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Current optimization of atrioventricular (AV) and interventricular (VV) intervals in cardiac resynchronization therapy (CRT) is time consuming and subject to noise. We aimed to prove the principle that the best hemodynamic effect of CRT is achieved by cancelation of opposing electrical forces, detectable from the QRS morphology in the 3D vectorcardiogram (VCG). Different degrees of left (LV) and right ventricular (RV) pre-excitation were induced, using variation in AV intervals during LV pacing in 20 patients with left bundle branch block (LBBB) and variation in VV intervals during biventricular pacing in 18 patients with complete AV block or atrial fibrillation. The smallest QRS vector area identified stimulation intervals with minimal systolic stretch (median difference [IQR] 20 ms [-20, 20 ms] and maximal hemodynamic response (10 ms [-20, 40 ms]). Reliability of VCG measurements was superior to hemodynamic measurements. This study proves the principle that VCG analysis may allow easy and reliable optimization of stimulation intervals in CRT patients.

Summary Background & aims Hypertriglyceridemia is commonly observed in patients with enterocutaneous fistulas, compromising their health status. In this study potential causes for hypertriglyceridemia in patients with an enterocutaneous fistula are explored and treatment options discussed accordingly. Methods A database was created consisting of all consecutively treated patients with an enterocutaneous fistula from 1991 until 2007. Two successive measures of serum triglyceride concentrations of more than 3.0 mmol/L (266 mg/dL) were regarded as hypertriglyceridemia. The relation between fistula specific characteristics and hypertriglyceridemia was analyzed using a multivariable Cox proportional hazard model with time-dependent covariates. Results A total 102 patients were eligible for this study of whom 25 had hypertriglyceridemia. Multivariable analysis showed that sepsis (HR 4.503, CI 1.778–11.401, P = 0.002), high output small bowel fistula (HR 3.534, CI 1.260–9.916, P = 0.016), parenteral nutrition (HR 5.689, CI 1.234–26.216, P = 0.026) and inflammatory diseases (inflammatory bowel disease vs. malignancy HR 6.211, CI 1.081–35.696, P = 0.041) were independent predictors of hypertriglyceridemia. Conclusions High triglyceride concentrations in patients with an enterocutaneous fistula were mainly associated with sepsis, a high output small bowel fistula, nutrition by the parenteral route and primary diseases with inflammatory aetiology. This should direct a treatment strategy that focuses on these aspects.

IntroductionDifferent outcomes of the effect of green tea on weight loss (WL) and weight maintenance (WM) have been reported in studies with subjects differing in ethnicity and habitual caffeine intake.PurposeTo elucidate by meta-analysis whether green tea indeed has a function in body weight regulation.MethodsEnglish-language studies about WL and WM after green tea supplementation were identified through PubMed and based on the references from retrieved articles. Out of the 49 studies initially identified, a total of 11 articles fitted the inclusion criteria and provided useful information for the meta-analysis. Effect sizes (mean weight change in treatment versus control group) were computed and aggregated based on a random-effects model. The influence of several moderators on the effect sizes was examined.ResultsCatechins significantly decreased body weight and significantly maintained body weight after a period of WL (\[mucirc]=-1.31 kg; P300 mg per day) failed to reach significance (\[mucirc]=-0.27 kg for high and \[mucirc]=-1.60 kg for low habitual caffeine intake; P=0.09). Also, the seemingly smaller effect of catechins in Caucasian (\[mucirc]=-0.82 kg) subjects compared with Asians (\[mucirc]=-1.51 kg; P=0.37) did not reach significance. Interaction of ethnicity and caffeine intake was a significant moderator (P=0.04).ConclusionsCatechins or an epigallocatechin gallate (EGCG)-caffeine mixture have a small positive effect on WL and WM. The results suggest that habitual caffeine intake and ethnicity may be moderators, as they may influence the effect of catechins.International Journal of Obesity advance online publication, 14 July 2009; doi:10.1038/ijo.2009.135.

Since pain-related fear may contribute to the development and maintenance of chronic low back pain (CLBP), an exposure in vivo treatment (EXP) was developed for CLBP patients. We examined the effectiveness as well as specific mediating mechanisms of EXP versus operant graded activity (GA) directly and 6 months post-treatment in a multi-centre randomized controlled trial. In total, 85 patients suffering from disabling non-specific CLBP reporting at least moderate pain-related fear were randomly allocated to EXP or GA. It was demonstrated that EXP, despite excelling in diminishing pain catastrophizing and perceived harmfulness of activities, was equally effective as GA in improving functional disability and main complaints, although the group difference almost reached statistical significance favouring EXP. Both treatment conditions did not differ in pain intensity and daily activity levels either. Nor was EXP superior to GA in the subgroup of highly fearful patients. Irrespective of treatment, approximately half the patients reported clinically relevant improvements in main complaints and functional disability, although for the latter outcome the group difference was almost significant favouring EXP. Furthermore, the effect of EXP relative to GA on functional disability and main complaints was mediated by decreases in catastrophizing and perceived harmfulness of activities. In sum, this study demonstrates that up to 6 months after treatment EXP is an effective treatment, but not more effective than GA, in moderately to highly fearful CLBP patients, although its superiority in altering pain catastrophizing and perceived harmfulness of activities is clearly established. Possible explanations for these findings are discussed.

Cluster randomized and multicentre trials evaluate the effect of a treatment on persons nested within clusters, for instance patients within clinics or pupils within schools. Although equal sample sizes per cluster are generally optimal for parameter estimation, they are rarely feasible. This paper addresses the relative efficiency (RE) of unequal versus equal cluster sizes for estimating variance components in cluster randomized trials and in multicentre trials with person randomization within centres, assuming a quantitative outcome. Starting from maximum likelihood estimation, the RE is investigated numerically for a range of cluster size distributions. An approximate formula is presented for computing the RE as a function of the mean and variance of cluster sizes and the intraclass correlation. The accuracy of this approximation is checked and found to be good. It is concluded that the loss of efficiency for variance component estimation due to variation of cluster sizes rarely exceeds 20% and can be compensated by sampling 25% more clusters.

Serial neuropsychological assessment is often conducted to monitor changes in the cognitive abilities of individuals over time. Because practice effects occur and the reliability of test scores is less than perfect, it is difficult to judge whether varying test results should be attributed to chance trends or to real changes in underlying cognitive abilities. In a large sample of adults (age range, 49–81 years), we evaluated the influence of age, gender, and education on test–retest changes in performance after 3 years on Rey's Verbal Learning Test (VLT), the Stroop Color-Word Test (SCWT), and the Letter Digit Substitution Test (LDST). A new statistical method was applied to assess the significance of changes in test performance (i.e., the regression-based change method). The results showed that test–retest changes differed as a function of age for the VLT Total recall 1–3, VLT Total recall 1–5, VLT Delayed recall, and LDST measures. An age × gender interaction was found for the SCWT Interference change score, suggesting that the age-related decline in executive functioning after 3 years was more pronounced for males than for females. A normative change table with appropriate corrections for the relevant independent variables was established. (JINS, 2008,14, 71–80.)

The effect of handedness on cognitive functioning has been the subject of much controversy. The influential "pathological left-handedness theory" posited by Coren and Halpern (1991) claims that left-handedness is probabilistically related to deviations from the neurological and cognitive norm. Many studies have failed to find negative effects of left-handedness on cognitive functioning, but most of these studies related handedness to cognition at one moment in time. Such studies do not exclude the possibility that sinistrality may be related to a more pronounced age-related longitudinal decline in cognitive functions. This hypothesis was tested in the present study. In a longitudinal study involving a large population sample of cognitively intact people aged at least 50 years at baseline, we evaluated the effect of handedness on age-related decline in four major cognitive domains: speed of information processing, verbal learning, long-term verbal memory, and executive functioning. The results failed to provide support for the hypothesis that sinistrality is associated with a more pronounced age-related cognitive decline. Recommendations for future studies are provided.

Background: To date, the causal effects of the knowledge of cancer-related symptoms and detection behavior on coping with cancer-related symptoms have not been identified. Therefore, the current study explored the effects of active or passive detection of supposedly well-known or less-known cancer-related symptoms on intended coping responses. In addition, we were interested in the extent to which these effects are driven by heightened perceptions of threat. Methods: In an experimental study using a 2 × 2 within-subject design, 221 Dutch adults from the general population responded to a survey study sent to their homes (18.4% response). They were asked to read scenario information about four cancer-related symptoms that were (a) well known or less known and (b) actively or passively detected (e.g., self-examination versus unusual blood loss). The authors measured intended coping responses to the detection of cancer-related symptoms as either adaptive (e.g., visiting a general practitioner) or maladaptive (e.g., denial of the symptom). Results: As expected, the findings revealed that well-known symptoms resulted in more anticipated adaptive coping and less anticipated maladaptive coping than less-known symptoms. Unfortunately, the findings also suggest that the active as opposed to passive detection of cancer symptoms (e.g., self-examination versus unusual blood loss) is likely to result in more maladaptive coping. These effects were mediated by heightened perceptions of threat. Conclusions: Future health education programs that aim to motivate people to be more active in the early detection of cancer symptoms should first focus on increasing people's knowledge about the early warning signs of cancer. (Cancer Epidemiol Biomarkers Prev 2008;17(4):818–26)

Background Patients with enterocutaneous fistulas undergo long intensive treatment. The aim of this study was to investigate the long-term health-related quality of life (HRQL) of these patients. Methods Consecutive patients treated for enterocutaneous fistula between 1990 and 2005 were eligible for this retrospective study. The Karnofsky Performance Scale (KPS), Short Form 36 (SF-36®) and the Inflammatory Bowel Disease Questionnaire were used to measure HRQL. The SF-36® was matched with results from healthy controls. Patients also gave information on concurrent medical illnesses. Results Of 135 patients, 44 died, 14 were lost to follow-up and 12 refused to participate; of the remaining 65, 62 participated (response rate 81 per cent). HRQL was independent of patient characteristics during treatment. Scores for SF-36® domains were lower than in their matched controls (P < 0·050). Concurrent medical illness (cancer, depression and gastrointestinal disease) significantly reduced HRQL (for example with a 40 per cent reduction in vitality). The median KPS score was 80, indicating that activities could be performed with effort and patients had some signs of disease. Conclusion HRQL is lower in patients treated for enterocutaneous fistula than in matched controls, particularly in those with concurrent medical illnesses. Patients treated successfully have normal independence in daily functioning.

This study investigates why consumers accept different genetically modified food products to different extents. The study shows that whether food products are genetically modified or not and whether they are processed or not are the two important features that affect the acceptance of food products and their evaluation (in terms of perceived healthiness, naturalness, necessity and tastiness). The extent to which these evaluation attributes and acceptance of a product are affected by genetic modification or processing depends on whether the product is negatively affected by the other technology: Any technological change to a 'natural' product (when nonprocessed products are genetically modified or when non-genetically modified products are processed) affect evaluation and acceptance stronger than a change to an technologically adapted product (when processed products are also genetically modified or vice versa). Furthermore, evaluation attributes appear to mediate the effects of genetic modification and processing on acceptance.

The aim of this study was to evaluate and compare the effectiveness of two primary school-based interventions on children's fruit and vegetable (F&V) consumption on the long term (2 years after the start of the interventions). Six primary schools were recruited and randomly assigned to (i) a daily free distribution program for the whole school or (ii) a multicomponent program consisting of a classroom curriculum and parental involvement (without free F&V), and six schools served as controls. Follow-up measurements were conducted at the end of the intervention (Follow-up I) and 1 year later (Follow-up II). Random coefficient analyses for longitudinal data showed that the effects of both interventions did not differ between the two follow-up measurements. The results showed similar effects for the free distribution program and the multicomponent program in increasing children's fruit consumption over time (respectively, 7.2 and 15.2 g day(-1)). The distribution program also increased children's vegetable consumption over time (3.25 g day(-1)), even after repeating the analyses using a pessimistic scenario. Despite the large dropout and its consequences for generalizability of our results, the distribution program is considered as the preferred intervention of the two, and implementation on a larger scale should be investigated.

Despite a growth of Internet-delivered interventions, exposure rates to such interventions are still low. In total, 35,104 adolescents participated in the E-MOVO project: an Internet-delivered lifestyle intervention aimed at multiple health behaviours. By means of multilevel analyses, we demonstrated the relationship between intention to change behaviour and adolescents' exposure to E-MOVO's functionalities. There was a clustering of intention to change risk taking behaviours in an unhealthy way and energy balance-related behaviours in a healthy way. This should be taken into account with the design of Internet-delivered interventions. AD - Maastricht University, The Netherlands. Rik.Crutzen@GVO.unimaas.nl. FAU - Crutzen, Rik AU - Crutzen R FAU - de Nooijer, Jascha AU - de Nooijer J FAU - Candel, Math J J M AU - Candel MJ FAU - de Vries, Nanne K AU - de Vries NK LA - eng PT - Journal Article PL - England TA - J Health Psychol JT - Journal of health psychology JID - 9703616 SB - IM

Determinants of intended condom use with steady and casual sex partners were examined among Dutch HIV-positive men who have sex with men (MSM) (N = 296). Given the proposition that safer sex behavior among HIV-positive people is a form of prosocial behavior, the present study extended the general framework of the Theory of Planned Behavior with Schwartz's norm-activation theory and tested the assumption that personal norms would mediate the effects of other psychosocial factors on intended condom use for anal sex. In addition, it was hypothesized that, depending on the context in which sex occurs, specific motives for unprotected anal sex may have a negative influence on intended condom use and, as such, undermine a prosocial tendency to practice safer sex. Therefore, we also investigated the influence of sexual motives for unprotected anal sex on intended condom use with steady and casual sex partners. Results indicated that the Theory of Planned Behavior adequately predicted condom use intentions (for casual sex partners and steady sex partners, the explained variance was 52% and 53%, respectively). However, our proposed model of sexual decision-making significantly improved the prediction of behavioral intentions. For steady and casual sex partners, the assumption of the mediating role of personal norms on condom use intention was confirmed empirically. Additionally, sexual motives for unprotected anal sex exerted, as expected, a direct, negative effect on condom use intention with casual sex partners. The implications of the findings for future research and the development of HIV-prevention programs for HIV-positive MSM are discussed.

Parenting style and smoking-related cognitions have both successfully predicted adolescent smoking behaviour. Data were collected among 482 Dutch adolescents to examine whether effects of parenting styles (authoritative, permissive, authoritarian, rejecting, neglecting, measured by underlying dimensions support, strict control, and psychological control) on adolescent lifetime smoking were mediated by cognitions (pro-smoking attitude, social norm, self-efficacy, intention) and to study the role of gender in this process. Support was not significantly associated with smoking behaviour. The inverse relation between strict control and smoking was partly mediated by attitude and intention, both associated with increased smoking. Psychological control related directly to increased lifetime smoking. Combinations of dimensions creating the specific styles were not associated with cognitions or behaviour. Maternal and paternal parenting were equally associated with smoking cognitions and behaviour; nor were effects moderated by adolescent gender. Interventions to prevent adolescent smoking initiation should aim at increasing strict control and reducing psychological control.

Contains fulltext : 56635.pdf (Publisher’s version ) (Closed access) Expectancy challenges (ECs) were used to change alcohol expectancies and alcohol consumption in young heavy drinking men (age 16–24) on holiday. The intervention took place in community centers and bars. Alcohol expectancies and consumption were assessed with paper and pencil measures prior to the intervention (N = 301) and 2 days afterwards (EC: n = 178; controls: n = 86). Six weeks after the EC, participants were interviewed by telephone (EC: n = 163; controls: n = 71). The intervention resulted in an increase in sedation expectancies in the EC group. Furthermore, the EC led to a differential reduction in alcohol consumption on a night out at the six-week posttest in the heaviest drinkers only. The reduction in alcohol consumption on a night out was not mediated by the change in sedation expectancies. These findings suggest that further research on the mechanisms of change is necessary before a single-session EC may be used in a real-life prevention setting. 14 p.

BACKGROUND: To improve the effective prevention and treatment of obesity, it is important to focus on body weight (BW) development and its determinants during childhood. OBJECTIVE: The aim of the present study was to investigate the effects of early development, parental and genetic variables, and behavioral determinants on overweight at 12 y. DESIGN: In a Dutch cohort of 105 children, anthropometric measurements were conducted from birth until age 7 y. At age 12 y, anthropometric measurements were obtained again, as were measurements of body composition, leptin concentration, 3 polymorphisms, and physical activity, and the Three-Factor Eating Questionnaire was conducted. In addition, parental body mass indexes (BMIs, in kg/m2) and Three-Factor Eating Questionnaire scores were determined. RESULTS: The children's mean (+/-SD) BMI at 12 y was 19.0 +/- 2.6, and 15.2% were classified as overweight. From the first year of life, BMI tracked significantly with BMI at age 12 y (r = 0.24, P < 0.05). Linear regression analyses showed that a rapid increase in BW during the first year of life, a high BMI of the father, and a high dietary restraint score of the mother were significantly associated with overweight at age 12 y (P < 0.05). No significant genetic relation was observed. In addition, overweight was positively associated with dietary restraint of the child, and percentage body fat was negatively associated with the child's activity score (P < 0.05). CONCLUSIONS: In this homogeneous cohort of normal-weight to moderately overweight children, tracking of BMI during childhood took place from the first year of life. Overweight at age 12 y was predicted by an early rapid increase in BW and parental influences. Overweight during childhood may be maintained or even promoted by a high dietary restraint score and low physical activity.

OBJECTIVE: To investigate the 10-year risk of dementia in subjects with mild cognitive impairment (MCI) ages 40 to 85 years. METHODS: We selected subjects from a memory clinic if they met one of the following definitions of MCI: cognitive complaints (n = 181), aging-associated cognitive decline (AACD) (n = 163), mild functional impairment (n = 86), or amnestic MCI (n = 64). Subjects were reassessed after 2, 5, and 10 years. The risk of dementia was calculated with Kaplan-Meier statistics. Analyses were conducted in the entire sample and in subgroups of subjects aged 40 to 54 years, 55 to 69 years, and 70 to 85 years. RESULTS: The 10-year risk of dementia was 0.27 (95% CI 0.20 to 0.34) in subjects with cognitive complaints, 0.28 (95% CI 0.21 to 0.35) in subjects with AACD, 0.44 (95% CI 0.32 to 0.56) in subjects with mild functional impairment, and 0.48 (95% CI 0.35 to 0.61) in subjects with amnestic MCI. Ninety-one percent of the demented subjects had probable AD. The risk of dementia increased with increasing age for all MCI definitions (p < 0.001). Depending on the MCI definition used, the risk for dementia ranged from 0 to 0.06 in subjects aged 40 to 54 years, from 0.37 to 0.52 in subjects aged 55 to 69 years, and from 0.77 to 1.0 in subjects aged 70 to 85 years. CONCLUSIONS: The majority of subjects with MCI do not progress to dementia at the long term. Age strongly influences the dementia risk. MCI often represents the predementia stage of a neurodegenerative disorder in elderly subjects but rarely in younger subjects.

The effect of number of repeated measures on the variance of the generalized least squares (GLS) treatment effect estimator is considered assuming a linearly divergent treatment effect, equidistant time-points and either a fixed number of subjects or a fixed study budget. The optimal combination of group sizes and number of repeated measures is calculated by minimizing this variance subject to a linear cost function. For a fixed number of subjects, the variance of the GLS treatment effect estimator can be decreased by adding intermediate measures per subject. This decrease is relatively large if a) the covariance structure is compound symmetric or b) the structure approaches compound symmetry and the con-elation between two repeated measures does not exceed 0.80, or c) the correlation between two repeated measures does not exceed 0.60 if the time-lag goes to zero. In case the sample sizes and number of repeated measures are limited by budget constraints and the covariance structure includes a first-order auto-regression part, two repeated measures per subject yield highly efficient treatment effect estimators. Otherwise, it is more efficient to have more than two repeated measures. If the covariance structure is unknown, the optimal design based oil a first-order auto-regressive structure with measurement error is preferable in terms of robustness against misspecification of the covariance structure. The numerical results are illustrated by three examples.

The European Smoking Prevention Framework Approach (ESFA) study in six countries tested the effects of a comprehensive smoking prevention approach after 24 (T3; N = 10,751) and 30 months (T4; N = 9,282). The programme targeted four levels, i.e. adolescents in schools, school policies, parents and the community. In Portugal, 12.4% of the T1 non-smokers in the control group had started smoking at T4 compared to 7.9% of the experimental group. Smoking onset in the experimental group was thus 36% lower. In Finland, 32.4% of the T1 non-smokers started smoking compared to 27.6% of the experimental group, implying a 15% lower onset in the experimental group. In Spain, 33.0% of the T1 non-smokers in the control group had started smoking, compared to 29.1% of the experimental group, implying a 12% lower onset. In The Netherlands, the ESFA programme was effective for non-native adolescents with 11.4% new weekly smokers compared to 19.9% in the control group. An opposite effect was found in native Dutch adolescents with 19.0% new weekly smokers in the comparison group compared to 24.0% new smokers in the experimental group. Future programmes should use more standardized ways to assess process evaluations and should assess which elements are responsible for behavioral effects.

Objective. The aim of this study was to evaluate the motivational determinants of the continuation of breast-feeding until 3 months postpartum. Methods. A prospective cohort study using the Integrated Change Model in 341 women in 5 child health care centers. Results. At birth, 73% of the mothers started with breast-feeding and 39% of them continued at least 3 months postpartum. Mothers who continued for 3 months differed in almost all the motivational determinants from mothers who discontinued. In the multiple logistic regression analysis, social support for formula feeding from significant others and situational self-efficacy for breast-feeding made a significant independent contribution to the continuation of breast-feeding. Among the predisposing determinants, the strongest positive predictor of continuation was the intention to return to work at 1 month postpartum. Conclusion. The Integrated Change Model is valid to explain and predict the continuation of breast-feeding. Hence, the results may be used to tailor future interventions aimed at promoting breast-feeding. In the discussion, we use the results to target interventions.

It is often assumed that when a neutral cue is presented in a spatial cueing task, attention remains at fixation until target onset. We hypothesized that variance in nonspatial attention and switches of attention toward target locations can account for variance in reaction times of neutral trials. Lateralized event-related potentials (ERPs) and changes in electroencephalogram (EEG) frequency bands served as predictor variables in a single-trial logistic regression analysis to predict the direction of spatial attention in cued and neutral trials. The contingent negative variation (CNV) and non-lateralized changes in the alpha band served as markers of nonspatial attention. The direction of attention in cued trials was reliably predicted from single-trial lateralized ERP components. In neutral trials, only evidence for nonspatial attention was found, indicated by increases in the CNV and decreases in alpha preceding targets to which responses were relatively fast.

Interventions to promote physical activity are important in preventing children from becoming overweight. Many projects have been developed but only a few showed (moderate) effects. JUMP-in is a systematically developed primary-school-based intervention that focuses on the use of theory, environmental changes, parental influences and cooperation with multi-level parties in intervention development. The effects of JUMP-in were evaluated with a quasi-experimental pre-test/post-test research design. In total, 510 children from Grades 4, 5 and 6 of four intervention schools and two control schools in Amsterdam were followed for an intervention period of one school year. Changes in physical activity as well as in the social cognitive determinants were assessed using self-reports. In addition, a process evaluation has been executed. The results show that JUMP-in was effective in influencing physical activity, especially among children from Grade 6. Children in the control group decreased their level of physical activity considerably, while activity levels in intervention children from Grade 6 remained stable. The intervention effects could not be explained by changes in the measured social cognitive determinants. In contrast, process information illuminated differences in intervention effects between the participating schools. The results from the JUMP-in study show the importance of intervention designs that focus on a theory-based mix of relevant environmental and social cognitive factors.

The Concept Shifting Test (CST) is a newly developed Trail Making Type test that measures concept shifting and executive functioning. The purpose of the present study was to determine whether CST performance was affected by age, gender, educational level, or handedness and to establish the normal range of test performance. The CST was administered to a large sample (N = 1,794) of cognitively intact adults (age range 24 to 81 years). The results showed that CST performance was superior in women, decreased with age, and increased with level of education. Handedness did not affect CST performance. Normative data that are corrected for the influences of these demographical variables were established with a regression-based normative approach.

Statistics is known to be a difficult subject, demanding students to perceive interrelations between numerous highly abstract concepts. Many students approach the subject with an evasive attitude, often resulting in rote learning yielding little conceptual understanding of statistics. Working from a constructivist paradigm, we aimed to stimulate students to self-explain the relationship between a number of concepts and principles related to descriptive statistics. To this end we developed two complementary methods which we tested in an experiment comparing a control group with three different experimental groups in which students charted important propositions related to statistical theory and, depending on their group, complemented this activity with a construction of arguments or with a study of preconstructed arguments. The results indicate an effect from the charting task and suggest a potential effect of constructing arguments.

BACKGROUND: Genetic variation in the peroxisome proliferator-activated receptor gamma2 (PPARgamma2), glucocorticoid receptor (GRL), and ciliary neurotrophic factor (CNTF) genes may play a role in the etiology of obesity. OBJECTIVE: We examined biological, psychological, and genetic determinants associated with weight maintenance (WM) after weight loss. DESIGN: Subjects (n = 120) followed a 6-wk diet and then a 1-y period of WM. Body weight (BW), body composition, leptin concentration, attitude toward eating (measured with the Three-Factor Eating Questionnaire), physical activity, and the polymorphisms of the PPARgamma2, GRL, and CNTF genes were measured. RESULTS: BW loss was 7.0 +/- 3.1 kg. After 1 y, 21 subjects showed successful WM (/=10% regain). Compared with unsuccessful subjects, successful subjects had a higher increase in dietary restraint over time (4.8 +/- 5.0 and 1.8 +/- 3.9, respectively; P < 0.01) but significantly less sensation of general hunger (-4.0 +/- 4.9 and -1.2 +/- 2.7, respectively; P < 0.05). Successful subjects had a significantly different frequency distribution for the PPARgamma2 (P = 0.05) and GRL (P < 0.05) genes than did unsuccessful subjects. The more successful genotypes showed a higher baseline body mass index and waist circumference (PPARgamma2), a greater decrease in disinhibition of dietary restraint (GRL), and less sensation of hunger (GRL). The G/G genotype (GRL) was an independent predictor of successful WM. CONCLUSION: The different genotypes of the PPARgamma2 and GRL genes contribute to WM, either directly (GRL) or indirectly (PPARgamma2 and GRL) via baseline body mass index and waist circumference, and to changes in Three-Factor Eating Questionnaire scores.

BACKGROUND This study was directed at illuminating a well known phenomenon in the medical expertise literature, the 'intermediate effect' in clinical case recall. This robust phenomenon consists of the finding that medical students of intermediate levels of expertise outperform both experts and novices in clinical case recall after diagnosing cases. It deals in particular with the findings of OME researchers who have reported a monotonically increasing recall with level of expertise. PURPOSE To address possible causes for this anomaly in medical expertise and to experimentally demonstrate how data elaboration can cause expertise effects in clinical case recall. METHOD Expert nephrologists, intermediate level students and novices were presented with 6 medical cases under 3 different conditions: laboratory data cases without special instructions, laboratory data cases with instructions to elaborate, and cases with laboratory data and a relevant clinical context. RESULTS Only when participants were required to elaborate on each of the information units presented to them did case recall show an expertise effect. If laboratory data are framed within the context of a patient's history and physical examination data, the 'intermediate effect' appears. CONCLUSIONS The instructions used in the elaboration condition seem to have induced a deeper, more detailed, analysis of the patient case. It is therefore interesting to note that these instructions only affected the recall of the experts and had no effect on the novices' or intermediates' recall. We might conclude from this that expertise effects in clinical case recall are only produced when the normal processing of patient information is disrupted.

BACKGROUND: Based on cognitive psychological research, a number of theoretical frameworks have been put forward to describe the structure of experts' medical knowledge and to explain experts' case-processing.PURPOSE: To provide evidence for the theory of knowledge encapsulation, which states that medical knowledge constitutes of interlinked biomedical and clinical knowledge.METHODS: Fourth-year medical students, clerks and medical experts evaluated six case descriptions, consisting of laboratory data either with or without a clinical context. For each case description, the participants were required to study the case, to formulate a diagnosis, and to write down everything they could remember of the case.RESULTS: When the laboratory data were not embedded within a clinical context, medical experts' case-processing increased and their diagnostic accuracy became worse. Furthermore, laboratory data recall of medical experts was more elaborate in cases where the laboratory data were presented without a clinical context. Similar results were obtained for students and clerks.CONCLUSIONS: The findings are only partially consistent with a prediction made by the theory of knowledge encapsulation. Further research, using a different paradigm than the traditionally used method of free recall, is required to unearth whether medical experts use qualitatively different knowledge structures than novices while solving cases.PMID: 15189258 [PubMed - indexed for MEDLINE]MeSH TermsMeSH Terms:Clinical Competence/standardsDiagnostic Techniques and Procedures/standards*Education, Medical/methodsHumansMedical History Taking/standards*Mental ProcessesMental RecallNetherlandsPhysicians, Family/standards*Problem Solving*Students, MedicalLinkOut - more resourcesFull Text Sources:Blackwell PublishingEBSCOIngenta plcOhioLINK Electronic Journal CenterOvid Technologies, Inc.Swets Information ServicesMedical:Family History - MedlinePlus Health Information

The reproducibility, relative validity, and responsiveness to change of an eight-item food frequency questionnaire designed to measure fruit and vegetable consumption was assessed among 157 women (mean age = 41 years) in the Netherlands from spring 2001 to spring 2002. Plasma concentrations of vitamin C and total and specific carotenoids served as biomarkers against which validity was assessed. The questionnaire was completed and biomarker concentrations were determined three times: immediately preceding and following a controlled intervention of 1 month aimed at increasing fruit and vegetable consumption and 1 year after the start of the intervention. The 1-month and 1-year reproducibility of total fruit and vegetable consumption assessed in the control group was 0.80 and 0.79 (Spearman's r ). Correlations between consumption and plasma carotenoids and vitamin C at baseline were 0.39 and 0.37, respectively, for fruits and 0.24 and 0.26, respectively, for vegetables. Correlations between changes in consumption and plasma carotenoids and vitamin C were 0.32 and 0.33, respectively, for fruits and 0.28 and 0.30, respectively, for vegetables. On the basis of similar correlations reported in the literature, the authors conclude that the questionnaire appears to be suitable for ranking individuals according to their consumption of fruits and vegetables and according to changes in their consumption. However, the validity of the questionnaire remains to be established in males, other age groups, and populations of lower educational levels.

The Dutch Heart Health community intervention 'Hartslag Limburg': results of an effect study at individual level.Ronda G, Van Assema P, Candel M, Ruland E, Steenbakkers M, Van Ree J, Brug J.Department of Health Education and Promotion, Maastricht University, Maastricht, The Netherlands. g.ronda@gvo.unimaas.nl'Hartslag Limburg' (Dutch for Heartbeat Limburg), a regional cardiovascular diseases (CVD) prevention program, integrates a community strategy and a high-risk strategy to reduce CVD risk behaviors. The present paper focuses on the effects of the community intervention on fat intake and physical activity. The project was based on community organization principles and health education theories and methods. In order to implement the intervention, nine local Health Committees were set up, each organizing activities that facilitate and encourage people to adopt a healthier lifestyle. A pre-test-post-test control group design with two post-tests was used to evaluate the intervention. At baseline, representative random cohort research samples were selected in the Maastricht region and in a control region. Data on fat intake and physical activity, and on the psychosocial determinants of these behaviors, were gathered by means of mail surveys. The present study indicates that the intervention had a significant effect on fat reduction, especially among respondents aged

The effectiveness of nutrition education and labeling in Dutch supermarkets.Steenhuis I, van Assema P, van Breukelen G, Glanz K.Department of Psychology, Open University, PO Box 2960, 6401 DL Heerlen, The Netherlands.PURPOSE: Nutrition education and labeling may help consumers to eat less fat. The purpose of this study is to assess the effect of nutrition education with and without shelf labeling on reduced fat intake in Dutch supermarkets. METHODS: The design consisted of a randomized, pretest-posttest, experimental control group design. In total, 2203 clients of 13 supermarkets were included in the sample. Total fat intake of clients and behavioral determinants of eating less fat were measured by a questionnaire. A mixed-effect regression model was used for the analysis. RESULTS: No significant effects were found for the educational intervention, alone or with the labeling, on total fat intake and the psychosocial determinants of eating less fat. CONCLUSION: Nutrition education and labeling of low-fat food products in supermarkets did not prove to be effective strategies. The fact that the supermarket is a highly competitive environment may have accounted for this lack of effect.

Physical activity levels in children and adolescents.Hoos MB, Gerver WJ, Kester AD, Westerterp KR.Department of Pediatrics, University of Maastricht, The Netherlands. Marije.Hoos@kg.unimaas.nlBACKGROUND: Reference data for physical activity level (PAL) and activity-related energy expenditure (AEE) are needed for a better understanding of the effect of activity on childhood health, growth and development OBJECTIVE: Data from 17 studies measuring TDEE (TDEE) with doubly labelled water DLW were combined to construct a reference line for PAL and AEE as a function of age. DESIGN: A total of 17 studies from the literature were analyzed; 17 on girls and 16 on boys. Children were aged 3-16 y and of Caucasian origin. Weighted least-squares regression was used to obtain reference lines for PAL and AEE as a function of age and gender. The relative numbers of children per study were used as a weighting factor. Basal metabolic rate (BMR) or nonfasted (NF) resting metabolic rate and sex were included in the analysis. RESULTS: Although there was no difference in PAL between boys and girls, a significant difference in AEE was found between the two sexes. PAL: 0.025 x age+1.40. AEE (MJ/day): boys 0.30 x age+0.025; girls 0.21 x age+0.33. If BMR is measured under NF conditions, the obtained value has to be reduced by 0.21 for PAL and 0.75 MJ/day for AEE. No relation was found between AEE/kg and age. CONCLUSIONS: PAL and AEE were found to increase with age, showing the importance of age-dependent recommendations. Recommendations for AEE need to be differentiated for sex. To compare PAL and AEE between studies, the measurement conditions of BMR have to be taken into account. The increase in PAL and AEE values can be attributed to an increase in weight, because there was no relation between AEE/kg and age.

Seasonal variation in sleeping metabolic rate, thyroid activity, and leptin.Plasqui G, Kester AD, Westerterp KR.Dept. of Human Biology, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands. G.Plasqui@HB.Unimaas.NLWe investigated seasonal variation in sleeping metabolic rate (SMR) and the possible relation to body composition, thyroid activity, and leptin. Twenty-five healthy volunteers were examined four times during the year: in spring (April, May), summer (July, August), autumn (October, November), and winter (January, February). Body composition was determined using a three-compartment model based on underwater weighing and the deuterium dilution method. SMR was measured during an overnight stay in a respiration chamber. A blood sample was taken for the analysis of free and total thyroxine, TSH, and leptin. SMR showed a significant seasonal variation (P < 0.01) with a maximum in winter (4.54 kJ/min) and a minimum in summer (4.34 kJ/min). The amplitude was 0.10 +/- 0.02 kJ/min, and the phase was November 5th. Season explained 17% of the intraindividual variation in SMR. The circannual rhythm in SMR could not be explained by changes in body composition, thyroid activity, or leptin. Interindividual variation in SMR was explained by fat-free mass (P < 0.001) and leptin (P < 0.001).

Comparison of near infrared reflectance analysis of fecal fat, nitrogen and water with conventional methods, and fecal energy content.Neucker AV, Bijleveld CM, Wolthers BG, Swaaneburg JC, Kester AD, Kreel B, Forget PP.Department of Pediatrics,University Hospital Maastricht, 6202 AZ, Maastricht, The Netherlands. avn@ms-azm-3.azm.nlOBJECTIVES: To evaluate Near-Infrared Analysis (NIRA) method for determining fecal fat, water and nitrogen. DESIGN AND METHODS: The results of fecal fat, water and nitrogen by NIRA were compared with results of van de Kamer and Acid Steatocrit (AS), Dumas and vacuum drying methods for fat, nitrogen and water respectively.Results of fat determining methods were also compared with total fecal energy as obtained by bomb calorimeter. RESULTS: NIRA results correlated significantly (p < 0.001) with standard methods for nitrogen (r = 0.79), fat (r = 0.84 and r = 0.88 for van de Kamer and AS respectively) and water (r = 0.91). The limits of agreement for nitrogen and fat results were too wide for the methods to be used interchangeably. The fecal fat results correlated significantly (p < 0.001) with fecal energy results. CONCLUSION: NIRA may be valuable for monitoring malabsorption but the diagnostic value remains to be determined.

Changes in pulmonary hyperinflation and bronchial hyperresponsiveness following treatment with lansoprazole in children with cystic fibrosis.Hendriks JJ, Kester AD, Donckerwolcke R, Forget PP, Wouters EF.Department of Paediatrics, University Hospital and University of Maastricht, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands. jhe@skin.azm.nlSUMMARY. In this prospective open study of 14 children with cystic fibrosis (CF), we evaluated the effect of 1 year adjuvant therapy with lansoprazole, a proton pump inhibitor (PPI), on growth, fecal fat loss, body composition and lung function. Only stable patients with pancreatic insufficiency were included, and their data were compared to those of a large Dutch pediatric normal reference population. During the use of the PPI, mean weight and height did not change significantly, while body mass index improved (P < 0.05). An immediate significant and persistent reduction of fecal acid steatocrit (P < 0.05) was demonstrated. Compared to normal Dutch children, the CF patients showed significantly decreased standard deviation scores (SDS) for total body fat (TBF, -0.966) and fat-free mass (FFM, -1.826). Under lansoprazole, TBF improved significantly (P < 0.05), while mean FFM remained unchanged. A significant improvement in total lung capacity (P < 0.05), residual volume (P = 0.055), and maximal inspiratory mouth pressure (P = 0.002) was also demonstrated. Hyperinflation tended to decrease during the use of a PPI. Daily recordings of peak expiratory flow (PEF) showed a maximal diurnal variability of 28% of recent best PEF and minimal morning PEF of 72% of recent best PEF, confirming that bronchial hyperresponsiveness is increased in CF. We conclude that adjuvant therapy with lansoprazole in young CF patients with persistent fat malabsorption, decreased fat losses and improved total body fat. Lung hyperinflation decreased, which may partly explain the improvement in inspiratory muscle performance. The simultaneous improvements in body composition and lung hyperinflation suggest a relationship between these two parameters. Further research is necessary to confirm such a relationship and to elucidate the mechanisms involved. Copyright 2001 Wiley-Liss, Inc

Arch Dis Child 2001 Jul;85(1):73-8 Related Articles, Books, LinkOut Energy metabolism in relation to body composition and gender in adolescents.van Mil EG, Westerterp KR, Kester AD, Saris WH.Departments of Human Biology and Paediatrics, Nutrition Toxicology and Environment Research Institute Maastricht, Maastricht University, PO Box 616, Maastricht 6200 MD, Netherlands. g.vanmil@hb.unimaas.nlOBJECTIVE: To study the effect of body composition on average daily metabolic rate (ADMR) and basal metabolic rate (BMR) in adolescence, and to examine current BMR prediction equations. STUDY: Dutch adolescents were pooled with previously reported American and British subjects (n = 90 overall). BMR and ADMR were analysed by multiple regression. RESULTS: Fat-free mass, BMR, and ADMR were higher in the obese than in the non-obese group (mean (SD): 53.2 (10.7) kg, 8.35 (1.57) MJ/d, and 13.64 (2.78) MJ/d, compared with 41.0 (8.1) kg, 6.42 (0.94) MJ/d, and 11.16 (2.21) MJ/d, respectively). BMR remained higher when adjusted for fat-free mass, age, and sex. ADMR adjusted for BMR was similar in the two groups. WHO equations overestimated BMR in obese boys and underestimated BMR in non-obese boys. CONCLUSIONS: BMR, but not activity, is increased in obese adolescents and in male adolescents. The WHO BMR equations for adults are recommended for obese adolescents.

Am J Epidemiol 2001 Jan 1;153(1):38-41 Related Articles, Books, LinkOut Alcohol consumption and bladder cancer risk: results from The Netherlands Cohort Study.Zeegers MP, Volovics A, Dorant E, Goldbohm RA, van den Brandt PA.Department of Epidemiology, Maastricht University, The Netherlands. mpa.zeegers@epid.unimaas.nlAlthough several epidemiologic studies have been conducted on alcohol consumption and bladder cancer risk, the risk according to quantity and type of alcohol consumed is not clear. The authors investigated these associations in a large prospective cohort study on diet and cancer among 120,852 subjects in the Netherlands aged 55-69 years at baseline (1986). Subjects completed a questionnaire on risk factors for cancer, including alcohol consumption. Follow-up for incident cancer was established by record linkage to cancer registries. The case-cohort analysis was restricted to a follow-up period of 6.3 years and was based on 594 cases with bladder cancer and 3,170 subcohort members. The authors corrected for age and smoking in multivariable analyses. The incidence rate ratios for men who consumed or =30 grams of alcohol per day were 1.49, 1.52, 1.16, and 1.63 compared with nondrinkers, respectively (p for trend = 0.13). Alcohol consumed from beer, wine, and liquor was associated with moderately elevated risks, although most were not statistically significant. The incidence rate ratios for women varied around unity. The results of this study do not suggest an important association between alcohol consumption and bladder cancer risk.

Mixed effects models for longitudinal data with fixed as well as random parameters are often used to describe average profiles. Influence measures are usually constructed to detect influential subjects and observations for the fixed regression parameters, treating the subject-specific parameters as nuisance parameters. One of these measures is the well-known Cook's distance. We show that this statistic may fail to detect or may incorrectly detect influential observations due to the random-effects variances and covariances. A conditional version of Cook's distance is proposed to assess the influence of observations on the estimated regression parameters.

Am J Clin Nutr 2001 Apr;73(4):797-806 Related Articles, Books, LinkOut Comment in: Am J Clin Nutr. 2001 Apr;73(4):671-2. Essential fatty acid composition of plasma phospholipids and birth weight: a study in term neonates.Rump P, Mensink RP, Kester AD, Hornstra G.Department of Human Biology and the Nutrition and Toxicology Research Institute Maastricht, Maastricht University, Maastricht, Netherlands. p.rump@hb.unimaas.nlBACKGROUND: Essential fatty acids (EFAs) in umbilical cord blood samples are associated with attained birth weight in premature infants and low-birth-weight neonates. OBJECTIVE: The objective was to investigate relations between the EFA composition of cord and maternal plasma phospholipids and birth weight in term neonates. DESIGN: This was a cross-sectional study in 627 singletons born at term. The plasma phospholipid EFA composition of the mothers was determined by gas-liquid chromatography at study entry (< or = 16 wk gestation), at delivery, and in cord plasma at birth. Birth weights were normalized to SD scores. RESULTS: In cord plasma, the dihomo-gamma-linolenic acid concentration was positively related to weight SD scores. Both arachidonic acid (AA) and docosahexaenoic acid (DHA) were negatively related to weight SD scores. EFA-status indicators showed similar negative associations, whereas eicosatrienoic acid concentrations were positively related to neonatal size. In maternal plasma, proportions of n-3 long-chain polyenes (LCPs) and n-6 LCPs decreased during pregnancy. Larger decreases in AA, DHA, n-3 LCP, and n-6 LCP fractions were observed in mothers of heavier babies. Higher concentrations of LCPs in maternal plasma were, however, not related to a larger infant size at birth. CONCLUSIONS: A lower biochemical EFA status in umbilical cord plasma and a larger decrease in maternal plasma LCP concentrations are associated with a higher weight-for-gestational-age at birth in term neonates. Our findings do not support a growth-stimulating effect of AA or DHA; however, they do suggest that maternal-to-fetal transfer of EFAs might be a limiting factor in determining neonatal EFA status.

Background In many western countries an increase in incidence of adenocarcinoma of the oesophagus and/or gastric cardia have been reported. The aim of this study was to describe and compare trends in incidence of adenocarcinoma of the oesophagus and gastric cardia in several areas of Europe, 1968-1995, using Eurocim (a database of cancer incidence and mortality data from 95 European cancer registries). Methods Time-trends in age-standardized incidence rates of adenocarcinomas of the oesophagus and gastric cardia are described in 11 population-based cancer registries from 10 countries in North, South, East, West and Central Europe, 1968-1995. The statistical significance of the time-trends in incidence was assessed using Poisson regression analysis. Results An increase in incidence of adenocarcinomas of the oesophagus and gastric cardia was observed in Northern Europe (Denmark), Southern Europe (Italy, Varese), Eastern Europe (Slovakia) and Western Europe (England and Wales, Scotland). In Central Europe (Switzerland, Basel) and in the cancer registries of Iceland (Northern Europe), France, Bas-Rhin and Calvados, Southern Ireland, and the Netherlands, Eindhoven (Western Europe) no rise in incidence was observed. The increase in incidence of adenocarcinomas of the oesophagus and gastric cardia was accompanied by a decrease in incidence of both adenocarcinomas and non-adenocarcinomas of the non-cardia part of the stomach in almost all of the 11 cancer registries studied. Increased histological verification of tumours of the oesophagus and stomach and improvement in precision of histological diagnosis may partly explain the increase in incidence of adenocarcinomas in some registries. Conclusions This study, using Eurocim data, supports the findings from other time-trend studies of population-based cancer registries in western countries.

OBJECTIVE: To measure activity related energy expenditure in Prader-Willi syndrome (PWS) corrected for body size. SUBJECTS: 17 PWS subjects (10 females, seven males, age 7.5-19.8 y) and 17 obese controls, matched for gender and bone age. MEASUREMENTS: Basal metabolic rate (BMR) was measured by ventilated hood and average daily metabolic rate (ADMR) was measured with doubly labelled water. Activity induced energy expenditure (AEE) was calculated as 0.9ADMR - BMR. Activity related energy expenditure was corrected for body size using the following measures: AEE per kg body weight (AEE/kg), ADMR/BMR (PAL), and the residual of the regression of ADMR on BMR (rADMR). Group differences were analyzed by analysis of covariance adjusting for bone age, fat mass (FM) and gender. RESULTS: ADMR, AEE and PAL were lower (P

Aim: To identify risk factors for early nonelective readmission in patients with chronic obstructive pulmonary disease, previously admitted for an exacerbation of their disease. Clinical characteristics were analysed with special emphasis on body weight on admission and weight changes during hospitalization. Methods: The computerized hospital database was used to select all hospital admissions in 1994 and 1995 with exacerbation of chronic obstructive pulmonary disease as main discharge diagnosis. Cases were retained if they were nonelectively readmitted within 14 days after prior discharge, and if they had no oedema. Controls were randomly selected from the discharge listing and were not readmitted within 3 months. Cases and controls were matched on several parameters including FEV1% predicted obtained during a stable phase of the disease. Hospital charts were reviewed for clinical parameters on admission, discharge and readmission. Results: Fourteen cases were retained in the study. On admission, lung function, blood gases and parameters describing morbidity and social factors, were not different in cases and controls. The discharge procedure was adequate. During hospitalization the cases lost weight (mean±SD) (−1.6±1.9 kg, P= 0.01), while controls remained weight stable. Using a matched pairs logistic regression analysis, weight loss during hospitalization (P= 0.011) and low BMI on admission (P= 0.046) were related to the increased risk of unplanned readmission. Conclusion: These findings provide further support for the concept that nutritional status is related to morbidity in COPD.

Background: Body composition evaluation by bioelectrical impedance analysis in children makes use of different group-specific population-derived equations. The present study was conducted to attempt to validate the use of population-independent physical model-derived equations in children. Methods: The validity of bioelectrical impedance analysis for the measurement of total body water in children was evaluated by comparing results of two physical model-derived and two population-derived equations with those of deuterium dilution as reference method in a group of 38 heterogeneous children. Results: Means +/- standard deviation (in liters) for total body water measured with deuterium dilution and the physical model 1-derived equation were 18.4 +/- 4.7 L and 18.1 +/- 4.4 L, respectively. This difference is not significant, whereas significant differences were found for all other tested equations. Significant smaller absolute differences between the model 1 equation and deuterium reference results were found when compared with the results of the other three tested equations. Conclusion: When compared with results of the reference deuterium method the physical model 1-derived equation was the only one that provided reliable total body water results by bioelectrical impedance analysis in children.

Several studies either implicitly or explicitly converted the well-known theory of reasoned action into a theory for choice. In this paper we elaborate upon such an attitude-based choice theory by proposing different model variants for binary choices. The models vary in two respects: (1) the level at which alternatives are compared (level of comparison), and (2) the way the comparison takes place at each of these levels in reaching a choice (comparison mechanism). Based on these dimensions 45 models were formulated that were examined empirically by logistic regression on choice probabilities. The data set consisted of measurements on 467 entrepreneurs for different financial services, one of which was an innovation. Of the different comparison mechanisms, subtraction, without explicitly incorporating the similarity of the choice alternatives, turned out to be the most adequate. For these models, equal weighting of the attitudinal components could not be rejected, which made it impossible to test at which level the alternatives were compared. Structural equation modeling of the same data shows that the equality of the weights for the attitudinal components can be explained by the affective component of attitude being a major predictor of choice.

Departments of Surgery, Anesthesiology,and Cardio-Thoracic Surgery, University Hospital Maastricht, The Netherlands.OBJECTIVE: This study was designed to clarify whether myocardial substrate uptake and oxidation change after a period of hypothermic cardioplegic arrest during coronary artery bypass grafting procedures. METHODS: In 30 patients arterial and coronary sinus blood was sampled and coronary sinus flow measurements were performed before and after sternotomy and 10 minutes, 20 minutes, 50 minutes, and 6 hours after release of the aortic crossclamp. Measurement of free fatty acids, lactate, glucose, oxygen content, and carbon dioxide content in arterial and coronary sinus blood allowed calculations of myocardial substrate use, respiratory quotients, and myocardial oxidation rates of carbohydrates and fat. RESULTS: Uptake of free fatty acids and lactate was significant throughout the study and did not change in association with release of the crossclamp. Free fatty acid and lactate uptake measured 6 +/- 4 micromol/min and 23 +/- 26 micromol/min, respectively, before crossclamping compared with 8 +/- 7 micromol/min and 19 +/- 21 micromol/min, respectively, after release of the clamp. Glucose uptake was significant only during the first hour after crossclamp release and increased from 7 +/- 50 to 28 +/- 34 micromol/L after crossclamp release. Myocardial oxygen consumption did not change significantly (0.5 +/- 0.2 mmol/L compared with 0.35 +/- 0.2 mmol/L) after release of the crossclamp. Myocardial oxygen extraction ratio decreased from 58% +/- 8% to 41% +/- 13% after crossclamp release. Respiratory quotient increased after crossclamp release (0.85 +/- 0. 2 compared with 1.00 +/- 0.2), which implies that carbohydrate oxidation increased at the expense of free fatty acid oxidation. CONCLUSION: We conclude that hypothermic cardioplegic arrest during coronary artery bypass graft operations is associated with a transiently increased uptake and oxidation of carbohydrates during the immediate reperfusion phase.

Department of General Internal Medicine, University Hospital Nijmegen, The Netherlands.It is unknown whether and to what extent changes in various endothelial functions and adrenergic responsiveness are related to the development of microvascular complications in type 1 diabetes. Therefore, endothelium-dependent and endothelium-independent vasodilatation, endothelium-dependent hemostatic factors, and one and two adrenergic vasoconstrictor responses were determined in type 1 patients with and without microvascular complications. A total of 34 patients with type 1 diabetes were studied under euglycemic conditions on two occasions (11 without microangiopathy, 10 with proliferative and preproliferative retinopathy previously treated by laser coagulation, 13 with microalbuminuria, and 12 healthy volunteers also were studied). Forearm vascular responses to brachial artery infusions of N(G)-monomethyl-L-arginine (L-NMMA), sodium nitroprusside, acetylcholine (ACh), clonidine, and phenylephrine were determined. The ACh infusions were repeated during coinfusion of L-arginine. Furthermore, plasminogen activator inhibitor type 1 (PAI-1) activity, tissue plasminogen activator antigen levels, von Willebrand factor antigen levels, tissue factor pathway inhibitor (TFPI) activity, and endothelin-1 levels were measured. No differences in endothelium-dependent or endothelium-independent vasodilatation or adrenergic constriction were observed between the diabetic patients and the healthy volunteers. In comparison to the first ACh infusion, the maximal response to repeated ACh during L-arginine administration was reduced in the diabetic patients, except in the patients with proliferative and preproliferative retinopathy previously treated by laser coagulation. In these patients, the combined infusion of L-arginine and ACh resulted in an enhanced response. TFPI activity was elevated, and PAI-1 activity was reduced in the type 1 diabetic patients. Furthermore, PAI-1 activity was positively correlated with urinary albumin excretion (r = 0.48, P < 0.01) and inversely correlated with the vasodilatory response to the highest ACh dose (r = -0.37, P < 0.05). The response to the highest ACh and L-NMMA dose were positively correlated with mean arterial blood pressure (r = 0.32, P < 0.01; r = 0.41, P < 0.01, respectively). Forearm endothelium-dependent and endothelium-independent vasodilatation and adrenergic responsiveness were unaltered in type 1 diabetic patients with and without microvascular complications. Relative to healthy control subjects, endothelium-dependent vasodilatation was depressed during a repeated ACh challenge (with L-arginine coinfusion) in the diabetic patients without complications or with microalbuminuria. In contrast, this vasodilatation was enhanced in the patients with retinopathy. Elevation of TFPI was the most consistent marker of endothelial damage of all the endothelial markers measured.

Items with the highest discrimination parameter values in a logistic item response theory model do not necessarily give maximum information. This paper derives discrimination parameter values, as functions of the guessing parameter and distances between person parameters and item difficulty, that yield maximum information for the three-parameter logistic item response theory model. An upper bound for information as a function of these parameters is also derived. An algorithm is suggested for the maximum information item selection criterion for adaptive testing and is compared with a full bank search algorithm.

Department of Gastroenterology, University Hospital Maastricht, Netherlands.AIM: To describe medico-social functioning after total gastrectomy and the factors determining it. PATIENTS AND METHODS: In three medical rehabilitation centres, 173 consecutive patients (female/male = 62/111) after potentially curative total gastrectomy for gastric malignancy 206 days earlier (median, interquartile range = IQR 56-644) were evaluated for different pre- and post-operative parameters with potential influence on post-operative medico-social functioning as measured with the Edinburgh Rehabilitation Status Scale (ERSS). Parameters evaluated were: gender, age, time since operation, tumour stage, type of operation, clinical centre of admittance, haemoglobin, ferritin, albumin, presence of small bowel bacterial overgrowth, rapid oro-coecal transit, dyspepsia, early satiety, reflux, dysphagia, vomiting, a symptom based score, body mass index in health, at operation and on admission, weight loss since operation, calorie intake, bowel habits, and fat malassimilation. Independent influential factors for the ERSS were identified in a linear regression analysis. RESULTS: The median ERSS-score was 4 (IQR 2-6) on a scale from 0 (best) to 28 (worst). There was a significant difference in the ERSS-scores between the three different clinics. The ERSS-scores improved significantly with time since operation (ca. 22% per year). ERSS-scores were higher in patients with intestino-oesophageal reflux (+71%), with dyspepsia (+65%), or with dysphagia (+62%). CONCLUSION: Medico-social functioning was acceptable in this patient population. After total gastrectomy, dyspepsia, dysphagia, and intestinal reflux into the oesophagus need special attention.

Department of Pediatrics, University Hospital of Maastricht, Maastricht University, The Netherlands.This retrospective study evaluates long-term growth of children with congenital heart disease (CHD) and looks for possible relationships between postsurgical catch-up growth and both severity of preoperative growth failure and operation age. Growth data of 123 children with isolated CHD were available. Mean z-scores and 95% confidence intervals for weight, height and weight-for-height were plotted for age-periods as well as for pre- and postoperative periods. Growth of children with a large VSD or a Tetralogy of Fallot was most abnormal and improved but did not normalize after operation. Catch-up growth for length was strongly correlated with severity of the preoperative growth failure (r = 0.92, p < 0.05) but not with operation age (r = 0.20, NS). We conclude that surgical correction results in catch-up growth for most individuals. Catch-up growth is positively correlated with the severity of the initial growth disturbance and not with age at the moment of surgical correction.