Variation in the sensitivity of predicted levels of atmospheric organic particulate matter (OPM).

This study examines the sensitivity in predicted levels of atmospheric organic particulate matter (M(o), microg m(-3)) to changes in the governing gas/particle partitioning constants and the tau(I) (levels of condensable organic compounds, microg m(-3)). M(o) is given by the difference between sigma tau(i) and the corresponding sum for the gas-phase levels. It is demonstrated that the sensitivity in predicted M(o) levels increases rapidly as M(o) becomes very small relative to sigma tau(i): as the tau(i), decrease, the gas phase becomes increasingly capable of holding the majority of all tau(i) and small changes in system parameters can cause large relative changes in M(o). These effects are illustrated using predictions for two values of the reacted hydrocarbon concentration (deltaHC) for each of three secondary organic aerosol systems for relative humidity (RH) = 20-80%. Specific structures for the oxidation products allows consideration of the effects of varying activity coefficients and water uptake. At low M(o)/sigma tau(i) (as may be found in the atmosphere away from sources and at warm temperatures), relatively small errors in model input parameters (e.g., vapor pressures, vaporization enthalpies, activity coefficient parameters, and the tau(i) values for low volatility compounds) will be amplified into large errors in the predicted M(o) values.

Parenteral aminosidine is not effective for Peruvian mucocutaneous leishmaniasis.

Few therapeutic options are available for mucocutaneous leishmaniasis (MCL). We conducted a randomized open trial to evaluate the efficacy, safety, and tolerance of parenteral aminosidine sulphate (AS) 14 mg/kg/d for 21 days compared with intravenous meglumine antimonate (MA) 20 mg/kg/d for 28 days in patients with moderate MCL in Cuzco, Peru. Cure was defined as complete healing with re-epithelialization within 1 year of follow-up. The trial was stopped after 38 patients were enrolled (17 in the MA group and 21 in the AS group) because of marked differences in response. Study groups were comparable in baseline characteristics. Cure rates were 0/21 in the AS group compared with 8/17 (47%, 95% confidence interval: 23-71%) in the MA group (P < 0.001). Side effects and laboratory abnormalities were mild in both groups. We conclude that parenteral AS given on its own is not effective for MCL in Peru.

Characterization of measured menthol in 48 U.S. cigarette sub-brands.

More than 25% of cigarettes sold in the United States are branded as mentholated, and these cigarettes are smoked disproportionately among populations with disparate tobacco-related health outcomes. This study is the first (independent of the tobacco industry) to report menthol for 48 popular commercially available mentholated cigarette sub-brands. The dependent variable "menthol per cigarette" was obtained by gas chromatography-mass spectrometer assay, whereas average per-cigarette milligram weight of tobacco filler ("tobacco per cigarette") was determined gravimetrically. Pearson's correlations assessed associations among continuous variables. Analyses of variance assessed mean differences on the independent variables of interest: manufacturer, brand family, industry descriptors of length (100 mm and King [85 mm]) and label (ultralight, light, medium/mild, and regular/full flavor), and a category constructed by the authors of exclusively menthol brand families (those without a non-menthol offering; Kool, Newport, and Salem) versus others (GPC, Camel, and Marlboro). Results showed menthol per cigarette and menthol per tobacco (i.e., milligrams of menthol per gram of tobacco filler) to be significantly greater in cigarettes labeled with industry descriptors of ultralight or light, belying the common consumer perception that "light" means less. Menthol per cigarette and tobacco per cigarette were significantly greater in 100-mm compared with 85-mm cigarettes. The study results are consistent with prior research that suggests menthol may be used to offset reductions in smoke delivery or impact and to facilitate compensatory smoke inhalation behaviors in smokers of cigarettes with reduced machine-measured smoke delivery. Tobacco manufacturers should be required by federal or other regulatory agencies to report the amount of menthol added to cigarettes.