Progression of brain volume changes in adolescent-onset psychosis

Little is known about the changes that take place in the adolescent brain over the first few years following the onset of psychosis. The present longitudinal study builds on an earlier cross-sectional report demonstrating brain abnormalities in adolescent-onset psychosis patients with a recent-onset first episode of psychosis. Magnetic resonance imaging studies were obtained at baseline and 2 years later from 21 adolescents with psychosis and 34 healthy controls matched for age, gender, and years of education. Whole-brain volumes and gray matter (GM) and cerebrospinal fluid (CSF) volumes of the frontal, parietal, temporal, and occipital lobes were measured at baseline and at 2-year follow-up. In the frontal lobe, the rate of GM volume loss was significantly higher in male patients (2.9% and 2.0%, respectively, for left and right) than in controls (1.2% and 0.7%, respectively, for left and right). In the left frontal lobe, male patients showed a significantly higher rate of CSF volume increase than controls (8.6% vs 6.4%). These differences in rates of volume change were observed in male and female patients, although only males showed significant time x diagnosis interactions. This negative finding in females should be interpreted with caution as the study was underpowered to detect change in women due to limited sample size. An exploratory analysis revealed that schizophrenia and nonschizophrenia psychotic disorders showed similar volume change patterns relative to controls. Change in clinical status was not correlated with longitudinal brain changes. Our results support progression of frontal lobe changes in males with adolescent-onset psychosis.     

Effects of the Administration of Feedback on Performance of the Bmx Cycling Gate Start

The aim of the present study was to determine the effect of the administration of external feedback (FB) on the time used to execute the gate start skill in BMX cycling discipline. The sample used was n = 6 riders from the Spanish national team (19.3 ± 2.1 years). An intragroup experimental design with repeated measures was used to compare the evolution of the skill developed by the participants before and after treatment, as well as the degree of retention of the possible learning. The results showed that there were no significant differences between the 2 first pre-test sessions (PRE), nor between any of the other treatment, post-test or re-test sessions (TREAT, POS and RET, respectively). Nevertheless, significant differences were observed between either of the PRE sessions and any of the TREAT, POS or RET sessions (p ≤ 0.028), showing a significant reduction of the time needed to perform this skill after TREAT (1.264 ± 0.045 ms in PRE, 1.047 ± 0.019 ms in POS, and 1.041 ± 0.021 ms in RET). In conclusion, the use of audiovisual FB and cognitive training of the skill can result in a significant improvement in the execution of the gate start in BMX reducing the time to develop the task.

Key points

• This work provides a practical application of many studies developed around teaching-learning technique in sport. In those studies this kind of applications were suggested as necessary.
• All the recent theories are applied in the real sport context, and using elite athletes.
• A successful program is proposed to be used by coaches and athletes just following a few simple guidelines, and this can be a really useful tool to follow.

Key words: BMX, cycling, gate start, feedback, motor learning     

Magnetic stimulation of the quadriceps: analysis of 2 stimulators used for diagnostic and therapeutic applications

Compromised muscle function can be evaluated in respiratory disease patients by supramaximal magnetic stimulation (isometric twitch) of the quadriceps, a technique that is reproducible and objective. We validated the technique, comparing a device used in our laboratory with another reference electromagnet. We also assessed whether the technique could potentially be used to train the muscle by repetitive stimulation. The Medtronic Magpro (MED) device with a circular coil and the Magstim 200 device (MAG) with a figure-of-eight coil (reference device) were used to stimulate the femoral nerve of 6 volunteers at different percentages of maximal output. MED stimulation was also applied on the quadriceps muscle. We measured voluntary contractions, comparing measurements from the 2 devices and on different days. The stimulation achieved with MED was lower than with MAG, showed greater day-to-day variability, and was not clearly supramaximal. MED quadriceps stimulation was 80.7% of MAG stimulation. In conclusion, supramaximal stimulation of the quadriceps cannot be guaranteed with MED and the circular coil. However, this device generates sufficient contraction when applied to the muscle to be used for repetitive stimulation.     

Sleep improves sequential motor learning and performance in patients with prefrontal lobe lesions

OBJECTIVES: Motor skill learning involves both practice and a latent, sleep-dependent process of consolidation that develops after training ("off-line" learning). Sleep consolidation is linked to reduced brain activation in prefrontal areas, along with strong involvement of parietal regions. The objective in this study was to investigate the influence of sleep on the consolidation process of a motor task in patients with prefrontal damage. PATIENTS AND METHODS: For that purpose 14 patients with acquired focal prefrontal lesions, 15 age-matched healthy controls, and five patients with parietal lesions were evaluated on a serial reaction time task, SRTT, before and after a night of monitored sleep. Verbal and working memory was also tested. We anticipated that patients with prefrontal lesions, who are impaired in the acquisition of motor tasks, would benefit greater from sleep than the other two groups, since consolidation does not depend on prefrontal regions. RESULTS: Prefrontal patients showed an erratic learning curve at night, with great inter- and intrasubject variability that normalized after sleep. They also showed higher overnight learning of the motor skill and improvement on speed performance on the SRTT. No differences in the other memory tests were found between sessions. CONCLUSION: Prefrontal-injured patients benefit from night sleep in terms of motor task learning and performance, likely related to an advantageous off-line learning. Sleep could play a role in motor rehabilitation programs in prefrontal patients.     

Independent deletions of a pathogen-resistance gene in Brassica and Arabidopsis

Plant disease resistance (R) genes confer race-specific resistance to pathogens and are genetically defined on the basis of intra-specific functional polymorphism. Little is known about the evolutionary mechanisms that generate this polymorphism. Most R loci examined to date contain alternate alleles and/or linked homologs even in disease-susceptible plant genotypes. In contrast, the resistance to Pseudomonas syringae pathovar maculicola (RPM1) bacterial resistance gene is completely absent (rpm1-null) in 5/5 Arabidopsis thaliana accessions that lack RPM1 function. The rpm1-null locus contains a 98-bp segment of unknown origin in place of the RPM1 gene. We undertook comparative mapping of RPM1 and flanking genes in Brassica napus to determine the ancestral state of the RPM1 locus. We cloned two B. napus RPM1 homologs encoding hypothetical proteins with ≈81% amino acid identity to Arabidopsis RPM1. Collinearity of genes flanking RPM1 is conserved between B. napus and Arabidopsis. Surprisingly, we found four additional B. napus loci in which the flanking marker synteny is maintained but RPM1 is absent. These B. napus rpm1-null loci have no detectable nucleotide similarity to the Arabidopsis rpm1-null allele. We conclude that RPM1 evolved before the divergence of the Brassicaceae and has been deleted independently in the Brassica and Arabidopsis lineages. These results suggest that functional polymorphism at R gene loci can arise from gene deletions.     

Ingesta de flúor a través del consumo de agua de abastecimiento público en la cohorte INMA-Gipuzkoa

Objective

To estimate fluoride intake through consumption of water from the municipal network in pregnant women and their children from the INMA-Gipuzkoa cohort and to compare these intakes with recommended levels. In Euskadi (Spain), fluoridation of drinking water is compulsory in water supplies for more than 30,000 inhabitants.

Health-Related Quality of Life for Eating Disorders questionnaire version-2 was responsive 1-year after initial assessment

OBJECTIVES: To assess the responsiveness of the Health-Related Quality of Life for Eating Disorders questionnaire version-2 (HeRQoLEDv2) and present the psychometric characteristics of a new binge domain. STUDY DESIGN AND SETTING: Patients with an eating disorder completed the HeRQoLEDv2, the Eating Attitudes Test-26, Short Form Health Survey-12, and two items from the Eating Disorder Inventory-2, at baseline and after 1 year. At the second assessment, patients completed the HeRQoLEDv2, as part of the battery of tests, along with health transitional questions. Validity and reliability analyses of the new binge domain were performed. Responsiveness was evaluated using distributional and anchor-based approaches, comparison of mean changes, mean change correlations, the minimal detectable change (MDC) at the individual and group level, and the minimal important difference (MID). RESULTS: Items in the binge domain loaded above 0.40. Cronbach alpha was 0.82. Regarding responsiveness, the mean changes detected by the HeRQoLEDv2 correlated above 0.30 with the criterion measures. Patients who reported improvement showed significant changes, and effect sizes above 0.30. The MDC(90%ind) was larger than the MID. CONCLUSION: The HeRQoLEDv2 includes the new binge domain. It responded to change at the group level. Further research regarding the MID is needed.