Objective To study the epidemiology of mycoplasma pneumonia (MP) infection in children and its relationship to meteorological conditions in Guilin. Methods Total of 1 342 hospitalized children with respiratory tract infections from Janu-ary 2011 to December 2012 were recruited, and the serum levels of mycoplasma pneumoniae antibody Ig (MP-Ig) were measured. Meanwhile, monthly meteorological conditions were collected. The relationships between the MP-Ig detection rates and meteoro-logical conditions were analyzed by multiple linear regression analysis. Results The total detection rate of MP-Ig was 23.2%with positive rates as 5.51%, 28.99%, 37.31%and 44.97%for 0-1, 1-3, 3-6 and>6 year-old groups respectively (P<0.01). The positive rate of female was higher than that of male with signiifcant difference (30.08%vs 19.05%, P<0.01). The positive rate of spring, summer, autumn and winter were 18.89%, 17.39%, 23.83%and 33.05%individually (P<0.01). Negative correlation was found be-tween detection rate of MP-Ig and monthly mean air temperature (P=0.001). Conclusion MP is one of the commonest pathogens of respiratory tract infection in children and mostly seen in elder female children with a higher incidence in winter. The main me-teorological factor is the low temperature that affects MP prevalence.

The poor stability of the ligustilide (LIG) makes its quantitation in Angelica sinensis (AS) difficult. This study establishes a chemical conversion method for the determination of ligustilide content in AS and proposes a national pharmacopoeia standard. Mechanical agitation and sonication of a powdered AS extract in a methanol/cyprolamine mixture facilitated the stabilization and transformation of ligustilide. Using an external reference HPLC-DAD method, the cyclopropyl-ligustilide (LIGc) content in the mixture could be determined. The content of ligustilide was greater than 1.0% based on 144 AS specimens including 68 obtained from the originally planted areas of Qinghai and Gansu Province; 55 specimens were obtained from Minxian and Weiyuan County medicine markets, and 21 specimens for which the storage period reached or exceeded 1.5 years. According to the Hong Kong Chinese materis medica standards, the content of ligustilide in AS should not be lower than 0.6%. The developed method could also be applied to the quality control of other Chinese medicinal materials (such as Ligusticum chuanxiong) or Chinese patent medicines in which ligustilide is the main component.