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Biomedical subjects

B Turner

Publications and source records attributed to B Turner.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of Erysipelothrix rhusiopathiae vaccines in pigs by intradermal challenge and immune responses.

In a vaccine trial, pigs were challenged intradermally with eight E. rhusiopathiae strains of serovars 1a, 1b or 2 given concurrently. The strains were derived from six herds affected with vaccine breakdowns in 1997-1999, one herd without vaccine breakdown and a serovar 2 reference strain. Responses to two commercial bacterins (one implicated in the vaccine breakdowns), and two experimental bacterins (based on field isolates from affected herds) showed distinct differences in protection, particularly in clinical responses measured at 72 h. Less protection was afforded against serovar 1 challenge by the vaccine implicated in the vaccine breakdowns. Antibody and cell-mediated immune (CMI) responses were significantly different between treatments, and highlighted a similar post-vaccinal antibody response was produced against serovar 2 lysate by all vaccines, but only those providing significant protection against serovar 1 [corrected] produced significantly elevated antiserovar I lysate [corrected] antibodies. Vaccination in general significantly reduced CMI responses to the mitogens concanavalin A and phytohaemagglutinin. This experimental pig challenge system was readily able to confirm suboptimal performance of a commercial bacterin that had passed potency tests in mice but was associated with vaccine failure in commercial herds. This vaccine was also the most immunosuppressive to CMI responses associated with E. rhusiopathiae-specific and non-specific stimulation. The best vaccine response was associated with the highest mean serovar 1 antibody response and the highest CMI response (by lymphoproliferation assay) to serovar 2.

Animals↗
PubMed2005

Diabetes services in the UK: fourth national survey; are we meeting NSF standards and NICE guidelines?

BACKGROUND: Previous surveys of children's diabetes service provision in the UK have shown gradual improvements but continuing deficiencies. AIM: To determine whether further improvements in services have occurred. METHODS: A questionnaire was mailed to all paediatricians in the UK identified as providing care for children and adolescents with diabetes. Responses were compared with results of three previous surveys, and with recommendations in the Diabetes NSF and the NICE type 1 diabetes guidelines. RESULTS: Replies were received from 187 consultant paediatricians in 169 centres looking after children; 89% expressed a special interest in diabetes, 98% saw children in a designated diabetic clinic, and 95% clinics now have more than 40 patients. In 98% of the clinics there was a specialist nurse (82% now children's trained), but 61% clinics had a nurse:patient ratio <1:100; 39% of clinics did not have a paediatric dietician and in 78% there was no access to psychology/psychiatry services in clinics. Glycated haemoglobin was measured routinely at clinics in 86%, annual screening for retinopathy performed in 80%, and microalbuminuria in 83%. All centres now have local protocols for ketoacidosis, but not for children undergoing surgery (90%) or severe hypoglycaemia (74%). Mean clinic HbA1c levels were significantly lower in the clinics run by specialists (8.9%) than generalists (9.4%). There have been incremental improvements over the last 14 years since the surveys began, but only two clinics met all the 10 previously published recommendations on standards of care. CONCLUSIONS: The survey shows continuing improvements in organisational structure of services for children with diabetes but serious deficiencies remain. Publication and dissemination of the results of the previous surveys may have been associated with these improvements and similar recurrent service review may be applicable to services for other chronic childhood conditions.

Adolescent↗
PubMed2005

A 125Te and 23Na NMR investigation of the structure and crystallisation of sodium tellurite glasses.

125Te static nuclear magnetic resonance (NMR) and 23Na and 125Te magic angle spinning (MAS) NMR have been used, in conjunction with X-ray diffraction, to examine the structure and crystallisation behaviour of glasses of composition xNa2O.(1-x)TeO2 (0.075 x 0.4). The MAS NMR 23Na spectra from the glasses are broad and featureless but shift by approximately +5 ppm with increased x, i.e. as the system becomes more ionic. The static 125Te NMR spectra show an increase in axial symmetry with increasing x, indicating a shift from predominantly [TeO4] to [TeO3] structural units. The 23Na and 125Te spectra from the crystallised samples have been fitted to obtain information on the sites in the metastable crystal phases, which are the first to form on heating and which are therefore more closely related to the glass structure than thermodynamically stable crystal phases. New sodium tellurite phases are reported, including a sodium stabilised, face centred cubic phase related to delta-TeO2; a metastable form of Na2Te4O9 containing 3 sodium and 4 tellurium sites; and a metastable form of Na2Te2O5 containing 2 sodium sites. There is evidence of oxidation of TeIV to TeVI occurring in glasses with high values of x and, at x=0.40 and 0.50 (outside the glass forming range), some sodium metatellurate (Na2TeO4) is formed at the same time as sodium metatellurite (Na2TeO3). The 125Te shift is very sensitive to environment within the sodium tellurite system, covering more than 320 ppm, with anisotropies varying from 640 to 1540 ppm. The lack of features in the 125Te spectra of the glass phases, combined with the large shift range and high but variable anisotropy, means than it is not possible to obtain a unique fit to any presumed species present. Furthermore, the chemical shift anisotropy parameters for three of the four Te sites in the Na2Te4O9 phase are found to lie outside the range used for previous simulations of glass spectra.

Journal Article↗
PubMed2004

Reduced forearm reactive hyperaemia in normoalbuminuric subjects with Type 1 diabetes and retinopathy.

AIM: To determine whether the forearm vasodilatory response to reactive hyperaemia (RH) is reduced in normoalbuminuric subjects with Type 1 diabetes mellitus and retinopathy compared with subjects with no retinopathy. METHODS: Forearm RH, an indicator of endothelial function, was measured, using strain-gauge plethysmography, in 39 normoalbuminuric subjects (22 with retinopathy) with long-standing Type 1 diabetes mellitus. RESULTS: were evaluated in relation to conventional risk factors for atherosclerosis, and C-reactive protein (CRP), which we have recently determined to be an independent correlate of forearm RH. RESULTS: Forearm RH was decreased in subjects with retinopathy compared with those with no retinopathy (219 +/- 182 vs. 473 +/- 355, P < 0.01). Both retinopathy and CRP proved to be independent and negative predictors, and explain 27% of the variance, in forearm RH. CONCLUSION: Retinopathy in subjects with Type 1 diabetes mellitus may reflect a generalized process of endothelial dysfunction, even in the absence of microalbuminuria.

Age Factors↗
PubMed2003

Use of cancer susceptibility testing among primary care physicians.

Primary care physicians (PCPs) are assuming greater roles in cancer risk assessment and susceptibility testing of patients. The objective of this study was to assess the beliefs and practices of PCPs relative to genetic susceptibility testing for cancer. A cross-sectional survey was mailed to 726 PCPs in community-based practices in southeastern Pennsylvania and southern New Jersey. Data were collected on physician background, cognitive and psychosocial factors, practice environment, and patient factors. The main outcome measure was physician self-reported recommendation or referral of patients for cancer genetic susceptibility testing in a 12-month period prior to the survey. Of those surveyed, 475 (65%) PCPs responded. Complete survey data were available for 433 PCPs. Multivariable analyses show that factors positively associated with PCP recommendation/referral included: patient inquiry about their need for genetic testing for cancer (p < 0.001); PCP belief that patient age is the best predictor of cancer risk (p = 0.01); PCP self-reported frequency of collecting patient diet information (p = 0.01) and medical history information (p = 0.01); and PCP participation in an integrated health system (p = 0.01). PCP use of cancer genetic susceptibility testing may be influenced by patient inquiry, provider beliefs about factors that affect cancer risk, provider collection of risk-assessment data, and provider practice environment.

Cross-Sectional Studies↗
PubMed2003

Low temperature episodes in development of blowflies: implications for postmortem interval estimation.

Traditionally the calculation of accumulated degree days or hours (ADD or ADH) involves the concept of a minimum threshold temperature below which development ceases. Hence in fluctuating conditions, where temperatures drop below this threshold, there may be periods of time when development is taken to be zero. This has important implications when the calculation of postmortem interval (PMI) is based on the ADD or ADH of larval dipterans. Normal development of larvae of the blowflies Calliphora vicina Robineau-Desvoidy and C. vomitoria L. (Diptera: Calliphoridae) at 20 degrees C was interrupted by cold episodes. The expectation was that total development time would increase by the period at low (therefore no development) temperature but the total ADD or ADH should be the same as non-cold treated cohorts. The results, however, showed that total ADH for both species decreased linearly with increasing temperature with no evidence of any minimum threshold temperature effect. The increased ADH at low temperatures may be due to either continued but reduced development or a delay in development restarting after the cold episode. Use of ADH in PMI estimations has shortcomings particularly during the winter period where low temperatures are involved or where there are sudden summer cold spells during the development period. As blowfly development progresses from egg to pupa such errors will be compounded.

Animals↗
PubMed2003

Spinal cord atrophy and disability in multiple sclerosis over four years: application of a reproducible automated technique in monitoring disease progression in a cohort of the interferon beta-1a (Rebif) treatment trial.

BACKGROUND: Pathology in the cervical spinal cord is considered an important cause of disability in multiple sclerosis. However, the majority of serial studies have failed to find a correlation between spinal cord atrophy and disability. OBJECTIVES: To use a highly reproducible and accurate method to quantify spinal cord area change on three dimensional magnetic resonance imaging and relate this to disability change in patients with multiple sclerosis. METHODS: 38 patients with multiple sclerosis (20 with the relapsing-remitting (RRMS) form and 18 with the secondary progressive (SPMS) form) were imaged at baseline and at months 6, 12, 18, and 48 during two treatment trials of the high dose subcutaneous thrice weekly interferon beta-1a (IFNbeta, Rebif). Thirty one healthy subjects were also imaged at baseline. Upper cervical cord area (UCCA) was measured using Sobel edge detection. RESULTS: The intraobserver coefficient of variation of the method was 0.42%. A significant reduction in UCCA was detected at month 6 in the placebo group (p = 0.04) and at month 12 for INFbeta (p = 0.03). The mean reduction of UCCA at month 48 was 5.7% for patients initially on placebo who received treatment at 24 months (RRMS) or at 36 months (SPMS), and 4.5% for those on IFNbeta throughout the study (p = 0.35). The change in UCCA was significantly correlated with change in the expanded disability status scale at month 12 (r = 0.4, p = 0.016), month 18 (r = 0.32, p = 0.05), and month 48 (r = 0.4, p = 0.016) in the total cohort. CONCLUSIONS: Despite the small number of patients studied and the possible confounding effects of interferon treatment, this study showed that edge detection is reproducible and sensitive to changes in spinal cord area, and that this change is related to changes in clinical disability. This suggests a role for measurement of spinal cord atrophy in monitoring disease progression and possible treatment effects in clinical trails.

Adult↗
PubMed2002

Diabetes UK funded surveys of the structural provision of primary care diabetes services in the UK.

AIM: To describe diabetes service provision in primary care in the UK. METHODS: Postal questionnaires were sent to all UK primary care organizations (PCOs), and to a sample of general practices in England and all practices in Wales and Scotland. The data collection period ended on 30 April 2001. RESULTS: Seventy-nine per cent of the PCOs and 40% of the practices provided usable information. There is evidence that respondents were not significantly biased in relation to their interest in diabetes care. Diabetes was included as a Health Improvement Programme (or equivalent) priority by 62% of PCOs and had been identified as a clinical governance priority by 27%. Sixty-five per cent had information about the ethnic composition of their general population, 57% had an estimate of the number of people with diabetes. Sixty-nine per cent had a local diabetes register but this was said to cover the entire local population in only 64% of these. At least one audit of diabetes care had been carried out (in the previous 5 years) in 75% and, in 76%, clinical guidelines on diabetes care were made available to practices. In the practices, 80% had a designated lead person for diabetes. Seventy-three per cent had at least one general practitioner with a special interest and 87% at least one nurse. Seventy-two per cent of practices ran specific diabetes clinics and 51% had a screening policy. Eighty-six per cent considered that they had adequate systems in place for the delivery of diabetes care. However, only 6% were able to offer a dedicated diabetes telephone help or advice line and only 9% an evening out of hours clinic. Regular practice meetings were held to discuss diabetes in 35%, whereas 39% had a formal shared care protocol. Fourteen per cent held regular joint meetings with the hospital-based team and in 38% there was membership of Diabetes UK for at least one partner or the practice itself. A third (34%) of responding practices were unsure whether a Local Diabetes Services Advisory Group or equivalent existed in their area. Geographical differences in service provision were identified with, for example, practices in London having fewer components in place that were specifically related to the provision of diabetes care. Single-handed practices, wherever they were situated, had in place fewer staff and facilities specifically for diabetes care.

Diabetes Mellitus↗
PubMed2002

Dermatitis herpetiformis and neurological dysfunction.

Dermatitis herpetiformis and coeliac disease are gluten sensitive diseases, which have common immunopathological and genetic mechanisms. Neuropsychiatric complications have been reported in up to 26% of patients with coeliac disease. This is probably an overestimate, because of the chance associations with some common neurological conditions such as epilepsy. The pathogenesis is speculative but it has been postulated that gluten is neurotoxic possibly via immune mechanisms. The frequency of neurological dysfunction in patients with dermatitis herpetiformis has not been characterised. Patients with dermatitis herpetiformis might be expected to be particularly susceptible to neuronal damage as some continue to consume gluten when their dermatological symptoms are controlled by dapsone. Thirty five patients were recruited with dermatitis herpetiformis from dermatology clinics at St Mary's Hospital, London and Queen's Medical Centre, Nottingham and investigated for evidence of neurological abnormality. All patients underwent a full neurological examination and were asked about their neurological and general medical history by means of a structured questionnaire. Serum samples were taken and screened for the presence of anti-neuronal antibodies (anti-Hu and Yo) as well as anti-gliadin (IgA and G) anti-endomysial (IgA), and anti-tissue transglutaminase (IgA) antibodies. Neurophysiological tests were carried out where appropriate. Only two patients were identified with unexplained neurological abnormalities (one essential tremor, and one chorea). Two other patients had a history of migraine. The patient with chorea also had borderline/equivocally positive anti-Hu antibodies by immunofluorescence assay. All other samples were negative for anti-neuronal antibodies. Fifteen patients were positive for anti-gliadin antibodies (IgA and/or IgG), four for anti-endomysial antibodies (monkey oesophagus or umbilical cord), and six for anti-tissue transglutaminase antibodies. The presence of these antibodies did not correlate with the presence of neurological abnormalities. No cases of "gluten ataxia" were identified. In conclusion, there was no convincing evidence for immune mediated neurological damage in this pilot study of dermatitis herpetiformis.

Adolescent↗
PubMed2002

Changes in third ventricular size with neuroendoscopic third ventriculostomy: a blinded study.

The objective was to study the relation between changes in cerebral ventricular size and clinical outcome after neuroendoscopic third ventriculostomy (NTV) in both primary (no previous surgery) and secondary (previous CSF diversion for hydrocephalus) NTV. Changes in ventricular size were related to the need for further surgery for CSF diversion. A blinded retrospective study of the pre-NTV and post-NTV sizes of the ventricles in an unselected series of patients undergoing this procedure was done. A decrease in third ventricular size was seen in significantly more patients in the primary group than in the secondary group. Median change in third ventricle width for those who did not require further CSF diversion was significantly greater than those with no clinical benefit (p=0.01). Positive predictive power for successful outcome was highest for measures of the third ventricle; 73% and 68% for third ventricle width and height respectively, 88% for anterior to posterior commissure distance. In conclusion, third ventricular size reduces after NTV. The use of such a change as an arbiter of success in this procedure is questionable as clinically successful cases can have no change in ventricular size. It is considered that clinical outcome is the most important guide to success or failure as reduction in ventricular size is by no means guaranteed. Radiological outcomes alone may be misleading and reliance on them should be avoided.

Adolescent↗
PubMed2001

Underuse of primary Mycobacterium avium complex and Pneumocystis carinii prophylaxis in the United States.

BACKGROUND: Little is known about the rates of Mycobacterium avium complex (MAC) and Pneumocystis carinii (PCP) prophylaxis adherence to guidelines and how they have changed after introduction of effective antiretroviral therapy. OBJECTIVE: To determine rates of primary prophylaxis for MAC and PCP and to evaluate the influence of sociodemographic characteristics, region, and provider experience. DESIGN: National probability sample cohort of HIV patients in care. SETTING: One hundred sixty HIV health care providers. PATIENTS: A total of 2864 patients interviewed in 1996 to 1997 (68% response) and 2267 follow-up interviews, representing 65% of surviving sampled patients (median follow-up, 15.1 months). MEASUREMENTS: Use of prophylactic drugs, most recent CD4 count, sociodemographics, and regional and total HIV patients/providers. RESULTS: Of patients eligible for primary MAC prophylaxis (most recent CD4 count <50/mm(3) ), 41% at baseline and 40% at follow-up patients were treated. Of patients eligible for primary PCP prophylaxis (i.e., those with CD4 counts <200/mm(3) ), 64% and 72% were treated, respectively. MAC prophylaxis at baseline was less likely in African American (adjusted odds ratio [OR], 35; 95% confidence interval [CI], 0.20-0.59), Hispanic (OR, 27; 95% CI, 0.08-0.94) and less-educated (OR, 0.61; 95% CI, 0.36-1.0) patients and more likely in U. S. geographic regions in the Pacific West (OR, 4.9; 95% CI, 1.0-23) and Midwest (OR, 6.4; 95% CI, 1.2-33) and in practices with more HIV patients. CONCLUSIONS: Most eligible patients did not receive MAC prophylaxis; PCP prophylaxis rates were better but still suboptimal. Our results support outreach efforts to African Americans, Hispanics, the less educated, and those in the northeastern United States and in practices with fewer HIV patients.

AIDS-Related Opportunistic Infections↗
PubMed2001

Relationship between DNA methylation, histone H4 acetylation and gene expression in the mouse imprinted Igf2-H19 domain.

DNA methylation and histone H4 acetylation play a role in gene regulation by modulating the structure of the chromatin. Recently, these two epigenetic modifications have dynamically and physically been linked. Evidence suggests that both modifications are involved in regulating imprinted genes - a subset of genes whose expression depends on their parental origin. Using immunoprecipitation assays, we investigate the relationship between DNA methylation, histone H4 acetylation and gene expression in the well-characterised imprinted Igf2-H19 domain on mouse chromosome 7. A systematic regional analysis of the acetylation status of the domain shows that parental-specific differences in acetylation of the core histone H4 are present in the promoter regions of both Igf2 and H19 genes, with the expressed alleles being more acetylated than the silent alleles. A correlation between DNA methylation, histone hypoacetylation and gene repression is evident only at the promoter region of the H19 gene. Treatment with trichostatin A, a specific inhibitor of histone deacetylase, reduces the expression of the active maternal H19 allele and this can be correlated with regional changes in acetylation within the upstream regulatory domain. The data suggest that histone H4 acetylation and DNA methylation have distinct functions on the maternal and paternal Igf2-H19 domains.

Acetylation↗
PubMed2001

Complete diagnostic evaluation in colorectal cancer screening: research design and baseline findings.

BACKGROUND: While indicated by guidelines, complete diagnostic evaluation, or CDE (i.e., colonoscopy or combined flexible sigmoidoscopy plus barium enema X ray), is often not recommended and performed for persons with an abnormal screening fecal occult blood test (FOBT) result. We initiated a randomized trial to assess the impact of a physician-oriented intervention on CDE rates in primary care practices. METHODS: In 1998, we identified 1,184 primary care physicians (PCPs) in 584 practices whose patients received FOBTs that are mailed annually by a managed care organization screening program. A total of 470 PCPs in 318 practices completed a baseline survey. Practices were randomly assigned either to a Control Group (N = 198) or to an Intervention Group (N = 120). Control Group practices received the screening program. Intervention Group practices received the screening program and the intervention (i.e., CDE reminder-feedback plus educational outreach). Practice CDE recommendation and performance rates are the primary outcomes to be measured in the study. RESULTS: Baseline CDE recommendation and performance rates were low and were comparable in Control and Intervention Group practices (54 to 57% and 39 to 40%, respectively). PCPs in the practices tended to view FOBT screening and CDE favorably, but had concerns about screening efficacy, time involved in CDE, and patient discomfort and adherence. Control Group physicians were more likely than Intervention Group physicians to believe that a mail-out FOBT screening program helps in the practice of medicine. CONCLUSIONS: We were able to enroll a high proportion of targeted primary care practices, measure practice characteristics and CDE rates at baseline, and develop and implement the intervention. Study outcome analyses will take into account baseline differences in practice characteristics.

Analysis of Variance↗
PubMed2001

Ventricular enlargement in multiple sclerosis: a comparison of three-dimensional and linear MRI estimates.

Atrophy of central white matter is related to irreversible clinical disability in multiple sclerosis (MS) and ventricular enlargement may be a sensitive marker of this tissue loss. Therapeutic trials in MS have provided MRI data for investigation of cerebral atrophy in MS. These studies use almost exclusively two-dimensional (2-D) images, which may be limited in the assessment of three-dimensional (3-D) structures. We used 3-D MRI data to estimate ventricular volumes in 40 patients with MS and 10 healthy controls, to look at associations with clinical disability and the stage of the disease. We then compared simple linear measures of ventricular size from conventional 2-D images, with 3-D volume estimates to establish the best available linear indices of ventricular volume. Mean ventricular volumes were increased in the patients and significantly larger in the more disabled patients. The estimated volume of the third ventricle obtained from 3-D MRI showed the strongest association with the clinical stage of the disease, duration of symptoms and levels of disability. Finally, we confirmed that in patients with MS accurate data on ventricular size can be obtained from 2-D images by two simple and convenient linear measures, the width of the third ventricle and of the anterior horn of the lateral ventricle.

Adult↗
PubMed2001

Allozyme polymorphism and variability in permethrin tolerance in British populations of the parthenogenetic stored product pest Liposcelis bostrychophila (Liposcelididae, Psocoptera).

Variability in allozyme patterns is demonstrated among 111 British populations of Liposcelis bostrychophila (Badonnel), an obligatory parthenogenetic liposcelid species that is a common domestic pest in the United Kingdom. In addition four tropical strains and a laboratory culture were included in the analysis. Permethrin toxicity was measured in a subset of the populations.Using cellulose acetate paper electrophoresis, 16 of 34 enzymes tested were found in the liposcelid material and, of these, four were polymorphic. A total of 47 distinct morphs were recognised. This enzyme variation appears to be random with respect to geography throughout the country.Permethrin tolerance was highly variable among populations. A significant relationship was demonstrated between the mean LC(50) for permethrin and latitude such that there appears to be higher levels of tolerance in southern, than in northern, Britain.No link could be established between the allozyme polymorphisms, particularly in the esterases, and permethrin tolerance.

Journal Article↗
PubMed2001

Communication between members of the cardiac arrest team--a postal survey.

AIMS: Effective communication enhances team building and is perceived to improve the quality of team performance. A recent publication from the Resuscitation Council (UK) has highlighted this fact and recommended that cardiac arrest team members make contact daily. We wished to identify how often members of this team communicate prior to a cardiopulmonary arrest. METHOD: A questionnaire on cardiac arrest team composition, leadership, communication and debriefing was distributed nationally to Resuscitation Training Officers (RTOs) and their responses analysed. RESULTS: One hundred and thirty (55%) RTOs replied. Physicians and anaesthetists were the most prominent members of the team. The Medical Senior House Officer is usually nominated as the team leader. Eighty-seven centres (67%) have no communication between team members prior to attending a cardiopulmonary arrest. In 33%, communication occurs but is either informal or fortuitous. The RTOs felt that communication is important to enhance team dynamics and optimise task allocation. Only 7% achieve a formal debrief following a cardiac arrest. CONCLUSION: Communication between members of the cardiac arrest team before and after a cardiac arrest is poor. Training and development of these skills may improve performance and should be prioritised. Team leadership does not necessarily reflect experience or training.

Communication↗