Optimisation of interdelta analysis for Saccharomyces cerevisiae strain characterisation

A new primer pair (delta12-delta21) for polymerase chain reaction-based yeast typing was designed using the yeast genome sequence. The specificity of this primer pair was checked by the comparison of the electrophoresis pattern with a virtual profile calculated from Blast data. The analysis of 53 commercial and laboratory Saccharomyces cerevisiae yeast strains showed a clear improvement of interdelta analysis using the newly designed primers.     

A novel polyacrylamide magnetic nanoparticle contrast agent for molecular imaging using MRI

A novel polyacrylamide superparamagnetic iron oxide nanoparticle platform is described which has been synthetically prepared such that multiple crystals of iron oxide are encapsulated within a single polyacrylamide matrix (PolyAcrylamide Magnetic [PAM] nanoparticles). This formulation provides for an extremely large T2 and T2* relaxivity of between 620 and 1140 sec(-1) mM(-1). Administration of PAM nanoparticles into rats bearing orthotopic 9L gliomas allowed quantitative pharmacokinetic analysis of the uptake of nanoparticles in the vasculature, brain, and glioma. Addition of polyethylene glycol of varying sizes (0.6, 2, and 10 kDa) to the surface of the PAM nanoparticles resulted in an increase in plasma half-life and affected tumor uptake and retention of the nanoparticles as quantified by changes in tissue contrast using MRI. The flexible formulation of these nanoparticles suggests that future modifications could be accomplished allowing for their use as a targeted molecular imaging contrast agent and/or therapeutic platform for multiple indications.     

Fatty acid composition of brain hemispheres of spontaneously hypertensive rats suckled by female Wistar rats

Total lipid fatty acid composition was investigated in brain hemispheres of male Spontaneously Hypertensive Rats (SHR), compared with normotensive Wistar Kyoto rats (WKY) used as controls. Both strains were suckled by adoptive Wistar mothers, and then fed a standard diet after weaning. No difference was observed between the two hemispheres of WKY killed either at 10 or 30 days. In SHR killed at 10 days, the two hemispheres showed differences, SHR left hemispheres exhibiting greater fatty acid composition changes than those of WKY, phenomenon that toned down at 30 days. Hence, SHR pups showed a different total lipid fatty acid composition of their brain hemispheres when compared with their WKY controls, though the two strains received the same diet. Genetically programmed hypertension might be, directly or not, involved in these changes.     

Detection of anti-tumor immunity induced by laser immunotherapy

Metastatic mammary tumors in rats were treated by laser immunotherapy. Tumors injected by a laserabsorbing dye and an immunoadjuvant were irradiated non-invasively by a near-infrared laser. The successfully cured rats developed a long-term resistance to repeated tumor challenges. Using the sera from cured rats as the source of primary antibodies, immune responses induced by laser immunotherapy were observed in both cellular and molecular levels using histochemical assays and Western blot analysis.     

BEPITOPE: predicting the location of continuous epitopes and patterns in proteins

In growing need of obtaining highly specific monoclonal antibodies against novel proteins, we developed new functions implemented in the program BEPITOPE to predict continuous protein epitopes. This program not only can compute, combine, display and print prediction profiles, but also provides a list of suggested linear peptides to be synthesized. Novel facilities incorporated in BEPITOPE include the treatment of a whole genome, the search for a user-defined pattern, and the combination of prediction to pattern profiles. This latter approach is useful to remove unwanted predictions such as those including glycosylation sites.     

Structure-activity relationship in the oxazolidinone-quinolone hybrid series: influence of the central spacer on the antibacterial activity and the mode of action

Oxazolidinone-quinolone hybrids, which combine the pharmacophores of a quinolone and an oxazolidinone, were synthesised and shown to be active against a variety of susceptible and resistant Gram-positive and Gram-negative bacteria. The nature of the spacer greatly influences the antibacterial activity by directing the mode of action, that is quinolone- and/or oxazolidinone-like activity. The best compounds in this series have a balanced dual mode of action and overcome all types of resistance, including resistance to quinolones and linezolid, in clinically relevant Gram-positive pathogens.     

Growth rate influences reductive biodegradation of the organophosphorus pesticide demeton by Corynebacterium glutamicum

The organophosphorous pesticide, demeton-S-methyl was transformed byCorynebacterium glutamicum in co-metabolism with more readilydegradable substrates. Glucose, acetate and fructose were tested as growth substrates, and the highest demeton-S-methyl biotransformation average rate (0.78 mg l^-1 h^-1) and maximum instantaneous rate (1.4 mg l^-1 h^-1) were achieved on fructose. This higher efficiency seems to be linked to the atypical behavior of C. glutamicum grown on fructose, characterized by a prolonged period of accelerating growth instead of a constant growth rate observed on glucose or acetate. More precisely, for growth rates in the 0.1–0.4 h^-1 range, a direct coupling between the specific demeton-S-methyl consumption rate and the growth rate was demonstrated on fructose during batch –, steady state continuous – or continuous cultures with a controlled transient growth rate (accelerostat technology). The demeton-S-methyl biotransformation was more favoured during an acceleration phase of the growth rate.     

Germline transformation of the silkworm Bombyx mori L. using a piggyBac transposon-derived vector

We have developed a system for stable germline transformation in the silkworm Bombyx mori L. using piggyBac, a transposon discovered in the lepidopteran Trichoplusia ni. The transformation constructs consist of the piggyBac inverted terminal repeats flanking a fusion of the B. mori cytoplasmic actin gene BmA3 promoter and the green fluorescent protein (GFP). A nonautonomous helper plasmid encodes the piggyBac transposase. The reporter gene construct was coinjected into preblastoderm eggs of two strains of B. mori. Approximately 2% of the individuals in the G1 broods expressed GFP. DNA analyses of GFP-positive G1 silkworms revealed that multiple independent insertions occurred frequently. The transgene was stably transferred to the next generation through normal Mendelian inheritance. The presence of the inverted terminal repeats of piggyBac and the characteristic TTAA sequence at the borders of all the analyzed inserts confirmed that transformation resulted from precise transposition events. This efficient method of stable gene transfer in a lepidopteran insect opens the way for promising basic research and biotechnological applications.