Analogs of the immunosuppressive cyclic undecapeptide cyclosporin A (CsA) with substitutions in positions 1, 4, 6, and/or 11 were rationally designed to possess substantially diminished or no immunosuppressive activity. When these compounds were assayed for their capacity to interfere with the replication of human immunodeficiency virus, some displayed a potent antiviral activity in newly infected cells. However, only CsA could interfere with virus replication in persistently infected cells. One CsA analog with antiviral activity costimulated the phytohemagglutinin-induced production of interleukin 2 by human lymphocytes. Human immunodeficiency virus particles from drug-exposed cells showed lower infectivity than virions from untreated cells. Thus, these nonimmunosuppressive analogs of CsA constitute a promising class of lead compounds to develop drugs for effective treatment of the acquired immunodeficiency syndrome.
Chronic mesenteric ischemia is a rare condition, generally characterized by postprandial abdominal pain. Although chronic mesenteric ischemia accounts for only a small percentage of all mesenteric ischemic events, it can have significant clinical consequences. There are multiple etiologies; however, the most common cause is atherosclerosis. The diagnosis of chronic mesenteric ischemia requires a high clinical index of suspicion. An imaging study can confirm the presence of a stenosis or occlusion involving the mesenteric vessels in patients who are suspected of having chronic mesenteric ischemia. The diagnosis is usually late in its course due to the slow progression of disease and the abundance of mesenteric collaterals. Because of the extensive collateral network, usually at least two of the three visceral vessels need to be affected before patients develop symptoms. Treatment is necessary to avoid progression to bowel ischemia and infarction. Once a diagnosis of chronic mesenteric ischemia is made, treatment options include open surgical revascularization and endovascular revascularization.
The membership of the Society of Interventional Radiology (SIR) Standards of Practice Committee represents experts in a broad spectrum of interventional procedures from the private and academic sectors of medicine. Generally, Standards of Practice Committee members dedicate the vast majority of their professional time to performing interventional procedures; as such, they represent a valid broad expert constituency of the subject matter under consideration for standards production.Technical documents specifying the exact consensus and literature review methodologies as well as the institutional affiliations and professional credentials of the authors of this document are available upon request from SIR, 3975 Fair Ridge Dr., Suite 400 N., Fairfax, VA 22033.
METHODOLOGYSIR produces its Standards of Practice documents using the following process. Standards documents of relevance and timeliness are conceptualized by the Standards of Practice Committee members. A recognized expert is identified to serve as the principal author for the standard. Additional authors may be assigned dependent upon the magnitude of the project.An in-depth literature search is performed using electronic medical literature databases. Then, a critical review of peer-reviewed articles is performed with regard to the study methodology, results, and conclusions. The qualitative weight of these articles is assembled into an evidence table, which is used to write the document such that it contains evidence-based data with respect to content, rates, and thresholds (Fig E1 and Table E1, available online at www.jvir.org).When the evidence of literature is weak, conflicting, or contradictory, consensus for the parameter is reached by a minimum of 12 Standards of Practice Committee members using a modified Delphi consensus method (Appendix A). For purposes of these documents, consensus is defined as 80% Delphi participant agreement on a value or parameter.The draft document is critically reviewed by the Standards of Practice Committee members by telephone conference calling or face-to-face meeting. The finalized draft from the Committee is sent to the SIR membership for further input/criticism during a 30-day comment period. These comments are discussed by the Standards of Practice Committee, and appropriate revisions are made to create the finished standards document. Prior to its publication, the document is endorsed by the SIR Executive Council.
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