Studi precedenti hanno permesso di definite l’esistenza di una retazione diretta e quantita-tiva che lega la composizione isotopica dell’ossigeno (<sup>18</sup>O/<sup>16</sup>O) nel fosfato d...Studi precedenti hanno permesso di definite l’esistenza di una retazione diretta e quantita-tiva che lega la composizione isotopica dell’ossigeno (<sup>18</sup>O/<sup>16</sup>O) nel fosfato delle ossa di diverse speciedi mammiferi con la temperatura media annua al suolo delle località di provenienza di tali animali.Potendo applicare tale relazione a campioni di mammiferi vissuti in età preistorica risulta evidente lapossibilità di compiere studi di tipo paleoclimatico e paleoidrologico. Si presentano i risuhati ottenuti da campioni provenienti da alcuni siti preistorici della Pianura Pada-na e dal villaggio di Fossacesia Marina sulla costa Adriatica. I dati isotopici si accordano bene con le informazioni sulla situazione climatica durante l’Atlanticoottenute con altre metodologie di studio; eventuali variazioni e fluttuazioni locali vengono discusse.Oxygen isotopes as climatic indicators. Some experimental data. Oxygen isotope composi-tion (<sup>18</sup>O/<sup>16</sup>O) of bone phosphate from different mammal species coming from some prehistoric sitesof the Po Valley and from the Neolithic village of Fossacesia Marina （CH） have been carried on. Previousstudies have demonstrated the existence of a direct, quantitative relationship between oxygen isotopiccomposition of bone phosphate and mean annual temperature. The existence of such relationship allowsto study the ancient environment and climate. The trend of climate, during prehistoric periods, agrees well with the data obtained from other me-thodology of study; some fluctuations of climate in the studied sites are also discussed.展开更多
Background Inflammation is one of important mechanisms for myocardial ischemia reperfusion injury （IRI）.Ischemia postconditioning （IPOC） can protect the heart against IRI by inhibiting inflammation,but its cardiop...Background Inflammation is one of important mechanisms for myocardial ischemia reperfusion injury （IRI）.Ischemia postconditioning （IPOC） can protect the heart against IRI by inhibiting inflammation,but its cardioprotection is weaker than that of ischemia preconditioning.Recently,the α7 subunit-containing nicotinic acetylcholine receptor （α7nAChR） agonist has shown anti-infiammatory effects in many diseases related to inflammation.This randomized controlled experiment was designed to evaluate whether combined postconditioning with IPOC and the α7nAChR agonist could produce an enhanced cardioprotection in a rat in vivo model of acute myocardial IRI.Methods Fifty Sprague-Dawley rats were randomly divided into five equal groups：sham group,control group,IPOC group,α7nAChR agonist postconditioning group （APOC group） and combined postconditioning with IPOC and α7nAChR agonist group （combined group）.Hemodynamic parameters were recorded during the periods of ischemia and reperfusion.Serum concentrations of troponin I （Tnl）,tumor necrosis factor α （TNF-α） and high-mobility group box 1 （HMGB-1） at 180 minutes after reperfusion were assayed in all groups.At the end of the experiment,the infarct size was assessed from excised hearts by Evans blue and triphenyl tetrazolium chloride staining.Results As compared to the sham group,the infarct size in the other four groups was significantly increased,serum levels of Tnl,TNF-α and HMGB1 in the control group and TNF-α,HMGB1 in the IPOC group were significantly increased.The infarct size and serum concentrations of TNF-α,HMGB1 and Tnl in the IPOC,APOC and combined groups were significantly lower than those in the control group.As compared to the IPOC group,the infarct size in the combined group was significantly decreased,serum concentrations of Tnl,TNF-α and HMGB1 in the APOC and combined groups were significantly reduced.Although the infarct size was significantly smaller in the combined group than in the APOC group,serum levels of TNF-α and HMGB1 were significantly higher in the combined group than in the APOC group.Conclusions In a rat in vivo model of acute myocardial IRI,combined postconditioning with IPOC and the α7nAChR agonist can produce enhanced protection against myocardial IRI by increasing the anti-inflammatory effect.展开更多
文摘Studi precedenti hanno permesso di definite l’esistenza di una retazione diretta e quantita-tiva che lega la composizione isotopica dell’ossigeno (<sup>18</sup>O/<sup>16</sup>O) nel fosfato delle ossa di diverse speciedi mammiferi con la temperatura media annua al suolo delle località di provenienza di tali animali.Potendo applicare tale relazione a campioni di mammiferi vissuti in età preistorica risulta evidente lapossibilità di compiere studi di tipo paleoclimatico e paleoidrologico. Si presentano i risuhati ottenuti da campioni provenienti da alcuni siti preistorici della Pianura Pada-na e dal villaggio di Fossacesia Marina sulla costa Adriatica. I dati isotopici si accordano bene con le informazioni sulla situazione climatica durante l’Atlanticoottenute con altre metodologie di studio; eventuali variazioni e fluttuazioni locali vengono discusse.Oxygen isotopes as climatic indicators. Some experimental data. Oxygen isotope composi-tion (<sup>18</sup>O/<sup>16</sup>O) of bone phosphate from different mammal species coming from some prehistoric sitesof the Po Valley and from the Neolithic village of Fossacesia Marina （CH） have been carried on. Previousstudies have demonstrated the existence of a direct, quantitative relationship between oxygen isotopiccomposition of bone phosphate and mean annual temperature. The existence of such relationship allowsto study the ancient environment and climate. The trend of climate, during prehistoric periods, agrees well with the data obtained from other me-thodology of study; some fluctuations of climate in the studied sites are also discussed.
文摘Background Inflammation is one of important mechanisms for myocardial ischemia reperfusion injury （IRI）.Ischemia postconditioning （IPOC） can protect the heart against IRI by inhibiting inflammation,but its cardioprotection is weaker than that of ischemia preconditioning.Recently,the α7 subunit-containing nicotinic acetylcholine receptor （α7nAChR） agonist has shown anti-infiammatory effects in many diseases related to inflammation.This randomized controlled experiment was designed to evaluate whether combined postconditioning with IPOC and the α7nAChR agonist could produce an enhanced cardioprotection in a rat in vivo model of acute myocardial IRI.Methods Fifty Sprague-Dawley rats were randomly divided into five equal groups：sham group,control group,IPOC group,α7nAChR agonist postconditioning group （APOC group） and combined postconditioning with IPOC and α7nAChR agonist group （combined group）.Hemodynamic parameters were recorded during the periods of ischemia and reperfusion.Serum concentrations of troponin I （Tnl）,tumor necrosis factor α （TNF-α） and high-mobility group box 1 （HMGB-1） at 180 minutes after reperfusion were assayed in all groups.At the end of the experiment,the infarct size was assessed from excised hearts by Evans blue and triphenyl tetrazolium chloride staining.Results As compared to the sham group,the infarct size in the other four groups was significantly increased,serum levels of Tnl,TNF-α and HMGB1 in the control group and TNF-α,HMGB1 in the IPOC group were significantly increased.The infarct size and serum concentrations of TNF-α,HMGB1 and Tnl in the IPOC,APOC and combined groups were significantly lower than those in the control group.As compared to the IPOC group,the infarct size in the combined group was significantly decreased,serum concentrations of Tnl,TNF-α and HMGB1 in the APOC and combined groups were significantly reduced.Although the infarct size was significantly smaller in the combined group than in the APOC group,serum levels of TNF-α and HMGB1 were significantly higher in the combined group than in the APOC group.Conclusions In a rat in vivo model of acute myocardial IRI,combined postconditioning with IPOC and the α7nAChR agonist can produce enhanced protection against myocardial IRI by increasing the anti-inflammatory effect.
