Background In the past few decades, it has been demonstrated with animal models and clinical studies that a chronic inflammatory process significantly contributes to Alzheimer's disease (AD) pathogenesis. Methods We systematically searched on PubMed and Web of Science for studies associated with peripheral inflammatory biomarkers in AD and mild cognitive impairment (MCI) before July 2018. Meta‐analysis was conducted to summarise results of studies relative to peripheral cytokines and chemokines in AD and MCI. Results Mean (± SD) concentrations of peripheral inflammatory biomarkers for AD, MCI and healthy controls were extracted from these studies. Our meta‐analysis revealed consistently elevated concentrations of inflammatory biomarkers such as C‐reactive protein, interleukin‐1β (IL‐1β), IL‐2, IL‐6, IL‐12, IL‐18, monocyte chemotactic protein‐1 (MCP‐1), MCP‐3, IL‐8 and interferon‐γ‐inducible protein 10 in AD patients, whereas no consistent results were obtained for elevated concentrations of cytokines or chemokines except MCP‐1 in MCI patients. Conclusions In conclusion, these results provided evidence to support that systematic inflammation might be a biomarker for AD diagnosis, whereas it might be a later event during AD disease progression.

<b><i>Background:</i></b> Previous studies have shown inconsistent results for associations between vitamin D and risk of stroke. We gathered the existing published articles and conducted this meta-analysis with the aim to explore the association between vitamin D and risk of stroke. <b><i>Methods:</i></b> We searched for articles exploring the association between vitamin D and risk of stroke and published before April 2021 in the following databases: PubMed, Web of Science, MEDLINE, EMBASE, and Google Scholar. All statistical analyses were made using STATA 12.0 software. Q test and <i>I</i>^<i>2</i> were applied to examine heterogeneities between studies. <b><i>Results:</i></b> For the association between serum levels of 25(OH) vitamin D and risks of stroke, the present analysis included 20 cohort studies (including 213,276 participants) and a case-control analysis (including 13,642 participants). Additionally, the analysis included 15 studies (including 41,146 participants given vitamin D supplementation and 41,163 participants given placebo) to evaluate the influence of vitamin D supplementation on risk of stroke. Higher circulating levels of 25(OH) vitamin D were associated with a reduced risk of stroke (odds ratio/relative risk = 0.78, 95% confidence interval [CI]: 0.70–0.86, <i>I</i>^<i>2</i> = 41.5%, <i>p</i> = 0.025). However, the present analysis showed that vitamin D supplementation did not influence the risk of stroke (hazard ratio = 1.05, 95% CI: 0.96–1.14, <i>I</i>² = 2.3%, <i>p</i> = 0.425). <b><i>Conclusions:</i></b> Our analysis indicated that lower circulating level of vitamin D was associated with an elevated risk of stroke, but extra supplement of vitamin D failed to show benefit in decreasing the risk of stroke. Further research and study are also needed to show the role of vitamin D in relation to stroke.

To evaluate the diagnostic value of combination of D-dimer and Doppler Intima-Media Thickness (IMT) based on clinical data for vascular dementia (VaD). In this study, 100 cases of initial VaD were diagnosed by Zhenjiang Fourth People Hospital as VaD group, and 100 healthy were engaged as control group, medical history and test results were collected for evaluation. IMT and D-dimer were highly correlated with the onset of VaD. The sensitivity of combination diagnosis for early VaD: 90.2%, the specificity: 87.9%, the area under the curve (AUC) is 0.872, which were superior to IMT or D-dimer alone. D-dimer and IMT are significantly increased in the initial onset of cerebrovascular diseases, and combined detection of them is conducive to early diagnosis and evaluation of the disease. Given the limitations of D-dimer and IMT, combined detection is more conducive to early diagnosis and prognosis, and can be used as screening and routine examination items, even evaluate the severity of cognitive decline.Abbreviations: AD = Alzheimer disease, AUC = area under the curve, IMT = intima-media thickness, NCI = neurocognitive index, VaD = vascular dementia.

Purpose: To investigate the protective effect of Acorus tatarinowii extract (ATE) against Alzheimer's disease in 3xTg-AD mice. Method: The cognitive function of 3xTg-AD mice was assessed using Morris water maze test. The levels of the amyloid beta deposits and NeuN in the hippocampus were evaluated by immunohistochemical assay while brain neurotrophic derived factor (BDNF) and tyrosine kinase B (TrkB) expressions were determined by western blot analysis. Results: ATE treatment significantly ameliorated learning and memory deficits in AD mice, as shown by increased time spent in the target zone during probe tests. The escape latency in animals treated with 600 mg/kg ATE (24.8 ± 1.3 s) was significantly increased relative to ontreated 3xTg-AD mice (8.5 ± 1.0 s, p < 0.01). In addition, ATE significantly decreased Aβ deposits, increased NeuN-positive cells, and upregulated the expression of BDNF (1.9 ± 0.4, p < 0.05) and TrkB (1.9 ± 0.2, p < 0.05) in 3xTg AD mice. Conclusion: These results suggest that ATE treatment may be a useful strategy for managing memory impairment induced by several neurodegenerative diseases.