227 research outputs found

    Ruthenium-Catalyzed Decarboxylative Rearrangement of 4-Alkenyl-isoxazol-5-ones to Pyrrole Derivatives

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    Easily accessible isoxazol-5(4H)-ones are useful precursors of heterocycles. In this context, we report the ruthenium-catalyzed transformation of 4-alkenyl-substituted isoxazol-5-ones to afford 1H-pyrrole derivatives. The operative conditions were proven to be effective also on cyclohexane-fused isoxazolones giving 4,5,6,7-tetrahydroindoles. The reactions, which allow for access to tri-and tetra-substituted pyrroles in moderate to high yields, occur through decarboxylative ring-opening/ring-closure involving C-H functionalization of the alkenyl moiety

    New Insights into the Lactate Shuttle: Role of MCT4 in the Modulation of the Exercise Capacity.

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    Lactate produced by muscle during high-intensity activity is an important end product of glycolysis that supports whole body metabolism. The lactate shuttle model suggested that lactate produced by glycolytic muscle fibers is utilized by oxidative fibers. MCT4 is a proton coupled monocarboxylate transporter preferentially expressed in glycolytic muscle fibers and facilitates the lactate efflux. Here we investigated the exercise capacity of mice with disrupted lactate shuttle due to global deletion of MCT4 (MCT4−/−) or muscle-specific deletion of the accessory protein Basigin (iMSBsg−/−). Although MCT4−/− and iMSBsg−/− mice have normal muscle morphology and contractility, only MCT4−/− mice exhibit an exercise intolerant phenotype. In vivo measurements of compound muscle action potentials showed a decrement in the evoked response in the MCT4−/− mice. This was accompanied by a significant structural degeneration of the neuromuscular junctions (NMJs). We propose that disruption of the lactate shuttle impacts motor function and destabilizes the motor unit

    TET3 prevents terminal differentiation of adult NSCs by a non-catalytic action at Snrpn.

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    Ten-eleven-translocation (TET) proteins catalyze DNA hydroxylation, playing an important role in demethylation of DNA in mammals. Remarkably, although hydroxymethylation levels are high in the mouse brain, the potential role of TET proteins in adult neurogenesis is unknown. We show here that a non-catalytic action of TET3 is essentially required for the maintenance of the neural stem cell (NSC) pool in the adult subventricular zone (SVZ) niche by preventing premature differentiation of NSCs into non-neurogenic astrocytes. This occurs through direct binding of TET3 to the paternal transcribed allele of the imprinted gene Small nuclear ribonucleoprotein-associated polypeptide N (Snrpn), contributing to transcriptional repression of the gene. The study also identifies BMP2 as an effector of the astrocytic terminal differentiation mediated by SNRPN. Our work describes a novel mechanism of control of an imprinted gene in the regulation of adult neurogenesis through an unconventional role of TET3

    Aberrant splicing and expression of the non muscle myosin heavy-chain gene MYH14 in DM1 muscle tissues

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    Myotonic dystrophy type 1 (DM1) is a complex multisystemic disorder caused by an expansion of a CTG repeat located at the 3' untranslated region (UTR) of DMPK on chromosome 19q13.3. Aberrant messenger RNA (mRNA) splicing of several genes has been reported to explain some of the symptoms of DM1 including insulin resistance, muscle wasting and myotonia. In this paper we analyzed the expression of the MYH14 mRNA and protein in the muscle of DM1 patients (n=12) with different expansion lengths and normal subjects (n=7). The MYH14 gene is located on chromosome 19q13.3 and encodes for one of the heavy chains of the so called class II "nonmuscle" myosins (NMHCII). MYH14 has two alternative spliced isoforms: the inserted isoform (NMHCII-C1) which includes 8 amino acids located in the globular head of the protein, not encoded by the non inserted isoform (NMHCII-C0). Results showed a splicing unbalance of the MYH14 gene in DM1 muscle, with a prevalent expression of the NMHCII-C0 isoform more marked in DM1 patients harboring large CTG expansions. Minigene assay indicated that levels of the MBNL1 protein positively regulates the inclusion of the MYH14 exon 6. Quantitative analysis of the MYH14 expression revealed a significant reduction in the DM1 muscle samples, both at mRNA and protein level. No differences were found between DM1 and controls in the skeletal muscle localization of MYH14, obtained through immunofluorescence analysis. In line with the thesis of an "RNA gain of function" hypothesis described for the CTG mutation, we conclude that the alterations of the MYH14 gene may contribute to the DM1 molecular pathogenesis

    Cyclin D1 Restrains Oncogene-Induced Autophagy by Regulating the AMPK-LKB1 Signaling Axis.

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    Autophagy activated after DNA damage or other stresses mitigates cellular damage by removing damaged proteins, lipids, and organelles. Activation of the master metabolic kinase AMPK enhances autophagy. Here we report that cyclin D1 restrains autophagy by modulating the activation of AMPK. In cell models of human breast cancer or in a cyclin D1-deficient model, we observed a cyclin D1-mediated reduction in AMPK activation. Mechanistic investigations showed that cyclin D1 inhibited mitochondrial function, promoted glycolysis, and reduced activation of AMPK (pT172), possibly through a mechanism that involves cyclin D1-Cdk4/Cdk6 phosphorylation of LKB1. Our findings suggest how AMPK activation by cyclin D1 may couple cell proliferation to energy homeostasis

    Kinase-independent role of cyclin D1 in chromosomal instability and mammary tumorigenesis

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    Cyclin D1 is an important molecular driver of human breast cancer but better understanding of its oncogenic mechanisms is needed, especially to enhance efforts in targeted therapeutics. Currently, pharmaceutical initiatives to inhibit cyclin D1 are focused on the catalytic component since the transforming capacity is thought to reside in the cyclin D1/CDK activity. We initiated the following study to directly test the oncogenic potential of catalytically inactive cyclin D1 in an in vivo mouse model that is relevant to breast cancer. Herein, transduction of cyclin D1(-/-) mouse embryonic fibroblasts (MEFs) with the kinase dead KE mutant of cyclin D1 led to aneuploidy, abnormalities in mitotic spindle formation, autosome amplification, and chromosomal instability (CIN) by gene expression profiling. Acute transgenic expression of either cyclin D1(WT) or cyclin D1(KE) in the mammary gland was sufficient to induce a high CIN score within 7 days. Sustained expression of cyclin D1(KE) induced mammary adenocarcinoma with similar kinetics to that of the wild-type cyclin D1. ChIP-Seq studies demonstrated recruitment of cyclin D1(WT) and cyclin D1(KE) to the genes governing CIN. We conclude that the CDK-activating function of cyclin D1 is not necessary to induce either chromosomal instability or mammary tumorigenesis

    Digital dermoscopy to determine skin melanin index as an objective indicator of skin pigmentation

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    Clinical assessment of skin photosensitivity is subjectively determined by erythema and tanning responses to sunlight recalled by the subject, alternatively known as Fitzpatrick Skin Phototype (SPT). Responses may be unreliable due to recall bias, subjective bias by clinicians and subjects, and lack of cultural sensitivity of the questions. Analysis of red-green-blue (RGB) color spacing of digital images may provide an objective determination of SPT. This paper presents the studies to assess the melanin index (MI), as determined by RGB images obtained by both standard digital camera as well as by videodermoscope, and to correlate the MI with SPT based upon subjects' verbal responses to standardized questions administered by a dermatologist. A sample of subjects representing all SPTs I–VI was selected. Both the digital camera and videodermoscope were calibrated at standard illumination, light source and white balance. Images of constitutive skin of the upper ventral arm were taken of each subject using both instruments. The studies showed that 58 subjects (20 M, 38 F) were enrolled in the study (mean age: 47 years; range: 20–89), stratified to skin phototype I–VI. MI obtained by using both digital camera and videodermoscope increased significantly as the SPT increased (p = 0.004 and p &lt; 0.0001, respectively) and positively correlated with dermatologist-assessed SPT (Spearman correlation, r = 0.48 and r = 0.84, respectively). Digital imaging can quantify melanin content in order to quantitatively approximate skin pigmentation in all skin phototypes including Type VI skin. This methodology holds promise as a simple, non-invasive, rapid and objective approach to reliably determine skin phototype and, with further investigation, may prove to be both practical and useful in the prediction of skin cancer risk.</p

    Enfermería : fármacos más utilizados en urgencias hospitalarias

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    El Servicio de Urgencias del C.H.G.U.V. cuenta con una plantilla de 84 Enfermeros/as. Una parte considerable de ellos es personal de nueva incorporación, de ahí que sea prioritaria la elaboración de protocolos de actuación. La administración de medicación intravenosa es sin duda una de las técnicas de mayor aplicación en los pacientes que acuden a Urgencias, que en nuestro Hospital oscila entre 550-600 atenciones diarias. Por ello nos planteamos, mediante la realización de reuniones de grupo, la elaboración del presente trabajo con el objetivo de elaborar un manual informativo sobre la medicación más habitual utilizada en nuestro Servicio de Urgencias; indicaciones, contraindicaciones, diluciones, cuidados y recomendaciones sobre la administración que nos ayude a visionar la practica en nuestro trabajo y la calidad del Servicio que prestamos a nuestros pacientes, y sirva de consulta sobre todo al personal de nueva incorporación.The First aid service of the C.H.G.U.V. Nurse is provided with a staff of 84, a considerable part of them is new staff, and therefore there is a priority of making of performance protocols. The administration of intravenous medication is undoubtedly one of the most used techniques in patients who come to the emergency room, which in our Hospital ranges between 550-600 daily attentions. For this reason, we considered that carrying out group meetings in order to elaborate the present essay. Our main objective is to prepare an informative guidebook about the most common used medicines in our first aid service: indications, contraindications, dilutions, care, and recommendations on the use. In this sense it will contribute to see the practice in our work and the service quality that we give to our patients. And what is more, it will serve as a reference particularly to the new [email protected]

    Biochemical parameters of silver catfish (Rhamdia quelen) after transport with eugenol or essential oil of Lippia alba added to the water

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    The transport of live fish is a routine practice in aquaculture and constitutes a considerable source of stress to the animals. The addition of anesthetic to the water used for fish transport can prevent or mitigate the deleterious effects of transport stress. This study investigated the effects of the addition of eugenol (EUG) (1.5 or 3.0 mu L L-1) and essential oil of Lippia alba (EOL) (10 or 20 mu L L-1) on metabolic parameters (glycogen, lactate and total protein levels) in liver and muscle, acetylcholinesterase activity (AChE) in muscle and brain, and the levels of protein carbonyl (PC), thiobarbituric acid reactive substances (TBARS) and nonprotein thiol groups (NPSH) and activity of glutathione-S-transferase in the liver of silver catfish (Rhamdia quelen; Quoy and Gaimard, 1824) transported for four hours in plastic bags (loading density of 169.2 g L-1). The addition of various concentrations of EUG (1.5 or 3.0 mu L L-1) and EOL (10 or 20 mu L L-1) to the transport water is advisable for the transportation of silver catfish, since both concentrations of these substances increased the levels of NPSH antioxidant and decreased the TBARS levels in the liver. In addition, the lower liver levels of glycogen and lactate in these groups and lower AChE activity in the brain (EOL 10 or 20 mu L L-1) compared to the control group indicate that the energetic metabolism and neurotransmission were lower after administration of anesthetics, contributing to the maintenance of homeostasis and sedation status.Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS/PRONEX) [10/0016-8]; Conselho Nacional de Pesquisa e Desenvolvimento Cientifico (CNPq) [470964/2009-0]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); CNPqinfo:eu-repo/semantics/publishedVersio

    Cultivo do girassol na época da safrinha no Rio Grande do Sul.

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