Microcirculation No-Reflow Phenomenon after Acute Ischemic Stroke.

BACKGROUND: The no-reflow phenomenon refers to a failure to restore normal cerebral microcirculation despite brain large artery recanalization after acute ischemic stroke, which was observed over 50 years ago. SUMMARY: Different mechanisms contributing to no-reflow extend across the endovascular, vascular wall, and extravascular factors. There are some clinical tools to evaluate cerebral microvascular hemodynamics and represent biomarkers of the no-reflow phenomenon. As substantial experimental and clinical data showed that clinical outcome was better correlated with reperfusion status rather than recanalization in patients with ischemic stroke, how to address the no-reflow phenomenon is critical. But effective treatments for restoring cerebral microcirculation have not been well established until now, so there is an urgent need for novel therapeutic perspectives to improve outcomes after recanalization therapies. CONCLUSION: Here, we review the occurrence of the no-reflow phenomenon after ischemic stroke and discuss its impact, detection method, and therapeutic strategies on the course of ischemic stroke, from basic science to clinical findings.

Chemical analysis of selected harmful and potentially harmful constituents and in vitro toxicological evaluation of leading flavoured e-cigarette aerosols in the Chinese market.

Use of electronic cigarettes (e-cigarettes) has increased significantly over the past decade due to consumer perception that these products represent a less risky alternative to combustible cigarettes. E-liquids generally contain a simple mix of vegetable glycerin, propylene glycerol, nicotine, organic acids, and flavourings. Regulators require that harmful and potentially harmful constituents (HPHCs) that might cause harm to the consumer must be monitored in the aerosol generated by e-cigarettes and in cigarette smoke (CS). To quantify HPHCs in aerosols from commercial flavoured e-cigarettes in Chinese market, this study has systematically compared levels of HPHCs, including eight carbonyls, five volatile organic compounds, four tobacco-specific nitrosamines, 16 polycyclic aromatic hydrocarbons, and seven heavy metals, in the aerosols of four market-leading flavoured e-cigarettes and mainstream CS, alongside in vitro cytotoxicity and mutagenicity assays. The vast majority of HPHCs were either undetected or significantly lower in the e-cigarette aerosols than in commercial CS or reference CS (3R4F). Where HPHCs were detected, there were small variations among the different flavoured e-cigarettes. In the neutral red uptake and Ames assays, aqueous extracts of the e-cigarette aerosols did not induce obvious cytotoxicity or mutagenicity, whereas CS aqueous extract showed dose-related cytotoxicity and mutagenicity. Collectively, these results indicate that use of e-cigarettes might potentially lead to a significant reduction in exposure to harmful substances, with fewer cytotoxic and mutagenic effects, as compared with conventional smoking. Further studies based on human puffing conditions and longer evaluation periods will be needed to substantiate this potential.

Determination and analysis of complete nucleotide sequence of Chinese genotype D hepatitis B virus: the first report.

OBJECTIVE: To determine the complete nucleotide sequence of a Chinese hepatitis B virus (HBV) strain of genotype D. METHOD: The complete nucleotide sequence of HBV derived from a Chinese chronic asymptomatic carrier was amplified by PCR and cloned to conduct sequence analysis. Homology of the resulted nucleotide sequence with those of published HBV strains was assessed by using DNASIS, and complete sequence analysis of the phylogenetic tree of 30 genotype D HBV strains conducted by the assistance of Clustalw. RESULTS: With the complete nucleotide sequnce of 3 182 bp, this HBV strain belongs to ayw3 subtype and D genotype, with the Genebank accession number AF280817. Its complete nucleotide homology is 98.3% to 94.5% with the published sequences of genotype D HBV strains and less than 89.5% with the other HBV strains of genotype A, B, C, E, F and G published in GenBank. CONCLUSION: The evolutionary relations of the complete nucleotide sequence of this HBV strain is the closest to those of the 4 Swedish strains out of the 30 genotype D strains published in GenBank.