SUMMARYAn automated method for the determination of N-acetyl-~-D-glucosaminidasein serum or plasma using p-nitrophenol (pNP) N-acetyl-~-D-glucosamineas substrate and a Pye Unicam AURA system is described. Normal samples had activities of 853 ± 146 (SO) nmol pNP liberated! ml/h, with intra-assay coefficient of variation I' 2 % and inter-assay coefficient of variation I· 6 %.Inhibition of enzyme activity by heparin in plasma samples can be reversed by the addition of calcium chloride to the buffer. liberated/ml plasma/hour. The standard was stable for one week at 4°C in a dark bottle, and the substrate for 48 hours at 4°C in a dark bottle.The effect of heparin upon enzyme activity was investigated by incubating serum samples at 37°C with heparin of different concentrations for times from 10 minutes to 4 hours and then determining enzyme activity using 2·9 mmol/l substrate. In addition, enzyme activities were measured in four blood samples collected into heparinised tubes which had been separated immediately and after 24 hours at 4°C. Material and methodsThe activity of N-acetyl-~-D-glucosaminidase in plasma and serum has been shown to be elevated in diabetics.I" It has been suggested that an increased activity of the enzyme might indicate development of microangiopathic changes," although this has not been confirmed.v" Considerable interest in monitoring the enzyme has encouraged requests for enzyme determinations. We report a simple colorimetric method which lends itself readily to automation and is suitable for performance on a routine basis. In addition, inhibition of enzyme activity by heparin is shown, and this inhibition is reversed by addition of calcium chloride to the reaction mixture.Optimum conditions for the automated assay were determined manually using freshly collected specimens. AUTOMATED METHODThe automated method used a Pye Unicam AURA system, which consisted of an ACI Chemistry Unit and an SP6-300 spectrophotometer coupled to a Hewlett Packard 9815A calculator.The instrument was set at 37"C with a 30-minute delay between dispensing of substrate and glycine/ NaOH. The first rack of sample cups and reaction MANUAL METHOD tubes contained alternate aliquots of water and All determinations were carried out in triplicate standard, 750 fJ.mol/1 p-nitrophenol, with which to at 37°C. To 0·1 ml plasma was added 0·9 ml calibrate the instrument, equivalent to 1500 nmol substrate, o·1-5·0 rnrnol/l p-nitrophenol N-acetyl-liberated/rnl plasma/hour. Subsequent racks con--D-glucosamine (Sigma) in 0·05 M Na citrate tained double cups with sample in both sides, one for buffer, pH 4·5. After 30 minutes incubation the test and one for sample blank. Plasma, 50 fJ.l, was reaction was stopped by the addition of I ·0 mil· 0 M washed into the system with 300 fJ.l of o·05M citrate NaOH containing 0·5 M glycine, and the optical buffer,0·25M CaCI 2 , pH 4·5. Reactionofthetestwas density was measured at 400 nm. Blanks, in which started by addition of 200 fJ.1 8·1 mmol/l substrate in the glycine/NaOH was added before the subs...
Research in care homes has demonstrated that medication management practices in patients with dysphagia and those receiving medicines covertly may be inappropriate, illegal, and potentially cause harm. This paper presents the results of a feasibility study piloting a resident and healthcare professional best practice charter to improve such practices in care home residents with dysphagia. A charter was developed through a multi-professional expert panel, implemented in one care home, and then piloted in 22 homes in England, Wales, and Northern Ireland. A website was setup and developed iteratively to support the process. Care home staff and residents provided initial feedback on the implementation process and on perceived outcomes six months post implementation. A total of 16 (88.9%) out of 18 respondents from nine homes for six months reported a positive response to the charter. More than 80% of responses regarding the implementation process, impact on staff confidence, and perceived usefulness of the charter were positive. Perceived effectiveness and usefulness could, however, be further improved especially the perceived effect on frequency of medication review, which is reliant on external stakeholder involvement. The charter and supporting website were well received with respondents believing that it was useful, staff showing more confidence, and residents having enhanced care. Approaches to enhancing the charter’s effectiveness were identified.
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