Culture du coton : manuel technique

Cette fiche technique sur la culture du coton a pour but de guider les agriculteurs dans la conduite de la culture cotonnière. Elle présente brièvement la plante, les variétés et dispositifs de multiplication, les produits et techniques pour le contrôle des ravageurs ainsi que l'itinéraire technique de la culture cotonnièr

WNT signaling enhances breast cancer cell motility and blockade of the WNT pathway by sFRP1 suppresses MDA-MB-231 xenograft growth

ABSTRACT: INTRODUCTION: In breast cancer deregulation of the WNT signaling pathway occurs by autocrine mechanisms. WNT ligands and Frizzled (FZD) receptors are coexpressed in primary breast tumors and cancer cell lines. Moreover, many breast tumors show hypermethylation of secreted Frizzled-related protein 1 (sFRP1)'s promoter region, causing low expression of this WNT antagonist. We have previously shown that the WNT pathway influences proliferation of breast cancer cell lines via activation of canonical signaling and epidermal growth factor receptor (EGFR) transactivation, and that interference with WNT signaling reduces proliferation. Here we examine the role of WNT signaling in breast tumor cell migration and on xenograft outgrowth. METHODS: The breast cancer cell line MDA-MB-231 was used to study WNT signaling. We examined the effects of activating or blocking the WNT pathway on cell motility by treatment with WNT ligands or by ectopic sFPR1 expression, respectively. The ability of sFRP1 expressing MDA-MB-231 cells to grow as xenografts was also tested. Microarray analyses were carried out to identify targets with roles in MDA-MB-231/sFRP1 tumor growth inhibition. RESULTS: We show that WNT stimulates the migratory ability of MDA-MB-231 cells. Furthermore, ectopic expression of sFRP1 in MDA-MB-231 cells blocks canonical WNT signaling and decreases their migratory potential. Moreover, the ability of MDA-MB-231/sFRP1 expressing cells to grow as xenografts in mammary glands and to form lung metastases is dramatically impaired. Microarray analyses led to the identification of two genes, CCND1 and CDKN1A, whose expression level is selectively altered in vivo in sFRP1 expressing tumors. The encoded proteins, Cyclin D1 and p21Cip1 were down- and up-regulated, respectively, in sFRP1 expressing tumors, suggesting that they are downstream mediators of WNT signaling. CONCLUSIONS: Our results show that the WNT pathway influences multiple biological properties of MDA-MB-231 breast cancer cells. WNT stimulates tumor cell motility; conversely sFRP1 mediated WNT pathway blockade reduces motility. Moreover, ectopic sFRP1 expression in MDA-MB-231 cells has a strong negative impact on tumor outgrowth and blocked lung metastases. These results suggest that interference with WNT signaling using sFRP1 to block the ligand-receptor interaction may be a valid therapeutic approach in breast cancer

Different Molecular Signatures in Magnetic Resonance Imaging-Staged Facioscapulohumeral Muscular Dystrophy Muscles

Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common muscular dystrophies and is characterized by a non-conventional genetic mechanism activated by pathogenic D4Z4 repeat contractions. By muscle Magnetic Resonance Imaging (MRI) we observed that T2-short tau inversion recovery (T2-STIR) sequences identify two different conditions in which each muscle can be found before the irreversible dystrophic alteration, marked as T1-weighted sequence hyperintensity, takes place. We studied these conditions in order to obtain further information on the molecular mechanisms involved in the selective wasting of single muscles or muscle groups in this disease

Down-regulation of SFRP1 as a putative tumor suppressor gene can contribute to human hepatocellular carcinoma

<p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma (HCC) is one of the most common cancers in the world. SFRP1 (the secreted frizzled-related protein 1), a putative tumor suppressor gene mapped onto chromosome 8p12-p11.1, the frequent loss of heterozygosity (LOH) region in human HCC, encodes a Wingless-type (Wnt) signaling antagonist and is frequently inactivated by promoter methylation in many human cancers. However, whether the down-regulation of SFRP1 can contribute to hepatocarcinogenesis still remains unclear.</p> <p>Methods</p> <p>We investigated the expression of SFRP1 through real time RT-PCR and immunohistochemistry staining. The cell growth and colony formation were observed as the overexpression and knockdown of SFRP1. The DNA methylation status within SFRP1 promoter was analyzed through methylation-specific PCR or bisulphate-treated DNA sequencing assays. Loss of heterozygosity was here detected with microsatellite markers.</p> <p>Results</p> <p>SFRP1 was significantly down-regulated in 76.1% (35/46) HCC specimens at mRNA level and in 30% (30/100) HCCs indicated by immunohistochemistry staining, as compared to adjacent non-cancerous livers. The overexpression of SFRP1 can significantly inhibit the cell growth and colony formation of YY-8103, SMMC7721, and Hep3B cells. The RNA interference against the constitutional SFRP1 in the offspring SMMC7721 cells, which were stably transfected by ectopic SFRP1, can markedly promote cell growth of these cells. LOH of both microsatellite markers D8S532 and D8SAC016868 flanking the gene locus was found in 13% (6 of 46 HCCs) and 6.5% (3 of 46 HCCs) of the informative cases, respectively, where 5 of 8 HCC specimens with LOH showed the down-regulation of SFRP1. DNA hypermethylation within SFRP1 promoter was identified in two of three HCC specimens without SFRP1 expression. Moreover, the DNA methylation of SFRP1 promoter was significantly reduced, along with the re-expression of the gene, in those HCC cell lines, Bel7404, QGY7701, and MHCC-H, as treated by DAC.</p> <p>Conclusion</p> <p>Our data suggested that the down-regulation of SFRP1 as a candidate tumor suppressor gene, triggered by the epigenetic and/or genetic events, could contribute to the oncogenesis of HCC.</p

Glucocorticoid receptor in astrocytes regulates midbrain dopamine neurodegeneration through connexin hemichannel activity

The precise contribution of astrocytes in neuroinflammatory process occurring in Parkinson's disease (PD) is not well characterized. In this study, using GR(Cx30CreERT2) mice that are conditionally inactivated for glucocorticoid receptor (GR) in astrocytes, we have examined the actions of astrocytic GR during dopamine neuron (DN) degeneration triggered by the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The results show significantly augmented DN loss in GR(Cx30CreERT2) mutant mice in substantia nigra (SN) compared to controls. Hypertrophy of microglia but not of astrocytes was greatly enhanced in SN of these astrocytic GR mutants intoxicated with MPTP, indicating heightened microglial reactivity compared to similarly-treated control mice. In the SN of GR astrocyte mutants, specific inflammation-associated transcripts ICAM-1, TNF-alpha and Il-1 beta as well as TNF-alpha protein levels were significantly elevated after MPTP neurotoxicity compared to controls. Interestingly, this paralleled increased connexin hemichannel activity and elevated intracellular calcium levels in astrocytes examined in acute midbrain slices from control and mutant mice treated with MPP+. The increased connexin-43 hemichannel activity was found in vivo in MPTP-intoxicated mice. Importantly, treatment of MPTP-injected GR(Cx30CreERT2) mutant mice with TAT-Gap19 peptide, a specific connexin-43 hemichannel blocker, reverted both DN loss and microglial activation; in wild-type mice there was partial but significant survival effect. In the SN of postmortem PD patients, a significant decrease in the number of astrocytes expressing nuclear GR was observed, suggesting the participation of astrocytic GR deregulation of inflammatory process in PD. Overall, these data provide mechanistic insights into GR-modulated processes in vivo, specifically in astrocytes, that contribute to a pro-inflammatory state and dopamine neurodegeneration in PD pathology

Elevation of the antifibrotic peptide N-acetyl-seryl-aspartyl-lysyl-proline: a blood pressure-independent beneficial effect of angiotensin I-converting enzyme inhibitors

Blockade of the renin-angiotensin system (RAS) is well recognized as an essential therapy in hypertensive, heart, and kidney diseases. There are several classes of drugs that block the RAS; these drugs are known to exhibit antifibrotic action. An analysis of the molecular mechanisms of action for these drugs can reveal potential differences in their antifibrotic roles. In this review, we discuss the antifibrotic action of RAS blockade with an emphasis on the potential importance of angiotensin I-converting enzyme (ACE) inhibition associated with the antifibrotic peptide N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP)

Spine surgery is kyphosing to spine surgeon

Spine surgery is a demanding surgical specialty which requires surgeons to operate for hours on end, often compromising good posture. Sustained poor posture in the operating room (OR) can be the source of many adverse health effects on spine surgeons. This study will analyze posture of a spine surgeon in different types of spine surgery cases. Posture of a surgeon was measured using the UPRIGHT Posture Training Device. The device was worn by the surgeon in the OR through a wide variety of spine surgery cases. The percent time spent slouched while performing cervical, adult deformity, and lumbar spine surgeries is 39.9, 58.9, and 38.6, respectively. For all surgeries recorded, the percent time slouched is 41.6. The average procedure time was 145.3 min, with adult deformity cases on average being the longest (245.6 min) followed by cervical (152.9 min) and then lumbar (122.5 min). Poor posture while operating is very likely to occur for many spine surgeons regardless of case type. This poor posture is maintained for long periods of time given the average spine surgery procedure recorded in the study was roughly 2.5 h long. Spine surgeons should be aware of the tendency for poor posture while operating, and they should try using posture-improving techniques to maintain good spine health

Performance Assessment of a Near Room Temperature Magnetic Cooling System

3rd International Conference on Energy and Environment Research (ICEER) -- SEP 07-11, 2016 -- Barcelona, SPAINWOS: 000400640900026In this study, performance of a near room temperature magnetic cooling system was investigated experimentally in terms of temperature span. The current setup has a permanent magnet pairs (0.7 Tesla), a magnetocaloric material (Gadolinium) and a heat transfer fluid (water, ethylene glycol and 10% ethanol-water mixing) furthermore solar energy was used as a power source of liner motion of the magnetic system. The obtained results showed that ethanol-water was the best heat transfer fluid and also that optimum magnetization-demagnetization period for the system was found 10 s. (C) 2016 The Authors. Published by Elsevier Ltd.Univ Poltecnica Catalunya, BarcelonaTECHThe Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114M829]The authors would like to thank The Scientific and Technological Research Council of Turkey (TUBITAK) for financial support given to the project entitled "Experimental Performance Evaluation of a Solar Assisted Magnetic Cooling System (114M829)