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Biomedical subjects

B Morris

Publications and source records attributed to B Morris.

At least 19 recordsLinked to original sources

Utility of admission cardiac troponin and "Ischemia Modified Albumin" measurements for rapid evaluation and rule out of suspected acute myocardial infarction in the emergency department.

OBJECTIVE: To assess if the combination of cardiac troponin (cTn) and Ischemia Modified Albumin (IMA) can be used for early exclusion of acute myocardial infarction (AMI). METHODS: Prospective consecutive admissions to the emergency department (ED) with undifferentiated chest pain were assessed clinically and by electrocardiography. A total of 539 patients (335 men, 204 women; median age 51.9 years) considered at low risk of AMI had blood drawn on admission. If the first sample was less than 12 hours from onset of chest pain, a second sample was drawn two hours later, at least six hours from onset of chest pain. Creatine kinase MB isoenzyme (CKMB) mass was measured on the first sample and CKMB mass and cTnT on the second sample. An aliquot from the first available sample was frozen and subsequently analysed for IMA. If cTnT had not been measured on the original sample cTnI was measured (n = 189). RESULTS: Complete data were available for 538/539 patients. IMA or cTn was elevated in the admission sample of all patients with a final diagnosis of AMI (n = 37) with IMA alone elevated in 2/37, cTn alone in 19/37, and both in 16/37. In 173/501 patients in whom AMI was excluded both tests were negative. In the non-AMI group 22 patients had elevation of both IMA and cTn in the initial sample, suggesting ischaemic disease. CONCLUSION: Admission measurement of cardiac troponin plus IMA can be used for early classification of patients presenting to the ED to assist in patient triage.

Adult↗

GIGANTEA: a circadian clock-controlled gene that regulates photoperiodic flowering in Arabidopsis and encodes a protein with several possible membrane-spanning domains.

Flowering of Arabidopsis is promoted by long days and delayed by short days. Mutations in the GIGANTEA (GI) gene delay flowering under long days but have little or no effect under short days. We have now isolated the GI gene and show that it encodes a novel, putative membrane protein. By comparing the sequence of the Arabidopsis gene with that of a likely rice orthologue and by sequencing mutant alleles, we identify regions of the GI protein that are likely to be important for its function. We show that GI expression is regulated by the circadian clock with a peak in transcript levels 8-10 h after dawn. The timing, height and duration of this peak are influenced by daylength. We analysed the interactions between GI and the LHY, CCA1 and ELF3 genes, previously shown to affect daylength responses; we show that the rhythmic pattern of GI expression is altered in the elf3, CCA1-OX and lhy genotypes, and that CCA1 and LHY expression are reduced by gi mutations. Our results are consistent with the idea that GI plays an important role in regulating the expression of flowering time genes during the promotion of flowering by photoperiod.

Alleles↗

Paediatric out-patient antiepileptic drug doses recorded in the medical charts are not reliable: implications for the notion of noncompliance.

There may be discrepancies between the antiepileptic drug (AED) doses the physician believes the patient is taking and what is actually taken. This prospective study assesses the extent of the problem in one paediatric epilepsy clinic. A questionnaire was administered to the parent or patient by the clinical nurse specialist (CNS) with the physician blind. All AED doses taken were recorded and the medical charts later reviewed by the CNS. Twenty-five unselected patients (1-16 years old) taking 40 AEDs were studied. Five per cent of current AED regimes were incorrectly documented in the charts. Furthermore the AEDs and doses taken had changed from those planned at the previous clinic visit for 44% of patients (30% of AEDs). Twenty per cent of patients had difficulty understanding the AED regime, even though 72% had it in writing. Although the discrepancies were not harmful, the unreliability of the medical charts' entries is demonstrated. Such errors could well be detrimental to patient care and are not simply a matter of non-compliance. Extra care needs to be taken to reduce these errors and studies of patient compliance should control for them.

Adolescent↗

Mutagenesis of the BC1 and BV1 genes of African cassava mosaic virus identifies conserved amino acids that are essential for spread.

The products of three open reading frames encoded by the bipartite geminiviruses have been implicated in viral spread: AC2, BV1 and BC1. Alignment of the DNA B encoded gene products, BV1 and BC1, from African cassava mosaic virus (ACMV) with six other bipartite geminiviruses showed several highly conserved regions. Specific amino acids were selected for mutagenic studies to ascertain the tolerance of the virus to change and to identify the regions within these two proteins required for normal functioning. Various mutant DNA B constructs, and a wild-type construct, were inoculated onto three host plant species with an equivalent DNA A construct. Three of the mutant constructs were infectious on Nicotiana benthamiana and N. clevelandii, but only two induced ACMV disease symptoms on N. tabacum cv. Samsun. Sequencing of the viral DNA extracted from the sap of systemically infected plants confirmed the maintenance of introduced base changes. The amino acid at position 95 on the BV1 gene product was identified as non-essential for normal functioning of the protein. The alteration of the amino acid at position 145 in BC1 demonstrated the ability of the virus to tolerate a conservative change. The lack of tolerance to other changes in amino acids has given an indication of the importance of maintaining protein structure for these proteins to function normally.

Amino Acid Sequence↗

Involving patients in the provision of community care: a change in philosophy.

The National Health Service (NHS) has many different kinds of professionals and managers working underneath its large umbrella: non-clinical managers administer the work of health-care professionals, who in turn are concerned with the management of patients' treatments. Delivery of health-care services involves the managers and professionals working together to achieve a service that is good for, and acceptable to, patients. A change in the philosophy of the NHS is indicated by the growing acceptance, by both managers and professionals, of the necessity to elicit the views of patients (i.e. the expectations and perceptions of service users) and to incorporate these views into the planning and implementation of services. Discusses one such attempt to elicit the perceptions of service users, and reports on the preliminary findings of a patient-centred audit which has been undertaken in Southend Community Care Services NHS Trust. Discusses the effects that the audit has had on the chiropody services in Southend, for both non-clinical managers and health-care professionals, in order to highlight the usefulness of the approach.

Community Health Services↗

Evidence for chromium acting as an essential trace element in insulin-dependent glucose uptake in cultured mouse myotubes.

Previous work from this and other laboratories has suggested that the trace element chromium plays some role in glucose homeostasis. In this study, we sought to characterise an in vitro cell culture model in which the effects of chromium on insulin-dependent glucose uptake could be studied. Mouse C2C12 myoblasts were differentiated to form myotubes in culture in chromium-replete or chromium-poor media. Chromium levels in standard media were 0.56 +/- 0.01 micrograms/l (mean +/- S.E.M.) compared with 0.09 +/- 0.01 micrograms/l in chromium-poor media. In chromium-poor media, insulin-stimulated uptake of radiolabelled glucose was reduced by almost 50% compared with that found in chromium-replete media. This decreased response could be restored by the addition of physiologically relevant (0.3 micrograms/l) concentrations of inorganic chromium (P < 0.001). The sensitivity of these cells to insulin was reduced dramatically by a reduction in the chromium content of the medium and was again increased (P < 0.001) by chromium addition. The concentrations of chromium required to restore the sensitivity to insulin were of the same order as those found physiologically; much higher concentrations of chromium could also stimulate glucose uptake in the absence of insulin but such concentrations were supra-physiological.

Animals↗

Growth factors in porcine full and partial thickness burn repair. Differing targets and effects of keratinocyte growth factor, platelet-derived growth factor-BB, epidermal growth factor, and neu differentiation factor.

The topical application of recombinant growth factors such as epidermal growth factor, platelet-derived growth factor-BB homodimer (rPDGF-BB), keratinocyte growth factor (rKGF), and neu differentiation factor has resulted in significant acceleration of healing in several animal models of wound repair. In this study, we established highly reproducible and quantifiable full and deep partial thickness porcine burn models in which burns were escharectomized 4 or 5 days postburn and covered with an occlusive dressing to replicate the standard treatment in human burn patients. We then applied these growth factors to assess their efficacy on several parameters of wound repair: extracellular matrix and granulation tissue production, percent reepithelialization, and new epithelial area. In full thickness burns, only rPDGF-BB and the combination of rPDGF-BB and rKGF induced significant changes in burn repair. rPDGF-BB induced marked extracellular matrix and granulation tissue production (P = 0.013) such that the burn defect was filled within several days of escharectomy, but had no effect on new epithelial area or reepithelialization. The combination of rPDGF-BB and rKGF in full thickness burns resulted in a highly significant increase in extracellular matrix and granulation tissue area (P = 0.0009) and a significant increase in new epithelial area (P = 0.007), but had no effect on reepithelialization. In deep partial thickness burns, rKGF induced the most consistent changes. Daily application of rKGF induced a highly significant increase in new epithelial area (P < 0.0001) but induced only a modest increase in reepithelialization (83.7% rKGF-treated versus 70.2% control; P = 0.016) 12 days postburn. rKGF also doubled the number of fully reepithelialized burns (P = 0.02) at 13 days postburn, at least partially because of marked stimulation of both epidermal and follicular proliferation as assessed by proliferating cell nuclear antigen expression. In situ hybridization for KGFR in porcine burns revealed strong expression of KGFR on hair follicles and basal epidermis, confirming direct rKGF action on follicular as well as epidermal keratinocytes. Although the epithelial proliferation induced by rKGF resulted in marked neoepidermal psoriasiform hyperplasia with exaggerated rete ridges and neoepidermal and follicular maturation as assessed by expression of cytokeratin 10, a marker of keratinocyte terminal differentiation was not delayed and appeared to be accelerated in some rKGF-treated burns. Recombinant epidermal growth factor induced a trend toward increased new epithelial area in deep partial thickness burns, but had no effect on reepithelialization. The recombinant neu differentiation factor-alpha 2 isoform had no significant biological effects in either full or deep partial thickness burns.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗