Hyperhomocysteinemia (HHcy) is an independent risk factor of atherosclerosis and other cardiovascular diseases. Unfortunately, Hcy-lowering strategies were found to have limited effects in reducing cardiovascular events. The underlying mechanisms remain unclear. Increasing evidence reveals a role of inflammation in the pathogenesis of HHcy. Homocysteine (Hcy) is a precursor of hydrogen sulfide (H₂S), which is formed via the transsulfuration pathway catalyzed by cystathionine β-synthase and cystathionine γ-lyase (CSE) and serves as a novel modulator of inflammation. In the present study, we showed that methionine supplementation induced mild HHcy in mice, associated with the elevations of TNF-α and IL-1β in the plasma and reductions of plasma H₂S level and CSE expression in the peritoneal macrophages. H₂S-releasing compound GYY4137 attenuated the increases of TNF-α and IL-1β in the plasma of HHcy mice and Hcy-treated raw264.7 cells while CSE inhibitor PAG exacerbated it. Moreover, the in vitro study showed that Hcy inhibited CSE expression and H₂S production in macrophages, accompanied by the increases of DNA methyltransferase (DNMT) expression and DNA hypermethylation in cse promoter region. DNMT inhibition or knockdown reversed the decrease of CSE transcription induced by Hcy in macrophages. In sum, our findings demonstrate that Hcy may trigger inflammation through inhibiting CSE-H₂S signaling, associated with increased promoter DNA methylation and transcriptional repression of cse in macrophages.

In recent decades, with the improvement of radiotherapy (RT) technology and comprehensive treatment, the survival rate of head and neck malignancies has gained remarkable progress. Vascular injury and subsequent carotid stenosis following RT, as the backbone of treatment, have received increasing attention. Many investigations have demonstrated that radiation can result in the increase in carotid intima-media thickness, carotid stenosis and consequently lead to a higher risk of cerebrovascular events such as transient ischemic attack and stroke. In this review, we will examine the incidence of radiation-induced carotid artery stenosis, its morphological and histological characteristics, as well as its pathogenesis. The treatment and prevention methods, including follow-up strategies, will also be discussed at the end of the present review.

Biologically plausible associations exist between climatic conditions and stroke risk, but study results are inconsistent. We aimed to summarize current evidence on ambient temperature and overall stroke occurrence, and by age, sex, and variation of temperature. We performed a systematic literature search across MEDLINE, Embase, PsycINFO, CINAHL, Web of Science, and GEOBASE, from inception to 16 October 2015 to identify all population-based observational studies. Where possible, data were pooled for meta-analysis with Odds ratios (OR) and corresponding 95% confidence intervals (CI) by means of the random effects meta-analysis. We included 21 studies with a total of 476,511 patients. The data were varied as indicated by significant heterogeneity across studies for both ischemic stroke (IS) and intracerebral hemorrhage (ICH). Pooled OR (95% CI) in every 1 degree Celsius increase in ambient temperature was significant for ICH 0.97 (0.94–1.00), but not for IS 1.00 (0.99–1.01) and subarachnoid hemorrhage (SAH) 1.00 (0.98–1.01). Meta-analysis was not possible for the pre-specified subgroup analyses by age, sex, and variation of temperature. Change in temperature over the previous 24 h appeared to be more important than absolute temperature in relation to the risk of stroke, especially in relation to the risk of ICH. Older age appeared to increase vulnerability to low temperature for both IS and ICH. To conclude, this review shows that lower mean ambient temperature is significantly associated with the risk of ICH, but not with IS and SAH. Larger temperature changes were associated with higher stroke rates in the elderly.

Background: Triglyceride glucose (TyG) index was recently reported to be associated with an increased risk of the development and recurrence of cardiovascular events, and atherosclerosis is a main speculative mechanism. However, data on the relationship between TyG index and atherosclerosis, especially in the setting of ischemic stroke, is rare. We aimed to explore the association between TyG index and carotid atherosclerosis in patients with ischemic stroke. Methods: A total of 1523 ischemic stroke patients with TyG index and carotid artery imaging data were enrolled in this analysis. The TyG index was calculated as ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Carotid atherosclerosis was measured by common carotid artery intima-media thickness (cIMT), and abnormal cIMT was defined as a mean cIMT and maximum cIMT value ≥ 1 mm. Multivariable logistic regression models and restricted cubic spline models were used to assess the relationships between TyG index and abnormal cIMT. Risk reclassification and calibration of models with TyG index were analyzed. Results: The multivariable-adjusted odds ratios (95% CIs) in quartile 4 versus quartile 1 of TyG index were 1.56 (1.06–2.28) for abnormal mean cIMT and 1.46 (1.02–2.08) for abnormal maximum cIMT, respectively. There were linear relationships between TyG index and abnormal mean cIMT (P for linearity = 0.005) and abnormal maximum cIMT (P for linearity = 0.027). In addition, the TyG index provided incremental predictive capacity beyond established risk factors, shown by an increase in net reclassification improvement and integrated discrimination improvement (all P < 0.05). Conclusions: A higher TyG index was associated with carotid atherosclerosis measured by cIMT in patients with ischemic stroke, suggesting that TyG could be a promising atherosclerotic marker.

Bow hunter's syndrome (BHS), also known as rotational vertebral artery (VA) occlusion syndrome, is a rare yet treatable type of symptomatic vertebrobasilar insufficiency resulting from mechanical occlusion or stenosis of the VA during head and neck rotation or extension. The symptoms of BHS range from transient vertigo to posterior circulation stroke. The underlying pathology is dynamic stenosis or compression of the VA by abnormal bony structures with neck rotation or extension in many cases, such as osteophyte, disc herniation, cervical spondylosis, tendinous bands or tumors. Imaging approaches, such as Doppler sonography, computed tomography and angiography, as well as magnetic resonance imaging and angiography, are widely used in the diagnosis and evaluation of this syndrome. Digital subtraction angiography with head rotation remains the gold standard diagnostic method. Conservative management, surgery and endovascular procedures are the three major treatment methods for BHS, whereas some symptomatic patients may need operative treatment including surgery and endovascular procedures when conservative management is not adequate.