2,224 research outputs found

    GALNT2 as a novel modulator of adipogenesis and adipocyte insulin signaling

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    Background/objectives: A better understanding of adipose tissue biology is crucial to tackle insulin resistance and eventually coronary heart disease and diabetes, leading causes of morbidity and mortality worldwide. GALNT2, a GalNAc-transferase, positively modulates insulin signaling in human liver cells by down-regulating ENPP1, an insulin signaling inhibitor. GALNT2 expression is increased in adipose tissue of obese as compared to that of non-obese individuals. Whether this association is secondary to a GALNT2-insulin sensitizing effect exerted also in adipocytes is unknown. We then investigated in mouse 3T3-L1 adipocytes the GALNT2 effect on adipogenesis, insulin signaling and expression levels of both Enpp1 and 72 adipogenesis-related genes. Methods: Stable over-expressing GALNT2 and GFP preadipocytes (T 0 ) were generated. Adipogenesis was induced with (R+) or without (R−) rosiglitazone and investigated after 15 days (T 15 ). Lipid accumulation (by Oil Red-O staining) and intracellular triglycerides (by fluorimetric assay) were measured. Lipid droplets (LD) measures were analyzed at confocal microscope. Gene expression was assessed by RT-PCR and insulin-induced insulin receptor (IR), IRS1, JNK and AKT phosphorylation by Western blot. Results: Lipid accumulation, triglycerides and LD measures progressively increased from T 0 to T 15 R- and furthermore to T 15 R+. Such increases were significantly higher in GALNT2 than in GFP cells so that, as compared to T 15 R+GFP, T 15 R- GALNT2 cells showed similar (intracellular lipid and triglycerides accumulation) or even higher (LD measures, p < 0.01) values. In GALNT2 preadipocytes, insulin-induced IR, IRS1 and AKT activation was higher than that in GFP cells. GALNT2 effect was totally abolished during adipocyte maturation and completely reversed at late stage maturation. Such GALNT2 effect trajectory was paralleled by coordinated changes in the expression of Enpp1 and adipocyte-maturation key genes. Conclusions: GALNT2 is a novel modulator of adipogenesis and related cellular phenotypes, thus becoming a potential target for tackling the obesity epidemics and its devastating sequelae

    On diamond-free subposets of the Boolean lattice

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    The Boolean lattice of dimension two, also known as the diamond, consists of four distinct elements with the following property: AB,CDA\subset B,C\subset D. A diamond-free family in the nn-dimensional Boolean lattice is a subposet such that no four elements form a diamond. Note that elements BB and CC may or may not be related. There is a diamond-free family in the nn-dimensional Boolean lattice of size (2o(1))(nn/2)(2-o(1)){n\choose\lfloor n/2\rfloor}. In this paper, we prove that any diamond-free family in the nn-dimensional Boolean lattice has size at most (2.25+o(1))(nn/2)(2.25+o(1)){n\choose\lfloor n/2\rfloor}. Furthermore, we show that the so-called Lubell function of a diamond-free family in the nn-dimensional Boolean lattice is at most 2.25+o(1)2.25+o(1), which is asymptotically best possible.Comment: 23 pages, 10 figures Accepted to Journal of Combinatorial Theory, Series

    Superselectors: Efficient Constructions and Applications

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    We introduce a new combinatorial structure: the superselector. We show that superselectors subsume several important combinatorial structures used in the past few years to solve problems in group testing, compressed sensing, multi-channel conflict resolution and data security. We prove close upper and lower bounds on the size of superselectors and we provide efficient algorithms for their constructions. Albeit our bounds are very general, when they are instantiated on the combinatorial structures that are particular cases of superselectors (e.g., (p,k,n)-selectors, (d,\ell)-list-disjunct matrices, MUT_k(r)-families, FUT(k, a)-families, etc.) they match the best known bounds in terms of size of the structures (the relevant parameter in the applications). For appropriate values of parameters, our results also provide the first efficient deterministic algorithms for the construction of such structures

    asociacion entre angioma cavernoso y glioma cerebral reporte de dos casos y revision de la literatura acerca de los llamados angiogliomas

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    La asociacion entre las malformaciones vasculares y los gliomas cerebrales es inusual. Mientras que la asociacion entre angioma cavernoso con lesiones gliomatosas es aun mas rara, es por esto considerado por algunos autores como una entidad patologica particular llamada angioglioma. Los autores reportan dos casos de asociacion de un angioma cavernoso con una ganglioglioma y un oligodendroglioma, respectivamente. Ademas se realizo una revision de la literatura sobre los llamados angiogliomas. En opinion de los autores, la entidad de los angiogliomas se presenta dentro de un espectro general de neoplasias angiomatosas, que incluyen tumores cerebrales, en su mayoria gliomas de bajo grado, asociados a su vez, con un componente vascular importante

    MicroRNA-221 silencing attenuates the degenerated phenotype of intervertebral disc cells.

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    The aim of this study was to investigate the role of an antichondrogenic factor, MIR221 (miR‐221), in intervertebral disc degeneration (IDD), and provide basic information for the development of a therapeutic strategy for the disc repair based on specific nucleic acid based drugs, such as miR‐221 silencing. We established a relatively quick protocol to minimize artifacts from extended in vitro culture, without selecting the different types of cells from intervertebral disc (IVD) or completely disrupting extracellular matrix (ECM), but by using the whole cell population with a part of resident ECM. During the de‐differentiation process miR‐221 expression significantly increased. We demonstrated the effectiveness of miR‐221 silencing in driving the cells towards chondrogenic lineage. AntagomiR‐221 treated cells showed in fact a significant increase of expression of typical chondrogenic markers including COL2A1, ACAN and SOX9, whose loss is associated with IDD. Moreover, antagomiR‐221 treatment restored FOXO3 expression and increased TRPS1 expression levels attenuating the severity grade of degeneration, and demonstrating in a context of tissue degeneration and inflammation not investigated before, that FOXO3 is target of miR‐221. Data of present study are promising in the definition of new molecules useful as potential intradiscal injectable biological agents

    Evaluation of the Iatrogenic Sciatic Nerve Injury following Double Pelvic Osteotomy Performed with Piezoelectric Cutting Tool in Dogs

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    (1) Background: The double pelvic osteotomy (DPO) is a prophylactic surgical procedure associated with 0.4% incidence of sciatic nerve injury. The piezoelectric cutting tool is a surgical device able to involve only mineralized tissue avoiding neurovascular tissue and other soft tissue. This study aimed to evaluate the sciatic nerve injury observed in dogs underwent iliac osteotomy performed using the piezoelectric cutting tool. (2) Methods: Dogs underwent DPO performed with piezoelectric cutting tool were included. Neurological assessment was performed 6 and 24 h after surgery and then repeated 12 days, 4 and 8 weeks after surgery. Temporary and or permanent sciatic nerve injury were recorded. (3) Results: 84 DPOs performed in fifty dogs were included. No temporary/permanent neurological disease associated with iatrogenic damage of the sciatic nerve were observed. (4) Conclusions: The iliac osteotomy performed with piezoelectric cutting tool was not associated to iatrogenic sciatic nerve injury

    Comparison of silver nanoparticles confined in nanoporous silica prepared by chemical synthesis and by ultra-short pulsed laser ablation in liquid

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    Hexagonally ordered mesoporous silica materials MCM-41 and SBA-15 have been synthesized and loaded with Ag nanoparticles, utilizing both chemical synthesis and ultra-short pulsed laser ablation in liquid. In laser ablation, a silver target, immersed in aqueous suspension of ordered mesoporous silica SBA-15, was irradiated by ultra-short laser pulses to generate silver nanoparticles. For comparison samples of similar silver contents were prepared either by incorporating silver into the SBA-15 during a hydrothermal synthesis or by introducing silver in MCM-41 by template ion-exchange. Samples were characterized by XRD, N2 physisorption, TEM and UV-vis spectroscopy. All preparations contained significant amount of 5-50 nm size silver agglomerates on the outer surface of the silica particles. The laser ablation process did not cause significant destruction of the SBA-15 structure and metallic silver (Ag0) nanoparticles were mainly generated. It is demonstrated that by laser ablation in aqueous silica suspension smaller and more uniform metallic silver particles can be produced and loaded on the surface of the silica support than by synthesis procedures. Catalytic properties of the samples have been tested in the total oxidation of toluene. Because of its favorable Ag dispersity the Ag/SBA-15 catalyst, generated by the laser ablation method, had better catalytic stability and, relative to its Ag load, higher activity than the conventional Ag/SBA-15 preparations

    Insulin-like growth factor-1 as predictive factor of difficult laryngoscopy in patients with GH-producing pituitary adenoma: A pilot study

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    Background: Growth hormone (GH)-producing pituitary tumors account for 10 to 15% of pituitary tumors. The hypersecretion of GH may induce changes in the airway anatomy through the activation of Insulin-like Growth factor 1(IGF-1) pathway. We sought investigate the role IGF-1 as a potential predictive factor of difficult laryngoscopy in patients with GH-producing pituitary adenoma. Methods: This study was a single center retrospective study. We included 33 patients undergoing transsphenoidal resection of GH-producing pituitary. We recorded demographic data, el-Ganzouri risk index (EGRI) and modified Look-Evaluate-Mallampati-Obstruction-Neck mobility (mLEMON) score, and pituitary hormone plasma levels. We performed ordinal logistic regression to analyze the relationship between IGF-1 and EGRI, mLEMON, and Cormack-Lehane Grade score and a multiple logistic regression to test the capability of EGRI, mLEMON and IGF-1 levels to predict Cormack-Lehane score. Receiver operating curve (ROC), area under the curve (AUC), and cut-off value of IGF-1 were calculated. Results: Only 14 (42.8%) and 12 (36.36%) patients showed predictive factors of difficult intubation according to EGRI and mLEMON score, respectively. IGF-1 significantly correlated with Cormack-Lehane (p = 0.005879) but not with mLEMON and EGRI (p = 0.3080 and 0.4146, respectively). In multiple regression model IGF-1 correlated only with Cormack-Lehane grade (p = 0.0089). Area under ROC was 0.8571 and cut-off value of IGF-1 was 186.15 ng/ml. Conclusion: Higher IGF-1 levels correlate with the probability of having a higher Cormack-Lehane score; classical bedside scores, such as mLEMON and EGRI, were not able to predict difficult laryngoscopy in our population
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