Presence of a drifting algal bed in the Mar Piccolo basin,Taranto (Ionian Sea,Southern Italy)

A survey is reported of the drifting algal community in Mar Piccolo, a polluted basin subject to sewage outlets. The key role was played by a few key species, mainly floridean red algae.     

Evidence for an inhibition of thyroid hormone effects during chronic treatment with amiodarone

The effects of chronic amiodarone treatment on several thyroid and cardiac function parameters were studied in 50 euthyroid patients with refractory ventricular arrhythmias, divided in responders and nonresponders according to their sensitivity to the antiarrhythmic action of the drug. No differences in the severity of cardiac disease and blood amiodarone concentrations were found in the two groups. Amiodarone induced a significant inhibition of peripheral T4 monodeiodination, more pronounced in responders compared to nonresponders. On the contrary, only in responsive patients, elevated basal and TRH-stimulated TSH levels were observed (despite serum T3 levels were not different from those in nonresponders) and the indirect indices of cardiac performance, particularly the systolic time intervals, fell in a range usually observed in the hypothyroid states. These findings suggest that amiodarone, besides the well-known inhibition of T4 to T3 conversion, also induces a partial resistance to the thyroid hormones, which is probably involved in the therapeutical effectiveness of the drug.     

Age-Related Changes in Aldehyde Dehydrogenase Activity of Rat Brain, Liver, and Heart

Abstract: Aldehyde dehydrogenase (ALDH) activity was measured in brains, livers, and hearts of 23–26-month-old and 3-month-old rats. A significant increase of ALDH activity was found in whole brain of old rats with both acetaldehyde (39%) and propionylaldehyde (15%) used as substrates. In different brain areas of old rats, with acetaldehyde used as substrate, a significant increase of ALDH activity was found in striatum (30–50%) and cerebral cortex (37%). However, no significant difference in ALDH activity was found in livers and hearts of young and old rats. Preliminary experiments showed a significant increase of aldehyde reductase activity (52%) with p -nitrobenzaldehyde used as substrate in whole brain of old rats compared with young rats. The present work indicates that an increase of ALDH activity in brain of old rats may be an adaptive phenomenon.     

Normal rat intestinal cells IEC-18: characterization and transfection with immortalizing oncogenes

IEC-18 cells, a cell line derived from the ileum of rat intestine, have the characteristics of normal cells since they have a contact inhibited cell growth, do not form colonies in soft agar and are not tumorigenic when injected in nude mice. IEC-18 cells were transfected with nuclear oncogenes, c-myc, v-myc and SV40 T antigen in order to obtain immortal cell lines. Independent clones were isolated and characterized for the growth properties. Expression of v-myc altered the morphology of the cells and shortened the doubling time. A slow growth together with a low cloning efficiency was associated with the expression of SV40 T antigen. No changes either in growth or in morphology were observed in c-myc-expressing IEC-18 cells. Expression of these nuclear oncogenes did not result in the neoplastic transformation of the IEC-18 cells, since none of the clones lost the anchorage dependence or were able to form tumors in vivo. The c-myc-containing IEC-18 cells were unable to secrete in the growth medium TGF and exposure to TGF inhibited the growth rate by 30%. All these observations are consistent with the conclusion that the expression of nuclear oncogenes does not lead to the neoplastic transformation of these cells.     

Clinical pharmacology of the new COMT inhibitor CGP 28 014

CGP 28 014 is a specific inhibitor of catechol-O-methyltransferase (COMT) in vivo. In humans, the inhibition was assessed by measuring urinary excretion of isoquinolines and with the levodopa test. Following administration of CGP 28 014, urinary excretion of isoquinolines was significantly increased. In rats, CGP 28 014 reduced plasma and striatal concentrations of 3-O-methyldopa (30MD) in a dose-dependent manner. Acute and subchronic administration of CGP 28 014 alone or in combination with the peripherally acting decarboxylase inhibitor benserazide decreased plasma 30MD as an index of COMT inhibition by about 50%. There seems to be a close relationship between the time-course of plasma concentrations of CGP 28 014 and the extent of COMT inhibition assessed by the 30MD/DOPA ratio in plasma.     

Mechanisms of Nitrosylation and Denitrosylation of Cytoplasmic Glyceraldehyde-3-phosphate Dehydrogenase from Arabidopsis thaliana

Nitrosylation is a reversible post-translational modification of protein cysteines playing a major role in cellular regulation and signaling in many organisms, including plants where it has been implicated in the regulation of immunity and cell death. The extent of nitrosylation of a given cysteine residue is governed by the equilibrium between nitrosylation and denitrosylation reactions. The mechanisms of these reactions remain poorly studied in plants. In this study, we have employed glycolytic GAPDH from Arabidopsis thaliana as a tool to investigate the molecular mechanisms of nitrosylation and denitrosylation using a combination of approaches, including activity assays, the biotin switch technique, site-directed mutagenesis, and mass spectrometry. Arabidopsis GAPDH activity was reversibly inhibited by nitrosylation of catalytic Cys-149 mediated either chemically with a strong NO donor or by trans-nitrosylation with GSNO. GSNO was found to trigger both GAPDH nitrosylation and glutathionylation, although nitrosylation was widely prominent. Arabidopsis GAPDH was found to be denitrosylated by GSH but not by plant cytoplasmic thioredoxins. GSH fully converted nitrosylated GAPDH to the reduced, active enzyme, without forming any glutathionylated GAPDH. Thus, we found that nitrosylation of GAPDH is not a step toward formation of the more stable glutathionylated enzyme. GSH-dependent denitrosylation of GAPC1 was found to be linked to the [GSH]/[GSNO] ratio and to be independent of the [GSH]/[GSSG] ratio. The possible importance of these biochemical properties for the regulation of Arabidopsis GAPDH functions in vivo is discussed.     

Screening of <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> wine strains for the production of acetic acid

In this study 80 wine strains of Saccharomyces cerevisiae were characterized for the production of acetic acid. A significant variability in the production levels was determined among the strains, which produced from a few mg/l to more than 1 g/l. Fifteen strains, differing in acetic acid production, were tested in fermentation of grape musts of different varieties (Aglianico Basilicata, Aglianico Apulia, Cannonau, Bombino nero, Nero d'Avola, Vermentino, Fiano). The results emphasized a great strain variability, but the best strain behaviour was strictly related to the must composition, which is a determinant factor on the expression of the best strain potentiality. Therefore, this study, confirming the high/low production of acetic acid as a strain characteristic, demonstrated also that the inoculated fermentation becomes more advantageous when the starter culture is chosen in relation to the interaction of yeast strain/vine variety.