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Biomedical subjects

J Evans

Publications and source records attributed to J Evans.

At least 19 recordsLinked to original sources
PubMed2007

Detection of genetic diversity by pulsed-field gel electrophoresis among Escherichia coli O157 isolated from bovine faecal samples by immunomagnetic separation technique.

AIMS: Escherichia coli O157 is considered to be one of most important human pathogens of animal origin which causes serious clinical complications. One of the most common methods to isolate E. coli O157 is the immunomagnetic separation (IMS) technique which employs specific antibodies coupled to magnetic beads to bind and extract cells from enrichment broths followed by plating onto sorbitol MacConkey agar supplemented with cefixime and potassium tellurite (CT-SMAC) plates. The aim of this study was to determine strain variation by pulsed-field gel electrophoresis (PFGE) among E. coli O157 on IMS/CT-SMAC plates. METHODS AND RESULTS: Every suspect colony of E. coli O157 was tested following isolation by the IMS/CT-SMAC technique. From 124 colonies detected; six XbaI-PFGE profiles were identified. CONCLUSIONS: Our results demonstrate that mixed populations of E. coli O157 with distinguishable PFGE profiles that are simultaneously present in bovine faeces can be isolated with IMS/CT-SMAC technique. SIGNIFICANCE AND IMPACT OF THE STUDY: If the aim of the study was to analyse diversity of PFGE profiles of E. coli O157 in a faecal sample following isolation by the IMS/CT-SMAC technique, at least five colonies per sample should be analysed to detect different PFGE subtypes if present.

Animals↗
PubMed2006

Sensitivity of an immunomagnetic-separation-based test for detecting Escherichia coli O26 in bovine feces.

The sensitivity of a test for cattle shedding Escherichia coli serogroup O26 was estimated using several fecal pats artificially inoculated at a range of concentrations with different E. coli O26 strains. The test involves the enrichment of fecal microflora in buffered peptone water, the selective concentration of E. coli O26 using antibody-coated immunomagnetic-separation beads, the identification of E. coli colonies on Chromocult tryptone bile X-glucuronide agar, and confirmation of the serogroup with E. coli serogroup O26-specific antisera using slide agglutination. The effective dose of E. coli O26 for an 80% test sensitivity (ED(80)) was 1.0 x 10(4) CFU g(-1) feces (95% confidence interval, 4.7 x 10(3) to 2.4 x 10(4)). Differences in test sensitivity between different E. coli O26 strains and fecal pats were also observed. Individual estimates of ED(80) for each strain and fecal pat combination ranged from 4.2 x 10(2) to 4.8 x 10(5) CFU g(-1). These results suggest that the test is useful for identifying individuals shedding a large number of E. coli O26 organisms or, if an appropriate number of individuals in a herd are sampled, for identifying affected herds. The study also provides a benchmark estimate of sensitivity that can be used to compare alternative tests for E. coli O26 and a methodological approach that can be applied to tests for other pathogenic members of the Enterobacteriaceae and other sample types.

Animals↗
PubMed2006

Age-related differences in renal function at onset of renal replacement therapy in chronic kidney disease stage 5 patients.

BACKGROUND: Guidelines for initiating renal replacement therapy (RRT) are based on renal function and not age, so renal function at onset of RRT is expected to be similar across age groups. AIM: To evaluate renal function at initiation of RRT across age groups. DESIGN: Observational cross-sectional study. METHODS: We extracted data for all incident chronic kidney disease (CKD) stage 5 patients (n = 322 064) commenced on chronic dialysis (haemodialysis and peritoneal) and renal transplant in the US from 1995 to 1999 from the US Renal Data Systems (USRDS). Subjects (n = 662) with incomplete data were excluded. The reminder (n = 321 402) were classified into five age groups: 0-19 years; 20-44 years; 45-64 years; 65-74 years; >/=75 years. Mean values of serum creatinine (Cr, mg/dl), creatinine clearance (CrCl, ml/min), body weight (kg) and body mass index (BMI, kg/m(2)) at onset of RRT were computed. Mean daily urinary creatinine excretion per kg body weight (CrCl x Cr/0.07/weight) was also calculated. RESULTS: Progressively lower serum creatinine levels were found in adult patients with increasing age (10.70, 8.56, 7.38 and 6.88 mg/dl in those aged 20-44 years, 45-64 years, 65-74 years, >/=75 years, respectively). CrCl was also lower in the same groups (14.76, 13.38, 11.63 and 11.60 ml/min, respectively). DISCUSSION: Older patients have a greater reduction in renal function than younger patients at onset of RRT, suggesting a delay in initiation of therapy.

Adolescent↗
PubMed2006

Surfactant era (1990-2002) 2-year outcomes of infants less than 1500 g from a Community Level 3 Neonatal Intensive Care Unit.

OBJECTIVE: To report Bayley scores of 572 twenty-four-month corrected age infants whose birth weights (BWs) were less than 1500 g cared for in a Community Level 3 Neonatal Intensive Care Unit (NICU) between 1990 and 2002 when surfactant was routinely used. STUDY DESIGN: Survival, "normal" defined as both Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI)>84, MDI>69 and MDI>84 were analyzed by gestational age (GA) and BW. Comparisons were made between infants born pre- and post-1996 when high-frequency oscillatory ventilation came into frequent use, Medicaid and non-Medicaid infants, multiples and singletons, outborn and inborn infants, boys and girls and infants with intrauterine growth retardation (IUGR) and those appropriate for gestational age (AGA). RESULTS: There was a correlation between GA and BW and improving outcomes. Scores do not approach those of normal standardization sample populations (60% for "normal", 68% for MDI>84 and 95% for MDI>69) until 1400 g and 30 weeks. Medicaid, outborn and IUGR infants, and boys did worse in some aspects. CONCLUSION: There was a correlation between both GA and BW and improving outcomes. Availability of these developmental data on a laminated pocket card can facilitate presentation of outcome experience to families by pediatric and obstetric caregivers.

Child Development↗
PubMed2006

CDKL5 mutations cause infantile spasms, early onset seizures, and severe mental retardation in female patients.

OBJECTIVE: To determine the frequency of mutations in CDKL5 in both male and female patients with infantile spasms or early onset epilepsy of unknown cause, and to consider whether the breadth of the reported phenotype would be extended by studying a different patient group. METHODS: Two groups of patients were investigated for CDKL5 mutations. Group 1 comprised 73 patients (57 female, 16 male) referred to Cardiff for CDKL5 analysis, of whom 49 (42 female, 7 male) had epileptic seizure onset in the first six months of life. Group 2 comprised 26 patients (11 female, 15 male) with infantile spasms previously recruited to a clinical trial, the UK Infantile Spasms Study. Where a likely pathogenic mutation was identified, further clinical data were reviewed. RESULTS: Seven likely pathogenic mutations were found among female patients from group 1 with epileptic seizure onset in the first six months of life, accounting for seven of the 42 in this group (17%). No mutations other than the already published mutation were found in female patients from group 2, or in any male patient from either study group. All patients with mutations had early signs of developmental delay and most had made little developmental progress. Further clinical information was available for six patients: autistic features and tactile hypersensitivity were common but only one had suggestive Rett-like features. All had a severe epileptic seizure disorder, all but one of whom had myoclonic jerks. The EEG showed focal or generalised changes and in those with infantile spasms, hypsarrhythmia. Slow frequencies were seen frequently with a frontal or fronto-temporal predominance and high amplitudes. CONCLUSIONS: The spectrum of the epileptic seizure disorder, and associated EEG changes, in those with CDKL5 mutations is broader than previously reported. CDKL5 mutations are a significant cause of infantile spasms and early epileptic seizures in female patients, and of a later intractable seizure disorder, irrespective of whether they have suspected Rett syndrome. Analysis should be considered in these patients in the clinical setting.

Adolescent↗
PubMed2006

Preclinical assessment of the feasibility of applying controlled release oral drug delivery to a lead series of atypical antipsychotics.

In this paper, we present a preclinical approach for evaluating the feasibility of applying controlled-release (CR) oral drug delivery to increase the duration of exposure and lower the C(max) of compounds in a lead series of short half-life atypical antipsychotics. Three lead compounds in the series had demonstrated potential pharmacological benefits for the treatment of psychosis, in preclinical studies. However, the compounds showed evidence of insufficient half-lives to enable a once-a-day (QD) product using immediate-release (IR) oral delivery. To evaluate and compare the potential for oral CR delivery to extend the duration of action and thereby enable QD administration, the in vitro solubility and permeability, and the duodenal and colonic absorption of three compounds in the series were measured. Based on the results, one candidate was selected for advancement that showed moderate in vitro solubility, but had the highest in vitro permeability and ratio of colonic to duodenal bioavailability (0.9) in the rat. The results from this study provided evidence that a CR drug delivery system could be used to extend the duration of exposure of the compounds in the series and a scientific basis for selecting one of the three compounds as a candidate.

Administration, Oral↗
PubMed2006

Physical and cognitive task analysis in interventional radiology.

AIM: To identify, describe and detail the cognitive thought processes, decision-making, and physical actions involved in the preparation and successful performance of core interventional radiology procedures. MATERIALS AND METHODS: Five commonly performed core interventional radiology procedures were selected for cognitive task analysis. Several examples of each procedure being performed by consultant interventional radiologists were videoed. The videos of those procedures, and the steps required for successful outcome, were analysed by a psychologist and an interventional radiologist. Once a skeleton algorithm of the procedures was defined, further refinement was achieved using individual interview techniques with consultant interventional radiologists. Additionally a critique of each iteration of the established algorithm was sought from non-participating independent consultant interventional radiologists. RESULTS: Detailed task descriptions and decision protocols were developed for five interventional radiology procedures (arterial puncture, nephrostomy, venous access, biopsy-using both ultrasound and computed tomography, and percutaneous transhepatic cholangiogram). Identical tasks performed within these procedures were identified and standardized within the protocols. CONCLUSIONS: Complex procedures were broken down and their constituent processes identified. This might be suitable for use as a training protocol to provide a universally acceptable safe practice at the most fundamental level. It is envisaged that data collected in this way can be used as an educational resource for trainees and could provide the basis for a training curriculum in interventional radiology. It will direct trainees towards safe practice of the highest standard. It will also provide performance objectives of a simulator model.

Cholangiography↗
PubMed2006

Two-view mammography at the incident round has improved the rate of screen-detected breast cancer in Wales.

AIM: To investigate whether pre-invasive and invasive cancer detection rates were improved in Wales after the introduction of two views at incident screens. METHODS: The records of women attending follow-up screening for 2 years before and 2 years after the introduction of two-view incident screening were analysed. Cancer detection rates were compared before and after introduction of two view screening. RESULTS: At the incident round 98,752 women had one and 95,464 had two views. Five hundred and fifty-five cancers were detected with one view and 744 with two, an increased detection rate from 5.6 to 7.8 cancers per 1000 women screened (p=0.01). Two hundred and thirty-nine small cancers were detected with one view and 323 with two, increasing the detection rate from 2.4 to 3.4 per 1000 women screened (p=0.05). CONCLUSIONS: Two-view mammography at incident rounds detects more cancers and more favourable prognosis small cancers than single-view mammograms.

Breast Neoplasms↗
PubMed2006

An unusual complication of ice skating and the emergence of a previously undiagnosed bleeding disorder.

We report the case of an 8-year-old boy with no prior abnormal bleeding history who presented with severe central abdominal pain following a freak accident at a local ice rink. Clinical examination confirmed a tender periumbilical mass. An ultrasound scan confirmed a large haemorrhagic fluid collection adjacent to the second part of his duodenum that was causing a subacute small-bowel obstruction. He was found to have a persistently prolonged prothrombin time between 17.3 and 18.1 s but normal liver function tests. There was no suggestion of dietary vitamin K deficiency. Further investigations confirmed factor VII deficiency with levels between 30.4 and 33.6 IU dL-1. His prothrombin time did not normalize with intravenous vitamin K. He was subsequently treated with three 30 microg kg-1 body weight doses of novoseven at 4-h interval and made an excellent recovery. The haematoma virtually resolved completely confirmed by a follow-up ultrasound scan 3 months after the initial event.

Accidental Falls↗
PubMed2006

Normalization of factor VIII levels in a patient with mild haemophilia A during a 35-year period.

We report the case of a 45-year-old man who was diagnosed in June 1969 9 years old as having mild haemophilia A following a traumatic left shoulder bleed when his factor VIII (FVIII) activity was 11 IU dL(-1) based on a two-stage assay. The bleed resolved following treatment with intravenous cryoprecipitate. There was no family history of haemophilia. Cryoprecipitate infusions were required to treat further traumatic bleeds between 1971 and 1981. During this time, his FVIII activity was confirmed at 14 IU dL(-1). He defaulted many hospital appointments until 1991 when his FVIII activity had risen to 42 IU dL(-1). There was no evidence of infection, inflammatory or liver disease to account for this change. By 2005 he had a normal FVIII activity of 62 IU dL(-1) based on a one-stage assay. FVIII gene analysis confirmed a codon 531 mutation. It appeared that the discrepant FVIII results related to whether a two-stage or one-stage assay was used that has been previously reported for other patients with these mutations. We felt it important to raise awareness that this phenomenon may lead to apparent correction of haemophilia A.

Blood Coagulation Tests↗
PubMed2006

Prevalence and virulence factors of Escherichia coli serogroups O26, O103, O111, and O145 shed by cattle in Scotland.

A national survey was conducted to determine the prevalence of Escherichia coli O26, O103, O111, and O145 in feces of Scottish cattle. In total, 6,086 fecal pats from 338 farms were tested. The weighted mean percentages of farms on which shedding was detected were 23% for E. coli O26, 22% for E. coli O103, and 10% for E. coli O145. The weighted mean prevalences in fecal pats were 4.6% for E. coli O26, 2.7% for E. coli O103, and 0.7% for E. coli O145. No E. coli O111 was detected. Farms with cattle shedding E. coli serogroup O26, O103, or O145 were widely dispersed across Scotland and were identified most often in summer and autumn. However, on individual farms, fecal shedding of E. coli O26, O103, or O145 was frequently undetectable or the numbers of pats testing positive were small. For serogroup O26 or O103 there was clustering of positive pats within management groups, and the presence of an animal shedding one of these serogroups was a positive predictor for shedding by others, suggesting local transmission of infection. Carriage of vtx was rare in E. coli O103 and O145 isolates, but 49.0% of E. coli O26 isolates possessed vtx, invariably vtx1 alone or vtx1 and vtx2 together. The carriage of eae and ehxA genes was highly associated in all three serogroups. Among E. coli serogroup O26 isolates, 28.9% carried vtx, eae, and ehxA-a profile consistent with E. coli O26 strains known to cause human disease.

Animal Husbandry↗
PubMed2006

Managing sexually transmitted infections in community sexual health clinics: an audit of a community service.

Traditional hospital-based genitourinary (GU) medicine services have been overwhelmed by the current sexual health crisis. In November 2001, the Community Sexual and Reproductive Health department in Lewisham, South East London started a treatment service for uncomplicated sexually transmitted infections (STI). An audit was conducted to evaluate the effectiveness of and demand for this service. Two years after its introduction the number of chlamydia tests increased by 94%, the number of men attending the service doubled, GU medicine referrals halved and the number of STI treatments had risen by 90%, mainly for chlamydia. Proposed national outcome standards were exceeded with treatment of 84% of chlamydia clients with a median delay of 14 days, partner notification documented in 88% of chlamydia treatments and 0.45 contacts per case of chlamydia treated. Community-based services can provide successful testing, treatment and partner notification for uncomplicated STI despite increasing demand and such services should be properly recognized, encouraged and financially supported.

Chlamydia Infections↗
PubMed2006

Changes in mRNAs encoding steroidogenic acute regulatory protein, steroidogenic enzymes and receptors for gonadotropins during spermatogenesis in rainbow trout testes.

In vertebrates, sperm development and maturation are directly regulated by gonadal steroid hormone secretion. The relationships among the expression of genes encoding steroidogenic proteins and receptors for gonadotropins, and testicular steroid production have not yet been comprehensively determined in male teleosts. In this study, the changes in levels of mRNAs encoding follicle-stimulating hormone (FSH) receptor, luteinizing hormone (LH) receptor, steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage, 3beta-hydroxysteroid dehydrogenase/delta5-4-isomerase, cytochrome P450 17alpha-hydroxylase/17,20-lyase, cytochrome P450 11beta-hydroxylase, 11beta-hydroxysteroid dehydrogenase and 20beta-hydroxysteroid dehydrogenase were determined by real-time, quantitative PCR assays and related to changes in serum steroid levels throughout the reproductive cycle in male rainbow trout. Serum 11-ketotestosterone and 17alpha,20beta-dihydroxy-4-pregnen-3-one levels were measured by RIA. Although the pattern of change in the mRNA levels for the enzymes was variable, the increases in steroidogenic enzyme mRNAs started prior to a significant increase of serum steroid levels. The patterns of transcript levels of FSH and LH receptors suggest that changes in StAR and steroidogenic enzyme transcripts are largely mediated by the FSH receptor during early and mid-spermatogenesis and by the LH receptor during late spermatogenesis and spermiation. Levels of StAR (10-fold) and P450 17alpha-hydroxylase/17,20-lyase (sevenfold) transcripts changed with the greatest magnitude and were closely related to the changes in serum steroids, suggesting that changes in StAR and P450 17alpha-hydroxylase/17,20-lyase abundance are likely to be the major influences on overall steroidogenic output during the reproductive cycle in male rainbow trout.

17-Hydroxysteroid Dehydrogenases↗
PubMed2005

Warming Echovist contrast medium for hysterocontrastsonography and the effect on the incidence of pelvic pain. A randomized controlled study.

BACKGROUND: Hysterocontrastsonography (HyCoSy) is a simple effective investigation of tubal patency. One common side effect is pelvic pain at the time of the procedure. The temperature of the contrast media used may be a causative agent for pelvic pain. This study was designed to assess the effect of warming the contrast to body temperature compared to room temperature on the incidence of pelvic pain. METHODS: A randomized controlled trial was carried out at the Cardiff Assisted Reproduction Unit. Following ethical approval, all women having HyCoSy for tubal assessment were asked if they would be willing to participate in the study. Computer-generated numbers were placed in opaque sealed envelopes, which were opened by the fertility nurse at the time of procedure. The women were randomized into two arms to receive the contrast medium at either room temperature or at body temperature. Randomization was done according to CONSORT guidelines. The pain experienced was then recorded by the patient on a 10-cm visual analogue scale. RESULTS: The mean pain scores in the room temperature and the body temperature arms were 5.1 and 3.86, respectively. This was statistically significant (P = 0.006). CONCLUSION: Warming of Echovist contrast media to body temperature is a simple and effective intervention in reducing discomfort at the time of HyCoSy.

Contrast Media↗
PubMed2005

In situ time-resolved characterization of Au-CeO2 and AuOx-CeO2 catalysts during the water-gas shift reaction: presence of Au and O vacancies in the active phase.

Synchrotron-based in situ time-resolved x-ray diffraction and x-ray absorption spectroscopies were used to study the behavior of nanostructured {Au+AuO(x)}-CeO(2) catalysts under the water-gas shift (WGS) reaction. At temperatures above 250 degrees C, a complete AuO(x)-->Au transformation was observed with high catalytic activity. Photoemission results for the oxidation and reduction of Au nanoparticles supported on rough ceria films or a CeO(2)(111) single crystal corroborate that cationic Au(delta+) species cannot be the key sites responsible for the WGS activity at high temperatures. The rate determining steps for the WGS seem to occur at the gold-ceria interface, with the active sites involving small gold clusters (<2 nm) and O vacancies.

Journal Article↗
PubMed2005

Determinants of false positive recall in an Australian mammographic screening program.

We conducted a case-control study (n=30128) to assess the importance of clinical (e.g., family history, age, hormone replacement therapy (HRT) use and duration) and service-related characteristics (e.g., time since introduction of Kodak MINR2000 film, year of screen) for false positive (FP) recall at BreastScreen Victoria, Australia. There was an age-adjusted upward trend in FP recall rates with year of screen at first (odds ratio (OR) 1.11, 95% confidence interval (95% CI) 1.08-1.13) and subsequent rounds (OR 1.04, 95% CI 1.01-1.06). In the multivariate analysis, the upward trend only remained for first round and age and family history also remained statistically significant at first round. At subsequent rounds the time since introduction of MINR2000, age, strong family history of breast cancer, use of HRT, recall at previous screen and previous screen at more than 27 months were all important predictors of FP recall. The rise in FP rates with year of screen at first round screening is of concern and may require further training of radiologists to improve confidence when viewing films when there a no films for comparison.

Age Factors↗
PubMed2005

Photodynamic therapy for neovascular age-related macular degeneration.

BACKGROUND: In neovascular age-related macular degeneration (AMD) new vessels grow under the retina distorting vision and leading to scarring. This is exacerbated if the blood vessels leak. Photodynamic therapy (PDT) has been investigated as a way to treat the neovascular membranes without affecting the retina. OBJECTIVES: The aim of this review was to examine the effects of PDT in the treatment of neovascular AMD. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which includes the Cochrane Eyes and Vision Group Trials Register) on The Cochrane Library (Issue 1, 2005), MEDLINE (1966 to January 2005), EMBASE (1980 to January 2005). We used the Science Citation Index to search for reports that cited relevant studies. We contacted experts in the field and searched the reference lists of relevant studies. SELECTION CRITERIA: We included randomised trials of PDT in people with choroidal neovascularisation due to AMD. DATA COLLECTION AND ANALYSIS: Two authors independently extracted the data. Relative risks were combined using a fixed-effect model after testing for heterogeneity. MAIN RESULTS: Two published trials were identified that randomised 948 participants to verteporfin therapy compared to 5% dextrose in water. Both trials were performed by the same investigators using largely the same clinical centres and funded by manufacturers of verteporfin. Outcome data were available at 12 and 24 months after the first treatment. Participants received on average five treatments over two years. The relative risk of losing three or more lines of visual acuity at 24 months comparing the intervention with the control group was 0.77 (95% confidence interval 0.69 to 0.87). The relative risk of losing six or more lines of visual acuity at 24 months comparing the intervention with the control group was 0.62 (95% confidence interval 0.50 to 0.76). The results at 12 months were similar to those at 24 months. The most serious adverse outcome, acute (within 7 days of treatment) severe visual acuity decrease, occurs in about one in 50 patients. AUTHORS' CONCLUSIONS: Photodynamic therapy in people with choroidal neovascularisation due to AMD is probably effective in preventing visual loss though there is doubt about the size of the effect. Outcomes and potential adverse effects of this treatment should be monitored closely. Further independent trials of verteporfin are required to establish that the effects seen in this study are consistent and to examine important issues not yet addressed, particularly relating to quality of life and cost.

Glucose↗