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Biomedical subjects

A Williams

Publications and source records attributed to A Williams.

At least 703 records · Page 39Linked to original sources
PubMed1967

Lysozyme-catalysed hydrolysis of some beta-aryl di-N-acetylchitobiosides.

1. Four beta-aryl di-N-acetylchitobiosides and beta-S-phenyl di-N-acetylthiochitobioside have been prepared and shown to be substrates for hen's-egg-white lysozyme. 2. The lysozyme-catalysed hydrolysis of these substrates obeys Michaelis-Menten kinetics. 3. The Michaelis constants, K(m), for the beta-aryl di-N-acetyl-chitobiosides are almost independent of the aglycone, whereas the catalytic constants, k(cat.), show a marked dependence, giving a Hammett reaction constant, rho, equal to 1.2; this suggests the rate-determining step involves concerted acid-base or acid-nucleophilic catalysis. 4. This conclusion is supported by the Michaelis-Menten constants found for beta-S-phenyl di-N-acetylthiochitobioside. 5. A three-step reaction pathway is proposed, and mechanisms are suggested that would account for the evidence currently available.

Animals↗
PubMedDate not supplied

The time trade-off method: results from a general population study.

An important consideration when establishing priorities in health care is the likely effects that alternative allocations of resources will have on health-related quality-of-life (HRQoL). This paper reports on a large-scale national study that elicited the relative valuations attached by the general public to different states of health (defined in HRQoL terms). Health state valuations were derived using the time trade-off (TTO) method. The data from 3395 respondents were highly consistent, suggesting that it is feasible to use the TTO method to elicit valuations from the general public. The paper shows that valuations for severe health states appear to be affected by the age and the sex of the respondent; those aged 18-59 have higher valuations than those aged 60 or over and men have higher valuations than women. These results contradict those reported elsewhere and suggest that the small samples used in other studies may be concealing real differences that exist between population sub-groups. This has important implications for public policy decisions.

Adolescent↗
PubMedDate not supplied

Intergenerational equity: an exploration of the 'fair innings' argument.

Many different equity principles may need to be traded off against efficiency when prioritizing health care. This paper explores one of them: the concept of a 'fair innings'. It reflects the feeling that everyone is entitled to some 'normal' span of health (usually expressed in life years, e.g. 'three score years and ten') and anyone failing to achieve this has been cheated, whilst anyone getting more than this is 'living on borrowed time'. Four important characteristics of the 'fair innings' notion are worth noting: firstly, it is outcome based, not process-based or resource-based; secondly, it is about a person's whole life-time experience, not about their state at any particular point in time; thirdly, it reflects an aversion to inequality; and fourthly, it is quantifiable. Even in common parlance it is usually expressed in numerical terms: death at 25 is viewed very differently from death at 85. But age at death should be no more than a first approximation, because the quality of a person's life is important as well as its length. The analysis suggests that this notion of intergenerational equity requires greater discrimination against the elderly than would be dictated simply by efficiency objectives.

Adolescent↗
PubMedDate not supplied

Recombinant interferon-alpha 2b and high dose methyl prednisolone in relapsed and resistant multiple myeloma.

Twenty-one patients with refractory myeloma (10 primary resistant and 11 relapsed resistant) were treated with a combination of high dose methyl prednisolone and recombinant interferon alpha 2b (IFN-alpha 2b). This treatment included three megaunits/m2 of IFN-alpha 2b three times a week for 12 weeks, plus 5-day pulsed high dose methyl prednisolone every 3 weeks for two courses. A partial response (more than 50 per cent reduction in paraprotein) was observed in six patients; two of these had a greater than 75 per cent reduction in paraprotein, and evaluation of bone marrow showed <5 per cent plasma cells. A minimal response (more than 25 per cent reduction in paraprotein) was seen in four patients, giving an overall objective response rate of 10/21 (48 per cent). Subjective response, in terms of subsidence of pain and improvement of performance status, was seen in all patients who had adequate therapy. The protocol was generally well tolerated with minimal side-effects. There were 4/21 (19 per cent) treatment-related deaths which, though considerable, was anticipated in such a study population. The excellent subjective response seen supplements the objective response observed, and suggests a potential role for the combination of methyl prednisolone and IFN-alpha 2b in refractory myeloma.

Aged↗
PubMedDate not supplied

A report on misonidazole in randomized trial in locally advanced head and neck cancer.

A prospective randomized trial is reported involving 97 patients with locally advanced cancer of the head and neck. Using six large fractions of radiation (3600 rad in 17 days) the addition of misonidazole (2.0gm per m2 body surface) with each fraction did not increase the local control rate at one year. It is thought that this is probably because of an inadequate tumor concentration of the drug.

Adult↗