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M Walsh

Publications and source records attributed to M Walsh.

At least 19 recordsLinked to original sources
PubMed2006

High-throughput sample handling and data collection at synchrotrons: embedding the ESRF into the high-throughput gene-to-structure pipeline.

An automatic data-collection system has been implemented and installed on seven insertion-device beamlines and a bending-magnet beamline at the ESRF (European Synchrotron Radiation Facility) as part of the SPINE (Structural Proteomics In Europe) development of an automated structure-determination pipeline. The system allows remote interaction with beamline-control systems and automatic sample mounting, alignment, characterization, data collection and processing. Reports of all actions taken are available for inspection via database modules and web services.

Data Collection↗
PubMed2006

Factors associated with pelvic retraction during gait in cerebral palsy.

Clinical and dynamic (gait-related) measures thought to be associated with pelvic retraction were investigated in patients with cerebral palsy. Gait laboratory data of 233 patients with cerebral palsy were studied retrospectively. Two groups were selected; those who demonstrated pelvic retraction during gait <-6.85 degrees (mean - 2 standard deviations from normal (n=88) and those with >-4.83 degrees (mean - 1 standard deviation from normal) (n=101). About 37.8% of the total population reviewed showed pelvic retraction of <-6.85 degrees . There was a higher prevalence of retraction among hemiplegics (46.3%) compared to diplegics (30.4%). Differences were also found between hemiplegic and diplegic subjects in terms of factors associated with pelvic retraction. Clinical and dynamic tightness of the gastro-soleus were the most significant features associated with pelvic retraction among hemiplegic subjects. Clinical and dynamic flexion and internal rotation of the hip were the most significant features associated with retraction in the diplegic population. This study suggests that pelvic retraction is multifactorial in origin and secondary to both static clinical measures as well as dynamic features during gait.

Adolescent↗
PubMed2006

Evolution of filament structures during edge-localized modes in the MAST Tokamak.

Edge-localized modes (ELMs) are repetitive instabilities that occur in the outer region of tokamak plasmas. This Letter provides new information on and the implications of the evolution of the filament structures observed during ELMs in the MAST tokamak. The filaments exist for the time over which particles are being released into the scrape off layer. They start off at the plasma edge rotating at the velocity of the pedestal, and then decelerate toroidally and accelerate radially outwards. As the filaments propagate radially they remain aligned with the local magnetic field line.

Journal Article↗
PubMed2006

Characteristics of adolescent smoking in high school students in California.

PURPOSE: This pilot study assessed smoking-related behaviors, experiences, and beliefs among a sample of continuation high school students in California to inform dental hygienists about adolescent tobacco use and to assist with the development of effective tobacco cessation intervention strategies. METHODS: After gaining informed consent, we conducted a self-administered questionnaire among 117 adolescent volunteers in rural northern California. The questionnaire assessed demographic variables, lifetime tobacco use, current alcohol use and tobacco use status, early smoking experiences and sensations, factors that might motivate a quit attempt, depression index scores, and other psychosocial variables associated with adolescent smoking. Means and frequencies were generated to evaluate characteristics of tobacco use in this sample of adolescents. Variables of interest were stratified by regular and social smokers. Univariate association of smoking with alcohol use is described by an odds ratio with a 95% confidence interval. Wilcoxon rank sum tests were used to evaluate gender differences among mean depression index scores. RESULTS: Fifty percent of subjects were current smokers, 21% had tried smoking, 5% were former smokers, and 24% had never smoked. Current smokers were 8 times more likely to drink alcohol compared to nonsmokers (OR = 8.0; 95% CI 3.1 - 21.2). Among current smokers, 32% were classified as regular smokers and 18% as social smokers. Sixty-three percent of regular smokers and 42% of social smokers reported smoking within 30 minutes of waking, an indicator of nicotine dependence. Patterns of smoking were variable in rate and frequency ranging from 1 to 30 cigarettes per day. Current female smokers scored higher on the modified Beck Depression Inventory (0-3) than current male smokers (p < 0.001). Oral health issues related to tobacco use, such as gum disease and tooth staining, were identified as factors that might motivate a quit attempt. Frequently reported reasons for use (eg, tension and craving) and reasons for relapse (eg, desire remained high, withdrawal symptoms) were related to nicotine dependence. Fifty-three percent of all smokers had tried to stop smoking but were unsuccessful. Intrapersonal characteristics such as risk-taking, rebellion, and impulsive spending appeared to be related to smoking. CONCLUSION: In this sample of adolescents, smoking patterns were variable and many adolescents experienced symptoms of nicotine dependence. The dental hygiene care appointment provides a unique opportunity to discuss oral health effects of smoking, relate oral changes to smoking, and to deliver a brief smoking cessation intervention.

Adolescent↗
PubMed2006

CT angiography of intracranial aneurysms related to arteriovenous malformations: a cautionary tale.

Computed tomographic angiography (CTA) has a high sensitivity and specificity for the detection of intracranial aneurysms and is increasingly used as the primary imaging modality in the investigation and pretreatment planning of patients presenting with acute subarachnoid haemorrhage. We present two cases in which CTA failed to demonstrate arteriovenous malformations associated with intracranial aneurysms.

Aged↗
PubMed2006

Pulse oximetry in very low birth weight infants: can oxygen saturation be maintained in the desired range?

OBJECTIVE: To determine if a change in the pulse oximeter goal range and high alarm limit for oxygen saturation (SpO2) alters the distribution of SpO2 for premature infants in oxygen. STUDY DESIGN: This was a prospective, observational analysis. For group 1 (February 2002 to April 2002, n = 23), pulse oximeter alarms were set at 80% (low) and 96% (high), and the goal range was 90-95%. For group 2 (May 2002 to August 2003, n = 49), the high alarm was lowered to 94%, and the goal range was 88 to 94%. The SpO2 values for 24 h were downloaded from Nellcor pulse oximeters during the two periods and the percent time within, above and below the goal range was derived and compared. RESULTS: Groups were similar except for use of post-natal steroids (group 2 > 1). The percent time within (57.7+/-9.8 vs 59.4+/-12.4%), above (15.4+/-10.6 vs 14+/-9.4%) and below (26.9+/-9.7 vs 26.6+/-10.2%) the goal range was similar for groups 1 and 2, respectively. However, the percent time with SpO2 <80% increased significantly for group 2 (4.0+/-2.7 vs 1.9+/-1.4%). CONCLUSIONS: Changes in pulse oximeter policy and alarms in labile, sick premature infants need evaluation for their effects on the distribution of SpO2 values before routine use.

Female↗
PubMed2006

Spinal deformity in a sandtiger shark, Carcharias taurus Rafinesque: a clinical-pathological study.

The present study investigated spinal deformity in a captive sandtiger shark and describes the clinical and histopathological features of the lesion. Clinically, the shark presented a marked spinal curvature in the region between the pectoral girdle and cranial dorsal fin. Radiographic studies revealed scoliosis and kyphosis of the vertebral column with a modification of the basic structure of five vertebrae. Post-mortem examination confirmed the results of radiographic studies and histological examination showed remodelling and cartilaginous proliferation of the vertebral bodies together with necrosis, haemorrhage and signs of a local chronic inflammatory response extending to the surrounding muscle. Different aetiologies are proposed and discussed but nutritional imbalance (dietary vitamin deficiency) and/or traumatic injury are considered the most likely contributing factors.

Animals↗
PubMed2006

Follow-up of basal cell carcinomas: an audit of current practice.

BACKGROUND: Follow-up of patients after treatment of basal cell carcinoma (BCC) allows for monitoring of recurrence and detection of new tumours, but adds a significant burden to outpatient clinics. At the skin tumour clinic in the dermatology department, the Royal Hospitals, Belfast, all patients are reviewed for 2 years after surgical excision of a low-risk primary BCC. OBJECTIVES: An audit was undertaken to determine the quality of data set recorded relating to prognostic factors for BCCs to determine the rate of recurrence and number of new primary tumours detected and to determine the completeness of follow-up by patients. METHOD: Patients who had primary BCCs treated by excision were identified from a database held at the clinic. Medical charts were reviewed to determine data recorded about lesions, the number of recurrent BCCs and new tumours detected, and the number of patients completing follow-up. RESULTS: Between January 1999 and December 2000, 114 patients had 121 primary BCCs excised. BCC location and size were recorded in 100% and 35% of cases, respectively. Histological type was stated for morphoeic or multifocal lesions. Two years of follow-up was completed by 53% of patients and 1 year by 78% of patients. The rate of recurrence was low, with 2 BCC recurring within 2 years of excision. The risk of developing a new BCC was 11.6% in the first year and 6.3% in the second year. CONCLUSIONS: Follow-up of patients after excision of a low-risk BCC at the clinic has been reduced to 1 year. A proforma has been developed to encourage documentation of prognostic factors.

Adolescent↗
PubMed2006

Improving the management and referral of patients with transient ischaemic attacks: a change strategy for a health community.

PROBLEM: Rapid referral and management of patients with transient ischaemic attacks is a key component in the national strategy for stroke prevention. However, patients with transient ischaemic attacks are poorly identified and undertreated. DESIGN AND SETTING: Before and after evaluation of quality improvement programme with controlled comparison in three primary care trusts reflecting diverse populations and organisational structures in an urban district in the North of England. KEY MEASURES FOR IMPROVEMENT: The proportion of patients receiving antiplatelet drugs and safe driving advice on referral to a specialty clinic, and the numbers of referrals, adjusted for age, to the specialist clinic before and after the improvement programme. STRATEGIES FOR CHANGE: Interviews with patient and professionals to identify gaps and barriers to good practice; development of evidence based guidelines for the management of patients with transient ischaemic attacks; interactive multidisciplinary workshops for each primary care trust with feedback of individual audit results of referral practice; outreach visits to teams who were unable to attend the workshops; referral templates and desktop summaries to provide reminders of the guidelines to clinicians; incorporation of standards into professional contracts. EFFECTS OF CHANGE: A significant improvement occurred in identification and referral of patients with transient ischaemic attacks to specialist clinics, with a 41% increase in referrals from trained practices compared with control practices. There were also significant improvements in the early treatment and safety advice provided to patients before referral. LESSONS LEARNT: A strategic approach to effective quality improvement across a diverse health community is feasible and achievable. Careful planning with patient and professional involvement to develop a tailored and multifaceted quality improvement programme to implement evidence based practice can work in very different primary care settings. Key components of the effectiveness of the model include contextual analysis, strong professional support, clear recommendations based on robust evidence, simplicity of adoption, good communication, and use of established networks and opinion leaders.

Communication↗
PubMed2006

Screening for patent ductus arteriosus.

The aim of our study was to look at the amount of training required to accurately assess ductal patency in very low birth weight infants and to show that this service could be provided by non-cardiologists. Training consisted of an introductory echocardiography course, a CD package, and a total of 3 hours of teaching with a paediatric cardiologist. All of this was accomplished within the 3 months preceding our study. All newborn infants less than 1500 grams or less than 30 weeks gestation had an echocardiogram performed in the first 48 hours of life. A prediction was then made based on the echocardiogram findings as to whether the arterial duct would become a clinically significant one. We based our prediction on established echocardiography criteria for the prediction of ductal patency, namely a ductal diameter of greater than 1.5 millimetres, a left atrial-to-aortic ratio of greater than 1.4, and an abnormal pattern of flow in the distal aorta. In total, 20 very low birth weight infants were screened from March 2005 to June 2005. Fifteen infants did not develop any signs of an arterial duct and this was predicted correctly in 13 cases. Of the 5 infants who developed a clinically apparent duct 4 were predicted correctly, giving us a sensitivity and specificity of 80% and 87%. Our study shows that it is possible to predict ductal patency without extensive echocardiography training. It also shows us that a neonatology based screening programme for pre-symptomatic arterial ducts in very low birth weight infants would be feasible.

Ductus Arteriosus, Patent↗
PubMed2005

Altering end-to-side anastomosis junction hemodynamics: the effects of flow-splitting.

The long-term patency rate of peripheral artery bypass grafts remains low. Several theories exist which attempt to explain the disease forming mechanisms at the disease prone distal junction of the bypass graft. Common to these theories is that abnormal hemodynamics and wall mechanics contribute to the development of disease at the junction. This study describes a means by which the hemodynamics in the end-to-side anastomosis can be altered by inserting a flow-split into the junction, the function of which is to divert the flow away from the artery bed and toward the sidewalls. Velocity vectors through the junction are significantly altered, and artery centreline WSS magnitudes decrease by up to 36% during the deceleration phase of the flow pulse. Corresponding wall shear stress gradients are found to decrease by 49%. However, locations along the artery sidewall have been identified with increased WSS. It is possible to significantly alter junction hemodynamics using a flow-splitter.

Anastomosis, Surgical↗
PubMed2005

Retrospective audit of a continuous infusion protocol for haemophilia A at a single haemophilia treatment centre.

Continuous infusion (CI) of factor concentrates has been suggested to decrease the risk of bleeding and reduce cost in the treatment of bleeding disorders. Concerns have also been raised regarding stability and sterility of products administered by CI, the risk of local thrombophlebitis and an association with the development of an inhibitor in mild haemophilia. A retrospective chart review was conducted to investigate a CI protocol regarding product use, maintenance of FVIII levels and the frequency of complications including inhibitor development. Twelve patients with haemophilia A received recombinant factor VIII by CI a total of 18 times between April 1998 and September 2003. Ages ranged from 4 months to 75 years and indications for treatment included severe bleeds and surgical prophylaxis. The protocol which was audited required a bolus of 50 U kg(-1) of FVIII followed by CI at an initial rate of 4 U kg(-1) hr(-1). All infusions were administered by i.v. infusion after diluting the reconstituted concentrate in saline. There were no documented cases of significant bleeding, adverse reactions, thrombophlebitis or infection. Two mild haemophilia A patients developed a low titre inhibitor after receiving CI. It is not clear in either case that CI was the main contributing factor. Our CI protocol will now be modified to use less product, aiming for more cost-effectiveness.

Adolescent↗
PubMed2005

Spontaneous major bleeding in acquired factor X deficiency secondary to AL-amyloidosis.

Abnormal bleeding may be seen in up to a third of patients with amyloidosis. Factor X deficiency is the commonest acquired coagulopathy in amyloidosis. While mild intracutaneous bleeding is common, spontaneous life-threatening haemorrhage is rare. We report a case of acquired FX deficiency due to amyloid light chain (AL)-amyloidosis presenting with spontaneous retroperitoneal bleeding. The diagnostic and management issues in this patient are discussed.

Aged↗
PubMed2005

3-D numerical simulation of blood flow through models of the human aorta.

A Spiral Computerized Tomography (CT) scan of the aorta were obtained from a single subject and three model variations were examined. Computational fluid dynamics modeling of all three models showed variations in the velocity contours along the aortic arch with differences in the boundary layer growth and recirculation regions. Further down-stream, all three models showed very similar velocity profiles during maximum velocity with differences occurring in the decelerating part of the pulse. Flow patterns obtained from transient 3-D computational fluid dynamics are influenced by different reconstruction methods and the pulsatility of the flow. Caution is required when analyzing models based on CT scans.

Aged↗
PubMed2005

Injection-moulded models of major and minor arteries: the variability of model wall thickness owing to casting technique.

Cardiovascular disease of major and minor arteries is a common cause of death in Western society. The wall mechanics and haemodynamics within the arteries are considered to be important factors in the disease formation process. This paper is concerned with the development of an efficient computer-integrated technique to manufacture idealized and realistic models of diseased major and minor arteries from radiological images and to address the issue of model wall thickness variability. Variations in wall thickness from the original computer models to the final castings are quantified using a CCD camera. The results found that wall thickness variation from the major and minor idealized artery models to design specification were insignificant, up to a maximum of 16 per cent. In realistic models, however, differences were up to 23 per cent in the major arterial models and 58 per cent in the minor arterial models, but the wall thickness variability remained within the limits of previously reported wall thickness results. It is concluded that the described injection moulding procedure yields idealized and realistic castings suitable for use in experimental investigations, with idealized models giving better agreement with design. Wall thickness is variable and should be assessed after the models are manufactured.

Anatomy, Cross-Sectional↗
PubMed2005

Anaplastic (undifferentiated) thyroid cancer: improved insight and therapeutic strategy into a highly aggressive disease.

BACKGROUND: This review article discusses the clinical and diagnostic implications of anaplastic thyroid cancer, recognizing the aggressive nature of the disease and extensive disease progression upon diagnosis. Standard treatment strategies (surgical, chemotherapy, radiation) are discussed, comparing adjuvant and neo-adjuvant regimens and the emergence of tumour resistance with expression of multidrug resistance pumps. We question the pathological evolution of anaplasia as a 'de novo' disease or a post malignant transformation or dedifferentiation and the therapeutic implications of p53 mutation. Future treatment options are reviewed with an emphasis on specific molecular targets responsible for the neoplastic phenotype. METHOD: An electronic search on Medline and Pubmed was performed under 'anaplastic thyroid carcinoma', 'anaplastic thyroid carcinogenesis', 'anaplastic thyroid carcinoma treatment reviews'. Relevant papers were systematically reviewed from 1965 to present.

Aged↗