This article was aimed to rapidly analyze chemical composition in A loe Barbadensis Mill, and to compare the chemical composition of commercial aloe vera medicinal materials with that of fresh aloe yellow exudate. An opti-mized liquid chromatography-mass spectrometry-ion trap-time-of-flight (LCMS-IT-TOF) method was applied for the analysis of commercial aloe vera medicinal materials and fresh aloe yellow exudates. The Agilent TC-C18 column (4.6 í 250 mm, 5 m) was used. The gradient elution was a solvent system of water(A)-methanol(B). ESI source was operated in both positive and negative ion modes. The results showed that chromones, pyrones, naphthalene deriva-tive, anthrones and anthraquinones were separated successfully, 30 compounds were characterized by the comparison of characteristic MS/MS fragment ions data with the literature. The diagnostic fragmentation patterns of different chemical compositions were also discussed on the basis of EST-IT-TOF MS data. It was concluded that the chemical composition of commercial aloe vera medicinal materials were significantly different from that of fresh aloe yellow ex-udate in terms of types and contents: the former one mainly contains isoaloeresin D and aloin, and few aloesin; but the latter is mainly composed of aloesin and aloin, and the content of aloesin is the highest. The LCMS-IT-TOF analysis can be used to rapidly obtain rich structural information of different chemical compositions, which improves the efficiency of qualitative analysis of chemical composition, and is of great significance to the quality control, eval-uation and the utilization of A loe Barbadensis Mill.

Objective To explore the distribution of inflam m atory cells and positive expression of P-se-lectin glycoprotein ligand-1 (PSG L-1) in infant brainstem tissue from hand-foot-m outh disease related fatal brainstem encephalitis. Methods Tw enty brainstem sam ples from infants suffered from brainstem en-cephalitis w ere collected as the experim ental group. Ten brainstem sam ples from infants died of non-brain diseases and injuries w ere collected as the control group. The distribution of inflam m atory cells and the expression of PSG L-1 in the tw o groups w ere exam ined by im m unohistochem ical m ethod. The characteristics of the positive cells w ere observed. Results In brainstem tissue of the experim ental group, there w ere sleeve infiltrations of inflam m atory cells around the vessels and in the glial nodule. Microglia was the m ost and following was neutrophils around the vessels and in the glial nodule. There was a significant statistical difference am ong m icroglias, neutrophils and lym phocytes (P<0.05). There was no sleeve infiltration in the control group. PSG L-1 protein was expressed w idely in inflam m atory cells in the experim ental group, especially in the inflam m atory cells around the vessels and in the glial nodule. B ut PSG L-1 positive staining could be observed significantly less in the control group com paring with the experim ental group (P<0.05). Conclusion Microglia is the m ain type of inflam m atory cells involved in the progress of the fatal disease. Moreover, PSG L-1 could participate in the pathogenesis of hand-foot-m outh disease related fatal brainstem encephalitis.