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D Jones

Publications and source records attributed to D Jones.

At least 73 records · Page 4Linked to original sources
PubMed2002

Adjustments and measures of differential expression for microarray data.

MOTIVATION: Existing analyses of microarray data often incorporate an obscure data normalization procedure applied prior to data analysis. For example, ratios of microarray channels intensities are normalized to have common mean over the set of genes. We made an attempt to understand the meaning of such procedures from the modeling point of view, and to formulate the model assumptions that underlie them. Given a considerable diversity of data adjustment procedures, the question of their performance, comparison and ranking for various microarray experiments was of interest. RESULTS: A two-step statistical procedure is proposed: data transformation (adjustment for slide-specific effect) followed by a statistical test applied to transformed data. Various methods of analysis for differential expression are compared using simulations and real data on colon cancer cell lines. We found that robust categorical adjustments outperform the ones based on a precisely defined stochastic model, including some commonly used procedures.

Colonic Neoplasms↗
PubMed2002

Prevalence of visual impairment in people aged 75 years and older in Britain: results from the MRC trial of assessment and management of older people in the community.

AIMS: To measure the prevalence of visual impairment in a large representative sample of people aged 75 years and over participating in the MRC trial of assessment and management of older people in the community. METHODS: 53 practices in the MRC general practice research framework. Data were obtained from 14 600 participants aged 75 years and older. Prevalence of visual impairment overall (binocular visual acuity <6/18) which was categorised separately into low vision (binocular visual acuity <6/18-3/60) or blindness (binocular visual acuity of <3/60). The prevalence of binocular acuity <6/12 was presented for comparison with other studies. Visual acuity was measured using Glasgow acuity charts; glasses, if worn, were not removed. RESULTS: Visual acuity was available for 14 600 people out of 21 241 invited (69%). Among people with visual acuity data, 12.4% overall (1803) were visually impaired (95% confidence intervals 10.8% to 13.9%); 1501 (10.3%) were categorised as having low vision (8.7% to 11.8%), and 302 (2.1%) were blind (1.8% to 2.4%). At ages 75-79, 6.2% of the cohort were visually impaired (5.1% to 7.3%) with 36.9% at age 90+ (32.5% to 41.3%). At ages 75-79, 0.6% (0.4% to 0.8%) of the study population were blind, with 6.9% (4.8% to 9.0%) at age 90+. In multivariate regression, controlling for age, women had significant excess risk of visual impairment (odds ratio 1.43, 95% confidence interval 1.29 to 1.58). Overall, 19.9% of study participants had a binocular acuity of less than 6/12 (17.8% to 22.0%). CONCLUSION: The results from this large study show that visual impairment is common in the older population and that this risk increases rapidly with advancing age, especially for women. A relatively conservative measure of visual impairment was used. If visual impairment had been defined as visual acuity of <6/12 (American definition of visual impairment), the age specific prevalence estimates would have increased by 60%.

Age Factors↗
PubMed2002

Caring for a relative with chronic fatigue syndrome: difficulties, cognition and acceptance over time.

The present study explored the difficulties experienced by carers of chronic fatigue syndrome (CFS) sufferers, their cognitions, and their efforts to accept the illness. Semi-structured interviews were conducted with 17 carers to study these issues, retrospectively, over three stages: before the diagnosis of CFS, shortly after the diagnosis, and at present. Surprisingly, the results suggested that carers, several of them absent from home during the day, felt that their lives were only minimally constrained by the illness. Nevertheless, all carers reported specific coping efforts to manage both the illness and their own distress, and indicated that they learned to accept the illness over time. However, acceptance appeared to be a form of resignation rather than a positive appreciation of the illness. In light of the uncertainties surrounding the origin of CFS and carers' apparent confusion, the results obtained in the present study are significant in that they increase our understanding of CFS carers' quality of life, their efforts to cope with the illness, and the physical and emotional help they may provide to the sufferer. Such information can be usefully employed in the increasing development of counselling interventions and instrumental support networks that involve both sufferers and their carers.

Adaptation, Psychological↗
PubMed2002

Osteoporosis in primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is an autoimmune liver disease that is typically progressive, with a significant proportion of patients going on to develop cirrhosis. It predominately affects women and typically develops in the middle years of life. In most centres the median age for presentation is in the range 55 to 60 years, with a significant proportion of patients first presenting over the age of 65. Due to earlier diagnosis, PBC has gone from being a rare disease, characterised by the complications of end-stage liver disease, to a significantly commoner disease (affecting up to 1 in 700 women over the age of 40) diagnosed often in an asymptomatic stage. Osteoporosis increases with advancing age and hence there is an increased prevalence of osteoporosis in older people. The question of whether osteoporosis occurs as a specific complication of PBC has latterly proved to be controversial. This article reviews the current literature and examines why differences occur in osteoporosis prevalence in the available studies. It becomes clear that when determining the true extent of the association between osteoporosis and PBC, conclusions must be drawn from large populations, and that when considering a disease such as osteoporosis that is common in older people, age matched values be used in order to draw these conclusions. As PBC is a disease that often presents for the first time over the age of 65, it is not surprising that osteoporosis is a common problem in a disease predominately affecting peri- or postmenopausal women.

Bone Diseases↗
PubMed2001

Randomised comparison of three methods of administering a screening questionnaire to elderly people: findings from the MRC trial of the assessment and management of older people in the community.

OBJECTIVE: To compare three different methods of administering a brief screening questionnaire to elderly people: post, interview by lay interviewer, and interview by nurse. DESIGN: Randomised comparison of methods within a cluster randomised trial. SETTING: 106 general practices in the United Kingdom. PARTICIPANTS: 32 990 people aged 75 years or over registered with participating practices. MAIN OUTCOME MEASURES: Response rates, proportion of missing values, prevalence of self reported morbidity, and sensitivity and specificity of self reported measures by method of administration of questionnaire for four domains. RESULTS: The response rate was higher for the postal questionnaire than for the two interview methods combined (83.5% v 74.9%; difference 8.5%, 95% confidence interval 4.4% to 12.7%, P<0.001). The proportion of missing or invalid responses was low overall (mean 2.1%) but was greater for the postal method than for the interview methods combined (4.1% v 0.9%; difference 3.2%, 2.7% to 3.6%, P<0.001). With a few exceptions, levels of self reported morbidity were lower in the interview groups, particularly for interviews by nurses. The sensitivity of the self reported measures was lower in the nurse interview group for three out of four domains, but 95% confidence intervals for the estimates overlapped. Specificity of the self reported measures varied little by method of administration. CONCLUSIONS: Postal questionnaires were associated with higher response rates but also higher proportions of missing values than were interview methods. Lower estimates of self reported morbidity were obtained with the nurse interview method and to a lesser extent with the lay interview method than with postal questionnaires.

Aged↗
PubMed2001

Long-term results with radiotherapy for Stage I-II follicular lymphomas.

PURPOSE: To analyze the long-term results with radiotherapy (RT) for early-stage, low-grade follicular lymphomas. METHODS AND MATERIALS: From 1960 to 1988, 80 patients with Stage I (n = 33) or II (n = 47), World Health Organization Grade 1 (n = 50) or 2 (n = 30) follicular lymphoma were treated with RT. The lymph nodes or spleen were involved in 97% of cases. The maximal tumor sizes ranged from 0.5 to 11.0 cm (median 2.0). The RT fields encompassed only the involved Ann Arbor nodal region (involved-field RT) in 9% of the patients. The fields also included 1-3 adjacent, grossly uninvolved nodal regions (regional RT) in 54% of patients but were smaller than mantle or whole abdominopelvic fields. Mantle or whole abdominopelvic fields encompassing up to 6 grossly uninvolved regions (extended-field RT) were used in the remaining 37% of patients. The total RT doses ranged from 26.2 to 50.0 Gy given in daily 1.0-3.0-Gy fractions. RESULTS: The follow-up of the surviving patients ranged from 3.5 to 28.7 years (median 19.0). No recurrences were found >17.0 years after RT, with 13 patients free of disease at their last follow-up visit 17.6-25.0 years after treatment. In 58% of cases, death was not from follicular lymphoma. The 15-year local control rate was 100% for 44 lymphomas <3.0 cm treated with only 27.8-30.8 Gy (median 30.0 in 20 fractions). Progression-free survival was affected by the maximal tumor size at the start of RT (15-year rate 49% vs. 29% for lymphomas <3.0 cm vs. > or =3.0 cm, respectively, p = 0.04) and Ann Arbor stage (15-year rate 66% vs. 26% for Stages I and II, respectively, p = 0.006). Ann Arbor stage also affected the cause-specific survival (15-year rate 87% vs. 54% for Stages I and II, respectively, p = 0.01). No significant difference was found in overall survival between those treated with extended-field RT and those treated with involved-field RT or regional RT (15-year rate 49% and 40%, respectively, p = 0.51). The 15-year incidence rate of Grade 3 or greater late complications according to the Subjective, Objective, Management, and Analytical scale in patients treated with 26.2-30.8 Gy vs. 30.9-50.0 Gy was 0% and 6%, respectively. CONCLUSIONS: RT can cure approximately one half of Stage I and one quarter of Stage II, World Health Organization Grade 1 or 2 follicular lymphomas. Follicular lymphomas <3.0 cm can be controlled locally with doses of 27.8-30.8 Gy, and there is a trend toward a higher incidence of late complications with doses of >30.8 Gy. Doses of 25-30 Gy delivered in 15-20 fractions should be examined prospectively in patients with follicular lymphomas of <3.0 cm.

Disease-Free Survival↗
PubMed2001

Local photorelease of caged thymosin beta4 in locomoting keratocytes causes cell turning.

The broad aim of this work was to explore the feasibility of using light-directed perturbation techniques to study cell locomotion. Specifically, a caged form of thymosin beta4 (Tbeta4) was photoactivated in a defined local region of locomoting fish scale keratocytes and the resulting perturbation of locomotion was studied. Purified Tbeta4 was produced in an inactive form by "caging" with ([n-nitroveratryl]oxy)chlorocarbamate. In vitro spectrophotofluorometric assays indicated that caged Tbeta4 did not change the normal actin polymerization kinetics, whereas photoactivated Tbeta4 significantly inhibited actin polymerization. With an a priori knowledge of the cytoplasmic diffusion coefficient of Tbeta4 as measured by fluorescence recovery after photobleaching experiments, the rapid sequestration of actin monomers by uncaged Tbeta4 and the consequent reduction in the diffusional spread of the Tbeta4-actin complex were predicted using Virtual Cell software (developed at the Center for Biomedical Imaging Technology, University of Connecticut Health Center). These simulations demonstrated that locally photoactivating Tbeta4 in keratocytes could potentially elicit a regional locomotory response. Indeed, when caged Tbeta4 was locally photoactivated at the wings of locomoting keratocytes, specific turning about the irradiated region was observed, whereas various controls were negative. Additionally, loading of exogenous Tbeta4 into both keratocytes and fibroblasts caused very rapid disassembly of actin filaments and reduction of cellular contractility. Based on these results, a mechanical model is proposed for the turning behavior of keratocytes in response to photoreleased Tbeta4.

3T3 Cells↗
PubMed2001

Expression of stromal-derived factor-1 is decreased by IL-1 and TNF and in dermal wound healing.

Stromal-derived factor-1 (SDF-1) is a CXC chemokine that is believed to be constitutively expressed by stromal cells of numerous tissues. In this report, we demonstrate that dermal fibroblasts and vessels of noninflamed tissues express SDF-1. Unexpectedly, we found that expression of SDF-1 is regulated by inflammation. Expression of SDF-1 by primary cultures of human gingival fibroblasts is potently inhibited by activated macrophages via secretion of IL-1alpha and TNF-alpha. Levels of SDF-1 mRNA also decrease in acutely inflamed mouse dermal wounds. We propose that SDF-1 functions as a homeostatic regulator of tissue remodeling, whose expression stabilizes existing dermal architecture.

Animals↗
PubMed2001

Osteobiology, strain, and microgravity. Part II: studies at the tissue level.

Loading microgravity, and/or defective mechanical strain-forces have important effects on bone cells and bone quality and quantity. The complex mechanisms induced by strain and microgravity on bone cells have been reviewed in Part I of this paper. In Part II, we have considered the data on the alterations induced by unloading and microgravity on the skeleton and the mechanisms that are involved at the tissue level in animals and humans.

Animals↗
PubMed2001

A comparison of physiotherapy techniques for patients with Parkinson's disease.

BACKGROUND: Despite optimal medical and surgical therapies for Parkinson's disease, patients develop progressive disability. The role of the physiotherapist is to maximise functional ability and minimise secondary complications through movement rehabilitation within a context of education and support for the whole person. What form of physiotherapy is most effective in the treatment of Parkinson's disease remains unclear. OBJECTIVES: 1. To compare the efficacy and effectiveness of novel physiotherapy techniques versus 'standard' physiotherapy in patients with Parkinson's disease. Standard physiotherapy is defined as the type of therapy that the physiotherapist would usually use to treat Parkinson's disease. 2. To compare the efficacy and effectiveness of one physiotherapy technique versus a second form of physiotherapy. SEARCH STRATEGY: Relevant trials were identified by electronic searches of MEDLINE, EMBASE, CINAHL, ISI-SCI, AMED, MANTIS, REHABDATA, REHADAT, GEROLIT, Pascal, LILACS, MedCarib, JICST-EPlus, AIM, IMEMR, SIGLE, ISI-ISTP, DISSABS, Conference Papers Index, Aslib Index to Theses, the Cochrane Controlled Trials Register, the CentreWatch Clinical Trials listing service, the metaRegister of Controlled Trials, ClinicalTrials.gov, CRISP, PEDro, NIDRR and NRR; and examination of the reference lists of identified studies and other reviews. SELECTION CRITERIA: Only randomised controlled trials (RCT) were included. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by KD and CEH and differences settled by discussion. MAIN RESULTS: Seven trials were identified with 142 patients. All used small numbers of patients and the method of randomisation and concealment of allocation was poor or not statedin all of the trials. These methodological problems could potentially lead to bias from a number of sources. The methods of physiotherapy varied so widely that the data could not be combined. REVIEWER'S CONCLUSIONS: Considering the small number of patients examined, the methodological flaws in many of the studies and the possibility of publication bias, there is insufficient evidence to support or refute the efficacy of any given form of physiotherapy over another in Parkinson's disease. Another Cochrane review, Physiotherapy for patients with Parkinson's Disease, found that there was insufficient evidence to support or refute the efficacy of physiotherapy compared to no physiotherapy in Parkinson's disease. A wide range of physiotherapy approaches were used in these studies and a survey of UK physiotherapists confirmed that they also use an eclectic combination of techniques in the treatment of Parkinson's disease (Plant 1999). Therefore a consensus must be found as to 'best practice' physiotherapy for Parkinson's disease. The efficacy of 'standard' physiotherapy should be proved first before examining variations in physiotherapy methods. Therefore large well designed randomised controlled trials are needed to judge the effect of physiotherapy in Parkinson's disease. After this large RCTs are needed to demonstrate the most effective form of physiotherapy in Parkinson's disease. Outcome measures with particular relevance to patients, carers, physiotherapists and physicians should be chosen and the patients monitored for at least 6 months to determine the duration of any effect. The trials should be reported according to CONSORT guidelines (CONSORT 1996).

Humans↗
PubMed2001

Physiotherapy for patients with Parkinson's Disease: a comparison of techniques.

BACKGROUND: Despite optimal medical and surgical therapies for Parkinson's disease, patients develop progressive disability. The role of the physiotherapist is to maximise functional ability and minimise secondary complications through movement rehabilitation within a context of education and support for the whole person. OBJECTIVES: To compare the efficacy and effectiveness of physiotherapy with placebo or no interventions in patients with Parkinson's disease. SEARCH STRATEGY: Relevant trials were identified by electronic searches of MEDLINE, EMBASE, CINAHL, ISI-SCI, AMED, MANTIS, REHABDATA, REHADAT, GEROLIT, Pascal, LILACS, MedCarib, JICST-EPlus, AIM, IMEMR, SIGLE, ISI-ISTP, DISSABS, Conference Papers Index, Aslib Index to Theses, the Cochrane Controlled Trials Register, the CentreWatch Clinical Trials listing service, the metaRegister of Controlled Trials, ClinicalTrials.gov, CRISP, PEDro, NIDRR and NRR; and examination of the reference lists of identified studies and other reviews. SELECTION CRITERIA: Only randomised controlled trials (RCT) were included, however those trials that allowed quasi-random methods of allocation were allowed. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by KD and DJ and differences settled by discussion. MAIN RESULTS: Eleven trials were identified with 280 patients. Eight trials did not have adequate placebo treatments, all used small numbers of patients and the method of randomisation and concealment of allocation was good in only four trials. These methodological problems could potentially lead to bias from a number of sources. Although ten of the trials claimed a positive effect from physiotherapy, few outcomes measured were statistically significant. Walking velocity was measured in four trials and increased significantly in two of them. Stride length was the only other outcome measured in more than one trial, it was significantly improved in two trials. Five other outcomes improved significantly in individual studies, but eight other outcomes did not improve significantly. REVIEWER'S CONCLUSIONS: Considering the methodological flaws in many of the studies, the small number of patients examined, and the possibility of publication bias, there is insufficient evidence to support or refute the efficacy of physiotherapy in Parkinson's disease. The studies illustrate that a wide range of approaches are being employed by physiotherapists to treat Parkinson's disease. This was confirmed by the UK survey of physiotherapists. There is a need to develop a consensus as to 'best-practice'. Large well designed placebo-controlled RCTs are then needed to demonstrate the efficacy and effectiveness of 'best practice' physiotherapy in Parkinson's disease. The stage of the disease at which the physiotherapy is given should be specified at the outset. Outcome measures with particular relevance to patients, carers, physiotherapists and physicians should be chosen and the patients monitored for at least six months to determine the duration of any beneficial effects. The trials should be reported according to CONSORT guidelines.

Humans↗
PubMed2001

Coping and illness cognitions: chronic fatigue syndrome.

The chronic fatigue syndrome (CFS) is described, and research on coping with this illness reviewed and analysed. CFS is a severely disabling illness of unknown etiology, which has occurred in epidemic forms all over the world. However, the number of sufferers has dramatically increased over previous years. The heterogeneous symptomatology of CFS was reviewed, and diagnostic criteria were discussed. The difficulty in establishing causality was emphasized. An interaction of factors appears most likely to be associated with illness onset and maintenance. As the mediating factor could be sufferers' coping behavior, the existing coping literature was reviewed. There might be an association between coping and physical and psychological well-being. Finally, recommendations are made for longitudinal research on coping and coping effectiveness, and for the development of therapeutic interventions.

Adaptation, Psychological↗
PubMed2001

Juvenile hormone III-dependent conformational changes of the nuclear receptor ultraspiracle.

The identification of potential endogenous or synthetic ligands for orphan receptors in the steroid receptor superfamily is important both for discerning endogenous regulatory pathways and for designing receptor inhibitors. The insect nuclear receptor Ultraspiracle (USP), an ortholog of vertebrate RXR, has long been treated as an orphan receptor. We have tested here the fit of terpenoid ligands to the JH III-binding site of monomeric and homo-oligomeric USP from Drosophila melanogaster (dUSP). dUSP specifically bound juvenile hormone III (JH III), but not control farnesol or JH III acid, and also specifically changed in conformation upon binding of JH III in a fluorescence binding assay. Juvenile hormone III binding caused intramolecular changes in receptor conformation, and stabilized the receptor's dimeric/oligomeric quaternary structure. In both a radiometric competition assay and the fluorescence binding assay the synthetic JH III agonist methoprene specifically competed with JH III for binding to dUSP, the first demonstration of specific binding of a biologically active JH III analog to an insect nuclear receptor. The recombinant dUSP bound with specificity to a DR12 hormone response element in a gel shift assay. The same DR12 element conferred enhanced transcriptional responsiveness of a transfected juvenile hormone esterase core promoter to treatment of transfected cells with JH III, but not to treatment with retinoic acid or T3. The activity of JH III or JH III-like structures, but not structures without JH III biological activity, to bind specifically to dUSP and activate its conformational change, provide evidence of a terpenoid endogenous ligand for Ultraspiracle, and offer the prospect that synthetic, terpenoid structures may be discovered that can agonize or antagonize USP function in vivo.

Animals↗