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61.
Dimas K Hatziantoniou S Tseleni S Khan H Georgopoulos A Alevizopoulos K Wyche JH Pantazis P Demetzos C 《Apoptosis : an international journal on programmed cell death》2007,12(4):685-694
Labd-14-ene-8, 13-diol (sclareol) is a labdane-type diterpene, which has demonstrated significant cytotoxic activity against
human leukemic cell lines, but its effect on solid tumor-derived cells is uknown. Here, we demonstrate that addition of sclareol
to cultures of human colon cancer HCT116 cells results in inhibition of DNA synthesis, arrest of cells at the G1 phase of the cell cycle, activation of caspases-8, -9, PARP degradation, and DNA fragmentation, events characteristic of
induction of apoptosis. Intraperitoneal (ip) administration of sclareol alone, at the maximum tolerated dose, was unable to
induce suppression of growth of HCT116 tumors established as xenografts in immunodeficient SCID mice. In contrast, ip administration
of liposome-encapsulated sclareol, following a specific schedule, induced suppression of tumor growth by arresting tumor cell
proliferation as assessed by detecting the presence of the cell proliferation-associated nuclear protein, Ki67, in thin tumor
sections. These findings suggest that sclareol incorporated into liposomes may possess chemotherapeutic potential for the
treatment of colorectal and other types of human cancer. 相似文献
62.
A Robust Structural PGN Model for Control of Cell-Cycle Progression Stabilized by Negative Feedbacks
Nestor Walter Trepode Hugo Aguirre Armelin Michael Bittner Junior Barrera Marco Dimas Gubitoso Ronaldo Fumio Hashimoto 《EURASIP Journal on Bioinformatics and Systems Biology》2007,2007(1):73109
The cell division cycle comprises a sequence of phenomena controlled by a stable and robust genetic network. We applied a probabilistic genetic network (PGN) to construct a hypothetical model with a dynamical behavior displaying the degree of robustness typical of the biological cell cycle. The structure of our PGN model was inspired in well-established biological facts such as the existence of integrator subsystems, negative and positive feedback loops, and redundant signaling pathways. Our model represents genes interactions as stochastic processes and presents strong robustness in the presence of moderate noise and parameters fluctuations. A recently published deterministic yeast cell-cycle model does not perform as well as our PGN model, even upon moderate noise conditions. In addition, self stimulatory mechanisms can give our PGN model the possibility of having a pacemaker activity similar to the observed in the oscillatory embryonic cell cycle. 相似文献
63.
Alessandra P. Vieira Graciele Berndt Ivan G. de Souza Junior Eduardo Di Mauro Andrea PaesanoJr Henrique de Santana Antonio Carlos S. da Costa Cássia T. B. V. Zaia Dimas A. M. Zaia 《Amino acids》2011,40(1):205-214
In the present paper, the adsorption of cysteine on hematite, magnetite and ferrihydrite was studied using FT-IR, electron paramagnetic resonance (EPR), Mössbauer spectroscopy and X-ray diffractometry. Cysteine was dissolved in artificial seawater (two different pHs) which contains the major constituents. There were two main findings described in this paper. First, after the cysteine adsorption, the FT-IR spectroscopy and X-ray diffractometry data showed the formation of cystine. Second, the Mössbauer spectroscopy did not show any increase in the amount of Fe2+ as expected due the oxidation of cysteine to cystine. An explanation could be that Fe2+ was oxidized by the oxygen present in the seawater or there occurred a reduction of cystine by Fe2+ generating cysteine and Fe3+. The specific surface area and pH at point of zero charge of the iron oxides were influenced by adsorption of cysteine. When compared to other iron oxides, ferrihydrite adsorbed significantly (p < 0.05) more cysteine. The pH has a significant (p < 0.05) effect only on cysteine adsorption on hematite. The FT-IR spectroscopy results showed that cystine remains adsorbed on the surface of the iron oxides even after being mixed with KCl and the amine and carboxylic groups are involved in this interaction. X-ray diffractometry showed no changes on iron oxides mineralogy and the following precipitated substances were found along with the iron oxides after drying the samples: cysteine, cystine and seawater salts. The EPR spectroscopy showed that cysteine interacts with iron oxides, changing the relative amounts of iron oxides and hydroxide. 相似文献
64.
Cristine E. A. Carneiro Graciele Berndt Ivan G. de Souza Junior Cl��udio M. D. de Souza Andrea Paesano Jr Antonio C. S. da Costa Eduardo di Mauro Henrique de Santana C��ssia T. B. V. Zaia Dimas A. M. Zaia 《Origins of life and evolution of the biosphere》2011,41(5):453-468
In the present work the interactions of nucleic acid bases with and adsorption on clays were studied at two pHs (2.00, 7.00) using different techniques. As shown by Mössbauer and EPR spectroscopies and X-ray diffractometry, the most important finding of this work is that nucleic acid bases penetrate into the interlayer of the clays and oxidize Fe2+ to Fe3+, thus, this interaction cannot be regarded as a simple physical adsorption. For the two pHs the order of the adsorption of nucleic acid bases on the clays was: adenine????cytosine?>?thymine?>?uracil. The adsorption of adenine and cytosine on clays increased with decreasing of the pH. For unaltered montmorillonite this result could be explained by electrostatic forces between adenine/cytosine positively charged and clay negatively charged. However for montmorillonite modified with Na2S, probably van der Waals forces also play an important role since both adenine/cytosine and clay were positively charged. FT-IR spectra showed that the interaction between nucleic acid bases and clays was through NH+ or NH 2 + groups. X-ray diffractograms showed that nucleic acid bases adsorbed on clays were distributed into the interlayer surface, edge sites and external surface functional groups (aluminol, silanol) EPR spectra showed that the intensity of the line g????2 increased probably because the oxidation of Fe2+ to Fe3+ by nucleic acid bases and intensity of the line g?=?4.1 increased due to the interaction of Fe3+ with nucleic acid bases. Mössbauer spectra showed a large decreased on the Fe2+ doublet area of the clays due to the reaction of nucleic acid bases with Fe2+. 相似文献
65.
Fontes AM Kashima S Bonfim-Silva R Azevedo R Abraham KJ Albuquerque SR Bordin JO Júnior DM Covas DT 《Genetics and molecular biology》2011,34(4):539-545
Complement receptor 1 (CR1) gene polymorphisms that are associated with Knops blood group antigens may influence the binding of Plasmodium parasites to erythrocytes, thereby affecting susceptibility to malaria. The aim of this study was to evaluate the genotype and allele and haplotype frequencies of single-nucleotide polymorphisms (SNPs) of Knops blood group antigens and examine their association with susceptibility to malaria in an endemic area of Brazil. One hundred and twenty-six individuals from the Brazilian Amazon were studied. The CR1-genomic fragment was amplified by PCR and six SNPs and haplotypes were identified after DNA sequence analysis. Allele and haplotype frequencies revealed that the Kn(b) allele and H8 haplotype were possibly associated with susceptibility to Plasmodium falciparum. The odds ratios were reasonably high, suggesting a potentially important association between two Knops blood antigens (Kn(b) and KAM(+)) that confer susceptibility to P. falciparum in individuals from the Brazilian Amazon. 相似文献
66.
Picanco-Castro V de Sousa Russo-Carbolante EM Tadeu Covas D 《Recent patents on DNA & gene sequences》2012,6(2):82-90
Lentiviral vectors are at the forefront of gene delivery systems for research and clinical applications. These vectors have the ability to efficiently transduce nondividing and dividing cells, to insert large genetic segment in the host chromatin, and to sustain stable long-term transgene expression. Most of lentiviral vectors systems in use are derived from HIV-1. Numerous modifications in the basic HIV structure have been made to ensure safety and to promote efficiency to vectors. Lentiviral vectors can be pseudotyped with distinct viral envelopes that influence vector tropism and transduction efficiency. Moreover, these vectors can be used to reprogram cells and generate induced pluripotent stem cells. This review aims to show the patents that resulted in improved safety and efficacy of lentiviral vector with important implications for clinical trials. 相似文献
67.
Riganas S Papanastasiou I Foscolos GB Tsotinis A Bourguignon JJ Serin G Mirjolet JF Dimas K Kourafalos VN Eleutheriades A Moutsos VI Khan H Georgakopoulou S Zaniou A Prassa M Theodoropoulou M Pondiki S Vamvakides A 《Bioorganic & medicinal chemistry》2012,20(10):3323-3331
The synthesis of N-{4-[a-(1-adamantyl)benzyl]phenyl}piperazines 2a-e is described. The in vitro antiproliferative activity of most compounds against main cancer cell lines is significant. The σ(1), σ(2)-receptors and sodium channels binding affinity of compounds 2 were investigated. One of the most active analogs, 2a, had an interesting in vivo anticancer profile against the BxPC-3 and Mia-Paca-2 pancreas cancer cell lines with caspase-3 activation, which was associated with an anagelsic activity against the neuropathic pain. 相似文献
68.
We describe the isolation and characterization of ten microsatellite loci from the red-winged tinamou (Rhynchotus rufescens) and also evaluated the cross-amplification of these loci and other ten loci previously developed for the great tinamou (Tinamus major) in other tinamous. Genetic variability was assessed using 24 individuals. Six loci were polymorphic with moderate to high
number of alleles per locus (2–12 alleles) and showed expected heterozygosity (HE) ranging from 0.267 to 0.860. All loci conformed
to the Hardy–Weinberg expectation and linkage disequilibrium was not significant for any pair of loci. This battery of polymorphic
loci showed high paternity exclusion probability (0.986) and low genetic identity probability (4.95 × 10−5), proving to be helpful for parentage tests and population analyses in the red-winged tinamou. The cross-amplification was
moderate where of the 160 locus/taxon combinations, 46 (28.75%) successfully amplified. 相似文献
69.
The demand for recombinant therapeutic proteins is significantly increasing. There is a constant need to improve the existing expression systems, and also developing novel approaches to face the therapeutic proteins demands. Human cell lines have emerged as a new and powerful alternative for the production of human therapeutic proteins because this expression system is expected to produce recombinant proteins with post translation modifications more similar to their natural counterpart and reduce the potential immunogenic reactions against nonhuman epitopes. Currently, little information about the cultivation of human cells for the production of biopharmaceuticals is available. These cells have shown efficient production in laboratory scale and represent an important tool for the pharmaceutical industry. This review presents the cell lines available for large-scale recombinant proteins production and evaluates critically the advantages of this expression system in comparison with other expression systems for recombinant therapeutic protein production. 相似文献
70.