Investigating Metal-Mediated DNA Damage Prevention by Antioxidants and Examining the Role of Metals in Fluconazole-Mediated DNA Damage

Reactive oxygen species (ROS) play an important role in the development of many diseases. Common assays to test the ability of hydrophobic compounds to prevent oxidative stress are radical scavenging assays and cell studies. However, these radical assays often do not accurately reflect biological outcomes, and the use of different cell lines limits the ability to directly compare compound efficacy (Chapter 1). Results from DNA damage prevention assays can directly compare antioxidant efficacy, but these assays have been limited to water-soluble compounds. Chapter 2 discusses the first assay that quantifiably evaluates the ability of hydrophobic compounds to prevent metal-mediated DNA damage inhibition via gel electrophoresis. This assay allows biologically relevant evaluation of compounds for their effectiveness under consistent conditions. The glutathione peroxidase mimic ebselen and its derivatives prevent copper-mediated DNA damage (IC50 values 280-450 µM), but do not significantly inhibit iron-mediated DNA damage. In combination with radical scavenging assays, these biologically relevant assays enable identification of structure-function relationships for hydrophobic antioxidant compounds and drugs. Studies presented in Chapter 3 investigate the effect of metal binding on drug properties. Fluconazole (FLC) binds both iron and copper, and stabilizes Cu+ and Fe2+ over Cu2+ and Fe3+, respectively, as measured by cyclic voltammetry. Using gel electrophoresis assays, the effects of FLC on copper- and iron-mediated DNA damage were determined. FLC does not cause DNA damage by itself, but addition of FLC lowers the concentration of Fe2+ or Cu+ needed to cause 50% DNA damage (EC50) by 50 and 40 %, respectively, increasing reactive oxygen species production. The studies described in Chapter 4 investigate the antioxidant capabilities of a series of plant-derived, procyanidin-rich condensed tannins (CTs) with different structural features for their ability to inhibit copper (IC50 162.5 ± 0.3 µM to 27% DNA damage inhibition at the highest concentration) and iron-mediated (IC50 0.75 ± 0.01 to 4.96 ± 0.01 µM) DNA damage. The activity of CTs are compared to six commercially available polyphenolic compounds. This is the first study to investigate structure-activity relationships for CTs and their abilities to prevent metal-mediated DNA damage

Scar appearance of different skin and subcutaneous tissue closure techniques in caesarean section: a randomized study

OBJECTIVES: To determine the role of skin and subcutaneous space closure in caesarean section on the cosmetic appearance of the scar and the patients' satisfaction. STUDY DESIGN: 153 patients undergoing caesarean section without prior abdominal delivery were included and randomly assigned in a non-blinded study to four different combinations of skin and subcutaneous tissue closure. The scar was assessed after a period of at least 4 months by a self-developed protocol and the patient was asked to complete a survey regarding her satisfaction with the scar. RESULTS: One hundred patients were eligible for long-term evaluation of the scar. Skin closure by either staples or intracutaneous suture in combination with closure or non-closure of the subcutaneous space has a comparable outcome in view of cosmetic outcome and patient satisfaction. CONCLUSIONS: All four methods of skin closure seem to be a reasonable choice in caesarean section because they have comparable cosmetic outcome, do not differ with respect to the patients' satisfaction and bear comparable costs

Der einfluss von epsilon-aminokapronsaure (eaca) auf die plasma-gerinnungszeit

Man bestimmte die Gerinnungszeit einer Mischung von 0.1 ml des frischen Zitratplasmas, 0.1 ml einer Epsilon-Aminokaprons&#228;ure-L&#246;sung in Konzentrationen von 0, 02, 0.5, 2.5, 10, 20, 50 und 100 gamma, 0.1 ml CaCl&#178; L&#246;sung und 0.1 ml Michaelis' Puffer. Die erw&#228;hnten EACA-Konzentrationen hatten keinen charakteristischen Einfluss auf die Rekalzifikationszeit des frischen und des gel&#246;sten lyophilisierten Plasmas.</p

Inactivation de la thrombine par l'urine humaine normale.

Les urines humaines normales inactivent immédiatement la thrombine ajoutée quand leur pH est acide ou au moindre degré quand leur pH est a1calin. Quand le pH d'urine est neutral ou légerement alcalin l'inactivation de thrombine est faible ou s'annule. Après une incubation de 10 et 20 minutes de l'urine avec la thrombine l'inactivation ne subit pas de changements essentiaux. Les résultats obtenus in vitro démontrent que l'alcalinisation d'urine a l'aide d'une diète appropri&#233;s ou des remèdes pharmacologiques peuvent favorablement influencer les hémorragies imminentes ou d&#233;ja existantes du systeme urinaire.</p

Impacts of invasive alien trees on threatened lowland vegetation types in the Cape Floristic Region, South Africa

This study investigated the autogenic recovery potential of native vegetation after clearing of dense stands of invasive alien trees in two critically endangered vegetation types in South Africa's Cape Floristic Region: Cape Flats Lowland Fynbos and Swartland Alluvium Fynbos. Sampling was done in areas previously occupied by the invasive tree Acacia saligna and plantations of Pinus radiata and in a fynbos reference site. Treatments varied in terms of the length of invasion and management histories. Plots previously under pines recovered well in terms of indigenous perennial species richness, but indigenous species cover decreased with increasing number of planting rotations. Areas cleared of acacia recovered poorly in terms of indigenous species cover (after one cycle of invasion), and indigenous species richness exhibited a declining trendwith increasing cycles of invasion. Proteoid overstoreywas lost in all previously invaded/planted plots and this elementwill need to be re-introduced to areas after one cycle of invasion regardless of the invasive species. Acacias changed some abiotic variables after two cycles of invasion. Follow-up clearing generally promoted better vegetation recovery in terms of overall species richness and structure but care should be taken not to damage indigenous ericoid shrubs. Overall, acacia invasion caused a greater change in biodiversity and vegetation structure than pine plantations

Decoherence-Free Quantum Information Processing with Four-Photon Entangled States

Decoherence-free states protect quantum information from collective noise, the predominant cause of decoherence in current implementations of quantum communication and computation. Here we demonstrate that spontaneous parametric down-conversion can be used to generate four-photon states which enable the encoding of one qubit in a decoherence-free subspace. The immunity against noise is verified by quantum state tomography of the encoded qubit. We show that particular states of the encoded qubit can be distinguished by local measurements on the four photons only.Comment: 4 pages, 4 eps figures, revtex

A solid-reagent dispenser for use in the azocoll protease assay (and other insoluble substrate analyses).

A solid-reagent dispenser for use in the azocoll protease assay (and other insoluble substrate analyses)

Investigations on Tetragonally Distorted Sodium Thallide NaTl‐tI8

In-depth investigations of the long-time known Zintl phase NaTl revealed a phase transition of tetragonal NaTl-tI8 [I4(1)/amd; a = 5.2268(9) angstrom, c = 7.539(1) angstrom, V = 205.97(9) angstrom(3)] to Zintl's cubic NaTl-cF16 [Fd3m; a = 7.4697(6) angstrom, V = 416.79(5) angstrom(3)] between 351 and 355 K. This phase transformation was observed for NaTl prepared by two different synthetic routes including Zintl's original procedure. An excess of sodium applied during the synthesis in liquid ammonia also resulted in the formation of NaTl-tI8. DSC measurements suggest a first order phase transition. In addition to in-situ temperature dependent powder X-ray diffraction experiments, DSC measurements and solid-state NMR investigations, we also performed theoretical DOS and band structure calculations for the cubic and tetragonal phase, respectively. The results suggest Na-Tl interactions in the second coordination sphere being responsible for the observed tetragonal distortion of Zintl's cubic NaTl

Group status drives majority and minority integration preferences

WOS:000300955100009 (Nº de Acesso Web of Science)“Prémio Científico ISCTE-IUL 2013”This research examined preferences for national-and campus-level assimilative and pluralistic policies among Black and White students under different contexts, as majority-and minority-group members. We targeted attitudes at two universities, one where 85% of the student body is White, and another where 76% of students are Black. The results revealed that when a group constituted the majority, its members generally preferred assimilationist policies, and when a group constituted the minority, its members generally preferred pluralistic policies. The results support a functional perspective: Both majority and minority groups seek to protect and enhance their collective identities