Targeted metabolomic analysis of phenylpropanoid metabolites in Astragalus membranaceus var. mongholicus in response to Fusarium solani infection / 药学学报

Root rot severely restricts the sustainable development of Astragalus membranaceus var. mongholicus (AMM) industry. Resistance breeding is an economical and environmentally safe way to manage the disease and its key lies in the obtaining of resistance indicators. This study aimed to quickly and accurately screen the resistance-related (RR) metabolites so as to provide reference for the screening of indicators of AMM breeding for resistance. LC-MS-based targeted metabolomics and real-time quantitative PCR technology were employed, in combination with multivariate statistical analysis, in analyzing the dynamic changes of phenylpropanoid metabolites in AMM in response to root rot pathogen Fusarium solani (FS) infection and identifying the differential metabolites. The LC-MS method established showed high sensitivity; each metabolite had a good linear relationship (R2 ≥ 0.968 9) in the corresponding linear range of the respective standard curve; the recoveries and the relative standard deviations (RSDs) (n = 6) ranged from 70% to 107% and from 1.2% to 9.9%, respectively. Obvious disturbances were observed in the changes of the targeted metabolites in AMM infected by FS. These metabolites, compared with the mock-inoculated (CK) group, showed different up or down regulation with time series. Calycosin-7-O-β-D-glucoside, ononin, calycosin and formononetin were identified as differential metabolites, and they all belong to flavonoids. The first three compounds were significantly negatively correlated (r ≤ -0.97, P < 0.05) with the content of FS in the root of AMM. As potential RR metabolites, they are helpful in obtaining promising resistance indicators for AMM against FS infection.

Estimation of postmortal interval by measuring the amount of DNA in cells / 法医学杂志

Although there are many methods to estimate the early postmortal interval, more attention has been paid to the research on measuring the amount of DNA in cells. This paper introduce several different measuring ways, law of variation and application situation of DNA in cells. In addition, the result evaluation of measuring methods and application prospect is given.

Effect of Helicobacter pylori infection on iron status among preschool children / 中华儿科杂志

<p><b>OBJECTIVE</b>To explore the relationship between Helicobacter pylori (Hp) infection and iron status using serum ferritin (SF) as a marker for total iron and to identify the related factors of iron nutritional status among preschool children.</p><p><b>METHODS</b>By cluster sampling, we recruited 475 preschool children aged 2 to 7 years. A structured questionnaire and diet form were sent to the parents of these children to obtain related information about the socioeconomic level and dietary intakes. After collecting blood samples, the following indexes were measured. Hp IgG antibodies were measured with a dot enzyme-linked immunoassay; hemoglobin, Hct, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red blood cell distribution width index (RDW) with automatic Complete Blood Count; SF with an immunoradiometric assay. Stool Hp antigen and occult bleeding were measured with ELISA among individuals who were Hp seropositive. Hp status was defined as positive when both serum and stool antigen tests were positive, Hp status was defined as negative when serum antigen test was negative; 24-hour weighting and recording methods were used to dietary survey for three days in May and December 2001, respectively, dietary intakes including energy, protein and micronutrient were calculated using nursery school nutrition software and evaluated by Chinese Dietary Reference Intakes (DRIs). Mann-Whitney test was used to compare mean ranks of SF in Hp-positive and Hp-negative children. To obtain an adjusted estimate of the impact of Hp infection on SF, a multivariate analysis of covariance was done to evaluate the different level of SF between Hp infected and non-infected status. The relationship between iron deficiency and gender, age, socioeconomic condition, iron intake, and calcium intake was assessed by univariate analysis. An unconditional multivariate logistic regression analysis was also performed. Iron deficiency status was dichotomized and placed as the dependent variable. Hp infection status was incorporated together with possible confounding factors as independent variables in a final logistic regression model. All the data were managed by EPI Info 5.01a and analyzed by SAS (Version 6.12).</p><p><b>RESULTS</b>Totally 64 children were diagnosed as Hp-positive and 305 as Hp-negative. Mann-Whitney test and multivariate analysis of covariance both showed that SF concentration was significantly lower in Hp infected individuals than non-infected individuals. Adjusted mean level and 95% confidence interval of SF in infected and non-infected children was 23.62 microg/L (7.13 microg/L-78.26 microg/L), 33.48 microg/L (10.28 microg/L-109.06 microg/L), respectively. The relationship between Hp infection and iron deficiency status persisted in logistic regression analysis after adjusting for possible confounding factors (OR: 7.95; 95% CI 2.56 - 24.67).</p><p><b>CONCLUSION</b>Iron nutritional status was reduced in Hp infected preschool children. Hp infection appears to be an independent risk factor or an added stressor on iron status among preschool children.</p>