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S Penfold

Publications and source records attributed to S Penfold.

6 recordsLinked to original sources
PubMed2001

Prevalence of diabetes in care home residents.

OBJECTIVE: To determine the prevalence of known and undetected diabetes diagnosed either by an elevated fasting baseline sample or by a 2-h post-glucose load sample in a group of residents of care homes in an urban-district setting. RESEARCH DESIGN AND METHODS: We completed individual interviews with patients and caregivers in 30 care homes (both residential and nursing homes) in two metropolitan districts of Birmingham, West Midlands, U.K. All care homes were under the supervision of primary care physicians (general practitioners). We carried out 75-g oral glucose tolerance tests (OGTTs) in consenting residents without previous known diabetes. Criteria for diagnosis of diabetes were obtained from the World Health Organization (1998) and the American Diabetes Association (1997). RESULTS: Of 636 residents available for study, 76 residents (12.0%) were known to have diabetes; of the 560 remaining residents, 286 either refused to participate or were deemed too ill or unavailable to undergo testing. Complete data on 274 OGTTs were obtained (median age 83 years, range 45-101). A total of 46 subjects were diagnosed as having diabetes and 94 as having impaired glucose tolerance. Allowing for subjects who refused or were unable to participate, the calculated total prevalence (which includes known and newly detected diabetes) was 26.7% (95% CI 21.9-32.0). The calculated overall prevalence of impaired glucose tolerance was 30.2% (25.2-35.6). CONCLUSIONS: In a group of care home residents not known to have diabetes and able to undergo testing, a substantial proportion have undetected diabetes based on a 2-h postglucose load. These residents warrant further study as they may be at higher cardiovascular risk and require an intervention.

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PubMed2000

C3H apoE(-/-) mice have less atherosclerosis than C57BL apoE(-/-) mice despite having a more atherogenic serum lipid profile.

Wild-type C57BL mice are known to be susceptible to diet-induced atherosclerosis, whilst C3H mice are resistant. We investigated the effect of these background strains on the hyperlipidaemia and atherosclerosis that develops in mice deficient in apolipoprotein E (apoE(-/-)). Male and female apoE(-/-) mice on C3H/HeNHsd (C3H) and C57BL/6J (C57) backgrounds were fed atherogenic Western diet for 12 weeks. Serum cholesterol and triglyceride concentrations were measured and atherosclerosis quantified in the aortic sinus. C3H apoE(-/-) mice fed normal diet had 1.5 2 fold higher serum cholesterol levels than C57 apoE(-/-) mice and 4-5 fold higher serum triglyceride concentrations. Feeding Western diet caused a 4-5 fold increase in serum cholesterol in all mice, but levels of triglyceride were either attenuated or were unaffected in C3H apoE(-/-) and C57 apoE(-/-) mice, respectively. C3H apoE(-/-) mice had approximately 2 fold higher serum cholesterol and 4 fold higher triglyceride concentrations than the C57 apoE(-/-) mice throughout the study. Serum triglyceride concentrations were 35-108% higher in male C3H apoE(-/-) than female C3H apoE(-/-) mice. Most of the lipids were present in the very low density lipoprotein (VLDL)/chylomicron fraction in both strains of mice whether they were fed normal or Western diet. Notwithstanding the lower plasma lipid concentrations, atherosclerotic lesion areas were more than 2-fold larger in C57 apoE(-/-) than in C3H apoE(-/-) mice (males 68 +/- 11 x 10(3) vs 30 +/- 6 x 10(3) females 102 +/- 12 x 10(3) vs 41 +/- 8 x 10(3) microm2. mean +/- SEM).

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PubMed1999

Deletion of the Cul1 gene in mice causes arrest in early embryogenesis and accumulation of cyclin E.

The stability of many proteins is controlled by the ubiquitin proteolytic system, which recognizes specific substrates through the action of E3 ubiquitin ligases [1]. The SCFs are a recently described class of ubiquitin ligase that target a number of cell cycle regulators and other proteins for degradation in both yeast and mammalian cells [2] [3] [4] [5] [6]. Each SCF complex is composed of the core protein subunits Skp1, Rbx1 and Cul1 (known as Cdc53 in yeast), and substrate-specific adaptor subunits called F-box proteins [2] [3] [4]. To understand the physiological role of SCF complexes in mammalian cells, we generated mice carrying a deletion in the Cul1 gene. Cul1(-/-) embryos arrested around embryonic day 6.5 (E6.5) before the onset of gastrulation. In all cells of the mutant embryos, cyclin E protein, but not mRNA, was highly elevated. Outgrowths of Cul1(-/-) blastocysts had limited proliferative capacity in vitro and accumulated cyclin E in all cells. Within Cul1(-/-) blastocyst cultures, trophoblast giant cells continued to endocycle despite the elevated cyclin E levels. These results suggest that cyclin E abundance is controlled by SCF activity, possibly through SCF-dependent degradation of cyclin E.

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PubMed1997

MCP-1-mediated chemotaxis requires activation of non-overlapping signal transduction pathways.

Monocyte chemoattractant protein-1 (MCP-1) is a CC chemokine that attracts monocytes and T lymphocytes. Its receptor (CCR2) is a heptahelical G-protein-coupled receptor (GPCR) whose signal transduction pathways for chemotaxis have not been completely defined. Because other GPCRs stimulate the mitogen-activated protein kinase (MAPK) cascade, we examined this pathway's activity in response to MCP-1. MCP-1 induced rapid and transient activation of MAPK in human monocytes and in Chinese hamster ovary cells expressing CCR2B. This effect was largely insensitive to pertussis toxin and wortmannin, and was protein kinase C-dependent and protein tyrosine kinase-independent. PD 098059, an inhibitor of MEK activation, not only prevented MAPK activation but also inhibited MCP-1-induced chemotaxis. Because pertussis toxin and wortmannin also efficiently inhibit chemotaxis but do not completely inhibit MAPK activation, these data may define non-overlapping signal transduction pathways that all must be activated to produce chemokine-mediated chemotaxis.

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