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Biomedical subjects

Mark Jones

Publications and source records attributed to Mark Jones.

At least 19 recordsLinked to original sources
PubMed2006

Risk and protective factors for medically serious suicide attempts: a comparison of hospital-based with population-based samples of young adults.

OBJECTIVE: To investigate risk and protective factors for medically serious suicide attempts among young Australian adults. METHOD: The study used a case-control design. A clinical sample of 18-24 year olds was recruited via the emergency department of a large public hospital following a suicide attempt (n=95) and was compared to a sample of 18-24 year olds who participated in a population-based survey (n=380). RESULTS: Risk factors for medically serious suicide attempts included early school leaving, parental divorce (males only), distress due to problems with parents (females only), distress due to problems with friends, distress due to the break-up of a romantic relationship, tobacco use, high alcohol use, current depressive symptomatology and a previous diagnosis of depression. Protective factors included social connectedness, problem-solving confidence and locus of control. There was a trend for social connectedness to be more protective among those with high rather than low levels of depressive symptomatology, and among smokers rather than non-smokers. CONCLUSIONS: Results are discussed in terms of designing evidence-based suicide prevention activities for young adults.

Adolescent↗
PubMed2005

The interpretation of experience and its relationship to body movement: a clinical reasoning perspective.

In this paper, we present findings from literature which suggests an intrinsic relationship in patients with chronic pain between the development of rigid and limited perspectives based on the interpretation of experience and the development of decreased repertoires of movement patterns. We present a research-based clinical reasoning model for conceptualising the teaching of movement for patients with chronic pain and contend that therapists can intentionally teach movement using fundamentally different reasoning and learning processes. We propose that these different kinds of learning will assist clinicians to translate the findings of diverse and complex pain research to clinical practice and, in particular, the teaching of these patients both new perspectives and movement patterns.

Chronic Disease↗
PubMed2005

Statin therapy is associated with fewer deaths in patients with bacteraemia.

OBJECTIVE: Beneficial effects with statin use are increasingly reported in a variety of patient groups. There is in vitro and clinical evidence for its antiinflammatory and immunomodulatory therapeutic roles. We aimed to assess the association between statin administration and mortality in bacteraemic patients. DESIGN: A retrospective cohort analysis. SETTING: A 300-bed acute general hospital. PATIENTS AND PARTICIPANTS: All patients (n=438) requiring hospital care for an episode of bacteraemia during the years 2000-2003 were included. Statin use, patient outcome, and clinical and laboratory variables were collected. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: There was a significant reduction in all-cause hospital mortality (10.6% vs. 23.1%, p=0.022) and death attributable to bacteraemia (6.1% vs. 18.3%, p=0.014) in patients who were receiving statin therapy at the time of bacteraemia (n=66). The reduction in all-cause hospital mortality (1.8% vs. 23.1%, p=0.0002) and death attributable to bacteraemia (1.8% vs. 18.3%, p=0.0018) was more pronounced in the patients who continued to receive statin therapy after the diagnosis of bacteraemia (n=56). The apparent mortality benefit persisted after controlling for differences between the groups. Statin use prior to admission was associated with a reduced adjusted hospital mortality rate (odds ratio 0.39; CI 95% 0.17, 0.91; p=0.029), and continuing statin use after bacteraemia increased this effect (odds ratio 0.06; CI 95% 0.01, 0.44; p=0.0056). CONCLUSION: This retrospective study demonstrates a significant survival benefit associated with continuing statin therapy in bacteraemic patients. The potential for statins as an adjuvant therapy in sepsis warrants further investigation.

Adult↗
PubMed2005

Sulfur accumulation in the timbers of King Henry VIII's warship Mary Rose: a pathway in the sulfur cycle of conservation concern.

In marine-archaeological oak timbers of the Mary Rose large amounts of reduced sulfur compounds abound in lignin-rich parts such as the middle lamella between the cell walls, mostly as thiols and disulfides, whereas iron sulfides and elemental sulfur occur in separate particles. Synchrotron-based x-ray microspectroscopy was used to reveal this environmentally significant accumulation of organosulfur compounds in waterlogged wood. The total concentration of sulfur in reduced forms is approximately 1 mass % throughout the timbers, whereas iron fluctuates up to several mass %. Conservation methods are being developed aiming to control acid-forming oxidation processes by removing the reactive iron sulfides and stabilizing the organosulfur compounds.

Archaeology↗
PubMed2005

Cellular differentiation hierarchies in normal and culture-adapted human embryonic stem cells.

Human embryonic stem cell (HESC) lines vary in their characteristics and behaviour not only because they are derived from genetically outbred populations, but also because they may undergo progressive adaptation upon long-term culture in vitro. Such adaptation may reflect selection of variants with altered propensity for survival and retention of an undifferentiated phenotype. Elucidating the mechanisms involved will be important for understanding normal self-renewal and commitment to differentiation and for validating the safety of HESC-based therapy. We have investigated this process of adaptation at the cellular and molecular levels through a comparison of early passage (normal) and late passage (adapted) sublines of a single HESC line, H7. To account for spontaneous differentiation that occurs in HESC cultures, we sorted cells for SSEA3, which marks undifferentiated HESC. We show that the gene expression programmes of the adapted cells partially reflected their aberrant karyotype, but also resulted from a failure in X-inactivation, emphasizing the importance in adaptation of karyotypically silent epigenetic changes. On the basis of growth potential, ability to re-initiate ES cultures and global transcription profiles, we propose a cellular differentiation hierarchy for maintenance cultures of HESC: normal SSEA3+ cells represent pluripotent stem cells. Normal SSEA3- cells have exited this compartment, but retain multilineage differentiation potential. However, adapted SSEA3+ and SSEA3- cells co-segregate within the stem cell territory, implying that adaptation reflects an alteration in the balance between self-renewal and differentiation. As this balance is also an essential feature of cancer, the mechanisms of culture adaptation may mirror those of oncogenesis and tumour progression.

Adaptation, Physiological↗
PubMed2005

SYBR Green I-induced fluorescence in cultured immune cells: a comparison with Acridine Orange.

Using fluorescence microscopy, we explored the ability of cultured immune cells to take up aqueous SYBR Green I (SGI). SYBR Green I, a highly sensitive fluorescent nucleic acid stain, which preferentially binds to dsDNA over ssDNA or RNA with little background fluorescence from unbound molecules. A time course study over 2h using final dilutions of SGI of 1:10,000 and 1:100,000 at 22 and 37 degrees C, revealed the dye quickly entered the cells, stained mitochondrial DNA then nuclear DNA, and SGI-induced green fluorescence increased over time. As staining progressed, heterochromatin appeared as more intense green fluorescent lines, patches and circles against the lower fluorescence of the nucleoplasm. The lower fluorescence from the nucleoplasm indicated SGI also bound to areas of euchromatin. Similar progressive uptake experiments were carried out with the permeant DNA dye Acridine Orange (AO) to provide insight into staining patterns and mode of uptake. Statistical analysis of cells prestained with SGI then tested with Trypan Blue for changes in membrane permeability, revealed no significant difference between controls and treatment for each temperature. It appears that SGI does not compromise cells for up to 2 h following initial exposure.

Acridine Orange↗
PubMed2005

Randomised controlled trial of the Lidcombe programme of early stuttering intervention.

OBJECTIVES: To evaluate the efficacy of the Lidcombe programme of early stuttering intervention by comparison to a control group. DESIGN: A pragmatic, open plan, parallel group, randomised controlled trial with blinded outcome assessment. SETTING: Two public speech clinics in New Zealand. PARTICIPANTS: Stuttering preschool children who presented to the speech clinics for treatment. Inclusion criteria were age 3-6 years and frequency of stuttering of at least 2% syllables stuttered. Exclusion criteria were onset of stuttering during the six months before recruitment and treatment for stuttering during the previous 12 months. 54 participants were randomised: 29 to the Lidcombe programme arm and 25 to the control arm. 12 of the participants were girls. INTERVENTION: Lidcombe programme of early stuttering intervention. MAIN OUTCOME MEASURES: Frequency of stuttering was measured as the proportion of syllables stuttered, from audiotaped recordings of participants' conversational speech outside the clinic. Parents in both arms of the trial collected speech samples in three different speaking situations before randomisation and at three, six, and nine months after randomisation. RESULTS: Analysis showed a highly significant difference (P = 0.003) at nine months after randomisation. The mean proportion of syllables stuttered at nine months after randomisation was 1.5% (SD 1.4) for the treatment arm and 3.9% (SD 3.5) for the control arm, giving an effect size of 2.3% of syllables stuttered (95% confidence interval 0.8 to 3.9). This effect size was more than double the minimum clinically worthwhile difference specified in the trial protocol. CONCLUSIONS: The results provide evidence from a randomised controlled trial to support early intervention for stuttering. The Lidcombe programme is an efficacious treatment for stuttering in children of preschool age.

Child↗
PubMed2005

Smoking cessation using mobile phone text messaging is as effective in Maori as non-Maori.

AIMS: To determine whether a smoking cessation service using mobile phone text messaging is as effective for Maori as non-Maori. METHODS: A single-blind randomised controlled trial was undertaken with recruitment targeted to maximise the participation of young Maori. The intervention included regular, personalised text messages providing smoking cessation advice, support, and distraction. Maori text messages related to Maori language, support messages (in Maori and English) and information on Maori traditions. Text messaging was free for 1 month. After 6 weeks, the number of messages reduced from 5 per day to 3 per week until the 26-week follow-up. RESULTS: Participants included 355 Maori and 1350 non-Maori. Maori in the intervention group were more likely to report quitting (no smoking in the past week) at 6 weeks (26.1%) than those in the control group (11.2%) RR 2.34, 95% CI: 1.44-3.79. There was no significant difference between the RR for Maori and that for non-Maori (RR: 2.16, 95%CI: 1.72-2.71). CONCLUSIONS: A mobile phone-based cessation programme was successful in recruiting young Maori, and was shown to be as effective for Maori as non-Maori at increasing short-term self-reported quit rates. This shows clear potential as a new public health initiative.

Adult↗
PubMed2005

The human colonic monocarboxylate transporter Isoform 1: its potential importance to colonic tissue homeostasis.

BACKGROUND & AIMS: Butyrate serves as the major source of energy for colonic epithelial cells, and has profound effects on their proliferation, differentiation, and apoptosis. Transport of butyrate across the colonocyte luminal membrane is mediated by the monocarboxylate transporter, MCT1; the expression of which is down-regulated dramatically during colon carcinogenesis. We have proposed that the decline in MCT1 expression during colon carcinogenesis may reduce the intracellular availability of butyrate required to regulate expression of genes associated with the processes maintaining tissue homeostasis within the colonic mucosa. METHODS: To test this hypothesis we used the technique of RNA interference to inhibit MCT1 expression specifically, and determined the consequences of this inhibition on the ability of butyrate to exert its recognized effects in vitro using flow cytometry, immunofluorescence, Northern analysis, and Western analysis. RESULTS: We show that inhibition of MCT1 expression, and hence butyrate uptake, has profound inhibitory effects on the ability of butyrate to regulate expression of key target genes: p21waf1/cip1 (p21), intestinal alkaline phosphatase (IAP), and cyclin D1, and their associated processes of proliferation and differentiation. In contrast, inhibition of MCT1 expression had no effect on the ability of butyrate to modulate expression of either bcl-XL or bak, and this was reflected in a corresponding lack of effect on butyrate induction of apoptosis. CONCLUSIONS: Collectively, these results show the importance of MCT1 to the ability of butyrate to induce cell-cycle arrest and differentiation, and suggest fundamental differences in the mechanisms by which butyrate modulates specific aspects of cell function.

Alkaline Phosphatase↗
PubMed2004

Leg ulceration and perceived health: a population based case-control study.

OBJECTIVES: To quantify the effect of leg ulceration on health-related quality of life and to estimate a health state value for leg ulceration. DESIGN: Population based case-control study. SETTING: Two New Zealand health districts (population 540,468 people). SUBJECTS: 241 people with a leg ulcer of any aetiology, and 224 controls randomly selected from the electoral roll using stratified sampling. MAIN OUTCOME MEASURES: health-related quality of life as measured by the eight domains of the Short Form 36 question Health Survey, adjusted for age, sex and confounding co-morbidities; the physical component summary and mental component summary scores of the Short Form 36 question Health Survey standardised for age and sex; preference-based health state value derived from the Short Form 36 question Health Survey. RESULTS: Completed Short Form 36 question Health Survey questionnaires were available for 230 cases (95%) and 218 controls (97%). Cases reported significantly lower mean scores than controls across all eight domains of the Short Form 36 question Health Survey (P < 0.0005). Mean domain scores for cases were also significantly lower than population norms. The mean physical component summary score for cases and controls was 45.2 versus 50.1 (P < 0.0001) and the mean mental component summary score was 48.1 for cases versus 51 for controls (P < 0.0001). The mean health state values (adjusted for age and sex) were 0.80 for cases and 0.89 for controls. CONCLUSION: Leg ulcers reduce quality of life to a similar extent as other common chronic conditions, such as arthritis and diabetes.

Adult↗
PubMed2004

Case Report. Nurse prescribing: a case study in policy influence.

The implementation of nurse prescribing is characterized by political machination, the need to construct an effective case, and deft manoevering within the corridors of power. This paper illustrates the approach taken by the Royal College of Nursing and its key members in policy formulation and influence as this key nursing tool was brought to the attention of government, and achieved passing of the legislation required to make it a reality.

Drug Prescriptions↗
PubMed2004

Clinical reasoning strategies in physical therapy.

BACKGROUND AND PURPOSE: Clinical reasoning remains a relatively under-researched subject in physical therapy. The purpose of this qualitative study was to examine the clinical reasoning of expert physical therapists in 3 different fields of physical therapy: orthopedic (manual) physical therapy, neurological physical therapy, and domiciliary care (home health) physical therapy. SUBJECTS: The subjects were 6 peer-designated expert physical therapists (2 from each field) nominated by leaders within the Australian Physiotherapy Association and 6 other interviewed experts representing each of the same 3 fields. METHODS: Guided by a grounded theory method, a multiple case study approach was used to study the clinical practice of the 6 physical therapists in the 3 fields. RESULTS: A model of clinical reasoning in physical therapy characterized by the notion of "clinical reasoning strategies" is proposed by the authors. Within these clinical reasoning strategies, the application of different paradigms of knowledge and their interplay within reasoning is termed "dialectical reasoning." DISCUSSION AND CONCLUSION: The findings of this study provide a potential clinical reasoning framework for the adoption of emerging models of impairment and disability in physical therapy.

Data Collection↗
PubMed2004

An e-textile system for motion analysis.

Electronic textiles (e-textiles) offer the promise of home health care devices that integrate seamlessly into the wearer's everyday lifestyle while providing a higher level of functionality than current devices. Existing gait analysis systems are cumbersome laboratory-based systems that, while providing valuable information, would be difficult or impossible to deploy in the home. Yet gait analysis systems offer the promise of preventing and/or mitigating the serious effects of falls in the elderly population. This paper proposes an e-textile solution to this problem along with a design approach for realizing a solution that is inexpensive and usable across the elderly population. Preliminary results are given to demonstrate the promise of the proposed system.

Aged↗
PubMed2003

A systematic review of physicians' survival predictions in terminally ill cancer patients.

OBJECTIVE: To systematically review the accuracy of physicians' clinical predictions of survival in terminally ill cancer patients. DATA SOURCES: Cochrane Library, Medline (1996-2000), Embase, Current Contents, and Cancerlit databases as well as hand searching. STUDY SELECTION: Studies were included if a physician's temporal clinical prediction of survival (CPS) and the actual survival (AS) for terminally ill cancer patients were available for statistical analysis. Study quality was assessed by using a critical appraisal tool produced by the local health authority. DATA SYNTHESIS: Raw data were pooled and analysed with regression and other multivariate techniques. RESULTS: 17 published studies were identified; 12 met the inclusion criteria, and 8 were evaluable, providing 1563 individual prediction-survival dyads. CPS was generally overoptimistic (median CPS 42 days, median AS 29 days); it was correct to within one week in 25% of cases and overestimated survival by at least four weeks in 27%. The longer the CPS the greater the variability in AS. Although agreement between CPS and AS was poor (weighted kappa 0.36), the two were highly significantly associated after log transformation (Spearman rank correlation 0.60, P < 0.001). Consideration of performance status, symptoms, and use of steroids improved the accuracy of the CPS, although the additional value was small. Heterogeneity of the studies' results precluded a comprehensive meta-analysis. CONCLUSIONS: Although clinicians consistently overestimate survival, their predictions are highly correlated with actual survival; the predictions have discriminatory ability even if they are miscalibrated. Clinicians caring for patients with terminal cancer need to be aware of their tendency to overestimate survival, as it may affect patients' prospects for achieving a good death. Accurate prognostication models incorporating clinical prediction of survival are needed.

Analysis of Variance↗
PubMed2003

Surgeon specific mortality in adult cardiac surgery: comparison between crude and risk stratified data.

OBJECTIVE: As a result of recent failures in clinical governance the government has made a commitment to bring individual surgeons' mortality data into the public domain. We have analysed a database to compare crude mortality after coronary artery bypass surgery with outcomes that were stratified by risk. DESIGN: Retrospective analysis of prospectively collected data. SETTING: All NHS centres in the geographical north west of England that undertake cardiac surgery in adults. PARTICIPANTS: All patients undergoing isolated bypass graft surgery for the first time between April 1999 and March 2002. MAIN OUTCOME MEASURES: Surgeon specific postoperative mortality and predicted mortality by EuroSCORE. RESULTS: 8572 patients were operated on by 23 surgeons. Overall mortality was 1.7%. Observed mortality between surgeons ranged from 0% to 3.7%; predicted mortality ranged from 2% to 3.7%. Eighty five per cent (7286) of the patients had a EuroSCORE of 5 or less; 49% of the deaths were in this lower risk group. A large proportion of the variability in predicted mortality between surgeons was due to a small but differing number of high risk patients. CONCLUSIONS: It is possible to collect risk stratified data on all patients undergoing coronary bypass surgery. For most the predicted mortality is low. The small proportion of high risk patients is responsible for most of the differences in predicted mortality between surgeons. Crude comparisons of death rates can be misleading and may encourage surgeons to practise risk averse behaviour. We recommend a comparison of death rates that is stratified by risk and based on low risk cases as the national benchmark for assessing consultant specific performance.

Adult↗