Multi-component content determination of Dracocephalum tanguticum by quantitative analysis of multi-components by single-marker / 中国中药杂志

This study aims to establish a method for the simultaneous determination of 7 active components in Dracocephalum tanguticum and to evaluate the quality of medicinal materials from different habitats. The method was established with high performance liquid chromatography(HPLC) and the gradient elution was performed with the mobile phase of acetonitrile-methanol-0.2% phosphoric acid solution at a column temperature of 35 ℃, an injection volume of 15 μL, and a flow rate of 0.6 mL·min~(-1). The detection wavelength was set as 215 nm. With rosmarinic acid as the internal reference, the relative correction factors and the content of other 6 components were calculated. The results were compared with those obtained with the external standard method. The results showed that the samples from Huangzhong county, Qinghai province had the best quality, with the highest content of p-hydroxybenzoic acid, cosmosiin, rosmarinic acid, oleanolic acid, and ursolic acid(9.29, 12.14, 6.02, 3.11, 17.67 mg·g~(-1) respectively). The samples from Chaya county, Tibet autonomous region ranked the second, with the highest content of betulin and betulinic acid(15.53, 7.17 mg·g~(-1), respectively). The method is accurate, reliable, and repeatable and suitable for the simultaneous determination of multiple components in D. tanguticum. The content of functional components varied in the samples from different producing areas and can be used as the indicator for the quality evaluation of medicinal materials.

Effect of gold nanoparticle on autophagy flux and exosome secretion of mesenchymal stem cells / 上海交通大学学报（医学版）

Objective·To investigate the effect of gold nanoparticles (AuNPs) on exosome secretion of mesenchymal stem cells (MSCs) via blocking autophagy flux.Methods·Rat derived MSCs were treated with AuNPs (0,15,30,90,150 μg/mL),and the cell proliferation was detected with CCK-8 assay to evaluate the cytotoxicity of AuNPs.Then,MSCs were divided into normal control group,AuNPs group (20 μg/mL AuNPs for 72 h) and positive control group (5 μmol/L chloroquine for 4 h).Transmission electron microscopy was used to observe the ultrastructure of MSCs,and exosomes were extracted by ultracentrifugation and tested with nanoparticle analyzer and scan electron microscopy.The autophagy was observed by confocal microscopy and verified by Western blotting.Results·Low concentrations of AuNPs (0 to 30 μg/mL) slightly affected the cell proliferation.MSCs of AuNPs group secreted more abundant and smaller exosomes than those of control group,and expressed significantly more LC3 and p62 (both P＜0.05).Autophagosomes in AuNPs group were increased and fusion of lysosomes and autophagosomes was blocked.Conclusion·AuNPs block the autophagy flux and regulates the secretion of exosomes.

Promoting effect of thrombin on proliferation of bone marrow-derived mesenchymal stem cells and its mechanisms / 中国实验血液学杂志

This study was aimed to investigate the growth-promoting activity of thrombin on mesenchymal stem cells (MSC) and its mechanisms. Human bone marrow MSC were cultured in serum-free medium supplemented with graded concentrations of thrombin, and the proliferation status of MSC was detected by MTT test. The expression levels of protease-activated receptors (PAR) and c-MYC gene were detected by PCR. Activated Akt signaling pathway was revealed by Western blot, and specific inhibitors of the signaling pathways were used to confirm the effects. The results showed that thrombin stimulated MSC proliferation in a dose-dependent manner; the minimal concentration of thrombin for stimulating MSC growth was 0.5 U/ml, and the promoting effect reached its maximum when thrombin at a dose of 8 U/ml was employed. PCR results showed that MSC expressed the two types of PAR1 and PAR2. After PAR1 was blocked with a specific inhibitor SCH79797, the growth-promoting effect of thrombin was inhibited, while this phenomenon was not observed when MSC were exposed to FSLLRY-NH2, a specific inhibitor for PAR2. Further experiments showed that after exposure to thrombin, the AKT signaling pathway in MSC was promptly activated, and c-MYC expression was greatly up-regulated. Meanwhile, when LY294002, a specific AKT inhibitor, was added into the culture medium, the up-regulation of c-MYC expression was reduced, accompanied by the low rate of MSC growth. It is concluded that thrombin can stimulate MSC proliferation by eliciting PAR1-mediated AKT activation and subsequent up-regulation of c-MYC expression.

Impact of systolic blood pressure on visit-to-visit blood pressure variability in middle-aged and elderly people / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the impact of systolic blood pressure (SBP) on visit-to-visit blood pressure variability (BPV) in middle-aged and elderly people.</p><p><b>METHODS</b>Visit-to-visit BPV was determined in 5440 workers in the Kailuan study cohort from 2006 to 2007. The subjects were ≥ 40 years-old and had no history of stroke, transient ischemic attack or myocardial infarction. Participants were divided into five groups according to different levels of SBP. Linear regression was used to analyze the related factors which might affect BPV.</p><p><b>RESULTS</b>Mean systolic BPV of all subjects was 10.35 mm Hg [coefficient of variation (CV 7.96%)]. The mean systolic BPV of males was 10.54 mm Hg (CV 7.90%) while the mean SBPV of females was 10.06 mm Hg (CV 7.90%). The BPV of males was significant higher than that of females (P < 0.001). CV of SBP was similar between males and females. Furthermore, higher SBP was associated with higher BPV. There were significant differences in BPV between different groups with different levels of SBP (P < 0.001). Linear regression analysis demonstrated that SBP, age, gender, high-sensitivity C-reactive protein (hsCRP) were affecting factors of BPV. Twenty mm Hg SBP increase was linked with 2.02 mm Hg BPV increase and 0.388%CV increase. Age increase of 1 year was associated with 0.044 mm Hg BPV increase and 0.029% CV increase.</p><p><b>CONCLUSION</b>SBP, age, gender and hsCRP are important factors affecting BPV in middle-aged and elderly people. Higher SBP is closely related to greater BPV in this cohort.</p>

Analysis on surveillance data regarding the level of Japanese encephalitis antibody in Heilongjiang. province, 2006 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the prevalent situation of Japanese encephalitis (JE) virus among healthy people in Heilongjiang province and to analyze its risk factors.</p><p><b>METHODS</b>7 national surveillance counties were selected and divided into 5 age groups as 1-2, 3-5, 6-10, 11-20 and 21-59 years and randomly sampled 7 person in each age group per county with the sample size as 1050. Quantitative Elisa test was used to detect Japanese encephalitis antibody IgG.</p><p><b>RESULTS</b>The adjusted standard antibody positive rate of people on 1-59 year olds was 70.62%, with lowest in 3-5 age group, and increasing by age (chi2 for trend test = 40.52, P < 0.001). The overall titer of IgG was low in general population but was different with age (Kruskal-Wallis test chi2 = 76.9, P < 0.001). Older age and lower latitude seemed to be two risk factors on JE antibody IgG.</p><p><b>CONCLUSION</b>JE virus infection had a long-term effect with low level, among general population. Age and latitude were two risk factors which suggesting the necessarily of strengthening the surveillance system for JE cases at risk in the prevalent areas on Heilongjiang province.</p>

Efficacy and mechanism of rhG-CSF in treatment of different leukopenia / 上海第二医科大学学报

Objective To explore efficacy and mechanism of recombinant human granulocyte-colony stimulating factor(rhG-CSF)in treatment of different leukopenia.Methods A total of 50 patients were divided into 4 groups:aplastic anemia(AA)group(n=10),myelodysplastic syndromes(MDS)group(n=10),drug-induced leukopenia group(n=20)(subdivided into hyperplasia group and hypoplasia group by the degree of cellularity)and iron deficiency anemia group(control group,n=10).The concentrations of G-CSF of peripheral blood were measured by ELISA method.The ratio of CD34+ cells and G-CSFR expression in blood marrow mononuclear cells(BMMNC)were measured by flow cytometry.Granulocyte colony-forming units(CFU-G)of MNC were cultured.Clinical efficacy of rhG-CSF to all patients were determined.Results The concentrations of G-CSF were higher in AA and drug-induced leukopenia groups than those of MDS and control groups(P0.05).Expressions of G-CSFR were lower in hypoplasia group than those in hyperplasia and control groups(P0.05).The ratio of CD34+ cells was lower in AA group than that of other groups(P0.05).Concentrations of CFU-G were lower in AA and MDS groups than those in drug-induced leukopenia and control groups(P0.05).The efficacy of rhG-CSF was superior in drug-induced leukopenia group than in MDS group,and superior in MDS group than in AA group(P

Establishment of a simple and convenient animal model of cardiac arrest for studying cerebral resuscitaion / 中华急诊医学杂志

Objective To establish an simple and convenient animal model of cardiac arrest for studying cerebral resuscitation.Method Clean male Sprague Dawley rats were randomly divided into sham group and experimental group.Cardiac arrest was induced by asphyxiation and ice-cold 0.5 mol KCl with blood flow cut off for 5 minutes.Animals were resuscitated with external cardiopulmonary resuscitation (CPR),mechanical ventilation,and epinephrine injection.Blood pressure,heart rate,successful ratio of resuscitation after 72 hours, time of cardiac arrest (T_(CA)) and return of spontaneous circulation (T_(ROSC)) were recorded.Neural deficit scores (NDS) and levels of maleic dialdehyde (MDA) in plasma were evaluated at 3,6,12,24,48,72 hours after ROSC.The damage score of cortex was measured by transmission electron microscope examination at 3 hours and 72 hours after ROSC.Results All the rats in experimental group had cardiac arrest rapidly.T_(CA) and T_(ROSC) were (137.3?10.2) seconds and (64.4?9.3) seconds,respectively,while the successful rate of resuscitation was 82.5%.The lowest NDS was at 3 hours after ROSC,while the NDS increased gradually.After CPR,the level of MDA in plasma increased significantly,slightly declined at 72 hours after ROSC,but still significantly higher than before the model.Electron microscope examination of cortex showed neuron slightly,organelle and astrocyte,but became better after 72 hours post ROSC.Conclusions The model of cardiac arrest was easy to establish,and the data provided was accurate,which is useful to study the mechanism of cerebral resuscitation.