Evaluating connectivity risk of farm roadway runoff with waters - Development and sensitivity analysis of a semi quantitative risk model

Farm roadways are an important sub-component of the nutrient transfer continuum (NTC) and roadway runoff (RR), leading to nutrient pressures in receiving waters at different times of the year at catchment scale. This study developed a semi-quantitative risk assessment model for dairy farms that once populated with data identifies roadway sections where RR enters waters. The model contains parameters that represent source, mobilisation and transport-connectivity stages of the NTC defined as continuous or categorical variables. Each parameter has a corresponding scoring system in terms of connectivity likelihood to waters (L) and the associated impact on water quality (I) from which field data can be converted to a risk score (RS). The connectivity or impact risk of any roadway section is a sum of all parameter scores, i.e. 'Total Risk Score' (TRS). The risk scores were classified into 5 categories (very low, low, moderate, high and very high). Field data from seven farms enabled five equal interval risk score classifications to be developed (very low (110-134), low (135-158), moderate (159-182), high (183-206), very high (207-230)). Fieldwork data showed differences between the number of mapped roadway sections ranging from 35 to 76, with the lowest and highest risk scores being 110 and 230, respectively. Out of all sections scored 25.9 %, 45.6 %, 20.4 %, 6.4 %, and 2 % were in very low, low, moderate, high and very high categories, respectively. In terms of management, only 8.4 % (i.e. high or very high scores) had all components of the NTC and required RR mitigation. An examination of the mobilisation parameter showed that the % of roadway sections needing mitigation is likely to increase if rainfall increases on these farms. An uncertainty assessment limiting the model to different levels of connectivity confirmed that all components of the NTC and those with greater than moderate risk should only be considered in future mitigation plans. Future work should concentrate on adapting this methodology to a wide range of farm enterprises.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

U.S. Federal Agency interests and key considerations for new approach methodologies for nanomaterials

Engineered nanomaterials (ENMs) come in a wide array of shapes, sizes, surface coatings, and compositions, and often possess novel or enhanced properties compared to larger sized particles of the same elemental composition. To ensure the safe commercialization of products containing ENMs, it is important to thoroughly understand their potential risks. Given that ENMs can be created in an almost infinite number of variations, it is not feasible to conduct in vivo testing on each type of ENM. Instead, new approach methodologies (NAMs) such as in vitro or in chemico test methods may be needed, given their capacity for higher throughput testing, lower cost, and ability to provide information on toxicological mechanisms. However, the different behaviors of ENMs compared to dissolved chemicals may challenge safety testing of ENMs using NAMs. In this study, member agencies within the Interagency Coordinating Committee on the Validation of Alternative Methods were queried about what types of ENMs are of agency interest and whether there is agency-specific guidance for ENM toxicity testing. To support the ability of NAMs to provide robust results in ENM testing, two key issues in the usage of NAMs, namely dosimetry and interference/bias controls, are thoroughly discussed.

Characterizing biopersistence potential of the metabolite 5:3 fluorotelomer carboxylic acid after repeated oral exposure to the 6:2 fluorotelomer alcohol

Our previous report on pharmacokinetic (PK) evaluation of 6:2 fluorotelomer alcohol (6:2 FTOH) examined the biopersistence potential of its metabolites based on data published from single inhalation and occupational 6:2 FTOH exposure studies. We calculated internal exposure estimates of three key metabolites of 6:2 FTOH, of which 5:3 fluorotelomer carboxylic acid (5:3 acid) had the highest internal exposure and the slowest clearance. No oral repeated 6:2 FTOH exposure data were available at the time to fully characterize the biopersistence potential of the metabolite 5:3 acid. We recently received additional data on 6:2 FTOH and 5:3 acid, which included a 90-day toxicokinetic study report on repeated oral 6:2 FTOH exposure to rats. We reviewed the study and analyzed the reported 5:3 acid concentrations in plasma, liver, and fat using one-compartment PK modeling and calculated elimination rate constants (k_el), elimination half-lives (t_1/2) and times to steady state (t_ss) of 5:3 acid at three 6:2 FTOH doses. Our results showed that t_ss of 5:3 acid in plasma and evaluated tissues were approximately close to 1 year, such that the majority of highest values were observed at the lowest 6:2 FTOH dose, indicating its association with the biopersistence of 6:2 FTOH. The results of our PK analysis are the first to characterize biopersistence potential of the 5:3 acid after repeated oral exposure to the parent compound 6:2 FTOH based on steady state PK parameters, and therefore, may have an impact on future study designs when conducting toxicity assays for such compounds.

Internal exposure-based pharmacokinetic evaluation of potential for biopersistence of 6:2 fluorotelomer alcohol (FTOH) and its metabolites

Polyfluorinated compounds (PFCs) are authorized for use as greaseproofing agents in food contact paper. As C8-PFCs (8-carbons) are known to accumulate in tissues, shorter-chain C6-PFCs (6-carbons) have replaced C8-PFCs in many food contact applications. However, the potential of C6-PFCs for human biopersistence has not been fully evaluated. For the first time, we provide internal exposure estimates to key metabolites of 6:2 fluorotelomer alcohol (6:2 FTOH), a monomeric component of C6-PFCs, to extend our understanding of exposure beyond estimates of external exposure. Pharmacokinetic data from published rat and human studies on 6:2 FTOH were used to estimate clearance and area under the curve (AUC) for its metabolites: 5:3 fluorotelomer carboxylic acid (5:3 A), perfluorohexanoic acid (PFHxA) and perfluoroheptanoic acid (PFHpA). Internal exposure to 5:3 A was the highest of evaluated metabolites across species and it had the slowest clearance. Additionally, 5:3 A clearance decreased with increasing 6:2 FTOH exposure. Our analysis provides insight into association of increased internal 5:3 A exposure with high biopersistence potential of 6:2 FTOH. Our results identify 5:3 A as an important biomarker of internal 6:2 FTOH exposure for use in biomonitoring studies, and are potentially useful for toxicological assessment of chronic dietary 6:2 FTOH exposure.

Evaluation of allocation methods for calculation of carbon footprint of grass-based dairy production

A major methodological issue for life cycle assessment, commonly used to quantify greenhouse gas emissions from livestock systems, is allocation from multifunctional processes. When a process produces more than one output, the environmental burden has to be assigned between the outputs, such as milk and meat from a dairy cow. In the absence of an objective function for choosing an allocation method, a decision must be made considering a range of factors, one of which is the availability and quality of necessary data. The objective of this study was to evaluate allocation methods to calculate the climate change impact of the economically average (€/ha) dairy farm in Ireland considering both milk and meat outputs, focusing specifically on the pedigree of the available data for each method. The methods were: economic, energy, protein, emergy, mass of liveweight, mass of carcass weight and physical causality. The data quality for each method was expressed using a pedigree score based on reliability of the source, completeness, temporal applicability, geographical alignment and technological appropriateness. Scenario analysis was used to compare the normalised impact per functional unit (FU) from the different allocation methods, between the best and worst third of farms (in economic terms, €/ha) in the national farm survey. For the average farm, the allocation factors for milk ranged from 75% (physical causality) to 89% (mass of carcass weight), which in turn resulted in an impact per FU, from 1.04 to 1.22 kg CO₂-eq/kg (fat and protein corrected milk). Pedigree scores ranged from 6.0 to 17.1 with protein and economic allocation having the best pedigree. It was concluded that when making the choice of allocation method, the quality of the data available (pedigree) should be given greater emphasis during the decision making process because the effect of allocation on the results. A range of allocation methods could be deployed to understand the uncertainty associated with the decision.

What Is the Relationship Between Morning Symptoms and Measures of Disease Activity in Patients With Rheumatoid Arthritis?

OBJECTIVE

Little is known about the relationship between morning symptoms of rheumatoid arthritis (RA) and measures of disease activity currently used to assess RA. Information available from the Circadian Administration of Prednisone in Rheumatoid Arthritis (CAPRA-2) study was used to investigate these relationships.

METHODS

CAPRA-2 included 350 patients with RA who were symptomatic despite treatment with disease-modifying antirheumatic drugs, randomized 2:1 to additional treatment with a 5-mg daily dose of delayed-release prednisone or placebo. Pearson's correlations were used to evaluate the relationships between change from baseline in symptoms (duration of morning stiffness, severity of morning stiffness, and intensity of pain on waking) and measures of disease activity (the American College of Rheumatology 20% improvement criteria [ACR20], the Disease Activity Score in 28 joints [DAS28], and the Health Assessment Questionnaire disability index). Correlations were defined as weak (<0.3), moderate (0.3-0.7), or strong (>0.7).

RESULTS

There was a strong correlation between the severity of morning stiffness and the intensity of morning pain (Pearson's correlation 0.91, P < 0.001). There was a weak correlation between the duration of morning stiffness and measures of disease activity (0.24-0.28), with moderate correlations between the severity of morning stiffness or intensity of pain on waking and DAS28 or ACR20 scores (0.44-0.48). Severity of morning stiffness showed less variability and a greater effect size than did duration of morning stiffness.

CONCLUSION

Morning symptoms and measures of disease activity show weak to moderate correlations. Severity of morning stiffness showed less variability and greater effect size than did duration of morning stiffness. These findings suggest that severity is the preferred construct to measure the impact of morning stiffness in patients with RA, information that is not fully captured in the RA core set.

Morning stiffness response with delayed-release prednisone after ineffective course of immediate-release prednisone

Objective: To assess morning stiffness in rheumatoid arthritis (RA) patients switched from immediate-release (IR) to delayed-release (DR) prednisone.

Method: Circadian Administration of Prednisone in Rheumatoid Arthritis-1 (CAPRA-1) is a 12-week, randomized, multicentre, active-controlled study of morning stiffness that consisted of a double-blind phase and a 9-month open-label extension. Patients receiving IR prednisone with no significant improvement after the double-blind study were switched to DR prednisone. Morning stiffness duration and median absolute and relative changes in pain and global assessment were evaluated (3, 6, and 9 months).

Results: In patients switched from IR to DR prednisone (n = 110), statistically significant reductions in morning stiffness occurred over 3 months and were sustained for 9 months. Absolute reduction of morning stiffness was ~50 min with > 40% relative reduction at each visit. Interleukin (IL)-6 levels were reduced by the same amount. Statistically significant and clinically meaningful mean reductions in morning stiffness were maintained at > 67 min at each visit along with significant improvements in pain and patient global assessment. There was no evidence of tachyphylaxis seen over the 9-month study.

Conclusions: Patients receiving disease-modifying anti-rheumatic drugs (DMARDs) and IR prednisone who had not had significant reductions in morning stiffness demonstrated statistically significant and clinically meaningful improvements when switched to DR prednisone.

Randomized trial of safinamide add-on to levodopa in Parkinson's disease with motor fluctuations

Levodopa is effective for the motor symptoms of Parkinson's disease (PD), but is associated with motor fluctuations and dyskinesia. Many patients require add-on therapy to improve motor fluctuations without exacerbating dyskinesia. The objective of this Phase III, multicenter, double-blind, placebo-controlled, parallel-group study was to evaluate the efficacy and safety of safinamide, an α-aminoamide with dopaminergic and nondopaminergic mechanisms, as add-on to l-dopa in the treatment of patients with PD and motor fluctuations. Patients were randomized to oral safinamide 100 mg/day (n = 224), 50 mg/day (n = 223), or placebo (n = 222) for 24 weeks. The primary endpoint was total on time with no or nontroublesome dyskinesia (assessed using the Hauser patient diaries). Secondary endpoints included off time, Unified Parkinson's Disease Rating Scale (UPDRS) Part III (motor) scores, and Clinical Global Impression-Change (CGI-C). At week 24, mean ± SD increases in total on time with no or nontroublesome dyskinesia were 1.36 ± 2.625 hours for safinamide 100 mg/day, 1.37 ± 2.745 hours for safinamide 50 mg/day, and 0.97 ± 2.375 hours for placebo. Least squares means differences in both safinamide groups were significantly higher versus placebo. Improvements in off time, UPDRS Part III, and CGI-C were significantly greater in both safinamide groups versus placebo. There were no significant between-group differences for incidences of treatment-emergent adverse events (TEAEs) or TEAEs leading to discontinuation. The addition of safinamide 50 mg/day or 100 mg/day to l-dopa in patients with PD and motor fluctuations significantly increased total on time with no or nontroublesome dyskinesia, decreased off time, and improved parkinsonism, indicating that safinamide improves motor symptoms and parkinsonism without worsening dyskinesia.

Reducing alcohol-related harm in disadvantaged men: development and feasibility assessment of a brief intervention delivered by mobile telephone

Background

Socially disadvantaged men suffer substantial harm from heavy drinking. Brief alcohol interventions are effective in reducing consumption when delivered via health care. There is a need for tailored brief interventions for disadvantaged men who seldom attend health care.

Objectives

(1) To investigate the best ways to recruit and retain disadvantaged men in a study aimed at reducing the frequency of heavy drinking. (2) To identify the type of content and timing of the delivery that is most likely to engage disadvantaged young to middle-aged men in an intervention delivered by text messages. (3) To determine whether or not the intervention is likely to be an acceptable way to influence the frequency of heavy drinking.

Design

A three-phase study involving the development of the recruitment strategy and the intervention, an assessment of the feasibility of a randomised controlled trial, and a post-study evaluation.

Setting

Community-based study, conducted in Dundee, UK.

Participants

Disadvantaged men aged 25–44 years who had two or more episodes of heavy drinking (≥ 8 units in a single session) in the preceding month. Two recruitment strategies were employed: recruitment through general practice (GP) registers and recruitment through a community outreach strategy.

Interventions

Focus groups explored drinking motives and behaviours of the target group. The intervention also drew on reviews of the literature on: alcohol brief interventions, text message studies, communication theory and behaviour change theories and techniques. The intervention group received 36 text messages with images sent over a 28-day period.

Main outcome measures

The outcome measures evaluated the likely success of a full trial: recruitment of the participants; construction and delivery of a theoretically and empirically based intervention that successfully engages disadvantaged men; potential for the intervention to influence binge drinking.

Results

The focus group analyses identified that personal experience and knowledge of the harmful effects of alcohol was widespread. Furthermore, there was a discrepancy between frequent binge drinking and perceived social expectations and duties. This could usefully be targeted in the intervention. Theoretically and empirically based behaviour change strategies were successfully rendered in attractive, colourful, brief text messages. Both recruitment strategies (GP registers and community outreach) proved successful and a total of 67 men were recruited, exceeding the target of 60. The participants were at high risk of harm because of frequent episodes of heavy binge drinking. Baseline interviews established that those recruited through community outreach drank substantially more and had more frequent binge drinking sessions than those recruited through GP registers. Retention at follow-up was 96%. Extensive process evaluation was conducted. The evaluation showed that 95% of text messages were successfully delivered to participants' telephones. Furthermore, there was a high level of engagement with text messages which sought responses. Most men replied to these texts, often giving carefully structured personal responses. Analyses of the responses indicated a high level of engagement with key components of the behaviour change strategy. Post-trial evaluation showed high levels of satisfaction with the intervention.

Conclusions

This study has shown that disadvantaged men can be recruited and retained in an alcohol intervention trial. A theoretically and empirically based intervention was successfully delivered by text message. Furthermore, the messages were well received and elicited the types of response intended. A full trial of the intervention, incorporating a cost-effectiveness study, should be carried out.

Study registration

This study is registered as ISRCTN10515845.

Funding

The National Institute for Health Research Public Health Research programme.

Silver nanoparticle-induced mutations and oxidative stress in mouse lymphoma cells

Silver nanoparticles (Ag-NPs) have increasingly been used for coatings on various textiles and certain implants, for the treatment of wounds and burns, as a water disinfectant, and in air-freshener sprays. The wide use of Ag-NPs may have potential human health impacts. In this study, the mutagenicity of 5-nm Ag-NPs was evaluated in the mouse lymphoma assay system, and modes of action were assessed using standard alkaline and enzyme-modified Comet assays and gene expression analysis. Treatments of L5178Y/Tk(+/-) mouse lymphoma cells with 5-nm uncoated Ag-NPs resulted in a significant yield of mutants at doses between 3 and 6 μg/mL; the upper range was limited by toxicity. Loss of heterozygosity analysis of the Tk mutants revealed that treatments with uncoated Ag-NPs induced mainly chromosomal alterations spanning less than 34 megabase pairs on chromosome 11. Although no significant induction of DNA damage in Ag-NP-treated mouse lymphoma cells was observed in the standard Comet assay, the Ag-NP treatments induced a dose-responsive increase in oxidative DNA damage in the enzyme-modified Comet assay in which oxidative lesion-specific endonucleases were added. Gene expression analysis using an oxidative stress and antioxidant defense polymerase chain reaction (PCR) array showed that the expressions of 17 of the 59 genes on the arrays were altered in the cells treated with Ag-NPs. These genes are involved in production of reactive oxygen species, oxidative stress response, antioxidants, oxygen transporters, and DNA repair. These results suggest that 5 nm Ag-NPs are mutagenic in mouse lymphoma cells due to induction of oxidative stress by the Ag-NPs.

Genotoxicity evaluation of titanium dioxide nanoparticles using the Ames test and Comet assay

Titanium dioxide nanoparticles (TiO2-NPs) are being used increasingly for various industrial and consumer products, including cosmetics and sunscreens because of their photoactive properties. Therefore, the toxicity of TiO2-NPs needs to be thoroughly understood. In the present study, the genotoxicity of 10nm uncoated sphere TiO2-NPs with an anatase crystalline structure, which has been well characterized in a previous study, was assessed using the Salmonella reverse mutation assay (Ames test) and the single-cell gel electrophoresis (Comet) assay. For the Ames test, Salmonella strains TA102, TA100, TA1537, TA98 and TA1535 were preincubated with eight different concentrations of the TiO2-NPs for 4 h at 37 °C, ranging from 0 to 4915.2 µg per plate. No mutation induction was found. Analyses with transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) showed that the TiO2-NPs were not able to enter the bacterial cell. For the Comet assay, TK6 cells were treated with 0-200 µg ml(-1) TiO2-NPs for 24 h at 37 °C to detect DNA damage. Although the TK6 cells did take up TiO2-NPs, no significant induction of DNA breakage or oxidative DNA damage was observed in the treated cells using the standard alkaline Comet assay and the endonuclease III (EndoIII) and human 8-hydroxyguanine DNA-glycosylase (hOGG1)-modified Comet assay, respectively. These results suggest that TiO2-NPs are not genotoxic under the conditions of the Ames test and Comet assay.

Thyroid dysfunction and fibrin network structure: a mechanism for increased thrombotic risk in hyperthyroid individuals

CONTEXT

Hyperthyroidism is associated with increased thrombosis risk, and fibrin clot structure determines susceptibility to vascular thrombotic events.

OBJECTIVE

Our objective was to investigate clot formation and lysis in hyperthyroidism using observational and interventional studies.

DESIGN

Ex vivo fibrin clot structure/fibrinolysis and plasma levels of thrombotic/inflammatory markers were investigated in hyperthyroid individuals (n = 24) and matched controls (n = 19), using turbidimetric assays, ELISA, and confocal and electron microscopy. The effects of normalizing thyroid function were analyzed (n = 19) and the role of short-term exogenous hyperthyroidism in healthy volunteers studied (n = 16).

RESULTS

Hyperthyroid subjects displayed higher clot maximum absorbance compared with controls (0.41 ± 0.03 and 0.27 ± 0.01 arbitrary units, respectively; P < 0.01), and longer clot lysis time (518 ± 23 and 461 ± 18 sec, respectively; P < 0.05), which correlated with free T(4) levels. Plasma levels of fibrinogen and plasminogen activator inhibitor-1 were significantly higher in patients compared with controls. Normalizing thyroid function in 19 subjects was associated with lower maximum absorbance and shorter lysis time, accompanied by reduction in fibrinogen, plasminogen activator inhibitor-1, and D-dimer levels. Complement C3, but not C-reactive protein, levels were higher in hyperthyroid subjects compared with controls (0.92 ± 0.05 and 0.64 ± 0.03 g/liter, respectively; P < 0.01), correlated with clot structure parameters, and decreased after intervention. Confocal and electron microscopy confirmed more compact clots and impaired fibrinolysis during hyperthyroidism. Exogenous hyperthyroidism in healthy volunteers had no effect on any of the clot structure parameters.

CONCLUSIONS

Endogenous hyperthyroidism is associated with more compact clots and resistance to fibrinolysis ex vivo, related to the degree of hyperthyroidism and C3 plasma levels, and these changes are modulated by achieving euthyroidism. Altered clot structure/lysis may be one mechanism for increased thrombotic risk in hyperthyroidism.

LIAD-fs scheme for studies of ultrafast laser interactions with gas phase biomolecules

Laser induced acoustic desorption (LIAD) has been used for the first time to study the parent ion production and fragmentation mechanisms of a biological molecule in an intense femtosecond (fs) laser field. The photoacoustic shock wave generated in the analyte substrate (thin Ta foil) has been simulated using the hydrodynamic HYADES code, and the full LIAD process has been experimentally characterised as a function of the desorption UV-laser pulse parameters. Observed neutral plumes of densities >10(9) cm(-3) which are free from solvent or matrix contamination demonstrate the suitability and potential of the source for studying ultrafast dynamics in the gas phase using fs laser pulses. Results obtained with phenylalanine show that through manipulation of fundamental femtosecond laser parameters (such as pulse length, intensity and wavelength), energy deposition within the molecule can be controlled to allow enhancement of parent ion production or generation of characteristic fragmentation patterns. In particular by reducing the pulse length to a timescale equivalent to the fastest vibrational periods in the molecule, we demonstrate how fragmentation of the molecule can be minimised whilst maintaining a high ionisation efficiency.

HIV point-of-care testing pitfalls

When counselling patients for postexposure prophylaxis after sexual exposure, we may need to inform them that the efficacy may be low, especially if the patient also had risks prior to the 72 hours between exposure and treatment. The use of a point-of-care test, as well as fourth generation HIV tests and HIV RNA in combination, can still miss seroconversion in the 'eclipse' phase of the infection as these tests are not designed to detect the earliest phase of infection.

A brief report on perceptions of alcohol and society among Scottish medical students

AIMS

To assess perceptions on alcohol misuse and addiction among medical students prior to in-depth training in order to determine areas of the curriculum that need to be reshaped or focused on.

METHODS

A questionnaire assessment of first- and second-year medical students' perceptions of alcohol misuse.

RESULTS

Students had some misconceptions about current alcohol misuse rates, including a perception that addiction is common among health professionals, that the under-25s had the fastest increasing rate of alcohol addiction and that British women had a more rapidly increasing rate of alcohol addiction than British men.

CONCLUSION

Encouragingly, students overwhelmingly felt that alcohol addiction was something to which they could make a difference. It highlights that early education about alcohol misuse is important in terms of teaching students how to recognize hazardous and harmful drinkers and how to manage them.

In-Vivo Assessment of Tissue Compatibility and Calcification of Bulk and Porous Silicon

The compatibility of both bulk and porous silicon at the subcutaneous site has been assessed for the first time, following ISO standard procedures. The in-vivo responses to implantation were monitored in the guinea pig and histopathological reactions evaluated at 1, 4, 12 and 26 weeks. Attention is focused here on the histological assessment protocols used, and the results demonstrating in-vivo evidence for good tissue compatibility, and porous Si bioactivity with regards calcification.

The injured lung: clinical issues and experimental models

Exposure of military and civilian populations to inhaled toxic chemicals can take place as a result of deliberate release (warfare, terrorism) or following accidental releases from industrial concerns or transported chemicals. Exposure to inhaled toxic chemicals can result in an acute lung injury, and in severe cases acute respiratory distress syndrome, for which there is currently no specific medical therapy, treatment remaining largely supportive. This treatment often requires intensive care facilities that may become overwhelmed in mass casualty events and may be of limited benefit in severe cases. There remains, therefore, a need for evidence-based treatment to inform both military and civilian medical response teams on the most appropriate treatment for chemically induced lung injury. This article reviews data used to derive potential clinical management strategies for chemically induced lung injury.

Nanoscale Elastic-Property Mapping with Contact-Resonance-Frequency AFM

We describe a dynamic atomic force microscopy (AFM) method to map the nanoscale elastic properties of surfaces, thin films, and nanostructures. Our approach is based on atomic force acoustic microscopy (AFAM) techniques previously used for quantitative measurements of elastic properties at a fixed sample position. AFAM measurements determine the resonant frequencies of an AFM cantilever in contact mode to calculate the tip-sample contact stiffness k*. Local values for elastic properties such as the indentation modulus M can be determined from k* with the appropriate contact-mechanics models. To enable imaging at practical rates, we have developed a frequency-tracking circuit based on digital signal processor architecture to rapidly locate the contact-resonance frequencies at each image position. We present contact-resonance frequency images obtained using both flexural and torsional cantilever images as well as the corresponding vertical contact-stiffness (k*) image calculated from flexural frequency images. Methods to obtain elastic-modulus images of M from vertical contact-stiffness images are also discussed.

Furosemide in the treatment of phosgene induced acute lung injury

METHOD

Using previously validated methods, 16 anaesthetised large white pigs were exposed to phosgene (target inhaled dose 0.3 mg kg(-1)), established on mechanical ventilation and randomised to treatment with either nebulised furosemide (4 ml of 10 mg x ml(-1) solution) or saline control. Treatments were given at 1, 3, 5, 7, 9, 12, 16 and 20 hours post phosgene exposure; the animals were monitored to 24 hours following phosgene exposure.

RESULTS

Furosemide treatment had no effect on survival, and had a deleterious effect on PaO2: FiO2 ratio between 19 and 24 hours. All other measures investigated were unaffected by treatment.

CONCLUSION

Nebulised furosemide treatment following phosgene induced acute lung injury does not improve survival and worsens PaO2: FiO2 ratio. Nebulised furosemide should be avoided following phosgene exposure.

Fabrication and characterization of a carbon nanotube-based nanoknife

We demonstrate the fabrication and testing of a prototype microtome knife based on a multiwalled carbon nanotube (MWCNT) for cutting approximately 100 nm thick slices of frozen-hydrated biological samples. A piezoelectric-based 3D manipulator was used inside a scanning electron microscope (SEM) to select and position individual MWCNTs, which were subsequently welded in place using electron beam-induced deposition. The knife is built on a pair of tungsten needles with provision to adjust the distance between the needle tips, accommodating various lengths of MWCNTs. We performed experiments to test the mechanical strength of a MWCNT in the completed device using an atomic force microscope tip. An increasing force was applied at the mid-point of the nanotube until failure occurred, which was observed in situ in the SEM. The maximum breaking force was approximately (8 x 10(-7)) N which corresponds well with the typical microtome cutting forces reported in the literature. In situ cutting experiments were performed on a cell biological embedding plastic (epoxy) by pushing it against the nanotube. Initial experiments show indentation marks on the epoxy surface. Quantitative analysis is currently limited by the surface asperities, which have the same dimensions as the nanotube.

Congenital cytomegalovirus: association between dried blood spot viral load and hearing loss

AIM

To investigate the relation between cytomegalovirus (CMV) viral load on dried blood spots (DBS) from newborn biochemical screening ("Guthrie") cards, and sensorineural hearing loss (SNHL) in congenital CMV.

DESIGN

Cross-sectional study with retrospective case-note review.

SETTING

Seven paediatric audiology departments in the United Kingdom.

PATIENTS

84 children, median age 7 years: 43 with known congenital CMV, 41 with unexplained SNHL.

INTERVENTIONS

Half a DBS was tested for CMV DNA viral load by quantitative real-time polymerase chain reaction (PCR).

MAIN OUTCOME MEASURES

Pure tone average hearing thresholds (0.5-4 kHz).

RESULTS

DBS CMV DNA viral load significantly correlated with hearing thresholds for the worse and better hearing ears (Spearman's rank correlations: r = 0.445, p = 0.008 and r = 0.481, p = 0.004 respectively). Multivariable logistic regression showed that the effect of DBS viral load on the risk of SNHL remained important, when age and central nervous system involvement had been taken into account (odds ratio (OR) 2.76, 95% confidence interval (CI) 1.14 to 6.63, p = 0.024). The mean log DBS viral load was significantly higher in children with SNHL than in those with normal hearing (2.69 versus 1.64, 95% CI -1.84 to -0.27, p = 0.01). 8/35 (23%) children with unexplained SNHL tested positive for CMV DNA on DBS. One false positive result was obtained.

CONCLUSION

The risk of SNHL increased with DBS viral load. Further studies should investigate whether DBS CMV testing has a role in identifying asymptomatic congenitally infected neonates at risk of SNHL, and whether antiviral treatment can reduce this risk.

The treatment of sulphur mustard burns with laser debridement

The chemical warfare agent, sulphur mustard (SM), is a potent blistering agent in man. Skin exposure can produce partial-thickness burns which take up to three months to heal. The aim of this study was to investigate the use of early laser ablation as a means of accelerating this exceptionally slow rate of healing. Four circular partial-thickness SM burns were induced on the dorsum of nine large white pigs (under general anaesthesia). At 72 h post-exposure, three burns per animal were ablated with a single pass of an UltraPulse 5000C CO(2) laser, at a fluence of 5-6 J cm(-2). All the burns were dressed with silver sulphadiazine and a semi-occlusive dressing. At one, two and three weeks post-surgery three animals were culled and all lesions excised for histological analysis. Burn depth was confirmed and measurements of the radii of regenerative epithelium were performed allowing the area of the zone of re-epithelialisation in each lesion to be calculated. Laser-treated lesions showed a significant increase (350%) in healing rates compared to controls (p<0.005). At two weeks, the laser-treated sites were 95% healed in comparison with control sites (28% healed). These data suggest that laser ablation may be effective in the treatment of partial-thickness SM-induced skin injury.

Clinical management of casualties exposed to lung damaging agents: a critical review

There is no specific antidote for the treatment of casualties exposed to chlorine, phosgene, or mustards; therefore, management is largely supportive. Corticosteroid treatment has been given to casualties accidentally exposed to chlorine. Clinical data on efficacy are inconclusive as the numbers given steroids have been small and the indications for administration unclear. There have been no clinical controlled studies. There is a stronger evidence base from animal studies, particularly from porcine and rodent models. Lung injury induced by phosgene and mustard appears to be mediated by glutathione depletion, lipid peroxidation, free radical generation, and subsequent cellular toxicity. There is limited evidence to suggest that repletion of glutathione reduces and/or prevents lung damage by these agents. This may provide an opportunity for therapeutic intervention.

SOAP-based services provided by the European Bioinformatics Institute

SOAP (Simple Object Access Protocol) () based Web Services technology () has gained much attention as an open standard enabling interoperability among applications across heterogeneous architectures and different networks. The European Bioinformatics Institute (EBI) is using this technology to provide robust data retrieval and data analysis mechanisms to the scientific community and to enhance utilization of the biological resources it already provides [N. Harte, V. Silventoinen, E. Quevillon, S. Robinson, K. Kallio, X. Fustero, P. Patel, P. Jokinen and R. Lopez (2004) Nucleic Acids Res., 32, 3–9]. These services are available free to all users from .

Retroperitoneal fibrosis: a rare cause of recurring abdominal pain

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Febrile-range hyperthermia augments neutrophil accumulation and enhances lung injury in experimental gram-negative bacterial pneumonia

We previously demonstrated that exposure to febrile-range hyperthermia (FRH) accelerates pathogen clearance and increases survival in murine experimental Klebsiella pneumoniae peritonitis. However, FRH accelerates lethal lung injury in a mouse model of pulmonary oxygen toxicity, suggesting that the lung may be particularly susceptible to injurious effects of FRH. In the present study, we tested the hypothesis that, in contrast with the salutary effect of FRH in Gram-negative peritonitis, FRH would be detrimental in multilobar Gram-negative pneumonia. Using a conscious, temperature-clamped mouse model and intratracheal inoculation with K. pneumoniae Caroli strain, we showed that FRH tended to reduce survival despite reducing the 3 day-postinoculation pulmonary pathogen burden by 400-fold. We showed that antibiotic treatment rescued the euthermic mice, but did not reduce lethality in the FRH mice. Using an intratracheal bacterial endotoxin LPS challenge model, we found that the reduced survival in FRH-treated mice was accompanied by increased pulmonary vascular endothelial injury, enhanced pulmonary accumulation of neutrophils, increased levels of IL-1beta, MIP-2/CXCL213, GM-CSF, and KC/CXCL1 in the bronchoalveolar lavage fluid, and bronchiolar epithelial necrosis. These results suggest that FRH enhances innate host defense against infection, in part, by augmenting polymorphonuclear cell delivery to the site of infection. The ultimate effect of FRH is determined by the balance between accelerated pathogen clearance and collateral tissue injury, which is determined, in part, by the site of infection.

A randomised comparison of oral misoprostol and vaginal prostaglandin E2 tablets in labour induction at term

OBJECTIVE

To compare the efficacy of 100 microg of oral misoprostol with 3 mg prostaglandin E2 vaginal tablets in term labour induction.

DESIGN

A non-blinded, randomised, controlled trial.

SETTING

A tertiary level, teaching Scottish Hospital.

POPULATION

Two hundred women at term with indications for labour induction and modified Bishop's cervical score of less than 8.

METHODS

The women were randomly allocated to receive either 100 microg of misoprostol orally (which could be repeated 4 hourly to a maximum of five doses if indicated), or a 3 mg tablet of prostaglandin E2 vaginally (which could be repeated in 6 hours, according to routine departmental protocol).

MAIN OUTCOME MEASURE

The number delivering vaginally within 24 hours of the induction.

RESULTS

Seventy-five women delivered vaginally in the misoprostol group and 73 in the PGE2 group. Of these, 50.7% in the misoprostol group and 54.8% in the PGE2 group delivered within 24 hours of the induction (RR 0.92, 95% CI 0.7 to 1.3). More women in the misoprostol group were given oxytocin, but this was not statistically significant (60%vs 47%, RR 1.3, 95% CI 0.98 to 1.7). Two women in the misoprostol group had uterine hyperstimulation. The neonatal outcomes were not significantly different in the two groups. There was a pound 1100 saving on direct drug costs in the misoprostol group.

CONCLUSIONS

Oral misoprostol (100 microg) has similar efficacy to vaginal PGE2 tablets, and may be an option to consider for term labour induction.

Cytomegalovirus infection in immunocompetent patients

Symptoms associated with cytomegalovirus (CMV) infection in immunocompetent patients are not well documented. From December 1998 through June 2001, serum samples obtained from 7630 patients in Cambridge and Chelmsford, United Kingdom, were tested for CMV immunoglobulin M. CMV immunoglobulin G avidity was used to confirm CMV infection. A total of 124 patients (106 patients treated by general practitioners [GPs] and 18 hospitalized patients) with CMV infection were identified. The most frequent symptoms were malaise (67%), fever (46%), and sweats (46%), and the most frequent finding was abnormal liver function test results (69%). Twelve percent of patients had a relapsing illness, and many had symptoms that lasted for up to 32 weeks (mean duration of symptoms, 7.8 weeks). GPs reported that there was a significant benefit in making the diagnosis of CMV infection; it provided reassurance and avoided the need for further investigations. We have identified symptoms associated with CMV infection in immunocompetent patients who present to GPs or who are admitted to the hospital.