Poly(styrene 4-sulfonate), cellulose sulfate, polymethylenehydroquinone, and PRO 2000 are sulfated or sulfonated polymers (SPs) under development as topical microbicides. They are presumed to work through similar mechanisms of action, although to date there has been no extensive comparison of their anti-human immunodeficiency virus activities. To determine whether any of these candidate microbicides offers a potential advantage, their in vitro activities, mechanisms of action, stabilities in biological secretions, and toxicities were compared. All four compounds were found to be active against X4, R5, and dualtropic primary isolates and against X4 and R5 laboratory-adapted strains in CD4 ؉ T cells, macrophages, and single-coreceptor cell lines. Our single-cycle experiments using pseudotyped virus suggest that all four SPs function at the binding and entry stages of the viral life cycle but differ in degree of postentry effect. Surface plasmon resonance analyses demonstrate that SPs bind to X4 and R5 monomeric glycoprotein 120 with similar high binding affinities. When mixed with cervicovaginal lavage fluid, SPs maintain inhibitory activity at concentrations achievable in formulations.
Presently marketed vaginal barrier methods are cytotoxic and damaging to the vaginal epithelium and natural vaginal flora when used frequently. Novel noncytotoxic agents are needed to protect men and women from sexually transmitted diseases. One novel candidate is a mandelic acid condensation polymer, designated SAMMA. The spectrum and mechanism of antiviral activity were explored using clinical isolates and laboratory-adapted strains of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). SAMMA is highly effective against all CCR5 and CXCR4 isolates of HIV in primary human macrophages and peripheral blood mononuclear cells. SAMMA also inhibits infection of cervical epithelial cells by HSV. Moreover, it exhibits little or no cytotoxicity and has an excellent selectivity index. SAMMA, although not a sulfonated or sulfated polymer, blocks the binding of HIV and HSV to cells by targeting the envelope glycoproteins gp120 and gB-2, respectively, and also inhibits HSV entry postattachment. SAMMA is an excellent, structurally novel candidate microbicide that warrants further preclinical evaluation.
Autopsy rates have been affected by a number of factors, including technological advances and clinician beliefs of the diminished value of the autopsy. Such factors have resulted in a cultural shift in medicine away from the autopsy. Despite this shift, a number of studies have shown significant differences between antemortem clinical diagnoses and postmortem findings. Surveys of clinician beliefs about the autopsy have pointed toward antemortem diagnostic advancements as an important factor in declining rates. No study to date has addressed the hypothesis that such perceptions in diagnostic certainty have been matched by an actual decay in the yield of valuable or new information obtained by the autopsy. To address this hypothesis, we retrospectively compared the class I and class II discrepancies identified in 284 patients who died in three clinical settings with differing intensities of antemortem diagnostic workup. Despite a significantly different intensity of antemortem workup for patients in each clinical setting, including patients on a medical intensive care unit, patients on a surgical service and patients in an affiliated nursing home, discrepancy rates were found to be similar. Overall discrepancy rates for the medical intensive care unit, surgery service and nursing home patients were 27.8, 32.7 and 31.3%, respectively (P ¼ 0.84). In addition, we found no statistical difference in the complexity of workup in discrepant and nondiscrepant cases in each clinical setting. Our study data refute the hypothesis that the intensity of antemortem diagnostic evaluation correlates with an actual decrease in the rate of major diagnostic discrepancies identified at autopsy.
The incidence of ischemic colitis is decreased in patients undergoing EVAR vs open repair. The cause of the ischemia is multifactorial and seems to differ between patients in the early and late groups. Microembolization tends to produce severe ischemic colitis and is usually fatal. There should be a low threshold for performing endoscopy in any patient thought to have ischemic colitis after EVAR.
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