A rapid microwave-assisted procedure for easy access to Nx polydentate ligands for potential application in α-RIT

International audienceHeterocycles bearing a hydrazine moiety react with bisaldehydes or bisketones to afford new Nx polydentate ligands suitable for α-radioimmunotherapy. We developed a fast and efficient method using microwave-assisted technology to obtain chelators with variable size and number of coordination centres which were fully characterized. The complexation efficiency with astatine will be assessed

Production/maintenance cooperative scheduling using multi-agents and fuzzy logic

Within companies, production is directly concerned with the manufacturing schedule, but other services like sales, maintenance, purchasing or workforce management should also have an influence on this schedule. These services often have together a hierarchical relationship, i.e. the leading function (most of the time sales or production) generates constraints defining the framework within which the other functions have to satisfy their own objectives. We show how the multi-agent paradigm, often used in scheduling for its ability to distribute decision-making, can also provide a framework for making several functions cooperate in the schedule performance. Production and maintenance have been chosen as an example: having common resources (the machines), their activities are actually often conflicting. We show how to use a fuzzy logic in order to model the temporal degrees of freedom of the two functions, and show that this approach may allow one to obtain a schedule that provides a better compromise between the satisfaction of the respective objectives of the two functions

Oligomeric Status and Nucleotide Binding Properties of the Plastid ATP/ADP Transporter 1: Toward a Molecular Understanding of the Transport Mechanism

Background: Chloroplast ATP/ADP transporters are essential to energy homeostasis in plant cells. However, their molecular mechanism remains poorly understood, primarily due to the difficulty of producing and purifying functional recombinant forms of these transporters. Methodology/Principal Findings: In this work, we describe an expression and purification protocol providing good yields and efficient solubilization of NTT1 protein from Arabidopsis thaliana. By biochemical and biophysical analyses, we identified the best detergent for solubilization and purification of functional proteins, LAPAO. Purified NTT1 was found to accumulate as two independent pools of well folded, stable monomers and dimers. ATP and ADP binding properties were determined, and Pi, a co-substrate of ADP, was confirmed to be essential for nucleotide steady-state transport. Nucleotide binding studies and analysis of NTT1 mutants lead us to suggest the existence of two distinct and probably inter-dependent binding sites. Finally, fusion and deletion experiments demonstrated that the C-terminus of NTT1 is not essential for multimerization, but probably plays a regulatory role, controlling the nucleotide exchange rate. Conclusions/Significance: Taken together, these data provide a comprehensive molecular characterization of a chloroplas

Crystal Structure of Escherichia coli CusC, the Outer Membrane Component of a Heavy Metal Efflux Pump

Background: While copper has essential functions as an enzymatic co-factor, excess copper ions are toxic for cells, necessitating mechanisms for regulating its levels. The cusCBFA operon of E. coli encodes a four-component efflux pump dedicated to the extrusion of Cu(I) and Ag(I) ions. Methodology/Principal Findings: We have solved the X-ray crystal structure of CusC, the outer membrane component of the Cus heavy metal efflux pump, to 2.3 A ˚ resolution. The structure has the largest extracellular opening of any outer membrane factor (OMF) protein and suggests, for the first time, the presence of a tri-acylated N-terminal lipid anchor. Conclusions/Significance: The CusC protein does not have any obvious features that would make it specific for metal ions, suggesting that the narrow substrate specificity of the pump is provided by other components of the pump, most likely by the inner membrane component CusA

Roles of IP3R and RyR Ca2+ Channels in Endoplasmic Reticulum Stress and β-Cell Death

OBJECTIVE—Endoplasmic reticulum (ER) stress has been implicated in the pathogenesis of diabetes, but the roles of specific ER Ca2+ release channels in the ER stress–associated apoptosis pathway remain unknown. Here, we examined the effects of stimulating or inhibiting the ER-resident inositol trisphosphate receptors (IP3Rs) and the ryanodine receptors (RyRs) on the induction of β-cell ER stress and apoptosis

Mdm2-SNP309 polymorphism in prostate cancer: no evidence for association with increased risk or histopathological tumour characteristics

The search for inherited cancer susceptibility factors is a major focus of epidemiologic cancer studies. Analyses of single-nucleotide polymorphisms (SNP) in a variety of genes revealed a correlation between a specific allele variant and cancer predisposition. Human mouse double-minute 2 protein (Mdm2) is a cellular E3 ligase capable of ubiquitination and degradation of p53. Therefore, Mdm2 is a crucial factor of cell cycle control and cell survival. The Mdm2 promoter SNP309 was shown to increase Mdm2 expression and can, thereby, inhibit the p53 pathway. This SNP was found to be associated with increased risk and early onset of various malignancies. For prostate cancer no studies are reported to date. In a case–control study we determined the distribution of the Mdm2 SNP309 in 145 male subjects with prostate cancer and in 124 male controls without any malignancy using RFLP analysis. Cases and controls showed a similar distribution of the SNP (P=0.299). Genotype distribution showed neither an association with histopathological characteristics of the tumours nor with prognosis. Age at disease onset was also not modified by the SNP. This first study of the Mdm2 SNP309 in prostate cancer patients suggests no correlation between a certain allelic variant and an increased cancer risk

Silibinin induces mitochondrial NOX4-mediated endoplasmic reticulum stress response and its subsequent apoptosis

Background: Silibinin, a biologically active compound of milk thistle, has chemopreventive effects on cancer cell lines. Recently it was reported that silibinin inhibited tumor growth through activation of the apoptotic signaling pathway. Although various evidences showed multiple signaling pathways of silibinin in apoptosis, there were no reports to address the clear mechanism of ROS-mediated pathway in prostate cancer PC-3 cells. Several studies suggested that reactive oxygen species (ROS) play an important role in various signaling cascades, but the primary source of ROS was currently unclear. Methods: The effect of silibinin was investigated on cell growth of prostate cell lines by MTT assay. We examined whether silibinin induced apoptosis through production of ROS using flow cytometry. Expression of apoptosis-, endoplasmic reticulum (ER)-related protein and gene were determined by western blotting and RT-PCR, respectively. Results: Results showed that silibinin triggered mitochondrial ROS production through NOX4 expression and finally led to induce apoptosis. In addition, mitochondrial ROS caused ER stress through disruption of Ca2+ homeostasis. Co-treatment of ROS inhibitor reduced the silibinin-induced apoptosis through the inhibition of NOX4 expression, resulting in reduction of both Ca2+ level and ER stress response. Conclusions: Taken together, silibinin induced mitochondrial ROS-dependent apoptosis through NOX4, which is associated with disruption of Ca2+ homeostasis and ER stress response. Therefore, the regulation of NOX4, mitochondrial ROS producer, could be a potential target for the treatment of prostate cancer.ope

IGL-1 solution reduces endoplasmic reticulum stress and apoptosis in rat liver transplantation

Injury due to cold ischemia reperfusion (I/R) is a major cause of primary graft non-function following liver transplantation. We postulated that I/R-induced cellular damage during liver transplantation might affect the secretory pathway, particularly at the endoplasmic reticulum (ER). We examined the involvement of ER stress in organ preservation, and compared cold storage in University of Wisconsin (UW) solution and in Institute Georges Lopez-1 (IGL-1) solution. In one group of rats, livers were preserved in UW solution for 8 h at 4 °C, and then orthotopic liver transplantation was performed according to Kamada's cuff technique. In another group, livers were preserved in IGL-1 solution. The effect of each preservation solution on the induction of ER stress, hepatic injury, mitochondrial damage and cell death was evaluated. As expected, we found increased ER stress after liver transplantation. IGL-1 solution significantly attenuated ER damage by reducing the activation of three pathways of unfolded protein response and their effector molecules caspase-12, C/EBP homologous protein-10, X-box-binding protein 1, tumor necrosis factor-associated factor 2 and eukaryotic translation initiation factor 2. This attenuation of ER stress was associated with a reduction in hepatic injury and cell death. Our results show that IGL-1 solution may be a useful means to circumvent excessive ER stress reactions associated with liver transplantation, and may optimize graft quality

Monoclonal antibodies directed to fucoidan preparations from brown algae

Cell walls of the brown algae contain a diverse range of polysaccharides with useful bioactivities. The precise structures of the sulfated fucan/fucoidan group of polysaccharides and their roles in generating cell wall architectures and cell properties are not known in detail. Four rat monoclonal antibodies, BAM1 to BAM4, directed to sulfated fucan preparations, have been generated and used to dissect the heterogeneity of brown algal cell wall polysaccharides. BAM1 and BAM4, respectively, bind to a non-sulfated epitope and a sulfated epitope present in the sulfated fucan preparations. BAM2 and BAM3 identified additional distinct epitopes present in the fucoidan preparations. All four epitopes, not yet fully characterised, occur widely within the major brown algal taxonomic groups and show divergent distribution patterns in tissues. The analysis of cell wall extractions and fluorescence imaging reveal differences in the occurrence of the BAM1 to BAM4 epitopes in various tissues of Fucus vesiculosus. In Ectocarpus subulatus, a species closely related to the brown algal model Ectocarpus siliculosus, the BAM4 sulfated epitope was modulated in relation to salinity levels. This new set of monoclonal antibodies will be useful for the dissection of the highly complex and yet poorly resolved sulfated polysaccharides in the brown algae in relation to their ecological and economic significance

Recent advances in radiotherapy

Radiation therapy has come a long way from treatment planning based on orthogonal radiographs with large margins around tumours. Advances in imaging and radiation planning software have led to three-dimensional conformal radiotherapy and, further, to intensity modulated radiotherapy (IMRT). IMRT permits sparing of normal tissues and hence dose-escalation to tumours. IMRT is the current standard in treatment of head and prostate cancer and is being investigated in other tumour sites. Exquisitely sculpted dose distributions (increased geographical miss) with IMRT, plus tumour motion and anatomical changes during radiotherapy make image guided radiotherapy an essential part of modern radiation delivery. Various hardware and software tools are under investigation for optimal IGRT