Value of diffusion-weighted imaging,H-magnetic resonance spectroscopy and 3D whole-brain arterial spin labeling in the diagnosis of medulloblastoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the value of diffusion-weighted imaging (DWI),H-magnetic resonance spectroscopy (1H-MRS) and 3D whole-brain arterial spin labeling (3D ASL) in the diagnosis of medulloblastoma in the posterior cranial fossa.</p><p><b>METHODS</b>The magnetic resonance imaging (MRI) findings of 16 patients with pathologically confirmed medulloblastoma in the posterior cranial fossa were analyzed retrospectively. All the patients were examined with plane and enhanced brain MRI scans; 5 patients also underwent examinations with DWI, 12 with MRS, and 5 with 3D ASL.</p><p><b>RESULTS</b>Medulloblastomas were found in the vermis and the fourth ventricle in 9 cases, in the cerebellar hemisphere in 5 cases, and in the cerebellopontine angle in 1 case; in 1 case multiple lesions were detected. The tumors showed iso-intense or slightly hypo-intense signals on TWI, and iso-intense or hyper-intense signals on TWI and FLAIR. The lesions showed high signals in DWI and low signals in ADC. Intra-lesion cysts were common (n=12), and calcification and bleeding were rarely seen. Mild patchy enhancement (n=6) or significant enhancement (n=10) was seen after contrast agent administration. Obstructive hydrocephalus was found in 12 cases and the subarachnoid space was involved in 3 cases. In all the 12 patients receiving MRS examination, high Cho and low NAA were found with significantly increased Cho/Cr (≥3.5) and Cho/NAA (≥4.0) ratios; Tau peak was seen in 8 cases, and Lip peak was found in 4 cases. All the 5 patients receiving 3D ASL examination showed decreased cerebral blood flow (CBF).</p><p><b>CONCLUSION</b>The characteristic features of medulloblastomas in DWI, MRS and 3D ASL offer assistance to the diagnosis of atypical medulloblastoma.</p>

Expression pattern changes of microRNA in the lung tissue of mice with acute lung injury induced by lipopolysaccharide / 中华实用儿科临床杂志

Objective To investigate the change of expression pattern of microRNA in the lung with acute lung injury (ALI)/acute respiratory distress syndrome(ARDS) induced by lipopolysaccharide (LPS),and to provide an evidence that microRNAs are involved in the pathogenesis of ALI/ARDS.Methods Twenty-four C57BL mice were randomly divided into control group and LPS treated group,12 mice in each group.The rats in LPS treated group were treated with intratracheal injection of LPS at a dose of 10 mg/kg body weight into the lung.The rats in control group were treated with the same dose of saline instead.All mice were sacrificed 24 hours after operation,the left lung was excised to measure the wet-to-dry weight (W/D) ratio,and the right upper lobe was stained with hematoxylin and eosin (HE).A microRNA microarray chip was used to profile miRNA expressions in the lung of rats in both LPS treated group and control group.Online software packages were used to predict the gene targeted by microRNAs.Results Compared with the control group,the LPS treated mice had obvious respiratory symptoms,the W/D ratio was significantly increased (P ＜ 0.01),and the pathology was characterized with ALI/ARDS.The microarray chip results demonstrated that the expressions of 48 microRNAs were significantly changed in the ALI/ARDS mice.Among these miRNA,27 cases were up-regulated,21 cases were down-regulated.The target genes of these microRNAs might be involved in regulating the signal pathway of inflammation.Conclusions Some miRNAs express differently in the model of ALI/ARDS,and they may play an important role in pathophysiological process of ALI/ARDS.

Expression of microRNA-646 in A549 cells treated by lipopolysaccharide and its function / 中华实用儿科临床杂志

Objective To measure the expression of microRNA-646 (miR-646) in A549 cells under different concentrations of lipopolysaccharide(LPS) treatment,and to explore the possible mechanism of miR-646 in A549 cells under LPS treatment.Methods A549 cells were divided into control group and experimental groups.A549 cells from the control group were treated with RPMI-1640 and A549 cells from the experimental groups were treated with LPS (5 mg/L,10 mg/L,15 mg/L) in a duration of 24 hours.Immunocytochemical method and Western blot were used to detect the changes in surfactant protein A (SP-A) and surfactant protein C (SP-C),and quantitative real-time polymerase chain reaction was used to detect the changes in miR-646 in all groups.Results Compared with control group,the expression of SP-A in cytoplasm of A549 cells were decreased in experimental groups (all P ＜ 0.05),and LPS in different concentrations induced the expression of SP-A in A549 cells in a dose-dependent manner.Compared with control group,the expression of SP-C in cytoplasm of A549 cells was decreased in experimental groups (all P ＜ 0.05).The expression of SP-C was the lowest in 10 mg/L LPS treatment group.The relative expression level of the control group of miR-646 was 0.9597 ±0.0200,in 5 mg/L LPS treatment group it was 1.6319 + 0.1325,in 10 mg/L LPS treatment group it was 2.4762 ±0.1380,and in 15 mg/L LPS treatment group it was 1.6642 ±0.0938.There were statistically significant differences between the experimental groups and control group (all P ＜ 0.01).Conclusion miR-646 may have a biological function in acute respiratory distress syndrome through inhibiting the transcription of SP-C.

Triterpenes from root of Rhaponticum uniflorum / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of the root of Rhaponticum uniflorum.</p><p><b>METHOD</b>Separation and purification were performed on silica gel and Sephadex LH-20 column chromatography. Their structure were elucidated on the basis of physicochemical and spectral analysis.</p><p><b>RESULT</b>Five triterpenoid compounds were isolated and identified as ursolic acid (1), 3-oxo-19alpha-hydroxyurs-12-en-28-oic acid (2), pomolic acid (3), arjunic acid (4) and tormentic acid (5), respectively.</p><p><b>CONCLUSION</b>Compounds 1 approximately 5 were isolated from the genus Rhaponticum for the first time.</p>