U-shaped association between low-density lipoprotein cholesterol levels and risk of futile reperfusion mediated by stroke-associated pneumonia in acute ischemic stroke after endovascular thrombectomy.

OBJECTIVE: Futile reperfusion (FR) is becoming a major challenge in the treatment of patients with acute ischaemic stroke (AIS) undergoing endovascular thrombectomy. This study aims to determine the dose-response relationship between low-density lipoprotein cholesterol (LDL-C) levels and the risk of FR in patients with AIS undergoing endovascular thrombectomy and to investigate potential mediators. METHODS: A total of 614 patients with AIS undergoing endovascular thrombectomy were enrolled and divided into five groups according to quintiles of LDL-C levels: Q1(≤2.27 mmol/l), Q2 (2.27-2.5 mmol/l), Q3 (2.5-2.59 mmol/l), Q4 (2.59-2.97 mmol/l) and Q5 (≥2.97 mmol/l). Associations between LDL-C levels and the risk of FR and stroke-associated pneumonia (SAP) were estimated using multivariate logistic regression models. Restricted cubic spline curves were used to describe the dose-response relationship between LDL-C levels and the risk of FR and SAP. Mediation effect analysis was performed in R software with 100 bootstrap samples. RESULTS: After adjustment for confounders, both low and high LDL-C levels were significantly associated with a higher risk of FR compared with the reference group (Q3). We observed a U-shaped association between LDL-C levels and the risk of FR (P for nonlinear =0.012). Mediation analysis showed that the association between LDL-C levels and the risk of FR was 29.7 % (95 % CI: 2.96 %-75.0 %, P=0.02) mediated by SAP. CONCLUSIONS: We found a U-shaped association between LDL-C levels and the risk of FR that was mediated by SAP. Clinicians should note that in AIS patients undergoing endovascular thrombectomy, lower LDL-C levels are not always better.

Short-term effect of ambient ozone pollution on respiratory diseases in western China.

Ambient air pollution has been regarded as an important cause of the morbidity and mortality of respiratory diseases. In the current work, a total of 469,490 respiratory emergency room (ER) visits in Lanzhou, China from Jan 1, 2013 to Dec 31, 2016 were collected. A generalized additive model (GAM) was used to investigate the association between O3 and respiratory ER visits for the different gender and age subgroups. The results showed that: (a) with per inter-quartile range (IQR) (31 µg/m3) increase in O3, the greatest relative risk (RR) of respiratory ER visits for the total was 1.014 (95% CI 1.008-1.020) at lag 4 days. Females and 16-to-45-year-olds were relatively more sensitive to O3; (b) the significant lag effects were found in single-day lag models, with the highest RR values for different groups were observed at lag 3-lag 5 days. The multi-day cumulative lag effects were stronger for the total; (c) in the multiple-pollutant models, the effects of O3 were generally increased when introducing other pollutants (PM10, PM2.5, SO2 and NO2) for adjustment. This study demonstrated that short-term exposure to O3 increased the RR of respiratory ER visits in Lanzhou, China.

Health risk of extreme low temperature on respiratory diseases in western China.

Previous studies have reported that daily average temperature is connected with respiratory diseases (RD), but proof is limited for the influence of the extreme low temperature on RD in Lanzhou, a northwestern China of temperate area. Generalized additive model (GAM) was built in this work to describe the relationship between daily mean temperature and RD in Lanzhou, China from 2012 to 2017. The results indicated that the exposure-response curve was inverse J-shaped, showing the lower the temperature, the larger the relative risk (RR). The RR of daily emergency room (ER) admissions in P5 extreme low temperature (the temperature below the fifth percentile, etc.) was larger than that in P10. The P5 extreme low temperature has the strongest effect at lag 0, and the RRs were 1.043 (95% CI: 1.030, 1.055) for the total, 1.031 (95% CI: 1.015, 1.046) for males and 1.058 (95% CI: 1.039, 1.077) for females. For different age groups, the largest RRs were 1.026 (95% CI: 1.013, 1.039) for the children (age < 16 years) at lag 5, 1.057 (95% CI: 1.030, 1.085) for the young adults (aged 16-45 years), 1.060 (95% CI: 1.023, 1.099) for the middle-aged (aged 46-60 years) and 1.121 (95% CI: 1.077, 1.166) for the elderly group of age > 60 years. Meanwhile, females and the elderly were more vulnerable to extreme temperature. The results could strengthen the scientific evidence of effects of extreme low temperature on RD in temperate areas.

Circulation weather types and hospital admissions for cardiovascular disease in Changchun, China.

Epidemiological studies have reported significant associations between weather situations and health. Cardiovascular disease is a serious chronic non-communicable disease which causes mortality and morbidity, bringing large economic burden to patients' families. This study explored the relationship between cardiovascular disease (CVD) and weather conditions in Changchun, northeast China. The frequency distributions of 13 main circulation weather types (CWTs) were analyzed, and a comparison between air mass classification and hospital admissions was performed for various groups using an admission index (AI). The results indicated that women had a lower risk of CVD than men did. The risk of CVD for older people (aged ≥ 65 years) was lower than that for young people (aged < 65 years). Younger men had the highest risk. The risks of CVD were higher in all groups (i.e., men, women, older, and younger) under southwesterly (SW) and northerly (N) CWTs and were lowest under the anticyclone (A) CWT. The risk of CVD among men was higher than that for women under these CWTs. N type circulation is characterized by cold, dry weather and was most closely associated with an increased incidence of CVD. The most significant effect of N type circulation on AI was observed with a delay of 2 days. SW type circulation is characterized by humid, hot weather and was the CWT that was second most closely associated with an increased incidence of CVD, with a peak in AI on the day that SW type circulation occurred. The results of this study could be provided to local health authorities as scientific guidelines for controlling and preventing CVD in Changchun, China.

Persistent pollution episodes, transport pathways, and potential sources of air pollution during the heating season of 2016-2017 in Lanzhou, China.

As one of the most important industrial cities in Northwest China, Lanzhou currently suffers from serious air pollution. This study analyzed the formation mechanism and potential source areas of persistent air pollution in Lanzhou during the heating period from November 1, 2016 to March 31, 2017 based on the air pollutant concentrations and relevant meteorological data. Our findings indicate that particulate pollution was extremely severe during the study period. The daily PM2.5 and PM10 concentrations had significantly negative correlations with daily temperature, wind speed, maximum daily boundary layer height, while the daily PM2.5 and PM10 concentrations showed significantly positive correlations with daily relative humidity. Five persistent pollution episodes were identified and classified as either stagnant accumulation or explosive growth types according to the mechanism of pollution formation and evolution. The PM2.5 and PM10 concentrations and PM2.5/PM10 ratio followed a growing "saw-tooth cycle" pattern during the stagnant accumulation type event. Dust storms caused abrupt peaks in PM10 and a sharp decrease in the PM2.5/PM10 ratio in explosive growth type events. The potential sources of PM10 were mainly distributed in the Kumtag Desert in Xinjiang Uygur Autonomous Region, the Qaidam Basin and Hehuang Valley in Qinghai Province, and the western and eastern Hexi Corridor in Gansu Province. The contributions to PM10 were more than 120 µg/m3. The important potential sources of PM2.5 were located in Hehuang Valley in Qinghai and Linxia Hui Autonomous Prefecture in Gansu; the concentrations of PM2.5 were more than 60 µg/m3.

Particulate matter pollution and emergency room visits for respiratory diseases in a valley Basin city of Northwest China.

Epidemiological studies have suggested that particulate matter (PM) pollution seriously affects human health, particularly it is closely associated with respiratory diseases. The aim of this study is to quantitatively evaluate the effect of PMs (PM10 and PM2.5) on emergency room (ER) visits for respiratory diseases in Lanzhou, a valley basin city in northwest China. Based on the data of the ER visits, daily concentration of particulate matters and daily meteorological elements from January 1, 2013, to July 31, 2017, we used a generalized additive model (GAM) of time series to evaluate the exposure-response relationship between PMs and respiratory ER visits. Seasonal modified effects of PM2.5 and PM10 on different age and gender groups were also performed. Results showed that the highest incidence of respiratory diseases occurred in winter. Respiratory ER visits for the total were significantly associated with PM2.5 (at lag 0 day) and PM10 (at lag 3 days), with relative risks (RRs) of 1.042 (95%CI: 1.036 -1.047) and 1.013 (95%CI: 1.011-1.016), respectively. Effects of PM pollutants on respiratory diseases are different among different age and gender groups. Children under 15 years and the elders over 60 years were the most sensitive to PM pollution, and males were more sensitive than females. The results obtained in the current study would provide a scientific evidence for local government to make policy decision for prevention of respiratory diseases.

Missense Variants in Hypoxia-Induced VEGFA/VEGFR2 Signaling Predict the Outcome of Large Artery Atherosclerotic Stroke.

Collateral density variations are a major determinant of stroke outcome. Here, we explored the association of missense variants in hypoxia-induced VEGFA/VEGFR2 signaling and stroke outcome. We recruited 683 large artery atherosclerotic (LAA) stroke patients as the training set from Nanjing Stroke Registry Program between August 2013 and January 2016. To validate the findings from the training set, we recruited an additional 333 LAA stroke patients between February 2016 and January 2017 as the validation set. Genotyping of target SNPs (rs11549465 [HIF-1α], rs11549467 [HIF-1α], rs1870377 [VEGFR2], and rs2305948 [VEGFR2]) was conducted using a SNPscan method. Unfavorable outcome was defined as a modified Rankin Scale (mRS) score > 2 at three months after index event. In the training set, the AA genotype of rs1870377 led to a decreased risk of unfavorable outcomes in the recessive model (AA vs. TA + TT, OR 0.60, 95% CI 0.38-0.95, P = 0.031). This was confirmed in the validation set (OR 0.43, 95% CI 0.21-0.86, P = 0.017) and the combined set (OR 0.54, 95% CI 0.36-0.79, P = 0.002). We also found that A allele was a protective factor for stroke outcome in both validation set and combined set (OR 0.70, 95% CI 0.49-0.99, P = 0.044 and OR 0.77, 95% CI 0.63-0.94, P = 0.012, respectively). In silico analysis indicated that the rs1870377 variant led to structural alterations in VEGFR2 that may influence its activity. Our findings demonstrate that the rs1870377 in the hypoxia-induced VEGFA/VEGFR2 axis predicts the 3-month outcome of patients with LAA stroke.

Leukoaraiosis and earlier neurological outcome after mechanical thrombectomy in acute ischemic stroke.

BACKGROUND AND PURPOSE: The aim of the study was to evaluate whether leukoaraiosis (LA) severity is associated with earlier neurological outcome in acute stroke patients undergoing mechanical thrombectomy. MATERIALS AND METHODS: In this retrospective multicenter study, we evaluated 273 acute stroke patients treated with mechanical thrombectomy. LA severity was graded as 0-2 (absent-to-moderate) versus 3-4 (severe) according to the van Swieten scale. The main clinical outcome was the proportion of early neurological improvement and early neurological deterioration. Early neurological improvement was defined as a decrease of≥4 points on the NIHSS, or an NIHSS score of zero 24hours after baseline assessment. Early neurological deterioration was defined as an increase of≥4 points on the NIHSS 24hours after baseline assessment. RESULTS: There was a significantly lower early neurological improvement rate (17.1% versus 39.2%; P=0.006) and non-significantly higher early neurological deterioration rate (29.3% versus 17.7%; P=0.084) in patients with severe LA (sLA) compared with patients with absent-to-moderate LA. In multivariable analysis, sLA was inversely associated with early neurological improvement (OR, 0.31; 95% CI, 0.13-0.78; P=0.012). There was no significant association of sLA with early neurological deterioration. However, in patients without symptomatic intracranial hemorrhage, sLA was an independent predictor of early neurological deterioration (OR, 2.65; 95% CI, 1.09-6.45; P=0.032). CONCLUSIONS: sLA is a significant negative predictor of early neurological improvement and is an independent predictor of early neurological deterioration in patients without symptomatic intracranial hemorrhage.

Efficacy and safety of endovascular thrombectomy in mild ischemic stroke: results from a retrospective study and meta-analysis of previous trials.

BACKGROUND: Mechanical thrombectomy has been proven as a standard care for moderate to severe ischemic stroke with anterior large vessel occlusion (LVO); however, whether it is equally effective in mild ischemic stroke (MIS) is controversial. METHODS: In this retrospective study, a total of 177 Chinese patients presenting with MIS (NIHSS ≤8) and LVO between January 2014 and September 2017 from seven comprehensive stroke centers were identified. Odds of good outcome with endovascular thrombectomy versus medical treatment were obtained by logistic regression analysis and propensity-score matching method, and a meta-analysis pooled results from six studies (n = 733). RESULTS: Good outcome (mRS: 0-1) was 58.2% (46/79) in the thrombectomy and 46.9% (46/98) in the medical group, which showed no statistical significance before adjustment (P = 0.13; OR = 1.57, 95% CI: 0.86 to 2.86). The adjusted ORs of thrombectomy versus medical group were 3.23 (95% CI, 1.35 to 7.73; P = 0.008) by multivariable logistic analysis, 2.78 (1.12 to 6.89; P = 0.02) by propensity score matching analysis, and 3.20 (1.22 to 8.37; P = 0.01) by propensity score matching analysis with additional adjustments, respectively. Thrombectomy treatment did not result in excessive mortality or symptomatic intracranial hemorrhage after adjustments. The meta-analysis did not confirm the associations between good outcome and endovascular treatment. CONCLUSIONS: The current study indicates that endovascular thrombectomy is associated with good functional outcome in MIS patients with LVO, and without additional risk of symptomatic intracranial hemorrhage and mortality. Although the meta-analysis failed to demonstrate its superiority compared to medical treatment, randomized clinical trials are needed.

Pollution characteristics in a dusty season based on highly time-resolved online measurements in northwest China.

To investigate the pollution characteristics and potential sources in a dusty season, an online analyzer was used to measure trace gases and major water-soluble ions in PM10 from April 1st to May 29th, 2011 in Lanzhou. The average concentrations of HONO, HNO3, HCl, SO2 and NH3 were 0.93, 1.16, 0.48, 9.29 and 5.54 µg/m3, respectively, and 2.8, 2.76, 8.28 and 2.48 µg/m3 for Cl-, NO3-, SO42- and NH4+. In the non-dust period, diurnal variations of SO42-, NO3- and their gaseous precursors showed similar change trend. NH4+ showed unimodal pattern whereas NH3 illustrated a bimodal pattern. HCl and Cl- showed an opposite diurnal pattern. In the dust event, temporal profiles of HCl and Cl-, SO2 and SO42- all presented similar change trend, and SO42- and Cl- preceded dust ions (Ca2+ and Mg2+) 13 h. The ratios of NO3- to SO42- were 0.65 in the non-dust period and 0.31 in the dust event. In the dust event, the sulfur oxidation ratio (SOR) was a factor of 1.33 greater than that in the non-dust period, and [SO42-]/[SO2] was 2.31 times of that in the non-dust period. The source apportionment using Probabilistic Matrix Factorization (PMF) suggested that fugitive dust (58.09%), secondary aerosols (33.98%), and biomass burning (7.93%) were the major sources in the non-dust period whereas dust (67.01%), salt lake (29.68%), biomass burning (0.8%), and motor vehicle (2.51%) were the primary sources in the dust event. Concentration weighted trajectory (CWT) model indicated that NO3-, Cl- and K+ could be regarded as local source species, the potential sources of Na+, Mg2+ and Ca2+ concentrated in the two large areas with the one covered in the junction areas of Xinjiang, Qinghai and Gansu and another one covered the places around in Lanzhou, the potential sources of SO42- were mainly localized in the areas adjacent to Lanzhou.

Leukoaraiosis severity and outcomes after mechanical thrombectomy with stent-retriever devices in acute ischemic stroke.

BACKGROUND AND PURPOSE: The aim of the study was to evaluate whether leukoaraiosis severity is associated with outcome in acute stroke patients undergoing mechanical thrombectomy with stent-retriever devices. METHODS: In this retrospective multicenter study, we evaluated 251 acute stroke patients (pretreatment National Institutes of Health Stroke Scale score ≥8) treated with stent-retriever devices. Leukoaraiosis severity was graded as 0-2 (absent-to-moderate) versus 3-4 (severe) according to the van Swieten scale. The main clinical outcome was the proportion of good functional outcome, defined as a modified Rankin Scale of 0-2 at 90 days. RESULTS: Significantly fewer patients in the severe LA group than in the absent-to-moderate LA group achieved a good functional outcome (18.4% vs 50.2%, P<0.001). In multivariable analysis, severe leukoaraiosis was a significant negative predictor of good functional outcome at 90 days (OR, 0.27; 95% CI 0.10-0.77; P=0.014). CONCLUSIONS: The severity of leukoaraiosis is independently associated with 90-day functional outcome in acute stroke patients undergoing mechanical thrombectomy with stent-retriever devices.

Feasibility of Thrombectomy in Treating Acute Ischemic Stroke Because of Cervical Artery Dissection.

Background and Purpose- Acute ischemic stroke caused by cervical artery dissection tend to result in unfavorable outcomes even with appropriate medical treatment. This study evaluated the safety and effectiveness of endovascular thrombectomy in treating acute ischemic stroke associated with cervical artery dissection. Methods- Patients with acute ischemic stroke and with large artery occlusion associated with dissection were selected. Propensity score matching was performed to increase the comparability. Patients with a 90-day modified Rankin Scale score of 0 to 2 were defined as with favorable outcome. Results- Eighty patients with and 80 patients without thrombectomy were enrolled. After propensity score matching, 48 patients with and 48 patients without thrombectomy were matched for further analysis. Proportion of favorable outcome (modified Rankin Scale score of 0-2) was higher in patients with thrombectomy than in those without (66.7% versus 39.6%; P=0.008). There were no significance differences about the incidence of symptomatic intracranial hemorrhage (8.3% versus 4.2%; P=0.677) and the 90-day mortality (10.4% versus 6.3%; P=0.714) between matched patients with and without thrombectomy. Conclusions- Endovascular thrombectomy seems to be an effective treatment in selected patients with acute ischemic stroke associated with cervical artery dissection, but the safety of thrombectomy needs further research.

125I inhibited the NSCLC both in vivo and in vitro.

Lung cancer is the main reason of cancer-linked death all over the world. Non-small cell lung cancer (NSCLC) patients always have an extremely poor prognosis. It is urgent to find novel treating methods. It was previously showed that 125I brachytherapy had been applied to the lung cancer treatment. However, fundamental researches are limited. In the present study, we first explored the mechanism by which 125I radiation induced arrest or apoptosis of the cell cycle and relevant protein expression. Furthermore, we explored its effect on the invasion. We found that 125I significantly induced cell apoptosis through mitochondrial pathway, triggered S phase arrest via regulating cyclinA2, p21 and CDK6 expressions. Meanwhile, 125I could inhibit invasion of NSCLC cells by altering the expression level of vimentin, N-cadherin and MMP-9. Furthermore, we confirmed the effects of 125I on NSCLC cell growth in vivo. The results indicated that 125I obviously inhibited the tumor growth. Thus, we determined that 125I brachytherapy remarkably restrained NSCLC cellular growth and intrusion by inducing apoptosis, S phase arrest and corresponding protein expression.

The application of technetium-99m-red blood cell scintigraphy in the diagnosis of orbital cavernous hemangioma.

OBJECTIVE: The purpose of this study was to evaluate the clinical value of technetium-99m-red blood cell (Tc-RBC) scintigraphy in the diagnosis of orbital cavernous hemangioma (OCH). PATIENTS AND METHODS: Forty-one patients with pathologically confirmed orbital mass, of which 10 were OCH, underwent Tc-RBC scintigraphy in this study. The scanning procedure included an initial perfusion phase, followed by an early and a delayed blood pool phase. All patients underwent ultrasonography and computed tomography (CT), and 15 patients also underwent MRI. RESULTS: All 10 OCH patients had no abnormal findings on radionuclide angiographic images and early blood pool phase, but increased activity was found during delayed blood pool phase. All other non-OCH orbital tumours did not have this tracer pattern. The radioactivity ratios of tumour to nontumour were 2.96±0.05 and 1.14±0.25, respectively, which had a statistically significant difference (t=15.18, P<0.001). Although nine of 10 OCH patients were diagnosed correctly with one false-positive case using ultrasound, both CT and MRI could not provide a definitive diagnosis. CONCLUSION: Tc-RBC scintigraphy is a reliable and useful procedure for the diagnosis of OCH. It may be considered as one of the routine clinical screening tools for the diagnosis of OCH and as a complement investigation to ultrasonography and CT.

[Effect of sand dust weather on major water-soluble ions in PM10 in Lanzhou, China].

The major water-soluble ions (Ca(2+), NH(4+), Mg(2+), K(+), Na(+), SO4(2-), NO3(-) and Cl-(-) in PM10 at 1-h interval were measured by an online analyzer for monitoring of Aerosols and Gases (MARGA) at the campus of Lanzhou University, from April 1 to June 30, 2011. There were 15 days of dust weather during the monitoring period. The main water-soluble ions in PM10 were Ca(2+), SO4(2-) and NO3(-). The concentration of NO3(-) and NH4(+) decreased during blowing sand weather comparing with non-dust, this phenomenon showed that the dust weather had the function of eliminating the local anthropogenic emissions. As the soil pollution marker, the concentration of Mg(2+), Na(+) and Ca(2+) increased during dust weather comparing with non-dust. The correlation coefficients between Na(+) and Mg(2+), Na(+) and Ca(2+), Mg(2+) and Ca(2+) during dust weather were 0.520, 0.659 and 0.671, respectively. The similar correlation coefficients indicated that some fraction of these species was derived from the same sources, such as soil dust. The correlation coefficients between Na(+) and Mg(2+), Na(+) and Ca(2+), Mg(2+) and Ca(2+) during non-dust weather were not strong, only 0.065, 0.131 and 0.163, respectively. The low correlation coefficients indicated that these species were derived from different sources. The mass concentration of Cl(-) in the dust weather was significantly higher than that of floating dust and non dust, indicating that soil dust was the main source of Cl(-).