Fear of movement and competence frustration mediate the relationship between pain catastrophising and physical function in people living with axSpA: an online cross-sectional survey

The objective of this study is to examine the contribution of pain catastrophising to Axial Spondyloarthritis (axSpA) patient's physical function and to test the mediating role of fear of movement, and uniquely, the contribution of competence frustration to the fear-avoidance model. Participants (N = 98, 70% female, M age = 45.62, SD 12.16) completed an online survey (December 2020-May 2021) distributed in the United Kingdom via the National Axial Spondyloarthritis Society (n ≈ 3500; NASS, 2019). The PROCESS SPSS macro was used to test three mediation models using percentile bootstrap 95% confidence intervals (PBCI). A significant indirect effect on the relationship between pain and physical function via fear of movement (β = 0.10, 95% PBCI = 0.030-0.183) was observed (Model 1). Model 2 showed the relationship between pain catastrophising and physical function to be significantly mediated by fear of movement (β = 0.16, 95% PBCI = 0.005-0.322). Finally, Model 3 showed a significant indirect effect on the relationship between pain catastrophising and physical function via competence frustration (β = 0.15, 95% PBCI = 0.014-0.309) but not through fear of movement (β = 0.062, 95% PBCI = - 0.134 to 0.248). To our knowledge, this is the first study to examine and demonstrate the unique contribution of competence need frustration to the Fear-avoidance model in people that live with axSpA. Identifying modifiable factors that contribute to disease outcomes such as physical function can improve the care and quality of life for people living with a disease currently without a cure.

Tissues and mechanisms associated with Verticillium wilt resistance in tomato using bi-grafted near-isogenic lines

Host resistance is the primary means to control Verticillium dahliae, a soil-borne pathogen causing major losses on a broad range of plants, including tomato. The tissues and mechanisms responsible for resistance remain obscure. In the field, resistant tomato used as rootstocks does not confer resistance. Here, we created bi-grafted plants with near-isogenic lines (NILs) exhibiting (Ve1) or lacking (ve1) resistance to V. dahliae race 1. Ten days after inoculation, scion and rootstock tissues were subjected to differential gene expression and co-expression network analyses. Symptoms only developed in susceptible scions regardless of the rootstock. Infection caused more dramatic alteration of tomato gene expression in susceptible compared with resistant tissues, including pathogen receptor, signaling pathway, pathogenesis-related protein, and cell wall modification genes. Differences were observed between scions and rootstocks, primarily related to physiological processes in these tissues. Gene expression in scions was influenced by the rootstock genotype. A few genes were associated with the Ve1 genotype, which was independent of infection or tissue type. Several were physically clustered, some near the Ve1 locus on chromosome 9. Transcripts mapped to V. dahliae were dominated by secreted candidate effector proteins. These findings advance knowledge of molecular mechanisms underlying the tomato-V. dahliae interaction.

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.

The experience of using prompting technology from the perspective of people with Dementia and their primary carers

OBJECTIVES

People who are living with dementia typically experience difficulties in completing multi-step, everyday tasks. However, digital technology such as touchscreen tablets provide a means of delivering concise personalised prompts that combine audio, text and pictures. This study was one component of a broader, mixed methods study that tested how an application (app) -based prompter running on a touchscreen tablet computer could support everyday activities in individuals with mild to moderate dementia. In this study we set out to understand the experiences of people living with dementia and their primary carer in using the prompter over a four-week period.

METHOD

We collected qualitative data using semi-structured interviews from 26 dyads, composed of a person living with dementia and their carer. Dyads were interviewed at the start and end of this period. Transcripts were then analysed using thematic analysis.

RESULTS

The study identified three overarching themes related to: participants' attitudes towards the technology; their judgements about how useful the prompter would be; and the emotional impact of using it.

CONCLUSION

Consistent with the Technology Acceptance Model, carers and participants were influenced by their approaches to technology and determined the usefulness of the prompter according to whether it worked for them and fitted into their routines. In addition, participants' decisions about using the prompter were also determined by the extent to which doing so would impact on their self-identity.

British Society for Echocardiography and British Cardio-Oncology Society guideline for transthoracic echocardiographic assessment of adult cancer patients receiving anthracyclines and/or trastuzumab

The subspecialty of cardio-oncology aims to reduce cardiovascular morbidity and mortality in patients with cancer or following cancer treatment. Cancer therapy can lead to a variety of cardiovascular complications, including left ventricular systolic dysfunction, pericardial disease, and valvular heart disease. Echocardiography is a key diagnostic imaging tool in the diagnosis and surveillance for many of these complications. The baseline assessment and subsequent surveillance of patients undergoing treatment with anthracyclines and/or human epidermal growth factor (EGF) receptor (HER) 2-positive targeted treatment (e.g. trastuzumab and pertuzumab) form a significant proportion of cardio-oncology patients undergoing echocardiography. This guideline from the British Society of Echocardiography and British Cardio-Oncology Society outlines a protocol for baseline and surveillance echocardiography of patients undergoing treatment with anthracyclines and/or trastuzumab. The methodology for acquisition of images and the advantages and disadvantages of techniques are discussed. Echocardiographic definitions for considering cancer therapeutics-related cardiac dysfunction are also presented.

BSE and BCOS Guideline for Transthoracic Echocardiographic Assessment of Adult Cancer Patients Receiving Anthracyclines and/or Trastuzumab

The subspecialty of cardio-oncology aims to reduce cardiovascular morbidity and mortality in patients with cancer or following cancer treatment. Cancer therapy can lead to a variety of cardiovascular complications, including left ventricular systolic dysfunction, pericardial disease, and valvular heart disease. Echocardiography is a key diagnostic imaging tool in the diagnosis and surveillance for many of these complications. The baseline assessment and subsequent surveillance of patients undergoing treatment with anthracyclines and/or human epidermal growth factor receptor (HER) 2-positive targeted treatment (e.g., trastuzumab and pertuzumab) form a significant proportion of cardio-oncology patients undergoing echocardiography. This guideline from the British Society of Echocardiography and British Cardio-Oncology Society outlines a protocol for baseline and surveillance echocardiography of patients undergoing treatment with anthracyclines and/or trastuzumab. The methodology for acquisition of images and the advantages and disadvantages of techniques are discussed. Echocardiographic definitions for considering cancer therapeutics-related cardiac dysfunction are also presented.

Axial spondyloarthritis 10 years on: still looking for the lost tribe

Despite the publication of various recommendations, quality standards and referral strategies to promote early diagnosis in axial SpA (axSpA) over the last decade, there remains a significant delay to diagnosis, leading to a lost tribe of undiagnosed, untreated patients with persistent back pain and axSpA symptoms. This review discusses the various factors contributing to diagnostic delay in axSpA, while providing recommendations to improve the diagnostic pathway, for example use of the online Spondyloarthritis Diagnosis Evaluation (SPADE) tool (http://www.spadetool.co.uk/). Significant shortcomings exist at both the primary and secondary care level, with healthcare professionals often lacking knowledge and awareness of axSpA. Myths regarding the classical signs and symptoms still prevail, including the perception of axSpA as a male disease, only occurring in individuals who are HLA-B27 positive with raised inflammatory markers. Individuals within this lost tribe of undiagnosed patients are likely lacking adequate treatment and are thereby at risk of worse clinical outcomes. It is therefore vital that public health initiatives are implemented to improve education of healthcare professionals and to ensure early specialist referral, to ultimately improve the lives of patients with axSpA.

Pathogenomics Characterization of an Emerging Fungal Pathogen, Fusarium oxysporum f. sp. lycopersici in Greenhouse Tomato Production Systems

In recent years, greenhouse-grown tomato (Solanum lycopersicum) plants showing vascular wilt and yellowing symptoms have been observed between 2015 and 2018 in North Carolina (NC) and considered as an emerging threat to profitability. In total, 38 putative isolates were collected from symptomatic tomatoes in 12 grower greenhouses and characterized to infer pathogenic and genomic diversity, and mating-type (MAT) idiomorphs distribution. Morphology and polymerase chain reaction (PCR) markers confirmed that all isolates were Fusarium oxysporum f. sp. lycopersici (FOL) and most of them were race 3. Virulence analysis on four different tomato cultivars revealed that virulence among isolates, resistance in tomato cultivars, and the interaction between the isolates and cultivars differed significantly (P < 0.001). Cultivar 'Happy Root' (I-1, I-2, and I-3 genes for resistance) was highly resistant to FOL isolates tested. We sequenced and examined for the presence of 15 pathogenicity genes from different classes (Fmk1, Fow1, Ftf1, Orx1, Pda1, PelA, PelD, Pep1, Pep2, eIF-3, Rho1, Scd1, Snf1, Ste12, and Sge1), and 14 Secreted In Xylem (SIX) genes to use as genetic markers to identify and differentiate pathogenic isolates of FOL. Sequence data analysis showed that five pathogenicity genes, Fmk1, PelA, Rho1, Sge1, and Ste12 were present in all isolates while Fow1, Ftf1, Orx1, Peda1, Pep1, eIF-3, Scd1, and Snf1 genes were dispersed among isolates. Two genes, Pep2 and PelD, were absent in all isolates. Of the 14 SIX genes assessed, SIX1, SIX3, SIX5, SIX6, SIX7, SIX8, SIX12, and SIX14 were identified in most isolates while the remaining SIX genes varied among isolates. All isolates harbored one of the two mating-type (MAT-1 or MAT-2) idiomorphs, but not both. The SIX4 gene was present only in race 1 isolates. Diversity assessments based on sequences of the effector SIX3- and the translation elongation factor 1-α encoding genes SIX3 and tef1-α, respectively were the most informative to differentiate pathogenic races of FOL and resulted in race 1, forming a monophyletic clade while race 3 comprised multiple clades. Furthermore, phylogeny-based on SIX3- and tef1-α gene sequences showed that the predominant race 3 from greenhouse production systems significantly overlapped with previously designated race 3 isolates from various regions of the globe.

Gene Genealogies Reveal High Nucleotide Diversity and Admixture Haplotypes Within Three Alternaria Species Associated with Tomato and Potato

Early blight (EB) and leaf blight are two destructive diseases of tomato in North Carolina (NC), caused by Alternaria linariae and A. alternata, respectively. During the last decade, EB caused by A. solani has increased in potato-producing areas in Wisconsin (WI). We collected 152 isolates of three Alternaria spp. associated with tomato and potato in NC and WI and used the gene genealogical approach to compare the genetic relationships among them. Two nuclear genes: the glyceraldehyde-3-phosphate dehydrogenase (GPDH), RNA polymerase second largest subunit (RPB2), and the rDNA internal transcribed spacer (ITS) region of these isolates were sequenced. Besides, sequences of the GPDH locus from international isolates described in previous studies were included for comparison purposes. A set of single nucleotide polymorphisms was assembled to identify locus-specific and species-specific haplotypes. Nucleotide diversity varied among gene sequences and species analyzed. For example, the estimates of nucleotide diversity and Watterson's theta were higher in A. alternata than in A. linariae and A. solani. There was little or no polymorphisms in the ITS sequences and thus restricted haplotype placement. The RPB2 sequences were less informative to detect haplotype diversity in A. linariae and A. solani, yet six haplotypes were detected in A. alternata. The GPDH sequences enabled strongly supported phylogenetic inferences with the highest haplotype diversity and belonged to five haplotypes (AaH1 to AaH5), which consisted of only A. alternata from NC. However, 13 haplotypes were identified within and among A. linariae and A. solani sequences. Among them, six (AsAlH1 to AsAlH6) were identical to previously reported haplotypes in global samples and the remaining were new haplotypes. The most divergent haplotypes were AaH1, AsAlH2/AsAlH3, and AsAlH4 and consisted exclusively of A. alternata, A. linariae, and A. solani, respectively. Neutrality tests suggested an excess of mutations and population expansion, and selection may play an important role in nucleotide diversity of Alternaria spp.

SAT0628-HPR “IT IS THE NEVER ENDING QUEST, HOW TO MOTIVATE PEOPLE” – HEALTH PROFESSIONALS’ PERSPECTIVES ON SUPPORTING PHYSICAL ACTIVITY MAINTENANCE IN THOSE LIVING WITH AXIAL SPONDYLOARTHRITIS

Background:

Physical activity (PA) has been identified as a primary treatment option for people living with axial spondyloarthritis (axSpA) [1]. Yet, people living with axSpA can find it difficult to maintain PA at levels required to gain the evidenced benefits [2]. Intensive rehabilitation programmes harness the benefits of physical activity, but little is known about how to support PA maintenance when patients return to everyday life. The perspectives’ of health professionals involved in rehabilitation programmes can provide important and rich insights into how people living with axSpA could be helped to maintain their PA.

Objectives:

To explore health professionals‘ experiences of supporting PA maintenance during and after a rehabilitation programme for those living with axial spondyloarthritis.

Methods:

A qualitative study was conducted using semi-structured interviews. Nine health professionals (i.e., 4 physiotherapists; 1 clinical nurse specialist; 1 rheumatology SpR; 1 psychologist; 1 occupational therapist; and 1 podiatrist) who contribute to a rehabilitation programme were recruited from the Royal National Hospital for Rheumatic Diseases in Bath, UK (Mtime contributing to course = 6.79 yrs, range 1-19.25 yrs; contact time over course range = 1 to 45 hrs). Interviews were audio recorded, transcribed verbatim, and a thematic analysis employed [3].

Results:

Maintaining a physically active lifestyle is a challenge for those living with axSpA and is an issue that is currently not being addressed. Health professionals’ perspectives on supporting PA maintenance was illustrated through four main themes: (1) Social environment (group dynamic, importance of others with the same condition, immersion of the disease, external peer groups); (2) Re-framing (education, ownership, exercise off the pedestal, combating fear, routine and habit); (3) PA support (enjoyment and interest, PA as flexible, encouragement and importance, balance and realistic expectations, internal and external feedback); and (4) Challenges for health professionals (training, resources, knowledge of transition process to everyday life, difficulty motivating). The reasons why people engage in PA play a key role within each of these themes.

Conclusion:

Results emphasize the current lack of support for the maintenance of PA and the complexities and challenges involved in maintaining PA for people living with axSpA. Interventions to support PA maintenance should pay particular attention to the importance of socially supportive environments, the need for enjoyment, and the use of internal and external feedback. The challenges faced by health professionals in motivating those living with axSpA to engage in PA regularly suggests a need for more training opportunities in motivation and health behaviour change.

References:

[1]Rausch Osthoff, A., Niedermann, K., Braun, J., et al., (2012) EULAR recommendations for physical activity in people with inflammatory arthritis and osteoarthritis. Annals of the Rheumatic Diseases, 77 (9), pp. 1251-60.

[2]McDonald, M. T., Siebert, S., Coulter, E. H., McDonald, D. A., and Paul, L. (2019) Level of adherence to prescribed exercise in spondyloarthritis and factors affecting this adherence: a systematic review.Rheumatology International, 39 (2), pp. 187-201.

[3]Braun, V., and Clarke, V. (2006) Using thematic analysis in psychology.Qualitative Research in Psychology, 3 (2), pp. 77-101.

Acknowledgments:

The authors would like to thank the Bath Institute for Rheumatic Diseases (BIRD) and the University of Bath for funding the PhD studentship associated with this project

Disclosure of Interests:

Thomas Ingram: None declared, Peter Rouse: None declared, Martyn Standage: None declared, Raj Sengupta Grant/research support from: Research grants from UCB, Pfizer, Abbvie and Novartis, Speakers bureau: Received honoraria for giving talks from Abbvie, Biogen, UCB, Novartis, Pfizer

Effects of fixatives on stable isotopes of fish muscle tissue: implications for trophic studies on preserved specimens

Isotopic ecology has been widely used to understand spatial connectivity and trophic interactions in marine systems. However, its potential for monitoring an ecosystem's health and function has been hampered by the lack of consistent sample storage and long-term studies. Preserved specimens from museum collections are a valuable source of tissue for analyses from ancient and pre-modern times, but isotopic signatures are known to be affected by commonly used fixatives. The aim of the present study was to understand the effects of fixatives on isotopic signatures of bulk tissue (δ¹³ C_m and δ¹⁵ N_m ) and amino acids (δ¹³ C_AA and δ¹⁵ N_AA ) of fish muscle and to provide correction equations for the isotopic shifts. Two specimens of each: blue cod (Parapercis colias), blue warehou (Seriolella brama), and king salmon (Oncorhynchus tschawytscha) were sampled at five locations along their dorsal musculature, at four time periods: (1) fresh, (2) after 1 month preserved in formalin, and after (3) 3 and (4) 12 months fixed in either ethanol or isopropanol. Lipid content was positively correlated with C:N ratio (r² = 0.83) and had a significant effect on δ¹³ C after treatments, but not on δ¹⁵ N. C:N ratio (for δ¹³ C_m ) and percent N (for δ¹⁵ N_m ) from preserved specimens contributed to the most parsimonious mixed models, which explained 79% of the variation due to fixation and preservation for δ¹³ C and 81% for δ¹⁵ N. δ¹³ C_AA were generally not affected by fixatives and preservatives, while most δ¹⁵ N_AA showed different signatures between treatments. δ¹⁵ N_AA variations did not affect the magnitude of differences between amino acids, allowing scientists to retrieve ecological information (e.g., trophic level) independently of time under preservation. Corrections were applied to the raw data of the experiment, highlighting the importance of δ¹³ C_m and δ¹⁵ N_m correction when fish muscle tissues from wet collections are compared to fresh samples. Our results make it possible to retrieve δ¹³ C_m , δ¹⁵ N_m , δ¹³ C_AA , and δ¹⁵ N_AA from museum specimens and can be applied to some of the fundamental questions in ecology, such as trophic baseline shifts and changes in community's food web structure through time.

A preliminary evaluation of a client-centred prompting tool for supporting everyday activities in individuals with mild to moderate levels of cognitive impairment due to dementia

Objectives

Technology-based prompting has the potential to support people with dementia to complete multistep tasks in the home. However, these devices can be complex to use. This paper reports a feasibility trial of a personalised touchscreen digital prompter designed for home use.

Methodology: A tablet-based prompter suitable for people living with dementia was developed, along with a detailed guidance manual. Carers loaded instructions for completing the task onto the prompter, and the person with dementia then used the tablet independently to complete a task. Eleven couples used the prompter ‘out-of-the-box’ with no support other than a guidance manual.

Results

The majority of participants with dementia could follow the steps on the prompter, and carers were able to breakdown and load tasks onto the prompter. Eight couples used the prompter successfully to complete goals that they had identified in advance. These included preparing simple snacks and using a TV remote control. Successfully achieving goals was associated with more frequent use of the prompting screen on more days, but not higher levels of editing or previewing of tasks.

Conclusion

The study provides the preliminary evidence that family caregivers can use a touchscreen tablet, software and manual package to identify specific tasks and break these down into steps and that people living with dementia can then follow the prompts to complete the tasks. This potentially represents an important advance in dementia care. Further testing is required to establish efficacy and to identify any factors that impact on outcomes.

P783 Global longitudinal strain detects trastuzumab induced cardiotoxicity early in a clinical population

Background

Trastuzumab is highly effective in the treatment of breast cancer, and is often used as an adjuvant therapy. Due to its potential cardiotoxicity, serial monitoring of cardiac function is vital. Ejection fraction (EF) by two-dimensional echocardiography is routinely used but has limitations in measurement variability. Myocardial deformation imaging, in particular Global Longitudinal Strain (GLS), can detect pre-clinical myocardial dysfunction. However, its use is not yet adopted into routine clinical practice.

Aims

Our aim was to ascertain if a clinically significant reduction in GLS (≥11% from baseline) occurred before the onset of EF reduction, in patients who developed cardiotoxicity whilst receiving trastuzumab.

Methods

Between January 2014 and January 2019, 235 consecutive patients received trastuzumab and underwent serial echocardiography at 3 monthly intervals at our institute. Cardiotoxicity is defined as a ≥10% EF reduction from baseline or an EF &lt;50%. Women who developed cardiotoxicity as defined by this change in EF were retrospectively studied.

Two-dimensional speckle tracking was used to derive peak longitudinal strain in each myocardial segment from the apical four-, three- and two-chamber view images. GLS was taken as the average value of all these segments. The median time to ≥11% GLS reduction and ≥10% EF reduction or EF &lt;50% was compared.

Results

Thirteen women (mean age 53 ± 9.5 years) developed cardiotoxicity. EF was 61.8 ± 4.4% at baseline and 45.7 ± 7.5% following therapy (p = 0.00). A ≥11% reduction in GLS from baseline was observed in all patients: GLS -20.2 ± 1.5% and -15.6 ± 2.1%, p = 0.00. The median time to cardiotoxicity as defined by EF and GLS was 6 months and 3 months, respectively (p = 0.031), as shown in Table 1. Repeatability analysis showed both EF and GLS measurements in our cohort have good measurement reproducibility. Inter-observer intraclass correlation (ICC) for EF and GLS were 0.912 and 0.913, respectively. Intra-observer ICC for EF and GLS were 0.925 and 0.900, respectively.

Conclusion

Cardiotoxicity developed in a significant portion (6%) of our patients receiving trastuzumab. As a reduction in GLS was detectable early and preceded that of EF by 3 months, this may represent a therapeutic window for initiation of cardio-protective medication, if and when the use of GLS is incorporated into routine practice for cardiotoxicity surveillance.

Table 1: Summary of Findings. Baseline Cardiotoxicity Paired t-test p value Median time of onset EF 61.8 ± 4.4% 45.7 ± 7.5% P &lt; 0.01 6 months* GLS -20.2 ± 1.5% -15.6 ± 2.1% P &lt; 0.01 3 months* *denotes exact sign-test p &lt; 0.05.

Proteomic profiling of mitochondria: what does it tell us about the ageing brain?

Mitochondrial dysfunction is evident in numerous neurodegenerative and age-related disorders. It has also been linked to cellular ageing, however our current understanding of the mitochondrial changes that occur are unclear. Functional studies have made some progress reporting reduced respiration, dynamic structural modifications and loss of membrane potential, though there are conflicts within these findings. Proteomic analyses, together with functional studies, are required in order to profile the mitochondrial changes that occur with age and can contribute to unravelling the complexity of the ageing phenotype. The emergence of improved protein separation techniques, combined with mass spectrometry analyses has allowed the identification of age and cell-type specific mitochondrial changes in energy metabolism, antioxidants, fusion and fission machinery, chaperones, membrane proteins and biosynthesis pathways. Here, we identify and review recent data from the analyses of mitochondria from rodent brains. It is expected that knowledge gained from understanding age-related mitochondrial changes of the brain should lead to improved biomarkers of normal ageing and also age-related disease progression.

First Report of Bacterial Blight of Sugar Beet Caused by Pseudomonas syringae pv. aptata in Georgia, USA

Sugar beet (Beta vulgaris L.) is not currently a commercial crop in Georgia, but experimental plantings as a winter rotational crop are promising in terms of yield and industrial sugar production (T. Brenneman, personal communication). A disease outbreak of suspected bacterial origin occurred in sugar beet plots (experimental lines Beta Seed energy beet 'BTS ENC115,' 'BTS EGC184,' 'BTS EGC195,' and 'BTS 1EN6702') in Tift Co., GA, in December 2012, at ~35% incidence. Foliar symptoms included circular to irregular spots, each with a tan center and dark margin. Ten leaves/experimental line with leaf spot symptoms were collected, and bacterial isolations made on King's B agar medium. After 48 h of incubation, cream-colored, fluorescent yellow, round colonies with smooth margins were isolated. The isolates were each gram negative, oxidase negative, non-pectolytic on potato, arginine dihydrolase negative, produced levan, and gave a hypersensitivity response (HR) on tobacco. These characteristics indicated that the isolates belonged to Pseudomonas syringae van Hall LOPAT group Ia (3). The 16S-23S rRNA (internal transcribed regions) (1) from four foliar isolates (SB-1, SB-2, SB-3, and SB-4), one/experimental line, was amplified, and the resultant PCR products were sequenced and BLAST searched in GenBank. The 16S-23S rRNA sequences matched those of P. syringae pv. syingae (Pss) (KF023189) and P. syringae pv. aptata (Psa) (AY342167.1) with 96 to 98% and 97 to 99% sequence identity, respectively. Also, the percent similarity of the 16S-23S rRNA sequences among the four isolates was >99% (KJ922021 to 24 for SB-1 to SB-4, respectively). The four test isolates also had ≤89 and ≤99% similarity with Pss and Psa, respectively, when tested with BIOLOG (Hayward, CA). In addition, four sugarbeet isolates along with a type strain of Psa (NCPPB 3539) were amplified using a PCR primer pair that detected the presence of the avrPphE gene, an avirulence gene present in Psa but absent in Pss (2). The type strain of Pss (NCPPB 1770) was not amplified using this primer pair. BOX-PCR analysis gave identical banding patterns for the four isolates as that of a type strain of Psa. In two independent experiments, 3-week-old seedlings of the sugar beet cv. Beta EGR099 (n = 10 seedlings/isolate/experiment) were spray-inoculated with a sterilized water suspension of 1 × 10⁸ CFU/ml of each of the isolates. All of the inoculated seedlings developed symptoms (water-soaked lesions that developed into necrotic spots) 10 days after inoculation (DAI) in greenhouse conditions (~30°C and ~80% RH). All of the seedlings inoculated with the type strain of Psa also produced typical bacterial blight symptoms at 10 DAI. In contrast, five control seedlings inoculated with sterilized water remained asymptomatic, and target bacterial colonies were not re-isolated from the leaves of these plants. Bacterial colonies were re-isolated from symptomatic seedlings, and showed similar characteristics based on physiological tests, BIOLOG profile, BOX-PCR analysis, and positive amplification with the avrPphE PCR assay, which indicated that these strains were Psa. To our knowledge, this is the first report of Psa in sugarbeet in Georgia. The fact that a Psa strain was also isolated from a sugar beet seed lot (data not shown) suggested that the pathogen may have been introduced on contaminated seeds. Knowledge of the presence of Psa in the agro-ecosystem of Georgia may encourage scientists to implement integrated management practices for this pathogen. References: (1) C. Guasp et al. Int. J. Syst. Evol. Microbiol. 50:1629, 2000. (2) Y. Inoue and Y. Takikawa. Page 687 in: Presentations 6th Int. Conf. Pseudomonas syringae Pathovars and Related Pathogens, 2003. (3) R. A. Lelliot et al. J. Appl. Bacteriol. 29:470, 1966.

Prediction of micelle/water and liposome/water partition coefficients based on molecular dynamics simulations, COSMO-RS, and COSMOmic

Liposomes and micelles find various applications as potential solubilizers in extraction processes or in drug delivery systems. Thermodynamic and transport processes governing the interactions of different kinds of solutes in liposomes or micelles can be analyzed regarding the free energy profiles of the solutes in the system. However, free energy profiles in heterogeneous systems such as micelles are experimentally almost not accessible. Therefore, the development of predictive methods is desirable. Molecular dynamics (MD) simulations reliably simulate the structure and dynamics of lipid membranes and micelles, whereas COSMO-RS accurately reproduces solvation free energies in different solvents. For the first time, free energy profiles in micellar systems, as well as mixed lipid bilayers, are investigated, taking advantage of both methods: MD simulations and COSMO-RS, referred to as COSMOmic (Klamt, A.; Huniar, U.; Spycher, S.; Keldenich, J. COSMOmic: A Mechanistic Approach to the Calculation of Membrane-Water Partition Coefficients and Internal Distributions within Membranes and Micelles. J. Phys. Chem. B 2008, 112, 12148-12157). All-atom molecular dynamics simulations of the system SDS/water and CTAB/water have been applied in order to retrieve representative micelle structures for further analysis with COSMOmic. For the system CTAB/water, different surfactant concentrations were considered, which results in different micelle sizes. Free energy profiles of more than 200 solutes were predicted and validated by means of experimental partition coefficients. To our knowledge, these are the first quantitative predictions of micelle/water partition coefficients, which are based on whole free energy profiles from molecular methods. Further, the partitioning in lipid bilayer systems containing different hydrophobic tail groups (DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine), SOPC (stearoyl-oleoylphosphatidylcholine), DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine), and POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine)) as well as mixed bilayers was calculated. Experimental partition coefficients (log P) were reproduced with a root-mean-square error (RMSE) of 0.62. To determine the influence of cholesterol as an important component of cellular membranes, free energy profiles in the presence of cholesterol were calculated and shown to be in good agreement with experimental data.

Partition coefficients of ionizable solutes in mixed nonionic/ionic micellar systems

Surfactant solutions in practical applications usually are mixtures of ionic and nonionic surfactants. Because of synergistic effects, the solubilization of hydrophobic compounds can be enhanced while decreasing the needed amount of surfactant at the same time. In this work, the influence of the composition of Brij 35/CTAB and Brij 35/SDS mixed micelles on the partition coefficient log D(MW) of various acids and bases over the entire pH range was investigated. Two experimental methods (MLC, micellar liquid chromatography; MEUF, micellar enhanced ultrafiltration) are evaluated for the determination of partition coefficients in mixed-micelle systems. Although MLC stands out because of its automation and easy handling, MEUF is applicable to a broader log D(MW) range. It is shown that the partitioning can be influenced dramatically by the two investigated parameters. By adjusting the pH value and the composition of the micelles, we can tailor the partition behavior of solutes for virtually any application. The thermodynamic model COSMO-RS gives valuable predictions of the partition coefficients if the composition of the micelle is available. Different approaches for the description of the micellar composition are evaluated in this work. On the basis of the cmc value of the single surfactants and the mixture only, it is shown that the regular solution approximation gives reasonable micellar compositions. The partition coefficients between water and the mixed micelles are predicted with the COSMO-RS model, in good agreement with the experimental data. Moreover, the micellar composition can be evaluated by fitting the prediction to the experimentally determined partition coefficients.

Niche diversification follows key innovation in Antarctic fish radiation

Antarctic notothenioid fishes provide a fascinating evolutionary laboratory for the study of adaptive radiation, as their diversification is linked to both isolation in an extreme environment and a key innovation that allows them to exploit it. In this issue of Molecular Ecology, Rutschmann et al. (2011) evaluate how dietary niche differences have evolved in notothenioids: rarely, or repeatedly in multiple lineages. The authors use stable isotopes to measure species’ use of benthic vs. pelagic resources and map resource use onto a molecular phylogeny. Their findings indicate that pelagic diets have evolved in multiple lineages in at least two families, indicating that dietary niche diversification has occurred repeatedly and in parallel.

Kinetic investigation of a solvent-free, chemoenzymatic reaction sequence towards enantioselective synthesis of a β-amino acid ester

A solvent-free, chemoenzymatic reaction sequence for the enantioselective synthesis of β-amino acid esters has been kinetically and thermodynamically characterized. The coupled sequence comprises a thermal aza-Michael addition of cheap starting materials and a lipase catalyzed aminolysis for the kinetic resolution of the racemic ester. Excellent ee values of >99% were obtained for the β-amino acid ester at 60% conversion. Kinetic constants for the aza-Michael addition were obtained by straightforward numerical integration of second-order rate equations and nonlinear fitting of the progress curves. A different strategy had to be devised for the biocatalytic reaction. Initially, a simplified Michaelis-Menten model including product inhibition was developed for the reaction running in THF as an organic solvent. Activity based parameters were used instead of concentrations in order to facilitate the transfer of the kinetic model to the solvent-free system. Observed solvent effects not accounted for by the use of thermodynamic activities were incorporated into the kinetic model. Enzyme deactivation was observed to depend on the ratio of the applied substrates and also included in the kinetic model. The developed simple model is in very good agreement with the experimental data and allows the simulation and optimization of the solvent-free process.

Experimental methods and prediction with COSMO-RS to determine partition coefficients in complex surfactant systems

Surfactant-based separation processes are a promising alternative to conventional organic solvent processes. A crucial parameter to describe the efficiency of such processes is the partition coefficient between the surfactant aggregates (micelles) and the aqueous bulk phase. In this work, several experimental methods to determine these partition coefficients (micellar liquid chromatography, micellar enhanced ultrafiltration, and cloud point extraction) are evaluated and compared. In addition, these results are compared to predictions with the thermodynamic model COSMO-RS. In particular, systems with the nonionic surfactant TritonX-100 are studied. The partition equilibria of various solutes (pyrene, naphthalene, phenanthrene, phenol, 3-methoxyphenol, and vanillin) and the influence of different additives (alcohols) are investigated. All experimental methods show very good reproducibility. Moreover, the results from different methods are in good agreement, supplementing one another concerning the temperature ranges. Notably, the COSMO-RS model is capable of predicting partition coefficients between micelles and water in the investigated temperature range and at different alcohol concentrations. The results demonstrate the potential of the model COSMO-RS to facilitate the selection of optimized process parameters for a given separation problem. By predicting partition equilibria in multicomponent systems, the selection of surfactant, temperature, and appropriate additives can be facilitated.

Comparison of different pretreatment methods for lignocellulosic materials. Part I: conversion of rye straw to valuable products

The conversion of lignocellulose to valuable products requires I: a fractionation of the major components hemicellulose, cellulose, and lignin, II: an efficient method to process these components to higher valued products. The present work compares liquid hot water (LHW) pretreatment to the soda pulping process and to the ethanol organosolv pretreatment using rye straw as a single lignocellulosic material. The organosolv pretreated rye straw was shown to require the lowest enzyme loading in order to achieve a complete saccharification of cellulose to glucose. At biomass loadings of up to 15% (w/w) cellulose conversion of LHW and organosolv pretreated lignocellulose was found to be almost equal. The soda pulping process shows lower carbohydrate and lignin recoveries compared to the other two processes. In combination with a detailed analysis of the different lignins obtained from the three pretreatment methods, this work gives an overview of the potential products from different pretreatment processes.

Comparison of different pretreatment methods for lignocellulosic materials. Part II: Influence of pretreatment on the properties of rye straw lignin

Several processes have been suggested to convert various types of lignocellulosic biomass into lignin products and saccharides. This paper evaluates the suitability of an organosolv process, a process using soda, a hydrothermal process and a process developed in this work, called the "Aquasolve process" for inclusion into a lignocellulosic biorefinery concept. Part II of this paper investigates the influence of the different pretreatment processes on the properties of rye straw lignin and evaluates their ability to produce high recoveries of high quality lignin. Specifications for high quality lignin products are defined and the isolated lignin fractions are analysed by Klason lignin, carbohydrate and ash content, elemental analysis, thermo-gravimetric analysis, (31)P NMR, and size exclusion chromatography. The organosolv process shows the largest lignin recovery, followed by the soda and Aquasolve processes. Lignin products from the soda process, the Aquasolve process and with reservation the organosolv process show interesting properties for polymer applications.

Comparison of novel cannabinoid partial agonists and SR141716A in the guinea-pig small intestine

The controversial nature of the CB(1) receptor antagonist, SR141716A, in the guinea-pig small intestine was investigated by comparing it with four analogues of Delta(8)-tetrahydrocannabinol (Delta(8)-THC): O-1184, O-1238, O-584 and O-1315. These compounds (10 - 1000 nM) inhibited the electrically-evoked contractions with a rank order of potency of O-1238>O-1184>O-584>O-1315. Log concentration-response curves for O-1238, O-1184 and O-1315 were significantly shifted to the right by SR141716A and the maxima were significantly less than that of the CB(1) agonist, WIN55212-2, an indication of partial agonism. Partial saturation of the triple bond in O-1184 to a cis double bond (O-1238) increased its potency as an agonist (pEC(50) from 6.42 to 7.63) and as an antagonist of WIN55212-2, (pK(B), from 8.36 to 9.49). Substitution of the terminal azide group by an ethyl group (O-584) or removal of the phenolic hydroxyl group (O-1315) had no significant effect on the agonist or antagonist potency. None of these analogues increased the twitch response in a manner resembling that of SR141716A. O-1184 (10 and 100 nM) shifted the log concentration-response curve of WIN55212-2 for inhibition of the twitch responses to the right with pK(B) values of 8.29 and 8.38, respectively. We conclude that these Delta(8)-THC analogues behave as partial agonists rather than silent antagonists at CB(1) binding sites in this tissue. There was no evidence of antagonism of endocannabinoids thus supporting the hypothesis that, in this tissue, SR141716A is an inverse agonist of constitutively active CB(1) receptors.

An outbreak of viral gastroenteritis associated with consumption of sandwiches: implications for the control of transmission by food handlers

Although food handlers are often implicated as the source of infection in outbreaks of food-borne viral gastroenteritis, little is known about the timing of infectivity in relation to illness. We investigated a gastroenteritis outbreak among employees of a manufacturing company and found an association (RR = 14.1, 95% CI = 2.0-97.3) between disease and eating sandwiches prepared by 6 food handlers, 1 of whom reported gastroenteritis which had subsided 4 days earlier. Norwalk-like viruses were detected by electron microscopy or reverse transcriptase-polymerase chain reaction (RT-PCR) in stool specimens from several company employees, the sick food handler whose specimen was obtained 10 days after resolution of illness, and an asymptomatic food handler. All RT-PCR product sequences were identical, suggesting a common source of infection. These data support observations from recent volunteer studies that current recommendations to exclude food handlers from work for 48-72 h after recovery from illness may not always prevent transmission of Norwalk-like viruses because virus can be shed up to 10 days after illness or while exhibiting no symptoms.

Comparison of the effects of selected dressings on the healing of standardized abrasions

OBJECTIVE

To find out which type of dressing (semipermeable film, hydrocolloid, conventional method, or no dressing) allowed abrasions to heal in the least amount of time and had the greatest decrease in wound area.

DESIGN AND SETTING

A 4 x 9 factorial was used for this study. There were two independent variables with four levels and two dependent variables. Research was performed at the Athletic Training Research Laboratory at Indiana State University.

SUBJECTS

Fourteen subjects (eight males, six females), ages 23 to 34 years, participated in this study.

MEASUREMENTS

From daily photographs, the day the wounds were healed was determined. The photographs were also used to measure wound area on the first and last days of the study. Subjects received four treatments (dressings and control), and placement of the dressings was determined by random assignment.

RESULTS

Data were analyzed using a repeated-measures multivariate analysis of variance to determine if differences existed among treatment groups for healing time and change in area. Student-Newman-Keuls post hoc testing was performed to determine specifically where the differences occurred. Our results indicate that healing time is affected by covering the wound, and area is decreased by using DuoDerm or Bioclusive.

CONCLUSIONS

Bioclusive should be used in the athletic training setting. Bioclusive and DuoDerm are equally effective, but Bioclusive is less expensive. Bioclusive is more expensive than Coverlet, but it is also more effective in reducing the area of the wound.

Quantitation of human immunoglobulin G and albumin in electroimmunodiffusion gels containing ionic and nonionic detergents

Quantitation of human immunoglobulin G (IgG) and albumin by agarose electroimmunodiffusion is influenced by the incorporation of ionic and nonionic detergents in the gel. The highest concentrations of each detergent at which human IgG and albumin determinations could be performed without perturbing the quantitations were 4% Triton X-100, 4% Tween 80, 1% NP-40, 0.5% sodium deoxycholate (SDOC), 0.5% Zwittergent, and 0.1% sodium dodecyl sulfate (SDS), and mixtures of Triton X-100, SDOC, and SDS. These detergent combinations all resulted in greater perturbations of albumin quantitation than of IgG. Immunoprecipitation of human IgG was quantitated in the absence and presence of Triton X-100, Zwittergent, and SDS. SDS was shown to cause nonspecific precipitation, whereas below 1% Triton X-100 or 0.5% Zwittergent no effects upon the immunoprecipitations were observed.