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Biomedical subjects

M Elliott

Publications and source records attributed to M Elliott.

At least 19 recordsLinked to original sources

Marine monitoring: Its shortcomings and mismatch with the EU Water Framework Directive's objectives.

The main goal of the EU Water Framework Directive (WFD) is to achieve good ecological status across European surface waters by 2015 and as such, it offers the opportunity and thus the challenge to improve the protection of our coastal systems. It is the main example for Europe's increasing desire to conserve aquatic ecosystems. Ironically, since c. 1975 the increasing adoption of EU directives has been accompanied by a decreasing interest of, for example, the Dutch government to assess the quality of its coastal and marine ecosystems. The surveillance and monitoring started in NL in 1971 has declined since the 1980s resulting in a 35% reduction of sampling stations. Given this and interruptions the remaining data series is considered to be insufficient for purposes other than trend analysis and compliance. The Dutch marine managers have apparently chosen a minimal (cost-effective) approach despite the WFD implicitly requiring the incorporation of the system's 'ecological complexity' in indices used to evaluate the ecological status of highly variable systems such as transitional and coastal waters. These indices should include both the community structure and system functioning and to make this really cost-effective a new monitoring strategy is required with a tailor-made programme. Since the adoption of the WFD in 2000 and the launching of the European Marine Strategy in 2002 (and the recently proposed Marine Framework Directive) we suggest reviewing national monitoring programmes in order to integrate water quality monitoring and biological monitoring and change from 'station oriented monitoring' to 'basin or system oriented monitoring' in combination with specific 'cause-effect' studies for highly dynamic coastal systems. Progress will be made if the collected information is integrated and aggregated in valuable tools such as structure- and functioning-oriented computer simulation models and Decision Support Systems. The development of ecological indices integrating community structure and system functioning, such as in Ecological Network Analysis, are proposed to meet a cost-effective approach at the national level and full assessment of the ecosystem status at the EU level. The WFD offers the opportunity to re-consider and re-invest in environmental research and monitoring. Using examples from the Netherlands and, to a lesser extent, the United Kingdom, the present paper therefore reviews marine monitoring and marine environmental research in combination and in the light of such major policy initiatives such as the WFD.

Animals↗

Protecting young workers in agriculture: participation in tractor certification training.

Tractor-related injuries among youth are an important public health problem. The major objectives of this study were to (1) provide a rigorous estimate of the number of youth operating tractors in Ohio and (2) assess the extent to which these youth are participating in federally mandated tractor safety training. A self-administered questionnaire was completed by approximately 4,000 students ages 14 or 15 years who were enrolled in a stratified cluster sample of 99 Ohio schools. Almost one-third of the youth (30%) reported having operated tractors, with 19% having operated a tractor on a farm not owned by a parent or guardian. More than half of the youth (52%) reported having operated a tractor and/or other hazardous machinery, with 25% having operated the machinery on a farm not owned or operated by a parent or guardian. Extrapolating from 4-H records and Ohio census data, fewer than 1% of the youth who are operating tractors or other hazardous machinery have participated in tractor certification training. Increasing participation in mandated training may be an important step in protecting the health of our nation's young agricultural workers.

Accidents, Occupational↗

"Virtual unwrapping" of a mummified hand.

The purpose of this work is to demonstrate the feasibility of medical virtual reality technologies in the investigation of a mummified hand. The Ulster Museum obtained the mummy hand, which originated from Thebes, without any identifying information. The mummified hand was investigated using conventional X-ray and 3D multi-slice Computed Tomography (CT). Imaging revealed a range of fractures of the wrist, metacarpals and phalanges whilst 3D CT demonstrated internal structures using volume rendering. The absence of any features of bone healing at the fracture sites would imply that they occurred just prior to death or in the mummified state possibly during excavation. Conventional X-ray imaging indicated that the hand, although small, was likely to have originated from an adult. Medical imaging and virtual reality display will enable us to produce a rapid prototyped model using fused deposition technology. Therefore, further paleopathological research can be performed on the replica without the need to handle the original specimen.

Computer Simulation↗

The use of environmental integrative indicators to assess seabed disturbance in estuaries and coasts: Application to the Humber Estuary, UK.

The coastal zone is subject to many and varied changes resulting from human activities and natural processes. Existing or emerging agreements and legislation acknowledge the relevance of indicators for monitoring these. In the UK, following a series of recent workshops, potential indicators of nearshore disturbance have been identified and grouped into three broad indices: 'Coastline Morphological Change', 'Resource Use Change' and 'Environmental Quality and its Perception'. The present study developed these indicators further and tested their use by applying them to 18 sections in the Humber Estuary, Eastern England. The results obtained reflect the current knowledge of the state of the Humber environment and show the potential of integrative indicators but indicate that further studies are required to assess the relative importance of the indicators and their value in reflecting the ability of the ecosystems to sustain natural habitats and populations at a good conservation status.

Animals↗

Carotid artery occlusion in association with a retropharyngeal abscess.

Deep neck space infections in children are not an uncommon presentation to an otolaryngologist and with appropriate antibiotic therapy, often in conjunction with surgical drainage, complications are rare. We report on a case of a 4-year boy who presented with a retropharyngeal abscess that was complicated by ipsilateral carotid artery and internal jugular vein compression. The patient was treated with intravenous broad-spectrum antibiotics and heparin. There were no subsequent neurological or vascular complications. An overview of the management of deep neck infections and their complications are discussed.

Carotid Artery Diseases↗

Oscillations in NF-kappaB signaling control the dynamics of gene expression.

Signaling by the transcription factor nuclear factor kappa B (NF-kappaB) involves its release from inhibitor kappa B (IkappaB) in the cytosol, followed by translocation into the nucleus. NF-kappaB regulation of IkappaBalpha transcription represents a delayed negative feedback loop that drives oscillations in NF-kappaB translocation. Single-cell time-lapse imaging and computational modeling of NF-kappaB (RelA) localization showed asynchronous oscillations following cell stimulation that decreased in frequency with increased IkappaBalpha transcription. Transcription of target genes depended on oscillation persistence, involving cycles of RelA phosphorylation and dephosphorylation. The functional consequences of NF-kappaB signaling may thus depend on number, period, and amplitude of oscillations.

Active Transport, Cell Nucleus↗

Anthropogenic regulation of the phosphorus balance in the Thau catchment-coastal lagoon system (Mediterraean Sea, France) over 24 years.

In the Thau lagoon, despite there being no phosphate limitation policy, the annual mean phosphate concentrations decreased by 90% between 1971 and 1994. The present study indicates a relationship between the decrease of phosphate concentrations and changes in urban, industrial and agricultural activities within the catchment generating phosphorus (P) inputs; and shellfish farming leading to phosphorus storage and export. The relationship (tonnes of P) is: P-PO(4)(3-) in the lagoon waters=1.0124 anthropogenic phosphorus balance--47.62 (r(2) = 0.824, p < 0.000). As population growth is expected in coastal zones, sustainable development requires the need for addressing the role played by human activities and the multi-scale regulation of them. As an element of integrated coastal zone management, the present study provides a regional scale analysis of these aspects.

Agrochemicals↗

A pilot study of evaluation of cerebral function by S100beta protein and near-infrared spectroscopy during cold and warm cardiopulmonary bypass in infants and children undergoing open-heart surgery.

Cerebral injury in children undergoing cardiopulmonary bypass (CPB) remains a major source of morbidity. The effect of cardiopulmonary bypass temperature on cerebral function in terms of serum S100beta protein level and cerebral oxygenation monitored by near infrared spectroscopy (NIRO-300) in children is not known. In this study, 18 children undergoing open-heart surgery at the Hospital for Sick Children in London were equally assigned by minimisation to warm (35 +/- 1 degrees C) or cold (25 +/- 1 degrees C) CPB. Changes in S100beta protein and cerebral oxygenation were studied in both groups. S100beta protein serum level increased significantly after CPB in both groups. There was no significant difference in serum S100beta protein concentrations between the two groups. However, cerebral oxygenation in terms of tissue oxygen index (TOI) was significantly impaired during rewarming from cold CPB. Five patients were desaturated (TOI < 50%) during rewarming in the cold bypass group compared to two in the warm patients. This study supports the use of warm CPB in children undergoing open-heart surgery, although further studies recruiting more patients are warranted.

Biomarkers↗

Cardiac ECMO for biventricular hearts after paediatric open heart surgery.

OBJECTIVE: To delineate predictors of hospital survival in a large series of children with biventricular physiology supported with extracorporeal membrane oxygenation (ECMO) after open heart surgery. RESULTS: 81 children were placed on ECMO after open heart surgery. 58% (47 of 81) were transferred directly from cardiopulmonary bypass to ECMO. Hospital survival was 49% (40 of 81) but there were seven late deaths among these survivors (18%). Factors that improved the odds of survival were initiation of ECMO in theatre (64% survival (30 of 47)) rather than the cardiac intensive care unit (29% survival (10 of 34)) and initiation of ECMO for reactive pulmonary hypertension. Important adverse factors for hospital survival were serious mechanical ECMO circuit problems, renal support, residual lesions, and duration of ECMO. CONCLUSIONS: Hospital survival of children with biventricular physiology who require cardiac ECMO is similar to that found in series that include univentricular hearts, suggesting that successful cardiac ECMO is critically dependent on the identification of hearts with reversible ventricular dysfunction. In our experience of postoperative cardiac ECMO, the higher survival of patients cannulated in the operating room than in the cardiac intensive care unit is due to early effective support preventing prolonged hypoperfusion and the avoidance of a catastrophic cardiac arrest.

Cardiopulmonary Bypass↗

Imatinib for systemic mast-cell disease.

Imatinib has shown to be effective against malignant disease driven by ckit. We prospectively treated 12 adults with symptomatic systemic mast-cell disease at a dose of either 100 mg or 400 mg per day. Of the ten patients who we could assess for response, five (50%) had a measurable response to the drug, four of whom had important mast-cell cytoreduction and two who had complete clinical and histological remission. In the five patients with eosinophilia, three had complete clinical and haematological remission. The other two, who did not respond to treatment, were the only patients with the ckit D816V mutation. Our results suggest that imatinib either inhibits the growth-promoting role of wild type ckit, or targets an oncogenic kinase.

Adult↗

Changes in soft-bottom macrobenthic assemblages after a sulphuric acid spill in the Rio Grande Harbor (RS, Brazil).

The structure of macrobenthic assemblages in Rio Grande Harbor was analyzed during and after a sulphuric acid spill in August 1988. Five stations were sampled four times between September 1988 and March 1999. At each station, three samples were taken using a van Veen grab (0.078 m2). A total of 22 taxa were collected including Crustacea (9 spp.), Polychaeta (7 spp.), Mollusca (3 spp.), Phoronida (1 sp.), Nemertinea (1 sp.), and Plathyelminthea (1 sp.). The macrobenthic assemblages suffered different impacts depending on station location and time: 1) immediate impact, i.e., during acid discharge, as at the station nearest (250 m) the acid spill source; 2) impact some time after the discharge, as at the station 500 m downstream from the acid spill source; and 3) absence of direct impact on the remaining sampling points, on the discharge area outer limit. The macrobenthic assemblage recovered six months after the sulphuric acid spill.

Accidents↗

Management of pulmonary venous obstruction after correction of TAPVC: risk factors for adverse outcome.

OBJECTIVE: Recurrent pulmonary venous obstruction (PVO) occurs in 0-18% of infants undergoing correction of total anomalous pulmonary venous connection (TAPVC). Limited published data suggest that PVO usually develops within 6 months of primary repair, and that outcomes of reoperations are poor. This study aimed to review our experience of reoperations for PVO post-TAPVC repair and to identify risk factors for adverse outcome. METHODS: Twenty patients underwent reoperation for PVO between 1982 and 2002. Clinical data were reviewed. TAPVC was mostly infracardiac (11 patients). TAPVC was obstructed in nine patients. PVO developed early (<6 months) in seven patients, and late in 13 (>6 months). Time of presentation was unrelated to type of PVO (anastomotic vs. ostial). Repair was accomplished using various techniques (anastomotic enlargement with native atrial tissue, enlargement with pericardium, free or in situ, or other prosthetic material). Follow-up ranged from 1 month to 15 years (average 44 months). RESULTS: Thirteen patients received one reoperation, while seven had multiple reoperations. In 13 patients, PVO was defined as new onset (no obstruction post-TAPVC repair), and in seven patients as residual (minimal obstructive changes post-TAPVC repair that progressed to PVO). Ten patients presented with anastomotic PVO, six with anastomotic and ostial PVO (involving the PVs), three with ostial PVO, and one with coronary sinus-left atrial junction stenosis. Mortality was 25% (5/20). Six of the ten patients with anastomotic PVO underwent one reoperation (2/6 died); the other four developed ostial PVO after reoperation, requiring multiple procedures (2/4 died). Mode of presentation (new onset vs. residual), site of obstruction (anastomotic vs. ostial), preoperative RV pressure (<0.8 vs. >0.8 systemic), number of reoperations (single vs. multiple), residual obstruction (presence or absence), and operative approach (Gore-tex or not) did not seem to affect outcomes. Risk factors for death were early presentation (<6 months) and persistence of pulmonary hypertension after reoperation; early presentation was also a risk factor for multiple reoperations. CONCLUSIONS: Our findings support the conclusion that early presentation and postoperative pulmonary hypertension have the greatest adverse impact on outcome. Of these, failure to achieve a low-pressure pulmonary vascular system seems to be the variable that most strongly prevents survival. In our series, neither ostial PVO nor multiple re-interventions significantly increased surgical risk. The negative impact of postoperative residual obstruction on outcome was not striking. However, an aggressive surgical approach to this disease is still warranted. Although the role of each technique in obtaining long-lasting relief of PVO remains to be established, the use of artificial material seems unwise.

Blood Vessel Prosthesis Implantation↗

Scanning surface confocal microscopy for simultaneous topographical and fluorescence imaging: application to single virus-like particle entry into a cell.

We have developed a method for simultaneous recording of high-resolution topography and cell surface fluorescence in a single scan which we call scanning surface confocal microscopy. The resolution of the system allows imaging of individual fluorescent particles in the nanometer range on fixed or live cells. We used this technique to record the interaction of single virus-like particles with the cell surface and demonstrated that single particles sink into the membrane in invaginations reminiscent of caveolae or pinocytic vesicles. This method provides a technique for elucidating the interaction of individual viruses and other nanoparticles, such as gene therapy vectors, with target cells. Furthermore, this technique should find widespread application for studying the relationship of fluorescently tagged molecules with components of the cell plasma membrane.

Animals↗

Zanamivir: from drug design to the clinic.

The development of the neuraminidase inhibitors has revolutionized the management options for influenza. Zanamivir was the first such inhibitor to be approved for the treatment of influenza in humans. It is delivered by inhalation to the respiratory tract, which is the site of viral replication, in order to ensure immediate antiviral activity. Early treatment with zanamivir in clinical trials rapidly reduced the severity and duration of influenza symptoms and associated complications. Furthermore, chemoprophylaxis with zanamivir was shown to be effective in the prevention of influenza illness. To date, there is no evidence for the emergence of clinically significant zanamivir-resistant isolates. In conclusion, zanamivir offers a useful complementary strategy to vaccination in the effective management of influenza.

Animals↗

Using nucleotide analogs to probe protein-RNA interactions.

Synthetic nucleotide analogs provide the opportunity to evaluate the importance of individual functional groups on the RNA in protein-RNA complexes. The general approach is to incorporate analogs at a defined position(s) in the RNA target and to evaluate the effect of this substitution on the thermodynamic stability of the protein-RNA complex. The underlying assumption is that if the presence of the analog reduces the stability of the complex, then the functional groups that are altered in the analog interact with the protein. Here we describe the protocols for incorporation of nucleotide analogs either by in vitro transcription using T7 RNA polymerase or by synthetic chemistry. We also describe how we have used this approach to study the interaction of the TRAP protein from Bacillus subtilis with its cognate RNAs consisting of 11 repeats of GAG and/or UAG triplets. By comparing the results of these analog studies with the crystal structure of TRAP bound to an RNA containing 11 GAG repeats, we are able to see that all the functional groups identified by analogs forge direct interactions with the protein. Analog studies also correctly identified residues that do not contact the protein. Moreover, analogs can have indirect effects on the complex stability by altering the structural properties of the RNA.

Bacillus subtilis↗