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R Pagnotta

Publications and source records attributed to R Pagnotta.

7 recordsLinked to original sources
PubMed1999

General features of the Adriatic Sea: the key role of carbon cycling.

Major inputs into the northern Adriatic Sea and critical problems affecting this basin are revised strengthening the need for a thorough knowledge of organic carbon cycling. Results gathered in the context of the PRISMA 2 project by our research group give information on the distribution and composition of organic matter in terms of major biochemical components, molecular weight sizes and biodegradability characteristics. Seasonal accumulation of dissolved organic matter in summer along with an increased role of carbohydrate and colloidal matter (being on average 15-20 and 60-65% of DOC, respectively) and restricted bacterial activity due to P deficiency are all priority subjects to be further investigated.

Bacteria↗
PubMed1985

Polycyclic aromatic hydrocarbon binding macromolecules. Identification, characterization and temperature activation of a 4.5 S binding nucleoprotein.

A macromolecule binding 3H-methylcholanthrene (3H-MCA) and 3H-benzo(a)pyrene (3H-BaP) and sedimenting in the 4-5 S region of sucrose gradient (4.5 S) was identified in rat liver cytosol. The binding was displaced by 100-fold molar excess unlabeled ligands whereas 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) was ineffective. The dissociation constant for both polycyclic aromatic hydrocarbons (PAHs) was of the order of 10(-8) M or lower. Both 3H-MCA and 3H-BaP bound to 4.5 S in a non covalent manner, since 92% of the bound radioactivity was extractable with ethyl ether. Furthermore the binding was strongly reduced by urea 8 M and by guanidine. HCl 4 M (99 and 70% respectively). Thin layer chromatography of the ethyl ether-solubilized radioactivity showed a peak comigrating with PAHs used as standards. When chromatographed on Sephadex G-200, 4.5 S was eluted as a sharp peak with an apparent molecular weight of 50-60,000 daltons. Enzyme treatment of liver cytosol showed that the 4.5 S binding sites were destroyed by micrococcal nuclease (92% of inhibition). Papain and phosphodiesterase I and II reduced the binding to 50%, whereas DNase I, DNase II, RNase, phospholipase A2 and C and trypsin were ineffective. These data suggest that the PAHs binding macromolecule of rat liver cytosol is a protein associated with a polynucleotide. The binding of both PAHs was enhanced by increasing the incubation temperature, the maximum being reached after 20-30 min at 37 degrees C. After 2.5 min at 65 degrees C, binding sites were completely destroyed. The same temperature-induced "activation" was obtained also by prewarming the cytosol at 37 degrees C in the absence of ligands.

Animals↗
PubMed1984

Interaction of rat liver glucocorticoid receptor with heparin.

When rat liver cytosol containing [3H]dexamethasone-glucocorticoid receptor complex is exposed to immobilized heparin (Sepharose-heparin; Seph-hep) the steroid receptor complex binds to the substituted Sepharose avidly [Kd = 3.5 (+/- 1.7) X 10(-10) M], and 80-90% of the receptor present is adsorbed to the solid phase after 40 min at 0 degree C. The binding is enhanced by Mn2+ (10 mM) and Mg2+, whereas Ca2+ and Sr2+ are ineffective. Sodium molybdate (10 mM) does not influence the reaction but enhances receptor stability. Moreover, binding of the receptor to Seph-hep is dependent on the ionic strength of the medium, because binding is totally reversed by 300 mM KCl. The bound [3H]dexamethasone-receptor complex can be recovered from Seph-hep with solutions (4 mg/mL) of heparin (95% release), dextran sulfate (88%), and chondroitin sulfate (63%); total calf liver RNA is less effective (9%), whereas dextran, D-glucosamine, N-acetyl-D-glucosamine, D-glucuronic acid, and sheared calf thymus DNA are totally ineffective (less than 3%). Both "native" and temperature "transformed" forms of the glucocorticoid receptor interact with immobilized heparin. These results strongly suggest that the receptor site that binds heparin is distinct from that binding DNA. An immediate application of this newly found ability of the glucocorticoid receptor to interact with heparin is the use of Seph-hep for affinity chromatography purification of the glucocorticoid receptor. A purification of 10-fold, with a recovery of 55-65%, can be achieved by using either 4 mg/mL heparin or 300 mM KCl to elute [3H]dexamethasone-receptor bound to the resin.

Animals↗
PubMedDate not supplied

[Coliphages, viral indicators of contamination].

This paper illustrates the importance of coliphages, which are specific bacteriophages for Escherichia coli strains, as viral indicators, and suggests the usefulness of a routine coliphage search in the detection of viral contamination. The samples studied consisted of 57 surface water, (46 of sea water and 11 of river water), 2 of mud taken from biological treatment plants and 3 samples of sludge. The results revealed that coliphages can be considered valid indicators of viral contamination as they show a good response to the general standards established for indicators. In particular: they are found in sludge (both untreated and treated) and in surface water (both river and sea) in higher concentrations than those of enterovirus; they show greater resistance than bacterial indicators to disinfection as, in different experimental conditions, the drop in the level does not exceed orders of magnitude they are relatively simple to identify, and are easily quantifiable by means of the MPN method, with the result that they can be used for the management of water resources. As regards the possible use of coliphages for the control of the necessary qualitative requisites of sea water for bathing, the relation with fecal coli enables us to make an assessment of coliphages corresponding to 100 fecal coli/100 ml. This levels is equivalent to 0.95 so that a suitable guide line for water for bathing purposes could for example be established at 10 coliphages/1. Although coliphages may be considered good indicators of viral contamination this clearly does not mean that they can replace classic bacterial indicators but rather, that they can provide useful additional information, particularly in those cases where a rapid drop in bacterial content may conceal high risk health and hygiene conditions.

Bacteria↗