Childhood upper respiratory infection caused by Mycoplasma pneumoniae / 中国当代儿科杂志

<p><b>OBJECTIVE</b>This study was designed to investigate the prevalence, clinical characteristics and outcome of upper respiratory infection (URI) caused by Mycoplasma pneumoniae (MP) in children.</p><p><b>METHODS</b>Pharyngeal cultures for MP antibody were performed in 960 children with acute URI. The samples were randomly collected from the outpatient room or emergency room (Observed group). Of the Observed group, there were 232 cases under 1 year of age, and the remainder, were between 1-12 years old. The samples from 100 healthy children aged from 6 months to 12 years were used as the Control group. The prevalence of MP infection between the two groups was compared. The clinical manifestations and the outcome between the patients with MP positive and negative were compared.</p><p><b>RESULTS</b>MP antibody was positive in 31.7% (304/960) of the Observed group but only 9.0% (9/100) in the Control group (P < 0.05). The URI patients under 1 year of age had a lower positive rate of MP than those over 1 year old (P < 0.05). Coughs and tonsillitis were more common (P < 0.05), but catarrh, gastroenteritic symptoms, herpes, and tetter were rare (P < 0.01) in URI patients with MP positive compared with those with MP negative. Pneumonia developed in 14.8% of the patients with MP positive but only 7.0% in those with MP negative (P < 0.01).</p><p><b>CONCLUSIONS</b>MP is one of the main pathogens of acute URI in children. Acute pharyngotonsillitis symptoms are predominately presented in children with MP infection. MP infection was commonly seen in children over 1 year old and they are prone to develop pneumonia.</p>

Isolation, expression analysis of a chilling induced cDNA from rice root with differential display: an evidence role for caffeine-sensitive calcium signal / 生物工程学报

Chilling-sensitive rice varieties acquire chilling tolerance when their roots are exposed to water stress for short time. Caffeine-sensitive calcium signal was involved in this procedure. By using total RNA differential display, a chilling induced cDNA(ICT: induction of chilling treatment) was isolated from roots of chilling-sensitive rice variety. It was determined that it is a novel cDNA by homology searching. The transcript level of ict mRNA is up-regulated under chilling stress, it is decreased to low level when the samples were transferred to standard culture conditions. Pre-treated with mannitol for two hours is beneficial to inducing ICT level of expression. This chilling induction was inhibited by caffeine, suggesting that it may play a putative role in signal transduction of caffeine-sensitive calcium.