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Biomedical subjects

B Healy

Publications and source records attributed to B Healy.

At least 19 recordsLinked to original sources

The value of follow-up after acute Q fever infection.

This is a case report of a 53-year-old woman involved in an outbreak of Q fever, in whom Q fever endocarditis was diagnosed 18 months after acute Q fever infection. At the time of diagnosis, she was completely asymptomatic and without screening for chronic Q fever, this severe potentially life-threatening infection would probably not have been recognised until significant valvular destruction had taken place. Early diagnosis enabled prompt, potentially curative medical treatment to start without the need for valvular heart surgery. The authors advocate that serological monitoring should be carried out every 4 months for a period of 2 years after acute Q fever and patients with high phase 1 IgG titres (>800) be investigated further and/or followed more closely depending on the clinical scenario. The case report also discusses the use of complement fixation testing in the diagnosis of Q fever endocarditis. The authors recommend that in cases of culture negative endocarditis, a single negative complement fixation test is not sufficient to exclude the diagnosis of Q fever endocarditis. Micro-immunofluorescence or repeat complement fixation testing is recommended when Q fever endocarditis is suspected clinically.

Anti-Bacterial Agents↗

A case of sepsis caused by Acidovorax.

This report documents a case of sepsis caused by a recently recognized environmental organism and demonstrates the pathogenicity of this bacterium in the clinical setting.

Blood↗

Biochemical and genetic evidence for a family of heterotrimeric G-proteins in Trichomonas vaginalis.

We have cloned a single copy gene from the human parasite Trichomonas vaginalis that encodes a putative protein of 402 amino acids with approximately 35% sequence identity to known alpha subunits of heterotrimeric G-proteins. It contains the characteristic GTP binding domains G-1 to G-5 with the key residues conserved. The new sequence has an unusual N-terminal extension of approximately 70 residues that cannot be aligned to reference G-proteins and which is characterised by proline-rich repeats. To investigate the expression and cellular localisation of the protein we produced specific antisera against a recombinant fusion protein. The antisera recognised a protein of an apparent molecular mass of 51 kDa in protein extracts from T. vaginalis and immunofluorescent microscopy established that the protein is localised to discrete endomembranes. Using a protocol designed to purify mammalian heterotrimeric G-proteins incorporating a GTPgammaS binding assay, we isolated two proteins from Trichomonas that are recognised by an heterologous GA/1 antisera raised to a peptide of the conserved G-1 domain of G-protein alpha subunits. These two proteins have an apparent molecular mass of 61 and 48 kDa, respectively, larger and smaller than the translation product of the cloned gene. Consistent with these results, the GA/1 antisera did not cross-react with the fusion protein produced from the gene we have cloned. These data suggest T. vaginalis possesses more than one heterotrimeric G-protein alpha subunit. Based on the sequence features of the cloned gene and the biochemical properties of the purified proteins, we suggest that these alpha subunits are likely to be part of classic heterotrimeric G-protein complexes.

Amino Acid Sequence↗

Discrepancies in volume calculations between different radiotherapy treatment planning systems.

It has been determined that, contrary to expectation, there is a clinically significant variation in the volume calculations of different RTPS (Radiotherapy Treatment Planning System) for identical contours. The situation was investigated prior to a multi-centre trial to determine whether tumour volume is an independent prognostic factor in NSCLC (non-small cell lung cancer) and included four of the commercially available RTPS. The four RTPS tested were, Theraplan Plus V3.0, Cadplan V6.2, Focus V2.6 and ADAC V3.0. Five randomly chosen clinical target related volumes (3 GTVs, one PTV and one CTV) from the trial database originally marked on the Cadplan system were transferred to the other four systems and the resulting volumes were calculated. It was found that Cadplan consistently underestimated the volume relative to the other three systems by 6-12%. This systematic underestimation was found to be caused by different assumptions made by the Cadplan system about the axial outer slice extension of the volume. Cadplan truncates the volume, while the other three systems extrapolate it by half the slice thickness at each end. A short program was written to apply the same method of volume extension to the Cadplan volume that is utilised by the other systems. This produced calculated volumes that were within +/- 1.0% of the average of the volumes calculated by the other three planning systems, and the maximum deviation from the average for any planning system was then reduced to 1.5%. This program was implemented at all participating trial centres utilising Cadplan, thus reducing the intersystem variability to a negligible factor in comparison to the estimates of inter-physician variation. This unexpected finding has significant implications for the validity of multi-centre trials using dose volume histograms, and indeed the adoption of any clinical protocol employing dose volume histogram constraints derived from experience at another centre employing a different RTPS.

Carcinoma, Non-Small-Cell Lung↗

Experimental determination of the diffusion coefficient in two-dimensions in ferrous sulphate gels using the finite element method.

A novel two-dimensional finite element method for modelling the diffusion which occurs in Fricke or ferrous sulphate type radiation dosimetry gels is presented. In most of the previous work, the diffusion coefficient has been estimated using simple one-dimensional models. This work presents a two-dimensional model which enables the diffusion coefficient to be determined in a much wider range of experimental situations. The model includes the provision for the determination of a drift parameter. To demonstrate the technique comparative diffusion measurements between ferrous sulphate radiation dosimetry gels, with and without xylenol orange chelating agent and carbohydrate additives have been undertaken. Diffusion coefficients of 9.7 +/- 0.4, 13.3 +/- 0.6 and 9.5 +/- 0.8 10(-3) cm2h-1 were determined for ferrous sulphate radiation dosimetry gels with and without xylenol orange and with xylenol orange and sucrose additives respectively.

Chelating Agents↗

An update on orthodontic manpower in ireland.

There has been considerable debate in Europe over the past few years on manpower requirements in orthodontics. In some countries today the need for orthodontic care cannot be accommodated due to lack of professional manpower whereas in others a surplus of orthodontic treatment facilities exists. The aim of the present study was to establish a baseline for orthodontic demographics in the Republic of Ireland. The number of orthodontists currently practising in Ireland was identified together with the number of Irish graduates currently on training programmes. Population figures were obtained from the Central Statistics Office. The orthodontic manpower situation has altered dramatically in the Republic of Ireland over the past 20 years. The number of 12-year-olds per orthodontist has reduced over the past 18 years from 2773 in 1980 to 890 in 1998. The age profile of the orthodontists presently practising in Ireland is low with an expected retirement over the next 20 years of only 28 of the 69 orthodontists identified. This study provides baseline information on orthodontic manpower in Ireland, and will facilitate Ireland's participation in similar or comparative studies in the future.

Birth Rate↗

Microsporidia are related to Fungi: evidence from the largest subunit of RNA polymerase II and other proteins.

We have determined complete gene sequences encoding the largest subunit of the RNA polymerase II (RBP1) from two Microsporidia, Vairimorpha necatrix and Nosema locustae. Phylogenetic analyses of these and other RPB1 sequences strongly support the notion that Microsporidia are not early-diverging eukaryotes but instead are specifically related to Fungi. Our reexamination of elongation factors EF-1alpha and EF-2 sequence data that had previously been taken as support for an early (Archezoan) divergence of these amitochondriate protists show such support to be weak and likely caused by artifacts in phylogenetic analyses. These EF data sets are, in fact, not inconsistent with a Microsporidia + Fungi relationship. In addition, we show that none of these proteins strongly support a deep divergence of Parabasalia and Metamonada, the other amitochondriate protist groups currently thought to compose early branches. Thus, the phylogenetic placement among eukaryotes for these protist taxa is in need of further critical examination.

Animals↗

Testing a rating scale of video-taped consultations to assess performance of trainee nurse practitioners in general practice.

BACKGROUND: Nurse practitioners (NPs) in the United Kingdom are taking on some of the consultation work previously done by general practitioners (GPs) without there being any established professional standards that they must achieve before doing so. There is a need to develop and test methods of assessing their consultation performance for reasons of professional accreditation and patient safety. AIMS: 1. To make independent summative assessments of trainee nurse practitioners' (TNPs) consultation performance. 2. To assess the validity and reliability of an existing video-taped assessment tool. METHOD: Four TNPs taking part in the EROS (extended roles of staff) study video recorded seven or eight consecutive consultations with typical patients during one surgery. Each consultation was rated nine times by members of a panel comprising eight independent GP trainers, four NPs and the GPs and TNPs in the EROS practices. A rating scale developed by Cox & Mulholland was used for the purpose. RESULTS: Eight of the 37 items and four consultations had more than 10% missing data, mean = 7.7 items per rater. Factor analysis yielded a single factor solution explaining 32.6% of the variance and indicated that items could be summed to provide a single score. Internal consistency was high, alpha coefficient = 0.92. Individual differences between raters in scoring consultations were taken into account in providing a score for each consultation. Scores obtained were found to cluster at the positive end of the distribution indicating a high level of performance. Greater differences were found between scorers than between consultations. CONCLUSIONS: This instrument is appropriate for scoring NP consultations and this small sample was rated as showing a uniformly high standard of performance. Some items could be deleted since they do not feature in the range of consultations currently performed. If this or a similar tool was to be adopted more widely for summative rating purposes then it should be tested rigorously for validity and reliability, training should be given to raters and criteria provided by which to make judgements.

Employee Performance Appraisal↗

Health outcomes as an organisation-wide quality initiative.

Since the burgeoning of the 'health outcomes' movement there has been an ever-increasing body of literature on health outcomes policy debates, directions, frameworks and tools for implementing health outcome-directed initiatives. There is a significant gap in the literature, however, in regard to translating a comprehensive health outcomes policy into practice at a local level. This paper addresses that gap. It describes the local implementation of a comprehensive health outcomes approach which works across the continuum of care. It identifies those organisation-wide structures and processes that support successful progress, thereby providing a useful guide to other organisations wishing to institutionalise the health outcomes approach.

Community Networks↗

A mitochondrial Hsp70 orthologue in Vairimorpha necatrix: molecular evidence that microsporidia once contained mitochondria.

Microsporidia are small (1-20 micron) obligate intracellular parasites of a variety of eukaryotes, and they are serious opportunistic pathogens of immunocompromised patients [1]. Microsporidia are often assigned to the first branch in gene trees of eukaryotes [2,3], and are reported to lack mitochondria [2,4]. Like diplomonads and trichomonads, microsporidia are hypothesised to have diverged from the main eukaryotic stock prior to the event that led to the mitochondrion endosymbiosis [2,4]. They have thus assumed importance as putative relics of premitochondrion eukaryote evolution. Recent data have now revealed that diplomonads and trichomonads contain genes that probably originated from the mitochondrion endosymbiont [5-9], leaving microsporidia as chief candidates for an extant primitively amitochondriate eukaryote group. We have now identified a gene in the microsporidium Vairimorpha necatrix that appears to be orthologous to the eukaryotic (symbiont-derived) Hsp70 gene, the protein product of which normally functions in mitochondria. The simplest interpretation of our data is that microporidia have lost mitochondria while retaining genetic evidence of their past presence. This strongly suggests that microsporidia are not primitively amitochondriate and makes feasible an evolutionary scenario whereby all extant eukaryotes share a common ancestor which contained mitochondria.

Animals↗