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Biomedical subjects

A Evans

Publications and source records attributed to A Evans.

At least 127 records · Page 7Linked to original sources
PubMed2000

Alternative strategies for stroke care: a prospective randomised controlled trial.

BACKGROUND: Organised specialist care for stroke improves outcome, but the merits of different methods of organisation are in doubt. This study compares the efficacy of stroke unit with stroke team or domiciliary care. METHODS: A single-blind, randomised, controlled trial was undertaken in 457 acute-stroke patients (average age 76 years, 48% women) randomly assigned to stroke unit, general wards with stroke team support, or domiciliary stroke care, within 72 h of stroke onset. Outcome was assessed at 3, 6, and 12 months. The primary outcome measure was death or institutionalisation at 12 months. Analyses were by intention to treat. FINDINGS: 152 patients were allocated to the stroke unit, 152 to stroke team, and 153 to domiciliary stroke care. 51 (34%) patients in the domiciliary group were admitted to hospital after randomisation. Mortality or institutionalisation at 1 year were lower in patients on a stroke unit than for those receiving care from a stroke team (21/152 [14%] vs 45/149 [30%]; p<0.001) or domiciliary care (21/152 [14%] vs 34/144 [24%]; p=0.03), mainly as a result of reduction in mortality. The proportion of patients alive without severe disability at 1 year was also significantly higher on the stroke unit compared with stroke team (129/152 [85%] vs 99/149 [66%]; p<0.001) or domiciliary care (129/152 [85%] vs 102/144 [71%]; p=0.002). These differences were present at 3 and 6 months after stroke. INTERPRETATION: Stroke units are more effective than a specialist stroke team or specialist domiciliary care in reducing mortality, institutionalisation, and dependence after stroke.

Aged↗
PubMed2000

Breast cancer diagnosis using scattered X-rays.

Small-angle X-ray diffraction data has been collected from 99 ;core-cut' breast tissue specimens representing a number of different pathologies. Data in the range 75-1390 A have been compared with controls from patients with no breast disease. Bessel functions and Bragg maxima resulting from the fibrillar structure of collagen have been identified. The Bragg maxima indexed onto a 649 A lattice. Systematic differences in the intensities and D-spacings between the collagen of malignant, benign and normal tissue groups have been clearly demonstrated and quantified. These differences appear to be due to a significantly lower structural order within the malignant tissues. Possible explanations for this are discussed and the potential for utilizing this observation in cancer diagnosis is considered.

Journal Article↗
PubMed2000

Associations between classical cardiovascular risk factors and coronary artery disease in two countries at contrasting risk for myocardial infarction: the PRIME study.

PURPOSE: In two countries with contrasting risk for coronary artery disease (CAD)-Northern Ireland and France-a case-control study was performed on baseline data within a cohort study to compare the strength of the associations between CAD prevalence and classical risk factors. METHOD AND RESULTS: A sample of 9561 men, aged 50-60 years, was studied: 382 had had myocardial infarction or angina, and 9179 were controls. In both countries, variables associated with CAD were age, body mass index, hypertension, diabetes, family history of myocardial infarction (MI), tobacco consumption, triglycerides, HDL-cholesterol, apolipoprotein A-I and B levels. Logistic regression analyses were conducted using standardized odds ratios. The strength of the associations with CAD was rather similar in the two countries (Northern Ireland versus France) for age [1.26 (1.10-1. 45) vs. 1.41 (1.17-1.69)], family history of MI [1.50 (1.04-2.15) vs. 1.83 (0.99-3.37)], hypertension [1.49 (1.13-1.97) vs. 1.67 (1.14-2. 44)], diabetes [5.42 (2.53-11.60) vs. 2.24 (1.06-4.73)], tobacco consumption [1.43 (1.27-1.60) vs. 1.39 (1.22-1.58)], HDL-cholesterol [0.80 (0.68-0.94) vs. 0.86 (0.70-1.06)] and triglyceride levels [1. 17 (1.01-1.36) vs. 1.10 (0.91-1.32)]. Discrepancies concerned lipoprotein(a) [1.22 (1.06-1.40) vs. 0.96 (0.81-1.15), P<0.01], with stronger associations in Northern Ireland than in France. CONCLUSION: It is concluded that the higher prevalence of CAD in Northern Ireland cannot be explained by major differences in the susceptibility to classical risk factors; the difference in risk of CAD appears mainly related in Northern Ireland to other risk factors including a worse lipid profile and genetic/environmental interactions.

Apolipoproteins↗
PubMed2000

Repeat HIV testing: high-risk behaviour or risk reduction strategy?

OBJECTIVE: To examine the characteristics of repeat and first-time HIV testers and consider their implications for HIV test counselling. METHODS: An anonymous questionnaire was completed by nearly 1500 people seeking an HIV test between September 1997 and July 1998 at a same-day HIV testing clinic in London, United Kingdom. Repeat testers were those people who had previously tested HIV negative and were returning for another test. Information was collected on self-reported unprotected penetrative sex (UPS) in the previous 3 months and reasons for seeking the present test. RESULTS: Overall, 50.6% (721/1446) of all clinic attenders were repeat testers: gay men 71.7% (337/470), heterosexual men 42.1% (208/494) and heterosexual women 38.6% (186/482). No significant differences were found between repeat and first time testers in the frequency of UPS (P > or = 0.06). However, gay men (but not heterosexual men and women) reporting three or more previous HIV tests were significantly more likely to report higher-risk UPS (i.e. with a partner whose HIV status was either positive or unknown) (42.2%) than those who had had one-two or no previous tests (25.3 and 25.4%, respectively; P = 0.002). Over half the heterosexual men and women, and one third of gay men said they were seeking the current HIV test in preparation for a new relationship; these proportions did not differ significantly between repeat and first-time testers (P > 0.1). CONCLUSION: In this London HIV testing clinic, no significant differences were found in the frequency of UPS between repeat and first-time testers with the exception of gay men with a history of three or more previous HIV tests, who reported elevated levels of high-risk sexual behaviour. For many people, repeat HIV testing has become part of a risk reduction strategy to establish seroconcordance with a regular partner. HIV test counselling provides the opportunity both to address high-risk behaviour and to reinforce personal risk-reduction strategies.

Female↗
PubMed2000

Estimation of contribution of changes in classic risk factors to trends in coronary-event rates across the WHO MONICA Project populations.

BACKGROUND: From the mid-1980s to mid-1990s, the WHO MONICA Project monitored coronary events and classic risk factors for coronary heart disease (CHD) in 38 populations from 21 countries. We assessed the extent to which changes in these risk factors explain the variation in the trends in coronary-event rates across the populations. METHODS: In men and women aged 35-64 years, non-fatal myocardial infarction and coronary deaths were registered continuously to assess trends in rates of coronary events. We carried out population surveys to estimate trends in risk factors. Trends in event rates were regressed on trends in risk score and in individual risk factors. FINDINGS: Smoking rates decreased in most male populations but trends were mixed in women; mean blood pressures and cholesterol concentrations decreased, bodymass index increased, and overall risk scores and coronary-event rates decreased. The model of trends in 10-year coronary-event rates against risk scores and single risk factors showed a poor fit, but this was improved with a 4-year time lag for coronary events. The explanatory power of the analyses was limited by imprecision of the estimates and homogeneity of trends in the study populations. INTERPRETATION: Changes in the classic risk factors seem to partly explain the variation in population trends in CHD. Residual variance is attributable to difficulties in measurement and analysis, including time lag, and to factors that were not included, such as medical interventions. The results support prevention policies based on the classic risk factors but suggest potential for prevention beyond these.

Adult↗
PubMed2000

Independent association of an APOE gene promoter polymorphism with increased risk of myocardial infarction and decreased APOE plasma concentrations-the ECTIM study.

Apolipoprotein E (APOE) is a major protein in lipid metabolism existing in three common isoforms: APOE2, -3 and -4. The varepsilon4 allele of the APOE gene ( APOE ) coding for the APOE4 isoform is associated with an increased risk of myocardial infarction (MI) and of Alzheimer's disease (AD). Recently, several polymorphisms in the APOE regulatory region have been reported. Some of these have been associated with AD and modified APOE allelic mRNA expression in AD brains. Here, we have investigated whether three of these promoter polymorphisms (-491AT, -427CT and -219GT) can also modify cardiovascular risk. The hypothesis was tested in a large multicentre case-control study of MI, the ECTIM Study, on 567 cases and 678 controls. Among the three APOE promoter polymorphisms tested, only the-219T allele was associated with a significantly increased risk of MI (OR = 1.29, 95% CI: 1.09-1.52, P < 0.003) and the effect was shown to be independent of the presence of the other mutations, including the APOE epsilon2/epsilon3/epsilon4 polymorphism. Moreover, the-219T allele greatly decreased the APOE plasma concentrations in a dose-dependent manner ( P < 0.008). These data indicate that the-219GT polymorphism of the APOE regulatory region emerges as a new genetic susceptibility risk factor for MI and constitutes another common risk factor for both neurodegenerative and cardiovascular diseases.

Adult↗
PubMed2000

Extensive association analysis between the CETP gene and coronary heart disease phenotypes reveals several putative functional polymorphisms and gene-environment interaction.

An extensive association analysis of a candidate gene for coronary heart disease, Cholesteryl Ester Transfer Protein (CETP) gene, was performed. Ten polymorphisms, out of which three were newly identified in regulatory regions, were investigated for association with myocardial infarction (MI) and 2 MI endophenotypes (CETP mass and HDL-cholesterol level) in 568 MI patients and 668 controls. The polymorphisms affecting codon 405 (Ile(405)Val) and the nucleotide 524 downstream from the stop codon (G(+524)T) were almost completely concordant and associated with plasma CETP mass (P < 0.001). The polymorphisms -629 (located in promoter), intron1 (Taq1B) and intron7 were almost completely concordant and associated with plasma CETP mass (P < 0.0001) and HDL-cholesterol levels (P < 0.0001). This latter association was not found in teetotalers and increased with the quantity of alcohol consumed. Heavy drinkers (>75g/day) homozygous for the (-628)A allele had a reduced risk of MI (OR = 0. 33, P < 0.02). Subjects both homozygous for (451)Arg and heterozygous for (373)Pro had decreased plasma HDL-cholesterol levels and this effect increased with alcohol consumption. The results illustrate the complexity of polymorphism-phenotype associations. They suggest that the CETP gene may carry several functional polymorphisms. Observed interactions between alcohol consumption and polymorphisms associated with HDL-cholesterol level constitute concrete examples of gene-environment interactions. Furthermore, the pattern of association between HDL-cholesterol levels and the polymorphisms at codons 373 and 451 illustrated how two polymorphisms may be confounders (in the usual epidemiological sense) one for the other: their marginal effects are neutralized because of linkage disequilibrium and thus are not detectable by standard univariate association analysis.

Adult↗
PubMed2000

Obstructed defecation after undiverted ileoanal pouch reconstruction for ulcerative colitis: pharmacologic approach. Report of a case.

PURPOSE: Obstructed defecation after ileal pouch construction has been reported only after closure of the diverting loop ileostomy, and biofeedback was an effective treatment modality. METHOD: This is a case report of a patient with immediate obstructed defecation after ileal pouch-anal anastomosis without a covering loop ileostomy and its successful pharmacologic management. RESULTS: A 38-year-old female underwent restorative proctectomy and stapled ileal J-pouch-anal anastomosis without a covering loop ileostomy. On the seventh postoperative day, her pouch catheter (in lieu of a covering loop ileostomy) was removed and she failed to evacuate. After ruling out any technical complications, diltiazem was commenced with successful spontaneous pouch emptying. Obstructed defecation reoccurred after cessation of diltiazem one week later, but the symptoms resolved once the diltiazem was recommenced. CONCLUSIONS: Obstructed defecation has been reported in patients after pelvic pouch reconstruction. However, in all those patients a diverting loop ileostomy had been raised and their obstructive symptoms were only apparent after closure of the ileostomy and when the pouch had healed. The concern regarding our patient was the complete outlet obstruction so soon after surgery, with undue strain on the anastomosis and the potential risk of disruption. Our only two options were either to create a diverting loop ileostomy or to try a fast-acting pharmacologic agent (diltiazem) to treat the presumed levator spasm. The latter option spared the patient a further operation.

Administration, Oral↗
PubMed2000

Identification of two polymorphisms in the early growth response protein-1 gene: possible association with lipid variables.

Early growth response factor (EGR)-1 may play an important role in the development of atherosclerosis by inducing the expression of several relevant genes which contribute to the complex modulation of vascular structure and function, leading to vascular occlusive lesions. To investigate the possible role of molecular variants in the human EGR-1 gene for the predisposition to atherosclerosis or coronary heart disease we screened the 5'- and 3'- flanking regions and the entire coding sequence for polymorphisms by polymerase chain reaction/single-strand conformation polymorphism analysis and sequencing. Male patients (n=615) with myocardial infarction and 720 age-matched, male control subjects of the Etude Cas-Témoin de l'Infarctus du Myocarde were genotyped for two newly identified polymorphisms in the 5'- (C-151T) and 3'- (T+861C) flanking region of the EGR-1 gene using hybridization with allele-specific oligonucleotides. Allele and genotype frequencies did not significantly differ between patients with myocardial infarction and control subjects without coronary heart disease. In controls not taking hypolipidemic drugs there was a significant association of the -151T allele with lower plasma levels of total cholesterol (P=0.029), low-density lipoprotein cholesterol (P=0.025) and apolipoprotein B (P=0.038) and a higher ratio of high-density to low-density lipoprotein (P=0.049) than with the C-151 allele. We conclude that the C-151T polymorphism of the EGR-1 gene may contribute to modifications of the lipid metabolism. Our findings need to be replicated in independent studies, and in vitro promoter studies should evaluate the functional consequence of the -151T allele, which disrupts a consensus core sequence for the ubiquitous transcription factor activator protein 4.

Adult↗
PubMed2000

Polymorphisms in the genes encoding platelet-derived growth factor A and alpha receptor.

Platelet-derived growth factors (PDGFs) may play an important role in the development of atherosclerosis acting as chemoattractants and mitogens for vascular smooth muscle cells and macrophages. Three dimeric forms of PDGF (AA, AB, BB) have different activities due to distinct binding properties mediated by two types of PDGF receptors (Ralpha, Rbeta). To investigate the possible contribution of molecular variants in the human PDGF-A and PDGF-Ralpha genes to coronary heart disease we screened these genes for polymorphisms by polymerase chain reaction/single-strand conformation polymorphism analysis. A total of 600 men with myocardial infarction and 717 age-matched male controls from four populations in Northern Ireland and France (the ECTIM Study) were gneotyped for newly identified polymorphisms in the genes encoding PDGF-A (C-26IN3T, H69H, C+12IN5T) and PDGF-Ralpha [-1630 I/D (+/-AACTT), A-1506G, C-1390G, G-956A, C-908A, G-793T, +69 I/D (+/-GA)] using allele-specific oligonucleotides. All PDGF-Ralpha polymorphisms, except C-908A, involving a nucleotide change in a common consensus site for GCF and SP-1 transcription factors, were in nearly complete association, generating two major haplotypes. The PDGF-A and PDGF-Ralpha polymorphisms provided a heterozygosity of 0.69 and 0.40, respectively. Genotype and allele frequencies of the PDGF-A and PDGF-Ralpha polymorphisms did not differ between patients with myocardial infarction and controls in either country. None of the polymorphisms investigated was associated with blood pressure, coronary artery stenosis, or any biochemical parameter available in the ECTIM Study.

Adult↗
PubMed2000

Is inflammation good for the ischemic heart--perspectives beyond the ordinary.

In recent years, early reperfusion of the myocardial infarct has become the mainstay of optimal therapeutic management since it limits ventricular injury and infarct expansion and improves patient survival [14]. It has become clear that reperfusion promotes effective tissue repair and decreases ventricular remodeling even under circumstances where reperfusion is effected at too late a time to limit myocardial necrosis [4]. One of the striking differences between reperfused and non-reperfused myocardial infarctions is that the early intense inflammatory reaction which ensues immediately upon reperfusion has been demonstrated to potentially extend myocardial injury [9]. Substantial evidence suggests that this inflammatory reaction is important in tissue repair, leading to an obvious paradox with regard to the role of the inflammatory reaction. This communication takes the position that inflammatory injury occurring upon reperfusion of the infarcted myocardium results from the overwhelming of tissue defenses against inflammation resulting from the sudden entry of large amounts of neutrophils to an area of infarction where chemotactic factors have built up to high concentration. However, we hypothesize that inflammation fundamentally evolved as a protective mechanism to promote tissue healing and protect jeopardized myocardium. In this presentation, we will discuss our approach and data designed to evaluate potential protective roles of the inflammatory reaction after reperfusion.

Animals↗
PubMed2000

Infection with virulent strains of Helicobacter pylori is not associated with ischaemic heart disease: evidence from a population-based case-control study of myocardial infarction.

BACKGROUND: Although the majority of evidence does not support association between Helicobacter pylori infection and ischaemic heart disease, the nature of this relationship may differ when virulence of the infecting strains are examined. METHODS AND RESULTS: The prevalence of IgG antibody evidence of infection with CagA positive stains of H. pylori was investigated in stored plasma samples from 259 cases of myocardial infarction (aged 25-70 years, 74 males) and 259 population based controls from the same area in Northern Ireland. Two-hundred and seventy (52.1%) subjects were seropositive for anti-CagA IgG. CagA seropositivity was more common in cases than in controls: 56.4 vs 47.9%, odds ratio for seropositivity in cases (95% CI) 1.41 (1.00, 1.99). Substantial attenuation of this relationship occurred on adjustment for age, sex, number of siblings, smoking and measures of socio-economic status: odds ratio (95% CI) 1.16 (0.79, 1.70). A similar pattern was seen for seropositivity for all H. pylori strains. CONCLUSION: Infection with the more virulent strains of H. pylori, as with all strains, is not associated with myocardial infarction.

Adult↗
PubMed2000

The relationship between apolipoprotein AI-containing lipoprotein fractions and environmental factors: the prospective epidemiological study of myocardial infarction (PRIME study).

Apolipoprotein (apo) AI is distributed within high-density lipoproteins (HDL) between different types of particles, one containing both apoAI and apoAII (LpAI:AII), the other containing no apoAII (LpAI). We investigated the associations between LpAI and LpAI:AII with several factors such as body mass index (BMI), waist to hip ratio (WHR), alcohol intake, cigarette consumption and physical activity, in three French and one Northern Irish male populations included in a prospective study (PRIME study). LpAI and LpAI:AII were associated with variations in all environmental factors, except LpAI:AII, which was not associated with WHR. These relationships were unchanged after adjustment for other environmental factors, but slightly modified after adjustment for triglyceride levels. LpAI decreased when BMI, WHR and cigarette smoking increased, and increased with alcohol consumption and physical activity. LpAI:AII had a similar variation except for the absence of LpAI:AII modification associated with WHR variation. The associations between LpAI and BMI, alcohol consumption and cigarette smoking were largely dependent on HDL-cholesterol as indicated by the lack of any significance when the adjustment for HDL-cholesterol was made. Conversely, after adjustment for HDL-cholesterol, the significant association between LpAI:AII and BMI disappeared, while the associations between LpAI:AII and alcohol consumption, cigarette smoking and physical activity remained significant. These results suggest that the mechanisms of LpAI and LpAI:AII modulations differ according to each environmental factor, some dependent on the lipid content of lipoproteins and others not, but LpAI and LpAI:AII levels seem independent of triglyceride concentration.

Alcohol Drinking↗
PubMed2000

Apolipoprotein E serum concentration and polymorphism in six European countries: the ApoEurope Project.

As part of the ApoEurope Project, the apolipoprotein E (apo E) serum concentration and polymorphism were determined in 6934 healthy subjects aged 25-64 years recruited in six European countries: Finland; France; Greece; Northern Ireland; Portugal and Spain. Age and sex influenced apo E concentration with concentrations being significantly higher in men than in women for those aged between 25 and 44 years. The age effect differed between the sexes after the age of 44 years, displaying a linear increase in women and a plateau in men. As expected, the serum apo E concentration was highest in varepsilon2 carriers and lowest in varepsilon4 carriers in each country with a significantly higher frequency of the varepsilon4 allele in the northern regions. The main finding of this study was a clear increasing North-South gradient in serum apo E concentration independent of age, sex and apo E genotype. In subjects aged <45 years and with the varepsilon3/varepsilon3 genotype, apo E concentration was higher in the South-East (Greece) as compared to the North by 20% for men and 32% for women. In addition to the genetic polymorphism, the geographical area is an important factor to take into account when studying serum apo E concentration in multicentre studies and defining reference values.

Adult↗