Nicotine microaerosol inhaler.

OBJECTIVE: To measure the droplet size distribution of a nicotine pressurized metered-dose inhaler using a nicotine in ethanol solution formulation with hydrofluoroalkane as propellant. MATERIALS AND METHODS: Sizing was performed at room temperature by multistage liquid impinger and quartz crystal impactor. RESULTS: The mass median aerodynamic diameter of the nicotine aerosol produced was measured at 1.6 mm by multistage liquid impinger and 1.5 mm by quartz crystal impactor. CONCLUSIONS: The inhaler formulation used produces a microaerosol of sufficiently fine droplet size that mimics the puff-by-puff pulmonary arterial bolus nicotine delivery of tobacco smoke. The absence of combustion products such as heat, carcinogens and carbon monoxide permits safer nicotine delivery via the inhaler than is possible via smoked tobacco.

Cancer grading by Fourier transform infrared spectroscopy.

Thirty-nine freeze-dried tissue samples from 17 lymphoid tumors (nine malignant non-Hodgkin's lymphomas) were studied by Fourier transform infrared (FTIR) spectroscopy. The absorbance ratio A1121/A1020 increased, along with the emergence of an absorbance pulse at 1121 cm-1, with increasing clinicopathological grade of malignant lymphoma. An increasing A1121/A1020 ratio from benign to malignant is evident in literature spectra from several different tissues; however, the present study is the first to comment on this effect and to propose it as an index of the cellular RNA/DNA ratio after subtraction of overlapping absorbances, if present, due to collagen or glycogen. Absorbance attributable to collagen increased with lymphoma grade and was greater in benign inflammatory tumors than in low-grade lymphomas. The A1121/A1020 trend observed here may form the basis of a universal cancer-grading parameter to assist with cancer treatment decisions and may also be useful in the analysis of cellular growth perturbation induced by drugs or other therapies. Our spectral findings may potentially be applied to cell clusters and discrete areas of tumor tissue sections using the FTIR microscope, allowing correlation with morphology and a high degree of spatial resolution.