Action research sets the stage to improve discharge preparation.

An action research project was conducted to explore parents' perceptions about discharge preparation for a child with a respiratory problem. The action research approach was selected to provide bedside nurses with an opportunity to participate in research activities and actively change practice. Seven bedside nurses were recruited and prepared to conduct home interviews of 14 urban families and telephone interviews of six rural families. Families not participating in interviews were asked to complete questionnaires. Data analysis revealed four major themes: (a) the parent as learner, (b) the content of teaching activities, (c) timing of discharge, and (d) the impact of hospitalization after discharge. All nurses were positive about their experience. Action research provided a nonthreatening opportunity to involve bedside nurses in a research project.

A comparison of two anaesthetic techniques for daycase arthroscopy.

A randomised, double-blind study of 100 patients admitted for daycase arthroscopy was undertaken. Fifty patients received alfentanil 500 micrograms and midazolam 5 mg, and 50 received alfentanil 500 micrograms alone, in each case 2 minutes before induction of anaesthesia with methohexitone. Anaesthesia was maintained in both groups with nitrous oxide, oxygen and enflurane. Recovery was assessed quantitatively by measuring time to when they awoke and by a comparison of pre- and postoperative performance of p-deletion and postbox tests. Qualitative assessment of recovery and of postoperative pain was also undertaken. Patients completed a questionnaire to record the incidence of any anaesthetic-related symptoms on the first and second postoperative days. Patients who received midazolam required a reduced dose of methohexitone but their initial recovery time was prolonged significantly. The incidences of anaesthetic-related side effects and postoperative pain were similar in the two groups and while the questionnaires did not reveal any statistically significant differences in symptoms on the first 2 postoperative days, the results indicated that patients who received a larger induction dose of methohexitone were subjectively drowsier on the first day after operation.

OSMOTIC ADJUSTMENT IN MARINE EUKARYOTIC ALGAE: THE ROLE OF INORGANIC IONS, QUATERNARY AMMONIUM, TERTIARY SULPHONIUM AND CARBOHYDRATE SOLUTES: I. DIATOMS AND A RHODOPHYTE.

The unicellular marine algae, Phaeodactylum tricornutum Bohlin, Cyclotella cryptica Reimann and Cyclotella meneghiniana Kützing (Bacillariophyceae) and Porphyridium aerugineum Geitler (Rhodophyceae) synthesized and accumulated glycine betaine and proline in response to increases of the NaCl concentration (150 to 1000 mol m-3 NaCl) of the growth medium. C. cryptica and C. meneghiniana also synthesized and accumulated homarine (N-methyl picolinic acid betaine). Both P. tricornutum and P. aerugineum synthesized increasing amounts of intracellular glycerol and P. aerugineum also formed the heteroside, floridoside [O-α-D-galactopyranosyl (1 → 2)-glycerol], in response to the elevated salinities. No major low molecular weight carbohydrates were found in Cyclotella. Sucrose was not detected in the algal extracts. Only P. tricornutum synthesized the tertiary sulphonium compound, ß-dimethylsulphoniopropionate (DMSP), and the quantity of this solute in the alga was dependent on the amount of NaCl in the medium. Intracellular K+ concentrations in the algae were three to six times greater than those of Na+ . Increases of the salinity of the media led to the uptake and accumulation of K+ by the cells, and smaller increases of Na+ and Cl-1 and loss of intracellular NO3 - . The inorganic cations Na+ and K+ , with their accompanying anions, and the estimated organic solutes could largely account for the osmotic balance of P. tricornutum and P. aerugineum.

OSMOTIC ADJUSTMENT IN MARINE EUKARYOTIC ALGAE: THE ROLE OF INORGANIC IONS, QUATERNARY AMMONIUM, TERTIARY SULPHONIUM AND CARBOHYDRATE SOLUTES: II. PRASINOPHYTES AND HAPTOPHYTES.

The effects of steady state salinities (150 to 700 mol m-3 NaCl) on the growth rates and intracellular solutes of the prasinophyte algae Tetraselmis chui Butcher and Prasinocladus Kuckuck and the prymnesiophyte algae, Prymnesium parvum Carter and Ruttnera spectabilis Geitler, are described. Maximum growth rates were reached in media approximating to the NaCl concentration of oceanic waters (about 500 mol m-3 ). The following intracellular organic solutes paralleled the increases of external salinity: the tertiary sulphonium compound ß-dimethylsulphoniopropionate (DMSP) in T. chui, Prasinocladus, P. parvum and R. spectabilis; the polyhydric alcohol, mannitol, in T. chui, Prasinocladus and R. spectabilis; the quaternary ammonium compounds (QACs), glycine betaine and homarine, in T. chui and Prasinocladus. QACs were not detected in P. parvum and R. spectabilis. An unknown polyol, which may be the cyclitol, 1,4/2,5 cyclohexanetetrol, was synthesized by P. parvum and R. spectabilis and in addition P. parvum contained significant concentrations of glucose. Sucrose was not detected in the algal extracts. Proline was an insignificant osmoticum in all the algae. Increases of the media NaCl concentration led to the uptake and accumulation of K+ in T. chui and Prasinocladus, with smaller increases of Na+ and Cl- . The intracellular K+ concentrations in the prasinophyte algae were about five times greater than those of Na+ . The inorganic cations Na+ and K+ , and their accompanying anions, and the organic solutes found could largely account for the osmotic balance of T. chui and Prasinocladus. The inorganic ions in P. parvum and R. spectabilis were not determined.

The role of ß-dimethylsulphoniopropionate, glycine betaine and homarine in the osmoacclimation of Platymonas subcordiformis.

The tertiary sulphonium compound, ß-dimethylsulphoniopropionate (DMSP) and the quaternary ammonium compounds glycine betaine and homarine are important osmotica in Platymonas subcordiformis cells. Following hypersaline stresses the compounds were accumulated after a lag period of 3 h and equilibrium concentrations were reached 6 h later. In contrast to these organic solutes, mannitol was synthesised immediately and equilibrium concentrations were reached within 90 min. Hyposaline stresses induced losses of the organic solutes from the cells. The ions K(+), Na(+), Cl(-) and the above organic solutes can account for the osmotic balance of the cells.

Osmotic adaptation in Ulva lactuca under fluctuating salinity regimes.

A study has been made of the osmotic responses of the green intertidal alga, Ulva lactuca, under two fluctuating salinity regimes; sinusoidal and square-wave fluctuations between 30 and 100% sea water in a 12 h cycle. These regimes closely resemble the tidal fluctuation of salinity encountered by the alga in its natural estuarine habitat. Data on changes in the inorganic ions, potassium, sodium, chloride and sulphate; in the organic solute, dimethylsulphoniopropionate; in the total sugar levels and estimated osmotic and turgor pressures under the two salinity regimes are reported. Significant differences in the solute responses under these different conditions were detected. In general, better control of ion fluxes appeared to be exercised under the sinusoidal conditions which also buffered changes in dimethylsulphoniopropionate levels. Influxes of potassium were highly light-dependent. Chloride levels conspicuously failed to reach the steady-state levels in the 6-h-hyper-osmotic part of either the abrupt or gradual cycle. The possible significance of these data, which may better reflect osmotic changes in the natural environment, and some of the problems encountered, particularly in accounting for charge balance under some conditions, are discussed.

Steady state osmotic adaptation inUlva lactuca.

The effects of hyper- and hypo-saline stresses on the levels of various inorganic and organic solutes inUlva lactuca have been recorded. Hypoosmotic stress decreased the tissue concentration of K(+), Na(+) and Cl(-) while hyper-osmotic stress caused a transient increase in Na(+) and a stable accumulation of K(+) and Cl(-). The tissue content of ß-dimethylsulphoniopropionate (ß-dimethylpropiothetin) responded to changes in salinity. The time course of hypersaline stress showed the ß-dimethylsulophoniopropionate concentration rose as the Na(+) level fell. The levels of free sugars and amino acids, including proline, were relatively low in this alga and did not appear to be important in osmotic adjustment. The possibility that tertiary sulphonium dipolar ions have an analogous role in some algae to glycinebetaine and possibly other quaternary nitrogen compounds in higher plants as cytoplasmic osmotica is discussed briefly.