Search results for "HeLa"

Porous gelatin cryogels as cell delivery tool in tissue engineering.

2007

Protective effect of O6-methylguanine-DNA methyltransferase (MGMT) on the cytotoxic and recombinogenic activity of different antineoplastic drugs

1996

The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) removes alkyl groups from the O6 position of guanine in DNA and thus may protect cells against genotoxic effects of agents inducing this lesion. To analyze quantitatively the level of protection mediated by MGMT against antineoplastic drugs, we determined the cytotoxic and recombinogenic (sister-chromatid exchange inducing) effects of various chemotherapeutic agents in a pair of isogenic Chinese hamster cell lines deficient and proficient for MGMT, generated upon transfection with human MGMT cDNA. Furthermore, we compared the responses of the human cell lines HeLa MR (MGMT deficient) and HeLa S3 (MGMT proficient) to the va…

Human tRNA(Sec) associates with HeLa membranes, cell lipid liposomes, and synthetic lipid bilayers.

2012

We have shown previously that simple RNA structures bind pure phospholipid liposomes. However, binding of bona fide cellular RNAs under physiological ionic conditions is shown here for the first time. Human tRNASec contains a hydrophobic anticodon-loop modification: N6-isopentenyladenosine (i6A) adjacent to its anticodon. Using a highly specific double-probe hybridization assay, we show mature human tRNASec specifically retained in HeLa intermediate-density membranes. Further, isolated human tRNASec rebinds to liposomes from isolated HeLa membrane lipids, to a much greater extent than an unmodified tRNASec transcript. To better define this affinity, experiments with pure lipids show that li…

Phenomenological ontology of breathing : the phenomenologico-ontological interpretation of the barbaric conviction of we breathe air and a new philos…

2018

The general topic of my philosophical dissertation is phenomenological ontology of breathing. I do not investigate the phenomenon of breathing as a natural scientific problem, but as a philosophical question. Within our tradition, breathing has been normally understood as a mechanistic-materialistic physiological life-sustaining process of gas exchange and cellular respiration which does not really seem to have any essential connection to human being’s spiritual, mental or philosophical capacities. On the contrary to this natural scientific view, I argue that breathing can be understood as a philosophical question that has phenomenological, experiential, ontological, spiritual, bodily, ment…

Organometallic Complexes with Biological Molecules: VII. Dialkyl- and Trialkyl-tin (IV)[meso-tetra(4-carboxyphenyl)porphinate] Derivatives: Solid-sta…

1997

The synthesis, the structural features and the in vivo biological activity of diorganotin(IV) and triorganotin(IV) derivatives of [meso-tetra(4-carboxyphenyl)porphine] (H 4 TPPC) are reported. Derivatives with general formula (R 2 Sn) 2 TPPC and (R 3 Sn) 4 TPPC (R=Me, Bu, and Ph) were obtained, and the main information extracted from the infrared and Mossbauer spectral data, in the solid state, was in favor of the occurrence of five-coordinated tin(IV) atoms, in a polymeric trigonal-bipyramidal configuration, attained through two differently coordinated, estertype and chelating respectively, carboxylate anions in [R 2 Sn] 2 TPPC, while in [Alk 3 Sn] 4 TPPC five-coordination of the tin(IV) a…

Studies on the antioxidant activity of the essential oil and extract of Tunisian Tetraclinis articulata (Vahl) Mast. (Cupressaceae).

2013

This study analyses the chemical composition and in vitro antioxidant activity of both the essential oil and the 80% aqueous acetone extract of Tetraclinis articulata leaves. The GC-MS analysis of the essential oil identified 66 components that comprise 93.5% of the oil. The major constituents of the oil are: bornyl acetate (31.4%), α-pinène (24.5%) and camphor (20.3%). Antioxidant activities of the samples were determined using four different test systems, namely DPPH, β-carotene/linoleic acid, reducing power and metal chelating activity assay. Test results from the DPPH system showed the strongest radical scavenging activity was exhibited by the 80% aqueous acetone extract (IC(50) = 5.5 µ…

Front Cover: The Scope of Application of Macrocyclic Polyamines Beyond Metal Chelation (Eur. J. Org. Chem. 36/2019)

2019

International audience

[Aquabis(nitrato-κO)copper(II)]-μ-{bis[5-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl]selenide}-[diaqua(nitrato-κO)copper(II)] nitrate monohydrate

2012

In the title binuclear complex, [Cu2(NO3)3(C18H16N6Se)(H2O)3]NO3·H2O, the Cu(II) ions are penta-coordinated in a tetra-gonal-pyramidal geometry. In both cases, the equatorial planes are formed by a chelating pyrazole-pyridine group, a water mol-ecule and a nitrate O atom, whereas the apical positions are occupied by a water mol-ecule for one Cu(II) ion and a nitrate O atom for the other. The organic selenide ligand adopts a trans configuration with respect to the C-Se-C plane. Numerous inter-molecular O-H⋯O and N-H⋯O hydrogen bonds between the coordinating and lattice water mol-ecules, nitrate anions and pyrazole groups are observed. π-π stacking inter-actions between the pyridine rings [av…

[Di-aqua-sesqui(nitrato-κO)hemi(perchlorato-κO)copper(II)]-μ-{bis-[5-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl] selenide}-[tri-aqua-(perchlorato-κO)cop…

2013

In the binuclear title complex, [Cu2(ClO4)1.5(NO3)1.5(C18H16N6Se)(H2O)5]NO3·H2O, both Cu(II) ions are hexa-coordinated by O and N atoms, thus forming axially elongated CuO4N2 octa-hedra. The equatorial plane of each octa-hedron is formed by one chelating pyrazole-pyridine fragment of the organic ligand and two water mol-ecules. The axial positions in one octa-hedron are occupied by a water mol-ecule and a monodentately coordinated perchlorate anion, while those in the other are occupied by a nitrate anion and a disordered perchlorate/nitrate anion with equal site occupancy. The pyrazole-pyridine units of the organic selenide are trans-oriented to each other with a C-Se-C angle of 96.01 (14)…

[(1R,4S)-(+)-3-Benzoyl-1,7,7-trimethyl­bicyclo­[2.2.1]heptan-2-olato-κ2 O 2,O 3](η4-norbornadiene)rhodium(I)

2010

In the title complex mol-ecule, [Rh(C(17)H(19)O(2))(C(7)H(8))], the rhodium(I) metal centre is coordinated by the O atoms of a benzoyl-camphorate anion and the C=C bonds of the norbornadiene mol-ecule into a slightly distorted square-planar coordination geometry. The six-membered chelate ring is essentially planar (r.m.s. deviation = 0.0378 Å) and forms a dihedral angle of 31.67 (11)° with the phenyl ring.