Development of MAPT S305 mutation models exhibiting elevated 4R tau expression, resulting in altered neuronal and astrocytic function.

Due to the importance of 4R tau in the pathogenicity of primary tauopathies, it has been challenging to model these diseases in iPSC-derived neurons, which express very low levels of 4R tau. To address this problem we have developed a panel of isogenic iPSC lines carrying the MAPT splice-site mutations S305S, S305I or S305N, derived from four different donors. All three mutations significantly increased the proportion of 4R tau expression in iPSC-neurons and astrocytes, with up to 80% 4R transcripts in S305N neurons from as early as 4 weeks of differentiation. Transcriptomic and functional analyses of S305 mutant neurons revealed shared disruption in glutamate signaling and synaptic maturity, but divergent effects on mitochondrial bioenergetics. In iPSC-astrocytes, S305 mutations induced lysosomal disruption and inflammation and exacerbated internalization of exogenous tau that may be a precursor to the glial pathologies observed in many tauopathies. In conclusion, we present a novel panel of human iPSC lines that express unprecedented levels of 4R tau in neurons and astrocytes. These lines recapitulate previously characterized tauopathy-relevant phenotypes, but also highlight functional differences between the wild type 4R and mutant 4R proteins. We also highlight the functional importance of MAPT expression in astrocytes. These lines will be highly beneficial to tauopathy researchers enabling a more complete understanding of the pathogenic mechanisms underlying 4R tauopathies across different cell types.

Behavioral and electrophysiological indicators of auditory distractibility in children with ADHD and comorbid ODD.

Involuntary switching of attention to distracting sounds was studied by measuring effects of these events on auditory discrimination performance and event-related brain potentials (ERPs) in 6-11-year-old boys with Attention Deficit-Hyperactivity Disorder (ADHD) and comorbid Oppositional Defiant Disorder (ODD) and in age-matched controls. The children were instructed to differentiate between two animal calls by pressing one response button, for example, to a dog bark and another button to a cat mew. These task-relevant sounds were presented from one of two loudspeakers in front of the child, and there were occasional task-irrelevant changes in the sound location, that is, the loudspeaker. In addition, novel sounds (e.g., a sound of hammer, rain, or car horn) unrelated to the task were presented from a loudspeaker behind the child. The percentage of correct responses was lower for target sounds preceded by a novel sound than for targets not preceded by such sound in the ADHD group, but not in the control group. In both groups, a biphasic positive P3a response was observed in ERPs to the novel sounds. The later part of the P3a appeared to continue longer over the frontal scalp areas in the ADHD group than in the controls presumably because a reorienting negativity (RON) ERP response following the P3a was smaller in the ADHD group than in the control group. This suggests that the children with ADHD had problems in reorienting their attention to the current task after a distracting novel sound leading to deterioration of performance in this task. The present study also indicates that children with ADHD and comorbid ODD show same kind of distractibility as found in previous studies for children with ADHD without systematic comorbid ODD.

How well do physical activity questions perform? A European cognitive testing study.

BACKGROUND: Only few studies have focused on the cognitive processes of the respondents that are involved when answering physical activity questionnaires (PAQs). This study aimed at examining whether two PAQs work as intended with different segments of the survey population in different cultural settings in Europe. METHODS: The International Physical Activity Questionnaire - Short Form (IPAQ-SF) and the US National Health Interview Survey - Adult Core Physical Activity Questionnaire (NHIS-PAQ) were tested in Belgium, Estonia, Germany and the UK using a standardized cognitive interviewing procedure. IPAQ-SF measures total vigorous physical activity (PA), moderate PA, walking and sitting. NHIS-PAQ measures leisure-time vigorous PA, light and moderate PA and muscle-strengthening PA. In total 62 persons completed cognitive interviews, at least 15 interviews were conducted in each country. RESULTS: Both PAQs performed as intended with young and high-skilled persons and those having a regular exercise schedule. For the others, however, the testing revealed that problems occurred with both PAQs relating to understanding the concepts of '(light and) moderate' and 'vigorous' PA, classifying activities into the provided answer options of different PA intensities, recalling instances of 'normal' activities such as walking and sitting, and calculating the total duration of more than one activity or instance of an activity. The revealed problems with the questionnaires were quite similar in different countries; profound cultural differences were not observed. CONCLUSIONS: Both questionnaires were difficult to answer for many respondents and rather user-unfriendly. They are designed to measure an exactness of PA quantity (frequency and duration) and intensity which would be desirable to obtain from a scientific point of view; however, respondents can hardly provide this information for cognitive reasons. Studies investigating the respondents' perspective are useful for improving physical activity information based on self-reports.

Effectiveness of the IDEFICS intervention on objectively measured physical activity and sedentary time in European children.

BACKGROUND: This paper reports on the effectiveness of the prevention of dietary- and lifestyle-induced health effects in children and infants (IDEFICS) intervention on objectively measured physical activity (PA) and sedentary time (ST) in 2- to 9.9-year-old European boys and girls. METHODS: The intervention was evaluated after 2 years through a non-randomized cluster-controlled trial in eight European countries (one control and one intervention community per country). All children in the intervention group received a culturally adapted childhood obesity prevention programme through the community, schools/kindergartens and family. A random sub-sample of children participating in the IDEFICS study wore an accelerometer at baseline and follow-up for at least 3 days (n = 9,184). Of this sample, 81% provided valid accelerometer data at baseline (n = 7,413; 51% boys; 6.21 ± 1.76 years; boys: 617 ± 170 cpm day(-1) ; girls 556 ± 156 cpm day(-1) ) and 3,010 children provided valid accelerometer data at baseline and during the follow-up survey 2 years later. RESULTS: In boys and girls, no significant differences in PA and ST were found between intervention and control groups over 2 years. Strong temporal effects were found in the total sample of boys and girls: the percentage of time spent in light PA per day decreased by 4 percentage points in both boys and girls between baseline and follow-up (both: p < 0.001), while time spent in ST per day increased by 4 percentage points in both sexes over time (both: p < 0.001). Percentage of time spent in moderate-to-vigorous PA per day remained stable over time in boys and girls. CONCLUSION: Despite the socio-ecological approach and implementation of a culturally adapted intervention in each country, no effects of the IDEFICS intervention were found on children's objectively measured PA and ST. Behavioural interventions for children may need to enhance specificity and intensity at the family level using other behaviour change techniques and more direct strategies to reach parents.

Physical fitness reference standards in European children: the IDEFICS study.

BACKGROUND/OBJECTIVES: A low fitness status during childhood and adolescence is associated with important health-related outcomes, such as increased future risk for obesity and cardiovascular diseases, impaired skeletal health, reduced quality of life and poor mental health. Fitness reference values for adolescents from different countries have been published, but there is a scarcity of reference values for pre-pubertal children in Europe, using harmonised measures of fitness in the literature. The IDEFICS study offers a good opportunity to establish normative values of a large set of fitness components from eight European countries using common and well-standardised methods in a large sample of children. Therefore, the aim of this study is to report sex- and age-specific fitness reference standards in European children. SUBJECTS/METHODS: Children (10,302) aged 6-10.9 years (50.7% girls) were examined. The test battery included: the flamingo balance test, back-saver sit-and-reach test (flexibility), handgrip strength test, standing long jump test (lower-limb explosive strength) and 40-m sprint test (speed). Moreover, cardiorespiratory fitness was assessed by a 20-m shuttle run test. Percentile curves for the 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentiles were calculated using the General Additive Model for Location Scale and Shape (GAMLSS). RESULTS: Our results show that boys performed better than girls in speed, lower- and upper-limb strength and cardiorespiratory fitness, and girls performed better in balance and flexibility. Older children performed better than younger children, except for cardiorespiratory fitness in boys and flexibility in girls. CONCLUSIONS: Our results provide for the first time sex- and age-specific physical fitness reference standards in European children aged 6-10.9 years.

Role of socio-cultural factors on changes in fitness and adiposity in youth: a 6-year follow-up study.

BACKGROUND AND AIMS: Optimal cardio-respiratory fitness and adiposity levels are tightly related to health in youth. We analysed changes in fitness and adiposity in young individuals from two countries, and examined the role of maternal education in these changes. METHODS AND RESULTS: A 6-year follow-up study was conducted on 483 Estonian children (9 years) and 466 Swedish children (9-10 years) and adolescents (15 years). Fitness was assessed by a maximal bike test, and total and central adiposity were indirectly estimated by skinfolds (Slaughter's equation for fat mass) and waist circumference. At follow-up, fitness and adiposity had increased in the children cohort (P ≤ 0.001), while small or no change occurred in the adolescent cohort. In the children cohort, Estonian participants had a lower increase in fitness and a higher increase in adiposity (total and central) than Swedish participants. Higher maternal education increased the odds of remaining fit (top quartile) by half and reduced the risk of remaining fat (top quartile) by half; odds ratios = 1.56 (1.00-2.43), 0.50 (0.32-0.77) and 0.61 (0.39-0.94) for fitness, total and central adiposity, respectively. CONCLUSIONS: Our data suggest that the socioeconomic situation of a country might influence key cardiovascular risk factors (fitness and adiposity), being at higher risk for a low-middle income country (Estonia) than a higher income country (Sweden). The findings stress the role of socioeconomic status, particularly maternal education, in the maintenance of healthy fitness and adiposity levels from childhood into later life. Preventive efforts have to be taken from early age.

Insulin sensitivity at childhood predicts changes in total and central adiposity over a 6-year period.

OBJECTIVE: To examine the associations of insulin resistance at childhood with adiposity changes over a 6-year period (from 9 to 15 years) in a sample of 659 Swedish and Estonian children (52.7% girls) participating in the European Youth Heart Study. RESEARCH, DESIGN AND METHODS: We measured weight, height, waist circumference, biceps, triceps, subscapular, suprailiac, and medial calf skinfolds, and we calculated body mass index (BMI), sum of five skinfolds, and body fat percentage. Fasting plasma glucose and insulin were measured and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. Changes in puberty stage, sex, centre and the corresponding baseline adiposity values were used as confounders in all analysis. RESULTS: HOMA-IR at childhood was significantly and positively associated with changes in BMI (ß=0.265; P=0.024), sum of five skinfolds (ß=0.3445; P=0.003), body fat percentage (ß=1.042; P=0.016) and waist circumference (ß=0.806; P=0.002) from childhood to adolescence. These relationships persisted when overweight children were excluded from the analysis. BMI, sum of five skinfolds, body fat percentage and waist circumference at childhood were not significantly associated with changes in HOMA-IR (P for all >0.1). CONCLUSIONS: These results give further support to the concept that lower insulin sensitivity at childhood may predict subsequent total and central adiposity gain at adolescence. These findings enhance the role of insulin sensitivity as a target of obesity prevention already from the first decades of life.

The value of histoquantitative measurements in prognostic assessment of renal adenocarcinoma.

In a series of 135 patients with renal-cell carcinomas (followed up for a mean of 9.5 years), a variety of clinical and histological factors were analyzed in relation to morphometric measurements of the nuclear parameters in the primary tumours to establish their value as prognostic factors. Clinical, histological and morphometric factors were significantly interrelated in that the metastatic high-grade tumours had larger nuclei, larger variation in nuclear size and shape, and were also rapidly proliferating. In a univariate analysis, the most important clinical predictor of recurrence-free survival (RFS) was T category, followed by combined nuclear grade, N category, nuclear grade, tumour size, sex and M category. The most important quantitative predictor of RFS was the mean area of the 10 largest nuclei (NA10), the mean of the longest nuclear axis (Dmax), SD of nuclear area (SDNA), the volume-corrected mitotic index (M/V index), inflammatory-cell reaction, SD of nuclear perimetry (SDPE), and the mean of nuclear area (NA). M category, T category, combined nuclear grade, nuclear grade and N category were significantly related to patient survival. Of the quantitative variables, M/V index, Dmax and NA were significant predictors of survival in a univariate analysis. Females had longer RFS than men, and density of tumour-infiltrating lymphocytes (TIL) referred to an increased risk of recurrent tumour in both sexes. In a multivariate analysis, the RFS was independently predicted by the clinical stage, female sex and mitotic frequency/mm2, while nuclear parameters or nuclear grading had no independent prognostic value. The extent of the primary tumour was the single most important determinant of survival, followed by the proliferation rate of the tumour. In local T1-2NOMO tumours, mitotic frequency/mm2 was the only independent prognostic factor for RFS. The clinical stage, mitotic frequency/mm2, nuclear grade and density of TIL were independent predictors in Cox's analysis. In these local tumours, mitotic frequency/mm2 of neoplastic epithelium was the only independent prognostic factor. The results indicate that although an accurate prognostic evaluation of renal-cell carcinomas can be based on subjective nuclear grading and histoquantitative measurements of nuclear parameters, the simple assessment of mitotic frequency alone supplies most of the prognostic data, particularly in local tumours.