Biomarkers of oxidative stress: methods and measures of oxidative DNA damage (COMET assay) and telomere shortening

Oxidative stress is fast becoming the nutritional and medical buzzword for the twenty-first century. The theoretical importance of oxidative stress in diabetes is highlighted by its potential double impact on metabolic dysfunction on one hand and the vascular system on the other hand. The new concept of oxidative stress, being an important trigger in the onset and progression of diabetes and its complications, emphasizes the need for measurement of markers of oxidation to assess the degree of oxidative stress. While we have been routinely measuring biomarkers in our molecular epidemiology projects, here we discuss the utility of two assays, (a) DNA damage assessment by COMET measurement and (b) telomere length measurement. As DNA damage is efficiently repaired by cellular enzymes, its measurement gives a snapshot view of the level of oxidative stress. The protocol allows for measurement of oxidative DNA damage (FPG-sensitive DNA strand breaks). Telomere length measured by Southern blotting technique allows one to estimate the chronic burden of oxidative stress at the molecular level and is now considered as biomarker of biological aging

Understanding the Global Problem of Drug Addiction is a Challenge for IDARS Scientists

IDARS is an acronym for the International Drug Abuse Research Society. Apart from our scientific and educational purposes, we communicate information to the general and scientific community about substance abuse and addiction science and treatment potential. Members of IDARS are research scientists and clinicians from around the world, with scheduled meetings across the globe. IDARS is developing a vibrant and exciting international mechanism not only for scientific interactions in the domain of addiction between countries but also ultimately as a resource for informing public policy across nations. Nonetheless, a lot more research needs to be done to better understand the neurobiological basis of drug addiction – A challenge for IDARS scientists

Long-Term Protective Effects of Methamphetamine Preconditioning Against Single-Day Methamphetamine Toxic Challenges

Methamphetamine (METH) use is associated with neurotoxic effects which include decreased levels of dopamine (DA), serotonin (5-HT) and their metabolites in the brain. We have shown that escalating METH dosing can protect against METH induced neurotoxicity in rats sacrificed within 24 hours after a toxic METH challenge. The purpose of the current study was to investigate if the protective effects of METH persisted for a long period of time. We also tested if a second challenge with a toxic dose of METH would cause further damage to monoaminergic terminals. Saline-pretreated rats showed significant METH-induced decreases in striatal DA and 5-HT levels in rats sacrificed 2 weeks after the challenge. Rats that received two METH challenges showed no further decreases in striatal DA or 5-HT levels in comparison to the single METH challenge. In contrast, METH-pretreated rats showed significant protection against METH-induced striatal DA and 5-HT depletion. In addition, the METH challenge causes substantial decreases in cortical 5-HT levels which were not further potentiated by a second drug challenge. METH preconditioning provided almost complete protection against METH –induced 5-HT depletion. These results are consistent with the idea that METH pretreatment renders the brain refractory to METH-induced degeneration of brain monoaminergic systems

Subdivisions de la forêt de bois de couleur à l'île de la Réunion

International audienc

Subdivisions de la forêt de bois de couleur à l'île de la Réunion

International audienc

Neurotensin receptors in human meningiomas.

We have investigated the presence of neurotensin receptors in human meningiomas by in vitro binding autoradiography. Ten of the 12 meningiomas tested displayed specific [3H]neurotensin binding. All meningothelial (n = 3) and transitional (n = 5) meningiomas were positive, whereas only 2 of the 4 fibroblastic meningiomas showed measurable concentrations of neurotensin binding sites. Within the tumors, [3H]neurotensin binding was preferentially observed in syncytial areas. Saturation experiments showed that the maximal binding capacity (Bmax) greatly varied among tumors, ranging from low values to more than 290 fmol/mg of protein. All positive tumors had neurotensin binding sites with a dissociation constant (kd) within the nanomolar range and a pharmacological specificity for [3H]neurotensin similar to neurotensin receptors