Association between anti-Ro 60kDa (SS-A) autoantibodies and hypocomplementemia in systemic lupus erythematosus patients from Algiers prefectures

AbstractBackgroundSystemic lupus erythematosus (SLE) is characterized by a vicious cycle maintaining systemic inflammation. It starts by autoantibody production, immune complex formation and complement activation that contribute to inflammation, tissue damage and further autoantibody production.Aim of the workTo evaluate the association between the auto-antibodies (abs), circulating immune complexes (CIC), and complement activity in SLE patients.Patients and methodsThis study involved 30 female SLE patients analyzed for autoantibodies, complement profile including complement hemolytic 50 (CH50), alternative pathway 50, factor B, C1q, C2, C3 and C4 as well as C1q-CIC. SLE disease activity was assessed by the SLE Disease Activity Index (SLEDAI).ResultsThe age of patients was 34±12.8years, disease duration was 5.2±3.2years and their mean SLEDAI was 9.96±4.2. Anti-SSA, anti-dsDNA, anti-C1q abs, and CIC were detected in 36.7%, 50%, 50% and 30% of patients, respectively. Anti-SSA were higher in patients with lower compared to normal CH50 activity and C3 level (24.7 vs 88.6U/ml; p=0.002 and 118.6±25.18U/ml vs 15.9±7.3; p<0.0001 respectively) than the other autoantibodies. Increased CIC were higher in patients with lupus nephritis and were associated with anti-SSA, anti-SSB, anti-C1q, anti-Sm and in patients with low CH50 activity. The CIC significantly correlated with anti-C1q (r=0.69, p<0.0001), anti-SSA (r=0.5, p=0.005) and negatively with CH50 (r=−0.4, p=0.046).ConclusionsThe current study confirms that the etiopathogenic anti-SSA autoantibodies are the most associated with hypocomplementemia in SLE. This would stimulate future researches for validation of predictive biomarkers earlier than hypocomplementemia which is still the major unmet need in lupus research and patient care

First-principles study of the electrooptic effect in ferroelectric oxides

We present a method to compute the electrooptic tensor from first principles, explicitly taking into account the electronic, ionic and piezoelectric contributions. It allows us to study the non-linear optic behavior of three ferroelectric ABO_3 compounds : LiNbO_3, BaTiO_3 and PbTiO_3. Our calculations reveal the dominant contribution of the soft mode to the electrooptic coefficients in LiNbO_3 and BaTiO_3 and identify the coupling between the electric field and the polar atomic displacements along the B-O chains as the origin of the large electrooptic response in these compounds.Comment: accepted for publication in Phys. Rev. Let

DYNAMIC DISORDER AT INTERMEDIATE TEMPERATURE AND ITS EFFECT ON THE MAGNETIC PROPERTIES OF THE ORGANIC SUPERCONDUCTOR κ-(BEDTTTF)2Cu[N(CN)2]Br

The k-(BEDT-TTF)X superconducting salts, [where BEDT-TTF is bis(ethylenedithio)-tetrathiafulvalene, abbreviated as ET, and X is a monovalent anion like Cu[N(CN) ]Br 2 , and for either Cu[N(CN) ]Cl 2 or ( )2 Cu NCN and so on], exhibit interestinmagnetic and superconducting phase transitions [1]. They are quasi-two-dimensional and the interplane coupling is very weak. The basic structural unit is a dimer consisting of two BEDTTTF molecules stacked on top of one another. This layered structure leads to highly anisotropic electronic properties. These organic superconductors have similar characteristic superconducting properties including the intrinsic Josephson Effect and the mixed-state properties. This similarity suggests the existence of the vortex phase transition in the organic layered superconductors as observed in HTSC. Because the temperature scale is much lower in organic materials, the thermal fluctuation is expected to be small compared to HTSC. Thus, the comparison between the high-Tc and organic superconductors can give important clues as to the nature of vortex phase transitions. Besides these anomalies around 50 K, unusual time dependencies in magnetic and transport properties have been reported for both deuterated and hydrogenated k-Br near 80 K. For - H - Br 8 k , the superconducting properties have been found to depend on the thermal history, in particular on how fast the sample had been cooled through 80 K. As mentioned above, the ground state of - D - Br 8 k is strongly sample-dependent: both superconducting as well as non-superconducting crystals are found. Furthermore, superconducting as well as insulating (possibly antiferromagnetic) phases in separated volume parts of the same sample have been reported. Their relative volume fraction was found to depend on the cooling rate Vc employed at around 80 K[2-3-4]: in fast cooled samples, a strong decrease of the diamagnetic signal has been observed, which has been interpreted as indicating a suppression of the superconducting in favour of the magnetic phase

A study of sorghum production potential in the semi-arid tropic of Brazil.

The paper presents the application of a computerized agroclimatic system to the study ofsorghum production potential in the semi-arid tropic of Brazil. After a brief description of the system, the results obtainae for a sample of counties are discussed. In particular, the paper illustrates the use of clustering techniques in connection to agroclimatic zoning. The use of the system in relation to complementary irrigaton studies is also stressed.bitstream/item/179497/1/FL-06852.pd

Vortex phase transition and superconducting properties of organic quasi-two-dimensional k-(BEDT-TTF) 2 Cu[N(CN) 2 ]Br

International audienceWe report investigations of the low temperature dc susceptibility and the magnetization on the layered organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br near 80K and the effect of disorder on the superconducting transition temperature Tc. The shielding effect (S) and the critical current density Jc were studied (with H parallel to the c axis of the crystal). Jc can be estimated by analysis of magnetic hysteresis measurement using the Bean model. For each temperature value, we observed two regimes in the critical current density Jc(H). This result implies that there exists a first-order phase transition in the vortex system in this organic superconductor. Our results show that the magnetic properties of these compounds depend strongly on the cooling rate. The structural transformation which occurs at the vicinity of 80K very strongly influences the physics of vortex lattice and the associated magnetic behavior

Crescimento e produção do feijoeiro em resposta à profundidade de aplicação de adubo fosfatado

Several depths (0, 5, 10, 15, 20, 25 and 30 cm) of fertilizer application were studied to observe the growth and development of roots and aerial parts of bean plants (Phaseolus vulgaris L.) in a clayey texture Purple Latosol (Haplortox). Aerial parts were enhanced by fertilizer placed from 10 to 25 cm of depth. Grain yield, however, was equal in all of the treatments, due to an adequate water supply even in the dry season. Toot weight, which was evaluated in greenhouse in PVC tubes with openings each 5 cm up to 30 cm, was influenced by the fertilizer, being increased in those layers where it was applied.Foram estudados os efeitos de diversas profundidades (0, 5, 10, 15, 20, 25 e 30 cm) de aplicação de adubo fosfatado, no crescimento e desenvolvimento de raízes e partes aéreas do feijoeiro (Phaseolus vulgaris L.), em um Latossolo Roxo (Haplortox), textura argilosa. Na avaliação das partes aéreas das plantas notaram-se valores maiores nos tratamentos de 10 a 25 cm de profundidade de aplicação do adubo. Contudo, as produções de grãos se igualaram nos tratamentos, graças ao regime hídrico satisfatório, ocorrido, inclusive, no período da seca. O crescimento das raízes, que foi avaliado em casa de vegetação, em tubos de PVC com uma abertura a cada 5 cm até 30 cm, acusou aumento de peso nas secções adubadas

KAT Ligation for Rapid and Facile Covalent Attachment of Biomolecules to Surfaces

The efficient and bioorthogonal chemical ligation reaction between potassium acyltrifluoroborates (KATs) and hydroxylamines (HAs) was used for the surface functionalization of a self-assembled monolayer (SAM) with biomolecules. An alkane thioether molecule with one terminal KAT group (S-KAT) was synthesized and adsorbed onto a gold surface, placing a KAT group on the top of the monolayer (KAT-SAM). As an initial test case, an aqueous solution of a hydroxylamine (HA) derivative of poly(ethylene glycol) (PEG) (HA-PEG) was added to this KAT-SAM at room temperature to perform the surface KAT ligation. Quartz crystal microbalance with dissipation (QCM-D) monitoring confirmed the rapid attachment of the PEG moiety onto the SAM. By surface characterization methods such as contact angle and ellipsometry, the attachment of PEG layer was confirmed, and covalent amide-bond formation was established by X-ray photoelectron spectroscopy (XPS). In a proof-of-concept study, the applicability of this surface KAT ligation for the attachment of biomolecules to surfaces was tested using a model protein, green fluorescent protein (GFP). A GFP was chemically modified with an HA linker to synthesize HA-GFP and added to the KAT-SAM under aqueous dilute conditions. A rapid attachment of the GFP on the surface was observed in real time by QCM-D. Despite the fact that such biomolecules have a variety of unprotected functional groups within their structures, the surface KAT ligation proceeded rapidly in a chemoselective manner. Our results demonstrate the versatility of the KAT ligation for the covalent attachment of a variety of water-soluble molecules onto SAM surfaces under dilute and biocompatible conditions to form stable, natural amide bonds

Common Co-activation of AXL and CDCP1 in EGFR-mutation-positive Non-smallcell Lung Cancer Associated With Poor Prognosis.

Epidermal growth factor receptor (EGFR)-mutation-positive non-smallcell lung cancer (NSCLC) is incurable, despite high rates of response to EGFR tyrosine kinase inhibitors (TKIs). We investigated receptor tyrosine kinases (RTKs), Src family kinases and focal adhesion kinase (FAK) as genetic modifiers of innate resistance in EGFR-mutation-positive NSCLC. We performed gene expression analysis in two cohorts (Cohort 1 and Cohort 2) of EGFR-mutation-positive NSCLC patients treated with EGFR TKI. We evaluated the efficacy of gefitinib or osimertinib with the Src/FAK/Janus kinase 2 (JAK2) inhibitor, TPX0005 in vitro and in vivo. In Cohort 1, CUB domain-containing protein-1 (CDCP1) was an independent negative prognostic factor for progression-free survival (hazard ratio of 1.79, p=0.0407) and overall survival (hazard ratio of 2.23, p=0.0192). A two-gene model based on AXL and CDCP1 expression was strongly associated with the clinical outcome to EGFR TKIs, in both cohorts of patients. Our preclinical experiments revealed that several RTKs and non-RTKs, were up-regulated at baseline or after treatment with gefitinib or osimertinib. TPX-0005 plus EGFR TKI suppressed expression and activation of RTKs and downstream signaling intermediates. Co-expression of CDCP1 and AXL is often observed in EGFR-mutation-positive tumors, limiting the efficacy of EGFR TKIs. Co-treatment with EGFR TKI and TPX-0005 warrants testing

Cell-cell adhesion regulates Merlin/NF2 interaction with the PAF complex

The PAF complex (PAFC) coordinates transcription elongation and mRNA processing and its CDC73/parafibromin subunit functions as a tumour suppressor. The NF2/Merlin tumour suppressor functions both at the cell cortex and nucleus and is a key mediator of contact inhibition but the molecular mechanisms remain unclear. In this study we have used affinity proteomics to identify novel Merlin interacting proteins and show that Merlin forms a complex with multiple proteins involved in RNA processing including the PAFC and the CHD1 chromatin remodeller. Tumour-derived inactivating mutations in both Merlin and the CDC73 PAFC subunit mutually disrupt their interaction and growth suppression by Merlin requires CDC73. Merlin interacts with the PAFC in a cell density-dependent manner and we identify a role for FAT cadherins in regulating the Merlin-PAFC interaction. Our results suggest that in addition to its function within the Hippo pathway, Merlin is part of a tumour suppressor network regulated by cell-cell adhesion which coordinates post-initiation steps of the transcription cycle of genes mediating contact inhibition