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Biomedical subjects

M Dolman

Publications and source records attributed to M Dolman.

8 recordsLinked to original sources
PubMed2000

Acid-base control for biocatalysis in organic media: new solid-state proton/cation buffers and an indicator

Although great care is generally taken to buffer aqueous enzyme reactions, active control of acid-base conditions for biocatalysis in low-water media is rarely considered. Here we describe a new class of solid-state acid-base buffers suitable for use in organic media. The buffers, composed of a zwitterion and its sodium salt, are able to set and maintain the ionisation state of an enzyme by the exchange of H+ and Na+ ions. Surprisingly, equilibrium is established between the different solid components quickly enough to provide a practical means of controlling acid-base conditions during biocatalysed reactions. We developed an organosoluble chromoionophore indicator to screen the behaviour of possible buffer pairs and quantify their relative H+/Na- exchange potential. The transesterification activity of an immobilised protease, subtilisin Carlsberg, was measured in toluene in the presence of a range of buffers. The large observed difference in rates showed good correlation with that expected from the measured exchange potentials. The maximum water activities accessible without formation of hydrates or solutions of the buffers are reported here. The indicator was also used to monitor, for the first time in situ, changes in the acid-base conditions of an enzyme-catalysed transesterification reaction in toluene. We found that even very minor amounts of an acidic by-product of hydrolysis were leading to protonation of the enzyme, resulting in rapid loss of activity. Addition of solid-state buffer was able to prevent this process, shortening reaction times and improving yields. Solid-state buffers offer a general and inexpensive way of precisely controlling acid-base conditions in organic solvents and thus also have potential applications outside of biocatalysis.

Journal Article↗
PubMed2000

Electromuscular stimulation for urinary incontinence: Levator 100.

Electromuscular stimulation (EMS) can be an effective conservative treatment option for pelvic floor muscle dysfunction for many women. This treatment can be administered by nurses in primary care and by practice nurses and specialist nurses in continence care, provided that they have received comprehensive training. Correct patient selection is essential for the treatment to succeed. This is done by assessing the patient fully and involves obtaining a clinical history and a physical examination of the pelvic floor muscle. Informed patient consent must be sought before commencing treatment. There are some contraindications to the use of EMS; however, when used with the right client for the right conditions, EMS is a safe treatment and can improve symptoms of urinary and faecal incontinence, dyspareunia, vaginismus or lax vaginal muscles. The outcome of an audit of the use of the Levator 100 EMS device, the forerunner to the newer Levator Turbo CS200, is examined.

Adult↗
PubMed1996

Comparison between the Health Belief Model and Subjective Expected Utility Theory: predicting incontinence prevention behaviour in post-partum women.

A small-scale study was undertaken to test the relative predictive power of the Health Belief Model and Subjective Expected Utility Theory for the uptake of a behaviour (pelvic floor exercises) to reduce post-partum urinary incontinence in primigravida females. A structured questionnaire was used to gather data relevant to both models from a sample antenatal and postnatal primigravida women. Questions examined the perceived probability of becoming incontinent, the perceived (dis)utility of incontinence, the perceived probability of pelvic floor exercises preventing future urinary incontinence, the costs and benefits of performing pelvic floor exercises and sources of information and knowledge about incontinence. Multiple regression analysis focused on whether or not respondents intended to perform pelvic floor exercises and the factors influencing their decisions. Aggregated data were analysed to compare the Health Belief Model and Subjective Expected Utility Theory directly.

Adult↗
PubMedDate not supplied

Midwives' recording of urinary output.

The prevalence of urinary incontinence in women has been well documented (1, 2, 3), but several women attending a continence clinic also complained of a feeling of not completely emptying their bladder. It was observed that these complaints tended to come from mothers who had had an epidural anaesthetic during labour, with or without a forceps delivery, and when a Foley catheter had been in situ. It occurred in both primigravidae and multigravidae pregnancies. This pilot study examined the extent of documentation of urinary output, measured by midwives, during labour and in the immediate postpartum period when epidural anaesthesia had been administered. This highly susceptible group of mothers can develop hypotonic detrusor activity, which may go unrecognised unless it has been carefully monitored (4). A sample of convenience, over a two-week period from two maternity units, provided 20 mothers for study. They all had epidural anaesthesia and vaginal deliveries. Two questionnaires with predetermined questions were used to collect the data, one for midwives, the other for the investigator in using patients' records. The results showed that documentation for urinary output during labour was recorded for 60 per cent of the sample, while 20 per cent had urinary output recorded in the postnatal ward. It is suggested that 50 per cent of the mothers could have been discharged home with unrecognised hypotonic detrusor activity.

Documentation↗