Antibodies to Cardiolipin in Patients with Primary Biliary Cirrhosis

Antibodies to cardiolipin have been recognized in up to 65% of patients with systemic lupus erythematosus. It has been claimed that they are significantly associated with intravascular thrombosis and with obstetrical complications. Thus far they have been found to be less prevalent in other diseases. Because of the high concentration of cardiolipin in mitochondrial membranes and the presence of antimitochondrial antibodies in patients with primary biliary cirrhosis, the authors investigated the prevalence of antibodies to cardiolipin in a group of 31 patients with primary biliary cirrhosis. lt was found that the prevalence and levels of anticardiolipin antibodies of lgG and lgA isotype are as high in patients with primary biliary cirrhosis as in 35 consecutive patients with systemic lupus erythematosus. None of the patients with primary biliary cirrhosis gave any history of venous or arterial thrombosis. The rate of miscarriage was less than that reported for the general population. The availability for study of a second group of patients with high levels of anticardiolipin antibodies should make it possible to determine whether the association of these antibodies with thrombosis and fetal wastage in patients with systemic lupus erythematosus is a direct relation ship or an epiphenomenon

Preparation and in vitro characterization of novel bioactive glass ceramic nanoparticles

SiO2-CaO-P2O5 ternary bioactive glass ceramic (BGC) nanoparticles with different compositions were prepared via a three-step sol-gel method. Polyethylene glycol was selected to be used as the surfactant to improve the dispersion of the nanoparticles. The morphology and composition of these BGC nanoparticles were observed by ESEM and EDX. All the BGC particles obtained in this method were about 20 nm in diameter. XRD analysis demonstrated that the different compositions can result in very different crystallinities for the BGC nanoparticles. Bioactivity tests in simulated body fluid solution (SBF), and degradability in phosphate buffer solution (PBS), were performed in vitro. SEM, EDX, and XRD were employed to monitor the surface variation of neat poly(L-lactic acid), PLLA, foam and PLLA/BGC porous scaffolds during incubation. The BGC nanoparticles with lower phosphorous and relative higher silicon content exhibited enhanced mineralization capability in SBF and a higher solubility in PBS medium. Such novel nanoparticles may have potential to be used in different biomedical applications, including tissue engineering or the orthopedic field.Contract grant sponsor: FCT; contract grant numbers: POCTI/FIS/61621/2004, SFRH/BPD/25828/2005, PTDC/QUI/69263/200

Co-ordinated expression of amino acid metabolism in response to N and S deficiency during wheat grain filling

Increasing demands for productivity together with environmental concerns about fertilizer use dictate that the future sustainability of agricultural systems will depend on improving fertilizer use efficiency. Characterization of the biological processes responsible for efficient fertilizer use will provide tools for crop improvement under reduced inputs. Transcriptomic and metabolomic approaches were used to study the impact of nitrogen (N) and sulphur (S) deficiency on N and S remobilization from senescing canopy tissues during grain filling in winter wheat (Triticum aestivum). Canopy tissue N was remobilized effectively to the grain after anthesis. S was less readily remobilized. Nuclear magnetic resonance (NMR) metabolite profiling revealed significant effects of suboptimal N or S supply in leaves but not in developing grain. Analysis of amino acid pools in the grain and leaves revealed a strategy whereby amino acid biosynthesis switches to the production of glutamine during grain filling. Glutamine accumulated in the first 7 d of grain development, prior to conversion to other amino acids and protein in the subsequent 21 d. Transcriptome analysis indicated that a down-regulation of the terminal steps in many amino acid biosynthetic pathways occurs to control pools of amino acids during leaf senescence. Grain N and S contents increased in parallel after anthesis and were not significantly affected by S deficiency, despite a suboptimal N:S ratio at final harvest. N deficiency resulted in much slower accumulation of grain N and S and lower final concentrations, indicating that vegetative tissue N has a greater control of the timing and extent of nutrient remobilization than S

The Monitor project: JW 380 -- a 0.26, 0.15 Msol pre main sequence eclipsing binary in the Orion Nebula Cluster

We report the discovery of a low-mass (0.26 +/- 0.02, 0.15 +/- 0.01 Msol) pre-main-sequence eclipsing binary with a 5.3 day orbital period. JW 380 was detected as part of a high-cadence time-resolved photometric survey (the Monitor project) using the 2.5m Isaac Newton Telescope and Wide Field Camera for a survey of a single field in the Orion Nebula Cluster (ONC) region in V and i bands. The star is assigned a 99 per cent membership probability from proper motion measurements, and radial velocity observations indicate a systemic velocity within 1 sigma of that of the ONC. Modelling of the combined light and radial velocity curves of the system gave stellar radii of 1.19 +0.04 -0.18 Rsol and 0.90 +0.17 -0.03 Rsol for the primary and secondary, with a significant third light contribution which is also visible as a third peak in the cross-correlation functions used to derive radial velocities. The masses and radii appear to be consistent with stellar models for 2-3 Myr age from several authors, within the present observational errors. These observations probe an important region of mass-radius parameter space, where there are currently only a handful of known pre-main-sequence eclipsing binary systems with precise measurements available in the literature.Comment: 11 pages, 9 figures, accepted for publication in MNRA

Planetary Dynamics and Habitable Planet Formation In Binary Star Systems

Whether binaries can harbor potentially habitable planets depends on several factors including the physical properties and the orbital characteristics of the binary system. While the former determines the location of the habitable zone (HZ), the latter affects the dynamics of the material from which terrestrial planets are formed (i.e., planetesimals and planetary embryos), and drives the final architecture of the planets assembly. In order for a habitable planet to form in a binary star system, these two factors have to work in harmony. That is, the orbital dynamics of the two stars and their interactions with the planet-forming material have to allow terrestrial planet formation in the habitable zone, and ensure that the orbit of a potentially habitable planet will be stable for long times. We have organized this chapter with the same order in mind. We begin by presenting a general discussion on the motion of planets in binary stars and their stability. We then discuss the stability of terrestrial planets, and the formation of potentially habitable planets in a binary-planetary system.Comment: 56 pages, 29 figures, chapter to appear in the book: Planets in Binary Star Systems (Ed. N. Haghighipour, Springer publishing company

Sensitivity to atypical mycobacterial antigens in patients with Crohn's disease

Twenty-two patients with Crohn's disease were investigated for the presence of delayed cutaneous reactions and precipitating antibodies to atypical mycobacterial antigens of Runyon's Groups I, II and III as well as standard PPD. The results obtained, when compared to the control groups, do not show an increased incidence of sensitivity to such antigens in patients with Crohn's disease. However, their potential relevance to the pathogenesis of this disorder remains to be determined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44374/1/10620_2005_Article_BF02236026.pd

A Genetic Screen Reveals Arabidopsis Stomatal and/or Apoplastic Defenses against Pseudomonas syringae pv. tomato DC3000

Bacterial infection of plants often begins with colonization of the plant surface, followed by entry into the plant through wounds and natural openings (such as stomata), multiplication in the intercellular space (apoplast) of the infected tissues, and dissemination of bacteria to other plants. Historically, most studies assess bacterial infection based on final outcomes of disease and/or pathogen growth using whole infected tissues; few studies have genetically distinguished the contribution of different host cell types in response to an infection. The phytotoxin coronatine (COR) is produced by several pathovars of Pseudomonas syringae. COR-deficient mutants of P. s. tomato (Pst) DC3000 are severely compromised in virulence, especially when inoculated onto the plant surface. We report here a genetic screen to identify Arabidopsis mutants that could rescue the virulence of COR-deficient mutant bacteria. Among the susceptible to coronatine-deficient Pst DC3000 (scord) mutants were two that were defective in stomatal closure response, two that were defective in apoplast defense, and four that were defective in both stomatal and apoplast defense. Isolation of these three classes of mutants suggests that stomatal and apoplastic defenses are integrated in plants, but are genetically separable, and that COR is important for Pst DC3000 to overcome both stomatal guard cell- and apoplastic mesophyll cell-based defenses. Of the six mutants defective in bacterium-triggered stomatal closure, three are defective in salicylic acid (SA)-induced stomatal closure, but exhibit normal stomatal closure in response to abscisic acid (ABA), and scord7 is compromised in both SA- and ABA-induced stomatal closure. We have cloned SCORD3, which is required for salicylic acid (SA) biosynthesis, and SCORD5, which encodes an ATP-binding cassette (ABC) protein, AtGCN20/AtABCF3, predicted to be involved in stress-associated protein translation control. Identification of SCORD5 begins to implicate an important role of stress-associated protein translation in stomatal guard cell signaling in response to microbe-associated molecular patterns and bacterial infection