258 research outputs found

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Multiple sclerosis drug FTY-720 toxicity is mediated by the heterotypic fusion of organelles in neuroendocrine cells

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    FTY-720 (Fingolimod) was one of the first compounds authorized for the treatment of multiple sclerosis. Among its other activities, this sphingosine analogue enhances exocytosis in neuroendocrine chromaffin cells, altering the quantal release of catecholamines. Surprisingly, the size of chromaffin granules is reduced within few minutes of treatment, a process that is paralleled by the homotypic fusion of granules and their heterotypic fusion with mitochondria, as witnessed by dynamic confocal and TIRF microscopy. Electron microscopy studies support these observations, revealing the fusion of several vesicles with individual mitochondria to form large, round mixed organelles. This cross-fusion is SNARE-dependent, being partially prevented by the expression of an inactive form of SNAP-25. Fused mitochondria exhibit an altered redox potential, which dramatically enhances cell death. Therefore, the cross-fusion of intracellular organelles appears to be a new mechanism to be borne in mind when considering the effect of FTY-720 on the survival of neuroendocrine cells

    ERK Is Involved in the Reorganization of Somatosensory Cortical Maps in Adult Rats Submitted to Hindlimb Unloading

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    Sensorimotor restriction by a 14-day period of hindlimb unloading (HU) in the adult rat induces a reorganization of topographic maps and receptive fields. However, the underlying mechanisms are still unclear. Interest was turned towards a possible implication of intracellular MAPK signaling pathway since Extracellular-signal-Regulated Kinase 1/2 (ERK1/2) is known to play a significant role in the control of synaptic plasticity. In order to better understand the mechanisms underlying cortical plasticity in adult rats submitted to a sensorimotor restriction, we analyzed the time-course of ERK1/2 activation by immunoblot and of cortical reorganization by electrophysiological recordings, on rats submitted to hindlimb unloading over four weeks. Immunohistochemistry analysis provided evidence that ERK1/2 phosphorylation was increased in layer III neurons of the somatosensory cortex. This increase was transient, and parallel to the changes in hindpaw cortical map area (layer IV). By contrast, receptive fields were progressively enlarged from 7 to 28 days of hindlimb unloading. To determine whether ERK1/2 was involved in cortical remapping, we administered a specific ERK1/2 inhibitor (PD-98059) through osmotic mini-pump in rats hindlimb unloaded for 14 days. Results demonstrate that focal inhibition of ERK1/2 pathway prevents cortical reorganization, but had no effect on receptive fields. These results suggest that ERK1/2 plays a role in the induction of cortical plasticity during hindlimb unloading

    Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and high plasma homocysteine in chronic hepatitis C (CHC) infected patients from the Northeast of Brazil

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    <p>Abstract</p> <p>Background/Aim</p> <p>Hyperhomocysteinemia due to Methylenetetrahydrofolate Reductase (<it>MTHFR</it>) gene, in particular the C677T (Ala222Val) polymorphism were recently associated to steatosis and fibrosis. We analyzed the frequency of <it>MTHFR </it>gene in a cross-sectional study of patients affected by Chronic Hepatitis C (CHC) from Northeast of Brazil.</p> <p>Method</p> <p>One hundred seven-four untreated patients with CHC were genotyped for the C677T <it>MTHFR</it>. Genomic DNA was extracted from peripheral blood cells and the C677T <it>MTHFR </it>polymorphism was identified by PCR-RFLP. The homocysteine (Hcy) levels were determined by chemiluminescence method. All patients were negative for markers of Wilson's disease, hemochromatosis and autoimmune diseases and have current and past daily alcohol intake less than 100 g/week.</p> <p>Results</p> <p>Among subjects infected with CHC genotype non-1 the frequency of <it>MTHFR </it>genotypes TT was 9.8% <it>versus </it>4.4% genotype 1 (p = 0.01). Nevertheless, association was found between the <it>MTHFR </it>genotype TT × CT/CC polymorphism and the degree of steatosis and fibrosis in both hepatitis C genotype (p < 0.05). A significant difference was found on plasma Hcy levels in patients with steatosis regardless of HCV genotype (p = 0.03).</p> <p>Conclusion</p> <p>Our results indicate that plasma Hcy levels is highly prevalent in subjects with chronic hepatits C with steatosis regardless of HCV genotype and vitamin deficiency. The presence of genotype TT of <it>MTHFR </it>C677T polymorphism was more common in CHC genotype non-1 infected patient regardless of histopathological classification and genotype TT+CT frequencies were significant in the presence of fibrosis grade 1+2 and of steatosis in CHC infected patients from the northeast of Brazil regardless of HCV genotype. The genetic susceptibility of <it>MTHFR </it>C677T polymorphism should be confirmed in a large population.</p

    The multiplex bead array approach to identifying serum biomarkers associated with breast cancer

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    Introduction Breast cancer is the most common type of cancer seen in women in western countries. Thus, diagnostic modalities sensitive to early-stage breast cancer are needed. Antibody-based array platforms of a data-driven type, which are expected to facilitate more rapid and sensitive detection of novel biomarkers, have emerged as a direct, rapid means for profiling cancer-specific signatures using small samples. In line with this concept, our group constructed an antibody bead array panel for 35 analytes that were selected during the discovery step. This study was aimed at testing the performance of this 35-plex array panel in profiling signatures specific for primary non-metastatic breast cancer and validating its diagnostic utility in this independent population. Methods Thirty-five analytes were selected from more than 50 markers through screening steps using a serum bank consisting of 4,500 samples from various types of cancer. An antibody-bead array of 35 markers was constructed using the Luminex (TM) bead array platform. A study population consisting of 98 breast cancer patients and 96 normal subjects was analysed using this panel. Multivariate classification algorithms were used to find discriminating biomarkers and validated with another independent population of 90 breast cancer and 79 healthy controls. Results Serum concentrations of epidermal growth factor, soluble CD40-ligand and proapolipoprotein A1 were increased in breast cancer patients. High-molecular-weight-kininogen, apolipoprotein A1, soluble vascular cell adhesion molecule-1, plasminogen activator inhibitor-1, vitamin-D binding protein and vitronectin were decreased in the cancer group. Multivariate classification algorithms distinguished breast cancer patients from the normal population with high accuracy (91.8% with random forest, 91.5% with support vector machine, 87.6% with linear discriminant analysis). Combinatorial markers also detected breast cancer at an early stage with greater sensitivity. Conclusions The current study demonstrated the usefulness of the antibody-bead array approach in finding signatures specific for primary non-metastatic breast cancer and illustrated the potential for early, high sensitivity detection of breast cancer. Further validation is required before array-based technology is used routinely for early detection of breast cancer.Kenny HA, 2008, J CLIN INVEST, V118, P1367, DOI 10.1172/JCI33775Shah FD, 2008, INTEGR CANCER THER, V7, P33, DOI 10.1177/1534735407313883Carlsson A, 2008, EUR J CANCER, V44, P472, DOI 10.1016/j.ejca.2007.11.025Nolen BM, 2008, BREAST CANCER RES, V10, DOI 10.1186/bcr2096Brogren H, 2008, THROMB RES, V122, P271, DOI 10.1016/j.thromres.2008.04.008Varki A, 2007, BLOOD, V110, P1723, DOI 10.1182/blood-2006-10-053736Madsen CD, 2007, J CELL BIOL, V177, P927, DOI 10.1083/jcb.200612058Levenson VV, 2007, BBA-GEN SUBJECTS, V1770, P847, DOI 10.1016/j.bbagen.2007.01.017VAZQUEZMARTIN A, 2007, EUR J CANCER, V43, P1117GARCIA M, 2007, GLOBAL CANC FACTS FIMoore LE, 2006, CANCER EPIDEM BIOMAR, V15, P1641, DOI 10.1158/1055-9965.EPI-05-0980Borrebaeck CAK, 2006, EXPERT OPIN BIOL TH, V6, P833, DOI 10.1517/14712598.6.8.833Zannis VI, 2006, J MOL MED-JMM, V84, P276, DOI 10.1007/s00109-005-0030-4Jemal A, 2006, CA-CANCER J CLIN, V56, P106Silva HC, 2006, NEOPLASMA, V53, P538Chahed K, 2005, INT J ONCOL, V27, P1425Jain KK, 2005, EXPERT OPIN PHARMACO, V6, P1463, DOI 10.1517/14656566.6.9.1463Abe O, 2005, LANCET, V365, P1687Paradis V, 2005, HEPATOLOGY, V41, P40, DOI 10.1002/hep.20505Molina R, 2005, TUMOR BIOL, V26, P281, DOI 10.1159/000089260Furberg AS, 2005, CANCER EPIDEM BIOMAR, V14, P33Benoy IH, 2004, CLIN CANCER RES, V10, P7157Song JS, 2004, BLOOD, V104, P2065, DOI 10.1182/blood-2004-02-0449Schairer C, 2004, J NATL CANCER I, V96, P1311, DOI 10.1093/jnci/djh253Hellman K, 2004, BRIT J CANCER, V91, P319, DOI 10.1038/sj.bjc.6601944Roselli M, 2004, CLIN CANCER RES, V10, P610Zhou AW, 2003, NAT STRUCT BIOL, V10, P541, DOI 10.1038/nsb943Hapke S, 2003, BIOL CHEM, V384, P1073Miller JC, 2003, PROTEOMICS, V3, P56Amirkhosravi A, 2002, BLOOD COAGUL FIBRIN, V13, P505Bonello N, 2002, HUM REPROD, V17, P2272Li JN, 2002, CLIN CHEM, V48, P1296Louhimo J, 2002, ANTICANCER RES, V22, P1759Knezevic V, 2001, PROTEOMICS, V1, P1271Di Micco P, 2001, DIGEST LIVER DIS, V33, P546Ferrigno D, 2001, EUR RESPIR J, V17, P667Webb DJ, 2001, J CELL BIOL, V152, P741Gion M, 2001, EUR J CANCER, V37, P355Schonbeck U, 2001, CELL MOL LIFE SCI, V58, P4Blackwell K, 2000, J CLIN ONCOL, V18, P600Carriero MV, 1999, CANCER RES, V59, P5307Antman K, 1999, JAMA-J AM MED ASSOC, V281, P1470Loskutoff DJ, 1999, APMIS, V107, P54Molina R, 1998, BREAST CANCER RES TR, V51, P109Bajou K, 1998, NAT MED, V4, P923Chan DW, 1997, J CLIN ONCOL, V15, P2322Chu KC, 1996, J NATL CANCER I, V88, P1571vanDalen A, 1996, ANTICANCER RES, V16, P2345Yamamoto N, 1996, CANCER RES, V56, P2827KOCH AE, 1995, NATURE, V376, P517HADDAD JG, 1995, J STEROID BIOCHEM, V53, P579FOEKENS JA, 1994, J CLIN ONCOL, V12, P1648GEARING AJH, 1993, IMMUNOL TODAY, V14, P506HUTCHENS TW, 1993, RAPID COMMUN MASS SP, V7, P576DECLERCK PJ, 1992, J BIOL CHEM, V267, P11693GABRIJELCIC D, 1992, AGENTS ACTIONS S, V38, P350BIEGLMAYER C, 1991, TUMOR BIOL, V12, P138DNISTRIAN AM, 1991, TUMOR BIOL, V12, P82VANDALEN A, 1990, TUMOR BIOL, V11, P189KARAS M, 1988, ANAL CHEM, V60, P2299, DOI 10.1021/ac00171a028LERNER WA, 1983, INT J CANCER, V31, P463WESTGARD JO, 1981, CLIN CHEM, V27, P493TROUSSEAU A, 1865, CLIN MED HOTEL DIEU, V3, P654*R PROJ, R PROJ STAT COMP1

    Modeling Planarian Regeneration: A Primer for Reverse-Engineering the Worm

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    A mechanistic understanding of robust self-assembly and repair capabilities of complex systems would have enormous implications for basic evolutionary developmental biology as well as for transformative applications in regenerative biomedicine and the engineering of highly fault-tolerant cybernetic systems. Molecular biologists are working to identify the pathways underlying the remarkable regenerative abilities of model species that perfectly regenerate limbs, brains, and other complex body parts. However, a profound disconnect remains between the deluge of high-resolution genetic and protein data on pathways required for regeneration, and the desired spatial, algorithmic models that show how self-monitoring and growth control arise from the synthesis of cellular activities. This barrier to progress in the understanding of morphogenetic controls may be breached by powerful techniques from the computational sciences—using non-traditional modeling approaches to reverse-engineer systems such as planaria: flatworms with a complex bodyplan and nervous system that are able to regenerate any body part after traumatic injury. Currently, the involvement of experts from outside of molecular genetics is hampered by the specialist literature of molecular developmental biology: impactful collaborations across such different fields require that review literature be available that presents the key functional capabilities of important biological model systems while abstracting away from the often irrelevant and confusing details of specific genes and proteins. To facilitate modeling efforts by computer scientists, physicists, engineers, and mathematicians, we present a different kind of review of planarian regeneration. Focusing on the main patterning properties of this system, we review what is known about the signal exchanges that occur during regenerative repair in planaria and the cellular mechanisms that are thought to underlie them. By establishing an engineering-like style for reviews of the molecular developmental biology of biomedically important model systems, significant fresh insights and quantitative computational models will be developed by new collaborations between biology and the information sciences

    Subtype-associated differences in HIV-1 reverse transcription affect the viral replication

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    Background: The impact of the products of the pol gene, specifically, reverse transcriptase (RT) on HIV-1 replication, evolution, and acquisition of drug resistance has been thoroughly characterized for subtype B. For subtype C, which accounts of almost 60% of HIV cases worldwide, much less is known. It has been reported that subtype C HIV-1 isolates have a lower replication capacity than B; however, the basis of these differences remains unclear. Results: We analyzed the impact of the pol gene products from HIV-1 B and C subtypes on the maturation of HIV virions, accumulation of reverse transcription products, integration of viral DNA, frequency of point mutations in provirus and overall viral replication. Recombinant HIV-1 viruses of B and C subtypes comprising the pol fragments encoding protease, integrase and either the whole RT or a chimeric RT from different isolates of the C and B subtypes, were used for infection of cells expressing CXCR4 or CCR5 co-receptors. The viruses carrying different fragments of pol from the isolates of B and C subtypes did not reveal differences in Gag and GagPol processing and viral RNA incorporation into the virions. However, the presence of the whole RT from subtype C, or the chimeric RT containing either the polymerase or the connection and RNase H domains from C isolates, caused significantly slower viral replication regardless of B or C viral backbone. Subtype C RT carrying viruses displayed lower levels of accumulation of strong-stop cDNA in permeabilized virions during endogenous reverse transcription, and decreased accumulation of both strong-stop and positive strand reverse transcription products in infected cells and in isolated reverse transcription complexes. This decreased accumulation correlated with lower levels of viral DNA integration in cells infected with viruses carrying the whole RT or RT domains from subtype C isolates. The single viral genome assay analysis did not reveal significant differences in the frequency of point mutations between the RT from B or C subtypes. Conclusions: These data suggest that the whole RT as well as distinct polymerase and connection-RNase H domains from subtype C HIV-1 confer a lower level of accumulation of reverse transcripts in the virions and reverse transcription complexes as compared to subtype B, resulting in a lower overall level of virus replication

    Cyclic Nucleotide Phosphodiesterases and Compartmentation in Normal and Diseased Heart

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    International audienceCyclic nucleotide phosphodiesterases (PDEs) degrade the second messengers cAMP and cGMP, thereby regulating multiple aspects of cardiac function. This highly diverse class of enzymes encoded by 21 genes encompasses 11 families which are not only responsible for the termination of cyclic nucleotide signalling, but are also involved in the generation of dynamic microdomains of cAMP and cGMP controlling specific cell functions in response to various neurohormonal stimuli. In myocardium, the PDE3 and PDE4 families are predominant to degrade cAMP and thereby regulate cardiac excitation-contraction coupling. PDE3 inhibitors are positive inotropes and vasodilators in human, but their use is limited to acute heart failure and intermittent claudication. PDE5 is particularly important to degrade cGMP in vascular smooth muscle, and PDE5 inhibitors are used to treat erectile dysfunction and pulmonary hypertension. However, these drugs do not seem efficient in heart failure with preserved ejection fraction. There is experimental evidence that these PDEs as well as other PDE families including PDE1, PDE2 and PDE9 may play important roles in cardiac diseases such as hypertrophy and heart failure. After a brief presentation of the cyclic nucleotide pathways in cardiac cells and the major characteristics of the PDE superfamily, this chapter will present their role in cyclic nucleotide compartmentation and the current use of PDE inhibitors in cardiac diseases together with the recent research progresses that could lead to a better exploitation of the therapeutic potential of these enzymes in the future

    Bezlotoxumab for Prevention of Recurrent Clostridium difficile Infection

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    BACKGROUND Clostridium difficile is the most common cause of infectious diarrhea in hospitalized patients. Recurrences are common after antibiotic therapy. Actoxumab and bezlotoxumab are human monoclonal antibodies against C. difficile toxins A and B, respectively. METHODS We conducted two double-blind, randomized, placebo-controlled, phase 3 trials, MODIFY I and MODIFY II, involving 2655 adults receiving oral standard-of-care antibiotics for primary or recurrent C. difficile infection. Participants received an infusion of bezlotoxumab (10 mg per kilogram of body weight), actoxumab plus bezlotoxumab (10 mg per kilogram each), or placebo; actoxumab alone (10 mg per kilogram) was given in MODIFY I but discontinued after a planned interim analysis. The primary end point was recurrent infection (new episode after initial clinical cure) within 12 weeks after infusion in the modified intention-to-treat population. RESULTS In both trials, the rate of recurrent C. difficile infection was significantly lower with bezlotoxumab alone than with placebo (MODIFY I: 17% [67 of 386] vs. 28% [109 of 395]; adjusted difference, −10.1 percentage points; 95% confidence interval [CI], −15.9 to −4.3; P<0.001; MODIFY II: 16% [62 of 395] vs. 26% [97 of 378]; adjusted difference, −9.9 percentage points; 95% CI, −15.5 to −4.3; P<0.001) and was significantly lower with actoxumab plus bezlotoxumab than with placebo (MODIFY I: 16% [61 of 383] vs. 28% [109 of 395]; adjusted difference, −11.6 percentage points; 95% CI, −17.4 to −5.9; P<0.001; MODIFY II: 15% [58 of 390] vs. 26% [97 of 378]; adjusted difference, −10.7 percentage points; 95% CI, −16.4 to −5.1; P<0.001). In prespecified subgroup analyses (combined data set), rates of recurrent infection were lower in both groups that received bezlotoxumab than in the placebo group in subpopulations at high risk for recurrent infection or for an adverse outcome. The rates of initial clinical cure were 80% with bezlotoxumab alone, 73% with actoxumab plus bezlotoxumab, and 80% with placebo; the rates of sustained cure (initial clinical cure without recurrent infection in 12 weeks) were 64%, 58%, and 54%, respectively. The rates of adverse events were similar among these groups; the most common events were diarrhea and nausea. CONCLUSIONS Among participants receiving antibiotic treatment for primary or recurrent C. difficile infection, bezlotoxumab was associated with a substantially lower rate of recurrent infection than placebo and had a safety profile similar to that of placebo. The addition of actoxumab did not improve efficacy. (Funded by Merck; MODIFY I and MODIFY II ClinicalTrials.gov numbers, NCT01241552 and NCT01513239.
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