54 research outputs found

    Spectroscopic studies on the anticancer antibiotic Altromycin H and the interaction with copper(II) ions

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    The antitumor antibiotic Altromycin H was studied using electronic absorption (UV-Vis.) and circular dichroism (CD) spectroscopy. The dissociation constants of the phenolic groups on C(5) and C(11) were estimated as pK 1 = 6.7 and pK 2 = 11.8 at 25°C, respectively, and a complete assignment of the CD and UV-Vis. bands is proposed. The interaction of Cu(II) ions with the Altromycin H has been also investigated by UV-Vis., CD and electron paramagnetic resonance (EPR) spectroscopy. A pH depended stepwise complex formation was observed. At pH < 4 no copper-Altromycin H interactions were detected. At the 4 < pH < 8 the Cu(II) ions coordinate to Altromycin H via the C(4)O and C(5)OH groups atoms of the chromophore ring and the [Cu(AltroH) 2] complex (formation constant, K f, 4.00 ± 0.9 × 10 11 M -2 at 25°C) is the predominant species. In alkaline solution the hydroxo-bridged complex, [Cu(OH)(AltroH)] 2, is proposed to be as the unique present species. © 2004 Elsevier Inc. All rights reserved

    Interactions of the anticancer antibiotic altromycin B with copper(II), palladium(II) and platinum(II) ions and in vitro activity of the formed complexes

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    Interaction of the anticancer antibiotic altromycin B with Cu(II), Pd(II) and Pt(II) ions was studied using 1H-NMR, EPR, electronic absorption and circular dichroism spectroscopy. The results derived from NMR studies where that the Pt(II) and Pd(II) ions interact with the nitrogen atom of the dimethylamino group of the C(10)-disaccharide, while the C(2)-epoxide group does not participate and remains intact. Cu(II) ions interact in a different way with altromycin B as was concluded by EPR and circular dichroism spectra. Altromycin B coordinates to the Cu(II) ions via the oxygen atoms of the C(11) phenolic and the C(12) carbonyl group while the nitrogen atom does not participate in the complexation. The presence of these metal ions improves the stability of altromycin B in solution. These complexes were studied in vitro against K562 leukemia sensitive and doxorubicin-resistant cells and GLC4 lung tumor cells, sensitive and doxorubicin-resistant. The activity of the complexes compared to the free drug is improved against resistant cells and is affected moderately against sensitive cells. Finally, 20% of platinum added as altromycin B metal complex entered GLC4 cells. Copyright © 2001 Elsevier Science Inc

    Biogeochemistry of lead in an urban forest in Athens, Greece

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    The distribution and cycling of lead (Pb) was examined in an urban forest of Aleppo pine stand in Athens. Concentrations of the soluble fraction of Pb in bulk and throughfall deposition were low, reflectingthe change in petrol form in recent years. However, Pb concentrations in forest floor remain high due to Pb accumulation in previous years. The soil A horizon showed unexpectedly high levels of Pb concentration resulted probably from Pb migration from organic horizons. Pb concentrations in pine needles, litterfall and wood were low, whereas tree bark acted as a sink for Pb and stored high amounts of the metal. © Springer 2005

    Biogeochemistry of lead in an urban forest in Athens, Greece

    No full text
    The distribution and cycling of lead (Pb) was examined in an urban forest of Aleppo pine stand in Athens. Concentrations of the soluble fraction of Pb in bulk and throughfall deposition were low, reflectingthe change in petrol form in recent years. However, Pb concentrations in forest floor remain high due to Pb accumulation in previous years. The soil A horizon showed unexpectedly high levels of Pb concentration resulted probably from Pb migration from organic horizons. Pb concentrations in pine needles, litterfall and wood were low, whereas tree bark acted as a sink for Pb and stored high amounts of the metal. © Springer 2005

    A randomized, placebo-controlled, single-blinded, split-faced clinical trial evaluating the efficacy and safety of KLOX-001 gel formulation with KLOX light-emitting diode light on facial rejuvenation

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    Andreas Nikolis,1 Steven Bernstein,2 Brian Kinney,3 Nicolo Scuderi,4 Shipra Rastogi,5 John S Sampalis6 1Victoria Park, Plastic Surgery Section, Westmount, QC, Canada; 2Dermatology Department, University of Montreal Health Centre, Montreal, QC, Canada; 3Department of Plastic Surgery, USC School of Medicine, Beverley Hills, CA, USA; 4Department of Plastic and Reconstructive Surgery, La Sapienza, Rome, Italy; 5KLOX Technologies, Laval, 6JSS Medical Research, Montreal, QC, Canada Purpose: Many treatment modalities exist to counteract the effects of cutaneous aging. Ablative methods have been the mainstay for nonsurgical facial rejuvenation. In recent years, nonablative techniques have been developed with the aim of achieving facial rejuvenation without epidermal damage. Light-emitting diode (LED) photorejuvenation is a novel nonablative technique that induces collagen synthesis through biophotomodulatory pathways. Materials and methods: A single-center, randomized, single-blinded, placebo-controlled, split-faced clinical trial was designed. Thirty-two patients were enrolled for a 12-week study. Patients were randomized into one of four groups: Group A, treatment with KLOX-001 gel formulation and white LED (placebo) light; Group B, treatment with a placebo/base gel (no active chromophore) formulation and KLOX LED light; Group C, treatment with KLOX-001 gel formulation and KLOX LED light; and Group D, treatment with the standard skin rejuvenating treatment (0.1% retinol-based cream). Patients received treatment at weeks 0, 1, 2, and 3, and returned to the clinic at weeks 4, 8, and 12 for clinical assessments performed by an independent, blinded committee of physicians using subjective clinician assessment scales. Tolerability, adverse outcomes, and patient satisfaction were also assessed. Results: Analysis demonstrated that the KLOX LED light with KLOX placebo/base gel and the KLOX LED light + KLOX-001 gel formulation groups were superior to standard of care and KLOX-001 gel formulation with placebo light on subjective clinical assessment and multiple wrinkle scales, with statistically significant results obtained for brow positioning, perioral wrinkling, and total wrinkle score. Conclusion: The study results show that KLOX LED light with KLOX-001 gel formulation and KLOX LED light with KLOX placebo/base gel are effective, safe, well-tolerated, and painless treatment modalities for skin rejuvenation. Keywords: biophotonics, skin rejuvenation, chromophore, rejuvenation, non-invasiv
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