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Obiective Alzheimer’s disease (AD) is a degenerative disease of the central nervous system (CNS) caused by a variety of risk factors. There are various pathological changes, but apoptosis of the neurological meridian cells is one of the most important pathological bases. Hyperlipidemia is a high-risk factor for the development of AD, which can lead to increased levels of oxidized low-density lipoprotein (ox-LDL) in brain tissues. PCSK9 is a protease closely related to lipid metabolism, but studies have shown that it may be related to the development of AD. LRP1 is abundantly expressed in neuronal cells, and it is an important transporter for the clearance of Aβ. There is now a large amount of literature confirming that PCSK9 can induce the degradation of LRP1. PI3K/AKT is an important signaling pathway in vivo, which plays an important role in apoptosis, and there is now a large amount of literature confirming that LRP1 activates the PI3K/AKT pathway, which has an anti-apoptotic effect. So can PCSK9 affect the PI3K/AKT pathway through LRP1 and thus regulate neuronal apoptosis? This deserves further investigation.The aim of this study was to explore the role of PCSK9 in mediating ox-LDL pro-apoptotic neuronal cell death and its mechanism, and then further elaborate the mechanism of hyperlipidemia leading to neurodegenerative diseases such as AD. MethodsFirstly, PC12 cells were treated with different concentrations of ox-LDL (0, 25, 50, 75 and 100 mg/L) for 24 h. Oil red O staining was used to detect lipid accumulation in PC12 cells, Hoechst33258 staining and flow cytometry to detect apoptosis in PC12 cells, ELISA to detect the content of Aβ secreted by PC12, Western blot to detect expression of SREBP2, PCSK9 and LRP1. Then PC12 cells were treated with 75 mg/L ox-LDL for different times (0, 6, 12, 24, 48 h), and Western blot were performed to detect the expression of SREBP2, PCSK9 and LRP1. Finally, after transfecting 100 nmol/L PCSK9 siRNA into PC12 cells for 48 h, PC12 cells were treated with 75 mg/L ox-LDL for 24 h, Hoechst33258 staining and flow cytometry to detect apoptosis rate of PC12 cells, and Western blot to detect PCSK9, LRP1, PI3K, AKT, P-PI3K , P-AKT, NF-κB, Bcl-2, Bax, Caspase-9 and Caspase-3 expression, and ELISA detected Aβ content secreted by PC12 cells. Resultsox-LDL increased lipid accumulation and promoted apoptosis and Aβ secretion in PC12 cells, as well as increasing the expression of SREBP2 and PCSK9 and decreasing the expression of LRP1 in PC12 cells. pCsk9 siRNA could be inhibited through the PI3K/AKT pathway and the NF-κB-Bcl-2/Bax-Caspase-9/3 pathway to inhibit ox-LDL-induced apoptosis in PC12 cells while increasing Aβ secretion in PC12 cells. Conclusionox-LDL plays a bidirectional regulatory role in ox-LDL-induced apoptosis of PC12 cells by inducing an increase in PCSK9 expression and a decrease in LRP1 expression in PC12 cells, which in turn affects different signaling pathways downstream.
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Objective:To compare the prediction of Ischemic Stroke Predictive Risk Score (iScore), Preadmission Comorbidities, Level of Consciousness, Age, and Neurologic Deficit (PLAN), Acute Stroke Registry and Analysis of Lausanne (ASTRAL) and Totaled Health Risks in Vascular Events (THRIVE) for short- and long-term death for patients with acute ischemic stroke (AIS). Methods:From August, 2015 to June, 2018, 323 AIS patients in emergency ward were included, and followed up 30 days, three months and a year after including. Receiver operating characteristic (ROC) curve was used to analyze the predictive effects of iScore, PLAN, ASTRAL and THRIVE. Results:The all-cause mortality 30 days, three months and a year after including was 12.4% (40/323), 17.3% (56/323) and 25.7% (83/323), respectively. The area under curve (AUC) from more to less arranged as iScore, PLAN, ASTRAL and THRIVES. There was significant difference of AUC between iScore and THRIVE (Z > 1.990, P < 0.05), but not among the others (Z < 1.943, P > 0.05). Conclusion:iScore, PLAN, ASTRAL and THRIVE may predict short- and long-term death of AIS patients in the emergency well, and iScore is the best. However, the procedure of iScore is complex, it is recommended to use PLAN and ASTRAL for emergency.
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Objective:To explore the change of serum 25-hydroxyvitamin D [25(OH)D] and prediction for outcome of acute ischemic stroke in emergency. Methods:From October, 2017 to September, 2019, 224 patients with acute ischemic stroke in emergency and 240 healthy controls were detected serum 25(OH)D within 24 hours after enrollment. The patients were assessed with National Institute of Health Stroke Scale (NIHSS) and Nutritional Risk Screening 2002 (NRS2002), and measured biochemics within 24 hours after admission. They were assessed with modified Rankin Scale (mRS) 180 days after stroke, and divided into favourable group (mRS ≤ 2, n = 106) and unfavourable group (mRS > 2, n = 118). The factors related with the outcome were analyzed with Logistic regression, and the prediction of 25(OH)D for the outcome were analyzed with receiver operator characteristic (ROC) curve. Results:Serum 25(OH)D was less in the patients than in the controls (Z = 4.296, P < 0.001), and less in the unfavourable group than in the favourable group (Z = 5.876, P < 0.001). Serum 25(OH)D (OR = 0.925, P < 0.05) was related with the outcome even controlling the impacts of age, sex, nutritional risk, infarct volume, scores of NIHSS, etc. The area under curve for serum 25(OH)D predicting outcome was 0.795 (P < 0.001). The cut-off point of prediction was 13.17 ng/ml, with the Yoden index of 0.548, which yielded a sensitivity of 0.746 and a specificity of 0.802. Conclusion:Serum 25-hydroxyvitamin D may predict the outcome 180 days after acute ischemic stroke, which may help for risk stratification in emergency.
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Objective:To explore the characteristics of nosocomial infection in patients with spinal cord injury, and analyze the risk factors. Methods:From January, 2015 to June, 2017, 526 patients with spinal cord injury in our hospital were reviewed. The distribution of pathogens and the characteristics of drug resistance of strains were summarized, and the risk factors of nosocomial infection were analyzed. Results:There were 159 person-times with nosocomial infection, and most of the infections were found in urinary tract (60.4%) and lower in respiratory tract (28.9%). The main pathogenic germs were Escherichia coli (39.0%), Pseudomonas aeruginosa (15.7%), Klebsiella pneumoniae (11.3%) and Proteus mirabilis (9.4%). The main pathogens were resistant to second or third generation of cephalosporins and quinolones moderately or severely, but sensitive to compound preparations containing beta-lactamase inhibitors, carbapenems and aminoglycosides. The risk factors for the nosocomial infections in the spinal cord injury patients included the hospitalization time, severity of spinal cord injury, invasive operation history, nutritional risk and use of antibiotics (P < 0.05). Conclusion:Most of the nosocomial infections in patients with spinal cord injury are in urinary tract and respiratory tract. Gram-negative bacilli are the main pathogenic bacteria, which often show multiple drug resistance. It is necessary to take targeted interventions according to the risk factors of nosocomial infections in order to improve the quality of life of patients.
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@#Objective To compare the performance of Prestroke Independence, Sex, Age, National Institutes of Health Stroke Scale (ISAN) score, Age, Atrial fibrillation, Dysphagia, Sex, Stroke Severity (A2DS2) score, acute ischemic stroke-as-sociated pneumonia score (AIS-APS), and Preventive ANtibacterial THERapy in Acute Ischemic Stroke (PAN-THERIS) score in predicting the risk of stroke-associated pneumonia (SAP). Methods The baseline characteristics and laboratory data of 338 patients with ischemic stroke in emergency ward from April, 2014 to December, 2017 were retrospectively analyzed. Patients were allocated into SAP group (n=125) and non-SAP group (n=213). Receiver operating characteristic curve (ROC) was used to evaluate the predictive effect of four different scoring systems for ischemic SAP. Results Totally, 125 (37.0%) patients developed SAP. There were significant differences in age, complications (atrial fi-brillation, coronary heart disease and history of stroke), Glasgow Coma Scale (GCS) score, National Institute of Health Stroke Scale (NIHSS) score, ISAN score, A2DS2 score, AIS-APS score and PANTHERIS score between two groups (P<0.05). The A value of PANTHERIS score was 0.818, which was the lowest among four scoring systems (P<0.05). No significant difference was found in the A value between A2DS2 score and ISAN score (P>0.05). Conclusion ISAN, A2DS2 and AIS-APS scoring systems all present good discrimination and calibration in predicting the risk of ischemic SAP. The AIS-APS score calculation is relatively complex, so it is suggested that ISAN and A2DS2 scoring systems be used in emergency.
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To test the hypothesis that concentration polarization of atherogenic lipids may occur in the arterial system and play an important role in localization of atherosclerosis, we simulated and measured in vitro the luminal surface concentration of low density lipoprotein (LDL) in local stenosis at the distal end of carotid artery by number simulation and laser scanning confocal microscopy, then we designed carotid stenosis model to test the role of LDL concentration polarization in atherogenesis. The in vitro experiment showed that the luminal surface LDL concentration was higher than the bulk concentration as predicted by the concentration polarization theory. The relative luminal surface LDL concentration changed with the flow velocity and ratio of stenosis. The wall concentration of LDL was highest in the round tube with 40% stenosis at the same velocity, while the wall concentration of LDL was higher when Re was 250 than Re was 500 at the same extent of narrowness. The animal experiment also revealed that general atherogenic plaques obviously occurred at the distal end of local stenosis where concentration polarized. The results strongly support our hypothesis that concentration polarization of lipoproteins occurs in local stenosis at the distal end of carotid artery, and this in turn promotes the localization of atherosclerosis which develops in the arterial system.
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Animals , Atherosclerosis , Carotid Stenosis , Disease Models, Animal , Lipoproteins, LDL , MetabolismABSTRACT
<p><b>AIM</b>To study the expressions of scavenger receptor class B type I(SR-BI) and peroxisome proliferator-activated receptor gamma (PPARgamma) in atherosclerotic mini swine and provide a new mechanism for investigating the pathogenesis of atherosclerosis.</p><p><b>METHODS</b>Chinese mini swine were fed by a normal control diet or a high fat/high cholesterol diet for 12 months after common carotid artery injury induced by balloon denudation. Plasma total cholesterol(TC), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) were determined by commercially enzymatic methods every two months. The sections, which were taken from liver and abdominal aorta, were stained with hematoxylin eosin. The expressions of SR-BI and PPARgamma mRNA and protein in liver and aorta tissue were detected by reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry respectively.</p><p><b>RESULTS</b>At the end of 12 months, plasma TC, HDL-C and TG in HFHC mini swine were increased. There were fatty liver and atherosclerotic plaque in mini swine live and aorta respectively. The expression of SR-BI was upregulated in HFHC mini swine liver and aorta tissue.</p><p><b>CONCLUSION</b>HFHC may induce atherosclerosis and the expression of SR-BI and PPARgamma. Upregulating SR-BI expression may inhibit atherosclerosis. Increasing SR-BI expression in liver and aorta may accelerate SR-BI-mediated reverse cholesterol transport and develop a new anti-atherogenic strategy.</p>