NutriColoring: designing a doodling toolkit to support daily self-reported dietary assessment among office workers

This study was motivated by a desire to help working-age individuals gain a better understanding of their daily nutritional intakes with a new self-reported dietary assessment method because an unhealthy eating behavior increases the risks of developing chronic diseases. In this study, we present the design and evaluation of NutriColoring, a food diary that leverages doodling on sketches to report and reflect on everyday diet in the working context. Through a 2-week field study involving 18 participants, the usefulness of NutriColoring in facilitating dietary assessment was tested by making comparisons with the typical bullet diary method. Our quantitative results showed that NutriColoring provided users with improved dietary assessment experience and intrinsic motivations, with significantly low task frustration and high enjoyment. Because of the freedom and playfulness in reporting intakes at work, the interview findings showed a high acceptance of employing NutriColoring at work. This article is concluded with a set of implications for the design and development of a Doodling toolkit to support healthy eating behaviors among office workers.

Co-Operative Design of a Coach Dashboard for Training Monitoring and Feedback

Athlete development depends on many factors that need to be balanced by the coach. The amount of data collected grows with the development of sensor technology. To make data-informed decisions for training prescription of their athletes, coaches could be supported by feedback through a coach dashboard. The aim of this paper is to describe the design of a coach dashboard based on scientific knowledge, user requirements, and (sensor) data to support decision making of coaches for athlete development in cyclic sports. The design process involved collaboration with coaches, embedded scientists, researchers, and IT professionals. A classic design thinking process was used to structure the research activities in five phases: empathise, define, ideate, prototype, and test phases. To understand the user requirements of coaches, a survey (n = 38), interviews (n = 8) and focus-group sessions (n = 4) were held. Design principles were adopted into mock-ups, prototypes, and the final coach dashboard. Designing a coach dashboard using the co-operative research design helped to gain deep insights into the specific user requirements of coaches in their daily training practice. Integrating these requirements, scientific knowledge, and functionalities in the final coach dashboard allows the coach to make data-informed decisions on training prescription and optimise athlete development.

TARGETing secondary school students’ motivation towards physical education: The role of student-perceived mastery climate teaching strategies

The aim of the present study was to explore the impact of TARGET-based teaching strategies on students’ motivation in a Dutch secondary school PE context. We examined to what extent mastery climate teaching strategies perceived by students (independently or interactively) explain variability in students’ motivation towards PE. In total 3,150 students (48.2% girls; 51.8% boys) with a mean age of 13.91 years (SD = 1.40) completed the Behavioural Regulations in Physical Education Questionnaire (BRPEQ), measuring students’ autonomous motivation, controlled motivation and amotivation, and the Mastery Teaching Perception Questionnaire (MTP-Q), measuring student-perceived application of mastery TARGET teaching strategies. Hierarchical regression analyses indicated that after controlling for gender, age, and educational type, the predictive effects of the perceived mastery climate teaching strategies differed by motivational outcome. Overall, students who reported higher levels of perceived application of mastery TARGET teaching strategies showed more autonomous motivation and less amotivation. Specifically, the teaching strategies within the task structure were the strongest predictors for students’ autonomous motivation and amotivation. No meaningful statistically significant two-way interaction effects between any of the TARGET variables were found, supporting the proposition of an additive relationship between the TARGET teaching strategies.

Two of a Kind? Similarities and Differences between Runners and Walkers in Sociodemographic Characteristics, Sports Related Characteristics and Wearable Usage

As the two prime examples of sport light, running and walking have become very popular sports activities in the past decades. There are references in the literature of similarities between both sports, however these parallels have never been studied. In addition, the current digitalisation of society can have important influences on the further diversification of profiles. Data of a large-scale population survey among runners and walkers (n = 4913) in Flanders (Belgium) were used to study their sociodemographic, sports related and attitudinal characteristics, and wearable usage. The results showed that walkers are more often female, older, lower educated, and less often use wearables. To predict wearable usage, sports-related and attitudinal characteristics are important among runners but not among walkers. Motivational variables to use wearables are important to predict wearable usage among both runners and walkers. Additionally, whether or not the runner or walker registers the heart rate is the most important predictor. The present study highlights similarities and differences between runners and walkers. By adding attitudinal characteristics and including walkers this article provides new insights to the literature, which can be used by policymakers and professionals in the field of sport, exercise and health, and technology developers to shape their services accordingly.

Runner's Perceptions of Reasons to Quit Running: Influence of Gender, Age and Running-Related Characteristics

Physical inactivity has become a major public health concern and, consequently, the awareness of striving for a healthy lifestyle has increased. As a result, the popularity of recreational sports, such as running, has increased. Running is known for its low threshold to start and its attractiveness for a heterogeneous group of people. Yet, one can still observe high drop-out rates among (novice) runners. To understand the reasons for drop-out as perceived by runners, we investigate potential reasons to quit running among short distance runners (5 km and 10 km) (n = 898). Data used in this study were drawn from the standardized online Eindhoven Running Survey 2016 (ERS16). Binary logistic regressions were used to investigate the relation between reasons to quit running and different variables like socio-demographic variables, running habits and attitudes, interests, and opinions (AIOs) on running. Our results indicate that, not only people of different gender and age show significant differences in perceived reasons to quit running, also running habits, (e.g., running context and frequency) and AIOs are related to perceived reasons to quit running too. With insights into these related variables, potential drop-out reasons could help health professionals in understanding and lowering drop-out rates among recreational runners.

How Do Runners Experience Personalization of Their Training Scheme: The Inspirun E-Coach?

Among runners, there is a high drop-out rate due to injuries and loss of motivation. These runners often lack personalized guidance and support. While there is much potential for sports apps to act as (e-)coaches to help these runners to avoid injuries, set goals, and maintain good intentions, most available running apps primarily focus on persuasive design features like monitoring, they offer few or no features that support personalized guidance (e.g., personalized training schemes). Therefore, we give a detailed description of the working mechanism of Inspirun e-Coach app and on how this app uses a personalized coaching approach with automatic adaptation of training schemes based on biofeedback and GPS-data. We also share insights into how end-users experience this working mechanism. The primary conclusion of this study is that the working mechanism (if provided with accurate data) automatically adapts training sessions to the runners' physical workload and stimulates runners' goal perception, motivation, and experienced personalization. With this mechanism, we attempted to make optimal use of the potential of wearable technology to support the large group of novice or less experienced runners and that by providing insight in our working mechanisms, it can be applied in other technologies, wearables, and types of sports.

Investigating longitudinal context-specific physical activity patterns in transition from primary to secondary school using accelerometers, GPS, and GIS

INTRODUCTION

Previous longitudinal studies indicate that physical activity (PA) significantly declines from primary-to secondary school, and report both changes in individual and environmental determinants of PA. In order to understand this transition and to prevent this negative trend, it is important to gather contextually rich data on possible mechanisms that drive this decline. Therefore, the aim of this study was to investigate changes of PA patterns in transition between primary and secondary school, and to add domain-specific insights of how, where, and when these changes occur.

METHODS

In total, 175 children participated in a 7-day accelerometer- and Global Positioning System (GPS) protocol at their last year of primary and their first year of secondary school. GPS data-points were overlaid with Geographical Information Systems (GIS) data using ArcGIS 10.1 software. Based on the GPS locations of individual data-points, we identified child's PA at home, school, local sports grounds, shopping centers, and other locations. Also, trips in active and passive transport were identified according to previously validated GPS speed-algorithms. Longitudinal multi-level linear mixed models were fitted adjusting for age, gender, meteorological circumstances, and the nested structure of days within children and children within schools. Outcome measures were minutes spent in light PA and moderate-to-vigorous PA, specified for the time-segments before school, during school, after school and weekend days.

RESULTS

Total PA significantly declined from primary to secondary school. Although transport-related PA increased before- and during school, decreases were found for especially afterschool time spent at sports grounds and transport-related PA during weekends.

CONCLUSIONS

This is the first study that demonstrated longitudinal changes of context- and domain-specific PA patterns in transition between primary and secondary school, based on device-assessed PA. Given the importance of this transition-period for the development of long-term PA patterns, results from this study warrant the development of evidence-based PA programs in this transition period, while acknowledging the integrative role of schools, parents, and afterschool sports providers. More specifically, the results underline the need to increase children's PA levels in primary schools, promote afterschool PA at secondary schools, and to prevent the drop-out in sports participation at secondary schools.

A Scoping Review of Digital Tools to Reduce Sedentary Behavior or Increase Physical Activity in Knowledge Workers

Background: There is increasing interest in the role that technology can play in improving the vitality of knowledge workers. A promising and widely adopted strategy to attain this goal is to reduce sedentary behavior (SB) and increase physical activity (PA). In this paper, we review the state-of-the-art SB and PA interventions using technology in the office environment. By scoping the existing landscape, we identified current gaps and underexplored possibilities. We discuss opportunities for future development and research on SB and PA interventions using technology. Methods: A systematic search was conducted in the Association for Computing Machinery digital library, the interdisciplinary library Scopus, and the Institute of Electrical and Electronics Engineers Xplore Digital Library to locate peer-reviewed scientific articles detailing SB and PA technology interventions in office environments between 2009 and 2019. Results: The initial search identified 1130 articles, of which 45 studies were included in the analysis. Our scoping review focused on the technologies supporting the interventions, which were coded using a grounded approach. Conclusion: Our findings showed that current SB and PA interventions using technology provide limited possibilities for physically active ways of working as opposed to the common strategy of prompting breaks. Interventions are also often offered as additional systems or services, rather than integrated into existing office infrastructures. With this work, we have mapped different types of interventions and provide an increased understanding of the opportunities for future multidisciplinary development and research of technologies to address sedentary behavior and physical activity in the office context.

Real-time feedback by wearables in running: Current approaches, challenges and suggestions for improvements

Injuries and lack of motivation are common reasons for discontinuation of running. Real-time feedback from wearables can reduce discontinuation by reducing injury risk and improving performance and motivation. There are however several limitations and challenges with current real-time feedback approaches. We discuss these limitations and challenges and provide a framework to optimise real-time feedback for reducing injury risk and improving performance and motivation. We first discuss the reasons why individuals run and propose that feedback targeted to these reasons can improve motivation and compliance. Secondly, we review the association of running technique and running workload with injuries and performance and we elaborate how real-time feedback on running technique and workload can be applied to reduce injury risk and improve performance and motivation. We also review different feedback modalities and motor learning feedback strategies and their application to real-time feedback. Briefly, the most effective feedback modality and frequency differ between variables and individuals, but a combination of modalities and mixture of real-time and delayed feedback is most effective. Moreover, feedback promoting perceived competence, autonomy and an external focus can improve motivation, learning and performance. Although the focus is on wearables, the challenges and practical applications are also relevant for laboratory-based gait retraining.

Does Social Capital Benefit Older Adults' Health and Well-Being? The Mediating Role of Physical Activity

Objectives: To assess whether social capital benefits older adults' self-rated health and well-being and whether physical activity mediates this relation. Methods: A survey study was conducted among members of a sociocultural organization (age ≥55 years), both cross-sectionally (baseline Time 1; N = 959) and longitudinally (3-year follow-up Time 2; N = 409). Results: Specific indicators of social capital were positively, though modestly, related to health and well-being at Time 1 and Time 2. Experienced connectedness with age peers emerged as the strongest predictor. Physical activity only mediated the relation with experienced safety in society. Discussion: The relative importance of older adults' experienced connectedness with their age peers underlines the importance of internalized group membership as a determinant of their health and well-being. Physical activity seems to play only a minor mediating role.

Attractive running environments for all? A cross-sectional study on physical environmental characteristics and runners' motives and attitudes, in relation to the experience of the running environment

Background

Running has become one of the most popular sports and has proven benefits for public health. Policy makers are increasingly aware that attractively designed public spaces may promote running. However, little is known about what makes a running environment attractive and restorative for runners and to what extent this depends on characteristics of the runner. This study aims to investigate 1) to what extent intrapersonal characteristics (i.e. motives and attitudes) and perceived environmental characteristics (e.g. quality of the running surface, greenness of the route, feelings of safety and hinderance by other road users) are associated with the perceived attractiveness and restorative capacity of the running environment and 2) to what extent the number of years of running experience modify these associations.

Methods

Cross-sectional data were collected through the online Eindhoven Running Survey 2015 (ERS15) among half marathon runners (N = 2477; response rate 26.6%). Linear regression analyses were performed for two outcomes separately (i.e. perceived attractiveness and perceived restorative capacity of the running environment) to investigate their relations with motives and attitudes, perceived environmental characteristics and interactions between perceived environmental characteristics and number of years of running experience.

Results

Perceived environmental characteristics, including green and lively routes and a comfortable running surface were more important for runners’ evaluation of the attractiveness and restorative capacity of the running environment than runners’ motives and attitudes. In contrast to experienced runners, perceived hinder from unleashed dogs and pedestrians positively impacted the attractiveness and restorative capacity for less experienced runners.

Conclusions

Perceived environmental characteristics were important determinants of the attractiveness and restorative capacity of the running environment for both novice and experienced runners. However, green and lively elements in the running environment and hinderances by cars were more important for less experienced runners. In order to keep novice runners involved in running it is recommended to design comfortable running tracks and routes and provide good access to attractive, green and lively spaces.

P35 Ability to quantify stereoelectroencephalography (SEEG) electrode trajectory proximity to vessels across imaging protocols

Objectives

Automated planning of stereoelectroencephalography (SEEG) electrode trajectories is dependent on vessel segmentation.1 We quantify imaging protocols ability to measure trajectory-to-vessel distance.

Design

Retrospective analysis.

Subjects

Ten consecutive patients were selected whom had SEEG implantation (95 electrodes) and Digital Catheter Subtraction Angiography (DSA) with catheterization of carotid or vertebral arteries, post-gadolinium T1-weighted (GAD), phase-contrast MR angiography and MR venography (MR) acquired.

Methods

SEEG trajectories were planned manually with DSA. Minimum distance to vessels and risk1 were computed for each trajectory using vessel segmentation from GAD, MR, or DSA. Vessel size was considered by including DSA vessels diameters above 1, 2, 3, or 4 mm.

Results

Minimum distance to a vessel was 6.2±3.9 mm (GAD), 2.5±1.6 mm (MR), and 1.5±1.2 mm (DSA). Based on DSA vessel size minimum distances were 2.0±1.5 mm (DSA >1 mm), 3.4±2.6 (DSA >2 mm), 6.6±4.6 mm (DSA >3 mm), and 11.8±7.9 mm (DSA >4 mm). Risk was 0.4±0.4 (GAD), 0.8±0.4 (MR), and 1.1±0.2 (all DSA), 1.0±0.2 (DSA >1 mm), 0.7±0.4 (DSA >2 mm), 0.4±0.5 (DSA >3 mm), and 0.2±0.3 (DSA >4 mm).

Conclusions

DSA is best able to segment vessels. MR has metrics similar to DSA vessels above 2 mm. GAD has metrics similar to DSA vessels above 3 mm.

'Take a Mental Break!' study: Role of mental aspects in running-related injuries using a randomised controlled trial

Background

Running-related injuries (RRIs) can be considered the primary enemy of runners. Most literature on injury prediction and prevention overlooks the mental aspects of overtraining and under-recovery, despite their potential role in injury prediction and prevention. Consequently, knowledge on the role of mental aspects in RRIs is lacking.

Objective

To investigate mental aspects of overtraining and under-recovery by means of an online injury prevention programme.

Methods and analysis

The ‘Take a Mental Break!’ study is a randomised controlled trial with a 12 month follow-up. After completing a web-based baseline survey, half and full marathon runners were randomly assigned to the intervention group or the control group. Participants of the intervention group obtained access to an online injury prevention programme, consisting of a running-related smartphone application. This app provided the participants of the intervention group with information on how to prevent overtraining and RRIs with special attention to mental aspects. The primary outcome measure is any self-reported RRI over the past 12 months. Secondary outcome measures include vigour, fatigue, sleep and perceived running performance. Regression analysis will be conducted to investigate whether the injury prevention programme has led to a lower prevalence of RRIs, better health and improved perceived running performance.

Ethics and dissemination

The Medical Ethics Committee of the University Medical Center Utrecht, the Netherlands, has exempted the current study from ethical approval (reference number: NL64342.041.17). Results of the study will be communicated through scientific articles in peer-reviewed journals, scientific reports and presentations on scientific conferences.

Analysis of the Features Important for the Effectiveness of Physical Activity-Related Apps for Recreational Sports: Expert Panel Approach

Background

A large number of people participate in individual or unorganized sports on a recreational level. Furthermore, many participants drop out because of injury or lowered motivation. Potentially, physical activity–related apps could motivate people during sport participation and help them to follow and maintain a healthy active lifestyle. It remains unclear what the quality of running, cycling, and walking apps is and how it can be assessed. Quality of these apps was defined as having a positive influence on participation in recreational sports. This information will show which features need to be assessed when rating physical activity–related app quality.

Objective

The aim of this study was to identify expert perception on which features are important for the effectiveness of physical activity–related apps for participation in individual, recreational sports.

Methods

Data were gathered via an expert panel approach using the nominal group technique. Two expert panels were organized to identify and rank app features relevant for sport participation. Experts were researchers or professionals in the field of industrial design and information technology (technology expert panel) and in the field of behavior change, health, and human movement sciences who had affinity with physical activity–related apps (health science expert panel). Of the 24 experts who were approached, 11 (46%) agreed to participate. Each panel session consisted of three consultation rounds. The 10 most important features per expert were collected. We calculated the frequency of the top 10 features and the mean importance score per feature (0-100). The sessions were taped and transcribed verbatim; a thematic analysis was conducted on the qualitative data.

Results

In the technology expert panel, applied feedback and feedforward (91.3) and fun (91.3) were found most important (scale 0-100). Together with flexibility and look and feel, these features were mentioned most often (all n=4 [number of experts]; importance scores=41.3 and 43.8, respectively). The experts in the health science expert panels a and b found instructional feedback (95.0), motivating or challenging (95.0), peer rating and use (92.0), motivating feedback (91.3), and monitoring or statistics (91.0) most important. Most often ranked features were monitoring or statistics, motivating feedback, works good technically, tailoring starting point, fun, usability anticipating or context awareness, and privacy (all n=3-4 [number of experts]; importance scores=16.7-95.0). The qualitative analysis resulted in four overarching themes: (1) combination behavior change, technical, and design features needed; (2) extended feedback and tailoring is advised; (3) theoretical or evidence base as standard; and (4) entry requirements related to app use.

Conclusions

The results show that a variety of features, including design, technical, and behavior change, are considered important for the effectiveness of physical activity–related apps by experts from different fields of expertise. These insights may assist in the development of an improved app rating scale.

Who uses running apps and sports watches? Determinants and consumer profiles of event runners' usage of running-related smartphone applications and sports watches

Individual and unorganized sports with a health-related focus, such as recreational running, have grown extensively in the last decade. Consistent with this development, there has been an exponential increase in the availability and use of electronic monitoring devices such as smartphone applications (apps) and sports watches. These electronic devices could provide support and monitoring for unorganized runners, who have no access to professional trainers and coaches. The purpose of this paper is to gain insight into the characteristics of event runners who use running-related apps and sports watches. This knowledge is useful from research, design, and marketing perspectives to adequately address unorganized runners' needs, and to support them in healthy and sustainable running through personalized technology. Data used in this study are drawn from the standardized online Eindhoven Running Survey 2014 (ERS14). In total, 2,172 participants in the Half Marathon Eindhoven 2014 completed the questionnaire (a response rate of 40.0%). Binary logistic regressions were used to analyze the impact of socio-demographic variables, running-related variables, and psychographic characteristics on the use of running-related apps and sports watches. Next, consumer profiles were identified. The results indicate that the use of monitoring devices is affected by socio-demographics as well as sports-related and psychographic variables, and this relationship depends on the type of monitoring device. Therefore, distinctive consumer profiles have been developed to provide a tool for designers and manufacturers of electronic running-related devices to better target (unorganized) runners' needs through personalized and differentiated approaches. Apps are more likely to be used by younger, less experienced and involved runners. Hence, apps have the potential to target this group of novice, less trained, and unorganized runners. In contrast, sports watches are more likely to be used by a different group of runners, older and more experienced runners with higher involvement. Although apps and sports watches may potentially promote and stimulate sports participation, these electronic devices do require a more differentiated approach to target specific needs of runners. Considerable efforts in terms of personalization and tailoring have to be made to develop the full potential of these electronic devices as drivers for healthy and sustainable sports participation.

Variety in diagnosis and treatment of periprosthetic joint infections in Belgium and the Netherlands

Recently, guidelines regarding diagnosis and treatment of periprosthetic joint infection (PJI) have been published, but it is unknown how well these are -followed in the Netherlands and Belgium. Therefore, a survey study was performed in the Netherlands and Belgium. 81 orthopedic departments responded (54% in the Netherlands, 52% in Belgium). The majority used protocols for antibiotic and surgical treatment. To discriminate between early and late infection, differences in periods used were seen between respondents, and between countries. Empirical antibiotic treatment varied greatly. Debridement, antibiotics, irrigation and retention of the prosthesis (DAIR) is the -almost unanimous treatment of choice for early PJI. Guidelines are available, but seem not (yet) to be -followed accurately, and do not have answers to all possible treatment options. Perhaps, national guidelines might produce more standardized care, and -consequentially, easier comparison for research, more transparency for patients, and less health care costs.

Direct anterior approach versus posterolateral approach in total hip arthroplasty : one surgeon, two approaches

Early research shows several advantages of the Direct Anterior Approach (DAA) in total hip arthroplasty (THA), although no studies evaluated the DAA on a regular operating table without using fluoroscopy. We performed a retrospective cohort study on the outcome of this variation of the DAA compared with the posterolateral approach (PLA) with one year follow-up. All procedures were uncemented THA performed in 2012 by a single surgeon. Patients in the DAA group (N = 45) had a lower Body Mass Index (p > .001) than the PLA group (N = 38). Functional outcome, pain scores and complications were comparable between the two approaches. Compared with PLA, the DAA was associated with longer operation time (p > 0.001), more blood loss (p > 0.001), shorter length of stay (p = .009), and more adequate acetabular cup inclination (p = .004). This study shows that the DAA on a regular operating table without using fluoroscopy has several advantages compared to the PLA.

Abstract P5-01-06: Differences in FGF1 and FGFR2 expression in BRCA1-associated, BRCA2-associated, and sporadic breast carcinomas

Introduction. In contrast to BRCA1-associated breast cancer, a distinctive phenotype for BRCA2-associated carcinomas has not been identified yet as there is no clear distinction between BRCA2- and non-BRCA mutation related or sporadic carcinomas. Recently, studies suggest overexpression of fibroblast growth factor 1 (FGF1) and fibroblast growth factor receptor 2 (FGFR2) in BRCA2 related cancers. The aim of the study was therefore to investigate whether there is differential expression of FGF1 and/or FGFR2 between BRCA2 related and sporadic and BRCA1 related cancers. This would reveal the usefulness of FGF1 and FGFR2 immunohistochemistry in daily pathology practise.

Method. Invasive breast carcinomas of 33 BRCA1 and 22 BRCA2 germline mutation carriers and a tissue microarray containing 104 sporadic invasive breast carcinomas were immunohistochemically stained for FGF1, FGFR2, estrogen receptor (ER), progesterone receptor (PR), HER2, epidermal growth factor receptor 1 (EGFR), cytokeratin (CK) 5/6 and CK14.

Results. FGFR2 expression was seen in 68.2% and 79.0% of BRCA2-associated and sporadic carcinomas respectively, in contrast to 22.6% of BRCA1-associated tumors (p = 0.000). FGF1 expression was seen in 72.7% of BRCA2-associated carcinomas and in 45.2% and 41.8% in BRCA1-associated and sporadic carcinomas, respectively (p = 0.032).

Conclusion. FGFR2 expression differs significantly between BRCA1- and BRCA2 associated breast carcinomas but not between BRCA2 and sporadic cancers. FGF1 expression differs significantly between BRCA2-associated and sporadic carcinomas and could be used as a BRCA2-specific biomarker.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-01-06.

Quality of life with heart failure: psychosocial determinants to be considered by cardiologists

BACKGROUND

Independent determinants of QOL (quality of life) with heart disease have been recognised and include factors such as severity of medical condition, comorbidity, and concomitant medication. Psychosocial factors, as 'ability to cope with the unpleasantness of the medical condition', 'want of information', and 'social identification' have an important influence on self-perceived wellbeing, but their influence on health-related QOL domains and self-perceived QOL in patients with heart failure has not been systematically studied.

OBJECTIVE

To assess correlation between such psychosocial factors and QOL in patients with heart failure.

METHODS

Patients from the outpatient heart failure clinic of the Martini Hospital, a 1000-bed community hospital in the city of Groningen, the Netherlands, were included if their ejection fractions were <40% and their medical diagnosis according to their cardiologists was stable chronic congestive heart failure. The following QOL estimators were applied: Pearlin's Mastery Scale, Stewart's Short Form 36 Quality of Life Questionnaire, Dupuy's Index of Wellbeing, Cantrill's Self-perceived Quality of Life Scale, Mester's Want of Information Scale. Internal consistency of the multi-item scales was estimated by Cronbach's alphas. Linear and multiple linear regression analyses were performed of the data.

RESULTS

Sixty patients were enrolled, 41 males and 19 females, average age 68 years (range 51 to 84 years). 'Ability to cope with the unpleasantness of the medical condition' was not only an independent determinant of self-perceived and health-related QOL (both p<0.001), but also of each domain of health-related QOL separately (p<0.001 for each domain). Lack of 'adequate medical information' and 'negative social identification' (identification with fellow-sufferers who are doing worse) were negative predictors of 'ability to cope' (p<0.01 and <0.001 respectively). 'Negative social identification' was also an independent determinant of self-perceived QOL, both unadjusted and after adjustment for 'ability to cope' and 'adequate medical information'.

CONCLUSION

Relevant recommendations from this paper to be considered by cardiologists during everyday office hours could include: 1. Patients who express having difficulties in coping with the unpleasant aspects of their underlying heart condition have low health-related QOL as well as low self-perceived QOL. 2. Providing adequate medical information is a significant contributor to both better 'ability to cope' and better self-perceived QOL. 3. Avoiding identifying with fellow-sufferers who are doing worse and, instead, starting to identify with those who are doing better, are significant contributors to both better 'ability to cope' and better self-perceived QOL.

Baccatin III induces assembly of purified tubulin into long microtubules

Baccatin III is widely considered to be an inactive derivative of Taxol. We have reexamined its effect on in vitro assembly of tubulin under a variety of conditions. We found baccatin III to be active in all circumstances in which Taxol is active: it assembled GTP-tubulin, GDP-tubulin, and microtubule protein into normal microtubules and stabilized these polymers against cold-induced disassembly. The effect of baccatin III on in vitro microtubule assembly was quantitatively assessed through determination of critical concentrations, which can be used to obtain the apparent equilibrium constants for the addition of tubulin subunits to growing microtubules. The apparent equilibrium constants for the growth reaction for baccatin III-induced GTP-tubulin and GDP-tubulin assembly measured at 37 degrees C were 4.2-4.6-fold less than those measured for Taxol-induced GTP-tubulin and GDP-tubulin assembly. These data indicate that the entire Taxol side chain contributes only about -1 kcal/mol to the apparent standard free energy of microtubule growth at 37 degrees C regardless of the nature of the E site nucleotide. These data also support the idea that the majority of the interactions between Taxol and tubulin that affect this equilibrium occur between the baccatin portion of the molecule and the binding site. We have also observed a structural difference in microtubules formed using baccatin III and Taxol. Baccatin III-induced microtubules were routinely much longer than those assembled by Taxol, even when very high concentrations of baccatin III were employed. One interpretation of these data is that baccatin III and Taxol differ in their abilities to nucleate GTP-tubulin. This difference in activity may have bearing on the large disparity in cytotoxicity of the two molecules.

Structures of free and complexed forms of Escherichia coli xanthine-guanine phosphoribosyltransferase

Structures of free, substrate-bound and product-bound forms of Escherichia coli xanthine-guanine phosphoribosyltransferase (XGPRT) have been determined by X-ray crystallography. These are compared with the previously determined structure of magnesium and sulphate-bound XPRT. The structure of free XGPRT at 2.25 A resolution confirms the flexibility of residues in and around a mobile loop identified in other PRTases and shows that the cis-peptide conformation of Arg37 at the active site is maintained in the absence of bound ligands. The structures of XGPRT complexed with the purine base substrates guanine or xanthine in combination with cPRib-PP, an analog of the second substrate PRib-PP, have been solved to 2.0 A resolution. In these two structures the disordered phosphate-binding loop of uncomplexed XGPRT becomes ordered through interactions with the 5'-phosphate group of cPRib-PP. The cyclopentane ring of cPRib-PP has the C3 exo pucker conformation, stabilised by the cPRib-PP-bound Mg2+. The purine base specificity of XGPRT appears to be due to water-mediated interactions between the 2-exocyclic groups of guanine or xanthine and side-chains of Glu136 and Asp140, as well as the main-chain oxygen atom of Ile135. Asp92, together with Lys115, could help stabilise the N7-protonated tautomer of the incoming base and could act as a general base to remove the proton from N7 when the nucleotide product is formed. The 2.6 A resolution structure of XGPRT complexed with product GMP is similar to the substrate-bound complexes. However, the ribose ring of GMP is rotated by approximately 24 degrees compared with the equivalent ring in cPRib-PP. This rotation results in the loss of all interactions between the ribosyl group and the enzyme in the product complex.

Smoking and schizophrenia

Individuals with schizophrenia have a high prevalence of smoking compared with the general population and little is known about why so many people with schizophrenia smoke. This paper reviews suggestions of differences in motivation for smoking. Possible explanations for smoking include psychological reasons, together with possible effects on positive and negative symptoms of schizophrenia and reduced side-effects of neuroleptics. Understanding complex issues related to smoking and schizophrenia is important prior to developing health promotion strategies.

Crystal structure of Escherichia coli xanthine phosphoribosyltransferase

Xanthine phosphoribosyltransferase (XPRT; EC 2.4.2.22) from Escherichia coli is a tetrameric enzyme having 152 residues per subunit. XPRT catalyzes the transfer of the phosphoribosyl group from 5-phospho-alpha-D-ribosyl 1-pyrophosphate (PRib-PP) to the 6-oxopurine bases guanine, xanthine, and hypoxanthine to form GMP, XMP, and IMP, respectively. Crystals grown in the absence of substrate or product were used to determine the structure of XPRT at a resolution of 1.8 A, by multiple isomorphous replacement. The core structure of XPRT includes a five-stranded parallel beta-sheet surrounded by three alpha-helices, which is similar to that observed in other known phosphoribosyltransferase (PRTase) structures. The XPRT structure also has several interesting features. A glutamine residue in the purine binding site may be responsible for the altered 6-oxopurine base specificity seen in this enzyme compared to other 6-oxopurine PRTases. Also, we observe both a magnesium ion and a sulfate ion bound at the PRib-PP binding site of XPRT. The sulfate ion interacts with Arg-37 which has a cis-peptide conformation, and the magnesium ion interacts with Asp-89, a highly conserved acidic residue in the PRib-PP binding site motif. The XPRT structure also incorporates a feature which has not been observed in other PRTase structures. The C-terminal 12 residues of XPRT adopt an unusual extended conformation and make interactions with a neighboring subunit. The very last residue, Arg-152, could form part of the active site of a symmetry-related subunit in the XPRT tetramer.

Crystallization and preliminary X-ray crystallographic studies of Escherichia coli xanthine phosphoribosyltransferase

Xanthine phosphoribosyltransferase (XPRT; EC 2.4.2.22) from Escherichia coli is a purine salvage enzyme which synthesizes the nucleotides GMP, XMP, and IMP. A mutant C59A, which is more stable than wild-type XPRT while retaining high activity, has been prepared and crystallized to give three different crystal forms (A, B, and C). Form A crystals are orthorhombic (P21212), with unit cell dimensions a = 59.2 A, b = 92.9 A, c = 53.2 A. Form B crystals are monoclinic (C2) with unit cell dimensions a = 84.4 A, b = 70.8 A, c = 54.1 A, and beta = 113.4 degrees, and form C crystals are tetragonal (P41212 or P43212) with unit cell dimensions a,b = 94 A, c = 167.5 A. Wild-type XPRT and a selenomethionine derivative of C59A XPRT have also been crystallized in the orthorhombic form. The selenomethionine derivative was prepared by expressing XPRT in the usual E. coli strain without the need for a methionine auxotroph. Cells were grown in a methionine-deficient medium supplemented with selenomethionine which gave >95% incorporation. Both the wild-type and selenomethionine C59A XPRT crystals are isomorphous with C59A form A crystals.