PubMed · 14798979
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F E ADLEY. 1951. Studying the environment.. https://pubmed.ncbi.nlm.nih.gov/14798979/
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beta-1,3- D-Glucan is a biologically active component mainly from fungi that has been shown in several studies to be related to respiratory health outcomes from damp building exposures. Here, we report the development and application of a method for the analysis of the glucan extracted in 0.5 N NaOH solution making use of an available preparation of Limulus amebocyte lysate (LAL). The method yields reproducible beta-1,3- D-glucan measurements from samples of outdoor air, yeast cells, fungal spore preparations and ragweed pollen, and is more sensitive than competing measurements. The LAL-based measurement compared favourably to that based on size-exclusion chromatography using UV and refractive index detection. Growth conditions of the fungi did not materially change the concentrations of glucan in spores indicating that this is a stable property. Glucan content was proportional to spore surface area; however, some species contain higher relative spore glucan contents.
A 100 ml bottle of polybutadiene, PBD, was repeatedly exposed to air over a period of 6 months. Samples were taken at time zero (PBD-0), after 3 months (PBD-3) and 6 months (PBD-6). These samples were sorbed onto HPLC silica by an open-air solution-evaporation procedure, which involved exposure to the atmosphere for 6 days. Portions of the three sets of samples were used to compare self-immobilization and the effects of 100 degrees C thermal treatments in air or nitrogen on HPLC performance of the resulting phases. It is concluded that self-immobilization is enhanced by prior exposure of sorbed PBD to air and subsequent heating at 100 degrees C further enhances column performance. The best performance (10(5) plates m(-1)) resulted from 4 h heating of PBD-6 material in nitrogen.
OBJECTIVE: To test whether a reduction in air temperature within the clinical range [37 degrees C to 30, 100% relative humidity (RH)] altered mucus transport velocity (MTV) and ciliary beat frequency (CBF) in an in vitro ovine tracheal model. DESIGN: Controlled laboratory study. SETTING: University research laboratory. SUBJECTS: Farm-reared sheep. INTERVENTIONS: Tracheae were mounted flat in an organ bath. Krebs Henseleit bathed the serosal surface and air at 100% (RH) was passed over the mucosal surface at 4 l/min. Cilial beat frequency (CBF) was measured photo-electrically and mucus transport velocity (MTV) by timing movement. After 2 h at 37 degrees C (100% RH) the tissue was either maintained with those settings (controls), or the air temperature reduced to 34 degrees C or 30 degrees C. Tissue was taken for histology before and after each experiment. MEASUREMENTS AND RESULTS: CBF was 19.8+/-2.7 beats/s and MTV 5.7+/-2.6 mm/min in tissue exposed to air at 37 degrees C. Cilial activity continued for up to 6 h in the controls but mucus transport was more fragile. Reduction of the air temperature to either 34 degrees C or 30 degrees C led to a decrease in both CBF and MTV and, frequently, total mucociliary failure. There was a reduction in epithelial mucous cell numbers in all preparations. Tissues exposed to low temperature had additional abnormal histology. CONCLUSIONS: Delivery of inspired gas at 30 degrees C, or even 34 degrees C, with 100% RH may not be sufficient to prevent epithelial damage occurring during 6 h exposure.