Clinical characteristics of human immunodeficiency virus patients being referred for liver transplant evaluation: a descriptive cohort study.

BACKGROUND: Liver transplantation (LT) is a treatment option for select human immunodeficiency virus (HIV)-infected patients with advanced liver disease. The aim of this study was to describe LT evaluation outcomes in HIV-infected patients. METHODS: All HIV-infected patients referred for their first LT evaluation at the Mount Sinai Medical Center were included in this retrospective, descriptive cohort study. Multivariable logistic regression was used to identify factors independently associated with listing. RESULTS: Between February 2000 and April 2012, 366 patients were evaluated for LT, with 66 (18.0%) listed for LT and 300 (82.0%) not listed. Fifty-one patients (13.9%) died before completing evaluation and 85 (23.2%) were too early for listing. Reasons patients were declined for listing were psychosocial (15.8%), HIV-related (10.4%), loss to follow-up (9.6%), surgical/medical (6.0%), liver-related (4.4%), patient choice (3.4%), and financial (1.6%). Listed patients were more likely to have hepatocellular carcinoma (HCC) (43.1% vs. 17.1%; P < 0.0001) and less likely to have hepatitis B (6.2% vs. 15.7%; P = 0.04) or a psychiatric history (19.7% vs. 35.2%; P = 0.02) than those not listed. In multivariable analysis, HCC (odds ratio [OR] 5.79; 95% confidence interval [95% CI]: 2.97-11.28), model for end-stage liver disease (MELD) score at referral (OR 1.06; 95% CI 1.01-1.11), and hepatitis B (OR 0.26; 95% CI 0.08-0.79) were associated with listing. CONCLUSION: MELD score and HCC were positive predictors of listing in HIV-infected patients referred for LT evaluation and, therefore, timely referrals are vital in these patients. As MELD is a predictor for death while undergoing evaluation, rapid evaluation should be performed in HIV-infected patients with a higher MELD score.

Foaming in simulated radioactive waste.

Radioactive waste treatment process usually involves concentration of radionuclides before waste can be immobilized by storing it in stable solid form. Foaming is observed at various stages of waste processing like SRAT (sludge receipt and adjustment tank) and melter operations. This kind of foaming greatly limits the process efficiency. The foam encountered can be characterized as a three-phase foam that incorporates finely divided solids (colloidal particles). The solid particles stabilize foaminess in two ways: by adsorption of biphilic particles at the surfaces of foam lamella and by layering of particles trapped inside the foam lamella. During bubble generation and rise, solid particles organize themselves into a layered structure due to confinement inside the foam lamella, and this structure provides a barrier against the coalescence of the bubbles, thereby causing foaming. Our novel capillary force balance apparatus was used to examine the particle-particle interactions, which affect particle layer formation in the foam lamella. Moreover, foaminess shows a maximum with increasing solid particle concentration. To explain the maximum in foaminess, a study was carried out on the simulated sludge, a non-radioactive simulant of the radioactive waste sludge at SRS, to identify the parameters that affect the foaming in a system characterized by the absence of surface-active agents. This three-phase foam does not show any foam stability unlike surfactant-stabilized foam. The parameters investigated were solid particle concentration, heating flux, and electrolyte concentration. The maximum in foaminess was found to be a net result of two countereffects that arise due to particle-particle interactions: structural stabilization and depletion destabilization. It was found that higher electrolyte concentration causes a reduction in foaminess and leads to a smaller bubble size. Higher heating fluxes lead to greater foaminess due to an increased rate of foam lamella generation in the sludge system.