[Zoning of water environment protection in Three Gorges Reservoir watershed].

Regional differences in socio-economic development, land use, vegetation cover, and relative location of water body within a watershed bring about significant effects on the water environment quality of the watershed. Concerning about the core demands of water body protection, it is important and necessary to carry out zoning water environment protection for whole watershed. With a view to the spatial differences in regional characteristics of eco-environment and water body pressure-respond features, this paper studied the zoning of water environment protection in the Three Gorges Reservoir watershed, based on the methods of ecological factors overlay and ecological sensitivity analysis. The factors considered included hydrothermal conditions, terrain topography, administrative unit, and ecological sensitivity. Three regions in the watershed were zoned, i. e., 1) red region, namely strictly protected region, with an area of 2924 km2 and occupying 5.1% of the total; 2) yellow region, namely first class protection region, with an area of 10477 km2 and occupying 18.4%; and 3) blue region, namely second class protection region, with an area of 43599 km2 and occupying 76.5%. The key environmental problems of the regions were identified, and the strategies for the regions' development and water environment protection were proposed.

Analysis of MECP2 gene copy number in boys with autism.

Autism is a severe neurodevelopmental disorder with a strong genetic basis.The methyl-CpG binding protein 2 gene (MECP2) is a dosage-sensitive gene in brain development and has been implicated as a candidate gene for autism. Duplication of the MECP2 gene has been reported in a few boys with autistic features. To further investigate the association of MECP2 duplication with autism, the authors performed real-time quantitative polymerase chain reaction (PCR) to detect copy number variations of the MECP2 gene in 82 autistic boys. No copy number variation was found in these patients, indicating that duplication of the MECP2 gene is not frequent in autistic patients. The authors consider that duplication of the MECP2 gene has no major effect on the susceptibility to autism. Replication of studies in a large-sized sample and a well-characterized subgroup of autism are warranted to further identify the association of MECP2 gene duplication with autism.

[Characteristics of developmental regression in autistic children].

OBJECTIVE: About 30% of autistic cases experience developmental regression around 2 years of age. The clinical course and manifestations of autistic children with regression remain unclear. This study investigated the clinical features of a group of autistic children with regression. METHODS: One hundred and fifty-two children at ages of 2.5-6.5 years confirmed with autism based on DSM-IV diagnostic criteria were enrolled. They were grouped according to language development: normal or regression. The perinatal history, developmental history and characteristics of regression were investigated. The symptoms were compared between the two groups. RESULTS: Regressions were observed in 33 children (21.7%) at age of between 16 and 21 months, with loss both in communicative skills and social engagement. The regressive group was scored significantly higher on the Childhood Autism Rating Scale (CARS) (P<0.05) and had a relatively higher proportion of severely ill children (66.7% vs 45.4%; P<0.05)compared with the non-regressive group. CONCLUSIONS: Regression as a characteristic symptom occurs in some autistic children and is of value for diagnosis of autism. The autistic children with regression display more severe social and language impairments than those without regression. Regressive autism may be a special subtype.

MeCP2 gene mutation analysis in autistic boys with developmental regression.

Autism and Rett syndrome are both pervasive developmental disorders and share many characteristics in common. One of these features is developmental regression with loss of social, cognitive and language skills after a period of apparently normal development during the first 1-2 years of life, which raises the question of whether there is a common pathway underlying regression in these two disorders. The Rett syndrome gene was identified as MeCP2 gene on Xq28, a powerful transcriptional repressor. To explore its possible role in the etiology of autism and involvement in regression, we searched for MeCP2 gene mutations in a well characterized sample of 31 autistic boys with developmental regression by direct sequencing. One sequence variant in 3' untranslated region was observed. The patient inherited the variant from his unaffected mother, so it may be a rare polymorphism. No coding sequence variant was found in any of the patients tested. We conclude that mutations in the coding sequence of MeCP2 are not a frequent cause of regression in autism. The long 3' untranslated region of MeCP2 is highly conserved across species, suggesting that they are important for the post-transcriptional regulation of MeCP2 gene. It may be worthwhile extending the mutation screening, with a larger sample of strictly defined phenotype, to regulatory elements and untranslated regions of this gene, to explore to what degree MeCP2 gene is involved in the etiology of autism and its possible role in the regression of autism.

[Behavioral patterns of autistic children during infancy].

OBJECTIVE: The present study investigated the behavioral patterns of autistic children during infancy to provide clues for early identification of childhood autism. METHODS: The abnormal behaviors of 30 children with autism and 26 children with other developmental disorders in infancy were investigated. RESULTS: The children with autism presented a series of abnormal behaviors, including no social smile, no eye contact and no respond to own name, and joint attention deficiency, which were distinguished from the children with other developmental disorders. The imitation and attachment behaviors were significantly different between the two groups. Repetitive motor actions and interest peculiarity were only seen in children with autism. CONCLUSIONS: The children with autism may present a series of abnormal behaviors as early as in infancy. The abnormal behaviors facilitate early diagnosis of autism.

Association between the polymorphism in the promoter region of dopamine D4 receptor gene and chronic tic disorder.

OBJECTIVE: To study a possible association between the three functional polymorphisms in the promoter region of dopamine D4 receptor (DRD4) gene and chronic tic disorder. METHODS: Genomic DNA was isolated from the venous blood leukocytes of 84 unrelated patients with chronic tic disorder (Study group) and 100 healthy unrelated individuals (Control group). Polymorphisms of DRD4, 1240L/S, 616C/G and 521C/T, were genotyped by the allele-specific primer (ASP) PCR. Genotype, allele and haplotype frequencies were analysed by SHEsis online. RESULTS: There were significant differences in both allele and genotype frequencies (chi(2) = 8.419, P < 0.01; chi(2) = 7.860, P < 0.05 respectively) of DRD4-616C/G between the Study and the Control groups. Haplotypic frequencies of LCT (1240L/S, 616C/G, 521C/T) in the Study group were noticeably higher than in the Control group (chi(2) = 6.371, P < 0.05). CONCLUSIONS: There is an association between the DRD4-616C/G polymorphism and chronic tic disorder. The individuals with haplotype LCT (1240L/S, 616C/G, 521C/T) are susceptible to this disorder.