–pyramidal structure. Only complex 2 retained its structure in methanolic solution. However, both complexes were able to catalyze the dismutation of superoxide anion (O₂^?) (pH 7.5) at micromolar concentrations. Therefore, these complexes behaved as useful SOD-mimetic compounds.     

Y chromosome haplogroups of elite Ethiopian endurance runners

Favourable genetic endowment has been proposed as part of the explanation for the success of East African endurance athletes, but no evidence has yet been presented. The Y chromosome haplogroup distribution of elite Ethiopian athletes (n=62) was compared with that of the general Ethiopian population (n=95) and a control group from Arsi (a region producing a disproportionate number of athletes; n=85). Athletes belonged to three groups: marathon runners (M; n=23), 5–km to 10–km runners (5–10K; n=21) and other track and field athletes (TF; n=18). DNA was extracted from buccal swabs and haplogroups were assigned after the typing of binary markers in multiplexed minisequencing reactions. Frequency differences between groups were assessed by using contingency exact tests and showed that Y chromosome haplogroups are not distributed amongst elite Ethiopian endurance runners in the same proportions as in the general population, with statistically significant (P<0.05) differences being found in four of the individual haplogroups. The geographical origins and languages of the athletes and controls suggest that these differences are less likely to be a reflection of population structure and that Y chromosome haplogroups may play a significant role in determining Ethiopian endurance running success.     

Deletion polymorphism in the gene for angiotensin converting enzyme is associated with elevated fasting blood glucose levels

The frequency and distribution of angiotensin converting enzyme insertion/deletion (ACE I/D) polymorphism, and its association with other known risk factors for coronary atherosclerosis, has been studied, in a normal south Italian population. Subjects homozygous for deletion showed elevated fasting blood glucose levels when compared with subjects homozygous for insertion. The difference was consistent with an increased number of type 2 diabetics among the former group of subjects.Recipient of a post-doctoral fellowship from the Associazione Italiana Ricerca sul Cancro (A.I.R.C.)     

Structure of the O polysaccharides and serological classification of Pseudomonas syringae pv. porri from genomospecies 4.

Strains of Pseudomonas syringae pv. porri are characterized by a number of pathovar-specific phenotypic and genomic characters and constitute a highly homogeneous group. Using monoclonal antibodies, they all were classified in a novel P. syringae serogroup O9. The O polysaccharides (OPS) isolated from the lipopolysaccharides (LPS) of P. syringae pv. porri NCPPB 3365 and NCPPB 3364T possess multiple oligosaccharide O repeats, some of which are linear and composed of l-rhamnose (l-Rha), whereas the major O repeats are branched with l-rhamnose in the main chain and GlcNAc in side chains (structures 1 and 2). Both branched O repeats, which differ in the position of substitution of one of the Rha residues and in the site of attachment of GlcNAc, were found in the two strains studied, O repeat 1 being major in strain NCPPB 3365 and 2 in strain NCPPB 3364T. [formula: see text]. The relationship between OPS chemotype and serotype on one hand and the genomic characters of P. syringae pv. porri and other pathovars delineated in genomospecies 4 on the other hand is discussed.     

Plant-mycorrhizal fungi feedbacks: potential accomplices of <Emphasis Type="Italic">Avena barbata</Emphasis>’s high invasiveness

Alteration of the soil microbial communities can have important effects on plant invasion. The interdependence between plants and soil microbes could generate complex dynamics in which the composition of plant communities is regulated by the feedbacks of microbial communities on plant growth. In a greenhouse experiment we tested whether the soil microbes in roots of an invasive annual (Avena barbata, wild oat) and a native grass (Rytidosperma caespitosum, wallaby grass) can affect invasive and/or native plant performance. Individuals of each plant species were planted in sterilized soil to which pieces of roots of the same or the other species were added as a layer below the top soil. When plants were harvested after 10 weeks, the addition of roots of any species reduced the total biomass of wild oat. On the other hand, addition of roots of wild oat caused a much stronger reduction of the growth of wallaby grass, while roots of wallaby grass tended to increase its plant growth and shifted biomass allocation patterns. On balance, given the strength of the negative effects, our results indicated that invasion-induced changes in the soil microbial community could contribute to a displacement of the native grass. Thus, these changes might induce a positive feedback mechanism, contributing to the increased dominance of wild oat over wallaby grass in South Australian grasslands.     

Protection induced by Plasmodium falciparum MSP1(42) is strain-specific, antigen and adjuvant dependent, and correlates with antibody responses

Vaccination with Plasmodium falciparum MSP1(42)/complete Freund's adjuvant (FA) followed by MSP1(42)/incomplete FA is the only known regimen that protects Aotus nancymaae monkeys against infection by erythrocytic stage malaria parasites. The role of adjuvant is not defined; however complete FA cannot be used in humans. In rodent models, immunity is strain-specific. We vaccinated Aotus monkeys with the FVO or 3D7 alleles of MSP1(42) expressed in Escherichia coli or with the FVO allele expressed in baculovirus (bv) combined with complete and incomplete FA, Montanide ISA-720 (ISA-720) or AS02A. Challenge with FVO strain P. falciparum showed that suppression of cumulative day 11 parasitemia was strain-specific and could be induced by E. coli expressed MSP1(42) in combination with FA or ISA-720 but not with AS02A. The coli42-FVO antigen induced a stronger protective effect than the bv42-FVO antigen, and FA induced a stronger protective effect than ISA-720. ELISA antibody (Ab) responses at day of challenge (DOC) were strain-specific and correlated inversely with c-day 11 parasitemia (r = -0.843). ELISA Ab levels at DOC meeting a titer of at least 115,000 ELISA Ab units identified the vaccinees not requiring treatment (noTx) with a true positive rate of 83.3% and false positive rate of 14.3 %. Correlation between functional growth inhibitory Ab levels (GIA) and cumulative day 11 parasitemia was weaker (r = -0.511), and was not as predictive for a response of noTx. The lowest false positive rate for GIA was 30% when requiring a true positive rate of 83.3%. These inhibition results along with those showing that antigen/FA combinations induced a stronger protective immunity than antigen/ISA-720 or antigen/AS02 combinations are consistent with protection as ascribed to MSP1-specific cytophilic antibodies. Development of an effective MSP1(42) vaccine against erythrocytic stage P. falciparum infection will depend not only on antigen quality, but also upon the selection of an optimal adjuvant component.     

The phospholipid base-exchange system as a possible modulator of γ-aminobutyric acid transport in brain cells

Mixed cell suspensions from rabbit brain have been used to study the effect of base exchange in membrane phospholipids, on amino acid accumulation in vitro. -Aminobutyric acid (GABA), glutamic acid, and aminoisobutyric acid have been used. The accumulation of [³H]GABA, at concentrations employing the high-affinity uptake system, was measured after base-exchange reactions with ethanolamine, choline, orL-serine. Serine incorporation induced an increase of GABA uptake at all the concentrations used, while choline incorporation essentially led to inhibition of GABA accumulation. Ethanolamine exchange produced both stimulation and inhibition. The observed effects were not specific for GABA. Neuronal and glial cell perikarya and synaptosomes were studied in the same system in an attempt to resolve the complex type of response obtained with the mixed suspension. Cell specificity was found with respect to stimulation or inhibition of GABA transport after base exchange but, in some cases, the isolated fractions retained the multiphasic response observed with the mixed suspension.