Ongoing prospective multicenter safety study of the cytoprotectant amifostine given subcutaneously: overview of trial design

The study is a prospective, open-label, multicenter safety study designed to identify treatment-related side effects of amifostine (Ethyol, WR-2721; MedImmune, Inc, Gaithersburg, MD) administered as a subcutaneous injection for the prevention of radiation-induced toxicities. More than 100 patients (68 males, 33 females; median age, 64 years) received 500 mg of amifostine by subcutaneous injection before daily radiation therapy. Four types of targeted adverse events were examined as to their occurrence and possible relationship with amifostine. These adverse events included nausea/vomiting, local skin reactions, skin rashes, and hypotension

Insulin suppresses ischemic preconditioning-mediated cardioprotection through Akt-dependent mechanisms

AbstractIt is believed that the diabetic myocardium is refractory to cardioprotection by ischemic preconditioning (IPC) mainly because of impaired insulin signaling to phosphatidylinositol 3-kinase (PI3K) and protein kinase B (PKB or Akt). However, human as well as animal studies have clearly showed that the hearts of type 2 diabetic humans and animals may exhibit increased signaling through PI3K–Akt but yet are resistant to cardioprotection by IPC or ischemic post-conditioning. Therefore, this study was designed to determine whether activation of insulin signaling prior to IPC is detrimental for cardioprotection and to assess the role of insulin receptors (IRs) and Akt in mediating this effect. Wild-type (WT) hearts, hearts lacking IRs or hearts expressing an active form of Akt (myrAkt1) were perfused ex vivo using a Langendorff preparation and were subjected to IPC (3cycles of 5min ischemia followed by 5min reflow before 30min no flow ischemia and then by 45min reperfusion) in the presence or absence of 1nmol/L insulin. Interestingly, whereas insulin was protective against I/R (30min no flow ischemia and 45min reperfusion), it completely abolished cardioprotection by IPC in WT hearts but not in mice lacking insulin receptors (IRs) in cardiomyocytes (CIRKO) or in all cardiac cells (TIRKO). The suppression of IPC-mediated cardioprotection was mediated through downstream signaling to Akt and Gsk3β. In addition, transgenic induction of Akt in the heart was sufficient to abrogate IPC even when insulin was absent, further confirming the involvement of Akt in insulin's suppression of cardioprotection by IPC. These data provide evidence that excessive insulin signaling to Akt is detrimental for cardioprotection by IPC and could explain the failure of the diabetic myocardium to precondition