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Biomedical subjects

J Grey

Publications and source records attributed to J Grey.

At least 19 recordsLinked to original sources
PubMed2002

Using stable isotope analyses to identify allochthonous inputs to Lake Naivasha mediated via the hippopotamus gut.

The hippopotamus grazes nocturnally on land and resides in water during the day. Much of the ingested material must therefore be defecated directly into the aquatic system and can thus be considered an allochthonous resource available to aquatic consumers. The utility of stable isotope analyses of carbon and nitrogen to distinguish hippo faecal matter from other potential basal resources was tested at Lake Naivasha, Kenya. Hippopotami proved faithful to a short grass diet although supplementary grazing of aquatic macrophytes was observed. The typical isotopic ratios of C4 grasses ingested were not altered substantially by gut processes, and were clearly distinct from algal and aquatic macrophyte isotopic ratios. However, marginal plants such as Cyperus papyrus exhibit C4 ratios, and so the technique is suitable only for use in localities where 'contamination' from such sources is negligible.

Animals↗
PubMed2001

Healing of an MRSA-colonized, hydroxyurea-induced leg ulcer with honey.

BACKGROUND: With the everincreasing emergence of antibiotic-resistant pathogens, in particular methicillin-resistant Staphylococcus aureus (MRSA) in leg ulcers, a means of reducing the bacterial bioburden of such ulcers, other than by the use of either topical or systemic antibiotics, is urgently required. METHODS: We report the case of an immunosuppressed patient who developed a hydroxyurea-induced leg ulcer with subclinical MRSA infection which was subsequently treated with topical application of manuka honey, without cessation of hydroxyurea or cyclosporin. RESULTS: MRSA was eradicated from the ulcer and rapid healing was successfully achieved. CONCLUSION: Honey is recognized to have antibacterial properties, and can also promote effective wound healing. A traditional therapy, therefore, appears to have enormous potential in solving new problems.

Administration, Topical↗
PubMed1999

Carbon stable isotopes reveal complex trophic interactions in lake plankton.

The lower trophic linkages in lake plankton food webs are generally described as relatively simple, even accounting for the additional complexity of potential 'microbial looping'. Crustacean zooplankton are frequently amalgamated into one trophic functional group as grazers of autotrophic production. The carbon stable isotope ratios for separated zooplankton species, particulate organic matter (POM) and phytoplankton from a number of lakes in Finland and the UK were analysed. These revealed greater complexity in trophic interactions than would otherwise be observed if the zooplankton had been represented by a mixed sample. Grazing zooplankton were usually depleted in (13)C relative to the bulk POM on which they might feed, with (13)C deviating by up to 17 per thousand There were no consistent differences between (13)C values for copepods and cladocerans. Predatory cladocerans were generally enriched by greater than 1 per thousand compared to their putative prey. We suggest that care in separating the zooplankton species for stable isotope analysis may expose otherwise undetected sources of carbon and facilitate unravelling trophic links further up the food web. Copyright 1999 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1999

Zidovudine (AZT) induced alterations in mitochondrial biogenesis in rat striated muscles.

Zidovudine (AZT) and didanosine (ddI), two drugs used in the treatment of AIDS, are also known to cause mitochondrial abnormalities. We investigated the physiological relevance of the mitochondrial defects by measuring in situ skeletal muscle performance and cytochrome c oxidase (CYTOX) enzyme activity in heart muscle, red highoxidative (RG) and white low-oxidative (WG) portions of the gastrocnemius muscle of control (n = 17), AZT-(n = 14), or ddI-treated (n = 11) rats for 28 days. We also evaluated the hypothesis that AZT treatment could alter the expression of the mitochondrial transcription factor A (mtTFA), a key molecule involved in mitochondrial DNA (mtDNA) replication and transcription. AZT had a pronounced effect on blood pressure and skeletal muscle performance, which were significantly decreased during contractile activity at 2 and 5 Hz, compared with control. A significant decrease in CYTOX activity in heart and RG, but not WG muscles, was also evident. In the heart, this was accompanied by an apparent compensatory increase in mtTFA mRNA level that could not be attributed to enhanced transcriptional activation mediated by nuclear respiratory factor 1 (NRF-1). In contrast with AZT, no effect of ddI was found on the extent of fatigue or muscle enzyme activity. These results indicate that AZT induces mitochondrial defects primarily in muscles with the highest oxidative capacities (heart and RG). The long-term effects of AZT on mitochondrial biogenesis have the potential to reduce muscle performance, but the effects on performance in this short-term study were likely due to an inability of the AZT-treated animals to maintain blood pressure during contractile activity.

Animals↗
PubMed1996

Clinical audit in the National Health Service: fact or fiction?

It is increasingly recognized that the repeated rhetorical emphasis from 1989 to date on achieving measurable benefits to patients from audit, in the face of inattention to the development of methodologies with which to realize such benefits in operational practice, has represented a serious deficiency in strategic planning and direction and a consequent failure to establish functional clinical audit within the NHS. A grand revision of strategy is therefore necessary, and this should begin with the development of a research-based method of audit, the training of clinicians and audit support staff in its use and a subsequent trial of its effectiveness prior to its implementation within the NHS. Only then will measurable improvements become possible, value for money be assured and clinicians' attitudes to audit change.

Attitude of Health Personnel↗
PubMed1996

The Total Health Care Audit System: a systematic methodology for clinical practice evaluation and development in NHS provider organizations.

Writing in Medical Education in 1982, Fowkes (1982) noted the lack of general agreement within the medical profession on methods of audit, a deficiency previously articulated by Shaw (1980) and later emphasized by McIntyre (1985). More recently, a study by Black & Thompson (1993) of consultant and junior medical staff in four London district general hospitals revealed that 'many doctors did not understand how to undertake audit', and major research by both Hopkins (1993, 1994) and Buttery et al. (1994) described a multiplicity of methodological deficiencies in the general approaches to audit adopted by clinicians since the promulgation of the White Paper definition in 1989. Soundness of methodological approach is fundamental to securing the success of clinical audit within Provider organizations and is thus central to the generation of measurable improvements in the quality of clinical care being delivered to patients. It is therefore disturbing that methodological deficiencies may still be observed in general approaches to audit (Buttery et al. 1994), with no author yet recommending a formal system for critical inquiry into clinical practice. It was the recognition of the unsatisfactory nature of this situation which led us to develop a system aimed at assessing, in a critical fashion, the quality of the totality of care dispensed within NHS provider organizations. The system is presented here for the first time.

Algorithms↗
PubMed1988

The effects of human insulin on antibody formation in pregnant diabetics and their newborns.

We studied the immunogenicity of human insulin in 11 diabetic mothers and their newborns. Serum antibody formation was assayed by two different methods. Upon switching four patients from beef/pork insulin to human insulin, we found that elevated baseline antibody levels in three women decreased, in two to undetectable levels at term. The fourth patient had undetectable antibody levels at baseline and borderline levels at term. Only one of their four newborns had antibodies. Upon initiation of insulin treatment in another five diabetics without detectable antibodies at baseline, only two developed antibodies, and only one of their newborns developed antibodies. Two other patients, initially not on insulin, had baseline elevations of antibody that decreased with administration of human insulin; both of their newborns had antibodies. Overt diabetes evolved subsequently in both mothers after pregnancy. We conclude the following: 1) Upon transfer from beef/pork insulin to human insulin, mothers and their newborns show a decrease in insulin antibodies; 2) new patients initiated on insulin develop low levels of antibodies, if any, and their newborns also have low levels of antibodies if any; and 3) the decreased or absent immunogenicity of human insulin supports its use in pregnant diabetics.

Adolescent↗