Planned care for patients with bronchiectasis

Bronchiectasis, for which once only the most elementary palliation could be offered, now often can be cured by operation or well controlled by conservative therapy. Since true bronchiectasis implies irreversible anatomic changes, operation offers the only hope of cure, and it should be undertaken whenever it is not contraindicated by extent of involvement, age of the patient or other factors. Surgical results are excellent and mortality is at a minimum. When operation is prohibited, good results can still be anticipated by conservative measures. Such conservative therapy should combine prolonged use of antimicrobial drugs with adequate drainage of the diseased segments and general supportive measures. Any residual infection can be controlled by moderate use of appropriate antimicrobial agents. It is emphasized, however, that the control of bronchiectasis requires very careful diagnostic studies and a detailed analysis of the patient's condition, and that the therapy itself must be carefully adjusted in terms of the individual situation.     

CO2 uptake by the cultivated hemiepiphytic cactus, Hylocereus undatus

The climate of the native tropical forest habitats of Hylocereus undatus, a hemiepiphytic cactus cultivated in 20 countries for its fruit, can help explain the response of its net CO2 uptake to environmental factors. Under wet conditions, about 85% of the total daily net CO₂ uptake occurs at night via Crassulacean acid metabolism, leading to a high water‐use efficiency. Total daily net CO₂ uptake is reduced 57% by only 10 days of drought, possibly involving stomatal closure induced by abscisic acid produced in the roots, which typically occupy a small substrate volume. Total daily net CO₂ uptake for H. undatus is maximal at day/night air temperatures of 30/20°C, optimal temperatures that are higher than those for desert cacti but representative of ambient temperatures in the tropics; its total daily net CO₂ uptake becomes zero at day/night air temperatures of 42/32°C. Stem damage occurs at 45°C for H. undatus, whose photosynthetic cells show little acclimation to high temperatures compared with other cacti and are also sensitive to low temperatures, ‐1.5°C killing half of these cells. Consistent with its shaded habitat, total daily net CO2 uptake is appreciable at a total daily PPF of only 2 mol m2 day' and is maximal at 20 mol m^?2 day^?1, above which photoinhibition reduces net CO₂ uptake. Net CO₂ uptake ability, which is highly correlated with stem nitrogen and chlorophyll contents, changes only gradually (halftimes of 2–3 months) as the concentration of applied N is changed. Doubling the atmospheric CO₂ concentration raises the total daily net CO₂ uptake of H. undatus by 34% under optimal conditions and by even larger percentages under adverse environmental conditions.