44 research outputs found

    Cuando Cuba entró en París : retombées barthesianas en la crítica literaria de Severo Sarduy

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    En el presente artículo se exploran los usos barthesianos de la crítica literaria de Severo Sarduy. En primer lugar, analizamos de qué manera la lectura estructuralista-telquelista realizada por Sarduy sobre las obras de Góngora y Lezama Lima le permitió elaborar el concepto de neobarroco como rasgo identitario de la cultura cubana. En segundo lugar, vemos cómo a través de la práctica del "habla indirecta" barthesiana Sarduy acaba constituyendo una crítica literaria en la que Cuba se afirma y se cuestiona a la vez.En el present article s'exploren els usos barthesianos de la crítica literària de Sever Sarduy. En primer lloc, analitzem de quina manera la lectura estructuralista-telquelista realitzada per Sarduy sobre les obres de Góngora i Lezama Lima li va permetre elaborar el concepte de neobarroc com a tret identitari de la cultura cubana. En segon lloc, veiem com a través de la pràctica del "parla indirecta" barthesiana Sarduy acaba constituint una crítica literària en què Cuba s'afirma i es qüestiona alhora.This article explores the uses of Roland Barthes in Severo Sarduy's literary criticism. First, we analyse how the structuralist-telquelist reading operated by Sarduy on the works of Luis de Góngora and José Lezama Lima allowed him to develop the concept of neo-baroque as an identifying feature of Cuban culture. Secondly, we explain how Sarduy constructs an affirming but questioning literary critique of Cuba through the practice of the 'indirect language' of Barthes

    Valepotriates From the Roots and Rhizomes of Valeriana jatamansi Jones as Novel N-Type Calcium Channel Antagonists

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    The roots and rhizomes of Valeriana jatamansi have long been used as folk medicine in Asia and usually named as “Zhizhuxiang” in Chinese for the treatment of abdominal distention and pain. However, its active ingredients and molecular targets for treatment of abdominal pain remain unrevealed. Inhibitors of Cav2.2 N-type voltage-gated calcium channels (VGCCs) are actively sought after for their potential in treating pain, especially chronic pain. As far as we know, the method used for seeking analgesic active ingredient from plant material has rarely been reported. The analgesic potentials of the EtOH extract (0.01 mg/ml) of the roots and rhizomes of V. jatamansi and its EtOAc, n-BuOH and H2O soluble parts (0.01 mg/ml, respectively) were tested herein on Cav2.2, using whole-oocyte recordings in vitro by tow-electrode voltage clamp. The results indicated that the EtOAc-soluble part exhibited the most potent inhibition of Cav2.2 peak current (20 mv). The EtOAc-soluble part was then subjected to silica gel column chromatography (CC) and giving 9 fractions. Phytochemical studies were carried out by repeated CC and extensive spectroscopic analyses after the fraction (0.01 mg/ml) was identified to be active and got seventeen compounds (1–17). All isolates were then sent for further bioactive verification (1 and 3 at concentration of 10 μM, others at 30 μM). In addition, the selectivity of the active compounds 1 and 3 were tested on various ion channels including Cav1.2, Cav2.1 and Cav3.1 VGCCs and Kv1.2, Kv2.1, Kv3.1 and BK potassium channels. The results indicated that compound 1 and 3 (an abundant compound) inhibited Cav2.2 with an EC50 of 3.3 and 4.8 μM, respectively, and had weaker or no effect on Cav1.2, Cav2.1 and Cav3.1 VGCCs and Kv1.2, Kv2.1, Kv3.1 and BK potassium channels. Compounds 1 and 3 appear to act as allosteric modulators rather than pore blockers of Cav2.2, which may play crucial role in attenuating nociception. The results of present research indicated that the ethnopharmacological utilization of V. jatamansi for relieving the abdominal distention and pain may mediate through Cav2.2 channel. Our work is the first demonstration of inhibition of Cav2.2 by iridoids, which may provide a fresh source for finding new analgesics

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Recent Advances in Synergistic Antitumor Effects Exploited from the Inhibition of Ataxia Telangiectasia and RAD3-Related Protein Kinase (ATR)

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    As one of the key phosphatidylinositol 3-kinase-related kinases (PIKKs) family members, ataxia telangiectasia and RAD3-related protein kinase (ATR) is crucial in maintaining mammalian cell genomic integrity in DNA damage response (DDR) and repair pathways. Dysregulation of ATR has been found across different cancer types. In recent years, the inhibition of ATR has been proven to be effective in cancer therapy in preclinical and clinical studies. Importantly, tumor-specific alterations such as ATM loss and Cyclin E1 (CCNE1) amplification are more sensitive to ATR inhibition and are being exploited in synthetic lethality (SL) strategy. Besides SL, synergistic anticancer effects involving ATRi have been reported in an increasing number in recent years. This review focuses on the recent advances in different forms of synergistic antitumor effects, summarizes the pharmacological benefits and ongoing clinical trials behind the biological mechanism, and provides perspectives for future challenges and opportunities. The hope is to draw awareness to the community that targeting ATR should have great potential in developing effective anticancer medicines

    Lancolides, Antiplatelet Aggregation Nortriterpenoids with Tricyclo[6.3.0.0<sup>2,11</sup>]undecane-Bridged System from <i>Schisandra lancifolia</i>

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    A new class of highly oxygenated <i>Schisandra</i> nortriterpenoids, lancolides A–D (<b>1</b>–<b>4</b>), from <i>Schisandra lancifolia</i>, represents the first example of natural products that possess a tricyclo[6.3.0.0<sup>2,11</sup>]undecane-bridged system. Their structures were elucidated by NMR spectra, X-ray diffraction, and quantum chemical calculations. Lancolides A (<b>1</b>) and D (<b>4</b>) had specific antiplatelet aggregation induced by platelet-activating factor (PAF)

    Design, Synthesis, and Structure–Activity Relationship of Novel Pyridazinone-Based PARP7/HDACs Dual Inhibitors for Elucidating the Relationship between Antitumor Immunity and HDACs Inhibition

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    Histone deacetylases (HDACs) inhibitors such as vorinostat (SAHA) has been used to treat hematologic malignancies (rather than solid tumors) and have been found to suppress the JAK/STAT, a critical signal pathway for antitumor immunity, while PARP7 inhibitor RBN-2397 could activate the type I interferons (IFN-I) pathway, facilitating downstream effects such as STAT1 phosphorylation and immune activation. To elucidate whether simultaneous inhibition of these two targets could interfere with these two signal pathways, a series of pyridazinone-based PARP7/HDACs dual inhibitors have been designed, synthesized, and evaluated in vitro and in vivo experiments. Compound 9l was identified as a potent and balanced dual inhibitor for the first time, exhibiting excellent antitumor capabilities both in vitro and in vivo. This suggests that 9l can be used as a valuable tool molecule for investigating the relationship between anticancer immunity and HDAC inhibition
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