Development of porous particles using dextran as an excipient for enhanced deep lung delivery of rifampicin.

This study aimed to develop a dry powder inhaler (DPI) formulation for enhanced deep lung delivery of rifampicin using dextrans of different molecular weights. Porous particles were formed by a spray-drying method, which was designed based on the Peclet number. The morphology of particles containing both rifampicin and dextran was dependent on the dextran concentration. The D50 values of SDPs containing rifampicin and dextran 40 or 70 at ratios of less than 1:10 were below 5 µm. The specific surface area values of spray-dried particles containing rifampicin and dextran 40 or 70 of more than 1:10 were over 20 m2/g, assuming that an increase in specific surface area was indicative of an increase in the formation ratio of a porous structure. DPI formulations that contained higher amounts of dextran had higher rifampicin contents. Thus, the formulations containing a dextran: rifampicin ratio of 1:20 had approximately 100% drug encapsulation. The formation of the porous particles can be explained by the related Peclet number, which correlates with the viscosity and surface tension of the ethanol-water solution used in preparing the particles. It was noted that the existence ratio of the porous particles increased as the viscosity of the mixed solution was increased. Furthermore, an increase in the proportion of dextran resulted in higher rifampicin loading into the particles and the formation of finer particle fractions (FPF) (<7.0 µm at a rate of 28.3 L/min, <4.8 um at a rate of 60.0 L/min). The formulations containing rifampicin and both dextrans at a ratio of more than 1:10 consisted of approximately 50% FPF at a rate of 28.3 L/min and 60.0 L/min. The results indicate that dextran is suitable to obtain porous particles via spray-drying. Additionally, the existence ratio of the porous particles can be improved by increasing the viscosity of the solution used in the preparation of the particles.

Impact of lifestyles of adolescents and their parents on cardiovascular risk factors in adolescents.

AIM: The aim of this study was to determine the impact of the lifestyles of adolescents and their parents on the levels of cardiovascular (CV) risk factors in the adolescents. METHODS: A total of 755 volunteers (331 male, 424 female) aged 15 to 18 years were included. Abdominal obesity, hypertension, elevated triglyceride levels, decreased high density lipoprotein-cholesterol levels, and hyperglycemia were considered to be CV risk factors. Self-reported lifestyle, including participation in school-based extracurricular (EC) physical activities, time spent on physical activity or watching television (TV), and average daily food intake were assessed. Parental information on weight status and lifestyle was also obtained. RESULTS: Multivariate regression analyses showed that participation in EC physical activities, time spent watching TV, regular breakfast consumption, total energy intake, fiber intake per 1,000 Kcal, and parental BMI were independently associated with the levels of one or more CV risk factors in adolescents. Among these, participation in EC physical activities had a profound effect on adolescent CV risk factor levels. The risk of male adolescent obesity was associated with paternal obesity, but not with maternal obesity. Conversely, the risk of female adolescent obesity was associated with maternal obesity but not with paternal obesity. CONCLUSIONS: Participation in EC physical activities may be the first-line approach for adolescents to maintain favorable CV risk factor levels. An association between paternal or maternal obesity and adolescent obesity differs between adolescent genders in Japan; thus, approaches focusing on parents should take the gender of the adolescent into consideration.

Residents' evaluation of urban environments: attraction of urban life and anxiety associated with traffic accidents and urban crimes.

The results of questionnaire and interview surveys conducted in Mitaka and Musashino cities are presented for investigating of residents' evaluation of their urban environment, particularly regarding its attractiveness. A special attention was paid to residents' evaluation with regard to anxiety associated with traffic accidents and urban crimes. The urban infrastructure and residents' responses were examined using a Geographic Information System (GIS). Attractiveness associated with the urban environment was classified into two categories: "attractiveness in daily life" and "attractiveness in non-daily life." The residents valued opportunities for relaxing and living in comfort. In non-daily life, the residents specifically valued improved living conditions and harmony between the natural environment and commercial facilities. They attributed crime anxiety to trees, narrow streets, obstructed views, dark areas and a gloomy atmosphere. Residents regarded violent crimes as being prevalent, but considered trespassing and property crimes infrequent. The residents' anxiety about traffic accidents was caused by reckless driving habits, narrow streets, lack of separation between roadway and pedestrians' ways, heavy traffic, and obstructed views. Residents cited main roads and intersections as locations of anxiety, which concurred with frequent accidents.

Predictive factors in the success of intervention to treat obesity in elementary school children.

BACKGROUND: Currently, a generalizable conclusion on the effectiveness of treatment programs for childhood obesity cannot be drawn, and how practical and effective the intervention strategies are remains a controversial subject. METHODS AND RESULTS: In the present study 36 obese elementary school children who visited an intervention program at least 4 times were followed for 12 months or more. A stepwise regression analysis was performed using the decrease in the percent relative body weight (%RBW) at 12 months after the first visit as a dependent variable, and the decrease in the %RBW and nutritional data between 2 successive visits as independent variables. The analysis revealed 4 significant predictive factors: (1) a higher ratio of energy intake from protein (20%) recommended at the first visit, (2) a greater decrease in the %RBW between the first and second visits, (3) higher age, and (4) a higher concentration of alanine aminotransferase at the first visit. CONCLUSION: Providing a strong motivation to change eating and activity behavior at the early stage of intervention and recommending diets with higher ratios of energy intake from protein are the most practical and effective strategies for treating obesity.