A bdominal aortic aneurysm (AAA), characterized by chronic aortic wall inflammation and destructive connective tissue remodeling, is one of the leading causes of sudden death in aging men (>55 years).1 Despite the current progress of surgical invasive repair or medical treatment, we lack a strategy to predict AAA rupture or to delay its progression. Epidemiological studies have identified several risk factors associated with AAA, including aging, male sex, smoking, and hypertension.1-3 However, the cause of AAA remains far from being fully elucidated. In This Issue, see p 1249Homocysteine (Hcy) is a sulfur-containing nonconstitutive amino acid derived from the essential amino acid methionine. The upper limit of the normal range for circulating Hcy is approximately 15 μmol/L, whereas a sex difference has been found, with approximately 10% to 15% higher levels in men versus women. Compelling evidence suggests that hyperhomocysteinemia (HHcy) is a strong independent risk factor of coronary heart disease and stroke in human.

Background: Cervical artery dissection (CAD) is a recognized cause of ischemic stroke. Hyperhomocysteinemia (HHcy), i.e. an elevated concentration of plasma homocysteine, is identified as an independent risk factor for stroke prevalence. However, an association between HHcy and CAD has so far remained unknown. Methods: A meta-analysis was performed to analyze the association between HHcy and CAD as well as the relevance of the C677T polymorphism of methylenetetrahydrofolate reductase (MTHFR), the key enzyme in homocysteine metabolism during CAD. We searched PubMed and Embase for studies reporting homocysteine concentrations or MTHFR genotype frequencies in CAD patients from 1990 to 2013. Outcomes were extracted from studies meeting the inclusion criteria and were subjected to a meta-analysis by the random-effect model. Heterogeneity was assessed by the I² test. Results: Eight case-control studies with 2,146 individuals fulfilled the required criteria and were included in the meta-analysis. HHcy was found to be significantly associated with CAD (pooled standardized mean difference: 0.96; 95% confidence interval, CI: 0.42-1.49; p < 0.01). We also found a significantly increased risk of CAD in individuals with the MTHFR C677T polymorphism by both the recessive model (TT vs. CT+CC; odds ratio, OR = 1.81; 95% CI: 1.22-2.67; p = 0.003) and the dominant model (TT+CT vs. CC; OR = 1.47; 95% CI: 1.08-1.99; p = 0.014). Conclusion: Our data suggest positive correlations between HHcy and CAD and between the C677T polymorphism of MTHFR and CAD.

The burden of incidence rate and mortality of cancer is increasing rapidly, and the development of precise intervention measures for cancer detection and treatment will help reduce the burden and pain of cancer. At present, the sensitivity and specificity of tumor markers such as CEA and CA-125 used clinically are low, while PET, SPECT, and other imaging diagnoses with high sensitivity possess shortcomings, including long durations to obtain formal reports and the inability to identify the molecular pathological type of cancer. Cancer surgery is limited by stage and easy to recur. Radiotherapy and chemotherapy often cause damage to normal tissues, leading to evident side effects. Aptamers can selectively and exclusively bind to biomarkers and have, therefore, gained attention as ligands to be targeted for cancer detection and treatment. Gold nanoparticles (AuNPs) are considered as promising nano carriers for cancer diagnosis and treatment due to their strong light scattering characteristics, effective biocompatibility, and easy surface modification with targeted agents. The aptamer-gold nanoparticles targeting delivery system developed herein can combine the advantages of aptamers and gold nanoparticles, and shows excellent targeting, high specificity, low immunogenicity, minor side effects, etc., which builds a bridge for cancer markers to be used in early and efficient diagnosis and precise treatment. In this review, we summarize the latest progress in the application of aptamer-modified gold nanoparticles in cancer targeted diagnosis and delivery of therapeutic agents to cancer cells and emphasize the prospects and challenges of transforming these studies into clinical applications.