Favorable neuroprotective effect of intra-arterial application of edaravone dexborneol in ischemic stroke rats.

OBJECTIVE: The aim of this study was to investigate the neuroprotective effects of intra-arterial administration of edaravone dexborneol in rats with acute ischemic stroke and determine the optimal dose. MATERIALS AND METHODS: Firstly, 120 male Sprague-Dawley rats (265-300 g) were selected to establish ischemic stroke models and were randomly divided into groups of sham-operation (Sham group), cerebral ischemia-reperfusion (IS group), permanent focal ischemia (PI group) and treatment (2MG group: 2 mg/kg, 4MG group: 4 mg/kg, 6MG group: 6 mg/kg) groups. There are 20 rats in each group, and ten rats in each group were randomly selected for Longa score and 2,3,5-triphenyl tetrazolium chloride staining to observe the changes in neurological function and the proportion of cerebral infarct volume in each group. Secondly, the remaining ten rats in each group were scored for Longa and tested for free radicals (hydroxyl radical; peroxynitrite; nitric oxide) and pro-inflammatory cytokines (interleukin 6; interleukin-1ß; tumor necrosis factor-α). We monitored changes in the indicators in each group of rats. RESULTS: There were no significant differences among the enrolled Sprague-Dawley rats concerning age, sex, and feeding conditions. Edaravone dexborneol could significantly reduce the cerebral levels of hydroxyl radical, interleukin 6, interleukin-1ß, tumor necrosis factor-α, and their behavioral scores of acute ischemic stroke rats after a single dose in the carotid artery. The results suggested that 4 mg/kg might be an appropriate dose. CONCLUSIONS: A single intra-arterial administration of edaravone dexborneol can improve neurobehavioral function and alleviate cerebral injury in acute ischemic stroke rats through anti-inflammatory and free radical scavenging effects.

Clinical Experience in the Diagnosis and Treatment of Adult Acute Necrotizing Encephalopathy.

PURPOSE: We report two cases diagnosed as acute necrotizing encephalopathy (ANE) with acute onset and various clinical manifestations. METHODS: The patients' data were obtained from the medical records of the Binzhou Medical University Hospital in Binzhou, China. The clinical symptoms, laboratory examination, neuroimaging, treatment, and prognosis of the 2 patients were collected and analyzed. RESULTS: We report 2 adult ANE patients with acute onset. The first symptom was fever, followed by symptoms and signs of damage to the central nervous system. The patients were infected with herpes simplex virus and influenza virus, respectively. The main manifestation on brain magnetic resonance imaging was a mixed-signal of a "three-layer structure" in the bilateral thalamus. The first patient died. Based on the experience of the diagnosis and treatment of the first patient, combined with a review of the literature, the second patient was immediately treated with glucocorticoid pulse therapy combined with gamma globulin injection. This patient's condition was controlled, and the prognosis was good. CONCLUSIONS: This study describes the clinical symptoms, laboratory examination, neuroimaging evidence, and treatment experience of ANE in adults. We believe that the progress of the disease may be controlled, and the prognosis may be improved if glucocorticoid pulse therapy combined with gamma globulin injection is used as soon as possible.

Research on Keyword Extraction Algorithm in English Text Based on Cluster Analysis.

How to facilitate users to quickly and accurately search for the text information they need is a current research hotspot. Text clustering can improve the efficiency of information search and is an effective text retrieval method. Keyword extraction and cluster center point selection are key issues in text clustering research. Common keyword extraction algorithms can be divided into three categories: semantic-based algorithms, machine learning-based algorithms, and statistical model-based algorithms. There are three common methods for selecting cluster centers: randomly selecting the initial cluster center point, manually specifying the cluster center point, and selecting the cluster center point according to the similarity between the points to be clustered. The randomly selected initial cluster center points may contain "outliers," and the clustering results are locally optimal. Manually specifying the cluster center points will be very subjective because each person's understanding of the text set is different, and it is not suitable for the case of a large number of text sets. Selecting the cluster center points according to the similarity between the points to be clustered can make the selected cluster center points distributed in each class and be as close as possible to the class center points, but it takes a long time to calculate the cluster centers. Aiming at this problem, this paper proposes a keyword extraction algorithm based on cluster analysis. The results show that the algorithm does not rely on background knowledge bases, dictionaries, etc., and obtains statistical parameters and builds models through training. Experiments show that the keyword extraction algorithm has high accuracy and can quickly extract the subject content of an English translation.

[Effects of chronic intermittent hypoxia on atrial electrical remodeling in rats].

OBJECTIVE: The aim of this study was to investigate the effects of chronic intermittent hypoxia (CIH) on atrial electrical remodeling in Sprague-Dawley (SD) rats, which provide the explication for the mechanisms of CIH promoting atrial fibrillation (AF). METHODS: Eighty SD rats were randomly divided into 2 groups: control group and CIH group (n=40). CIH rats were subjected to CIH 8 h/d for 30 days. After the echocardiography and hemodynamics examination, cardiac electrophysiological experiments, histological experiments, and molecular biological experiments were executed. AF susceptibility was measured by isolated heart electrophysiological experiments. Masson's trichrome stain was used to assess the degree of atrial fibrosis. The protein expression levels of sodium voltage-gated channel alpha subunit 5 (SCN5A/Nav1.5), calcium voltage-gated channel subunit alpha1 C (CACNA1C/Cav1.2) and potassium voltage-gated channel subfamily D member 3 (KCND3/Kv4.3) were measured by Western blot. In whole-cell patch clamp experiments, current clamp mode was used to record AP, and APD90 and APD50 were analyzed and compared between the two groups. In voltage clamp mode, INa, ICa-L, Ito and their kinetic parameters were recorded and compared between the two groups. RESULTS: Compared to the control rats, atrial interstitial collagen deposition (P＜0.01) and AF inducibility (P＜0.05) were increased in CIH rats, whereas the expression levels of Nav1.5, Cav1.2 and Kv4.3 were decreased (P＜0.05). APD90 and APD50 in CIH rats' atrial myocytes were longer than those of control rats, and CIH rats showed decreased current density of INa, ICa-L(P＜0.01) and Ito(P＜0.01). CONCLUSION: CIH-induced changes in the protein expression levels of ion channel subunits, current intensity, APD, and AF susceptibility, which may be the mechanisms of CIH promoting AF.

Prognostic value of PD-L1 expression in patients with pancreatic cancer: A PRISMA-compliant meta-analysis.

BACKGROUND: Programmed cell death ligand 1 (PD-L1) expression was reported to be associated with poor prognosis in various solid tumors. However, the prognosis value of PD-L1 in pancreatic cancer remained inconclusive. We performed a meta-analysis to assess the clinical value of PD-L1 as a novel prognostic biomarker of pancreatic cancer. METHODS: PubMed, Embase, and Web of Science were searched up to October 2018. The HRs and 95% CIs for overall survival (OS) and cancer-specific survival (CSS) according to the expressional status of PD-L1 were pooled. The combined odd ratios (ORs) and 95% CIs were utilized to assess the association between PD-L1 and clinicopathological characteristics. RESULTS: A total of 9 studies with 993 patients were included. Elevated PD-L1 expression was related with poor OS (HR = 1.63, 95% CI = 1.34-1.98, P < .001) and CSS (HR = 1.86, 95% CI = 1.34-2.57, P < .001). Furthermore, high PD-L1 expression was also demonstrated to be associated with positive N stage (OR = 1.81, 95% CI = 1.21-2.71, P = .004), advanced T stage (OR = 1.86, 95% CI = 1.08-3.19, P = .025), and low differentiation (OR = 2.24, 95% CI = 1.16-4.33, P = .017). However, PD-L1 has nonsignificant correlation with M stage, gender, or age. CONCLUSION: This study suggests that PD-L1 is a potential prognostic biomarker and may be helpful to clinicians aiming to select the appropriate immunotherapy for pancreatic cancer.