Endogenous opioids in marine invertebrates

A study of the presence of opioids in invertebrates was carried out on 11 species of marine organisms, ranging from sponges to tunicates. Delipidized acid-acetone extracts from whole organisms or dissected organs were assayed by receptor binding assays and radioimmuno assays. The extracts from all species tested were found to contain substances capable of competing in both assays with opioid peptides.     

Occurrence and distribution of some novel bromine containing pigments in scleractinians

The occurrence and isolation of two new yellow pigments, leptopsammin A and B, from methanolic extract of Leptopsammia pruvoti are described. The spectral properties (UV and MS) and colorimetric reactions of the leptopsammins suggest they are bromophenol compounds, characterised by a previously unknown chromophore. Among twelve different species of scleractinians examined, leptopsammins were found to be present in only two genera, Leptopsammia and Dendrophyllia.     

Reconstruction of the Evolutionary Dynamics of A(H3N2) Influenza Viruses Circulating in Italy from 2004 to 2012

Background

Influenza A viruses are characterised by their rapid evolution, and the appearance of point mutations in the viral hemagglutinin (HA) domain causes seasonal epidemics. The A(H3N2) virus has higher mutation rate than the A(H1N1) virus. The aim of this study was to reconstruct the evolutionary dynamics of the A(H3N2) viruses circulating in Italy between 2004 and 2012 in the light of the forces driving viral evolution.

Methods

Phylodinamic analyses were made using a Bayesian method, and codon-specific positive selection acting on the HA coding sequence was evaluated.

Results

Global and local phylogenetic analyses showed that the Italian strains collected between 2004 and 2012 grouped into five significant Italian clades that included viral sequences circulating in different epidemic seasons. The time of the most recent common ancestor (tMRCA) of the tree root was between May and December 2003. The tMRCA estimates of the major clades suggest that the origin of a new viral strain precedes the effective circulation of the strain in the Italian population by 6–31 months, thus supporting a central role of global migration in seeding the epidemics in Italy. The study of selection pressure showed that four codons were under positive selection, three of which were located in antigenic sites. Analysis of population dynamics showed the alternation of periods of exponential growth followed by a decrease in the effective number of infections corresponding to epidemic and inter-epidemic seasons.

Conclusions

Our analyses suggest that a complex interaction between the immune status of the population, migrations, and a few selective sweeps drive the influenza A(H3N2) virus evolution. Our findings suggest the possibility of the year-round survival of local strains even in temperate zones, a hypothesis that warrants further investigation.     

High potential of adhesion to abiotic and biotic materials in fish aquaculture facility by Vibrio alginolyticus strains

Aims:  The ability of Vibrio alginolyticus strains isolated from Sparus aurata and Dicentrarchus labrax nursery to adhere to epithelial cell lines (Hep-2 and Caco-2), fish mucus and their ability to form a biofilm on different surfaces (glass, polystyrene, polyethylene and polyvinyl-chloride) was investigated in this study.
Methods and Results:  The extracellular products were rich in enzymes and the strains were haemolytic on Wagatsuma agar and possessed several hydrolytic exoenzymes such as proteases, DNase and lipases. Most strains tested were multiresistant to the 17 antibiotics tested including those used in the farm to treat vibriosis.
Conclusions:  These bacteria were able to form a biofilm on all the surfaces tested and the cell density was the highest on the PVC surface followed by that on the glass slides, polystyrene and the polyethylene surface. More than 50% of the tested strains were adhesive to the epithelial cell lines (Hep-2 and Caco-2).
Significance and Impact of the Study:  These properties allow these bacteria to survive, proliferate and persist in all stages of fish rearing nursery even after seawater treatment with UV light.     

Inhibition of NTPDase, 5′-nucleotidase, Na/K-ATPase and acetylcholinesterase activities by subchronic treatment with Casearia sylvestris

The aqueous extract of Casearia sylvestris was tested in cortical membrane preparations. C. sylvestris was obtained commercially from two different sources, designated as Sample A and Sample B. The enzymes studied in this work were NTPDase-like, 5'-Nucleotidase, Na(+)/K(+)-ATPase and acetylcholinesterase (AChE). Adult rats received aqueous extracts from C. sylvestris in a dose of 20mg/kg body wt. daily for a 75-day-period, by oral administration (gavage). Our study showed that this treatment caused an inhibition of NTPDase-like activity with both, ATP (19.41% with Sample A and 25.03% with Sample B) and ADP (41.57% with Sample A and 31.20% with Sample B) as substrates. This treatment also caused an inhibition of 5'-nucleotidase activity (28.34% with Sample A and 31.46% with Sample B) and Na(+)/K(+)-ATPase (25.08% with Sample A and 24.81% with Sample B). The rate of acetylcholine degradation was reduced, as shown by the inhibition of AChE (31.65% and 26.74%, Samples A and B, respectively). These results suggest that extracts of C. sylvestris can cause neurochemical alterations in the purinergic and cholinergic systems of the central nervous system.     

Osservazioni Preliminari sui Sistemi Degradanti dell'RNA nei semi di Ricino

Abstract

Preliminary observations on the enzymatic degradation of RNA in castor bean seeds. — Cocucci, Maggio, Monroy and Marrè have shown the decrease of RNA content during ripening in castor bean seeds, and its increase during germination. Furthermore, these Authors have demonstrated that in the dry ripe seeds the ribosomes are undetectable, and that they increase rapidly during germination. Two peaks of ribosomes are easily detected upon ultracentrifugal analysis in germinating seeds (Cocucci and Sturani). These observations were the basis for our investigations of the enzymes of RNA metabolism in castor bean seeds. This paper deals with our preliminary observations on RNA degrading enzymes in these tissues. We have been able to measure RNase activity, phosphodiesterase, 3′-,5′- and 2′-nucleotidases in castor bean seeds at different stages of development. RNase activity (measured in crude extracts) changes little during the ripening process, its rate corresponding to 40–50 μMoles of nucleotides liberated from RNA per hour and per gram of fresh weight. In the dry seeds, RNase activity is 30–40 μMoles of nucleotides/h.g.f.w., and it increases to about 60–70 μMoles/h/g.f.w. after 72 hours of germination.

Phosphodiesterase activity is about 4–5 μMoles/h.g.f.w.

The following rates have been found in seeds almost completely ripe seeds for 3′-, 5′- and 2′-nucleotidase activities, respectively 45–50 μMoles/h.g.f.w.; 6–7 μMoles/h.g.f.w.; 8 μMoles/h.g.f.w.; ATP-ase activity was of about 80–100 μMoles of phosphate liberated /h.g.f.w. - The high activity of 3′-nucleotidase, of the same order of that of RNase, suggests that these two enzymes are responsible for degradation of RNA to nucleosides and inorganic phosphate. Further investigations are being carried on to define the biochemical properties of castor bean RN-ase.