Blood-derived amyloid-ß protein induces Alzheimer's disease pathologies.

The amyloid-ß protein (Aß) protein plays a pivotal role in the pathogenesis of Alzheimer's disease (AD). It is believed that Aß deposited in the brain originates from the brain tissue itself. However, Aß is generated in both brain and peripheral tissues. Whether circulating Aß contributes to brain AD-type pathologies remains largely unknown. In this study, using a model of parabiosis between APPswe/PS1dE9 transgenic AD mice and their wild-type littermates, we observed that the human Aß originated from transgenic AD model mice entered the circulation and accumulated in the brains of wild-type mice, and formed cerebral amyloid angiopathy and Aß plaques after a 12-month period of parabiosis. AD-type pathologies related to the Aß accumulation including tau hyperphosphorylation, neurodegeneration, neuroinflammation and microhemorrhage were found in the brains of the parabiotic wild-type mice. More importantly, hippocampal CA1 long-term potentiation was markedly impaired in parabiotic wild-type mice. To the best of our knowledge, our study is the first to reveal that blood-derived Aß can enter the brain, form the Aß-related pathologies and induce functional deficits of neurons. Our study provides novel insight into AD pathogenesis and provides evidence that supports the development of therapies for AD by targeting Aß metabolism in both the brain and the periphery.

[The situation of social support and its relationship with antenatal depression among 1 075 Zhejiang primiparas in their third trimesters].

Objective: To investigate the situation of social support (SS), and explore its relationship with antenatal depression (AD) among Zhejiang primiparas in their third trimesters. Methods: From March to August 2016, a cross-sectional study was conducted and the questionnaire was used at the outpatient consulting room of one maternity hospital in Hangzhou. Inclusion criteria includes the primiparas over 18 years old, gestation from 30 to 36 weeks, been able to understand and complete the questionnaires independently, no family history and history of mental disorders and no use of psychotropic drugs, without serious illness and so on. Exclusion criteria was that the primiparas were unable to complete all the contents of the questionnaire and of poor compliance. 1 150 questionnaires were actually given out, and 1 075 questionnaires were valid, so the valid rate was 93.48%. AD was evaluated by the Edinburgh Postnatal Depression Scale (EPDS) and SS was evaluated by the Perceived Social Support Scale (PSSS). SS between the non-AD group and the AD group was compared. The correlation between SS and AD was analyzed. Binary logistic regression model was used to assess the relationship between SS and AD. The level of SS was divided by average scores, groups lower than the average score was defined as the low-score group, groups higher than the average score was defined as the high-score group. Results: The prevalence of AD (score≥9) was 27.3% (293/1 075) among Zhejiang primiparas in their third trimesters. The scores of family support, friend support and other support, and the total score of SS among the non-AD group were 24.80±2.83, 23.40±3.00, 21.91±3.54 and 70.11±7.92, respectively, which were higher than those in the AD group (22.71±3.88, 21.45±3.59, 19.95±3.97, 64.10±10.01), (t values were 8.43, 8.29, 7.83 and 9.25, respectively, P<0.001 for all). The scores of family support, friend support and other support, and the total score of SS were negatively correlated with AD (rs values were-0.26,-0.25,-0.22 and-0.28, respectively, P<0.001 for all). Compared with low-score group, the scores of family support, friend support and other support, and the total score of SS among the high-score group had a lower risk of antenata depression among primiparas in their third trimesters, OR(95%CI) values were 0.56 (0.41-0.77), 0.66(0.47-0.92), 0.57(0.41-0.79) and 0.36(0.27-0.48), respectively. Conclusion: The prevalence of AD among Zhejiang primiparas was relatively high, and AD was negatively associated with SS level. We suggest adding SS in community pregnancy health management service in the future.

[A new method for predicting retention time of solutes under linear gradient elution conditions in RP-HPLC].

A new method for predicting the retention time of solutes under linear gradient elution has been established. In this method, the migration distance of solutes in column and the mobile phase gradient were modified simultaneously according to the distribution of mobile phase in column. The prediction results of retention time of both weakly and strongly retentive solutes were accurate in different instrumental systems using this method. In order to test and verify this method, the retention time of fifteen amino acids and eight homologous compounds of benzene were predicted. The predicted results were compared with those predicted by the method in common use. The relative average errors between predicted and experimental values were 3.70% and 4.90% for the weakly retentive solutes, far smaller than those obtained by the reference method (23.61% and 31.16%). For the strongly retentive solutes, the relative average errors were 0.21% and 6.01% respectively, slightly smaller than those obtained by the reference method (0.81% and 6.69%). It is seen that this new method has many advantages.