333 research outputs found

    Paeonol Protects Memory after Ischemic Stroke via Inhibiting β-Secretase and Apoptosis

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    Poststroke dementia commonly occurs following stroke, with its pathogenesis related to β-amyloid production and apoptosis. The present study evaluate the effects of paeonol, one of the phenolic phytochemicals isolated from the Chinese herb Paeonia suffruticosa Andrews (MC), on protection from memory loss after ischemic stroke in the subacute stage. Rats were subjected to transient middle cerebral artery occlusion (tMCAo) with 10 min of ischemia. The data revealed that paeonol recovered the step-through latency in the retrieval test seven days after tMCAo, but did not improve the neurological deficit induced by tMCAo. Levels of Amyloid precursor protein (APP)- and beta-site APP cleaving enzyme (BACE; β-secretase)-immunoreactive cells, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells decreased in the paeonol-administered group. Western blotting revealed decreased levels of Bax protein in mitochondria and apoptosis-inducing factor (AIF) in cytosol following paeonol treatment. In conclusion, we speculate that paeonol protected memory after ischemic stroke via reducing APP, BACE, and apoptosis. Supression the level of Bax and blocking the release of AIF into cytosol might participate in the anti-apoptosis provided by paeonol

    A Grammar-Based Semantic Similarity Algorithm for Natural Language Sentences

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    This paper presents a grammar and semantic corpus based similarity algorithm for natural language sentences. Natural language, in opposition to "artificial language", such as computer programming languages, is the language used by the general public for daily communication. Traditional information retrieval approaches, such as vector models, LSA, HAL, or even the ontologybased approaches that extend to include concept similarity comparison instead of cooccurrence terms/words, may not always determine the perfect matching while there is no obvious relation or concept overlap between two natural language sentences. This paper proposes a sentence similarity algorithm that takes advantage of corpus-based ontology and grammatical rules to overcome the addressed problems. Experiments on two famous benchmarks demonstrate that the proposed algorithm has a significant performance improvement in sentences/short-texts with arbitrary syntax and structure

    Neuroprotective Effect of Paeonol Mediates Anti-Inflammation via Suppressing Toll-Like Receptor 2 and Toll-Like Receptor 4 Signaling Pathways in Cerebral Ischemia-Reperfusion Injured Rats

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    Paeonol is a phenolic compound derived from Paeonia suffruticosa Andrews (MC) and P. lactiflora Pall (PL). Paeonol can reduce cerebral infarction volume and improve neurological deficits through antioxidative and anti-inflammatory effects. However, the anti-inflammatory pathway of paeonol remains unclear. This study investigated the relationship between anti-inflammatory responses of paeonol and signaling pathways of TLR2 and TLR4 in cerebral infarct. We established the cerebral ischemia-reperfusion model in Sprague Dawley rats by occluding right middle cerebral artery for 60 min, followed by reperfusion for 24 h. The neurological deficit score was examined, and the brains of the rats were removed for cerebral infarction volume and immunohistochemistry (IHC) analysis. The infarction volume and neurological deficits were lower in the paeonol group (pretreatment with paeonol; 20 mg/kg i.p.) than in the control group (without paeonol treatment). The IHC analysis revealed that the number of TLR2-, TLR4-, Iba1-, NF-κB- (P50-), and IL-1β-immunoreactive cells and TUNEL-positive cells was significantly lower in the paeonol group; however, the number of TNF-α-immunoreactive cells did not differ between the paeonol and control groups. The paeonol reveals some neuroprotective effects in the model of ischemia, which could be due to the reduction of many proinflammatory receptors/mediators, although the mechanisms are not clear

    General Versus Spinal Anesthesia: Which is a Risk Factor for Octogenarian Hip Fracture Repair Patients?

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    SummaryBackgroundMost studies have shown no difference between the two types of anesthesia administered to hip fracture patients. This study compared postoperative morbidity and mortality in octogenarian patients who received either general or spinal anesthesia for hip fracture repair.MethodsWe retrospectively analyzed the hospital records of 335 octogenarian patients who received hip fracture repair in our teaching hospital between 2002 and 2006. A total of 167 and 168 patients received general and spinal anesthesia, respectively. Morbidity, mortality, and intraoperative and preoperative variables were compared between groups.ResultsThere were no mortality differences between spinal and general anesthesia groups. However, the overall morbidity was greater in the general anesthesia group than in the spinal anesthesia group (21/167 [12.6%] vs. 9/168 [5.4%]; p = 0.02). Respiratory system-related morbidity was also higher in the general anesthesia group than in the spinal anesthesia group (11/167 [6.6%] vs. 3/168 [1.8%]; p = 0.03). Logistic regression analysis revealed two significant predictors of postoperative morbidity: anesthesia type (general; odds ratio, 2.39) and preexisting respiratory diseases (odds ratio, 3.38).ConclusionGeneral anesthesia increased the risk of postoperative morbidity in octogenarian patients after hip fracture repair, and patients with preexisting respiratory diseases were especially vulnerable. Spinal anesthesia is strongly recommended in such individuals

    Nonlinear and nonreciprocal transport effects in untwinned thin films of ferromagnetic Weyl metal SrRuO3_3

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    The identification of distinct charge transport features, deriving from nontrivial bulk band and surface states, has been a challenging subject in the field of topological systems. In topological Dirac and Weyl semimetals, nontrivial conical bands with Fermi-arc surfaces states give rise to negative longitudinal magnetoresistance due to chiral anomaly effect and unusual thickness dependent quantum oscillation from Weyl-orbit effect, which were demonstrated recently in experiments. In this work, we report the experimental observations of large nonlinear and nonreciprocal transport effects for both longitudinal and transverse channels in an untwinned Weyl metal of SrRuO3_3 thin film grown on a SrTiO3_{3} substrate. From rigorous measurements with bias current applied along various directions with respect to the crystalline principal axes, the magnitude of nonlinear Hall signals from the transverse channel exhibits a simple sinα\alpha dependent at low temperatures, where α\alpha is the angle between bias current direction and orthorhombic [001]o_{\rm o}, reaching a maximum when current is along orthorhombic [1-10]o_{\rm o}. On the contrary, the magnitude of nonlinear and nonreciprocal signals in the longitudinal channel attains a maximum for bias current along [001]o_{\rm o}, and it vanishes for bias current along [1-10]o_{\rm o}. The observed α\alpha-dependent nonlinear and nonreciprocal signals in longitudinal and transverse channels reveal a magnetic Weyl phase with an effective Berry curvature dipole along [1-10]o_{\rm o} from surface states, accompanied by 1D chiral edge modes along [001]o_{\rm o}.Comment: 24 pages, 6 figure

    Impact of Irradiation on the Pharmacokinetics and Biotransformation of Tamoxifen.

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    BACKGROUND: The optimal procedure for combining radiotherapy (RT) with tamoxifen treatment is controversial as RT may alter the pharmacokinetics and biotransformation of tamoxifen. The present study investigated this potential interaction by assessing the pharmacokinetics of tamoxifen during concurrent and sequential RT. METHOD: Plasma tamoxifen concentration was measured in rats with or without RT 2.0 Gy (RT2.0Gy) or 0.5 Gy (RT0.5Gy) with ultra-high-performance liquid chromatography-tandem mass spectrometry after tamoxifen administration (10 mg/kg, p.o., n = 6). Tamoxifen was either administered 1 h after RT (concurrent condition) or 24 h after RT (sequential condition). RESULTS: Pharmacokinetic data analysis demonstrated that the area under the curve (AUC) and half-life of tamoxifen were 2,004 ± 241 h ng/ml and 6.23 ± 1.21 h, respectively, after tamoxifen administration (10 mg/kg, p.o.). The respective conversion rate of 4-hydroxytamoxifen, N-desmethytamoxifen, and endoxifen for tamoxifen metabolism was 20%, 16%, and 5%. The AUC value of tamoxifen in the RT0.5Gy group was 1.5- to 1.7-fold higher than in the sham and RT2.0Gy groups. The relative bioavailability of tamoxifen at concurrent RT0.5Gy and RT2.0Gy groups ranged from 127% to 202% and from 71% to 152%, respectively. The magnitude of endoxifen, which converted from 4-hydroxytamoxifen and N-desmethyltamoxifen, increased 3- to 5-fold in the concurrent RT groups. By contrast, the AUC of tamoxifen decreased by roughly 24% in the sequential RT2.0Gy group. The conversion ratio of endoxifen was four times higher than that in the sequential RT2.0Gy group compared with rats not exposed to RT. CONCLUSION: The current study provides advanced pharmacokinetic data to confirm the interaction between RT and hormone therapy. Our findings indicate that RT facilitates the metabolism of tamoxifen to active metabolites and thus imply that combination RT-tamoxifen has potential benefits for the treatment of hormone-dependent breast cancer

    Induction chemotherapy with dose-modified docetaxel, cisplatin, and 5-fluorouracil in Asian patients with borderline resectable or unresectable head and neck cancer

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    BackgroundSignificant ethnic differences in susceptibility to the effects of chemotherapy exist. Here, we retrospectively analyzed the safety and efficacy of induction chemotherapy (ICT) with dose-modified docetaxel, cisplatin, and 5-fluorouracil (TPF) in Asian patients with borderline resectable or unresectable head and neck squamous cell carcinoma (HNSCC).MethodsBased on the incidence of adverse events that occurred during daily practice, TPF90 (90% of the original TPF dosage; docetaxel 67.5 mg/m2 on Day 1, cisplatin 67.5 mg/m2 on Day 1, and 5-fluorouracil 675 mg/m2 on Days 1–5) was used for HNSCC patients who were scheduled to receive ICT TPF.ResultsBetween March 2011 and May 2014, 52 consecutive patients with borderline resectable or unresectable HNSCC were treated with ICT TPF90 followed by concurrent chemoradiotherapy. Forty-four patients (84.6%) received at least three cycles of ICT TPF90. The most commonly observed Grade 3–4 adverse events included neutropenia (35%), anemia (25%), stomatitis (35%), diarrhea (16%), and infections (13.5%). In an intention-to-treat analysis, the complete and partial response rates after ICT TPF90 were 13.5% and 59.6%, respectively. The complete and partial response rates following radiotherapy and salvage surgery were 42.3% and 25.0%, respectively. The estimated 3-year overall survival and progression-free survival rates were 41% [95% confidence interval (CI): 25–56%] and 23% (95% CI: 10–39%), respectively. The observed median overall survival and progression-free survival were 21.0 months (95% CI: 13.3–28.7 months) and 16.0 months (95% CI: 10.7–21.3 months), respectively.ConclusionTPF90 is a suitable option for Asian patients with borderline resectable or unresectable HNSCC who are scheduled for ICT
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