Serum NGF levels in children and adolescents with either Williams syndrome or Down syndrome

The neurotrophin nerve growth factor (NGF) is a major regulator of peripheral and central nervous system development. Serum NGF was measured in normally developing control children (n=26) and in individuals affected by congenital syndromes associated with learning disability: either Williams syndrome (WS; n=12) or Down syndrome (DS; n=21). Participants were assessed at three distinct developmental stages: early childhood (2 to 6 years), childhood (8 to 12 years), and adolescence (14 to 20 years). A sample was taken only once from each individual. Serum NGF levels were markedly higher in participants with WS, than DS and control participants. In addition, different developmental profiles emerged in the three groups: while in normally developing individuals NGF levels were higher in early childhood than later on, children with WS showed constantly elevated NGF levels. When compared to control participants, those with DS showed lower NGF levels only during early childhood. Neuropsychological assessment confirmed previously reported differences among the three groups in the development of linguistic/cognitive abilities. Some features of individuals with WS, such as hyperacusis and hypertension, could be related to high-circulating NGF levels.     

Increased serum neopterin levels in adults with Down syndrome

We quantitated serum neopterin levels in Down syndrome (DS), normal controls, Alzheimer's disease, multiple sclerosis and other neurological diseases. We then analyzed the relationships with age, sex, apolipoprotein E (Apo E) phenotype, and amyloid beta protein 1-40 (Abeta40) and 1-42 (Abeta42) levels. Neopterin levels were higher in DS than all other groups. Levels in young DS (< 40 years of age) and old DS (> 41 years) were similar. There was no significant correlation between neopterin levels and age, sex, Apo E phenotype, and Abeta40 or Abeta42 levels in DS. This lack of correlation between neopterin and Abeta levels suggests that the higher neopterin concentrations in DS group reflect inflammatory cell activation rather than AD neuropathology.     

Voluntary orienting among children and adolescents with Down syndrome and MA-matched typically developing children

A forced-choice reaction-time (RT) task was used to examine voluntary visual orienting among children and adolescents with trisomy 21 Down syndrome and typically developing children matched at an MA of approximately 5.6 years, an age when the development of orienting abilities reaches optimal adult-like efficiency. Both groups displayed faster reaction times (RTs) when the target location was cued correctly than when cued incorrectly under both short and long SOA conditions, indicating intact orienting among children with Down syndrome. This finding is further evidence that the efficiency of many of the primary components of attention among persons with Down syndrome is consistent with their developmental level.     

Characteristic developmental expression of amyloid beta40, 42 and 43 in patients with Down syndrome

We immunohistochemically studied the expression of beta-amyloid precursor protein (APP), Abeta40, Abeta42, and Abeta43 in the frontal lobes of 20 Down syndrome (DS) patients and 13 controls. The immunoreactivity for each antibody was different in the degree of intensity and the chronological pattern of expression. APP and Abeta43 immunoreactivity was increased in neurons initially, and then Abeta43 and 42 immunoreactivity appeared in diffuse plaques from 32 years of age. APP and Abeta43 were characteristically observed in axons around senile plaques. Finally, Abeta40 immunoreactivity was detected in the cores of senile plaques. This time course of immunoreactive expression may be related to the pathogenetic process of Alzheimer-type dementia in DS, and the axonal damage in senile plaques may lead to the formation of neurofibrillary tangles (NFT) or neuronal death through axonal flow disturbance and accumulation of Abeta43 in cortical neurons.     

A pilot exploration with Posiphen to normalize amyloid precursor protein in Down syndrome

正Down syndrome (DS) pathology:DS is the mostcommoncauseofAlzheimer’sdisease(AD)andhasaknownAD-causinggenetic variation which is trisomy of the whole or part ofHomo sapienschromosome21(HSA21)(ChenandMobley,2019a).Comparedwith AD,     

Observational assessment and maternal reports of motivation in children and adolescents with Down syndrome

Despite a lack of consistent empirical evidence, there has been an ongoing assumption that intellectual disability is associated with reduced levels of motivation. The participants in this study were 33 children with Down syndrome ages 10-15 years and 33 typically developing 3-8-year-old children. Motivation was measured through observational assessments of curiosity, preference for challenge, and persistence, as well as maternal reports. There were no significant group differences on motivation tasks, but mothers of children with Down syndrome rated their children significantly lower on motivation than did parents of typically developing children. There were some intriguing group differences in the pattern of correlations among observations and parent reports. The findings challenge long-held views that individuals with intellectual disability are invariably deficient in motivation.     

Increase in beta-amyloid levels in cerebrospinal fluid of children with Down syndrome

BACKGROUND: Individuals with Down syndrome (DS) invariably develop Alzheimer's disease (AD) during their life span. It is therefore of importance to study young DS patients when trying to elucidate early events in AD pathogenesis. AIM: To investigate how levels of different amyloid-beta (Abeta) peptides, as well as tau and phosphorylated tau, in cerebrospinal fluid (CSF) from children with DS change over time. The first CSF sample was taken at 8 months and the following two samples at 20-40 and 54 months of age. RESULTS: Individual levels of the Abeta peptides, as well as total Abeta levels in CSF increased over time when measured with Western blot. Tau in CSF decreased whereas there was no change in levels of phosphorylated tau over time. CONCLUSION: The increasing levels of Abeta in CSF during early childhood of DS patients observed in this study are probably due to the trisomy of the Abeta precursor APP, which leads to an overproduction of Abeta. Despite the increased CSF concentrations of Abeta, there were no signs of an AD-indicating tau pattern in CSF, since the levels of total tau decreased and phosphorylated tau remained unchanged. This observation further strengthens the theory of Abeta pathology preceding tau pathology in AD.     

Relationships between task-oriented postural control and motor ability in children and adolescents with Down syndrome

Individuals with Down syndrome (DS) have been characterized by greater postural sway in quiet stance and insufficient motor ability. However, there is a lack of studies to explore the properties of dynamic postural sway, especially under conditions of task-oriented movement. The purpose of this study was to investigate the relationships between task-oriented postural control and motor ability in children and adolescents with DS. The participants were 23 children and adolescents with DS (DS group, M±SD age, 14.4±2.8 years) and 18 age- and gender-matched peers (M±SD age, 13.8±3.6 years). A force plate was used to collect postural data represented by center of pressure (COP) parameters. Postural measurements were conducted for both groups in quiet standing with eyes open and with eyes closed, and also while throwing a ball at erect standing. Assessments of motor ability were only applied to the DS group by using two dimensions of the original version of Gross Motor Function Measure and 4 subtests of the Bruininks Oseretsky Test of Motor Proficiency, second edition. The results showed that while the participants with DS showed greater displacement and higher velocity of COP sways at quiet standing, they exhibited smaller COP displacement in anterior/posterior direction during throwing the ball. Three areas of motor ability, including standing motor skills, walk/run/jump motor skills and muscle strength, were found to make a significant contribution to the displacement and velocity of postural sway during the voluntary movement. It is suggested that future research should focus on investigating the definite underlying mechanism of postural sway during movement and the influence of increasing motor ability on the reactive postural sway in this population.     

Static standing balance in adolescents with Down syndrome

AimTo analyse static-standing-balance of adolescents with Down syndrome (DS).MethodsThirty-two adolescents with DS aged 10–19 years (DSG); 33 adolescents, age/sex-matched, without DS (CG). Static-standing-balance under four conditions (C1: open-eyes/fixed-foot-support; C2: closed-eyes/fixed-foot-support; C3: open-eyes/compliant-foot-support; closed-eyes/compliant-foot-support) was examined by means of time and frequency Postural-Parameters (PPs). To evaluate the contribution of each sensory system influencing postural control ratios among the four conditions were calculated. Mean values of all PPs were higher in the DSG than in the CG. Mean values of time PPs were higher in both groups on compliant-foot-support (with open and closed eyes) than on fixed-foot-support. Ratios C2/C1 were significantly lower in DSG than in CG; ratios C3/C1 presented higher values in DSG than in CG, with significant differences in length path and RMS-velocity; there were no differences in ratios C4/C1.ConclusionsIn our group of DS adolescents the shift from visual to multimodal control of stance had occurred and they showed similar postural control patterns than non-DS. Even though, they presented worse static balance than their peers without DS and they had more problems with altered somasosensory input. An adequate rehabilitation program insisting on somatosensory input could be a useful measure to improve balance.     

急性脑梗死患者血浆β淀粉样蛋白的水平及意义

目的探讨急性脑梗死患者血浆β淀粉样蛋白(Aβ)的水平及其意义。方法采用放射免疫分析法测定95例急性脑梗死患者血浆中Aβ的水平,并与72例健康对照者进行比较。结果急性脑梗死患者血浆Aβ水平显著高于健康对照者,两组之间差异有统计学意义,急性脑梗死患者血浆Aβ水平与梗死体积大小以及NIHSS评分无相关性。结论急性脑梗死患者血浆Aβ水平异常增高,这些异常增多的Aβ可能会通过受损的血脑屏障进入脑内,发挥神经毒性作用,促使Alzheimer病(AD)的发生或加速AD的进展。     

Decreased protein levels of stathmin in adult brains with Down syndrome and Alzheimer's disease

Stathmin, distributed in neurons with high abundance, acts as an intracellular relay, integrating various transduction pathways triggered by extracellular signals and it is involved in physiological regulation of microtubule destabilization. Stathmin has been also shown to be a critical molecule in pathology of neurodegeneration such as Alzheimer's disease (AD), particularly, in neurofibrillary tangle (NFT) formation. Here we evaluated protein levels of stathmin in adult brain from patients with AD and Down syndrome (DS) showing AD-like pathology by applying proteomic technologies with two-dimensional (2-D) gel electrophoresis, matrix-assisted laser desorption ionization mass spectroscopy (MALDI-MS) identification and specific software for quantification of proteins. Significantly decreased protein levels of stathmin were observed in frontal (2.12+/-1.17, n = 6) and temporal (3.05+/-2.81, n = 10) cortices of AD compared to controls (frontal cortex: 4.41+/-1.70, n = 8; temporal cortex: 5.26+/-2.26, n = 13). Stathmin was also significantly decreased in frontal (2.47+/-1.11, n = 7) and temporal (2.02+/-1.18, n = 9) cortices of DS. We also investigated stathmin levels in fetal brain. Stathmin was not significantly changed between fetal DS brain and controls. We suggest that the decreased protein level of stathmin in brains is associated with tangle formation and microtubule instability in DS as well as AD, but stathmin is not involved in the abnormal development of fetal DS brain.     

Patterns of participation and enjoyment in adolescents with Down syndrome

This study aimed to determine participation and enjoyment in young people with Down syndrome (DS) in Taiwan and to assess how participation varies across gender, cognitive, and motor function variables. Using the Children's Assessment of Participation and Enjoyment, data on participation were collected from 997 adolescents with DS and their families. Findings indicated limited diversity and intensity of participation, with proportionately greater involvement in informal activities. Youth with better cognitive and motor functions participated more often in activities and reported higher enjoyment and social engagement with these. These findings provide a foundation for an improved understanding of activity participation of youth with DS. Service providers and families could provide and plan activities to ensure more satisfying and meaningful participation.     

Phonological awareness in children with Down syndrome

Research in the area of phonological awareness has mainly focused on the nature of the relationship between reading ability and awareness of phonemes. However, a recent study of phonological awareness in children with Down syndrome questioned the existence of any necessary relationship (Cossu, Rossini & Marshall, 1993). This paper describes a study of phonological awareness in children with Down syndrome with varying levels of reading ability. The sample consisted of 10 male and 7 female children with Down syndrome (aged 9 years 2 months to 14 years 5 months). All children received a battery of tests which consisted of assessments of: 1) phonological awareness, 2) reading and spelling competence, 3) non-word reading and spelling ability, and 4) non-verbal measures. Children with Down syndrome demonstrated measurable levels of phonological awareness. Significant positive correlations were found between phonological awareness and: reading and spelling competence, ability to spell non-words and non-verbal measures.     

Object-related generativity in children with Down syndrome

Children with Down syndrome (DS) show challenges in some aspects of goal-directed behavior when compared to developmentally matched children (Daunhauer et al., 2014; Lee et al., 2011), particularly in the area of goal-directed action on objects (Fidler et al., 2005a, Fidler et al., 2005b). In this study, we examined one aspect of goal-directed action on objects, object-related generativity, in school-aged children with DS (n = 52), a developmentally matched group of children with intellectual disability, but not Down syndrome (DD; n = 21), and a group of chronologically younger, but developmentally matched typically developing children (TD; n = 34). We administered the Leiter-R, the Oral and Written Language Scales (OWLS), and an Object-Related Generativity Task, which involved 2 min of unstructured play with a variety of objects that have divergent usages. Children with DS generated significantly fewer instances of initiating actions on new objects than children in both comparison groups, were less likely to produce novel functional action on any object (new or familiar) than TD children, and they showed fewer instances of novel functional object engagement with new objects overall than TD children. Frequency of acts on new objects in DS was associated with Leiter-R Form Completion and Repeated Patterns Raw Scores and OWLS Listening Comprehension Raw Scores. These findings contribute to the growing knowledge base regarding goal-directed behavior and self-regulation in individuals with Down syndrome. Implications for education and intervention are discussed.     

Household task participation of children and adolescents with cerebral palsy,Down syndrome and typical development

This cross-sectional study compared patterns of household task participation (e.g., performance, assistance and independence) of youth with cerebral palsy (CP), Down syndrome (DS) and typical development (TD). Parents of 75 children and adolescents were interviewed to report on their youths’ active engagement in daily self-care and family-care tasks, using the children helping out: responsibilities, expectations and supports (CHORES) questionnaire. Groups were equivalent in age (mean = 9.3 years; SD = 2.2 years), sex (male = 39; female = 36), respondent education, presence of maid, and number of siblings at home, but differed on child cognitive function and family socioeconomic status, with the DS and the CP groups scoring lower than the TD group but not different from each other. ANOVA revealed group differences on CHORES performance of self-care tasks (p = 0.004), on total participation score (p = 0.04) and on assistance scores (p < 0.02). Post hoc comparisons showed that TD group scored higher than CP and DS groups on performance and assistance in self-care tasks and total assistance; TD and CP groups were similar on total performance and assistance in family-care tasks. The groups also differed on independence indices; the TD index was greater than the CP and DS, and the CP index was greater than the DS. Parents from the three groups did not differ on ratings of importance regarding their children's household participation (p = 0.416). In spite of observed differences, children and adolescents with CP and DS are actively engaged in daily self-care and family-care tasks; their participation at home is not prevented by the presence of their disabilities.     

The perfective past tense in Greek adolescents with Down syndrome

This study investigates the ability of a group of eight Greek-speaking adolescents with Down Syndrome (DS) (aged 12.1-18.7) to handle the perfective past tense using an acceptability judgement task. The performance of the DS participants was compared with that of 16 typically-developing children whose chronological age was matched with the mental age of the DS group. For existing verbs, both groups showed high accuracy scores for the sigmatic past tense whilst for (potential but non-existing) nonce verbs the DS group performed differently from the controls. Specifically, their judgements were unaffected by a nonce verb's similarity to existing verbs, unlike those of the controls, suggesting that the DS participants were less reliant on similarity-based generalisations when encountering a nonce word than the controls. Apart from that, it was found that people with DS did not show any kind of morphological impairment, replicating previous findings on past tense production in DS.