551 research outputs found

    N-Acetylcysteine Amide Decreases Oxidative Stress but Not Cell Death Induced by Doxorubicin in H9c2 Cardiomyocytes

    Get PDF
    Background: While doxorubicin (DOX) is widely used in cancer chemotherapy, long-term severe cardiotoxicity limits its use. This is the first report of the chemoprotective efficacy of a relatively new thiol antioxidant, N-acetylcysteine amide (NACA), on DOX-induced cell death in cardiomyocytes. We hypothesized that NACA would protect H9c2 cardiomyocytes from DOX-induced toxicity by reducing oxidative stress. Accordingly, we determined the ability of NACA to mitigate the cytotoxicity of DOX in H9c2 cells and correlated these effects with the production of indicators of oxidative stress. Results: DOX at 5 μM induced cardiotoxicity while 1) increasing the generation of reactive oxygen species (ROS), 2) decreasing levels and activities of antioxidants and antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase) and 3) increasing lipid peroxidation. NACA at 750 μM substantially reduced the levels of ROS and lipid peroxidation, as well as increased both GSH level and GSH/GSSG ratio. However, treating H9c2 cells with NACA did little to protect H9c2 cells from DOX-induced cell death. Conclusion: Although NACA effectively reduced oxidative stress in DOX-treated H9c2 cells, it had minimal effects on DOX-induced cell death. NACA prevented oxidative stress by elevation of GSH and CYS, reduction of ROS and lipid peroxidation, and restoration of antioxidant enzyme activities. Further studies to identify oxidative stress-independent pathways that lead to DOX-induced cell death in H9c2 are warranted

    The Arabidopsis Malectin-Like/LRR-RLK IOS1 is Critical for BAK1-Dependent and BAK1-Independent Pattern-Triggered Immunity

    Get PDF
    Plasma membrane-localized pattern recognition receptors (PRRs) such as FLAGELLIN SENSING2 (FLS2), EF-TU RECEPTOR (EFR) and CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1) recognize microbe-associated molecular patterns (MAMPs) to activate pattern-triggered immunity (PTI). A reverse genetics approach on genes responsive to the priming agent beta-aminobutyric acid (BABA) revealed IMPAIRED OOMYCETE SUSCEPTIBILITY1 (IOS1) as a critical PTI player. Arabidopsis thaliana ios1 mutants were hyper-susceptible to Pseudomonas syringae bacteria. Accordingly, ios1 mutants showed defective PTI responses, notably delayed up-regulation of the PTI-marker gene FLG22-INDUCED RECEPTOR-LIKE KINASE1 (FRK1), reduced callose deposition and mitogen-activated protein kinase activation upon MAMP treatment. Moreover, Arabidopsis lines over-expressing IOS1 were more resistant to bacteria and showed a primed PTI response. In vitro pull-down, bimolecular fluorescence complementation, co-immunoprecipitation, and mass spectrometry analyses supported the existence of complexes between the membrane-localized IOS1 and BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1)-dependent PRRs FLS2 and EFR, as well as with the BAK1-independent PRR CERK1. IOS1 also associated with BAK1 in a ligand-independent manner, and positively regulated FLS2-BAK1 complex formation upon MAMP treatment. In addition, IOS1 was critical for chitin-mediated PTI. Finally, ios1 mutants were defective in BABA-induced resistance and priming. This work reveals IOS1 as a novel regulatory protein of FLS2-, EFR- and CERK1-mediated signaling pathways that primes PTI activation

    Low-Level Laser-Accelerated Peripheral Nerve Regeneration within a Reinforced Nerve Conduit across a Large Gap of the Transected Sciatic Nerve in Rats

    Get PDF
    This study proposed a novel combination of neural regeneration techniques for the repair of damaged peripheral nerves. A biodegradable nerve conduit containing genipin-cross-linked gelatin was annexed using beta-tricalcium phosphate (TCP) ceramic particles (genipin-gelatin-TCP, GGT) to bridge the transection of a 15 mm sciatic nerve in rats. Two trigger points were irradiated transcutaneously using 660 nm of gallium-aluminum arsenide phosphide (GaAlAsP) via laser diodes for 2 min daily over 10 consecutive days. Walking track analysis showed a significant improvement in sciatic functional index (SFI) (P<0.01) and pronounced improvement in the toe spreading ability of rats undergoing laser stimulation. Electrophysiological measurements (peak amplitude and area) illustrated by compound muscle action potential (CMAP) curves demonstrated that laser stimulation significantly improved nerve function and reduced muscular atrophy. Histomorphometric assessments revealed that laser stimulation accelerated nerve regeneration over a larger area of neural tissue, resulting in axons of greater diameter and myelin sheaths of greater thickness than that observed in rats treated with nerve conduits alone. Motor function, electrophysiological reactions, muscular reinnervation, and histomorphometric assessments all demonstrate that the proposed therapy accelerated the repair of transected peripheral nerves bridged using a GGT nerve conduit

    Extensive Reading with Guidance

    Get PDF
    A language learning mode called “word-focused extensive reading” has been proposed to facilitate word-usage learning. The user inputs a word in the computer program designed and implemented for reading to find its usage in the context of a sentence. The computer program then searches for the knowledge base for the word and provides guidance to show a summary of the salient features of word collocation. Sentences with the word in question are displayed one at a time. For each sentence the relevant collocating words are highlighted. In this way the reader sees the word collocation so as to recognize the salient features of the word and thus incrementally acquires the knowledge of word usage. The program works with large Chinese and English collections of texts. For Chinese the knowledge of word collocation was built on the basis of the Balanced Corpus of Academia Sinica. The English collocation features were collected from the British National Corpus. The program can also be useful for learning to differentiate near-synonyms

    The 3D-tomography of the nano-clusters formed by Fe-coating and annealing of diamond films for enhancing their surface electron field emitters

    Get PDF
    [[abstract]]The Fe-coating and H2-annealed processes markedly increased the conductivity and enhanced the surface electron field emission (s-EFE) properties for the diamondfilms. The enhancement on the s-EFE properties for the diamondfilms is presumably owing to the formation of nano-graphite clusters on the surface of the films via the Fe-to-diamond interaction. However, the extent of enhancement varied with the granular structure of the diamondfilms. For the microcrystalline (MCD)films, the s-EFE process can be turned on at (E0)MCD = 1.9 V/μm, achieving a large s-EFE current density of (Je)MCD = 315 μA/cm2 at an applied field of 8.8 V/μm. These s-EFE properties are markedly better than those for Fe-coated/annealed ultrananocrystalline diamond(UNCD)films with (E0)UNCD = 2.0 V/μm and (Je)UNCD = 120 μA/cm2. The transmission electron microscopy showed that the nano-graphite clusters formed an interconnected network for MCDfilms that facilitated the electron transport more markedly, as compared with the isolated nano-graphitic clusters formed at the surface of the UNCDfilms. Therefore, the Fe-coating/annealing processes improved the s-EFE properties for the MCDfilms more markedly than that for the UNCDfilms. The understanding on the distribution of the nano-clusters is of critical importance in elucidating the authentic factor that influences the s-EFE properties of the diamondfilms. Such an understanding is possible only through the 3D-tomographic investigations.[[journaltype]]國外[[ispeerreviewed]]Y[[booktype]]電子版[[countrycodes]]US

    Developing the Effective Method of Spectral Harmonic Energy Ratio to Analyze the Arterial Pulse Spectrum

    Get PDF
    In this article, we analyze the arterial pulse in the spectral domain. A parameter, the spectral harmonic energy ratio (SHER), is developed to assess the features of the overly decreased spectral energy in the fourth to sixth harmonic for palpitation patients. Compared with normal subjects, the statistical results reveal that the mean value of SHER in the patient group (57.7 ± 27.9) is significantly higher than that of the normal group (39.7 ± 20.9) (P-value = .0066 < .01). This means that the total energy in the fourth to sixth harmonic of palpitation patients is significantly less than it is in normal subjects. In other words, the spectral distribution of the arterial pulse gradually decreases for normal subjects while it decreases abruptly in higher-order harmonics (the fourth, fifth and sixth harmonics) for palpitation patients. Hence, SHER is an effective method to distinguish the two groups in the spectral domain. Also, we can thus know that a “gradual decrease” might mean a “balanced” state, whereas an “abrupt decrease” might mean an “unbalanced” state in blood circulation and pulse diagnosis. By SHER, we can determine the ratio of energy distribution in different harmonic bands, and this method gives us a novel viewpoint from which to comprehend and quantify the spectral harmonic distribution of circulation information conveyed by the arterial pulse. These concepts can be further applied to improve the clinical diagnosis not only in Western medicine but also in traditional Chinese medicine (TCM)

    Epidemic Pleurodynia Caused by Coxsackievirus B3 at a Medical Center in Northern Taiwan

    Get PDF
    Epidemic pleurodynia is seldom reported in Southeast Asia and there has been no report from Taiwan. We conducted a retrospective chart review of children = 18 years of age in the National Taiwan University Hospital from January 1 to December 31, 2005. Epidemic pleurodynia was defined as an acute illness characterized by sharp localized pain over the chest or upper abdomen. Patients with known heart diseases or pulmonary consolidations were excluded. In total, 28 patients met the case definition of epidemic pleurodynia. Coxsackievirus B3 (CB3) was isolated in 15 (60%) of the 25 throat swab specimens. Four (14%) of the 28 patients presented chest wall tenderness and only one (6%) of the 18 patients tested had an elevated creatinine kinase level. Twenty-one (75%) of the 28 patients described pleuritic chest pains and 10 (45%) of the 22 chest radiographies exhibited pulmonary infiltrates or pleural effusions. Six patients were observed with tonsillar exudates and one was confirmed to have a CB3 urinary tract infection. The clinical features and radiological findings suggest that CB3-associated epidemic pleurodynia might be a disease of the pleura and occasionally spreads to nearby tissues, resulting in chest wall myositis, pulmonary infiltrates and myopericarditis

    Impacts of increasing typhoons on the structure and function of a subtropical forest: reflections of a changing climate

    Get PDF
    Due to their destructive and sporadic nature, it is often difficult to evaluate and predict the effects of typhoon on forest ecosystem patterns and processes. We used a 21-yr record of litterfall rates to explore the influence of typhoon frequency and intensity, along with other meteorological variables, on ecosystem dynamics in a subtropical rainforest. Over the past half century there has been an increasing frequency of strong typhoons (category 3; >49.6 m s-1; increase of 1.5 typhoons/decade) impacting the Fushan Experimental Forest, Taiwan. At Fushan strong typhoons drive total litterfall mass with an average of 1100 kg ha-1 litterfall typhoon-1. While mean typhoon season litterfall has been observed to vary by an order of magnitude, mean litterfall rates associated with annual leaf senescence vary by <20%. In response to increasing typhoon frequency, total annual litter mass increased gradually over the 21-year record following three major typhoons in 1994. Monthly maximum wind speed was predictive of monthly litterfall, yet the influence of precipitation and temperature was only evident in non-typhoon affected months. The response of this subtropical forest to strong typhoons suggests that increasing typhoon frequency has already shifted ecosystem structure and function (declining carbon sequestration and forest stature)

    Clinical Outcome of Mycobacterium abscessus Infection and Antimicrobial Susceptibility Testing

    Get PDF
    Background/PurposeMycobacterium abscessus is the most resistant and rapidly growing mycobacterium and causes a wide range of clinical infectious diseases. The relationship between antimicrobial susceptibility and clinical outcome needs to be further evaluated.MethodsForty M. abscessus isolates were obtained from clinical specimens of 40 patients at the Taichung Veterans General Hospital from January 2006 to December 2008. Antimicrobial susceptibility testing was performed using the broth microdilution method according to the recommendations of the National Committee for Clinical Laboratory Standards. The clinical manifestations and outcomes were reviewed from medical records.ResultsTwenty-two patients were diagnosed with M. abscessus infection. Cough (86.3%), hemoptysis (31.8%) and fever (18.1%) were the most common symptoms. The radiographic findings included reticulonodular opacities (50.0%), consolidation (31.8%) and cavitary lesions (18.1%). The 40 isolates were susceptible to amikacin (95.0%), cefoxitin (32.5%), ciprofloxacin (10.0%), clarithromycin (92.5%), doxycycline (7.5%), imipenem (12.5%), moxifloxacin (22.5%), sulfamethoxazole (7.5%) and tigecycline (100%). The rate of treatment failure was 27.3% at the end of the 12th month after the start of treatment, although these patients were treated with a combination of clarithromycin and other antimicrobial agents.ConclusionM. abscessus is naturally susceptible to clarithromycin and amikacin, variably susceptible to cefoxitin and imipenem, and resistant to most other antimicrobial drugs. Combination therapy with clarithromycin, amikacin and other active antimicrobial agents may lead to clinical improvement; however, the rate of treatment failure is still high
    corecore