Cooperation between glutathione depletion and protein synthesis inhibition against naturally occurring neuronal death

It is generally agreed that naturally-occurring neuronal death in developing animals is dependent on the synthesis of proteins. Oxidative stress, as when intracellular concentrations of free radicals are raised or when cell constituents such as membrane lipids or protein thiols are oxidized, is also involved in various types of neuronal death. In the present report, we show that the number of naturally dying retinal cells in the chick embryo can be reduced by intraocular injections of cycloheximide, an inhibitor of protein synthesis. L-buthionine-[S,R]-sulfoximine, an inhibitor of glutathione synthesis, can either enhance or diminish the cell death, depending on the conditions of treatment. Moreover, when the two inhibitors are combined, L-buthionine-[S,R]-sulfoximine potentiates the neuroprotective effects of cycloheximide. Measurements of retinal glutathione concentration and protein synthesis show the specificity of the treatments: buthionine-sulfoximine diminishes glutathione concentrations but not protein synthesis whereas cycloheximide inhibits protein synthesis without decreasing glutathione concentrations. Naturally-occurring neuronal death thus seems to involve the synthesis of proteins, and is also influenced by oxidative phenomena. Our results extend previous data in tectal-lesioned embryos, and suggest that a moderate, non-lethal oxidative stress can enhance the resistance of ganglion cells that might otherwise have died (spontaneously or following axotomy) owing to insufficient retrograde trophic support.     

Ultrasonic wave attenuation as a tool for estimating frost action on limestone rocks

Observations about the evolution of damage to limestone during freeze/thaw cycles using ultrasonic methods (involving wave velocity and attenuation) help understand the physical mechanisms which give rise to damage under frost action. The ultrasonic methods commonly applied rely on theoretical models of frost propagation in porous media and are based on thermodynamic considerations and on capillarity theory. Under the necessary conditions of rock damage formation,i.e. high degrees of saturation and negative temperatures, the geometry of the porous network constitutes the dominant factor which determines the nature of the resulting damages. This parameter controls the degree of saturation of materials both in structural work and under natural conditions. The degree of saturation is among the major factors which aggravate frost degradation of limestone at temperatures below 0°C. Data supplied by the recordings of ultrasonic wave attenuation in limestone during freeze/thaw cycles help characterise and identify the different types of damage.     

Generation of Graphs for the Identification of Various Types of Scientific Collaboration in an Academic Institution

Programming and Computer Software - Scientific collaborations have made important contributions to the scientific community. Various institutions have considered publications made by various...     

Deploying deep learning approaches to left ventricular non-compaction measurement

The Journal of Supercomputing - Left ventricular non-compaction (LVNC) is a rare cardiomyopathy characterized by abnormal trabeculations in the left ventricle cavity. Although traditional computer...     

A comparison study of wavelet transforms for the visualization of differentially methylated regions in DNA samples

The Journal of Supercomputing - DNA methylation analysis has become an important topic in the study of human health. DNA methylation analysis requires not only a specific treatment of DNA samples...     

Integrating supercomputing clusters into education: a case study in biotechnology

The Journal of Supercomputing - The integration of a Supercomputer in the educational process improves student’s technological skills. The aim of the paper is to study the interaction between...     

Observing Inequality: Can Ergonomic Observations Help Interventions Transform the Role of Gender in Work Activity?

Computer Supported Cooperative Work (CSCW) - Work activity ergonomics (sometimes called francophone ergonomics) draws heavily on observation in order to support transformation of work to arrive at...     

30th Anniversary of Applied Intelligence: A combination of bibliometrics and thematic analysis using SciMAT

Applied Intelligence - Applied Intelligence is one of the most important international scientific journals in the field of artificial intelligence. From 1991, Applied Intelligence has been oriented...