Transmission electron microscopy assessment of a novel method for isolating pure exosomes from serum.

Serum exosomes frequently are used for liquid biopsy. Serum exosomes normally are isolated using ultracentrifugation; however, ultracentrifugation is time-consuming, labor intensive and requires a high-speed centrifuge. Many commercial kits use a precipitation-based method; however, this process can result in substantial contamination. We developed a new method to isolate pure serum exosomes. We isolated serum exosomes using precipitation, extracted them using acetone, then isolated them again by precipitation. We used transmission electron microscopy (TEM) to examine the morphology of serum exosomes. TEM indicated that our isolated exosomes were pure with typical morphology and with a size ranging from 40 to 150 nm. Flow cytometry revealed expression of exosome markers, CD63, CA81 and CD9. Our double precipitation method enables ready extraction of pure exosomes from serum. Our double precipitation method simplifies detection of serum exosomal biomarkers for diagnosis and prognosis of disease.

Effect of a risk-stratified intervention strategy on surgical complications: experience from a multicentre prospective study in China.

OBJECTIVES: To develop a risk-stratified intervention strategy and evaluate its effect on reducing surgical complications. DESIGN: A multicentre prospective study with preintervention and postintervention stages: period I (January to June 2015) to develop the intervention strategy and period II (January to June 2016) to evaluate its effectiveness. SETTING: Four academic/teaching hospitals representing major Chinese administrative and economic regions. PARTICIPANTS: All surgical (elective and emergent) inpatients aged ≥14 years with a minimum hospital stay of 24 hours, who underwent a surgical procedure requiring an anesthesiologist. INTERVENTIONS: Targeted complications were grouped into three categories (common, specific, serious) according to their incidence pattern, severity and preventability. The corresponding expert consensus-generated interventions, which focused on both regulating medical practices and managing inherent patient-related risks, were implemented in a patient-tailored way via an electronic checklist system. PRIMARY AND SECONDARY OUTCOMES: Primary outcomes were (1) in-hospital death/confirmed death within 30 days after discharge and (2) complications during hospitalisation. Secondary outcome was length of stay (LOS). RESULTS: We included 51 030 patients in this analysis (eligibility rate 87.7%): 23 413 during period I, 27 617 during period II. Patients' characteristics were comparable during the two periods. After adjustment, the mean number of overall complications per 100 patients decreased from 8.84 to 7.56 (relative change 14.5%; P<0.0001). Specifically, complication rates decreased from 3.96 to 3.65 (7.8%) for common complications (P=0.0677), from 0.50 to 0.36 (28.0%) for specific complications (P=0.0153) and from 3.64 to 2.88 (20.9%) for serious complications (P<0.0001). From period I to period II, there was a decreasing trend for mortality (from 0.64 to 0.53; P=0.1031) and median LOS (by 1 day; P=0.8293), without statistical significance. CONCLUSIONS: Implementing a risk-stratified intervention strategy may be a target-sensitive, convenient means to improve surgical outcomes.

Assessment of Tuberous Sclerosis Complex Associated With Renal Lesions by Targeted Next-generation Sequencing in Mainland China.

OBJECTIVE: To identify the TSC1 and TSC2 mutations in patients with tuberous sclerosis complex (TSC) associated with renal lesions, and to explore the relationship between genotypes and phenotypes. MATERIALS AND METHODS: We analyzed 43 individuals affected with TSC accompanied by renal lesions using next-generation sequencing (NGS). We also performed Sanger sequencing to validate the NGS results. RESULTS: We reported a comprehensive mutation analysis of 43 affected individuals with TSC accompanied by renal lesions using NGS. Forty-one of 43 patients (95%) had at least 1 detectable mutation in the TSC1 or TSC2 gene. We identified 14 novel nucleotide alterations, including 11 novel small mutations and 3 large-deletion mutations for the first time. Our study showed that patients with TSC2 mutations had higher frequency of hypomelanotic macules and dental enamel pits and larger angiomyolipomas (AMLs) than patient populations with non-TSC2 mutations through analysis of the correlated mutation findings with clinical features. CONCLUSION: In conclusion, patients with TSC2 mutations had higher frequency of hypomelanotic macules and dental enamel pits, along with larger renal AMLs, compared with patient populations with non-TSC2 mutations. Patients with large deletions and frameshift mutations of the TSC1 or TSC2 gene showed larger AML diameters than patients with other kinds of mutations.