Clinical therapeutic evaluation of methylcysteine hydrochloride in patients with chronic obstructive bronchitis: a balanced double-blind trial with placebo control.

A double-blind, between-patient, placebo controlled trial was carried out to investigate the effects of methylcysteine hydrochloride in patients with chronic obstructive bronchitis. After a 2-week washout period on placebo, 30 patients were allocated at random to treatment for 6 weeks with either methylcysteine (1200 mg daily in Week 1, 800 mg daily in Week 2, then 600 mg daily) or with identical placebo tablets on the same regimen. During the post-treatment period, all patients returned to a single-blind placebo regimen (6 tablets daily) for a further 14 days. Assessments were made at the start, at regular intervals during the trial, and at the end of the post-treatment period, of subjective and objective measures of clinical response, and measurements of pulmonary function and certain physico-chemical properties of sputum. The results showed that methylcysteine increased sputum volume, reduced the viscidity of sputum, and significantly improved the subjective assessments of ease of expectoration and severity and frequency of cough, leading to a definite improvement in the patients' clinical state. No side-effects of clinical significance were reported and no abnormalities were found in any of the haematological, hepatic and renal function tests carried out.

The treatment of stable paediatric forearm fractures using a cast that may be removed at home: comparison with traditional management in a randomised controlled trial.

We investigated whether, in the management of stable paediatric fractures of the forearm, flexible casts that can be removed at home are as clinically effective, cost-effective and acceptable to both patient and parent as management using a cast conventionally removed in hospital. A single-centre randomised controlled trial was performed on 317 children with a mean age of 9.3 years (2 to 16). No significant differences were seen in the change in Childhood Health Assessment Questionnaire index score (p = 0.10) or EuroQol 5-Dimensions domain scores between the two groups one week after removal of the cast or the absolute scores at six months. There was a significantly lower overall median treatment cost in the group whose casts were removed at home (£150.88 (sem 1.90) vs £251.62 (sem 2.68); p < 0.001). No difference was seen in satisfaction between the two groups (p = 0.48).

Drug combinations in syringe drivers: the compatibility and stability of diamorphine with cyclizine and haloperidol.

The compatibility and stability of 2B combinations of diamorphine hydrochloride (5-100 mg/ml) with cyclizine lactate (5-50 mg/ml), eight combinations of diamorphine (10-100 mg/ml) with haloperidol (2-4 mg/ml) and eight combinations of all three drugs was assessed after storage in 1 ml polypropylene syringes. Samples were stored for periods up to seven days in the light and at room temperature (22 degrees C). Five combinations of diamorphine with cyclizine precipitated immediately upon preparation. After analysis and determination of t90% values (the time taken for 10% degradation). 16 of the remaining 23 combinations were judged to be compatible (no signs of crystallization or precipitation) and stable (less than 10% loss of potency of either drug) after storage for 24 h. After seven days storage only four remained compatible and stable. The results indicate that ratios of diamorphine to cyclizine of 1:1 are stable at concentrations up to 20 mg/ml. An increase in diamorphine concentration necessitates a reduction in cyclizine to 10 mg/ml, and an increase in cyclizine concentration necessitates a reduction in concentration of diamorphine to 15 mg/ml to maintain stability over 24 h. All the combinations of diamorphine with haloperidol remained compatible and stable for seven days. The addition of haloperidol (2 mg/ml) to the diamorphine and cyclizine combinations had no detrimental effect on their compatibility and stability. A stability curve is included as an easy way for palliative care personnel to avoid potential problems with incompatibilities and reduced stability when using these combinations. Furthermore, to reduce the possibility of precipitation with mixtures containing cyclizine, the use of 0.9% sodium chloride should be avoided.

Film thickness effects on the distribution of high-molecular-weight heterotelechelic polymers.

High-molecular-weight heterotelechelic deuteriopolystyrene, NDPSF, possessing an amine functional group at one end of the chain and a fluorocarbon group at the other was tethered to a silicon substrate by its amine functional group. These layers were coated with an unfunctionalised polystyrene matrix, HPS, such that the total film thickness covered a range from 2.2 to 9 times the radius of gyration of NDPSF. The detailed distribution of the polymers after annealing for times much greater than the reptation period of either of the components, was obtained using neutron reflectometry. No evidence for bridging of the two interfaces was found for the thicker films, but the finite concentration of the NDPSF polymer observed for the thinnest films may be due to bridging since the energy gain of the fluorocarbon end is just greater than the loss due to configurational entropy losses. A linear increase in the ellipsometric thickness of the excess of NDPSF at the substrate was discovered and we attribute this to the NDPSF slowly being leached out of the layer initially at the substrate followed by diffusion into the bulk of the film. The concentration profiles obtained are consistent with hindered relaxation of the large NDPSF molecules, when they are tethered at the substrate or at the vacuum surface.

Neutron-mapping polymer flow: scattering, flow visualization, and molecular theory.

Flows of complex fluids need to be understood at both macroscopic and molecular scales, because it is the macroscopic response that controls the fluid behavior, but the molecular scale that ultimately gives rise to rheological and solid-state properties. Here the flow field of an entangled polymer melt through an extended contraction, typical of many polymer processes, is imaged optically and by small-angle neutron scattering. The dual-probe technique samples both the macroscopic stress field in the flow and the microscopic configuration of the polymer molecules at selected points. The results are compared with a recent "tube model" molecular theory of entangled melt flow that is able to calculate both the stress and the single-chain structure factor from first principles. The combined action of the three fundamental entangled processes of reptation, contour length fluctuation, and convective constraint release is essential to account quantitatively for the rich rheological behavior. The multiscale approach unearths a new feature: Orientation at the length scale of the entire chain decays considerably more slowly than at the smaller entanglement length.