Search

Since asthma is the most common chronic illness in childhood, many of the problems associated with this condition will impact on the child's education. Because of widespread concerns regarding the management of asthma in schools, a subcommittee of the Thoracic Society of Australia and New Zealand, Asthma Special Interest Group, was convened to draw up national guidelines for school staff in order to provide optimal management of asthma in the school setting. We used current medial literature and the clinical experience of the authors who have dealt with children and adolescents suffering from asthma in the hospital, community and school environment. A number of issues had been identified, including: the availability of an asthma first aid kit; correct use of bronchodilator aerosols by puffer and spacer devices; and clear instructions as to when to notify parents and when to call an ambulance to the school.(ABSTRACT TRUNCATED AT 250 WORDS)

Standardization of radionuclides. Proceedings of a symposium, October 10-14, 1966, Vienna, Austria

The aquatic angiosperm Hydrilla verticillata lacks Kranz anatomy, but has an inducible, C-4-based, CO2 concentrating mechanism (CCM) that concentrates CO2 in the chloroplasts. Both C-3 and C-4 Hydrilla leaves showed light-dependent pH polarity that was suppressed by high dissolved inorganic carbon (DIC). At low DIC (0.25 mol m(-)3), pH values in the unstirred water layer on the abaxial and adaxial sides of the leaf were 4.2 and10.3, respectively. Abaxial apoplastic acidification served as a CO2 flux mechanism (CFM), making HCO3- available for photosynthesis by conversion to CO2. DIC at 10 mol m(-3) completely suppressed acidification and alkalization. The data, along with previous results, indicated that inhibition was specific to DIC, and not a buffer effect. Acidification and alkalization did not necessarily show 1:1 stoichiometry; their kinetics for the apolar induction phase differed, and alkalization was less inhibited by 2.5 mol m(-3) DIC. At low irradiance (50 mu mol photons m(-2) s(-1)), where CCM activity in C-4 leaves is minimized, both leaf types had similar DIC inhibition of pH polarity. However, as irradiance increased, DIC inhibition of C-3 leaves decreased. In C-4 leaves the CFM and CCM seemed to compete for photosynthetic ATP and/or reducing power. The CFM may require less, as at low irradiance it still operated maximally, if [DIC] was low. Iodoacetamide (IA), which inhibits CO2 fixation in Hydrilla, also suppressed acidification and alkalization, especially in C-4 leaves. IA does not inhibit the C-4 CCM, which suggests that the CFM and CCM can operate independently. It has been hypothesized that irradiance and DIC regulate pH polarity by altering the chloroplastic [DIC], which effects the chloroplast redox state and subsequently redox regulation of a plasma-membrane H+-ATPase. The results lend partial support to a down-regulatory role for high chloroplastic [DIC], but do not exclude other sites of DIC action. IA inhibition of pH polarity seems inconsistent with the chloroplast NADPH/NADP(+) ratio being the redox transducer. The possibility that malate and oxaloacetate shuttling plays a role in CFM regulation requires further investigation.