A dry powder combination of pyrazinoic acid and its n-propyl ester for aerosol administration to animals.

Combining the advantage of higher efficacy due to local pulmonary administration of pyrazinoic acid (POA) and potent effect of pyrazinoic acid ester (PAE) delivered as an aerosol would aid in tuberculosis therapy. A combination spray dried dry powder, composed of POA, PAE (n-propyl POA), maltodextrin and leucine, was prepared for aerosol delivery to animals. Solid-state characteristics of morphology (scanning electron microscopy) crystallinity (X-ray powder diffraction), thermal properties (thermogravimetric analysis and differential scanning calorimetry) and moisture content (Karl Fisher) were evaluated. Particle size distributions, by volume (laser diffraction) for the dispersed powder and by mass (inertial impaction) were determined. Efficient delivery of the powder to a nose only animal exposure chamber employed a novel rotating brush/micro-fan apparatus. Spherical, crystalline particles were prepared. The volume median diameter, ∼1.5µm, was smaller than the mass median aerodynamic diameter, ∼3.0µm, indicating modest aggregation. Drug content variations were observed across the particle size distribution and may be explained by PAE evaporative losses. Delivery to the nose-only exposure chamber indicated that boluses could be administered at approximately 3min intervals to avoid aerosol accumulation and effect uniform dose delivery with successive doses suitable for future pharmacokinetic and pharmacodynamic studies.

Evaluation of nursing practice: process and critique.

This article describes the difficulties in conducting clinical trials to evaluate nursing practice models. Suggestions are offered for strengthening the process. A clinical trial of a nursing practice model based on a synthesis of Aristotelian theory with Rogers' science is described. The rationale for decisions regarding the research procedures used in presented. Methodological limitations of the study design and the specifications of the practice model are examined. It is concluded that clear specification of theoretical relationships within a practice model and clear identification of key intervening variables will enable researchers to better connect the treatment with the outcome.

LIGHT model: an effective intervention model to change high-risk AIDS behaviors among hard-to-reach urban drug users.

Two thousand thirty-three hospital emergency room (ER) patients who were current, active injecting drug users (IDUs) were voluntary participants in a pretest, posttest research project which utilized a nursing model, the Personalized Nursing LIGHT Model, as a counseling approach to decrease high-risk AIDS behaviors. The LIGHT Model works by directly improving well-being and thereby indirectly decreasing high-risk behaviors associated with AIDS. Addicts from an urban ER in each of three cities (Detroit, Michigan; Brooklyn, New York; and Baltimore, Maryland) were treated with teams consisting of nurses and indigenous outreach workers. Posttest data were gathered on 995 of the clients who received the Personalized Nursing LIGHT Model teaching and counseling intervention. In a posttest at least 3 months after the initial interview, these IDUs reported a significant increase in well-being, t(530) = -11.77; p < .001, and significant reductions in frequency of IV heroin use, z = -18.4; p < .001, IV cocaine use, z = -16.0; p < .001, and IV speedball use, z = -14.3; p < .001, as well as significant decreases in sharing of cookers (a type of drug-using equipment), z = -13.8; p < .001, and other high-risk behaviors associated with AIDS acquisition and transmission. At a second posttest, at least 6 months after the initial interview, these results were unchanged.

Sampling a hidden population: noninstitutionalized drug users.

As the spread of AIDS continues, there is an urgent need to understand patterns of drug use among drug users. While it is recognized that probability samples are scientifically preferable, there is a need to balance the realities of field research targeting an elusive population with the need for a sound sampling plan. A purposive or targeted sampling plan can increase the possibility of obtaining a representative sample of drug users. Targeted sampling involves using several sampling methods. First, neighborhoods with high concentrations of drug users are identified within the community in order to identify clusters of individuals in the target population. Once the geographic areas from which to sample have been identified, stratification can be used as an effective way to get a representative sample from neighborhoods with differing drug use patterns. The sampling plan can be further strengthened by the use of quota sampling to ensure that subgroups of drug users are adequately represented in the sample.