Objective To investigate the polymorphisms of human cytomegalovirus ( HCMV ) UL146 gene in asymptomatic children. Methods Urine samples were collected from 47 asymptomatic chil-dren who were positive for HCMV DNA. PCR was performed to amplify the open reading frame ( ORF) of UL146 gene. Positive bands were sequenced and variations in UL146 gene were analyzed by using bioinfor-matics software. Results Seventeen samples were successfully amplified and sequenced. Variations spread all over the sequence of UL146 gene and the variability in nucleotide and amino acid sequences ranged from 0％ to 42. 5％ and 0％ to 67. 7％ respectively. Compared with the Towne strain, there was diversity in sig-nal sequence and C-terminal region. Phylogenetic analysis indicated that UL146 in the 17 asymptomatic chil-dren belonged to four genotypes, which were G1, G8, G9 and G11. Forms of post-translational modification varied greatly among the four genotypes, while the important functional region of ELRCXC chemokine was highly conservative. Secondary structure prediction showed that random-coli conformation was the predomi-nant structure of active proteins. Isoelectric point ( PI) and molecular weight ( MW) were dissimilar among the four genotypes. Conclusion HCMV UL146 gene in asymptomatic children was hypervariable in both nucleotide sequence and amino acid structure. However, the important functional region was highly con-served. The predominant genotypes of UL146 in these children were G1, G8, G9 and G11, and the geno-type distribution in them showed no significant difference with previous findings in children with symptomatic HCMV infection.

It was generally believed that muscular atrophy of paralyzed limbs after stroke was due to disuse. However, recent studies have found that secondary lesions of motor neurons in the contralateral anterior horn of the spinal cord and the decrease of motor units lead to denervation, which plays an essential role in muscular atrophy and muscle fiber type transition. This article reviews the phenomenon and mechanism of muscular atrophy and denervation of paralyzed limbs after stroke, to provide a reference for clinical evaluation and experimental research.