Polymorphisms of the lamina maturation pathway and their association with the metabolic syndrome: the DESIR prospective study

Laminopathies are rare monogenic diseases, some of them exhibiting features of the metabolic syndrome. These diseases are mainly due to mutations in LMNA, encoding A-type lamins. One LMNA polymorphism, rs4641, has been associated with the metabolic syndrome, but results have been controversial. We therefore investigated the effect of single nucleotide polymorphisms (SNPs) in the LMNA gene in combination with four other genes encoding enzymes influencing lamin post-translational maturation on risk of metabolic syndrome (MS). Twenty-three tagging SNPs characterising the haplotypic variability of five genes (LMNA, ICMT, ZMPSTE24, FNTA and FNTB) were genotyped in 3,916 French men and women who took part in the prospective DESIR study. Single locus and haplotype analyses were performed but did not detect any significant association with the risk of MS. No robust interaction between SNPs located in different genes on the risk of MS was identified. In conclusion, we did not observe any convincing evidence that common polymorphisms of the lamina pathway could modulate the risk of MS.     

Predictors of 6-minute walk test and 12-minute walk/run test in obese children and adolescents

The purpose of this study was to identify predictors of the distance achieved during a 6-minute walk test and a 12-minute walk/run test (Cooper test) in obese children and adolescents and to evaluate the influence of a residential treatment on the association of these predictors with the distance. A search of the Revalidation Centre Zeepreventorium (De Haan, Belgium) medical records database of all children and adolescents (age 10 to 18 yrs) treated for obesity between September 2003 and February 2006, revealed 65 charts with all relevant data (anthropometrical, maximal graded exercise, lung function, 6-minute walk test and 12-minute walk/run test) at admission as well as after 3 months treatment. The multidisciplinary treatment has a positive influence on anthropometrical variables, endurance capacity, vital capacity, and residual volume (p < 0.05). The distance covered during the 6-minute walk test and the 12-minute walk/run test is correlated with all anthropometrical data and peak VO₂ (p < 0.05). After 3 months of treatment, bivariate correlation was stronger for almost every parameter compared to admission. Following a stepwise regression, BMI z-score is a dominant predictor of both field tests at admission and after 3 months treatment. VO₂peak contributes only significantly in the 12-minute walk/run test at admission. Conclusion: In obese children and adolescents BMI z-score is the most dominant predictor of the variability in performances on the 6-minute walk test and the 12-minute walk/run test at admission as well as after 3 months of treatment.     

Neighborhood SES and walkability are related to physical activity behavior in Belgian adults

ObjectiveTo investigate whether neighborhood walkability (higher residential density, land use mix, street connectivity) is positively associated with physical activity in Belgian adults and whether this association is moderated by neighborhood SES.MethodsThe Belgian Environmental Physical Activity Study (BEPAS) was conducted in Ghent, Belgium. Data were collected between May 2007 and September 2008. Twenty-four neighborhoods were selected, stratified on GIS-based walkability and neighborhood SES. In total, 1200 adults (aged 20–65 years; 50 per neighborhood) completed the International Physical Activity Questionnaire and wore an accelerometer for seven days. After omitting participants with missing accelerometer data, the final sample consisted of 1166 adults.ResultsLiving in a high-walkable neighborhood was associated with more accelerometer-based minutes of moderate-to-vigorous physical activity (38.6 vs. 31.8 min/day, p < 0.001), transportational walking and cycling, recreational walking, and less motorized transport (all p < 0.05). Low neighborhood SES was related to more cycling for transport and less motorized transport (all p < 0.05). No interactions between walkability and neighborhood SES were found.ConclusionsThe BEPAS results generally confirmed the findings from Australia and the US showing that, in Europe, walkability is also positively related to physical activity. As neighborhood SES was not a significant moderator, walkability appears beneficial for all economic strata.     

Magnetization transfer‐based 3D visualization of foot peripheral nerves

Purpose:

To investigate magnetization transfer (MT) effects as a new source of contrast for imaging and tracking of peripheral foot nerves.

Materials and Methods:

Two sets of 3D spoiled gradient‐echo images acquired with and without a saturation pulse were used to generate MT ratio (MTR) maps of 260 μm in‐plane resolution for eight volunteers at 3T. Scan parameters were adjusted to minimize signal loss due to T2 dephasing, and a dedicated coil was used to improve the inherently low signal‐to‐noise ratio of small voxels. Resulting MTR values in foot nerves were compared with those in surrounding muscle tissue.

Results:

Average MTR values for muscle (45.5 ± 1.4%) and nerve (21.4 ± 3.1%) were significantly different (P < 0.0001). In general, the difference in MTR values was sufficiently large to allow for intensity‐based segmentation and tracking of foot nerves in individual subjects. This procedure was termed MT‐based 3D visualization.

Conclusion:

The MTR serves as a new source of contrast for imaging of peripheral foot nerves and provides a means for high spatial resolution tracking of these structures. The proposed methodology is directly applicable on standard clinical MR scanners and could be applied to systemic pathologies, such as diabetes. J. Magn. Reson. Imaging 2013;37:1234–1237. © 2012 Wiley Periodicals, Inc.     

‘More shades of grey in my answers’: an interview study revisiting attitude erosion during clerkships

Context Small declines in patient‐centred attitudes during medical education have caused great concern. Although some of the self‐report scales applied have solid psychometric foundations, validity evidence for the interpretation of attitude erosion during clerkships remains weak. Objectives We sought to address this gap in a qualitative study of the relationships between scores on four commonly used attitude scales and participants’ experiences and reflections. Our aim was to gain a better understanding of the score changes from the participants’ perspectives. Methods We conducted semi‐structured interviews with 15 junior doctors from a cohort (n = 37) that had previously shown a small decline in patient‐centred attitudes during clerkships, measured on four self‐report scales. In the interviews, we explored interviewees’ experiences of their development of patient‐centredness and subsequently discussed their scale scores, particularly for those items that contributed to a rise or decline in scores. We analysed the data using a process of constant comparison among personal experiences, scale scores and participants’ explanations of score changes, applying the coding techniques of grounded theory. Results The analysis revealed important response distortions that might be responsible for small declines in scores during clerkships separately from changes in attitudes. The drastic alterations to the participants’ frame of reference, attributable to the transition to clinical practice, represented the most prominent cause of distortion. More nuanced, context‐specific, patient‐centred reasoning resulted in more neutral responses after clerkships, paradoxically causing a decline in scores. In addition to response distortions, the interviews revealed shortcomings in content validity such as an ‘extreme’ construct of patient‐centredness. Conclusions This study calls into question the validity of the interpretation of attitude erosion during clerkships. The findings suggest that small declines in scores on self‐report attitude scales are related to a recalibration of trainees’ understandings of patient‐centredness as they grow more clinically experienced. The evolved construct of patient‐centredness and the way attitudes are measured require special attention in the development of future instruments.     

FDG-PET, 99mTc-HMPAO white blood cell SPET and bone scintigraphy in the evaluation of painful total knee arthroplasties

Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET), technetium-99m hexamethylpropylene amine oxime (HMPAO)-labelled white blood cell (WBC) scintigraphy and bone scintigraphy were used in the evaluation of total knee arthroplasties (TKAs). We prospectively included 21 patients who had a three-phase bone scan for exclusion of infection of TKAs. Four hours after injection of 185 MBq ^99mTc-HMPAO-labelled WBCs, planar and single-photon emission tomographic (SPET) imaging was performed. Planar imaging was repeated at 24 h p.i. Consecutively images of the knees were obtained with a dedicated PET system 60 min following the injection of 370 MBq of FDG. Focal tracer uptake was scored on SPET and PET visually (0=no uptake, 4=intense uptake). In addition, SUV (standardised uptake value) per voxel was calculated from attenuation-corrected PET images using the MLAA algorithm. Focal uptake at the bone-prosthesis interface was used as the criterion for infection before and after correlation with the third phase of the bone scan. Final diagnosis was based on operative findings, culture and clinical outcome. In the infected TKAs, the WBC scan showed focal activity of grade 2 (n=2), 3 (n=1) or 4 (n=2). PET scan revealed focal activity of grade 4 (n=5) or 3 (n=1). WBC scan alone had a specificity for infection of 53% [positive predictive value (PPV) 42%, sensitivity 100%], compared with 73% for PET scan (PPV 60%, sensitivity 100%). Considering only lesions at the bone-prosthesis interface that were also present on the third phase of the bone scan, we found a specificity of 93% (PPV 83%) for WBC scan. Using these criteria, a specificity of 80% (PPV 67%) was obtained for PET scan. Two out of three false-positive PET scans were due to loosening of the TKA. It is concluded that WBC scintigraphy in combination with bone scintigraphy has a high specificity in the detection of infected TKAs. FDG-PET seems to offer no additional benefit.