Bacterial filtration efficiency of medical face masks - Evaluation of the use of disposable plastic petri dishes in Andersen impactor.

Bacterial filtration efficiency is the main characteristic of medical face masks effectivity and quality. The testing method is given by European and US, respectively, standard. The method is based on the analysis of biological aerosol with the bacterium Staphylococcus aureus in Andersen cascade impactor. The Andersen impactor contains six stages simulating the different parts of the respiratory tract, from the upper part with the larger droplets to the lungs with the small aerosol particles of the submicron size. The particles are separated depending on the size and sediment on agar medium in Petri dishes filled in the impactor. The use of the glass Petri dishes is recommended for the Andersen impactor, but the most of laboratories prefer the disposable plastic dishes, actually. The evaluation of the use of plastic dishes in Andersen impactor for the determination of the bacterial filtration efficiency of the medical face masks is the aim of this study.

[Changes of plasma obestatin and ghrelin levels after soluble fiber with glucose and after fiber alone in healthy women and in patients with bulimia nervosa]. / Zmeny plazmatických hladin obestatinu a ghrelinu po podání rozpustné vlákniny s glukózou a samotné vlákniny zdravým zenám a pacientkám s bulimia nervosa.

BACKGROUND: The recent identification of obestatin, a novel peptide hormone derived from the same gene as ghrelin, has added further complexity to ghrelin physiology. Despite the rapid progress, many questions remain unanswered, including the regulation of orexigen ghrelin and putative anorexigen obestatin secretion by food composition in humans. The present study was undertaken to investigate the influence of caloric and noncaloric food on plasma ghrelin and obestatin concentrations in healthy women (n = 6; age 23.83 +/- 1.1 years; BMI 20.85 +/- 0.87 kg/m2) and in bulimia nervosa patients (n = 6; age 26.6 +/- 5.2 years; BMI 19.2 +/- 1.44 kg/m2), characterized by abnormal eating behaviour and imbalance in energy homeostasis. METHODS AND RESULTS: After overnight fasting, plasma ghrelin and obestatin were measured by commercial radioimmunoassay kits before and after consumption of soluble fiber alone or with glucose. In both groups plasma ghrelin and obestatin levels did not change after fiber alone, but decreased after fiber with glucose. During 30-90 min after ingestion we observed significant decrease (p < 0.05) of plasma ghrelin and obestatin levels after soluble fiber with glucose in healthy women and also in patients with bulimia nervosa, after then the levels of both hormones started to increase to preprandial levels. CONCLUSIONS: We conclude that postprandial ghrelin and obestatin plasma levels decrease in relation to caloric content of the meal in healthy women and in patients with bulimia nervosa.