Is Response to Genotoxic Stress Similar in Populations of African and European Ancestry? A Study of Dose-Response After Irradiation.

Exposure to genotoxic stress such as radiation is an important public health issue affecting a large population. The necessity of analyzing cytogenetic effects of such exposure is related to the need to estimate the associated risk. Cytogenetic biological dosimetry is based on the relationship between the absorbed dose and the frequency of scored chromosomal aberrations.

[Development of Ethylcellulose/Eudragit matrix for controlled and continuous release of insulin].

Purpose: Diabetes Type I is a chronic disease requiring insulin repeated injections by parenteral during a lifetime. This method of administration as well as traumatic can be a problem for adherence of patients to treatment. In order to overcome these difficulties, we considered the development of therapeutic transdermal drug delivery (TTDD) of insulin.

[Quality control of antibiotics used in Senegal].

To slow the spread of bacterial resistance and promote safety in the use of medicines, development of quality control tools is indispensable. The purpose of this study was to evaluate the quality of several antibiotic agents used in Senegal and to assess the utility of the mini laboratory as a quality control tool. The mini laboratory and all materials necessary for this study were provided by the German Pharma Health Fund.

Liquid ordered and gel phases of lipid bilayers: fluorescent probes reveal close fluidity but different hydration.

Hydration and fluidity of lipid bilayers in different phase states were studied using fluorescent probes selectively located at the interface. The probe of hydration was a recently developed 3-hydroxyflavone derivative, which is highly sensitive to the environment, whereas the probe of fluidity was the diphenylhexatriene derivative, 1-[4-(trimethylamino)phenyl]-6-phenylhexa-1,3,5-triene. By variation of the cholesterol content and temperature in large unilamellar vesicles composed of sphingomyelin or dipalmitoylphosphatidlycholine, we generated different phases: gel, liquid ordered (raft), liquid crystalline, and liquid disordered (considered as liquid crystalline phase with cholesterol).

Fluorescent dyes undergoing intramolecular proton transfer with improved sensitivity to surface charge in lipid bilayers.

4'-(Dialkylamino)-3-hydroxyflavones are characterized by an excited-state proton transfer reaction between two tautomeric excited states, which results in two emission bands well separated on the wavelength scale. Due to the high sensitivity of the relative intensities of the two emission bands to solvent polarity, hydrogen bonding and local electric fields, these dyes found numerous applications in biomembrane studies. In order to further improve their fluorescence characteristics, we have synthesized new dyes where the 2-phenyl group is substituted with a 2-thienyl group.