OBJECTIVE: Child learning disability is a basic academic skill acquiring obstacle, often presented by learning difficulty and abnormality in emotion and behaviors. Those who cannot receive in-time intervention would likely to appear immorality, depression, even personality obstacle and countersocial behaviors. Therefore, to review on the causes and early signs of child learning difficulties is important for finding the common reasons and main manifestations, and benefiting for the early diagnosis and interventions for children with learning disabilities.DATA SOURCES: Using the terms "Learning disabilities, Children, Survey documents", the relative articles published in the English from January 1985 to December 2003, were searched in PubMed database by computer.A search in China periodical database and Wanfang database was also conducted using the key word of "Learning disabilities, Children, review"for related articles published in Chinese from January 1990 to December 2003.STUYD SELECTION: Original articles were selected after elimination of the irrelative ones, inclusion criteria: randomized control study of the cause, early manifestations of children learning disability, as well as prognosis and correcting methods were selected.DATA EXTRACTION: Of the total 25 articles were about children learning disability, 16 were found closely related to be subjected and concerned and 9 were repetition ones.DATA SYNTHESIS: Totally 3 132 children with learning difficulties according to the diagnostic standards involved in the 16 experiments.And 2 081 children in 10 articles were investigated and revealed, the cause might involve heredity factors, brain dysfunction, brain structural abnormality, brain trauma and environment influence; 1 051 cases in 6 articles were analyzed and indicated that the main presentation of children learning disability consists of reading obstacle, spelling and writing difficulties, calculating obstacle, mood and behavior problems, moreover the prognosis and correcting methods were also mentioned.CONCLUSION: The cause of children learning disability is still unclear,it might be the combined results of multiple intrinsic and extrinsic factors,and divided into reading obstacle, spelling and writing difficulties, calculating skill obstacle, mood and behavior problems. The most important thing for the correction of children learning disability is early diagnosis and treatment.

Searching for new antidiabetic lead compound, 4-(1-aryl-3-oxo-5-phenylpentylamino) benzenesulfonamides were designed and synthesized directly by three component one-pot condensation of 4-phenyl-2-butanone and sulfanilamide with some aromatic aldehydes at an yield of 23%-97%. The chemical structures of the twelve new Mannich bases were confirmed by 1H NMR, 13C NMR, FTIR, ESI-MS and HR-MS. The screening results of antidiabetic activity indicated that most of these title compounds possess alpha-glucosidase inhibitory activity, among which compound le is the strongest one. And compound 11 possesses good peroxisome proliferator-activated receptor response element (PPRE) agonist activity. The structure-activity relationship of these new beta-amino ketones containing benzenesulfonamide unit was also discussed preliminarily.