Science – A life fully lived: Joe Sodroski wins the 2006 Retrovirology Prize

The 2006 M Jeang Retrovirology Prize for HIV research has been awarded to Dr Joe Sodroski     

Nickel plasma produced by 532-nm and 1064-nm pulsed laser ablation

A comparison between laser ablation of nickel in vacuum by using 532-and 1064-nm Nd:YAG (Yttrium Aluminium Garnet) laser wavelengths, with an intensity of 5 × 10⁹ W/cm², is reported. Nanosecond pulsed ablation produces high nonisotropic emission of neutrals and ionic species. For 532-nm laser irradiation, mass quadrupole spectrometry, coupled to electrostatic ion deflection and time-of-flight measurements, allows estimation of the energy distributions of the emitted species from plasma. For 1064-nm laser ablation, a cylindrical electrostatic ion analyzer permits one to measure the yield and the charge state of the emitted ions and reconstruct the ion energy and charge state distributions. Neutrals show typical Boltzmann-like distributions, while ions show Coulomb-Boltzmann-shifted distributions depending on their charge state. Surface profiles of the ablated craters permitted study of the ablation threshold and yields of nickel in vacuum versus the laser fluence. The plasma temperature was evaluated using experimental data. Special regard is given to the ion acceleration process occurring inside the plasma due to the high electrical field generated at nonequilibrium plasma conditions and the angular distribution of the emitted species. Published in Russian in Fizika Plazmy, 2008, Vol. 34, No. 7, pp. 598–606. The text was submitted by the authors in English.     

Changes of expression of mitochondrial proteins involved in energy transduction in rat brain during aging

Dantrolene – an inhibitor of ryanodine receptors and calcium stabilizer – prevents ischemia- and excitotoxicity-evoked neurodegeneration. To elucidate the mechanisms of this phenomenon, we investigated effects of dantrolene on the NMDA- and glutamate-induced lesion and stimulation of ⁴⁵Ca uptake in primary cultures of rat cerebellar granule neurons. Neurodegeneration was evaluated after 24 h with the propidium iodide staining. Bcl-2 immunoreactivity in cell homogenates was measured by immunoblotting. The results demonstrated that dantrolene applied at micromolar concentrations inhibits in a dose-dependent manner NMDA- and glutamate-evoked ⁴⁵Ca uptake in neurones and induces neuroprotection. This effect was additive to known effects of DMSO, a vehicle to dantrolene. Dantrolene failed to induce changes in Bcl-2 immunoreactivity. Thus, dantrolene-induced neuroprotection against excitotoxicity may be at least partially mediated by its inhibitory effect on the NMDA receptors.     

Labeling of RNA in young and adult rat brain: Evidence for different RNA processing

The labeling of RNA in young and adult rat brain has been studied by measuring in vitro (tissue slices incubation) the incorporation of labeled uridine into RNA of total tissue and of the various subcellular fractions purified from cerebral hemispheres of 1- and 10-month-old rats. Gel electrophoretic analysis of the newly synthesized nuclear and microsomal RNA was also accomplished. An active metabolism of RNA in adult animals was found; moreover, distinct differences in ribosomal RNA processing in cerebral hemispheres of 1- and 10-month-old rats, with a more rapid processing in the brain of adult animals, were obtained.