Differential Expression of Two Copies of the irmA Gene in the Enteroaggregative E. coli Strain 042.

Gene duplications significantly impact the gene repertoires of both eukaryotic and prokaryotic microorganisms. The genomes of pathogenic Escherichia coli strains share a group of duplicated genes whose function is mostly unknown. The irmA gene is one of the duplicates encoded in several pathogenic E. coli strains. The function of its gene product was investigated in the uropathogenic E. coli strain CFT073, which contains a single functional copy. The IrmA protein structure mimics that of human interleukin receptors and likely plays a role during infection. The enteroaggregative E. coli strain 042 contains two functional copies of the irmA gene. In the present work, we investigated their biological roles. The irmA_4509 allele is expressed under several growth conditions. Its expression is modulated by the global regulators OxyR and Hha, with optimal expression at 37°C and under nutritional stress conditions. Expression of the irmA_2244 allele can only be detected when the irmA_4509 allele is knocked out. Differences in the promoter regions of both alleles account for their differential expression. Our results show that under several environmental conditions, the expression of the IrmA protein in strain 042 is dictated by the irmA_4509 allele. The irmA_2244 allele appears to play a backup role to ensure IrmA expression when the irmA_4509 allele loses its function. IMPORTANCE Gene duplications occur in prokaryotic genomes at a detectable frequency. In many instances, the biological function of the duplicates is unknown, and hence, the significance of the presence of multiple copies of these genes remains unclear. In pathogenic E. coli isolates, the irmA gene can be present either as a single copy or in two or more copies. We focused our work on studying why a different pathogenic E. coli strain encodes two functional copies of the irmA gene. We show that under several environmental conditions, one of the alleles dictates IrmA expression, and the second remains silent. The latter allele is only expressed when the former is silenced. The presence of more than one functional copy of the irmA gene in some pathogenic E. coli strains can result in sufficient expression of this virulence factor during the infection process.

Increased thin-spine density in frontal cortex pyramidal neurons in a genetic rat model of schizophrenia-relevant features.

The cellular mechanisms altered during brain wiring leading to cognitive disturbances in neurodevelopmental disorders remain unknown. We have previously reported altered cortical expression of neurodevelopmentally regulated synaptic markers in a genetic animal model of schizophrenia-relevant behavioral features, the Roman-High Avoidance rat strain (RHA-I). To further explore this phenotype, we looked at dendritic spines in cortical pyramidal neurons, as changes in spine density and morphology are one of the main processes taking place during adolescence. An HSV-viral vector carrying green fluorescent protein (GFP) was injected into the frontal cortex (FC) of a group of 11 RHA-I and 12 Roman-Low Avoidance (RLA-I) male rats. GFP labeled dendrites from pyramidal cells were 3D reconstructed and number and types of spines quantified. We observed an increased spine density in the RHA-I, corresponding to a larger fraction of immature thin spines, with no differences in stubby and mushroom spines. Glia cells, parvalbumin (PV) and somatostatin (SST) interneurons and surrounding perineuronal net (PNN) density are known to participate in FC and pyramidal neuron dendritic spine maturation. We determined by stereological-based quantification a significantly higher number of GFAP-positive astrocytes in the FC of the RHA-I strain, with no difference in microglia (Iba1-positive cells). The number of inhibitory PV, SST interneurons or PNN density, on the contrary, was unchanged. Results support our belief that the RHA-I strain presents a more immature FC, with some structural features like those observed during adolescence, adding construct validity to this strain as a genetic behavioral model of neurodevelopmental disorders.

ACTN3 R577X polymorphism related to sarcopenia and physical fitness in active older women.

BACKGROUND: As the population is getting older, physical activity promotion becomes a good strategy to increase quality of life in the elderly; but genetic condition also plays an important role. The purpose of this study was to examine the association of the ACTN3 R577X polymorphism with physical fitness and muscle mass in physically active older women. METHODS: A cross-sectional study was performed with two groups of older women who practiced physical exercise regularly. The first cohort comprised 164 women (age 69.7 ± 3.2 years) and the second cohort 131 women (age 78.5 ± 3.0 years). The main outcome measures were anthropometric measures with assessment of sarcopenia and sarcopenic obesity, self-reported physical activity EXERNET questionnaire (EEPAQ), evaluation of physical fitness (muscle strength and flexibility test), and ACTN3 genotyping. RESULTS: Women above 75 years old with allele R presented a higher risk of experiencing sarcopenia compared to ACTNR XX homozygous women (odds ratio 0.356, 95% confidence interval 0.139-0.915, p = 0.026). Furthermore, statistically significant differences were found in the chair stand test (p = 0.04), as well as in the sit and reach test (p = 0.01), with better results for women below 75 years old with the ACTN3 XX genotype. CONCLUSIONS: Sarcopenia and physical fitness show differences based on the ACTN3 R577X genotype in active older women.

Dissociation between schizophrenia-relevant behavioral profiles and volumetric brain measures after long-lasting social isolation in Roman rats.

Social isolation rearing of rodents is an environmental manipulation known to induce or potentiate psychotic-like symptoms and attentional and cognitive impairments relevant for schizophrenia. When subjected to a 28-week isolation rearing treatment, the Roman high-avoidance (RHA-I) rats display the common behavioral social isolation syndrome, with prepulse inhibition (PPI) deficits, hyperactivity, increased anxiety responses and learning/memory impairments when compared to their low-avoidance (RLA-I) counterparts. These results add face validity to the RHA-I rats as an animal model for schizophrenia-relevant behavioral and cognitive profiles and confirm previous results. The aim here was to further investigate the neuroanatomical effects of the isolation rearing, estimated through volume differences in medial prefrontal cortex (mPFC), dorsal striatum (dSt) and hippocampus (HPC). Results showed a global increase in volume in the mPFC in the isolated rats of both strains, as well as strain effects (RLA > RHA) in the three brain regions. These unexpected but robust results, might have unveiled some kind of compensatory mechanisms due to the particularly long-lasting isolation rearing period, much longer than those commonly used in the literature (which usually range from 4 to 12 weeks).

ADHD medication and the inverted U-shaped curve: A pharmacological study in female mice performing the rodent Continuous Performance Test (rCPT).

BACKGROUND: The rodent Continuous Performance Test (rCPT) is an analogue of human CPTs where mice have to discriminate between target and non-target stimuli. The rCPT offers a readout of attentional performance and impulsive behaviour. This study aimed to determine if female C57BL/6 J mice could be trained in the rCPT since previously published rCPT studies have only used male mice and to study whether the effects of methylphenidate (MPH), atomoxetine (ATX), and dexamphetamine (AMPH) on attention and impulsivity depend on baseline (reference) levels of performance. METHODS: 48 female mice underwent rCPT training. Effects of MPH (1, 2, and 3 mg/kg), ATX (1, 3, and 5 mg/kg) and AMPH (0.3, 0.6, and 1 mg/kg) were assessed in a variable stimulus duration probe. Drugs were administered intraperitoneally and sequentially tested following a Latin-square design. Data were analysed using a repeated measurements mixed effect model and reference-dependent effects were studied. RESULTS: ATX and AMPH improved performance as seen by increases in discriminability. These improvements were a result of a decreased false-alarm rate. AMPH showed a reference-dependent effect, improving the task performance of low-performing mice and decreasing the performance of high-performing mice. MPH also showed this reference-dependent effects, albeit to a lesser extent. ATX and AMPH decreased premature responses and increased response criterion, but no reference-dependent effects were observed for these parameters. CONCLUSION: This study presents a novel method to analyse baseline-dependent effects. It shows that the rCPT can be successfully used in pharmacological studies in female mice and demonstrates that the effect of ADHD medication is in line with the inverted U-shape theory of performance-arousal relationship.

Evolution of Bacterial Global Modulators: Role of a Novel H-NS Paralogue in the Enteroaggregative Escherichia coli Strain 042.

Bacterial genomes sometimes contain genes that code for homologues of global regulators, the function of which is unclear. In members of the family Enterobacteriaceae, cells express the global regulator H-NS and its paralogue StpA. In Escherichia coli, out of providing a molecular backup for H-NS, the role of StpA is poorly characterized. The enteroaggregative E. coli strain 042 carries, in addition to the hns and stpA genes, a third gene encoding an hns paralogue (hns2). We present in this paper information about its biological function. Transcriptomic analysis has shown that the H-NS2 protein targets a subset of the genes targeted by H-NS. Genes targeted by H-NS2 correspond mainly with horizontally transferred (HGT) genes and are also targeted by the Hha protein, a fine-tuner of H-NS activity. Compared with H-NS, H-NS2 expression levels are lower. In addition, H-NS2 expression exhibits specific features: it is sensitive to the growth temperature and to the nature of the culture medium. This novel H-NS paralogue is widespread within the Enterobacteriaceae. IMPORTANCE Global regulators such as H-NS play key relevant roles enabling bacterial cells to adapt to a changing environment. H-NS modulates both core and horizontally transferred (HGT) genes, but the mechanism by which H-NS can differentially regulate these genes remains to be elucidated. There are several instances of bacterial cells carrying genes that encode homologues of the global regulators. The question is what the roles of these proteins are. We noticed that the enteroaggregative E. coli strain 042 carries a new hitherto uncharacterized copy of the hns gene. We decided to investigate why this pathogenic E. coli strain requires an extra H-NS paralogue, termed H-NS2. In our work, we show that H-NS2 displays specific expression and regulatory properties. H-NS2 targets a subset of H-NS-specific genes and may help to differentially modulate core and HGT genes by the H-NS cellular pool.

Tetracycline alters gene expression in Salmonella strains that harbor the Tn10 transposon.

In this report, we show that bacterial plasmids that harbor the Tn10 transposon (i.e., the IncHI1 plasmid R27) modify expression of different Salmonella regulons responding to the presence of tetracycline (Tc) in the medium. By using as a model the Tc-dependent upregulation of the ibpAB operon (which belongs to the heat shock regulon), we have identified Tn10-tetA (coding for a Tc efflux pump) and adjacent tetC sequences as required for ibpAB upregulation. Characterization of transcripts in the tetAC region showed that tetA transcription can continue into tetC sequences, generating a long 3'UTR sequence, which can protect transcripts from RNA processing, thus increasing the expression of TetA protein. In the presence of Tc, the DnaK and IbpA chaperones are overexpressed and translocated to the periplasm and to the membrane fraction respectively. DnaK targeting unfolded proteins is known to induce heat shock by avoiding RpoH proteolysis. We correlate expression levels of Tn10-encoded TetA protein with heat shock induction in Salmonella, likely because TetA activity compromises protein secretion.

Psychosocial and Environmental Correlates of Sedentary Behaviors in Spanish Children.

Purpose. To evaluate children's psychosocial and environmental factors associated with sedentary behavior (SB). Method. The study involved a total of 420 children (mean 9.2 years; 52.9% girls) from the community of Madrid, Spain. SB and physical activity (PA) were objectively measured using accelerometers. TV viewing and potential correlates were assessed by questionnaire. Mixed-model regression analysis, adjusted for clustering within school locations, evaluated the relation of each independent variable with SBs. Results. Girls showed higher levels of SB than boys, whereas boys reported more TV viewing (p < .001 in all cases). Regression analysis showed that MVPA levels were negatively related to objective SB measurement in both boys and girls (p < .001). Parent and friend support to PA were negatively associated with SB on weekdays in boys and girls, respectively (p < .05). In the boys' group, parental professional level was a positive predictor of SB on weekend days (p = .011). Boys with more positive neighborhood perceptions spent less time watching TV (p < .001), whereas mother's leisure-time PA level was a negative correlate of TV viewing in girls' group (p < .01). Conclusion. Different psychosocial and environmental correlates of SB were identified. Present findings are promising targets for interventions to improve children's health.

Tryptophan depletion affects compulsive behaviour in rats: strain dependent effects and associated neuromechanisms.

RATIONALE: Compulsive behaviour, present in different psychiatric disorders, such as obsessive-compulsive disorder, schizophrenia and drug abuse, is associated with altered levels of monoamines, particularly serotonin (5-hydroxytryptamine) and its receptor system. OBJECTIVES: The present study investigated whether 5-HT manipulation, through a tryptophan (TRP) depletion by diet in Wistar and Lister Hooded rats, modulates compulsive drinking in schedule-induced polydipsia (SIP) and locomotor activity in the open-field test. The levels of dopamine, noradrenaline, serotonin and its metabolite were evaluated, as well as the 5-HT2A and 5-HT1A receptor binding, in different brain regions. METHODS: Wistar rats were selected as high (HD) or low (LD) drinkers according to their SIP behaviour, while Lister hooded rats did not show SIP acquisition. Both strains were fed for 14 days with either a TRP-free diet (T-) or a TRP-supplemented diet (T+) RESULTS: The TRP depletion diet effectively reduced 5-HT levels in the frontal cortex, amygdala and hippocampus in both strains of rats. The TRP-depleted HD Wistar rats were more sensitive to 5-HT manipulation, exhibiting more licks on SIP than did the non-depleted HD Wistar rats, while the LD Wistar and the Lister Hooded rats did not exhibit differences in SIP. In contrast, the TRP-depleted Lister Hooded rats increased locomotor activity compared to the non-depleted rats, while no differences were found in the Wistar rats. Serotonin 2A receptor binding in the striatum was significantly reduced in the TRP-depleted HD Wistar rats. CONCLUSIONS: These results suggest that alterations of the serotonergic system could be involved in compulsive behaviour in vulnerable populations.

El recreo escolar como oportunidad de espacio y tiempo saludable / The recess school space and time as an opportunity healthy

El propósito de nuestro estudio piloto fue medir de forma objetiva la AF saludable de la población infantil a lo largo de una semana e identificar cuanta de la misma se realizaba dentro del tiempo dedicado al recreo escolar. La muestra estaba compuesta por 36 niños de 11 a 12 años de una escuela de la provincia de Toledo en España. El instrumento utilizado fue el acelerómetro. La mayoría de los niños y niñas no cumplían las recomendaciones de AF saludable. En relación a la cantidad de AF saludable realizada en los recreos durante la semana, ésta presentó un peso importante (AU)

The purpose of our pilot study was to measure objectively the amount of moderate to vigorous PA (MVPA) children engaged over a week and to identify how much of it was carried out during recess time. The sample comprised 36 children aged 11 to 12 from a school in the province of Toledo in Spain. PA was measured with the accelerometer GT1M. Most of the children did not meet the PA recommendations for health. In relation to the amount of MVPA achieved during recess time, our study suggests that recess time represents an important load of the total amount of children’s MVPA registered per day (AU)

Evaluación de la actividad física en la población general; cuestionarios validados / Physical activity assessment in the general population; validated self-report methods

Los cuestionarios auto-administrados han sido comúnmente utilizados en los estudios con grandes cohortes, con el fin de evaluar la actividad física de sus participantes. Como consecuencia de ello, existe una considerable cantidad de evidencias científicas sobre el efecto protector de la actividad física sobre la salud. Sin embargo, los estudios de validación que utilizan métodos objetivos, cómo métodos de referencia o «Gold Standard», para la cuantificación de la actividad física o el gasto energético (el agua doblemente marcada, los acelerómetros, los podómetros, etc.), indican que la precisión de los cuestionarios es limitada. Los cuestionarios de actividad física pueden fallar especialmente al estimar la actividad física no vigorosa, y suelen centrarse de forma específica en el ejercicio planificado (ir en bicicleta, correr, andar,…) y no suelen recoger las actividades de la vida diaria y movimientos de intensidad baja no planificada. Por ello, la estimación del gasto energético a partir de estos datos no es muy recomendable. Por otro lado, y a pesar de que los métodos objetivos deberían ser la primera elección a la hora de evaluar la actividad física, los cuestionarios se mantienen todavía como herramientas válidas y con muchas ventajas. Una de las ventajas es la buena implementación para estudios epidemiológicos y su bajo coste. Además, este tipo de instrumentos están específicamente diseñados y validados para diferentes grupos de edad y proporcionan información valiosa e importante, sobre todo, del patrón de actividad física. Sin embargo, aún son necesarios futuros estudios que investiguen en métodos más precisos para medir la actividad física respecto a la que proporcionan los cuestionarios. Podemos concluir que probablemente un método mixto que combine los métodos objetivos y subjetivos, y que incluya nuevos sistemas y registros electrónicos, sería lo más recomendable (AU)

Self-reported questionnaires have been commonly used to assess physical activity levels in large cohort studies. As a result, strong and convincing evidences that physical activity can protect health are widely recognized. However, validation studies using objective measures of physical activity or energy expenditure (double labelled water, accelerometers, pedometers, etc.) indicate that the accuracy and precision of survey techniques are limited. Physical activity questionnaires could fail in estimating particularly non-vigorous physical activity. They have a disproportionate focus on volitional type exercise (i.e. biking, jogging, and walking), while not capturing the activities of daily living and low to moderate intensity movements. Energy expenditure estimates from these data are not recommended. On the other hand, despite objective tools should be the measurement of choice to assess PA level, self-reported questionnaires remain valid, and have many advantages. i.e. low costs. These kind of recalls are designed and validated for different age groups and provide value and important information, mainly about physical activity pattern. Future studies will require more precision and accuracy in physical activity measurement than those provided by traditional survey methods. We can conclude that probably a mixed approach that combines both the objective and subjective techniques involving novel devices and electronic capture of physical activity questionnaires will be more effective (AU)

Estimación de la actividad física en población general: métodos instrumentales y nuevas tecnologías / Physical activity assessment in the general population; instruments methods and new technologies

La cuantificación de la actividad Física (AF) es tan importante como compleja. Compleja porque es un comportamiento humano, e importante porque la relación de la actividad física y la salud depende en gran medida de la precisión de la medición de la misma. La medición objetiva del movimiento humano y la cuantificación del gasto energético debido a la actividad física es una necesidad identificada tanto en la investigación como en la clínica. Los métodos de referencia validados y bien definidos (el agua doblemente marcada, la calorimetría directa, la calorimetría indirecta) son caros y prácticamente se limitan a la investigación en el laboratorio. Por lo tanto, en los últimos años, se han desarrollado diferentes dispositivos de medición objetiva que son apropiados para los estudios de campo y clínicos. No hay ningún método de referencia (“gold standard”) entre ellos, ya que todos tienen sus limitaciones. Los podómetros son ligeros, poco costosos, cuentan los pasos y aportan información sobre la actividad física total, pero no sobre el comportamiento y los patrones de actividad física. Los acelerómetros son más caros, aportan información sobre patrón, frecuencia, duración e intensidad de la actividad física, pero no sobre el tipo de actividad física. Los podómetros y acelerómetros únicamente recogen información sobre el movimiento del movimiento corporal, pero la validez en la estimación del gasto energético es limitada. La monitorización de la frecuencia cardíaca relaciona intensidad del ejercicio con gasto de energía, pero no aporta información sobre otras dimensiones de la actividad física. Los dispositivos GPS son portátiles, relativamente asequibles, no invasivos y recogen distancia, velocidad y perfil con hora y lugar exactos, pero quizás estén limitados para la evaluación de movimientos cortos a alta intensidad y elevado gasto energético. Los dispositivos de última generación combinan acelerometría con la medición de variables fisiológicas, comparten las ventajas de los dispositivos individuales y son más precisos. Para el cálculo del gasto energético se aplican algoritmos específicos de la actividad incluidos en el software del fabricante que pueden afectar a los resultados. La mayoría de los dispositivos estiman con mayor precisión el gasto energético a intensidades ligeras y moderadas, pero subestiman el gasto a intensidades muy ligeras y de intensidad extrema (AU)

Physical activity measurement is as important as complex. It is complex because it is a human behaviour and it is important because the relationship between physical activity and health depends mainly upon the accuracy of its measurement. The objective measurement of human movement and the quantification of energy expenditure due to physical activity is an identified need in both, research and the clinical setting. Validated and well-defined reference methods (double labelled water, direct calorimetry, indirect calorimetry) are expensive and mostly limited to the laboratory setting. Therefore, in the last years, several objective measurement devices have been developed which are appropriate for field studies and clinical settings. There is no gold standard among them, as all of them have their limitations. Pedometers are small, nonexpensive, count the steps taken and give information on total physical activity, but not about physical activity patterns and behaviour. Accelerometers are expensive, record information about frequency, duration and intensity of physical activity, but not about type of physical activity. Both pedometers and accelerometers are not good at recording upper body movement, and the reliability about the estimation of energy expenditure is limited. Heart rate monitoring relates intensity to energy expenditure, but gives no information about any other dimension of physical activity. GPS watches are portable, relatively inexpensive, non-invasive and provide distance, speed, and profile with exact time and location, but are limited for the assessment of brief higher speed movement and energy expenditure. Combined motion sensors combine accelerometry with the measurement of physiological variables, and share advantages of single devices and are more precise. Manufacturer software, which applies activity-specific algorithms for the calculation of energy expenditure, can affect energy expenditure results. Most of the devices estimate energy expenditure more accurately at light to moderate intensities; underestimation increases at very light and extremely high intensity activities (AU)

5-HT(2A) and mGlu2 receptor binding levels are related to differences in impulsive behavior in the Roman Low- (RLA) and High- (RHA) avoidance rat strains.

The Roman Low- and High-Avoidance rat strains (RLA-I vs RHA-I) have been bidirectionally selected and bred according to their performance in the two-way active avoidance response in the shuttle-box test. Numerous studies have reported a pronounced divergence in emotionality between the two rat strains including differences in novelty seeking, anxiety, stress coping, and susceptibility to addictive substances. However, the underlying molecular mechanisms behind these divergent phenotypes are not known. Here, we determined impulsivity using the 5-choice serial reaction time task and levels of serotonin transporter (SERT), 5-HT(2A) and 5-HT(1A) receptor binding using highly specific radioligands ((3)H-escitalopram, (3)H-MDL100907 and (3)H-WAY100635) and mGlu2/3 receptor binding ((3)H-LY341495) using receptor autoradiography in fronto-cortical sections from RLA-I (n=8) and RHA-I (n=8) male rats. In the more impulsive RHA-I rats, 5-HT(2A), 5-HT(1A) and SERT binding in the frontal cortex was significantly higher compared to RLA-I rats. In contrast, mGlu2/3 receptor binding was decreased by 40% in RHA-I rats compared to RLA-I rats. To differentiate between mGlu2 and mGlu3 receptor protein levels, these were further studied using western blotting, which showed non-detectable levels of mGlu2 receptor protein in RHA rats, while no differences were observed for mGlu3 receptor protein levels. Collectively, these data show general congenital differences in the serotonergic system and a pronounced difference in mGlu2 receptor protein levels. We suggest that the differences in the serotonergic system may mediate some of the phenotypic characteristics in this strain such as hyper-impulsivity and susceptibility to drug addiction.

Recommended levels of physical activity to avoid adiposity in Spanish children.

UNLABELLED: What is already known about this subject There is an association between adiposity levels and physical activity guidelines for adolescents. Achieving physical activity recommendations helps adolescents to prevent obesity status. What this study adds This paper presents an association between physical activity levels and obesity status. This paper supports physical activity recommendations to avoid children's obesity levels. This paper emphasizes vigorous physical activity for this matter. BACKGROUND: There is no information about physical activity (PA) recommendations to avoid children's obesity levels and how much of vigorous PA (VPA) is included into the '60 minutes of MVPA 5 days a week' recommendation for children. OBJECTIVE: The aim of this study was to examine the association between PA and adiposity in children and to examine whether the current PA guidelines are associated with a low risk of having excess of body fat in children, with special focus on sex differences, and PA intensity. METHODS: A sample of 439 Spanish children aged 8-10 years from the European Youth Heart Study participated in the study. The variables measured were anthropometric characteristics (height, weight, body mass index [BMI], skin-folds and waist circumference) and PA was measured during 6 consecutive days using the GT1M accelerometer. RESULTS: Receiver operating characteristic analysis showed significant cut-off points associated with non-overweight: 45 min d(-1) of VPA and 67 min d(-1) of moderate-to-vigorous physical activity (MVPA) (using BMI categories); and non-fat: 41 min d(-1) of VPA and 67 min d(-1) of MVPA (using percentage of body fat) and 38 min d(-1) of VPA and 47 min d(-1) of MVPA (using waist circumference categories) for boys. For girls, the optimal cut-offs of moderate-to-vigorous activity and MVPA associated with non-overweight were 24 and 57 min d(-1) , respectively (BMI). Boys who did not meet 67 min in MVPA had an increased risk of being overweight + obese and overfat + obese (odds ratio [OR] = 2.48, 95% confidence interval [CI] = 1.36, 4.53, and OR = 2.56, 95% CI = 1.12, 5.82). CONCLUSIONS: The findings support current PA recommendations (60 min d(-1) of MVPA) to avoid excess of body fat in Spanish children. However, VPA appears to be an important component for the prevention of obesity, and our findings suggest that PA recommendations should specify the dose of VPA required for optimal health. Therefore, public health PA recommendations should incorporate specifically a greater dose of VPA into the total amount of MVPA in 8- to 10-year-old boys.

Heart rate recovery is associated with obesity traits and related cardiometabolic risk factors in children and adolescents.

BACKGROUND AND AIMS: Increased vagal activity is associated with obesity and metabolic risk in children and adolescents. The aim of the present cross-sectional study was to examine the association of parasympathetic function, as assessed by heart rate recovery (HRR) from a maximal exercise cycle-ergometer test, with obesity traits and related cardiometabolic risk factors in Spanish children and adolescents. METHODS AND RESULTS: A sample of 437 Spanish 9-year-old-children and 235 15-year-old-adolescents participated in the study. The variables measured were anthropometric characteristics (height, body mass and waist circumference) and physical activity using the Actigraph accelerometer. Additional measured outcomes included fasting insulin, triglycerides, high-density lipoprotein cholesterol (HDLc) and blood pressure. A metabolic risk score was computed as the mean of the standardised outcomes scores. The HRR was calculated as the difference between peak heart rate and heart rate 1, 3 and 5 min after cessation of the maximal ergometer test. Diastolic blood pressure was associated with all the HRR parameters in 9-year-old-girls. In 9-year-old-boys, the 3-min HRR was inversely associated with systolic blood pressure (p < 0.05) and Homeostasis Model Assessment (HOMA) (p < 0.05). Five minute HRR was inversely associated with waist circumference (p < 0.05), sum of five skinfolds (p < 0.01) and HOMA (p = 0.004). There were no significant associations in adolescents. In 9-year-old-girls, the adjusted 5-min HRR showed significant differences between quartile 2 and 4 of metabolic risk (p = 0.011). In all samples, the adjusted HRR (1-, 3- and 5-min HRR) did not show significant differences across quartiles. CONCLUSION: HRR was inversely associated with obesity traits and related cardiometabolic risk factors mainly in healthy boys.

Physical fitness levels among independent non-institutionalized Spanish elderly: the elderly EXERNET multi-center study.

BACKGROUND: Physical fitness is gaining in importance in all population groups, including elderly, but data are still scarce. The aim of this study was to report gender and age specific physical fitness levels in non-institutionalized Spanish elderly. METHODS: A representative sample of 3136 elderly (≥ 65 y), 724 men and 2412 women, from 6 Regions of Spain: Madrid, Aragón, Castilla y León, Castilla-La Mancha, Extremadura and Canarias were assessed in the elderly EXERNET multi-center study between 2008 and 2009. The authors assessed static balance, muscular strength, flexibility, agility, walking speed and cardiorespiratory fitness using eight different fitness tests: one leg balance, chair stand, arm curl, chair sit-and-reach, back scratch, 8-foot up-and-go, 30-m walk, and 6 min walk tests. RESULTS: The authors derived gender and age-specific normative values for physical fitness in the non-institutionalized Spanish elderly. The figures showed greater physical fitness in the elderly men than in women, except for the flexibility test, and a trend toward decreased physical fitness in both genders as their age increased. CONCLUSIONS: The normative values hereby provided will enable evaluation and correct interpretation of independent non-institutionalized Spanish elderly fitness status.

The microtubule-associated protein 1A (MAP1A) is an early molecular target of soluble Aß-peptide.

A progressive accumulation of amyloid ß-protein (Aß) is widely recognized as a pathological hallmark of Alzheimer's disease (AD). Substantial progress has been made toward understanding the neurodegenerative cascade initiated by small soluble species of Aß and recent evidence supports the notion that microtubule rearrangements may be proximate to neuritic degeneration and deficits in episodic declarative memory. Here, we examined primary cortical neurons for changes in markers associated with synaptic function following exposure to sublethal concentrations of non-aggregated Aß-peptide. This data show that soluble Aß species at a sublethal concentration induce degradation of the microtubule-associated protein 1A (MAP1A) without concurrently affecting dendritic marker MAP2 and/or the pre-synaptic marker synaptophysin. In addition, MAP1A was found to highly co-localize with the postsynaptic density-95 (PSD-95) protein, proposing that microtubule perturbations might be central for the Aß-induced neuronal dysfunctions as PSD-95 plays a key role in synaptic plasticity. In conclusion, this study suggests that disruption of MAP1A could be a very early manifestation of Aß-mediated synaptic dysfunction-one that presages the clinical onset of AD by years. Moreover, our data support the notion of microtubule-stabilizing agents as effective AD drugs.

Novelty-induced activity-regulated cytoskeletal-associated protein (Arc) expression in frontal cortex requires serotonin 2A receptor activation.

Many psychiatric disorders are characterized by cognitive and emotional alterations that are related to abnormal function of the frontal cortex (FC). FC is involved in working memory and decision making and is activated following exposure to a novel environment. The serotonin 2A receptor (5-HT(2A)R) is highly expressed in the FC where its activation induces hallucinations, while blockade of 5-HT(2A)Rs contributes to the therapeutic effects of atypical antipsychotic drugs. The purpose of the present study was to investigate the involvement of 5-HT(2A)R in FC activation following exposure to a novel environment. As an output of FC activation we measured expression of activity-regulated cytoskeletal-associated protein (Arc). Novelty-exposure (open-field arena) robustly up-regulated FC Arc mRNA expression (∼160%) in mice compared to home-cage controls. This response was inhibited with the 5-HT(2A)R antagonists ketanserin and MDL100907, but not with the selective 5-HT(2C)R antagonist SB242084. Novelty-exposure also induced Arc mRNA expression in hippocampus (∼150%), but not in cerebellum or brainstem. Pretreatment with 5-HT(2A)R antagonist ketanserin did not repress the Arc induction in hippocampus, indicating that the involvement of 5-HT(2A)R in this response is restricted to the FC. Similarly, the novelty-induced stress as determined by increasing levels of plasma corticosterone, was not influenced by 5-HT(2A)R antagonism suggesting that Arc mRNA and stress are activated via distinct mechanisms. Taken together, our results demonstrate that the induction of Arc in the FC following exposure to a novel environment is dependent on the 5-HT(2A)R, and that the simultaneous release of corticosterone is regulated via another system independent of 5-HT(2A)R activation.

Prevalence of overweight and obesity in non-institutionalized people aged 65 or over from Spain: the elderly EXERNET multi-centre study.

Coupled with the growth of the older population, an increase in the prevalence of overweight and obesity in this age group has occurred in the last decades. The main aims of the present study were (i) to provide an updated prevalence of overweight and obesity in a representative sample of the Spanish elderly population; (ii) to calculate the prevalence of sarcopenic obesity (SO) and (iii) to analyse the relationships between adiposity measurements and lifestyle. A cross-sectional study was carried out in a sample of 3136 persons representative of the non-institutionalized population ≥65 years of age. Anthropometric measurements were obtained using standardized techniques and equipment. Overall, 84% of the population can be categorized as overweight and/or obese. The present study indicates that 67% of the Spanish elderly population has an increased percentage of fat mass and more than 56% suffer from central obesity. Moreover, SO is present in 15% of the Spanish elderly population. Finally, a strong relationship between both physically active and sedentary lifestyles and the level of adiposity was found. Prevalence of overweight and obesity among elderly people in Spain is very high and is still increasing. Lifestyle seems to be a determinant factor in the development of obesity among elderly people.

Patterns of physical activity in Spanish children: a descriptive pilot study.

BACKGROUND: The majority of Spanish adults and children do not engage in enough physical activity to be beneficial for health. There is a need for objective and accurate assessment of the proportion of children meeting the physical activity recommendation for health. Assessing patterns of physical activity both between days (during weekdays and weekend days) and within days is of interest to improve our understanding of the variation in Spanish children's physical activity and to provide efficient intervention programmes. METHODS: A sample of 221 children: 136 9-year-old children (68 boys and 68 girls) and 85 15-year-old children (36 girls and 49 boys) from 12 urban public schools in Madrid, Spain entered the study. The variables measured were anthropometric characteristics (height, weight, body mass index) and physical activity measured during four consecutive days using the GT1M accelerometer. RESULTS: Younger children were more active and less sedentary than older ones during week and weekend days. Nine-year-old boys and girls achieved significantly (P < 0.05) more moderate to vigorous physical activity (MVPA) and significantly (P < 0.01) less sedentary time than older 15-year-old children. During weekdays more children achieved physical activity recommendations versus weekend days. Physical activity patterns analyses indicated that boys achieved relatively high values of MVPA from 1100 till 1300 h (school break) and from 1800 till 2000 h in comparison with the rest of the day. Girls were substantially different, with the 9-year-old girls having only two obvious peaks of weekday MVPA at lunch (1300) and after school (1900 h) while the adolescent girls had no clear peak of MVPA. CONCLUSIONS: Few children achieved the level of MVPA recommended for health; at particular risk were adolescent girls. More effort needs to be devoted to promoting appropriate opportunities for Spanish girls across the day and to promoting physical activity during weekends for all children.