L'educazione fisica in Italia: scenari, sfide, prospettive

Il documento di consenso è il tentativo, di un ampio gruppo di ricercatori italiani che si occupano di Educazione Fisica, di condividere contenuti, riferimenti culturali e prospettive della disciplina per rispondere alle sfide che gli anni ’20 del 2000 propongono. Non risulta sia mai stato fatto prima in questa forma collettiva. Lo scopo principale consiste nel contribuire ad una più chiara ed aggiornata definizione della disciplina che oggi è posta di fronte a pressanti richieste della collettività. C’è un’esigenza di chiarezza cui si è cercato di contribuire, innanzitutto, elaborando un articolato glossario di termini e concetti. Tante sono le “scienze” e le “pratiche” che hanno influenzato l’Educazione Fisica lasciando in eredità un linguaggio ampio, ma spesso confuso e non sempre coerente. Si è ritenuto che rendere esplicita questa complessità e proporre delle scelte possa servire a capirci meglio nella comunità di chi opera nell’Educazione Fisica e a farci meglio comprendere ed apprezzare da studenti e società. I riferimenti culturali della disciplina sono stati individuati, con un amplissimo confronto, sia attingendoli dalla tradizione che interpretando le attuali sollecitazioni della ricerca e dell’elaborazione culturale internazionali. Le indicazioni metodologico-didattiche per la progettazione e la conduzione dell’educazione Fisica cercano di riepilogare l’eterogeneità dei contributi della ricerca scientifica internazionale con ricadute necessarie e fondamentali anche nella formazione iniziale e in itinere dei docenti. Il contributo, frutto di un anno di lavoro da parte di una trentina di ricercatori di sedici università italiane, è a disposizione di insegnanti, ricercatori, responsabili di corsi universitari di scienze motorie e di politici. Le riflessioni, le critiche i suggerimenti che ci faranno pervenire aiuteranno a crescere tutta la comunità dell’Educazione Fisica italiana

Interaction between copper and zinc in metal accumulation in rats with particular reference to the synthesis of induced-metallothionein

The effectiveness of Zn at moderating the pro-oxidant effects of Cu was evaluated in two rat models that differed in the route and mode of administration. The endpoints investigated included measurement of the concentrations of Cu, Zn, metallothionein and glutathione concentrations, as well as SOD and catalase activity, in liver, kidneys and intestine. In a sub-chronic animal model, the hepatic accumulation of Cu was achieved by administration of dietary Cu (1.8 g/kg solid diet) for 30 days after which oral Zn (6 g/kg solid diet) was given. Cu treatment induced an increase in the hepatic and intestinal concentration of Cu of 66 and 455%, respectively, that was not associated with synthesis of metallothionein synthesis, but rather appeared to be related to the higher activity of SOD. Subsequent administration with Zn after dietary Cu induced an increase in the hepatic and intestinal metallothionein content of more twice and reduced the Cu content to control values. Thus, Zn could act as both a competitor for absorption on the luminal side of the intestinal epithelium inducing the synthesis of metallothionein. In the second animal model, we studied the effects of interaction between Cu and Zn administered by i.p. injection at the dose of 3 and 10 mg/kg, respectively; Zn was administered subsequent to Cu overload. In this case, when Zn was administered, Cu was already deposited in tissues and thus there is no competition between two metals at the level of membrane transport. In this experimental model treatment with Cu alone induced liver metallothionein synthesis, and the subsequent treatment with Zn did not decrease the hepatic content of Cu. One explanation for these observations is that Zn induces the synthesis of metallothionein, which binds Cu for which it has a higher affinity. Moreover, after treatment with Zn, SOD activity in the liver decreases of almost 30% with respect to treatment with alone Cu, suggesting that Zn has a protective effect. (c) 2005 Elsevier Ireland Ltd. All rights reserved

Effects of cadmium on catfish, Ictalurus melas, humoral immune response

Catfish (I. melas) were exposed to 10, 20 or 30 \u3bcg 1-1 of cadmium (CdCl2) toassess its in vivo effects on the humoral immune response. After one week of cadmium exposure, the titer of total non-specific immunoglobulins was remarkably reduced but, after 2 weeks of exposure the IgM titer increased, and no differences between treated and control fish could be observed. Immunization of catfish with sheep red blood cells (SRBC) was also performed to assess the effect of cadmium on the immune response to a specific antigen. Fish exposed to cadmium (20 \u3bcg 1-1) required a shorter period to reach the peak of IgM anti-SRBC titer; moreover, fish exposed to Cd for 2 weeks before immunization reached peak antibody response more quickly and also revealed a remarkable increase in antibody titer

Effects of cadmium on lymphocyte proliferation and macrophage activation in catfish, Ictalurus melas

The effects of cadmium (Cd) (in vitroandin vivo) on phytohaemoagglutinin(PHA)- or lipopolysaccharide(LPS)-induced lymphocyte proliferation were investigated in the catfish,Ictalurus melas. The effects of Cd on macrophage activation by Concanavallina A orSaccharomyces cerevisiae, as measured by superoxide (O2-) production, were investigated. Dose-independent (except at 2 \u3bcmCd) inhibition of T cell stimulation and dose-dependent inhibition of B cell stimulation, by lymphocytes exposedin vitroto 2-40 \u3bcmCd, was found.In vivo, 20 \u3bcg l-1Cd inhibited both PHA- and LPS-induced lymphocyte proliferation, at 4 days of exposure and throughout the duration of the experiment. During the first week of exposure, Cd significantly decreased spontaneous3H-methyl-thymidine uptake from unstimulated lymphocytes; however, 15 days after exposure unstimulated cells recovered their basal level of spontaneous thymidine uptake.In vitro2-40 \u3bcmCd enhanced O2-production by activated macrophages, while the addition of 50-100 \u3bcmCd had no significant effects

Effects of cadmium on catfish, Ictalurus melas, humoral immune responses

Catfish (I. melas) were exposed to 10, 20 or 30 \u3bcg 1-1 of cadmium (CdCl2) toassess its in vivo effects on the humoral immune response. After one week of cadmium exposure, the titer of total non-specific immunoglobulins was remarkably reduced but, after 2 weeks of exposure the IgM titer increased, and no differences between treated and control fish could be observed. Immunization of catfish with sheep red blood cells (SRBC) was also performed to assess the effect of cadmium on the immune response to a specific antigen. Fish exposed to cadmium (20 \u3bcg 1-1) required a shorter period to reach the peak of IgM anti-SRBC titer; moreover, fish exposed to Cd for 2 weeks before immunization reached peak antibody response more quickly and also revealed a remarkable increase in antibody titer