Shared care: a review of the literature

This review examines broad issues of concern regarding the primary/secondarycare interface. The main purpose was to identify areas of goodpractice which could be adapted for more general use. One ofthe most fundamental aspects identified was communication, whichis discussed in some detail. Also covered are shared prescribingand disease management. The data suggest that the most effectivesystem(s) of shared care has yet to be established. Furtherqualitative and economic evaluations are required, taking intoaccount patient preferences. Although the literature does describecertain practice exemplars, it is clear that inter- and intra-professionalcommunication continues to be a problem. Whilst informationtechnology may provide some of the solutions, it is concludedthat a culture change, which compels health professionals tomake sharing of patient information a much higher priority,is reauired. Keywords. Shared care, seamless care, hospital, general practice, family practice.     

Asbestos-related focal lung masses: manifestations on conventional and high-resolution CT scans

In 260 asbestos-exposed individuals evaluated by means of computed tomography (CT), 43 unsuspected pulmonary masses were found in 27 individuals. The masses included fissural pleural plaques (n = 10), dense fibrotic bands (n = 3), round atelectasis (n = 11), carcinomas (n = 3), and other presumed benign masses (n = 16). The most helpful features in the diagnosis of rounded atelectasis with CT were (a) contiguity to areas of diffuse pleural thickening, (b) a lentiform or wedge-shaped outline, (c) evidence of volume loss in the adjacent lung, and (d) a characteristic "comet tail" of vessels and bronchi sweeping into the margins of the mass. Less advanced areas of focal atelectasis had fewer classic features. Intrafissural pleural plaques were readily identified with high-resolution CT. In asbestos-related masses, the demonstration of stability over time is necessary. Careful interpretation of CT and high-resolution CT features and close surveillance can obviate the need for biopsy in the majority of instances.     

The effect of temperature change upon transmitter release, facilitation and post-tetanic potentiation

1. End-plate potentials (e.p.p.s) and miniature end-plate potentials (m.e.p.p.s) were intracellularly recorded from rat diaphragm phrenic nerve preparations in vitro at temperatures between 7 degrees and 40 degrees C.2. The quantal content of e.p.p.s and the frequency of m.e.p.p.s showed broadly similar relationships with temperature, with maxima about 20 degrees and above 39 degrees C.3. Analysis of the change in e.p.p. quantal content showed that the maximum about 20 degrees C was accompanied by a similar maximum of p, the probability of release of quanta. The maximum above 39 degrees C was associated with a rise in n, a presynaptic store of material needed for release.4. The rate at which transmitter could be mobilized was linear in an Arrhenius plot with an apparent activation energy of 25 kcal deg(-1).5. Facilitation and post-tetanic potentiation (PTP) were shown to be entirely attributable to changes in p.6. It is suggested that facilitation and PTP have a common basis and that the (temperature-dependent) rate of Ca removal from intracellular sites at which it exerts its action is as important a determinant of the magnitude of quantal release as is the amount of Ca combining with these sites.     

On the mechanism by which calcium and magnesium affect the release of transmitter by nerve impulses

1. The relationship between the quantal content of end-plate potentials (e.p.p.s) and the bathing [Ca] and [Mg] was determined at neuromuscular junctions in the rat diaphragm in vitro.2. E.p.p.s were recorded intracellularly from preparations exposed to solutions with [Ca] between 0.05 and 10 mM and [Mg] between 0.1 and 12.5 mM. The quantal content of e.p.p.s was increased by raising the [Ca] over this range and decreased by raising the [Mg]. There appeared to be competition of Mg with Ca at three sites in the nerve terminal membrane.3. A kinetic scheme based on competition of Ca and Mg at three sites could quantitatively explain the effects of Ca and Mg upon the quantal content of e.p.p.s and also the effects of these ions upon miniature end-plate potential frequency.