Objective:To investigate the development of vestibular system function in 7 to 14 years old normal boys and the ADHD boys;Methods:The present study involved two groups of subjects:148 ADHD boys(age range 7 years to 14 years) diagnosed with DSM-IV diagnostic criteria and 148 normal boys with the same age.Each group was divided into 4 clusters according to two years gap.All subjects were tested for the vestibular system function by the Vestibular Function Test System 2000/ ENG-V600 with the eye movement index.Results:From 7 to 14 years,the development of vestibular system function in normal boys had the characters as the description below.The optokinetic system function exhibited more development from seven years in the normal group.From 7 to 10 years,the time delay of saccade and anti-saccade in normal boys was significantly shorter(In the normal controls,the delay time of left saccade was 149?66 ms in 7-8 years old boys,108?64 ms in 9-10 years old boys,117?72 ms in 9-10 years old boys,the delay time of left anti-saccade was 178?127ms in 7-8 years old boys,101?88 ms in 9-10 years old boys,P

AIM: Centrifuge training can improve forward acceleration (+Gz) endurance. This study was to analyzed the gene expression of rat heart affected by centrifuge, and to research the molecular mechanism of improving +Gz endurance by centrifuge training. METHODS: Differential expressed genes between high+Gz endurance (+16Gz) rats, of test group after trained 12 d and control were screened using suppression subtractive hybridization (SSH) and dot blot hybridization. The obtained expressed sequence tags (ESTs)were used as probes to perform RNA slot hybridization with heart total RNA isolated from each gruop of centrifuge training and high+Gz endurance and low+Gz endurance (+12Gz) rats, respectively. The positive ESTs were sequenced and analyzed using BLAST(nr) at NCBI.RESULTS: Three down-regulated ESTs were obtained from heart samples, all of them are new, and their expression levels were decreasing during centrifuge training. CONCLUSION: Centrifuge training can significantly affect the special gene expressions of rat heart, and the expression changes of these genes may be ralated to the mechainism that +Gz endurance can be improved by centrifuge training.

BACKGROUNDAttention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed psychiatric disorder in childhood. ADHD children with overlapping symptoms and signs of motor problems have more serious prognosis than that of children with ADHD only. However, the motor and sensory processing problems in children with ADHD have not been studied well. Few people adopt the technique of computerized dynamic posturography (CDP) in the study of ADHD, which is applied widely in clinical and laboratory research to objectively evaluate human's balance performance. This study aimed to assess the characteristics of postural control and sensory information processing of boys with two subtypes of ADHD by using CDP, so as to provide the proof for non-drug therapy of ADHD.

METHODFrom June 2003 to September 2004, a total of 73 boys (7-15 years of age) with ADHD and 73 normal developing boys matched by age and intelligence quotient from Peking University Institute of Mental Health were recruited in the study. The Sensory Organization Test was adopted to test the static balance performance under six sensory input conditions by SMART EquiTest 8.0 (NeuroCom) instrument. The sensory information from three sensory systems were available under condition 1, the visual inputs were removed or distorted under condition 2 or 3, the somatosensory inputs were in conflict with or without the visual inputs removed under condition 4 or 5, and both the visual and somatosensory inputs were in conflict under condition 6. The indexes of equilibrium score, somatosensory, vestibular, and visual ratios, and strategy scores were analyzed to indicate the subjects' postural control ability.

RESULTSADHD boys had significantly lower composite equilibrium score (CES) than the normal group (P < 0.05). Under condition 1 and conditions 3-6, the equilibrium scores (ES) of the ADHD group were significantly lower (all P < 0.05) than those of the control. Significantly lower visual and vestibular ratios and strategy scores under conditions 4-6 were found in boys with ADHD compared with the control group (P < 0.05). Boys of ADHD-predominantly inattentive (ADHD-I) type had a significantly lower CES and ES under conditions 4-6 than the controls (all P < 0.05) while the ESs of ADHD-combined type (ADHD-C) boys under each condition were similar with that of boys with ADHD-I and no significant difference was found between boys with ADHD-C and the control group (all P > 0.05). Compared with the control group, the ADHD-I boys showed significantly lower visual and vestibular ratios and strategy scores under conditions 4-6 whereas the ADHD-C boys showed a trend of lower visual ratio (all P < 0.05).

CONCLUSIONSADHD boys had a poorer static postural control ability and impaired function of processing visual and vestibular information compared with the normal control. Boys with ADHD-I showed particularly severe defect of static postural control and vestibular function integrating conflict information than normal boys. These deficits may be an important contributor to the clinical presentation of ADHD children and their cognitive deficits. Assessment and training of postural control function would be suggested during the diagnosis and treatment of ADHD children.

Adolescent ; Attention Deficit Disorder with Hyperactivity ; physiopathology ; Case-Control Studies ; Child ; Humans ; Male ; Postural Balance ; physiology