Remarkable photo-induced anticancer activity of vitamin-S6 Schiff base copper(II) complexes of pyridyl bases

Vitamin-B6 (VB6) Schiff base (H2L) copper(II) complexes of pyridyl bases, viz. Cu(bpy)(L)] (1), Cu(phen)(L)] (2) and Cu(dppz)(L)] (3), where bpy is 2,2'-bipyridine, phen is 1,10-phenanthroline and dppz is dipyrido3,2-a:2',3'c]phenazine are synthesized, characterized and their phto-induced anticancer activity studied. The non-electrolytic one electron paramagnetic complexes exhibit a d-d band near 700 nm in DMF. The dppz complex intercalatively binds to calf-thymus DNA with binding constant (K-b) values of similar to 10(6) M-1. This complex exhibits low chemical nuclease activity but excellent DNA photocleavage activity when irradiated with red light of 705 nm forming (OH)-O-center dot radical. It displays remarkable photocytotoxicity in human cervical cancer cells (HeLa) giving IC50 value of 0.9 mu M in visible light (400-700 nm) while being less toxic in darkness (IC50 : 23 mu M). The cellular uptake of the complexes seems to be via VB6 transporting membrane carrier mediated diffusion pathway. Photo-induced cell death follows apoptotic pathway involving photo-generated intracellular reactive oxygen species.

HSPC117 deficiency in cloned embryos causes placental abnormality and fetal death

Somatic cell nuclear transfer (SCNT) has been successfully used in many species to produce live cloned offspring, albeit with low efficiency. The low frequency of successful development has usually been ascribed to incomplete or inappropriate reprogramming of the transferred nuclear genome. Elucidating the genetic differences between normal fertilized and cloned embryos is key to understand the low efficiency of SCNT. Here, we show that expression of HSPC117, which encodes a hypothetical protein of unknown function, was absent or very low in cloned mouse blastocysts. To investigate the role of HSPC117 in embryo development, we knocked-down this gene in normal fertilized embryos using RNA interference. We assessed the post-implantation survival of HSPC117 knock-down embryos at 3 stages: E9 (prior to placenta formation); E12 (after the placenta was fully functional) and E19 (post-natal). Our results show that, although siRNA-treated in vivo fertilized/produced (IVP) embryos could develop to the blastocyst stage and implanted without any difference from control embryos, the knock-down embryos showed substantial fetal death, accompanied by placental blood clotting, at E12. Furthermore, comparison of HSPC117 expression in placentas of nuclear transfer (NT), intracytoplasmic sperm injection (ICSI) and IVP embryos confirmed that HSPC117 deficiency correlates well with failures in embryo development: all NT embryos with a fetus, as well as IVP and ICSI embryos, had normal placental HSPC117 expression while those NT embryos showing reduced or no expression of HSPC117 failed to form a fetus. In conclusion, we show that HSPC117 is an important gene for post-implantation development of embryos, and that HSPC117 deficiency leads to fetal abnormalities after implantation, especially following placental formation. We suggest that defects in HSPC117 expression may be an important contributing factor to loss of cloned NT embryos in vivo. (C) 2010 Elsevier Inc. All rights reserved.

Outer membrane proteins induced by iron deficiency in Anabaena sp PCC 7120

Iron deficiency can induce cyanobacteria to synthesize siderophore receptor proteins on the outer membrane to enhance the uptake of iron. In this study, an outer membrane of high purity was prepared from Anabaena sp. PCC 7120 based on aqueous polymer two-phase partitioning and discontinuous sucrose density ultra-centrifugation, and the induction of outer membrane proteins by iron deficiency was investigated using 2-D gel electrophoresis. At least. five outer membrane proteins were newly synthesized or significantly up-regulated in cells transferred to iron-deficient conditions, which were all identified to be siderophore receptor proteins according to MALDI-TOF-MS analyses. Bacterial luciferase reporter genes luxAB were employed to monitor the transcription of the encoding genes. The genes were induced by iron deficiency at the transcriptional level in different responsive modes. Luciferase activity expressed from an iron-regulated promoter may be used as a bioreporter for utilizable iron in natural water samples. (C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.

维生素C二步混菌发酵中L-山梨糖脱氢酶的研究

以氧化葡萄糖酸杆菌和巨大芽孢杆菌混合培养物的无细胞抽提液建立了Vc二步发酵离体实验系统.反应体系中加入山梨糖在pH7.0,35℃下保温24h，2-酮基-L-古龙酸（2KGA）生成.巨大芽孢杆菌胞外活性物质对离体系统的产酸没有影响，一定量的L-山梨糖脱氢酶可促进产酸.从氧化葡萄糖酸杆菌细胞质中分离纯化出L-山梨糖脱氢酶.L-山梨糖脱氢酶酶活与2KGA的形成呈正相关：L-山梨糖的转化是在细胞内进行的;亲缘关系相差甚远的伴生菌均能促进小菌产酸，且“伴生”效率相近;伴生菌通过促进产酸菌生长和提高其L-山梨糖脱氢酶比活力而提高发酵系统中L-山梨糖脱氢酶总活力，并且通过促进产酸菌合成新的RNA而增强其代谢力，从而促进产酸;通过对不同发酵时间L-山梨糖脱氢酶酶活及2KGA累积量的比较表明，此酶可作为生产上2KGA生成的实时监控的指示酶;环境因子通过提高酶活力促进产酸.

维生素C二步混菌发酵中伴生菌作用机制的研究

该文对维生素C“二步发酵法”第二步混合发酵中伴生菌对产酸菌——氧化葡萄糖酸杆菌作用机制进行了研究.除巨大芽孢杆菌外，还选用另外几种芽孢杆菌及酵母菌作为产酸菌的伴生菌.各伴生菌及其胞外液对产酸菌生长和2-酮基-L-古龙酸合成能力均有刺激作用，表明产酸菌的伴生菌具有广谱性.利用膜超滤浓缩、柱层析及电泳等技术，从伴生菌B2980胞外液中分离纯化出达电泳均一纯的高纯度活性蛋白质样品，并对其部分基本特性进行分析.结果表明：该活性物质是分子量为36300道尔顿，等电点为4.75的酸性蛋白质，并且是由一个亚基构成的单体蛋白.活性蛋白质的结晶呈规则的菱形形状，其水溶液显著提高产酸菌中SDH酶活性.试验中依伴生菌胞外液对产酸菌中SDH酶活性的作用，建立了该研究中目标活性物质的快速检测方法.

Electrochemical and spectroscopic study of vitamin D-2 by in situ thin layer CD spectroelectrochemistry

The electrooxidation of vitamin D-2 (VD2) was studied by cyclic voltammetry and in situ circular dichroic (CD) spectroelectrochemistry for the first time, The mechanism of electrooxidation and some useful kinetic and adsorption parameters were obtained. The results showed that the oxidation of VD2 in ethanol solution is an irreversible diffusion controlled process following a weak adsorption of the electroinactive product at a glassy carbon electrode, which blocks the electrochemical reaction. The electrooxidation occurs mainly at the triene moieties of the VD2 molecule. The CD spectroelectrochemical data were treated by the double logarithm method together with nonlinear regression, from which the formal potential E-0 = 1.08 V, alphan = 0.245, the standard electrochemical rate constant k(0) = 4.30( +/- 0.58) x 10(-4) cm s(-1) and the adsorption constant beta = 1.77(+/- 0.25) were obtained. (C) 2001 Elsevier Science B.V. All rights reserved.

Voltammetric study of vitamin K-3 at interdigitated array microelectrodes

Cyclic voltammetry of Vitamin K-3 (V-K3) was measured with Pt disk electrode, platinum interdigitated array (Pt-IDA) and Au-IDA microelectrodes in single and dual modes. The effects of pH, scan rate and collector potential on the current of generator and collector were studied. The collection efficiency of V-K3 at IDA electrodes was measured. The linear ranges for current response as a function of V-K3 concentration were found to he 10 mu M-1 mM (i(g)) and 1 mu M - 1 mM (i(c)) for the generator and collector of the Pt-IDA electrode, respectively. The effects of waiting time, potential difference and pulse electrolysis time in differential pulse voltammetry (DPV) on the peak current of V-K3 were studied to get the optimal condition at 0.1 M Na2HPO4, pH 11.50 and 11.0 for Au-IDA and Pt-IDA, respectively.

Anticancer and antiangiogenic activity of surfactant-free nanoparticles based on self-assembled polymeric derivatives of vitamin e: Structure-activity relationship

α-Tocopheryl succinate (α-TOS) is a well-known mitochondrially targeted anticancer compound, however, it is highly hydrophobic and toxic. In order to improve its activity and reduce its toxicity, new surfactant-free biologically active nanoparticles (NP) were synthesized. A methacrylic derivative of α-TOS (MTOS) was prepared and incorporated in amphiphilic pseudoblock copolymers when copolymerized with N-vinylpyrrolidone (VP) by free radical polymerization (poly(VP-co-MTOS)). The selected poly(VP-co-MTOS) copolymers formed surfactant-free NP by nanoprecipitation with sizes between 96 and 220 nm and narrow size distribution, and the in vitro biological activity was tested. In order to understand the structure-activity relationship three other methacrylic monomers were synthesized and characterized: MVE did not have the succinate group, SPHY did not have the chromanol ring, and MPHY did not have both the succinate group and the chromanol ring.

Analysis of the peripheral T-cell compartment in the MHC class II deficiency syndrome.

To analyse the impact of lack of MHC class II expression on the composition of the peripheral T-cell compartment in man, the expression characteristics of several membrane antigens were examined on peripheral blood lymphocytes (PBL) and cultured T cells derived from an MHC-class-II-deficient patient. No MHC class II expression could be detected on either PBL or activated T cells. Moreover, the expression of MHC class I was reduced both on PBL and in vitro activated T cells compared to the healthy control. However, the reduced expression of CD26 observed on the PBL of the patient was restored after in vitro expansion. Despite the presumably class-II-deficient thymic environment, a distinct but reduced single CD4+ T-cell population was observed in the PBL of the patient. After in vitro expansion, the percentage of CD4+ cells dropped even further, most likely due to a proliferative disadvantage, compared to the single CD8+ T-cell population. However, proliferation analysis showed that T-cell activation via the TcR/CD3 pathway is not affected by the MHC class II deficiency.

Antibody deficiency due to a missense mutation in CD19 demonstrates the importance of the conserved tryptophan 41 in immunoglobulin superfamily domain formation.

Immunoglobulin superfamily (IgSF) domains are conserved structures present in many proteins in eukaryotes and prokaryotes. These domains are well-capable of facilitating sequence variation, which is most clearly illustrated by the variable regions in immunoglobulins (Igs) and T cell receptors (TRs). We studied an antibody-deficient patient suffering from recurrent respiratory infections and with impaired antibody responses to vaccinations. Patient's B cells showed impaired Ca(2+) influx upon stimulation with anti-IgM and lacked detectable CD19 membrane expression. CD19 sequence analysis revealed a homozygous missense mutation resulting in a tryptophan to cystein (W52C) amino acid change. The affected tryptophan is CONSERVED-TRP 41 located on the C-strand of the first extracellular IgSF domain of CD19 and was found to be highly conserved, not only in mammalian CD19 proteins, but in nearly all characterized IgSF domains. Furthermore, the tryptophan is present in all variable domains in Ig and TR and was not mutated in 117 Ig class-switched transcripts of B cells from controls, despite an overall 10% amino acid change frequency. In vitro complementation studies and CD19 western blotting of patient's B cells demonstrated that the mutated protein remained immaturely glycosylated. This first missense mutation resulting in a CD19 deficiency demonstrates the crucial role of a highly conserved tryptophan in proper folding or stability of IgSF domains.

Antibody-deficiency and Acute Nephritic Syndrome in a Patient with Homozygous Disruption of the CD81 Gene

info:eu-repo/semantics/nonPublished

Antibody-deficiency and Acute Nephritic Syndrome in a Patient with Homozygous Disruption of the CD81 Gene

info:eu-repo/semantics/nonPublished

CD19-Complex deficiencies :a newly emerging homogeneous antibody deficiency

info:eu-repo/semantics/nonPublished

Modelling the Stoichiometric Regulation of C-Rich Toxins in Marine Dinoflagellates

Toxin production in marine microalgae was previously shown to be tightly coupled with cellular stoichiometry. The highest values of cellular toxin are in fact mainly associated with a high carbon to nutrient cellular ratio. In particular, the cellular accumulation of C-rich toxins (i.e., with C:N > 6.6) can be stimulated by both N and P deficiency. Dinoflagellates are the main producers of C-rich toxins and may represent a serious threat for human health and the marine ecosystem. As such, the development of a numerical model able to predict how toxin production is stimulated by nutrient supply/deficiency is of primary utility for both scientific and management purposes. In this work we have developed a mechanistic model describing the stoichiometric regulation of C-rich toxins in marine dinoflagellates. To this purpose, a new formulation describing toxin production and fate was embedded in the European Regional Seas Ecosystem Model (ERSEM), here simplified to describe a monospecific batch culture. Toxin production was assumed to be composed by two distinct additive terms; the first is a constant fraction of algal production and is assumed to take place at any physiological conditions. The second term is assumed to be dependent on algal biomass and to be stimulated by internal nutrient deficiency. By using these assumptions, the model reproduced the concentrations and temporal evolution of toxins observed in cultures of Ostreopsis cf. ovata, a benthic/epiphytic dinoflagellate producing C-rich toxins named ovatoxins. The analysis of simulations and their comparison with experimental data provided a conceptual model linking toxin production and nutritional status in this species. The model was also qualitatively validated by using independent literature data, and the results indicate that our formulation can be also used to simulate toxin dynamics in other dinoflagellates. Our model represents an important step towards the simulation and prediction of marine algal toxicity.