Myoinositol Abnormalities in Temporal Lobe Epilepsy

Purpose: This study used magnetic resonance spectroscopy (MRS) to examine metabolite abnormalities in the temporal and frontal lobe of patients with temporal lobe epilepsy (TLE) of differing severity. Methods: We investigated myoinositol in TLE by using short-echo MRS in 34 TLE patients [26 late onset (LO-TLE), eight hippocampal sclerosis (HS-TLE)], and 16 controls. Single-voxel short-echo (35 ms) MR spectra of temporal and frontal lobes were acquired at 1.5 T and analyzed by using LCModel. Results: The temporal lobe ipsilateral to seizure origin in HS-TLE, but not LO-TLE, had reduced N-acetylaspartate (NA) and elevated myoinositol (MI; HS-TLE NA, 7.8 ± 1.9 mM, control NA, 9.2 ± 1.3 mM; p < 0.05; HS-TLE MI, 6.1 ± 1.6 mM, control mI 4.9 ± 0.8 mM, p< 0.05). Frontal lobe MI was low in both patient groups (LO-TLE, 4.3 ± 0.8 mM; p < 0.05; HS-TLE, 3.6 ±.05 mM; p < 0.001; controls, 4.8 ± 0.5 mM). Ipsilateral frontal lobes had lower MI (3.8 ± 0.7 mM; p < 0.01) than contralateral frontal lobes (4.3 ± 0.8 mM; p < 0.05). Conclusions: MI changes may distinguish between the seizure focus, where MI is increased, and areas of seizure spread where MI is decreased.

Implications of lipid biology for the pathogenesis of schizophrenia

Objective: Preclinical and clinical data suggest that lipid biology is integral to brain development and neurodegeneration. Both aspects are proposed as being important in the pathogenesis of schizophrenia. The purpose of this paper is to examine the implications of lipid biology, in particular the role of essential fatty acids (EFA), for schizophrenia. Methods: Medline databases were searched from 1966 to 2001 followed by the crosschecking of references. Results: Most studies investigating lipids in schizophrenia described reduced EFA, altered glycerophospholipids and an increased activity of a calcium-independent phospholipase A2 in blood cells and in post-mortem brain tissue. Additionally, in vivo brain phosphorus-31 Magnetic Resonance Spectroscopy (31P-MRS) demonstrated lower phosphomonoesters (implying reduced membrane precursors) in first- and multi-episode patients. In contrast, phosphodiesters were elevated mainly in first-episode patients (implying increased membrane breakdown products), whereas inconclusive results were found in chronic patients. EFA supplementation trials in chronic patient populations with residual symptoms have demonstrated conflicting results. More consistent results were observed in the early and symptomatic stages of illness, especially if EFA with a high proportion of eicosapentaenoic acid was used. Conclusion: Peripheral blood cell, brain necropsy and 31P-MRS analysis reveal a disturbed lipid biology, suggesting generalized membrane alterations in schizophrenia. 31P-MRS data suggest increased membrane turnover at illness onset and persisting membrane abnormalities in established schizophrenia. Cellular processes regulating membrane lipid metabolism are potential new targets for antipsychotic drugs and might explain the mechanism of action of treatments such as eicosapentaenoic acid.

133Cs relaxation times in rat tissues

133Cs relaxation-time studies of tissues from rats into which cesium has been incorporated by dietary loading have been carried out in vivo and in vitro. Whereas tissue T1 values are on the order of seconds, T2 values are as low as a few tens of milliseconds, 133Cs tissue relaxation times are analogous to those of 39K in the same tissues, but are more readily measured because of the greater sensitivity of 133Cs compared with 39K, T1 and T2 data of excised tissue at two resonance frequencies (65.60 and 39.37 MHz) and temperatures (302 and 278 K) have been analyzed in terms of a general description of spin- relaxation. The results are consistent with most of the cesium ions being in a free state, undergoing fast exchange with bound ions having long correlation times located in one or more intracellular compartments,

Education and training of medical physicists in south East Asia: Accomplishments and challenges

John Cameron has made significant contributions to the field of Medical Physics. His contributions encompassed research and development, technical developments and education. He had a particular interest in the education of medical physicists in developing countries. Structured clinical training is also an essential component of the professional development of a medical physicist. This paper considers aspects of the clinical training and education of medical physicists in South-East Asia and the challenges facing the profession in the region if it is to keep pace with the rapid increase in the amount and technical complexity of medical physics infrastructure in the region.

Three-dimensional medical ultrasound

A number of groups around the world are working in the field of three dimensional(3D) ultrasound (US) in order to obtain higher quality diagnostic information. 3D US, in general, involves collecting a sequence of conventional 2D US images along with information on the position and orientation of each image plane. A transformation matrix is calculated relating image space to real world space. This allows image pixels and region of interest (ROI) points drawn on the image to be displayed in 3D. The 3D data can be used for the production of volume or surface rendered images, or for the direct calculation of ROI volumes.

Evaluation of coronary angiographic projections to balance the clinical yield with the radiation risk

Objective: Radiation safety principles dictate that imaging procedures should minimise the radiation risks involved, without compromising diagnostic performance. This study aims to define a core set of views that maximises clinical information yield for minimum radiation risk. Angiographers would supplement these views as clinically indicated. Methods: An algorithm was developed to combine published data detailing the quality of information derived for the major coronary artery segments through the use of a common set of views in angiography with data relating to the dose–area product and scatter radiation associated with these views. Results: The optimum view set for the left coronary system comprised four views: left anterior oblique (LAO) with cranial (Cr) tilt, shallow right anterior oblique (AP-RAO) with caudal (Ca) tilt, RAO with Ca tilt and AP-RAO with Cr tilt. For the right coronary system three views were identified: LAO with Cr tilt, RAO and AP-RAO with Cr tilt. An alternative left coronary view set including a left lateral achieved minimally superior efficiency (,5%), but with an ,8% higher radiation dose to the patient and 40% higher cardiologist dose. Conclusion: This algorithm identifies a core set of angiographic views that optimises the information yield and minimises radiation risk. This basic data set would be supplemented by additional clinically determined views selected by the angiographer for each case. The decision to use additional views for diagnostic angiography and interventions would be assisted by referencing a table of relative radiation doses for the views being considered.

Morphometry and abnormalities of the feet of Kaimanawa feral horses in New Zealand

Objective: The present study investigated the foot health of the Kaimanawa feral horse population and tested the hypotheses that horses would have a large range of foot morphology and that the incidence of foot abnormality would be significantly high. Procedures: Abnormality was defined as a variation from what the two veterinarian assessors considered as optimal morphology and which was considered to impact negatively on the structure and/or function of the foot. Fifteen morphometric variables were measured on four calibrated photographic views of all four feet of 20 adult Kaimanawa feral horses. Four morphometric variables were measured from the lateromedial radiographs of the left forefoot of each horse. In addition, the study identified the incidence of gross abnormality observed on the photographs and radiographs of all 80 feet. Results: There was a large variation between horses in the morphometric dimensions, indicating an inconsistent foot type. Mean hoof variables were outside the normal range recommended by veterinarians and hoof care providers; 35% of all feet had a long toe conformation and 15% had a mediolateral imbalance. Abnormalities included lateral (85% of horses) and dorsal (90% of horses) wall flares, presence of laminar rings (80% of horses) and bull-nose tip of the distal phalanx (75% of horses). Both hypotheses were therefore accepted. Conclusions: The Kaimanawa feral horse population demonstrated a broad range of foot abnormalities and we propose that one reason for the questionable foot health and conformation is lack of abrasive wearing by the environment. In comparison with other feral horse populations in Australia and America there may be less pressure on the natural selection of the foot of the Kaimanawa horses by the forgiving environment of the Kaimanawa Ranges. Contrary to popular belief, the feral horse foot type should not be used as an ideal model for the domestic horse foot.

Autologous vs. allogenic mesenchymal progenitor cells for the reconstruction of critical-sized segmental tibial bone defects in aged sheep

Mesenchymal progenitor cells (MPCs) represent an attractive cell population for bone tissue engineering. Their special immunological characteristics suggest that MPCs may be used in an allogenic application. The objective of this study was to compare the regenerative potential of autologous vs. allogenic MPCs in an ovine critical-sized segmental defect model. Ovine MPCs were isolated from bone marrow aspirates, expanded and cultured with osteogenic media for two weeks before implantation. Autologous and allogenic transplantation was performed by using the cell-seeded scaffolds, unloaded scaffolds and the application of autologous bone grafts served as control groups (n=6). Bone healing was assessed twelve weeks after surgery by radiology, micro computed tomography, biomechanical testing and histology. Radiology, biomechanical testing and histology revealed no significant difference in bone formation between the autologous and allogenic group. Both cell groups showed more bone formation than the scaffold alone, whereas the biomechanical data showed no significant differences between the cell-groups and the unloaded scaffolds. The results of the study suggest that scaffold based bone tissue engineering using allogenic cells offers the potential for an off the shelf product. Therefore, the results of this study serve as an important baseline for the translation of the assessed concepts into clinical application.

Radiographic projections for acute shoulder trauma: A review of current practice

A review of radiographers was undertaken to determine the specific projections currently performed for patients with acute presentation for shoulder trauma. Radiographers were asked to indicate projections they would perform for specific patient presentations. This poster presents a snapshot of the diversity of projections performed and a review of the current evidence of the most appropriate projections

Non-acute shoulder imaging: Which projections do we really need?

While Magentic Resonance Imaging and Ultrasound are used extensively for non-acute shoulder imaging, plain images are regularly required as a first investigation. This paper presents a snapshot of the diversity of projections performed and a review of the current evidence of the most appropriate projections. The projections recommended are suitable as a first investigation, and also to complement more advanced imaging.

Validation and consistency in the application of a trauma team activation system at a level 1 trauma centre

- The RAH was activated over 2500 trauma calls in 2009. This figure is over twice the number of calls put out by similar services. - Many trauma calls (in particular L2 trauma calls) from the existing system do not warrant activation of the trauma team - Sometimes trauma calls are activated for nontrauma reasons (eg rapid access to radiology, departmental pressures etc) - The excess of trauma calls has several deleterious effects particularly on time management for the trauma service staff: ward rounds/tertiary survey rounds, education, quality improvement, research

Nurse-administered procedural sedation and analgesia in the cardiac catheterisation laboratory : a mixed methods study

The cardiac catheterisation laboratory (CCL) is a specialised medical radiology facility where both chronic-stable and life-threatening cardiovascular illness is evaluated and treated. Although there are many potential sources of discomfort and distress associated with procedures performed in the CCL, a general anaesthetic is not usually required. For this reason, an anaesthetist is not routinely assigned to the CCL. Instead, to manage pain, discomfort and anxiety during the procedure, nurses administer a combination of sedative and analgesic medications according to direction from the cardiologist performing the procedure. This practice is referred to as nurse-administered procedural sedation and analgesia (PSA). While anecdotal evidence suggested that nurse-administered PSA was commonly used in the CCL, it was clear from the limited information available that current nurse-led PSA administration and monitoring practices varied and that there was contention around some aspects of practice including the type of medications that were suitable to be used and the depth of sedation that could be safely induced without an anaesthetist present. The overall aim of the program of research presented in this thesis was to establish an evidence base for nurse-led sedation practices in the CCL context. A sequential mixed methods design was used over three phases. The objective of the first phase was to appraise the existing evidence for nurse-administered PSA in the CCL. Two studies were conducted. The first study was an integrative review of empirical research studies and clinical practice guidelines focused on nurse-administered PSA in the CCL as well as in other similar procedural settings. This was the first review to systematically appraise the available evidence supporting the use of nurse-administered PSA in the CCL. A major finding was that, overall, nurse-administered PSA in the CCL was generally deemed to be safe. However, it was concluded from the analysis of the studies and the guidelines that were included in the review, that the management of sedation in the CCL was impacted by a variety of contextual factors including local hospital policy, workforce constraints and cardiologists’ preferences for the type of sedation used. The second study in the first phase was conducted to identify a sedation scale that could be used to monitor level of sedation during nurse-administered PSA in the CCL. It involved a structured literature review and psychometric analysis of scale properties. However, only one scale was found that was developed specifically for the CCL, which had not undergone psychometric testing. Several weaknesses were identified in its item structure. Other sedation scales that were identified were developed for the ICU. Although these scales have demonstrated validity and reliability in the ICU, weaknesses in their item structure precluded their use in the CCL. As findings indicated that no existing sedation scale should be applied to practice in the CCL, recommendations for the development and psychometric testing of a new sedation scale were developed. The objective of the second phase of the program of research was to explore current practice. Three studies were conducted in this phase using both quantitative and qualitative research methods. The first was a qualitative explorative study of nurses’ perceptions of the issues and challenges associated with nurse-administered PSA in the CCL. Major themes emerged from analysis of the qualitative data regarding the lack of access to anaesthetists, the limitations of sedative medications, the barriers to effective patient monitoring and the impact that the increasing complexity of procedures has on patients' sedation requirements. The second study in Phase Two was a cross-sectional survey of nurse-administered PSA practice in Australian and New Zealand CCLs. This was the first study to quantify the frequency that nurse-administered PSA was used in the CCL setting and to characterise associated nursing practices. It was found that nearly all CCLs utilise nurse-administered PSA (94%). Of note, by characterising nurse-administered PSA in Australian and New Zealand CCLs, several strategies to improve practice, such as setting up protocols for patient monitoring and establishing comprehensive PSA education for CCL nurses, were identified. The third study in Phase Two was a matched case-control study of risk factors for impaired respiratory function during nurse-administered PSA in the CCL setting. Patients with acute illness were found to be nearly twice as likely to experience impaired respiratory function during nurse-administered PSA (OR=1.78; 95%CI=1.19-2.67; p=0.005). These significant findings can now be used to inform prospective studies investigating the effectiveness of interventions for impaired respiratory function during nurse-administered PSA in the CCL. The objective of the third and final phase of the program of research was to develop recommendations for practice. To achieve this objective, a synthesis of findings from the previous phases of the program of research informed a modified Delphi study, which was conducted to develop a set of clinical practice guidelines for nurse-administered PSA in the CCL. The clinical practice guidelines that were developed set current best practice standards for pre-procedural patient assessment and risk screening practices as well as the intra and post-procedural patient monitoring practices that nurses who administer PSA in the CCL should undertake in order to deliver safe, evidence-based and consistent care to the many patients who undergo procedures in this setting. In summary, the mixed methods approach that was used clearly enabled the research objectives to be comprehensively addressed in an informed sequential manner, and, as a consequence, this thesis has generated a substantial amount of new knowledge to inform and support nurse-led sedation practice in the CCL context. However, a limitation of the research to note is that the comprehensive appraisal of the evidence conducted, combined with the guideline development process, highlighted that there were numerous deficiencies in the evidence base. As such, rather than being based on high-level evidence, many of the recommendations for practice were produced by consensus. For this reason, further research is required in order to ascertain which specific practices result in the most optimal patient and health service outcomes. Therefore, along with necessary guideline implementation and evaluation projects, post-doctoral research is planned to follow up on the research gaps identified, which are planned to form part of a continuing program of research in this field.