Encystation of Entamoeba histolytica in Axenic Culture

Entamoeba histolytica is a parasitic protozoan that causes amoebic dysentery, which affects approximately 90 million people each year worldwide. E. histolytica is transmitted through ingestion of food and water contaminated with the cyst form, which undergoes excystation in the small intestine to the trophozoite form that colonizes the large intestine. The reptile pathogen Entamoeba invadens has served as a model for studying stage conversion between the trophozoite and cyst form due to lack of reproducible encystation of E. histolytica in the laboratory. Although much has been learned about encystation and excystation using E. invadens, the findings do not fully translate to E. histolytica due to the extensive genetic and host differences between these species. Here, we present the first reproducible encystation of E. histolytica in vitro. The cysts produced were viable and displayed the four characteristic hallmarks: round shape, chitinous cell wall, tetranucleation, and detergent resistance. Using flow cytometry analysis, glucose limitation and high cell density were key for encystation, as for E. invadens. Entry into encystation was enhanced by the short-chain fatty acids acetate and propionate, unlike for E. invadens. This new model will now allow the further study of E. histolytica stage conversion, transmission, and treatment.

The key components of a successful model of midwifery-led continuity of carer, without continuity at birth: findings from a qualitative implementation evaluation

BACKGROUND

Recent UK maternity policy changes recommend that a named midwife supports women throughout their pregnancy, birth and postnatal care. Whilst many studies report high levels of satisfaction amongst women receiving, and midwives providing, this level of continuity of carer, there are concerns some midwives may experience burnout and stress. In this study, we present a qualitative evaluation of the implementation of a midwife-led continuity of carer model that excluded continuity of carer at the birth.

METHODS

Underpinned by the Conceptual Model for Implementation Fidelity, our evaluation explored the implementation, fidelity, reach and satisfaction of the continuity of carer model. Semi-structured interviews were undertaken with midwives (n = 7) and women (n = 15) from continuity of carer team. To enable comparisons between care approaches, midwives (n = 7) and women (n = 10) from standard approach teams were also interviewed. Interviews were recorded, transcribed and analysed using thematic analysis.

RESULTS

For continuity of carer team midwives, manageable caseloads, extended appointment times, increased team stability, and flexible working patterns facilitated both care provided and midwives' job satisfaction. Both continuity of carer and standard approach midwives reported challenges in providing postnatal continuity given the unpredictable timing of labour and birth. Time constraints, inadequate staffing and lack of administrative support were reported as additional barriers to implementing continuity of carer within standard approach teams. Women reported continuity was integral to building trust with midwives, encouraged them to disclose mental health issues and increased their confidence in making birth choices.

CONCLUSIONS

Our evaluation highlighted the successful implementation of a continuity of carer model for ante and postnatal care. Despite exclusion of the birth element in the model, both women and midwives expressed high levels of satisfaction in comparison to women and midwives within the standard approach. Implementation successes were largely due to structural and resource factors, particularly the combination of additional time and smaller caseloads of women. However, these resources are not widely available within the resources of maternity unit budgets. Future research should further explore whether a continuity of carer model focusing on antenatal and postnatal care delivery is a feasible and sustainable model of care for all women.

Characteristics of Vibrio vulnificus isolates from clinical and environmental sources

Researchers have developed multiple methods to characterize clinical and environmental strains of Vibrio vulnificus. The aim of our study was to use four assays to detect virulence factors in strains from infected patients and those from surface waters/sediments/oysters of South Carolina and the Gulf of Mexico. Vibrio vulnificus strains from clinical (n = 81) and environmental (n = 171) sources were tested using three real-time PCR methods designed to detect polymorphisms in the 16S rRNA, vcg and pilF genes and a phenotypic method, the ability to ferment D-mannitol. Although none of the tests correctly categorized all isolates, the differentiation between clinical and environmental isolates was similar for the pilF, vcgC/E and 16S rRNA assays, with sensitivities of 74.1-79.2% and specificities of 77.4-82.7%. The pilF and vcgC/E assays are comparable in efficacy to the widely used 16S rRNA method, while the D-mannitol fermentation test is less discriminatory (sensitivity = 77.8%, specificity = 61.4%). Overall percent agreement for the D-mannitol fermentation method was also lower (66.7%) than overall percent agreement for the 3 molecular assays (78.0%-80.2%). This study demonstrated, using a large, diverse group of Vibrio vulnificus isolates, that three assays could be used to distinguish most clinical vs environmental isolates; however, additional assays are needed to increase accuracy.

Reverse engineering of fatty acid-tolerant Escherichia coli identifies design strategies for robust microbial cell factories

Adaptive laboratory evolution is often used to improve the performance of microbial cell factories. Reverse engineering of evolved strains enables learning and subsequent incorporation of novel design strategies via the design-build-test-learn cycle. Here, we reverse engineer a strain of Escherichia coli previously evolved for increased tolerance of octanoic acid (C8), an attractive biorenewable chemical, resulting in increased C8 production, increased butanol tolerance, and altered membrane properties. Here, evolution was determined to have occurred first through the restoration of WaaG activity, involved in the production of lipopolysaccharides, then an amino acid change in RpoC, a subunit of RNA polymerase, and finally mutation of the BasS-BasR two component system. All three mutations were required in order to reproduce the increased growth rate in the presence of 20 mM C8 and increased cell surface hydrophobicity; the WaaG and RpoC mutations both contributed to increased C8 titers, with the RpoC mutation appearing to be the major driver of this effect. Each of these mutations contributed to changes in the cell membrane. Increased membrane integrity and rigidity and decreased abundance of extracellular polymeric substances can be attributed to the restoration of WaaG. The increase in average lipid tail length can be attributed to the RpoC^H419P mutation, which also confers tolerance to other industrially-relevant inhibitors, such as furfural, vanillin and n-butanol. The RpoC^H419P mutation may impact binding or function of the stringent response alarmone ppGpp to RpoC site 1. Each of these mutations provides novel strategies for engineering microbial robustness, particularly at the level of the microbial cell membrane.

Use of progression criteria to support monitoring and commissioning decision making of public health services: lessons from Better Start Bradford

BACKGROUND

Commissioning and monitoring of community-based interventions is a challenge due to the complex nature of the environment and the lack of any explicit cut-offs to guide decision making. At what point, for example, is participant enrolment to interventions, course completion or satisfaction deemed to be acceptable or sufficient for continued funding? We aimed to identify and quantify key progression criteria for fourteen early years interventions by (1) agreeing the top three criteria for monitoring of successful implementation and progress; and (2) agreeing boundaries to categorise interventions as 'meeting anticipated target' (green); 'falling short of targets' (amber) and 'targets not being met' (red).

METHODS

We ran three workshops in partnership with the UK's Big Lottery Fund commissioned programme 'Better Start Bradford' (implementing more than 20 interventions to improve the health, wellbeing and development of children aged 0-3) to support decision making by agreeing progression criteria for the interventions being delivered. Workshops included 72 participants, representing a range of professional groups including intervention delivery teams, commissioners, intervention-monitoring teams, academics and community representatives. After discussion and activities, final decisions were submitted using electronic voting devices. All participants were invited to reconsider their responses via a post-workshop questionnaire.

RESULTS

Three key progression criteria were assigned to each of the 14 interventions. Overall, criteria that participants most commonly voted for were recruitment, implementation and reach, but these differed according to each intervention. Cut-off values used to indicate when an intervention moved to 'red' varied by criteria; the lowest being for recruitment, where participants agreed that meeting less than 65% of the targeted recruitment would be deemed as 'red' (falling short of target).

CONCLUSIONS

Our methodology for monitoring the progression of interventions has resulted in a clear pathway which will support commissioners and intervention teams in local decision making within the Better Start Bradford programme and beyond. This work can support others wishing to implement a formal system for monitoring the progression of public health interventions.

Strawberry: Fast and accurate genome-guided transcript reconstruction and quantification from RNA-Seq

We propose a novel method and software tool, Strawberry, for transcript reconstruction and quantification from RNA-Seq data under the guidance of genome alignment and independent of gene annotation. Strawberry consists of two modules: assembly and quantification. The novelty of Strawberry is that the two modules use different optimization frameworks but utilize the same data graph structure, which allows a highly efficient, expandable and accurate algorithm for dealing large data. The assembly module parses aligned reads into splicing graphs, and uses network flow algorithms to select the most likely transcripts. The quantification module uses a latent class model to assign read counts from the nodes of splicing graphs to transcripts. Strawberry simultaneously estimates the transcript abundances and corrects for sequencing bias through an EM algorithm. Based on simulations, Strawberry outperforms Cufflinks and StringTie in terms of both assembly and quantification accuracies. Under the evaluation of a real data set, the estimated transcript expression by Strawberry has the highest correlation with Nanostring probe counts, an independent experiment measure for transcript expression. Availability: Strawberry is written in C++14, and is available as open source software at https://github.com/ruolin/strawberry under the MIT license.

Transcript assembly and quantification are important bioinformatics applications of RNA-Seq. The difficulty of solving these problem arises from the ambiguity of reads assignment to isoforms uniquely. This challenge is twofold: statistically, it requires a high-dimensional mixture model, and computationally, it needs to process datasets that commonly consist of tens of millions of reads. Existing algorithms either use very complex models that are too slow or assume no models, rather heuristic, and thus less accurate. Strawberry seeks to achieve a great balance between the model complexity and speed. Strawberry effectively leverages a graph-based algorithm to utilize all possible information from pair-end reads and, to our knowledge, is the first to apply a flow network algorithm on the constrained assembly problem. We are also the first to formulate the quantification problem in a latent class model. All of these features not only lead to a more flexible and complex quantification model but also yield software that is easier to maintain and extend. In this method paper, we have shown that the Strawberry method is novel, accurate, fast and scalable using both simulated data and real data.

Temporal and Environmental Factors Driving Vibrio Vulnificus and V. Parahaemolyticus Populations and Their Associations With Harmful Algal Blooms in South Carolina Detention Ponds and Receiving Tidal Creeks

Incidences of harmful algal blooms (HABs) and Vibrio infections have increased over recent decades. Numerous studies have tried to identify environmental factors driving HABs and pathogenic Vibrio populations separately. Few have considered the two simultaneously, though emerging evidence suggests that algal blooms enhance Vibrio growth and survival. This study examined various physical, nutrient, and temporal factors associated with incidences of HABs, V. vulnificus, and V. parahaemolyticus in South Carolina coastal stormwater detention ponds, managed systems where HABs often proliferate, and their receiving tidal creek waters. Five blooms occurred during the study (2008-2009): two during relatively warmer months (an August 2008 cyanobacteria bloom and a November 2008 dinoflagellate bloom) followed by increases in both Vibrio species and V. parahaemolyticus, respectively, and three during cooler months (December 2008 through February 2009) caused by dinoflagellates and euglenophytes that were not associated with marked changes in Vibrio abundances. Vibrio concentrations were positively and significantly associated with temperature and dissolved organic matter, dinoflagellate blooms, negatively and significantly associated with suspended solids, but not significantly correlated with chlorophyll or nitrogen. While more research involving longer time series is needed to increase robustness, findings herein suggest that certain HAB species may augment Vibrio occurrences during warmer months.

A cluster randomised controlled trial and economic evaluation of a structured training programme for caregivers of inpatients after stroke: the TRACS trial

BACKGROUND

The majority of stroke patients are discharged home dependent on informal caregivers, usually family members, to provide assistance with activities of daily living (ADL), including bathing, dressing and toileting. Many caregivers feel unprepared for this role and this may have a detrimental effect on both the patient and caregiver.

OBJECTIVE

To evaluate whether or not a structured, competency-based training programme for caregivers [the London Stroke Carer Training Course (LSCTC)] improved physical and psychological outcomes for patients and their caregivers after disabling stroke, and to determine if such a training programme is cost-effective.

DESIGN

A pragmatic, multicentre, cluster randomised controlled trial.

SETTING

Stratified randomisation of 36 stroke rehabilitation units (SRUs) to the intervention or control group by geographical region and quality of care.

PARTICIPANTS

A total of 930 stroke patient and caregiver dyads were recruited. Patients were eligible if they had a confirmed diagnosis of stroke, were medically stable, were likely to return home with residual disability at the time of discharge and had a caregiver available, willing and able to provide support after discharge. The caregiver was defined as the main person--other than health, social or voluntary care provider--helping with ADL and/or advocating on behalf of the patient.

INTERVENTION

The intervention (the LSCTC) comprised a number of caregiver training sessions and competency assessment delivered by SRU staff while the patient was in the SRU and one recommended follow-up session after discharge. The control group continued to provide usual care according to national guidelines. Recruitment was completed by independent researchers and participants were unaware of the SRUs' allocation.

MAIN OUTCOME MEASURES

The primary outcomes were self-reported extended ADL for the patient and caregiver burden measured at 6 months after recruitment. Secondary outcomes included quality of life, mood and cost-effectiveness, with final follow-up at 12 months.

RESULTS

No differences in primary outcomes were found between the groups at 6 months. Adjusted mean differences were -0.2 points [95% confidence interval (CI) -3.0 to 2.5 points; p = 0.866; intracluster correlation coefficient (ICC) = 0.027] for the patient Nottingham Extended Activities of Daily Living score and 0.5 points (95% CI -1.7 to 2.7 points; p = 0.660; ICC = 0.013) for the Caregiver Burden Scale. Furthermore, no differences were detected in any of the secondary outcomes. Intervention compliance varied across the units. Half of the participating centres had a compliance rating of > 60%. Analysis showed no evidence of higher levels of patient independence or lower levels of caregiver burden in the SRUs with better levels of intervention compliance. The economic evaluation suggests that from a patient and caregiver perspective, health and social care costs, societal costs and outcomes are similar for the intervention and control groups at 6 months, 12 months and over 1 year.

CONCLUSIONS

We have conducted a robust multicentre, cluster randomised trial, demonstrating for the first time that this methodology is feasible in stroke rehabilitation research. There was no difference between the LSCTC and usual care with respect to improving stroke patients' recovery, reducing caregivers' burden, or improving other physical and psychological outcomes, nor was it cost-effective compared with usual care. Compliance with the intervention varied, but analysis indicated that a dose effect was unlikely. It is possible that the immediate post-stroke period may not be the ideal time for the delivery of structured training. The intervention approach might be more relevant if delivered after discharge by community-based teams.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN49208824.

FUNDING

This project was funded by the MRC and is managed by the NIHR (project number 09/800/10) on behalf of the MRC-NIHR partnership, and will be published in full in Health Technology Assessment; Vol. 17, No. 46. See the NIHR Journals Library website for further project information.

Introducing structured caregiver training in stroke care: findings from the TRACS process evaluation study

OBJECTIVE

To evaluate the process of implementation of the modified London Stroke Carers Training Course (LSCTC) in the Training Caregivers After Stroke (TRACS) cluster randomised trial and contribute to the interpretation of the TRACS trial results. The LSCTC was a structured competency-based training programme designed to help develop the knowledge and skills (eg, patient handling or transfer skills) essential for the day-to-day management of disabled survivors of stroke. The LSCTC comprised 14 components, 6 were mandatory (and delivered to all) and 8 non-mandatory, to be delivered based on individual assessment of caregiver need.

DESIGN

Process evaluation using non-participant observation, documentary analysis and semistructured interviews.

PARTICIPANTS

Patients with stroke (n=38), caregivers (n=38), stroke unit staff (n=53).

SETTINGS

10 of the 36 stroke units participating in the TRACS trial in four English regions (Yorkshire, North West, South East and South West, Peninsula).

RESULTS

Preparatory cascade training on delivery of the LSCTC did not reach all staff and did not lead to multidisciplinary team (MDT) wide understanding of, engagement with or commitment to the LSCTC. Although senior therapists in most intervention units observed developed ownership of the LSCTC, MDT working led to separation rather than integration of delivery of LSCTC elements. Organisational features of stroke units and professionals' patient-focused practices limited the involvement of caregivers. Caregivers were often invited to observe therapy or care being provided by professionals but had few opportunities to make sense of, or to develop knowledge and stroke-specific skills provided by the LSCTC. Where provided, caregiver training came very late in the inpatient stay. Assessment and development of caregiver competence was not commonly observed.

CONCLUSIONS

Contextual factors including service improvement pressures and staff perceptions of the necessity for and work required in caregiver training impacted negatively on implementation of the caregiver training intervention. Structured caregiver training programmes such as the LSCTC are unlikely to be practical in settings with short inpatient stays. Stroke units where early supported discharge is in place potentially offer a more effective vehicle for introducing competency based caregiver training.

LINKED TRACS CLUSTER RANDOMISED CONTROLLED TRIAL NUMBER

ISRCTN49208824.

Transcriptomic analysis of carboxylic acid challenge in Escherichia coli: beyond membrane damage

Carboxylic acids are an attractive biorenewable chemical. Enormous progress has been made in engineering microbes for production of these compounds though titers remain lower than desired. Here we used transcriptome analysis of Escherichia coli during exogenous challenge with octanoic acid (C8) at pH 7.0 to probe mechanisms of toxicity. This analysis highlights the intracellular acidification and membrane damage caused by C8 challenge. Network component analysis identified transcription factors with altered activity including GadE, the activator of the glutamate-dependent acid resistance system (AR2) and Lrp, the amino acid biosynthesis regulator. The intracellular acidification was quantified during exogenous challenge, but was not observed in a carboxylic acid producing strain, though this may be due to lower titers than those used in our exogenous challenge studies. We developed a framework for predicting the proton motive force during adaptation to strong inorganic acids and carboxylic acids. This model predicts that inorganic acid challenge is mitigated by cation accumulation, but that carboxylic acid challenge inverts the proton motive force and requires anion accumulation. Utilization of native acid resistance systems was not useful in terms of supporting growth or alleviating intracellular acidification. AR2 was found to be non-functional, possibly due to membrane damage. We proposed that interaction of Lrp and C8 resulted in repression of amino acid biosynthesis. However, this hypothesis was not supported by perturbation of lrp expression or amino acid supplementation. E. coli strains were also engineered for altered cyclopropane fatty acid content in the membrane, which had a dramatic effect on membrane properties, though C8 tolerance was not increased. We conclude that achieving higher production titers requires circumventing the membrane damage. As higher titers are achieved, acidification may become problematic.

Comparative analysis of grapevine whole-genome gene predictions, functional annotation, categorization and integration of the predicted gene sequences

BACKGROUND

The first draft assembly and gene prediction of the grapevine genome (8X base coverage) was made available to the scientific community in 2007, and functional annotation was developed on this gene prediction. Since then additional Sanger sequences were added to the 8X sequences pool and a new version of the genomic sequence with superior base coverage (12X) was produced.

RESULTS

In order to more efficiently annotate the function of the genes predicted in the new assembly, it is important to build on as much of the previous work as possible, by transferring 8X annotation of the genome to the 12X version. The 8X and 12X assemblies and gene predictions of the grapevine genome were compared to answer the question, "Can we uniquely map 8X predicted genes to 12X predicted genes?" The results show that while the assemblies and gene structure predictions are too different to make a complete mapping between them, most genes (18,725) showed a one-to-one relationship between 8X predicted genes and the last version of 12X predicted genes. In addition, reshuffled genomic sequence structures appeared. These highlight regions of the genome where the gene predictions need to be taken with caution. Based on the new grapevine gene functional annotation and in-depth functional categorization, twenty eight new molecular networks have been created for VitisNet while the existing networks were updated.

CONCLUSIONS

The outcomes of this study provide a functional annotation of the 12X genes, an update of VitisNet, the system of the grapevine molecular networks, and a new functional categorization of genes. Data are available at the VitisNet website (http://www.sdstate.edu/ps/research/vitis/pathways.cfm).

MetNet: Software to Build and Model the Biogenetic Lattice of Arabidopsis

MetNet (http://www.botany.iastate.edu/∼mash/metnetex/metabolicnetex.html) is publicly available software in development for analysis of genome-wide RNA, protein and metabolite profiling data. The software is designed to enable the biologist to visualize, statistically analyse and model a metabolic and regulatory network map of Arabidopsis, combined with gene expression profiling data. It contains a JAVA interface to an interactions database (MetNetDB) containing information on regulatory and metabolic interactions derived from a combination of web databases (TAIR, KEGG, BRENDA) and input from biologists in their area of expertise. FCModeler captures input from MetNetDB in a graphical form. Sub-networks can be identified and interpreted using simple fuzzy cognitive maps. FCModeler is intended to develop and evaluate hypotheses, and provide a modelling framework for assessing the large amounts of data captured by high-throughput gene expression experiments. FCModeler and MetNetDB are currently being extended to three-dimensional virtual reality display. The MetNet map, together with gene expression data, can be viewed using multivariate graphics tools in GGobi linked with the data analytic tools in R. Users can highlight different parts of the metabolic network and see the relevant expression data highlighted in other data plots. Multi-dimensional expression data can be rotated through different dimensions. Statistical analysis can be computed alongside the visual. MetNet is designed to provide a framework for the formulation of testable hypotheses regarding the function of specific genes, and in the long term provide the basis for identification of metabolic and regulatory networks that control plant composition and development.

Health services use in eating disorders

BACKGROUND

This study examined healthcare services used by adults diagnosed with an eating disorder (ED) in a large health maintenance organization in the Pacific Northwest.

METHOD

Electronic medical records were used to collect information on all out-patient and in-patient visits and medication dispenses, from 2002 to 2004, for adults aged 18-55 years who received an ED diagnosis during 2003. Healthcare services received the year prior to, and following, the receipt of an ED diagnosis were examined. Cases were matched to five comparison health plan members who had a health plan visit close to the date of the matched case's ED diagnosis.

RESULTS

Incidence of EDs (0.32% of the 104,130 females, and 0.02% of the 93,628 males) was consistent with prior research employing treatment-based databases, though less than community-based samples. Most cases (50%) were first identified during a primary-care visit and psychiatric co-morbidity was high. Health services use was significantly elevated in all service sectors among those with an ED when compared with matched controls both in the year preceding and that following the receipt of the incident ED diagnosis. Contrary to expectations, healthcare utilization was found to be similarly high across the spectrum of EDs (anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified).

CONCLUSIONS

The elevation in health service use among women both before and after diagnosis suggests that EDs merit identification and treatment efforts commensurate with other mental health disorders (e.g. depression) which have similar healthcare impact.

Cardiovascular and respiratory responses during musical mood induction

Music is used to induce moods in experimental settings as well as for therapeutic purposes. Prior studies suggest that subjects listening to certain types of music experience strong moods and show physiological responses associated with the induced emotions. We hypothesized that cardiovascular and respiratory patterns could discriminate moods induced via music. 18 healthy subjects listened to 12 music clips, four each to induce happiness, sadness, and fear, while cardiovascular and respiratory responses were recorded using an electrocardiogram and chest strain-gauge belt. After each clip subjects completed a questionnaire. Subjects consistently reported experiencing the targeted mood, suggesting successful mood induction. Cardiovascular activity was measured by calculating time domain measures and heart rate changes during each clip. Respiratory activity was measured by total, inspiration, and expiration lengths as well as changes in mean respiration rate during each clip. Evaluation of individuals' patterns and mixed-model analyses were performed. Contrary to expectations, the time domain measures of subjects' cardiovascular responses did not vary significantly between the induced moods, although a heart rate deceleration was found during the sadness inductions and acceleration during the fear inductions. The time domain respiratory measures varied with clip type: the mean breath length was longest for the sad induction, intermediate during fear, and shortest during the happiness induction. However, analysis using normalized least mean squares adaptive filters to measure time correlation indicated that much of this difference may be attributable to entrainment of respiration to characteristics of the music which varied between the stimuli. Our findings point to the difficulty in detecting psychophysiological correlates of mood induction, and further suggest that part of this difficulty may arise from failure to differentiate it from tempo-related contributions when music is used as the inducer.

Bioinformatics and its applications in plant biology

Bioinformatics plays an essential role in today's plant science. As the amount of data grows exponentially, there is a parallel growth in the demand for tools and methods in data management, visualization, integration, analysis, modeling, and prediction. At the same time, many researchers in biology are unfamiliar with available bioinformatics methods, tools, and databases, which could lead to missed opportunities or misinterpretation of the information. In this review, we describe some of the key concepts, methods, software packages, and databases used in bioinformatics, with an emphasis on those relevant to plant science. We also cover some fundamental issues related to biological sequence analyses, transcriptome analyses, computational proteomics, computational metabolomics, bio-ontologies, and biological databases. Finally, we explore a few emerging research topics in bioinformatics.

Sub-types of deep dyslexia: a case study of central deep dyslexia

A case study is reported of a female patient (JAH), who following a left middle cerebral artery infarct, presented with the cardinal symptoms of deep dyslexia and deep dysphasia (semantic errors when reading and repeating words aloud, respectively). Detailed assessment revealed impaired performance across modalities for many tasks, but particularly those tasks that depend on an intact store of semantic knowledge. Her acquired dyslexia is best characterised as deep dyslexia of a central sub-type.

Travoprost compared with latanoprost and timolol in patients with open-angle glaucoma or ocular hypertension

PURPOSE

This study evaluated the safety and intraocular pressure-lowering efficacy of two concentrations of travoprost (0.0015% and 0.004%) compared with latanoprost 0.005% and timolol 0.5% in patients with open-angle glaucoma or ocular hypertension.

METHODS

Eight hundred one patients with open-angle glaucoma or ocular hypertension were randomly assigned to travoprost 0.0015%, travoprost 0.004%, latanoprost 0.005%, or timolol 0.5%. The efficacy and safety of travoprost (0.0015% and 0.004%) daily was compared with latanoprost daily and timolol twice daily for a period of 12 months.

RESULTS

Travoprost was equal or superior to latanoprost and superior to timolol with mean intraocular pressure over visits and time of day ranging from 17.9 to 19.1 mm Hg (travoprost 0.0015%), 17.7 to 19.1 mm Hg (travoprost 0.004%), 18.5 to 19.2 mm Hg (latanoprost), and 19.4 to 20.3 mm Hg (timolol). For all visits pooled, the mean intraocular pressure at 4 PM for travoprost was 0.7 mm Hg (0.0015%, P =.0502) and 0.8 mm Hg (0.004%, P =.0191) lower than for latanoprost. Travoprost 0.004% was more effective than latanoprost and timolol in reducing intraocular pressure in black patients by up to 2.4 mm Hg (versus latanoprost) and 4.6 mm Hg (versus timolol). Based on a criterion of 30% or greater intraocular pressure reduction from diurnal baseline or intraocular pressure 17 mm Hg or less, travoprost 0.0015% and 0.004% had an overall response to treatment of 49.3% and 54.7%, respectively, compared with 49.6% for latanoprost and 39.0% for timolol. Iris pigmentation change was observed in 10 of 201 of patients (5.0%) receiving travoprost 0.0015%, six of 196 of patients (3.1%) receiving travoprost 0.004%, 10 of 194 of patients (5.2%) receiving latanoprost, and none of the patients receiving timolol (0 of 196). The average ocular hyperemia score was less than 1 on a scale of 0 to 3, indicating that on average patients experienced between none/trace and mild for all treatment groups. There were no serious, unexpected, related adverse events reported for any therapy.

CONCLUSIONS

Travoprost (0.0015% and 0.004%), a highly selective, potent prostaglandin F (FP) receptor agonist, is equal or superior to latanoprost and superior to timolol in lowering intraocular pressure in patients with open-angle glaucoma or ocular hypertension. In addition, travoprost 0.004% is significantly better than either latanoprost or timolol in lowering intraocular pressure in black patients. Travoprost is safe and generally well tolerated in the studied patient population.

Subarachnoid-pleural fistula treated with noninvasive positive-pressure ventilation. Case report

The authors describe the case of a 24-year-old man who underwent an L-1 corpectomy for spinal decompression and stabilization following an injury that caused an L-1 burst fracture. Postoperatively, an accumulation of spinal fluid developed in the pleural space, which was refractory to 1 week of thoracostomy tube drainage and lumbar cerebrospinal fluid (CSF) diversion. The authors then initiated a regimen of positive-pressure ventilation in which a bi-level positive airway pressure (PAP) mask was used. After 5 days, the CSF collection in the pleural space resolved. Use of a bi-level PAP mask represents a safe, noninvasive method of reducing the negative intrathoracic pressure that promotes CSF leakage into the pleural cavity and may be a useful adjunct in the treatment of subarachnoid-pleural fistula.

Malignant melanoma of the foot and ankle

Malignant melanoma is a serious and devastating skin disease that podiatrists may be called upon to treat. It is pertinent that delays in diagnosis and treatment of malignant melanoma be avoided. Some of the topics discussed in this article are causes, clinical features, classification, and treatment of malignant melanoma, focusing on the foot and ankle.

Gait and postural stability in obese and nonobese prepubertal boys

OBJECTIVE

To examine differences in gait and postural stability of obese and nonobese prepubertal boys.

DESIGN

Percentage of gait cycle in double support was examined to determine significant differences. Postural stability was compared using temporal and frequency measures of the center of pressure in static stance.

SETTING

Gait was examined using videography on a 30-meter walkway. Postural stability was examined using a measurement platform.

PARTICIPANTS

Ten obese (>95th percentile in body mass index) and 10 nonobese (15th to 90th percentile in body mass index) prepubertal boys aged 8 to 10yrs.

INTERVENTION

Participants were examined at three walking cadences as determined by preferred gait cadence. Full vision, darkness, and visually confused conditions were used to accentuate static postural stability differences.

MAIN OUTCOME MEASURES

In the presence of dynamic stability differences (gait), static stability measures further investigated stability differences.

RESULTS

Obese boys spent significantly (p < .02) greater percentage of gait cycle in dual stance. Obese boys showed significantly (p < .01) greater sway areas, energy, and variability primarily in the medial/lateral direction.

CONCLUSIONS

Dual stance differences suggest diminished dynamic stability in obese boys. Greater sway areas in medial/lateral direction in obese boys and the absence of significant frequency measures suggest that the instability observed in obese boys is caused by excess weight rather than underlying postural instability.

Percutaneous retrogasserian glycerol rhizolysis for treatment of chronic intractable cluster headaches: long-term results

OBJECTIVE

To analyze the long-term effectiveness and safety of percutaneous retrogasserian glycerol rhizolysis (PRGR) in the treatment of medically refractive chronic cluster headache (CH). The current mainstay of surgical intervention for these patients is percutaneous radiofrequency retrogasserian rhizotomy (PRFR). However, when performed for V1 distribution pathology, PRFR can lead to corneal anesthesia, which places the patient at risk for future visual loss. It also increases the risk of facial dysesthesia.

METHODS

In a prospective, consecutive series, 18 patients with intractable CH were followed for a mean of 5.2 years (range, 40-78 mo) after they had undergone PRGR, performed using a standard technique. The significance of this technique as an alternative to PRFR is that it should result in a lower rate of both corneal and facial anesthesia and provide an acceptable degree of pain relief.

RESULTS

Fifteen patients (83%) obtained immediate pain relief after one or two injections; the majority of them experienced relief after the first injection. CH recurred in seven patients (39%) over the course of the study. Two of these patients received a second injection, and both met with equal success. Two other patients underwent PRFR. Excluding those who underwent PRFR, the overall daily headache frequency decreased from 3.5 +/- 0.3 attacks per day preoperatively to 0.6 +/- 0.2 attacks per day at last follow-up. The severity of these headaches, as assessed by verbal pain scales, also decreased from 10 preoperatively to 4.4 +/- 1.4 at follow-up. None of the patients, including those who required a second procedure, experienced corneal anesthesia or facial dysesthesia.

CONCLUSION

This study provides the first long-term evaluation of PRGR for the treatment of medically refractive chronic CH and lends support to both the safety and long-term efficacy of this procedure. Further investigations are needed to compare directly the relative efficacy and safety of PRGR and PRFR.

Survival and functional outcome after prolonged intensive care unit stay

OBJECTIVE

To examine the functional outcome and costs of a prolonged illness requiring a stay in the surgical intensive care unit (SICU) of 7 of more days.

SUMMARY BACKGROUND DATA

The long-term benefits and costs after a prolonged SICU stay have not been well studied.

METHODS

All patients with an SICU length of stay of 7 or more days from July 1, 1996, to June 30, 1997, were enrolled. One hundred twenty-eight patients met the entry criteria, and mortality status was known in 127. Functional outcome was determined at baseline and at 1, 3, 6, and 12 months using the Sickness Impact Profile score, which ranges from 0 to 100, with a score of 30 being severely disabled. Hospital costs for the index admission and for all readmissions to Johns Hopkins Hospital were obtained. All data are reported as median values.

RESULTS

For the index admission, age was 57 and APACHE II score was 23. The initial length of stay in the ICU was 11 days; the hospital length of stay was 31 days. The Sickness Impact Profile score was 20.2 at baseline, 42.9 at 1 month, 36.2 at 3 months, and 20.3 at 6 months, and was lower than baseline at 1 year. The actual 1-year survival rate was 45.3%. The index admission median cost was $85,806, with 65 total subsequent admissions to this facility. The cost for a single 1-year survivor was $282,618 (1996).

CONCLUSIONS

An acute surgical illness that results in a prolonged SICU stay has a substantial in-hospital death rate and is costly, but the functional outcome from both a physical and physiologic standpoint is compatible with a good quality of life.

Effects of damp and mould in the home on respiratory health: a review of the literature

This review examines whether there is a direct or indirect relation between damp or mould in the home and respiratory health. Home dampness is thought to have health consequences because it has the potential to increase the proliferation of house-dust mites and moulds, both of which are allergenic. The results from the many studies conducted to investigate whether damp and mould are associated with health outcomes are difficult to compare because the methods of measuring exposures and health outcomes have not been standardized. However, the studies that have been conducted in children are probably the most reliable because the confounding effects of active smoking or occupational exposures are absent, and because the presence of symptoms of cough and wheeze have been consistently investigated in many studies. The increased risk of children having these symptoms if the home has damp or mould is fairly small with an odds ratio that is generally in the range 1.5-3.5, these estimates being statistically significant when the sample size has been large enough. This range is consistent with the measured effects of other environmental exposures which are considered important to health, such as environmental tobacco smoke or outdoor air pollutants. The potential benefits of reducing mould in the home have not been investigated, and the few studies that have investigated health improvements as a result of increasing ventilation or reducing damp in order to reduce house-dust mite levels suggest that this intervention is expensive, requires a large commitment, and is unlikely to be successful in the long term. This implies that houses need to be specifically designed for primary prevention of respiratory problems associated with indoor allergen proliferation rather than using post hoc procedures to improve indoor climate and reduce allergen load as a secondary or tertiary preventive strategy.

Spectral characteristics of postural control in elderly individuals

OBJECTIVE

To examine the feasibility of using spectral analysis techniques to identify potential biomarkers of diminished postural control in elderly individuals.

DESIGN

Data from spectral signatures (derived from postural sway) of 21 young adults and 42 elderly individuals classified as "high" or "low" risk with regard to functional balance capacity were analyzed using Risk Category (3) x Sensory Condition (3) multivariate analyses of variance. Postural control was challenged by varying the visual conditions under which individuals stood on a measurement platform.

RESULTS

Results indicated that measures of central tendency and dispersion of the spectral frequency distribution from medial-lateral components of sway (but not antero-posterior sway) clearly differentiated between "high" and "low" risk elderly. Low risk elderly were not different from young adults. High risk elderly exhibited greater dispersion and lower mean frequency than other groups.

CONCLUSIONS

Differences in spectral characteristics of medial-lateral components of sway were more related to risk category than to age. Elderly persons with high functional balance capacity displayed characteristics similar to those of young adults. Thus, spectral frequency analysis techniques may be a clinically useful tool for identifying individuals potentially at risk of falling.

An increase in hookworm infection temporally associated with ecologic change

This report describes a significant increase in the prevalence of hookworm infection in an area of Haiti where intestinal parasites are common, but hookworm has not been common. Changing environmental conditions, specifically deforestation and subsequent silting of a local river, have caused periodic flooding with deposition of a layer of sandy loam topsoil and increased soil moisture. We speculate that these conditions, conducive to transmission of the infection, have allowed hookworm to reemerge as an important human pathogen.

The problem of hospital-induced malnutrition

This paper discusses the problem of hospital-induced malnutrition. Patients particularly at risk are identified and the causes of PEM are outlined.

Glomerular expression of monocyte chemoattractant protein-1 in experimental and human glomerulonephritis

BACKGROUND

Glomerular monocytes are found in a variety of renal diseases and appear to be important in the pathogenesis of glomerular injury. The mediators responsible for recruiting monocytes to the glomerulus are not well characterized. We have recently established that cultured human mesangial cells produce the specific monocyte chemoattractant, monocyte chemoattractant protein-1 (MCP-1) in response to inflammatory cytokines commonly found in glomeruli during glomerulonephritis (GN). This suggested that MCP-1 may be involved in recruiting leukocytes to the glomerulus. To date however, there is little information regarding the expression of MCP-1 during renal disease. The present study was undertaken to investigate the in vivo expression of MCP-1 during experimental and human GN.

EXPERIMENTAL DESIGN

A rodent model of anti-glomerular basement membrane GN was used to investigate glomerular MCP-1 mRNA regulation and protein expression. The presence of MCP-1 in human renal tissue was studied by immunostaining kidney biopsy material from patients with a variety of glomerulopathies.

RESULTS

MCP-1 mRNA was transiently upregulated during the early stages of experimental GN. Message levels increased in association with the monocyte influx and correlated with expression of immunoreactive MCP-1 in the nephritic glomeruli. Glomerular MCP-1 was also found in human inflammatory glomerulopathies, but not in glomerular diseases lacking a prominent monocyte infiltrate.

CONCLUSIONS

These data support a role for MCP-1 in the pathogenesis of glomerular inflammation.

Spectral signature of forces to discriminate perturbations in standing posture

This study proposes a methodology for the collection and analysis of the spectral characteristics of human movement patterns. Specifically, the purpose of this study was to determine the reliability of the spectral signature obtained from postural forces and the usefulness of the technique in identifying perturbations in standing posture. Data collected included trials of the experimental protocol under normal standing conditions and under three experimental conditions designed to perturb stability. Results of this investigation indicated that spectral signatures created from ground forces using the methodology proposed in this study were highly reliable within individuals and across different testing sessions. These data further indicate that spectral signatures obtained from ground reaction forces during standing provide a sensitive indicator of an individual's postural stability.

The Neurobehavioural Rating Scale: replication in an acute, inpatient rehabilitation setting

The Neurobehavioural Rating Scale (NRS) was developed to allow quantification of clinical observations of the behaviour of individuals following traumatic head injury. Initial validation of this instrument reported satisfactory interobserver reliability, as well as preliminary support for its validity in differentiating both severity and chronicity of head injury. In the present study, reliability and content validity of the NRS were replicated using a population of severe head injury patients undergoing inpatient rehabilitation. Concurrent, independent assessment using the NRS was conducted weekly by two members of an inpatient, traumatic head injury team. Acceptable levels of interobserver reliability were found, despite less control over observed behaviour in the naturalistic setting used. Content validity was also supported in this replication, although recommendations for 'tightening' the NRS included better definition of the seven-point severity rating for each item, as well as potential deletion of two items that contributed little to differential variance in the total NRS score. The NRS appears to be a promising clinical and research tool for assessing the neurobehavioural sequelae of traumatic head injury. Its strengths include efficiency of administration and the flexibility to administer through brief, structured interviews or observations in a naturalistic setting. Continued research on the NRS in different settings and with different populations is required to establish its validity.

Pharmacokinetics of 14C-etretinate in healthy volunteers and two patients with biliary T-tube drainage

The pharmacokinetic profile of 14C-etretinate, a retinoid that is effective in the treatment of psoriasis, was studied in six healthy male volunteers and two biliary T-tube patients. Following a 100 mg oral dose of 14C-etretinate (20 microcurie), etretinate and its major blood metabolites (etretin, isoetretin) were measured by HPLC and total carbon-14 was measured in blood, bile, urine, and feces by liquid scintillation counting. Etretinate was extensively metabolized in healthy volunteers and in T-tube patients. During the absorption phase, 75 per cent of the total radioactivity in the blood could be accounted for as etretinate, etretin, and isoetretin whereas these compounds accounted for only approximately 12 per cent of the blood radioactivity in T-tube patients over the same time period. The blood concentrations of etretinate, etretin, and isoetretin appeared to be substantially reduced in T-tube patients compared to those in healthy volunteers. A higher proportion of the total drug was excreted in the feces and bile of the T-tube patients (84 per cent) than in the feces of healthy volunteers (62 per cent). The major factor responsible for the observed decrease in etretinate blood concentrations following biliary cannulation appears to be the reduced absorption of etretinate due to the elimination of solubilizing bile salts in the duodenum. Carbon-14 related material was detected in urine and feces for as long as 3 weeks in healthy subjects supporting the previous observation that a long terminal elimination half-life exists for etretinate, even following a single dose of the compound.

The quality of life: design and evaluation of a self-assessment instrument for use with cancer patients

An attempt was made to define the concept of 'quality of life' and outline the development of a self-assessment instrument for detecting the changes in life as a whole which result from the presence and treatment of malignant disease. A comparison was made between three different scoring systems, familiar in psychometric assessment, although less familiar in nursing. The items selected for inclusion in the measurement instrument were based on an existing symptom distress scale and on the previously identified concerns of cancer patients. The relationship between such symptoms and the activities of daily living was explored. Each item, and the instrument as a whole, appeared to be reliable and to represent a valid means of assessing the impact of the disease on patient well-being. It was simple to use and straightforward to score and appeared accurately to reflect the patients' general condition.

Comparison of dental crown height in bite impressions

A wax bite impression can serve as a reliable identification of missing and unknown children, particularly in the absence of caries and restorations. Dental crown heights in bite impressions made from noncontoured and contoured wax wafers were compared in ten patients, ranging in age from three to eight years. The contoured wax wafer produced significantly greater crown heights in the casts which were fabricated from it. The differences were most pronounced in the anterior teeth; but generally true for all the teeth.

Babesiosis in Wisconsin. A new focus of disease transmission

A confirmed case of human babesiosis was identified in August 1983 in a 54-year-old asplenic Wisconsin resident. Babesia microti was identified as the causative agent by blood smear morphology and hamster inoculation techniques. The patient's wife had clinically confirmed Lyme disease in 1981 and had serologic evidence (immunofluorescent antibody to a B microti titer of 1:1,024) of recent Babesia infection in August 1983. Mice (Peromyscus species) trapped on the patients' property and elsewhere in their Wisconsin county of residence were infected with B microti. Lyme disease and babesiosis have the same tick vector and animal reservoir; serum samples from 116 Wisconsin and Minnesota residents with clinically confirmed Lyme disease between 1980 and 1983 were tested, and none were found to have concurrent Babesia infection. This area of Wisconsin is identified as a new focus for babesiosis transmission, but the risk of transmission seems to be low.