Acute aortic abnormalities.

Aneurysm and type B dissections account for most acute abdominal aortic abnormalities. The postsurgical aorta deserves special attention owing to the risk of complications. Most aortic abnormalities presenting acutely are emergencies that carry a high risk of mortality, and imaging plays a critical role in patient evaluation. Modern helical CT scanners provide excellent spatial resolution, are readily available, and allow for rapid imaging. For these reasons, helical CT angiography is the imaging modality of choice for initial evaluation of the acute aorta.

Evaluation of pseudoenhancement of renal cysts during contrast-enhanced CT.

OBJECTIVE: The purpose of our study was to evaluate renal cyst pseudoenhancement during helical CT in a phantom model and in patients. MATERIALS AND METHODS: Iodine baths containing water-filled spheres and cylinders were constructed to simulate cysts in enhancing renal parenchyma. Iodine concentration, cyst size and location, collimation, and peak kilovoltage were varied and cyst attenuation was measured. Data were analyzed with the mixed linear models and Mantel-Haenszel tests. Subsequently, a paired t test compared CT attenuation values before and after contrast material enhancement in 40 patients with 68 renal cysts (radiographic stability >3 months). RESULTS: The attenuation values of phantom cysts increased when placed in a contrast media bath (p = 0.001). The increase in attenuation values became more pronounced with increasing iodine concentrations, decreasing peak kilovoltage, and smaller sphere sizes. In patients, mean cyst attenuation increased 3.4 +/- 6.2 H after administration of contrast material (p = 0.00002). The attenuation did not increase more than 10 H in any of the 37 cysts larger than 2 cm found in patients. Eight (26%) of the 31 cysts smaller than 2 cm found in patients increased by at least 10 H. CONCLUSION: In a phantom model, at simulated physiologic levels of renal enhancement, cysts may pseudoenhance by more than 10 H. Similarly, in patients, cysts may also pseudoenhance; however, most pseudoenhancement does not exceed 10 H. In patients, pseudoenhancement of at least 10 H is more likely in cysts smaller than 2 cm.

Actions of interleukin-2 on amnion prostaglandin biosynthesis.

Preterm labor is associated with increased intrauterine prostaglandin (PG) production. Intrauterine infections are frequently associated with preterm labor and increased cytokine production. The cytokine interleukin-2 (IL-2) is a potent T-cell growth factor necessary for effective cell-mediated immunity. In this study we evaluated the effects of IL-2 on PGE2 biosynthesis by human amnion cells. IL-2 alone modestly but significantly inhibited amnion PGE2 production. Moreover, IL-2 also attenuated, in a concentration-related fashion, the stimulatory actions of IL-1 beta on PGE2 production by amnion cells. These data suggest that IL-2 could potentially represent a negative regulatory element in the mechanisms of preterm labor in association with intrauterine infection.

Actions of interleukin-2 on chorio-decidual prostaglandin biosynthesis.

The onset of preterm labor requires increased intrauterine prostaglandin production. Intrauterine infections are frequently associated with preterm labor and increased cytokine production. The cytokine interleukin-2 (IL-2) is a potent T-cell growth factor necessary for effective cell-mediated immunity. In this study we evaluated the effect IL-2 has on prostaglandin E2 (PGE2) biosynthesis by human chorion and decidual cells. IL-2 alone significantly stimulated decidual and chorion PGE2 production. IL-2 enhanced the stimulatory actions of interleukin-1 (IL-1), epidermal growth factor (EGF), ionomycin, and phorbol 12-myristate 13-acetate (PMA) on PGE2 production by decidual cells. Similarly, IL-2 enhanced the stimulatory actions of EGF and PMA, but not IL-1 or ionomycin, on PGE2 production by chorion cells. These data suggest that IL-2 could potentially participate in the mechanisms of preterm labor in association with intrauterine infection.

Update on immunotherapy for recurrent pregnancy loss.

Results of recent, randomized, placebo-controlled clinical trials have raised questions about the efficacy of immunotherapy for recurrent spontaneous abortion (RSA). Most of the clinical trials have shown a 70% successful pregnancy rate with immunotherapy. The controversy comes from variations in success rates in the control populations, which have ranged from 29% to 76%. Explanations for these variations includes small sample sizes and heterogeneity by the populations studied as well as cointervention by the placebo. A meta-analysis has been proposed to investigate these explanations. Because the trials have largely used husband's leukocytes for immunization, alternative forms of immunotherapy have been sought. Two treatments that have been proposed but have not completed testing a randomized, placebo-controlled trials are intravenous immunoglobulin (IVIG) and immunization with seminal plasma. A safe and efficacious method is needed to treat recurrent spontaneous abortion; it is hoped that results of proposed studies will answer this controversy.