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S Pearson

Publications and source records attributed to S Pearson.

At least 19 recordsLinked to original sources
PubMed2006

Wavelet-based feature extraction applied to small-angle x-ray scattering patterns from breast tissue: a tool for differentiating between tissue types.

This paper reports on the application of wavelet decomposition to small-angle x-ray scattering (SAXS) patterns from human breast tissue produced by a synchrotron source. The pixel intensities of SAXS patterns of normal, benign and malignant tissue types were transformed into wavelet coefficients. Statistical analysis found significant differences between the wavelet coefficients describing the patterns produced by different tissue types. These differences were then correlated with position in the image and have been linked to the supra-molecular structural changes that occur in breast tissue in the presence of disease. Specifically, results indicate that there are significant differences between healthy and diseased tissues in the wavelet coefficients that describe the peaks produced by the axial d-spacing of collagen. These differences suggest that a useful classification tool could be based upon the spectral information within the axial peaks.

Algorithms↗
PubMed2004

Inhibitor development in patients receiving recombinant factor VIII (Recombinate rAHF/Bioclate): a prospective pharmacovigilance study.

Clinical trials to date have not been adequately powered to assess comparatively infrequent events such as inhibitor development in previously treated patients (PTPs). Comprehensive large-scale pharmacovigilance studies can be useful for this purpose. We prospectively collected inhibitor development reports worldwide among recipients of Recombinate rAHF recombinant factor VIII (rFVIII), also formerly distributed under the product name Bioclate, for the entire postlicensure period from 1993 through 2002. To determine level of exposure to rFVIII we also compiled the Recombinate rAHF/Bioclate International Units (IU) distributed annually. To estimate inhibitor incidence separately for previously untreated or minimally treated patients (PUPs) with 1-50 exposure days and PTPs with >50 exposure days, we used haemophilia A incidence and prevalence data and pooled mean annual rFVIII consumption per PUP and PTP from international multicentre prospective clinical trials. Documented inhibitor cases totalled 89, and the total quantity of Recombinate rAHF/Bioclate rFVIII distributed was 6.48 x10(9) IU. No lot association or other clustering of inhibitor events was evident in PTPs. The incidence of all reported inhibitors, expressed as a percentage of patients treated, was 11.9% (CI: 5.05-28.0%) for PUPs when compared with 0.123% (CI: 0.030-0.512%) for PTPs. The rates for high-titre inhibitors (>5 BU) only were 5.96% (CI: 3.00-11.8%) for PUPs and 0.0554% (CI: 0.0113-0.271%) for PTPs. Thus, incidence rates for both all inhibitors and high-titre inhibitors in PTPs were 1% of the corresponding rates in PUPs. Data from prospective PUP clinical trials involving intensive active monitoring suggest that true inhibitor incidence may be approximately twice that estimated in this pharmacovigilance study. Nevertheless, inhibitor development in PTPs receiving Recombinate rAHF/Bioclate is infrequent.

Adolescent↗
PubMed2003

Management of atrial fibrillation in the emergency department.

Abstract Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is a frequent cause for presentation to the emergency department. With an understanding of the pathophysiology and types of AF, efficient and effective management strategies for AF can be formulated. Patients with paroxysmal AF will often revert spontaneously and can initially be managed on an outpatient basis, unless an antiarrhythmic is commenced. In patients with AF and severe underlying heart disease, the management is primarily directed at the underlying heart disease, supplemented with rate-controlling measures, and prevention of thromboembolic complications. In patients with persistent AF good rate control, early cardioversion and initiation of an antiarrhythmic are likely to reduce the risk of recurrence.

Anti-Arrhythmia Agents↗
PubMed2002

The effect of a separate stream for minor injuries on accident and emergency department waiting times.

INTRODUCTION: To decrease waiting times within accident and emergency (A&E) departments, various initiatives have been suggested including the use of a separate stream of care for minor injuries ("fast track"). This study aimed to assess whether a separate stream of minor injuries care in a UK A&E department decreases the waiting time, without delaying the care of those with more serious injury. INTERVENTION: A doctor saw any ambulant patients with injuries not requiring an examination couch or an urgent intervention. Any patients requiring further treatment were returned to the sub-wait area until a nurse could see them in another cubicle. METHOD: Data were retrospectively extracted from the routine hospital information systems for all patients attending the A&E department for five weeks before the institution of the separate stream system and for five weeks after. RESULTS: 13 918 new patients were seen during the 10 week study period; 7117 (51.1%) in the first five week period and 6801 (49.9%) in the second five week period when a separate stream was operational. Recorded time to see a doctor ranged from 0-850 minutes. Comparison of the two five week periods demonstrated that the proportion of patients waiting less than 30 and less than 60 minutes both improved (p<0.0001). The relative risk of waiting more than one hour decreased by 32%. The improvements in waiting times were not at the expense of patients with more urgent needs. CONCLUSIONS: The introduction of a separate stream for minor injuries can produce an improvement in the number of trauma patients waiting over an hour of about 30%. If this is associated with an increase in consultant presence on the shop floor it may be possible to achieve a 50% improvement. It is recommended that departments use a separate stream for minor injuries to decrease the number of patients enduring long waits in A&E departments.

Appointments and Schedules↗
PubMed2002

Chlamydia trachomatis infection and non-gonococcal urethritis in homosexual and heterosexual men in Edinburgh.

In 1998, when ligase chain reaction testing for chlamydial infection was introduced in our clinic in Edinburgh, routine clinic protocol included the testing of all heterosexual, but not homosexual, men for urethral chlamydial infection. We audited all new homosexual and bisexual male attendees with a diagnosis of chlamydial infection or non-gonococcal urethritis (NGU) in 1999, together with heterosexual men with the same diagnoses attending in alternate months of the same year. Urethral Chlamydia trachomatis infection was detected in 14.6% (350/2402) of heterosexual men and 2.4% (11/465) of homosexual men tested. Fifty percent of chlamydial infections were asymptomatic. In this population 44% (84/190) of NGU in heterosexual men is attributable to C. trachomatis as opposed to only 10% (6/59) of that in homosexual men. These rates of chlamydial infection differ from previous reports in Scotland and recent studies from the USA. Our clinic protocol has been revised to include routine testing for chlamydial infection in all men.

Ambulatory Care↗
PubMed2001

'Real life' clinical learning on an interprofessional training ward.

This paper describes the multi-method evaluation of an interprofessional training ward placement for medical, nursing, occupational therapy and physiotherapy students. Unique in the UK, and an extension of pioneering work in Sweden (Wahlström et al. 1997, Wahlstroöm & Sandén 1998), this interprofessional clinical placement allowed senior pre-qualifying students, under the supervision of practitioners, to plan and deliver interprofessional care for a group of orthopaedic and rheumatology patients. This responsibility enabled students to develop both their profession-specific skills in a real-world setting and the quality of their interprofessional teamwork. Student teams were supported by facilitators who led reflective sessions and acted as a resource for the students' problem-based learning. The training ward was evaluated by a multi-method approach, incorporating interviews, observations and questionnaires with students, patients and clinical staff. The evaluation findings have been grouped into a number of themes which offer an insight into the varying perspectives of training ward students, patients and staff. This paper pays particular attention to the nursing perspective of the interprofessional training ward pilot.

Education, Nursing↗
PubMed2001

Identifying medical school learning needs: a survey of Australian interns.

OBJECTIVES: To survey interns regarding their opinion of medical school learning needs for a range of core skills. METHODS: A random sample of interns practising in New South Wales, Australia, who graduated from the state's three medical schools were surveyed two-thirds of the way through their first hospital year. They were asked whether there was a need for further medical school education for each of 226 core skills. Skills were grouped into five themes: management of clinical conditions; clinical investigations; clinical procedures; core practice; and professional development. RESULTS: Frequency distributions weighted for age, gender and medical school background were calculated for each item. The 20 most frequently identified needs related to examinations of the eye and ear, nose and throat; managing uncooperative patients and difficult patient interactions; prescribing; writing not for resuscitation orders and death certificates. Also included were procedural needs related to ear, nose and throat; plastering and wound management; and needs for more education in the management of clinical conditions related predominantly to "acute" cases such as anaphylaxis and diabetic ketoacidosis. CONCLUSION: Interns were able to discriminate between their needs for different skills and identified many core skills for which they perceived there was a need for more medical school education. The implications for medical education are discussed.

Journal Article↗
PubMed2001

Improving quantitative flowering models through a better understanding of the phases of photoperiod sensitivity.

A quantitative understanding of the phases of sensitivity to photo-thermal environment is important if the accuracy of flowering models is to be improved and if the timing of long and short day treatments in protected cropping is to be optimized. A simple method of quantifying the duration of the phases of sensitivity to photoperiod is through the use of reciprocal transfer experiments where plants are transferred between long and short days at regular intervals throughout development. The advantages and disadvantages of different analytical approaches used to analyse such data sets are examined. Inconsistencies between the approaches are highlighted, as are differences in the way authors have interpreted data. The problem of confounding the effects of photoperiod and light integral is considered, as is the need to separate the number of inductive cycles needed for flower commitment from the length of the juvenile phase. The effects of photo-thermal environment on the duration of these phases of photoperiod sensitivity are discussed, together with topics requiring further development.

Magnoliopsida↗
PubMed2001

Educating students with TBI: themes and recommendations.

Ten educational consultants and researchers, each with extensive experience working with children with traumatic brain injury (TBI) in school settings, identified seven themes related to serving this population in public schools. These themes are discussed under the headings (1) incidence of TBI and prevalence of persistent educational disability, (2) diversity and central tendencies within the population, (3) assessment, (4) intervention and support in school settings, (5) training and support for educators, (6) intervention and support for families, and (7) systems change and flexibility. For each theme, a set of recommendations is provided, forming an educational research and policy agenda for pediatric TBI.

Adolescent↗
PubMed2001

Outcomes of patients using a tiered trauma response protocol.

OBJECTIVES: This study evaluated processes of care and outcome for injured patients at a Level I trauma center who had been either treated as a full trauma team activation (FULL) or managed with a modified trauma team activation (MOD). METHODS: A retrospective methodology was used to evaluate all patients entered into the regional trauma system and transported from the scene to a Level I trauma center. Patients treated during a 2-year period of exclusively FULL trauma team protocols were compared with patients managed during a subsequent 2-year period after implementation of a two-tiered response. In the later era, trauma system patients were designated before hospital arrival as either FULL or MOD trauma team responses. An additional case-control analysis was conducted on a subset of MOD trauma team response patients who were undertriaged; that is, in retrospect, they met criteria for a FULL response. The outcomes in the case-control group were compared by chi2 tests and Mann-Whitney U tests. Statistical significance was assumed for p < 0.05. RESULTS: During the presystem period, 1,740 patients were transported as trauma system entries to Oregon Health Sciences University. During the postsystem period, 2,333 patients were transported to Oregon Health Sciences University as either MOD trauma system entries (1,272 [55%]) or as FULL trauma system entries (1,061 [45%]). Postsystem patients had longer time intervals in the emergency department compared with presystem patients. Death rates for patients who died in the emergency department or before hospital discharge were similar. Among patients who were designated as MOD trauma system entries and were subsequently categorized as meeting FULL trauma team criteria, mortality rate was low. CONCLUSION: Implementation of the tiered response protocol led to a substantial change in the operational response in the emergency department. Although processes of care were nominally prolonged, adverse consequences were not identified. We concluded from this quality improvement review that implementation of a tiered response protocol was satisfactory and improved efficiency. Further work is required to improve accuracy of the categorization of trauma system patients as either MOD or FULL trauma codes.

Adult↗
PubMed2001

After hospital: working with schools and families to support the long term needs of children with brain injuries.

Medical and rehabilitation systems care for children who sustain brain injuries. Their much needed services, however, are short in comparison with the long term needs of these children and their families. For the most part, it is schools and families who provide the long term supports to help children make the best outcomes and create a better quality of life. Professionals and families who develop collaborative models find that they can more effectively manage services for these children by carefully crafting Individual Education Plans (IEP's). Through the IEP process students' complex needs; the multiple transitions they experience; and their long term needs can be met.

Brain Injuries↗
PubMed2000

Crystal structure of the IMP-1 metallo beta-lactamase from Pseudomonas aeruginosa and its complex with a mercaptocarboxylate inhibitor: binding determinants of a potent, broad-spectrum inhibitor.

Metallo beta-lactamase enzymes confer antibiotic resistance to bacteria by catalyzing the hydrolysis of beta-lactam antibiotics. This relatively new form of resistance is spreading unchallenged as there is a current lack of potent and selective inhibitors of metallo beta-lactamases. Reported here are the crystal structures of the native IMP-1 metallo beta-lactamase from Pseudomonas aeruginosa and its complex with a mercaptocarboxylate inhibitor, 2-[5-(1-tetrazolylmethyl)thien-3-yl]-N-[2-(mercaptomethyl)-4 -(phenylb utyrylglycine)]. The structures were determined by molecular replacement, and refined to 3.1 A (native) and 2.0 A (complex) resolution. Binding of the inhibitor in the active site induces a conformational change that results in closing of the flap and transforms the active site groove into a tunnel-shaped cavity enclosing 83% of the solvent accessible surface area of the inhibitor. The inhibitor binds in the active site through interactions with residues that are conserved among metallo beta-lactamases; the inhibitor's carboxylate group interacts with Lys161, and the main chain amide nitrogen of Asn167. In the "oxyanion hole", the amide carbonyl oxygen of the inhibitor interacts through a water molecule with the side chain of Asn167, the inhibitor's thiolate bridges the two Zn(II) ions in the active site displacing the bridging water, and the phenylbutyryl side chain binds in a hydrophobic pocket (S1) at the base of the flap. The flap is displaced 2.9 A compared to the unbound structure, allowing Trp28 to interact edge-to-face with the inhibitor's thiophene ring. The similarities between this inhibitor and the beta-lactam substrates suggest a mode of substrate binding and the role of the conserved residues in the active site. It appears that the metallo beta-lactamases bind their substrates by establishing a subset of binding interactions near the catalytic center with conserved characteristic chemical groups of the beta-lactam substrates. These interactions are complemented by additional nonspecific binding between the more variable groups in the substrates and the flexible flap. This unique mode of binding of the mercaptocarboxylate inhibitor in the enzyme active site provides a binding model for metallo beta-lactamase inhibition with utility for future drug design.

Binding Sites↗
PubMed2000

Pressurised liquid extraction of pentachlorophenol from dyestuffs and cotton.

Pressurised liquid extraction (PLE) was used to extract pentachlorophenol from cotton and dyestuffs. Five dyes and one dyed cotton were investigated for pentachlorophenol. The dyed cotton was found to have between 5.3 and 5.9 microg g(-1) pentachlorophenol, while the dyes were found to have between 42 and 2569 microg g(-1) pentachlorophenol present. The latter were found to be dye and manufacturing site dependant. Recovery experiments, in all cases, were found to be quantitative indicating appropriate sample work-up and manipulations.

Coloring Agents↗
PubMed2000

Ultrasound criteria in the diagnosis of polycystic ovary syndrome (PCOS).

Not all women with the polycystic ovary syndrome (PCOS) on ultrasound (US) will have the syndrome, and clinical and biochemical features of PCOS may be present without US features. The sensitivity of US in detecting PCOS was, therefore, prospectively determined in 72 women (32 PCOS and 40 controls). The most sensitive features were the presence of 10 or more follicles (82% and 69% in the left and right ovary) and a peripheral distribution of follicles (81.8% and 71.9% in the left and right ovary). Although ovarian enlargement and stromal brightness were not as sensitive as the previous criteria, stromal brightness was most specific. Combining all the criteria predicted a diagnosis of PCOS or control correctly in 86.4% of cases. This study shows that established US criteria of polycystic ovaries remain of value in the diagnosis of PCOS; however, the discrepancy between the left and right ovaries is an interesting but unexplained finding.

Female↗
PubMed2000

A transient assay for regulatory gene function in haemopoietic progenitor cells.

This work aimed to provide a means of assaying directly the effects of transient expression of introduced genes on the survival, proliferation, lineage commitment and differentiation of haemopoietic progenitor cells. For this purpose, we have developed a system that allows isolation of productively transfected, mulitipotent haemopoietic cells within a few hours of the introduction of test genes. We have shown that FDCP-mix cells productively transfected with expression plasmids encoding green fluorescent protein (GFP) differentiate normally and retain colony-forming potential. We constructed an expression vector consisting of a bicistronic cassette in which a GFP marker gene and a test gene are driven from the same promoter. The vector design has been optimized for co-expression and the test gene was shown to be biologically active. The expression profile from a transiently transfected template under different growth conditions reveals that active expression continues for at least 2 d after transfection. The transient transfection of FDCP-mix cells with the vectors described provides a powerful tool for analysis of the immediate early effects of test gene overexpression during haemopoietic differentiation.

Animals↗
PubMed2000

Clinical pathway management of total knee arthroplasty: a retrospective comparative study.

BACKGROUND: Clinical pathways facilitate the management of defined patient groups using interdisciplinary plans of care. The aim of the present study was to evaluate the effectiveness of a clinical pathway in improving a range of selected outcome measures in patients who have undergone total knee arthroplasty (TKA). METHODS: The present study was conducted at Queen Elizabeth Hospital, Adelaide. Using a retrospective comparative study design, 119 TKA patients who were managed on a clinical pathway from July 1997 to January 1998 (group 2) were compared with a retrospective group of 58 patients who underwent the same procedure from July 1996 to January 1997 (group 1) prior to the pathway's implementation. The following outcomes were measured: length of hospital stay; postoperative complications; readmissions and emergency service visits within 6 months of discharge; day of transfer to the convalescent unit; convalescent unit utilization and admission and discharge times. RESULTS: There was a significant reduction in the median length of stay in group 2 patients (9 vs 7 days; P < 0.0001). In addition there was a 66% increase in the proportion of patients in group 2 who were admitted on the day of surgery (P < 0.0001) and a 19.6% increase in the number of patients discharged within 8 postoperative days (P < 0.01). There were no significant differences between the groups with respect to the occurrence of postoperative complications. Although there was a trend toward a reduction in emergency service utilization and readmissions within 6 months of discharge for patients managed on the pathway, this was not significant. CONCLUSIONS: The development and implementation of a TKA clinical pathway resulted in a significant reduction in length of stay and improved streamlining of admission, discharge and transfer processes without adversely affecting patient outcomes.

Aged↗