624 research outputs found

    Identification of phenolic compounds from inflorescences of non-psychoactive Cannabis sativa L. by UHPLC-HRMS and in vitro assessment of the antiproliferative activity against colorectal cancer

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    Phenolic compounds from Cannabis sativa L. (Cannabaceae family), in particular cannflavins, are known to possess several biological properties. However, their antiproliferative activity, being of great interest from a medicinal chemistry point of view, has not been deeply investigated so far in the literature. In the light of this, the aim of this study was to obtain an enriched fraction of polyphenols (namely PEF) from inflorescences of a non-psychoactive C. sativa (hemp) variety and to evaluate its antiproliferative activity against cancer cells, capitalizing on a new and selective extraction method for hemp polyphenols, followed by preparative flash column chromatography. Untargeted metabolomics, using a new method based on ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS), was applied here for the first time to fully characterize PEF. Then, the main phenolic compounds were quantified by HPLC-UV. The antiproliferative activity of PEF and of the isolated compounds was assessed in vitro for the first time against Caco-2 and SW480 human colon adenocarcinoma cell lines providing promising IC50 values, in comparison with the reference drug used in therapy for this cancer type. Based on these results, PEF can be considered as a new highly potential therapeutic product to be further investigated against colorectal cancer, thanks to the possible synergistic interaction of its compounds

    Antioxidant activities of hydroxylated naphthalenes: the role of aryloxyl radicals

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    Herein is delineated a first systematic framework for the definition of structure-antioxidant property relationships in the dihydroxynaphthalene (DHN) series. The results obtained by a combined experimental and theoretical approach revealed that 1,8-DHN is the best performing antioxidant platform, with its unique hydrogen-bonded peri-hydroxylation pattern contributing to a fast H atom transfer process. Moreover, the comparative analysis of the antioxidant properties of DHNs carried out by performing DPPH and FRAP assays and laser flash photolysis experiments, revealed the higher antioxidant power associated with an α-substitution pattern (i. e. in 1,8- and 1,6-DHN) with respect to DHNs exhibiting a β-substitution pattern (i. e. in 2,6- and 2,7-DHN). DFT calculations and isolation and characterization of the main oligomer intermediates formed during the oxidative polymerization of DHNs supported this evidence by providing unprecedented insight into the generation and fate of the intermediate naphthoxyl radicals, which emerged as the main factor governing the antioxidant activity of DHNs

    Dynamical Casimir Effect in a Leaky Cavity at Finite Temperature

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    The phenomenon of particle creation within an almost resonantly vibrating cavity with losses is investigated for the example of a massless scalar field at finite temperature. A leaky cavity is designed via the insertion of a dispersive mirror into a larger ideal cavity (the reservoir). In the case of parametric resonance the rotating wave approximation allows for the construction of an effective Hamiltonian. The number of produced particles is then calculated using response theory as well as a non-perturbative approach. In addition we study the associated master equation and briefly discuss the effects of detuning. The exponential growth of the particle numbers and the strong enhancement at finite temperatures found earlier for ideal cavities turn out to be essentially preserved. The relevance of the results for experimental tests of quantum radiation via the dynamical Casimir effect is addressed. Furthermore the generalization to the electromagnetic field is outlined.Comment: 48 pages, 8 figures typos corrected & references added and update

    Search for gamma-ray emission from the Lagrangian points of PSR 1957+20

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    Compton Gamma Ray Observatory data of the COMPTEL and EGRET telescopes from 3 viewing periods have been used to search for gamma-ray emission from the Lagrangian points L_4_ and L_5_ of the binary system including the eclipsing pulsar PSR1957+20. The result was negative and the upper limits derived remain significantly below detections reported earlier

    Genetic inhibition of neurotransmission reveals role of glutamatergic input to dopamine neurons in high-effort behavior

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    Midbrain dopamine neurons are crucial for many behavioral and cognitive functions. As the major excitatory input, glutamatergic afferents are important for control of the activity and plasticity of dopamine neurons. However, the role of glutamatergic input as a whole onto dopamine neurons remains unclear. Here we developed a mouse line in which glutamatergic inputs onto dopamine neurons are specifically impaired, and utilized this genetic model to directly test the role of glutamatergic inputs in dopamine-related functions. We found that while motor coordination and reward learning were largely unchanged, these animals showed prominent deficits in effort-related behavioral tasks. These results provide genetic evidence that glutamatergic transmission onto dopaminergic neurons underlies incentive motivation, a willingness to exert high levels of effort to obtain reinforcers, and have important implications for understanding the normal function of the midbrain dopamine system.Fil: Hutchison, M. A.. National Institutes of Health; Estados UnidosFil: Gu, X.. National Institutes of Health; Estados UnidosFil: Adrover, Martín Federico. National Institutes of Health; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Lee, M. R.. National Institutes of Health; Estados UnidosFil: Hnasko, T. S.. University of California at San Diego; Estados UnidosFil: Alvarez, V. A.. National Institutes of Health; Estados UnidosFil: Lu, W.. National Institutes of Health; Estados Unido

    Scn1a gene reactivation after symptom onset rescues pathological phenotypes in a mouse model of Dravet syndrome

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    Dravet syndrome is a severe epileptic encephalopathy caused primarily by haploinsufficiency of the SCN1A gene. Repetitive seizures can lead to endurable and untreatable neurological deficits. Whether this severe pathology is reversible after symptom onset remains unknown. To address this question, we generated a Scn1a conditional knock-in mouse model (Scn1a Stop/+) in which Scn1a expression can be re-activated on-demand during the mouse lifetime. Scn1a gene disruption leads to the development of seizures, often associated with sudden unexpected death in epilepsy (SUDEP) and behavioral alterations including hyperactivity, social interaction deficits and cognitive impairment starting from the second/third week of age. However, we showed that Scn1a gene re-activation when symptoms were already manifested (P30) led to a complete rescue of both spontaneous and thermic inducible seizures, marked amelioration of behavioral abnormalities and normalization of hippocampal fast-spiking interneuron firing. We also identified dramatic gene expression alterations, including those associated with astrogliosis in Dravet syndrome mice, that, accordingly, were rescued by Scn1a gene expression normalization at P30. Interestingly, regaining of Nav1.1 physiological level rescued seizures also in adult Dravet syndrome mice (P90) after months of repetitive attacks. Overall, these findings represent a solid proof-of-concept highlighting that disease phenotype reversibility can be achieved when Scn1a gene activity is efficiently reconstituted in brain cells

    Flagellin delays spontaneous human neutrophil apoptosis

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    Neutrophils are short-lived cells that rapidly undergo apoptosis. However, their survival can be regulated by signals from the environment. Flagellin, the primary component of the bacterial flagella, is known to induce neutrophil activation. In this study we examined the ability of flagellin to modulate neutrophil apoptosis. Neutrophils cultured for 12 and 24 h in the presence of flagellin from Salmonella thyphimurim at concentrations found in pathological situations underwent a marked prevention of apoptosis. In contrast, Helicobacter pylori flagellin did not affect neutrophil survival, suggesting that Salmonella flagellin exerts the antiapoptotic effect by interacting with TLR5. The delaying in apoptosis mediated by Salmonella flagellin was coupled to higher expression levels of the antiapoptotic protein Mcl-1 and lower levels of activated caspase-3. Analysis of the signaling pathways indicated that Salmonella flagellin induced the activation of the p38 and ERK1/2 MAPK pathways as well as the PI3K/Akt pathway. Furthermore, it also stimulated IBα degradation and the phosphorylation of the p65 subunit, suggesting that Salmonella flagellin also triggers NF-B activation. Moreover, the pharmacological inhibition of ERK1/2 pathway and NF-B activation partially prevented the antiapoptotic effects exerted by flagellin. Finally, the apoptotic delaying effect exerted by flagellin was also evidenced when neutrophils were cultured with whole heat-killed S. thyphimurim. Both a wild-type and an aflagellate mutant S. thyphimurim strain promoted neutrophil survival; however, when cultured in low bacteria/neutrophil ratios, the flagellate bacteria showed a higher capacity to inhibit neutrophil apoptosis, although both strains showed a similar ability to induce neutrophil activation. Taken together, our results indicate that flagellin delays neutrophil apoptosis by a mechanism partially dependent on the activation of ERK1/2 MAPK and NF-B. The ability of flagellin to delay neutrophil apoptosis could contribute to perpetuate the inflammation during infections with flagellated bacteria.Facultad de Ciencias Exacta

    Prediction of first test day milk yield using historical records in dairy cows

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    The transition between two lactations remains one of the most critical periods during the productive life of dairy cows. In this study, we aimed to develop a model that predicts the milk yield of dairy cows from test day milk yield data collected in the previous lactation. In the past, data routinely collected in the context of herd improvement programmes on dairy farms have been used to provide insights in the health status of animals or for genetic evaluations. Typically, only data from the current lactation is used, comparing expected (i.e., unperturbed) with realised milk yields. This approach cannot be used to monitor the transition period due to the lack of unperturbed milk yields at the start of a lactation. For multiparous cows, an opportunity lies in the use of data from the previous lactation to predict the expected production of the next one. We developed a methodology to predict the first test day milk yield after calving using information from the previous lactation. To this end, three random forest models (nextMILKFULL, nextMILKPH, and nextMILKP) were trained with three different feature sets to forecast the milk yield on the first test day of the next lactation. To evaluate the added value of using a machine-learning approach against simple models based on contemporary animals or production in the previous lactation, we compared the nextMILK models with four benchmark models. The nextMILK models had an RMSE ranging from 6.08 to 6.24 kg of milk. In conclusion, the nextMILK models had a better prediction performance compared to the benchmark models. Application-wise, the proposed methodology could be part of a monitoring tool tailored towards the transition period. Future research should focus on validation of the developed methodology within such tool

    Histopathologic and mr imaging appearance of spontaneous and radiation-induced necrosis in uveal melanomas: Initial results

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    Necrosis in uveal melanomas can be spontaneous or induced by radiotherapy. The purpose of our study was to compare the histopathologic and MRI findings of radiation-induced necrosis of a group of proton beam-irradiated uveal melanomas with those of spontaneous necrosis of a control group of patients undergoing primary enucleation. 11 uveal melanomas who had undergone proton beam radiotherapy, MRI and secondary enucleation, and a control group of 15 untreated uveal melanomas who had undergone MRI and primary enucleation were retrospectively identi-fied. Within the irradiated and nonirradiated group, 7 and 6 eyes with histological evidence of necrosis respectively, were furtherly selected for the final analysis; the appearance of necrosis was assessed at histopathologic examination and MRI. Irradiated melanomas showed a higher degree of necrosis as compared with nonirradiated tumors. Irradiated and nonirradiated lesions differed based on the appearance and distribution of necrosis. Irradiated tumors showed large necrotic foci, sharply demarcated from the viable neoplastic tissue; nonirradiated tumors demonstrated small, distinct foci of necrosis. Radiation-induced necrosis, more pigmented than surrounding viable tumor, displayed high signal intensity on T1-weighted and low signal intensity on T2-weighted images. The hemorrhagic/coagulative necrosis, more prevalent in nonirradiated tumors (4 out of 6 vs. 1 out of 7 cases), appeared hyperintense on T2-weighted and hypointense on T1-weighted images. Our study boosts the capability to recognize radiation-induced alterations in uveal melanomas at MRI and may improve the accuracy of radiologists in the evaluation of follow-up MR examination after radiotherapy

    CATANA protontherapy facility: The state of art of clinical and dosimetric experience

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    After nine years of activity, about 220 patients have been treated at the CATANA Eye Protontherapy facility. A 62MeV proton beam produced by a Superconducting Cyclotron is dedicated to radiotherapy of eye lesions, as uveal melanomas. Research and development work has been done to test different dosimetry devices to be used for reference and relative dosimetry, in order to achieve dose delivering accuracy. The follow-up results demonstrated the efficacy of proton beams and encouraged us in our activity in the fight against cancer
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